WorldWideScience

Sample records for earth system grid

  1. 5th Annual Earth System Grid Federation

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Dean N. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-04-01

    The purpose of the Fifth Annual Earth System Grid Federation (ESGF) Face-to-Face (F2F) Conference was to present the most recent information on the state of ESGF’s software stack and to identify and address the data needs and gaps for the climate and weather communities that ESGF supports.

  2. 2016 Earth System Grid Federation Annual Report

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Dean N. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-05-10

    The Earth System Grid Federation (ESGF) experienced a major setback in June 2015, when it experienced a security incident that brought all systems to a halt for more than half a year. However, federation developers and management committee members turned the incident into an opportunity to dramatically upgrade the system security and functionality and to develop planning and policy documents to guide ESGF evolution and success. Moreover, despite the incident, ESGF developer working teams continue to make strong and significant progress on various enhancement projects that will help ensure ESGF can meet the needs of the climate community in the coming years.

  3. PMEL contributions to the collaboration: SCALING THE EARTH SYSTEM GRID TO PETASCALE DATA for the DOE SciDACs Earth System Grid Center for Enabling Technologies

    Energy Technology Data Exchange (ETDEWEB)

    Hankin, Steve

    2012-06-01

    Drawing to a close after five years of funding from DOE's ASCR and BER program offices, the SciDAC-2 project called the Earth System Grid (ESG) Center for Enabling Technologies has successfully established a new capability for serving data from distributed centers. The system enables users to access, analyze, and visualize data using a globally federated collection of networks, computers and software. The ESG software now known as the Earth System Grid Federation (ESGF) has attracted a broad developer base and has been widely adopted so that it is now being utilized in serving the most comprehensive multi-model climate data sets in the world. The system is used to support international climate model intercomparison activities as well as high profile U.S. DOE, NOAA, NASA, and NSF projects. It currently provides more than 25,000 users access to more than half a petabyte of climate data (from models and from observations) and has enabled over a 1,000 scientific publications.

  4. Data management and analysis for the Earth System Grid

    Energy Technology Data Exchange (ETDEWEB)

    Williams, D N; Drach, R; Henson, V E [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Ananthakrishnan, R; Foster, I T; Siebenlist, F [Argonne National Laboratory, Argonne, IL 60439 (United States); Bernholdt, D E; Chen, M; Schwidder, J [Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Bharathi, S; Chervenak, A L; Schuler, R [University of Southern California, Information Sciences Institute, Marina del Ray, CA 90292 (United States); Brown, D; Cinquini, L; Fox, P; Middleton, D E [National Center for Atmospheric Research, Boulder, CO 80307 (United States); Hankin, S; Schweitzer, R [National Oceanic and Atmospheric Administration (PMEL), Seattle, WA 98115 (United States); Jones, P [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Shoshani, A [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States)], E-mail: williams13@llnl.gov, E-mail: don@ucar.edu, E-mail: itf@mcs.anl.gov, E-mail: bernholdtde@ornl.gov (and others)

    2008-07-15

    The international climate community is expected to generate hundreds of petabytes of simulation data within the next five to seven years. This data must be accessed and analyzed by thousands of analysts worldwide in order to provide accurate and timely estimates of the likely impact of climate change on physical, biological, and human systems. Climate change is thus not only a scientific challenge of the first order but also a major technological challenge. In order to address this technological challenge, the Earth System Grid Center for Enabling Technologies (ESG-CET) has been established within the U.S. Department of Energy's Scientific Discovery through Advanced Computing (SciDAC)-2 program, with support from the offices of Advanced Scientific Computing Research and Biological and Environmental Research. ESG-CET's mission is to provide climate researchers worldwide with access to the data, information, models, analysis tools, and computational capabilities required to make sense of enormous climate simulation datasets. Its specific goals are to (1) make data more useful to climate researchers by developing Grid technology that enhances data usability; (2) meet specific distributed database, data access, and data movement needs of national and international climate projects; (3) provide a universal and secure web-based data access portal for broad multi-model data collections; and (4) provide a wide-range of Grid-enabled climate data analysis tools and diagnostic methods to international climate centers and U.S. government agencies. Building on the successes of the previous Earth System Grid (ESG) project, which has enabled thousands of researchers to access tens of terabytes of data from a small number of ESG sites, ESG-CET is working to integrate a far larger number of distributed data providers, high-bandwidth wide-area networks, and remote computers in a highly collaborative problem-solving environment.

  5. Data management and analysis for the Earth System Grid

    Science.gov (United States)

    Williams, D. N.; Ananthakrishnan, R.; Bernholdt, D. E.; Bharathi, S.; Brown, D.; Chen, M.; Chervenak, A. L.; Cinquini, L.; Drach, R.; Foster, I. T.; Fox, P.; Hankin, S.; Henson, V. E.; Jones, P.; Middleton, D. E.; Schwidder, J.; Schweitzer, R.; Schuler, R.; Shoshani, A.; Siebenlist, F.; Sim, A.; Strand, W. G.; Wilhelmi, N.; Su, M.

    2008-07-01

    The international climate community is expected to generate hundreds of petabytes of simulation data within the next five to seven years. This data must be accessed and analyzed by thousands of analysts worldwide in order to provide accurate and timely estimates of the likely impact of climate change on physical, biological, and human systems. Climate change is thus not only a scientific challenge of the first order but also a major technological challenge. In order to address this technological challenge, the Earth System Grid Center for Enabling Technologies (ESG-CET) has been established within the U.S. Department of Energy's Scientific Discovery through Advanced Computing (SciDAC)-2 program, with support from the offices of Advanced Scientific Computing Research and Biological and Environmental Research. ESG-CET's mission is to provide climate researchers worldwide with access to the data, information, models, analysis tools, and computational capabilities required to make sense of enormous climate simulation datasets. Its specific goals are to (1) make data more useful to climate researchers by developing Grid technology that enhances data usability; (2) meet specific distributed database, data access, and data movement needs of national and international climate projects; (3) provide a universal and secure web-based data access portal for broad multi-model data collections; and (4) provide a wide-range of Grid-enabled climate data analysis tools and diagnostic methods to international climate centers and U.S. government agencies. Building on the successes of the previous Earth System Grid (ESG) project, which has enabled thousands of researchers to access tens of terabytes of data from a small number of ESG sites, ESG-CET is working to integrate a far larger number of distributed data providers, high-bandwidth wide-area networks, and remote computers in a highly collaborative problem-solving environment.

  6. Earth System Grid and EGI interoperability

    Science.gov (United States)

    Raciazek, J.; Petitdidier, M.; Gemuend, A.; Schwichtenberg, H.

    2012-04-01

    The Earth Science data centers have developed a data grid called Earth Science Grid Federation (ESGF) to give the scientific community world wide access to CMIP5 (Coupled Model Inter-comparison Project 5) climate data. The CMIP5 data will permit to evaluate the impact of climate change in various environmental and societal areas, such as regional climate, extreme events, agriculture, insurance… The ESGF grid provides services like searching, browsing and downloading of datasets. At the security level, ESGF data access is protected by an authentication mechanism. An ESGF trusted X509 Short-Lived EEC certificate with the correct roles/attributes is required to get access to the data in a non-interactive way (e.g. from a worker node). To access ESGF from EGI (i.e. by earth science applications running on EGI infrastructure), the security incompatibility between the two grids is the challenge: the EGI proxy certificate is not ESGF trusted nor it contains the correct roles/attributes. To solve this problem, we decided to use a Credential Translation Service (CTS) to translate the EGI X509 proxy certificate into the ESGF Short-Lived EEC certificate (the CTS will issue ESGF certificates based on EGI certificate authentication). From the end user perspective, the main steps to use the CTS are: the user binds his two identities (EGI and ESGF) together in the CTS using the CTS web interface (this steps has to be done only once) and then request an ESGF Short-Lived EEC certificate every time is needed, using a command-line tools. The implementation of the CTS is on-going. It is based on the open source MyProxy software stack, which is used in many grid infrastructures. On the client side, the "myproxy-logon" command-line tools is used to request the certificate translation. A new option has been added to "myproxy-logon" to select the original certificate (in our case, the EGI one). On the server side, MyProxy server operates in Certificate Authority mode, with a new module

  7. Grid for Earth Science Applications

    Science.gov (United States)

    Petitdidier, Monique; Schwichtenberg, Horst

    2013-04-01

    The civil society at large has addressed to the Earth Science community many strong requirements related in particular to natural and industrial risks, climate changes, new energies. The main critical point is that on one hand the civil society and all public ask for certainties i.e. precise values with small error range as it concerns prediction at short, medium and long term in all domains; on the other hand Science can mainly answer only in terms of probability of occurrence. To improve the answer or/and decrease the uncertainties, (1) new observational networks have been deployed in order to have a better geographical coverage and more accurate measurements have been carried out in key locations and aboard satellites. Following the OECD recommendations on the openness of research and public sector data, more and more data are available for Academic organisation and SMEs; (2) New algorithms and methodologies have been developed to face the huge data processing and assimilation into simulations using new technologies and compute resources. Finally, our total knowledge about the complex Earth system is contained in models and measurements, how we put them together has to be managed cleverly. The technical challenge is to put together databases and computing resources to answer the ES challenges. However all the applications are very intensive computing. Different compute solutions are available and depend on the characteristics of the applications. One of them is Grid especially efficient for independent or embarrassingly parallel jobs related to statistical and parametric studies. Numerous applications in atmospheric chemistry, meteorology, seismology, hydrology, pollution, climate and biodiversity have been deployed successfully on Grid. In order to fulfill requirements of risk management, several prototype applications have been deployed using OGC (Open geospatial Consortium) components with Grid middleware. The Grid has permitted via a huge number of runs to

  8. The Earth System Grid Federation (ESGF) Project

    Science.gov (United States)

    Carenton-Madiec, Nicolas; Denvil, Sébastien; Greenslade, Mark

    2015-04-01

    The Earth System Grid Federation (ESGF) Peer-to-Peer (P2P) enterprise system is a collaboration that develops, deploys and maintains software infrastructure for the management, dissemination, and analysis of model output and observational data. ESGF's primary goal is to facilitate advancements in Earth System Science. It is an interagency and international effort led by the US Department of Energy (DOE), and co-funded by National Aeronautics and Space Administration (NASA), National Oceanic and Atmospheric Administration (NOAA), National Science Foundation (NSF), Infrastructure for the European Network of Earth System Modelling (IS-ENES) and international laboratories such as the Max Planck Institute for Meteorology (MPI-M) german Climate Computing Centre (DKRZ), the Australian National University (ANU) National Computational Infrastructure (NCI), Institut Pierre-Simon Laplace (IPSL), and the British Atmospheric Data Center (BADC). Its main mission is to support current CMIP5 activities and prepare for future assesments. The ESGF architecture is based on a system of autonomous and distributed nodes, which interoperate through common acceptance of federation protocols and trust agreements. Data is stored at multiple nodes around the world, and served through local data and metadata services. Nodes exchange information about their data holdings and services, trust each other for registering users and establishing access control decisions. The net result is that a user can use a web browser, connect to any node, and seamlessly find and access data throughout the federation. This type of collaborative working organization and distributed architecture context en-lighted the need of integration and testing processes definition to ensure the quality of software releases and interoperability. This presentation will introduce the ESGF project and demonstrate the range of tools and processes that have been set up to support release management activities.

  9. 6th Annual Earth System Grid Federation Face to Face Conference Report

    Energy Technology Data Exchange (ETDEWEB)

    Williams, D. N. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-03-06

    The Sixth Annual Face-to-Face (F2F) Conference of the Earth System Grid Federation (ESGF), a global consortium of international government agencies, institutions, and companies dedicated to the creation, management, analysis, and distribution of extreme-scale scientific data, was held December 5–9, 2016, in Washington, D.C.

  10. The Effect of Phase-to-earth Faults on the Operating Conditions of a Separated 110 kV Grid Normally Operated with Effectively Earthed Neutral, and Temporarily Supplied from a Compensated 110 kV Grid

    Directory of Open Access Journals (Sweden)

    Wilhelm Rojewski

    2015-06-01

    Full Text Available The paper discusses the interoperability of the German compensated 110 kV grid and the Polish effectively earthed 110 kV grid. It is assumed that an area of one grid, separated from its power system, will be temporarily supplied from the other grid in its normal regime. Reference is made to the risks associated with phase-to-earth faults in grids so interconnected. Particular attention is paid to the working conditions of surge arresters and voltage transformers in the Polish 110 kV grid deprived of its neutral earthing when supplied from the German grid.

  11. Enhancing GIS Capabilities for High Resolution Earth Science Grids

    Science.gov (United States)

    Koziol, B. W.; Oehmke, R.; Li, P.; O'Kuinghttons, R.; Theurich, G.; DeLuca, C.

    2017-12-01

    Applications for high performance GIS will continue to increase as Earth system models pursue more realistic representations of Earth system processes. Finer spatial resolution model input and output, unstructured or irregular modeling grids, data assimilation, and regional coordinate systems present novel challenges for GIS frameworks operating in the Earth system modeling domain. This presentation provides an overview of two GIS-driven applications that combine high performance software with big geospatial datasets to produce value-added tools for the modeling and geoscientific community. First, a large-scale interpolation experiment using National Hydrography Dataset (NHD) catchments, a high resolution rectilinear CONUS grid, and the Earth System Modeling Framework's (ESMF) conservative interpolation capability will be described. ESMF is a parallel, high-performance software toolkit that provides capabilities (e.g. interpolation) for building and coupling Earth science applications. ESMF is developed primarily by the NOAA Environmental Software Infrastructure and Interoperability (NESII) group. The purpose of this experiment was to test and demonstrate the utility of high performance scientific software in traditional GIS domains. Special attention will be paid to the nuanced requirements for dealing with high resolution, unstructured grids in scientific data formats. Second, a chunked interpolation application using ESMF and OpenClimateGIS (OCGIS) will demonstrate how spatial subsetting can virtually remove computing resource ceilings for very high spatial resolution interpolation operations. OCGIS is a NESII-developed Python software package designed for the geospatial manipulation of high-dimensional scientific datasets. An overview of the data processing workflow, why a chunked approach is required, and how the application could be adapted to meet operational requirements will be discussed here. In addition, we'll provide a general overview of OCGIS

  12. A grid portal for Earth Observation community

    International Nuclear Information System (INIS)

    Aloisio, G.; Cafaro, M.; Carteni, G.; Epicoco, I.; Quarta, G.

    2005-01-01

    Earth Observation techniques offer many powerful instruments far Earth planet study, urban development planning, military intelligence helping and so on. Tera bytes of EO and geo spatial data about lands, oceans, glaciers, cities, etc. are continuously downloaded through remote-sensing infrastructures and stored into heterogeneous, distributed repositories usually belonging to different virtual organizations. A problem-solving environment can be a viable solution to handle, coordinate and share heterogeneous and distributed resources. Moreover, grid computing is an emerging technology to salve large-scale problems in dynamic, multi-institutional Virtual Organizations coordinated by sharing resources such as high-performance computers, observation devices, data and databases aver high-speed networks, etc. In this paper we present the Italian Grid far Earth Observation (I-GEO) project, a pervasive environment based on grid technology to help the integration and processing of Earth Observation data, providing a tool to share and access data, applications and computational resources among several organizations

  13. Enhancing the Earth System Grid Authentication Infrastructure through Single Sign-On and Autoprovisioning

    Energy Technology Data Exchange (ETDEWEB)

    Siebenlist, Frank [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bernholdt, David E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Williams, Dean N. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2009-01-01

    Climate scientists face an overarching need to efficiently access and manipulate climate model data. Increasingly, researchers must assemble and analyze large datasets that are archived in different formats on disparate platforms and must extract portions of datasets to compute statistical or diagnostic metrics in place. The need for a common virtual environment in which to access both climate model datasets and analysis tools is therefore keenly felt. The software infrastructure to support such an environment must not only provide ready access to climate data but must also facilitate the use of visualization software, diagnostic algorithms, and related resources. To this end, the Earth System Grid Center for Enabling Technologies (ESG-CET) was established in 2006 by the Scientific Discovery through Advanced Computing program of the U.S. Department of Energy through the Office of Advanced Scientific Computing Research and the Office Biological and Environmental Research within the Office of Science. ESG-CET is working to advance climate science by developing computational resources for accessing and managing model data that are physically located in distributed multiplatform archives. In this paper, we discuss recent development and implementation efforts by the Earth System Grid (ESG) concerning its security infrastructure. ESG's requirements are to make user logon as easy as possible and to facilitate the integration of security services and Grid components for both developers and system administrators. To meet that goal, we leverage existing primary authentication mechanisms, deploy a 'lightweight' but secure OpenID WebSSO, deploy a 'lightweight' X.509-PKI, and use autoprovisioning to ease the burden of security configuration management. We are close to completing the associated development and deployment.

  14. Earth System Grid II, Turning Climate Datasets into Community Resources

    Energy Technology Data Exchange (ETDEWEB)

    Middleton, Don

    2006-08-01

    The Earth System Grid (ESG) II project, funded by the Department of Energy’s Scientific Discovery through Advanced Computing program, has transformed climate data into community resources. ESG II has accomplished this goal by creating a virtual collaborative environment that links climate centers and users around the world to models and data via a computing Grid, which is based on the Department of Energy’s supercomputing resources and the Internet. Our project’s success stems from partnerships between climate researchers and computer scientists to advance basic and applied research in the terrestrial, atmospheric, and oceanic sciences. By interfacing with other climate science projects, we have learned that commonly used methods to manage and remotely distribute data among related groups lack infrastructure and under-utilize existing technologies. Knowledge and expertise gained from ESG II have helped the climate community plan strategies to manage a rapidly growing data environment more effectively. Moreover, approaches and technologies developed under the ESG project have impacted datasimulation integration in other disciplines, such as astrophysics, molecular biology and materials science.

  15. EASE-Grid 2.0: Incremental but Significant Improvements for Earth-Gridded Data Sets

    OpenAIRE

    Brodzik, Mary J.; Billingsley, Brendan; Haran, Terry; Raup, Bruce; Savoie, Matthew H.

    2012-01-01

    Defined in the early 1990s for use with gridded satellite passive microwave data, the Equal-Area Scalable Earth Grid (EASE-Grid) was quickly adopted and used for distribution of a variety of satellite and in situ data sets. Conceptually easy to understand, EASE-Grid suffers from limitations that make it impossible to format in the widely popular GeoTIFF convention without reprojection. Importing EASE-Grid data into standard mapping software packages is nontrivial and error-prone. This article...

  16. The Earth System Grid Center for Enabling Technologies (ESG-CET): Scaling the Earth System Grid to Petascale Data

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Dean N. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2007-09-27

    This report, which summarizes work carried out by the ESG-CET during the period April 1, 2007 through September 30, 2007, includes discussion of overall progress, period goals, highlights, collaborations and presentations. To learn more about our project, please visit the Earth System Grid website. In addition, this report will be forwarded to the DOE SciDAC project management, the Office of Biological and Environmental Research (OBER) project management, national and international stakeholders (e.g., the Community Climate System Model (CCSM), the Intergovernmental Panel on Climate Change (IPCC) 5th Assessment Report (AR5), the Climate Science Computational End Station (CCES), etc.), and collaborators. The ESG-CET executive committee consists of David Bernholdt, ORNL; Ian Foster, ANL; Don Middleton, NCAR; and Dean Williams, LLNL. The ESG-CET team is a collective of researchers and scientists with diverse domain knowledge, whose home institutions include seven laboratories (ANL, LANL, LBNL, LLNL, NCAR, ORNL, PMEL) and one university (ISI/USC); all work in close collaboration with the project's stakeholders and domain researchers and scientists. During this semi-annual reporting period, the ESG-CET increased its efforts on completing requirement documents, framework design, and component prototyping. As we strove to complete and expand the overall ESG-CET architectural plans and use-case scenarios to fit our constituency's scope of use, we continued to provide production-level services to the community. These services continued for IPCC AR4, CCES, and CCSM, and were extended to include Cloud Feedback Model Intercomparison Project (CFMIP) data.

  17. EASE-Grid 2.0: Incremental but Significant Improvements for Earth-Gridded Data Sets

    Directory of Open Access Journals (Sweden)

    Matthew H. Savoie

    2012-03-01

    Full Text Available Defined in the early 1990s for use with gridded satellite passive microwave data, the Equal-Area Scalable Earth Grid (EASE-Grid was quickly adopted and used for distribution of a variety of satellite and in situ data sets. Conceptually easy to understand, EASE-Grid suffers from limitations that make it impossible to format in the widely popular GeoTIFF convention without reprojection. Importing EASE-Grid data into standard mapping software packages is nontrivial and error-prone. This article defines a standard for an improved EASE-Grid 2.0 definition, addressing how the changes rectify issues with the original grid definition. Data distributed using the EASE-Grid 2.0 standard will be easier for users to import into standard software packages and will minimize common reprojection errors that users had encountered with the original EASE-Grid definition.

  18. 3rd Annual Earth System Grid Federation and 3rd Annual Earth System Grid Federation and Ultrascale Visualization Climate Data Analysis Tools Face-to-Face Meeting Report December 2013

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Dean N. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2014-02-21

    The climate and weather data science community gathered December 3–5, 2013, at Lawrence Livermore National Laboratory, in Livermore, California, for the third annual Earth System Grid Federation (ESGF) and Ultra-scale Visualization Climate Data Analysis Tools (UV-CDAT) Face-to-Face (F2F) Meeting, which was hosted by the Department of Energy, National Aeronautics and Space Administration, National Oceanic and Atmospheric Administration, the European Infrastructure for the European Network of Earth System Modelling, and the Australian Department of Education. Both ESGF and UV-CDAT are global collaborations designed to develop a new generation of open-source software infrastructure that provides distributed access and analysis to observed and simulated data from the climate and weather communities. The tools and infrastructure developed under these international multi-agency collaborations are critical to understanding extreme weather conditions and long-term climate change, while the F2F meetings help to build a stronger climate and weather data science community and stronger federated software infrastructure. The 2013 F2F meeting determined requirements for existing and impending national and international community projects; enhancements needed for data distribution, analysis, and visualization infrastructure; and standards and resources needed for better collaborations.

  19. Effect of wind generation system types on Micro-Grid (MG) fault performance during both standalone and grid connected modes

    International Nuclear Information System (INIS)

    Kamel, Rashad M.

    2014-01-01

    Highlights: • This paper evaluated the effects of different wind system types on fault performance of Micro-Grid. • Both standalone and grid connected modes are considered. • The MG earthing system configuration is taken in consideration. - Abstract: Recently, there are three wind generation (WG) system types. The first type is called Fixed Speed Wind Generation (FSWG) system, which employs squirrel cage induction generators. Double Fed Induction Generator (DFIG) is utilized in the second type. The third type is called Full Converter Wind Generation (FCWG) system, which is interfaced with Micro-Grid (MG) through a back to back converter. During fault occurrence, each WG has its performance and characteristics which are determined by the generator physical characteristics and the MG earthing system configuration. For some WG types, the fault current depends also on the control algorithm of the power converter. The main target of this paper is to investigate and estimate how the fault performance of MG during both standalone and grid-connected modes is influenced by the type of WG. It is found during standalone mode that the type of the employed WG has a dominant impact on the MG performance under fault disturbance. On the contrary, the type of the employed WG has a negligible effect on the MG fault performance during grid-connected mode. This is because the main grid contributes most of the fault current. Effects of earthing system type on MG performance are highlighted

  20. The Earth System Grid Federation : an Open Infrastructure for Access to Distributed Geospatial Data

    Science.gov (United States)

    Cinquini, Luca; Crichton, Daniel; Mattmann, Chris; Harney, John; Shipman, Galen; Wang, Feiyi; Ananthakrishnan, Rachana; Miller, Neill; Denvil, Sebastian; Morgan, Mark; hide

    2012-01-01

    The Earth System Grid Federation (ESGF) is a multi-agency, international collaboration that aims at developing the software infrastructure needed to facilitate and empower the study of climate change on a global scale. The ESGF's architecture employs a system of geographically distributed peer nodes, which are independently administered yet united by the adoption of common federation protocols and application programming interfaces (APIs). The cornerstones of its interoperability are the peer-to-peer messaging that is continuously exchanged among all nodes in the federation; a shared architecture and API for search and discovery; and a security infrastructure based on industry standards (OpenID, SSL, GSI and SAML). The ESGF software is developed collaboratively across institutional boundaries and made available to the community as open source. It has now been adopted by multiple Earth science projects and allows access to petabytes of geophysical data, including the entire model output used for the next international assessment report on climate change (IPCC-AR5) and a suite of satellite observations (obs4MIPs) and reanalysis data sets (ANA4MIPs).

  1. 2014 Earth System Grid Federation and Ultrascale Visualization Climate Data Analysis Tools Conference Report

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Dean N. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-01-27

    The climate and weather data science community met December 9–11, 2014, in Livermore, California, for the fourth annual Earth System Grid Federation (ESGF) and Ultrascale Visualization Climate Data Analysis Tools (UV-CDAT) Face-to-Face (F2F) Conference, hosted by the Department of Energy, National Aeronautics and Space Administration, National Oceanic and Atmospheric Administration, the European Infrastructure for the European Network of Earth System Modelling, and the Australian Department of Education. Both ESGF and UVCDATremain global collaborations committed to developing a new generation of open-source software infrastructure that provides distributed access and analysis to simulated and observed data from the climate and weather communities. The tools and infrastructure created under these international multi-agency collaborations are critical to understanding extreme weather conditions and long-term climate change. In addition, the F2F conference fosters a stronger climate and weather data science community and facilitates a stronger federated software infrastructure. The 2014 F2F conference detailed the progress of ESGF, UV-CDAT, and other community efforts over the year and sets new priorities and requirements for existing and impending national and international community projects, such as the Coupled Model Intercomparison Project Phase Six. Specifically discussed at the conference were project capabilities and enhancements needs for data distribution, analysis, visualization, hardware and network infrastructure, standards, and resources.

  2. Geospatial Information Service System Based on GeoSOT Grid & Encoding

    Directory of Open Access Journals (Sweden)

    LI Shizhong

    2016-12-01

    Full Text Available With the rapid development of the space and earth observation technology, it is important to establish a multi-source, multi-scale and unified cross-platform reference for global data. In practice, the production and maintenance of geospatial data are scattered in different units, and the standard of the data grid varies between departments and systems. All these bring out the disunity of standards among different historical periods or orgnizations. Aiming at geospatial information security library for the national high resolution earth observation, there are some demands for global display, associated retrieval and template applications and other integrated services for geospatial data. Based on GeoSOT grid and encoding theory system, "geospatial information security library information of globally unified grid encoding management" data subdivision organization solutions have been proposed; system-level analyses, researches and designs have been carried out. The experimental results show that the data organization and management method based on GeoSOT can significantly improve the overall efficiency of the geospatial information security service system.

  3. Journal of Earth System Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science. Samadrita Mukherjee. Articles written in Journal of Earth System Science. Volume 122 Issue 3 June 2013 pp 869-886. Evaluation of topographic index in relation to terrain roughness and DEM grid spacing · Samadrita Mukherjee Sandip Mukherjee R D Garg A Bhardwaj ...

  4. Grid interoperability: joining grid information systems

    International Nuclear Information System (INIS)

    Flechl, M; Field, L

    2008-01-01

    A grid is defined as being 'coordinated resource sharing and problem solving in dynamic, multi-institutional virtual organizations'. Over recent years a number of grid projects, many of which have a strong regional presence, have emerged to help coordinate institutions and enable grids. Today, we face a situation where a number of grid projects exist, most of which are using slightly different middleware. Grid interoperation is trying to bridge these differences and enable Virtual Organizations to access resources at the institutions independent of their grid project affiliation. Grid interoperation is usually a bilateral activity between two grid infrastructures. Recently within the Open Grid Forum, the Grid Interoperability Now (GIN) Community Group is trying to build upon these bilateral activities. The GIN group is a focal point where all the infrastructures can come together to share ideas and experiences on grid interoperation. It is hoped that each bilateral activity will bring us one step closer to the overall goal of a uniform grid landscape. A fundamental aspect of a grid is the information system, which is used to find available grid services. As different grids use different information systems, interoperation between these systems is crucial for grid interoperability. This paper describes the work carried out to overcome these differences between a number of grid projects and the experiences gained. It focuses on the different techniques used and highlights the important areas for future standardization

  5. Journal of Earth System Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science. Devesh Kumar Maurya. Articles written in Journal of Earth System Science. Volume 125 Issue 5 July 2016 pp 935-944. Validation of two gridded soil moisture products over India with in-situ observations · C K Unnikrishnan John P George Abhishek Lodh Devesh Kumar ...

  6. Grid-based platform for training in Earth Observation

    Science.gov (United States)

    Petcu, Dana; Zaharie, Daniela; Panica, Silviu; Frincu, Marc; Neagul, Marian; Gorgan, Dorian; Stefanut, Teodor

    2010-05-01

    GiSHEO platform [1] providing on-demand services for training and high education in Earth Observation is developed, in the frame of an ESA funded project through its PECS programme, to respond to the needs of powerful education resources in remote sensing field. It intends to be a Grid-based platform of which potential for experimentation and extensibility are the key benefits compared with a desktop software solution. Near-real time applications requiring simultaneous multiple short-time-response data-intensive tasks, as in the case of a short time training event, are the ones that are proved to be ideal for this platform. The platform is based on Globus Toolkit 4 facilities for security and process management, and on the clusters of four academic institutions involved in the project. The authorization uses a VOMS service. The main public services are the followings: the EO processing services (represented through special WSRF-type services); the workflow service exposing a particular workflow engine; the data indexing and discovery service for accessing the data management mechanisms; the processing services, a collection allowing easy access to the processing platform. The WSRF-type services for basic satellite image processing are reusing free image processing tools, OpenCV and GDAL. New algorithms and workflows were develop to tackle with challenging problems like detecting the underground remains of old fortifications, walls or houses. More details can be found in [2]. Composed services can be specified through workflows and are easy to be deployed. The workflow engine, OSyRIS (Orchestration System using a Rule based Inference Solution), is based on DROOLS, and a new rule-based workflow language, SILK (SImple Language for worKflow), has been built. Workflow creation in SILK can be done with or without a visual designing tools. The basics of SILK are the tasks and relations (rules) between them. It is similar with the SCUFL language, but not relying on XML in

  7. EMAG2: Earth Magnetic Anomaly Grid (2-arc-minute resolution)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — EMAG2 is a global Earth Magnetic Anomaly Grid compiled from satellite, ship, and airborne magnetic measurements. It is a significant update of our previous candidate...

  8. Calibrated, Enhanced-Resolution Brightness Temperature Earth System Data Record: A New Era for Gridded Passive Microwave Data

    Science.gov (United States)

    Hardman, M.; Brodzik, M. J.; Long, D. G.

    2017-12-01

    Since 1978, the satellite passive microwave data record has been a mainstay of remote sensing of the cryosphere, providing twice-daily, near-global spatial coverage for monitoring changes in hydrologic and cryospheric parameters that include precipitation, soil moisture, surface water, vegetation, snow water equivalent, sea ice concentration and sea ice motion. Up until recently, the available global gridded passive microwave data sets have not been produced consistently. Various projections (equal-area, polar stereographic), a number of different gridding techniques were used, along with various temporal sampling as well as a mix of Level 2 source data versions. In addition, not all data from all sensors have been processed completely and they have not been processed in any one consistent way. Furthermore, the original gridding techniques were relatively primitive and were produced on 25 km grids using the original EASE-Grid definition that is not easily accommodated in modern software packages. As part of NASA MEaSUREs, we have re-processed all data from SMMR, all SSM/I-SSMIS and AMSR-E instruments, using the most mature Level 2 data. The Calibrated, Enhanced-Resolution Brightness Temperature (CETB) Earth System Data Record (ESDR) gridded data are now available from the NSIDC DAAC. The data are distributed as netCDF files that comply with CF-1.6 and ACDD-1.3 conventions. The data have been produced on EASE 2.0 projections at smoothed, 25 kilometer resolution and spatially-enhanced resolutions, up to 3.125 km depending on channel frequency, using the radiometer version of the Scatterometer Image Reconstruction (rSIR) method. We expect this newly produced data set to enable scientists to better analyze trends in coastal regions, marginal ice zones and in mountainous terrain that were not possible with the previous gridded passive microwave data. The use of the EASE-Grid 2.0 definition and netCDF-CF formatting allows users to extract compliant geotiff images and

  9. Extending Climate Analytics-As to the Earth System Grid Federation

    Science.gov (United States)

    Tamkin, G.; Schnase, J. L.; Duffy, D.; McInerney, M.; Nadeau, D.; Li, J.; Strong, S.; Thompson, J. H.

    2015-12-01

    We are building three extensions to prior-funded work on climate analytics-as-a-service that will benefit the Earth System Grid Federation (ESGF) as it addresses the Big Data challenges of future climate research: (1) We are creating a cloud-based, high-performance Virtual Real-Time Analytics Testbed supporting a select set of climate variables from six major reanalysis data sets. This near real-time capability will enable advanced technologies like the Cloudera Impala-based Structured Query Language (SQL) query capabilities and Hadoop-based MapReduce analytics over native NetCDF files while providing a platform for community experimentation with emerging analytic technologies. (2) We are building a full-featured Reanalysis Ensemble Service comprising monthly means data from six reanalysis data sets. The service will provide a basic set of commonly used operations over the reanalysis collections. The operations will be made accessible through NASA's climate data analytics Web services and our client-side Climate Data Services (CDS) API. (3) We are establishing an Open Geospatial Consortium (OGC) WPS-compliant Web service interface to our climate data analytics service that will enable greater interoperability with next-generation ESGF capabilities. The CDS API will be extended to accommodate the new WPS Web service endpoints as well as ESGF's Web service endpoints. These activities address some of the most important technical challenges for server-side analytics and support the research community's requirements for improved interoperability and improved access to reanalysis data.

  10. Toward server-side, high performance climate change data analytics in the Earth System Grid Federation (ESGF) eco-system

    Science.gov (United States)

    Fiore, Sandro; Williams, Dean; Aloisio, Giovanni

    2016-04-01

    In many scientific domains such as climate, data is often n-dimensional and requires tools that support specialized data types and primitives to be properly stored, accessed, analysed and visualized. Moreover, new challenges arise in large-scale scenarios and eco-systems where petabytes (PB) of data can be available and data can be distributed and/or replicated (e.g., the Earth System Grid Federation (ESGF) serving the Coupled Model Intercomparison Project, Phase 5 (CMIP5) experiment, providing access to 2.5PB of data for the Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report (AR5). Most of the tools currently available for scientific data analysis in the climate domain fail at large scale since they: (1) are desktop based and need the data locally; (2) are sequential, so do not benefit from available multicore/parallel machines; (3) do not provide declarative languages to express scientific data analysis tasks; (4) are domain-specific, which ties their adoption to a specific domain; and (5) do not provide a workflow support, to enable the definition of complex "experiments". The Ophidia project aims at facing most of the challenges highlighted above by providing a big data analytics framework for eScience. Ophidia provides declarative, server-side, and parallel data analysis, jointly with an internal storage model able to efficiently deal with multidimensional data and a hierarchical data organization to manage large data volumes ("datacubes"). The project relies on a strong background of high performance database management and OLAP systems to manage large scientific data sets. It also provides a native workflow management support, to define processing chains and workflows with tens to hundreds of data analytics operators to build real scientific use cases. With regard to interoperability aspects, the talk will present the contribution provided both to the RDA Working Group on Array Databases, and the Earth System Grid Federation (ESGF

  11. Development of a Grid-Independent Geos-Chem Chemical Transport Model (v9-02) as an Atmospheric Chemistry Module for Earth System Models

    Science.gov (United States)

    Long, M. S.; Yantosca, R.; Nielsen, J. E; Keller, C. A.; Da Silva, A.; Sulprizio, M. P.; Pawson, S.; Jacob, D. J.

    2015-01-01

    The GEOS-Chem global chemical transport model (CTM), used by a large atmospheric chemistry research community, has been re-engineered to also serve as an atmospheric chemistry module for Earth system models (ESMs). This was done using an Earth System Modeling Framework (ESMF) interface that operates independently of the GEOSChem scientific code, permitting the exact same GEOSChem code to be used as an ESM module or as a standalone CTM. In this manner, the continual stream of updates contributed by the CTM user community is automatically passed on to the ESM module, which remains state of science and referenced to the latest version of the standard GEOS-Chem CTM. A major step in this re-engineering was to make GEOS-Chem grid independent, i.e., capable of using any geophysical grid specified at run time. GEOS-Chem data sockets were also created for communication between modules and with external ESM code. The grid-independent, ESMF-compatible GEOS-Chem is now the standard version of the GEOS-Chem CTM. It has been implemented as an atmospheric chemistry module into the NASA GEOS- 5 ESM. The coupled GEOS-5-GEOS-Chem system was tested for scalability and performance with a tropospheric oxidant-aerosol simulation (120 coupled species, 66 transported tracers) using 48-240 cores and message-passing interface (MPI) distributed-memory parallelization. Numerical experiments demonstrate that the GEOS-Chem chemistry module scales efficiently for the number of cores tested, with no degradation as the number of cores increases. Although inclusion of atmospheric chemistry in ESMs is computationally expensive, the excellent scalability of the chemistry module means that the relative cost goes down with increasing number of cores in a massively parallel environment.

  12. EMAG2v3: Earth Magnetic Anomaly Grid (2-arc-minute resolution)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — EMAG2v3 is a global Earth Magnetic Anomaly Grid compiled from satellite, ship, and airborne magnetic measurements. It is a significant update of the previous release...

  13. The Sun/Earth System and Space Weather

    Science.gov (United States)

    Poland, Arthur I.; Fox, Nicola; Lucid, Shannon

    2003-01-01

    Solar variability and solar activity are now seen as significant drivers with respect to the Earth and human technology systems. Observations over the last 10 years have significantly advanced our understanding of causes and effects in the Sun/Earth system. On a practical level the interactions between the Sun and Earth dictate how we build our systems in space (communications satellites, GPS, etc), and some of our ground systems (power grids). This talk will be about the Sun/Earth system: how it changes with time, its magnetic interactions, flares, the solar wind, and how the Sun effects human systems. Data will be presented from some current spacecraft which show, for example, how we are able to currently give warnings to the scientific community, the Government and industry about space storms and how this data has improved our physical understanding of processes on the Sun and in the magnetosphere. The scientific advances provided by our current spacecraft has led to a new program in NASA to develop a 'Space Weather' system called 'Living With a Star'. The current plan for the 'Living With a Star' program will also be presented.

  14. Geodynamo and mantle convection simulations on the Earth Simulator using the Yin-Yang grid

    International Nuclear Information System (INIS)

    Kageyama, Akira; Yoshida, Masaki

    2005-01-01

    We have developed finite difference codes based on the Yin-Yang grid for the geodynamo simulation and the mantle convection simulation. The Yin-Yang grid is a kind of spherical overset grid that is composed of two identical component grids. The intrinsic simplicity of the mesh configuration of the Yin-Yang grid enables us to develop highly optimized simulation codes on massively parallel supercomputers. The Yin-Yang geodynamo code has achieved 15.2 Tflops with 4096 processors on the Earth Simulator. This represents 46% of the theoretical peak performance. The Yin-Yang mantle code has enabled us to carry out mantle convection simulations in realistic regimes with a Rayleigh number of 10 7 including strongly temperature dependent viscosity with spatial contrast up to 10 6

  15. Multi-objective optimization of GENIE Earth system models.

    Science.gov (United States)

    Price, Andrew R; Myerscough, Richard J; Voutchkov, Ivan I; Marsh, Robert; Cox, Simon J

    2009-07-13

    The tuning of parameters in climate models is essential to provide reliable long-term forecasts of Earth system behaviour. We apply a multi-objective optimization algorithm to the problem of parameter estimation in climate models. This optimization process involves the iterative evaluation of response surface models (RSMs), followed by the execution of multiple Earth system simulations. These computations require an infrastructure that provides high-performance computing for building and searching the RSMs and high-throughput computing for the concurrent evaluation of a large number of models. Grid computing technology is therefore essential to make this algorithm practical for members of the GENIE project.

  16. iSERVO: Implementing the International Solid Earth Research Virtual Observatory by Integrating Computational Grid and Geographical Information Web Services

    Science.gov (United States)

    Aktas, Mehmet; Aydin, Galip; Donnellan, Andrea; Fox, Geoffrey; Granat, Robert; Grant, Lisa; Lyzenga, Greg; McLeod, Dennis; Pallickara, Shrideep; Parker, Jay; Pierce, Marlon; Rundle, John; Sayar, Ahmet; Tullis, Terry

    2006-12-01

    We describe the goals and initial implementation of the International Solid Earth Virtual Observatory (iSERVO). This system is built using a Web Services approach to Grid computing infrastructure and is accessed via a component-based Web portal user interface. We describe our implementations of services used by this system, including Geographical Information System (GIS)-based data grid services for accessing remote data repositories and job management services for controlling multiple execution steps. iSERVO is an example of a larger trend to build globally scalable scientific computing infrastructures using the Service Oriented Architecture approach. Adoption of this approach raises a number of research challenges in millisecond-latency message systems suitable for internet-enabled scientific applications. We review our research in these areas.

  17. Synchronization in single-phase grid-connected photovoltaic systems under grid faults

    DEFF Research Database (Denmark)

    Yang, Yongheng; Blaabjerg, Frede

    2012-01-01

    The highly increasing penetration of single-phase photovoltaic (PV) systems pushes the grid requirements related to the integration of PV power systems to be updated. These upcoming regulations are expected to direct the grid-connected renewable generators to support the grid operation and stabil......The highly increasing penetration of single-phase photovoltaic (PV) systems pushes the grid requirements related to the integration of PV power systems to be updated. These upcoming regulations are expected to direct the grid-connected renewable generators to support the grid operation...

  18. SciDAC's Earth System Grid Center for Enabling Technologies Semi-Annual Progress Report for the Period October 1, 2009 through March 31, 2010

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Dean N. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Foster, I. T. [Argonne National Lab. (ANL), Argonne, IL (United States); Middleton, D. E. [National Center for Atmospheric Research (NCAR), Boulder, CO (United States); Ananthakrishnan, R. [Argonne National Lab. (ANL), Argonne, IL (United States); Siebenlist, F. [Argonne National Lab. (ANL), Argonne, IL (United States); Shoshani, A. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Sim, A. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Bell, G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Drach, R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ahrens, J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Jones, P. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Brown, D. [National Center for Atmospheric Research (NCAR), Boulder, CO (United States); Chastang, J. [National Center for Atmospheric Research (NCAR), Boulder, CO (United States); Cinquini, L. [National Center for Atmospheric Research (NCAR), Boulder, CO (United States); Fox, P. [National Center for Atmospheric Research (NCAR), Boulder, CO (United States); Harper, D. [National Center for Atmospheric Research (NCAR), Boulder, CO (United States); Hook, N. [National Center for Atmospheric Research (NCAR), Boulder, CO (United States); Nienhouse, E. [National Center for Atmospheric Research (NCAR), Boulder, CO (United States); Strand, G. [National Center for Atmospheric Research (NCAR), Boulder, CO (United States); West, P. [National Center for Atmospheric Research (NCAR), Boulder, CO (United States); Wilcox, H. [National Center for Atmospheric Research (NCAR), Boulder, CO (United States); Wilhelmi, N. [National Center for Atmospheric Research (NCAR), Boulder, CO (United States); Zednik, S. [National Center for Atmospheric Research (NCAR), Boulder, CO (United States); Hankin, S. [National Oceanic and Atmospheric Administration (NOAA), Washington, DC (United States); Schweitzer, R. [National Oceanic and Atmospheric Administration (NOAA), Washington, DC (United States); Bernholdt, D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Chen, M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Miller, R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Shipman, G. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wang, F. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bharathi, S. [Univ. of Southern California, Marina Del Rey, CA (United States). Information Sciences Institute; Chervenak, A. [Univ. of Southern California, Marina Del Rey, CA (United States). Information Sciences Institute; Schuler, R. [Univ. of Southern California, Marina Del Rey, CA (United States). Information Sciences Institute; Su, M. [Univ. of Southern California, Marina Del Rey, CA (United States). Information Sciences Institute

    2010-04-21

    This report summarizes work carried out by the ESG-CET during the period October 1, 2009 through March 31, 2009. It includes discussion of highlights, overall progress, period goals, collaborations, papers, and presentations. To learn more about our project, and to find previous reports, please visit the Earth System Grid Center for Enabling Technologies (ESG-CET) website. This report will be forwarded to the DOE SciDAC program management, the Office of Biological and Environmental Research (OBER) program management, national and international collaborators and stakeholders (e.g., the Community Climate System Model (CCSM), the Intergovernmental Panel on Climate Change (IPCC) 5th Assessment Report (AR5), the Climate Science Computational End Station (CCES), the SciDAC II: A Scalable and Extensible Earth System Model for Climate Change Science, the North American Regional Climate Change Assessment Program (NARCCAP), and other wide-ranging climate model evaluation activities).

  19. Building the Platform of Digital Earth with Sphere Split Bricks

    Directory of Open Access Journals (Sweden)

    WANG Jinxin

    2015-06-01

    Full Text Available Discrete global grids, a modeling framework for big geo-spatial data, is always used to build the Digital Earth platform. Based on the sphere split bricks (Earth system spatial grids, it can not only build the true three-dimensional digital Earth model, but also can achieve integration, fusion, expression and application of the spatial data which locates on, under or above the Earth subsurface. The theoretical system of spheroid geodesic QTM octree grid is discussed, including the partition principle, analysis of grid geometry features and coding/ decoding method etc, and a prototype system of true-3D digital Earth platform with the sphere split bricks is developed. The functions of the system mainly include the arbitrary sphere segmentation and the visualization of physical models of underground, surface and aerial entities. Results show that the sphere geodesic QTM octree grid has many application advantages, such as simple subdivision rules, the grid system neat, clear geometric features, strong applicability etc. In particular, it can be extended to the ellipsoid, so it can be used for organization, management, integration and application of the global spatial big data.

  20. Grid-Tied Photovoltaic Power System

    Science.gov (United States)

    Eichenberg, Dennis J.

    2011-01-01

    A grid-tied photovoltaic (PV) power system is connected directly to the utility distribution grid. Facility power can be obtained from the utility system as normal. The PV system is synchronized with the utility system to provide power for the facility, and excess power is provided to the utility. Operating costs of a PV power system are low compared to conventional power technologies. This method can displace the highest-cost electricity during times of peak demand in most climatic regions, and thus reduce grid loading. Net metering is often used, in which independent power producers such as PV power systems are connected to the utility grid via the customers main service panels and meters. When the PV power system is generating more power than required at that location, the excess power is provided to the utility grid. The customer pays the net of the power purchased when the on-site power demand is greater than the onsite power production, and the excess power is returned to the utility grid. Power generated by the PV system reduces utility demand, and the surplus power aids the community. Modern PV panels are readily available, reliable, efficient, and economical, with a life expectancy of at least 25 years. Modern electronics have been the enabling technology behind grid-tied power systems, making them safe, reliable, efficient, and economical with a life expectancy equal to the modern PV panels. The grid-tied PV power system was successfully designed and developed, and this served to validate the basic principles developed, and the theoretical work that was performed. Grid-tied PV power systems are reliable, maintenance- free, long-life power systems, and are of significant value to NASA and the community. Of particular value are the analytical tools and capabilities that have been successfully developed. Performance predictions can be made confidently for grid-tied PV systems of various scales. The work was done under the NASA Hybrid Power Management (HPM

  1. Grid Technology as a Cyberinfrastructure for Delivering High-End Services to the Earth and Space Science Community

    Science.gov (United States)

    Hinke, Thomas H.

    2004-01-01

    Grid technology consists of middleware that permits distributed computations, data and sensors to be seamlessly integrated into a secure, single-sign-on processing environment. In &is environment, a user has to identify and authenticate himself once to the grid middleware, and then can utilize any of the distributed resources to which he has been,panted access. Grid technology allows resources that exist in enterprises that are under different administrative control to be securely integrated into a single processing environment The grid community has adopted commercial web services technology as a means for implementing persistent, re-usable grid services that sit on top of the basic distributed processing environment that grids provide. These grid services can then form building blocks for even more complex grid services. Each grid service is characterized using the Web Service Description Language, which provides a description of the interface and how other applications can access it. The emerging Semantic grid work seeks to associates sufficient semantic information with each grid service such that applications wii1 he able to automatically select, compose and if necessary substitute available equivalent services in order to assemble collections of services that are most appropriate for a particular application. Grid technology has been used to provide limited support to various Earth and space science applications. Looking to the future, this emerging grid service technology can provide a cyberinfrastructures for both the Earth and space science communities. Groups within these communities could transform those applications that have community-wide applicability into persistent grid services that are made widely available to their respective communities. In concert with grid-enabled data archives, users could easily create complex workflows that extract desired data from one or more archives and process it though an appropriate set of widely distributed grid

  2. DOE SciDAC's Earth System Grid Center for Enabling Technologies Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Dean N. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2011-09-27

    The mission of the Earth System Grid Federation (ESGF) is to provide the worldwide climate-research community with access to the data, information, model codes, analysis tools, and intercomparison capabilities required to make sense of enormous climate data sets. Its specific goals are to (1) provide an easy-to-use and secure web-based data access environment for data sets; (2) add value to individual data sets by presenting them in the context of other data sets and tools for comparative analysis; (3) address the specific requirements of participating organizations with respect to bandwidth, access restrictions, and replication; (4) ensure that the data are readily accessible through the analysis and visualization tools used by the climate research community; and (5) transfer infrastructure advances to other domain areas. For the ESGF, the U.S. Department of Energy's (DOE's) Earth System Grid Center for Enabling Technologies (ESG-CET) team has led international development and delivered a production environment for managing and accessing ultra-scale climate data. This production environment includes multiple national and international climate projects (such as the Community Earth System Model and the Coupled Model Intercomparison Project), ocean model data (such as the Parallel Ocean Program), observation data (Atmospheric Radiation Measurement Best Estimate, Carbon Dioxide Information and Analysis Center, Atmospheric Infrared Sounder, etc.), and analysis and visualization tools, all serving a diverse user community. These data holdings and services are distributed across multiple ESG-CET sites (such as ANL, LANL, LBNL/NERSC, LLNL/PCMDI, NCAR, and ORNL) and at unfunded partner sites, such as the Australian National University National Computational Infrastructure, the British Atmospheric Data Centre, the National Oceanic and Atmospheric Administration Geophysical Fluid Dynamics Laboratory, the Max Planck Institute for Meteorology, the German Climate

  3. Production grid systems and their programming

    CERN Document Server

    Kacsuk, P; Stefan, P

    2004-01-01

    Summary form only given. There are a large variety of grid test-beds that can be used for experimental purposes by a small community. However, the number of production grid systems that can be used as a service for a large community is very limited. The current tutorial provides introduction to three of these very few production grid systems. They represent different models and policies of using grid resources and hence understanding and comparing them is an extremely useful exercise to everyone interested in grid technology. The Hungarian ClusterGrid infrastructure connects clusters during the nights and weekends. These clusters are used during the day for educational purposes at the Hungarian universities and polytechnics. Therefore, a unique feature of this grid is the switching mechanism by which the day time and night time working modes are loaded to the computers. In order to manage the system as a production, one, the system is homogeneous, all the machines should install the same grid software package...

  4. Benchmarking of Grid Fault Modes in Single-Phase Grid-Connected Photovoltaic Systems

    DEFF Research Database (Denmark)

    Yang, Yongheng; Blaabjerg, Frede; Zou, Zhixiang

    2013-01-01

    Pushed by the booming installations of singlephase photovoltaic (PV) systems, the grid demands regarding the integration of PV systems are expected to be modified. Hence, the future PV systems should become more active with functionalities of Low Voltage Ride-Through (LVRT) and grid support...... phase systems under grid faults. The intent of this paper is to present a benchmarking of grid fault modes that might come in future single-phase PV systems. In order to map future challenges, the relevant synchronization and control strategies are discussed. Some faulty modes are studied experimentally...... and provided at the end of this paper. It is concluded that there are extensive control possibilities in single-phase PV systems under grid faults. The Second Order General Integral based PLL technique might be the most promising candidate for future single-phase PV systems because of its fast adaptive...

  5. Synchronization method for grid integrated battery storage systems during asymmetrical grid faults

    Directory of Open Access Journals (Sweden)

    Popadić Bane

    2017-01-01

    Full Text Available This paper aims at presenting a robust and reliable synchronization method for battery storage systems during asymmetrical grid faults. For this purpose, a Matlab/Simulink based model for testing of the power electronic interface between the grid and the battery storage systems has been developed. The synchronization method proposed in the paper is based on the proportional integral resonant controller with the delay signal cancellation. The validity of the synchronization method has been verified using the advanced laboratory station for the control of grid connected distributed energy sources. The proposed synchronization method has eliminated unfavourable components from the estimated grid angular frequency, leading to the more accurate and reliable tracking of the grid voltage vector positive sequence during both the normal operation and the operation during asymmetrical grid faults. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. III 042004: Integrated and Interdisciplinary Research entitled: Smart Electricity Distribution Grids Based on Distribution Management System and Distributed Generation

  6. Versioning for CMIP6 in the Earth System Grid Federation

    Science.gov (United States)

    Weigel, Tobias; Kindermann, Stephan; Lautenschlager, Michael

    2015-04-01

    The Earth System Grid Federation (ESGF) has been used as the e-infrastructure to provide access to CMIP5 data and is expected to serve CMIP6 data as well. 2015 marks the year of continued planning and preparation where new concepts can still be implemented for the operational phase of CMIP6. A particular concern within ESGF operations is the versioning and automated replication of data. From CMIP5 experience we know that the pathway between initial submission of modelling data to the ESGF data space and quality-controlled long-term archival of the final products is long and far from linear. Data may be retracted, amended and updated, and metadata may accumulate at different stages. It is unrealistic to assume that a simple and straightforward process can be used as a role model to build ESGF services around the different stages data will pass through during the active phase of CMIP6. Nonetheless, at the technical level ESGF requires some form of automated control and management. At the same time, the accountability of data products must be made transparent to guard against misinterpretation, increase user experience and promote open and reproducible science. To address the challenges, first some essential versioning policies must be agreed upon and enforced through technical means and organizational processes. The volatile readiness state of CMIP data cannot be changed as it is given by the users; however its management can be improved. A promising approach is to embed persistent identifiers in all CMIP6 data objects and register them so they can be globally resolved by any user and used as reference points within ESGF management processes. A specific conceptual interpretation and management of such identifiers can ensure that they remain valid and useful even if the data objects change or become unavailable. For this, identifiers must be assigned to individual versions and aggregations, connected with each other and integrated in the existing ESGF publication

  7. Geospatial Applications on Different Parallel and Distributed Systems in enviroGRIDS Project

    Science.gov (United States)

    Rodila, D.; Bacu, V.; Gorgan, D.

    2012-04-01

    The execution of Earth Science applications and services on parallel and distributed systems has become a necessity especially due to the large amounts of Geospatial data these applications require and the large geographical areas they cover. The parallelization of these applications comes to solve important performance issues and can spread from task parallelism to data parallelism as well. Parallel and distributed architectures such as Grid, Cloud, Multicore, etc. seem to offer the necessary functionalities to solve important problems in the Earth Science domain: storing, distribution, management, processing and security of Geospatial data, execution of complex processing through task and data parallelism, etc. A main goal of the FP7-funded project enviroGRIDS (Black Sea Catchment Observation and Assessment System supporting Sustainable Development) [1] is the development of a Spatial Data Infrastructure targeting this catchment region but also the development of standardized and specialized tools for storing, analyzing, processing and visualizing the Geospatial data concerning this area. For achieving these objectives, the enviroGRIDS deals with the execution of different Earth Science applications, such as hydrological models, Geospatial Web services standardized by the Open Geospatial Consortium (OGC) and others, on parallel and distributed architecture to maximize the obtained performance. This presentation analysis the integration and execution of Geospatial applications on different parallel and distributed architectures and the possibility of choosing among these architectures based on application characteristics and user requirements through a specialized component. Versions of the proposed platform have been used in enviroGRIDS project on different use cases such as: the execution of Geospatial Web services both on Web and Grid infrastructures [2] and the execution of SWAT hydrological models both on Grid and Multicore architectures [3]. The current

  8. Reliability analysis in interdependent smart grid systems

    Science.gov (United States)

    Peng, Hao; Kan, Zhe; Zhao, Dandan; Han, Jianmin; Lu, Jianfeng; Hu, Zhaolong

    2018-06-01

    Complex network theory is a useful way to study many real complex systems. In this paper, a reliability analysis model based on complex network theory is introduced in interdependent smart grid systems. In this paper, we focus on understanding the structure of smart grid systems and studying the underlying network model, their interactions, and relationships and how cascading failures occur in the interdependent smart grid systems. We propose a practical model for interdependent smart grid systems using complex theory. Besides, based on percolation theory, we also study the effect of cascading failures effect and reveal detailed mathematical analysis of failure propagation in such systems. We analyze the reliability of our proposed model caused by random attacks or failures by calculating the size of giant functioning components in interdependent smart grid systems. Our simulation results also show that there exists a threshold for the proportion of faulty nodes, beyond which the smart grid systems collapse. Also we determine the critical values for different system parameters. In this way, the reliability analysis model based on complex network theory can be effectively utilized for anti-attack and protection purposes in interdependent smart grid systems.

  9. Derivation and Error Analysis of the Earth Magnetic Anomaly Grid at 2 arc min Resolution Version 3 (EMAG2v3)

    Science.gov (United States)

    Meyer, B.; Chulliat, A.; Saltus, R.

    2017-12-01

    The Earth Magnetic Anomaly Grid at 2 arc min resolution version 3, EMAG2v3, combines marine and airborne trackline observations, satellite data, and magnetic observatory data to map the location, intensity, and extent of lithospheric magnetic anomalies. EMAG2v3 includes over 50 million new data points added to NCEI's Geophysical Database System (GEODAS) in recent years. The new grid relies only on observed data, and does not utilize a priori geologic structure or ocean-age information. Comparing this grid to other global magnetic anomaly compilations (e.g., EMAG2 and WDMAM), we can see that the inclusion of a priori ocean-age patterns forces an artificial linear pattern to the grid; the data-only approach allows for greater complexity in representing the evolution along oceanic spreading ridges and continental margins. EMAG2v3 also makes use of the satellite-derived lithospheric field model MF7 in order to accurately represent anomalies with wavelengths greater than 300 km and to create smooth grid merging boundaries. The heterogeneous distribution of errors in the observations used in compiling the EMAG2v3 was explored, and is reported in the final distributed grid. This grid is delivered at both 4 km continuous altitude above WGS84, as well as at sea level for all oceanic and coastal regions.

  10. A Grid Voltage Measurement Method for Wind Power Systems during Grid Fault Conditions

    OpenAIRE

    Yoo, Cheol-Hee; Chung, Il-Yop; Yoo, Hyun-Jae; Hong, Sung-Soo

    2014-01-01

    Grid codes in many countries require low-voltage ride-through (LVRT) capability to maintain power system stability and reliability during grid fault conditions. To meet the LVRT requirement, wind power systems must stay connected to the grid and also supply reactive currents to the grid to support the recovery from fault voltages. This paper presents a new fault detection method and inverter control scheme to improve the LVRT capability for full-scale permanent magnet synchronous generator (P...

  11. Benchmarking of grid fault modes in single-phase grid-connected photovoltaic systems

    DEFF Research Database (Denmark)

    Yang, Yongheng; Blaabjerg, Frede; Zou, Zhixiang

    2012-01-01

    Pushed by the booming installations of single-phase photovoltaic (PV) systems, the grid demands regarding the integration of PV systems are expected to be modified. Hence, the future PV systems should become more active with functionalities of low voltage ride-through (LVRT) and the grid support...

  12. EarthCube - Earth System Bridge: Spanning Scientific Communities with Interoperable Modeling Frameworks

    Science.gov (United States)

    Peckham, S. D.; DeLuca, C.; Gochis, D. J.; Arrigo, J.; Kelbert, A.; Choi, E.; Dunlap, R.

    2014-12-01

    In order to better understand and predict environmental hazards of weather/climate, ecology and deep earth processes, geoscientists develop and use physics-based computational models. These models are used widely both in academic and federal communities. Because of the large effort required to develop and test models, there is widespread interest in component-based modeling, which promotes model reuse and simplified coupling to tackle problems that often cross discipline boundaries. In component-based modeling, the goal is to make relatively small changes to models that make it easy to reuse them as "plug-and-play" components. Sophisticated modeling frameworks exist to rapidly couple these components to create new composite models. They allow component models to exchange variables while accommodating different programming languages, computational grids, time-stepping schemes, variable names and units. Modeling frameworks have arisen in many modeling communities. CSDMS (Community Surface Dynamics Modeling System) serves the academic earth surface process dynamics community, while ESMF (Earth System Modeling Framework) serves many federal Earth system modeling projects. Others exist in both the academic and federal domains and each satisfies design criteria that are determined by the community they serve. While they may use different interface standards or semantic mediation strategies, they share fundamental similarities. The purpose of the Earth System Bridge project is to develop mechanisms for interoperability between modeling frameworks, such as the ability to share a model or service component. This project has three main goals: (1) Develop a Framework Description Language (ES-FDL) that allows modeling frameworks to be described in a standard way so that their differences and similarities can be assessed. (2) Demonstrate that if a model is augmented with a framework-agnostic Basic Model Interface (BMI), then simple, universal adapters can go from BMI to a

  13. Development of the AuScope Australian Earth Observing System

    Science.gov (United States)

    Rawling, T.

    2017-12-01

    Advances in monitoring technology and significant investment in new national research initiatives, will provide significant new opportunities for delivery of novel geoscience data streams from across the Australian continent over the next decade. The AuScope Australian Earth Observing System (AEOS) is linking field and laboratory infrastructure across Australia to form a national sensor array focusing on the Solid Earth. As such AuScope is working with these programs to deploy observational infrastructure, including MT, passive seismic, and GNSS networks across the entire Australian Continent. Where possible the observational grid will be co-located with strategic basement drilling in areas of shallow cover and tied with national reflection seismic and sampling transects. This integrated suite of distributed earth observation and imaging sensors will provide unprecedented imaging fidelity of our crust, across all length and time scales, to fundamental and applied researchers in the earth, environmental and geospatial sciences. The AEOS will the Earth Science community's Square Kilometer Array (SKA) - a distributed telescope that looks INTO the earth rather than away from it - a 10 million SKA. The AEOS is strongly aligned with other community strategic initiatives including the UNCOVER research program as well as other National Collaborative Research Infrastructure programs such as the Terrestrial Environmental Research Network (TERN) and the Integrated Marine Observing System (IMOS) providing an interdisciplinary collaboration platform across the earth and environmental sciences. There is also very close alignment between AuScope and similar international programs such as EPOS, the USArray and EarthCube - potential collaborative linkages we are currently in the process of pursuing more fomally. The AuScope AEOS Infrastructure System is ultimately designed to enable the progressive construction, refinement and ongoing enrichment of a live, "FAIR" four

  14. Grid-code of Croatian power system

    International Nuclear Information System (INIS)

    Toljan, I.; Mesic, M.; Kalea, M.; Koscak, Z.

    2003-01-01

    Grid Rules by the Croatian Electricity Utility deal with the control and usage of the Croatian power system's transmission and distribution grid. Furthermore, these rules include obligations and permissions of power grid users and owners, with the aim of a reliable electricity supply.(author)

  15. Harnessing Big Data to Represent 30-meter Spatial Heterogeneity in Earth System Models

    Science.gov (United States)

    Chaney, N.; Shevliakova, E.; Malyshev, S.; Van Huijgevoort, M.; Milly, C.; Sulman, B. N.

    2016-12-01

    Terrestrial land surface processes play a critical role in the Earth system; they have a profound impact on the global climate, food and energy production, freshwater resources, and biodiversity. One of the most fascinating yet challenging aspects of characterizing terrestrial ecosystems is their field-scale (˜30 m) spatial heterogeneity. It has been observed repeatedly that the water, energy, and biogeochemical cycles at multiple temporal and spatial scales have deep ties to an ecosystem's spatial structure. Current Earth system models largely disregard this important relationship leading to an inadequate representation of ecosystem dynamics. In this presentation, we will show how existing global environmental datasets can be harnessed to explicitly represent field-scale spatial heterogeneity in Earth system models. For each macroscale grid cell, these environmental data are clustered according to their field-scale soil and topographic attributes to define unique sub-grid tiles. The state-of-the-art Geophysical Fluid Dynamics Laboratory (GFDL) land model is then used to simulate these tiles and their spatial interactions via the exchange of water, energy, and nutrients along explicit topographic gradients. Using historical simulations over the contiguous United States, we will show how a robust representation of field-scale spatial heterogeneity impacts modeled ecosystem dynamics including the water, energy, and biogeochemical cycles as well as vegetation composition and distribution.

  16. Fuel Cell Backup Power System for Grid Service and Micro-Grid in Telecommunication Applications: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Zhiwen [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Eichman, Joshua D [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Kurtz, Jennifer M [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2018-03-22

    This paper presents the feasibility and economics of using fuel cell backup power systems in telecommunication cell towers to provide grid services (e.g., ancillary services, demand response). The fuel cells are able to provide power for the cell tower during emergency conditions. This study evaluates the strategic integration of clean, efficient, and reliable fuel cell systems with the grid for improved economic benefits. The backup systems have potential as enhanced capability through information exchanges with the power grid to add value as grid services that depend on location and time. The economic analysis has been focused on the potential revenue for distributed telecommunications fuel cell backup units to provide value-added power supply. This paper shows case studies on current fuel cell backup power locations and regional grid service programs. The grid service benefits and system configurations for different operation modes provide opportunities for expanding backup fuel cell applications responsive to grid needs.

  17. OGC and Grid Interoperability in enviroGRIDS Project

    Science.gov (United States)

    Gorgan, Dorian; Rodila, Denisa; Bacu, Victor; Giuliani, Gregory; Ray, Nicolas

    2010-05-01

    EnviroGRIDS (Black Sea Catchment Observation and Assessment System supporting Sustainable Development) [1] is a 4-years FP7 Project aiming to address the subjects of ecologically unsustainable development and inadequate resource management. The project develops a Spatial Data Infrastructure of the Black Sea Catchment region. The geospatial technologies offer very specialized functionality for Earth Science oriented applications as well as the Grid oriented technology that is able to support distributed and parallel processing. One challenge of the enviroGRIDS project is the interoperability between geospatial and Grid infrastructures by providing the basic and the extended features of the both technologies. The geospatial interoperability technology has been promoted as a way of dealing with large volumes of geospatial data in distributed environments through the development of interoperable Web service specifications proposed by the Open Geospatial Consortium (OGC), with applications spread across multiple fields but especially in Earth observation research. Due to the huge volumes of data available in the geospatial domain and the additional introduced issues (data management, secure data transfer, data distribution and data computation), the need for an infrastructure capable to manage all those problems becomes an important aspect. The Grid promotes and facilitates the secure interoperations of geospatial heterogeneous distributed data within a distributed environment, the creation and management of large distributed computational jobs and assures a security level for communication and transfer of messages based on certificates. This presentation analysis and discusses the most significant use cases for enabling the OGC Web services interoperability with the Grid environment and focuses on the description and implementation of the most promising one. In these use cases we give a special attention to issues such as: the relations between computational grid and

  18. Grid Converters for Photovoltaic and Wind Power Systems

    DEFF Research Database (Denmark)

    Teodorescu, Remus; Liserre, Marco; Rodriguez, Pedro

    power, operation within a wide range of voltage and frequency, voltage ride-through capability, reactive current injection during faults, grid services support. This book explains the topologies, modulation and control of grid converters for both photovoltaic and wind power applications. In addition...... to power electronics, this book focuses on the specific applications in photovoltaic wind power systems where grid condition is an essential factor. With a review of the most recent grid requirements for photovoltaic and wind power systems, the book discusses these other relevant issues: Modern grid...... inverter topologies for photovoltaic and wind turbines Islanding detection methods for photovoltaic systems Synchronization techniques based on second order generalized integrators (SOGI) Advanced synchronization techniques with robust operation under grid unbalance condition grid filter design and active...

  19. A Grid Voltage Measurement Method for Wind Power Systems during Grid Fault Conditions

    Directory of Open Access Journals (Sweden)

    Cheol-Hee Yoo

    2014-11-01

    Full Text Available Grid codes in many countries require low-voltage ride-through (LVRT capability to maintain power system stability and reliability during grid fault conditions. To meet the LVRT requirement, wind power systems must stay connected to the grid and also supply reactive currents to the grid to support the recovery from fault voltages. This paper presents a new fault detection method and inverter control scheme to improve the LVRT capability for full-scale permanent magnet synchronous generator (PMSG wind power systems. Fast fault detection can help the wind power systems maintain the DC-link voltage in a safe region. The proposed fault detection method is based on on-line adaptive parameter estimation. The performance of the proposed method is verified in comparison to the conventional voltage measurement method defined in the IEC 61400-21 standard.

  20. Study of the integration of distributed generation systems in the grid: application in micro-grids

    International Nuclear Information System (INIS)

    Gaztanaga Arantzamendi, H.

    2006-12-01

    The present PhD deals with an original micro-grid concept and its application as a Renewable Energy Source's (RES) grid integration scheme. This micro-grid is composed of RES generators as well as support systems that incorporate additional functionalities in order to improve RES integration into the grid. According to this concept, two practical micro-grid applications have been studied in detail: a residential micro-grid and a wind farm supported by DFACTS systems (STATCOM and DVR). In both applications, the control structures which are implemented at different levels and applied to the different micro-grid elements have been developed, analyzed by means of off-line simulations and finally validated in real-time conditions with physical reduced-scale prototypes. (author)

  1. Building a global federation system for climate change research: the earth system grid center for enabling technologies (ESG-CET)

    International Nuclear Information System (INIS)

    Ananthakrishnan, R; Bernholdt, D E; Bharathi, S; Brown, D; Chen, M; Chervenak, A L; Cinquini, L; Drach, R; Foster, I T; Fox, P; Fraser, D; Halliday, K; Hankin, S; Jones, P; Kesselman, C; Middleton, D E; Schwidder, J; Schweitzer, R; Schuler, R; Shoshani, A; Siebenlist, F; Sim, A; Strand, W G; Wilhelmi, N; Su, M; Williams, D N

    2007-01-01

    The recent release of the Intergovernmental Panel on Climate Change (IPCC) 4th Assessment Report (AR4) has generated significant media attention. Much has been said about the US role in this report, which included significant support from the Department of Energy through the Scientific Discovery through Advanced Computing (SciDAC) and other Department of Energy (DOE) programs for climate model development and the production execution of simulations. The SciDAC-supported Earth System Grid Center for Enabling Technologies (ESG-CET) also played a major role in the IPCC AR4: all of the simulation data that went into the report was made available to climate scientists worldwide exclusively via the ESG-CET At the same time as the IPCC AR4 database was being developed, the National Center for Atmospheric Research (NCAR), a leading US climate science laboratory and a ESG participant, began publishing model runs from the Community Climate System Model (CCSM), and its predecessor the Parallel Coupled Model (PCM) through ESG In aggregate, ESG-CET provides seamless access to over 180 terabytes of distributed climate simulation data to over 6,000 registered users worldwide, who have taken delivery of more than 250 terabytes from the archive. Not only does this represent a substantial advance in scientific knowledge, it is also a major step forward in how we conduct the research process on a global scale. Moving forward, the next IPCC assessment report, AR5, will demand multi-site metadata federation for data discovery and cross-domain identity management for single sign-on of users in a more diverse federation enterprise environment. Towards this aim, ESG is leading the effort in the climate community towards standardization of material for the global federation of metadata, security, and data services required to standardize, analyze, and access data worldwide

  2. Grid-connected photovoltaic (PV) systems with batteries storage as solution to electrical grid outages in Burkina Faso

    International Nuclear Information System (INIS)

    Abdoulaye, D; Koalaga, Z; Zougmore, F

    2012-01-01

    This paper deals with a key solution for power outages problem experienced by many African countries and this through grid-connected photovoltaic (PV) systems with batteries storage. African grids are characterized by an insufficient power supply and frequent interruptions. Due to this fact, users who especially use classical grid-connected photovoltaic systems are unable to profit from their installation even if there is sun. In this study, we suggest the using of a grid-connected photovoltaic system with batteries storage as a solution to these problems. This photovoltaic system works by injecting the surplus of electricity production into grid and can also deliver electricity as a stand-alone system with all security needed. To achieve our study objectives, firstly we conducted a survey of a real situation of one African electrical grid, the case of Burkina Faso (SONABEL: National Electricity Company of Burkina). Secondly, as study case, we undertake a sizing, a modeling and a simulation of a grid-connected PV system with batteries storage for the LAME laboratory at the University of Ouagadougou. The simulation shows that the proposed grid-connected system allows users to profit from their photovoltaic installation at any time even if the public electrical grid has some failures either during the day or at night.

  3. Grid Voltage Synchronization for Distributed Generation Systems under Grid Fault Conditions

    DEFF Research Database (Denmark)

    Luna, Alvaro; Rocabert, J.; Candela, I.

    2015-01-01

    on the installation of STATCOMs and DVRs, as well as on advanced control functionalities for the existing power converters of distributed generation plants, have contributed to enhance their response under faulty and distorted scenarios and, hence, to fulfill these requirements. In order to achieve satisfactory......The actual grid code requirements for the grid connection of distributed generation systems, mainly wind and PV systems, are becoming very demanding. The Transmission System Operators (TSOs) are especially concerned about the Low Voltage Ride Through requirements. Solutions based...

  4. AGIS: The ATLAS Grid Information System

    CERN Document Server

    Anisenkov, A; The ATLAS collaboration; Klimentov, A; Senchenko, A

    2012-01-01

    The ATLAS Computing model embraces the Grid paradigm and a high degree of decentralization and computing resources able to meet ATLAS requirements of petabytes scale data operations. In this paper we present ATLAS Grid Information System (AGIS) designed to integrate configuration and status information about resources, services and topology of whole ATLAS Grid needed by ATLAS Distributed Computing applications and services.

  5. Volcano deformation analysis based an on-demand DInSAR-GRID system: the SBAS-GPOD solution

    Science.gov (United States)

    Manunta, M.; Casu, F.; Cossu, R.; Fusco, L.; Guarino, S.; Lanari, R.; Mazzarella, G.; Sansosti, E.

    2009-04-01

    Differential SAR Interferometry (DInSAR) has already demonstrated to be an effective technique to detect and monitor ground displacements with centimeter accuracy. Moreover, the recent development of advanced DInSAR techniques, aimed at the generation of deformation time series, has led to the exploitation of the large archive of SAR data acquired all over the world, during the last 16 years, by the ERS, ENVISAT and RADARSAT satellites. Among these advanced approaches, we focus on the Small BAseline Subset (SBAS) algorithm that relies on the combination of DInSAR data pairs, characterized by a small separation between the acquisition orbits (baseline), in order to produce mean deformation velocity maps and the corresponding time series, maximizing the coherent pixel density of the investigated area. One of the main capabilities of the SBAS approach is the possibility to work at two spatial resolution scales, thus allowing us to investigate deformation phenomena affecting both extended areas (with resolution of about 100 by 100 m) and selected zones, in the latter case highlighting localized displacements that may affect single structures or buildings (at the full instrument resolution). Similarly to other advanced DInSAR techniques, the SBAS approach requires extended data storage and processing capabilities due to the large amount of data exploited for the generation of the final products. Accordingly, we present in this work the results of the first experiment to "plug" the robustness of the SBAS algorithm into the high computing capability provided by a GRID-based system. In particular, we have exploited the low-resolution SBAS algorithm [1] and the ESA Grid Processing-on-Demand (G-POD) system. This environment is one of the results achieved by the ESA Science and Application Department of Earth Observation Programmes Directorate at ESRIN that focused, following the participation to the DATAGRID project (the first large European Commission funded Grid project

  6. An Evaluation of Information Consistency in Grid Information Systems

    CERN Document Server

    Field, Laurence

    2017-01-01

    A Grid information system resolves queries that may need to consider all information sources (Grid services), which are widely distributed geographically, in order to enable efficient Grid functions that may utilise multiple cooperating services. Fundamentally this can be achieved by either moving the query to the data (query shipping) or moving the data to the query (data shipping). Existing Grid information system implementations have adopted one of the two approaches. This paper explores the two approaches in further detail by evaluating them to the best possible extent with respect to Grid information system benchmarking metrics. A Grid information system that follows the data shipping approach based on the replication of information that aims to improve the currency for highly-mutable information is presented. An implementation of this, based on an Enterprise Messaging System, is evaluated using the benchmarking method and the consequence of the results for the design of Grid information systems is discu...

  7. TOMS/Earth Probe UV Reflectivity Daily L3 Global 1x1.25 deg Lat/Lon Grid V008

    Data.gov (United States)

    National Aeronautics and Space Administration — This data product contains TOMS/Earth Probe UV Reflectivity Daily L3 Global 1x1.25 deg Lat/Lon Grid Version 8 data in ASCII format. (The shortname for this Level-3...

  8. Intelligent grid management with variable grid fees as indirect control system for Distribution System Operators; Intelligentes Netzlastmanagement mit variablen Netzentgelten als indirektes Steuerungsinstrument fuer Verteilnetzbetreiber

    Energy Technology Data Exchange (ETDEWEB)

    Engel, Stephan; Nestle, David; Selzam, Patrick; Strauss, Philipp [Fraunhofer Institut fuer Windenergie und Energiesystemtechnik, Kassel (Germany)

    2011-07-01

    Variable grid fees are an incentive system to motivate the grid customers to adjust their energy consumption to the requirements of the distribution grid. Therefore, the Distribution System Operator can reduce grid peak load, improve the integration of fluctuating renewable power producers and optimize the grid load prediction. Compared to variable grid fees which are just in the research stage, peak power demand prices are an existing incentive system. The comparison between these two incentive systems demonstrates which system can support more efficiently the requirements of a sustainable energy system. In E-Energy-Project ''Modellstadt Mannheim'', a proposal for a transparent calculation of variable grid fees will be developed and a technical solution deployed. (orig.)

  9. Geometrical Approach to the Grid System in the KOPEC Pilot Code

    International Nuclear Information System (INIS)

    Lee, E. J.; Park, C. E.; Lee, S. Y.

    2008-01-01

    KOPEC has been developing a pilot code to analyze two phase flow. The earlier version of the pilot code adopts the geometry with one-dimensional structured mesh system. As the pilot code is required to handle more complex geometries, a systematic geometrical approach to grid system has been introduced. Grid system can be classified as two types; structured grid system and unstructured grid system. The structured grid system is simple to apply but is less flexible than the other. The unstructured grid system is more complicated than the structured grid system. But it is more flexible to model the geometry. Therefore, two types of grid systems are utilized to allow code users simplicity as well as the flexibility

  10. Overview of Single-Phase Grid-Connected Photovoltaic Systems

    DEFF Research Database (Denmark)

    Yang, Yongheng; Blaabjerg, Frede

    2017-01-01

    A continuous booming installation of solar photovoltaic (PV) systems has been witnessed worldwide. It is mainly driven by the imperative demand of “clean” power generation from renewables. Grid-connected PV systems will thus become an even more active player in the future mixed power systems, which...... systems. This chapter thus gives an overview of the advancement of power electronics converters in single-phase grid-connected PV systems, being commonly used in residential applications. Demands to single-phase grid-connected PV systems and the general control strategies are also addressed...... are linked together by a vast of power electronics converters and the power grid. In order to achieve a reliable and efficient power generation from PV systems, more stringent demands have been imposed on the entire PV system. It, in return, advances the development of the power converter technology in PV...

  11. Establishment of key grid-connected performance index system for integrated PV-ES system

    Science.gov (United States)

    Li, Q.; Yuan, X. D.; Qi, Q.; Liu, H. M.

    2016-08-01

    In order to further promote integrated optimization operation of distributed new energy/ energy storage/ active load, this paper studies the integrated photovoltaic-energy storage (PV-ES) system which is connected with the distribution network, and analyzes typical structure and configuration selection for integrated PV-ES generation system. By combining practical grid- connected characteristics requirements and technology standard specification of photovoltaic generation system, this paper takes full account of energy storage system, and then proposes several new grid-connected performance indexes such as paralleled current sharing characteristic, parallel response consistency, adjusting characteristic, virtual moment of inertia characteristic, on- grid/off-grid switch characteristic, and so on. A comprehensive and feasible grid-connected performance index system is then established to support grid-connected performance testing on integrated PV-ES system.

  12. DOE SciDAC’s Earth System Grid Center for Enabling Technologies Final Report for University of Southern California Information Sciences Institute

    Energy Technology Data Exchange (ETDEWEB)

    Chervenak, Ann Louise [Univ. of Southern California Information Sciences Inst., Marina del Rey, CA (United States)

    2013-12-19

    The mission of the Earth System Grid Federation (ESGF) is to provide the worldwide climate-research community with access to the data, information, model codes, analysis tools, and intercomparison capabilities required to make sense of enormous climate data sets. Its specific goals are to (1) provide an easy-to-use and secure web-based data access environment for data sets; (2) add value to individual data sets by presenting them in the context of other data sets and tools for comparative analysis; (3) address the specific requirements of participating organizations with respect to bandwidth, access restrictions, and replication; (4) ensure that the data are readily accessible through the analysis and visualization tools used by the climate research community; and (5) transfer infrastructure advances to other domain areas. For the ESGF, the U.S. Department of Energy’s (DOE’s) Earth System Grid Center for Enabling Technologies (ESG-CET) team has led international development and delivered a production environment for managing and accessing ultra-scale climate data. This production environment includes multiple national and international climate projects (such as the Community Earth System Model and the Coupled Model Intercomparison Project), ocean model data (such as the Parallel Ocean Program), observation data (Atmospheric Radiation Measurement Best Estimate, Carbon Dioxide Information and Analysis Center, Atmospheric Infrared Sounder, etc.), and analysis and visualization tools, all serving a diverse user community. These data holdings and services are distributed across multiple ESG-CET sites (such as ANL, LANL, LBNL/NERSC, LLNL/PCMDI, NCAR, and ORNL) and at unfunded partner sites, such as the Australian National University National Computational Infrastructure, the British Atmospheric Data Centre, the National Oceanic and Atmospheric Administration Geophysical Fluid Dynamics Laboratory, the Max Planck Institute for Meteorology, the German Climate Computing

  13. Analysis of the influences of grid-connected PV power system on distribution grids

    Directory of Open Access Journals (Sweden)

    Dumitru Popandron

    2013-12-01

    Full Text Available This paper presents the analysis of producing an electric power of 2.8 MW using a solar photovoltaic plant. The PV will be grid connected to the distribution network. The study is focused on the influences of connecting to the grid of a photovoltaic system, using modern software for analysis, modeling and simulation in power systems.

  14. TOMS/Earth Probe UV Aerosol Index Monthly L3 Global 1x1.25 deg Lat/Lon Grid V008

    Data.gov (United States)

    National Aeronautics and Space Administration — This data product contains TOMS/Earth Probe UV Aerosol Index Monthly L3 Global 1x1.25 deg Lat/Lon Grid Version 8 data in ASCII format. (The shortname for this...

  15. TOMS/Earth Probe Total Column Ozone Daily L3 Global 1x1.25 deg Lat/Lon Grid V008

    Data.gov (United States)

    National Aeronautics and Space Administration — This data product contains TOMS/Earth Probe Total Column Ozone Daily L3 Global 1x1.25 deg Lat/Lon Grid Version 8 data in ASCII format. (The shortname for this...

  16. MAGNETOHYDRODYNAMIC MODELING OF SOLAR SYSTEM PROCESSES ON GEODESIC GRIDS

    Energy Technology Data Exchange (ETDEWEB)

    Florinski, V. [Department of Physics, University of Alabama, Huntsville, AL 35899 (United States); Guo, X. [Center for Space Plasma and Aeronomic Research, University of Alabama, Huntsville, AL 35899 (United States); Balsara, D. S.; Meyer, C. [Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States)

    2013-04-01

    This report describes a new magnetohydrodynamic numerical model based on a hexagonal spherical geodesic grid. The model is designed to simulate astrophysical flows of partially ionized plasmas around a central compact object, such as a star or a planet with a magnetic field. The geodesic grid, produced by a recursive subdivision of a base platonic solid (an icosahedron), is free from control volume singularities inherent in spherical polar grids. Multiple populations of plasma and neutral particles, coupled via charge-exchange interactions, can be simulated simultaneously with this model. Our numerical scheme uses piecewise linear reconstruction on a surface of a sphere in a local two-dimensional 'Cartesian' frame. The code employs Haarten-Lax-van-Leer-type approximate Riemann solvers and includes facilities to control the divergence of the magnetic field and maintain pressure positivity. Several test solutions are discussed, including a problem of an interaction between the solar wind and the local interstellar medium, and a simulation of Earth's magnetosphere.

  17. MAGNETOHYDRODYNAMIC MODELING OF SOLAR SYSTEM PROCESSES ON GEODESIC GRIDS

    International Nuclear Information System (INIS)

    Florinski, V.; Guo, X.; Balsara, D. S.; Meyer, C.

    2013-01-01

    This report describes a new magnetohydrodynamic numerical model based on a hexagonal spherical geodesic grid. The model is designed to simulate astrophysical flows of partially ionized plasmas around a central compact object, such as a star or a planet with a magnetic field. The geodesic grid, produced by a recursive subdivision of a base platonic solid (an icosahedron), is free from control volume singularities inherent in spherical polar grids. Multiple populations of plasma and neutral particles, coupled via charge-exchange interactions, can be simulated simultaneously with this model. Our numerical scheme uses piecewise linear reconstruction on a surface of a sphere in a local two-dimensional 'Cartesian' frame. The code employs Haarten-Lax-van-Leer-type approximate Riemann solvers and includes facilities to control the divergence of the magnetic field and maintain pressure positivity. Several test solutions are discussed, including a problem of an interaction between the solar wind and the local interstellar medium, and a simulation of Earth's magnetosphere.

  18. Electromagnetic Calculation of Combined Earthing System with Ring Earth Electrode and Vertical Rods for Wind Turbine

    Science.gov (United States)

    Fujii, Toshiaki; Yasuda, Yoh; Ueda, Toshiaki

    With the worldwide spread of wind turbine installations, various problems such as landscape issues, bird strikes and grid connections have arisen. Protection of wind turbines from lightning is cited as one of the main problems. Wind turbines are often struck by lightning because of their open-air locations, such as in mountainous areas, and their special configuration and very-high construction. Especially, low-voltage and control circuits can fail or suffer burnout while blades can incur serious damage if struck by lightning. Wind turbine failures caused by lightning strikes account for approximately 25% of all failures. The problem is regarded as a global one that needs immediate resolution. It is important to understand the impedance characteristics of wind turbine earthing systems from the viewpoint of lightning protection. A report from IEC TR61400-24 recommends a “ring earth electrode”. This was originally defined in IEC 61024 (currently revised and re-numbered as IEC 62305), where such an electrode is recommended to reduce touch and step voltages in households and buildings. IEC TR61400-24 also recommended additional electrodes of vertical or horizontal rods. However, these concepts have not been fully discussed from the viewpoint of its application to wind turbines. To confirm the effect of a combination of a ring earth electrode and additional vertical rods for protection of a wind turbine, this report uses the Finite Difference Time Domain (FDTD) method to present an electromagnetic transient analysis on such a wind turbine earthing system. The results show that an optimal combination can be arranged from viewpoints of lightning protection and construction cost. Thus, this report discusses how to establish a quantitative design methodology of the wind turbine earthing system to provide effective lightning protection.

  19. GStat 2.0: Grid Information System Status Monitoring

    CERN Document Server

    Field, L; Tsai, M; CERN. Geneva. IT Department

    2010-01-01

    Grid Information Systems are mission-critical components in today's production grid infrastructures. They enable users, applications and services to discover which services exist in the infrastructure and further information about the service structure and state. It is therefore important that the information system components themselves are functioning correctly and that the information content is reliable. Grid Status (GStat) is a tool that monitors the structural integrity of the EGEE information system, which is a hierarchical system built out of more than 260 site-level and approximately 70 global aggregation services. It also checks the information content and presents summary and history displays for Grid Operators and System Administrators. A major new version, GStat 2.0, aims to build on the production experience of GStat and provides additional functionality, which enables it to be extended and combined with other tools

  20. Low-voltage grid-connection of photovoltaic power systems

    Energy Technology Data Exchange (ETDEWEB)

    Collinson, A.; Thornycroft, J.

    1999-07-01

    This report summarises the results of a project aimed at developing technical guidelines concerning grid connected photovoltaic (PV) inverter generators which are to be published in draft form as the {sup U}K Technical Guidelines for Inverter Connected Single Phase Photovoltaic (PV) Generators up to 5kVA{sup .} The background to the use of PV in the UK is traced, and the technical criteria for electrical integration of PV systems, and UK guidelines for grid connected PV systems are examined. The findings of the working group of the International Energy Agency (IEA) Implementing Agreement on Photovoltaic Power Systems are also presented in this report. Appendices discuss the UK technical guidelines, the IEA Task V activities,, utility aspects of grid-connected PV systems, and demonstration tests on grid-connected PV systems, and lists Task V reports.

  1. Security Challenges in Smart-Grid Metering and Control Systems

    Directory of Open Access Journals (Sweden)

    Xinxin Fan

    2013-07-01

    Full Text Available The smart grid is a next-generation power system that is increasingly attracting the attention of government, industry, and academia. It is an upgraded electricity network that depends on two-way digital communications between supplier and consumer that in turn give support to intelligent metering and monitoring systems. Considering that energy utilities play an increasingly important role in our daily life, smart-grid technology introduces new security challenges that must be addressed. Deploying a smart grid without adequate security might result in serious consequences such as grid instability, utility fraud, and loss of user information and energy-consumption data. Due to the heterogeneous communication architecture of smart grids, it is quite a challenge to design sophisticated and robust security mechanisms that can be easily deployed to protect communications among different layers of the smart grid-infrastructure. In this article, we focus on the communication-security aspect of a smart-grid metering and control system from the perspective of cryptographic techniques, and we discuss different mechanisms to enhance cybersecurity of the emerging smart grid. We aim to provide a comprehensive vulnerability analysis as well as novel insights on the cybersecurity of a smart grid.

  2. The dynamic management system for grid resources information of IHEP

    International Nuclear Information System (INIS)

    Gu Ming; Sun Gongxing; Zhang Weiyi

    2003-01-01

    The Grid information system is an essential base for building a Grid computing environment, it collects timely the resources information of each resource in a Grid, and provides an entire information view of all resources to the other components in a Grid computing system. The Grid technology could support strongly the computing of HEP (High Energy Physics) with big science and multi-organization features. In this article, the architecture and implementation of a dynamic management system are described, as well as the grid and LDAP (Lightweight Directory Access Protocol), including Web-based design for resource information collecting, querying and modifying. (authors)

  3. The GridSite Web/Grid security system

    International Nuclear Information System (INIS)

    McNab, Andrew; Li Yibiao

    2010-01-01

    We present an overview of the current status of the GridSite toolkit, describing the security model for interactive and programmatic uses introduced in the last year. We discuss our experiences of implementing these internal changes and how they and previous rounds of improvements have been prompted by requirements from users and wider security trends in Grids (such as CSRF). Finally, we explain how these have improved the user experience of GridSite-based websites, and wider implications for portals and similar web/grid sites.

  4. GStat 2.0: Grid Information System Status Monitoring

    OpenAIRE

    Field, L; Huang, J; Tsai, M

    2009-01-01

    Grid Information Systems are mission-critical components in today's production grid infrastructures. They enable users, applications and services to discover which services exist in the infrastructure and further information about the service structure and state. It is therefore important that the information system components themselves are functioning correctly and that the information content is reliable. Grid Status (GStat) is a tool that monitors the structural integrity of the EGEE info...

  5. I/O Parallelization for the Goddard Earth Observing System Data Assimilation System (GEOS DAS)

    Science.gov (United States)

    Lucchesi, Rob; Sawyer, W.; Takacs, L. L.; Lyster, P.; Zero, J.

    1998-01-01

    The National Aeronautics and Space Administration (NASA) Data Assimilation Office (DAO) at the Goddard Space Flight Center (GSFC) has developed the GEOS DAS, a data assimilation system that provides production support for NASA missions and will support NASA's Earth Observing System (EOS) in the coming years. The GEOS DAS will be used to provide background fields of meteorological quantities to EOS satellite instrument teams for use in their data algorithms as well as providing assimilated data sets for climate studies on decadal time scales. The DAO has been involved in prototyping parallel implementations of the GEOS DAS for a number of years and is now embarking on an effort to convert the production version from shared-memory parallelism to distributed-memory parallelism using the portable Message-Passing Interface (MPI). The GEOS DAS consists of two main components, an atmospheric General Circulation Model (GCM) and a Physical-space Statistical Analysis System (PSAS). The GCM operates on data that are stored on a regular grid while PSAS works with observational data that are scattered irregularly throughout the atmosphere. As a result, the two components have different data decompositions. The GCM is decomposed horizontally as a checkerboard with all vertical levels of each box existing on the same processing element(PE). The dynamical core of the GCM can also operate on a rotated grid, which requires communication-intensive grid transformations during GCM integration. PSAS groups observations on PEs in a more irregular and dynamic fashion.

  6. GStat 2.0: Grid Information System Status Monitoring

    International Nuclear Information System (INIS)

    Field, Laurence; Huang, Joanna; Tsai, Min

    2010-01-01

    Grid Information Systems are mission-critical components in today's production grid infrastructures. They enable users, applications and services to discover which services exist in the infrastructure and further information about the service structure and state. It is therefore important that the information system components themselves are functioning correctly and that the information content is reliable. Grid Status (GStat) is a tool that monitors the structural integrity of the EGEE information system, which is a hierarchical system built out of more than 260 site-level and approximately 70 global aggregation services. It also checks the information content and presents summary and history displays for Grid Operators and System Administrators. A major new version, GStat 2.0, aims to build on the production experience of GStat and provides additional functionality, which enables it to be extended and combined with other tools. This paper describes the new architecture used for GStat 2.0 and how it can be used at all levels to help provide a reliable information system.

  7. Carbon footprint reductions via grid energy storage systems

    Energy Technology Data Exchange (ETDEWEB)

    Hale, Trevor S. [Naval Facilities Engineering Service Center, 1100 23rd Avenue, Port Huenem, CA 93043 (United States); Department of Management, Marketing, and Business Administration, University of Houston - Downtown, Houston, Texas (United States); Weeks, Kelly [Department of Maritime Administration, Texas A and M University at Galveston, Galveston, TX 77553 (United States); Tucker, Coleman [Department of Management, Marketing, and Business Administration, University of Houston - Downtown, Houston, Texas 77002 (United States)

    2011-07-01

    This effort presents a framework for reducing carbon emissions through the use of large-scale grid-energy-storage (GES) systems. The specific questions under investigation herein are as follows: Is it economically sound to invest in a GES system and is the system at least carbon footprint neutral? This research will show the answer to both questions is in the affirmative. Scilicet, when utilized judiciously, grid energy storage systems can be both net present value positive as well as be total carbon footprint negative. The significant contribution herein is a necessary and sufficient condition for achieving carbon footprint reductions via grid energy storage systems.

  8. Intelligent Operation and Maintenance of Micro-grid Technology and System Development

    Science.gov (United States)

    Fu, Ming; Song, Jinyan; Zhao, Jingtao; Du, Jian

    2018-01-01

    In order to achieve the micro-grid operation and management, Studying the micro-grid operation and maintenance knowledge base. Based on the advanced Petri net theory, the fault diagnosis model of micro-grid is established, and the intelligent diagnosis and analysis method of micro-grid fault is put forward. Based on the technology, the functional system and architecture of the intelligent operation and maintenance system of micro-grid are studied, and the microcomputer fault diagnosis function is introduced in detail. Finally, the system is deployed based on the micro-grid of a park, and the micro-grid fault diagnosis and analysis is carried out based on the micro-grid operation. The system operation and maintenance function interface is displayed, which verifies the correctness and reliability of the system.

  9. AGIS: The ATLAS Grid Information System

    CERN Document Server

    Anisenkov, Alexey; Di Girolamo, Alessandro; Gayazov, Stavro; Klimentov, Alexei; Oleynik, Danila; Senchenko, Alexander

    2012-01-01

    ATLAS is a particle physics experiment at the Large Hadron Collider at CERN. The experiment produces petabytes of data annually through simulation production and tens petabytes of data per year from the detector itself. The ATLAS Computing model embraces the Grid paradigm and a high degree of decentralization and computing resources able to meet ATLAS requirements of petabytes scale data operations. In this paper we present ATLAS Grid Information System (AGIS) designed to integrate configuration and status information about resources, services and topology of whole ATLAS Grid needed by ATLAS Distributed Computing applications and services.

  10. Preface: Workshop on Off-Grid Technology Systems

    Science.gov (United States)

    Alonso-Marroquin, Fernando

    2017-06-01

    Off-grid houses are dwellings that do not rely on water supply, sewer, or electrical power grid, and are able to operate independently of all public utility services. These houses are ideal for remote communities or population suffering natural or human-made disasters. Our aim is to develop compact and affordable off-grid technologies by integrating high-end nano-engineering with systems that imitates natural biological processes. The key areas of focus in the workshop were: solar energy harvesting using nanotechnology, wind energy harvesting from vertical-axis wind turbines, supercapacitors energy storage systems, treatment of greywater, and green roofs to achieve air comfort.

  11. Persistent identifiers for CMIP6 data in the Earth System Grid Federation

    Science.gov (United States)

    Buurman, Merret; Weigel, Tobias; Juckes, Martin; Lautenschlager, Michael; Kindermann, Stephan

    2016-04-01

    The Earth System Grid Federation (ESGF) is a distributed data infrastructure that will provide access to the CMIP6 experiment data. The data consist of thousands of datasets composed of millions of files. Over the course of the CMIP6 operational phase, datasets may be retracted and replaced by newer versions that consist of completely or partly new files. Each dataset is hosted at a single data centre, but can have one or several backups (replicas) at other data centres. To keep track of the different data entities and relationships between them, to ensure their consistency and improve exchange of information about them, Persistent Identifiers (PIDs) are used. These are unique identifiers that are registered at a globally accessible server, along with some metadata (the PID record). While usually providing access to the data object they refer to, as long as it exists, the metadata record will remain available even beyond the object's lifetime. Besides providing access to data and metadata, PIDs will allow scientists to communicate effectively and on a fine granularity about CMIP6 data. The initiative to introduce PIDs in the ESGF infrastructure has been described and agreed upon through a series of white papers governed by the WGCM Infrastructure Panel (WIP). In CMIP6, each dataset and each file is assigned a PID that keeps track of the data object's physical copies throughout the object lifetime. In addition to this, its relationship with other data objects is stored in the PID recordA human-readable version of this information is available on an information page also linked in the PID record. A possible application that exploits the information available from the PID records is a smart information tool, which a scientific user can call to find out if his/her version was replaced by a new one, to view and browse the related datasets and files, and to get access to the various copies or to additional metadata on a dedicated website. The PID registration process is

  12. Distribution Grid Integration of Photovoltaic Systems in Germany – Implications on Grid Planning and Grid Operation

    International Nuclear Information System (INIS)

    Stetz, Thomas

    2017-01-01

    Photovoltaic is the most dispersed renewable energy source in Germany, typically interconnected to low and medium voltage systems. In recent years, cost-intensive grid reinforcements had to be undertaken all across Germany’s distribution grids in order to increase their hosting capacity for these photovoltaic installations. This paper presents an overview on research results which show that photovoltaic itself can provide ancillary services to reduce its cost of interconnection. Especially the provision of reactive power turned out to be a technically effective and economically efficient method to increase a grid’s hosting capacity for photovoltaic capacity. Different reactive power control methods were investigated, revealing significant differences with regards to their grid operation implications. Business cases for residential-scale photovoltaic applications have shifted from feed-in-tariff based active power feed-in to self-consumption. However, increasing the photovoltaic self-consumption by additional battery-storage systems is still not economically reliable in Germany. (author)

  13. A single phase photovoltaic inverter control for grid connected system

    Indian Academy of Sciences (India)

    This paper presents a control scheme for single phase grid connected photovoltaic (PV) system operating under both grid connected and isolated grid mode. The control techniques include voltage and current control of grid-tie PV inverter. During grid connected mode, grid controls the amplitude and frequency of the PV ...

  14. Grid architecture for future distribution system — A cyber-physical system perspective

    DEFF Research Database (Denmark)

    Li, Chendan; Dragicevic, Tomislav; Leonardo Diaz Aldana, Nelson

    2017-01-01

    system need more insight into the system architecture of the grid. In this paper, in light of the start-of-the-art control strategies for microgrids which rely on power electronics systems, a grid architecture model for future distribution system is proposed based on microgrid clusters. Both the physical...

  15. A HYBRID SOLAR WIND MODEL OF THE CESE+HLL METHOD WITH A YIN-YANG OVERSET GRID AND AN AMR GRID

    International Nuclear Information System (INIS)

    Feng Xueshang; Zhang Shaohua; Xiang Changqing; Yang Liping; Jiang Chaowei; Wu, S. T.

    2011-01-01

    A hybrid three-dimensional (3D) MHD model for solar wind study is proposed in the present paper with combined grid systems and solvers. The computational domain from the Sun to Earth space is decomposed into the near-Sun and off-Sun domains, which are respectively constructed with a Yin-Yang overset grid system and a Cartesian adaptive mesh refinement (AMR) grid system and coupled with a domain connection interface in the overlapping region between the near-Sun and off-Sun domains. The space-time conservation element and solution element method is used in the near-Sun domain, while the Harten-Lax-Leer method is employed in the off-Sun domain. The Yin-Yang overset grid can avoid well-known singularity and polar grid convergence problems and its body-fitting property helps achieve high-quality resolution near the solar surface. The block structured AMR Cartesian grid can automatically capture far-field plasma flow features, such as heliospheric current sheets and shock waves, and at the same time, it can save significant computational resources compared to the uniformly structured Cartesian grid. A numerical study of the solar wind structure for Carrington rotation 2069 shows that the newly developed hybrid MHD solar wind model successfully produces many realistic features of the background solar wind, in both the solar corona and interplanetary space, by comparisons with multiple solar and interplanetary observations.

  16. Ion extraction capabilities of two-grid accelerator systems

    International Nuclear Information System (INIS)

    Rovang, D.C.; Wilbur, P.J.

    1984-02-01

    An experimental investigation into the ion extraction capabilities of two-grid accelerator systems common to electrostatic ion thrusters is described. This work resulted in a large body of experimental data which facilitates the selection of the accelerator system geometries and operating parameters necessary to maximize the extracted ion current. Results suggest that the impingement-limited perveance is not dramatically affected by reductions in screen hole diameter to 0.5 mm. Impingement-limited performance is shown to depend most strongly on grid separation distance, accelerator hole diameter ratio, the discharge-to-total accelerating voltage ratio, and the net-to-total accelerating voltage ratio. Results obtained at small grid separation ratios suggest a new grid operating condition where high beam current per hole levels are achieved at a specified net accelerating voltage. It is shown that this operating condition is realized at an optimum ratio of net-to-total accelerating voltage ratio which is typically quite high. The apparatus developed for this study is also shown to be well suited measuring the electron backstreaming and electrical breakdown characteristics of two-grid accelerator systems

  17. Grid Computing BOINC Redesign Mindmap with incentive system (gamification)

    OpenAIRE

    Kitchen, Kris

    2016-01-01

    Grid Computing BOINC Redesign Mindmap with incentive system (gamification) this is a PDF viewable of https://figshare.com/articles/Grid_Computing_BOINC_Redesign_Mindmap_with_incentive_system_gamification_/1265350

  18. Trends and Potentials of the Smart Grid Infrastructure: From ICT Sub-System to SDN-Enabled Smart Grid Architecture

    Directory of Open Access Journals (Sweden)

    Jaebeom Kim

    2015-10-01

    Full Text Available Context and situational awareness are key features and trends of the smart grid and enable adaptable, flexible and extendable smart grid services. However, the traditional hardware-dependent communication infrastructure is not designed to identify the flow and context of data, and it focuses only on packet forwarding using a pre-defined network configuration profile. Thus, the current network infrastructure may not dynamically adapt the various business models and services of the smart grid system. To solve this problem, software-defined networking (SDN is being considered in the smart grid, but the design, architecture and system model need to be optimized for the smart grid environment. In this paper, we investigate the state-of-the-art smart grid information subsystem, communication infrastructure and its emerging trends and potentials, called an SDN-enabled smart grid. We present an abstract business model, candidate SDN applications and common architecture of the SDN-enabled smart grid. Further, we compare recent studies into the SDN-enabled smart grid depending on its service functionalities, and we describe further challenges of the SDN-enabled smart grid network infrastructure.

  19. Optimizing electrical load pattern in Kuwait using grid connected photovoltaic systems

    International Nuclear Information System (INIS)

    Al-Hasan, A.Y.; Ghoneim, A.A.; Abdullah, A.H.

    2004-01-01

    Grid connected photovoltaic systems is one of the most promising applications of photovoltaic systems. These systems are employed in applications where utility service is already available. In this case, there is no need for battery storage because grid power may be used to supplement photovoltaic systems (PV) when the load exceeds available PV generation. The load receives electricity from both the photovoltaic array and the utility grid. In this system, the load is the total electrical energy consumption. The main objective of the present work is to optimize the electrical load pattern in Kuwait using grid connected PV systems. In this situation, the electric load demand can be satisfied from both the photovoltaic array and the utility grid. The performance of grid connected photovoltaic systems in the Kuwait climate has been evaluated. It was found that the peak load matches the maximum incident solar radiation in Kuwait, which would emphasize the role of using the PV station to minimize the electrical load demand. In addition, a significant reduction in peak load can be achieved with grid connected PV systems

  20. A Guidebook on Grid Interconnection and Islanded Operation of Mini-Grid Power Systems Up to 200 kW

    Energy Technology Data Exchange (ETDEWEB)

    Greacen, Chris [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Engel, Richard [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Quetchenbach, Thomas [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2013-04-01

    A Guidebook on Grid Interconnection and Islanded Operation of Mini-Grid Power Systems Up to 200 kW is intended to help meet the widespread need for guidance, standards, and procedures for interconnecting mini-grids with the central electric grid as rural electrification advances in developing countries, bringing these once separate power systems together. The guidebook aims to help owners and operators of renewable energy mini-grids understand the technical options available, safety and reliability issues, and engineering and administrative costs of different choices for grid interconnection. The guidebook is intentionally brief but includes a number of appendices that point the reader to additional resources for indepth information. Not included in the scope of the guidebook are policy concerns about “who pays for what,” how tariffs should be set, or other financial issues that are also paramount when “the little grid connects to the big grid.”

  1. An energy management system for off-grid power systems

    Energy Technology Data Exchange (ETDEWEB)

    Zelazo, Daniel [Universitaet Stuttgart, Institute for Systems Theory and Automatic Control, Stuttgart (Germany); Dai, Ran; Mesbahi, Mehran [University of Washington, Department of Aeronautics and Astronautics, Seattle, WA (United States)

    2012-06-15

    Next generation power management at all scales will rely on the efficient scheduling and operation of both generating units and loads to maximize efficiency and utility. The ability to schedule and modulate the demand levels of a subset of loads within a power system can lead to more efficient use of the generating units. These methods become increasingly important for systems that operate independently of the main utility, such as microgrid and off-grid systems. This work extends the principles of unit commitment and economic dispatch problems to off-grid power systems where the loads are also schedulable. We propose a general optimization framework for solving the energy management problem in these systems. An important contribution is the description of how a wide range of sources and loads, including those with discrete states, non-convex, and nonlinear cost or utility functions, can be reformulated as a convex optimization problem using, for example, a shortest path description. Once cast in this way, solution are obtainable using a sub-gradient algorithm that also lends itself to a distributed implementation. The methods are demonstrated by a simulation of an off-grid solar powered community. (orig.)

  2. Grid Monitoring and Advanced Control of Distributed Power Generation Systems

    DEFF Research Database (Denmark)

    Timbus, Adrian Vasile

    . As an example, the latest published grid codes stress the ability of distributed generators, especially wind turbines, to stay connected during short grid disturbances and in addition to provide active/reactive power control at the point of common coupling. Based on the above facts, the need for improving...... reported in some countries creating concerns about power system stability. This leads to a continuous evolution of grid interconnection requirements towards a better controllability of generated power and an enhanced contribution of distributed power generation systems to power system stability...... and adding more features to the control of distributed power generation systems (DPGS) arises. As a consequence, this thesis focuses on grid monitoring methods and possible approaches in control in order to obtain a more reliable and  exible power generation system during normal and faulty grid conditions...

  3. A Subdivision Method to Unify the Existing Latitude and Longitude Grids

    Directory of Open Access Journals (Sweden)

    Chengqi Cheng

    2016-09-01

    Full Text Available As research on large regions of earth progresses, many geographical subdivision grids have been established for various spatial applications by different industries and disciplines. However, there is no clear relationship between the different grids and no consistent spatial reference grid that allows for information exchange and comprehensive application. Sharing and exchange of data across departments and applications are still at a bottleneck. It would represent a significant step forward to build a new grid model that is inclusive of or compatible with most of the existing geodesic grids and that could support consolidation and exchange within existing data services. This study designs a new geographical coordinate global subdividing grid with one dimension integer coding on a 2n tree (GeoSOT that has 2n coordinate subdivision characteristics (global longitude and latitude subdivision and can form integer hierarchies at degree, minute, and second levels. This grid has the multi-dimensional quadtree hierarchical characteristics of a digital earth grid, but also provides good consistency with applied grids, such as those used in mapping, meteorology, oceanography and national geographical, and three-dimensional digital earth grids. No other existing grid codes possess these characteristics.

  4. An automated method for estimating reliability of grid systems using Bayesian networks

    International Nuclear Information System (INIS)

    Doguc, Ozge; Emmanuel Ramirez-Marquez, Jose

    2012-01-01

    Grid computing has become relevant due to its applications to large-scale resource sharing, wide-area information transfer, and multi-institutional collaborating. In general, in grid computing a service requests the use of a set of resources, available in a grid, to complete certain tasks. Although analysis tools and techniques for these types of systems have been studied, grid reliability analysis is generally computation-intensive to obtain due to the complexity of the system. Moreover, conventional reliability models have some common assumptions that cannot be applied to the grid systems. Therefore, new analytical methods are needed for effective and accurate assessment of grid reliability. This study presents a new method for estimating grid service reliability, which does not require prior knowledge about the grid system structure unlike the previous studies. Moreover, the proposed method does not rely on any assumptions about the link and node failure rates. This approach is based on a data-mining algorithm, the K2, to discover the grid system structure from raw historical system data, that allows to find minimum resource spanning trees (MRST) within the grid then, uses Bayesian networks (BN) to model the MRST and estimate grid service reliability.

  5. The Design of Distributed Micro Grid Energy Storage System

    Science.gov (United States)

    Liang, Ya-feng; Wang, Yan-ping

    2018-03-01

    Distributed micro-grid runs in island mode, the energy storage system is the core to maintain the micro-grid stable operation. For the problems that it is poor to adjust at work and easy to cause the volatility of micro-grid caused by the existing energy storage structure of fixed connection. In this paper, an array type energy storage structure is proposed, and the array type energy storage system structure and working principle are analyzed. Finally, the array type energy storage structure model is established based on MATLAB, the simulation results show that the array type energy storage system has great flexibility, which can maximize the utilization of energy storage system, guarantee the reliable operation of distributed micro-grid and achieve the function of peak clipping and valley filling.

  6. Development of hybrid 3-D hydrological modeling for the NCAR Community Earth System Model (CESM)

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Xubin [Univ. of Arizona, Tucson, AZ (United States); Troch, Peter [Univ. of Arizona, Tucson, AZ (United States); Pelletier, Jon [Univ. of Arizona, Tucson, AZ (United States); Niu, Guo-Yue [Univ. of Arizona, Tucson, AZ (United States); Gochis, David [NCAR Research Applications Lab., Boulder, CO (United States)

    2015-11-15

    This is the Final Report of our four-year (3-year plus one-year no cost extension) collaborative project between the University of Arizona (UA) and the National Center for Atmospheric Research (NCAR). The overall objective of our project is to develop and evaluate the first hybrid 3-D hydrological model with a horizontal grid spacing of 1 km for the NCAR Community Earth System Model (CESM).

  7. The Role of Discrete Global Grid Systems in the Global Statistical Geospatial Framework

    Science.gov (United States)

    Purss, M. B. J.; Peterson, P.; Minchin, S. A.; Bermudez, L. E.

    2016-12-01

    The United Nations Committee of Experts on Global Geospatial Information Management (UN-GGIM) has proposed the development of a Global Statistical Geospatial Framework (GSGF) as a mechanism for the establishment of common analytical systems that enable the integration of statistical and geospatial information. Conventional coordinate reference systems address the globe with a continuous field of points suitable for repeatable navigation and analytical geometry. While this continuous field is represented on a computer in a digitized and discrete fashion by tuples of fixed-precision floating point values, it is a non-trivial exercise to relate point observations spatially referenced in this way to areal coverages on the surface of the Earth. The GSGF states the need to move to gridded data delivery and the importance of using common geographies and geocoding. The challenges associated with meeting these goals are not new and there has been a significant effort within the geospatial community to develop nested gridding standards to tackle these issues over many years. These efforts have recently culminated in the development of a Discrete Global Grid Systems (DGGS) standard which has been developed under the auspices of Open Geospatial Consortium (OGC). DGGS provide a fixed areal based geospatial reference frame for the persistent location of measured Earth observations, feature interpretations, and modelled predictions. DGGS address the entire planet by partitioning it into a discrete hierarchical tessellation of progressively finer resolution cells, which are referenced by a unique index that facilitates rapid computation, query and analysis. The geometry and location of the cell is the principle aspect of a DGGS. Data integration, decomposition, and aggregation is optimised in the DGGS hierarchical structure and can be exploited for efficient multi-source data processing, storage, discovery, transmission, visualization, computation, analysis, and modelling. During

  8. Development of Resource Sharing System Components for AliEn Grid Infrastructure

    CERN Document Server

    Harutyunyan, Artem

    2010-01-01

    The problem of the resource provision, sharing, accounting and use represents a principal issue in the contemporary scientific cyberinfrastructures. For example, collaborations in physics, astrophysics, Earth science, biology and medicine need to store huge amounts of data (of the order of several petabytes) as well as to conduct highly intensive computations. The appropriate computing and storage capacities cannot be ensured by one (even very large) research center. The modern approach to the solution of this problem suggests exploitation of computational and data storage facilities of the centers participating in collaborations. The most advanced implementation of this approach is based on Grid technologies, which enable effective work of the members of collaborations regardless of their geographical location. Currently there are several tens of Grid infrastructures deployed all over the world. The Grid infrastructures of CERN Large Hadron Collider experiments - ALICE, ATLAS, CMS, and LHCb which are exploi...

  9. Particle simulation of grid system for krypton ion thrusters

    Directory of Open Access Journals (Sweden)

    Maolin CHEN

    2018-04-01

    Full Text Available The transport processes of plasmas in grid systems of krypton (Kr ion thrusters at different acceleration voltages were simulated with a 3D-PIC model, and the result was compared with xenon (Xe ion thrusters. The variation of the screen grid transparency, the accelerator grid current ratio and the divergence loss were explored. It is found that the screen grid transparency increases with the acceleration voltage and decreases with the beam current, while the accelerator grid current ratio and divergence loss decrease first and then increase with the beam current. This result is the same with Xe ion thrusters. Simulation results also show that Kr ion thrusters have more advantages than Xe ion thrusters, such as higher screen grid transparency, smaller accelerator grid current ratio, larger cut-off current threshold, and better divergence loss characteristic. These advantages mean that Kr ion thrusters have the ability of operating in a wide range of current. Through comprehensive analyses, it can be concluded that using Kr as propellant is very suitable for a multi-mode ion thruster design. Keywords: Grid system, Ion thrusters, Krypton, Particle in cell method, Plasma

  10. Intelligent Control for a DC Micro-Grid System

    DEFF Research Database (Denmark)

    Martino, Michele; Quiñones, Yamshid Farhat; Raboni, Pietro

    2012-01-01

    This paper presents the dynamic response of a DC–micro-grid (DC-MG) controlled in master-slave mode. The benefits of the micro-grids (MGs) are the low cost in terms of power electronics converters and the high reliability and quality, even in case of loss connection to the transmission system. A ...... the units, especially in case of variable weather conditions with different DC loads. Thus the voltage level of the system and the power flow are shown, out of a detailed description of the power electronic interfaces featuring the distributed generators (DGs).......This paper presents the dynamic response of a DC–micro-grid (DC-MG) controlled in master-slave mode. The benefits of the micro-grids (MGs) are the low cost in terms of power electronics converters and the high reliability and quality, even in case of loss connection to the transmission system. A DC......-MG in fact can survive in standalone mode if properly managed. The considered system is made by a photovoltaic array (PV), a wind turbine (WT), a gas engine (GE) and an energy storage system (ESS). The DC-MG behavior is analyzed in different scenarios to demonstrate the efficacy of the control for all...

  11. New grid-planning and certification approaches for the large-scale offshore-wind farm grid-connection systems

    Energy Technology Data Exchange (ETDEWEB)

    Heising, C.; Bartelt, R. [Avasition GmbH, Dortmund (Germany); Zadeh, M. Koochack; Lebioda, T.J.; Jung, J. [TenneT Offshore GmbH, Bayreuth (Germany)

    2012-07-01

    Stable operation of the offshore-wind farms (OWF) and stable grid connection under stationary and dynamic conditions are essential to achieve a stable public power supply. To reach this aim, adequate grid-planning and certification approaches are a major advantage. Within this paper, the fundamental characteristics of the offshore-wind farms and their grid-connection systems are given. The main goal of this research project is to study the stability of the offshore grid especially in terms of subharmonic stability for the likely future extension stage of the offshore grids i.e. having parallel connection of two or more HVDC links and for certain operating scenarios e.g. overload scenario. The current requirements according to the grid code are not the focus of this research project. The goal is to study and define potential additional grid code requirements, simulations, tests and grid planning methods for the future. (orig.)

  12. AGIS: The ATLAS Grid Information System

    OpenAIRE

    Anisenkov, Alexey; Belov, Sergey; Di Girolamo, Alessandro; Gayazov, Stavro; Klimentov, Alexei; Oleynik, Danila; Senchenko, Alexander

    2012-01-01

    ATLAS is a particle physics experiment at the Large Hadron Collider at CERN. The experiment produces petabytes of data annually through simulation production and tens petabytes of data per year from the detector itself. The ATLAS Computing model embraces the Grid paradigm and a high degree of decentralization and computing resources able to meet ATLAS requirements of petabytes scale data operations. In this paper we present ATLAS Grid Information System (AGIS) designed to integrate configurat...

  13. Large-scale, high-performance and cloud-enabled multi-model analytics experiments in the context of the Earth System Grid Federation

    Science.gov (United States)

    Fiore, S.; Płóciennik, M.; Doutriaux, C.; Blanquer, I.; Barbera, R.; Williams, D. N.; Anantharaj, V. G.; Evans, B. J. K.; Salomoni, D.; Aloisio, G.

    2017-12-01

    The increased models resolution in the development of comprehensive Earth System Models is rapidly leading to very large climate simulations output that pose significant scientific data management challenges in terms of data sharing, processing, analysis, visualization, preservation, curation, and archiving.Large scale global experiments for Climate Model Intercomparison Projects (CMIP) have led to the development of the Earth System Grid Federation (ESGF), a federated data infrastructure which has been serving the CMIP5 experiment, providing access to 2PB of data for the IPCC Assessment Reports. In such a context, running a multi-model data analysis experiment is very challenging, as it requires the availability of a large amount of data related to multiple climate models simulations and scientific data management tools for large-scale data analytics. To address these challenges, a case study on climate models intercomparison data analysis has been defined and implemented in the context of the EU H2020 INDIGO-DataCloud project. The case study has been tested and validated on CMIP5 datasets, in the context of a large scale, international testbed involving several ESGF sites (LLNL, ORNL and CMCC), one orchestrator site (PSNC) and one more hosting INDIGO PaaS services (UPV). Additional ESGF sites, such as NCI (Australia) and a couple more in Europe, are also joining the testbed. The added value of the proposed solution is summarized in the following: it implements a server-side paradigm which limits data movement; it relies on a High-Performance Data Analytics (HPDA) stack to address performance; it exploits the INDIGO PaaS layer to support flexible, dynamic and automated deployment of software components; it provides user-friendly web access based on the INDIGO Future Gateway; and finally it integrates, complements and extends the support currently available through ESGF. Overall it provides a new "tool" for climate scientists to run multi-model experiments. At the

  14. ROADNET: A Real-time Data Aware System for Earth, Oceanographic, and Environmental Applications

    Science.gov (United States)

    Vernon, F.; Hansen, T.; Lindquist, K.; Ludascher, B.; Orcutt, J.; Rajasekar, A.

    2003-12-01

    The Real-time Observatories, Application, and Data management Network (ROADNet) Program aims to develop an integrated, seamless, and transparent environmental information network that will deliver geophysical, oceanographic, hydrological, ecological, and physical data to a variety of users in real-time. ROADNet is a multidisciplinary, multinational partnership of researchers, policymakers, natural resource managers, educators, and students who aim to use the data to advance our understanding and management of coastal, ocean, riparian, and terrestrial Earth systems in Southern California, Mexico, and well off shore. To date, project activity and funding have focused on the design and deployment of network linkages and on the exploratory development of the real-time data management system. We are currently adapting powerful "Data Grid" technologies to the unique challenges associated with the management and manipulation of real-time data. Current "Grid" projects deal with static data files, and significant technical innovation is required to address fundamental problems of real-time data processing, integration, and distribution. The technologies developed through this research will create a system that dynamically adapt downstream processing, cataloging, and data access interfaces when sensors are added or removed from the system; provide for real-time processing and monitoring of data streams--detecting events, and triggering computations, sensor and logger modifications, and other actions; integrate heterogeneous data from multiple (signal) domains; and provide for large-scale archival and querying of "consolidated" data. The software tools which must be developed do not exist, although limited prototype systems are available. This research has implications for the success of large-scale NSF initiatives in the Earth sciences (EarthScope), ocean sciences (OOI- Ocean Observatories Initiative), biological sciences (NEON - National Ecological Observatory Network) and

  15. AGIS: The ATLAS Grid Information System

    CERN Document Server

    Anisenkov, A; The ATLAS collaboration; Klimentov, A; Oleynik, D; Petrosyan, A

    2014-01-01

    In this paper we describe ATLAS Grid Information System (AGIS), the system designed to integrate configuration and status information about resources, services and topology of the computing infrastructure used by ATLAS Distributed Computing applications and services.

  16. AGIS: The ATLAS Grid Information System

    OpenAIRE

    Anisenkov, A; Di Girolamo, A; Klimentov, A; Oleynik, D; Petrosyan, A

    2013-01-01

    In this paper we describe ATLAS Grid Information System (AGIS), the system designed to integrate configuration and status information about resources, services and topology of the computing infrastructure used by ATLAS Distributed Computing applications and services.

  17. Agent-based Decentralization of Applications in Distributed Smart Grid Systems

    DEFF Research Database (Denmark)

    Kienesberger, Georg; Xypolytou, Evangelia; Marchgraber, Jurgen

    2015-01-01

    systems (DMACS) and aims to give an overview on the different requirements and challenges on the way from current centralized control systems to DMACS. Therefore, different ICT scenarios and MAS topologies are employed to discuss the decentralization of three exemplary smart grid applications: voltage......Smart grid technology promises to prepare today’s power systems for the challenges of the future by extensive integration of information and communication technology (ICT). One key aspect is the control paradigm which will have to be shifted from completely centralized control systems to more...... dezentralized concepts in order to adapt to the distributed nature of smart grids. Multi-agent systems (MAS) are a very promising approach for designing distributed, decentralized systems, naturally also in the field of smart grids. This work introduces the notion of decentralized multi-agent-based control...

  18. Hardware-in-the-loop grid simulator system and method

    Science.gov (United States)

    Fox, John Curtiss; Collins, Edward Randolph; Rigas, Nikolaos

    2017-05-16

    A hardware-in-the-loop (HIL) electrical grid simulation system and method that combines a reactive divider with a variable frequency converter to better mimic and control expected and unexpected parameters in an electrical grid. The invention provides grid simulation in a manner to allow improved testing of variable power generators, such as wind turbines, and their operation once interconnected with an electrical grid in multiple countries. The system further comprises an improved variable fault reactance (reactive divider) capable of providing a variable fault reactance power output to control a voltage profile, therein creating an arbitrary recovery voltage. The system further comprises an improved isolation transformer designed to isolate zero-sequence current from either a primary or secondary winding in a transformer or pass the zero-sequence current from a primary to a secondary winding.

  19. System performance of a three-phase PV-grid-connected system installed in Thailand. Data monitored analysis

    International Nuclear Information System (INIS)

    Boonmee, Chaiyant; Watjanatepin, Napat; Plangklang, Boonyang

    2009-01-01

    PV-grid-connected systems are worldwide installed because it allows consumer to reduce energy consumption from the electricity grid and to feed the surplus energy back into the grid. The system needs no battery so therefore the system price is very cheap comparing to other PV systems. PV-grid-connected systems are used in buildings that already hooked up to the electrical grid. Finding efficiency of the PV-grid-connected system can be done by using a standard instrument which needs to disconnect the PV arrays from the grid before measurement. The measurement is also difficult and we lose energy during the measurement. This paper will present the system performance of a PV-grid-connected system installed in Thailand by using a monitoring system. The monitored data are installed by acquisition software into a computer. Analysis of monitored data will be done to find out the system performance without disconnecting the PV arrays from the system. The monitored data include solar radiation, PV voltage, PV current, and PV power which has been recorded from a 5 kWp system installed of amorphous silicon PV at Rajamangala University of Technology Suvarnabhumi, Nonthaburi, Thailand. The system performance of the system by using the data monitored is compared to the standard instrument measurement. The paper will give all details about system components, monitoring system, and monitored data. The result of data analysis will be fully given. (author)

  20. Evaluation of Smart Grid Technologies Employed for System Reliability Improvement: Pacific Northwest Smart Grid Demonstration Experience

    Energy Technology Data Exchange (ETDEWEB)

    Agalgaonkar, Yashodhan P.; Hammerstrom, Donald J.

    2017-06-01

    The Pacific Northwest Smart Grid Demonstration (PNWSGD) was a smart grid technology performance evaluation project that included multiple U.S. states and cooperation from multiple electric utilities in the northwest region. One of the local objectives for the project was to achieve improved distribution system reliability. Toward this end, some PNWSGD utilities automated their distribution systems, including the application of fault detection, isolation, and restoration and advanced metering infrastructure. In light of this investment, a major challenge was to establish a correlation between implementation of these smart grid technologies and actual improvements of distribution system reliability. This paper proposes using Welch’s t-test to objectively determine and quantify whether distribution system reliability is improving over time. The proposed methodology is generic, and it can be implemented by any utility after calculation of the standard reliability indices. The effectiveness of the proposed hypothesis testing approach is demonstrated through comprehensive practical results. It is believed that wider adoption of the proposed approach can help utilities to evaluate a realistic long-term performance of smart grid technologies.

  1. Development of a hybrid 3-D hydrological model to simulate hillslopes and the regional unconfined aquifer system in Earth system models

    Science.gov (United States)

    Hazenberg, P.; Broxton, P. D.; Brunke, M.; Gochis, D.; Niu, G. Y.; Pelletier, J. D.; Troch, P. A. A.; Zeng, X.

    2015-12-01

    The terrestrial hydrological system, including surface and subsurface water, is an essential component of the Earth's climate system. Over the past few decades, land surface modelers have built one-dimensional (1D) models resolving the vertical flow of water through the soil column for use in Earth system models (ESMs). These models generally have a relatively coarse model grid size (~25-100 km) and only account for sub-grid lateral hydrological variations using simple parameterization schemes. At the same time, hydrologists have developed detailed high-resolution (~0.1-10 km grid size) three dimensional (3D) models and showed the importance of accounting for the vertical and lateral redistribution of surface and subsurface water on soil moisture, the surface energy balance and ecosystem dynamics on these smaller scales. However, computational constraints have limited the implementation of the high-resolution models for continental and global scale applications. The current work presents a hybrid-3D hydrological approach is presented, where the 1D vertical soil column model (available in many ESMs) is coupled with a high-resolution lateral flow model (h2D) to simulate subsurface flow and overland flow. H2D accounts for both local-scale hillslope and regional-scale unconfined aquifer responses (i.e. riparian zone and wetlands). This approach was shown to give comparable results as those obtained by an explicit 3D Richards model for the subsurface, but improves runtime efficiency considerably. The h3D approach is implemented for the Delaware river basin, where Noah-MP land surface model (LSM) is used to calculated vertical energy and water exchanges with the atmosphere using a 10km grid resolution. Noah-MP was coupled within the WRF-Hydro infrastructure with the lateral 1km grid resolution h2D model, for which the average depth-to-bedrock, hillslope width function and soil parameters were estimated from digital datasets. The ability of this h3D approach to simulate

  2. Degenerate Quadtree Latitude/Longitude Grid Based on WGS-84 Ellipsoidal Facet

    Directory of Open Access Journals (Sweden)

    HU Bailin

    2016-12-01

    Full Text Available For the needs of digital earth development and solving many global problems, a new discrete global grid system-DQLLG (degenerate quadtree latitude/longitude grid was put forward, which was based on WGS-84 ellipsoidal facet. The hierarchical subdivision method, characteristics and grid column/row coordinate system were detailed. The Latitude/Longitude coordinate, area and side length of multi-resolution meshes on different subdivision levels were calculated. Then the changes of mesh areas and side lengths were analyzed and compared that with spherical DQLLG. The research indicates that the DQLLG had many excellent features:uniformity, hierarchy, consistency of direction, extensive data compatibility and so on. It has certain practicality for Global GIS in the future.

  3. Modeling the earth system

    Energy Technology Data Exchange (ETDEWEB)

    Ojima, D. [ed.

    1992-12-31

    The 1990 Global Change Institute (GCI) on Earth System Modeling is the third of a series organized by the Office for Interdisciplinary Earth Studies to look in depth at particular issues critical to developing a better understanding of the earth system. The 1990 GCI on Earth System Modeling was organized around three themes: defining critical gaps in the knowledge of the earth system, developing simplified working models, and validating comprehensive system models. This book is divided into three sections that reflect these themes. Each section begins with a set of background papers offering a brief tutorial on the subject, followed by working group reports developed during the institute. These reports summarize the joint ideas and recommendations of the participants and bring to bear the interdisciplinary perspective that imbued the institute. Since the conclusion of the 1990 Global Change Institute, research programs, nationally and internationally, have moved forward to implement a number of the recommendations made at the institute, and many of the participants have maintained collegial interactions to develop research projects addressing the needs identified during the two weeks in Snowmass.

  4. The Earth System Model

    Science.gov (United States)

    Schoeberl, Mark; Rood, Richard B.; Hildebrand, Peter; Raymond, Carol

    2003-01-01

    The Earth System Model is the natural evolution of current climate models and will be the ultimate embodiment of our geophysical understanding of the planet. These models are constructed from components - atmosphere, ocean, ice, land, chemistry, solid earth, etc. models and merged together through a coupling program which is responsible for the exchange of data from the components. Climate models and future earth system models will have standardized modules, and these standards are now being developed by the ESMF project funded by NASA. The Earth System Model will have a variety of uses beyond climate prediction. The model can be used to build climate data records making it the core of an assimilation system, and it can be used in OSSE experiments to evaluate. The computing and storage requirements for the ESM appear to be daunting. However, the Japanese ES theoretical computing capability is already within 20% of the minimum requirements needed for some 2010 climate model applications. Thus it seems very possible that a focused effort to build an Earth System Model will achieve succcss.

  5. TOMS/Earth Probe UV-B Erythemal Local Noon Irradiance Monthly L3 Global 1x1.25 deg Lat/Lon Grid V008

    Data.gov (United States)

    National Aeronautics and Space Administration — This data product contains TOMS/Earth Probe UV-B Erythemal Local Noon Irradiance Monthly L3 Global 1x1.25 deg Lat/Lon Grid Version 8 data in ASCII format. (The...

  6. UNH Data Cooperative: A Cyber Infrastructure for Earth System Studies

    Science.gov (United States)

    Braswell, B. H.; Fekete, B. M.; Prusevich, A.; Gliden, S.; Magill, A.; Vorosmarty, C. J.

    2007-12-01

    to spend considerable amount of time to solve basic data management and preprocessing tasks and deal with low level computational design problems like parallelization of model codes. Our modeling infrastructure is designed to take care the bulk of the common tasks found in complex earth system models like I/O handling, computational domain and time management, parallel execution of the modeling tasks, etc. The modeling infrastructure allows scientists to focus on the numerical implementation of the physical processes on a single computational objects(typically grid cells) while the framework takes care of the preprocessing of input data, establishing of the data exchange between computation objects and the execution of the science code. In our presentation, we will discuss the key concepts of our modeling infrastructure. We will demonstrate integration of our modeling framework with data services offered by the UNH Earth System Data Collaborative via web interfaces. We will layout the road map to turn our prototype modeling environment into a truly community framework for wide range of earth system scientists and environmental managers.

  7. Grid-connected inverter for wind power generation system

    Institute of Scientific and Technical Information of China (English)

    YANG Yong; RUAN Yi; SHEN Huan-qing; TANG Yan-yan; YANG Ying

    2009-01-01

    In wind power generation system the grid-connected inverter is an important section for energy conversion and transmission, of which the performance has a direct influence on the entire wind power generation system. The mathematical model of the grid-connected inverter is deduced firstly. Then, the space vector pulse width modulation (SVPWM) is analyzed. The power factor can be controlled close to unity, leading or lagging, which is realized based on PI-type current controller and grid voltage vector-oriented control. The control strategy is verified by the simulation and experimental results with a good sinusoidal current, a small harmonic component and a fast dynamic response.

  8. Earth Science community support in the EGI-Inspire Project

    Science.gov (United States)

    Schwichtenberg, H.

    2012-04-01

    be accessed from EGI resources to enable future research activities by this HUC. The international climate community for IPCC has created the Earth System Grid (ESG) to store and share climate data. There is a need to interface ESG with EGI for climate studies - parametric, regional and impact aspects. Critical points concern the interoperability of security mechanism between both "organisations", data protection policy, data transfer, data storage and data caching. Presenter: Horst Schwichtenberg Co-Authors: Monique Petitdidier (IPSL), Andre Gemünd (SCAI), Wim Som de Cerff (KNMI), Michael Schnell (SCAI)

  9. Incorporating Parallel Computing into the Goddard Earth Observing System Data Assimilation System (GEOS DAS)

    Science.gov (United States)

    Larson, Jay W.

    1998-01-01

    Atmospheric data assimilation is a method of combining actual observations with model forecasts to produce a more accurate description of the earth system than the observations or forecast alone can provide. The output of data assimilation, sometimes called the analysis, are regular, gridded datasets of observed and unobserved variables. Analysis plays a key role in numerical weather prediction and is becoming increasingly important for climate research. These applications, and the need for timely validation of scientific enhancements to the data assimilation system pose computational demands that are best met by distributed parallel software. The mission of the NASA Data Assimilation Office (DAO) is to provide datasets for climate research and to support NASA satellite and aircraft missions. The system used to create these datasets is the Goddard Earth Observing System Data Assimilation System (GEOS DAS). The core components of the the GEOS DAS are: the GEOS General Circulation Model (GCM), the Physical-space Statistical Analysis System (PSAS), the Observer, the on-line Quality Control (QC) system, the Coupler (which feeds analysis increments back to the GCM), and an I/O package for processing the large amounts of data the system produces (which will be described in another presentation in this session). The discussion will center on the following issues: the computational complexity for the whole GEOS DAS, assessment of the performance of the individual elements of GEOS DAS, and parallelization strategy for some of the components of the system.

  10. Gridded daily Indian monsoon rainfall for 14 seasons: Merged ...

    Indian Academy of Sciences (India)

    Indian monsoon is an important component of earth's climate system. Daily rainfall data for longer period is vital to study components and processes related to Indian monsoon. Daily observed gridded rainfall data covering both land and adjoining oceanic regions are required for numerical model vali- dation and model ...

  11. DC Grid Control Concept for Expandable Multi-terminal HVDC Transmission Systems

    DEFF Research Database (Denmark)

    Irnawan, Roni; Silva, Filipe Miguel Faria da; Bak, Claus Leth

    2018-01-01

    In areas where there are already several HVDC links in operation or under construction, it is more likely that a DC grid emerges as a gradual process. Although the DC grid control concept has been widely discussed, the implementation in the expandable multi-terminal HVDC (MTDC) transmission systems...... still faces challenges. The existing converter control system needs to be adjusted when a point-to-point (PtP) link is operated into MTDC system, or when an additional converter is interconnected with an existing MTDC system, or even when a new DC grid control strategy is applied. In this paper, a new...... DC grid control concept is proposed that conserves and uses the existing converter control when an existing PtP link is extended into MTDC system or the existing MTDC system is expanded. An interface is proposed to decouple the DC grid secondary with converter control structures. By using...

  12. RIMS: An Integrated Mapping and Analysis System with Applications to Earth Sciences and Hydrology

    Science.gov (United States)

    Proussevitch, A. A.; Glidden, S.; Shiklomanov, A. I.; Lammers, R. B.

    2011-12-01

    A web-based information and computational system for analysis of spatially distributed Earth system, climate, and hydrologic data have been developed. The System allows visualization, data exploration, querying, manipulation and arbitrary calculations with any loaded gridded or vector polygon dataset. The system's acronym, RIMS, stands for its core functionality as a Rapid Integrated Mapping System. The system can be deployed for a Global scale projects as well as for regional hydrology and climatology studies. In particular, the Water Systems Analysis Group of the University of New Hampshire developed the global and regional (Northern Eurasia, pan-Arctic) versions of the system with different map projections and specific data. The system has demonstrated its potential for applications in other fields of Earth sciences and education. The key Web server/client components of the framework include (a) a visualization engine built on Open Source libraries (GDAL, PROJ.4, etc.) that are utilized in a MapServer; (b) multi-level data querying tools built on XML server-client communication protocols that allow downloading map data on-the-fly to a client web browser; and (c) data manipulation and grid cell level calculation tools that mimic desktop GIS software functionality via a web interface. Server side data management of the system is designed around a simple database of dataset metadata facilitating mounting of new data to the system and maintaining existing data in an easy manner. RIMS contains "built-in" river network data that allows for query of upstream areas on-demand which can be used for spatial data aggregation and analysis of sub-basin areas. RIMS is an ongoing effort and currently being used to serve a number of websites hosting a suite of hydrologic, environmental and other GIS data.

  13. Grid system design on the plasma cathode electron source

    International Nuclear Information System (INIS)

    Agus Purwadi

    2014-01-01

    It has been designed the grid system on the Plasma Cathode Electron Source (PCES). Grid system with the electron emission hole of (15 x 60) cm 2 , the single aperture grid size of (0,5 x O,5) mm 2 and the grid wire diameter of 0,25 mm, will be used on the plasma generator chamber. If the sum of grid holes known and the value of electron emission current through every the grid hole known too then the total value of electron emission Current which emits from the plasma generator chamber can be determined It has been calculated the value of electron emission current I e as function of the grid radius r e =(0.28, 0.40, 0.49, 0.56, 0.63, 0.69) mm on the electron temperature of T e = 5 eV for varying of the value plasma electron densities n e = (10 15 , 10 16 , 10 17 , 10 18 ) m -3 . Also for the value of electron emission current fe as function of the grid radius r e = (0.28, 0.40, 0.49. 0.56, 0.63,0.69) mm on the electron density n e = 10 17 m -3 for varying of the value of plasma electron temperatures T e = (1, 2, 3, 4, 5) eV. electron emission current will be increase by increasing grid radius, electron temperature as well as plasma electron density. (author)

  14. Grid-friendly wind power systems based on the synchronverter technology

    International Nuclear Information System (INIS)

    Zhong, Qing-Chang; Ma, Zhenyu; Ming, Wen-Long; Konstantopoulos, George C.

    2015-01-01

    Highlights: • A grid-friendly wind power system that uses the synchronverter technology is proposed. • Both the rotor-side and the grid-side converters act as synchronverters. • The complete generator–motor–generator system improves the performance under grid faults. • Real-time digital simulation results verify the effectiveness of the proposed method. - Abstract: Back-to-back PWM converters are becoming a realistic alternative to conventional converters in high-power wind power applications. In this paper, a control strategy based on the synchronverter technology is proposed for back-to-back PWM converters. Both converters are run as synchronverters, which are mathematically equivalent to the conventional synchronous generators. The rotor-side converter is responsible for maintaining the DC link voltage and the grid-side converter is responsible for the maximum power point tracking (MPPT). As the two converters are operated using the synchronverter technology, the formed wind power system becomes more friendly to the grid. Extensive real-time digital simulation results are presented to verify the effectiveness of the proposed method under normal operation and grid-fault scenarios

  15. Mammography with rare earth intensifying screens

    International Nuclear Information System (INIS)

    Maurer, H.J.; Goos, F.

    1987-01-01

    Screens basing on rare earth phosphors with suitable films green or blue sensitive may be used in mammography with grids without diagnostic losses. Highest definition will be obtained with medium densities on film. High-speed screens may reduce dose, but definition is poor. Best compromise between speed and high definition may be reached with relative low thickness of phosphor layers. A system of high definition films (Medichrome) and special rare earth screens give best results. (orig.) [de

  16. The International Solid Earth Research Virtual Observatory

    Science.gov (United States)

    Fox, G.; Pierce, M.; Rundle, J.; Donnellan, A.; Parker, J.; Granat, R.; Lyzenga, G.; McLeod, D.; Grant, L.

    2004-12-01

    We describe the architecture and initial implementation of the International Solid Earth Research Virtual Observatory (iSERVO). This has been prototyped within the USA as SERVOGrid and expansion is planned to Australia, China, Japan and other countries. We base our design on a globally scalable distributed "cyber-infrastructure" or Grid built around a Web Services-based approach consistent with the extended Web Service Interoperability approach. The Solid Earth Science Working Group of NASA has identified several challenges for Earth Science research. In order to investigate these, we need to couple numerical simulation codes and data mining tools to observational data sets. This observational data are now available on-line in internet-accessible forms, and the quantity of this data is expected to grow explosively over the next decade. We architect iSERVO as a loosely federated Grid of Grids with each country involved supporting a national Solid Earth Research Grid. The national Grid Operations, possibly with dedicated control centers, are linked together to support iSERVO where an International Grid control center may eventually be necessary. We address the difficult multi-administrative domain security and ownership issues by exposing capabilities as services for which the risk of abuse is minimized. We support large scale simulations within a single domain using service-hosted tools (mesh generation, data repository and sensor access, GIS, visualization). Simulations typically involve sequential or parallel machines in a single domain supported by cross-continent services. We use Web Services implement Service Oriented Architecture (SOA) using WSDL for service description and SOAP for message formats. These are augmented by UDDI, WS-Security, WS-Notification/Eventing and WS-ReliableMessaging in the WS-I+ approach. Support for the latter two capabilities will be available over the next 6 months from the NaradaBrokering messaging system. We augment these

  17. Development of laser weld monitoring system for PWR space grid

    International Nuclear Information System (INIS)

    Chung, Chin Man; Kim, Cheol Jung; Kim, Min Suk

    1998-06-01

    The laser welding monitoring system was developed to inspect PWR space grid welding for KNFC. The demands for this optical monitoring system were applied to Q.C. and process control in space grid welding. The thermal radiation signal from weld pool can be get the variation of weld pool size. The weld pool size and depth are verified by analyzed wavelength signals from weld pool. Applied this monitoring system in space grid weld, improved the weld productivity. (author). 4 refs., 5 tabs., 31 figs

  18. Grid Inertial Response with Lithium-ion Battery Energy Storage Systems

    DEFF Research Database (Denmark)

    Knap, Vaclav; Sinha, Rakesh; Swierczynski, Maciej Jozef

    2014-01-01

    of this paper is to evaluate the technical viability of utilizing energy storage systems based on Lithium-ion batteries for providing inertial response in grids with high penetration levels of wind power. In order to perform this evaluation, the 12-bus system grid model was used; the inertia of the grid...... was varied by decreasing the number of conventional power plants in the studied grid model while in the same time increasing the load and the wind power penetration levels. Moreover, in order to perform a realistic investigation, a dynamic model of the Lithium-ion battery was considered and parameterized...

  19. Electricity tariff systems for informatics system design regarding consumption optimization in smart grids

    Directory of Open Access Journals (Sweden)

    Simona Vasilica OPREA

    2016-01-01

    Full Text Available High volume of data is gathered via sensors and recorded by smart meters. These data are processed at the electricity consumer and grid operators' side by big data analytics. Electricity consumption optimization offers multiple advantages for both consumers and grid operators. At the electricity customer level, by optimizing electricity consumption savings are significant, but the main benefits will come from indirect aspects such as avoiding onerous grid investments, higher volume of renewable energy sources' integration, less polluted environment etc. In order to optimize electricity consumption, advanced tariff systems are essential due to the financial incentive they provide for electricity consumers' behaviour change. In this paper several advanced tariff systems are described in details. These systems are applied in England, Spain, Italy, France, Norway and Germany. These systems are compared from characteristics, advantages/disadvantages point of view. Then, different tariff systems applied in Romania are presented. Romanian tariff systems have been designed for various electricity consumers' types. Different tariff systems applied by grid operators or electricity suppliers will be included in the database model that is part of an informatics system for electricity consumption optimization.

  20. Smart Grid Communications System Blueprint

    Science.gov (United States)

    Clark, Adrian; Pavlovski, Chris

    2010-10-01

    Telecommunications operators are well versed in deploying 2G and 3G wireless networks. These networks presently support the mobile business user and/or retail consumer wishing to place conventional voice calls and data connections. The electrical power industry has recently commenced transformation of its distribution networks by deploying smart monitoring and control devices throughout their networks. This evolution of the network into a `smart grid' has also motivated the need to deploy wireless technologies that bridge the communication gap between the smart devices and information technology systems. The requirements of these networks differ from traditional wireless networks that communications operators have deployed, which have thus far forced energy companies to consider deploying their own wireless networks. We present our experience in deploying wireless networks to support the smart grid and highlight the key properties of these networks. These characteristics include application awareness, support for large numbers of simultaneous cell connections, high service coverage and prioritized routing of data. We also outline our target blueprint architecture that may be useful to the industry in building wireless and fixed networks to support the smart grid. By observing our experiences, telecommunications operators and equipment manufacturers will be able to augment their current networks and products in a way that accommodates the needs of the emerging industry of smart grids and intelligent electrical networks.

  1. A Grid storage accounting system based on DGAS and HLRmon

    International Nuclear Information System (INIS)

    Cristofori, A; Fattibene, E; Veronesi, P; Gaido, L; Guarise, A

    2012-01-01

    Accounting in a production-level Grid infrastructure is of paramount importance in order to measure the utilization of the available resources. While several CPU accounting systems are deployed within the European Grid Infrastructure (EGI), storage accounting systems, stable enough to be adopted in a production environment are not yet available. As a consequence, there is a growing interest in storage accounting and work on this is being carried out in the Open Grid Forum (OGF) where a Usage Record (UR) definition suitable for storage resources has been proposed for standardization. In this paper we present a storage accounting system which is composed of three parts: a sensor layer, a data repository with a transport layer (Distributed Grid Accounting System - DGAS) and a web portal providing graphical and tabular reports (HLRmon). The sensor layer is responsible for the creation of URs according to the schema (described in this paper) that is currently being discussed within OGF. DGAS is one of the CPU accounting systems used within EGI, in particular by the Italian Grid Infrastructure (IGI) and some other National Grid Initiatives (NGIs) and projects. DGAS architecture is evolving in order to collect Usage Records for different types of resources. This improvement allows DGAS to be used as a ‘general’ data repository and transport layer. HLRmon is the web portal acting as an interface to DGAS. It has been improved to retrieve storage accounting data from the DGAS repository and create reports in an easy way. This is very useful not only for the Grid users and administrators but also for the stakeholders.

  2. Simplify and Accelerate Earth Science Data Preparation to Systemize Machine Learning

    Science.gov (United States)

    Kuo, K. S.; Rilee, M. L.; Oloso, A.

    2017-12-01

    Data preparation is the most laborious and time-consuming part of machine learning. The effort required is usually more than linearly proportional to the varieties of data used. From a system science viewpoint, useful machine learning in Earth Science likely involves diverse datasets. Thus, simplifying data preparation to ease the systemization of machine learning in Earth Science is of immense value. The technologies we have developed and applied to an array database, SciDB, are explicitly designed for the purpose, including the innovative SpatioTemporal Adaptive-Resolution Encoding (STARE), a remapping tool suite, and an efficient implementation of connected component labeling (CCL). STARE serves as a universal Earth data representation that homogenizes data varieties and facilitates spatiotemporal data placement as well as alignment, to maximize query performance on massively parallel, distributed computing resources for a major class of analysis. Moreover, it converts spatiotemporal set operations into fast and efficient integer interval operations, supporting in turn moving-object analysis. Integrative analysis requires more than overlapping spatiotemporal sets. For example, meaningful comparison of temperature fields obtained with different means and resolutions requires their transformation to the same grid. Therefore, remapping has been implemented to enable integrative analysis. Finally, Earth Science investigations are generally studies of phenomena, e.g. tropical cyclone, atmospheric river, and blizzard, through their associated events, like hurricanes Katrina and Sandy. Unfortunately, except for a few high-impact phenomena, comprehensive episodic records are lacking. Consequently, we have implemented an efficient CCL tracking algorithm, enabling event-based investigations within climate data records beyond mere event presence. In summary, we have implemented the core unifying capabilities on a Big Data technology to enable systematic machine learning in

  3. Interharmonics from Grid-Connected PV Systems

    DEFF Research Database (Denmark)

    Sangwongwanich, Ariya; Yang, Yongheng; Sera, Dezso

    2017-01-01

    As the penetration level of grid-connected Photovoltaic (PV) systems increases, the power quality is one of the major concerns for system operators and the demands are becoming even stricter. The impact of interharmonics on the grid has been acknowledged in recent research when considering a large......-scale adoption of PV inverters. However, the origins of interharmonics remain unclear. Thus, this paper performs tests on a commercial PV inverter to explore interharmonic generation and more important investigates the mechanism of interharmonic emission. The investigation reveals that the perturbation...... of the solutions. Simulation results indicate that the constant-voltage MPPT method is the most suitable solution to the mitigation of interharmonics introduced by the MPPT operation, as it avoids the perturbation in the PV voltage during operation....

  4. AGIS: The ATLAS Grid Information System

    Science.gov (United States)

    Anisenkov, A.; Di Girolamo, A.; Klimentov, A.; Oleynik, D.; Petrosyan, A.; Atlas Collaboration

    2014-06-01

    ATLAS, a particle physics experiment at the Large Hadron Collider at CERN, produced petabytes of data annually through simulation production and tens of petabytes of data per year from the detector itself. The ATLAS computing model embraces the Grid paradigm and a high degree of decentralization and computing resources able to meet ATLAS requirements of petabytes scale data operations. In this paper we describe the ATLAS Grid Information System (AGIS), designed to integrate configuration and status information about resources, services and topology of the computing infrastructure used by the ATLAS Distributed Computing applications and services.

  5. Contribution of domestic heating systems to smart grid control

    DEFF Research Database (Denmark)

    Tahersima, Fatemeh; Stoustrup, Jakob; Meybodi, Soroush Afkhami

    2011-01-01

    How and to what extent, domestic heating systems can be helpful in regaining power balance in a smart grid, is the question to be answered in this paper. Our case study is an under-floor heating system supplied with a geothermal heat pump which is driven by electrical power from the grid. The idea...... is to deviate power consumption of the heat pump from its optimal value, in order to compensate power imbalances in the grid. Heating systems could be forced to consume energy, i.e. storing it in heat buffers when there is a power surplus in the grid; and be prevented from using power, in case of power shortage....... We have investigated how much power imbalance could be compensated, provided that a certain, yet user adjustable, level of residents' thermal comfort is satisfied. It is shown that the large heat capacity of the concrete floor alleviates undesired temperature fluctuations. Therefore, incorporating...

  6. The Geographic Information Grid System Based on Mobile Agent

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    We analyze the deficiencies of current application systems, and discuss the key requirements of distributed Geographic Information service (GIS). We construct the distributed GIS on grid platform. Considering the flexibility and efficiency, we integrate the mobile agent technology into the system. We propose a new prototype system, the Geographic Information Grid System (GIGS) based on mobile agent. This system has flexible services and high performance, and improves the sharing of distributed resources. The service strategy of the system and the examples are also presented.

  7. Applying Hillslope Hydrology to Bridge between Ecosystem and Grid-Scale Processes within an Earth System Model

    Science.gov (United States)

    Subin, Z. M.; Sulman, B. N.; Malyshev, S.; Shevliakova, E.

    2013-12-01

    Soil moisture is a crucial control on surface energy fluxes, vegetation properties, and soil carbon cycling. Its interactions with ecosystem processes are highly nonlinear across a large range, as both drought stress and anoxia can impede vegetation and microbial growth. Earth System Models (ESMs) generally only represent an average soil-moisture state in grid cells at scales of 50-200 km, and as a result are not able to adequately represent the effects of subgrid heterogeneity in soil moisture, especially in regions with large wetland areas. We addressed this deficiency by developing the first ESM-coupled subgrid hillslope-hydrological model, TiHy (Tiled-hillslope Hydrology), embedded within the Geophysical Fluid Dynamics Laboratory (GFDL) land model. In each grid cell, one or more representative hillslope geometries are discretized into land model tiles along an upland-to-lowland gradient. These geometries represent ~1 km hillslope-scale hydrological features and allow for flexible representation of hillslope profile and plan shapes, in addition to variation of subsurface properties among or within hillslopes. Each tile (which may represent ~100 m along the hillslope) has its own surface fluxes, vegetation state, and vertically-resolved state variables for soil physics and biogeochemistry. Resolution of water state in deep layers (~200 m) down to bedrock allows for physical integration of groundwater transport with unsaturated overlying dynamics. Multiple tiles can also co-exist at the same vertical position along the hillslope, allowing the simulation of ecosystem heterogeneity due to disturbance. The hydrological model is coupled to the vertically-resolved Carbon, Organisms, Respiration, and Protection in the Soil Environment (CORPSE) model, which captures non-linearity resulting from interactions between vertically-heterogeneous soil carbon and water profiles. We present comparisons of simulated water table depth to observations. We examine sensitivities to

  8. Grid-Connected Photovoltaic System with Active Power Filtering Functionality

    Directory of Open Access Journals (Sweden)

    Joaquín Vaquero

    2018-01-01

    Full Text Available Solar panels are an attractive and growing source of renewable energy in commercial and residential applications. Its use connected to the grid by means of a power converter results in a grid-connected photovoltaic system. In order to optimize this system, it is interesting to integrate several functionalities into the power converter, such as active power filtering and power factor correction. Nonlinear loads connected to the grid generate current harmonics, which deteriorates the mains power quality. Active power filters can compensate these current harmonics. A photovoltaic system with added harmonic compensation and power factor correction capabilities is proposed in this paper. A sliding mode controller is employed to control the power converter, implemented on the CompactRIO digital platform from National Instruments Corporation, allowing user friendly operation and easy tuning. The power system consists of two stages, a DC/DC boost converter and a single-phase inverter, and it is able to inject active power into the grid while compensating the current harmonics generated by nonlinear loads at the point of common coupling. The operation, design, simulation, and experimental results for the proposed system are discussed.

  9. Frequency scanning-based stability analysis method for grid-connected inverter system

    DEFF Research Database (Denmark)

    Wang, Yanbo; Wang, Xiongfei; Blaabjerg, Frede

    2017-01-01

    This paper proposes a frequency scanning-based impedance analysis for stability assessment of grid-connected inverter system, which is able to perform stability assessment without using system mathematical models and inherit the superior feature of impedance-based stability criterion with conside......This paper proposes a frequency scanning-based impedance analysis for stability assessment of grid-connected inverter system, which is able to perform stability assessment without using system mathematical models and inherit the superior feature of impedance-based stability criterion...... with consideration of the inverter nonlinearities. Small current disturbance is injected into grid-connected inverter system in a particular frequency range, and the impedance is computed according to the harmonic-frequency response using Fourier analysis, and then the stability is predicted on the basis...... of the impedance stability criterion. The stability issues of grid-connected inverters with grid-current feedback and the converter-current feedback are addressed using the proposed method. The results obtained from simulation and experiments validate the effectiveness of the method. The frequency scanning...

  10. The effects of spatial heterogeneity and subsurface lateral transfer on evapotranspiration estimates in large scale Earth system models

    Science.gov (United States)

    Rouholahnejad, E.; Fan, Y.; Kirchner, J. W.; Miralles, D. G.

    2017-12-01

    Most Earth system models (ESM) average over considerable sub-grid heterogeneity in land surface properties, and overlook subsurface lateral flow. This could potentially bias evapotranspiration (ET) estimates and has implications for future temperature predictions, since overestimations in ET imply greater latent heat fluxes and potential underestimation of dry and warm conditions in the context of climate change. Here we quantify the bias in evaporation estimates that may arise from the fact that ESMs average over considerable heterogeneity in surface properties, and also neglect lateral transfer of water across the heterogeneous landscapes at global scale. We use a Budyko framework to express ET as a function of P and PET to derive simple sub-grid closure relations that quantify how spatial heterogeneity and lateral transfer could affect average ET as seen from the atmosphere. We show that averaging over sub-grid heterogeneity in P and PET, as typical Earth system models do, leads to overestimation of average ET. Our analysis at global scale shows that the effects of sub-grid heterogeneity will be most pronounced in steep mountainous areas where the topographic gradient is high and where P is inversely correlated with PET across the landscape. In addition, we use the Total Water Storage (TWS) anomaly estimates from the Gravity Recovery and Climate Experiment (GRACE) remote sensing product and assimilate it into the Global Land Evaporation Amsterdam Model (GLEAM) to correct for existing free drainage lower boundary condition in GLEAM and quantify whether, and how much, accounting for changes in terrestrial storage can improve the simulation of soil moisture and regional ET fluxes at global scale.

  11. Freva - Freie Univ Evaluation System Framework for Scientific HPC Infrastructures in Earth System Modeling

    Science.gov (United States)

    Kadow, C.; Illing, S.; Schartner, T.; Grieger, J.; Kirchner, I.; Rust, H.; Cubasch, U.; Ulbrich, U.

    2017-12-01

    The Freie Univ Evaluation System Framework (Freva - freva.met.fu-berlin.de) is a software infrastructure for standardized data and tool solutions in Earth system science (e.g. www-miklip.dkrz.de, cmip-eval.dkrz.de). Freva runs on high performance computers to handle customizable evaluation systems of research projects, institutes or universities. It combines different software technologies into one common hybrid infrastructure, including all features present in the shell and web environment. The database interface satisfies the international standards provided by the Earth System Grid Federation (ESGF). Freva indexes different data projects into one common search environment by storing the meta data information of the self-describing model, reanalysis and observational data sets in a database. This implemented meta data system with its advanced but easy-to-handle search tool supports users, developers and their plugins to retrieve the required information. A generic application programming interface (API) allows scientific developers to connect their analysis tools with the evaluation system independently of the programming language used. Users of the evaluation techniques benefit from the common interface of the evaluation system without any need to understand the different scripting languages. The integrated web-shell (shellinabox) adds a degree of freedom in the choice of the working environment and can be used as a gate to the research projects HPC. Plugins are able to integrate their e.g. post-processed results into the database of the user. This allows e.g. post-processing plugins to feed statistical analysis plugins, which fosters an active exchange between plugin developers of a research project. Additionally, the history and configuration sub-system stores every analysis performed with the evaluation system in a database. Configurations and results of the tools can be shared among scientists via shell or web system. Furthermore, if configurations match

  12. Flexible Mode Control of Grid Connected Wind Energy Conversion System Using Wavelet

    OpenAIRE

    Jain, Bhavna; Singh, Sameer; Jain, Shailendra; Nema, R. K.

    2015-01-01

    Small wind turbine systems offer services to critical loads during grid faults and also connected back to grid in normal condition. The connection of a wind energy conversion system to the grid requires a robust phase locked loop (PLL) and continuous monitoring of the grid conditions such as overvoltage, undervoltage, overfrequency, underfrequency, and grid outages. This paper describes a flexible control operation to operate a small wind turbine in both stand-alone mode via planned islanding...

  13. Regional Data Assimilation Using a Stretched-Grid Approach and Ensemble Calculations

    Science.gov (United States)

    Fox-Rabinovitz, M. S.; Takacs, L. L.; Govindaraju, R. C.; Atlas, Robert (Technical Monitor)

    2002-01-01

    The global variable resolution stretched grid (SG) version of the Goddard Earth Observing System (GEOS) Data Assimilation System (DAS) incorporating the GEOS SG-GCM (Fox-Rabinovitz 2000, Fox-Rabinovitz et al. 2001a,b), has been developed and tested as an efficient tool for producing regional analyses and diagnostics with enhanced mesoscale resolution. The major area of interest with enhanced regional resolution used in different SG-DAS experiments includes a rectangle over the U.S. with 50 or 60 km horizontal resolution. The analyses and diagnostics are produced for all mandatory levels from the surface to 0.2 hPa. The assimilated regional mesoscale products are consistent with global scale circulation characteristics due to using the SG-approach. Both the stretched grid and basic uniform grid DASs use the same amount of global grid-points and are compared in terms of regional product quality.

  14. Optimum Design Of On Grid Pv System Using Tracking System

    Directory of Open Access Journals (Sweden)

    Saeed Mansour

    2015-05-01

    Full Text Available Abstract The fossil fuel is a main issue in the world due to the increase of fossil fuel cost and the depletion of the fossil fuel with continuous increasing demand on electricity. With continuous decrease of PV panels cost it is interesting to consider generation of electricity from PV system. To provide electric energy to a load in a remote area where electric grid utility is not available or connection with grid utility is available there are two approaches of photovoltaic system PV without tracking system Fixed System and PV with tracking systems. The result shows that the energy production by using PV with tracking system generates more energy in comparison with fixed panels system. However the cost per produced KWH is less in case of using fixed panels. This is the backbone in choice between two approaches of photovoltaic system. In this work a system design and cost analysis for two approaches of photovoltaic system are considered.

  15. Development and Testing of a Prototype Grid-Tied Photovoltaic Power System

    Science.gov (United States)

    Eichenberg, Dennis J.

    2009-01-01

    The NASA Glenn Research Center (GRC) has developed and tested a prototype 2 kW DC grid-tied photovoltaic (PV) power system at the Center. The PV system has generated in excess of 6700 kWh since operation commenced in July 2006. The PV system is providing power to the GRC grid for use by all. Operation of the prototype PV system has been completely trouble free. A grid-tied PV power system is connected directly to the utility distribution grid. Facility power can be obtained from the utility system as normal. The PV system is synchronized with the utility system to provide power for the facility, and excess power is provided to the utility. The project transfers space technology to terrestrial use via nontraditional partners. GRC personnel glean valuable experience with PV power systems that are directly applicable to various space power systems, and provide valuable space program test data. PV power systems help to reduce harmful emissions and reduce the Nation s dependence on fossil fuels. Power generated by the PV system reduces the GRC utility demand, and the surplus power aids the community. Present global energy concerns reinforce the need for the development of alternative energy systems. Modern PV panels are readily available, reliable, efficient, and economical with a life expectancy of at least 25 years. Modern electronics has been the enabling technology behind grid-tied power systems, making them safe, reliable, efficient, and economical with a life expectancy of at least 25 years. Based upon the success of the prototype PV system, additional PV power system expansion at GRC is under consideration. The prototype grid-tied PV power system was successfully designed and developed which served to validate the basic principles described, and the theoretical work that was performed. The report concludes that grid-tied photovoltaic power systems are reliable, maintenance free, long life power systems, and are of significant value to NASA and the community.

  16. Modeling and simulation of a micro grid-connected solar PV system

    Directory of Open Access Journals (Sweden)

    Rameen AbdelHady

    2017-04-01

    Full Text Available In 2012, the Ministry of Electricity and Renewable Energy (MERE; began promoting the system of ‘Feed-in Tariff’ in billing. The introduced system allows the user to generate electricity through solar panels mounted on the roofs of residential buildings and governmental organizations and tied to the grid. To benefit from MERE’s approach, the National Water Research Center (NWRC (Qanatir, Egypt set up a pilot rooftop 91 kW PV system. All the generated electricity is fed into the 220 V, 50 Hz low voltage grid serving NWRC premises. In this manuscript a MATLAB Simulink model is constructed mimicking a detailed representation of the system tied either to the local low voltage grid or to the national high voltage grid. The aim of such modeling effort is to provide early evaluation of the system performance. The economical savings of both scenarios are compared based on the new billing system. Results show that the current system saves 100 thousand L.E./year, while tying the system to the national grid will save 235.8 thousand L.E./year.

  17. Service Oriented Gridded Atmospheric Radiances (SOAR)

    Science.gov (United States)

    Halem, M.; Goldberg, M. D.; Tilmes, C.; Zhou, L.; Shen, S.; Yesha, Y.

    2005-12-01

    responsively meeting diverse user specified requests in terms of the spatial and temporal compositing of radiance fields. Moreover, the volume of sounder data records produced from current and future instruments varies from GB's to TB's per day and griding these sounding data can thin the volume to KB's to MB's per day making them easier to download to desktops and laptops. This not only will better serve a wider earth science community but makes these capabilities more readily useful to the education community. This presentation will describe the rationale for the project, an overview of the system architecture, a description of the framework for executing the applications on the distributed cluster and present examples of gridded service requests that are currently available. This demonstration project represents a foundation for the development of a distributed web service architecture that will be able to invoke requested services for temperature and moisture retrievals for arbitrary integrated gridded radiance data sets. We plan to extend the framework to accommodate such services for other earth observing instruments as well.

  18. Preliminary thermal analysis of grids for twin source extraction system

    International Nuclear Information System (INIS)

    Pandey, Ravi; Bandyopadhyay, Mainak; Chakraborty, Arun K.

    2017-01-01

    The TWIN (Two driver based Indigenously built Negative ion source) source provides a bridge between the operational single driver based negative ion source test facility, ROBIN in IPR and an ITER-type multi driver based ion source. The source is designed to be operated in CW mode with 180kW, 1MHz, 5s ON/600s OFF duty cycle and also in 5Hz modulation mode with 3s ON/20s OFF duty cycle for 3 such cycle. TWIN source comprises of ion source sub-assembly (consist of driver and plasma box) and extraction system sub-assembly. Extraction system consists of Plasma grid (PG), extraction grid (EG) and Ground grid (GG) sub assembly. Negative ion beams produced at plasma grid seeing the plasma side of ion source will receive moderate heat flux whereas the extraction grid and ground grid would be receiving majority of heat flux from extracted negative ion and co-extracted electron beams. Entire Co-extracted electron beam would be dumped at extraction grid via electron deflection magnetic field making the requirement of thermal and hydraulic design for extraction grid to be critical. All the three grids are made of OFHC Copper and would be actively water cooled keeping the peak temperature rise of grid surface within allowable limit with optimum uniformity. All the grids are to be made by vacuum brazing process where joint strength becomes crucial at elevated temperature. Hydraulic design must maintain the peak temperature at the brazing joint within acceptable limit

  19. 5-minute Gridded Global Relief Data (ETOPO5)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Earth topography five minute grid (ETOPO5) is a gridded data base of worldwide elevations derived from several sources at a resolution of 5 minutes of latitude and...

  20. Grid-connected wind and photovoltaic system

    Science.gov (United States)

    Devabakthuni, Sindhuja

    The objective of this thesis is to design a grid connected wind and photovoltaic system. A new model of converter control was designed which maintains the voltage of the bus to grid as constant when combined system of solar and wind is connected to AC bus. The model is designed to track maximum power at each point irrespective of changes in irradiance, temperature and wind speed which affects the power supplied to grid. Solar power from the sun is not constant as it is affected by changes in irradiances and temperature. Even the wind power is affected by wind speed. A MPPT controller was designed for both systems. A boost converter is designed which uses the pulses from MPPT controller to boost the output. Wind system consists of wind turbine block from the MATLAB with a pitch angle controller to maintain optimum pitch angle. The output from wind turbine is connected to a permanent magnet synchronous generator. The unregulated DC output from the photovoltaic system is directly given to boost converter. The AC output from the wind system is given to an uncontrolled rectifier to get a unregulated DC output. The unregulated DC output goes to the boost converter. A voltage source inverter was designed which converts the rectified DC output from the boost converter to AC power. The inverter is designed to maintain constant AC bus voltage irrespective of the disturbances in the power supply. Photovoltaic and wind systems are individually designed for 5KW each in MATLAB-Simulink environment. In this thesis, the models were subjected to changes in irradiance, temperature and wind speed and the results were interpreted. The model was successful in tracking maximum at every instant and the AC bus voltage was maintained constant throughout the simulation.

  1. NASA's Earth Science Data Systems

    Science.gov (United States)

    Ramapriyan, H. K.

    2015-01-01

    NASA's Earth Science Data Systems (ESDS) Program has evolved over the last two decades, and currently has several core and community components. Core components provide the basic operational capabilities to process, archive, manage and distribute data from NASA missions. Community components provide a path for peer-reviewed research in Earth Science Informatics to feed into the evolution of the core components. The Earth Observing System Data and Information System (EOSDIS) is a core component consisting of twelve Distributed Active Archive Centers (DAACs) and eight Science Investigator-led Processing Systems spread across the U.S. The presentation covers how the ESDS Program continues to evolve and benefits from as well as contributes to advances in Earth Science Informatics.

  2. The Australian Computational Earth Systems Simulator

    Science.gov (United States)

    Mora, P.; Muhlhaus, H.; Lister, G.; Dyskin, A.; Place, D.; Appelbe, B.; Nimmervoll, N.; Abramson, D.

    2001-12-01

    Numerical simulation of the physics and dynamics of the entire earth system offers an outstanding opportunity for advancing earth system science and technology but represents a major challenge due to the range of scales and physical processes involved, as well as the magnitude of the software engineering effort required. However, new simulation and computer technologies are bringing this objective within reach. Under a special competitive national funding scheme to establish new Major National Research Facilities (MNRF), the Australian government together with a consortium of Universities and research institutions have funded construction of the Australian Computational Earth Systems Simulator (ACcESS). The Simulator or computational virtual earth will provide the research infrastructure to the Australian earth systems science community required for simulations of dynamical earth processes at scales ranging from microscopic to global. It will consist of thematic supercomputer infrastructure and an earth systems simulation software system. The Simulator models and software will be constructed over a five year period by a multi-disciplinary team of computational scientists, mathematicians, earth scientists, civil engineers and software engineers. The construction team will integrate numerical simulation models (3D discrete elements/lattice solid model, particle-in-cell large deformation finite-element method, stress reconstruction models, multi-scale continuum models etc) with geophysical, geological and tectonic models, through advanced software engineering and visualization technologies. When fully constructed, the Simulator aims to provide the software and hardware infrastructure needed to model solid earth phenomena including global scale dynamics and mineralisation processes, crustal scale processes including plate tectonics, mountain building, interacting fault system dynamics, and micro-scale processes that control the geological, physical and dynamic

  3. Energy Systems Integration: Demonstrating Distributed Grid-Edge Control Hierarchy

    Energy Technology Data Exchange (ETDEWEB)

    2017-01-01

    Overview fact sheet about the OMNETRIC Group Integrated Network Testbed for Energy Grid Research and Technology Experimentation (INTEGRATE) project at the Energy Systems Integration Facility. INTEGRATE is part of the U.S. Department of Energy's Grid Modernization Initiative.

  4. Doubly Fed Induction Generator Wind Turbine Systems Subject to Recurring Symmetrical Grid Faults

    DEFF Research Database (Denmark)

    Chen, Wenjie; Blaabjerg, Frede; Zhu, Nan

    2016-01-01

    New grid codes demand the wind turbine systems to ride through recurring grid faults. In this paper, the performance of the doubly Ffed induction generator (DFIG) wind turbine system under recurring symmetrical grid faults is analyzed. The mathematical model of the DFIG under recurring symmetrical...... grid faults is established. The analysis is based on the DFIG wind turbine system with the typical low-voltage ride-through strategy-with rotor-side crowbar. The stator natural flux produced by the voltage recovery after the first grid fault may be superposed on the stator natural flux produced...... by the second grid fault, so that the transient rotor and stator current and torque fluctuations under the second grid fault may be influenced by the characteristic of the first grid fault, including the voltage dips level and the grid fault angle, as well as the duration between two faults. The mathematical...

  5. Distribution System Reliability Analysis for Smart Grid Applications

    Science.gov (United States)

    Aljohani, Tawfiq Masad

    Reliability of power systems is a key aspect in modern power system planning, design, and operation. The ascendance of the smart grid concept has provided high hopes of developing an intelligent network that is capable of being a self-healing grid, offering the ability to overcome the interruption problems that face the utility and cost it tens of millions in repair and loss. To address its reliability concerns, the power utilities and interested parties have spent extensive amount of time and effort to analyze and study the reliability of the generation and transmission sectors of the power grid. Only recently has attention shifted to be focused on improving the reliability of the distribution network, the connection joint between the power providers and the consumers where most of the electricity problems occur. In this work, we will examine the effect of the smart grid applications in improving the reliability of the power distribution networks. The test system used in conducting this thesis is the IEEE 34 node test feeder, released in 2003 by the Distribution System Analysis Subcommittee of the IEEE Power Engineering Society. The objective is to analyze the feeder for the optimal placement of the automatic switching devices and quantify their proper installation based on the performance of the distribution system. The measures will be the changes in the reliability system indices including SAIDI, SAIFI, and EUE. The goal is to design and simulate the effect of the installation of the Distributed Generators (DGs) on the utility's distribution system and measure the potential improvement of its reliability. The software used in this work is DISREL, which is intelligent power distribution software that is developed by General Reliability Co.

  6. Flexible Mode Control of Grid Connected Wind Energy Conversion System Using Wavelet

    Directory of Open Access Journals (Sweden)

    Bhavna Jain

    2015-01-01

    Full Text Available Small wind turbine systems offer services to critical loads during grid faults and also connected back to grid in normal condition. The connection of a wind energy conversion system to the grid requires a robust phase locked loop (PLL and continuous monitoring of the grid conditions such as overvoltage, undervoltage, overfrequency, underfrequency, and grid outages. This paper describes a flexible control operation to operate a small wind turbine in both stand-alone mode via planned islanding and grid connected mode as well. In particular, a proper monitoring and control algorithm is required for transition between the modes. A wavelet based energy function is used for detection of grid disturbances as well as recovery of grid so that transition between the modes is made. To obtain good power quality LCL filter is used to reduce ripples. PLL is used for synchronization whenever mode changes from stand-alone to grid connected. Simulation results from a 10 kW wind energy conversion system are included to show the usefulness of the proposed methods. The control method is tested by generated gate pulses for single phase bridge inverter using field programmable gate array (FPGA.

  7. Freva - Freie Univ Evaluation System Framework for Scientific Infrastructures in Earth System Modeling

    Science.gov (United States)

    Kadow, Christopher; Illing, Sebastian; Kunst, Oliver; Schartner, Thomas; Kirchner, Ingo; Rust, Henning W.; Cubasch, Ulrich; Ulbrich, Uwe

    2016-04-01

    The Freie Univ Evaluation System Framework (Freva - freva.met.fu-berlin.de) is a software infrastructure for standardized data and tool solutions in Earth system science. Freva runs on high performance computers to handle customizable evaluation systems of research projects, institutes or universities. It combines different software technologies into one common hybrid infrastructure, including all features present in the shell and web environment. The database interface satisfies the international standards provided by the Earth System Grid Federation (ESGF). Freva indexes different data projects into one common search environment by storing the meta data information of the self-describing model, reanalysis and observational data sets in a database. This implemented meta data system with its advanced but easy-to-handle search tool supports users, developers and their plugins to retrieve the required information. A generic application programming interface (API) allows scientific developers to connect their analysis tools with the evaluation system independently of the programming language used. Users of the evaluation techniques benefit from the common interface of the evaluation system without any need to understand the different scripting languages. Facilitation of the provision and usage of tools and climate data automatically increases the number of scientists working with the data sets and identifying discrepancies. The integrated web-shell (shellinabox) adds a degree of freedom in the choice of the working environment and can be used as a gate to the research projects HPC. Plugins are able to integrate their e.g. post-processed results into the database of the user. This allows e.g. post-processing plugins to feed statistical analysis plugins, which fosters an active exchange between plugin developers of a research project. Additionally, the history and configuration sub-system stores every analysis performed with the evaluation system in a database

  8. Design and Implementation of the Battery Energy Storage System in DC Micro-Grid Systems

    Directory of Open Access Journals (Sweden)

    Yuan-Chih Chang

    2018-06-01

    Full Text Available The design and implementation of the battery energy storage system in DC micro-grid systems is demonstrated in this paper. The battery energy storage system (BESS is an important part of a DC micro-grid because renewable energy generation sources are fluctuating. The BESS can provide energy while the renewable energy is absent in the DC micro-grid. The circuit topology of the proposed BESS will be introduced. The design of the voltage controller and the current controller for the battery charger/discharger are also illustrated. Finally, experimental results are provided to validate the performance of the BESS.

  9. Agent based approach for engineering and control of micro-grids

    International Nuclear Information System (INIS)

    Basso, Gillian

    2013-01-01

    Energy management is, nowadays, a subject of uttermost importance. Indeed, we are facing growing concerns such as petroleum reserve depletion, earth global warming or power quality (e.g. avoiding blackouts during peak times). Smart grids is an attempt to solve such problems, by adding to power grids bidirectional communications and ICT capabilities in order to provide an intelligent autonomic management for the grid. This thesis focuses on the management of micro-grids thanks to multi-agent systems (MAS). Micro-grids are low-power networks, composed of small and decentralized energy producers (possibly renewable) and consumers. These networks can be connected to the main grid or islanded, this make them more complex. Due to their complexity and their geographical distribution, smart grids and micro-grids can not be easily managed by a centralized system. Distributed artificial intelligences especially MAS appear to be a solution to resolve problems related to smart grids. Firstly we defined an approach implementing feedback loops. These feedback loops exist in complex systems which can be defined with several abstraction levels. Two levels are interacting. The micro-level contains a set of agents owning behaviours that can be combined. The result of the combination impact the state of the system. The macro-level processes these influences to define a new state of the system which will impact the agents behaviours at the micro-level. This feedback loop separates behaviours on several levels. This approach is used to defined a demand and supply matching problem in micro-grid. This problem afford to manage a set of goals which currently are independently processed. Finally, an application is developed using MAS that ensures grid stability thanks to storage systems. This application was thought to be integrated to the approach detailed above. Secondly, a grid simulator id developed. This simulator allows dynamic control of devices. It is based on three main principles

  10. A policy system for Grid Management and Monitoring

    International Nuclear Information System (INIS)

    Stagni, Federico; Santinelli, Roberto

    2011-01-01

    Organizations using a Grid computing model are faced with non-traditional administrative challenges: the heterogeneous nature of the underlying resources requires professionals acting as Grid Administrators. Members of a Virtual Organization (VO) can use a subset of available resources and services in the grid infrastructure and in an ideal world, the more resources are exploited the better. In the real world, the less faulty services, the better: experienced Grid administrators apply procedures for adding and removing services, based on their status, as it is reported by an ever-growing set of monitoring tools. When a procedure is agreed and well-exercised, a formal policy could be derived. For this reason, using the DIRAC framework in the LHCb collaboration, we developed a policy system that can enforce management and operational policies, in a VO-specific fashion. A single policy makes an assessment on the status of a subject, relative to one or more monitoring information. Subjects of the policies are monitored entities of an established Grid ontology. The status of a same entity is evaluated against a number of policies, whose results are then combined by a Policy Decision Point. Such results are enforced in a Policy Enforcing Point, which provides plug-ins for actions, like raising alarms, sending notifications, automatic addition and removal of services and resources from the Grid mask. Policy results are shown in the web portal, and site-specific views are provided also. This innovative system provides advantages in terms of procedures automation, information aggregation and problem solving.

  11. A policy system for Grid Management and Monitoring

    Science.gov (United States)

    Stagni, Federico; Santinelli, Roberto; LHCb Collaboration

    2011-12-01

    Organizations using a Grid computing model are faced with non-traditional administrative challenges: the heterogeneous nature of the underlying resources requires professionals acting as Grid Administrators. Members of a Virtual Organization (VO) can use a subset of available resources and services in the grid infrastructure and in an ideal world, the more resoures are exploited the better. In the real world, the less faulty services, the better: experienced Grid administrators apply procedures for adding and removing services, based on their status, as it is reported by an ever-growing set of monitoring tools. When a procedure is agreed and well-exercised, a formal policy could be derived. For this reason, using the DIRAC framework in the LHCb collaboration, we developed a policy system that can enforce management and operational policies, in a VO-specific fashion. A single policy makes an assessment on the status of a subject, relative to one or more monitoring information. Subjects of the policies are monitored entities of an established Grid ontology. The status of a same entity is evaluated against a number of policies, whose results are then combined by a Policy Decision Point. Such results are enforced in a Policy Enforcing Point, which provides plug-ins for actions, like raising alarms, sending notifications, automatic addition and removal of services and resources from the Grid mask. Policy results are shown in the web portal, and site-specific views are provided also. This innovative system provides advantages in terms of procedures automation, information aggregation and problem solving.

  12. Adaptive Harmonic Compensation in Residential Distribution Grid by Roof-Top PV Systems

    DEFF Research Database (Denmark)

    Zangeneh Bighash, Esmaeil; Sadeghzadeh, Seyed Mohammad; Ebrahimzadeh, Esmaeil

    2018-01-01

    grid- connected roof-top PV inverters in residential distribution grid can be an opportunity to engage these systems in the power quality issues as custom power devices. By implementing a proper control for roof-top PV inverters, these systems may in addition to inject the fundamental current......, additionally act like a virtual harmonic resistance and dedicate their additional current capacity to compensate the harmonics of residential distribution grid. In this paper, each roof-top PV system is a grid harmonic supervisor, where it continually measures the PCC voltage harmonics by Sliding Discrete...

  13. Static Equivalent of Distribution Grids With High Penetration of PV Systems

    DEFF Research Database (Denmark)

    Samadi, Afshin; Söder, Lennart; Shayesteh, Ebrahim

    2015-01-01

    High penetrations of photovoltaic (PV) systems within load pockets in distribution grids have changed pure consumers to prosumers. This can cause technical challenges in distribution and transmission grids, such as overvoltage and reverse power flow. Embedding voltage support schemes into PVs...... equivalent that can fairly capture the dominant behavior of the distribution grids. The aim of this paper is to use gray-box modeling concepts to develop a static equivalent of distribution grids comprising a large number of PV systems embedded with voltage support schemes. In the proposed model, the PV...... systems are aggregated as a separate entity, and not as a negative load, which is traditionally done. The results demonstrate the superior quality of the proposed model compared with the model with PV systems as the negative load....

  14. Distributed Power System Virtual Inertia Implemented by Grid-Connected Power Converters

    DEFF Research Database (Denmark)

    Fang, Jingyang; Li, Hongchang; Tang, Yi

    2018-01-01

    Renewable energy sources (RESs), e.g. wind and solar photovoltaics, have been increasingly used to meet worldwide growing energy demands and reduce greenhouse gas emissions. However, RESs are normally coupled to the power grid through fast-response power converters without any inertia, leading...... to decreased power system inertia. As a result, the grid frequency may easily go beyond the acceptable range under severe frequency events, resulting in undesirable load-shedding, cascading failures, or even large-scale blackouts. To address the ever-decreasing inertia issue, this paper proposes the concept...... of distributed power system virtual inertia, which can be implemented by grid-connected power converters. Without modifications of system hardware, power system inertia can be emulated by the energy stored in the dc-link capacitors of grid-connected power converters. By regulating the dc-link voltages...

  15. Study of the integration of distributed generation systems in the grid: application in micro-grids; Etude de structures d'integration des systemes de generation decentralisee: application aux microreseaux

    Energy Technology Data Exchange (ETDEWEB)

    Gaztanaga Arantzamendi, H

    2006-12-15

    The present PhD deals with an original micro-grid concept and its application as a Renewable Energy Source's (RES) grid integration scheme. This micro-grid is composed of RES generators as well as support systems that incorporate additional functionalities in order to improve RES integration into the grid. According to this concept, two practical micro-grid applications have been studied in detail: a residential micro-grid and a wind farm supported by DFACTS systems (STATCOM and DVR). In both applications, the control structures which are implemented at different levels and applied to the different micro-grid elements have been developed, analyzed by means of off-line simulations and finally validated in real-time conditions with physical reduced-scale prototypes. (author)

  16. Grid converters for photovoltaic and wind power systems

    CERN Document Server

    Teodorescu, Remus; Rodríguez, Pedro

    2011-01-01

    "Grid Converters for Photovoltaic and Wind Power Systems provides a comprehensive description of the control of grid converters for photovoltaic and wind power systems. The authors present a range of control methods for meeting the latest application, power quality and power conversion requirements and standards, as well as looking towards potential future control functions. Practical examples, exercises, and an accompanying website with simulation models using Matlab and Simulink environments, and PSIM software make this text a pragmatic resource for electrical engineers as well as students taking related courses"--

  17. Study of Security Attributes of Smart Grid Systems- Current Cyber Security Issues

    Energy Technology Data Exchange (ETDEWEB)

    Wayne F. Boyer; Scott A. McBride

    2009-04-01

    This document provides information for a report to congress on Smart Grid security as required by Section 1309 of Title XIII of the Energy Independence and Security Act of 2007. The security of any future Smart Grid is dependent on successfully addressing the cyber security issues associated with the nation’s current power grid. Smart Grid will utilize numerous legacy systems and technologies that are currently installed. Therefore, known vulnerabilities in these legacy systems must be remediated and associated risks mitigated in order to increase the security and success of the Smart Grid. The implementation of Smart Grid will include the deployment of many new technologies and multiple communication infrastructures. This report describes the main technologies that support Smart Grid and summarizes the status of implementation into the existing U.S. electrical infrastructure.

  18. Analyzing Effect of System Inertia on Grid Frequency Forecasting Usnig Two Stage Neuro-Fuzzy System

    Science.gov (United States)

    Chourey, Divyansh R.; Gupta, Himanshu; Kumar, Amit; Kumar, Jitesh; Kumar, Anand; Mishra, Anup

    2018-04-01

    Frequency forecasting is an important aspect of power system operation. The system frequency varies with load-generation imbalance. Frequency variation depends upon various parameters including system inertia. System inertia determines the rate of fall of frequency after the disturbance in the grid. Though, inertia of the system is not considered while forecasting the frequency of power system during planning and operation. This leads to significant errors in forecasting. In this paper, the effect of inertia on frequency forecasting is analysed for a particular grid system. In this paper, a parameter equivalent to system inertia is introduced. This parameter is used to forecast the frequency of a typical power grid for any instant of time. The system gives appreciable result with reduced error.

  19. Design of Energy Storage Management System Based on FPGA in Micro-Grid

    Science.gov (United States)

    Liang, Yafeng; Wang, Yanping; Han, Dexiao

    2018-01-01

    Energy storage system is the core to maintain the stable operation of smart micro-grid. Aiming at the existing problems of the energy storage management system in the micro-grid such as Low fault tolerance, easy to cause fluctuations in micro-grid, a new intelligent battery management system based on field programmable gate array is proposed : taking advantage of FPGA to combine the battery management system with the intelligent micro-grid control strategy. Finally, aiming at the problem that during estimation of battery charge State by neural network, initialization of weights and thresholds are not accurate leading to large errors in prediction results, the genetic algorithm is proposed to optimize the neural network method, and the experimental simulation is carried out. The experimental results show that the algorithm has high precision and provides guarantee for the stable operation of micro-grid.

  20. Integration of Vehicle-to-Grid in Western Danish Power System

    DEFF Research Database (Denmark)

    Pillai, Jayakrishnan Radhakrishna; Bak-Jensen, Birgitte

    2011-01-01

    capabilities of large power plants in the future, demands for new balancing solutions like Vehicle-to-Grid systems. In this article, aggregated electric vehicle based battery storage representing a Vehicle-to-Grid system is modelled for the use in long term dynamic power system simulations. Further...... Transmission) control areas are significantly minimized by the faster up and down regulation characteristics of the electric vehicle battery storage....

  1. Single stage three level grid interactive MPPT inverter for PV systems

    International Nuclear Information System (INIS)

    Ozdemir, Saban; Altin, Necmi; Sefa, Ibrahim

    2014-01-01

    Highlights: • A three phase three-level NPC inverter for grid interactive PV systems is proposed. • A novel MPPT algorithm is introduced for single stage systems. • The proposed algorithm is robust with respect to parameter variations of PV system. • THD level is measured as 3.45% and it meets the international standards (<5%). • Total system efficiency is measured as 93.08%. - Abstract: In this study, three-phase, single stage neutral point clamped grid interactive inverter is designed and implemented. The reference current of the voltage source inverter is determined by maximum power point tracking sub-program in order to obtain maximum power from photovoltaic modules instantaneously. Proposed control is realized via TMS320F28335 32-bit floating point processor. The modified incremental conductance method is applied for maximum power point tracking; the PI regulator is used to control the inverter output current shape and level. Galvanic isolation is provided by a line frequency transformer that matches inverter output voltage to the grid voltage level and prevents DC current injection into the grid. Experimental results show that the designed inverter imports energy to the grid with unity power factor, total harmonic distortion level is 3.45% and this value is in the limits of the international standards. In addition, the total efficiency of the system is measured as 93.08%. The proposed system gets the maximum power from photovoltaic module and dispatches into the grid without using additional DC/DC converter

  2. On-grid and Off-grid Operation of Multi-Input Single-Output DC/DC Converter based Fuel Cell Generation System

    Directory of Open Access Journals (Sweden)

    Noroozian

    2009-06-01

    Full Text Available This paper presents the modeling and simulation of a proton exchange membrane fuel cell (PEMFC generation system for off-grid and on-grid operation and configuration. A fuel cell DG system consists of a fuel cell power plant, a DC/DC converter and a DC/AC inverter. The dynamic model for fuel cell array and its power electronic interfacing are presented also a multi-input single output (MISO DC/DC converter and its control scheme is proposed and analyzed. This DC/DC converter is capable of interfacing fuel cell arrays to the DC/AC inverter. Also the mathematical model of the inverter is obtained by using average technique. Then the novel control strategy of DC/AC inverter for different operating conditions is demonstrated. The simulation results show the effectiveness of the suggested control systems under both on-grid and off-grid operation modes.

  3. Cyber physical systems approach to smart electric power grid

    CERN Document Server

    Khaitan, Siddhartha Kumar; Liu, Chen Ching

    2015-01-01

    This book documents recent advances in the field of modeling, simulation, control, security and reliability of Cyber- Physical Systems (CPS) in power grids. The aim of this book is to help the reader gain insights into working of CPSs and understand their potential in transforming the power grids of tomorrow. This book will be useful for all those who are interested in design of cyber-physical systems, be they students or researchers in power systems, CPS modeling software developers, technical marketing professionals and business policy-makers.

  4. Adapting a commercial power system simulator for smart grid based system study and vulnerability assessment

    Science.gov (United States)

    Navaratne, Uditha Sudheera

    The smart grid is the future of the power grid. Smart meters and the associated network play a major role in the distributed system of the smart grid. Advance Metering Infrastructure (AMI) can enhance the reliability of the grid, generate efficient energy management opportunities and many innovations around the future smart grid. These innovations involve intense research not only on the AMI network itself but as also on the influence an AMI network can have upon the rest of the power grid. This research describes a smart meter testbed with hardware in loop that can facilitate future research in an AMI network. The smart meters in the testbed were developed such that their functionality can be customized to simulate any given scenario such as integrating new hardware components into a smart meter or developing new encryption algorithms in firmware. These smart meters were integrated into the power system simulator to simulate the power flow variation in the power grid on different AMI activities. Each smart meter in the network also provides a communication interface to the home area network. This research delivers a testbed for emulating the AMI activities and monitoring their effect on the smart grid.

  5. Research on Control Strategy of Complex Systems through VSC-HVDC Grid Parallel Device

    Directory of Open Access Journals (Sweden)

    Xue Mei-Juan

    2014-07-01

    Full Text Available After the completion of grid parallel, the device can turn to be UPFC, STATCOM, SSSC, research on the conversion circuit and transform method by corresponding switching operation. Accomplish the grid parallel and comprehensive control of the tie-line and stable operation and control functions of grid after parallel. Defines the function select operation switch matrix and grid parallel system branch variable, forming a switch matrix to achieve corresponding function of the composite system. Formed a criterion of the selection means to choose control strategy according to the switch matrix, to accomplish corresponding function. Put the grid parallel, STATCOM, SSSC and UPFC together as a system, improve the stable operation and flexible control of the power system.

  6. Next generation framework for aquatic modeling of the Earth System

    Science.gov (United States)

    Fekete, B. M.; Wollheim, W. M.; Wisser, D.; Vörösmarty, C. J.

    2009-03-01

    Earth System model development is becoming an increasingly complex task. As scientists attempt to represent the physical and bio-geochemical processes and various feedback mechanisms in unprecedented detail, the models themselves are becoming increasingly complex. At the same time, the complexity of the surrounding IT infrastructure is growing as well. Earth System models must manage a vast amount of data in heterogeneous computing environments. Numerous development efforts are on the way to ease that burden and offer model development platforms that reduce IT challenges and allow scientists to focus on their science. While these new modeling frameworks (e.g. FMS, ESMF, CCA, OpenMI) do provide solutions to many IT challenges (performing input/output, managing space and time, establishing model coupling, etc.), they are still considerably complex and often have steep learning curves. The Next generation Framework for Aquatic Modeling of the Earth System (NextFrAMES, a revised version of FrAMES) have numerous similarities to those developed by other teams, but represents a novel model development paradigm. NextFrAMES is built around a modeling XML that lets modelers to express the overall model structure and provides an API for dynamically linked plugins to represent the processes. The model XML is executed by the NextFrAMES run-time engine that parses the model definition, loads the module plugins, performs the model I/O and executes the model calculations. NextFrAMES has a minimalistic view representing spatial domains and treats every domain (regardless of its layout such as grid, network tree, individual points, polygons, etc.) as vector of objects. NextFrAMES performs computations on multiple domains and interactions between different spatial domains are carried out through couplers. NextFrAMES allows processes to operate at different frequencies by providing rudimentary aggregation and disaggregation facilities. NextFrAMES was designed primarily for

  7. Benchmarking of Phase Locked Loop based Synchronization Techniques for Grid-Connected Inverter Systems

    DEFF Research Database (Denmark)

    Yang, Yongheng; Hadjidemetriou, Lenos; Blaabjerg, Frede

    2015-01-01

    Grid-connected renewables are increasingly developed in recent years, e.g. wind turbine systems and photovoltaic systems. Synchronization of the injected current with the grid is mandatory. However, grid disturbances like voltage sags, harmonics, and frequency deviations may occur during operatio...

  8. GridCom, Grid Commander: graphical interface for Grid jobs and data management

    International Nuclear Information System (INIS)

    Galaktionov, V.V.

    2011-01-01

    GridCom - the software package for maintenance of automation of access to means of distributed system Grid (jobs and data). The client part, executed in the form of Java-applets, realises the Web-interface access to Grid through standard browsers. The executive part Lexor (LCG Executor) is started by the user in UI (User Interface) machine providing performance of Grid operations

  9. Performance test of a grid-tied PV system to power a split air conditioner system in Surabaya

    Science.gov (United States)

    Tarigan, E.

    2017-11-01

    Air conditioner for cooling air is one of the major needs for those who live in hot climate area such as Indonesia. This work presents the performance test of a grid-tied PV system to power air conditioner under a hot tropical climate in Surabaya, Indonesia. A 800 WP grid-tied photovoltaic (PV) system was used, and its performance was tested to power a 0.5 pk of split air conditioner system. It was found that about 3.5 kWh daily energy was consumed by the tested air conditioner system, and about 80% it could be supplied from the PV system. While the other 20% was supplied by the grid during periods of low solar irradiation, 440 Wh of energy was fed into the grid during operation out of office hours. By using the grid-tied PV system, the energy production by PV system did not need to match the consumption of the air conditioner. However, a larger capacity of PV system would mean that a higher percentage of the load would be covered by PV system.

  10. Review international standards for grid connected photovoltaic systems in Malaysia

    International Nuclear Information System (INIS)

    Mekhilef, S.; Rahim, N.A.

    2006-01-01

    Grid connected PV is being applied on variety application including large centralised stations, commercial building and individual houses. There is a need for specific standard to address distinctive new issue created by grid connected PV power system. Internationally many countries are attempting to develop standards for building integration, Dc side issues and grid connection issues. This paper surveys the current development state of the major countries standards in this area, comparing and contrasting, standards and guideline under development, also addressing the need of standards for grid connected in Malaysia

  11. Towards grid parity in insular energy systems: The case of photovoltaics (PV) in Cyprus

    International Nuclear Information System (INIS)

    Fokaides, Paris A.; Kylili, Angeliki

    2014-01-01

    Grid parity is defined as the threshold at which a grid-connected renewable energy sources (RES) system supplies electricity to the end user at the same price as grid-supplied electricity. Predictions from the 2006 time-frame expected retail grid parity for solar in the 2016 to 2020 era, but due to rapid downward pricing changes, more recent calculations have forced dramatic reductions in time scale, and the suggestion that solar has already reached grid parity in a wide variety of locations. This study presents aspects of achieving grid parity in insular energy systems, based on a case study applied in Cyprus. The analysis presents the variation of the manufacturing cost, the selling price of the produced energy, and the performance of the solar panels to examine the conditions of accomplishing grid parity event. It is also concluded that grid parity may be easier achieved in insular energy systems due to the higher cost of primary energy. - Highlights: • This study presents aspects of achieving grid parity in insular energy systems, based on a case study applied in Cyprus. • The impact of the manufacturing cost and the feed in tariff on accomplishing grid parity event is analysed. • A sensitivity analysis is conducted to define the parameters that strongly affect the goal of grid parity. • It is concluded that grid parity may be easier achieved in insular energy systems due to the higher cost of primary energy

  12. The eGo grid model: An open-source and open-data based synthetic medium-voltage grid model for distribution power supply systems

    Science.gov (United States)

    Amme, J.; Pleßmann, G.; Bühler, J.; Hülk, L.; Kötter, E.; Schwaegerl, P.

    2018-02-01

    The increasing integration of renewable energy into the electricity supply system creates new challenges for distribution grids. The planning and operation of distribution systems requires appropriate grid models that consider the heterogeneity of existing grids. In this paper, we describe a novel method to generate synthetic medium-voltage (MV) grids, which we applied in our DIstribution Network GeneratOr (DINGO). DINGO is open-source software and uses freely available data. Medium-voltage grid topologies are synthesized based on location and electricity demand in defined demand areas. For this purpose, we use GIS data containing demand areas with high-resolution spatial data on physical properties, land use, energy, and demography. The grid topology is treated as a capacitated vehicle routing problem (CVRP) combined with a local search metaheuristics. We also consider the current planning principles for MV distribution networks, paying special attention to line congestion and voltage limit violations. In the modelling process, we included power flow calculations for validation. The resulting grid model datasets contain 3608 synthetic MV grids in high resolution, covering all of Germany and taking local characteristics into account. We compared the modelled networks with real network data. In terms of number of transformers and total cable length, we conclude that the method presented in this paper generates realistic grids that could be used to implement a cost-optimised electrical energy system.

  13. ATLAS Grid Data Processing: system evolution and scalability

    CERN Document Server

    Golubkov, D; The ATLAS collaboration; Klimentov, A; Minaenko, A; Nevski, P; Vaniachine, A; Walker, R

    2012-01-01

    The production system for Grid Data Processing handles petascale ATLAS data reprocessing and Monte Carlo activities. The production system empowered further data processing steps on the Grid performed by dozens of ATLAS physics groups with coordinated access to computing resources worldwide, including additional resources sponsored by regional facilities. The system provides knowledge management of configuration parameters for massive data processing tasks, reproducibility of results, scalable database access, orchestrated workflow and performance monitoring, dynamic workload sharing, automated fault tolerance and petascale data integrity control. The system evolves to accommodate a growing number of users and new requirements from our contacts in ATLAS main areas: Trigger, Physics, Data Preparation and Software & Computing. To assure scalability, the next generation production system architecture development is in progress. We report on scaling up the production system for a growing number of users provi...

  14. Issues regarding the modelling and simulation of hybrid micro grid systems

    Science.gov (United States)

    Szeidert, I.; Filip, I.; Prostean, O.

    2016-02-01

    The main followed objectives within control strategies dedicated to hybrid micro grid systems (wind/hydro/solar), that operate based on maximum power point tracking (MPPT) techniques are to improve the conversion systems efficiency and to maintain the quality of the produced electrical energy (the voltage and power factor control). One of the main goals of maximum power point tracking strategy is to achieve the harvesting of the maximal possible energy within a pre-set time period. In order to implement the control strategies for micro grid systems that operate at time variable parameter, there are usually required specific transducers (anemometer for wind speed measurement, optical rotational transducers, taco generators, etc.). In the technical literature there are presented several variants of the MPPT techniques, which are particularized at several applications (wind energy conversion systems, solar systems, hydro plants and micro grid hybrid systems). The maximum power point tracking implementations are mainly based on two-level architecture. The inferior level controls the primary variables, while the superior level represents the MPPT control structure. In the paper, authors present some micro grid structures proposed at Politehnica University Timisoara within the frame of a research grant. The paper is focused on the application of MPPT strategies on hybrid micro grid systems. There are presented several structures and control strategies and are highlighted their advantages and disadvantages, together with practical implementation guidelines.

  15. Task 5. Grid interconnection of building integrated and other dispersed photovoltaic power systems. International guideline for the certification of photovoltaic system components and grid-connected systems

    Energy Technology Data Exchange (ETDEWEB)

    Bower, W.

    2002-02-15

    This report for the International Energy Agency (IEA) made by Task 5 of the Photovoltaic Power Systems (PVPS) programme presents a guideline for the certification of photovoltaic system components and grid-connected systems. The mission of the Photovoltaic Power Systems Programme is to enhance the international collaboration efforts which accelerate the development and deployment of photovoltaic solar energy. Task 5 deals with issues concerning grid-interconnection and distributed PV power systems. This generic international guideline for the certification of photovoltaic system components and complete grid-connected photovoltaic systems describes a set of recommended methods and tests that may be used to verify the integrity of hardware and installations, compliance with applicable standards/codes and can be used to provide a measure of the performance of components or of entire systems. The guideline is to help ensure that photovoltaic installations are both safe for equipment as well as for personnel when used according to the applicable installation standards and codes. The guideline may be used in any country using the rules stipulated by the applicable standards and codes and by applying them to the guideline's recommended tests. This document uses examples for some tests but does not specify exact test set-ups, equipment accuracy, equipment manufacturers or calibration procedures.

  16. Studies with the EC-Earth seamless Earth system prediction model

    NARCIS (Netherlands)

    Hazeleger, W.; Bintanja, R.

    2012-01-01

    EC-Earth is a new Earth System Model (ESM) based on the operational seasonal forecast system of the European Centre for Medium-Range Weather Forecasts (ECMWF). Climate and weather forecasting applications share a common ancestry and are build on the same physical principles. The emerging concept of

  17. Simulation of wind power with front-end converter into interconnected grid system

    Directory of Open Access Journals (Sweden)

    Sharad W. Mohod

    2009-09-01

    Full Text Available In the growing electricity supply industry and open access market for electricity worldwide, renewable sources are getting added into the grid system. This affects the grid power quality. To assess the impact on grid due to wind energy integration, the knowledge of electrical characteristic of wind turbine and associated control equipments are required. The paper presents a simulation set-up for wind turbine in MATLAB / SIMULINK, with front end converter and interconnected system. The presented control scheme provides the wind power flow to the grid through a converter. The injected power in the system at the point of common coupling is ensured within the power quality norms.

  18. Zero-voltage ride-through capability of single-phase grid-connected photovoltaic systems

    DEFF Research Database (Denmark)

    Zhang, Zhen; Yang, Yongheng; Ma, Ruiqing

    2017-01-01

    Distributed renewable energy systems play an increasing role in today’s energy paradigm. Thus, intensive research activities have been centered on improving the performance of renewable energy systems, including photovoltaic (PV) systems, which should be of multiple-functionality. That is, the PV...... systems should be more intelligent in the consideration of grid stability, reliability, and fault protection. Therefore, in this paper, the performance of single-phase grid-connected PV systems under an extreme grid fault (i.e., when the grid voltage dips to zero) is explored. It has been revealed...... that combining a fast and accurate synchronization mechanism with appropriate control strategies for the zero-voltage ride-through (ZVRT) operation is mandatory. Accordingly, the representative synchronization techniques (i.e., the phase-locked loop (PLL) methods) in the ZVRT operation are compared in terms...

  19. Power system SCADA and smart grids

    CERN Document Server

    Thomas, Mini S

    2015-01-01

    Power System SCADA and Smart Grids brings together in one concise volume the fundamentals and possible application functions of power system supervisory control and data acquisition (SCADA). The text begins by providing an overview of SCADA systems, evolution, and use in power systems and the data acquisition process. It then describes the components of SCADA systems, from the legacy remote terminal units (RTUs) to the latest intelligent electronic devices (IEDs), data concentrators, and master stations, as well as:Examines the building and practical implementation of different SCADA systemsOf

  20. Student Learning of Complex Earth Systems: Conceptual Frameworks of Earth Systems and Instructional Design

    Science.gov (United States)

    Scherer, Hannah H.; Holder, Lauren; Herbert, Bruce

    2017-01-01

    Engaging students in authentic problem solving concerning environmental issues in near-surface complex Earth systems involves both developing student conceptualization of Earth as a system and applying that scientific knowledge using techniques that model those used by professionals. In this first paper of a two-part series, we review the state of…

  1. Electric grid stability and the design of sustainable energy systems

    DEFF Research Database (Denmark)

    Lund, Henrik

    2005-01-01

    The article presents technical designs of potential future flexible energy systems, which will be able both to balance production and demand and to secure voltage and frequency requirements on the grid.......The article presents technical designs of potential future flexible energy systems, which will be able both to balance production and demand and to secure voltage and frequency requirements on the grid....

  2. Issues regarding the usage of MPPT techniques in micro grid systems

    Science.gov (United States)

    Szeidert, I.; Filip, I.; Dragan, F.; Gal, A.

    2018-01-01

    The main objective of the control strategies applied at hybrid micro grid systems (wind/hydro/solar), that function based on maximum power point tracking (MPPT) techniques is to improve the conversion system’s efficiency and to preserve the quality of the generated electrical energy (voltage and power factor). One of the main goals of maximum power point tracking strategy is to achieve the harvesting of the maximal possible energy within a certain time period. In order to implement the control strategies for micro grid, there are typically required specific transducers (sensor for wind speed, optical rotational transducers, etc.). In the technical literature, several variants of the MPPT techniques are presented and particularized at some applications (wind energy conversion systems, solar systems, hydro plants, micro grid hybrid systems). The maximum power point tracking implementations are mainly based on two-level architecture. The lower level controls the main variable and the superior level represents the MPPT control structure. The paper presents micro grid structures developed at Politehnica University Timisoara (PUT) within the frame of a research grant. The paper is focused on the application of MPPT strategies on hybrid micro grid systems. There are presented several structures and control strategies and are highlighted their advantages and disadvantages, together with practical implementation guidelines.

  3. Electrical Market Management Considering Power System Constraints in Smart Distribution Grids

    Directory of Open Access Journals (Sweden)

    Poria Hasanpor Divshali

    2016-05-01

    Full Text Available Rising demand, climate change, growing fuel costs, outdated power system infrastructures, and new power generation technologies have made renewable distribution generators very attractive in recent years. Because of the increasing penetration level of renewable energy sources in addition to the growth of new electrical demand sectors, such as electrical vehicles, the power system may face serious problems and challenges in the near future. A revolutionary new power grid system, called smart grid, has been developed as a solution to these problems. The smart grid, equipped with modern communication and computation infrastructures, can coordinate different parts of the power system to enhance energy efficiency, reliability, and quality, while decreasing the energy cost. Since conventional distribution networks lack smart infrastructures, much research has been recently done in the distribution part of the smart grid, called smart distribution grid (SDG. This paper surveys contemporary literature in SDG from the perspective of the electricity market in addition to power system considerations. For this purpose, this paper reviews current demand side management methods, supply side management methods, and electrical vehicle charging and discharging techniques in SDG and also discusses their drawbacks. We also present future research directions to tackle new and existing challenges in the SDG.

  4. Battery Storage Systems as Grid-Balancing Measure in Low-Voltage Distribution Grids with Distributed Generation

    Directory of Open Access Journals (Sweden)

    Bernhard Faessler

    2017-12-01

    Full Text Available Due to the promoted integration of renewable sources, a further growth of strongly transient, distributed generation is expected. Thus, the existing electrical grid may reach its physical limits. To counteract this, and to fully exploit the viable potential of renewables, grid-balancing measures are crucial. In this work, battery storage systems are embedded in a grid simulation to evaluate their potential for grid balancing. The overall setup is based on a real, low-voltage distribution grid topology, real smart meter household load profiles, and real photovoltaics load data. An autonomous optimization routine, driven by a one-way communicated incentive, determines the prospective battery operation mode. Different battery positions and incentives are compared to evaluate their impact. The configurations incorporate a baseline simulation without storage, a single, central battery storage or multiple, distributed battery storages which together have the same power and capacity. The incentives address either market conditions, grid balancing, optimal photovoltaic utilization, load shifting, or self-consumption. Simulations show that grid-balancing incentives result in lowest peak-to-average power ratios, while maintaining negligible voltage changes in comparison to a reference case. Incentives reflecting market conditions for electricity generation, such as real-time pricing, negatively influence the power quality, especially with respect to the peak-to-average power ratio. A central, feed-in-tied storage performs better in terms of minimizing the voltage drop/rise and shows lower distribution losses, while distributed storages attached at nodes with electricity generation by photovoltaics achieve lower peak-to-average power ratios.

  5. Validation of two gridded soil moisture products over India with in ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science; Volume 125; Issue 5. Validation of two gridded soil moisture products over India with in-situ observations. C K Unnikrishnan John P George Abhishek Lodh Devesh Kumar Maurya Swapan Mallick E N Rajagopal Saji Mohandas. Volume 125 Issue 5 July 2016 pp 935-944 ...

  6. NASA'S Earth Science Data Stewardship Activities

    Science.gov (United States)

    Lowe, Dawn R.; Murphy, Kevin J.; Ramapriyan, Hampapuram

    2015-01-01

    NASA has been collecting Earth observation data for over 50 years using instruments on board satellites, aircraft and ground-based systems. With the inception of the Earth Observing System (EOS) Program in 1990, NASA established the Earth Science Data and Information System (ESDIS) Project and initiated development of the Earth Observing System Data and Information System (EOSDIS). A set of Distributed Active Archive Centers (DAACs) was established at locations based on science discipline expertise. Today, EOSDIS consists of 12 DAACs and 12 Science Investigator-led Processing Systems (SIPS), processing data from the EOS missions, as well as the Suomi National Polar Orbiting Partnership mission, and other satellite and airborne missions. The DAACs archive and distribute the vast majority of data from NASA’s Earth science missions, with data holdings exceeding 12 petabytes The data held by EOSDIS are available to all users consistent with NASA’s free and open data policy, which has been in effect since 1990. The EOSDIS archives consist of raw instrument data counts (level 0 data), as well as higher level standard products (e.g., geophysical parameters, products mapped to standard spatio-temporal grids, results of Earth system models using multi-instrument observations, and long time series of Earth System Data Records resulting from multiple satellite observations of a given type of phenomenon). EOSDIS data stewardship responsibilities include ensuring that the data and information content are reliable, of high quality, easily accessible, and usable for as long as they are considered to be of value.

  7. SciDAC's Earth System Grid Center for Enabling Technologies Semiannual Progress Report October 1, 2010 through March 31, 2011

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Dean N. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2011-04-02

    This report summarizes work carried out by the Earth System Grid Center for Enabling Technologies (ESG-CET) from October 1, 2010 through March 31, 2011. It discusses ESG-CET highlights for the reporting period, overall progress, period goals, and collaborations, and lists papers and presentations. To learn more about our project and to find previous reports, please visit the ESG-CET Web sites: http://esg-pcmdi.llnl.gov/ and/or https://wiki.ucar.edu/display/esgcet/Home. This report will be forwarded to managers in the Department of Energy (DOE) Scientific Discovery through Advanced Computing (SciDAC) program and the Office of Biological and Environmental Research (OBER), as well as national and international collaborators and stakeholders (e.g., those involved in the Coupled Model Intercomparison Project, phase 5 (CMIP5) for the Intergovernmental Panel on Climate Change (IPCC) 5th Assessment Report (AR5); the Community Earth System Model (CESM); the Climate Science Computational End Station (CCES); SciDAC II: A Scalable and Extensible Earth System Model for Climate Change Science; the North American Regional Climate Change Assessment Program (NARCCAP); the Atmospheric Radiation Measurement (ARM) program; the National Aeronautics and Space Administration (NASA), the National Oceanic and Atmospheric Administration (NOAA)), and also to researchers working on a variety of other climate model and observation evaluation activities. The ESG-CET executive committee consists of Dean N. Williams, Lawrence Livermore National Laboratory (LLNL); Ian Foster, Argonne National Laboratory (ANL); and Don Middleton, National Center for Atmospheric Research (NCAR). The ESG-CET team is a group of researchers and scientists with diverse domain knowledge, whose home institutions include eight laboratories and two universities: ANL, Los Alamos National Laboratory (LANL), Lawrence Berkeley National Laboratory (LBNL), LLNL, NASA/Jet Propulsion Laboratory (JPL), NCAR, Oak Ridge National

  8. Energy storage systems: power grid and energy market use cases

    Directory of Open Access Journals (Sweden)

    Komarnicki Przemysław

    2016-09-01

    Full Text Available Current power grid and market development, characterized by large growth of distributed energy sources in recent years, especially in Europa, are according energy storage systems an increasingly larger field of implementation. Existing storage technologies, e.g. pumped-storage power plants, have to be upgraded and extended by new but not yet commercially viable technologies (e.g. batteries or adiabatic compressed air energy storage that meet expected demands. Optimal sizing of storage systems and technically and economically optimal operating strategies are the major challenges to the integration of such systems in the future smart grid. This paper surveys firstly the literature on the latest niche applications. Then, potential new use case and operating scenarios for energy storage systems in smart grids, which have been field tested, are presented and discussed and subsequently assessed technically and economically.

  9. A Sensorless Power Reserve Control Strategy for Two-Stage Grid-Connected PV Systems

    DEFF Research Database (Denmark)

    Sangwongwanich, Ariya; Yang, Yongheng; Blaabjerg, Frede

    2017-01-01

    Due to the still increasing penetration of grid-connected Photovoltaic (PV) systems, advanced active power control functionalities have been introduced in grid regulations. A power reserve control, where namely the active power from the PV panels is reserved during operation, is required for grid...... support. In this paper, a cost-effective solution to realize the power reserve for two-stage grid-connected PV systems is proposed. The proposed solution routinely employs a Maximum Power Point Tracking (MPPT) control to estimate the available PV power and a Constant Power Generation (CPG) control...... performed on a 3-kW two-stage single-phase grid-connected PV system, where the power reserve control is achieved upon demands....

  10. SciDAC's Earth System Grid Center for Enabling Technologies Semi-Annual Progress Report for the Period April 1, 2009 through September 30, 2009

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Dean N. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Foster, I. T. [Argonne National Lab. (ANL), Argonne, IL (United States); Middleton, D. E. [National Center for Atmospheric Research (NCAR), Boulder, CO (United States)

    2009-10-15

    This report summarizes work carried out by the ESG-CET during the period April 1, 2009 through September 30, 2009. It includes discussion of highlights, overall progress, period goals, collaborations, papers, and presentations. To learn more about our project, and to find previous reports, please visit the Earth System Grid Center for Enabling Technologies (ESG-CET) website. This report will be forwarded to the DOE SciDAC program management, the Office of Biological and Environmental Research (OBER) program management, national and international collaborators and stakeholders (e.g., the Community Climate System Model (CCSM), the Intergovernmental Panel on Climate Change (IPCC) 5th Assessment Report (AR5), the Climate Science Computational End Station (CCES), the SciDAC II: A Scalable and Extensible Earth System Model for Climate Change Science, the North American Regional Climate Change Assessment Program (NARCCAP), and other wide-ranging climate model evaluation activities). During this semi-annual reporting period, the ESG-CET team continued its efforts to complete software components needed for the ESG Gateway and Data Node. These components include: Data Versioning, Data Replication, DataMover-Lite (DML) and Bulk Data Mover (BDM), Metrics, Product Services, and Security, all joining together to form ESG-CET's first beta release. The launch of the beta release is scheduled for late October with the installation of ESG Gateways at NCAR and LLNL/PCMDI. Using the developed ESG Data Publisher, the ESG II CMIP3 (IPCC AR4) data holdings - approximately 35 TB - will be among the first datasets to be published into the new ESG enterprise system. In addition, the NCAR's ESG II data holdings will also be published into the new system - approximately 200 TB. This period also saw the testing of the ESG Data Node at various collaboration sites, including: the British Atmospheric Data Center (BADC), the Max-Planck-Institute for Meteorology, the University of Tokyo

  11. Near-Body Grid Adaption for Overset Grids

    Science.gov (United States)

    Buning, Pieter G.; Pulliam, Thomas H.

    2016-01-01

    A solution adaption capability for curvilinear near-body grids has been implemented in the OVERFLOW overset grid computational fluid dynamics code. The approach follows closely that used for the Cartesian off-body grids, but inserts refined grids in the computational space of original near-body grids. Refined curvilinear grids are generated using parametric cubic interpolation, with one-sided biasing based on curvature and stretching ratio of the original grid. Sensor functions, grid marking, and solution interpolation tasks are implemented in the same fashion as for off-body grids. A goal-oriented procedure, based on largest error first, is included for controlling growth rate and maximum size of the adapted grid system. The adaption process is almost entirely parallelized using MPI, resulting in a capability suitable for viscous, moving body simulations. Two- and three-dimensional examples are presented.

  12. Non-rocket Earth-Moon transport system

    Science.gov (United States)

    Bolonkin, Alexander

    2003-06-01

    This paper proposes a new transportation system for travel between Earth and Moon. This transportation system uses mechanical energy transfer and requires only minimal energy, using an engine located on Earth. A cable directly connects a pole of the Earth through a drive station to the lunar surface_ The equation for an optimal equal stress cable for complex gravitational field of Earth-Moon has been derived that allows significantly lower cable masses. The required strength could be provided by cables constructed of carbon nanotubes or carbon whiskers. Some of the constraints on such a system are discussed.

  13. Considerations on the modeling of photovoltaic systems for grid impact studies

    NARCIS (Netherlands)

    Cuk, V.; Ribeiro, P.F.; Cobben, J.F.G.; Kling, W.L.; Isleifsson, F.R.; Bindner, H.W.; Martensen, N.; Samadi, A.; Söder, L.

    2011-01-01

    Photovoltaic systems continue to be deployed at increasing levels and their impact on the electric grid needs to be evaluated more accurately. This includes the impact both in the local grid where they are connected and the impact on the operation of the whole system. As a consequence, adequate

  14. Global distribution of grid connected electrical energy storage systems

    Directory of Open Access Journals (Sweden)

    Katja Buss

    2016-06-01

    Full Text Available This article gives an overview of grid connected electrical energy storage systems worldwide, based on public available data. Technologies considered in this study are pumped hydroelectric energy storage (PHES, compressed air energy storage (CAES, sodium-sulfur batteries (NaS, lead-acid batteries, redox-flow batteries, nickel-cadmium batteries (NiCd and lithium-ion batteries. As the research indicates, the worldwide installed capacity of grid connected electrical energy storage systems is approximately 154 GW. This corresponds to a share of 5.5 % of the worldwide installed generation capacity. Furthermore, the article gives an overview of the historical development of installed and used storage systems worldwide. Subsequently, the focus is on each considered technology concerning the current storage size, number of plants and location. In summary it can be stated, PHES is the most commonly used technology worldwide, whereas electrochemical technologies are increasingly gaining in importance. Regarding the distribution of grid connected storage systems reveals the share of installed storage capacity is in Europe and Eastern Asia twice as high as in North America.

  15. Optimal economic and environment operation of micro-grid power systems

    International Nuclear Information System (INIS)

    Elsied, Moataz; Oukaour, Amrane; Gualous, Hamid; Lo Brutto, Ottavio A.

    2016-01-01

    Highlights: • Real-time energy management system for Micro-Grid power systems is introduced. • The management system considered cost objective function and emission constraints. • The optimization problem is solved using Binary Particle Swarm Algorithm. • Advanced real-time interface libraries are used to run the optimization code. - Abstract: In this paper, an advanced real-time energy management system is proposed in order to optimize micro-grid performance in a real-time operation. The proposed strategy of the management system capitalizes on the power of binary particle swarm optimization algorithm to minimize the energy cost and carbon dioxide and pollutant emissions while maximizing the power of the available renewable energy resources. Advanced real-time interface libraries are used to run the optimization code. The simulation results are considered for three different scenarios considering the complexity of the proposed problem. The proposed management system along with its control system is experimentally tested to validate the simulation results obtained from the optimization algorithm. The experimental results highlight the effectiveness of the proposed management system for micro-grids operation.

  16. A new PLL system using full order observer and PLL system modeling in a single phase grid-connected inverter

    DEFF Research Database (Denmark)

    Ko, Youngjong; Park, Kiwoo; Lee, Kyo-Beum

    2011-01-01

    In a grid connected power conversion system, the phase angle information of a grid voltage is very essential for supplying power to the grid since it is used for active and reactive power control. A Phase Locked Loop (PLL) system is used and should be robust because often the actual grid voltages...

  17. What hampers energy system transformations? The case of smart grids

    International Nuclear Information System (INIS)

    Muench, Stefan; Thuss, Sebastian; Guenther, Edeltraud

    2014-01-01

    Energy systems are undergoing significant change. Many countries have ambitions to increase the share of renewable energy in their energy mix. This development entails the challenge of incorporating an increasing amount of volatile energy supply and a higher number of energy providers on distribution grid level. The smart grid could be a solution for this challenge. However, the implementation of smart grid technologies is rather slow. In this paper, we examine which barriers exist for the implementation of smart grid technologies. Fourteen in-depth expert interviews were conducted and qualitatively analysed using the grounded theory approach. First, a dynamic definition framework of the term “smart grid” was developed that incorporates contextual factors. Second, barriers to the implementation of smart grid technologies were gathered. We identified (1) cost and benefit, (2) knowledge, and (3) institutional mechanisms as barrier categories. Third, policy implications were derived. We recommend (1) the acceptance of a diversity of solutions, (2) the acceptance of incremental change, (3) the implementation of a stable regulatory framework, (4) the alignment of interests of individual market participants with the entire system, (5) the definition of a suitable scope of regulations, and (6) the collection of problem-specific information. - Highlights: • Fourteen in-depth expert interviews were conducted and qualitatively analysed. • We provide a dynamic smart grid definition framework. • We examine barriers to smart grid technology implementation. • We provide recommendations to overcome these barriers

  18. Doubly fed induction generator based wind turbine systems subject to recurring grid faults

    DEFF Research Database (Denmark)

    Chen, Wenjie; Blaabjerg, Frede; Zhu, Nan

    2014-01-01

    New grid codes demand the wind turbine systems to ride through recurring grid faults. In this paper, the performance of the Doubly Fed Induction Generator wind turbine system under recurring grid faults is analyzed. The stator natural flux produced by the voltage recovery after the first grid fault...... may be superposed on the stator natural flux produced by the second grid fault, and it may result in large current and voltage transient. The damping of the stator natural flux can be accelerated with a rotor natural current in its opposite direction after voltage recovery, but larger torque....... The performance of DFIG under recurring grid faults is verified by the simulation and experiments....

  19. Performance Analyses of IDEAL Algorithm on Highly Skewed Grid System

    Directory of Open Access Journals (Sweden)

    Dongliang Sun

    2014-03-01

    Full Text Available IDEAL is an efficient segregated algorithm for the fluid flow and heat transfer problems. This algorithm has now been extended to the 3D nonorthogonal curvilinear coordinates. Highly skewed grids in the nonorthogonal curvilinear coordinates can decrease the convergence rate and deteriorate the calculating stability. In this study, the feasibility of the IDEAL algorithm on highly skewed grid system is analyzed by investigating the lid-driven flow in the inclined cavity. It can be concluded that the IDEAL algorithm is more robust and more efficient than the traditional SIMPLER algorithm, especially for the highly skewed and fine grid system. For example, at θ = 5° and grid number = 70 × 70 × 70, the convergence rate of the IDEAL algorithm is 6.3 times faster than that of the SIMPLER algorithm, and the IDEAL algorithm can converge almost at any time step multiple.

  20. The signature of atmospheric tides in sub-daily variations of Earth rotation as unveiled by globally-gridded atmospheric angular momentum functions

    Science.gov (United States)

    Schindelegger, M.; Böhm, J.; Salstein, D. A.; Schuh, H.

    2012-12-01

    Thermally-driven atmospheric tides provide a small but distinct contribution to shortperiod variations of Earth rotation parameters (ERP). The effect of diurnal and semi-diurnal tides, commonly denoted as S1 and S2, respectively, is in the range of 2 - 10 uas for polar motion and 2 - 10 uas for changes in length-of-day (LOD). Even though ocean tides represent a much more dominant driving agent for ERP fluctuations at short time scales, high-frequency atmospheric effects are non-negligible, particularly given the prospective measurement accuracy of space geodetic techniques. However, previous studies, such as Brzezinski et al. (2002), de Viron et al. (2005) or Schindelegger et al. (2011), have been noticeably inconclusive on the exact amplitude and phase values of S1 and S2 atmospheric excitation signals. This study aims at shedding light on the origin of these uncertainties with respect to the axial component of Earth's rotation vector by investigating times series of atmospheric angular momentum (AAM) functions that are given on global grids and computed from three-hourly meteorological data of the European Centre for Medium-Range Weather Forecasts (ECMWF). The signature of diurnal and semi-diurnal atmospheric tides is clearly visible in the gridded axial AAM functions, revealing a distinct spatial and temporal phase difference between pressure and wind tidal constituents of about ± π. It is shown that due to this counterbalance and the explicit axisymmetric spatial structure of S1 and S2, the net effect in sub-diurnal AAM (which is calculated from the global sum of gridded AAM functions) is always a small quantity, particularly sensitive to minor differences between the analysis fields of numerical weather models.

  1. Solar Energy Grid Integration Systems (SEGIS): adding functionality while maintaining reliability and economics

    Science.gov (United States)

    Bower, Ward

    2011-09-01

    An overview of the activities and progress made during the US DOE Solar Energy Grid Integration Systems (SEGIS) solicitation, while maintaining reliability and economics is provided. The SEGIS R&D opened pathways for interconnecting PV systems to intelligent utility grids and micro-grids of the future. In addition to new capabilities are "value added" features. The new hardware designs resulted in smaller, less material-intensive products that are being viewed by utilities as enabling dispatchable generation and not just unpredictable negative loads. The technical solutions enable "advanced integrated system" concepts and "smart grid" processes to move forward in a faster and focused manner. The advanced integrated inverters/controllers can now incorporate energy management functionality, intelligent electrical grid support features and a multiplicity of communication technologies. Portals for energy flow and two-way communications have been implemented. SEGIS hardware was developed for the utility grid of today, which was designed for one-way power flow, for intermediate grid scenarios, AND for the grid of tomorrow, which will seamlessly accommodate managed two-way power flows as required by large-scale deployment of solar and other distributed generation. The SEGIS hardware and control developed for today meets existing standards and codes AND provides for future connections to a "smart grid" mode that enables utility control and optimized performance.

  2. Earth Systems Science: An Analytic Framework

    Science.gov (United States)

    Finley, Fred N.; Nam, Younkeyong; Oughton, John

    2011-01-01

    Earth Systems Science (ESS) is emerging rapidly as a discipline and is being used to replace the older earth science education that has been taught as unrelated disciplines--geology, meteorology, astronomy, and oceanography. ESS is complex and is based on the idea that the earth can be understood as a set of interacting natural and social systems.…

  3. Vegetation Earth System Data Record from DSCOVR EPIC Observations

    Science.gov (United States)

    Knyazikhin, Y.; Song, W.; Yang, B.; Mottus, M.; Rautiainen, M.; Stenberg, P.

    2017-12-01

    The NASA's Earth Polychromatic Imaging Camera (EPIC) onboard NOAA's Deep Space Climate Observatory (DSCOVR) mission was launched on February 11, 2015 to the Sun-Earth Lagrangian L1 point where it began to collect radiance data of the entire sunlit Earth every 65 to 110 min in June 2015. It provides imageries in near backscattering directions with the scattering angle between 168° and 176° at ten ultraviolet to near infrared (NIR) narrow spectral bands centered at 317.5 (band width 1.0) nm, 325.0 (2.0) nm, 340.0 (3.0) nm, 388.0 (3.0) nm, 433.0 (3.0) nm, 551.0 (3.0) nm, 680.0 (3.0) nm, 687.8 (0.8) nm, 764.0 (1.0) nm and 779.5 (2.0) nm. This poster presents current status of the Vegetation Earth System Data Record of global Leaf Area Index (LAI), solar zenith angle dependent Sunlit Leaf Area Index (SLAI), Fraction vegetation absorbed Photosynthetically Active Radiation (FPAR) and Normalized Difference Vegetation Index (NDVI) derived from the DSCOVR EPIC observations. Whereas LAI is a standard product of many satellite missions, the SLAI is a new satellite-derived parameter. Sunlit and shaded leaves exhibit different radiative response to incident Photosynthetically Active Radiation (400-700 nm), which in turn triggers various physiological and physical processes required for the functioning of plants. FPAR, LAI and SLAI are key state parameters in most ecosystem productivity models and carbon/nitrogen cycle. The product at 10 km sinusoidal grid and 65 to 110 min temporal frequency as well as accompanying Quality Assessment (QA) variables will be publicly available from the NASA Langley Atmospheric Science Data Center. The Algorithm Theoretical Basis (ATBD) and product validation strategy are also discussed in this poster.

  4. The construction of power grid operation index system considering the risk of maintenance

    Science.gov (United States)

    Tang, Jihong; Wang, Canlin; Jiang, Xinfan; Ye, Jianhui; Pan, Feilai

    2018-02-01

    In recent years, large-scale blackout occurred at home and abroad caused widespread concern about the operation of the grid in the world, and the maintenance risk is an important indicator of grid safety. The barrier operation of the circuit breaker exists in the process of overhaul of the power grid. The operation of the different barrier is of great significance to the change of the power flow, thus affecting the safe operation of the system. Most of the grid operating status evaluation index system did not consider the risk of maintenance, to this end, this paper from the security, economy, quality and cleanliness of the four angles, build the power grid operation index system considering the risk of maintenance.

  5. A Sensorless Power Reserve Control Strategy for Two-Stage Grid-Connected PV Systems

    OpenAIRE

    Sangwongwanich, Ariya; Yang, Yongheng; Blaabjerg, Frede

    2017-01-01

    Due to the still increasing penetration of grid-connected Photovoltaic (PV) systems, advanced active power control functionalities have been introduced in grid regulations. A power reserve control, where namely the active power from the PV panels is reserved during operation, is required for grid support. In this paper, a cost-effective solution to realize the power reserve for two-stage grid-connected PV systems is proposed. The proposed solution routinely employs a Maximum Power Point Track...

  6. Research and design of smart grid monitoring control via terminal based on iOS system

    Science.gov (United States)

    Fu, Wei; Gong, Li; Chen, Heli; Pan, Guangji

    2017-06-01

    Aiming at a series of problems existing in current smart grid monitoring Control Terminal, such as high costs, poor portability, simple monitoring system, poor software extensions, low system reliability when transmitting information, single man-machine interface, poor security, etc., smart grid remote monitoring system based on the iOS system has been designed. The system interacts with smart grid server so that it can acquire grid data through WiFi/3G/4G networks, and monitor each grid line running status, as well as power plant equipment operating conditions. When it occurs an exception in the power plant, incident information can be sent to the user iOS terminal equipment timely, which will provide troubleshooting information to help the grid staff to make the right decisions in a timely manner, to avoid further accidents. Field tests have shown the system realizes the integrated grid monitoring functions, low maintenance cost, friendly interface, high security and reliability, and it possesses certain applicable value.

  7. Modelling and Simulation of Grid Connected SPV System with Active Power Filtering Features

    Science.gov (United States)

    Saroha, Jaipal; Pandove, Gitanjali; Singh, Mukhtiar

    2017-09-01

    In this paper, the detailed simulation studies for a grid connected solar photovoltaic system (SPV) have been presented. The power electronics devices like DC-DC boost converter and grid interfacing inverter are most important components of proposed system. Here, the DC-DC boost converter is controlled to extract maximum power out of SPV under different irradiation levels, while the grid interfacing inverter is utilized to evacuate the active power and feed it into grid at synchronized voltage and frequency. Moreover, the grid interfacing inverter is also controlled to sort out the issues related to power quality by compensating the reactive power and harmonics current component of nearby load at point of common coupling. Besides, detailed modeling of various component utilized in proposed system is also presented. Finally, extensive simulations have been performed under different irradiation levels with various kinds of load to validate the aforementioned claims. The overall system design and simulation have been performed by using Sim Power System toolbox available in the library of MATLAB.

  8. Reactive Power Injection Strategies for Single-Phase Photovoltaic Systems Considering Grid Requirements

    DEFF Research Database (Denmark)

    Yang, Yongheng; Wang, Huai; Blaabjerg, Frede

    2014-01-01

    As the development and installation of photovoltaic (PV) systems are still growing at an exceptionally rapid pace, relevant grid integration policies are going to change consequently in order to accept more PV systems in the grid. The next generation PV systems will play an even more active role...

  9. Model of interaction in Smart Grid on the basis of multi-agent system

    Science.gov (United States)

    Engel, E. A.; Kovalev, I. V.; Engel, N. E.

    2016-11-01

    This paper presents model of interaction in Smart Grid on the basis of multi-agent system. The use of travelling waves in the multi-agent system describes the behavior of the Smart Grid from the local point, which is being the complement of the conventional approach. The simulation results show that the absorption of the wave in the distributed multi-agent systems is effectively simulated the interaction in Smart Grid.

  10. Grid Integration Science, NREL Power Systems Engineering Center

    Energy Technology Data Exchange (ETDEWEB)

    Kroposki, Benjamin [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2017-04-25

    This report highlights journal articles published in 2016 by researchers in the Power Systems Engineering Center. NREL's Power Systems Engineering Center published 47 journal and magazine articles in the past year, highlighting recent research in grid modernization.

  11. Sustainable recycling technologies for Solar PV off-grid system

    Science.gov (United States)

    Uppal, Bhavesh; Tamboli, Adish; Wubhayavedantapuram, Nandan

    2017-11-01

    Policy makers throughout the world have accepted climate change as a repercussion of fossil fuel exploitation. This has led the governments to integrate renewable energy streams in their national energy mix. PV off-grid Systems have been at the forefront of this transition because of their permanently increasing efficiency and cost effectiveness. These systems are expected to produce large amount of different waste streams at the end of their lifetime. It is important that these waste streams should be recycled because of the lack of available resources. Our study found that separate researches have been carried out to increase the efficiencies of recycling of individual PV system components but there is a lack of a comprehensive methodical research which details efficient and sustainable recycling processes for the entire PV off-grid system. This paper reviews the current and future recycling technologies for PV off-grid systems and presents a scheme of the most sustainable recycling technologies which have the potential for adoption. Full Recovery End-of-Life Photovoltaic (FRELP) recycling technology can offer opportunities to sustainably recycle crystalline silicon PV modules. Electro-hydrometallurgical process & Vacuum technologies can be used for recovering lead from lead acid batteries with a high recovery rate. The metals in the WEEE can be recycled by using a combination of biometallurgical technology, vacuum metallurgical technology and other advanced metallurgical technologies (utrasonical, mechano-chemical technology) while the plastic components can be effectively recycled without separation by using compatibilizers. All these advanced technologies when used in combination with each other provide sustainable recycling options for growing PV off-grid systems waste. These promising technologies still need further improvement and require proper integration techniques before implementation.

  12. GridCom, Grid Commander: graphical interface for Grid jobs and data management; GridCom, Grid Commander: graficheskij interfejs dlya raboty s zadachami i dannymi v gride

    Energy Technology Data Exchange (ETDEWEB)

    Galaktionov, V V

    2011-07-01

    GridCom - the software package for maintenance of automation of access to means of distributed system Grid (jobs and data). The client part, executed in the form of Java-applets, realises the Web-interface access to Grid through standard browsers. The executive part Lexor (LCG Executor) is started by the user in UI (User Interface) machine providing performance of Grid operations

  13. Smart grid technologies in local electric grids

    Science.gov (United States)

    Lezhniuk, Petro D.; Pijarski, Paweł; Buslavets, Olga A.

    2017-08-01

    The research is devoted to the creation of favorable conditions for the integration of renewable sources of energy into electric grids, which were designed to be supplied from centralized generation at large electric power stations. Development of distributed generation in electric grids influences the conditions of their operation - conflict of interests arises. The possibility of optimal functioning of electric grids and renewable sources of energy, when complex criterion of the optimality is balance reliability of electric energy in local electric system and minimum losses of electric energy in it. Multilevel automated system for power flows control in electric grids by means of change of distributed generation of power is developed. Optimization of power flows is performed by local systems of automatic control of small hydropower stations and, if possible, solar power plants.

  14. Study on optimal configuration of the grid-connected wind-solar-battery hybrid power system

    Science.gov (United States)

    Ma, Gang; Xu, Guchao; Ju, Rong; Wu, Tiantian

    2017-08-01

    The capacity allocation of each energy unit in the grid-connected wind-solar-battery hybrid power system is a significant segment in system design. In this paper, taking power grid dispatching into account, the research priorities are as follows: (1) We establish the mathematic models of each energy unit in the hybrid power system. (2) Based on dispatching of the power grid, energy surplus rate, system energy volatility and total cost, we establish the evaluation system for the wind-solar-battery power system and use a number of different devices as the constraint condition. (3) Based on an improved Genetic algorithm, we put forward a multi-objective optimisation algorithm to solve the optimal configuration problem in the hybrid power system, so we can achieve the high efficiency and economy of the grid-connected hybrid power system. The simulation result shows that the grid-connected wind-solar-battery hybrid power system has a higher comprehensive performance; the method of optimal configuration in this paper is useful and reasonable.

  15. Multi-agent grid system Agent-GRID with dynamic load balancing of cluster nodes

    Science.gov (United States)

    Satymbekov, M. N.; Pak, I. T.; Naizabayeva, L.; Nurzhanov, Ch. A.

    2017-12-01

    In this study the work presents the system designed for automated load balancing of the contributor by analysing the load of compute nodes and the subsequent migration of virtual machines from loaded nodes to less loaded ones. This system increases the performance of cluster nodes and helps in the timely processing of data. A grid system balances the work of cluster nodes the relevance of the system is the award of multi-agent balancing for the solution of such problems.

  16. Zero-Voltage Ride-Through Capability of Single-Phase Grid-Connected Photovoltaic Systems

    Directory of Open Access Journals (Sweden)

    Zhen Zhang

    2017-03-01

    Full Text Available Distributed renewable energy systems play an increasing role in today’s energy paradigm. Thus, intensive research activities have been centered on improving the performance of renewable energy systems, including photovoltaic (PV systems, which should be of multiple-functionality. That is, the PV systems should be more intelligent in the consideration of grid stability, reliability, and fault protection. Therefore, in this paper, the performance of single-phase grid-connected PV systems under an extreme grid fault (i.e., when the grid voltage dips to zero is explored. It has been revealed that combining a fast and accurate synchronization mechanism with appropriate control strategies for the zero-voltage ride-through (ZVRT operation is mandatory. Accordingly, the representative synchronization techniques (i.e., the phase-locked loop (PLL methods in the ZVRT operation are compared in terms of detection precision and dynamic response. It shows that the second-order generalized integrator (SOGI-PLL is a promising solution for single-phase systems in the case of fault ride-through. A control strategy by modifying the SOGI-PLL scheme is then introduced to single-phase grid-connected PV systems for ZVRT operation. Simulations are performed to verify the discussions. The results have demonstrated that the proposed method can help single-phase PV systems to temporarily ride through zero-voltage faults with good dynamics.

  17. Advanced Grid Control Technologies Workshop Series | Energy Systems

    Science.gov (United States)

    : Smart Grid and Beyond John McDonald, Director, Technical Strategy and Policy Development, General Control Technologies Workshop Series In July 2015, NREL's energy systems integration team hosted workshops the Energy Systems Integration Facility (ESIF) and included a technology showcase featuring projects

  18. Task 5. Grid interconnection of building integrated and other dispersed photovoltaic power systems. Grid-connected photovoltaic power systems: power value and capacity value of PV systems

    Energy Technology Data Exchange (ETDEWEB)

    Groppi, F.

    2002-02-15

    This report for the International Energy Agency (IEA) made by Task 5 of the Photovoltaic Power Systems (PVPS) programme takes a look at the power value and capacity value of photovoltaic power systems. The mission of the Photovoltaic Power Systems Programme is to enhance the international collaboration efforts which accelerate the development and deployment of photovoltaic solar energy. Task 5 deals with issues concerning grid-interconnection and dispersed PV power systems. This report summarises the results of a study aimed to assess the benefits that may be obtained when distributed PV production systems are present in a low-voltage grid. The basic aspects concerning the power-value and those related to the capacity-value are discussed. Data obtained from simulations are presented and discussed. A simple concept shows that great variation occurs if varying load patterns are taken into account. The power-value of PV generation in the grid varies instant by instant depending on the current level of power production and on the surrounding load conditions. Although the three case-studies considered do not cover all the possibilities of coupling between PV and loads, the results obtained show a good differentiation among users with PV production which leads to interesting conclusions.

  19. Active and reactive power neurocontroller for grid-connected photovoltaic generation system

    Directory of Open Access Journals (Sweden)

    I. Abadlia

    2016-03-01

    Full Text Available Many researchers have contributed to the development of a firm foundation for analysis and design of control applications in grid-connected renewable energy sources. This paper presents an intelligent control algorithm fond on artificial neural networks for active and reactive power controller in grid-connected photovoltaic generation system. The system is devices into two parts in which each part contains an inverter with control algorithm. A DC/DC converter in output voltage established by control magnitude besides maximum power point tracker algorithm always finds optimal power of the PV array in use. A DC/AC hysteresis inverter designed can synchronize a sinusoidal current output with the grid voltage and accurate an independent active and reactive power control. Simulation results confirm the validation of the purpose. Neurocontroller based active and reactive power presents an efficiency control that guarantees good response to the steps changing in active and reactive power with an acceptable current/voltage synchronism. In this paper the power circuit and the control system of the presented grid-connected photovoltaic generation system is simulated and tested by MatLab/Simulink.

  20. Smart EV Energy Management System to Support Grid Services

    Science.gov (United States)

    Wang, Bin

    Under smart grid scenarios, the advanced sensing and metering technologies have been applied to the legacy power grid to improve the system observability and the real-time situational awareness. Meanwhile, there is increasing amount of distributed energy resources (DERs), such as renewable generations, electric vehicles (EVs) and battery energy storage system (BESS), etc., being integrated into the power system. However, the integration of EVs, which can be modeled as controllable mobile energy devices, brings both challenges and opportunities to the grid planning and energy management, due to the intermittency of renewable generation, uncertainties of EV driver behaviors, etc. This dissertation aims to solve the real-time EV energy management problem in order to improve the overall grid efficiency, reliability and economics, using online and predictive optimization strategies. Most of the previous research on EV energy management strategies and algorithms are based on simplified models with unrealistic assumptions that the EV charging behaviors are perfectly known or following known distributions, such as the arriving time, leaving time and energy consumption values, etc. These approaches fail to obtain the optimal solutions in real-time because of the system uncertainties. Moreover, there is lack of data-driven strategy that performs online and predictive scheduling for EV charging behaviors under microgrid scenarios. Therefore, we develop an online predictive EV scheduling framework, considering uncertainties of renewable generation, building load and EV driver behaviors, etc., based on real-world data. A kernel-based estimator is developed to predict the charging session parameters in real-time with improved estimation accuracy. The efficacy of various optimization strategies that are supported by this framework, including valley-filling, cost reduction, event-based control, etc., has been demonstrated. In addition, the existing simulation-based approaches do

  1. Emerging economic viability of grid defection in a northern climate using solar hybrid systems

    International Nuclear Information System (INIS)

    Kantamneni, Abhilash; Winkler, Richelle; Gauchia, Lucia; Pearce, Joshua M.

    2016-01-01

    High demand for photovoltaic (PV), battery, and small-scale combined heat and power (CHP) technologies are driving a virtuous cycle of technological improvements and cost reductions in off-grid electric systems that increasingly compete with the grid market. Using a case study in the Upper Peninsula of Michigan, this paper quantifies the economic viability of off-grid PV+battery+CHP adoption and evaluates potential implications for grid-based utility models. The analysis shows that already some households could save money by switching to a solar hybrid off-grid system in comparison to the effective electric rates they are currently paying. Across the region by 2020, 92% of seasonal households and ~75% of year-round households are projected to meet electricity demands with lower costs. Furthermore, ~65% of all Upper Peninsula single-family owner-occupied households will both meet grid parity and be able to afford the systems by 2020. The results imply that economic circumstances could spur a positive feedback loop whereby grid electricity prices continue to rise and increasing numbers of customers choose alternatives (sometimes referred to as a “utility death spiral”), particularly in areas with relatively high electric utility rates. Utility companies and policy makers must take the potential for grid defection seriously when evaluating energy supply strategies. - Highlights: •Quantifies the economic viability of off-grid hybrid photovoltaic (PV) systems. •PV is backed up with batteries and combined heat and power (CHP). •Case study in Michigan by household size (energy demand) and income. •By 2020, majority of single-family owner-occupied households can defect. •To prevent mass-scale grid defection policies needed for grid-tied PV systems.

  2. A two-stage cluster sampling method using gridded population data, a GIS, and Google EarthTM imagery in a population-based mortality survey in Iraq

    Directory of Open Access Journals (Sweden)

    Galway LP

    2012-04-01

    Full Text Available Abstract Background Mortality estimates can measure and monitor the impacts of conflict on a population, guide humanitarian efforts, and help to better understand the public health impacts of conflict. Vital statistics registration and surveillance systems are rarely functional in conflict settings, posing a challenge of estimating mortality using retrospective population-based surveys. Results We present a two-stage cluster sampling method for application in population-based mortality surveys. The sampling method utilizes gridded population data and a geographic information system (GIS to select clusters in the first sampling stage and Google Earth TM imagery and sampling grids to select households in the second sampling stage. The sampling method is implemented in a household mortality study in Iraq in 2011. Factors affecting feasibility and methodological quality are described. Conclusion Sampling is a challenge in retrospective population-based mortality studies and alternatives that improve on the conventional approaches are needed. The sampling strategy presented here was designed to generate a representative sample of the Iraqi population while reducing the potential for bias and considering the context specific challenges of the study setting. This sampling strategy, or variations on it, are adaptable and should be considered and tested in other conflict settings.

  3. A Harmonic Impedance Measurement System for Reduction of Harmonics in the Electricity Grid

    NARCIS (Netherlands)

    Heskes, P.J.M.; Myrzik, J.M.A.; Kling, W.L.

    2009-01-01

    This paper describes the development of a Complex Harmonic Impedance Measurement system, called the CHIME-system. This system performs on-line impedance measurements in the electricity grid and will be designed for implementation in Digital Signal Processor (DSP) control systems of grid-connected

  4. A harmonic impedance measurement system for reduction of harmonics in the electricity grid

    NARCIS (Netherlands)

    Heskes, P.J.M.; Myrzik, J.M.A.; Kling, W.L.

    2009-01-01

    This paper describes the development of a Complex Harmonic Impedance Measurement system, called the CHIME-system. This system performs on-line impedance measurements in the electricity grid and will be designed for implementation in Digital Signal Processor (DSP) control systems of grid-connected

  5. Multi-agent approach for power system in a smart grid protection context

    DEFF Research Database (Denmark)

    Abedini, Reza; Pinto, Tiago; Morais, Hugo

    2013-01-01

    electricity markets and in the other hand with increasing penetration of Distributed Generation (DG) because of environment issues and diminishing in fossil fuel reserves and its price growth, made microgrid more attractive. Micro grids are considers as partial of SmartGrid system to accommodate DGs as well......With increasing penetration of electricity application in society and the need of majority of appliance to electricity, high level of reliability becomes more essential; in one hand with deregulation of electricity market in production, transmission and distribution and emerge of competitive...... proposes a new approach for protection in a Microgrid environment as a part of SmartGrid: Multi-agent system to Protections Coordination (MAS-ProteC) which integrated in MASGriP (Multi-Agent Smart Grid Platform), providing protection services within network operation in SmartGrid in electricity market...

  6. Spatial and temporal patterns of plantation forests in the United States since the 1930s: an annual and gridded data set for regional Earth system modeling

    Science.gov (United States)

    Chen, Guangsheng; Pan, Shufen; Hayes, Daniel J.; Tian, Hanqin

    2017-08-01

    Plantation forest area in the conterminous United States (CONUS) ranked second among the world's nations in the land area apportioned to forest plantation. As compared to the naturally regenerated forests, plantation forests demonstrate significant differences in biophysical characteristics, and biogeochemical and hydrological cycles as a result of more intensive management practices. Inventory data have been reported for multiple time periods on plot, state, and regional scales across the CONUS, but the requisite annual and spatially explicit plantation data set over a long-term period for analysis of the role of plantation management on regional or national scales is lacking. Through synthesis of multiple inventory data sources, this study developed methods to spatialize the time series plantation forest and tree species distribution data for the CONUS over the 1928-2012 time period. According to this new data set, plantation forest area increased from near zero in the 1930s to 268.27 thousand km2 in 2012, accounting for 8.65 % of the total forestland area in the CONUS. Regionally, the South contained the highest proportion of plantation forests, accounting for about 19.34 % of total forestland area in 2012. This time series and gridded data set developed here can be readily applied in regional Earth system modeling frameworks for assessing the impacts of plantation management practices on forest productivity, carbon and nitrogen stocks, and greenhouse gases (e.g., CO2, CH4, and N2O) and water fluxes on regional or national scales. The gridded plantation distribution and tree species maps, and the interpolated state-level annual tree planting area and plantation area during 1928-2012, are available from PANGAEA.873558" target="_blank">https://doi.org/10.1594/PANGAEA.873558.

  7. Grid-connected photovoltaic power systems: survey of inverter and related protection equipments

    Energy Technology Data Exchange (ETDEWEB)

    Ishikawa, T

    2002-12-15

    This report for the International Energy Agency (IEA) made by Task 5 of the Photovoltaic Power Systems (PVPS) programme reports on a survey made on inverter and related protection equipment. The mission of the Photovoltaic Power Systems Programme is to enhance the international collaboration efforts which accelerate the development and deployment of photovoltaic solar energy. Task 5 deals with issues concerning grid-interconnection and distributed PV power systems. This report summarises the data obtained from survey of recent inverter technology and inverter protection equipment for grid interconnected PV systems. The results are based on the surveys using a questionnaire to identify the current status of grid-interconnection inverters. This report is to serve as a reference for those interested in installing grid-connected PV systems, electric utility company personnel, manufacturers and researchers. The results of the survey are presented and discussed. Technical and financial data is reviewed and two appendices provide details on the results obtained and those institutions involved in the survey.

  8. Earth System Science Project

    Science.gov (United States)

    Rutherford, Sandra; Coffman, Margaret

    2004-01-01

    For several decades, science teachers have used bottles for classroom projects designed to teach students about biology. Bottle projects do not have to just focus on biology, however. These projects can also be used to engage students in Earth science topics. This article describes the Earth System Science Project, which was adapted and developed…

  9. Renewable energy off-grid power systems: options for energy suppliers

    International Nuclear Information System (INIS)

    Trouchet, K.

    1992-01-01

    SURVIVOR ENERGY SYSTEMS package a range of wind-based renewable energy systems for the supply of 24-hour power to off-grid homesteads and communities. This paper presents a leasing package for these power users and illustrates their cost effectiveness in comparison with stand-alone diesel and comparative hybrid power options. This offer is seen as a alternative for energy planners and supply agencies for their off-grid clients. 6 refs., 3 tabs., 3 figs

  10. Grid-connected photovoltaic power systems. Technical and potential problems. A review

    International Nuclear Information System (INIS)

    Eltawil, Mohamed A.; Zhao, Zhengming

    2010-01-01

    Traditional electric power systems are designed in large part to utilize large baseload power plants, with limited ability to rapidly ramp output or reduce output below a certain level. The increase in demand variability created by intermittent sources such as photovoltaic (PV) presents new challenges to increase system flexibility. This paper aims to investigate and emphasize the importance of the grid-connected PV system regarding the intermittent nature of renewable generation, and the characterization of PV generation with regard to grid code compliance. The investigation was conducted to critically review the literature on expected potential problems associated with high penetration levels and islanding prevention methods of grid tied PV. According to the survey, PV grid connection inverters have fairly good performance. They have high conversion efficiency and power factor exceeding 90% for wide operating range, while maintaining current harmonics THD less than 5%. Numerous large-scale projects are currently being commissioned, with more planned for the near future. Prices of both PV and balance of system components (BOS) are decreasing which will lead to further increase in use. The technical requirements from the utility power system side need to be satisfied to ensure the safety of the PV installer and the reliability of the utility grid. Identifying the technical requirements for grid interconnection and solving the interconnect problems such as islanding detection, harmonic distortion requirements and electromagnetic interference are therefore very important issues for widespread application of PV systems. The control circuit also provides sufficient control and protection functions like maximum power tracking, inverter current control and power factor control. Reliability, life span and maintenance needs should be certified through the long-term operation of PV system. Further reduction of cost, size and weight is required for more utilization of PV

  11. A survey on the contributions of power electronics to smart grid systems

    OpenAIRE

    COLAK ILHAMI; KABALCI Ersan; FULLI Gianluca; LAZAROU STAVROS

    2014-01-01

    The smart grid (SG) as a research area is advancing dealing with a wider range of topics such as power systems, energy generation and telecommunication. The conventional utility grid used to operate in a passive mode absorbing energy from the substations and delivering it to the customers. This approach is well developed but the needs of the state-of-the-art technology require a bidirectional flow of power and data. Nevertheless, smart grid systems provide more flexible, reliable, sustainable...

  12. Overview of Single-Phase Grid-Connected Photovoltaic Systems

    DEFF Research Database (Denmark)

    Yang, Yongheng; Blaabjerg, Frede

    2015-01-01

    A still booming installation of solar photovoltaic (PV) systems has been witnessed worldwide. It is mainly driven by the demand of “clean” power generation. Grid-connected PV systems will become an even active player in the future mixed power systems, which are linked by a vast of power electronics...

  13. Research on a New Control Scheme of Photovoltaic Grid Power Generation System

    Directory of Open Access Journals (Sweden)

    Dong-Hui Li

    2014-01-01

    Full Text Available A new type of photovoltaic grid power generation system control scheme to solve the problems of the conventional photovoltaic grid power generation systems is presented. To aim at the oscillation and misjudgment of traditional perturbation observation method, an improved perturbation observation method comparing to the next moment power is proposed, combining with BOOST step-up circuit to realize the maximum power tracking. To counter the harmonic pollution problem in photovoltaic grid power generation system, the deadbeat control scheme in fundamental wave synchronous frequency rotating coordinate system of power grid is presented. A parameter optimization scheme based on positive feedback of active frequency shift island detection to solve the problems like the nondetection zone due to the import of disturbance in traditional island detection method is proposed. Finally, the results in simulation environment by MATLAB/Simulink simulation and experiment environment verify the validity and superiority of the proposed scheme.

  14. Smarter Earth Science Data System

    Science.gov (United States)

    Huang, Thomas

    2013-01-01

    The explosive growth in Earth observational data in the recent decade demands a better method of interoperability across heterogeneous systems. The Earth science data system community has mastered the art in storing large volume of observational data, but it is still unclear how this traditional method scale over time as we are entering the age of Big Data. Indexed search solutions such as Apache Solr (Smiley and Pugh, 2011) provides fast, scalable search via keyword or phases without any reasoning or inference. The modern search solutions such as Googles Knowledge Graph (Singhal, 2012) and Microsoft Bing, all utilize semantic reasoning to improve its accuracy in searches. The Earth science user community is demanding for an intelligent solution to help them finding the right data for their researches. The Ontological System for Context Artifacts and Resources (OSCAR) (Huang et al., 2012), was created in response to the DARPA Adaptive Vehicle Make (AVM) programs need for an intelligent context models management system to empower its terrain simulation subsystem. The core component of OSCAR is the Environmental Context Ontology (ECO) is built using the Semantic Web for Earth and Environmental Terminology (SWEET) (Raskin and Pan, 2005). This paper presents the current data archival methodology within a NASA Earth science data centers and discuss using semantic web to improve the way we capture and serve data to our users.

  15. High voltage direct current transmission converters, systems and DC grids

    CERN Document Server

    Jovcic, Dragan

    2015-01-01

    This comprehensive reference guides the reader through all HVDC technologies, including LCC (Line Commutated Converter), 2-level VSC and VSC HVDC based on modular multilevel converters (MMC) for an in-depth understanding of converters, system level design, operating principles and modeling. Written in a tutorial style, the book also describes the key principles of design, control, protection and operation of DC transmission grids, which will be substantially different from the practice with AC transmission grids. The first dedicated reference to the latest HVDC technologies and DC grid developments; this is an essential resource for graduate students and researchers as well as engineers and professionals working on the design, modeling and operation of DC grids and HVDC.

  16. A Stationary Reference Frame Grid Synchronization System for Three-Phase Grid-Connected Power Converters Under Adverse Grid Conditions

    DEFF Research Database (Denmark)

    Rodríguez, P.; Luna, A.; Muñoz-Aguilar, R. S.

    2012-01-01

    synchronization method for three-phase three-wire networks, namely dual second-order generalized integrator (SOGI) frequency-locked loop. The method is based on two adaptive filters, implemented by using a SOGI on the stationary αβ reference frame, and it is able to perform an excellent estimation......Grid synchronization algorithms are of great importance in the control of grid-connected power converters, as fast and accurate detection of the grid voltage parameters is crucial in order to implement stable control strategies under generic grid conditions. This paper presents a new grid...

  17. ESIF 2016: Modernizing Our Grid and Energy System

    Energy Technology Data Exchange (ETDEWEB)

    Van Becelaere, Kimberly [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2017-03-09

    This 2016 annual report highlights work conducted at the Energy Systems Integration Facility (ESIF) in FY 2016, including grid modernization, high-performance computing and visualization, and INTEGRATE projects.

  18. Solar Irradiance & On Grid Solar Power Systems with Net Metering in Pakistan

    Directory of Open Access Journals (Sweden)

    Haleema Qamar

    2016-06-01

    Full Text Available This paper presents a case study of solar irradiance and scope of on-grid solar power systems with net-metering in Pakistan. Detailed analysis of solar irradiance in Pakistan is being carried out by developing the dedicated solar excel sheets. The need of on grid solar power systems for the present energy crisis in developing countries like Pakistan is also discussed. It also presents the inclination of many countries especially USA and Europe towards it. Identification of barriers for implementing on grid net metered solar power systems in Pakistan along with solutions of these barriers is carried out.

  19. Smart grid

    International Nuclear Information System (INIS)

    Choi, Dong Bae

    2001-11-01

    This book describes press smart grid from basics to recent trend. It is divided into ten chapters, which deals with smart grid as green revolution in energy with introduction, history, the fields, application and needed technique for smart grid, Trend of smart grid in foreign such as a model business of smart grid in foreign, policy for smart grid in U.S.A, Trend of smart grid in domestic with international standard of smart grid and strategy and rood map, smart power grid as infrastructure of smart business with EMS development, SAS, SCADA, DAS and PQMS, smart grid for smart consumer, smart renewable like Desertec project, convergence IT with network and PLC, application of an electric car, smart electro service for realtime of electrical pricing system, arrangement of smart grid.

  20. Methodology to determine the technical performance and value proposition for grid-scale energy storage systems :

    Energy Technology Data Exchange (ETDEWEB)

    Byrne, Raymond Harry; Loose, Verne William; Donnelly, Matthew K.; Trudnowski, Daniel J.

    2012-12-01

    As the amount of renewable generation increases, the inherent variability of wind and photovoltaic systems must be addressed in order to ensure the continued safe and reliable operation of the nation's electricity grid. Grid-scale energy storage systems are uniquely suited to address the variability of renewable generation and to provide other valuable grid services. The goal of this report is to quantify the technical performance required to provide di erent grid bene ts and to specify the proper techniques for estimating the value of grid-scale energy storage systems.

  1. Sustainable recycling technologies for Solar PV off-grid system

    Directory of Open Access Journals (Sweden)

    Uppal Bhavesh

    2017-01-01

    Full Text Available Policy makers throughout the world have accepted climate change as a repercussion of fossil fuel exploitation. This has led the governments to integrate renewable energy streams in their national energy mix. PV off-grid Systems have been at the forefront of this transition because of their permanently increasing efficiency and cost effectiveness. These systems are expected to produce large amount of different waste streams at the end of their lifetime. It is important that these waste streams should be recycled because of the lack of available resources. Our study found that separate researches have been carried out to increase the efficiencies of recycling of individual PV system components but there is a lack of a comprehensive methodical research which details efficient and sustainable recycling processes for the entire PV off-grid system. This paper reviews the current and future recycling technologies for PV off-grid systems and presents a scheme of the most sustainable recycling technologies which have the potential for adoption. Full Recovery End-of-Life Photovoltaic (FRELP recycling technology can offer opportunities to sustainably recycle crystalline silicon PV modules. Electro-hydrometallurgical process & Vacuum technologies can be used for recovering lead from lead acid batteries with a high recovery rate. The metals in the WEEE can be recycled by using a combination of biometallurgical technology, vacuum metallurgical technology and other advanced metallurgical technologies (utrasonical, mechano-chemical technology while the plastic components can be effectively recycled without separation by using compatibilizers. All these advanced technologies when used in combination with each other provide sustainable recycling options for growing PV off-grid systems waste. These promising technologies still need further improvement and require proper integration techniques before implementation.

  2. Impact of Degraded Communication on Interdependent Power Systems: The Application of Grid Splitting

    Directory of Open Access Journals (Sweden)

    Di-An Tian

    2016-08-01

    Full Text Available Communication is increasingly present for managing and controlling critical infrastructures strengthening their cyber interdependencies. In electric power systems, grid splitting is a topical communication-critical application. It amounts to separating a power system into islands in response to an impending instability, e.g., loss of generator synchronism due to a component fault, by appropriately disconnecting transmission lines and grouping synchronous generators. The successful application of grid splitting depends on the communication infrastructure to collect system-wide synchronized measurements and to relay the command to open line switches. Grid splitting may be ineffective if communication is degraded and its outcome may also depend on the system loading conditions. This paper investigates the effects of degraded communication and load variability on grid splitting. To this aim, a communication delay model is coupled with a transient electrical model and applied to the IEEE 39-Bus and the IEEE 118-Bus Test System. Case studies show that the loss of generator synchronism following a fault is mitigated by timely splitting the network into islands. On the other hand, the results show that communication delays and increased network flows can degrade the performance of grid splitting. The developed framework enables the identification of the requirements of the dedicated communication infrastructure for a successful grid-splitting procedure.

  3. Current Grid operation and future role of the Grid

    Science.gov (United States)

    Smirnova, O.

    2012-12-01

    Grid-like technologies and approaches became an integral part of HEP experiments. Some other scientific communities also use similar technologies for data-intensive computations. The distinct feature of Grid computing is the ability to federate heterogeneous resources of different ownership into a seamless infrastructure, accessible via a single log-on. Like other infrastructures of similar nature, Grid functioning requires not only technologically sound basis, but also reliable operation procedures, monitoring and accounting. The two aspects, technological and operational, are closely related: weaker is the technology, more burden is on operations, and other way around. As of today, Grid technologies are still evolving: at CERN alone, every LHC experiment uses an own Grid-like system. This inevitably creates a heavy load on operations. Infrastructure maintenance, monitoring and incident response are done on several levels, from local system administrators to large international organisations, involving massive human effort worldwide. The necessity to commit substantial resources is one of the obstacles faced by smaller research communities when moving computing to the Grid. Moreover, most current Grid solutions were developed under significant influence of HEP use cases, and thus need additional effort to adapt them to other applications. Reluctance of many non-HEP researchers to use Grid negatively affects the outlook for national Grid organisations, which strive to provide multi-science services. We started from the situation where Grid organisations were fused with HEP laboratories and national HEP research programmes; we hope to move towards the world where Grid will ultimately reach the status of generic public computing and storage service provider and permanent national and international Grid infrastructures will be established. How far will we be able to advance along this path, depends on us. If no standardisation and convergence efforts will take place

  4. Current Grid operation and future role of the Grid

    International Nuclear Information System (INIS)

    Smirnova, O

    2012-01-01

    Grid-like technologies and approaches became an integral part of HEP experiments. Some other scientific communities also use similar technologies for data-intensive computations. The distinct feature of Grid computing is the ability to federate heterogeneous resources of different ownership into a seamless infrastructure, accessible via a single log-on. Like other infrastructures of similar nature, Grid functioning requires not only technologically sound basis, but also reliable operation procedures, monitoring and accounting. The two aspects, technological and operational, are closely related: weaker is the technology, more burden is on operations, and other way around. As of today, Grid technologies are still evolving: at CERN alone, every LHC experiment uses an own Grid-like system. This inevitably creates a heavy load on operations. Infrastructure maintenance, monitoring and incident response are done on several levels, from local system administrators to large international organisations, involving massive human effort worldwide. The necessity to commit substantial resources is one of the obstacles faced by smaller research communities when moving computing to the Grid. Moreover, most current Grid solutions were developed under significant influence of HEP use cases, and thus need additional effort to adapt them to other applications. Reluctance of many non-HEP researchers to use Grid negatively affects the outlook for national Grid organisations, which strive to provide multi-science services. We started from the situation where Grid organisations were fused with HEP laboratories and national HEP research programmes; we hope to move towards the world where Grid will ultimately reach the status of generic public computing and storage service provider and permanent national and international Grid infrastructures will be established. How far will we be able to advance along this path, depends on us. If no standardisation and convergence efforts will take place

  5. Advanced Platform for Development and Evaluation of Grid Interconnection Systems Using Hardware-in-the-Loop: Part III - Grid Interconnection System Evaluator

    Energy Technology Data Exchange (ETDEWEB)

    Lundstrom, B.; Shirazi, M.; Coddington, M.; Kroposki, B.

    2013-01-01

    This paper describes a Grid Interconnection System Evaluator (GISE) that leverages hardware-in-the-loop (HIL) simulation techniques to rapidly evaluate the grid interconnection standard conformance of an ICS according to the procedures in IEEE Std 1547.1. The architecture and test sequencing of this evaluation tool, along with a set of representative ICS test results from three different photovoltaic (PV) inverters, are presented. The GISE adds to the National Renewable Energy Laboratory's (NREL) evaluation platform that now allows for rapid development of ICS control algorithms using controller HIL (CHIL) techniques, the ability to test the dc input characteristics of PV-based ICSs through the use of a PV simulator capable of simulating real-world dynamics using power HIL (PHIL), and evaluation of ICS grid interconnection conformance.

  6. Profitability of smart grid solutions applied in power grid

    Directory of Open Access Journals (Sweden)

    Katić Nenad A.

    2016-01-01

    Full Text Available The idea of a Smart Grid solution has been developing for years, as complete solution for a power utility, consisting of different advanced technologies aimed at improving of the efficiency of operation. The trend of implementing various smart systems continues, e.g. Energy Management Systems, Grid Automation Systems, Advanced Metering Infrastructure, Smart power equipment, Distributed Energy Resources, Demand Response systems, etc. Futhermore, emerging technologies, such as energy storages, electrical vehicles or distributed generators, become integrated in distribution networks and systems. Nowadays, the idea of a Smart Grid solution becomes more realistic by full integration of all advanced operation technologies (OT within IT environment, providing the complete digitalization of an Utility (IT/OT integration. The overview of smart grid solutions, estimation of investments, operation costs and possible benefits are presented in this article, with discusison about profitability of such systems.

  7. The CrossGrid project

    International Nuclear Information System (INIS)

    Kunze, M.

    2003-01-01

    There are many large-scale problems that require new approaches to computing, such as earth observation, environmental management, biomedicine, industrial and scientific modeling. The CrossGrid project addresses realistic problems in medicine, environmental protection, flood prediction, and physics analysis and is oriented towards specific end-users: Medical doctors, who could obtain new tools to help them to obtain correct diagnoses and to guide them during operations; industries, that could be advised on the best timing for some critical operations involving risk of pollution; flood crisis teams, that could predict the risk of a flood on the basis of historical records and actual hydrological and meteorological data; physicists, who could optimize the analysis of massive volumes of data distributed across countries and continents. Corresponding applications will be based on Grid technology and could be complex and difficult to use: the CrossGrid project aims at developing several tools that will make the Grid more friendly for average users. Portals for specific applications will be designed, that should allow for easy connection to the Grid, create a customized work environment, and provide users with all necessary information to get their job done

  8. Impact of Rural Grid-Connected Photovoltaic Generation Systems on Power Quality

    Directory of Open Access Journals (Sweden)

    Rita Pinto

    2016-09-01

    Full Text Available Photovoltaic (PV generation systems have been increasingly used to generate electricity from renewable sources, attracting a growing interest. Recently, grid connected PV micro-generation facilities in individual homes have increased due to governmental policies as well as greater attention by industry. As low voltage (LV distribution systems were built to make energy flow in one direction, the power feed-in of PV generation in rural low-voltage grids can influence power quality (PQ as well as facility operation and reliability. This paper presents results on PQ analysis of a real PV generation facility connected to a rural low-voltage grid. Voltage fluctuations and voltage harmonic contents were observed. Statistical analysis shows a negative impact on PQ produced by this PV facility and also that only a small fraction of the energy available during a sunny day is converted, provoking losses of revenue and forcing the converter to work in an undesirable operating mode. We discuss the disturbances imposed upon the grid and their outcome regarding technical and economic viability of the PV system, as well as possible solutions. A low-voltage grid strengthening has been suggested and implemented. After that a new PQ analysis shows an improvement in the impact upon PQ, making this facility economically viable.

  9. New Boundary Constraints for Elliptic Systems used in Grid Generation Problems

    Science.gov (United States)

    Kaul, Upender K.; Clancy, Daniel (Technical Monitor)

    2002-01-01

    This paper discusses new boundary constraints for elliptic partial differential equations as used in grid generation problems in generalized curvilinear coordinate systems. These constraints, based on the principle of local conservation of thermal energy in the vicinity of the boundaries, are derived using the Green's Theorem. They uniquely determine the so called decay parameters in the source terms of these elliptic systems. These constraints' are designed for boundary clustered grids where large gradients in physical quantities need to be resolved adequately. It is observed that the present formulation also works satisfactorily for mild clustering. Therefore, a closure for the decay parameter specification for elliptic grid generation problems has been provided resulting in a fully automated elliptic grid generation technique. Thus, there is no need for a parametric study of these decay parameters since the new constraints fix them uniquely. It is also shown that for Neumann type boundary conditions, these boundary constraints uniquely determine the solution to the internal elliptic problem thus eliminating the non-uniqueness of the solution of an internal Neumann boundary value grid generation problem.

  10. Storage systems for improved grid integration of photovoltaic systems; Speichersysteme fuer eine verbesserte Netzintegration von Photovoltaikanlagen

    Energy Technology Data Exchange (ETDEWEB)

    Ying, Shaoqing [Brandenburgische Technische Univ. Cottbus (Germany). CEBra-Research

    2013-07-15

    Since the enactment of the Renewable Energy Law in the year 2000 Germany has seen a massive increase in capacity for energy production from renewable resources. Of these, wind power and photovoltaics show heavily fluctuating supply profiles, with significant impact on energy supply grids. One approach to lessening the load on power grids, aside from their expansion, is to install energy storage systems. Recent studies on the use of such storage systems for improved grid integration of photovoltaic systems have shown the viability of this approach for ground-mounted plants connected to the medium or high voltage level as well as for roof-mounted plants for the low-voltage level.

  11. From the grid to the smart grid, topologically

    Science.gov (United States)

    Pagani, Giuliano Andrea; Aiello, Marco

    2016-05-01

    In its more visionary acceptation, the smart grid is a model of energy management in which the users are engaged in producing energy as well as consuming it, while having information systems fully aware of the energy demand-response of the network and of dynamically varying prices. A natural question is then: to make the smart grid a reality will the distribution grid have to be upgraded? We assume a positive answer to the question and we consider the lower layers of medium and low voltage to be the most affected by the change. In our previous work, we analyzed samples of the Dutch distribution grid (Pagani and Aiello, 2011) and we considered possible evolutions of these using synthetic topologies modeled after studies of complex systems in other technological domains (Pagani and Aiello, 2014). In this paper, we take an extra important step by defining a methodology for evolving any existing physical power grid to a good smart grid model, thus laying the foundations for a decision support system for utilities and governmental organizations. In doing so, we consider several possible evolution strategies and apply them to the Dutch distribution grid. We show how increasing connectivity is beneficial in realizing more efficient and reliable networks. Our proposal is topological in nature, enhanced with economic considerations of the costs of such evolutions in terms of cabling expenses and economic benefits of evolving the grid.

  12. STRUCTURAL AND DESIGN SPECIFICS OF SPACE GRID SYSTEMS

    Directory of Open Access Journals (Sweden)

    G. M. Gasii

    2017-01-01

    Full Text Available The aim of the study is to identify main trends in the development of space grid structures. In order to reach the purpose it is necessary to conduct a review of the known structural concepts, nodal connections and specifics of the space grid structures and to make conclusions on feasibility improvement of the considered structural concepts that make it possible to develop new solutions without disadvantages residing in the analogues. Analysis of papers written by foreign and national scientists and devoted to theoretical, numerical and experimental studies of stress-strain state, influence of different factors on it and geometrical optimization and designing of space grid structures has been conducted in order to achieve the objectives. Space grid structures and, in particular, flat double-layer grid and most frequent nodes have been studied in the paper. The paper contains a short review of the history on development of space grid structures. It has been found that a rapid development of structural designs was caused by scientific and technical progress and, in particular, improvement of physical and mechanical properties of materials, development of calculation methods, application of software systems for simulating behavior of the structure under load, which significantly increased the calculation accuracy and reduced complexity of design. It has been also established that main parameters that have influence on effectiveness of a structural design are geometric dimensions of its modular elements, ratio of its depth to the span. The world experience on development of connection components has been studied in the paper. The paper presents general classification of nodal connections. Main advantages and disadvantages of existing space grid structures are highlighted and it allows to determine possible methods for their improvement. Theoretical research has permitted to establish that the main direction of spatial grid structures improvement

  13. International off-grid market assessment for dish/Stirling systems

    International Nuclear Information System (INIS)

    Lilienthal, P.; Campbell, K.

    1998-01-01

    Several features of dish/Stirling technology offer potential advantages for off-grid power generation. Dish/Stirling technology's size, modularity, the ease with which it might be hybridized with a storable fuel, the elimination of batteries and inverters, and the production of pure sine-wave AC power without a diesel all indicate that a reliable dish/Stirling module could fit well into an off-grid electrification scheme. At the same time, a combination of factors makes success in off-grid applications difficult, regardless of the technology under consideration. Obstacles include consumer expectations (formed by a long history of subsidies) that electricity should be cheap, existing support infrastructure, and the economic resources of rural communities. Cost is always a factor, but reliability and access to parts and service have been more significant barriers so far in the establishment of renewables. This paper summarizes a much more extensive market assessment. Initial research indicates that a reliable 25 kW dish/Stirling system with reasonable servicing requirements could compete well with other off-grid power systems at a cost considered achievable at early production levels ($3,500 per kW). However, by itself the off-grid power market in regions with adequate solar insolation and inviting political regimes does not justify an adequate scale of production. It is estimated that the aggregate market in five of the largest and most promising countries for which adequate information was available could be 23,000 to 38,000 units of 25 kW dish/Stirling systems. Including the rest of the developing world could more than double this number. However, at a reasonable initial market penetration rate of 1% per year this market is not sufficient, by itself, for the mass production rates required to achieve the necessary economies of scale

  14. The UK Earth System Model project

    Science.gov (United States)

    Tang, Yongming

    2016-04-01

    In this talk we will describe the development and current status of the UK Earth System Model (UKESM). This project is a NERC/Met Office collaboration and has two objectives; to develop and apply a world-leading Earth System Model, and to grow a community of UK Earth System Model scientists. We are building numerical models that include all the key components of the global climate system, and contain the important process interactions between global biogeochemistry, atmospheric chemistry and the physical climate system. UKESM will be used to make key CMIP6 simulations as well as long-time (e.g. millennium) simulations, large ensemble experiments and investigating a range of future carbon emission scenarios.

  15. EarthN: A new Earth System Nitrogen Model

    OpenAIRE

    Johnson, Benjamin W.; Goldblatt, Colin

    2018-01-01

    The amount of nitrogen in the atmosphere, oceans, crust, and mantle have important ramifications for Earth's biologic and geologic history. Despite this importance, the history and cycling of nitrogen in the Earth system is poorly constrained over time. For example, various models and proxies contrastingly support atmospheric mass stasis, net outgassing, or net ingassing over time. In addition, the amount available to and processing of nitrogen by organisms is intricately linked with and prov...

  16. Experimental grid connected PV system power analysis

    Science.gov (United States)

    Semaoui, Smail; Abdeladim, Kamel; Arab, Amar Hadj; Boulahchich, Saliha; Amrouche, Said Ould; Yassaa, Noureddine

    2018-05-01

    Almost 80 % of Algerian territory is appropriate for the exploitation of solar energy. The Algerian energetic strategy provides a substantial injection of PV electricity to the national grid. Currently, about 344 MWp of PV arrays which corresponds approximately to 2,34 km2 of module surfaces, are connected on electricity grid over the national territory. The Algerian Northern regions are characterized by strong pollution and high humidity. These phenomena affect the energetic productivity of PV generator. The objective of our study is to analyze experimental grid connected PV system power in coastal locations. Hence, experiments have been conducted on three identical PV systems to determine the electrical performances. Transformer-less inverters are the most attractive for the ground-based photovoltaic (PV) system due to their efficiencies, reduced cost and weight. Besides, the absence of the galvanic isolation generates problems of capacitive leakage current on the AC side and the degradation of the insulation resistance on the DC side of the inverter. In this work, experimental study of the behavior of single-phase inverters without transformers is presented. The main objective of this work is to study the degradation of the insulation resistance at the input of the inverter, and the capacitive leakage current at the output of the inverter. This study was achieved at the CDER on a rainy day of 15/03/2017, on the first PV plant connected to the low voltage network in Algeria. This investigation can help forecasting the PV array energetic production by taking into account natural conditions.

  17. Grid-system element of LCG-2 in DLNP

    International Nuclear Information System (INIS)

    Dolbilov, A.G.; Ivanov, Yu.P.

    2008-01-01

    We present here the description of the computer cluster at the Dzhelepov Laboratory of Nuclear Problems of JINR, where the second Grid note at JINR was realized. The configuration of the system, which allows effective joint usage of cluster resources both for local users and for others within the framework of the ATLAS collaboration is examined. Examples are given for basic stages of preparing and running ordinary cluster jobs and with the Grid usages, starting from obtaining CA certificates, submitting jobs and retrieving the results. Perspectives of the cluster upgrade are discussed

  18. Optimal sizing of grid-independent hybrid photovoltaic–battery power systems for household sector

    International Nuclear Information System (INIS)

    Bianchi, M.; Branchini, L.; Ferrari, C.; Melino, F.

    2014-01-01

    Highlights: • A feasibility study on a stand-alone solar–battery power generation system is carried out. • An in-house developed calculation code able to estimate photovoltaic panels behaviour is described. • The feasibility of replacing grid electricity with hybrid system is examined. • Guidelines for optimal photovoltaic design are given. • Guidelines for optimal storage sizing in terms of batteries number and capacity are given. - Abstract: The penetration of renewable sources into the grid, particularly wind and solar, have been increasing in recent years. As a consequence, there have been serious concerns over reliable and safety operation of power systems. One possible solution, to improve grid stability, is to integrate energy storage devices into power system network: storing energy produced in periods of low demand to later use, ensuring full exploitation of intermittent available sources. Focusing on stand-alone photovoltaic (PV) energy system, energy storage is needed with the purpose of ensuring continuous power flow, to minimize or, if anything, to neglect electrical grid supply. A comprehensive study on a hybrid stand-alone photovoltaic power system using two different energy storage technologies has been performed. The study examines the feasibility of replacing electricity provided by the grid with hybrid system to meet household demand. In particular, this paper presents first results for photovoltaic (PV)/battery (B) hybrid configuration. The main objective of this paper is focused on PV/B system, to recommend hybrid system optimal design in terms of PV module number, PV module tilt, number and capacity of batteries to minimize or, if possible, to neglect grid supply. This paper is the early stage of a theoretical and experimental study in which two different hybrid power system configurations will be evaluated and compared: (i) PV/B system and (ii) PV/B/fuel cell (FC) system. The aim of the overall study will be the definition of the

  19. Integrated assessment of water-power grid systems under changing climate

    Science.gov (United States)

    Yan, E.; Zhou, Z.; Betrie, G.

    2017-12-01

    Energy and water systems are intrinsically interconnected. Due to an increase in climate variability and extreme weather events, interdependency between these two systems has been recently intensified resulting significant impacts on both systems and energy output. To address this challenge, an Integrated Water-Energy Systems Assessment Framework (IWESAF) is being developed to integrate multiple existing or developed models from various sectors. In this presentation, we are focusing on recent improvement in model development of thermoelectric power plant water use simulator, power grid operation and cost optimization model, and model integration that facilitate interaction among water and electricity generation under extreme climate events. A process based thermoelectric power water use simulator includes heat-balance, climate, and cooling system modules that account for power plant characteristics, fuel types, and cooling technology. The model is validated with more than 800 power plants of fossil-fired, nuclear and gas-turbine power plants with different cooling systems. The power grid operation and cost optimization model was implemented for a selected regional in the Midwest. The case study will be demonstrated to evaluate the sensitivity and resilience of thermoelectricity generation and power grid under various climate and hydrologic extremes and potential economic consequences.

  20. Performance Parameters for Grid-Connected PV Systems

    Energy Technology Data Exchange (ETDEWEB)

    Marion, B.; Adelstein, J.; Boyle, K.; Hayden, H.; Hammond, B.; Fletcher, T.; Canada, B.; Narang, D.; Shugar, D.; Wenger, H.; Kimber, A.; Mitchell, L.; Rich, G.; Townsend, T.

    2005-02-01

    The use of appropriate performance parameters facilitates the comparison of grid-connected photovoltaic (PV) systems that may differ with respect to design, technology, or geographic location. Four performance parameters that define the overall system performance with respect to the energy production, solar resource, and overall effect of system losses are the following: final PV system yield, reference yield, performance ratio, and PVUSA rating. These performance parameters are discussed for their suitability in providing desired information for PV system design and performance evaluation and are demonstrated for a variety of technologies, designs, and geographic locations. Also discussed are methodologies for determining system a.c. power ratings in the design phase using multipliers developed from measured performance parameters.The use of appropriate performance parameters facilitates the comparison of grid-connected photovoltaic (PV) systems that may differ with respect to design, technology, or geographic location. Four performance parameters that define the overall system performance with respect to the energy production, solar resource, and overall effect of system losses are the following: final PV system yield, reference yield, performance ratio, and PVUSA rating. These performance parameters are discussed for their suitability in providing desired information for PV system design and performance evaluation and are demonstrated for a variety of technologies, designs, and geographic locations. Also discussed are methodologies for determining system a.c. power ratings in the design phase using multipliers developed from measured performance parameters.

  1. Review of DC System Technologies for Large Scale Integration of Wind Energy Systems with Electricity Grids

    Directory of Open Access Journals (Sweden)

    Sheng Jie Shao

    2010-06-01

    Full Text Available The ever increasing development and availability of power electronic systems is the underpinning technology that enables large scale integration of wind generation plants with the electricity grid. As the size and power capacity of the wind turbine continues to increase, so is the need to place these significantly large structures at off-shore locations. DC grids and associated power transmission technologies provide opportunities for cost reduction and electricity grid impact minimization as the bulk power is concentrated at single point of entry. As a result, planning, optimization and impact can be studied and carefully controlled minimizing the risk of the investment as well as power system stability issues. This paper discusses the key technologies associated with DC grids for offshore wind farm applications.

  2. Grid Converters for Stationary Battery Energy Storage Systems

    DEFF Research Database (Denmark)

    Trintis, Ionut

    The integration of renewable energy sources in the power system, with high percentage, is a well known challenge nowadays. Power sources like wind and solar are highly volatile, with uctuations on various time scales. One long term solution is to build a continentwide or worldwide supergrid....... Another solution is to use distributed energy storage units, and create virtual power plants. Stationary energy storage is a complementary solution, which can postpone the network expansion and can be optimized for dierent kind of grid services. As an energy storage solution with timing for few seconds...... multilevel converter structure with integrated energy storage is introduced. This converter structure is suitable to interface low and medium voltage energy storage units to medium and high voltage grids. It can also interconnect a DC and AC grid with bidirectional power ow, were both can be backed...

  3. Optimal system sizing in grid-connected photovoltaic applications

    Science.gov (United States)

    Simoens, H. M.; Baert, D. H.; de Mey, G.

    A costs/benefits analysis for optimizing the combination of photovoltaic (PV) panels, batteries and an inverter for grid interconnected systems at a 500 W/day Belgian residence is presented. It is assumed that some power purchases from the grid will always be necessary, and that excess PV power can be fed into the grid. A minimal value for the cost divided by the performance is defined for economic optimization. Shortages and excesses are calculated for PV panels of 0.5-10 kWp output, with consideration given to the advantages of a battery back-up. The minimal economic value is found to increase with the magnitude of PV output, and an inverter should never be rated at more than half the array maximum output. A maximum panel size for the Belgian residence is projected to be 6 kWp.

  4. Implementation of a novel two-attractor grid multi-scroll chaotic system

    International Nuclear Information System (INIS)

    Xiao-Hua, Luo; Zheng-Wei, Tu; Xi-Rui, Liu; Chang, Cai; Pu, Gong; Yi-Long, Liang

    2010-01-01

    This paper proposed a method of generating two attractors in a novel grid multi-scroll chaotic system. Based on a newly generated three-dimensional system, a two-attractor grid multi-scroll attractor system can be generated by adding two triangular waves and a sign function. Some basic dynamical properties, such as equilibrium points, bifurcations, and phase diagrams, were studied. Furthermore, the system was experimentally confirmed by an electronic circuit. The circuit simulation results and numerical simulation results verified the feasibility of this method. (general)

  5. Power systems signal processing for smart grids

    NARCIS (Netherlands)

    Ribeiro, P.F.; Duque, C.A.; Da Silveira, P.M.; Cerqueira, A.S.

    2013-01-01

    With special relation to smart grids, this book provides clear and comprehensive explanation of how Digital Signal Processing (DSP) and Computational Intelligence (CI) techniques can be applied to solve problems in the power system. Its unique coverage bridges the gap between DSP, electrical power

  6. Foundational Report Series. Advanced Distribution management Systems for Grid Modernization (Importance of DMS for Distribution Grid Modernization)

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jianhui [Argonne National Lab. (ANL), Argonne, IL (United States)

    2015-09-01

    Grid modernization is transforming the operation and management of electric distribution systems from manual, paper-driven business processes to electronic, computer-assisted decisionmaking. At the center of this business transformation is the distribution management system (DMS), which provides a foundation from which optimal levels of performance can be achieved in an increasingly complex business and operating environment. Electric distribution utilities are facing many new challenges that are dramatically increasing the complexity of operating and managing the electric distribution system: growing customer expectations for service reliability and power quality, pressure to achieve better efficiency and utilization of existing distribution system assets, and reduction of greenhouse gas emissions by accommodating high penetration levels of distributed generating resources powered by renewable energy sources (wind, solar, etc.). Recent “storm of the century” events in the northeastern United States and the lengthy power outages and customer hardships that followed have greatly elevated the need to make power delivery systems more resilient to major storm events and to provide a more effective electric utility response during such regional power grid emergencies. Despite these newly emerging challenges for electric distribution system operators, only a small percentage of electric utilities have actually implemented a DMS. This paper discusses reasons why a DMS is needed and why the DMS may emerge as a mission-critical system that will soon be considered essential as electric utilities roll out their grid modernization strategies.

  7. Chemical Mechanisms and Their Applications in the Goddard Earth Observing System (GEOS) Earth System Model.

    Science.gov (United States)

    Nielsen, J Eric; Pawson, Steven; Molod, Andrea; Auer, Benjamin; da Silva, Arlindo M; Douglass, Anne R; Duncan, Bryan; Liang, Qing; Manyin, Michael; Oman, Luke D; Putman, William; Strahan, Susan E; Wargan, Krzysztof

    2017-12-01

    NASA's Goddard Earth Observing System (GEOS) Earth System Model (ESM) is a modular, general circulation model (GCM), and data assimilation system (DAS) that is used to simulate and study the coupled dynamics, physics, chemistry, and biology of our planet. GEOS is developed by the Global Modeling and Assimilation Office (GMAO) at NASA Goddard Space Flight Center. It generates near-real-time analyzed data products, reanalyses, and weather and seasonal forecasts to support research targeted to understanding interactions among Earth System processes. For chemistry, our efforts are focused on ozone and its influence on the state of the atmosphere and oceans, and on trace gas data assimilation and global forecasting at mesoscale discretization. Several chemistry and aerosol modules are coupled to the GCM, which enables GEOS to address topics pertinent to NASA's Earth Science Mission. This paper describes the atmospheric chemistry components of GEOS and provides an overview of its Earth System Modeling Framework (ESMF)-based software infrastructure, which promotes a rich spectrum of feedbacks that influence circulation and climate, and impact human and ecosystem health. We detail how GEOS allows model users to select chemical mechanisms and emission scenarios at run time, establish the extent to which the aerosol and chemical components communicate, and decide whether either or both influence the radiative transfer calculations. A variety of resolutions facilitates research on spatial and temporal scales relevant to problems ranging from hourly changes in air quality to trace gas trends in a changing climate. Samples of recent GEOS chemistry applications are provided.

  8. Rapid islanding detection using multi-level inverter for grid-interactive PV system

    International Nuclear Information System (INIS)

    Tsang, K.M.; Chan, W.L.

    2014-01-01

    Graphical abstract: - Highlights: • Novel reference signal is used to form an islanding detection scheme for PV system. • Supply fixed magnitude sinusoidal signal even if utility grid is disconnected. • Seamless transfer between grid-connected and stand-alone modes is possible. - Abstract: A novel reference signal generator is combined with a multi-level inverter to form a rapid islanding detection scheme for grid-interactive PV system. The reference signal generator can easily be synchronized with the utility grid signal and produced a fixed magnitude and very low total harmonic distortion (THD) sinusoidal signal which is in phase with the utility grid signal. Unlike conventional phase-locked loop (PLL) circuitry, the reference signal generator can also provide a fixed magnitude sinusoidal signal even if the utility grid is disconnected and automatically re-synchronous with the grid rapidly. Consequently, seamless transfer between grid-connected and stand-alone modes could easily be achieved if anti-islanding protection is not required. If a saturation element is applied to the raw reference signal followed by the synthesis of the truncated signal using a multi-level inverter, the distinct flat-top feature of the synthesized signal can quickly and easily be identified if the network is in islanding mode at the point of common coupling. Experimental results are included to demonstrate the effectiveness of the proposed detection scheme

  9. Suggested Grid Code Modifications to Ensure Wide-Scale Adoption of Photovoltaic Energy in Distributed Power Generation Systems

    DEFF Research Database (Denmark)

    Yang, Yongheng; Enjeti, Prasad; Blaabjerg, Frede

    2013-01-01

    Current grid standards seem to largely require low power (e.g. several kilowatts) single-phase photovoltaic (PV) systems to operate at unity power factor with maximum power point tracking, and disconnect from the grid under grid faults. However, in case of a wide-scale penetration of single......-phase PV systems in the distributed grid, the disconnection under grid faults can contribute to: a) voltage flickers, b) power outages, and c) system instability. In this paper, grid code modifications are explored for wide-scale adoption of PV systems in the distribution grid. More recently, Italy...... and Japan, have undertaken a major review of standards for PV power conversion systems connected to low voltage networks. In view of this, the importance of low voltage ride-through for single-phase PV power systems under grid faults along with reactive power injection is studied in this paper. Three...

  10. Modeling and power system stability of VSC-HVDC systems for grid-connection of large offshore windfarms

    Energy Technology Data Exchange (ETDEWEB)

    Xue Yijing [Vestas China, Beijing (China); Akhmatov, Vladislav [Technical Univ. of Denmark, Lyngby (Denmark). Centre for Electric Technology

    2009-07-01

    Utilization of Voltage Source Converter (VSC) - High Voltage Direct Current (HVDC) systems for grid-connection of large offshore windfarms becomes relevant as installed power capacities as well as distances to the connection points of on-land transmission systems increase. At the same time, the grid code requirements of the Transmission System Operators (TSO), including ancillary system services and Low-Voltage Fault-Ride-Through (LVFRT) capability of large offshore windfarms, become more demanding. This paper presents a general-level model of and a LVFRT solution for a VSC-HVDC system for grid-connection of large offshore windfarms. The VSC-HVDC model is implemented using a general approach of independent control of active and reactive power in normal operations. The on-land VSC inverter, i.e. a grid-side inverter, provides voltage support to the transmission system and comprises a LVFRT solution in short-circuit faults. The presented model, LVFRT solution and impact on the system stability are investigated as a case study of a 1,000 MW offshore windfarm grid-connected through a VSC-HVDC system. The investigation is carried out on a model of the west Danish, with some elements of the north German, 400 kV, 220 kV and 150 kV transmission systems stage 2005-2006 using the DIgSILENT PowerFactory simulation program. In the investigation, a thermal power plant just south to the Danish border has been substituted by this 1,000 MW offshore windfarm utilizing the VSC-HVDC system. The investigation has shown that the substitution of a thermal power plant by a VSC-HVDC connected offshore windfarm should not have any negative impact on the short-term stability of the west Danish transmission system. The investigation should be repeated applying updated system model stages and offshore wind power commissioning schedules in the North and Baltic Seas. (orig.)

  11. A software application for energy flow simulation of a grid connected photovoltaic system

    International Nuclear Information System (INIS)

    Hamad, Ayman A.; Alsaad, Mohammad A.

    2010-01-01

    A computer software application was developed to simulate hourly energy flow of a grid connected photovoltaic system. This software application enables conducting an operational evaluation of a studied photovoltaic system in terms of energy exchange with the electrical grid. The system model consists of a photovoltaic array, a converter and an optional generic energy storage component that supports scheduled charging/discharging. In addition to system design parameters, the software uses hourly solar data and hourly load data to determine the amount of energy exchanged with electrical grid for each hour of the simulated year. The resulting information is useful in assessing the impact of the system on demand for electrical energy of a building that uses it. The software also aggregates these hourly results in daily, monthly and full year sums. The software finds the financial benefit of the system as the difference in grid electrical energy cost between two simultaneously considered cases. One is with load supplied only by the electrical grid, while the other is with the photovoltaic system present and contributing energy. The software supports the energy pricing scheme used in Jordan for domestic consumers, which is based on slices of monthly consumption. By projecting the yearly financial results on the system lifetime, the application weighs the financial benefit resulting from using the system against its cost, thus facilitating an economical evaluation.

  12. Phase-lock loop of Grid-connected Voltage Source Converter under non-ideal grid condition

    DEFF Research Database (Denmark)

    Wang, Haojie; Sun, Hai; Han, Minxiao

    2015-01-01

    It is a normal practice that the DC micro-grid is connected to AC main grid through Grid-connected Voltage Source Converter (G-VSC) for voltage support. Accurate control of DC micro-grid voltage is difficult for G-VSC under unbalanced grid condition as the fundamental positive-sequence component...... and distorted system voltage the proposed PLL can accurately detect the fundamental positive-sequence component of grid voltage thus accurate control of DC micro-grid voltage can be realized....... phase information cannot be accurately tracked. Based on analysis of the cause of double-frequency ripple when unbalance exists in main grid, a phase-locked loop (PLL) detection technique is proposed. Under the conditions of unsymmetrical system voltage, varying system frequency, single-phase system...

  13. Grid3: An Application Grid Laboratory for Science

    CERN Multimedia

    CERN. Geneva

    2004-01-01

    level services required by the participating experiments. The deployed infrastructure has been operating since November 2003 with 27 sites, a peak of 2800 processors, work loads from 10 different applications exceeding 1300 simultaneous jobs, and data transfers among sites of greater than 2 TB/day. The Grid3 infrastructure was deployed from grid level services provided by groups and applications within the collaboration. The services were organized into four distinct "grid level services" including: Grid3 Packaging, Monitoring and Information systems, User Authentication and the iGOC Grid Operatio...

  14. Experimental evaluation of 8kW grid-connected photovoltaic system in Egypt

    OpenAIRE

    Elkholy, A.; Fahmy, F.H.; Abou El-Ela, A.A.; Nafeh, Abd El-Shafy A.; Spea, S.R.

    2016-01-01

    An experimental observation study of 8 kW grid-connected photovoltaic (PV) system that is installed at Electronics Research Institute (ERI), Giza, Egypt (Latitude 30.04°N, Longitude 31.21°E), is presented. This study includes the quality of the electrical power generated and injected into the network. The considered system consists of 28 × 295 Wp multicrystalline PV modules, StecaGrid three-phase 8 kW grid-connected inverter and a Solar-Log 300 PM+ for data acquisition and remote monitoring. ...

  15. Research on simulated devices for Solar photovoltaic grid-connected generation system

    Directory of Open Access Journals (Sweden)

    quan-zhu Zhang

    2017-01-01

    Full Text Available On the standpoint of energy conservation and emission reduction, one device simulated photovoltaic grid-connected generation system based on SPWM was designed in the paper. And DC/AC inverter could transduce efficiently direct current to alternating current. The MCU(Micro-Control-Unit, in this system could achieve the control method for maximum-power-point and tracking for frequency and phase. Moreover, the MCU could implement PWM (Plus-Width Modulating through programming. The system showed clearly the whole photovoltaic grid-connected generation system using simulated methods and ways.

  16. Global Change and the Earth System

    Science.gov (United States)

    Pollack, Henry N.

    2004-08-01

    The Earth system in recent years has come to mean the complex interactions of the atmosphere, biosphere, lithosphere and hydrosphere, through an intricate network of feedback loops. This system has operated over geologic time, driven principally by processes with long time scales. Over the lifetime of the solar system, the Sun has slowly become more radiant, and the geography of continents and oceans basins has evolved via plate tectonics. This geography has placed a first-order constraint on the circulation of ocean waters, and thus has strongly influenced regional and global climate. At shorter time scales, the Earth system has been influenced by Milankovitch orbital factors and occasional exogenous events such as bolide impacts. Under these influences the system chugged along for eons, until some few hundred thousand years ago, when one remarkable species evolved: Homo sapiens. As individuals, humans are of course insignificant in shaping the Earth system, but collectively the six billion human occupants of the planet now rival ``natural'' processes in modifying the Earth system. This profound human influence underlies the dubbing of the present epoch of geologic history as the ``Anthropocene.''

  17. Comparison of publically available Moho depth and crustal thickness grids with newly derived grids by 3D gravity inversion for the High Arctic region.

    Science.gov (United States)

    Lebedeva-Ivanova, Nina; Gaina, Carmen; Minakov, Alexander; Kashubin, Sergey

    2016-04-01

    We derived Moho depth and crustal thickness for the High Arctic region by 3D forward and inverse gravity modelling method in the spectral domain (Minakov et al. 2012) using lithosphere thermal gravity anomaly correction (Alvey et al., 2008); a vertical density variation for the sedimentary layer and lateral crustal variation density. Recently updated grids of bathymetry (Jakobsson et al., 2012), gravity anomaly (Gaina et al, 2011) and dynamic topography (Spasojevic & Gurnis, 2012) were used as input data for the algorithm. TeMAr sedimentary thickness grid (Petrov et al., 2013) was modified according to the most recently published seismic data, and was re-gridded and utilized as input data. Other input parameters for the algorithm were calibrated using seismic crustal scale profiles. The results are numerically compared with publically available grids of the Moho depth and crustal thickness for the High Arctic region (CRUST 1 and GEMMA global grids; the deep Arctic Ocean grids by Glebovsky et al., 2013) and seismic crustal scale profiles. The global grids provide coarser resolution of 0.5-1.0 geographic degrees and not focused on the High Arctic region. Our grids better capture all main features of the region and show smaller error in relation to the seismic crustal profiles compare to CRUST 1 and GEMMA grids. Results of 3D gravity modelling by Glebovsky et al. (2013) with separated geostructures approach show also good fit with seismic profiles; however these grids cover the deep part of the Arctic Ocean only. Alvey A, Gaina C, Kusznir NJ, Torsvik TH (2008). Integrated crustal thickness mapping and plate recon-structions for the high Arctic. Earth Planet Sci Lett 274:310-321. Gaina C, Werner SC, Saltus R, Maus S (2011). Circum-Arctic mapping project: new magnetic and gravity anomaly maps of the Arctic. Geol Soc Lond Mem 35, 39-48. Glebovsky V.Yu., Astafurova E.G., Chernykh A.A., Korneva M.A., Kaminsky V.D., Poselov V.A. (2013). Thickness of the Earth's crust in the

  18. Optimizing Resource Utilization in Grid Batch Systems

    International Nuclear Information System (INIS)

    Gellrich, Andreas

    2012-01-01

    On Grid sites, the requirements of the computing tasks (jobs) to computing, storage, and network resources differ widely. For instance Monte Carlo production jobs are almost purely CPU-bound, whereas physics analysis jobs demand high data rates. In order to optimize the utilization of the compute node resources, jobs must be distributed intelligently over the nodes. Although the job resource requirements cannot be deduced directly, jobs are mapped to POSIX UID/GID according to the VO, VOMS group and role information contained in the VOMS proxy. The UID/GID then allows to distinguish jobs, if users are using VOMS proxies as planned by the VO management, e.g. ‘role=production’ for Monte Carlo jobs. It is possible to setup and configure batch systems (queuing system and scheduler) at Grid sites based on these considerations although scaling limits were observed with the scheduler MAUI. In tests these limitations could be overcome with a home-made scheduler.

  19. Benchmarking of Constant Power Generation Strategies for Single-Phase Grid-Connected Photovoltaic Systems

    DEFF Research Database (Denmark)

    Sangwongwanich, Ariya; Yang, Yongheng; Blaabjerg, Frede

    2016-01-01

    With a still increase of grid-connected Photovoltaic (PV) systems, challenges have been imposed on the grid due to the continuous injection of a large amount of fluctuating PV power, like overloading the grid infrastructure (e.g., transformers) during peak power production periods. Hence, advanced...

  20. Power systems signal processing for smart grids

    CERN Document Server

    Ribeiro, Paulo Fernando; Ribeiro, Paulo Márcio; Cerqueira, Augusto Santiago

    2013-01-01

    With special relation to smart grids, this book provides clear and comprehensive explanation of how Digital Signal Processing (DSP) and Computational Intelligence (CI) techniques can be applied to solve problems in the power system. Its unique coverage bridges the gap between DSP, electrical power and energy engineering systems, showing many different techniques applied to typical and expected system conditions with practical power system examples. Surveying all recent advances on DSP for power systems, this book enables engineers and researchers to understand the current state of the art a

  1. Grid integration and smart grid implementation of emerging technologies in electric power systems through approximate dynamic programming

    OpenAIRE

    Xiao, Jingjie

    2013-01-01

    A key hurdle for implementing real-time pricing of electricity is a lack of con-sumers’ responses. Solutions to overcome the hurdle include the energy management system that automatically optimizes household appliance usage such as plug-in hybrid electric vehicle charging (and discharging with vehicle-to-grid) via a two-way com-munication with the grid. Real-time pricing, combined with household automation devices, has a potential to accommodate an increasing penetration of plug-in hybrid ele...

  2. Micro grids toward the smart grid

    International Nuclear Information System (INIS)

    Guerrero, J.

    2011-01-01

    Worldwide electrical grids are expecting to become smarter in the near future, with interest in Microgrids likely to grow. A microgrid can be defined as a part of the grid with elements of prime energy movers, power electronics converters, distributed energy storage systems and local loads, that can operate autonomously but also interacting with main grid. Thus, the ability of intelligent Microgrids to operate in island mode or connected to the grid will be a keypoint to cope with new functionalities and the integration of renewable energy resources. The functionalities expected for these small grids are: black start operation, frequency and voltage stability, active and reactive power flow control, active power filter capabilities, and storage energy management. In this presentation, a review of the main concepts related to flexible Microgrids will be introduced, with examples of real Microgrids. AC and DC Microgrids to integrate renewable and distributed energy resources will also be presented, as well as distributed energy storage systems, and standardization issues of these Microgrids. Finally, Microgrid hierarchical control will be analyzed looking at three different levels: i) a primary control based on the droop method, including an output impedance virtual loop; ii) a secondary control, which enables restoring any deviations produced by the primary control; and iii) a tertiary control to manage the power flow between the microgrid and the external electrical distribution system.

  3. SCALEA-G: A Unified Monitoring and Performance Analysis System for the Grid

    Directory of Open Access Journals (Sweden)

    Hong-Linh Truong

    2004-01-01

    Full Text Available This paper describes SCALEA-G, a unified monitoring and performance analysis system for the Grid. SCALEA-G is implemented as a set of grid services based on the Open Grid Services Architecture (OGSA. SCALEA-G provides an infrastructure for conducting online monitoring and performance analysis of a variety of Grid services including computational and network resources, and Grid applications. Both push and pull models are supported, providing flexible and scalable monitoring and performance analysis. Source code and dynamic instrumentation are implemented to perform profiling and monitoring of Grid applications. A novel instrumentation request language for dynamic instrumentation and a standardized intermediate representation for binary code have been developed to facilitate the interaction between client and instrumentation services.

  4. Grid Integration Research | Wind | NREL

    Science.gov (United States)

    Grid Integration Research Grid Integration Research Researchers study grid integration of wind three wind turbines with transmission lines in the background. Capabilities NREL's grid integration electric power system operators to more efficiently manage wind grid system integration. A photo of

  5. Real-Time Business Intelligence in the MIRABEL Smart Grid System

    DEFF Research Database (Denmark)

    Fischer, Ulrike; Kaulakiene, Dalia; Khalefa, Mohamed

    2012-01-01

    of energy related data, and must be able to react rapidly (but intelligently) when conditions change, leading to substantial real-time business intelligence challenges. This paper discusses these challenges and presents data management solutions in the European smart grid project MIRABEL. These solutions......) data. Experimental studies show that the proposed solutions support important real-time business intelligence tasks in a smart grid system....

  6. Grid-connected photovoltaic system design for local government ...

    African Journals Online (AJOL)

    Grid-connected photovoltaic system design for local government offices in Nigeria. ... Nigerian Journal of Technology. Journal Home ... It is neat, silent and elegant process of generating electric power in environmentally friendly manner. In this ...

  7. NASA's Earth Observing System Data and Information System - EOSDIS

    Science.gov (United States)

    Ramapriyan, Hampapuram K.

    2011-01-01

    This slide presentation reviews the work of NASA's Earth Observing System Data and Information System (EOSDIS), a petabyte-scale archive of environmental data that supports global climate change research. The Earth Science Data Systems provide end-to-end capabilities to deliver data and information products to users in support of understanding the Earth system. The presentation contains photographs from space of recent events, (i.e., the effects of the tsunami in Japan, and the wildfires in Australia.) It also includes details of the Data Centers that provide the data to EOSDIS and Science Investigator-led Processing Systems. Information about the Land, Atmosphere Near-real-time Capability for EOS (LANCE) and some of the uses that the system has made possible are reviewed. Also included is information about how to access the data, and evolutionary plans for the future of the system.

  8. A Thermal grid coordinated by a Multi Agent Energy Management System

    NARCIS (Netherlands)

    Pruissen, O.P. van; Kamphuis, V.; Togt, A. van der; Werkman, E.

    2013-01-01

    In the near future an increase of both thermal grids and sustainable suppliers of heat with intermittency behavior, connected to these heat grids, is expected. For smart operation this challenges the current centralized management systems. To deal with this and to optimize cost and energy efficiency

  9. Smart grid in Denmark 2.0. Implementing three key recommendations from the Smart Grid Network. [DanGrid]; Smart Grid i Danmark 2.0. Implementering af tre centrale anbefalinger fra Smart Grid netvaerket

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-11-01

    In 2011 the Smart Grid Network, established by the Danish Climate and Energy minister in 2010, published a report which identifies 35 recommendations for implementing smart grid in Denmark. The present report was prepared by the Danish Energy Association and Energinet.dk and elaborates three of these recommendations: Concept for controlling the power system; Information model for the dissemination of data; Roadmap for deployment of smart grid. Concept of Smart Grid: The concept mobilizes and enables electric power demand response and production from smaller customers. This is done by customers or devices connected to the power system modify their behavior to meet the needs of the power system. The concept basically distinguishes between two different mechanisms to enable flexibility. One is the use of price signals (variable network tariffs and electricity prices), which gives customers a financial incentive to move their electricity consumption and production to times when it is of less inconvenience to the power system. The second is flexibility products, where a pre-arranged and well-specified performance - for example, a load reduction in a defined network area - can be activated as required by grid operators and / or Energinet.dk at an agreed price. Information Model for Disseminating Data: The future power system is complex with a large number of physical units, companies and individuals are actively involved in the power system. Similarly, the amount of information needed to be collected, communicated and processed grows explosively, and it is therefore essential to ensure a well-functioning IT infrastructure. A crucial element is a standardized information model in the Danish power system. The concept therefore indicates to use international standards to define an information model. Roadmap Focusing on Grid Companies' Role: There is a need to remove two key barriers. The first barrier is that the existing regulation does not support the grid using

  10. Implementation of a Wind Farm Turbine Control System with Short-Term Grid Faults Management

    DEFF Research Database (Denmark)

    Marra, Francesco; Rasmussen, Tonny Wederberg; Garcia-Valle, Rodrigo

    2010-01-01

    restrictions for the wind turbines behavior especially under grid faults. Wind turbines are requested to stay connected even during faults. These new requirements are challenging the control of the wind turbines and new control strategies are required to meet the target. This paper dealt...... with the implementation of a control strategy in order to stay connected under grid faults. The method aimed to ensure that a wind farm turbine remains connected and no electric power is delivered to the grid during the fault period. The overall system was modelled and simulated by using the software Matlab/Simulink.......The increased penetration of wind power in the grid has led to important technical barriers that limit the development, where the stability of the system plays a key issue. Grid operators in different countries are issuing new grid requirements, the so-called grid codes that impose more...

  11. Decentralized electricity generation by using photovoltaic grid-connected solar system

    International Nuclear Information System (INIS)

    Tyutyundziev, N.; Vitanov, P.; Radkov, R.; Grottke, M.

    2006-01-01

    AcadPV is the first demonstration installation connected permanently to LV grid in Sofia, Bulgaria aiming at assessment of PV efficiencies and cost-effectiveness. A thorough analysis has been carried out in order to select PV system site, supporting construction design and orientation. The PV generator is divided to 3 PV subfields equipped by 3 SUNPOWER inverters connected to 3 separated phases of the grid. The performance of 10kWp PV system has been evaluated during the first year of operation and compared to PV simulation software results

  12. Danish experiments with a grid system tested in the North Sea shrimp fishery

    DEFF Research Database (Denmark)

    Madsen, Niels; Hansen, K.E.

    2001-01-01

    can retain marketable catches of roundfish and Norway lobster (Nephrops norvegicus). The grid system was made of polyamide with a fish escape hole at the top and a Norway lobster escape hole at the bottom. Hinges made the grid flexible. The grid system was developed acid tested in a flume tank......), haddock (Melanogrammus aeglefinus). whiting (Merlangius merlangus), saithe (Pollachius virens), Norway pout (Trisopterus esmarki). Norway lobster, herring (Clupea harengus) and witch (Glyptocephalus cynoglossus) but no significant difference in weight of shrimp and monkfish (Lophius piscatorius......) in the first experiment. The grid system was altered in experiment 2 resulting in no significant difference in the catch of cod and saithe above the minimum landing size while the catch of Norway lobster and shrimp improved significantly. Experiments with collecting bags indicated that most fish went through...

  13. Global Earth Observation System of Systems: Characterizing Uncertainties of Space- based Measurements and Earth System Models Informing Decision Tools

    Science.gov (United States)

    Birk, R. J.; Frederick, M.

    2006-05-01

    The Global Earth Observation System of Systems (GEOSS) framework identifies the benefits of systematically and scientifically networking the capacity of organizations and systems into solutions that benefit nine societal benefit areas. The U.S. Integrated Earth Observation System (IEOS), the U.S. contribution to the GEOSS, focuses on near-term, mid-term, and long-term opportunities to establish integrated system solutions based on capacities and capabilities of member agencies and affiliations. Scientists at NASA, NOAA, DOE, NSF and other U.S. agencies are evolving the predictive capacity of models of Earth processes based on space-based, airborne and surface-based instruments and their measurements. NASA research activities include advancing the power and accessibility of computational resources (i.e. Project Columbia) to enable robust science data analysis, modeling, and assimilation techniques to rapidly advance. The integration of the resulting observations and predictions into decision support tools require characterization of the accuracies of a range of input measurements includes temperature and humidity profiles, wind speed, ocean height, sea surface temperature, and atmospheric constituents that are measured globally by U.S. deployed spacecraft. These measurements are stored in many data formats on many different information systems with widely varying accessibility and have processes whose documentation ranges from extremely detailed to very minimal. Integrated and interdisciplinary modeling (enabled by the Earth System Model Framework) enable the types of ensemble analysis that are useful for decision processes associated with energy management, public health risk assessments, and optimizing transportation safety and efficiency. Interdisciplinary approaches challenge systems integrators (both scientists and engineers) to expand beyond the traditional boundaries of particular disciplines to develop, verify and validate, and ultimately benchmark the

  14. Grid-connection of offshore wind farms using VSC-HVDC systems

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Xiaofan; Dessaint, Louis A. [Ecole de Technologie Superieure, Montreal, QC (Canada). Dept. of Electrical Engineering; Gagnon, Richard [Hydro-Quebec Research Institute, Montreal, QC (Canada)

    2011-07-01

    In this paper, the structure of variable speed PMSG-based offshore wind farms connected to the grid through VSC-HVDC link is presented. And the system models are developed. Also, the corresponding control strategy for this system is proposed. The control objective of the generator side VSC is to achieve the optimal wind power by adjusting the speed of permanent magnet synchronous generator, while the grid side VSC is to maintain DC voltage constant. Furthermore, a case study of 100MW offshore wind farm consisting of 50 individual 2MW PSMG-based wind turbines is developed in MATLAB/SimPowerSystems. Simulation results show the proposed scheme works well. (orig.)

  15. Shining examples of grid applications

    CERN Multimedia

    Hammerle, Hannelore

    2006-01-01

    Users in more than 150 virtual organisations from fields as diverse as biomedicine, earth Sciences and high-energy physics are now using the distributed computing infrastructure of the enabling grids for E-sciencE (EGEE) project, which shows the wide adoption and versatiblity of this new technology (1 page)

  16. Probabilistic Modelling of Robustness and Resilience of Power Grid Systems

    DEFF Research Database (Denmark)

    Qin, Jianjun; Sansavini, Giovanni; Nielsen, Michael Havbro Faber

    2017-01-01

    The present paper proposes a framework for the modeling and analysis of resilience of networked power grid systems. A probabilistic systems model is proposed based on the JCSS Probabilistic Model Code (JCSS, 2001) and deterministic engineering systems modeling techniques such as the DC flow model...... cascading failure event scenarios (Nan and Sansavini, 2017). The concept of direct and indirect consequences proposed by the Joint Committee on Structural Safety (JCSS, 2008) is utilized to model the associated consequences. To facilitate a holistic modeling of robustness and resilience, and to identify how...... these characteristics may be optimized these characteristics, the power grid system is finally interlinked with its fundamental interdependent systems, i.e. a societal model, a regulatory system and control feedback loops. The proposed framework is exemplified with reference to optimal decision support for resilience...

  17. Mapping of grid faults and grid codes

    DEFF Research Database (Denmark)

    Iov, F.; Hansen, Anca Daniela; Sørensen, Poul Ejnar

    loads of wind turbines. The goal is also to clarify and define possible new directions in the certification process of power plant wind turbines, namely wind turbines, which participate actively in the stabilisation of power systems. Practical experience shows that there is a need...... challenges for the design of both the electrical system and the mechanical structure of wind turbines. An overview over the frequency of grid faults and the grid connection requirements in different relevant countries is done in this report. The most relevant study cases for the quantification of the loads......The present report is a part of the research project ''Grid fault and designbasis for wind turbine'' supported by Energinet.dk through the grant PSO F&U 6319. The objective of this project is to investigate into the consequences of the new grid connection requirements for the fatigue and extreme...

  18. Wind energy management for smart grids with storage systems

    Energy Technology Data Exchange (ETDEWEB)

    Gasco, Manuel [Universidad de Alicante (Spain). Area de Ingenieria Electrica; Rios, Alberto [Universidad Europea de Madrid (Spain). Area de Ingenieria Electrica

    2012-07-01

    Increasing integration of wind energy into the power system makes the optimal management of different situations that can occur more and more important. The objective of the present study is to replace the power necessary for electrical feed when the wind resources are not available, and to make a continuous demand tracking of the power. The energy storage systems treated in this study are as follows: a fuel cell, flywheel, pump systems and turbine systems, compressed air systems, electrochemical cells, electric vehicles, supercapacitors and superconductors. As a result the maximum benefit of the smart grid is achieved and it includes coexistence of the energy storage systems described and integrated in the numerous microgrids which can form the distribution grid. The current capacity is observed in order to be able to manage the wind generation for short periods of time. This way it is possible to plan the production which would be adjusted to the variations through these storage systems allowing the systems to maintain their constant programming for the base plants, adjusting the variations in these systems in the short term. (orig.)

  19. A novel grid multiwing chaotic system with only non-hyperbolic equilibria

    Science.gov (United States)

    Zhang, Sen; Zeng, Yicheng; Li, Zhijun; Wang, Mengjiao; Xiong, Le

    2018-05-01

    The structure of the chaotic attractor of a system is mainly determined by the nonlinear functions in system equations. By using a new saw-tooth wave function and a new stair function, a novel complex grid multiwing chaotic system which belongs to non-Shil'nikov chaotic system with non-hyperbolic equilibrium points is proposed in this paper. It is particularly interesting that the complex grid multiwing attractors are generated by increasing the number of non-hyperbolic equilibrium points, which are different from the traditional methods of realising multiwing attractors by adding the index-2 saddle-focus equilibrium points in double-wing chaotic systems. The basic dynamical properties of the new system, such as dissipativity, phase portraits, the stability of the equilibria, the time-domain waveform, power spectrum, bifurcation diagram, Lyapunov exponents, and so on, are investigated by theoretical analysis and numerical simulations. Furthermore, the corresponding electronic circuit is designed and simulated on the Multisim platform. The Multisim simulation results and the hardware experimental results are in good agreement with the numerical simulations of the same system on Matlab platform, which verify the feasibility of this new grid multiwing chaotic system.

  20. Design of investment management optimization system for power grid companies under new electricity reform

    Science.gov (United States)

    Yang, Chunhui; Su, Zhixiong; Wang, Xin; Liu, Yang; Qi, Yongwei

    2017-03-01

    The new normalization of the economic situation and the implementation of a new round of electric power system reform put forward higher requirements to the daily operation of power grid companies. As an important day-to-day operation of power grid companies, investment management is directly related to the promotion of the company's operating efficiency and management level. In this context, the establishment of power grid company investment management optimization system will help to improve the level of investment management and control the company, which is of great significance for power gird companies to adapt to market environment changing as soon as possible and meet the policy environment requirements. Therefore, the purpose of this paper is to construct the investment management optimization system of power grid companies, which includes investment management system, investment process control system, investment structure optimization system, and investment project evaluation system and investment management information platform support system.

  1. Does Your Domestic Photovoltaic Energy System Survive Grid Outages?

    Directory of Open Access Journals (Sweden)

    Marijn R. Jongerden

    2016-09-01

    Full Text Available Domestic renewable energy systems, including photovoltaic energy generation, as well as local storage, are becoming increasingly popular and economically feasible, but do come with a wide range of options. Hence, it can be difficult to match their specification to specific customer’s needs. Next to the usage-specific demand profiles and location-specific production profiles, local energy storage through the use of batteries is becoming increasingly important, since it allows one to balance variations in production and demand, either locally or via the grid. Moreover, local storage can also help to ensure a continuous energy supply in the presence of grid outages, at least for a while. Hybrid Petri net (HPN models allow one to analyze the effect of different battery management strategies on the continuity of such energy systems in the case of grid outages. The current paper focuses on one of these strategies, the so-called smart strategy, that reserves a certain percentage of the battery capacity to be only used in case of grid outages. Additionally, we introduce a new strategy that makes better use of the reserved backup capacity, by reducing the demand in the presence of a grid outage through a prioritization mechanism. This new strategy, called power-save, only allows the essential (high-priority demand to draw from the battery during power outages. We show that this new strategy outperforms previously-proposed strategies through a careful analysis of a number of scenarios and for a selection of survivability measures, such as minimum survivability per day, number of survivable hours per day, minimum survivability per year and various survivability quantiles.

  2. Greening the Grid - Advancing Solar, Wind, and Smart Grid Technologies (Spanish Version)

    Energy Technology Data Exchange (ETDEWEB)

    2016-04-01

    This is the Spanish version of 'Greening the Grid - Advancing Solar, Wind, and Smart Grid Technologies'. Greening the Grid provides technical assistance to energy system planners, regulators, and grid operators to overcome challenges associated with integrating variable renewable energy into the grid.

  3. Earth Observing System Covariance Realism Updates

    Science.gov (United States)

    Ojeda Romero, Juan A.; Miguel, Fred

    2017-01-01

    This presentation will be given at the International Earth Science Constellation Mission Operations Working Group meetings June 13-15, 2017 to discuss the Earth Observing System Covariance Realism updates.

  4. The computational challenges of Earth-system science.

    Science.gov (United States)

    O'Neill, Alan; Steenman-Clark, Lois

    2002-06-15

    The Earth system--comprising atmosphere, ocean, land, cryosphere and biosphere--is an immensely complex system, involving processes and interactions on a wide range of space- and time-scales. To understand and predict the evolution of the Earth system is one of the greatest challenges of modern science, with success likely to bring enormous societal benefits. High-performance computing, along with the wealth of new observational data, is revolutionizing our ability to simulate the Earth system with computer models that link the different components of the system together. There are, however, considerable scientific and technical challenges to be overcome. This paper will consider four of them: complexity, spatial resolution, inherent uncertainty and time-scales. Meeting these challenges requires a significant increase in the power of high-performance computers. The benefits of being able to make reliable predictions about the evolution of the Earth system should, on their own, amply repay this investment.

  5. CoSimulating Communication Networks and Electrical System for Performance Evaluation in Smart Grid

    Directory of Open Access Journals (Sweden)

    Hwantae Kim

    2018-01-01

    Full Text Available In smart grid research domain, simulation study is the first choice, since the analytic complexity is too high and constructing a testbed is very expensive. However, since communication infrastructure and the power grid are tightly coupled with each other in the smart grid, a well-defined combination of simulation tools for the systems is required for the simulation study. Therefore, in this paper, we propose a cosimulation work called OOCoSim, which consists of OPNET (network simulation tool and OpenDSS (power system simulation tool. By employing the simulation tool, an organic and dynamic cosimulation can be realized since both simulators operate on the same computing platform and provide external interfaces through which the simulation can be managed dynamically. In this paper, we provide OOCoSim design principles including a synchronization scheme and detailed descriptions of its implementation. To present the effectiveness of OOCoSim, we define a smart grid application model and conduct a simulation study to see the impact of the defined application and the underlying network system on the distribution system. The simulation results show that the proposed OOCoSim can successfully simulate the integrated scenario of the power and network systems and produce the accurate effects of the networked control in the smart grid.

  6. Grid Computing Making the Global Infrastructure a Reality

    CERN Document Server

    Fox, Geoffrey C; Hey, Anthony J G

    2003-01-01

    Grid computing is applying the resources of many computers in a network to a single problem at the same time Grid computing appears to be a promising trend for three reasons: (1) Its ability to make more cost-effective use of a given amount of computer resources, (2) As a way to solve problems that can't be approached without an enormous amount of computing power (3) Because it suggests that the resources of many computers can be cooperatively and perhaps synergistically harnessed and managed as a collaboration toward a common objective. A number of corporations, professional groups, university consortiums, and other groups have developed or are developing frameworks and software for managing grid computing projects. The European Community (EU) is sponsoring a project for a grid for high-energy physics, earth observation, and biology applications. In the United States, the National Technology Grid is prototyping a computational grid for infrastructure and an access grid for people. Sun Microsystems offers Gri...

  7. Online grid impedance estimation for single-phase grid-connected systems using PQ variations

    DEFF Research Database (Denmark)

    Ciobotaru, Mihai; Teodorescu, Remus; Rodriguez, Pedro

    2007-01-01

    algorithms are used in order to estimate the value of the grid impedance. The online grid impedance estimation method can be used for compliance with the anti-islanding standard requirements (IEEE1574, IEEE929 and VDE0126) and for adaptive control of the grid-connected converters. The proposed method...

  8. Operation and control of a DC-grid offshore wind farm under DC transmission system faults

    DEFF Research Database (Denmark)

    Deng, Fujin; Chen, Zhe

    2013-01-01

    . Consequently, the protection and control strategies of dc systems need to be established. This paper studies a dc-grid offshore wind farm, where the wind power collection system and power transmission system adopt dc technology. In this paper, the redundancy of the HVDC transmission system under faults...... is studied, and a fault ridethrough strategy for the dc-grid offshore wind farm is proposed. The proposed strategy can effectively minimize the impacts of the power transmission system disturbance on the offshore wind farm, and on the ac grid. A dc-grid offshore wind farm example is simulated with PSCAD....../EMTDC, and the results validate the feasibility of the presented redundancy configuration and operation approach, and the fault ridethrough control strategy....

  9. A Generic Danish Distribution Grid Model for Smart Grid Technology Testing

    DEFF Research Database (Denmark)

    Cha, Seung-Tae; Wu, Qiuwei; Østergaard, Jacob

    2012-01-01

    This paper describes the development of a generic Danish distribution grid model for smart grid technology testing based on the Bornholm power system. The frequency dependent network equivalent (FDNE) method has been used in order to accurately preserve the desired properties and characteristics...... as a generic Smart Grid benchmark model for testing purposes....... by comparing the transient response of the original Bornholm power system model and the developed generic model under significant fault conditions. The results clearly show that the equivalent generic distribution grid model retains the dynamic characteristics of the original system, and can be used...

  10. Design and installation of earth energy systems

    Energy Technology Data Exchange (ETDEWEB)

    Loggia, S; Adragna, M; Coyle, S; Foley, C; Hawryn, S; Martin, A; McConnell, J [eds.

    2002-07-01

    This first edition of the Canadian Standards Association (CSA) Standard C448 Series, replaces CSA Standards CAN/CSA-C445-M92 entitled Design and Installation of Earth Energy Heat Pump Systems for Residential and Other Small Buildings, as well as C447-94 entitled Design and Installation of Earth Energy Heat Pump Systems for Commercial and Institutional Buildings. This standard document consists of three parts: (C448.1) Design and installation of earth energy systems for commercial and institutional buildings; (C448.2) Design and installation of earth energy systems for residential and small buildings; and, (C448.3) Design and installation of underground thermal energy storage systems for commercial and institutional buildings. In C448.1, the requirements applicable to any system falling within the scope of the C448 series were included. Alternative requirements for houses and small buildings were added in C448.2. It was noted that either standard may be implemented. The standards applicable to the intentional storage of energy in the earth for later use were presented in C448.3. This latter section includes a brief introduction on underground thermal energy storage (UTES). tabs.

  11. Advanced Platform for Development and Evaluation of Grid Interconnection Systems Using Hardware-in-the-Loop: Part III -- Grid Interconnection System Evaluator: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Lundstrom, B.; Shirazi, M.; Coddington, M.; Kroposki, B.

    2013-01-01

    This paper, presented at the IEEE Green Technologies Conference 2013, describes a Grid Interconnection System Evaluator (GISE) that leverages hardware-in-the-loop (HIL) simulation techniques to rapidly evaluate the grid interconnection standard conformance of an ICS according to the procedures in IEEE Std 1547.1 (TM). The architecture and test sequencing of this evaluation tool, along with a set of representative ICS test results from three different photovoltaic (PV) inverters, are presented. The GISE adds to the National Renewable Energy Laboratory's (NREL) evaluation platform that now allows for rapid development of ICS control algorithms using controller HIL (CHIL) techniques, the ability to test the dc input characteristics of PV-based ICSs through the use of a PV simulator capable of simulating real-world dynamics using power HIL (PHIL), and evaluation of ICS grid interconnection conformance.

  12. Policy incentives and grid-connected photovoltaics system development in China

    Energy Technology Data Exchange (ETDEWEB)

    Wang Jing; Xu Yugao

    2007-07-01

    China has made considerable progress in solar PV generation technology. However, compared with conventional generation technologies or even other renewables such as wind and biomass, grid-connected PV technology is in its early stage and has not reached an adequate level of economic performance. Therefore, policy incentives will play important roles in attracting more social investments to facilitate the development of grid-connected PV generation. This paper is focused on analyzing the role of incentive policies in enhancing the market competitiveness of grid-connected solar PV systems in the context of China with an economic model and some policy suggestions are given based on simulation modeling efforts. (auth)

  13. Earth System Science Education Interdisciplinary Partnerships

    Science.gov (United States)

    Ruzek, M.; Johnson, D. R.

    2002-05-01

    Earth system science in the classroom is the fertile crucible linking science with societal needs for local, national and global sustainability. The interdisciplinary dimension requires fruitful cooperation among departments, schools and colleges within universities and among the universities and the nation's laboratories and agencies. Teaching and learning requires content which brings together the basic and applied sciences with mathematics and technology in addressing societal challenges of the coming decades. Over the past decade remarkable advances have emerged in information technology, from high bandwidth Internet connectivity to raw computing and visualization power. These advances which have wrought revolutionary capabilities and resources are transforming teaching and learning in the classroom. With the launching of NASA's Earth Observing System (EOS) the amount and type of geophysical data to monitor the Earth and its climate are increasing dramatically. The challenge remains, however, for skilled scientists and educators to interpret this information based upon sound scientific perspectives and utilize it in the classroom. With an increasing emphasis on the application of data gathered, and the use of the new technologies for practical benefit in the lives of ordinary citizens, there comes the even more basic need for understanding the fundamental state, dynamics, and complex interdependencies of the Earth system in mapping valid and relevant paths to sustainability. Technology and data in combination with the need to understand Earth system processes and phenomena offer opportunities for new and productive partnerships between researchers and educators to advance the fundamental science of the Earth system and in turn through discovery excite students at all levels in the classroom. This presentation will discuss interdisciplinary partnership opportunities for educators and researchers at the undergraduate and graduate levels.

  14. Transmission grid security

    CERN Document Server

    Haarla, Liisa; Hirvonen, Ritva; Labeau, Pierre-Etienne

    2011-01-01

    In response to the growing importance of power system security and reliability, ""Transmission Grid Security"" proposes a systematic and probabilistic approach for transmission grid security analysis. The analysis presented uses probabilistic safety assessment (PSA) and takes into account the power system dynamics after severe faults. In the method shown in this book the power system states (stable, not stable, system breakdown, etc.) are connected with the substation reliability model. In this way it is possible to: estimate the system-wide consequences of grid faults; identify a chain of eve

  15. Sensorless Reserved Power Control Strategy for Two-Stage Grid-Connected Photovoltaic Systems

    DEFF Research Database (Denmark)

    Sangwongwanich, Ariya; Yang, Yongheng; Blaabjerg, Frede

    2016-01-01

    Due to still increasing penetration level of grid-connected Photovoltaic (PV) systems, advanced active power control functionalities have been introduced in grid regulations. A reserved power control, where the active power from the PV panels is reserved during operation, is required for grid...... support. In this paper, a cost-effective solution to realize the reserved power control for grid-connected PV systems is proposed. The proposed solution routinely employs a Maximum Power Point Tracking (MPPT) control to estimate the available PV power and a Constant Power Generation (CPG) control...... to achieve the power reserve. In this method, the irradiance measurements that have been used in conventional control schemes to estimate the available PV power are not required, and thereby being a sensorless solution. Simulations and experimental tests have been performed on a 3-kW two-stage single...

  16. The Representation of Tropical Cyclones Within the Global William Putman Non-Hydrostatic Goddard Earth Observing System Model (GEOS-5) at Cloud-Permitting Resolutions

    Science.gov (United States)

    Putman, William M.

    2010-01-01

    The Goddard Earth Observing System Model (GEOS-S), an earth system model developed in the NASA Global Modeling and Assimilation Office (GMAO), has integrated the non-hydrostatic finite-volume dynamical core on the cubed-sphere grid. The extension to a non-hydrostatic dynamical framework and the quasi-uniform cubed-sphere geometry permits the efficient exploration of global weather and climate modeling at cloud permitting resolutions of 10- to 4-km on today's high performance computing platforms. We have explored a series of incremental increases in global resolution with GEOS-S from irs standard 72-level 27-km resolution (approx.5.5 million cells covering the globe from the surface to 0.1 hPa) down to 3.5-km (approx. 3.6 billion cells).

  17. Requirements to be met by superconducting storage systems to satisfy the demands of grid operation

    International Nuclear Information System (INIS)

    Handschin, E.; Stoeber, P.

    1989-01-01

    Superconducting magnetic energy storage systems (SMES) permit functions and quality enhancements not achievable by conventional measures. A simulation of operating conditions using an SMES connected to the grid, SMES control being done by the control system of the grid, indicates considerable enhancements in the static and dynamic behaviour of the grid. Dimensioning of such an SMES will depend on the grid and the purpose of its application. A study investigating an SMES application for improvement of the dynamic behaviour, and back-up of the primary control, of a large power plant unit shows that the system can be designed and realized in the required dimensions. The operating interactions of the SMES and the grid are discussed in the conference paper. (orig.) [de

  18. Mapping of grid faults and grid codes

    DEFF Research Database (Denmark)

    Iov, Florin; Hansen, A.D.; Sørensen, P.

    loads of wind turbines. The goal is also to clarify and define possible new directions in the certification process of power plant wind turbines, namely wind turbines, which participate actively in the stabilisation of power systems. Practical experience shows that there is a need...... challenges for the design of both the electrical system and the mechanical structure of wind turbines. An overview over the frequency of grid faults and the grid connection requirements in different relevant countries is done in this report. The most relevant study cases for the quantification of the loads......The present report is a part of the research project "Grid fault and design basis for wind turbine" supported by Energinet.dk through the grant PSO F&U 6319. The objective of this project is to investigate into the consequences of the new grid connection requirements for the fatigue and extreme...

  19. Application of DC micro grids for integration of solar home systems in smart grids

    NARCIS (Netherlands)

    Alipuria, B.; Asare-Bediako, B.; Slootweg, J.G.; Kling, W.L.

    2013-01-01

    Smart Grids have been a prime focus of studies for the past few years on power systems. The goal is to make the power infrastructure more reliable and effective to cater for the needs of the future. Another goal for improving the power infrastructure is to incorporate renewable energy sources in an

  20. Smart Grid Research: Control Systems - IEEE Vision for Smart Grid Controls

    DEFF Research Database (Denmark)

    Aho, Jacob; Arnold, George; Buckspan, Andrew

    This document highlights the role of control systems in the evolution of the Smart Grid. It includes an overview of research investigations that are needed for renewable integration, reliability, self-healing, energy efficiency, and resilience to physical and cyber attacks. These investigations...... are encapsulated in several loci of control including: new methodologies for transmission, distribution, and renewable energy, and storage; new roles in emerging topics such as electricity markets, demand-response, microgrids, and virtual power plants; and new solutions for efficiency, heating and cooling...

  1. Baltic Earth - Earth System Science for the Baltic Sea Region

    Science.gov (United States)

    Meier, Markus; Rutgersson, Anna; Lehmann, Andreas; Reckermann, Marcus

    2014-05-01

    The Baltic Sea region, defined as its river catchment basin, spans different climate and population zones, from a temperate, highly populated, industrialized south with intensive agriculture to a boreal, rural north. It encompasses most of the Scandinavian Peninsula in the west; most of Finland and parts of Russia, Belarus, and the Baltic states in the east; and Poland and small parts of Germany and Denmark in the south. The region represents an old cultural landscape, and the Baltic Sea itself is among the most studied sea areas of the world. Baltic Earth is the new Earth system research network for the Baltic Sea region. It is the successor to BALTEX, which was terminated in June 2013 after 20 years and two successful phases. Baltic Earth stands for the vision to achieve an improved Earth system understanding of the Baltic Sea region. This means that the research disciplines of BALTEX continue to be relevant, i.e. atmospheric and climate sciences, hydrology, oceanography and biogeochemistry, but a more holistic view of the Earth system encompassing processes in the atmosphere, on land and in the sea as well as in the anthroposphere shall gain in importance in Baltic Earth. Specific grand research challenges have been formulated, representing interdisciplinary research questions to be tackled in the coming years. A major means will be scientific assessments of particular research topics by expert groups, similar to the BACC approach, which shall help to identify knowledge gaps and develop research strategies. Preliminary grand challenges and topics for which Working Groups have been installed include: • Salinity dynamics in the Baltic Sea • Land-Sea biogeochemical feedbacks in the Baltic Sea region • Natural hazards and extreme events in the Baltic Sea region • Understanding sea level dynamics in the Baltic Sea • Understanding regional variability of water and energy exchange • Utility of Regional Climate Models • Assessment of Scenario Simulations

  2. Evolving NASA's Earth Science Data Systems

    Science.gov (United States)

    Walter, J.; Behnke, J.; Murphy, K. J.; Lowe, D. R.

    2013-12-01

    NASA's Earth Science Data and Information System Project (ESDIS) is charged with managing, maintaining, and evolving NASA's Earth Observing System Data and Information System (EOSDIS) and is responsible for processing, archiving, and distributing NASA Earth science data. The system supports a multitude of missions and serves diverse science research and other user communities. Keeping up with ever-changing information technology and figuring out how to leverage those changes across such a large system in order to continuously improve and meet the needs of a diverse user community is a significant challenge. Maintaining and evolving the system architecture and infrastructure is a continuous and multi-layered effort. It requires a balance between a "top down" management paradigm that provides a coherent system view and maintaining the managerial, technological, and functional independence of the individual system elements. This presentation will describe some of the key elements of the current system architecture, some of the strategies and processes we employ to meet these challenges, current and future challenges, and some ideas for meeting those challenges.

  3. Development of a large scale Chimera grid system for the Space Shuttle Launch Vehicle

    Science.gov (United States)

    Pearce, Daniel G.; Stanley, Scott A.; Martin, Fred W., Jr.; Gomez, Ray J.; Le Beau, Gerald J.; Buning, Pieter G.; Chan, William M.; Chiu, Ing-Tsau; Wulf, Armin; Akdag, Vedat

    1993-01-01

    The application of CFD techniques to large problems has dictated the need for large team efforts. This paper offers an opportunity to examine the motivations, goals, needs, problems, as well as the methods, tools, and constraints that defined NASA's development of a 111 grid/16 million point grid system model for the Space Shuttle Launch Vehicle. The Chimera approach used for domain decomposition encouraged separation of the complex geometry into several major components each of which was modeled by an autonomous team. ICEM-CFD, a CAD based grid generation package, simplified the geometry and grid topology definition by provoding mature CAD tools and patch independent meshing. The resulting grid system has, on average, a four inch resolution along the surface.

  4. Mission Profile Translation to Capacitor Stresses in Grid-Connected Photovoltaic Systems

    DEFF Research Database (Denmark)

    Yang, Yongheng; Ma, Ke; Wang, Huai

    2014-01-01

    DC capacitors are widely adopted in grid-connected PhotoVoltaic(PV) systems for power stabilization and control decoupling. They have become one of the critical components in grid-connected PV inverters in terms of cost, reliability and volume. The electrical and thermal stresses of the DC...... stresses of the DC capacitors under both normal and abnormal grid conditions. As a consequence, this investigation provides new insights into the sizing and reliability prediction of those capacitors with respect to priorart studies. Two study cases on a single-stage PV inverter and a two-stage PV inverter...

  5. Grids heat loading of an ion source in two-stage acceleration system

    International Nuclear Information System (INIS)

    Okumura, Yoshikazu; Ohara, Yoshihiro; Ohga, Tokumichi

    1978-05-01

    Heat loading of the extraction grids, which is one of the critical problems limiting the beam pulse duration at high power level, has been investigated experimentally, with an ion source in a two-stage acceleration system of four multi-aperture grids. The loading of each grid depends largely on extraction current and grid gap pressures; it decreases with improvement of the beam optics and with decrease of the pressures. In optimum operating modes, its level is typically less than -- 2% of the total beam power or -- 200 W/cm 2 at beam energies of 50 - 70 kV. (auth.)

  6. Grid synchronization for advanced power processing and FACTS in wind power systems

    DEFF Research Database (Denmark)

    Luna, A.; Rocabert, J.; Vazquez, G.

    2010-01-01

    The high penetration of wind power systems in the electrical network has introduced new issues in the stability and transient operation of the grid. By means of providing advanced functionalities to the existing power converters of such power plants it is possible to enhance their performance...... and also to support the grid operation, as the new grid codes demand. The connection of FACTS based on power converters, such as STATCOMs, are also contributing to the integration of renewable energies improving their behavior under contingencies. However, in both cases it is needed to have a grid voltage...

  7. Universities Earth System Scientists Program

    Science.gov (United States)

    Estes, John E.

    1995-01-01

    This document constitutes the final technical report for the National Aeronautics and Space Administration (NASA) Grant NAGW-3172. This grant was instituted to provide for the conduct of research under the Universities Space Research Association's (USRA's) Universities Earth System Scientist Program (UESSP) for the Office of Mission to Planet Earth (OMTPE) at NASA Headquarters. USRA was tasked with the following requirements in support of the Universities Earth System Scientists Programs: (1) Bring to OMTPE fundamental scientific and technical expertise not currently resident at NASA Headquarters covering the broad spectrum of Earth science disciplines; (2) Conduct basic research in order to help establish the state of the science and technological readiness, related to NASA issues and requirements, for the following, near-term, scientific uncertainties, and data/information needs in the areas of global climate change, clouds and radiative balance, sources and sinks of greenhouse gases and the processes that control them, solid earth, oceans, polar ice sheets, land-surface hydrology, ecological dynamics, biological diversity, and sustainable development; (3) Evaluate the scientific state-of-the-field in key selected areas and to assist in the definition of new research thrusts for missions, including those that would incorporate the long-term strategy of the U.S. Global Change Research Program (USGCRP). This will, in part, be accomplished by study and evaluation of the basic science needs of the community as they are used to drive the development and maintenance of a global-scale observing system, the focused research studies, and the implementation of an integrated program of modeling, prediction, and assessment; and (4) Produce specific recommendations and alternative strategies for OMTPE that can serve as a basis for interagency and national and international policy on issues related to Earth sciences.

  8. Modelling security properties in a grid-based operating system with anti-goals

    OpenAIRE

    Arenas, A.; Aziz, Benjamin; Bicarregui, J.; Matthews, B.; Yang, E.

    2008-01-01

    In this paper, we discuss the use of formal requirements-engineering techniques in capturing security requirements for a Grid-based operating system. We use KAOS goal model to represent two security goals for Grid systems, namely authorisation and single-sign on authentication. We apply goal-refinement to derive security requirements for these two security goals and we develop a model of antigoals and show how system vulnerabilities and threats to the security goals can arise from such anti-m...

  9. The international earth observing system: a cultural debate about earth sciences from space

    NARCIS (Netherlands)

    Menenti, M.

    1996-01-01

    This paper gives an overview of the International Earth Observing System, i.e. the combined earth observation programmes of space agencies worldwide and of the relevance of advanced space-borne sensor systems to the study and understanding of interactions between land surface and atmosphere. The

  10. Integrating decentralized electrically powered thermal supply systems into a Smart Grid

    OpenAIRE

    Hasselmann, Maike; Beier, Carsten

    2015-01-01

    The goal of the project “Smart Region Pellworm” is the establishment and operation of a smart grid with a hybrid energy storage system on the German island of Pellworm. One part of the project is the integration of power-to-heat appliances into the smart grid for demand side management purposes. This paper deals with the prerequisites and lessons learned from the integration of electric night storage heaters into Pellworm's energy management system. Special focus lies on the development of a ...

  11. Development of a Hydrogen Energy System as a Grid Frequency Management Tool

    Energy Technology Data Exchange (ETDEWEB)

    Ewan, Mitch [Univ. of Hawaii, Honolulu, HI (United States); Rocheleau, Richard [Univ. of Hawaii, Honolulu, HI (United States); Swider-Lyons, Karen [U.S. Naval Research Lab., Washington, DC (United States); Virji, Meheboob [GRandalytics, Honolulu, HI (United States); Randolph, Guenter [Hydrogen Renewable Energy System Analysis, Pickering, ON (Canada)

    2016-07-15

    The Hawai‘i Natural Energy Institute (HNEI) is conducting research to assess the technical potential of using an electrolyzer-based hydrogen (H2) production and storage system as a grid demand response tool using battery data from a 200 MW grid to show the kind of response required. The hydrogen produced by the electrolyzer is used for transportation. A 65 kg/day hydrogen energy system (HES) consisting of a PEM electrolyzer, 35 bar buffer tank, 450 bar compressor, and associated chiller systems was purchased and installed at the Hawaii Natural Energy Laboratory Hawaii Authority (NELHA) to demonstrate long-term durability of the electrolyzer under cyclic operation required for frequency regulation on an island grid system. The excess hydrogen was stored for use by three fuel-cell buses to be operated at Hawai‘i Volcanoes National Park (HAVO) and by the County of Hawai‘i Mass Transit Agency (MTA). This paper describes the site selection and equipment commissioning, plus a comprehensive test plan that was developed to characterize the performance and durability of the electrolyzer under dynamic load conditions. The controls were modified for the operating envelope and dynamic limits of the electrolyzer. While the data showed these modifications significantly improved the system response time, it is not fast enough to match a BESS response time for grid frequency management. The electrolyzer can only be used for slower acting changes (1 to 0.5 Hz). A potential solution is to design an electrolyzer/BESS hybrid system and develop a modeling program to find the optimum mix of battery and electrolyzer to provide the maximum grid regulation services at minimum cost.

  12. Overview of Single-Phase Grid-Connected Photovoltaic Systems

    OpenAIRE

    Yang, Yongheng; Blaabjerg, Frede

    2015-01-01

    A still booming installation of solar photovoltaic (PV) systems has been witnessed worldwide. It is mainly driven by the demand of “clean” power generation. Grid-connected PV systems will become an even active player in the future mixed power systems, which are linked by a vast of power electronics converters. In order to achieve a reliable and efficient power generation from PV systems, stringent demands have been imposed on the entire PV system. It in return advances the development of powe...

  13. Mitigating Space Weather Impacts on the Power Grid in Real-Time: Applying 3-D EarthScope Magnetotelluric Data to Forecasting Reactive Power Loss in Power Transformers

    Science.gov (United States)

    Schultz, A.; Bonner, L. R., IV

    2017-12-01

    Current efforts to assess risk to the power grid from geomagnetic disturbances (GMDs) that result in geomagnetically induced currents (GICs) seek to identify potential "hotspots," based on statistical models of GMD storm scenarios and power distribution grounding models that assume that the electrical conductivity of the Earth's crust and mantle varies only with depth. The NSF-supported EarthScope Magnetotelluric (MT) Program operated by Oregon State University has mapped 3-D ground electrical conductivity structure across more than half of the continental US. MT data, the naturally occurring time variations in the Earth's vector electric and magnetic fields at ground level, are used to determine the MT impedance tensor for each site (the ratio of horizontal vector electric and magnetic fields at ground level expressed as a complex-valued frequency domain quantity). The impedance provides information on the 3-D electrical conductivity structure of the Earth's crust and mantle. We demonstrate that use of 3-D ground conductivity information significantly improves the fidelity of GIC predictions over existing 1-D approaches. We project real-time magnetic field data streams from US Geological Survey magnetic observatories into a set of linear filters that employ the impedance data and that generate estimates of ground level electric fields at the locations of MT stations. The resulting ground electric fields are projected to and integrated along the path of power transmission lines. This serves as inputs to power flow models that represent the power transmission grid, yielding a time-varying set of quasi-real-time estimates of reactive power loss at the power transformers that are critical infrastructure for power distribution. We demonstrate that peak reactive power loss and hence peak risk for transformer damage from GICs does not necessarily occur during peak GMD storm times, but rather depends on the time-evolution of the polarization of the GMD's inducing fields

  14. Smart Grid Technology

    OpenAIRE

    Cosma Sorinel

    2010-01-01

    The largest interconnected machine on Earth, the century-old power grid is so massively complex and inextricably linked to human involvement and endeavor that it has been called an ecosystem. To meet sustainability requirements, the electric industry is poised to make the transformation from a centralized, producer-controlled network to one that is less centralized and more consumerinteractive. This move promises to change the industry’s entire business model and its relationship with all sta...

  15. Supervision and control of grid connected PV-Storage systems with the five level diode clamped inverter

    International Nuclear Information System (INIS)

    Himour, Kamal; Ghedamsi, Kaci; Berkouk, El Madjid

    2014-01-01

    Highlights: • Use of battery bank in grid connection photovoltaic system to ensure the energetic autonomy of the system. • Improve the quality of energy by the use of five-level inverter in a grid connection PV generation system. • Control of inverter by fast and simplified space vector pulse width modulation. • Control and supervision of active and reactive power in the grid. - Abstract: This paper aimed to evaluate the use of photovoltaic-battery storage systems to supply electric power in the distribution grid through a multilevel inverter. The proposed system is composed by four PV generators with MPPT (P and O) control, four battery storage systems connected to each capacitor of the DC link and a five level diode clamped inverter connected to the grid by a traditional three phase transformer. The proposed control has a hierarchical structure with both a grid side control level to regulate the power and the current injected to the grid and four input side regulation units. The system operator controls the power production of the four PV generators by sending out reference power signals to each input side regulation unit, the input side regulation units regulate the voltage of each capacitor of the DC link, regulate the voltage and the state of charge of each battery storage system

  16. Bus.py: A GridLAB-D Communication Interface for Smart Distribution Grid Simulations

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, Timothy M.; Palmintier, Bryan; Suryanarayanan, Siddharth; Maciejewski, Anthony A.; Siegel, Howard Jay

    2015-07-03

    As more Smart Grid technologies (e.g., distributed photovoltaic, spatially distributed electric vehicle charging) are integrated into distribution grids, static distribution simulations are no longer sufficient for performing modeling and analysis. GridLAB-D is an agent-based distribution system simulation environment that allows fine-grained end-user models, including geospatial and network topology detail. A problem exists in that, without outside intervention, once the GridLAB-D simulation begins execution, it will run to completion without allowing the real-time interaction of Smart Grid controls, such as home energy management systems and aggregator control. We address this lack of runtime interaction by designing a flexible communication interface, Bus.py (pronounced bus-dot-pie), that uses Python to pass messages between one or more GridLAB-D instances and a Smart Grid simulator. This work describes the design and implementation of Bus.py, discusses its usefulness in terms of some Smart Grid scenarios, and provides an example of an aggregator-based residential demand response system interacting with GridLAB-D through Bus.py. The small scale example demonstrates the validity of the interface and shows that an aggregator using said interface is able to control residential loads in GridLAB-D during runtime to cause a reduction in the peak load on the distribution system in (a) peak reduction and (b) time-of-use pricing cases.

  17. Earth Observing System, Conclusions and Recommendations

    Science.gov (United States)

    1984-01-01

    The following Earth Observing Systems (E.O.S.) recommendations were suggested: (1) a program must be initiated to ensure that present time series of Earth science data are maintained and continued. (2) A data system that provides easy, integrated, and complete access to past, present, and future data must be developed as soon as possible. (3) A long term research effort must be sustained to study and understand these time series of Earth observations. (4) The E.O.S. should be established as an information system to carry out those aspects of the above recommendations which go beyond existing and currently planned activities. (5) The scientific direction of the E.O.S. should be established and continued through an international scientific steering committee.

  18. Design of a Glenn Research Center Solar Field Grid-Tied Photovoltaic Power System

    Science.gov (United States)

    Eichenberg, Dennis J.

    2009-01-01

    The NASA Glenn Research Center (GRC) designed, developed, and installed, a 37.5 kW DC photovoltaic (PV) Solar Field in the GRC West Area in the 1970s for the purpose of testing PV panels for various space and terrestrial applications. The PV panels are arranged to provide a nominal 120 VDC. The GRC Solar Field has been extremely successful in meeting its mission. The PV panels and the supporting electrical systems are all near their end of life. GRC has designed a 72 kW DC grid-tied PV power system to replace the existing GRC West Area Solar Field. The 72 kW DC grid-tied PV power system will provide DC solar power for GRC PV testing applications, and provide AC facility power for all times that research power is not required. A grid-tied system is connected directly to the utility distribution grid. Facility power can be obtained from the utility system as normal. The PV system is synchronized with the utility system to provide power for the facility, and excess power is provided to the utility for use by all. The project transfers space technology to terrestrial use via nontraditional partners. GRC personnel glean valuable experience with PV power systems that are directly applicable to various space power systems, and provide valuable space program test data. PV power systems help to reduce harmful emissions and reduce the Nation s dependence on fossil fuels. Power generated by the PV system reduces the GRC utility demand, and the surplus power aids the community. Present global energy concerns reinforce the need for the development of alternative energy systems. Modern PV panels are readily available, reliable, efficient, and economical with a life expectancy of at least 25 years. Modern electronics has been the enabling technology behind grid-tied power systems, making them safe, reliable, efficient, and economical with a life expectancy of at least 25 years. The report concludes that the GRC West Area grid-tied PV power system design is viable for a reliable

  19. Performance Analysis of 14 MW Grid-Connected Photovoltaic System

    International Nuclear Information System (INIS)

    Kagilik, Ahmed S.; Tawel, Abduraouf M.

    2015-01-01

    Many Libyan authorities proposed to investigate the possibility of utilizing a suitable terrain in Libya to add generation capacity of large-scale photovoltaic power plants. In this paper, the first grid-connected PV plant of 14 MWp which will be executed in Hoon city and supported by the Renewable Energy Authority of Libya (REAOL) is presented. To understand and improve the operational behavior of PV system, a comprehensive study including the plant design and detailed performance analysis under a local climate conditions is performed. Using polycrystalline silicon technology, the first year energy yield is estimated and the monthly system output for this plant is calculated. The performance ratio and various power losses (temperature, irradiance, power electronics, interconnection, etc.) are determined. The PV system supplied 24964 MWh to the grid during the first year giving an average annual overall yield factor 1783 kWh/kWp and average annual performance ratio of the system of 76.9%.(author)

  20. Evolutionary Hierarchical Multi-Criteria Metaheuristics for Scheduling in Large-Scale Grid Systems

    CERN Document Server

    Kołodziej, Joanna

    2012-01-01

    One of the most challenging issues in modelling today's large-scale computational systems is to effectively manage highly parametrised distributed environments such as computational grids, clouds, ad hoc networks and P2P networks. Next-generation computational grids must provide a wide range of services and high performance computing infrastructures. Various types of information and data processed in the large-scale dynamic grid environment may be incomplete, imprecise, and fragmented, which complicates the specification of proper evaluation criteria and which affects both the availability of resources and the final collective decisions of users. The complexity of grid architectures and grid management may also contribute towards higher energy consumption. All of these issues necessitate the development of intelligent resource management techniques, which are capable of capturing all of this complexity and optimising meaningful metrics for a wide range of grid applications.   This book covers hot topics in t...

  1. Analysis and Modeling of Interharmonics from Grid-Connected Photovoltaic Systems

    DEFF Research Database (Denmark)

    Sangwongwanich, Ariya; Yang, Yongheng; Sera, Dezso

    2018-01-01

    The industry of solar Photovoltaic (PV) energy and its exploitation are still booming to enhance the sustainability of the society. When PV systems are connected to the grid, challenging issues should be addressed. One of the challenges is related to interharmonics in PV systems, especially...... with a largescale adoption of PV systems. However, the origins of interharmonics remain unclear, although the impact of interhamonics has been reported in literature. Thus, this paper explores the generation mechanisms of interharmonics in PV systems and its characteristics. The exploration reveals...... that the perturbation from the Maximum Power Point Tracking (MPPT) algorithm is one of the origins of interharmonics appearing in the grid current. Accordingly, the MPPT controller parameters such as the perturbation step-size and the sampling rate have an inevitable impact on the interharmonic characteristics...

  2. Performance of R-GMA based grid job monitoring system for CMS data production

    CERN Document Server

    Byrom, Robert; Fisher, Steve M; Grandi, Claudio; Hobson, Peter R; Kyberd, Paul; MacEvoy, Barry; Nebrensky, Jindrich Josef; Tallini, Hugh; Traylen, Stephen

    2004-01-01

    High Energy Physics experiments, such as the Compact Muon Solenoid (CMS) at the CERN laboratory in Geneva, have large-scale data processing requirements, with stored data accumulating at a rate of 1 Gbyte/s. This load comfortably exceeds any previous processing requirements and we believe it may be most efficiently satisfied through Grid computing. Management of large Monte Carlo productions (~3000 jobs) or data analyses and the quality assurance of the results requires careful monitoring and bookkeeping, and an important requirement when using the Grid is the ability to monitor transparently the large number of jobs that are being executed simultaneously at multiple remote sites. R-GMA is a monitoring and information management service for distributed resources based on the Grid Monitoring Architecture of the Global Grid Forum. We have previously developed a system allowing us to test its performance under a heavy load while using few real Grid resources. We present the latest results on this system and comp...

  3. AirNow Information Management System - Global Earth Observation System of Systems Data Processor for Real-Time Air Quality Data Products

    Science.gov (United States)

    Haderman, M.; Dye, T. S.; White, J. E.; Dickerson, P.; Pasch, A. N.; Miller, D. S.; Chan, A. C.

    2012-12-01

    Built upon the success of the U.S. Environmental Protection Agency's (EPA) AirNow program (www.AirNow.gov), the AirNow-International (AirNow-I) system contains an enhanced suite of software programs that process and quality control real-time air quality and environmental data and distribute customized maps, files, and data feeds. The goals of the AirNow-I program are similar to those of the successful U.S. program and include fostering the exchange of environmental data; making advances in air quality knowledge and applications; and building a community of people, organizations, and decision makers in environmental management. In 2010, Shanghai became the first city in China to run this state-of-the-art air quality data management and notification system. AirNow-I consists of a suite of modules (software programs and schedulers) centered on a database. One such module is the Information Management System (IMS), which can automatically produce maps and other data products through the use of GIS software to provide the most current air quality information to the public. Developed with Global Earth Observation System of Systems (GEOSS) interoperability in mind, IMS is based on non-proprietary standards, with preference to formal international standards. The system depends on data and information providers accepting and implementing a set of interoperability arrangements, including technical specifications for collecting, processing, storing, and disseminating shared data, metadata, and products. In particular, the specifications include standards for service-oriented architecture and web-based interfaces, such as a web mapping service (WMS), web coverage service (WCS), web feature service (WFS), sensor web services, and Really Simple Syndication (RSS) feeds. IMS is flexible, open, redundant, and modular. It also allows the merging of data grids to create complex grids that show comprehensive air quality conditions. For example, the AirNow Satellite Data Processor

  4. Reliable Grid Condition Detection and Control of Single-Phase Distributed Power Generation Systems

    DEFF Research Database (Denmark)

    Ciobotaru, Mihai

    standards addressed to the grid-connected systems will harmonize the combination of the DPGS and the classical power plants. Consequently, the major tasks of this thesis were to develop new grid condition detection techniques and intelligent control in order to allow the DPGS not only to deliver power...... to the utility grid but also to sustain it. This thesis was divided into two main parts, namely "Grid Condition Detection" and "Control of Single-Phase DPGS". In the first part, the main focus was on reliable Phase Locked Loop (PLL) techniques for monitoring the grid voltage and on grid impedance estimation...... techniques. Additionally, a new technique for detecting the islanding mode has been developed and successfully tested. In the second part, the main reported research was concentrated around adaptive current controllers based on the information provided by the grid condition detection techniques. To guarantee...

  5. Development of Phase Lock Loop System for Synchronisation of a Hybrid System with the Grid

    Directory of Open Access Journals (Sweden)

    A. S. Abubakar

    2016-06-01

    Full Text Available Phase locked loop (PLL is an important part of the control unit of the grid connected power converter. The method of zero crossing detection (ZCD does not produce accurate phase information when grid is non-ideal. In this work, a synchronous reference frame (SRF PLL method to obtain accurate phase information when the grid voltages are unbalanced is proposed. The performances of the PLL have been verified for ideal and abnormal grid conditions such as unbalance, voltage sag, faults condition etc. Based on the results obtained, the developed PLL gives better fault ride when unbalances in the three phase input signals are overall handled well by the PLL system as it locks the two signal back within the first cycle. It also overcomes a phase jump after 5 milli-seconds from the time the fault was introduced and performs better tracking of the grid voltage and that of the renewable energy source.

  6. Development of Phase Lock Loop System for Synchronisation of a Hybrid System with the Grid

    Directory of Open Access Journals (Sweden)

    A. S. Abubakar

    2016-12-01

    Full Text Available Phase locked loop (PLL is an important part of the control unit of the grid connected power converter. The method of zero crossing detection (ZCD does not produce accurate phase information when grid is non-ideal. In this work, a synchronous reference frame (SRF PLL method to obtain accurate phase information when the grid voltages are unbalanced is proposed. The performances of the PLL have been verified for ideal and abnormal grid conditions such as unbalance, voltage sag, faults condition etc. Based on the results obtained, the developed PLL gives better fault ride when unbalances in the three phase input signals are overall handled well by the PLL system as it locks the two signal back within the first cycle. It also overcomes a phase jump after 5 milli-seconds from the time the fault was introduced and performs better tracking of the grid voltage and that of the renewable energy source.

  7. Repetitive controller for improving grid-connected photovoltaic systems

    NARCIS (Netherlands)

    Almeida, de P.M.; Duarte, J.L.; Ribeiro, P.F.; Barbosa, P.G.

    2014-01-01

    This study presents the modelling and design steps of a discrete time recursive repetitive controller (RC) to be used in a grid-connected photovoltaic (PV) system. It is shown that the linear synchronous reference frame proportional-integral controller, originally designed to control the converter's

  8. Performance of Grid-Connected Photovoltaic System in Two Sites in Kuwait

    Directory of Open Access Journals (Sweden)

    Ali Hajiah

    2012-01-01

    Full Text Available This paper presents an assessment of the electricity generated by photovoltaic (PV grid-connected systems in Kuwait. Three years of meteorological data are provided for two main sites in Kuwait, namely, Al-Wafra and Mutla. These data and a PV grid-connected system mathematical model are used to assist a 100 kWp grid-connected PV system proposed for both sites. The proposed systems show high energy productivity whereas the annual capacity factors for Mutla and Al-Wafra are 22.25% and 21.6%, respectively. Meanwhile the annual yield factors for Mutla and Al-Wafra are 1861 kWh/kWp/year and 1922.7 kWh/kWp/year, respectively. On the other hand the cost of the energy generated by both systems is about 0.1 USD/kWh which is very close to the price of the energy sold by the Ministry of Electricity and Water (MEW. Furthermore the invested money is recovered during the assumed life cycle time whereas the payback period for both sites is about 15 years. This work contains worthwhile technical information for those who are interested in PV technology investment in Kuwait.

  9. A portable grid-enabled computing system for a nuclear material study

    International Nuclear Information System (INIS)

    Tsujita, Yuichi; Arima, Tatsumi; Takekawa, Takayuki; Suzuki, Yoshio

    2010-01-01

    We have built a portable grid-enabled computing system specialized for our molecular dynamics (MD) simulation program to study Pu material easily. Experimental approach to reveal properties of Pu materials is often accompanied by some difficulties such as radiotoxicity of actinides. Since a computational approach reveals new aspects to researchers without such radioactive facilities, we address an MD computation. In order to have more realistic results about e.g., melting point or thermal conductivity, we need a large scale of parallel computations. Most of application users who don't have supercomputers in their institutes should use a remote supercomputer. For such users, we have developed the portable and secured grid-enabled computing system to utilize a grid computing infrastructure provided by Information Technology Based Laboratory (ITBL). This system enables us to access remote supercomputers in the ITBL system seamlessly from a client PC through its graphical user interface (GUI). Typically it enables seamless file accesses on the GUI. Furthermore monitoring of standard output or standard error is available to see progress of an executed program. Since the system provides fruitful functionalities which are useful for parallel computing on a remote supercomputer, application users can concentrate on their researches. (author)

  10. Grid Integration Webinars | Energy Systems Integration Facility | NREL

    Science.gov (United States)

    Grid Integration Webinars Grid Integration Webinars Watch presentations from NREL analysts on various topics related to grid integration. Wind Curtailment and the Value of Transmission under a 2050 renewable curtailment under these high wind scenarios. Text Version Grid Integration Webinar: Exploring

  11. An automatic and accurate x-ray tube focal spot/grid alignment system for mobile radiography: System description and alignment accuracy

    International Nuclear Information System (INIS)

    Gauntt, David M.; Barnes, Gary T.

    2010-01-01

    Purpose: A mobile radiography automatic grid alignment system (AGAS) has been developed by modifying a commercially available mobile unit. The objectives of this article are to describe the modifications and operation and to report on the accuracy with which the focal spot is aligned to the grid and the time required to achieve the alignment. Methods: The modifications include an optical target arm attached to the grid tunnel, a video camera attached to the collimator, a motion control system with six degrees of freedom to position the collimator and x-ray tube, and a computer to control the system. The video camera and computer determine the grid position, and then the motion control system drives the x-ray focal spot to the center of the grid focal axis. The accuracy of the alignment of the focal spot with the grid and the time required to achieve alignment were measured both in laboratory tests and in clinical use. Results: For a typical exam, the modified unit automatically aligns the focal spot with the grid in less than 10 s, with an accuracy of better than 4 mm. The results of the speed and accuracy tests in clinical use were similar to the results in laboratory tests. Comparison patient chest images are presented--one obtained with a standard mobile radiographic unit without a grid and the other obtained with the modified unit and a 15:1 grid. The 15:1 grid images demonstrate a marked improvement in image quality compared to the nongrid images with no increase in patient dose. Conclusions: The mobile radiography AGAS produces images of significantly improved quality compared to nongrid images with alignment times of less than 10 s and no increase in patient dose.

  12. Comparative Analysis of Inversors for Small PV Systems Grid Connected

    International Nuclear Information System (INIS)

    Sidrach de Cardona, M.; Ramirez, L.

    2001-01-01

    The energy produced by a grid connected photovoltaic system is a function of weather conditions, mainly available radiation and temperature, photovoltaic array efficiency and inverter characteristics. The results obtained in experimental measurements with four small grid-connected inverters are described in this work. The main goal is to know the inverter performance in real operation conditions. For this purpose a 2 kW photovoltaic system has been used. These results allow us to know both the inverter efficiency and its output power quality. The following parameters have been evaluated as a function of output inverter power: efficiency, point of maximum power tracking, intensity and voltage waveform, total harmonic distortion and harmonic values to 31 order, frequency, power factor and reactive power. Other interesting parameters like stand-by energy consumption and daily losses due to the inverter threshold have also been analyzed. The results allow us to know the inverter features as a function of its real work point. In our comparative study it is possible to observe remarkable differences between the inverters; these results show how important it is to have a unique standard for inverters to photovoltaic grid-connected systems. (Author) 10 refs

  13. The Grid

    CERN Document Server

    Klotz, Wolf-Dieter

    2005-01-01

    Grid technology is widely emerging. Grid computing, most simply stated, is distributed computing taken to the next evolutionary level. The goal is to create the illusion of a simple, robust yet large and powerful self managing virtual computer out of a large collection of connected heterogeneous systems sharing various combinations of resources. This talk will give a short history how, out of lessons learned from the Internet, the vision of Grids was born. Then the extensible anatomy of a Grid architecture will be discussed. The talk will end by presenting a selection of major Grid projects in Europe and US and if time permits a short on-line demonstration.

  14. Grid-interfacing converter systems with enhanced voltage quality for microgrid application : concept and implementation

    NARCIS (Netherlands)

    Wang, F.; Duarte, J.L.; Hendrix, M.A.M.

    2011-01-01

    Grid-interfacing converter systems with enhanced voltage quality are proposed for microgrid application in this paper. By adapting the conventional series-parallel structure, a group of grid-interfacing system topologies are proposed for the purpose of interfacing local generation/microgrid to the

  15. Grid connection of active stall wind farms using a VSC based DC transmission system

    DEFF Research Database (Denmark)

    Iov, F.; Sørensen, Poul Ejnar; Hansen, A.D.

    2005-01-01

    Currently, there is an increasing trend to connect large MW wind farms to the transmission system. Requirements that focus on the influence of the farms on the grid stability and power quality, and on the control capabilities of wind farms have already been established. The main trends of modern...... wind turbines/farms are clearly the variable speed operation and a grid connection through a power electronic interface, especially using doubly fed induction generators. Using power electronics the control capabilities of these wind turbines/farms are extended and thus the grid requirements...... are fulfilled. However, the traditional squirrel-cage generators based wind turbines/wind farms directly connected to the grid have less control capabilities. These wind turbines/farms cannot regulate their production and contribute to power system stability. A DC transmission system for connection...

  16. Earth Observing Data System Data and Information System (EOSDIS) Overview

    Science.gov (United States)

    Klene, Stephan

    2016-01-01

    The National Aeronautics and Space Administration (NASA) acquires and distributes an abundance of Earth science data on a daily basis to a diverse user community worldwide. The NASA Big Earth Data Initiative (BEDI) is an effort to make the acquired science data more discoverable, accessible, and usable. This presentation will provide a brief introduction to the Earth Observing System Data and Information System (EOSDIS) project and the nature of advances that have been made by BEDI to other Federal Users.

  17. Smart grids in the colombian electric system: Current situation and potential opportunities

    Directory of Open Access Journals (Sweden)

    William Mauricio Giral Ramírez

    2017-07-01

    Full Text Available Context: This paper focuses on providing a functional analysis of smart grids, with the purpose of establishing a framework to identify the main characteristics of the current electric interconnection system in Colombia. It also names the positive incentives proposed by the Colombian government to support both research and development projects that implement non-conventional energy sources and promoting energy management based on efficiency. Method: An architecture model that describes the components interoperability of a smart grid is presented using a descriptive methodology. Results: The results include a list of the objectives established by the Colombian public and private entities related to energy development, specially focusing on the opportunities to provide some kind of artificial intelligence to the current electrical system. Conclusions: It is necessary for the Colombian energy system to supply the energy demand considering electrical safety, social equity, and the minimum environmental impact. These restrictions impose new challenges for the energy system itself: From a technical point of view, the traditional electrical grid must be outfitted with the characteristics of a smart grid, and from a legal perspective, it is essential to generate a clear regulatory framework that promotes the development of this type of technology.

  18. Performance of a grid connected PV system used as active filter

    International Nuclear Information System (INIS)

    Calleja, Hugo; Jimenez, Humberto

    2004-01-01

    In this paper, the performance of a grid connected photovoltaic (PV) system used as an active filter is presented. Its main feature is the capability to compensate the reactive and harmonic currents drawn by nonlinear loads while simultaneously injecting into the grid the maximum power available from the cells. The system can also operate as a stand alone active filter. The system was connected to a 1 kW PV array and tested with the loads typically found in households: small motors, personal computers and electronic ballasts. The results show that the system can correct the power factor to values close to unity for all the cases tested, thereby improving the efficiency of the electric energy supply

  19. Land Boundary Conditions for the Goddard Earth Observing System Model Version 5 (GEOS-5) Climate Modeling System: Recent Updates and Data File Descriptions

    Science.gov (United States)

    Mahanama, Sarith P.; Koster, Randal D.; Walker, Gregory K.; Takacs, Lawrence L.; Reichle, Rolf H.; De Lannoy, Gabrielle; Liu, Qing; Zhao, Bin; Suarez, Max J.

    2015-01-01

    The Earths land surface boundary conditions in the Goddard Earth Observing System version 5 (GEOS-5) modeling system were updated using recent high spatial and temporal resolution global data products. The updates include: (i) construction of a global 10-arcsec land-ocean lakes-ice mask; (ii) incorporation of a 10-arcsec Globcover 2009 land cover dataset; (iii) implementation of Level 12 Pfafstetter hydrologic catchments; (iv) use of hybridized SRTM global topography data; (v) construction of the HWSDv1.21-STATSGO2 merged global 30 arc second soil mineral and carbon data in conjunction with a highly-refined soil classification system; (vi) production of diffuse visible and near-infrared 8-day MODIS albedo climatologies at 30-arcsec from the period 2001-2011; and (vii) production of the GEOLAND2 and MODIS merged 8-day LAI climatology at 30-arcsec for GEOS-5. The global data sets were preprocessed and used to construct global raster data files for the software (mkCatchParam) that computes parameters on catchment-tiles for various atmospheric grids. The updates also include a few bug fixes in mkCatchParam, as well as changes (improvements in algorithms, etc.) to mkCatchParam that allow it to produce tile-space parameters efficiently for high resolution AGCM grids. The update process also includes the construction of data files describing the vegetation type fractions, soil background albedo, nitrogen deposition and mean annual 2m air temperature to be used with the future Catchment CN model and the global stream channel network to be used with the future global runoff routing model. This report provides detailed descriptions of the data production process and data file format of each updated data set.

  20. The Application of Stationary VOC-PR with PLL for Grid side Converter-based Wind Power Generation System

    DEFF Research Database (Denmark)

    Guo, Yougui; Zeng, Ping; Li, Lijuan

    2010-01-01

    Voltage oriented control PR is combined with space vector modulation and phase locked loop to control the grid side converter in wind power generation system in this paper. First the mathematical models of grid side converter and LCL filter as well as grid are given. Then the control strategy...... of grid side converter-based wind power generation system is given in detail. Finally the simulation model consisting of the grid side converter wind power generation system is set up. The simulation results have verified that the control strategy is feasible to be used for control of gird currents......, active power, reactive power and DC-link voltage in wind power generation system. It has laid a good basis for the real system development....

  1. Smart grid communication-enabled intelligence for the electric power grid

    CERN Document Server

    Bush, Stephen F

    2014-01-01

    This book bridges the divide between the fields of power systems engineering and computer communication through the new field of power system information theory. Written by an expert with vast experience in the field, this book explores the smart grid from generation to consumption, both as it is planned today and how it will evolve tomorrow. The book focuses upon what differentiates the smart grid from the ""traditional"" power grid as it has been known for the last century. Furthermore, the author provides the reader with a fundamental understanding of both power systems and communication ne

  2. Overview of NASA's Earth Science Data Systems

    Science.gov (United States)

    McDonald, Kenneth

    2004-01-01

    For over the last 15 years, NASA's Earth Science Enterprise (ESE) has devoted a tremendous effort to design and build the Earth Observing System (EOS) Data and Information System (EOSDIS) to acquire, process, archive and distribute the data of the EOS series of satellites and other ESE missions and field programs. The development of EOSDIS began with an early prototype to support NASA data from heritage missions and progressed through a formal development process to today's system that supports the data from multiple missions including Landsat 7, Terra, Aqua, SORCE and ICESat. The system is deployed at multiple Distributed Active Archive Centers (DAACs) and its current holdings are approximately 4.5 petabytes. The current set of unique users requesting EOS data and information products exceeds 2 million. While EOSDIS has been the centerpiece of NASA's Earth Science Data Systems, other initiatives have augmented the services of EOSDIS and have impacted its evolution and the future directions of data systems within the ESE. ESDIS had an active prototyping effort and has continued to be involved in the activities of the Earth Science Technology Office (ESTO). In response to concerns from the science community that EOSDIS was too large and monolithic, the ESE initiated the Earth Science Information Partners (ESP) Federation Experiment that funded a series of projects to develop specialized products and services to support Earth science research and applications. Last year, the enterprise made 41 awards to successful proposals to the Research, Education and Applications Solutions Network (REASON) Cooperative Agreement Notice to continue and extend the ESP activity. The ESE has also sponsored a formulation activity called the Strategy for the Evolution of ESE Data Systems (SEEDS) to develop approaches and decision support processes for the management of the collection of data system and service providers of the enterprise. Throughout the development of its earth science

  3. Transient Control of Synchronous Machine Active and Reactive Power in Micro-grid Power Systems

    Science.gov (United States)

    Weber, Luke G.

    There are two main topics associated with this dissertation. The first is to investigate phase-to-neutral fault current magnitude occurring in generators with multiple zero-sequence current sources. The second is to design, model, and tune a linear control system for operating a micro-grid in the event of a separation from the electric power system. In the former case, detailed generator, AC8B excitation system, and four-wire electric power system models are constructed. Where available, manufacturers data is used to validate the generator and exciter models. A gain-delay with frequency droop control is used to model an internal combustion engine and governor. The four wire system is connected through a transformer impedance to an infinite bus. Phase-to-neutral faults are imposed on the system, and fault magnitudes analyzed against three-phase faults to gauge their severity. In the latter case, a balanced three-phase system is assumed. The model structure from the former case - but using data for a different generator - is incorporated with a model for an energy storage device and a net load model to form a micro-grid. The primary control model for the energy storage device has a high level of detail, as does the energy storage device plant model in describing the LC filter and transformer. A gain-delay battery and inverter model is used at the front end. The net load model is intended to be the difference between renewable energy sources and load within a micro-grid system that has separated from the grid. Given the variability of both renewable generation and load, frequency and voltage stability are not guaranteed. This work is an attempt to model components of a proposed micro-grid system at the University of Wisconsin Milwaukee, and design, model, and tune a linear control system for operation in the event of a separation from the electric power system. The control module is responsible for management of frequency and active power, and voltage and reactive

  4. Distributed Secondary Control for Islanded MicroGrids – A Networked Control Systems Approach

    DEFF Research Database (Denmark)

    Shafiee, Qobad; Vasquez, Juan Carlos; Guerrero, Josep M.

    2012-01-01

    This paper presents a novel approach to conceive the secondary control in droop-controlled MicroGrids. The conventional approach is based on restoring the frequency and amplitude deviations produced by the local droop controllers by using a MicroGrid Central Controller. A distributed networked...... control system is used in order to implement a distributed secondary control thus avoiding the use of a MicroGrid Central Control. The proposed approach is not only able to restore frequency and voltage of the MicroGrid but also ensures reactive power sharing. The distributed secondary control do...

  5. A roadmap for caGrid, an enterprise Grid architecture for biomedical research.

    Science.gov (United States)

    Saltz, Joel; Hastings, Shannon; Langella, Stephen; Oster, Scott; Kurc, Tahsin; Payne, Philip; Ferreira, Renato; Plale, Beth; Goble, Carole; Ervin, David; Sharma, Ashish; Pan, Tony; Permar, Justin; Brezany, Peter; Siebenlist, Frank; Madduri, Ravi; Foster, Ian; Shanbhag, Krishnakant; Mead, Charlie; Chue Hong, Neil

    2008-01-01

    caGrid is a middleware system which combines the Grid computing, the service oriented architecture, and the model driven architecture paradigms to support development of interoperable data and analytical resources and federation of such resources in a Grid environment. The functionality provided by caGrid is an essential and integral component of the cancer Biomedical Informatics Grid (caBIG) program. This program is established by the National Cancer Institute as a nationwide effort to develop enabling informatics technologies for collaborative, multi-institutional biomedical research with the overarching goal of accelerating translational cancer research. Although the main application domain for caGrid is cancer research, the infrastructure provides a generic framework that can be employed in other biomedical research and healthcare domains. The development of caGrid is an ongoing effort, adding new functionality and improvements based on feedback and use cases from the community. This paper provides an overview of potential future architecture and tooling directions and areas of improvement for caGrid and caGrid-like systems. This summary is based on discussions at a roadmap workshop held in February with participants from biomedical research, Grid computing, and high performance computing communities.

  6. A GRID-CONNECTED HYBRID WIND-SOLAR POWER SYSTEM

    Directory of Open Access Journals (Sweden)

    MAAMAR TALEB

    2017-06-01

    Full Text Available A hybrid renewable energy system consisting of a photovoltaic generator and a wind driven DC machine is interconnected with the power utilities grid. The interconnection is done through the use of two separate single phase full wave controlled bridge converters. The bridge converters are operated in the “inverter mode of operation”. That is to guaranty the extraction of the real powers from the wind driven generator as well as from the photovoltaic generator and inject them into the power utilities grid. At any pretended surrounding weather conditions, maximum extraction of powers from both renewable energy sources is targeted. This is done through the realization of self-adjusted firing angle controllers responsible of triggering the semiconductor elements of the controlled converters. An active power filter is shunted with the proposed setup to guaranty the sinusoid quality of the power utilities line current. The overall performance of the proposed system has been simulated in MATLAB/SIMULINK environment. Quite satisfactory and encouraging results have been obtained.

  7. Grid connectivity issues and the importance of GCC. [GCC - Grid Code Compliance

    Energy Technology Data Exchange (ETDEWEB)

    Das, A.; Schwartz, M.-K. [GL Renewable Certification, Malleswaram, Bangalore (India)

    2012-07-01

    In India, the wind energy is concentrated in rural areas with a very high penetration. In these cases, the wind power has an increasing influence on the power quality on the grids. Another aspect is the influence of weak grids on the operation of wind turbines. Hence it becomes very much essential to introduce such a strong grid code which is particularly applicable to wind sector and suitable for Indian environmental grid conditions. This paper focuses on different international grid codes and their requirement with regard to the connection of wind farms to the electric power systems to mitigate the grid connectivity issues. The requirements include the ways to achieve voltage and frequency stability in the grid-tied wind power system. In this paper, comparative overview and analysis of the main grid connecting requirements will be conducted, comprising several national and regional codes from many countries where high wind penetration levels have been achieved or are expected in the future. The objective of these requirements is to provide wind farms with the control and regulation capabilities encountered in conventional power plants and are necessary for the safe, reliable and economic operation of the power system. This paper also provides a brief idea on the Grid Code Compliance (GCC) certification procedure implemented by the leading accredited certifying body like Germanischer Lloyd Renewables Certification (GL RC), who checks the conformity of the wind turbines as per region specific grid codes. (Author)

  8. Summary of the fuel rod support system (grids) design for LWBR (LWBR development program)

    International Nuclear Information System (INIS)

    Richardson, K.D.

    1979-02-01

    Design features of the fuel rod support system (grids) for the Light Water Breeder Reactor (LWBR) installed in the Shippingport Atomic Power Station, Shippingport, Pennsylvania, are described. The grids are fabricated from AM-350 stainless steel and provide lateral support of the fuel rods in the three regions (seed, blanket, and reflector) of the reactor. A comparison is made of the LWBR grids, whose cells are arranged in triangular-pitched arrays, with rod support systems employed in commercial light water reactors

  9. Keeping Earth at work: Using thermodynamics to develop a holistic theory of the Earth system

    Science.gov (United States)

    Kleidon, Axel

    2010-05-01

    The Earth system is unique among terrestrial planets in that it is maintained in a state far from thermodynamic equilibrium. Practically all processes are irreversible in their nature, thereby producing entropy, and these would act to destroy this state of disequilibrium. In order to maintain disequilibrium in steady state, driving forces are required that perform the work to maintain the Earth system in a state far from equilibrium. To characterize the functioning of the Earth system and the interactions among its subsystems we need to consider all terms of the first and second law of thermodynamics. While the global energy balance is well established in climatology, the global entropy and work balances receive little, if any, attention. Here I will present first steps in developing a holistic theory of the Earth system including quantifications of the relevant terms that is based on the first and second laws of thermodynamics. This theory allows us to compare the significance of different processes in driving and maintaining disequilibrium, allows us to explore interactions by investigating the role of power transfer among processes, and specifically illustrate the significance of life in driving planetary disequilibrium. Furthermore, the global work balance demonstrates the significant impact of human activity and it provides an estimate for the availability of renewable sources of free energy within the Earth system. Hence, I conclude that a holistic thermodynamic theory of the Earth system is not just some academic exercise of marginal use, but essential for a profound understanding of the Earth system and its response to change.

  10. Experimental evaluation of 8 kW grid-connected photovoltaic system in Egypt

    Directory of Open Access Journals (Sweden)

    A. Elkholy

    2016-09-01

    Full Text Available An experimental observation study of 8 kW grid-connected photovoltaic (PV system that is installed at Electronics Research Institute (ERI, Giza, Egypt (Latitude 30.04°N, Longitude 31.21°E, is presented. This study includes the quality of the electrical power generated and injected into the network. The considered system consists of 28 × 295 Wp multicrystalline PV modules, StecaGrid three-phase 8 kW grid-connected inverter and a Solar-Log 300 PM+ for data acquisition and remote monitoring. The power quality parameters at the inverter output side have been measured using CA8335 power quality analyzer. The system has been installed in August 2014 and generated 5.7 MWh till February 2015. The produced electricity by the system is injected directly into the grid without storage device. The purpose of this paper is to present and evaluate the measurements of the power quality parameters obtained from the PV site. Also, this paper presents a comprehensive evaluation of the performance of the system over a period of one week. The observation and analyses exploitation of the collected data can help to evaluate the performance of the PV system connected to the network.

  11. Distributed Energy Systems Integration and Demand Optimization for Autonomous Operations and Electric Grid Transactions

    Energy Technology Data Exchange (ETDEWEB)

    Ghatikar, Girish [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Greenlots, San Francisco, CA (United States); Mashayekh, Salman [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Stadler, Michael [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Center for Energy and Innovation Technologies (Austria); Yin, Rongxin [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Liu, Zhenhua [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2015-11-29

    Distributed power systems in the U.S. and globally are evolving to provide reliable and clean energy to consumers. In California, existing regulations require significant increases in renewable generation, as well as identification of customer-side distributed energy resources (DER) controls, communication technologies, and standards for interconnection with the electric grid systems. As DER deployment expands, customer-side DER control and optimization will be critical for system flexibility and demand response (DR) participation, which improves the economic viability of DER systems. Current DER systems integration and communication challenges include leveraging the existing DER and DR technology and systems infrastructure, and enabling optimized cost, energy and carbon choices for customers to deploy interoperable grid transactions and renewable energy systems at scale. Our paper presents a cost-effective solution to these challenges by exploring communication technologies and information models for DER system integration and interoperability. This system uses open standards and optimization models for resource planning based on dynamic-pricing notifications and autonomous operations within various domains of the smart grid energy system. It identifies architectures and customer engagement strategies in dynamic DR pricing transactions to generate feedback information models for load flexibility, load profiles, and participation schedules. The models are tested at a real site in California—Fort Hunter Liggett (FHL). Furthermore, our results for FHL show that the model fits within the existing and new DR business models and networked systems for transactive energy concepts. Integrated energy systems, communication networks, and modeling tools that coordinate supply-side networks and DER will enable electric grid system operators to use DER for grid transactions in an integrated system.

  12. Development and Testing of the Glenn Research Center Visitor's Center Grid-Tied Photovoltaic Power System

    Science.gov (United States)

    Eichenberg, Dennis J.

    2009-01-01

    The NASA Glenn Research Center (GRC) has developed, installed, and tested a 12 kW DC grid-tied photovoltaic (PV) power system at the GRC Visitor s Center. This system utilizes a unique ballast type roof mount for installing the photovoltaic panels on the roof of the Visitor s Center with no alterations or penetrations to the roof. The PV system has generated in excess of 15000 kWh since operation commenced in August 2008. The PV system is providing power to the GRC grid for use by all. Operation of the GRC Visitor s Center PV system has been completely trouble free. A grid-tied PV power system is connected directly to the utility distribution grid. Facility power can be obtained from the utility system as normal. The PV system is synchronized with the utility system to provide power for the facility, and excess power is provided to the utility. The project transfers space technology to terrestrial use via nontraditional partners. GRC personnel glean valuable experience with PV power systems that are directly applicable to various space power systems, and provides valuable space program test data. PV power systems help to reduce harmful emissions and reduce the Nation s dependence on fossil fuels. Power generated by the PV system reduces the GRC utility demand, and the surplus power aids the community. Present global energy concerns reinforce the need for the development of alternative energy systems. Modern PV panels are readily available, reliable, efficient, and economical with a life expectancy of at least 25 years. Modern electronics has been the enabling technology behind grid-tied power systems, making them safe, reliable, efficient, and economical with a life expectancy of at least 25 years. Based upon the success of the GRC Visitor s Center PV system, additional PV power system expansion at GRC is under consideration. The GRC Visitor s Center grid-tied PV power system was successfully designed and developed which served to validate the basic principles

  13. Modeling and control of sustainable power systems. Towards smarter and greener electric grids

    Energy Technology Data Exchange (ETDEWEB)

    Lingfeng Wang (ed.) [Toledo Univ., OH (United States). Electrical Engineering and Computer Science Dept.

    2012-07-01

    The concept of the smart grid promises the world an efficient and intelligent approach of managing energy production, transportation, and consumption by incorporating intelligence, efficiency, and optimality into the power grid. Both energy providers and consumers can take advantage of the convenience, reliability, and energy savings achieved by real-time and intelligent energy management. To this end, the current power grid is experiencing drastic changes and upgrades. For instance, more significant green energy resources such as wind power and solar power are being integrated into the power grid, and higher energy storage capacity is being installed in order to mitigate the intermittency issues brought about by the variable energy resources. At the same time, novel power electronics technologies and operating strategies are being invented and adopted. For instance, Flexible AC transmission systems and phasor measurement units are two promising technologies for improving the power system reliability and power quality. Demand side management will enable the customers to manage the power loads in an active fashion. As a result, modeling and control of modern power grids pose great challenges due to the adoption of new smart grid technologies. In this book, chapters regarding representative applications of smart grid technologies written by world-renowned experts are included, which explain in detail various innovative modeling and control methods. (orig.)

  14. Urban micro-grids

    International Nuclear Information System (INIS)

    Faure, Maeva; Salmon, Martin; El Fadili, Safae; Payen, Luc; Kerlero, Guillaume; Banner, Arnaud; Ehinger, Andreas; Illouz, Sebastien; Picot, Roland; Jolivet, Veronique; Michon Savarit, Jeanne; Strang, Karl Axel

    2017-02-01

    ENEA Consulting published the results of a study on urban micro-grids conducted in partnership with the Group ADP, the Group Caisse des Depots, ENEDIS, Omexom, Total and the Tuck Foundation. This study offers a vision of the definition of an urban micro-grid, the value brought by a micro-grid in different contexts based on real case studies, and the upcoming challenges that micro-grid stakeholders will face (regulation, business models, technology). The electric production and distribution system, as the backbone of an increasingly urbanized and energy dependent society, is urged to shift towards a more resilient, efficient and environment-friendly infrastructure. Decentralisation of electricity production into densely populated areas is a promising opportunity to achieve this transition. A micro-grid enhances local production through clustering electricity producers and consumers within a delimited electricity network; it has the ability to disconnect from the main grid for a limited period of time, offering an energy security service to its customers during grid outages for example. However: The islanding capability is an inherent feature of the micro-grid concept that leads to a significant premium on electricity cost, especially in a system highly reliant on intermittent electricity production. In this case, a smart grid, with local energy production and no islanding capability, can be customized to meet relevant sustainability and cost savings goals at lower costs For industrials, urban micro-grids can be economically profitable in presence of high share of reliable energy production and thermal energy demand micro-grids face strong regulatory challenges that should be overcome for further development Whether islanding is or is not implemented into the system, end-user demand for a greener, more local, cheaper and more reliable energy, as well as additional services to the grid, are strong drivers for local production and consumption. In some specific cases

  15. Robust Grid-Current-Feedback Resonance Suppression Method for LCL-Type Grid-Connected Inverter Connected to Weak Grid

    DEFF Research Database (Denmark)

    Zhou, Xiaoping; Zhou, Leming; Chen, Yandong

    2018-01-01

    In this paper, a robust grid-current-feedback reso-nance suppression (GCFRS) method for LCL-type grid-connected inverter is proposed to enhance the system damping without introducing the switching noise and eliminate the impact of control delay on system robustness against grid-impedance variation....... It is composed of GCFRS method, the full duty-ratio and zero-beat-lag PWM method, and the lead-grid-current-feedback-resonance-suppression (LGCFRS) method. Firstly, the GCFRS is used to suppress the LCL-resonant peak well and avoid introducing the switching noise. Secondly, the proposed full duty-ratio and zero......-beat-lag PWM method is used to elimi-nate the one-beat-lag computation delay without introducing duty cycle limitations. Moreover, it can also realize the smooth switching from positive to negative half-wave of the grid current and improve the waveform quality. Thirdly, the proposed LGCFRS is used to further...

  16. Incorporating Geoethics in Introductory Earth System Science Courses

    Science.gov (United States)

    Schmitt, J.

    2014-12-01

    The integrative nature of Earth System Science courses provides extensive opportunities to introduce students to geoethical inquiry focused on globally significant societal issues. Geoscience education has traditionally lagged in its efforts to increase student awareness of the significance of geologic knowledge to understanding and responsibly confronting causes and possible solutions for emergent, newly emerging, and future problems of anthropogenic cause and consequence. Developing an understanding of the human impact on the earth system requires early (lower division) and for geoscience majors, repeated (upper division) curricular emphasis on the interactions of the lithosphere, hydrosphere, atmosphere, biosphere, and pedosphere across space and through time. Capturing the interest of university students in globally relevant earth system issues and their ethical dimensions while first learning about the earth system is an important initial step in bringing geoethical deliberation and awareness to the next generation of geoscientists. Development of a new introductory Earth System Science course replacing a traditional introductory Physical Geology course at Montana State University has involved abandonment of concept-based content organization in favor of a place-based approach incorporating examination of the complex interactions of earth system components and emergent issues and dilemmas deriving from the unique component interactions that characterize each locale. Thirteen different place-based week-long modules (using web- and classroom-based instruction) were developed to ensure cumulative broad coverage across the earth geographically and earth system components conceptually. Each place-based instructional module contains content of societal relevance requiring synthesis, critical evaluation, and reflection by students. Examples include making linkages between deforestation driven by economics and increased seismicity in Haiti, agriculture and development

  17. Direct AC–AC grid interface converter for ocean wave energy system

    International Nuclear Information System (INIS)

    Tsang, K.M.; Chan, W.L.

    2015-01-01

    Highlights: • Novel power grid interface converter for ocean wave energy system. • Unlike conventional approach, generator output is directly converted into fixed frequency AC for synchronous connection. • High conversion efficient and power quality could be achieved. - Abstract: Ocean wave energy is very promising. However, existing systems are using rectifying circuits to convert variable voltage and variable frequency output of electric generator into DC voltage and then use grid-tied inverter to connect to the power grid. Such arrangement will not only reduce the overall efficient but also increase the cost of the system. A direct AC–AC converter is a desirable solution. In this paper, a six-switch AC–AC converter has been proposed as a single phase grid-connected interface. New switching scheme has been derived for the converter such that the virtual input AC–DC conversion and the output DC–AC conversion can be decoupled. State-space averaging model and pulse width modulation scheme have been derived for the converter. As the input and the output operations can be decoupled, two independent controllers have been designed to handle the input AC–DC regulation and the output DC–AC regulation. The proposed scheme demands for two separate duty ratios and novel switching scheme has been derived to realize the combined duty ratios in one switching cycle. Power regulation, harmonics elimination and power factor correction control algorithms have also been derived for the converter when it is connected to the supply grid. Experimental results of a small scale model are included to demonstrate the effectiveness of the proposed switching and control schemes

  18. Modeling Supermarket Refrigeration Systems for Supervisory Control in Smart Grid

    DEFF Research Database (Denmark)

    Shafiei, Seyed Ehsan; Rasmussen, Henrik; Stoustrup, Jakob

    2013-01-01

    A modular modeling approach of supermarket refrigeration systems (SRS) which is appropriate for smart grid control purposes is presented in this paper. Modeling and identification are performed by just knowing the system configuration and measured data disregarding the physical details. So...

  19. Stoplight Grid: a color-coded visual system for per diem staff assignment.

    Science.gov (United States)

    Ernst, P

    1989-02-01

    What is the best way to appropriately assign per diem nursing personnel? The author describes a systematic approach to per diem staff assignment called the Stoplight Grid. The Stoplight Grid correlates staff skills and preferences with unit needs and integrates this data into a color-coded system for staff assignment.

  20. Final Report. Evaluating the Climate Sensitivity of Dissipative Subgrid-Scale Mixing Processes and Variable Resolution in NCAR's Community Earth System Model

    Energy Technology Data Exchange (ETDEWEB)

    Jablonowski, Christiane [Univ. of Michigan, Ann Arbor, MI (United States)

    2015-12-14

    The goals of this project were to (1) assess and quantify the sensitivity and scale-dependency of unresolved subgrid-scale mixing processes in NCAR’s Community Earth System Model (CESM), and (2) to improve the accuracy and skill of forthcoming CESM configurations on modern cubed-sphere and variable-resolution computational grids. The research thereby contributed to the description and quantification of uncertainties in CESM’s dynamical cores and their physics-dynamics interactions.

  1. Research for Forming up the Controlling Diagram Utilizing the Connection of a LV Resistor on Voltage Transformer’s Open-Triagle Coil to Reduce over Voltage Caused by Earth Fault in 6 kV Grid of QuangNinh Underground Mines

    Directory of Open Access Journals (Sweden)

    Viet Bun Ho

    2018-01-01

    Full Text Available Single phase earth-fault in MV grids usually causes overvoltage that harm to human being and electric equipment. If the magnitude of over voltage is so great, many grids’ eco-technical parameters will be affected. The paper analyzes all possible consequences of over voltage occurred in 6 kV grid of QuangNinh underground mines. Base on the analysis, a controlling diagram utilizing the connection of a LV resistor on voltage transformer’s open-triangle coil to reduce over voltage is recommended. The simulation results of the diagram are used to prove the effectiveness of solution: the over voltage magnitude is only in the range of (2,1–2,4.Uf. Other advantage that solution brings to relay system will be pointed out.

  2. Smart Grid as Multi-layer Interacting System for Complex Decision Makings

    Science.gov (United States)

    Bompard, Ettore; Han, Bei; Masera, Marcelo; Pons, Enrico

    This chapter presents an approach to the analysis of Smart Grids based on a multi-layer representation of their technical, cyber, social and decision-making aspects, as well as the related environmental constraints. In the Smart Grid paradigm, self-interested active customers (prosumers), system operators and market players interact among themselves making use of an extensive cyber infrastructure. In addition, policy decision makers define regulations, incentives and constraints to drive the behavior of the competing operators and prosumers, with the objective of ensuring the global desired performance (e.g. system stability, fair prices). For these reasons, the policy decision making is more complicated than in traditional power systems, and needs proper modeling and simulation tools for assessing "in vitro" and ex-ante the possible impacts of the decisions assumed. In this chapter, we consider the smart grids as multi-layered interacting complex systems. The intricacy of the framework, characterized by several interacting layers, cannot be captured by closed-form mathematical models. Therefore, a new approach using Multi Agent Simulation is described. With case studies we provide some indications about how to develop agent-based simulation tools presenting some preliminary examples.

  3. Large-scale visualization system for grid environment

    International Nuclear Information System (INIS)

    Suzuki, Yoshio

    2007-01-01

    Center for Computational Science and E-systems of Japan Atomic Energy Agency (CCSE/JAEA) has been conducting R and Ds of distributed computing (grid computing) environments: Seamless Thinking Aid (STA), Information Technology Based Laboratory (ITBL) and Atomic Energy Grid InfraStructure (AEGIS). In these R and Ds, we have developed the visualization technology suitable for the distributed computing environment. As one of the visualization tools, we have developed the Parallel Support Toolkit (PST) which can execute the visualization process parallely on a computer. Now, we improve PST to be executable simultaneously on multiple heterogeneous computers using Seamless Thinking Aid Message Passing Interface (STAMPI). STAMPI, we have developed in these R and Ds, is the MPI library executable on a heterogeneous computing environment. The improvement realizes the visualization of extremely large-scale data and enables more efficient visualization processes in a distributed computing environment. (author)

  4. The International Symposium on Grids and Clouds and the Open Grid Forum

    Science.gov (United States)

    The International Symposium on Grids and Clouds 20111 was held at Academia Sinica in Taipei, Taiwan on 19th to 25th March 2011. A series of workshops and tutorials preceded the symposium. The aim of ISGC is to promote the use of grid and cloud computing in the Asia Pacific region. Over the 9 years that ISGC has been running, the programme has evolved to become more user community focused with subjects reaching out to a larger population. Research communities are making widespread use of distributed computing facilities. Linking together data centers, production grids, desktop systems or public clouds, many researchers are able to do more research and produce results more quickly. They could do much more if the computing infrastructures they use worked together more effectively. Changes in the way we approach distributed computing, and new services from commercial providers, mean that boundaries are starting to blur. This opens the way for hybrid solutions that make it easier for researchers to get their job done. Consequently the theme for ISGC2011 was the opportunities that better integrated computing infrastructures can bring, and the steps needed to achieve the vision of a seamless global research infrastructure. 2011 is a year of firsts for ISGC. First the title - while the acronym remains the same, its meaning has changed to reflect the evolution of computing: The International Symposium on Grids and Clouds. Secondly the programming - ISGC 2011 has always included topical workshops and tutorials. But 2011 is the first year that ISGC has been held in conjunction with the Open Grid Forum2 which held its 31st meeting with a series of working group sessions. The ISGC plenary session included keynote speakers from OGF that highlighted the relevance of standards for the research community. ISGC with its focus on applications and operational aspects complemented well with OGF's focus on standards development. ISGC brought to OGF real-life use cases and needs to be

  5. Quantitative Analysis Method of Output Loss due to Restriction for Grid-connected PV Systems

    Science.gov (United States)

    Ueda, Yuzuru; Oozeki, Takashi; Kurokawa, Kosuke; Itou, Takamitsu; Kitamura, Kiyoyuki; Miyamoto, Yusuke; Yokota, Masaharu; Sugihara, Hiroyuki

    Voltage of power distribution line will be increased due to reverse power flow from grid-connected PV systems. In the case of high density grid connection, amount of voltage increasing will be higher than the stand-alone grid connection system. To prevent the over voltage of power distribution line, PV system's output will be restricted if the voltage of power distribution line is close to the upper limit of the control range. Because of this interaction, amount of output loss will be larger in high density case. This research developed a quantitative analysis method for PV systems output and losses to clarify the behavior of grid connected PV systems. All the measured data are classified into the loss factors using 1 minute average of 1 second data instead of typical 1 hour average. Operation point on the I-V curve is estimated to quantify the loss due to the output restriction using module temperature, array output voltage, array output current and solar irradiance. As a result, loss due to output restriction is successfully quantified and behavior of output restriction is clarified.

  6. Comparison and selection of off-grid PV systems

    Science.gov (United States)

    Izmailov, Andrey Yu.; Lobachevsky, Yakov P.; Shepovalova, Olga V.

    2018-05-01

    This work deals with comparison, evaluation and selection of PV systems of the same type based on their technical parameters either indicated in their technical specifications or calculated ones. Stand-alone and grid backed up photoelectric systems have been considered. General requirements for photoelectric system selection and evaluation have been presented that ensure system operability and required efficiency in operation conditions. Generic principles and definition of photoelectric systems characteristics have been considered. The described method is mainly targeted at PV engineering personnel and private customers purchasing PV systems. It can be also applied in the course of project contests, tenders, etc.

  7. Solar Energy Grid Integration Systems -- Energy Storage (SEGIS-ES).

    Energy Technology Data Exchange (ETDEWEB)

    Hanley, Charles J.; Ton, Dan T. (U.S. Department of Energy, Washington, D.C.); Boyes, John D.; Peek, Georgianne Huff

    2008-07-01

    This paper describes the concept for augmenting the SEGIS Program (an industry-led effort to greatly enhance the utility of distributed PV systems) with energy storage in residential and small commercial applications (SEGIS-ES). The goal of SEGIS-ES is to develop electrical energy storage components and systems specifically designed and optimized for grid-tied PV applications. This report describes the scope of the proposed SEGIS-ES Program and why it will be necessary to integrate energy storage with PV systems as PV-generated energy becomes more prevalent on the nation's utility grid. It also discusses the applications for which energy storage is most suited and for which it will provide the greatest economic and operational benefits to customers and utilities. Included is a detailed summary of the various storage technologies available, comparisons of their relative costs and development status, and a summary of key R&D needs for PV-storage systems. The report concludes with highlights of areas where further PV-specific R&D is needed and offers recommendations about how to proceed with their development.

  8. Smart grids - French Expertise

    International Nuclear Information System (INIS)

    2015-11-01

    The adaptation of electrical systems is the focus of major work worldwide. Bringing electricity to new territories, modernizing existing electricity grids, implementing energy efficiency policies and deploying renewable energies, developing new uses for electricity, introducing electric vehicles - these are the challenges facing a multitude of regions and countries. Smart Grids are the result of the convergence of electrical systems technologies with information and communications technologies. They play a key role in addressing the above challenges. Smart Grid development is a major priority for both public and private-sector actors in France. The experience of French companies has grown with the current French electricity system, a system that already shows extensive levels of 'intelligence', efficiency and competitiveness. French expertise also leverages substantial competence in terms of 'systems engineering', and can provide a tailored response to meet all sorts of needs. French products and services span all the technical and commercial building blocks that make up the Smart Grid value chain. They address the following issues: Improving the use and valuation of renewable energies and decentralized means of production, by optimizing the balance between generation and consumption. Strengthening the intelligence of the transmission and distribution grids: developing 'Supergrid', digitizing substations in transmission networks, and automating the distribution grids are the focus of a great many projects designed to reinforce the 'self-healing' capacity of the grid. Improving the valuation of decentralized flexibilities: this involves, among others, deploying smart meters, reinforcing active energy efficiency measures, and boosting consumers' contribution to grid balancing, via practices such as demand response which implies the aggregation of flexibility among residential, business, and/or industrial sites. Addressing current technological challenges, in

  9. Modal analysis of a grid-connected direct-drive permanent magnet synchronous generator wind turbine system

    DEFF Research Database (Denmark)

    Tan, Jin; Wang, Xiao Ru; Chen, Zhe

    2013-01-01

    In order to study the stability of a grid-connected direct-drive permanent magnet synchronous generator (PMSG) wind turbine systems, this paper presents the modal analysis of a PMSG wind turbine system. A PMSG model suitable for small signal stability analysis is presented. The modal properties...... of a grid-connected PMSG wind turbine system are studied. Then the comprehensive impacts of the shaft model, shaft parameters, operation points and lengths of the transmission line on the modal characteristic of the system are investigated by the eigenvalue analysis method. Meanwhile, the corresponding...... analysis. It offers a better understanding about the essence of the stability of grid-connected PMSG wind turbine system....

  10. Energy Management Strategy for Micro-Grids with PV-Battery Systems and Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Jose Luis Torres-Moreno

    2018-02-01

    Full Text Available This paper analyzes the impact of photovoltaic (PV systems on storage and electric vehicles in micro-grids. As these kinds of systems are becoming increasingly popular in the residential sector, the development of a new generation of equipment, such as more efficient batteries or solar panels, makes further study necessary. These systems are especially interesting in commercial or office buildings, since they have a more repetitive daily pattern of electricity consumption, which usually occurs within the maximum solar radiation hours. Based on this need, a novel control strategy aimed at efficiently managing this kind of micro-grid is proposed. The core of this strategy is a rule-based controller managing the power flows between the grid and the batteries of both the PV system and the electric vehicle. Through experimental data and simulations, this strategy was tested under different scenarios. The selected testbed consisted of the laboratory of a research center, which could be easily scalable to the entire building. Results showed the benefits of using an electric vehicle as an active agent in energy balance, leading to a reduction of the energetic costs of a micro-grid.

  11. Incorporating solar home system for smart grid application

    NARCIS (Netherlands)

    Alipuria, B.; Asare-Bediako, B.; Groot, de R.J.W.; Sarker, M.J.; Slootweg, J.G.; Kling, W.L.

    2012-01-01

    Smart Grids have been one of the prime focuses of studies for the past few years on power systems. The goal is to make the power infrastructure more reliable and effective to cater for the needs of the future. Another goal for improving the power infrastructure is to incorporate renewable energy

  12. Development of stable Grid service at the next generation system of KEKCC

    Science.gov (United States)

    Nakamura, T.; Iwai, G.; Matsunaga, H.; Murakami, K.; Sasaki, T.; Suzuki, S.; Takase, W.

    2017-10-01

    A lot of experiments in the field of accelerator based science are actively running at High Energy Accelerator Research Organization (KEK) by using SuperKEKB and J-PARC accelerator in Japan. In these days at KEK, the computing demand from the various experiments for the data processing, analysis, and MC simulation is monotonically increasing. It is not only for the case with high-energy experiments, the computing requirement from the hadron and neutrino experiments and some projects of astro-particle physics is also rapidly increasing due to the very high precision measurement. Under this situation, several projects, Belle II, T2K, ILC and KAGRA experiments supported by KEK are going to utilize Grid computing infrastructure as the main computing resource. The Grid system and services in KEK, which is already in production, are upgraded for the further stable operation at the same time of whole scale hardware replacement of KEK Central Computer System (KEKCC). The next generation system of KEKCC starts the operation from the beginning of September 2016. The basic Grid services e.g. BDII, VOMS, LFC, CREAM computing element and StoRM storage element are made by the more robust hardware configuration. Since the raw data transfer is one of the most important tasks for the KEKCC, two redundant GridFTP servers are adapted to the StoRM service instances with 40 Gbps network bandwidth on the LHCONE routing. These are dedicated to the Belle II raw data transfer to the other sites apart from the servers for the data transfer usage of the other VOs. Additionally, we prepare the redundant configuration for the database oriented services like LFC and AMGA by using LifeKeeper. The LFC servers are made by two read/write servers and two read-only servers for the Belle II experiment, and all of them have an individual database for the purpose of load balancing. The FTS3 service is newly deployed as a service for the Belle II data distribution. The service of CVMFS stratum-0 is

  13. LHCb: A Policy System for Grid Management and Monitoring

    CERN Multimedia

    Stagni, F; Sapunov, M

    2010-01-01

    Organizations using a Grid computing model are faced with non-traditional administrative challenges: the heterogeneous nature of the underlying resources requires professionals acting as Grid Administrators. Members of a Virtual Organization (VO) can use a mask composed by services exposed b y local resources. In an ideal world, the more services in a mask, the better. In the real world, the less faulty services, the better: experienced Grid administrators apply procedures for adding and removing services, based on their status, as it is reported by an ever-growing set of monitoring tools. When a procedure is agreed and well-exercised, a formal policy could be derived. For this reason, using the DIRAC framework in the LHCb collaboration, we developed a policy system that can enforce management and operational policies, in a VO-specific fashion. A single policy makes an assessment on the status of a subject, relative to one or more monitoring information. Subjects of the policies are monitored entities of an e...

  14. Operation strategy for a lab-scale grid-connected photovoltaic generation system integrated with battery energy storage

    International Nuclear Information System (INIS)

    Jou, Hurng-Liahng; Chang, Yi-Hao; Wu, Jinn-Chang; Wu, Kuen-Der

    2015-01-01

    Highlights: • The operation strategy for grid-connected PV generation system integrated with battery energy storage is proposed. • The PV system is composed of an inverter and two DC-DC converter. • The negative impact of grid-connected PV generation systems on the grid can be alleviated by integrating a battery. • The operation of the developed system can be divided into nine modes. - Abstract: The operation strategy for a lab-scale grid-connected photovoltaic generation system integrated with battery energy storage is proposed in this paper. The photovoltaic generation system is composed of a full-bridge inverter, a DC–DC boost converter, an isolated bidirectional DC–DC converter, a solar cell array and a battery set. Since the battery set acts as an energy buffer to adjust the power generation of the solar cell array, the negative impact on power quality caused by the intermittent and unstable output power from a solar cell array is alleviated, so the penetration rate of the grid-connected photovoltaic generation system is increased. A lab-scale prototype is developed to verify the performance of the system. The experimental results show that it achieves the expected performance

  15. Integrating Variable Renewable Energy into the Grid: Key Issues, Greening the Grid (Spanish Version)

    Energy Technology Data Exchange (ETDEWEB)

    2016-04-01

    This is the Spanish version of 'Greening the Grid - Integrating Variable Renewable Energy into the Grid: Key Issues'. To foster sustainable, low-emission development, many countries are establishing ambitious renewable energy targets for their electricity supply. Because solar and wind tend to be more variable and uncertain than conventional sources, meeting these targets will involve changes to power system planning and operations. Grid integration is the practice of developing efficient ways to deliver variable renewable energy (VRE) to the grid. Good integration methods maximize the cost-effectiveness of incorporating VRE into the power system while maintaining or increasing system stability and reliability. When considering grid integration, policy makers, regulators, and system operators consider a variety of issues, which can be organized into four broad topics: New Renewable Energy Generation, New Transmission, Increased System Flexibility, and Planning for a High RE Future.

  16. Distributed Energy Systems: Security Implications of the Grid of the Future

    Energy Technology Data Exchange (ETDEWEB)

    Stamber, Kevin L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Kelic, Andjelka [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Taylor, Robert A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Henry, Jordan M [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Stamp, Jason E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-01-01

    Distributed Energy Resources (DER) are being added to the nation's electric grid, and as penetration of these resources increases, they have the potential to displace or offset large-scale, capital-intensive, centralized generation. Integration of DER into operation of the traditional electric grid requires automated operational control and communication of DER elements, from system measurement to control hardware and software, in conjunction with a utility's existing automated and human-directed control of other portions of the system. Implementation of DER technologies suggests a number of gaps from both a security and a policy perspective. This page intentionally left blank.

  17. The German experience with grid-connected PV-systems

    International Nuclear Information System (INIS)

    Erge, T.; Hoffmann, V.U.; Kiefer, K.

    2001-01-01

    Grid-connected photovoltaics experienced increasing attention in Germany in recent years and are expected to face a major boost at the beginning of the new millennium. Highlights like the German 100,000-Roofs-Solar-Programme, PV programmes at schools financed by utilities and governments (e.g. 'SONNEonline' by PreussenElektra, 'Sonne in der Schule' by BMWi and 'Sonne in der Schule' by Bayernwerk) and large centralised installations of MW size ('Neue Messe Munchen' by Bayernwerk and 'Energiepark Mont-Cenis' by state Nordrhein-Westfalen, Stadtwerke Herne and European Union) count for the potential of grid-connected PV. Today in Germany a typical grid-connected PV installation of 1 kW nominal power produces average annual energy yields of 700 kWh (dependent on location and system components) and shows a high operating availability. The price per kWh from PV installations is still significantly higher than the price for conventional energy, but new funding schemes and cost models (like the large increase of feed-in tariff in Germany due to the Act on Granting Priority to Renewable Energy Sources in 2000) give optimism about the future. (Author)

  18. Harmonic resonance assessment of multiple paralleled grid-connected inverters system

    DEFF Research Database (Denmark)

    Wang, Yanbo; Wang, Xiongfei; Blaabjerg, Frede

    2017-01-01

    This paper presents an eigenvalue-based impedance stability analytical method of multiple paralleled grid-connected inverter system. Different from the conventional impedance-based stability criterion, this work first built the state-space model of paralleled grid-connected inverters. On the basis...... of this, a bridge between the state-space-based modelling and impedance-based stability criterion is presented. The proposed method is able to perform stability assessment locally at the connection points of the component. Meanwhile, the eigenvalue-based sensitivity analysis is adopted to identify...

  19. Intelligent Anti Misoperation System for Power Grid Dispatching of Regions and Counties

    Science.gov (United States)

    Ji, Yuan; Zhang, Yunju; Zhou, Siming; Wang, Xiangdong; Ma, Jianwei

    2018-01-01

    With the power system of large capacity, large units, high voltage development trend, dispatching operations becoming more frequent, complex, and probability of mistakes are increasing. For the existing grid dispatching integrated system loss of anti-error function, single dispatching function, low efficiency, according to the existing conditions of Anshun Power Supply Bureau, the Intelligent anti misoperation system for power grid dispatching of regions and counties is designed, introduced the technologies such as the intelligent anti misoperation analysis, automatic process control, and interactive constraint, the system has the advantages of scientific, reasonable and efficient, and providing the technical support for anti misoperation of regions and counties.

  20. A decision modeling for phasor measurement unit location selection in smart grid systems

    Science.gov (United States)

    Lee, Seung Yup

    As a key technology for enhancing the smart grid system, Phasor Measurement Unit (PMU) provides synchronized phasor measurements of voltages and currents of wide-area electric power grid. With various benefits from its application, one of the critical issues in utilizing PMUs is the optimal site selection of units. The main aim of this research is to develop a decision support system, which can be used in resource allocation task for smart grid system analysis. As an effort to suggest a robust decision model and standardize the decision modeling process, a harmonized modeling framework, which considers operational circumstances of component, is proposed in connection with a deterministic approach utilizing integer programming. With the results obtained from the optimal PMU placement problem, the advantages and potential that the harmonized modeling process possesses are assessed and discussed.

  1. Scaling Up Renewable Energy Generation: Aligning Targets and Incentives with Grid Integration Considerations, Greening The Grid

    Energy Technology Data Exchange (ETDEWEB)

    Katz, Jessica; Cochran, Jaquelin

    2015-05-27

    Greening the Grid provides technical assistance to energy system planners, regulators, and grid operators to overcome challenges associated with integrating variable renewable energy into the grid. This document, part of a Greening the Grid toolkit, provides power system planners with tips to help secure and sustain investment in new renewable energy generation by aligning renewable energy policy targets and incentives with grid integration considerations.

  2. A Systems Approach to Analyzing Cyber-Physical Threats in the Smart Grid

    Energy Technology Data Exchange (ETDEWEB)

    Almajali, Anas; Rice, Eric; Viswanathan, Arun; Tan, Kymie; Neuman, Clifford

    2016-10-01

    This paper presents a systems analysis approach to characterizing the risk of a Smart Grid to a load-drop attack. A characterization of the risk is necessary for the design of detection and remediation strategies to address the consequences of such attacks. Using concepts from systems health management and system engineering, this work (a) first identifies metrics that can be used to generate constraints for security features, and (b) lays out an end-to-end integrated methodology using separate network and power simulations to assess system risk. We demonstrate our approach by performing a systems-style analysis of a load-drop attack implemented over the AMI subsystem and targeted at destabilizing the underlying power grid.

  3. Knowledge Discovery for Smart Grid Operation, Control, and Situation Awareness -- A Big Data Visualization Platform

    Energy Technology Data Exchange (ETDEWEB)

    Gu, Yi; Jiang, Huaiguang; Zhang, Yingchen; Zhang, Jun Jason; Gao, Tianlu; Muljadi, Eduard

    2016-11-21

    In this paper, a big data visualization platform is designed to discover the hidden useful knowledge for smart grid (SG) operation, control and situation awareness. The spawn of smart sensors at both grid side and customer side can provide large volume of heterogeneous data that collect information in all time spectrums. Extracting useful knowledge from this big-data poll is still challenging. In this paper, the Apache Spark, an open source cluster computing framework, is used to process the big-data to effectively discover the hidden knowledge. A high-speed communication architecture utilizing the Open System Interconnection (OSI) model is designed to transmit the data to a visualization platform. This visualization platform uses Google Earth, a global geographic information system (GIS) to link the geological information with the SG knowledge and visualize the information in user defined fashion. The University of Denver's campus grid is used as a SG test bench and several demonstrations are presented for the proposed platform.

  4. A Cost-Effective Power Ramp-Rate Control Strategy for Single-Phase Two-Stage Grid-Connected Photovoltaic Systems

    DEFF Research Database (Denmark)

    Sangwongwanich, Ariya; Yang, Yongheng; Blaabjerg, Frede

    2016-01-01

    In the case of a wide-scale adoption of grid-connected Photovoltaic (PV) systems, more fluctuated power will be injected into the grid due to the intermittency of solar PV energy. A sudden change in the PV power can potentially induce grid voltage fluctuations, and thus challenge the stability......-point. Experiments conducted on a 3-kW single-phase two-stage grid-connected PV system have verified that the proposed solution can accomplish fast dynamics, high accuracy, and high robustness in the power ramp-rate control for PV systems....

  5. Modeling and design of a multivariable control system for multi-paralleled grid-connected inverters with LCL filter

    DEFF Research Database (Denmark)

    Akhavan, Ali; Mohammadi, Hamid Reza; Guerrero, Josep M.

    2018-01-01

    The quality of injected current in multi-paralleled grid-connected inverters is a matter of concern. The current controlled grid-connected inverters with LCL filter are widely used in the distributed generation (DG) systems due to their fast dynamic response and better power features. However...... with resonances in the system, damping methods such as passive or active damping is necessary. Secondly and perhaps more importantly, paralleled grid-connected inverters in a microgrid are coupled due to grid impedance. Generally, the coupling effect is not taken into account when designing the control systems...

  6. Constructing low emitting power systems through grid extension in Papua New Guinea (PNG) with rural electrification

    Energy Technology Data Exchange (ETDEWEB)

    Nagai, Y. [Institute of Industrial Science, The University of Tokyo, Ogimoto Lab. 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505 (Japan); Yamamoto, H. [Department of Advanced Energy, The University of Tokyo, 5-4-5 Kashiwanoha, Kashiwa-shi, Chiba-ken 277-8561 (Japan); Yamaji, K. [Department of Electrical Engineering and Information Systems, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan)

    2010-05-15

    The effective rural electrification method varies with economic status and geographical location, and the benefits of decentralized generation differ for each energy system depending on its characteristics. This paper evaluates the most effective generation strategies with rural electrification in an optimized power system of Papua New Guinea (PNG) using a linear programming model. The energy system model developed for the study includes decentralized generation, centralized generation, and grid systems of electricity and gas with consideration for the current energy system and infrastructure. Two methods of rural electrification, decentralized generation and grid extension, are compared with and without the Clean Development Mechanism (CDM). The results of simulations show that extending the power grid that allows economical generation such as coal-fired power and hydropower to supply rural electricity is a more cost effective way for rural electrification. Although grid extension is more capital intensive than decentralized generation, the former reduces the total system cost through reduction of the fossil fuel use. Extending the power grid is also effective at attracting CDM investments, since it makes the power system flexible and provides opportunities to advance low emitting energy such as hydropower. (author)

  7. Electricity distribution management Smart Grid system model

    Directory of Open Access Journals (Sweden)

    Wiesław Nowak

    2012-06-01

    Full Text Available This paper presents issues concerning the implementation of Smart Grid solutions in a real distribution network. The main components possible to quick implementation were presented. Realization of these ideas should bring tangible benefi ts to both customers and distribution system operators. Moreover the paper shows selected research results which examine proposed solutions in area of improving supply reliability and reducing energy losses in analysed network.

  8. SuperGrid or SmartGrid: Competing strategies for large-scale integration of intermittent renewables?

    International Nuclear Information System (INIS)

    Blarke, Morten B.; Jenkins, Bryan M.

    2013-01-01

    This paper defines and compares two strategies for integrating intermittent renewables: SuperGrid and SmartGrid. While conventional energy policy suggests that these strategies may be implemented alongside each other, the paper identifies significant technological and socio-economic conflicts of interest between the two. The article identifies differences between a domestic strategy for the integration of intermittent renewables, vis-à-vis the SmartGrid, and a cross-system strategy, vis-à-vis the SuperGrid. Policy makers and transmission system operators must understand the need for both strategies to evolve in parallel, but in different territories, or with strategic integration, avoiding for one strategy to undermine the feasibility of the other. A strategic zoning strategy is introduced from which attentive societies as well as the global community stand to benefit. The analysis includes a paradigmatic case study from West Denmark which supports the hypothesis that these strategies are mutually exclusive. The case study shows that increasing cross-system transmission capacity jeopardizes the feasibility of SmartGrid technology investments. A political effort is required for establishing dedicated SmartGrid innovation zones, while also redefining infrastructure to avoid the narrow focus on grids and cables. SmartGrid Investment Trusts could be supported from reallocation of planned transmission grid investments to provide for the equitable development of SmartGrid strategies. - Highlights: • Compares SuperGrid and SmartGrid strategies for integrating intermittent renewables. • Identifies technological and socio-economic conflicts of interest between the two. • Proposes a strategic zoning strategy allowing for both strategies to evolve. • Presents a paradigmatic case study showing that strategies are mutually exclusive. • Proposes dedicated SmartGrid innovation zones and SmartGrid investment trusts

  9. A business case for Smart Grid technologies: A systemic perspective

    International Nuclear Information System (INIS)

    Giordano, Vincenzo; Fulli, Gianluca

    2012-01-01

    The digitalization of the electricity grid opens the way to bundle value added services to the electricity commodity, and possibly shift business value to electricity services in line with the notions of efficiency, conservation and sustainability. In this context, market forces should be mobilized within the boundaries of energy policy goals to contribute to the massive investments that are required to fulfill the Smart Grid vision. In this paper, we present a systemic perspective aimed at establishing technical and economic synergies that may improve the business cases of individual different Smart Grid technologies and contribute to reverse the consumption-driven paradigm of the electricity sector. Our analysis is supported by evidence from applications in the electric vehicle and smart meter ecosystems. Throughout the paper, an EU (European Union) perspective is primarily considered. - Highlights: ► We show how the analysis of systemic effects can play a fundamental role in offering a business case to Smart Grid technology and in providing some guidance to new policy interventions and initiatives. ► We base our discussion on two case studies: the set-up of business platforms for (1) Electric Vehicles and E-mobility services and (2) Smart Meters and Smart Home Services. ► We highlight how new business arrangements might leverage technological/business synergies, foster investments and shift business value to electricity services. ► We discuss possible downsides and challenges such as privacy concerns, dominant positions in new business platforms, and consumers' resistance.

  10. Gridded Data in the Arctic; Benefits and Perils of Publicly Available Grids

    Science.gov (United States)

    Coakley, B.; Forsberg, R.; Gabbert, R.; Beale, J.; Kenyon, S. C.

    2015-12-01

    Our understanding of the Arctic Ocean has been hugely advanced by release of gridded bathymetry and potential field anomaly grids. The Arctic Gravity Project grid achieves excellent, near-isotropic coverage of the earth north of 64˚N by combining land, satellite, airborne, submarine, surface ship and ice set-out measurements of gravity anomalies. Since the release of the V 2.0 grid in 2008, there has been extensive icebreaker activity across the Amerasia Basin due to mapping of the Arctic coastal nation's Extended Continental Shelves (ECS). While grid resolution has been steadily improving over time, addition of higher resolution and better navigated data highlights some distortions in the grid that may influence interpretation. In addition to the new ECS data sets, gravity anomaly data has been collected from other vessels; notably the Korean Icebreaker Araon, the Japanese icebreaker Mirai and the German icebreaker Polarstern. Also the GRAV-D project of the US National Geodetic Survey has flown airborne surveys over much of Alaska. These data will be Included in the new AGP grid, which will result in a much improved product when version 3.0 is released in 2015. To make use of these measurements, it is necessary to compile them into a continuous spatial representation. Compilation is complicated by differences in survey parameters, gravimeter sensitivity and reduction methods. Cross-over errors are the classic means to assess repeatability of track measurements. Prior to the introduction of near-universal GPS positioning, positional uncertainty was evaluated by cross-over analysis. GPS positions can be treated as more or less true, enabling evaluation of differences due to contrasting sensitivity, reference and reduction techniques. For the most part, cross-over errors for racks of gravity anomaly data collected since 2008 are less than 0.5 mGals, supporting the compilation of these data with only slight adjustments. Given the different platforms used for various

  11. Grid Voltage Modulated Control of Grid-Connected Voltage Source Inverters under Unbalanced Grid Conditions

    DEFF Research Database (Denmark)

    Li, Mingshen; Gui, Yonghao; Quintero, Juan Carlos Vasquez

    2017-01-01

    In this paper, an improved grid voltage modulated control (GVM) with power compensation is proposed for grid-connected voltage inverters when the grid voltage is unbalanced. The objective of the proposed control is to remove the power ripple and to improve current quality. Three power compensation...... objectives are selected to eliminate the negative sequence components of currents. The modified GVM method is designed to obtain two separate second-order systems for not only the fast convergence rate of the instantaneous active and reactive powers but also the robust performance. In addition, this method...

  12. NASA's Earth Science Data Systems - Lessons Learned and Future Directions

    Science.gov (United States)

    Ramapriyan, Hampapuram K.

    2010-01-01

    In order to meet the increasing demand for Earth Science data, NASA has significantly improved the Earth Science Data Systems over the last two decades. This improvement is reviewed in this slide presentation. Many Earth Science disciplines have been able to access the data that is held in the Earth Observing System (EOS) Data and Information System (EOSDIS) at the Distributed Active Archive Centers (DAACs) that forms the core of the data system.

  13. A new program in earth system science education

    Science.gov (United States)

    Huntress, Wesley; Kalb, Michael W.; Johnson, Donald R.

    1990-01-01

    A program aimed at accelerating the development of earth system science curricula at the undergraduate level and at seeding the establishment of university-based mechanisms for cooperative research and education among universities and NASA has been initiated by the Universities Space Research Association (USRA) in conjunction with NASA. Proposals were submitted by 100 U.S. research universities which were selected as candidates to participate in a three-year pilot program to develop undergraduate curricula in earth system science. Universities were then selected based upon peer review and considerations of overall scientific balance among proposed programs. The program will also aim to integrate a number of universities with evolving earth system programs, linking them with a cooperative curriculum, shared faculty, and NASA scientists in order to establish a stronger base for earth systems related education and interdisciplinary research collaboration.

  14. Observability of Low Voltage grids

    DEFF Research Database (Denmark)

    Martin-Loeches, Ruben Sánchez; Iov, Florin; Kemal, Mohammed Seifu

    2017-01-01

    Low Voltage (LV) distribution power grids are experiencing a transformation from a passive to a more active role due to the increasing penetration of distributed generation, heat pumps and electrical vehicles. The first step towards a smarter operation of LV electrical systems is to provide grid ...... an updated state of the art on DSSE-AMI based, adaptive data collection techniques and database management system types. Moreover, the ongoing Danish RemoteGRID project is presented as a realistic case study.......Low Voltage (LV) distribution power grids are experiencing a transformation from a passive to a more active role due to the increasing penetration of distributed generation, heat pumps and electrical vehicles. The first step towards a smarter operation of LV electrical systems is to provide grid....... It becomes unrealistic to provide near real time full observability of the LV grid by applying Distribution System State Estimation (DSSE) utilizing the classical data collection and storage/preprocessing techniques. This paper investigates up-todate the observability problem in LV grids by providing...

  15. Grid Based Integration Technologies of Virtual Measurement System

    International Nuclear Information System (INIS)

    Zhang, D P; He, L S; Yang, H

    2006-01-01

    This paper presents a novel integrated architecture of measurement system for the new requirements of measurement collaboration, measurement resource interconnection and transparent access etc in the wide-area and across organization in the context of a grid. The complexity of integration on a grid arises from the scale, dynamism, autonomy, and distribution of the measurement resources. The main argument of this paper is that these complexities should be made transparent to the collaborative measurement, via flexible reconfigurable mechanisms and dynamic virtualization services. The paper is started by discussing the integration-oriented measurement architecture which provides collaborative measurement services to distributed measurement resources and then the measurement mechanisms are discussed which implements the transparent access and collaboration of measurement resources by providing protocols, measurement schedule and global data driven model

  16. Workshop on Human Activity at Scale in Earth System Models

    Energy Technology Data Exchange (ETDEWEB)

    Allen, Melissa R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Aziz, H. M. Abdul [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Coletti, Mark A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Kennedy, Joseph H. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Nair, Sujithkumar S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Omitaomu, Olufemi A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-01-26

    Changing human activity within a geographical location may have significant influence on the global climate, but that activity must be parameterized in such a way as to allow these high-resolution sub-grid processes to affect global climate within that modeling framework. Additionally, we must have tools that provide decision support and inform local and regional policies regarding mitigation of and adaptation to climate change. The development of next-generation earth system models, that can produce actionable results with minimum uncertainties, depends on understanding global climate change and human activity interactions at policy implementation scales. Unfortunately, at best we currently have only limited schemes for relating high-resolution sectoral emissions to real-time weather, ultimately to become part of larger regions and well-mixed atmosphere. Moreover, even our understanding of meteorological processes at these scales is imperfect. This workshop addresses these shortcomings by providing a forum for discussion of what we know about these processes, what we can model, where we have gaps in these areas and how we can rise to the challenge to fill these gaps.

  17. Development of 3-D Flow Analysis Code for Fuel Assembly using Unstructured Grid System

    Energy Technology Data Exchange (ETDEWEB)

    Myong, Hyon Kook; Kim, Jong Eun; Ahn, Jong Ki; Yang, Seung Yong [Kookmin Univ., Seoul (Korea, Republic of)

    2007-03-15

    The flow through a nuclear rod bundle with mixing vanes are very complex and required a suitable turbulence model to be predicted accurately. Final objective of this study is to develop a CFD code for fluid flow and heat transfer analysis in a nuclear fuel assembly using unstructured grid system. In order to develop a CFD code for fluid flow and heat transfer analysis in a nuclear fuel assembly using unstructured grid system, the following researches are made: - Development of numerical algorithm for CFD code's solver - Grid and geometric connectivity data - Development of software(PowerCFD code) for fluid flow and heat transfer analysis in a nuclear fuel assembly using unstructured grid system - Modulation of software(PowerCFD code) - Development of turbulence model - Development of analysis module of RANS/LES hybrid models - Analysis of turbulent flow and heat transfer - Basic study on LES analysis - Development of main frame on pre/post processors based on GUI - Algorithm for fully-developed flow.

  18. Development of 3-D Flow Analysis Code for Fuel Assembly using Unstructured Grid System

    International Nuclear Information System (INIS)

    Myong, Hyon Kook; Kim, Jong Eun; Ahn, Jong Ki; Yang, Seung Yong

    2007-03-01

    The flow through a nuclear rod bundle with mixing vanes are very complex and required a suitable turbulence model to be predicted accurately. Final objective of this study is to develop a CFD code for fluid flow and heat transfer analysis in a nuclear fuel assembly using unstructured grid system. In order to develop a CFD code for fluid flow and heat transfer analysis in a nuclear fuel assembly using unstructured grid system, the following researches are made: - Development of numerical algorithm for CFD code's solver - Grid and geometric connectivity data - Development of software(PowerCFD code) for fluid flow and heat transfer analysis in a nuclear fuel assembly using unstructured grid system - Modulation of software(PowerCFD code) - Development of turbulence model - Development of analysis module of RANS/LES hybrid models - Analysis of turbulent flow and heat transfer - Basic study on LES analysis - Development of main frame on pre/post processors based on GUI - Algorithm for fully-developed flow

  19. Energy Storage Management in Grid Connected Solar Photovoltaic System

    OpenAIRE

    Vidhya M.E

    2015-01-01

    The penetration of renewable sources in the power system network in the power system has been increasing in the recent years. One of the solutions being proposed to improve the reliability and performance of these systems is to integrate energy storage device into the power system network. This paper discusses the modeling of photo voltaic and status of the storage device such as lead acid battery for better energy management in the system. The energy management for the grid conne...

  20. WHERE TO FIND HABITABLE ''EARTHS'' IN CIRCUMBINARY SYSTEMS

    International Nuclear Information System (INIS)

    Liu Huigen; Zhang Hui; Zhou Jilin

    2013-01-01

    Six P-type planets have been found thus far around five binary systems, i.e., Kepler-16b, 34b, 35b, 38b, and 47b and c, which are all Neptune- or Jupiter-like planets. The stability of planets and the habitable zones are influenced by the gravitational and radiative perturbations of binary companions. In this Letter, we check the stability of an additional habitable Earth-mass planet in each system. Based on our simulations in 10 Myr, a habitable ''Earth'' is hardly stable in Kepler-16, while a stable ''Earth'' in Kepler-47 close to the boundaries of the habitable zone is possible. In contrast, Kepler-34, 35, and 38 seem to have high probabilities of being able to tolerante a stable ''Earth'' in their habitable zones. The affects of transit time variations are quite small due to the small mass of an undetected ''Earth,'' except that of Kepler-16b. With a time precision of 10 –3 day (∼88 s), an ''Earth'' in the corotational resonance with Kepler-16b can be detected in three years, while habitable ''Earths'' in the Kepler-34 and 38 systems can be detected in 10 yr. Habitable ''Earths'' in Kepler-35 and 47 are not likely to be detected in 10 yr under this precision.

  1. EOS Reference Handbook 1999: A Guide to NASA's Earth Science Enterprise and the Earth Observing System

    Science.gov (United States)

    King, M. D. (Editor); Greenstone, R. (Editor)

    2000-01-01

    The content of this handbook includes Earth Science Enterprise; The Earth Observing System; EOS Data and Information System (EOSDIS); Data and Information Policy; Pathfinder Data Sets; Earth Science Information Partners and the Working Prototype-Federation; EOS Data Quality: Calibration and Validation; Education Programs; International Cooperation; Interagency Coordination; Mission Elements; EOS Instruments; EOS Interdisciplinary Science Investigations; and Points-of-Contact.

  2. Renewable Electricity-to-Grid Integration | Energy Systems Integration

    Science.gov (United States)

    Facility | NREL Renewable Electricity-to-Grid Integration Renewable Electricity-to-Grid Integration NREL works with industry partners to optimize strategies for effectively interconnecting renewable renewable electric grid integration work includes research and development (R&D) on advanced inverters

  3. LVRT Capability of Single-Phase Grid-Connected HERIC Inverter in PV Systems by a Look-up Table Based Predictive Control

    DEFF Research Database (Denmark)

    Zangeneh Bighash, Esmaeil; Sadeghzadeh, Seyed Mohammad; Ebrahimzadeh, Esmaeil

    2017-01-01

    Nowadays capacity of the photovoltaic systems in the grid is remarkable and provides a major part of energy in the grid. Therefore, an abruption of these systems from the grid can create a damage to the grid. Unlike in the past that PV systems disconnected from the grid when a voltage drop occurred......, nowadays these systems should have Low Voltage Ride-Through (LVRT) capability. The PV system should stay connected to the grid at fault time and help to recover the grid voltage by injecting the reactive power like in a power plant or a custom power device. There are two important factors for single phase...... grid connected PV inverters. The first one is the structure of the inverter and the second one is the control part. In this regard, the HERIC inverter can be a good selection among the transformerless inverters for a PV system due to its high efficiency. For the control part, this paper presents a look...

  4. Optimal sizing and control strategy of isolated grid with wind power and energy storage system

    International Nuclear Information System (INIS)

    Luo, Yi; Shi, Lin; Tu, Guangyu

    2014-01-01

    Highlights: • An energy storage sizing scheme for wind powered isolated grid is developed. • A bi-level control strategy for wind-battery isolated grid is proposed. • The energy storage type selection method for Nan’ao island grid is presented. • The sizing method and the control strategy are verified based on the Nan’ao island. • The wind-battery demonstration system has great benefit for remote areas. - Abstract: Integrating renewable energy and energy storage system provides a prospective way for power supply of remote areas. Focused on the isolated grids comprising renewable energy generation and energy storage, an energy storage sizing method for taking account of the reliability requirement and a bi-level control strategy of the isolated grids are presented in this paper. Based on comparative analysis of current energy storage characteristics and practicability, Sodium–sulfur battery is recommended for power balance control in the isolated grids. The optimal size of the energy storage system is determined by genetic algorithm and sequential simulation. The annualized cost considering the compensation cost of curtailed wind power and load is minimized when the reliability requirement can be satisfied. The sizing method emphasizes the tradeoff between energy storage size and reliability of power supply. The bi-level control strategy is designed as upper level wide area power balance control in dispatch timescale and lower level battery energy storage system V/f control in real-time range for isolated operation. The mixed timescale simulation results of Nan’ao Island grid verify the effectiveness of the proposed sizing method and control strategy

  5. Energy efficiency design strategies for buildings with grid-connected photovoltaic systems

    Science.gov (United States)

    Yimprayoon, Chanikarn

    The building sector in the United States represents more than 40% of the nation's energy consumption. Energy efficiency design strategies and renewable energy are keys to reduce building energy demand. Grid-connected photovoltaic (PV) systems installed on buildings have been the fastest growing market in the PV industry. This growth poses challenges for buildings qualified to serve in this market sector. Electricity produced from solar energy is intermittent. Matching building electricity demand with PV output can increase PV system efficiency. Through experimental methods and case studies, computer simulations were used to investigate the priorities of energy efficiency design strategies that decreased electricity demand while producing load profiles matching with unique output profiles from PV. Three building types (residential, commercial, and industrial) of varying sizes and use patterns located in 16 climate zones were modeled according to ASHRAE 90.1 requirements. Buildings were analyzed individually and as a group. Complying with ASHRAE energy standards can reduce annual electricity consumption at least 13%. With energy efficiency design strategies, the reduction could reach up to 65%, making it possible for PV systems to meet reduced demands in residential and industrial buildings. The peak electricity demand reduction could be up to 71% with integration of strategies and PV. Reducing lighting power density was the best single strategy with high overall performances. Combined strategies such as zero energy building are also recommended. Electricity consumption reductions are the sum of the reductions from strategies and PV output. However, peak electricity reductions were less than their sum because they reduced peak at different times. The potential of grid stress reduction is significant. Investment incentives from government and utilities are necessary. The PV system sizes on net metering interconnection should not be limited by legislation existing in

  6. Control of Grid Connected Photovoltaic Systems with Microinverters

    DEFF Research Database (Denmark)

    Yahya, Abdelhafid; El Fadil, Hassan; Oulcaid, Mustapha

    2018-01-01

    This paper addresses the problem of controlling grid connected photovoltaic (PV) systems that are driven with microinverters. The systems to be controlled consist of a solar panel, a boost dc–dc converter, a DC link capacitor, a single-phase full-bridge inverter, a filter inductor, and an isolation...... transformer. We seek controllers that are able to simultaneously achieve four control objectives, namely: (i) asymptotic stability of the closed loop control system; (ii) maximum power point tracking (MPPT) of the PV module; (iii) tight regulation of the DC bus voltage; and (iv) unity power factor (PF...

  7. Grid-connected photovoltaic systems for Malaysian residential sector: Effects of component costs, feed-in tariffs, and carbon taxes

    International Nuclear Information System (INIS)

    Lau, K.Y.; Muhamad, N.A.; Arief, Y.Z.; Tan, C.W.; Yatim, A.H.M.

    2016-01-01

    Blessed with abundant solar radiation, Malaysia has a huge potential for grid-connected PV (photovoltaic) installations, particularly for its fast-growing residential sector. Nevertheless, Malaysia's PV installation capacity is relatively small compared with the global PV capacity. Significantly, the pricing mechanisms for grid-connected PV projects need to be appropriately assessed to build up the public's confidence to invest in PV projects. In this paper, we analyze the effects of component costs, FiTs (feed-in tariffs), and carbon taxes on grid-connected PV systems in Malaysian residential sector using the HOMER (Hybrid Optimization of Multiple Energy Resources) software. Results demonstrate that the implementation of grid-connected PV systems is highly feasible with PV array costs of $ 1120/kW or lower. For higher PV array costs up to $ 2320/kW, introducing an FiT rate three times higher ($ 0.30/kWh) than the grid tariff for a 100 kW grid sale capacity will, NPC-wise, prioritize grid-connected PV systems over the utility grid. By implementing the FiT ($ 0.50/kWh) and the carbon tax ($ 36/metric ton) schemes simultaneously, grid-connected PV systems will remain as the optimal systems even for costly PV arrays (up to $ 4000/kW). The findings are of paramount importance as far as PV pricing variability is concerned. - Highlights: • Grid-connected PV for Malaysian residential sector has been analyzed using HOMER. • Component costs, feed-in tariffs, and carbon taxes affect optimal system types. • Grid-connected PV projects are feasible for low PV array costs ($ 1120/kW or lower). • For higher PV array and inverter costs, feed-in tariffs should be implemented. • Combining feed-in tariffs with carbon taxes are effective for further lowering NPCs.

  8. Global Renewable Energy-Based Electricity Generation and Smart Grid System for Energy Security

    Science.gov (United States)

    Islam, M. A.; Hasanuzzaman, M.; Rahim, N. A.; Nahar, A.; Hosenuzzaman, M.

    2014-01-01

    Energy is an indispensable factor for the economic growth and development of a country. Energy consumption is rapidly increasing worldwide. To fulfill this energy demand, alternative energy sources and efficient utilization are being explored. Various sources of renewable energy and their efficient utilization are comprehensively reviewed and presented in this paper. Also the trend in research and development for the technological advancement of energy utilization and smart grid system for future energy security is presented. Results show that renewable energy resources are becoming more prevalent as more electricity generation becomes necessary and could provide half of the total energy demands by 2050. To satisfy the future energy demand, the smart grid system can be used as an efficient system for energy security. The smart grid also delivers significant environmental benefits by conservation and renewable generation integration. PMID:25243201

  9. Global renewable energy-based electricity generation and smart grid system for energy security.

    Science.gov (United States)

    Islam, M A; Hasanuzzaman, M; Rahim, N A; Nahar, A; Hosenuzzaman, M

    2014-01-01

    Energy is an indispensable factor for the economic growth and development of a country. Energy consumption is rapidly increasing worldwide. To fulfill this energy demand, alternative energy sources and efficient utilization are being explored. Various sources of renewable energy and their efficient utilization are comprehensively reviewed and presented in this paper. Also the trend in research and development for the technological advancement of energy utilization and smart grid system for future energy security is presented. Results show that renewable energy resources are becoming more prevalent as more electricity generation becomes necessary and could provide half of the total energy demands by 2050. To satisfy the future energy demand, the smart grid system can be used as an efficient system for energy security. The smart grid also delivers significant environmental benefits by conservation and renewable generation integration.

  10. Global Renewable Energy-Based Electricity Generation and Smart Grid System for Energy Security

    Directory of Open Access Journals (Sweden)

    M. A. Islam

    2014-01-01

    Full Text Available Energy is an indispensable factor for the economic growth and development of a country. Energy consumption is rapidly increasing worldwide. To fulfill this energy demand, alternative energy sources and efficient utilization are being explored. Various sources of renewable energy and their efficient utilization are comprehensively reviewed and presented in this paper. Also the trend in research and development for the technological advancement of energy utilization and smart grid system for future energy security is presented. Results show that renewable energy resources are becoming more prevalent as more electricity generation becomes necessary and could provide half of the total energy demands by 2050. To satisfy the future energy demand, the smart grid system can be used as an efficient system for energy security. The smart grid also delivers significant environmental benefits by conservation and renewable generation integration.

  11. Challenges in Modeling the Sun-Earth System

    Science.gov (United States)

    Spann, James

    2004-01-01

    The transfer of mass, energy and momentum through the coupled Sun-Earth system spans a wide range of scales in time and space. While profound advances have been made in modeling isolated regions of the Sun-Earth system, minimal progress has been achieved in modeling the end-to-end system. Currently, end-to-end modeling of the Sun-Earth system is a major goal of the National Space Weather and NASA Living With a Star (LWS) programs. The uncertainty in the underlying physics responsible for coupling contiguous regions of the Sun-Earth system is recognized as a significant barrier to progress. Our limited understanding of the underlying coupling physics is illustrated by the following example questions: how does the propagation of a typical CME/solar flare influence the measured properties of the solar wind at 1 AU? How does the solar wind compel the dynamic response of the Earth's magnetosphere? How is variability in the ionosphere-thermosphere system coupled to magnetospheric variations? Why do these and related important questions remain unanswered? What are the primary problems that need to be resolved to enable significant progress in comprehensive modeling of the Sun-Earth system? Which model/technique improvements are required and what new data coverage is required to enable full model advances? This poster opens the discussion for how these and other important questions can be addressed. A workshop scheduled for October 8-22, 2004 in Huntsville, Alabama, will be a forum for identifying ana exploring promising new directions and approaches for characterizing and understanding the system. To focus the discussion, the workshop will emphasize the genesis, evolution, propagation and interaction of high-speed solar wind streamers or CME/flares with geospace and the subsequent response of geospace from its outer reaches in the magnetosphere to the lower edge of the ionosphere-mesosphere-thermosphere. Particular emphasis will be placed on modeling the coupling aspects

  12. Synchronization of grid-connected renewable energy sources under highly distorted voltages and unbalanced grid faults

    DEFF Research Database (Denmark)

    Hadjidemetriou, Lenos; Kyriakides, Elias; Blaabjerg, Frede

    2013-01-01

    Renewable energy sources require accurate and appropriate performance not only under normal grid operation but also under abnormal and faulty grid conditions according to the modern grid codes. This paper proposes a novel phase-locked loop algorithm (MSHDC-PLL), which can enable the fast...... and dynamic synchronization of the interconnected renewable energy system under unbalanced grid faults and under highly harmonic distorted voltage. The outstanding performance of the suggested PLL is achieved by implementing an innovative multi-sequence/harmonic decoupling cell in order to dynamically cancel...... renewable energy systems. Therefore, the performance of the new PLL can increase the quality of the injected power under abnormal conditions and in addition enable the renewable energy systems to provide the appropriate support to the grid under balanced and unbalanced grid faults....

  13. Balancing Area Coordination: Efficiently Integrating Renewable Energy Into the Grid, Greening the Grid

    Energy Technology Data Exchange (ETDEWEB)

    Katz, Jessica; Denholm, Paul; Cochran, Jaquelin

    2015-06-01

    Greening the Grid provides technical assistance to energy system planners, regulators, and grid operators to overcome challenges associated with integrating variable renewable energy into the grid. Coordinating balancing area operation can promote more cost and resource efficient integration of variable renewable energy, such as wind and solar, into power systems. This efficiency is achieved by sharing or coordinating balancing resources and operating reserves across larger geographic boundaries.

  14. A Grid Architecture for Manufacturing Database System

    Directory of Open Access Journals (Sweden)

    Laurentiu CIOVICĂ

    2011-06-01

    Full Text Available Before the Enterprise Resource Planning concepts business functions within enterprises were supported by small and isolated applications, most of them developed internally. Yet today ERP platforms are not by themselves the answer to all organizations needs especially in times of differentiated and diversified demands among end customers. ERP platforms were integrated with specialized systems for the management of clients, Customer Relationship Management and vendors, Supplier Relationship Management. They were integrated with Manufacturing Execution Systems for better planning and control of production lines. In order to offer real time, efficient answers to the management level, ERP systems were integrated with Business Intelligence systems. This paper analyses the advantages of grid computing at this level of integration, communication and interoperability between complex specialized informatics systems with a focus on the system architecture and data base systems.

  15. Offshore Wind Farms and HVDC Grids Modeling as a Feedback Control System for Stability Analysis

    DEFF Research Database (Denmark)

    Bidadfar, Ali; Saborío-Romano, Oscar; Altin, Müfit

    The low impedance characteristics of DC transmission lines cause the voltage source converter (VSC) in HVDC networks to become electrically closer together and increase the risk of severe interactions between the converters. Such interactions, in turn, intensify the implementation of the grid...... control schemes and may lead the entire system to instability. Assessing the stability and adopting complex coordinated control schemes in an HVDC grid and wind farm turbines are challenging and require a precise model of the HVDC grid, wind farm, and the controllers. In this paper, a linear multivariable...... feedback control system (FCS) model is proposed to represent the dynamic characteristics of HVDC grids and their controllers. The FCS model can be used for different dynamic analyses in time and frequency domains. Moreover, using the FCS model the system stability is analyzed in both open- and closed...

  16. The GridShare solution: a smart grid approach to improve service provision on a renewable energy mini-grid in Bhutan

    International Nuclear Information System (INIS)

    Quetchenbach, T G; Harper, M J; Jacobson, A E; Robinson IV, J; Hervin, K K; Chase, N A; Dorji, C

    2013-01-01

    This letter reports on the design and pilot installation of GridShares, devices intended to alleviate brownouts caused by peak power use on isolated, village-scale mini-grids. A team consisting of the authors and partner organizations designed, built and field-tested GridShares in the village of Rukubji, Bhutan. The GridShare takes an innovative approach to reducing brownouts by using a low cost device that communicates the state of the grid to its users and regulates usage before severe brownouts occur. This demand-side solution encourages users to distribute the use of large appliances more evenly throughout the day, allowing power-limited systems to provide reliable, long-term renewable electricity to these communities. In the summer of 2011, GridShares were installed in every household and business connected to the Rukubji micro-hydro mini-grid, which serves approximately 90 households with a 40 kW nominal capacity micro-hydro system. The installation was accompanied by an extensive education program. Following the installation of the GridShares, the occurrence and average length of severe brownouts, which had been caused primarily by the use of electric cooking appliances during meal preparation, decreased by over 92%. Additionally, the majority of residents surveyed stated that now they are more certain that their rice will cook well and that they would recommend installing GridShares in other villages facing similar problems. (letter)

  17. Distributed visualization of gridded geophysical data: the Carbon Data Explorer, version 0.2.3

    Science.gov (United States)

    Endsley, K. A.; Billmire, M. G.

    2016-01-01

    Due to the proliferation of geophysical models, particularly climate models, the increasing resolution of their spatiotemporal estimates of Earth system processes, and the desire to easily share results with collaborators, there is a genuine need for tools to manage, aggregate, visualize, and share data sets. We present a new, web-based software tool - the Carbon Data Explorer - that provides these capabilities for gridded geophysical data sets. While originally developed for visualizing carbon flux, this tool can accommodate any time-varying, spatially explicit scientific data set, particularly NASA Earth system science level III products. In addition, the tool's open-source licensing and web presence facilitate distributed scientific visualization, comparison with other data sets and uncertainty estimates, and data publishing and distribution.

  18. Power grids

    International Nuclear Information System (INIS)

    Viterbo, J.

    2012-01-01

    The implementation of renewable energies represents new challenges for electrical systems. The objective: making power grids smarter so they can handle intermittent production. The advent of smart grids will allow flexible operations like distributing energy in a multidirectional manner instead of just one way and it will make electrical systems capable of integrating actions by different users, consumers and producers in order to maintain efficient, sustainable, economical and secure power supplies. Practically speaking, they associate sensors, instrumentation and controls with information processing and communication systems in order to create massively automated networks. Smart grids require huge investments: for example more than 7 billion dollars have been invested in China and in the Usa in 2010 and France is ranked 9. worldwide with 265 million dollars invested. It is expected that smart grids will promote the development of new business models and a change in the value chain for energy. Decentralized production combined with the probable introduction of more or less flexible rates for sales or purchases and of new supplier-customer relationships will open the way to the creation of new businesses. (A.C.)

  19. PV-hybrid and mini-grid

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-07-01

    Within the 5th European PV-hybrid and mini-grid conference 29th and 30th April, 2010 in Tarragona (Spain) the following lectures were held: (1) Overview of IEA PVPS Task 11 PV-hybrid systems within mini grids; (2) Photovoltaic revolution for deployment in developing countries; (3) Legal and financial conditions for the sustainable operation of mini-grids; (4) EU instruments to promote renewable energies in developing countries; (5) PV hybridization of diesel electricity generators: Conditions of profitability and examples in differential power and storage size ranges; (6) Education suit of designing PV hybrid systems; (7) Sustainable renewable energy projects for intelligent rural electrification in Laos, Cambodia and Vietnam; (8) Techno-economic feasibility of energy supply of remote villages in Palestine by PV systems, diesel generators and electric grid (Case studies: Emnazeil and Atouf villages); (9) Technical, economical and sustainability considerations of a solar PV mini grid as a tool for rural electrification in Uganda; (10) Can we rate inverters for rural electrification on the basis of energy efficiency?; (11) Test procedures for MPPT charge controllers characterization; (12) Energy storage for mini-grid stabilization; (13) Redox flow batteries - Already an alternative storage solution for hybrid PV mini-grids?; (14) Control methods for PV hybrid mini-grids; (15) Partial AC-coupling in mini-grids; (15) Normative issues of small wind turbines in PV hybrid systems; (16) Communication solutions for PV hybrid systems; (17) Towards flexible control and communication of mini-grids; (18) PV/methanol fuel cell hybrid system for powering a highway security variable message board; (19) Polygeneration smartgrids: A solution for the supply of electricity, potable water and hydrogen as fuel for transportation in remote Areas; (20) Implementation of the Bronsbergen micro grid using FACDS; (21) A revisited approach for the design of PV wind hybrid systems; (22

  20. A New Power Calculation Method for Single-Phase Grid-Connected Systems

    DEFF Research Database (Denmark)

    Yang, Yongheng; Blaabjerg, Frede

    2013-01-01

    A new method to calculate average active power and reactive power for single-phase systems is proposed in this paper. It can be used in different applications where the output active power and reactive power need to be calculated accurately and fast. For example, a grid-connected photovoltaic...... system in low voltage ride through operation mode requires a power feedback for the power control loop. Commonly, a Discrete Fourier Transform (DFT) based power calculation method can be adopted in such systems. However, the DFT method introduces at least a one-cycle time delay. The new power calculation...... method, which is based on the adaptive filtering technique, can achieve a faster response. The performance of the proposed method is verified by experiments and demonstrated in a 1 kW single-phase grid-connected system operating under different conditions.Experimental results show the effectiveness...

  1. NASA's Earth Observing Data and Information System

    Science.gov (United States)

    Mitchell, A. E.; Behnke, J.; Lowe, D.; Ramapriyan, H. K.

    2009-12-01

    NASA’s Earth Observing System Data and Information System (EOSDIS) has been a central component of NASA Earth observation program for over 10 years. It is one of the largest civilian science information system in the US, performing ingest, archive and distribution of over 3 terabytes of data per day much of which is from NASA’s flagship missions Terra, Aqua and Aura. The system supports a variety of science disciplines including polar processes, land cover change, radiation budget, and most especially global climate change. The EOSDIS data centers, collocated with centers of science discipline expertise, archive and distribute standard data products produced by science investigator-led processing systems. Key to the success of EOSDIS is the concept of core versus community requirements. EOSDIS supports a core set of services to meet specific NASA needs and relies on community-developed services to meet specific user needs. EOSDIS offers a metadata registry, ECHO (Earth Observing System Clearinghouse), through which the scientific community can easily discover and exchange NASA’s Earth science data and services. Users can search, manage, and access the contents of ECHO’s registries (data and services) through user-developed and community-tailored interfaces or clients. The ECHO framework has become the primary access point for cross-Data Center search-and-order of EOSDIS and other Earth Science data holdings archived at the EOSDIS data centers. ECHO’s Warehouse Inventory Search Tool (WIST) is the primary web-based client for discovering and ordering cross-discipline data from the EOSDIS data centers. The architecture of the EOSDIS provides a platform for the publication, discovery, understanding and access to NASA’s Earth Observation resources and allows for easy integration of new datasets. The EOSDIS also has developed several methods for incorporating socioeconomic data into its data collection. Over the years, we have developed several methods for

  2. NASA's Earth Observing Data and Information System

    Science.gov (United States)

    Mitchell, Andrew E.; Behnke, Jeanne; Lowe, Dawn; Ramapriyan, H. K.

    2009-01-01

    NASA's Earth Observing System Data and Information System (EOSDIS) has been a central component of NASA Earth observation program for over 10 years. It is one of the largest civilian science information system in the US, performing ingest, archive and distribution of over 3 terabytes of data per day much of which is from NASA s flagship missions Terra, Aqua and Aura. The system supports a variety of science disciplines including polar processes, land cover change, radiation budget, and most especially global climate change. The EOSDIS data centers, collocated with centers of science discipline expertise, archive and distribute standard data products produced by science investigator-led processing systems. Key to the success of EOSDIS is the concept of core versus community requirements. EOSDIS supports a core set of services to meet specific NASA needs and relies on community-developed services to meet specific user needs. EOSDIS offers a metadata registry, ECHO (Earth Observing System Clearinghouse), through which the scientific community can easily discover and exchange NASA s Earth science data and services. Users can search, manage, and access the contents of ECHO s registries (data and services) through user-developed and community-tailored interfaces or clients. The ECHO framework has become the primary access point for cross-Data Center search-and-order of EOSDIS and other Earth Science data holdings archived at the EOSDIS data centers. ECHO s Warehouse Inventory Search Tool (WIST) is the primary web-based client for discovering and ordering cross-discipline data from the EOSDIS data centers. The architecture of the EOSDIS provides a platform for the publication, discovery, understanding and access to NASA s Earth Observation resources and allows for easy integration of new datasets. The EOSDIS also has developed several methods for incorporating socioeconomic data into its data collection. Over the years, we have developed several methods for determining

  3. Properties and uses of storage for enhancing the grid penetration of very large photovoltaic systems

    International Nuclear Information System (INIS)

    Solomon, A.A.; Faiman, D.; Meron, G.

    2010-01-01

    In this third paper, which studies the hourly generation data for the year 2006 from the Israel Electric Corporation, with a view to incorporating very large photovoltaic (PV) power plants, we address the question: What properties should storage have in order to enhance the grid penetration of large PV systems in an efficient and substantial manner? We first impose the constraint that no PV energy losses are permitted other than those due to storage inefficiency. This constraint leads to powerful linkages between the energy capacity and power capacity of storage, and PV system size, and their combined effect on grid penetration. Various strategies are then examined for enhancing grid penetration, based upon this newfound knowledge. Specific strategies examined include PV energy dumping and baseload rescheduling both on a seasonal basis and shorter time periods. We found, inter alia, that at high grid flexibilities (in the range ff=0.8-1), PV grid penetration levels could be possible in the range 60-90% of annual requirements. Moreover, with appropriately designed storage and accurate forecasting, a future grid could be operated at ff=1.

  4. SuperGrid or SmartGrid: Competing strategies for large-scale integration of intermittent renewables?

    DEFF Research Database (Denmark)

    Blarke, Morten; M. Jenkins, Bryan

    2013-01-01

    This paper defines and compares two strategies for integrating intermittent renewables: SuperGrid and SmartGrid. While conventional energy policy suggests that these strategies may be implemented alongside each other, the paper identifies significant technological and socio-economic conflicts...... of interest between the two. The article identifies differences between a domestic strategy for the integration of intermittent renewables, vis-à-vis the SmartGrid, and a cross-system strategy, vis-à-vis the SuperGrid. Policy makers and transmission system operators must understand the need for both...... a paradigmatic case study from West Denmark which supports the hypothesis that these strategies are mutually exclusive. The case study shows that increasing cross-system transmission capacity jeopardizes the feasibility of SmartGrid technology investments. A political effort is required for establishing...

  5. Power conditioning system topology for grid integration of wind and fuell cell energy

    Directory of Open Access Journals (Sweden)

    Marian GAICEANU

    2006-12-01

    Full Text Available This paper shows the topology of the hybrid grid-connected power system and the performances of the front-end three-phase power inverter. The renewable sources of the hybrid power system consist of a solid oxide fuel cell and a wind-turbine. This type of combination is the most efficient one. The proposed topology benefits of the one common DC-AC inverter which injects the generated power into the grid. The architecture diminishes the cost of the power conditioning system. Moreover, due to the power balance control of the entire power conditioning system the bulk dc link electrolytic capacitor is replaced with a small plastic film one. The final power conditioning system has the following advantages: independent control of the reactive power, minimize harmonic current distortion offering a nearly unity power factor operation (0,998 operation capability, dc link voltage regulation (up to 5% ripple in the dc-link voltage in any operated conditions, fast disturbance compensation capability, high reliability, and low cost. The experimental test has been performed and the performances of the grid power inverter are shown.

  6. Development of an Advanced Grid-Connected PV-ECS System Considering Solar Energy Estimation

    Science.gov (United States)

    Rahman, Md. Habibur; Yamashiro, Susumu; Nakamura, Koichi

    In this paper, the development and the performance of a viable distributed grid-connected power generation system of Photovoltaic-Energy Capacitor System (PV-ECS) considering solar energy estimation have been described. Instead of conventional battery Electric Double Layer Capacitors (EDLC) are used as storage device and Photovoltaic (PV) panel to generate power from solar energy. The system can generate power by PV, store energy when the demand of load is low and finally supply the stored energy to load during the period of peak demand. To realize the load leveling function properly the system will also buy power from grid line when load demand is high. Since, the power taken from grid line depends on the PV output power, a procedure has been suggested to estimate the PV output power by calculating solar radiation. In order to set the optimum value of the buy power, a simulation program has also been developed. Performance of the system has been studied for different load patterns in different weather conditions by using the estimated PV output power with the help of the simulation program.

  7. A Fuzzy ANP Model Integrated with Benefits, Opportunities, Costs, and Risks to Prioritize Intelligent Power Grid Systems

    Directory of Open Access Journals (Sweden)

    Hsing Hung Chen

    2013-01-01

    Full Text Available Although growth of renewable energy is envisaged, many concerns are critical like the ability to maintain the balance between demands and supply and the variability, noncontrollability, and flexibility of the sources. Then, what will be the future concerns about the main composition of intelligent power grid systems in the future? There is no such research tackled before. Thus, this paper first finds critical success criteria of intelligent power grid systems and then constructs a multiple criteria and decision making model to help in identifying the suitable trends under complex economic performance, environmental impacts, and rapid technological and marketing changes. After empirical demonstration, the paper summarizes that the most suitable composition of future intelligent power grid systems should be constituted by “DHT” P2P grid, “C&D workflow” P2P scheduling, “GARCM” trustworthy P2P grid, and “multipurpose” grid applications in the future.

  8. Non-equilibrium thermodynamics, maximum entropy production and Earth-system evolution.

    Science.gov (United States)

    Kleidon, Axel

    2010-01-13

    The present-day atmosphere is in a unique state far from thermodynamic equilibrium. This uniqueness is for instance reflected in the high concentration of molecular oxygen and the low relative humidity in the atmosphere. Given that the concentration of atmospheric oxygen has likely increased throughout Earth-system history, we can ask whether this trend can be generalized to a trend of Earth-system evolution that is directed away from thermodynamic equilibrium, why we would expect such a trend to take place and what it would imply for Earth-system evolution as a whole. The justification for such a trend could be found in the proposed general principle of maximum entropy production (MEP), which states that non-equilibrium thermodynamic systems maintain steady states at which entropy production is maximized. Here, I justify and demonstrate this application of MEP to the Earth at the planetary scale. I first describe the non-equilibrium thermodynamic nature of Earth-system processes and distinguish processes that drive the system's state away from equilibrium from those that are directed towards equilibrium. I formulate the interactions among these processes from a thermodynamic perspective and then connect them to a holistic view of the planetary thermodynamic state of the Earth system. In conclusion, non-equilibrium thermodynamics and MEP have the potential to provide a simple and holistic theory of Earth-system functioning. This theory can be used to derive overall evolutionary trends of the Earth's past, identify the role that life plays in driving thermodynamic states far from equilibrium, identify habitability in other planetary environments and evaluate human impacts on Earth-system functioning. This journal is © 2010 The Royal Society

  9. Rethinking the Future Grid: Integrated Nuclear Renewable Energy Systems: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Bragg-Sitton, S. M.; Boardman, R.; Ruth, M.; Zinaman, O.; Forsberg, C.

    2015-01-01

    The U.S. DOE is supporting research and development that could lead to more efficient utilization of clean energy generation sources, including renewable and nuclear options, to meet both grid demand and thermal energy needs in the industrial sector. One concept under consideration by the DOE-NE and DOE-EERE is tighter coupling of nuclear and renewable energy sources in a manner that better optimizes energy use for the combined electricity, industrial manufacturing, and transportation sectors. This integration concept has been referred to as a 'hybrid system' that is capable of apportioning thermal and electrical energy to first meet the grid demand (with appropriate power conversion systems), then utilizing excess thermal and, in some cases, electrical energy to drive a process that results in an additional product.

  10. Optimising the economic viability of grid-connected photovoltaic systems

    International Nuclear Information System (INIS)

    Mondol, Jayanta Deb; Yohanis, Yigzaw G; Norton, Brian

    2009-01-01

    The impact of photovoltaic (PV) array size, orientation, inclination, load profile, electricity buying price, feed-in tariffs, PV/inverter sizing ratio ('sizing ratio') and PV/inverter cost ratio ('cost ratio') on the economic viability of a grid-connected PV system was investigated using a validated TRNSYS simulation model. The results showed that the fractional load met directly by a PV system depends on matching between PV supply and building load profile, sizing ratio and PV inclination. The profitability of a grid-connected PV system increases if the PV system is sized to reduce excess PV electrical energy fed to the grid when the feed-in tariff is lower than electricity buying price. The effect of feed-in tariffs on PV saving for selected European countries has been shown. The cost of the PV electricity depends on sizing ratio, PV and inverter lifetimes, cost ratio, PV inclination and financial parameters. The effect of cost ratio on the optimum PV/inverter sizing ratio is less significant when the cost ratio lies within 7-11. The minimum PV electricity cost at low and high insolation conditions were obtained for sizing ratios of 1.6 and 1.2, respectively. The lowest PV electricity cost was found for surface slopes within 30-40 for the selected European locations. The PV electricity cost for cost ratio of 5 and 13 varied from 0.44-0.85 EURkWh -1 to 0.38-0.76 EURkWh -1 , respectively within high to low insolation conditions when the PV module unit cost, market discount rate, PV size, PV lifetime and inverter lifetime were assumed to be 6.5 EURW p -1 , 3%, 13 kW p , 20 years and 10 years, respectively. (author)

  11. Integration of new nuclear power plants into transmission grids part I: Transmission system issues

    International Nuclear Information System (INIS)

    Abi-Samra, N.

    2008-01-01

    Integration of new nuclear plants into a transmission system is a two sided problem. On one side, adding the nuclear plant into an existing grid will change the attributes of that grid: e.g., loading of certain transmission lines will increase; voltages will be affected, etc. On the other side, the grid itself will affect the plant, and the plant needs to be designed to accommodate the specifics of the grid. Based on that, this paper is divided into two parts. Part I addresses the grid issues with the integration of the new plant, with emphasis on the electrical aspects of these issues. Part II of this paper, concentrates on the vulnerability of the plant from grid disturbances. Part II reintroduces a relatively new concept by this author called the Zone of Vulnerability (ZoV) for the new nuclear plants. (authors)

  12. Journal of Earth System Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    The Journal of Earth System Science was earlier a part of the Proceedings of the Indian Academy of Sciences – Section A begun in 1934, and later split in 1978 into theme journals. This journal was published as Proceedings – Earth and Planetary Sciences since 1978, and in 2005 was renamed 'Journal of Earth System ...

  13. Grid-Tied PV System with Energy Optimization

    OpenAIRE

    Maryam Shahjehan; Waleed Shahjehan; Muhammad Naeem Arbab

    2017-01-01

    International audience; Electricity that is generated from coal, natural gas and fossil fuel has an impact on human health and also causes global warming. The integration of renewable energy sources with the grid is a good solution to these problems. This approach is known as smart grid. Sources of renewable energy such as wind or PV are not able to provide a continuous supply of energy to the load due to periodic or seasonal variations. Connecting these renewable sources to the grid can help...

  14. Wireless Communications in Smart Grid

    Science.gov (United States)

    Bojkovic, Zoran; Bakmaz, Bojan

    Communication networks play a crucial role in smart grid, as the intelligence of this complex system is built based on information exchange across the power grid. Wireless communications and networking are among the most economical ways to build the essential part of the scalable communication infrastructure for smart grid. In particular, wireless networks will be deployed widely in the smart grid for automatic meter reading, remote system and customer site monitoring, as well as equipment fault diagnosing. With an increasing interest from both the academic and industrial communities, this chapter systematically investigates recent advances in wireless communication technology for the smart grid.

  15. A Theorem on Grid Access Control

    Institute of Scientific and Technical Information of China (English)

    XU ZhiWei(徐志伟); BU GuanYing(卜冠英)

    2003-01-01

    The current grid security research is mainly focused on the authentication of grid systems. A problem to be solved by grid systems is to ensure consistent access control. This problem is complicated because the hosts in a grid computing environment usually span multiple autonomous administrative domains. This paper presents a grid access control model, based on asynchronous automata theory and the classic Bell-LaPadula model. This model is useful to formally study the confidentiality and integrity problems in a grid computing environment. A theorem is proved, which gives the necessary and sufficient conditions to a grid to maintain confidentiality.These conditions are the formalized descriptions of local (node) relations or relationship between grid subjects and node subjects.

  16. Large scale and cloud-based multi-model analytics experiments on climate change data in the Earth System Grid Federation

    Science.gov (United States)

    Fiore, Sandro; Płóciennik, Marcin; Doutriaux, Charles; Blanquer, Ignacio; Barbera, Roberto; Donvito, Giacinto; Williams, Dean N.; Anantharaj, Valentine; Salomoni, Davide D.; Aloisio, Giovanni

    2017-04-01

    In many scientific domains such as climate, data is often n-dimensional and requires tools that support specialized data types and primitives to be properly stored, accessed, analysed and visualized. Moreover, new challenges arise in large-scale scenarios and eco-systems where petabytes (PB) of data can be available and data can be distributed and/or replicated, such as the Earth System Grid Federation (ESGF) serving the Coupled Model Intercomparison Project, Phase 5 (CMIP5) experiment, providing access to 2.5PB of data for the Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report (AR5). A case study on climate models intercomparison data analysis addressing several classes of multi-model experiments is being implemented in the context of the EU H2020 INDIGO-DataCloud project. Such experiments require the availability of large amount of data (multi-terabyte order) related to the output of several climate models simulations as well as the exploitation of scientific data management tools for large-scale data analytics. More specifically, the talk discusses in detail a use case on precipitation trend analysis in terms of requirements, architectural design solution, and infrastructural implementation. The experiment has been tested and validated on CMIP5 datasets, in the context of a large scale distributed testbed across EU and US involving three ESGF sites (LLNL, ORNL, and CMCC) and one central orchestrator site (PSNC). The general "environment" of the case study relates to: (i) multi-model data analysis inter-comparison challenges; (ii) addressed on CMIP5 data; and (iii) which are made available through the IS-ENES/ESGF infrastructure. The added value of the solution proposed in the INDIGO-DataCloud project are summarized in the following: (i) it implements a different paradigm (from client- to server-side); (ii) it intrinsically reduces data movement; (iii) it makes lightweight the end-user setup; (iv) it fosters re-usability (of data, final

  17. SmartGrid: Future networks for New Zealand power systems incorporating distributed generation

    International Nuclear Information System (INIS)

    Nair, Nirmal-Kumar C.; Zhang Lixi

    2009-01-01

    The concept of intelligent electricity grids, which primarily involves the integration of new information and communication technologies with power transmission lines and distribution cables, is being actively explored in the European Union and the United States. Both developments share common technological developmental goals but also differ distinctly towards the role of distributed generation for their future electrical energy security. This paper looks at options that could find relevance to New Zealand (NZ), in the context of its aspiration of achieving 90% renewable energy electricity generation portfolio by 2025. It also identifies developments in technical standardization and industry investments that facilitate a pathway towards an intelligent or smart grid development for NZ. Some areas where policy can support research in NZ being a 'fast adapter' to future grid development are also listed. This paper will help policy makers quickly review developments surrounding SmartGrid and also identify its potential to support NZ Energy Strategy in the electricity infrastructure. This paper will also help researchers and power system stakeholders for identifying international standardization, projects and potential partners in the area of future grid technologies.

  18. Young Earth System Scientists (YESS) Community

    Science.gov (United States)

    Reed, K. A.; Langendijk, G.; Bahar, F.; Huang-Lachmann, J. T.; Osman, M.; Mirsafa, M.; Sonntag, S.

    2017-12-01

    The Young Earth System Scientists (YESS) community is compiled of early career researchers (including students) coming from a range of scientific backgrounds, spanning both natural and social sciences. YESS unifies young researchers in an influential network to give them a collective voice and leverage within the geosciences community, while supporting career development. The YESS community has used its powerful network to provide a unified perspective on the future of Earth system science (Rauser et al. 2017), to be involved in the organization of international conferences, and to engage with existing international structures that coordinate science. Since its founding in Germany in 2010, the YESS community has grown extensively across the globe, with currently almost 1000 members from over 80 countries, and has become truly interdisciplinary. Recently, the organization has carried elections for Regional Representatives and the Executive Committee as part of its self-sustained governance structure. YESS is ready to continue pioneering crucial areas of research which provide solutions to benefit society for the long-term advancement of Earth system science.

  19. Output-Feedback Nonlinear Adaptive Control Strategy of the Single-Phase Grid-Connected Photovoltaic System

    Directory of Open Access Journals (Sweden)

    Abdelmajid Abouloifa

    2018-01-01

    Full Text Available This paper addresses the problem of controlling the single-phase grid connected to the photovoltaic system through a full bridge inverter with LCL-filter. The control aims are threefold: (i imposing the voltage in the output of PV panel to track a reference provided by the MPPT block; (ii regulating the DC-link voltage to guarantee the power exchange between the source and AC grid; (iii ensuring a satisfactory power factor correction (PFC. The problem is dealt with using a cascade nonlinear adaptive controller that is developed making use of sliding-mode technique and observers in order to estimate the state variables and grid parameters, by measuring only the grid current, PV voltage, and the DC bus voltage. The control problem addressed by this work involves several difficulties, including the uncertainty of some parameters of the system and the numerous state variables are inaccessible to measurements. The results are confirmed by simulation under MATLAB∖Simulink∖SimPowerSystems, which show that the proposed regulator is robust with respect to climate changes.

  20. Grid Transmission Expansion Planning Model Based on Grid Vulnerability

    Science.gov (United States)

    Tang, Quan; Wang, Xi; Li, Ting; Zhang, Quanming; Zhang, Hongli; Li, Huaqiang

    2018-03-01

    Based on grid vulnerability and uniformity theory, proposed global network structure and state vulnerability factor model used to measure different grid models. established a multi-objective power grid planning model which considering the global power network vulnerability, economy and grid security constraint. Using improved chaos crossover and mutation genetic algorithm to optimize the optimal plan. For the problem of multi-objective optimization, dimension is not uniform, the weight is not easy given. Using principal component analysis (PCA) method to comprehensive assessment of the population every generation, make the results more objective and credible assessment. the feasibility and effectiveness of the proposed model are validated by simulation results of Garver-6 bus system and Garver-18 bus.

  1. A gridded air counter for measuring exoelectrons

    International Nuclear Information System (INIS)

    Nagase, Makoto; Chiba, Yoshiya; Kirihata, Humiaki.

    1980-01-01

    A gridded air counter with a quenching circuit is described, which serves to detect low-energy electrons such as thermionic electrons, photoelectrons and exoelectrons emitted into the atmospheric air. The air counter consists of a loop-shaped anode and two grids provided for quenching the gas discharge and for protecting the electron emitter from the positive ion bombardment. The quenching circuit with a high input sensitivity of 5 mV detects the initiation gas discharge caused by an incident electron and immediately supplies a rectangular wave pulse of 300 V in amplitude and of more than 3 msec in width to the quenching grid near the anode. Simultaneously, the voltage of the suppressor grid is brought down and kept at -30 V against the earthed sample for the same period of time. Performance of the gridded air counter was examined by use of photoelectrons emitted from an abraded aluminum plate. The quenching action was successfully accomplished in the anode voltage range from 3.65 to 3.95 kV. The photoelectrons emitted into the atmosphere could be counted stably by use of this counter. (author)

  2. A novel off-grid hybrid power system comprised of solar photovoltaic, wind, and hydro energy sources

    International Nuclear Information System (INIS)

    Bhandari, Binayak; Lee, Kyung-Tae; Lee, Caroline Sunyong; Song, Chul-Ki; Maskey, Ramesh K.; Ahn, Sung-Hoon

    2014-01-01

    Highlights: • We propose two hybridization methods for small off-grid power systems consisting solar (PV), wind, and micro-hydro sources. • One of the methods was implemented in a mini-grid connecting Thingan and Kolkhop villages in Makawanpur District, Nepal. • The results can be applied to help achieve Millennium Development Goal 7: Ensuring environmental sustainability. • This is the first implementation anywhere comprising of three renewable energy power, in a single off-grid power system. • This research may be applied as a practical guide for implementing similar systems in various locations. - Abstract: Several factors must be considered before adopting a full-phase power generation system based on renewable energy sources. Long-term necessary data (for one year if possible) should be collected before making any decisions concerning implementation of such a systems. To accurately assess the potential of available resources, we measured solar irradiation, wind speed, and ambient temperature at two high-altitude locations in Nepal: the Lama Hotel in Rasuwa District and Thingan in Makawanpur District. Here, we propose two practical, economical hybridization methods for small off-grid systems consisting entirely of renewable energy sources—specifically solar photovoltaic (PV), wind, and micro-hydro sources. One of the methods was tested experimentally, and the results can be applied to help achieve Millennium Development Goal 7: Ensuring environmental sustainability. Hydro, wind, and solar photovoltaic energy are the top renewable energy sources in terms of globally installed capacity. However, no reports have been published about off-grid hybrid systems comprised of all three sources, making this implementation the first of its kind anywhere. This research may be applied as a practical guide for implementing similar systems in various locations. Of the four off-grid PV systems installed by the authors for village electrification in Nepal, one was

  3. Solution of underdetermined systems of equations with gridded a priori constraints.

    Science.gov (United States)

    Stiros, Stathis C; Saltogianni, Vasso

    2014-01-01

    The TOPINV, Topological Inversion algorithm (or TGS, Topological Grid Search) initially developed for the inversion of highly non-linear redundant systems of equations, can solve a wide range of underdetermined systems of non-linear equations. This approach is a generalization of a previous conclusion that this algorithm can be used for the solution of certain integer ambiguity problems in Geodesy. The overall approach is based on additional (a priori) information for the unknown variables. In the past, such information was used either to linearize equations around approximate solutions, or to expand systems of observation equations solved on the basis of generalized inverses. In the proposed algorithm, the a priori additional information is used in a third way, as topological constraints to the unknown n variables, leading to an R(n) grid containing an approximation of the real solution. The TOPINV algorithm does not focus on point-solutions, but exploits the structural and topological constraints in each system of underdetermined equations in order to identify an optimal closed space in the R(n) containing the real solution. The centre of gravity of the grid points defining this space corresponds to global, minimum-norm solutions. The rationale and validity of the overall approach are demonstrated on the basis of examples and case studies, including fault modelling, in comparison with SVD solutions and true (reference) values, in an accuracy-oriented approach.

  4. Heterogeneous Wireless Networks for Smart Grid Distribution Systems: Advantages and Limitations.

    Science.gov (United States)

    Khalifa, Tarek; Abdrabou, Atef; Shaban, Khaled; Gaouda, A M

    2018-05-11

    Supporting a conventional power grid with advanced communication capabilities is a cornerstone to transferring it to a smart grid. A reliable communication infrastructure with a high throughput can lay the foundation towards the ultimate objective of a fully automated power grid with self-healing capabilities. In order to realize this objective, the communication infrastructure of a power distribution network needs to be extended to cover all substations including medium/low voltage ones. This shall enable information exchange among substations for a variety of system automation purposes with a low latency that suits time critical applications. This paper proposes the integration of two heterogeneous wireless technologies (such as WiFi and cellular 3G/4G) to provide reliable and fast communication among primary and secondary distribution substations. This integration allows the transmission of different data packets (not packet replicas) over two radio interfaces, making these interfaces act like a one data pipe. Thus, the paper investigates the applicability and effectiveness of employing heterogeneous wireless networks (HWNs) in achieving the desired reliability and timeliness requirements of future smart grids. We study the performance of HWNs in a realistic scenario under different data transfer loads and packet loss ratios. Our findings reveal that HWNs can be a viable data transfer option for smart grids.

  5. Heterogeneous Wireless Networks for Smart Grid Distribution Systems: Advantages and Limitations

    Directory of Open Access Journals (Sweden)

    Tarek Khalifa

    2018-05-01

    Full Text Available Supporting a conventional power grid with advanced communication capabilities is a cornerstone to transferring it to a smart grid. A reliable communication infrastructure with a high throughput can lay the foundation towards the ultimate objective of a fully automated power grid with self-healing capabilities. In order to realize this objective, the communication infrastructure of a power distribution network needs to be extended to cover all substations including medium/low voltage ones. This shall enable information exchange among substations for a variety of system automation purposes with a low latency that suits time critical applications. This paper proposes the integration of two heterogeneous wireless technologies (such as WiFi and cellular 3G/4G to provide reliable and fast communication among primary and secondary distribution substations. This integration allows the transmission of different data packets (not packet replicas over two radio interfaces, making these interfaces act like a one data pipe. Thus, the paper investigates the applicability and effectiveness of employing heterogeneous wireless networks (HWNs in achieving the desired reliability and timeliness requirements of future smart grids. We study the performance of HWNs in a realistic scenario under different data transfer loads and packet loss ratios. Our findings reveal that HWNs can be a viable data transfer option for smart grids.

  6. Output Control Technologies for a Large-scale PV System Considering Impacts on a Power Grid

    Science.gov (United States)

    Kuwayama, Akira

    The mega-solar demonstration project named “Verification of Grid Stabilization with Large-scale PV Power Generation systems” had been completed in March 2011 at Wakkanai, the northernmost city of Japan. The major objectives of this project were to evaluate adverse impacts of large-scale PV power generation systems connected to the power grid and develop output control technologies with integrated battery storage system. This paper describes the outline and results of this project. These results show the effectiveness of battery storage system and also proposed output control methods for a large-scale PV system to ensure stable operation of power grids. NEDO, New Energy and Industrial Technology Development Organization of Japan conducted this project and HEPCO, Hokkaido Electric Power Co., Inc managed the overall project.

  7. Brief analysis of Jiangsu grid security and stability based on multi-infeed DC index in power system

    Science.gov (United States)

    Zhang, Wenjia; Wang, Quanquan; Ge, Yi; Huang, Junhui; Chen, Zhengfang

    2018-02-01

    The impact of Multi-infeed HVDC has gradually increased to security and stability operating in Jiangsu power grid. In this paper, an appraisal method of Multi-infeed HVDC power grid security and stability is raised with Multi-Infeed Effective Short Circuit Ratio, Multi-Infeed Interaction Factor and Commutation Failure Immunity Index. These indices are adopted in security and stability simulating calculation of Jiangsu Multi-infeed HVDC system. The simulation results indicate that Jiangsu power grid is operating with a strong DC system. It has high level of power grid security and stability, and meet the safety running requirements. Jinpin-Suzhou DC system is located in the receiving end with huge capacity, which is easily leading to commutation failure of the transmission line. In order to resolve this problem, dynamic reactive power compensation can be applied in power grid near Jinpin-Suzhou DC system. Simulation result shows this method is feasible to commutation failure.

  8. Optical grid alignment system for portable radiography and portable radiography apparatus incorporating same

    International Nuclear Information System (INIS)

    MacMahon, H.

    1993-01-01

    A grid alignment system is described for use in a portable radiographic apparatus for aligning x-ray film with an x-ray source within said portable radiographic apparatus, comprising: a grid cassette, movable relative to said x-ray source, including an x-ray film holding portion, an anti-scatter grid substantially fixed relative to said x-ray film holding portion and positioned between said x-ray film holding portion and said x-ray source, and a reflector element substantially fixed relative to said grid, said reflector element including a reflective surface for reflecting said incident light beam to produce a reflected light beam, and an imaging surface for producing images of said incident light beam and said reflected light beam, said images providing an indication of alignment between said grid cassette and said x-ray source; and a light beam projector substantially fixed relative to said x-ray source, said light-beam projector projecting said incident light beam upon said reflector element to provide said indication of alignment between said grid cassette and said x-ray source

  9. Optimal Utilization of Microgrids Supplemented with Battery Energy Storage Systems in Grid Support Applications

    DEFF Research Database (Denmark)

    Anvari-Moghaddam, Amjad; Dragicevic, Tomislav; Vasquez, Juan Carlos

    2015-01-01

    This paper proposes a control scheme which minimizes the operating cost of a grid connected micro-grid supplemented by battery energy storage system (BESS). What distinguishes approach presented here from conventional strategies is that not only the price of electricity is considered...

  10. Probability of islanding in utility networks due to grid connected photovoltaic power systems

    Energy Technology Data Exchange (ETDEWEB)

    Verhoeven, B.

    2002-09-15

    This report for the International Energy Agency (IEA) made by Task 5 of the Photovoltaic Power Systems (PVPS) programme takes a look at the probability of islanding in utility networks due to grid-connected photovoltaic power systems. The mission of the Photovoltaic Power Systems Programme is to enhance the international collaboration efforts which accelerate the development and deployment of photovoltaic solar energy. Task 5 deals with issues concerning grid-interconnection and distributed PV power systems. This report summarises the results on a study on the probability of islanding in power networks with a high penetration level of grid connected PV-systems. The results are based on measurements performed during one year in a Dutch utility network. The measurements of active and reactive power were taken every second for two years and stored in a computer for off-line analysis. The area examined and its characteristics are described, as are the test set-up and the equipment used. The ratios between load and PV-power are discussed. The general conclusion is that the probability of islanding is virtually zero for low, medium and high penetration levels of PV-systems.

  11. A techno-economic assessment of grid connected photovoltaic system for hospital building in Malaysia

    Science.gov (United States)

    Mat Isa, Normazlina; Tan, Chee Wei; Yatim, AHM

    2017-07-01

    Conventionally, electricity in hospital building are supplied by the utility grid which uses mix fuel including coal and gas. Due to enhancement in renewable technology, many building shall moving forward to install their own PV panel along with the grid to employ the advantages of the renewable energy. This paper present an analysis of grid connected photovoltaic (GCPV) system for hospital building in Malaysia. A discussion is emphasized on the economic analysis based on Levelized Cost of Energy (LCOE) and total Net Present Post (TNPC) in regards with the annual interest rate. The analysis is performed using Hybrid Optimization Model for Electric Renewables (HOMER) software which give optimization and sensitivity analysis result. An optimization result followed by the sensitivity analysis also being discuss in this article thus the impact of the grid connected PV system has be evaluated. In addition, the benefit from Net Metering (NeM) mechanism also discussed.

  12. Smart Grid Integration Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Troxell, Wade [Colorado State Univ., Fort Collins, CO (United States)

    2011-12-22

    The initial federal funding for the Colorado State University Smart Grid Integration Laboratory is through a Congressionally Directed Project (CDP), DE-OE0000070 Smart Grid Integration Laboratory. The original program requested in three one-year increments for staff acquisition, curriculum development, and instrumentation all which will benefit the Laboratory. This report focuses on the initial phase of staff acquisition which was directed and administered by DOE NETL/ West Virginia under Project Officer Tom George. Using this CDP funding, we have developed the leadership and intellectual capacity for the SGIC. This was accomplished by investing (hiring) a core team of Smart Grid Systems engineering faculty focused on education, research, and innovation of a secure and smart grid infrastructure. The Smart Grid Integration Laboratory will be housed with the separately funded Integrid Laboratory as part of CSU's overall Smart Grid Integration Center (SGIC). The period of performance of this grant was 10/1/2009 to 9/30/2011 which included one no cost extension due to time delays in faculty hiring. The Smart Grid Integration Laboratory's focus is to build foundations to help graduate and undergraduates acquire systems engineering knowledge; conduct innovative research; and team externally with grid smart organizations. Using the results of the separately funded Smart Grid Workforce Education Workshop (May 2009) sponsored by the City of Fort Collins, Northern Colorado Clean Energy Cluster, Colorado State University Continuing Education, Spirae, and Siemens has been used to guide the hiring of faculty, program curriculum and education plan. This project develops faculty leaders with the intellectual capacity to inspire its students to become leaders that substantially contribute to the development and maintenance of Smart Grid infrastructure through topics such as: (1) Distributed energy systems modeling and control; (2) Energy and power conversion; (3

  13. Feasibility analysis of a smart grid photovoltaics system for the subarctic rural region in Alaska

    Science.gov (United States)

    Yao, Lei

    A smart grid photovoltaics system was developed to demonstrate that the system is feasible for a similar off-grid rural community in the subarctic region in Alaska. A system generation algorithm and a system business model were developed to determine feasibility. Based on forecasts by the PV F-Chart software, a 70° tilt angle in winter, and a 34° tilt angle in summer were determined to be the best angles for electrical output. The proposed system's electricity unit cost was calculated at 32.3 cents/kWh that is cheaper than current unsubsidized electricity price (46.8 cents/kWh) in off-grid rural communities. Given 46.8 cents/kWh as the electricity unit price, the system provider can break even when 17.3 percent of the total electrical revenue through power generated by the proposed system is charged. Given these results, the system can be economically feasible during the life-cycle period. With further incentives, the system may have a competitive advantage.

  14. The Crew Earth Observations Experiment: Earth System Science from the ISS

    Science.gov (United States)

    Stefanov, William L.; Evans, Cynthia A.; Robinson, Julie A.; Wilkinson, M. Justin

    2007-01-01

    This viewgraph presentation reviews the use of Astronaut Photography (AP) as taken from the International Space Station (ISS) in Earth System Science (ESS). Included are slides showing basic remote sensing theory, data characteristics of astronaut photography, astronaut training and operations, crew Earth observations group, targeting sites and acquisition, cataloging and database, analysis and applications for ESS, image analysis of particular interest urban areas, megafans, deltas, coral reefs. There are examples of the photographs and the analysis.

  15. System modelling and energy management for grid connected PV systems associated with storage

    OpenAIRE

    Riffonneau , Yann; DELAILLE , Arnaud; Barruel , Franck; Bacha , Seddik

    2008-01-01

    International audience; This paper presents the modelling and energy management of a grid connected PV system associatedwith storage. Within the economic, energetic and environmental context, objective of the system is to ensure loadssupply at the least cost by optimising the use of solar power. Therefore, due to the complicated operating patterns, anenergy management system which decides on energy flow for any moment is necessary. First, we present the systemstudied. Based on an AC bus typol...

  16. Mapping of grid faults and grid codes[Wind turbines

    Energy Technology Data Exchange (ETDEWEB)

    Iov, F. [Aalborg Univ., Inst. of Energy Technology (Denmark); Hansen, Anca D.; Soerensen, Poul; Cutululis, N.A. [Risoe National Lab. - DTU, Wind Enegy Dept., Roskilde (Denmark)

    2007-06-15

    The objective of this project is to investigate into the consequences of the new grid connection requirements for the fatigue and extreme loads of wind turbines. The goal is also to clarify and define possible new directions in the certification process of power plant wind turbines, namely wind turbines, which participate actively in the stabilisation of power systems. Practical experience shows that there is a need for such investigations. The grid connection requirements for wind turbines have increased significantly during the last 5-10 years. Especially the requirements for wind turbines to stay connected to the grid during and after voltage sags, imply potential challenges in the design of wind turbines. These requirements pose challenges for the design of both the electrical system and the mechanical structure of wind turbines. An overview over the frequency of grid faults and the grid connection requirements in different relevant countries is done in this report. The most relevant study cases for the quantification of the loads' impact on the wind turbines' lifetime are defined. The goal of this report is to present a mapping of different grid fault types and their frequency in different countries. The report provides also a detailed overview of the Low Voltage Ride-Through Capabilities for wind turbines in different relevant countries. The most relevant study cases for the quantification of the loads' impact on the wind turbines' lifetime are defined. (au)

  17. Characterization of Slosh Damping for Ortho-Grid and Iso-Grid Internal Tank Structures

    Science.gov (United States)

    Westra, Douglas G.; Sansone, Marco D.; Eberhart, Chad J.; West, Jeffrey S.

    2016-01-01

    Grid stiffened tank structures such as Ortho-Grid and Iso-Grid are widely used in cryogenic tanks for providing stiffening to the tank while reducing mass, compared to tank walls of constant cross-section. If the structure is internal to the tank, it will positively affect the fluid dynamic behavior of the liquid propellant, in regard to fluid slosh damping. As NASA and commercial companies endeavor to explore the solar system, vehicles will by necessity become more mass efficient, and design margin will be reduced where possible. Therefore, if the damping characteristics of the Ortho-Grid and Iso-Grid structure is understood, their positive damping effect can be taken into account in the systems design process. Historically, damping by internal structures has been characterized by rules of thumb and for Ortho-Grid, empirical design tools intended for slosh baffles of much larger cross-section have been used. There is little or no information available to characterize the slosh behavior of Iso-Grid internal structure. Therefore, to take advantage of these structures for their positive damping effects, there is much need for obtaining additional data and tools to characterize them. Recently, the NASA Marshall Space Flight Center conducted both sub-scale testing and computational fluid dynamics (CFD) simulations of slosh damping for Ortho-Grid and Iso-Grid tanks for cylindrical tanks containing water. Enhanced grid meshing techniques were applied to the geometrically detailed and complex Ortho-Grid and Iso-Grid structures. The Loci-STREAM CFD program with the Volume of Fluid Method module for tracking and locating the water-air fluid interface was used to conduct the simulations. The CFD simulations were validated with the test data and new empirical models for predicting damping and frequency of Ortho-Grid and Iso-Grid structures were generated.

  18. Encyclopedia of earth system science

    National Research Council Canada - National Science Library

    Nierenberg, William Aaron

    1992-01-01

    .... The very diversity of the articles attests to the complexity of earth system science as a unique interdisciplinary venture to place humanity in a position to move wisely to protect the global habitat...

  19. Solar photovoltaic systems and their use as grid-connected generators in the United Kingdom

    Energy Technology Data Exchange (ETDEWEB)

    Munro, D K; Hacker, R J; Thornycroft, J M [Halcrow Gilbert Associates Ltd., Swindon (United Kingdom)

    1995-10-01

    There is an increasing interest in the use of building-integrated solar photovoltaic generators as grid-connected generators. This paper discusses the experience with this technology in Europe. Typical systems and their integration into domestic and non-domestic buildings are described. Information is provided on the energy output that can be expected from the systems and the economics of their use. The paper provides an overview of the requirements for photovoltaic systems as grid-connected generation plant in the United Kingdom. (Author)

  20. Calculation of cell face velocity of non-staggered grid system

    KAUST Repository

    Li, Wang; Yu, Bo; Wang, Xinran; Sun, Shuyu

    2012-01-01

    In this paper, the cell face velocities in the discretization of the continuity equation, the momentum equation, and the scalar equation of a non-staggered grid system are calculated and discussed. Both the momentum interpolation and the linear