WorldWideScience

Sample records for previous grid generators

  1. TIGER: Turbomachinery interactive grid generation

    Science.gov (United States)

    Soni, Bharat K.; Shih, Ming-Hsin; Janus, J. Mark

    1992-01-01

    A three dimensional, interactive grid generation code, TIGER, is being developed for analysis of flows around ducted or unducted propellers. TIGER is a customized grid generator that combines new technology with methods from general grid generation codes. The code generates multiple block, structured grids around multiple blade rows with a hub and shroud for either C grid or H grid topologies. The code is intended for use with a Euler/Navier-Stokes solver also being developed, but is general enough for use with other flow solvers. TIGER features a silicon graphics interactive graphics environment that displays a pop-up window, graphics window, and text window. The geometry is read as a discrete set of points with options for several industrial standard formats and NASA standard formats. Various splines are available for defining the surface geometries. Grid generation is done either interactively or through a batch mode operation using history files from a previously generated grid. The batch mode operation can be done either with a graphical display of the interactive session or with no graphics so that the code can be run on another computer system. Run time can be significantly reduced by running on a Cray-YMP.

  2. Grid generation methods

    CERN Document Server

    Liseikin, Vladimir D

    2017-01-01

    This new edition provides a description of current developments relating to grid methods, grid codes, and their applications to actual problems. Grid generation methods are indispensable for the numerical solution of differential equations. Adaptive grid-mapping techniques, in particular, are the main focus and represent a promising tool to deal with systems with singularities. This 3rd edition includes three new chapters on numerical implementations (10), control of grid properties (11), and applications to mechanical, fluid, and plasma related problems (13). Also the other chapters have been updated including new topics, such as curvatures of discrete surfaces (3). Concise descriptions of hybrid mesh generation, drag and sweeping methods, parallel algorithms for mesh generation have been included too. This new edition addresses a broad range of readers: students, researchers, and practitioners in applied mathematics, mechanics, engineering, physics and other areas of applications.

  3. DIGRD: an interactive grid generating program

    International Nuclear Information System (INIS)

    Foote, H.P.; Rice, W.A.; Kincaid, C.T.

    1982-11-01

    Pacific Northwest Laboratory has completed the development and documentation of an interactive grid generating program (DIGRD, digitize grid). This program is designed to rapidly generate or modify grids necessary for the unsaturated flow code TRUST. In addition to the code, a user's manual was prepared. Unfortunately, the computer hardware that comprises the PNL interactive graphics capability is unique. Direct technology transfer is not possible, therefore, this report is intended to convey the utility of interactive graphics in supplying a grid generating capability. DIGRD has already been effectively used in the preparation of grids for the analysis of leachate movement from uranium mill tailings. The principal conclusion is that the interactive graphics employed in DIGRD are useful and economical in the development of complex grids. Grid generation activities that previously took between a half- and a full-man month can now be completed in less than a week. DIGRD users have recommended development of an uniform grid of either rectangles or equilateral triangles, which could be superimposed on any domain and then adjusted through the DIGRD program to match the boundaries of a tailings disposal facility. This improvement to the DIGRD package could further reduce the effort in grid generation while providing more optimal grids

  4. Workshop on Future Generation Grids

    CERN Document Server

    Laforenza, Domenico; Reinefeld, Alexander

    2006-01-01

    The Internet and the Web continue to have a major impact on society. By allowing us to discover and access information on a global scale, they have created entirely new businesses and brought new meaning to the term surf. In addition, however, we want processing, and increasingly, we want collaborative processing within distributed teams. This need has led to the creation of the Grid - an infrastructure that enables us to share capabilities, and integrate services and resources within and across enterprises. "Future Generation Grids" is the second in the "CoreGRID" series. This edited volume brings together contributed articles by scientists and researchers in the Grid community in an attempt to draw a clearer picture of the future generation Grids. This book also identifies some of the most challenging problems on the way to achieving the invisible Grid ideas

  5. Grid Synchronization for Distributed Generations

    DEFF Research Database (Denmark)

    Peyghami, Saeed; Mokhtari, Hossein; Blaabjerg, Frede

    2017-01-01

    Distributed generators (DGs) like photovoltaic arrays, wind turbines, and fuel cell modules, as well as distributed storage (DS) units introduce some advantages to the power systems and make it more reliable, flexible, and controllable in comparison with the conventional power systems. Grid...... of interfaces needs to be synchronized with the grid or microgird, and hence, a precise synchronization algorithm—mostly based on phase-locked loop—is required to estimate the phase angle and frequency of the voltage at the coupling point. Unlike synchronous generators, in power electronic interfaced DGs...... grid. Therefore, the synchronization is an important issue in DGs to have a stable and reliable operation....

  6. Wavelet-Based Grid Generation

    Science.gov (United States)

    Jameson, Leland

    1996-01-01

    Wavelets can provide a basis set in which the basis functions are constructed by dilating and translating a fixed function known as the mother wavelet. The mother wavelet can be seen as a high pass filter in the frequency domain. The process of dilating and expanding this high-pass filter can be seen as altering the frequency range that is 'passed' or detected. The process of translation moves this high-pass filter throughout the domain, thereby providing a mechanism to detect the frequencies or scales of information at every location. This is exactly the type of information that is needed for effective grid generation. This paper provides motivation to use wavelets for grid generation in addition to providing the final product: source code for wavelet-based grid generation.

  7. Progress in Grid Generation: From Chimera to DRAGON Grids

    Science.gov (United States)

    Liou, Meng-Sing; Kao, Kai-Hsiung

    1994-01-01

    Hybrid grids, composed of structured and unstructured grids, combines the best features of both. The chimera method is a major stepstone toward a hybrid grid from which the present approach is evolved. The chimera grid composes a set of overlapped structured grids which are independently generated and body-fitted, yielding a high quality grid readily accessible for efficient solution schemes. The chimera method has been shown to be efficient to generate a grid about complex geometries and has been demonstrated to deliver accurate aerodynamic prediction of complex flows. While its geometrical flexibility is attractive, interpolation of data in the overlapped regions - which in today's practice in 3D is done in a nonconservative fashion, is not. In the present paper we propose a hybrid grid scheme that maximizes the advantages of the chimera scheme and adapts the strengths of the unstructured grid while at the same time keeps its weaknesses minimal. Like the chimera method, we first divide up the physical domain by a set of structured body-fitted grids which are separately generated and overlaid throughout a complex configuration. To eliminate any pure data manipulation which does not necessarily follow governing equations, we use non-structured grids only to directly replace the region of the arbitrarily overlapped grids. This new adaptation to the chimera thinking is coined the DRAGON grid. The nonstructured grid region sandwiched between the structured grids is limited in size, resulting in only a small increase in memory and computational effort. The DRAGON method has three important advantages: (1) preserving strengths of the chimera grid; (2) eliminating difficulties sometimes encountered in the chimera scheme, such as the orphan points and bad quality of interpolation stencils; and (3) making grid communication in a fully conservative and consistent manner insofar as the governing equations are concerned. To demonstrate its use, the governing equations are

  8. Structured grid generator on parallel computers

    International Nuclear Information System (INIS)

    Muramatsu, Kazuhiro; Murakami, Hiroyuki; Higashida, Akihiro; Yanagisawa, Ichiro.

    1997-03-01

    A general purpose structured grid generator on parallel computers, which generates a large-scale structured grid efficiently, has been developed. The generator is applicable to Cartesian, cylindrical and BFC (Boundary-Fitted Curvilinear) coordinates. In case of BFC grids, there are three adaptable topologies; L-type, O-type and multi-block type, the last of which enables any combination of L- and O-grids. Internal BFC grid points can be automatically generated and smoothed by either algebraic supplemental method or partial differential equation method. The partial differential equation solver is implemented on parallel computers, because it consumes a large portion of overall execution time. Therefore, high-speed processing of large-scale grid generation can be realized by use of parallel computer. Generated grid data are capable to be adjusted to domain decomposition for parallel analysis. (author)

  9. New challenges in grid generation and adaptivity for scientific computing

    CERN Document Server

    Formaggia, Luca

    2015-01-01

    This volume collects selected contributions from the “Fourth Tetrahedron Workshop on Grid Generation for Numerical Computations”, which was held in Verbania, Italy in July 2013. The previous editions of this Workshop were hosted by the Weierstrass Institute in Berlin (2005), by INRIA Rocquencourt in Paris (2007), and by Swansea University (2010). This book covers different, though related, aspects of the field: the generation of quality grids for complex three-dimensional geometries; parallel mesh generation algorithms; mesh adaptation, including both theoretical and implementation aspects; grid generation and adaptation on surfaces – all with an interesting mix of numerical analysis, computer science and strongly application-oriented problems.

  10. Column generation based planning in smart grids using TRIANA

    NARCIS (Netherlands)

    Toersche, Hermen; Molderink, Albert; Hurink, Johann L.; Smit, Gerardus Johannes Maria

    2013-01-01

    Column generation is applied to the TRIANA smart grid framework's planner and combined with distributed dynamic programming. Simulations show that this improves the resulting planning compared to methods described in previous work (extra peak reduction of 7.3%; large fluctuation reduction) at the

  11. 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.

  12. Simulation of grid connected PM generator for wind turbines

    OpenAIRE

    Van Dessel, Michel; Deconinck, Geert; Gay, Michael

    2010-01-01

    This paper discusses the simulation of a power electronic converter used for grid connection of a permanent magnet generator designed for variable speed wind turbines. Previous work on the power converter is described, followed by the design parameters of the permanent magnet synchronous generator developed for wind turbines in the 10 kW range. The power electronic converter consisting of the Active Front End controlling the DC link voltage and Motion Control inverter controlling the ge...

  13. Grid code requirements for wind power generation

    International Nuclear Information System (INIS)

    Djagarov, N.; Filchev, S.; Grozdev, Z.; Bonev, M.

    2011-01-01

    In this paper production data of wind power in Europe and Bulgaria and plans for their development within 2030 are reviewed. The main characteristics of wind generators used in Bulgaria are listed. A review of the grid code in different European countries, which regulate the requirements for renewable sources, is made. European recommendations for requirements harmonization are analyzed. Suggestions for the Bulgarian gird code are made

  14. Emissions & Generation Resource Integrated Database (eGRID), eGRID2012

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Emissions emissions rates; net generation; resource mix; and many other attributes. eGRID2012 Version 1.0 is the eighth edition of eGRID, which contains the...

  15. Grid-Connected Inverter for Distributed Generation in Microgrid

    DEFF Research Database (Denmark)

    Naderipour, Amirreza; Miveh, Mohammad Reza; Guerrero, Josep M.

    for power generation. DGS units can operate in parallel to the main grid or in a Microgrid (MG) mode. An MG is a discrete energy system consisting of DGSs and loads capable of operating in parallel with, or independently from, the main grid. Meanwhile, Grid-Connected Inverters (GCIs) are typically used...

  16. Cubic Splines for Trachea and Bronchial Tubes Grid Generation

    Directory of Open Access Journals (Sweden)

    Eliandro Rodrigues Cirilo

    2006-02-01

    Full Text Available Grid generation plays an important role in the development of efficient numerical techniques for solving complex flows. Therefore, the present work develops a method for bidimensional blocks structured grid generation for geometries such as the trachea and bronchial tubes. A set of 55 blocks completes the geometry, whose contours are defined by cubic splines. Besides, this technique build on early ones because of its simplicity and efficiency in terms of very complex geometry grid generation.

  17. Free piston linear generator for low grid power generation

    Directory of Open Access Journals (Sweden)

    Abdalla Izzeldin

    2017-01-01

    Full Text Available Generating power is of great importance nowadays across the world. However, recently, the world became aware of the climatic changes due to the greenhouse effect caused by CO2 emissions and began seeking solutions to reduce the negative impact on the environment. Besides, the exhaustion of fossil fuels and their environmental impact, make it is crucial to develop clean energy sources, and efforts are focused on developing and improving the efficiency of all energy consuming systems. The tubular permanent magnet linear generators (TPMLGs are the best candidate for energy converters. Despite being suffering problem of attraction force between permanent magnets and stator teeth, to eliminate such attraction force, ironless-stator could be considered. Thus, they could waive the presence of any magnetic attraction between the moving and stator part. This paper presents the design and analysis of ironless -cored TPMLG for low grid power generation. The main advantages of this generator are the low cogging force and high efficiency. Therefore, the magnetic field computation of the proposed generator has been performed by applying a magnetic vector potential and utilizing a 2-D finite element analysis (FEA. Moreover, the experimental results for the current profile, pressure profile and velocity profile have been presented.

  18. Emission & Generation Resource Integrated Database (eGRID)

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Emissions & Generation Resource Integrated Database (eGRID) is an integrated source of data on environmental characteristics of electric power generation....

  19. 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)

  20. MESH2D Grid generator design and use

    Energy Technology Data Exchange (ETDEWEB)

    Flach, G. P. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-10-31

    Mesh2d is a Fortran90 program originally designed to generate two-dimensional structured grids of the form [x(i),y(i,j)] where [x,y] are grid coordinates identified by indices (i,j). x-coordinates depending only on index i implies strictly vertical x-grid lines, whereas the y-grid lines can undulate. Mesh2d also assigns an integer material type to each grid cell, mtyp(i,j), in a user-specified manner. The complete grid is specified through three separate input files defining the x(i), y(i,j), and mtyp(i,j) variations. Since the original development effort, Mesh2d has been extended to more general two-dimensional structured grids of the form [x(i,j),(i,j)].

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

    DEFF Research Database (Denmark)

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

    2015-01-01

    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 on the installat...

  2. Elliptic Volume Grid Generation for Viscous CFD Parametric Design Studies

    Science.gov (United States)

    Alter, Stephen J.; Cheatwood, F. McNeil

    1996-01-01

    This paper presents a robust method for the generation of zonal volume grids of design parametrics for aerodynamic configurations. The process utilizes simple algebraic techniques with parametric splines coupled with elliptic volume grid generation to generate isolated zonal grids for changes in body configuration needed to perform parametric design studies. Speed of the algorithm is maximized through the algebraic methods and reduced number of grid points to be regenerated for each design parametric without sacrificing grid quality and continuity within the volume domain. The method is directly applicable to grid reusability, because it modifies existing ow adapted volume grids and enables the user to restart the CFD solution process with an established flow field. Use of this zonal approach reduces computer usage time to create new volume grids for design parametric studies by an order of magnitude, as compared to current methods which require the regeneration of an entire volume grid. A sample configuration of a proposed Single Stage-to-Orbit Vehicle is used to illustrate an application of this method.

  3. Parallel and Streaming Generation of Ghost Data for Structured Grids

    Energy Technology Data Exchange (ETDEWEB)

    Isenburg, M; Lindstrom, P; Childs, H

    2008-04-15

    Parallel simulations decompose large domains into many blocks. A fundamental requirement for subsequent parallel analysis and visualization is the presence of ghost data that supplements each block with a layer of adjacent data elements from neighboring blocks. The standard approach for generating ghost data requires all blocks to be in memory at once. This becomes impractical when there are fewer processors - and thus less aggregate memory - available for analysis than for simulation. We describe an algorithm for generating ghost data for structured grids that uses many fewer processors than previously possible. Our algorithm stores as little as one block per processor in memory and can run on as few processors as are available (possibly just one). The key idea is to slightly change the size of the original blocks by declaring parts of them to be ghost data, and by later padding adjacent blocks with this data.

  4. A Computational Differential Geometry Approach to Grid Generation

    CERN Document Server

    Liseikin, Vladimir D

    2007-01-01

    The process of breaking up a physical domain into smaller sub-domains, known as meshing, facilitates the numerical solution of partial differential equations used to simulate physical systems. This monograph gives a detailed treatment of applications of geometric methods to advanced grid technology. It focuses on and describes a comprehensive approach based on the numerical solution of inverted Beltramian and diffusion equations with respect to monitor metrics for generating both structured and unstructured grids in domains and on surfaces. In this second edition the author takes a more detailed and practice-oriented approach towards explaining how to implement the method by: Employing geometric and numerical analyses of monitor metrics as the basis for developing efficient tools for controlling grid properties. Describing new grid generation codes based on finite differences for generating both structured and unstructured surface and domain grids. Providing examples of applications of the codes to the genera...

  5. A Survey on Next-generation Power Grid Data Architecture

    Energy Technology Data Exchange (ETDEWEB)

    You, Shutang [University of Tennessee, Knoxville (UTK); Zhu, Dr. Lin [University of Tennessee (UT); Liu, Yong [ORNL; Liu, Yilu [ORNL; Shankar, Mallikarjun (Arjun) [ORNL; Robertson, Russell [Grid Protection Alliance; King Jr, Thomas J [ORNL

    2015-01-01

    The operation and control of power grids will increasingly rely on data. A high-speed, reliable, flexible and secure data architecture is the prerequisite of the next-generation power grid. This paper summarizes the challenges in collecting and utilizing power grid data, and then provides reference data architecture for future power grids. Based on the data architecture deployment, related research on data architecture is reviewed and summarized in several categories including data measurement/actuation, data transmission, data service layer, data utilization, as well as two cross-cutting issues, interoperability and cyber security. Research gaps and future work are also presented.

  6. Emissions & Generation Resource Integrated Database (eGRID), eGRID2010

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Emissions emissions rates; net generation; resource mix; and many other attributes. eGRID2010 contains the complete release of year 2007 data, as well as years...

  7. Grid voltage synchronization for distributed generation systems under grid fault conditions

    OpenAIRE

    Luna Alloza, Álvaro; Rocabert Delgado, Joan; Candela García, José Ignacio; Hermoso Costa, Juan Ramón; Teodorescu, Remus; Blaabjerg, Frede; Rodríguez Cortés, Pedro

    2015-01-01

    The actual grid code requirements for the grid connection of distributed generation systems, mainly wind and photovoltaic (PV) systems, are becoming very demanding. The transmission system operators (TSOs) are especially concerned about the low-voltage-ride-through requirements. Solutions based on the installation of STATCOMs and dynamic voltage regulators (DVRs), as well as on advanced control functionalities for the existing power converters of distributed generation plants, have contribute...

  8. Emissions & Generation Resource Integrated Database (eGRID), eGRID2010

    Science.gov (United States)

    The Emissions & Generation Resource Integrated Database (eGRID) is a comprehensive source of data on the environmental characteristics of almost all electric power generated in the United States. These environmental characteristics include air emissions for nitrogen oxides, sulfur dioxide, carbon dioxide, methane, and nitrous oxide; emissions rates; net generation; resource mix; and many other attributes.eGRID2010 contains the complete release of year 2007 data, as well as years 2005 and 2004 data. Excel spreadsheets, full documentation, summary data, eGRID subregion and NERC region representational maps, and GHG emission factors are included in this data set. The Archived data in eGRID2002 contain years 1996 through 2000 data.For year 2007 data, the first Microsoft Excel workbook, Plant, contains boiler, generator, and plant spreadsheets. The second Microsoft Excel workbook, Aggregation, contains aggregated data by state, electric generating company, parent company, power control area, eGRID subregion, NERC region, and U.S. total levels. The third Microsoft Excel workbook, ImportExport, contains state import-export data, as well as U.S. generation and consumption data for years 2007, 2005, and 2004. For eGRID data for years 2005 and 2004, a user friendly web application, eGRIDweb, is available to select, view, print, and export specified data.

  9. Generating one-column grids with fractal flow dimension

    Science.gov (United States)

    Doughty, Christine

    2017-11-01

    The grid generation capability built into the numerical simulator TOUGH for multi-phase fluid and heat flow through geologic media can create one-column grids with linear or radial geometry, corresponding to one-dimensional or two-dimensional radial flow, respectively. The integral-finite-difference-method that TOUGH employs for spatial discretization makes it very simple to generalize the grid-generation algorithm from integer to non-integer (fractal) flow dimension. Here the grid-generation algorithm is generalized to create one-column grids with fractal flow dimension ranging from less than 1 to 3. The fractal grid generation method is verified by comparing numerical simulation results to an analytical solution for a generalized Theis solution for integer and non-integer flow dimensions between 0.4 and 3. It is then applied to examine gas production decline curves from hydraulically fractured shale that is modeled as a fractal-dimensioned fracture network with flow dimensions between 0.25 and 3. Grids with fractal flow dimension are useful for representing flow through fracture networks or highly heterogeneous geologic media with fractal geometry, and may be particularly useful for inverse methods.

  10. Grid-Connected Inverter for Distributed Generation in Microgrid

    DEFF Research Database (Denmark)

    Naderipour, Amirreza; Miveh, Mohammad Reza; Guerrero, Josep M.

    The need to increase access to electricity has played a significant role in economic and technical growth within international development. In this respect, Distributed Generation Sources (DGSs) have become more important in recent years for supplementing traditional fossil energy resources...... for power generation. DGS units can operate in parallel to the main grid or in a Microgrid (MG) mode. An MG is a discrete energy system consisting of DGSs and loads capable of operating in parallel with, or independently from, the main grid. Meanwhile, Grid-Connected Inverters (GCIs) are typically used...

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

    DEFF Research Database (Denmark)

    Timbus, Adrian Vasile

    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......The movement towards a clean technology for energy production and the constraints in reducing the CO2 emissions are some factors facilitating the growth of distributed power generation systems based on renewable energy resources. Consequently, large penetration of distributed generators has been...... 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...

  12. Modelling of Diesel Generator Sets That Assist Off-Grid Renewable Energy Micro-grids

    Directory of Open Access Journals (Sweden)

    Johanna Salazar

    2015-08-01

    Full Text Available This paper focuses on modelling diesel generators for off-grid installations based on renewable energies. Variations in Environmental Variables (for example, Solar Radiation and Wind Speed make necessary to include these auxiliary systems in off-grid renewable energy installations, in order to ensure minimal services when the produced renewable energy is not sufficient to fulfill the demand. This paper concentrates on modelling the dynamical behaviour of the diesel generator, in order to use the models and simulations for developing and testing advanced controllers for the overall off-grid system. The Diesel generator is assumed to consist of a diesel motor connected to a synchronous generator through an electromagnetic clutch, with a flywheel to damp variations. Each of the components is modelled using physical models, with the corresponding control systems also modelled: these control systems include the speed and the voltage regulation (in cascade regulation.

  13. Wingridder - an interactive grid generator for TOUGH2

    International Nuclear Information System (INIS)

    Pan, Lehua

    2003-01-01

    The TOUGH (Transport Of Unsaturated Groundwater and Heat) family of codes has great flexibility in handling the variety of grid information required to describe a complex subsurface system. However, designing and generating such a grid can be a tedious and error-prone process. This is especially true when the number of cells and connections is very large. As a user-friendly, efficient, and effective grid generating software, WinGridder has been developed for designing, generating, and visualizing (at various spatial scales) numerical grids used in reservoir simulations and groundwater modeling studies. It can save mesh files for TOUGH family codes. It can also output additional grid information for various purposes in either graphic format or plain text format. It has user-friendly graphical user interfaces, along with an easy-to-use interactive design and plot tools. Many important features, such as inclined faults and offset, layering structure, local refinements, and embedded engineering structures, can be represented in the grid

  14. Triangle geometry processing for surface modeling and cartesian grid generation

    Science.gov (United States)

    Aftosmis, Michael J [San Mateo, CA; Melton, John E [Hollister, CA; Berger, Marsha J [New York, NY

    2002-09-03

    Cartesian mesh generation is accomplished for component based geometries, by intersecting components subject to mesh generation to extract wetted surfaces with a geometry engine using adaptive precision arithmetic in a system which automatically breaks ties with respect to geometric degeneracies. During volume mesh generation, intersected surface triangulations are received to enable mesh generation with cell division of an initially coarse grid. The hexagonal cells are resolved, preserving the ability to directionally divide cells which are locally well aligned.

  15. Grid support by power electronic converters of distributed generation units

    NARCIS (Netherlands)

    Morren, J.

    2006-01-01

    An increasing number of small Distributed Generation (DG) units are connected to the grid. The introduction of DG causes several problems, which are mainly related to the differences between DG units and conventional generators. Four problems have been considered in this thesis: damping of

  16. Distributed Generation to Counter Grid Vulnerability

    National Research Council Canada - National Science Library

    Nerad, Anton H

    2007-01-01

    ... power generation and distribution capabilities, outline several terrorist designs for disruption to it and the resulting economic impact, and provide a possible solution with the adoption of a concept...

  17. GENERATION ALGORITHM OF DISCRETE LINE IN MULTI-DIMENSIONAL GRIDS

    Directory of Open Access Journals (Sweden)

    L. Du

    2017-09-01

    Full Text Available Discrete Global Grids System (DGGS is a kind of digital multi-resolution earth reference model, in terms of structure, it is conducive to the geographical spatial big data integration and mining. Vector is one of the important types of spatial data, only by discretization, can it be applied in grids system to make process and analysis. Based on the some constraint conditions, this paper put forward a strict definition of discrete lines, building a mathematic model of the discrete lines by base vectors combination method. Transforming mesh discrete lines issue in n-dimensional grids into the issue of optimal deviated path in n-minus-one dimension using hyperplane, which, therefore realizing dimension reduction process in the expression of mesh discrete lines. On this basis, we designed a simple and efficient algorithm for dimension reduction and generation of the discrete lines. The experimental results show that our algorithm not only can be applied in the two-dimensional rectangular grid, also can be applied in the two-dimensional hexagonal grid and the three-dimensional cubic grid. Meanwhile, when our algorithm is applied in two-dimensional rectangular grid, it can get a discrete line which is more similar to the line in the Euclidean space.

  18. Generation Algorithm of Discrete Line in Multi-Dimensional Grids

    Science.gov (United States)

    Du, L.; Ben, J.; Li, Y.; Wang, R.

    2017-09-01

    Discrete Global Grids System (DGGS) is a kind of digital multi-resolution earth reference model, in terms of structure, it is conducive to the geographical spatial big data integration and mining. Vector is one of the important types of spatial data, only by discretization, can it be applied in grids system to make process and analysis. Based on the some constraint conditions, this paper put forward a strict definition of discrete lines, building a mathematic model of the discrete lines by base vectors combination method. Transforming mesh discrete lines issue in n-dimensional grids into the issue of optimal deviated path in n-minus-one dimension using hyperplane, which, therefore realizing dimension reduction process in the expression of mesh discrete lines. On this basis, we designed a simple and efficient algorithm for dimension reduction and generation of the discrete lines. The experimental results show that our algorithm not only can be applied in the two-dimensional rectangular grid, also can be applied in the two-dimensional hexagonal grid and the three-dimensional cubic grid. Meanwhile, when our algorithm is applied in two-dimensional rectangular grid, it can get a discrete line which is more similar to the line in the Euclidean space.

  19. Parallel grid generation algorithm for distributed memory computers

    Science.gov (United States)

    Moitra, Stuti; Moitra, Anutosh

    1994-01-01

    A parallel grid-generation algorithm and its implementation on the Intel iPSC/860 computer are described. The grid-generation scheme is based on an algebraic formulation of homotopic relations. Methods for utilizing the inherent parallelism of the grid-generation scheme are described, and implementation of multiple levELs of parallelism on multiple instruction multiple data machines are indicated. The algorithm is capable of providing near orthogonality and spacing control at solid boundaries while requiring minimal interprocessor communications. Results obtained on the Intel hypercube for a blended wing-body configuration are used to demonstrate the effectiveness of the algorithm. Fortran implementations bAsed on the native programming model of the iPSC/860 computer and the Express system of software tools are reported. Computational gains in execution time speed-up ratios are given.

  20. Turbulent premixed flames on fractal-grid-generated turbulence

    Science.gov (United States)

    Soulopoulos, N.; Kerl, J.; Sponfeldner, T.; Beyrau, F.; Hardalupas, Y.; Taylor, A. M. K. P.; Vassilicos, J. C.

    2013-12-01

    A space-filling, low blockage fractal grid is used as a novel turbulence generator in a premixed turbulent flame stabilized by a rod. The study compares the flame behaviour with a fractal grid to the behaviour when a standard square mesh grid with the same effective mesh size and solidity as the fractal grid is used. The isothermal gas flow turbulence characteristics, including mean flow velocity and rms of velocity fluctuations and Taylor length, were evaluated from hot-wire measurements. The behaviour of the flames was assessed with direct chemiluminescence emission from the flame and high-speed OH-laser-induced fluorescence. The characteristics of the two flames are considered in terms of turbulent flame thickness, local flame curvature and turbulent flame speed. It is found that, for the same flow rate and stoichiometry and at the same distance downstream of the location of the grid, fractal-grid-generated turbulence leads to a more turbulent flame with enhanced burning rate and increased flame surface area.

  1. Improving nuclear generating station response for electrical grid islanding

    International Nuclear Information System (INIS)

    Chou, Q.B.; Kundur, P.; Acchione, P.N.; Lautsch, B.

    1989-01-01

    This paper describes problems associated with the performance characteristics of nuclear generating stations which do not have their overall plant control design functions co-ordinated with the other grid controls. The paper presents some design changes to typical nuclear plant controls which result in a significant improvement in both the performance of the grid island and the chances of the nuclear units staying on-line following the disturbance. This paper focuses on four areas of the overall unit controls and turbine governor controls which could be modified to better co-ordinate the control functions of the nuclear units with the electrical grid. Some simulation results are presented to show the performance of a typical electrical grid island containing a nuclear unit with and without the changes

  2. Discussion of grid generation for catamaran resistance calculation

    Science.gov (United States)

    Deng, Rui; Huang, De-Bo; Li, Jia; Cheng, Xuan-Kai; Yu, Lei

    2010-06-01

    In order to get some useful parameters for grid generation of catamaran, the CFD software FLUENT is used to investigate the main effects of grid generation on flow field calculation. The influences of some elements are investigated with a series of calculations in the present paper, and some alteratives are proposed. The proposed alteratives based on the analysis of the effects are used for a catamaran resistance calculation, comparisons of the calculated results with experimental data show good agreement. It shows that the research result of this paper is useful for the numerical calculation of catamaran.

  3. Solution adaptive meshes with a hyperbolic grid generator

    Science.gov (United States)

    Klopfer, G. H.

    An alternative numerical procedure to generate solution-adaptive grids for use in CFD simulations is developed analytically and demonstrated. The approach is based on the hyperbolic generation scheme of Steger and Chausee (1980), with terms added to achieve line clustering while fulfilling orthogonality and smoothness requirements. The formulation of the method is outlined, and adapted meshes for a shock-shock interaction at freestream Mach number 8.03 and Reynolds number 387,500 are presented graphically. The hyperbolic approach is shown to be significantly faster than comparable elliptic-grid methods and capable of producing an arbitrarily high degree of clustering on structured meshes.

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

    OpenAIRE

    Timbus, Adrian Vasile

    2007-01-01

    The movement towards a clean technology for energy production and the constraints in reducing the CO2 emissions are some factors facilitating the growth of distributed power generation systems based on renewable energy resources. Consequently, large penetration of distributed generators has been 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...

  5. Distributed voltage control coordination between renewable generation plants in MV distribution grids

    DEFF Research Database (Denmark)

    Petersen, Lennart; Iov, Florin

    2017-01-01

    This study focuses on distributed voltage control coordination between renewable generation plants in medium-voltage distribution grids (DGs). A distributed offline coordination concept has been defined in a previous publication, leading to satisfactory voltage regulation in the DG. However, here...

  6. Dynamic performance of doubly-fed induction generator stator flux during consecutive grid voltage variations

    DEFF Research Database (Denmark)

    Zhu, Rongwu; Chen, Zhe; Wu, Xiaojie

    2015-01-01

    For the grid-connected doubly-fed induction generator (DFIG)-based wind turbine, because of the stator connected to the grid directly, the stator flux easily suffers from the effects of grid voltage variations, such as grid disturbances and grid faults. Moreover, since the magnetic field is excited...

  7. Integrating Renewable Generation into Grid Operations: Four International Experiences

    Energy Technology Data Exchange (ETDEWEB)

    Weimar, Mark R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Mylrea, Michael E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Levin, Todd [Argonne National Lab. (ANL), Argonne, IL (United States); Botterud, Audun [Argonne National Lab. (ANL), Argonne, IL (United States); O' Shaughnessy, Eric [National Renewable Energy Lab. (NREL), Golden, CO (United States); Bird, Lori [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-04-22

    International experiences with power sector restructuring and the resultant impacts on bulk power grid operations and planning may provide insight into policy questions for the evolving United States power grid as resource mixes are changing in response to fuel prices, an aging generation fleet and to meet climate goals. Australia, Germany, Japan and the UK were selected to represent a range in the level and attributes of electricity industry liberalization in order to draw comparisons across a variety of regions in the United States such as California, ERCOT, the Southwest Power Pool and the Southeast Reliability Region. The study draws conclusions through a literature review of the four case study countries with regards to the changing resource mix and the electricity industry sector structure and their impact on grid operations and planning. This paper derives lessons learned and synthesizes implications for the United States based on answers to the above questions and the challenges faced by the four selected countries. Each country was examined to determine the challenges to their bulk power sector based on their changing resource mix, market structure, policies driving the changing resource mix, and policies driving restructuring. Each countries’ approach to solving those changes was examined, as well as how each country’s market structure either exacerbated or mitigated the approaches to solving the challenges to their bulk power grid operations and planning. All countries’ policies encourage renewable energy generation. One significant finding included the low- to zero-marginal cost of intermittent renewables and its potential negative impact on long-term resource adequacy. No dominant solution has emerged although a capacity market was introduced in the UK and is being contemplated in Japan. Germany has proposed the Energy Market 2.0 to encourage flexible generation investment. The grid operator in Australia proposed several approaches to maintaining

  8. Grid-Connected Distributed Generation: Compensation Mechanism Basics

    Energy Technology Data Exchange (ETDEWEB)

    Aznar, Alexandra Y [National Renewable Energy Laboratory (NREL), Golden, CO (United States); ; ; ; Zinaman, Owen R [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-10-02

    This short report defines compensation mechanisms for grid-connected, behind-the-meter distributed generation (DG) systems as instruments that comprise three core elements: (1) metering and billing arrangements, (2) sell rate design, and (3) retail rate design. This report describes metering and billing arrangements, with some limited discussion of sell rate design. We detail the three possible arrangements for metering and billing of DG: net energy metering (NEM); buy all, sell all; and net billing.

  9. Impact of Converter Interfaced Generation and Load on Grid Performance

    Science.gov (United States)

    Ramasubramanian, Deepak

    Alternate sources of energy such as wind, solar photovoltaic and fuel cells are coupled to the power grid with the help of solid state converters. Continued deregulation of the power sector coupled with favorable government incentives has resulted in the rapid growth of renewable energy sources connected to the distribution system at a voltage level of 34.5kV or below. Of late, many utilities are also investing in these alternate sources of energy with the point of interconnection with the power grid being at the transmission level. These converter interfaced generation along with their associated control have the ability to provide the advantage of fast control of frequency, voltage, active, and reactive power. However, their ability to provide stability in a large system is yet to be investigated in detail. This is the primary objective of this research. In the future, along with an increase in the percentage of converter interfaced renewable energy sources connected to the transmission network, there exists a possibility of even connecting synchronous machines to the grid through converters. Thus, all sources of energy can be expected to be coupled to the grid through converters. The control and operation of such a grid will be unlike anything that has been encountered till now. In this dissertation, the operation and behavior of such a grid will be investigated. The first step in such an analysis will be to build an accurate and simple mathematical model to represent the corresponding components in commercial software. Once this bridge has been crossed, conventional machines will be replaced with their solid state interfaced counterparts in a phased manner. At each stage, attention will be devoted to the control of these sources and also on the stability performance of the large power system. This dissertation addresses various concerns regarding the control and operation of a futuristic power grid. In addition, this dissertation also aims to address the issue

  10. On the integration of wind generators on weak grids and island grids

    International Nuclear Information System (INIS)

    Laverdure, N.

    2005-12-01

    Wind energy is now an energy that can not be ignored. Because of intrinsic characteristics (scattered primary energy, generators with different technologies, use of power electronics interface), wind energy system integration in distribution grids leads to real problems in terms of impacts. With recent standard changes, it is necessary to study the possibilities of each technology of wind turbines to answer or not to these new constraints. This PhD thesis focuses on a comparison of the main present wind turbines concerning three points of discussion: energy quality, fault ride through, ancillary services (voltage and frequency). It insists on the possibilities in terms of control laws for variable speed wind turbines. (author)

  11. Current Control Method for Distributed Generation Power Generation Plants under Grid Fault Conditions

    DEFF Research Database (Denmark)

    Rodriguez, Pedro; Luna, Alvaro; Hermoso, Juan Ramon

    2011-01-01

    The operation of distributed power generation systems under grid fault conditions is a key issue for the massive integration of renewable energy systems. Several studies have been conducted to improve the response of such distributed generation systems under voltage dips. In spite of being less s...

  12. Refinements and practical implementation of a power based loss of grid detection algorithm for embedded generators

    Science.gov (United States)

    Barrett, James

    The incorporation of small, privately owned generation operating in parallel with, and supplying power to, the distribution network is becoming more widespread. This method of operation does however have problems associated with it. In particular, a loss of the connection to the main utility supply which leaves a portion of the utility load connected to the embedded generator will result in a power island. This situation presents possible dangers to utility personnel and the public, complications for smooth system operation and probable plant damage should the two systems be reconnected out-of-synchronism. Loss of Grid (or Islanding), as this situation is known, is the subject of this thesis. The work begins by detailing the requirements for operation of generation embedded in the utility supply with particular attention drawn to the requirements for a loss of grid protection scheme. The mathematical basis for a new loss of grid protection algorithm is developed and the inclusion of the algorithm in an integrated generator protection scheme described. A detailed description is given on the implementation of the new algorithm in a microprocessor based relay hardware to allow practical tests on small embedded generation facilities, including an in-house multiple generator test facility. The results obtained from the practical tests are compared with those obtained from simulation studies carried out in previous work and the differences are discussed. The performance of the algorithm is enhanced from the theoretical algorithm developed using the simulation results with simple filtering together with pattern recognition techniques. This provides stability during severe load fluctuations under parallel operation and system fault conditions and improved performance under normal operating conditions and for loss of grid detection. In addition to operating for a loss of grid connection, the algorithm will respond to load fluctuations which occur within a power island

  13. Emissions & Generation Resource Integrated Database (eGRID), eGRID2002 (with years 1996 - 2000 data)

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Emissions emissions rates; net generation; resource mix; and many other attributes. eGRID2002 (years 1996 through 2000 data) contains 16 Excel spreadsheets and...

  14. Electric Grid Expansion Planning with High Levels of Variable Generation

    Energy Technology Data Exchange (ETDEWEB)

    Hadley, Stanton W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); You, Shutang [Univ. of Tennessee, Knoxville, TN (United States); Shankar, Mallikarjun [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Liu, Yilu [Univ. of Tennessee, Knoxville, TN (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-02-01

    Renewables are taking a large proportion of generation capacity in U.S. power grids. As their randomness has increasing influence on power system operation, it is necessary to consider their impact on system expansion planning. To this end, this project studies the generation and transmission expansion co-optimization problem of the US Eastern Interconnection (EI) power grid with a high wind power penetration rate. In this project, the generation and transmission expansion problem for the EI system is modeled as a mixed-integer programming (MIP) problem. This study analyzed a time series creation method to capture the diversity of load and wind power across balancing regions in the EI system. The obtained time series can be easily introduced into the MIP co-optimization problem and then solved robustly through available MIP solvers. Simulation results show that the proposed time series generation method and the expansion co-optimization model and can improve the expansion result significantly after considering the diversity of wind and load across EI regions. The improved expansion plan that combines generation and transmission will aid system planners and policy makers to maximize the social welfare. This study shows that modelling load and wind variations and diversities across balancing regions will produce significantly different expansion result compared with former studies. For example, if wind is modeled in more details (by increasing the number of wind output levels) so that more wind blocks are considered in expansion planning, transmission expansion will be larger and the expansion timing will be earlier. Regarding generation expansion, more wind scenarios will slightly reduce wind generation expansion in the EI system and increase the expansion of other generation such as gas. Also, adopting detailed wind scenarios will reveal that it may be uneconomic to expand transmission networks for transmitting a large amount of wind power through a long distance

  15. Rating Requirements of the UPQC to Integrate the FSIG Type Wind Generation to the Grid

    OpenAIRE

    Jayanti, N.; Basu, Malabika; Conlon, Michael; Gaughan, Kevin

    2009-01-01

    The ability of wind generation to remain connected to the grid in the event of system faults and dynamic reactive power compensation are two aspects of grid integration, which have received particular attention. The wind driven, fixed-speed induction generator (FSIG) on its own fails to fulfil these requirements of grid integration. The application of a unified power quality conditioner (UPQC) to overcome the grid integration problems of the FSIG is investigated. The role of the UPQC in enhan...

  16. 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

  17. Comparison of control strategies for Doubly fed induction generator under recurring grid faults

    DEFF Research Database (Denmark)

    Chen, Wenjie; Blaabjerg, Frede; Zhu, Nan

    2014-01-01

    The new grid codes demand the wind turbine systems to ride through recurring grid faults. Many control strategies have been proposed for the Doubly Fed Induction Generator under single grid fault, but their performance under recurring grid faults have not been studied yet. In this paper, five...... different control strategies for DFIG to ride through single grid faults are presented, and their performance under recurring grid faults are analyzed. The controllable range, stator time constant and torque fluctuations of the DFIG with different control strategies are compared. The results are verified...

  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. Economic aspects of grid connected solar electricity generation

    International Nuclear Information System (INIS)

    Pharabod, F.

    1993-01-01

    Experience gained with available solar thermal technologies enlighten on options for research and development on solar electricity generation. The proposed analysis of new solar technologies concerns market, costs and profit viewpoint: - Systems under development have to fit with consumers' needs and utilities' specifications, technology is not the only item to study. - Expense headings depend on technological options and operation procedures such as size of the plant, solar only or hybrid concept. - Anticipation of revenues highly depends on direct insolation quality and on local conditions for introducing the electric power generated into the network: daily direct insolation measurements and annual local load curve are prerequisite data. Strategic advantages regarding environment and sustainable development are to be pointed out, specially in industrialized countries or for projects including financing institutions. As far as generating electric power on the grid is a major challenge in the development of a number of countries in the sun belt, cooperation between industrialized and developing countries, under the auspices of international organization, has to be promoted. (Author) 12 refs

  20. High Order Sliding Mode Control of Doubly-fed Induction Generator under Unbalanced Grid Faults

    DEFF Research Database (Denmark)

    Zhu, Rongwu; Chen, Zhe; Wu, Xiaojie

    2013-01-01

    This paper deals with a doubly-fed induction generator-based (DFIG) wind turbine system under grid fault conditions such as: unbalanced grid voltage, three-phase grid fault, using a high order sliding mode control (SMC). A second order sliding mode controller, which is robust with respect...

  1. 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...

  2. Efficient identification of opportunities for Distributed Generation based on Smart Grid Technology

    DEFF Research Database (Denmark)

    Mutule, Anna; Obushevs, Artjoms; Lvov, Aleksandr

    2013-01-01

    The paper presents the main goals and achievements of the Smart Grids ERA-NET project named “Efficient identification of opportunities for Distributed Generation based on Smart Grid Technology (SmartGen)” during the second stage of project implementation. A description of Smart Grid Technology (S......) models developed within the framework of the project is given. The performed study cases where the SGT-models were implemented to analyze the impact of the electrical grid are discussed....

  3. Specialized CFD Grid Generation Methods for Near-Field Sonic Boom Prediction

    Science.gov (United States)

    Park, Michael A.; Campbell, Richard L.; Elmiligui, Alaa; Cliff, Susan E.; Nayani, Sudheer N.

    2014-01-01

    Ongoing interest in analysis and design of low sonic boom supersonic transports re- quires accurate and ecient Computational Fluid Dynamics (CFD) tools. Specialized grid generation techniques are employed to predict near- eld acoustic signatures of these con- gurations. A fundamental examination of grid properties is performed including grid alignment with ow characteristics and element type. The issues a ecting the robustness of cylindrical surface extrusion are illustrated. This study will compare three methods in the extrusion family of grid generation methods that produce grids aligned with the freestream Mach angle. These methods are applied to con gurations from the First AIAA Sonic Boom Prediction Workshop.

  4. SPAGETTA: a Multi-Purpose Gridded Stochastic Weather Generator

    Science.gov (United States)

    Dubrovsky, M.; Huth, R.; Rotach, M. W.; Dabhi, H.

    2017-12-01

    SPAGETTA is a new multisite/gridded multivariate parametric stochastic weather generator (WG). Site-specific precipitation occurrence and amount are modelled by Markov chain and Gamma distribution, the non-precipitation variables are modelled by an autoregressive (AR) model conditioned on precipitation occurrence, and the spatial coherence of all variables is modelled following the Wilks' (2009) approach. SPAGETTA may be run in two modes. Mode 1: it is run as a classical WG, which is calibrated using weather series from multiple sites, and only then it may produce arbitrarily long synthetic series mimicking the spatial and temporal structure of the calibration data. To generate the weather series representing the future climate, the WG parameters are modified according to the climate change scenario, typically derived from GCM or RCM simulations. Mode 2: the user provides only basic information (not necessarily to be realistic) on the temporal and spatial auto-correlation structure of the weather variables and their mean annual cycle; the generator itself derives the parameters of the underlying AR model, which produces the multi-site weather series. Optionally, the user may add the spatially varying trend, which is superimposed to the synthetic series. The contribution consists of following parts: (a) Model of the WG. (b) Validation of WG in terms of the spatial temperature and precipitation characteristics, including characteristics of spatial hot/cold/dry/wet spells. (c) Results of the climate change impact experiment, in which the WG parameters representing the spatial and temporal variability are modified using the climate change scenarios and the effect on the above spatial validation indices is analysed. In this experiment, the WG is calibrated using the E-OBS gridded daily weather data for several European regions, and the climate change scenarios are derived from the selected RCM simulations (CORDEX database). (d) The second mode of operation will be

  5. WinGridder - An interactive grid generator for TOUGH - A user's manual (Version 1.0)

    International Nuclear Information System (INIS)

    Pan, Lehua; Hinds, Jennifer; Haukwa, Charles; Wu, Yu-Shu; Bodvarsson, Gudmundur

    2001-01-01

    WinGridder is a Windows-based software package for designing, generating, and visualizing at various spatial scales numerical grids used in reservoir simulations and groundwater modeling studies. Development of this software was motivated by the requirements of the TOUGH (Transport of Unsaturated Groundwater and Heat) family of codes (Pruess 1987, 1991) for simulating subsurface processes related to high-level nuclear waste isolation in partially saturated geological media. Although the TOUGH family of codes has great flexibility in handling the variety of grid information required to describe complex objects, designing and generating a suitable irregular grid can be a tedious and error-prone process, even with the help of existing grid generating programs. This is especially true when the number of cells and connections is very large. The processes of inspecting the quality of the grid or extracting sub-grids or other specific grid information are also complex. The mesh maker embedded within TOUGH2 generates only uniform numerical grids and handles only one set of uniform fracture and matrix properties throughout the model domain. This is not suitable for grid generation in complex flow and transport simulations (such as those of Yucca Mountain, which have heterogeneity in both fracture and matrix media). As a result, the software program Amesh (Haukwa 2000) was developed to generate irregular, effective-continuum (ECM) grids

  6. Job system generation in grid taking into account user preferences

    Directory of Open Access Journals (Sweden)

    D. M. Yemelyanov

    2016-01-01

    Full Text Available Distributed computing environments like Grid are characterized by heterogeneity, low cohesion and dynamic structure of computing nodes. This is why the task of resource scheduling in such environments is complex. Different approaches to job scheduling in grid exist. Some of them use economic principles. Economic approaches to scheduling have shown their efficiency. One of such approaches is cyclic scheduling scheme which is considered in this paper.Cyclic scheduling scheme takes into account the preferences of computing environment users by means of an optimization criterion, which is included in the resource request. Besides, the scheme works cyclically by scheduling a certain job batch at each scheduling step. This is why there is a preliminary scheduling step which is job batch generation.The purpose of this study was to estimate the infl uence of job batch structure by the user criterion on the degree of its satisfaction. In other words we had to find the best way to form the batch with relation to the user optimization criterion. For example if it is more efficient to form the batch with jobs with the same criterion value or with different criterion values. Also we wanted to find the combination of criterion values which would give the most efficient scheduling results.To achieve this purpose an experiment in a simulation environment was conducted. The experiment consisted of scheduling of job batches with different values of the user criterion, other parameters of the resource request and the characteristics of the computing environment being the same. Three job batch generation strategies were considered. In the first strategy the batch consisted of jobs with the same criterion value. In the second strategy the batch consisted of jobs with all the considered criteria equally likely. The third strategy was similar to the second one, but only two certain criteria were considered. The third strategy was considered in order to find the most

  7. Online Energy Management System for Distributed Generators in a Grid-Connected Microgrid

    DEFF Research Database (Denmark)

    Hernández, Adriana Carolina Luna; Aldana, Nelson Leonardo Diaz; Graells, Moises

    2015-01-01

    A microgrid is an energy subsystem composed of generation units, energy storage, and loads that requires power management in order to supply the load properly according to defined objectives. This paper proposes an online energy management system for a storage based grid-connected microgrid...... data and adjusted weather forecast data previously scaled in each iteration considering the current status. The proposed structure is tested in a real time simulation platform (dSPACE 1006) for the microgrid model, by using Labview to data acquisition and Matlab to implement the energy management...

  8. Numerical Study of Multigrid Methods with Various Smoothers for the Elliptical Grid Generation Equations

    Science.gov (United States)

    Golik, W. L.

    1996-01-01

    A robust solver for the elliptic grid generation equations is sought via a numerical study. The system of PDEs is discretized with finite differences, and multigrid methods are applied to the resulting nonlinear algebraic equations. Multigrid iterations are compared with respect to the robustness and efficiency. Different smoothers are tried to improve the convergence of iterations. The methods are applied to four 2D grid generation problems over a wide range of grid distortions. The results of the study help to select smoothing schemes and the overall multigrid procedures for elliptic grid generation.

  9. Modelling grid losses and the geographic distribution of electricity generation

    DEFF Research Database (Denmark)

    Østergaard, Poul Alberg

    2005-01-01

    In Denmark more than 40% of the electricity consumption is covered by geographically scattered electricity sources namely wind power and local CHP (cogeneration of heat and power) plants. This causes problems in regard to load balancing and possible grid overloads. The potential grid problems...

  10. 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.

  11. Application of numerical grid generation for improved CFD analysis of multiphase screw machines

    Science.gov (United States)

    Rane, S.; Kovačević, A.

    2017-08-01

    Algebraic grid generation is widely used for discretization of the working domain of twin screw machines. Algebraic grid generation is fast and has good control over the placement of grid nodes. However, the desired qualities of grid which should be able to handle multiphase flows such as oil injection, may be difficult to achieve at times. In order to obtain fast solution of multiphase screw machines, it is important to further improve the quality and robustness of the computational grid. In this paper, a deforming grid of a twin screw machine is generated using algebraic transfinite interpolation to produce initial mesh upon which an elliptic partial differential equations (PDE) of the Poisson’s form is solved numerically to produce smooth final computational mesh. The quality of numerical cells and their distribution obtained by the differential method is greatly improved. In addition, a similar procedure was introduced to fully smoothen the transition of the partitioning rack curve between the rotors thus improving continuous movement of grid nodes and in turn improve robustness and speed of the Computational Fluid Dynamic (CFD) solver. Analysis of an oil injected twin screw compressor is presented to compare the improvements in grid quality factors in the regions of importance such as interlobe space, radial tip and the core of the rotor. The proposed method that combines algebraic and differential grid generation offer significant improvement in grid quality and robustness of numerical solution.

  12. Geometry modeling and grid generation using 3D NURBS control volume

    Science.gov (United States)

    Yu, Tzu-Yi; Soni, Bharat K.; Shih, Ming-Hsin

    1995-01-01

    The algorithms for volume grid generation using NURBS geometric representation are presented. The parameterization algorithm is enhanced to yield a desired physical distribution on the curve, surface and volume. This approach bridges the gap between CAD surface/volume definition and surface/volume grid generation. Computational examples associated with practical configurations have shown the utilization of these algorithms.

  13. Generating Free-Form Grid Truss Structures from 3D Scanned Point Clouds

    Directory of Open Access Journals (Sweden)

    Hui Ding

    2017-01-01

    Full Text Available Reconstruction, according to physical shape, is a novel way to generate free-form grid truss structures. 3D scanning is an effective means of acquiring physical form information and it generates dense point clouds on surfaces of objects. However, generating grid truss structures from point clouds is still a challenge. Based on the advancing front technique (AFT which is widely used in Finite Element Method (FEM, a scheme for generating grid truss structures from 3D scanned point clouds is proposed in this paper. Based on the characteristics of point cloud data, the search box is adopted to reduce the search space in grid generating. A front advancing procedure suit for point clouds is established. Delaunay method and Laplacian method are used to improve the quality of the generated grids, and an adjustment strategy that locates grid nodes at appointed places is proposed. Several examples of generating grid truss structures from 3D scanned point clouds of seashells are carried out to verify the proposed scheme. Physical models of the grid truss structures generated in the examples are manufactured by 3D print, which solidifies the feasibility of the scheme.

  14. Multi-pole permanent magnet synchronous generator wind turbines' grid support capability in uninterrupted operation during grid faults

    DEFF Research Database (Denmark)

    Hansen, Anca Daniela; Michalke, G.

    2009-01-01

    Emphasis in this paper is on the fault ride-through and grid support capabilities of multi-pole permanent magnet synchronous generator (PMSG) wind turbines with a full-scale frequency converter. These wind turbines are announced to be very attractive, especially for large offshore wind farms....... A control strategy is presented, which enhances the fault ride-through and voltage support capability of such wind turbines during grid faults. Its design has special focus on power converters' protection and voltage control aspects. The performance of the presented control strategy is assessed...... to ride through a grid fault, without implementation of any additional ride-through control strategy in the active stall wind farm....

  15. Sonora: A New Generation Model Atmosphere Grid for Brown Dwarfs and Young Extrasolar Giant Planets

    Science.gov (United States)

    Marley, Mark S.; Saumon, Didier; Fortney, Jonathan J.; Morley, Caroline; Lupu, Roxana E.; Freedman, Richard; Visscher, Channon

    2017-06-01

    Brown dwarf and giant planet atmospheric structure and composition has been studied both by forward models and, increasingly so, by retrieval methods. While indisputably informative, retrieval methods are of greatest value when judged in the context of grid model predictions. Meanwhile retrieval models can test the assumptions inherent in the forward modeling procedure.In order to provide a new, systematic survey of brown dwarf atmospheric structure, emergent spectra, and evolution, we have constructed a new grid of brown dwarf model atmospheres. We ultimately aim for our grid to span substantial ranges of atmospheric metallilcity, C/O ratios, cloud properties, atmospheric mixing, and other parameters. Spectra predicted by our modeling grid can be compared to both observations and retrieval results to aid in the interpretation and planning of future telescopic observations.We thus present Sonora, a new generation of substellar atmosphere models, appropriate for application to studies of L, T, and Y-type brown dwarfs and young extrasolar giant planets. The models describe the expected temperature-pressure profile and emergent spectra of an atmosphere in radiative-convective equilibrium for ranges of effective temperatures and gravities encompassing 200 ≤ Teff ≤ 2400 K and 2.5 ≤ log g ≤ 5.5. In our poster we briefly describe our modeling methodology, enumerate various updates since our group's previous models, and present our initial tranche of models for cloudless, solar metallicity, and solar carbon-to-oxygen ratio, chemical equilibrium atmospheres. These models will be available online and will be updated as opacities and cloud modeling methods continue to improve.

  16. Sonora: A New Generation Model Atmosphere Grid for Brown Dwarfs and Young Extrasolar Giant Planets

    Science.gov (United States)

    Marley, Mark S.; Saumon, Didier; Fortney, Jonathan J.; Morley, Caroline; Lupu, Roxana Elena; Freedman, Richard; Visscher, Channon

    2017-01-01

    Brown dwarf and giant planet atmospheric structure and composition has been studied both by forward models and, increasingly so, by retrieval methods. While indisputably informative, retrieval methods are of greatest value when judged in the context of grid model predictions. Meanwhile retrieval models can test the assumptions inherent in the forward modeling procedure. In order to provide a new, systematic survey of brown dwarf atmospheric structure, emergent spectra, and evolution, we have constructed a new grid of brown dwarf model atmospheres. We ultimately aim for our grid to span substantial ranges of atmospheric metallilcity, C/O ratios, cloud properties, atmospheric mixing, and other parameters. Spectra predicted by our modeling grid can be compared to both observations and retrieval results to aid in the interpretation and planning of future telescopic observations. We thus present Sonora, a new generation of substellar atmosphere models, appropriate for application to studies of L, T, and Y-type brown dwarfs and young extrasolar giant planets. The models describe the expected temperature-pressure profile and emergent spectra of an atmosphere in radiative-convective equilibrium for ranges of effective temperatures and gravities encompassing 200 less than or equal to T(sub eff) less than or equal to 2400 K and 2.5 less than or equal to log g less than or equal to 5.5. In our poster we briefly describe our modeling methodology, enumerate various updates since our group's previous models, and present our initial tranche of models for cloudless, solar metallicity, and solar carbon-to-oxygen ratio, chemical equilibrium atmospheres. These models will be available online and will be updated as opacities and cloud modeling methods continue to improve.

  17. Integration of renewable generation and elastic loads into distribution grids

    CERN Document Server

    Ardakanian, Omid; Rosenberg, Catherine

    2016-01-01

    This brief examines the challenges of integrating distributed energy resources and high-power elastic loads into low-voltage distribution grids, as well as the potential for pervasive measurement. It explores the control needed to address these challenges and achieve various system-level and user-level objectives. A mathematical framework is presented for the joint control of active end-nodes at scale, and extensive numerical simulations demonstrate that proper control of active end-nodes can significantly enhance reliable and economical operation of the power grid.

  18. A brief overview of the distribution test grids with a distributed generation inclusion case study

    Directory of Open Access Journals (Sweden)

    Stanisavljević Aleksandar M.

    2018-01-01

    Full Text Available The paper presents an overview of the electric distribution test grids issued by different technical institutions. They are used for testing different scenarios in operation of a grid for research, benchmarking, comparison and other purposes. Their types, main characteristics, features as well as application possibilities are shown. Recently, these grids are modified with inclusion of distributed generation. An example of modification and application of the IEEE 13-bus for testing effects of faults in cases without and with a distributed generator connection to the grid is presented. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. III 042004: Smart Electricity Distribution Grids Based on Distribution Management System and Distributed Generation

  19. Online Detection and Estimation of Grid Impedance Variation for Distributed Power Generation

    DEFF Research Database (Denmark)

    Jebali-Ben Ghorbal, Manel; Ghzaiel, Walid; Slama-Belkhodja, Ilhem

    2012-01-01

    A better knowledge of the grid impedance is essential in order to improve power quality and control of the Distributed Power Generation Systems (DPGS) and also for a safe connection or reconnection to the utility grid. An LCL-filter associated to a Voltage Source Inverter (VSI) is usually used...

  20. Hybrid mini-grid systems - distributed generation systems for communities based on renewable energy resources

    CSIR Research Space (South Africa)

    Szewczuk, S

    2009-06-01

    Full Text Available energy/economic framework and describes the CSIR's role in the formulation of South Africa's first hybrid mini-grids and the lessons learnt. The hybrid mini-grid systems can also be classified as distributed generation systems....

  1. Generating Realistic Dynamic Prices and Services for the Smart Grid

    NARCIS (Netherlands)

    Pagani, G. A.; Aiello, M.

    2014-01-01

    The smart grid promises to change the way people manage their energy needs, to facilitate the inclusion of small-scale renewable sources, and to open the energy market to all. One of the enabling instruments is the real-time pricing of energy at the retail level: dynamic and flexible tariffs will

  2. Digital control of grid connected converters for distributed power generation

    Energy Technology Data Exchange (ETDEWEB)

    Skjellnes, Tore

    2008-07-01

    Pulse width modulated converters are becoming increasingly popular as their cost decreases and power rating increases. The new trend of small scale power producers, often using renewable energy sources, has created new demands for delivery of energy to the grid. A major advantage of the pulse width modulated converter is the ability to control the output voltage at any point in the voltage period. This enables rapid response to load changes and non-linear loads. In addition it can shape the voltage in response to the output current to create an outward appearance of a source impedance. This is called a virtual impedance. This thesis presents a controller for a voltage controlled three phase pulse width modulated converter. This controller enables operation in standalone mode, in parallel with other converters in a micro grid, and in parallel with a strong main grid. A time varying virtual impedance is presented which mainly attenuates reactive currents. A method of investigating the overall impedance including the virtual impedance is presented. New net standards have been introduced, requiring the converter to operate even during severe dips in the grid voltage. Experiments are presented verifying the operation of the controller during voltage dips. (Author). 37 refs., 65 figs., 10 tabs

  3. Computational Needs for the Next Generation Electric Grid Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Birman, Kenneth; Ganesh, Lakshmi; Renessee, Robbert van; Ferris, Michael; Hofmann, Andreas; Williams, Brian; Sztipanovits, Janos; Hemingway, Graham; University, Vanderbilt; Bose, Anjan; Stivastava, Anurag; Grijalva, Santiago; Grijalva, Santiago; Ryan, Sarah M.; McCalley, James D.; Woodruff, David L.; Xiong, Jinjun; Acar, Emrah; Agrawal, Bhavna; Conn, Andrew R.; Ditlow, Gary; Feldmann, Peter; Finkler, Ulrich; Gaucher, Brian; Gupta, Anshul; Heng, Fook-Luen; Kalagnanam, Jayant R; Koc, Ali; Kung, David; Phan, Dung; Singhee, Amith; Smith, Basil

    2011-10-05

    The April 2011 DOE workshop, 'Computational Needs for the Next Generation Electric Grid', was the culmination of a year-long process to bring together some of the Nation's leading researchers and experts to identify computational challenges associated with the operation and planning of the electric power system. The attached papers provide a journey into these experts' insights, highlighting a class of mathematical and computational problems relevant for potential power systems research. While each paper defines a specific problem area, there were several recurrent themes. First, the breadth and depth of power system data has expanded tremendously over the past decade. This provides the potential for new control approaches and operator tools that can enhance system efficiencies and improve reliability. However, the large volume of data poses its own challenges, and could benefit from application of advances in computer networking and architecture, as well as data base structures. Second, the computational complexity of the underlying system problems is growing. Transmitting electricity from clean, domestic energy resources in remote regions to urban consumers, for example, requires broader, regional planning over multi-decade time horizons. Yet, it may also mean operational focus on local solutions and shorter timescales, as reactive power and system dynamics (including fast switching and controls) play an increasingly critical role in achieving stability and ultimately reliability. The expected growth in reliance on variable renewable sources of electricity generation places an exclamation point on both of these observations, and highlights the need for new focus in areas such as stochastic optimization to accommodate the increased uncertainty that is occurring in both planning and operations. Application of research advances in algorithms (especially related to optimization techniques and uncertainty quantification) could accelerate power

  4. Control strategies for gas turbine generators for grid connected and islanding operations

    DEFF Research Database (Denmark)

    Mahat, Pukar; Chen, Zhe; Bak-Jensen, Birgitte

    2010-01-01

    fine while a DG is connected to a grid, might not work as desired while it is islanded and vise versa. This paper presents a strategy to operate distribution systems with a small gas turbine generator (GTG), which is capable of supplying local loads, in both islanding and grid connected conditions....... Separate strategies are used to control the GTG while it is connected to the grid and while it is islanded. Switching between the control strategies is achieved through a state detection algorithm that includes islanding and grid re-connection detections. An existing islanding detection technique has been...... used and a grid re-connection detection algorithm has been developed. Simulation results show that the proposed method is effective in operating GTG optimally while it is either connected to the grid or islanded....

  5. ASP - Grid connections of large power generating units; ASP - Anslutning av stoerre produktionsanlaeggningar till elnaetet

    Energy Technology Data Exchange (ETDEWEB)

    Larsson, Aake; Larsson, Richard [Vattenfall Power Consultants, Stockholm (Sweden)

    2006-12-15

    Grid connections of large power generating units normally require more detailed studies compared to small single units. The required R and D-level depends on the specific characteristics of the production units and the connecting grid. An inquiry for a grid connection will raise questions for the grid owner regarding transmission capability, losses, fault currents, relay protection, dynamic stability etc. Then only a few larger wind farms have been built, the experiences from these types of grid connections are limited and for that reason it can be difficult to identify issues appropriate for further studies. To ensure that electric power generating units do not have unacceptable impact on the grid, directions from the Swedish TSO (Svenska Kraftnaet) have been stated. The directions deal, for example, with power generation in specific ranges of voltage level and frequency and the possibility to remain connected to the grid when different faults occur. The requirements and the consequences of these directions are illustrated. There are three main issues that should be considered: Influence on the power flow from generating units regarding voltage level, currents, losses etc.; Different types of electric systems in generating units contribute to different levels of fault currents. For that reason the resulting fault current levels have to be studied; It is required that generating units should remain connected to the grid at different modes of operation and faults. These modes have to be verified. Load flow and dynamic studies normally demand computer models. Comprehensive models, for instance of wind farms, can bee difficult to design and normally large computer capacity is required. Therefore simplified methods to perform relevant studies are described. How to model an electric power generating unit regarding fault currents and dynamic stability is described. An inquiry for a grid connection normally brings about a discussion concerning administration. To make it

  6. Experimental evaluation of square bar and fractal grid-generated turbulent flow inside recirculating water tunnel

    Science.gov (United States)

    Bornemeier, Matthew; Luznik, Luksa

    2017-11-01

    High resolution, two dimensional PIV measurements of grid-generated turbulence in the US Naval Academy's recirculating water tunnel (1.8m test section with 0.41m x 0.41m cross sectional area) are presented for two different grid designs. The first grid is a uniform square bar grid with mesh width, M =3.9cm, bar thickness t0 = 1cm, a streamwise thickness of 1cm and resulting solidity of 44%, similar to the conventional grid used by Krogstad and Davidson (2012). The other is Mazellier & Vassilicos' (2010) square fractal grid, SFG17, with fractal iteration count, N =4, thickness ratio tr = 17 and length ratio Lr = 8. Grid patterns differ from the published designs by a circular hole with 4.30cm diameter in the middle that will accept, in future experiments, a shaft connected to an axisymmetric rotating wake generator with diameter, D. Grids were designed to generate turbulence of specific integral length scale of O(D) and intensity of 6% at the prescribed downstream location. Mean tunnel centerline velocity is 2 m/s and measurements are made in a streamwise vertical center plane with nominal individual field of view (FOV) of 12x8 cm2. Spatial coverage in the test section is accomplished by ``tiling'' individual FOV with approximately 2cm overlap. Results will focus on characterizing resulting turbulence in the test section and discussion will include comparison between published results and the present measurements.

  7. Application of Load Compensation in Voltage Controllers of Large Generators in the Polish Power Grid

    Directory of Open Access Journals (Sweden)

    Bogdan Sobczak

    2014-03-01

    Full Text Available The Automatic Voltage Regulator normally controls the generator stator terminal voltage. Load compensation is used to control the voltage which is representative of the voltage at a point either within or external to the generator. In the Polish Power Grid (PPG compensation is ready to use in every AVR of a large generator, but it is utilized only in the case of generators operating at the same medium voltage buses. It is similar as in most European Power Grids. The compensator regulating the voltage at a point beyond the machine terminals has significant advantages in comparison to the slower secondary Voltage and Reactive Power Control System (ARNE1. The compensation stiffens the EHV grid, which leads to improved voltage quality in the distribution grid. This effect may be particularly important in the context of the dynamic development of wind and solar energy.

  8. Direct Current Smart Micro-grids for Distributed Generation with Renewable Sources

    Directory of Open Access Journals (Sweden)

    Renato RIZZO

    2013-06-01

    Full Text Available The wide diffusion of renewable energy sources encourage the distribution of electrical energy by the so called Distributed Generation, where large power plants are substituted by small-scale environmentally friendly technologies. Moreover micro-grids are considered which concept assumes a cluster of loads and micro-sources operating as a single controllable system that provides both power and heat to its local area. This influences the operation of distributed generation. This research paper deals with the distributed generation evolution, considering the technologies for generation from renewable sources, up to the smart micro-grids, i.e. in domestic applications where direct current micro-grids are considered and smart micro-grid concept is introduced.

  9. Optimal Operation of Micro-grids Considering the Uncertainties of Demand and Renewable Energy Resources Generation

    OpenAIRE

    Malek Jasemi; Farid Adabi; Babak Mozafari; Samira Salahi

    2016-01-01

    Nowadays, due to technical and economic reasons, the distributed generation (DG) units are widely connected to the low and medium voltage network and created a new structure called micro-grid. Renewable energies (especially wind and solar) based DGs are one of the most important generations units among DG units. Because of stochastic behavior of these resources, the optimum and safe management and operation of micro-grids has become one of the research priorities for researchers. So, in this ...

  10. Use of thermoelectric generators for improve power dependability over grid power

    Energy Technology Data Exchange (ETDEWEB)

    Archer, Jack [Global Thermoelectric, Calgary (Canada)

    2005-07-01

    A natural gas transportation company was experiencing extensive pipeline corrosion on some sections of their pipeline protected by impressed current using grid power and rectifiers. After determining that grid power was being interrupted on the affected sections, the gas transporter began looking for a more dependable power supply and chose thermoelectric generators. Since installing thermoelectric generators in 2002, the pipeline potentials have stabilized and transporter was able to experience 100% operational time on affected sections. (author)

  11. Online Optimization Method for Operation of Generators in a Micro Grid

    Science.gov (United States)

    Hayashi, Yasuhiro; Miyamoto, Hideki; Matsuki, Junya; Iizuka, Toshio; Azuma, Hitoshi

    Recently a lot of studies and developments about distributed generator such as photovoltaic generation system, wind turbine generation system and fuel cell have been performed under the background of the global environment issues and deregulation of the electricity market, and the technique of these distributed generators have progressed. Especially, micro grid which consists of several distributed generators, loads and storage battery is expected as one of the new operation system of distributed generator. However, since precipitous load fluctuation occurs in micro grid for the reason of its smaller capacity compared with conventional power system, high-accuracy load forecasting and control scheme to balance of supply and demand are needed. Namely, it is necessary to improve the precision of operation in micro grid by observing load fluctuation and correcting start-stop schedule and output of generators online. But it is not easy to determine the operation schedule of each generator in short time, because the problem to determine start-up, shut-down and output of each generator in micro grid is a mixed integer programming problem. In this paper, the authors propose an online optimization method for the optimal operation schedule of generators in micro grid. The proposed method is based on enumeration method and particle swarm optimization (PSO). In the proposed method, after picking up all unit commitment patterns of each generators satisfied with minimum up time and minimum down time constraint by using enumeration method, optimal schedule and output of generators are determined under the other operational constraints by using PSO. Numerical simulation is carried out for a micro grid model with five generators and photovoltaic generation system in order to examine the validity of the proposed method.

  12. Computing Aerodynamic Performance of a 2D Iced Airfoil: Blocking Topology and Grid Generation

    Science.gov (United States)

    Chi, X.; Zhu, B.; Shih, T. I.-P.; Slater, J. W.; Addy, H. E.; Choo, Yung K.; Lee, Chi-Ming (Technical Monitor)

    2002-01-01

    The ice accrued on airfoils can have enormously complicated shapes with multiple protruded horns and feathers. In this paper, several blocking topologies are proposed and evaluated on their ability to produce high-quality structured multi-block grid systems. A transition layer grid is introduced to ensure that jaggedness on the ice-surface geometry do not to propagate into the domain. This is important for grid-generation methods based on hyperbolic PDEs (Partial Differential Equations) and algebraic transfinite interpolation. A 'thick' wrap-around grid is introduced to ensure that grid lines clustered next to solid walls do not propagate as streaks of tightly packed grid lines into the interior of the domain along block boundaries. For ice shapes that are not too complicated, a method is presented for generating high-quality single-block grids. To demonstrate the usefulness of the methods developed, grids and CFD solutions were generated for two iced airfoils: the NLF0414 airfoil with and without the 623-ice shape and the B575/767 airfoil with and without the 145m-ice shape. To validate the computations, the computed lift coefficients as a function of angle of attack were compared with available experimental data. The ice shapes and the blocking topologies were prepared by NASA Glenn's SmaggIce software. The grid systems were generated by using a four-boundary method based on Hermite interpolation with controls on clustering, orthogonality next to walls, and C continuity across block boundaries. The flow was modeled by the ensemble-averaged compressible Navier-Stokes equations, closed by the shear-stress transport turbulence model in which the integration is to the wall. All solutions were generated by using the NPARC WIND code.

  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. Nuclear Power as an Option in Electrical Generation Planning for Small Economy and Electricity Grid

    International Nuclear Information System (INIS)

    Tomsic, Z.

    2012-01-01

    Implementing a NPP in countries with relatively small total GDP (small economy) and usually with small electricity grid face two major problems and constrains: the ability to obtain the considerable financial resources required on reasonable terms and to connect large NPP to small electricity grid. Nuclear generation financing in developing countries involves complex issues that need to be fully understood and dealt with by all the parties involved. The main topics covered by paper will be the: special circumstances related to the financing of NPP, costs and economic feasibility of NPP, conventional approaches for financing power generation projects in developing countries, alternative approaches for mobilizing financial resources. The safe and economic operation of a nuclear power plant (NPP) requires the plant to be connected to an electrical grid system that has adequate capacity for exporting the power from the NPP, and for providing a reliable electrical supply to the NPP for safe start-up, operation and normal or emergency shut-down of the plant. Connection of any large new power plant to the electrical grid system in a country may require significant modification and strengthening of the grid system, but for NPPs there may be added requirements to the structure of the grid system and the way it is controlled and maintained to ensure adequate reliability. Paper shows the comparative assesment of differrent base load technologies as an option in electrical generation planning for small economy and electricity grid.(author).

  15. Mixing in 3D Sparse Multi-Scale Grid Generated Turbulence

    Science.gov (United States)

    Usama, Syed; Kopec, Jacek; Tellez, Jackson; Kwiatkowski, Kamil; Redondo, Jose; Malik, Nadeem

    2017-04-01

    Flat 2D fractal grids are known to alter turbulence characteristics downstream of the grid as compared to the regular grids with the same blockage ratio and the same mass inflow rates [1]. This has excited interest in the turbulence community for possible exploitation for enhanced mixing and related applications. Recently, a new 3D multi-scale grid design has been proposed [2] such that each generation of length scale of turbulence grid elements is held in its own frame, the overall effect is a 3D co-planar arrangement of grid elements. This produces a 'sparse' grid system whereby each generation of grid elements produces a turbulent wake pattern that interacts with the other wake patterns downstream. A critical motivation here is that the effective blockage ratio in the 3D Sparse Grid Turbulence (3DSGT) design is significantly lower than in the flat 2D counterpart - typically the blockage ratio could be reduced from say 20% in 2D down to 4% in the 3DSGT. If this idea can be realized in practice, it could potentially greatly enhance the efficiency of turbulent mixing and transfer processes clearly having many possible applications. Work has begun on the 3DSGT experimentally using Surface Flow Image Velocimetry (SFIV) [3] at the European facility in the Max Planck Institute for Dynamics and Self-Organization located in Gottingen, Germany and also at the Technical University of Catalonia (UPC) in Spain, and numerically using Direct Numerical Simulation (DNS) at King Fahd University of Petroleum & Minerals (KFUPM) in Saudi Arabia and in University of Warsaw in Poland. DNS is the most useful method to compare the experimental results with, and we are studying different types of codes such as Imcompact3d, and OpenFoam. Many variables will eventually be investigated for optimal mixing conditions. For example, the number of scale generations, the spacing between frames, the size ratio of grid elements, inflow conditions, etc. We will report upon the first set of findings

  16. Control of Doubly-Fed Induction Generator to Ride-Through Recurring Grid Faults

    DEFF Research Database (Denmark)

    Chen, Wenjie; Xu, Dehong; Zhu, Nan

    2016-01-01

    The wind turbine system (WTS) is required to ride-through recurring grid faults by the new grid codes. Under single grid faults, the fault ride-through (FRT) strategy with rotor-side crowbar is normally used for the doubly-fed induction generator (DFIG) WTS. However, under recurring faults, larger...... transient current and voltage may be produced, and the DFIG may fail to ride-through the second fault even with the rotor-side crowbar. The crowbar can be active again during the voltage recovery, but large electromagnetic torque (EM-torque) fluctuations will be introduced. The reliability of the mechanical...... system will be influenced. In this paper, an FRT strategy for the DFIG WTS to ride-through recurring symmetrical grid faults is investigated. An improved control strategy is introduced and it is applied during the voltage recovery of the grid faults. The decay of the stator natural flux can...

  17. Distributed generation incorporated with the thermal generation for optimum operation of a smart grid considering forecast error

    International Nuclear Information System (INIS)

    Howlader, Harun Or Rashid; Matayoshi, Hidehito; Senjyu, Tomonobu

    2015-01-01

    Highlights: • Optimal operation of the thermal generation for the smart grid system. • Different distributed generations are considered as the power generation sources. • Forecast error of the renewable energy systems is considered. • Controllable loads of the smart houses are considered to achieve the optimal operation. • Economical benefits can be achieved for the smart grid system. - Abstract: This paper concentrates on the optimal operation of the conventional thermal generators with distributed generations for a smart grid considering forecast error. The distributed generations are considered as wind generators, photovoltaic generators, battery energy storage systems in the supply side and a large number of smart houses in the demand side. A smart house consists of the electric vehicle, heat pump, photovoltaic generator and solar collector. The electric vehicle and heat pump are considered as the controllable loads which can compensate the power for the forecast error of renewable energy sources. As a result, power generation cost of the smart grid can reduce through coordinated with distributed generations and thermal units scheduling process. The electric vehicles of the smart house are considered as the spinning reserve in the scheduling process which lead to lessen the additional operation of thermal units. Finally, obtained results of the proposed system have been compared with the conventional method. The conventional method does not consider the electric vehicle in the smart houses. The acquired results demonstrate that total power generation cost of the smart grid has been reduced by the proposed method considering forecast error. Effectiveness of the proposed method has been verified by the extensive simulation results using MATLAB® software

  18. Message passing for integrating and assessing renewable generation in a redundant power grid

    Energy Technology Data Exchange (ETDEWEB)

    Zdeborova, Lenka [Los Alamos National Laboratory; Backhaus, Scott [Los Alamos National Laboratory; Chertkov, Michael [Los Alamos National Laboratory

    2009-01-01

    A simplified model of a redundant power grid is used to study integration of fluctuating renewable generation. The grid consists of large number of generator and consumer nodes. The net power consumption is determined by the difference between the gross consumption and the level of renewable generation. The gross consumption is drawn from a narrow distribution representing the predictability of aggregated loads, and we consider two different distributions representing wind and solar resources. Each generator is connected to D consumers, and redundancy is built in by connecting R {le} D of these consumers to other generators. The lines are switchable so that at any instance each consumer is connected to a single generator. We explore the capacity of the renewable generation by determining the level of 'firm' generation capacity that can be displaced for different levels of redundancy R. We also develop message-passing control algorithm for finding switch sellings where no generator is overloaded.

  19. Characterization of a Power Electronic Grid Simulator for Wind Turbine Generator Compliance Testing

    DEFF Research Database (Denmark)

    Glasdam, Jakob Bærholm; Gevorgian, V.; Wallen, R.

    2014-01-01

    This paper presents the commissioning results and testing capabilities of a multi-megawatt power electronic grid simulator situated in National Renewable Energy Laboratory’s (NREL’s) new testing facility. The commissioning is done using a commercial type 4 multi-megawatt sized wind turbine...... generator (WTG) installed in NREL’s new 5 MW dynamometer and a kilowatt sized type 1 WTG connected to the existing 2.5 MW dynamometer at NREL. The paper demonstrates the outstanding testing capability of the grid simulator and its application in the grid code compliance evaluation of WTGs including balanced...

  20. Foam: Multi-Dimensional General Purpose Monte Carlo Generator With Self-Adapting Simplical Grid

    OpenAIRE

    Jadach, S.

    1999-01-01

    A new general purpose Monte Carlo event generator with self-adapting grid consisting of simplices is described. In the process of initialization, the simplex-shaped cells divide into daughter subcells in such a way that: (a) cell density is biggest in areas where integrand is peaked, (b) cells elongate themselves along hyperspaces where integrand is enhanced/singular. The grid is anisotropic, i.e. memory of the axes directions of the primary reference frame is lost. In particular, the algorit...

  1. Foam: Multi-Dimensional General Purpose Monte Carlo Generator With Self-Adapting Symplectic Grid

    OpenAIRE

    Jadach, Stanislaw

    2000-01-01

    A new general purpose Monte Carlo event generator with self-adapting grid consisting of simplices is described. In the process of initialization, the simplex-shaped cells divide into daughter subcells in such a way that: (a) cell density is biggest in areas where integrand is peaked, (b) cells elongate themselves along hyperspaces where integrand is enhanced/singular. The grid is anisotropic, i.e. memory of the axes directions of the primary reference frame is lost. In particular, the algorit...

  2. Fair division of generation profile and fuel consumption in isolated micro-grids

    DEFF Research Database (Denmark)

    Kosek, Anna Magdalena; Heussen, Kai

    2014-01-01

    Islands and rural areas can decrease their cost of energy by exploiting renewable energy as compared to diesel- only generation. Operation of such isolated micro-grids requires allocation of units for grid stability. Depending on the control strategy employed, the fluctuating renewable production...... to provide a proof-of-concept case study of an isolated micro-grid with two wind turbines and three diesel generators. In comparison with a simple master- slave allocation, the proposed coordination scheme improves the distribution of fuel allocation by 27,5%, reduces under-load time by 43,5% and decreases...... leads to more stressed loading conditions of diesel generators. We propose a control strategy employing fair division of generator allocation using a compensation procedure based on social choice methods. A co-simulation set up with separate power system and control strategy simulators is used...

  3. Control of power converters in distributed generation applications under grid fault conditions

    DEFF Research Database (Denmark)

    Rodriguez, Pedro; Luna, Alvaro; Munoz-Aguilar, Raul

    2011-01-01

    The operation of distributed power generation systems under grid fault conditions is a key issue for the massive integration of renewable energy systems. Several studies have been conducted to improve the response of such distributed generation systems under voltage dips. In spite of being less s...

  4. Optimal Operation of Micro-grids Considering the Uncertainties of Demand and Renewable Energy Resources Generation

    Directory of Open Access Journals (Sweden)

    Malek Jasemi

    2016-11-01

    Full Text Available Nowadays, due to technical and economic reasons, the distributed generation (DG units are widely connected to the low and medium voltage network and created a new structure called micro-grid. Renewable energies (especially wind and solar based DGs are one of the most important generations units among DG units. Because of stochastic behavior of these resources, the optimum and safe management and operation of micro-grids has become one of the research priorities for researchers. So, in this study, the optimal operation of a typical micro-grid is investigated in order to maximize the penetration of renewable energy sources with the lowest operation cost with respect to the limitations for the load supply and the distributed generation resources. The understudy micro-grid consists of diesel generator, battery, wind turbines and photovoltaic panels. The objective function comprises of fuel cost, start-up cost, spinning reserve cost, power purchasing cost from the upstream grid and the sales revenue of the power to the upstream grid. In this paper, the uncertainties of demand, wind speed and solar radiation are considered and the optimization will be made by using the GAMS software and mixed integer planning method (MIP. Article History: Received May 21, 2016; Received in revised form July 11, 2016; Accepted October 15, 2016; Available online How to Cite This Article: Jasemi, M.,  Adabi, F., Mozafari, B., and Salahi, S. (2016 Optimal Operation of Micro-grids Considering the Uncertainties of Demand and Renewable Energy Resources Generation, Int. Journal of Renewable Energy Development, 5(3,233-248. http://dx.doi.org/10.14710/ijred.5.3.233-248

  5. Interconnector capacity allocation in offshore grids with variable wind generation

    DEFF Research Database (Denmark)

    Schröder, Sascha Thorsten

    2013-01-01

    its generation flows only to the high-price market. Granting the high-price market income for wind generation as the opposite design option reduces congestion rents. Otherwise, compensation measures through support schemes or different balancing responsibilities may be discussed....... with onshore installations to reduce balancing demand. This is not necessarily the case if the interconnector capacity is sold through implicit or explicit auctions. Different design options are discussed and quantified for a number of examples based on Danish, Dutch, German and Norwegian power markets....... It is concluded that treating offshore generation as a single price zone within the interconnector reduces the wind operator’s ability to pool it with other generation. Furthermore, a single offshore price zone between two markets will always receive the lower spot market price of the neighbouring zones, although...

  6. Special issue on advancing grid-connected renewable generation systems

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Yang, Yongheng

    2017-01-01

    Renewables are heavily involved in power generation, as an essential component for today’s energy paradigm. Energy structure—both national and international—has been undergoing significant changes over the past few decades. For instance, in Denmark, power generation is shifting from fossil......-fuel-based to renewable-based in terms of energy sources, from centralized to decentralized in terms of architectures, and from sole to miscellaneous in terms of energy varieties [1]. In this energy evolution, the power electronic technology plays an enabling role in the integration and advancements of renewables...

  7. A GIS/PSS planning tool for the initial grid connection assessment of renewable generation

    Energy Technology Data Exchange (ETDEWEB)

    Quinonez-Varela, G.; Cruden, A. [Electronic and Electrical Engineering (EEE), University of Strathclyde, Glasgow G1 1XW (United Kingdom); Graham, C. [Scottish Power plc, Transmission and Distribution, Glasgow ML4 3FF (United Kingdom); Punton, B. [Scottish and Southern Energy plc, Transmission and Distribution, Perth PH1 3AQ (United Kingdom); Blair, L.; Thomson, J. [Scottish Executive, Renewables and Consents Policy, Glasgow G2 6AT (United Kingdom)

    2007-04-15

    A fully integrated planning tool capable of undertaking an initial grid connection assessment for prospective renewable energy generators (REG) has been developed to support the Scottish Executive achieve their targets for renewable energy utilisation, and to assist the Scottish electric utility companies to optimise and expedite the significant volume of applications for new connections. This paper presents the conceptual design of the novel integrated planning tool intended to automate the preliminary grid connection assessments. The computer-based (PC) framework combines the analytical capabilities of modern Geographic Information Systems and existing industry-standard Power Systems Simulators. The tool allows the prompt, automated determination of the preferred grid connection route, coupling points and undertakes a capacity and voltage limit analysis of the technical feasibility analysis of the proposed REG. Simple adjustments are also permitted to investigate constraining the REG development or upgrading the existing grid connection lines. (author)

  8. Risk-based generation dispatch in the power grid for resilience against extreme weather events

    Science.gov (United States)

    Javanbakht, Pirooz

    Natural disasters have been considered as one of the main causes of the largest blackouts in North America. When it comes to power grid resiliency against natural hazards, different solutions exist that are mainly categorized based on the time-frame of analysis. At the design stage, robustness and resiliency may be improved through redundant designs and inclusion of advanced measurement, monitoring, control and protection systems. However, since massive destructive energy may be released during the course of a natural disaster (such as a hurricane) causing large-scale and widespread disturbances, design-stage remedies may not be sufficient for ensuring power grid robustness. As a result, to limit the consequent impacts on the operation of the power grid, the system operator may be forced to take immediate remedial actions in real-time. To effectively manage the disturbances caused by severe weather events, weather forecast information should be incorporated into the operational model of the power grid in order to predict imminent contingencies. In this work, a weather-driven generation dispatch model is developed based on stochastic programming to provide a proactive solution for power grid resiliency against imminent large-scale disturbances. Hurricanes and ice storms are studied as example disaster events to provide numerical results. In this approach, the statistics of the natural disaster event are taken into account along with the expected impact on various power grid components in order to determine the availability of the grid. Then, a generation dispatch strategy is devised that helps operate the grid subject to weather-driven operational constraints.

  9. A Novel Grid Impedance Estimation Technique based on Adaptive Virtual Resistance Control Loop Applied to Distributed Generation Inverters

    DEFF Research Database (Denmark)

    Ghzaiel, Walid; Jebali-Ben Ghorbal, Manel; Slama-Belkhodja, Ilhem

    2013-01-01

    The penetration of the distributed power generation systems (DPGSs) based on renewable sources (PV, WT) is strongly dependent on the quality of the power injected to the utility grid. However, the grid impedance variation, mainly caused by grid faults somewhere in the electric network, can degrade...

  10. Integrated Design Engineering Analysis (IDEA) Environment Automated Generation of Structured CFD Grids using Topology Methods

    Science.gov (United States)

    Kamhawi, Hilmi N.

    2012-01-01

    This report documents the work performed from March 2010 to March 2012. The Integrated Design and Engineering Analysis (IDEA) environment is a collaborative environment based on an object-oriented, multidisciplinary, distributed framework using the Adaptive Modeling Language (AML) as a framework and supporting the configuration design and parametric CFD grid generation. This report will focus on describing the work in the area of parametric CFD grid generation using novel concepts for defining the interaction between the mesh topology and the geometry in such a way as to separate the mesh topology from the geometric topology while maintaining the link between the mesh topology and the actual geometry.

  11. 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.

  12. Mesh Generation via Local Bisection Refinement of Triangulated Grids

    Science.gov (United States)

    2015-06-01

    Science and Technology Organisation DSTO–TR–3095 ABSTRACT This report provides a comprehensive implementation of an unstructured mesh generation method...and Technology Organisation 506 Lorimer St, Fishermans Bend, Victoria 3207, Australia Telephone: 1300 333 362 Facsimile: (03) 9626 7999 c© Commonwealth...their behaviour is critically linked to Maubach’s method and the data structures N and T . The top- level mesh refinement algorithm is also presented

  13. 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

  14. 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.

  15. 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.

  16. Compensating customer-generators: a taxonomy describing methods of compensating customer-generators for electricity supplied to the grid

    International Nuclear Information System (INIS)

    Hughes, Larry; Bell, Jeff

    2006-01-01

    The increasing popularity of on-site power generation is driving the demand for methods to compensate customer-generators that supply electricity to the grid. Although many practices exist for providing such compensation, confusion surrounds the terms often used to describe such practices (notably, net metering and net billing). To help clarify this situation, the following paper proposes a taxonomy that distinguishes between 16 distinct compensation practices

  17. WinGridder - An interactive grid generator for TOUGH - A user's manual (Version 1.0)

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Lehua; Hinds, Jennifer; Haukwa, Charles; Wu, Yu-Shu; Bodvarsson, Gudmundur

    2001-07-18

    WinGridder is a Windows-based software package for designing, generating, and visualizing at various spatial scales numerical grids used in reservoir simulations and groundwater modeling studies. Development of this software was motivated by the requirements of the TOUGH (Transport of Unsaturated Groundwater and Heat) family of codes (Pruess 1987, 1991) for simulating subsurface processes related to high-level nuclear waste isolation in partially saturated geological media. Although the TOUGH family of codes has great flexibility in handling the variety of grid information required to describe complex objects, designing and generating a suitable irregular grid can be a tedious and error-prone process, even with the help of existing grid generating programs. This is especially true when the number of cells and connections is very large. The processes of inspecting the quality of the grid or extracting sub-grids or other specific grid information are also complex. The mesh maker embedded within TOUGH2 generates only uniform numerical grids and handles only one set of uniform fracture and matrix properties throughout the model domain. This is not suitable for grid generation in complex flow and transport simulations (such as those of Yucca Mountain, which have heterogeneity in both fracture and matrix media). As a result, the software program Amesh (Haukwa 2000) was developed to generate irregular, effective-continuum (ECM) grids.

  18. Parametric Geometry, Structured Grid Generation, and Initial Design Study for REST-Class Hypersonic Inlets

    Science.gov (United States)

    Ferlemann, Paul G.; Gollan, Rowan J.

    2010-01-01

    Computational design and analysis of three-dimensional hypersonic inlets with shape transition has been a significant challenge due to the complex geometry and grid required for three-dimensional viscous flow calculations. Currently, the design process utilizes an inviscid design tool to produce initial inlet shapes by streamline tracing through an axisymmetric compression field. However, the shape is defined by a large number of points rather than a continuous surface and lacks important features such as blunt leading edges. Therefore, a design system has been developed to parametrically construct true CAD geometry and link the topology of a structured grid to the geometry. The Adaptive Modeling Language (AML) constitutes the underlying framework that is used to build the geometry and grid topology. Parameterization of the CAD geometry allows the inlet shapes produced by the inviscid design tool to be generated, but also allows a great deal of flexibility to modify the shape to account for three-dimensional viscous effects. By linking the grid topology to the parametric geometry, the GridPro grid generation software can be used efficiently to produce a smooth hexahedral multiblock grid. To demonstrate the new capability, a matrix of inlets were designed by varying four geometry parameters in the inviscid design tool. The goals of the initial design study were to explore inviscid design tool geometry variations with a three-dimensional analysis approach, demonstrate a solution rate which would enable the use of high-fidelity viscous three-dimensional CFD in future design efforts, process the results for important performance parameters, and perform a sample optimization.

  19. Aerodynamic Optimal Shape Design Based on Body-Fitted Grid Generation

    Directory of Open Access Journals (Sweden)

    Farzad Mohebbi

    2014-01-01

    Full Text Available This paper is concerned with an optimal shape design problem in aerodynamics. The inverse problem in question consists in finding the optimal shape an airfoil placed in a potential flow at a given angle of attack should have such that the pressure distribution on its surface matches a desired one. The numerical method to achieve this aim is based on a body-fitted grid generation technique (elliptic, O-type to generate a mesh over the airfoil surface and solve for the flow equation. The O-type scheme is used due to its ability to generate a high quality (fine and orthogonal grid around the airfoil surface. This paper describes a novel and very efficient sensitivity analysis scheme to compute the sensitivity of the pressure distribution to variation of grid node positions and both the conjugate gradient method (CGM and a version of the quasi-Newton method (i.e., BFGS are used as optimization algorithms to minimize the difference between the computed pressure distribution on the airfoil surface and desired one. The elliptic grid generation technique allows us to map the physical domain (body onto a fixed computational domain and to discretize the flow equation using the finite difference method (FDM.

  20. A Theoretical Secure Enterprise Architecture for Multi Revenue Generating Smart Grid Sub Electric Infrastructure

    Science.gov (United States)

    Chaudhry, Hina

    2013-01-01

    This study is a part of the smart grid initiative providing electric vehicle charging infrastructure. It is a refueling structure, an energy generating photovoltaic system and charge point electric vehicle charging station. The system will utilize advanced design and technology allowing electricity to flow from the site's normal electric service…

  1. Identification of Synchronous Generator Electric Parameters Connected to the Distribution Grid

    Directory of Open Access Journals (Sweden)

    Frolov M. Yu.

    2017-04-01

    Full Text Available According to modern trends, the power grids with distributed generation will have an open system architecture. It means that active consumers, owners of distributed power units, including mobile units, must have free access to the grid, like when using internet, so it is necessary to have plug and play technologies. Thanks to them, the system will be able to identify the unit type and the unit parameters. Therefore, the main aim of research, described in the paper, was to develop and research a new method of electric parameters identification of synchronous generator. The main feature of the proposed method is that parameter identification is performed while the generator to the grid, so it fits in the technological process of operation of the machine and does not influence on the connection time of the machine. For the implementation of the method, it is not necessary to create dangerous operation modes for the machine or to have additional expensive equipment and it can be used for salient pole machines and round rotor machines. The parameter identification accuracy can be achieved by more accurate account of electromechanical transient process, and making of overdetermined system with many more numbers of equations. Parameter identification will be made with each generator connection to the grid. Comparing data obtained from each connection, the middle values can be find by numerical method, and thus, each subsequent identification will accurate the machine parameters.

  2. Grid generation methodology and CFD simulations in sliding vane compressors and expanders

    Science.gov (United States)

    Bianchi, Giuseppe; Rane, Sham; Kovacevic, Ahmed; Cipollone, Roberto; Murgia, Stefano; Contaldi, Giulio

    2017-08-01

    The limiting factor for the employment of advanced 3D CFD tools in the analysis and design of rotary vane machines is the unavailability of methods for generation of computational grids suitable for fast and reliable numerical analysis. The paper addresses this challenge presenting the development of an analytical grid generation for vane machines that is based on the user defined nodal displacement. In particular, mesh boundaries are defined as parametric curves generated using trigonometrical modelling of the axial cross section of the machine while the distribution of computational nodes is performed using algebraic algorithms with transfinite interpolation, post orthogonalisation and smoothing. Algebraic control functions are introduced for distribution of nodes on the rotor and casing boundaries in order to achieve good grid quality in terms of cell size and expansion. In this way, the moving and deforming fluid domain of the sliding vane machine is discretized and the conservation of intrinsic quantities in ensured by maintaining the cell connectivity and structure. For validation of generated grids, a mid-size air compressor and a small-scale expander for Organic Rankine Cycle applications have been investigated in this paper. Remarks on implementation of the mesh motion algorithm, stability and robustness experienced with the ANSYS CFX solver as well as the obtained flow results are presented.

  3. A testing procedure for wind turbine generators based on the power grid statistical model

    DEFF Research Database (Denmark)

    Farajzadehbibalan, Saber; Ramezani, Mohammad Hossein; Nielsen, Peter

    2017-01-01

    In this study, a comprehensive test procedure is developed to test wind turbine generators with a hardware-in-loop setup. The procedure employs the statistical model of the power grid considering the restrictions of the test facility and system dynamics. Given the model in the latent space, the j...

  4. Modeling and Stress Analysis of Doubly-Fed Induction Generator during Grid Voltage Swell

    DEFF Research Database (Denmark)

    Zhou, Dao; Song, Yipeng; Blaabjerg, Frede

    2016-01-01

    The Doubly-Fed Induction Generator (DFIG) based wind turbine system is presently dominant in the wind turbine market. Due to heavy load switch-off and faults in the power grid, voltage swells may occur and this phenomenon is currently given sufficient insights. This paper starts to describe the D...

  5. Modeling and Control of Grid Side Converter in Wind Power Generation System Based on Synchronous VFDPC with PLL

    DEFF Research Database (Denmark)

    Guo, Yougui; Zeng, Ping; Li, Lijuan

    2011-01-01

    Virtual flux oriented direct power control (VFDPC) is combined space vector modulation (SVM) with PI of DC-link voltage, active power and reactive power to control the grid side converter in wind power generation system in this paper. VFDPC has reached good performances with PLL (phase lock loop......). First the mathematical models of grid side converter, LCL filter and phase lock loop are given. Then the control strategy of grid side converter-based wind power generation system is given in detail. Finally the simulation model is modeled consisting of power circuits, such as the grid side converter...... in wind power generation system....

  6. Unbalanced voltage control of virtual synchronous generator in isolated micro-grid

    Science.gov (United States)

    Cao, Y. Z.; Wang, H. N.; Chen, B.

    2017-06-01

    Virtual synchronous generator (VSG) control is recommended to stabilize the voltage and frequency in isolated micro-grid. However, common VSG control is challenged by widely used unbalance loads, and the linked unbalance voltage problem worsens the power quality of the micro-grid. In this paper, the mathematical model of VSG was presented. Based on the analysis of positive- and negative-sequence equivalent circuit of VSG, an approach was proposed to eliminate the negative-sequence voltage of VSG with unbalance loads. Delay cancellation method and PI controller were utilized to identify and suppress the negative-sequence voltages. Simulation results verify the feasibility of proposed control strategy.

  7. Understanding the Temporal and Spatial Variability of New Generation Gridded TMYs

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, Anthony

    2017-04-26

    Presentation at ASHRAE about the spatial and temporal variability of gridded TMYs, discussing advanced GIS and Web services that allow for direct access to data, surface-based observations for thousands of stations, climate reanalysis data, and products derived from satellite data; new developments in NREL's solar databases based on both observed data and satellite-derived gridded data, status of TMY3 weather files, and NREL's plans for the next-generation TMY weather files; and also covers what is new and different in the Climatic Design Conditions Table in the 2013 ASHRAE Handbook of Fundamentals.

  8. Forecasting Wind and Solar Generation: Improving System Operations, Greening the Grid (Spanish Version)

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Tian; Chernyakhovskiy, Ilya; Brancucci Martinez-Anido, Carlo

    2016-04-01

    This document is the Spanish version of 'Greening the Grid- Forecasting Wind and Solar Generation Improving System Operations'. It discusses improving system operations with forecasting with and solar generation. By integrating variable renewable energy (VRE) forecasts into system operations, power system operators can anticipate up- and down-ramps in VRE generation in order to cost-effectively balance load and generation in intra-day and day-ahead scheduling. This leads to reduced fuel costs, improved system reliability, and maximum use of renewable resources.

  9. Grid Generation Issues in the CFD Modelling of Two-Phase Flow in a Pipe

    Directory of Open Access Journals (Sweden)

    V. Hernandez-Perez

    2011-03-01

    Full Text Available The grid generation issues found in the 3D simulation of two-phase flow in a pipe using Computational Fluid Dynamics (CFD are discussed in this paper. Special attention is given to the effect of the element type and structure of the mesh. The simulations were carried out using the commercial software package STAR-CCM+, which is designed for numerical simulation of continuum mechanics problems. The model consisted of a cylindrical vertical pipe. Different mesh structures were employed in the computational domain. The condition of two-phase flow was simulated with the Volume of Fluid (VOF model, taking into consideration turbulence effects using the k-e model. The results showed that there is a strong dependency of the flow behaviour on the mesh employed. The best result was obtained with the grid known as butterfly grid, while the cylindrical mesh produced misleading results. The simulation was validated against experimental results.

  10. Characterization of a Power Electronic Grid Simulator for Wind Turbine Generator Compliance Testing

    DEFF Research Database (Denmark)

    Glasdam, Jakob Bærholm; Gevorgian, V.; Wallen, R.

    2014-01-01

    This paper presents the commissioning results and testing capabilities of a multi-megawatt power electronic grid simulator situated in National Renewable Energy Laboratory’s (NREL’s) new testing facility. The commissioning is done using a commercial type 4 multi-megawatt sized wind turbine...... generator (WTG) installed in NREL’s new 5 MW dynamometer and a kilowatt sized type 1 WTG connected to the existing 2.5 MW dynamometer at NREL. The paper demonstrates the outstanding testing capability of the grid simulator and its application in the grid code compliance evaluation of WTGs including balanced...... and unbalanced voltage low and high fault ride-through. Furthermore, the paper provides insight into the performance of commercial WTGs during both normal and abnormal operating conditions....

  11. Passivity-Based Control of a Doubly Fed Induction Generator System under Unbalanced Grid Voltage Conditions

    Directory of Open Access Journals (Sweden)

    Jiawei Huang

    2017-08-01

    Full Text Available According to the theory of passivity-based control (PBC, this paper establishes a port-controlled Hamiltonian system with dissipation (PCHD model for a doubly fed induction generator (DFIG system under unbalanced grid voltage conditions and proposes a method of interconnection and damping assignment passivity-based control (IDA-PBC of the system under such conditions. By using this method, the rotor-side converter and grid-side converter can be controlled simultaneously in order to improve fault ride-through capability of the DFIG system. Simulation results indicate that this IDA-PBC strategy effectively suppresses fluctuations of output current and power in the DFIG system during unbalanced grid voltage sag/swell, enhances dynamic performance, and improves the robustness of the system.

  12. Fast calculation method of computer-generated hologram using a depth camera with point cloud gridding

    Science.gov (United States)

    Zhao, Yu; Shi, Chen-Xiao; Kwon, Ki-Chul; Piao, Yan-Ling; Piao, Mei-Lan; Kim, Nam

    2018-03-01

    We propose a fast calculation method for a computer-generated hologram (CGH) of real objects that uses a point cloud gridding method. The depth information of the scene is acquired using a depth camera and the point cloud model is reconstructed virtually. Because each point of the point cloud is distributed precisely to the exact coordinates of each layer, each point of the point cloud can be classified into grids according to its depth. A diffraction calculation is performed on the grids using a fast Fourier transform (FFT) to obtain a CGH. The computational complexity is reduced dramatically in comparison with conventional methods. The feasibility of the proposed method was confirmed by numerical and optical experiments.

  13. 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)

  14. The political economy of grid-connected distributed power generation systems in California

    Science.gov (United States)

    Tongsopit, Sopitsuda

    For nearly two decades, distributed generation (DG) has been touted as a disruptive technology that could revolutionize the way electricity is produced and delivered. Whether this vision will be realized depends upon how this new technology, the existing technological system, i.e., the electric power grid, and the regulatory structure governing these systems co-evolve. My dissertation examines the interface between distributed generation and the electric power grid in California. Drawing upon published materials and interviews with members of the electric utility industry, I analyze technical, economic, and property rights conflicts between the two technological systems that together constitute what I hereby call the problem of interconnection. In attempting to understand the problem of interconnection, I seek answers to the following questions: (1) How and why are key decisions regarding interconnections made in California? (2) How do existing institutions adapt to the changing environment of more DG utilization? (3) To what extent are the DG-grid interactions shaped by technical, economic, and political factors? It is found that the California approach toward DG-grid interconnection is only one among many possible approaches and not necessarily the most technically or economically efficient. DG is integrated such that it becomes a passive extension to the centralized, hierarchical grid. This technical approach has been standardized while excluding possibilities that had historically seemed possible. The dissertation then poses the problem of interconnection in the context of evolving property rights to the U.S. power grid. California's distribution sector has been exposed to the same kinds of pressures that have diluted and diffused utilities' rights to generation and transmission control. But unlike the latter two sectors, the institutional recognition of distribution monopolies is still dominant. As a result, local distribution monopolies have been able to

  15. Enhanced Control of a DFIG-Based Wind-Power Generation System With Series Grid-Side Converter Under Unbalanced Grid Voltage Conditions

    DEFF Research Database (Denmark)

    Yao, Jun; Li, Hui; Chen, Zhe

    2013-01-01

    This paper presents an enhanced control method for a doubly fed induction generator (DFIG)-based wind-power generation system with series grid-side converter (SGSC) under unbalanced grid voltage conditions. The behaviors of the DFIG system with SGSC during network unbalance are described....... By injecting a series control voltage generated from the SGSC to balance the stator voltage, the adverse effects of voltage unbalance upon the DFIG, such as stator and rotor current unbalances, electromagnetic torque, and power pulsations, can be removed, and then the conventional vector control strategy...... to the grid. Furthermore, a precise current reference generation strategy for the PGSC has been proposed for the PGSC to further improve the operation performance of the whole system. Finally, the proposed coordinated control strategy for the DFIG system with SGSC has been validated by the simulation results...

  16. Dynamic analysis of combined photovoltaic source and synchronous generator connected to power grid

    Science.gov (United States)

    Mahabal, Divya

    In the world of expanding economy and technology, the energy demand is likely to increase even with the global efforts of saving and increasing energy efficiency. Higher oil prices, effects of greenhouse gases, and concerns over other environmental impacts gave way to Distributed Generation (DG). With adequate awareness and support, DG's can meet these rising energy demands at lower prices compared to conventional methods. Extensive research is taking place in different areas like fuel cells, photovoltaic cells, wind turbines, and gas turbines. DG's when connected to a grid increase the overall efficiency of the power grid. It is believed that three-fifth of the world's electricity would account for renewable energy by middle of 21st century. This thesis presents the dynamic analysis of a grid connected photovoltaic (PV) system and synchronous generator. A grid is considered as an infinite bus. The photovol-taic system and synchronous generator act as small scale distributed energy resources. The output of the photovoltaic system depends on the light intensity, temperature, and irradiance levels of sun. The maximum power point tracking and DC/AC converter are also modeled for the photovoltaic system. The PV system is connected to the grid through DC/AC system. Different combinations of PV and synchronous generator are modeled with the grid to study the dynamics of the proposed system. The dynamics of the test system is analyzed by subjecting the system to several disturbances under various conditions. All modules are individually modeled and con-nected using MATLAB/Simulink software package. Results from the study show that, as the penetration of renewable energy sources like PV increases into the power system, the dynamics of the system becomes faster. When considering cases such as load switching, PV cannot deliver more power as the performance of PV depends on environmental conditions. Synchronous generator in power system can produce the required amount of

  17. 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.

  18. Operation Optimization in a Smart Micro-Grid in the Presence of Distributed Generation and Demand Response

    Directory of Open Access Journals (Sweden)

    Yongli Wang

    2018-03-01

    Full Text Available With the application of distributed generation and the development of smart grid technology, micro-grid, an economic and stable power grid, tends to play an important role in the demand side management. Because micro-grid technology and demand response have been widely applied, what Demand Response actions can realize the economic operation of micro-grid has become an important issue for utilities. In this proposed work, operation optimization modeling for micro-grid is done considering distributed generation, environmental factors and demand response. The main contribution of this model is to optimize the cost in the context of considering demand response and system operation. The presented optimization model can reduce the operation cost of micro-grid without bringing discomfort to the users, thus increasing the consumption of clean energy effectively. Then, to solve this operational optimization problem, genetic algorithm is used to implement objective function and DR scheduling strategy. In addition, to validate the proposed model, it is employed on a smart micro-grid from Tianjin. The obtained numerical results clearly indicate the impact of demand response on economic operation of micro-grid and development of distributed generation. Besides, a sensitivity analysis on the natural gas price is implemented according to the situation of China, and the result shows that the natural gas price has a great influence on the operation cost of the micro-grid and effect of demand response.

  19. There is need in new generation smart grid for the space and ground energy systems

    Directory of Open Access Journals (Sweden)

    Ageev Alexander

    2018-01-01

    Full Text Available The aim of the article is to considerate the opportunities of synchronization of the space and ground systems that generate and transfer energy on the basis of new generation smart grid using. The authors substantiate the necessity of new intellectual monitoring services that assess the processes took place in "generation-transportation-distribution-consumption" space and ground systems. This is made in order to improve the dynamic indicators of the energy system and to avoid the emergencies. The authors also give a prognosis of the dynamic indicators of the electric power super-system in analyzing metastable conditions in different energy modes.

  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. A comparative study of the parabolized Navier-Stokes code using various grid-generation techniques

    Science.gov (United States)

    Kaul, U. K.; Chaussee, D. S.

    1985-01-01

    The parabolized Navier-Stokes (PNS) equations are used to calculate the flow-field characteristics about the hypersonic research aircraft X-24C. A comparison of the results obtained using elliptic, hyperbolic and algebraic grid generators is presented. The outer bow shock is treated as a sharp discontinuity, and the discontinuities within the shock layer are captured. Surface pressures and heat-transfer results at angles of attack of 6 deg and 20 deg, obtained using the three grid generators, are compared. The PNS equations are marched downstream over the body in both Cartesian and cylindrical base coordinate systems, and the results are compared. A robust marching procedure is demonstrated by successfully using large marching-step sizes with the implicit shock fitting procedure. A correlation is found between the marching-step size, Reynolds number and the angle of attack at fixed values of smoothing and stability coefficients for the marching scheme.

  2. High efficiency H6 single-phase transformerless grid-tied PV inverter with proposed modulation for reactive power generation

    Science.gov (United States)

    Almasoudi, Fahad M.; Alatawi, Khaled S.; Matin, Mohammad

    2017-08-01

    Implementation of transformerless inverters in PV grid-tied system offer great benefits such as high efficiency, light weight, low cost, etc. Most of the proposed transformerless inverters in literature are verified for only real power application. Currently, international standards such as VDE-AR-N 4105 has demanded that PV grid-tied inverters should have the ability of controlling a specific amount of reactive power. Generation of reactive power cannot be accomplished in single phase transformerless inverter topologies because the existing modulation techniques are not adopted for a freewheeling path in the negative power region. This paper enhances a previous high efficiency proposed H6 trnasformerless inverter with SiC MOSFETs and demonstrates new operating modes for the generation of reactive power. A proposed pulse width modulation (PWM) technique is applied to achieve bidirectional current flow through freewheeling state. A comparison of the proposed H6 transformerless inverter using SiC MOSFETs and Si MOSFTEs is presented in terms of power losses and efficiency. The results show that reactive power control is attained without adding any additional active devices or modification to the inverter structure. Also, the proposed modulation maintains a constant common mode voltage (CM) during every operating mode and has low leakage current. The performance of the proposed system verifies its effectiveness in the next generation PV system.

  3. A sparse grid based method for generative dimensionality reduction of high-dimensional data

    Science.gov (United States)

    Bohn, Bastian; Garcke, Jochen; Griebel, Michael

    2016-03-01

    Generative dimensionality reduction methods play an important role in machine learning applications because they construct an explicit mapping from a low-dimensional space to the high-dimensional data space. We discuss a general framework to describe generative dimensionality reduction methods, where the main focus lies on a regularized principal manifold learning variant. Since most generative dimensionality reduction algorithms exploit the representer theorem for reproducing kernel Hilbert spaces, their computational costs grow at least quadratically in the number n of data. Instead, we introduce a grid-based discretization approach which automatically scales just linearly in n. To circumvent the curse of dimensionality of full tensor product grids, we use the concept of sparse grids. Furthermore, in real-world applications, some embedding directions are usually more important than others and it is reasonable to refine the underlying discretization space only in these directions. To this end, we employ a dimension-adaptive algorithm which is based on the ANOVA (analysis of variance) decomposition of a function. In particular, the reconstruction error is used to measure the quality of an embedding. As an application, the study of large simulation data from an engineering application in the automotive industry (car crash simulation) is performed.

  4. 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

  5. Analysis of SDFT based phase detection system for grid synchronization of distributed generation systems

    Directory of Open Access Journals (Sweden)

    B. Chitti Babu

    2014-12-01

    Full Text Available A fast and exact detection of phase and fundamental frequency of grid voltage/current is essential for calculating accurate reference signal in order to implement the control algorithm of inverter-interfaced distributed generation (DG system and realize precise harmonic compensation. However, the methods adapted in the literature based on phase locked loop (PLL exhibits large phase error, be difficult to implement, and their performance is also indistinct under conditions where the grid frequency varies or the supply is distorted with low frequency harmonics. This paper explores an improved phase detection system for DG system based on Sliding Discrete Fourier Transform (SDFT. The proposed SDFT based phase detection shows a robust phase tracking capability with fast transient response under adverse situation of the grid. Moreover, SDFT phase detection system is more efficient as it requires small number of operations to extract a single frequency component, thereby reducing computational complexity and simpler than DFT. The superior performance of proposed SDFT phase detection system is analyzed and the obtained results are compared with Discrete Fourier Transform (DFT filtering to confirm the feasibility of the study under different grid environment such as high frequency harmonic injection, frequency deviation, and phase variation etc.

  6. A Vertical-Axis Off-Grid Squirrel-Cage Induction Generator Wind Power System

    Directory of Open Access Journals (Sweden)

    Peifeng Xu

    2016-10-01

    Full Text Available In order to broaden the limited utilization range of wind power and improve the charging and discharging control performance of the storage battery in traditional small wind power generation systems, a wind power system based on a vertical-axis off-grid induction generator is proposed in this paper. The induction generator not only can run in a wide wind speed range but can also assist the vertical-axis wind turbine to realize self-starting at low wind speed. Combined with the maximum power point tracking method, the slip frequency control strategy is employed to regulate the pulse width modulation (PWM converter to control the output power of the proposed system when the wind speed and load change. The charge and discharge of the storage battery is realized by the segmented current-limiting control strategy by means of an electric power unloader device connected to the DC bus. All these implement a balanced and stable operation of the proposed power generation system. The experimental research on the 5.5 kW prototype system is developed, and the corresponding results verify the correctness and feasibility of the system design and control strategy. Some comparison experiments with a magnetic suspension permanent magnet synchronous generator (PMSG demonstrate the application prospect of the proposed vertical-axis off-grid induction generator wind power system.

  7. Optimal Power Flow Management Control for Grid Connected Photovoltaic/Wind turbine/Diesel generator (GCPWD) Hybrid System with Batteries

    OpenAIRE

    Murugan, Bala; S., Manoharan

    2016-01-01

    This paper proposes a Optimal Power Flow Management control for Grid Connected Photovoltaic/Wind turbine/ Diesel generator (GCPWD) Hybrid System with hybrid storage system. The energy system having a photo voltaic (PV) panel, wind turbine (WT) and diesel generator (DG) for continuous power flow management. A diesel generator is added to ensure uninterrupted power supply due to the discontinuous nature of solar and wind resources. The developed Grid Connected Photovoltaic/Wind turbine/ Diesel ...

  8. Adaptive Hysteresis Band Current Control (AHB) with PLL of Grid Side Converter-Based Wind Power Generation System

    DEFF Research Database (Denmark)

    Guo, Yougui; Zeng, Ping; Li, Lijuan

    2011-01-01

    Adaptive hysteresis band current control(AHB CC) is used to control the three-phase grid currents by means of grid side converter in wind power generation system in this paper. AHB has reached the good purpose with PLL (Lock phase loop). First the mathematical models of each part are given. Then ......, transformer and grid, and control parts, etc. The simulation results have verified that the control strategy is feasible to fit for control of gird currents, active power, reactive power and DC-link voltage in wind power generation system.......Adaptive hysteresis band current control(AHB CC) is used to control the three-phase grid currents by means of grid side converter in wind power generation system in this paper. AHB has reached the good purpose with PLL (Lock phase loop). First the mathematical models of each part are given...

  9. RMS Current of a Photovoltaic Generator in Grid-Connected PV Systems: Definition and Application

    Directory of Open Access Journals (Sweden)

    P. J. Pérez

    2008-01-01

    Full Text Available This paper includes a definition of a new and original concept in the photovoltaic field, RMS current of a photovoltaic generator for grid-connected systems. The RMS current is very useful for calculating energy losses in cables used in a PV generator. As well, a current factor has been defined in order to simplify RMS current calculation. This factor provides an immediate (quick and easy calculation method for the RMS current that does not depend on the case particular conditions (orientation, location, etc.. RMS current and current factor values have been calculated for different locations and modules.

  10. Minimum-block-generated flexible-grouping-based spectrum assignment for flex-grid optical networks

    Science.gov (United States)

    Qiu, Yang; Xu, Jing

    2017-11-01

    We investigate the spectrum fragmentation issue in flex-grid optical networks and propose a minimum-block-generated flexible-grouping-based spectrum assignment algorithm. By dividing the spectrum resources into several flexible groups according to the bandwidth requirements of service requests for their accommodation and minimizing the generated isolated spectrum blocks inside each spectrum group, the proposed algorithm can not only reduce spectrum fragments but also enhance networking performance (e.g. blocking probability) due to the improved spectrum contiguity inside each spectrum group with no traffic disruption or any extra components. The simulation results verify that the proposed algorithm can remarkably reduce spectrum fragments with a low blocking probability.

  11. Constant Power Generation of Photovoltaic Systems Considering the Distributed Grid Capacity

    DEFF Research Database (Denmark)

    Yang, Yongheng; Blaabjerg, Frede; Wang, Huai

    2014-01-01

    With an imperative demand of clean and reliable electricity generation in some countries, the increasing adoption of new photovoltaic (PV) systems pushes the Distribution System Operators (DSOs) to expand the transmission/distributed lines. However, the potential cost brought by such extensions...... contribute to a weakened requirement of grid expansion and at the same time an increased penetration level. Therefore, to meet the need of this emerging ancillary service provided by future PV systems, a Constant Power Generation (CPG) control concept of PV inverters is proposed in this paper. Accordingly...

  12. JIGSAW-GEO (1.0): locally orthogonal staggered unstructured grid generation for general circulation modelling on the sphere

    Science.gov (United States)

    Engwirda, Darren

    2017-06-01

    An algorithm for the generation of non-uniform, locally orthogonal staggered unstructured spheroidal grids is described. This technique is designed to generate very high-quality staggered Voronoi-Delaunay meshes appropriate for general circulation modelling on the sphere, including applications to atmospheric simulation, ocean-modelling and numerical weather prediction. Using a recently developed Frontal-Delaunay refinement technique, a method for the construction of high-quality unstructured spheroidal Delaunay triangulations is introduced. A locally orthogonal polygonal grid, derived from the associated Voronoi diagram, is computed as the staggered dual. It is shown that use of the Frontal-Delaunay refinement technique allows for the generation of very high-quality unstructured triangulations, satisfying a priori bounds on element size and shape. Grid quality is further improved through the application of hill-climbing-type optimisation techniques. Overall, the algorithm is shown to produce grids with very high element quality and smooth grading characteristics, while imposing relatively low computational expense. A selection of uniform and non-uniform spheroidal grids appropriate for high-resolution, multi-scale general circulation modelling are presented. These grids are shown to satisfy the geometric constraints associated with contemporary unstructured C-grid-type finite-volume models, including the Model for Prediction Across Scales (MPAS-O). The use of user-defined mesh-spacing functions to generate smoothly graded, non-uniform grids for multi-resolution-type studies is discussed in detail.

  13. Modified Perfect Harmonics Cancellation Control of a Grid Interfaced SPV Power Generation

    Science.gov (United States)

    Singh, B.; Shahani, D. T.; Verma, A. K.

    2015-03-01

    This paper deals with a grid interfaced solar photo voltaic (SPV) power generating system with modified perfect harmonic cancellation (MPHC) control for power quality improvement in terms of mitigation of the current harmonics, power factor correction, control of point of common coupling (PCC) voltage with reactive power compensation and load balancing in a three phase distribution system. The proposed grid interfaced SPV system consists of a SPV array, a dc-dc boost converter and a voltage source converter (VSC) used for the compensation of other connected linear and nonlinear loads at PCC. The reference grid currents are estimated using MPHC method and control signals are derived by using pulse width modulation (PWM) current controller of VSC. The SPV power is fed to the common dc bus of VSC and dc-dc boost converter using maximum power point tracking (MPPT). The dc link voltage of VSC is regulated by using dc voltage proportional integral (PI) controller. The analysis of the proposed SPV power generating system is carried out under dc/ac short circuit and severe SPV-SX and SPV-TX intrusion.

  14. Simulation of off-grid generation options for remote villages in Cameroon

    International Nuclear Information System (INIS)

    Nfah, E.M.; Ngundam, J.M.; Vandenbergh, M.; Schmid, J.

    2008-01-01

    Off-grid generation options have been simulated for remote villages in Cameroon using a load of 110 kWh/day and 12 kWp. The energy costs of proposed options were simulated using HOMER, a typical village load profile, the solar resource of Garoua and the flow of river Mungo. For a 40% increase in the cost of imported power system components, the cost of energy was found to be 0.296 EUR/kWh for a micro-hydro hybrid system comprising a 14 kW micro-hydro generator, a 15 kW LPG generator and 36 kWh of battery storage. The cost of energy for photovoltaic (PV) hybrid systems made up of an 18 kWp PV generator, a 15 kW LPG generator and 72 kWh of battery storage was also found to be 0.576 EUR/kWh for remote petrol price of 1 EUR/l and LPG price of 0.70 EUR/m 3 . The micro-hydro hybrid system proved to be the cheapest option for villages located in the southern parts of Cameroon with a flow rate of at least 200l/s, while the PV hybrid system was the cheapest option for villages in the northern parts of Cameroon with an insolation level of at least 5.55 kWh/m 2 /day. For a single-wire grid extension cost of 5000 EUR/km, operation and maintenance costs of 125 EUR/yr/km and a local grid power price of 0.1 EUR/kWh, the breakeven grid extension distances were found to be 15.4 km for micro-hydro/LPG generator systems and 37.4 km for PV/LPG generator systems respectively. These results could be used in Cameroon's National Energy Action Plan for the provision of energy services in the key sectors involved in the fight against poverty. (author)

  15. Impedance-Based Stability Analysis in Grid Interconnection Impact Study Owing to the Increased Adoption of Converter-Interfaced Generators

    Directory of Open Access Journals (Sweden)

    Youngho Cho

    2017-09-01

    Full Text Available This study investigates the emerging harmonic stability concerns to be addressed by grid planners in generation interconnection studies, owing to the increased adoption of renewable energy resources connected to the grid via power electronic converters. The wideband and high-frequency electromagnetic transient (EMT characteristics of these converter-interfaced generators (CIGs and their interaction with the grid impedance are not accurately captured in the typical dynamic studies conducted by grid planners. This paper thus identifies the desired components to be studied and subsequently develops a practical process for integrating a new CIG into a grid with the existing CIGs. The steps of this process are as follows: the impedance equation of a CIG using its control dynamics and an interface filter to the grid, for example, an LCL filter (inductor-capacitor-inductor type, is developed; an equivalent impedance model including the existing CIGs nearby and the grid observed from the point of common coupling are derived; the system stability for credible operating scenarios is assessed. Detailed EMT simulations validate the accuracy of the impedance models and stability assessment for various connection scenarios. By complementing the conventional EMT simulation studies, the proposed analytical approach enables grid planners to identify critical design parameters for seamlessly integrating a new CIG and ensuring the reliability of the grid.

  16. A Vector Control for Grid-connected Wind Power Generation with Doubly Fed Induction Generator

    Science.gov (United States)

    Kai, Takaaki; Tanaka, Yuji; Kaneda, Hirotoshi; Kobayashi, Daichi; Tanaka, Akio

    Recently, doubly fed induction generator (DFIG) and synchronous generator are mostly applied for wind power generation due to high efficiently for wind energy capture. An inverter system is required to control wind turbine speed and power factor in those generators. The inverter rating of the synchronous generator equals to generator rating. However, DFIG has the advantage that the inverter rating is about 25% to the generator rating. The paper describes a vector control of DFIG inter-connected to power line. The performance of proposed vector control is examined using power system simulation software PSCAD/EMTDC for the DFIG inter-connected to 6.6kv distribution line. The results show good dynamic responses and high accuracy to the stator active power control and the stator reactive power control.

  17. Flexible voltage support control for three-phase distributed generation inverters under grid fault

    DEFF Research Database (Denmark)

    Camacho, Antonio; Castilla, Miguel; Miret, Jaume

    2013-01-01

    connected inverters is proposed. In three phase balanced voltage sags, the inverter should inject reactive power in order to raise the voltage in all phases. In one or two phase faults, the main concern of the distributed generation inverter is to equalize voltages by reducing the negative symmetric...... Operators describe the behavior of the energy source, regulating voltage limits and reactive power injection to remain connected and support the grid under fault. On the basis that different kinds of voltage sags require different voltage support strategies, a flexible control scheme for three phase grid...... sequence and clear the phase jump. Due to system limitations, a balance between these two extreme policies is mandatory. Thus, over-voltage and undervoltage can be avoided, and the proposed control scheme prevents disconnection while achieving the desired voltage support service. The main contribution...

  18. Analysis and estimation of transient stability for a grid-connected wind turbine with induction generator

    DEFF Research Database (Denmark)

    Li, H.; Zhao, B.; Yang, C.

    2011-01-01

    of a grid-connected wind turbine with squirrel cage induction generator (SCIG). Firstly, by using an equivalent lump mass method, a three-mass wind turbine equivalent model is proposed considering both the blades and the shaft flexibility of the wind turbine drive train system. Combined with the detailed......Increasing levels of wind energy in modern electrical power system is initiating a need for accurate analysis and estimation of transient stability of wind turbine generation systems. This paper investigates the transient behaviors and possible direct methods for transient stability evaluation...... electromagnetic transient models of a SCIG, the transient behaviors of the wind turbine generation system during a three-phase fault are simulated and compared with the traditional models. Secondly, in order to quickly estimate the transient stability limit of the wind turbine generation system, a direct method...

  19. Power Smoothing and MPPT for Grid-connected Wind Power Generation with Doubly Fed Induction Generator

    Science.gov (United States)

    Kai, Takaaki; Tanaka, Yuji; Kaneda, Hirotoshi; Kobayashi, Daichi; Tanaka, Akio

    Recently, doubly fed induction generator (DFIG) and synchronous generator are mostly applied for wind power generation, and variable speed control and power factor control are executed for high efficiently for wind energy capture and high quality for power system voltage. In variable speed control, a wind speed or a generator speed is used for maximum power point tracking. However, performances of a wind generation power fluctuation due to wind speed variation have not yet investigated for those controls. The authors discuss power smoothing by those controls for the DFIG inter-connected to 6.6kV distribution line. The performances are verified using power system simulation software PSCAD/EMTDC for actual wind speed data and are examined from an approximate equation of wind generation power fluctuation for wind speed variation.

  20. Power Quality Improvement Utilizing Photovoltaic Generation Connected to a Weak Grid

    Energy Technology Data Exchange (ETDEWEB)

    Muljadi, Eduard [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Tumbelaka, Hanny H. [Petra Christian University; Gao, Wenzhong [UNiversity of Denver

    2017-11-07

    Microgrid research and development in the past decades have been one of the most popular topics. Similarly, the photovoltaic generation has been surging among renewable generation in the past few years, thanks to the availability, affordability, technology maturity of the PV panels and the PV inverter in the general market. Unfortunately, quite often, the PV installations are connected to weak grids and may have been considered as the culprit of poor power quality affecting other loads in particular sensitive loads connected to the same point of common coupling (PCC). This paper is intended to demystify the renewable generation, and turns the negative perception into positive revelation of the superiority of PV generation to the power quality improvement in a microgrid system. The main objective of this work is to develop a control method for the PV inverter so that the power quality at the PCC will be improved under various disturbances. The method is to control the reactive current based on utilizing the grid current to counteract the negative impact of the disturbances. The proposed control method is verified in PSIM platform. Promising results have been obtained.

  1. Visualization of grid-generated turbulence in He II using PTV

    Science.gov (United States)

    Mastracci, B.; Guo, W.

    2017-12-01

    Due to its low viscosity, cryogenic He II has potential use for simulating large-scale, high Reynolds number turbulent flow in a compact and efficient apparatus. To realize this potential, the behavior of the fluid in the simplest cases, such as turbulence generated by flow past a mesh grid, must be well understood. We have designed, constructed, and commissioned an apparatus to visualize the evolution of turbulence in the wake of a mesh grid towed through He II. Visualization is accomplished using the particle tracking velocimetry (PTV) technique, where μm-sized tracer particles are introduced to the flow, illuminated with a planar laser sheet, and recorded by a scientific imaging camera; the particles move with the fluid, and tracking their motion with a computer algorithm results in a complete map of the turbulent velocity field in the imaging region. In our experiment, this region is inside a carefully designed He II filled cast acrylic channel measuring approximately 16 × 16 × 330 mm. One of three different grids, which have mesh numbers M = 3, 3.75, or 5 mm, can be attached to the pulling system which moves it through the channel with constant velocity up to 600 mm/s. The consequent motion of the solidified deuterium tracer particles is used to investigate the energy statistics, effective kinematic viscosity, and quantized vortex dynamics in turbulent He II.

  2. A Framework for Parallel Unstructured Grid Generation for Complex Aerodynamic Simulations

    Science.gov (United States)

    Zagaris, George; Pirzadeh, Shahyar Z.; Chrisochoides, Nikos

    2009-01-01

    A framework for parallel unstructured grid generation targeting both shared memory multi-processors and distributed memory architectures is presented. The two fundamental building-blocks of the framework consist of: (1) the Advancing-Partition (AP) method used for domain decomposition and (2) the Advancing Front (AF) method used for mesh generation. Starting from the surface mesh of the computational domain, the AP method is applied recursively to generate a set of sub-domains. Next, the sub-domains are meshed in parallel using the AF method. The recursive nature of domain decomposition naturally maps to a divide-and-conquer algorithm which exhibits inherent parallelism. For the parallel implementation, the Master/Worker pattern is employed to dynamically balance the varying workloads of each task on the set of available CPUs. Performance results by this approach are presented and discussed in detail as well as future work and improvements.

  3. Control and Modulation Techniques for a Centralized PV Generation System Grid Connected via an Interleaved Inverter

    Directory of Open Access Journals (Sweden)

    Gianluca Brando

    2016-09-01

    Full Text Available In the context of grid connected photovoitaic (PV generation systems, there are two paramount aspects regarding the Maximum Power Point Tracking (MPPT of the photovoltaic units and the continuity of the service. The most diffused MPPT algorithms are based on either perturb and observe, or on an incremental conductance approach and need both PV current and voltage measurements. Several topology reconfigurable converters are also associated with the PV plants, guaranteeing fault-tolerant features. The generation continuity can also be assured by interleaved inverters, which keep the system operating at reduced maximum power in case of failure. In this paper, an evolution of a hysteresis based MPPT algorithm is presented, based on the measurement of only one voltage, together with a novel space vector modulation suitable for a two-channel three-phase grid connected interleaved inverter. The proposed MMPT algorithm and modulation technique are tested by means of several numerical analyses on a PV generation system of about 200 kW maximum power. The results testify the validity of the proposed strategies, showing good performance, even during a fault occurrence and in the presence of deep shading conditions.

  4. Artificial Bee Colony Algorithm for Transient Performance Augmentation of Grid Connected Distributed Generation

    Science.gov (United States)

    Chatterjee, A.; Ghoshal, S. P.; Mukherjee, V.

    In this paper, a conventional thermal power system equipped with automatic voltage regulator, IEEE type dual input power system stabilizer (PSS) PSS3B and integral controlled automatic generation control loop is considered. A distributed generation (DG) system consisting of aqua electrolyzer, photovoltaic cells, diesel engine generator, and some other energy storage devices like flywheel energy storage system and battery energy storage system is modeled. This hybrid distributed system is connected to the grid. While integrating this DG with the onventional thermal power system, improved transient performance is noticed. Further improvement in the transient performance of this grid connected DG is observed with the usage of superconducting magnetic energy storage device. The different tunable parameters of the proposed hybrid power system model are optimized by artificial bee colony (ABC) algorithm. The optimal solutions offered by the ABC algorithm are compared with those offered by genetic algorithm (GA). It is also revealed that the optimizing performance of the ABC is better than the GA for this specific application.

  5. Mathematical model of an off-grid hybrid solar and wind power generating system

    Science.gov (United States)

    Blasone, M.; Dell'Anno, F.; De Luca, R.; Torre, G.

    2014-12-01

    The dynamics of an off-grid power generating system, coupled to a storage unit and to household appliances, is described by means of an analytic hydrodynamic analog. Following this analogy, by noticing that the effux rate from a leaking bucket is described, in terms of the liquid content, by Torricelli's formula, we denote as "Torricelli's smart consumer" a user being able to calibrate its energy consumption rate with respect to the energy level in the storage unit as if the hydrodynamic model would strictly apply. Simple solutions to the nonlinear dynamic problem associated to this type of smart consumer are found and generalization to other types of smart consumers are sought.

  6. Demand response impacts on off-grid hybrid photovoltaic-diesel generator microgrids

    Directory of Open Access Journals (Sweden)

    Aaron St. Leger

    2015-08-01

    Full Text Available Hybrid microgrids consisting of diesel generator set(s and converter based power sources, such as solar photovoltaic or wind sources, offer an alternative to generator based off-grid power systems. The hybrid approach has been shown to be economical in many off-grid applications and can result in reduced generator operation, fuel requirements, and maintenance. However, the intermittent nature of demand and renewable energy sources typically require energy storage, such as batteries, to properly operate the hybrid microgrid. These batteries increase the system cost, require proper operation and maintenance, and have been shown to be unreliable in case studies on hybrid microgrids. This work examines the impacts of leveraging demand response in a hybrid microgrid in lieu of energy storage. The study is performed by simulating two different hybrid diesel generator—PV microgrid topologies, one with a single diesel generator and one with multiple paralleled diesel generators, for a small residential neighborhood with varying levels of demand response. Various system designs are considered and the optimal design, based on cost of energy, is presented for each level of demand response. The solar resources, performance of solar PV source, performance of diesel generators, costs of system components, maintenance, and operation are modeled and simulated at a time interval of ten minutes over a twenty-five year period for both microgrid topologies. Results are quantified through cost of energy, diesel fuel requirements, and utilization of the energy sources under varying levels of demand response. The results indicate that a moderate level of demand response can have significant positive impacts to the operation of hybrid microgrids through reduced energy cost, fuel consumption, and increased utilization of PV sources.

  7. Coordinated Control of a DFIG-Based Wind-Power Generation System with SGSC under Distorted Grid Voltage Conditions

    Directory of Open Access Journals (Sweden)

    Aolin Liu

    2013-05-01

    Full Text Available This paper presents a coordinated control method for a doubly-fed induction generator (DFIG-based wind-power generation system with a series grid-side converter (SGSC under distorted grid voltage conditions. The detailed mathematical models of the DFIG system with SGSC are developed in the multiple synchronous rotating reference frames. In order to counteract the adverse effects of the voltage harmonics upon the DFIG, the SGSC generates series compensation control voltages to keep the stator voltage sinusoidal and symmetrical, which allows the use of the conventional vector control strategy for the rotor-side converter (RSC, regardless of grid voltage harmonics. Meanwhile, two control targets for the parallel grid-side converter (PGSC are identified, including eliminating the oscillations in total active and reactive power entering the grid or suppressing the fifth- and seventh-order harmonic currents injected to the grid. Furthermore, the respective PI-R controller in the positive synchronous reference frame for the SGSC voltage control and PGSC current control have been developed to achieve precise and rapid regulation of the corresponding components. Finally, the proposed coordinated control strategy has been fully validated by the simulation results of a 2 MW DFIG-based wind turbine with SGSC under distorted grid voltage conditions.

  8. Computing confidence intervals on solution costs for stochastic grid generation expansion problems.

    Energy Technology Data Exchange (ETDEWEB)

    Woodruff, David L..; Watson, Jean-Paul

    2010-12-01

    A range of core operations and planning problems for the national electrical grid are naturally formulated and solved as stochastic programming problems, which minimize expected costs subject to a range of uncertain outcomes relating to, for example, uncertain demands or generator output. A critical decision issue relating to such stochastic programs is: How many scenarios are required to ensure a specific error bound on the solution cost? Scenarios are the key mechanism used to sample from the uncertainty space, and the number of scenarios drives computational difficultly. We explore this question in the context of a long-term grid generation expansion problem, using a bounding procedure introduced by Mak, Morton, and Wood. We discuss experimental results using problem formulations independently minimizing expected cost and down-side risk. Our results indicate that we can use a surprisingly small number of scenarios to yield tight error bounds in the case of expected cost minimization, which has key practical implications. In contrast, error bounds in the case of risk minimization are significantly larger, suggesting more research is required in this area in order to achieve rigorous solutions for decision makers.

  9. Foam Multi-Dimensional General Purpose Monte Carlo Generator With Self-Adapting Symplectic Grid

    CERN Document Server

    Jadach, Stanislaw

    2000-01-01

    A new general purpose Monte Carlo event generator with self-adapting grid consisting of simplices is described. In the process of initialization, the simplex-shaped cells divide into daughter subcells in such a way that: (a) cell density is biggest in areas where integrand is peaked, (b) cells elongate themselves along hyperspaces where integrand is enhanced/singular. The grid is anisotropic, i.e. memory of the axes directions of the primary reference frame is lost. In particular, the algorithm is capable of dealing with distributions featuring strong correlation among variables (like ridge along diagonal). The presented algorithm is complementary to others known and commonly used in the Monte Carlo event generators. It is, in principle, more effective then any other one for distributions with very complicated patterns of singularities - the price to pay is that it is memory-hungry. It is therefore aimed at a small number of integration dimensions (<10). It should be combined with other methods for higher ...

  10. Foam: Multi-dimensional general purpose Monte Carlo generator with self-adapting simplical grid

    Science.gov (United States)

    Jadach, S.

    2000-08-01

    A new general purpose Monte Carlo event generator with self-adapting grid consisting of simplices is described. In the process of initialization, the simplex-shaped cells divide into daughter subcells in such a way that: (a) cell density is biggest in areas where integrand is peaked, (b) cells elongate themselves along hyperspaces where integrand is enhanced/singular. The grid is anisotropic, i.e. memory of the axes directions of the primary reference frame is lost. In particular, the algorithm is capable of dealing with distributions featuring strong correlation among variables (like ridge along diagonal). The presented algorithm is complementary to others known and commonly used in the Monte Carlo event generators. It is, in principle, more effective than any other one for distributions with very complicated patterns of singularities - the price to pay is that it is memory-hungry. It is therefore aimed at a small number of integration dimensions ( <10 ). It should be combined with other methods for higher dimension. The source code in Fortran 77 is available from http://home.cern.ch/ hadach.

  11. Distributed Generation Integration in the Electric Grid: Energy Storage System for Frequency Control

    Directory of Open Access Journals (Sweden)

    Maurizio Delfanti

    2014-01-01

    Full Text Available During the last few years generation from renewable energy sources (RESs has grown considerably in European electrical networks. Transmission system operators are greatly concerned about the impact of RESs on the operational security and efficiency of their networks and more in general of the ENTSO-E interconnected system. Grid codes are to be revised in order to harmonise the rules regarding the connection of RES power plants. A main issue concerns frequency control: frequency is greatly affected by RESs intermittency and its deviations must be limited as much as possible in order to guarantee a suitable level of power quality. To improve frequency stability, in the future, Grid codes could extend frequency control requirements also to RES units, whereas today they are applied only to conventional power plants. Energy storage systems can be a possible solution to increase the flexibility and performance of RES power plants: they allow generators to modulate their power injections without wasting renewable energy. In this paper, the authors studied the suitability of extending frequency control to RES units integrating them with energy storage systems. In particular, the paper focuses on the impact of frequency control on the storage lifetime by analysing the power charge/discharge in response to real frequency oscillations.

  12. Computing confidence intervals on solution costs for stochastic grid generation expansion problems

    International Nuclear Information System (INIS)

    Woodruff, David L.; Watson, Jean-Paul

    2010-01-01

    A range of core operations and planning problems for the national electrical grid are naturally formulated and solved as stochastic programming problems, which minimize expected costs subject to a range of uncertain outcomes relating to, for example, uncertain demands or generator output. A critical decision issue relating to such stochastic programs is: How many scenarios are required to ensure a specific error bound on the solution cost? Scenarios are the key mechanism used to sample from the uncertainty space, and the number of scenarios drives computational difficultly. We explore this question in the context of a long-term grid generation expansion problem, using a bounding procedure introduced by Mak, Morton, and Wood. We discuss experimental results using problem formulations independently minimizing expected cost and down-side risk. Our results indicate that we can use a surprisingly small number of scenarios to yield tight error bounds in the case of expected cost minimization, which has key practical implications. In contrast, error bounds in the case of risk minimization are significantly larger, suggesting more research is required in this area in order to achieve rigorous solutions for decision makers.

  13. Renewable energy technology for off-grid power generation solar hybrid system

    International Nuclear Information System (INIS)

    Mohd Azhar Abd Rahman

    2006-01-01

    Off-grid power generation is meant to supply remote or rural area, where grid connection is almost impossible in terms of cost and geography, such as island, aborigine's villages, and areas where nature preservation is concern. Harnessing an abundance renewable energy sources using versatile hybrid power systems can offer the best, least-cost alternative solution for extending modern energy services to remote and isolated communities. The conventional method for off-grid power generation is using diesel generator with a renewable energy (RE) technology utilizing solar photovoltaic, wind, biomass, biogas and/or mini/micro hydro. A hybrid technology is a combination of multiple source of energy; such as RE and diesel generator and may also include energy storage such as battery. In our design, the concept of solar hybrid system is a combination of solar with diesel genset and battery as an energy storage. The main objective of the system are to reduce the cost of operation and maintenance, cost of logistic and carbon dioxide (CO 2 ) emission. The operational concept of solar hybrid system is that solar will be the first choice of supplying load and excess energy produced will be stored in battery. Genset will be a secondary source of energy. The system is controlled by a microprocessor-based controlled to manage the energy supplied and load demand. The solar hybrid system consists of one or two diesel generator with electronic control system, lead-acid battery system, solar PV, inverter module and system controller with remote monitoring capability. The benefits of solar hybrid system are: Improved reliability, Improved energy services, reduced emissions and pollution, provide continuous power supply, increased operational life, reduced cost, and more efficient use of power. Currently, such system has been installed at Middle and Top Station of Langkawi Cable Car, Langkawi and Aborigines Village Kg Denai, Rompin, Pahang. The technology is considered new in Malaysia

  14. Renewable Distributed Generation Models in Three-Phase Load Flow Analysis for Smart Grid

    Directory of Open Access Journals (Sweden)

    K. M. Nor

    2013-11-01

    Full Text Available The paper presents renewable distributed generation  (RDG models as three-phase resource in load flow computation and analyzes their effect when they are connected in composite networks. The RDG models that have been considered comprise of photovoltaic (PV and wind turbine generation (WTG. The voltage-controlled node and complex power injection node are used in the models. These improvement models are suitable for smart grid power system analysis. The combination of IEEE transmission and distribution data used to test and analyze the algorithm in solving balanced/unbalanced active systems. The combination of IEEE transmission data and IEEE test feeder are used to test the the algorithm for balanced and unbalanced multi-phase distribution system problem. The simulation results show that by increased number and size of RDG units have improved voltage profile and reduced system losses.

  15. New-generation flexible ureterorenoscopes are more durable than previous ones.

    Science.gov (United States)

    Traxer, Olivier; Dubosq, Francis; Jamali, Karim; Gattegno, Bernard; Thibault, Philippe

    2006-08-01

    To determine the deterioration in the maximal active deflection and flow capabilities of a new-generation flexible ureteroscope (URS). We performed 50 ureterorenoscopies using the same URS: a Karl Storz 11278 AU1 Flex-X, which is capable of a 270 degree active deflection in the ventral and dorsal directions. Postoperatively, we evaluated the maximal active ventral and dorsal deflection, irrigation flow at 100 cm H2O, and the number of broken optical fibers. The URS was used for a total of 76 hours, 15 minutes (average 95 minutes per procedure). The maximal ventral deflection had deteriorated from 270 degrees to 208 degrees at the last procedure. The maximal dorsal deflection had decreased from 270 degrees to 133 degrees. The irrigation flow at 100 cm H2O had decreased from 50 mL/min initially to 40 mL/min at the last procedure. The number of broken image fibers had reached six at the 50th procedure. One repair was necessary at the 50th procedure because of a laser perforation of the working channel. The need for repair occurs less frequently with the new-generation of URSs, especially when they are used by an experienced endourologist. In the future, improvements in the durability of the flexible URS will still be key for widespread use of the technique and especially to limit damage by the laser to the working channel.

  16. Integration of permanent magnet synchronous generator wind turbines into power grid

    Science.gov (United States)

    Abedini, Asghar

    The world is seeing an ever-increasing demand for electrical energy. The future growth of electrical power generation needs to be a mix of technologies including fossil fuels, hydro, nuclear, wind, and solar. The federal and state energy agencies have taken several proactive steps to increase the share of renewable energy in the total generated electrical power. In 2005, 11.1% of the total 1060 GW electricity generation capacity was from Renewable Energy Sources (RES) in the US. The power capacity portfolio included 9.2% from hydroelectric, 0.87% from wind, and 0.7% from biomass. Other renewable power capacity included 2.8 GW of geothermal, 0.4 GW of solar thermal, and 0.2 GW of solar PV. Although the share of renewable energy sources is small compared with the total power capacity, they are experiencing a high and steady growth. The US is leading the world in wind energy growth with a 27% increase in 2006 and a projected 26% increase in 2007, according to the American Wind Energy Association (AWEA). The US Department of Energy benchmarked a goal to meet 5% of the nation's energy need by launching the Wind Powering America (WPA) program. Although renewable energy sources have many benefits, their utilization in the electrical grid does not come without cost. The higher penetration of RES has introduced many technical and non-technical challenges, including power quality, reliability, safety and protection, load management, grid interconnections and control, new regulations, and grid operation economics. RES such as wind and PV are also intermittent in nature. The energy from these sources is available as long as there is wind or sunlight. However, these are energies that are abundant in the world and the power generated from these sources is pollution free. Due to high price of foundation of wind farms, employing variable speed wind turbines to maximize the extracted energy from blowing wind is more beneficial. On the other hand, since wind power is intermittent

  17. Grid-Forming-Mode Operation of Boost-Power-Stage Converter in PV-Generator-Interfacing Applications

    Directory of Open Access Journals (Sweden)

    Jukka Viinamäki

    2017-07-01

    Full Text Available The application of constant power control and inclusion of energy storage in grid-connected photovoltaic (PV energy systems may increase the use of two-stage system structures composed of DC–DC-converter-interfaced PV generator and grid-connected inverter connected in cascade. A typical PV-generator-interfacing DC–DC converter is a boost-power-stage converter. The renewable energy system may operate in three different operation modes—grid-forming, grid-feeding, and grid-supporting modes. In the last two operation modes, the outmost feedback loops are taken from the input terminal of the associated power electronic converters, which usually does not pose stability problems in terms of their input sources. In the grid-forming operation mode, the outmost feedback loops have to be connected to the output terminal of the associated power electronic converters, and hence the input terminal will behave as a negative incremental resistor at low frequencies. This property will limit the operation of the PV interfacing converter in either the constant voltage or constant current region of the PV generator for ensuring stable operation. The boost-power-stage converter can be applied as a voltage or current-fed converter limiting the stable operation region accordingly. The investigations of this paper show explicitly that only the voltage-fed mode would provide feasible dynamic and stability properties as a viable interfacing converter.

  18. Analysis and MPPT control of a wind-driven three-phase induction generator feeding single-phase utility grid

    Directory of Open Access Journals (Sweden)

    Krishnan Arthishri

    2017-05-01

    Full Text Available In this study, a three-phase diode bridge rectifier and a single-phase voltage source inverter topology has been proposed for feeding single-phase utility grid employing a three-phase induction generator fed from wind energy. A self-excited induction generator configuration has been chosen for wide speed operation of wind turbine system, which gives the scope for extracting maximum power available in the wind. In addition to maximum power point tracking (MPPT, the generator can be loaded to its rated capacity for feeding single-phase utility grid using a three-phase induction machine, whereas it is not possible with existing configurations because of the absence of power converters. For the proposed system, MPPT algorithm has been devised by continuously monitoring the grid current and a proportional resonant controller has been employed for grid synchronisation of voltage source inverter with single-phase grid. A MATLAB/Simulink model of the proposed system has been developed to ascertain its successful working by predetermining the overall performance characteristics. The present proposal has also been tested with sag, swell and distortion in the grid voltage. The control strategy has been implemented using field programmable gate array (FPGA controller with modularised programming approach. The efficacy of the system has been demonstrated with the results obtained from an experimental set-up in the laboratory.

  19. Impact of Distributed Generation Grid Code Requirements on Islanding Detection in LV Networks

    Directory of Open Access Journals (Sweden)

    Fabio Bignucolo

    2017-01-01

    Full Text Available The recent growing diffusion of dispersed generation in low voltage (LV distribution networks is entailing new rules to make local generators participate in network stability. Consequently, national and international grid codes, which define the connection rules for stability and safety of electrical power systems, have been updated requiring distributed generators and electrical storage systems to supply stabilizing contributions. In this scenario, specific attention to the uncontrolled islanding issue has to be addressed since currently required anti-islanding protection systems, based on relays locally measuring voltage and frequency, could no longer be suitable. In this paper, the effects on the interface protection performance of different LV generators’ stabilizing functions are analysed. The study takes into account existing requirements, such as the generators’ active power regulation (according to the measured frequency and reactive power regulation (depending on the local measured voltage. In addition, the paper focuses on other stabilizing features under discussion, derived from the medium voltage (MV distribution network grid codes or proposed in the literature, such as fast voltage support (FVS and inertia emulation. Stabilizing functions have been reproduced in the DIgSILENT PowerFactory 2016 software environment, making use of its native programming language. Later, they are tested both alone and together, aiming to obtain a comprehensive analysis on their impact on the anti-islanding protection effectiveness. Through dynamic simulations in several network scenarios the paper demonstrates the detrimental impact that such stabilizing regulations may have on loss-of-main protection effectiveness, leading to an increased risk of unintentional islanding.

  20. Reduced Cost of Reactive Power in Doubly Fed Induction Generator Wind Turbine System with Optimized Grid Filter

    DEFF Research Database (Denmark)

    Zhou, Dao; Blaabjerg, Frede; Franke, Toke

    2014-01-01

    The modern grid requirement has caused that the wind power system behaves more like conventional rotating generators and it is able to support certain amount of the reactive power. For a typical doubly-fed induction generator wind turbine system, the reactive power can be supported either through...

  1. A report on the performance of a grid connected photovoltaic power generation system

    International Nuclear Information System (INIS)

    Mohd Azhar Abdul Rahman; Mohd Surif Abdul Wahab; Azmi Omar

    2000-01-01

    Malaysia is located almost on the equator and is blessed with an abundance of sunlight almost all year round. So obviously, with the right planning and strategies that are coupled to the right technology and development in the market, the potential for photovoltaic system as an alternative source of power in this country looks promising and is constantly gaining ground and popularity. Sunlight is free and the photovoltaic system is also emission and pollution free which is a guest boost to the current worldwide effort to reduce the global environmental problems. Utility giant Tenaga Nasional Berhad is in line with the Government aspiration to promote the development of solar photovoltaic in the country, who believe in the success and acceptance potential of the photovoltaic system as an alternative source of power generation for long term energy option. In March 1998, a contract was awarded by Tenaga Nasional Berhad to its research subsidiary, Tenaga Nasional Research and Development Sdn. Bhd. to undertake a pilot research project on the development of a grid connected photovoltaic system. This research project is co-funded by the Electric Supply Industry Trust fund. One of the main objective of this research project is to seek the best approach to popularize the Grid Connected Photovoltaic System for domestic as well as suitable commercial premises in this country. This paper will report the initial findings of the project in terms of technical capability and commercial liability. (Author)

  2. Evaluation small scale, grid connected wind and solar distributed generation systems in Jordan

    International Nuclear Information System (INIS)

    Naji, G. J.; Tahboub, K. K.; Jalham, I. S.

    2011-01-01

    In this paper, the potential of utilizing wind and solar Private Distributed Generation (PDG) for utility interactive systems is investigated for 11 selected stations (sites) in Jordan. Six customer categories are considered: residential, office, commercial mall, school, hospital and hotel. The main goal of this study was to evaluate the potential of utilizing different grid connected PDG under different conditions such as their location, size, served building category, number of people who share and own the equipment and system type whether wind, solar or hybrid based. It was found that solar systems are still not attractive for all location due to their associated high cost, while wind systems would vary widely depending on the customer category, location and the size of the equipment. Based on the Benefit to Cost ratio criterion, the most attractive sites for installing wind PDGS for residential communities are Ras Muneef, Mafraq, Aqaba, Irbid and H5, while it doesn't seem attractive at Amman,Shoubak, Ghor Essafi, Deir Alla, Maan and H4. On the other hand, the wind on-grid PDGS is very attractive at Ras Muneef, mafraq and Aqaba for commercial buildings, less attractive at H5 and irbid, while it's not attractive at the other sites. The attraction for hybrid PDG systems is closer to those of wind systems alone. (authors).

  3. Thermo-economic optimization of the impact of renewable generators on poly-generation smart-grids including hot thermal storage

    International Nuclear Information System (INIS)

    Rivarolo, M.; Greco, A.; Massardo, A.F.

    2013-01-01

    Highlights: ► We model a poly-generation grid including thermal storage and renewable generators. ► We analyze the impact of random renewable generators on the grid performance. ► We carry out the grid optimization using a time-dependent thermo-economic approach. ► We present the importance of the storage system to optimize the RES impact. - Abstract: In this paper, the impact of not controllable renewable energy generators (wind turbines and solar photovoltaic panels) on the thermo-economic optimum performance of poly-generation smart grids is investigated using an original time dependent hierarchical approach. The grid used for the analysis is the one installed at the University of Genoa for research activities. It is based on different prime movers: (i) 100 kWe micro gas turbine, (ii) 20 kWe internal combustion engine powered by gases to produce both electrical and thermal (hot water) energy and (iii) a 100 kWth adsorption chiller to produce cooling (cold water) energy. The grid includes thermal storage tanks to manage the thermal demand load during the year. The plant under analysis is also equipped with two renewable non-controllable generators: a small size wind turbine and photovoltaic solar panels. The size and the management of the system studied in this work have been optimized, in order to minimize both capital and variable costs. A time-dependent thermo-economic hierarchical approach developed by the authors has been used, considering the time-dependent electrical, thermal and cooling load demands during the year as problem constraints. The results are presented and discussed in depth and show the strong interaction between fossil and renewable resources, and the importance of an appropriate storage system to optimize the RES impact taking into account the multiproduct character of the grid under investigation.

  4. Design and Implementation of a High Quality Power Supply Scheme for Distributed Generation in a Micro-Grid

    Directory of Open Access Journals (Sweden)

    Mingchao Xia

    2013-09-01

    Full Text Available A low carbon, high efficiency and high quality power supply scheme for Distributed Generation (DG in a micro-grid is presented. A three-phase, four-leg DG grid-interfacing converter based on the improved structure of a Unified Power Quality Conditioner (UPQC, including a series converter and a parallel converter is adopted, and improved indirect and direct control strategies are proposed. It can be observed that these strategies effectively compensate for voltage sags, voltage swells and voltage distortion, as well as voltage power quality problems resulting from the nonlinear and unbalanced loads in a micro-grid. While solving the coupling interference from series–parallel, the grid-interfacing converter can achieve proper load power sharing in a micro-grid. In particular, an improved minimum-energy compensation method is proposed that can overcome the conventional compensation algorithm defects, ensure the load voltage’s phase angle stability, improve the voltage compensating ability and range, reduce the capacity and cost of converters, and reduce the shock of micro-grid switching between grid-connected mode and islanded mode. Moreover, the advantages/disadvantages and application situation of the two improved control strategies are analyzed. Finally, the performance of the proposed control strategies has been verified through a MATLAB/Simulink simulation under various operating conditions.

  5. A Current-Forced Line-Commutated Inverter for Single-Phase Grid-Connected Photovoltaic Generation Systems

    Directory of Open Access Journals (Sweden)

    UNLU, M.

    2015-05-01

    Full Text Available A simple power electronic interface based on the line-commutated inverter (LCI has been developed in order to inject sinusoidal current to the grid for single-phase grid-connected photovoltaic (PV energy generation systems. The proposed inverter facilitates controlling the injecting/grid current with a controllable power factor in contrast to the conventional LCI system. It is achieved that the total harmonic distortion (THD of the injecting currents for the different firing angles/power factors and reference currents is about 5% or less than 5%. Thus, the grid-connected standards for injecting current are satisfied without filter equipment unlike the conventional LCI system. The proposed system has been built in MATLAB/Simulink and examined experimentally on PV array of 160 W. The simulation and experimental results are better performance than the conventional line-commutated inverter methods reported in the literature. The proposed LCI has a simple and robust structure, and it can be easily synchronized with grid thanks to self-latching property of SCRs. Therefore, it is a good alternative for the power transferring from PV panels to the utility grid in grid-connected PV systems.

  6. Effect of Doubly Fed Induction GeneratorTidal Current Turbines on Stability of a Distribution Grid under Unbalanced Voltage Conditions

    Directory of Open Access Journals (Sweden)

    Dahai Zhang

    2017-02-01

    Full Text Available This paper analyses the effects of doubly fed induction generator (DFIG tidal current turbines on a distribution grid under unbalanced voltage conditions of the grid. A dynamic model of an electrical power system under the unbalanced network is described in the paper, aiming to compare the system performance when connected with and without DFIG at the same location in a distribution grid. Extensive simulations of investigating the effect of DFIG tidal current turbine on stability of the distribution grid are performed, taking into account factors such as the power rating, the connection distance of the turbine and the grid voltage dip. The dynamic responses of the distribution system are examined, especially its ability to ride through fault events under unbalanced grid voltage conditions. The research has shown that DFIG tidal current turbines can provide a good damping performance and that modern DFIG tidal current power plants, equipped with power electronics and low-voltage ride-through capability, can stay connected to weak electrical grids even under the unbalanced voltage conditions, whilst not reducing system stability.

  7. Generation-Side Power Scheduling in a Grid-Connected DC Microgrid

    DEFF Research Database (Denmark)

    Hernández, Adriana Carolina Luna; Aldana, Nelson Leonardo Diaz; Meng, Lexuan

    2015-01-01

    In this paper, a constrained mixed-integer programming model for scheduling the active power supplied by the generation units in storage-based DC microgrids is presented. The optimization problem minimizes operating costs taking into account a two-stage mode operation of the energy storage system...... so that a more accurate model for optimization of the microgrid operation can be obtained. The model is used in a particular grid-connected DC microgrid that includes two renewable energy sources and an energy storage system which supply a critical load. The results of the scheduling process...... are including in simulation by establishing a MATLAB/Simulink model of the microgrid and setting several initial conditions of the state of charge of the energy storage system. As a result, we obtain reductions in costs and at the same time guarantee safe levels of state of charge to increase the life...

  8. Economic Power Dispatch of Distributed Generators in a Grid-Connected Microgrid

    DEFF Research Database (Denmark)

    Hernández, Adriana Carolina Luna; Aldana, Nelson Leonardo Diaz; Andrade, Fabio

    2015-01-01

    Grid-connected microgrids with storage systems are reliable configurations for critical loads which can not tolerate interruptions of energy supply. In such cases, some of the energy resources should be scheduled in order to coordinate optimally the power generation according to a defined objective...... function. This paper defines a generationside power scheduling and economic dispatch of a gridconnected microgrid that supplies a fixed load and then, the scheduling is enhanced by including penalties in order to increase the use of the renewable energy sources and guarantee a high state of charge...... in the storage system for the next day. Linear models are proposed for the scheduling which are implemented in GAMS. The microgrid model is obtained deploying MATLAB/Simulink toolbox and then downloaded into dSPACE 1006 platform based on real-time simulation to test the economic dispatch. A compromise between...

  9. Mathematical model of an off-grid hybrid solar and wind power generating system

    Directory of Open Access Journals (Sweden)

    Blasone M.

    2014-01-01

    Full Text Available The dynamics of an off-grid power generating system, coupled to a storage unit and to household appliances, is described by means of an analytic hydrodynamic analog. Following this analogy, by noticing that the effux rate from a leaking bucket is described, in terms of the liquid content, by Torricelli's formula, we denote as “Torricelli's smart consumer” a user being able to calibrate its energy consumption rate with respect to the energy level in the storage unit as if the hydrodynamic model would strictly apply. Simple solutions to the nonlinear dynamic problem associated to this type of smart consumer are found and generalization to other types of smart consumers are sought.

  10. Materials Innovation for Next-Generation T&D Grid Components. Workshop Summary Report

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, Emmanuel [Energetics Incorporated, Columbia, MD (United States); Kramer, Caroline [Energetics Incorporated, Columbia, MD (United States); Marchionini, Brian [Energetics Incorporated, Columbia, MD (United States); Sabouni, Ridah [Energetics Incorporated, Columbia, MD (United States); Cheung, Kerry [U.S. Department of Energy (DOE), Washington, DC (United States). Office of Electricity Delivery and Energy Reliability (OE); Lee, Dominic F [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-10-01

    The Materials Innovations for Next-Generation T&D Grid Components Workshop was co-sponsored by the U.S. Department of Energy (DOE) Office of Electricity Delivery and Energy Reliability and the Oak Ridge National Laboratory (ORNL) and held on August 26 27, 2015, at the ORNL campus in Oak Ridge, Tennessee. The workshop was planned and executed under the direction of workshop co-chair Dr. Kerry Cheung (DOE) and co-chair Dr. Dominic Lee (ORNL). The information contained herein is based on the results of the workshop, which was attended by nearly 50 experts from government, industry, and academia. The research needs and pathways described in this report reflect the expert opinions of workshop participants, but they are not intended to represent the views of the entire electric power community.

  11. Modified Grid-Connected CSI for Hybrid PV/Wind Power Generation System

    Directory of Open Access Journals (Sweden)

    D. Amorndechaphon

    2012-01-01

    Full Text Available The principle of a power conditioning unit for hybrid PV/wind power generation system is proposed. The proposed power conditioner is based on the current source inverter (CSI topology. All energy sources are connected in parallel with a DC-bus through the modified wave-shaping circuits. To achieve the unity power factor at the utility grid, the DC-link current can be controlled via the wave-shaping circuits with the sinusoidal PWM scheme. In this work, the carrier-based PWM scheme is also proposed to minimize the utility current THD. The power rating of the proposed system can be increased by connecting more PV/wind modules through their wave-shaping circuits in parallel with the other modules. The details of the operating principles, the system configurations, and the design considerations are described. The effectiveness of the proposed CSI is demonstrated by simulation results.

  12. Grids for Kids gives next-generation IT an early start

    CERN Document Server

    2008-01-01

    "Grids for Kids gives children a crash course in grid computing," explains co-organiser Anna Cook of the Enabling Grids for E-sciencE project. "We introduce them to concepts such as middleware, parallel processing and supercomputing, and give them opportunities for hands-on learning.

  13. Cartographic Production for the FLaSH Map Study: Generation of Rugosity Grids, 2008

    Science.gov (United States)

    Robbins, Lisa L.; Knorr, Paul O.; Hansen, Mark

    2010-01-01

    Project Summary This series of raster data is a U.S. Geological Survey (USGS) Data Series release from the Florida Shelf Habitat Project (FLaSH). This disc contains two raster images in Environmental Systems Research Institute, Inc. (ESRI) raster grid format, jpeg image format, and Geo-referenced Tagged Image File Format (GeoTIFF). Data is also provided in non-image ASCII format. Rugosity grids at two resolutions (250 m and 1000 m) were generated for West Florida shelf waters to 250 m using a custom algorithm that follows the methods of Valentine and others (2004). The Methods portion of this document describes the specific steps used to generate the raster images. Rugosity, also referred to as roughness, ruggedness, or the surface-area ratio (Riley and others, 1999; Wilson and others, 2007), is a visual and quantitative measurement of terrain complexity, a common variable in ecological habitat studies. The rugosity of an area can affect biota by influencing habitat, providing shelter from elements, determining the quantity and type of living space, influencing the type and quantity of flora, affecting predator-prey relationships by providing cover and concealment, and, as an expression of vertical relief, can influence local environmental conditions such as temperature and moisture. In the marine environment rugosity can furthermore influence current flow rate and direction, increase the residence time of water in an area through eddying and current deflection, influence local water conditions such as chemistry, turbidity, and temperature, and influence the rate and nature of sedimentary deposition. State-of-the-art computer-mapping techniques and data-processing tools were used to develop shelf-wide raster and vector data layers. Florida Shelf Habitat (FLaSH) Mapping Project (http://coastal.er.usgs.gov/flash) endeavors to locate available data, identify data gaps, synthesize existing information, and expand our understanding of geologic processes in our dynamic

  14. Coordinated control of a DFIG-based wind-power generation system with SGSC under distorted grid voltage conditions

    DEFF Research Database (Denmark)

    Yao, Jun; Li, Qing; Chen, Zhe

    2013-01-01

    This paper presents a coordinated control method for a doubly-fed induction generator (DFIG)-based wind-power generation system with a series grid-side converter (SGSC) under distorted grid voltage conditions. The detailed mathematical models of the DFIG system with SGSC are developed...... in the multiple synchronous rotating reference frames. In order to counteract the adverse effects of the voltage harmonics upon the DFIG, the SGSC generates series compensation control voltages to keep the stator voltage sinusoidal and symmetrical, which allows the use of the conventional vector control strategy...... strategy has been fully validated by the simulation results of a 2 MW DFIG-based wind turbine with SGSC under distorted grid voltage conditions...

  15. Energy solutions in rural Africa: mapping electrification costs of distributed solar and diesel generation versus grid extension

    Energy Technology Data Exchange (ETDEWEB)

    Szabo, S; Bodis, K; Huld, T [European Commission Joint Research Centre, Institute for Energy, Renewable Energy Unit, 2749 via Enrico Fermi, TP450, 21027 Ispra (Vatican City State, Holy See) (Italy); Moner-Girona, M, E-mail: Sandor.Szabo@ec.europa.eu [UNEP Energy Branch Division of Technology, Industry and Economics, 15 rue de Milan, F-75441, Paris CEDEX09 (France)

    2011-07-15

    Three rural electrification options are analysed showing the cost optimal conditions for a sustainable energy development applying renewable energy sources in Africa. A spatial electricity cost model has been designed to point out whether diesel generators, photovoltaic systems or extension of the grid are the least-cost option in off-grid areas. The resulting mapping application offers support to decide in which regions the communities could be electrified either within the grid or in an isolated mini-grid. Donor programs and National Rural Electrification Agencies (or equivalent governmental departments) could use this type of delineation for their program boundaries and then could use the local optimization tools adapted to the prevailing parameters.

  16. Energy solutions in rural Africa: mapping electrification costs of distributed solar and diesel generation versus grid extension

    International Nuclear Information System (INIS)

    Szabo, S; Bodis, K; Huld, T; Moner-Girona, M

    2011-01-01

    Three rural electrification options are analysed showing the cost optimal conditions for a sustainable energy development applying renewable energy sources in Africa. A spatial electricity cost model has been designed to point out whether diesel generators, photovoltaic systems or extension of the grid are the least-cost option in off-grid areas. The resulting mapping application offers support to decide in which regions the communities could be electrified either within the grid or in an isolated mini-grid. Donor programs and National Rural Electrification Agencies (or equivalent governmental departments) could use this type of delineation for their program boundaries and then could use the local optimization tools adapted to the prevailing parameters.

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

    DEFF Research Database (Denmark)

    Ciobotaru, Mihai

    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...... of the entire system. Regarding the advance control of DPGS, an active damping technique for grid-connected systems using inductor-capacitorinductor (LCL) filters was proposed in the thesis. The method is based on a notch filter, whose stopband can be automatically adjusted in relation with an estimated value...

  18. Adaptive Droop Control Applied to Distributed Generation Inverters Connected to the Grid

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Teodorescu, Remus; Vásquez, Juan C.

    2008-01-01

    This paper proposes a novel control for voltage source inverters connected to the grid. The control scheme is based on the droop method, and it uses some estimated variables from the grid such as the voltage and the frequency, and the magnitude and angle of the grid impedance. Hence, the inverter...... is able to inject independently active and reactive power to the grid. The controller provides a proper dynamics decoupled from the grid impedance. Simulation results are provided in order to show the feasibility of the control proposed....

  19. Effect of recovery time of fault current limiter on over current from distributed generator in micro grid after voltage sag

    Directory of Open Access Journals (Sweden)

    Daisuke Iioka

    2016-01-01

    Full Text Available This paper describes an effect of recovery time of fault current limiter on over current from a micro grid system which is interconnected to a power distribution system. We have assumed that the semi-conductor type fault current limiter is installed between the micro grid system with the synchronous generator and the power distribution system, measured the over current after a voltage sag occurrence in the power distribution system and a recovery of fault current limiter by experiments in our laboratory. Finally, it was found that the introduction of recovery time for fault current limiter after voltage sag is useful for suppressing the over current from the distributed generator.

  20. Reduced Cost of Reactive Power in Doubly Fed Induction Generator Wind Turbine System With Optimized Grid Filter

    DEFF Research Database (Denmark)

    Zhou, Dao; Blaabjerg, Frede; Franke, Toke

    2015-01-01

    The modern grid requirement has caused that the wind power system behaves more like conventional rotating generators, and it is able to support certain amount of the reactive power. For a typical doubly fed induction generator (DFIG) wind turbine system, the reactive power can be supported either...... in a down-scaled DFIG system. It is concluded that overexcited reactive power injected from the grid-side converter has lower energy loss per year compared to the overexcited reactive power covered by the rotor-side converter. Furthermore, it is also found that the annual energy loss could even become lower...

  1. Modelling and Analysis of Variable Speed Wind Turbines with Induction Generator during Grid Fault

    DEFF Research Database (Denmark)

    Bolik, Sigrid Mechthild

    are stated. The main motivations are the challenges related to the grid connection of wind turbines. The second chapter elucidates recent thinking in the area of grid connection by discussing several grid codes or grid requirements. In the discussion it is tried to present the view of the transmission line...... production of several countries around the world. These developments raise a number of challenges to be dealt with now and in the future. The penetration of wind energy in the grid raises questions about the compatibility of the wind turbine power production with the grid. In particular, the contribution...... to grid stability, power quality and behaviour during fault situations plays therefore as important a role as the reliability. The introduction of the present work briefly presents the development of wind turbine technology. Several wind turbine types are discussed and the motivations for this project...

  2. Controllable Grid Interface for Testing Ancillary Service Controls and Fault Performance of Utility-Scale Wind Power Generation: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Gevorgian, Vahan; Koralewicz, Przemyslaw; Wallen, Robb; Muljadi, Eduard

    2017-02-01

    The rapid expansion of wind power has led many transmission system operators to demand modern wind power plants to comply with strict interconnection requirements. Such requirements involve various aspects of wind power plant operation, including fault ride-through and power quality performance as well as the provision of ancillary services to enhance grid reliability. During recent years, the National Renewable Energy Laboratory (NREL) of the U.S. Department of Energy has developed a new, groundbreaking testing apparatus and methodology to test and demonstrate many existing and future advanced controls for wind generation (and other renewable generation technologies) on the multimegawatt scale and medium-voltage levels. This paper describes the capabilities and control features of NREL's 7-MVA power electronic grid simulator (also called a controllable grid interface, or CGI) that enables testing many active and reactive power control features of modern wind turbine generators -- including inertial response, primary and secondary frequency responses, and voltage regulation -- under a controlled, medium-voltage grid environment. In particular, this paper focuses on the specifics of testing the balanced and unbalanced fault ride-through characteristics of wind turbine generators under simulated strong and weak medium-voltage grid conditions. In addition, this paper provides insights on the power hardware-in-the-loop feature implemented in the CGI to emulate (in real time) the conditions that might exist in various types of electric power systems under normal operations and/or contingency scenarios. Using actual test examples and simulation results, this paper describes the value of CGI as an ultimate modeling validation tool for all types of 'grid-friendly' controls by wind generation.

  3. ANALYSIS AND VALIDATION OF GRID DEM GENERATION BASED ON GAUSSIAN MARKOV RANDOM FIELD

    Directory of Open Access Journals (Sweden)

    F. J. Aguilar

    2016-06-01

    Full Text Available Digital Elevation Models (DEMs are considered as one of the most relevant geospatial data to carry out land-cover and land-use classification. This work deals with the application of a mathematical framework based on a Gaussian Markov Random Field (GMRF to interpolate grid DEMs from scattered elevation data. The performance of the GMRF interpolation model was tested on a set of LiDAR data (0.87 points/m2 provided by the Spanish Government (PNOA Programme over a complex working area mainly covered by greenhouses in Almería, Spain. The original LiDAR data was decimated by randomly removing different fractions of the original points (from 10% to up to 99% of points removed. In every case, the remaining points (scattered observed points were used to obtain a 1 m grid spacing GMRF-interpolated Digital Surface Model (DSM whose accuracy was assessed by means of the set of previously extracted checkpoints. The GMRF accuracy results were compared with those provided by the widely known Triangulation with Linear Interpolation (TLI. Finally, the GMRF method was applied to a real-world case consisting of filling the LiDAR-derived DSM gaps after manually filtering out non-ground points to obtain a Digital Terrain Model (DTM. Regarding accuracy, both GMRF and TLI produced visually pleasing and similar results in terms of vertical accuracy. As an added bonus, the GMRF mathematical framework makes possible to both retrieve the estimated uncertainty for every interpolated elevation point (the DEM uncertainty and include break lines or terrain discontinuities between adjacent cells to produce higher quality DTMs.

  4. Streamline integration as a method for two-dimensional elliptic grid generation

    Energy Technology Data Exchange (ETDEWEB)

    Wiesenberger, M., E-mail: Matthias.Wiesenberger@uibk.ac.at [Institute for Ion Physics and Applied Physics, Universität Innsbruck, A-6020 Innsbruck (Austria); Held, M. [Institute for Ion Physics and Applied Physics, Universität Innsbruck, A-6020 Innsbruck (Austria); Einkemmer, L. [Numerical Analysis group, Universität Innsbruck, A-6020 Innsbruck (Austria)

    2017-07-01

    We propose a new numerical algorithm to construct a structured numerical elliptic grid of a doubly connected domain. Our method is applicable to domains with boundaries defined by two contour lines of a two-dimensional function. Furthermore, we can adapt any analytically given boundary aligned structured grid, which specifically includes polar and Cartesian grids. The resulting coordinate lines are orthogonal to the boundary. Grid points as well as the elements of the Jacobian matrix can be computed efficiently and up to machine precision. In the simplest case we construct conformal grids, yet with the help of weight functions and monitor metrics we can control the distribution of cells across the domain. Our algorithm is parallelizable and easy to implement with elementary numerical methods. We assess the quality of grids by considering both the distribution of cell sizes and the accuracy of the solution to elliptic problems. Among the tested grids these key properties are best fulfilled by the grid constructed with the monitor metric approach. - Graphical abstract: - Highlights: • Construct structured, elliptic numerical grids with elementary numerical methods. • Align coordinate lines with or make them orthogonal to the domain boundary. • Compute grid points and metric elements up to machine precision. • Control cell distribution by adaption functions or monitor metrics.

  5. An approach for generating synthetic fine temporal resolution solar radiation time series from hourly gridded datasets

    Directory of Open Access Journals (Sweden)

    Matthew Perry

    2017-06-01

    Full Text Available A tool has been developed to statistically increase the temporal resolution of solar irradiance time series. Fine temporal resolution time series are an important input into the planning process for solar power plants, and lead to increased understanding of the likely short-term variability of solar energy. The approach makes use of the spatial variability of hourly gridded datasets around a location of interest to make inferences about the temporal variability within the hour. The unique characteristics of solar irradiance data are modelled by classifying each hour into a typical weather situation. Low variability situations are modelled using an autoregressive process which is applied to ramps of clear-sky index. High variability situations are modelled as a transition between states of clear sky conditions and different levels of cloud opacity. The methods have been calibrated to Australian conditions using 1 min data from four ground stations for a 10 year period. These stations, together with an independent dataset, have also been used to verify the quality of the results using a number of relevant metrics. The results show that the method generates realistic fine resolution synthetic time series. The synthetic time series correlate well with observed data on monthly and annual timescales as they are constrained to the nearest grid-point value on each hour. The probability distributions of the synthetic and observed global irradiance data are similar, with Kolmogorov-Smirnov test statistic less than 0.04 at each station. The tool could be useful for the estimation of solar power output for integration studies.

  6. Renewable Energy Jobs. Status, prospects and policies. Biofuels and grid-connected electricity generation

    Energy Technology Data Exchange (ETDEWEB)

    Lucas, H.; Ferroukhi, R. [et al.] [IRENA Policy Advisory Services and Capacity Building Directorate, Abu Dhabi (United Arab Emirates)

    2012-01-15

    Over the past years, interest has grown in the potential for the renewable energy industry to create jobs. Governments are seeking win-win solutions to the dual challenge of high unemployment and climate change. By 2010, USD 51 billion had been pledged to renewables in stimulus packages, and by early 2011 there were 119 countries with some kind of policy target and/or support policy for renewable energy, such as feed-in tariffs, quota obligations, favourable tax treatment and public loans or grants, many of which explicitly target job creation as a policy goal. Policy-makers in many countries are now designing renewable energy policies that aim to create new jobs, build industries and benefit particular geographic areas. But how much do we know for certain about the job creation potential for renewable energy? This working paper aims to provide an overview of current knowledge on five questions: (1) How can jobs in renewable energy be characterised?; (2) How are they shared out across the technology value chain and what skill levels are required?; (3) How many jobs currently exist and where are they in the world?; (4) How many renewable energy jobs could there be in the future?; and (5) What policy frameworks can be used to promote employment benefits from renewable energy? This paper focuses on grid-connected electricity generation technologies and biofuels. Since the employment potential of off-grid applications is large, it will be covered by a forthcoming study by IRENA on job creation in the context of energy access, based on a number of case studies.

  7. Optimal Dispatch of Unreliable Electric Grid-Connected Diesel Generator-Battery Power Systems

    Science.gov (United States)

    Xu, D.; Kang, L.

    2015-06-01

    Diesel generator (DG)-battery power systems are often adopted by telecom operators, especially in semi-urban and rural areas of developing countries. Unreliable electric grids (UEG), which have frequent and lengthy outages, are peculiar to these regions. DG-UEG-battery power system is an important kind of hybrid power system. System dispatch is one of the key factors to hybrid power system integration. In this paper, the system dispatch of a DG-UEG-lead acid battery power system is studied with the UEG of relatively ample electricity in Central African Republic (CAR) and UEG of poor electricity in Congo Republic (CR). The mathematical models of the power system and the UEG are studied for completing the system operation simulation program. The net present cost (NPC) of the power system is the main evaluation index. The state of charge (SOC) set points and battery bank charging current are the optimization variables. For the UEG in CAR, the optimal dispatch solution is SOC start and stop points 0.4 and 0.5 that belong to the Micro-Cycling strategy and charging current 0.1 C. For the UEG in CR, the optimal dispatch solution is of 0.1 and 0.8 that belongs to the Cycle-Charging strategy and 0.1 C. Charging current 0.1 C is suitable for both grid scenarios compared to 0.2 C. It makes the dispatch strategy design easier in commercial practices that there are a few very good candidate dispatch solutions with system NPC values close to that of the optimal solution for both UEG scenarios in CAR and CR.

  8. Dynamic modeling of wind turbine based axial flux permanent magnetic synchronous generator connected to the grid with switch reduced converter

    Directory of Open Access Journals (Sweden)

    Ali Reza Dehghanzadeh

    2018-03-01

    Full Text Available This paper studies the power electronic converters for grid connection of axial flux permanent magnetic synchronous generators (AFPMSG based variable speed wind turbine. In this paper, a new variable speed wind turbine with AFPMSG and Z-source inverter is proposed to improve number of switches and topology reliability. Besides, dynamic modeling of AFPMSG is presented to analyze grid connection of the proposed topology. The Z-source inverter controls maximum power point tracking (MPPT and delivering power to the grid. Therefore other DC–DC chopper is not required to control the rectified output voltage of generator in view of MPPT. As a result, the proposed topology requires less power electronic switches and the suggested system is more reliable against short circuit. The ability of proposed energy conversion system with AFPMSG is validated with simulation results and experimental results using PCI-1716 data acquisition system.

  9. Empirical Analysis of the Variability of Wind Generation in India: Implications for Grid Integration

    Energy Technology Data Exchange (ETDEWEB)

    Phadke, Amol; Abhyankar, NIkit; Rao, Poorvi

    2014-06-17

    We analyze variability in load and wind generation in India to assess its implications for grid integration of large scale wind projects using actual wind generation and load data from two states in India, Karnataka and Tamil Nadu. We compare the largest variations in load and net load (load ?wind, i.e., load after integrating wind) that the generation fleet has to meet. In Tamil Nadu, where wind capacity is about 53percent of the peak demand, we find that the additional variation added due to wind over the current variation in load is modest; if wind penetration reaches 15percent and 30percent by energy, the additional hourly variation is less than 0.5percent and 4.5percent of the peak demand respectively for 99percent of the time. For wind penetration of 15percent by energy, Tamil Nadu system is found to be capable of meeting the additional ramping requirement for 98.8percent of the time. Potential higher uncertainty in net load compared to load is found to have limited impact on ramping capability requirements of the system if coal plants can me ramped down to 50percent of their capacity. Load and wind aggregation in Tamil Nadu and Karnataka is found to lower the variation by at least 20percent indicating the benefits geographic diversification. These findings suggest modest additional flexible capacity requirements and costs for absorbing variation in wind power and indicate that the potential capacity support (if wind does not generate enough during peak periods) may be the issue that has more bearing on the economics of integrating wind

  10. Minimum short-circuit ratios for grid interconnection of wind farms with induction generators

    Energy Technology Data Exchange (ETDEWEB)

    Reginatto, Romeu; Rocha, Carlos [Western Parana State University (UNIOESTE), Foz do Iguacu, PR (Brazil). Center for Engineering and Exact Sciences], Emails: romeu@unioeste.br, croberto@unioeste.br

    2009-07-01

    This paper concerns the problem of determining the minimum value for the short-circuit ratio which is adequate for the interconnection of a given wind farms to a given grid point. First, a set of 3 criteria is defined in order to characterize the quality/safety of the interconnection: acceptable terminal voltage variations, a minimum active power margin, and an acceptable range for the internal voltage angle. Then, the minimum short circuit ratio requirement is determined for 6 different induction generator based wind turbines, both fixed-speed (with and without reactive power compensation) and variable-speed (with the following control policies: reactive power, power factor, and terminal voltage regulation). The minimum short-circuit ratio is determined and shown in graphical results for the 6 wind turbines considered, for X/R in the range 0-15, also analyzing the effect of more/less stringent tolerances for the interconnection criteria. It is observed that the tighter the tolerances the larger the minimum short-circuit ratio required. For the same tolerances in the interconnection criteria, a comparison of the minimum short circuit ratio required for the interconnection of both squirrel-cage and doubly-fed induction generators is presented, showing that the last requires much smaller values for the short-circuit ratio. (author)

  11. Differential Evolution Based IDWNN Controller for Fault Ride-Through of Grid-Connected Doubly Fed Induction Wind Generators.

    Science.gov (United States)

    Manonmani, N; Subbiah, V; Sivakumar, L

    2015-01-01

    The key objective of wind turbine development is to ensure that output power is continuously increased. It is authenticated that wind turbines (WTs) supply the necessary reactive power to the grid at the time of fault and after fault to aid the flowing grid voltage. At this juncture, this paper introduces a novel heuristic based controller module employing differential evolution and neural network architecture to improve the low-voltage ride-through rate of grid-connected wind turbines, which are connected along with doubly fed induction generators (DFIGs). The traditional crowbar-based systems were basically applied to secure the rotor-side converter during the occurrence of grid faults. This traditional controller is found not to satisfy the desired requirement, since DFIG during the connection of crowbar acts like a squirrel cage module and absorbs the reactive power from the grid. This limitation is taken care of in this paper by introducing heuristic controllers that remove the usage of crowbar and ensure that wind turbines supply necessary reactive power to the grid during faults. The controller is designed in this paper to enhance the DFIG converter during the grid fault and this controller takes care of the ride-through fault without employing any other hardware modules. The paper introduces a double wavelet neural network controller which is appropriately tuned employing differential evolution. To validate the proposed controller module, a case study of wind farm with 1.5 MW wind turbines connected to a 25 kV distribution system exporting power to a 120 kV grid through a 30 km 25 kV feeder is carried out by simulation.

  12. Differential Evolution Based IDWNN Controller for Fault Ride-Through of Grid-Connected Doubly Fed Induction Wind Generators

    Science.gov (United States)

    Manonmani, N.; Subbiah, V.; Sivakumar, L.

    2015-01-01

    The key objective of wind turbine development is to ensure that output power is continuously increased. It is authenticated that wind turbines (WTs) supply the necessary reactive power to the grid at the time of fault and after fault to aid the flowing grid voltage. At this juncture, this paper introduces a novel heuristic based controller module employing differential evolution and neural network architecture to improve the low-voltage ride-through rate of grid-connected wind turbines, which are connected along with doubly fed induction generators (DFIGs). The traditional crowbar-based systems were basically applied to secure the rotor-side converter during the occurrence of grid faults. This traditional controller is found not to satisfy the desired requirement, since DFIG during the connection of crowbar acts like a squirrel cage module and absorbs the reactive power from the grid. This limitation is taken care of in this paper by introducing heuristic controllers that remove the usage of crowbar and ensure that wind turbines supply necessary reactive power to the grid during faults. The controller is designed in this paper to enhance the DFIG converter during the grid fault and this controller takes care of the ride-through fault without employing any other hardware modules. The paper introduces a double wavelet neural network controller which is appropriately tuned employing differential evolution. To validate the proposed controller module, a case study of wind farm with 1.5 MW wind turbines connected to a 25 kV distribution system exporting power to a 120 kV grid through a 30 km 25 kV feeder is carried out by simulation. PMID:26516636

  13. Differential Evolution Based IDWNN Controller for Fault Ride-Through of Grid-Connected Doubly Fed Induction Wind Generators

    Directory of Open Access Journals (Sweden)

    N. Manonmani

    2015-01-01

    Full Text Available The key objective of wind turbine development is to ensure that output power is continuously increased. It is authenticated that wind turbines (WTs supply the necessary reactive power to the grid at the time of fault and after fault to aid the flowing grid voltage. At this juncture, this paper introduces a novel heuristic based controller module employing differential evolution and neural network architecture to improve the low-voltage ride-through rate of grid-connected wind turbines, which are connected along with doubly fed induction generators (DFIGs. The traditional crowbar-based systems were basically applied to secure the rotor-side converter during the occurrence of grid faults. This traditional controller is found not to satisfy the desired requirement, since DFIG during the connection of crowbar acts like a squirrel cage module and absorbs the reactive power from the grid. This limitation is taken care of in this paper by introducing heuristic controllers that remove the usage of crowbar and ensure that wind turbines supply necessary reactive power to the grid during faults. The controller is designed in this paper to enhance the DFIG converter during the grid fault and this controller takes care of the ride-through fault without employing any other hardware modules. The paper introduces a double wavelet neural network controller which is appropriately tuned employing differential evolution. To validate the proposed controller module, a case study of wind farm with 1.5 MW wind turbines connected to a 25 kV distribution system exporting power to a 120 kV grid through a 30 km 25 kV feeder is carried out by simulation.

  14. An Optimal Integrated Control Scheme for Permanent Magnet Synchronous Generator-Based Wind Turbines under Asymmetrical Grid Fault Conditions

    Directory of Open Access Journals (Sweden)

    Dan Wang

    2016-04-01

    Full Text Available In recent years, the increasing penetration level of wind energy into power systems has brought new issues and challenges. One of the main concerns is the issue of dynamic response capability during outer disturbance conditions, especially the fault-tolerance capability during asymmetrical faults. In order to improve the fault-tolerance and dynamic response capability under asymmetrical grid fault conditions, an optimal integrated control scheme for the grid-side voltage-source converter (VSC of direct-driven permanent magnet synchronous generator (PMSG-based wind turbine systems is proposed in this paper. The optimal control strategy includes a main controller and an additional controller. In the main controller, a double-loop controller based on differential flatness-based theory is designed for grid-side VSC. Two parts are involved in the design process of the flatness-based controller: the reference trajectories generation of flatness output and the implementation of the controller. In the additional control aspect, an auxiliary second harmonic compensation control loop based on an improved calculation method for grid-side instantaneous transmission power is designed by the quasi proportional resonant (Quasi-PR control principle, which is able to simultaneously restrain the second harmonic components in active power and reactive power injected into the grid without the respective calculation for current control references. Moreover, to reduce the DC-link overvoltage during grid faults, the mathematical model of DC-link voltage is analyzed and a feedforward modified control factor is added to the traditional DC voltage control loop in grid-side VSC. The effectiveness of the optimal control scheme is verified in PSCAD/EMTDC simulation software.

  15. On the integration of wind generators on weak grids and island grids; Sur l'integration des generateurs eoliens dans les reseaux faibles ou insulaires

    Energy Technology Data Exchange (ETDEWEB)

    Laverdure, N

    2005-12-15

    Wind energy is now an energy that can not be ignored. Because of intrinsic characteristics (scattered primary energy, generators with different technologies, use of power electronics interface), wind energy system integration in distribution grids leads to real problems in terms of impacts. With recent standard changes, it is necessary to study the possibilities of each technology of wind turbines to answer or not to these new constraints. This PhD thesis focuses on a comparison of the main present wind turbines concerning three points of discussion: energy quality, fault ride through, ancillary services (voltage and frequency). It insists on the possibilities in terms of control laws for variable speed wind turbines. (author)

  16. Coordinated Control Scheme of Battery Energy Storage System (BESS) and Distributed Generations (DGs) for Electric Distribution Grid Operation

    DEFF Research Database (Denmark)

    Cha, Seung-Tae; Zhao, Haoran; Wu, Qiuwei

    2012-01-01

    This paper describes a coordinated control scheme of battery energy storage system (BESS) and distributed generations (DGs) for electric distribution grid operation. The BESS is designed to stabilize frequency and voltages as a primary control after the electric distribution system enters...

  17. Comparison and analysis of transient performances for doubly fed induction generator wind turbine under grid voltage dip

    DEFF Research Database (Denmark)

    Li, H.; Ye, R.; Han, L.

    2010-01-01

    In order to entirely analyze the transient performances of a grid-connected doubly fed induction generator (DFIG) wind turbine under the different operational states, based on the transient models of DFIG, a two-mass wind turbine electrical equivalent model considering the torsional flexibility o...

  18. 77 FR 47051 - The Incorporated Village of Port Jefferson v. National Grid Generation LLC; Notice of Complaint

    Science.gov (United States)

    2012-08-07

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. EL12-89-000] The Incorporated Village of Port Jefferson v. National Grid Generation LLC; Notice of Complaint Take notice that on July 30, 2012, pursuant to Rule 206 of the Federal Energy Regulatory Commission's (Commission) Rules of Practice and Procedure; 18 CFR 385.206 (2011...

  19. Cost on Reliability and Production Loss for Power Converters in the Doubly Fed Induction Generator to Support Modern Grid Codes

    DEFF Research Database (Denmark)

    Zhou, Dao; Blaabjerg, Frede; Lau, Mogens

    2016-01-01

    As wind farms are normally located in remote areas, many grid codes have been issued especially related to the reactive power support. Although the Doubly-Fed Induction Generator (DFIG) based power converter is able to control the active power and reactive power independently, the effects of prov...

  20. 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...

  1. a Hadoop-Based Algorithm of Generating dem Grid from Point Cloud Data

    Science.gov (United States)

    Jian, X.; Xiao, X.; Chengfang, H.; Zhizhong, Z.; Zhaohui, W.; Dengzhong, Z.

    2015-04-01

    Airborne LiDAR technology has proven to be the most powerful tools to obtain high-density, high-accuracy and significantly detailed surface information of terrain and surface objects within a short time, and from which the Digital Elevation Model of high quality can be extracted. Point cloud data generated from the pre-processed data should be classified by segmentation algorithms, so as to differ the terrain points from disorganized points, then followed by a procedure of interpolating the selected points to turn points into DEM data. The whole procedure takes a long time and huge computing resource due to high-density, that is concentrated on by a number of researches. Hadoop is a distributed system infrastructure developed by the Apache Foundation, which contains a highly fault-tolerant distributed file system (HDFS) with high transmission rate and a parallel programming model (Map/Reduce). Such a framework is appropriate for DEM generation algorithms to improve efficiency. Point cloud data of Dongting Lake acquired by Riegl LMS-Q680i laser scanner was utilized as the original data to generate DEM by a Hadoop-based algorithms implemented in Linux, then followed by another traditional procedure programmed by C++ as the comparative experiment. Then the algorithm's efficiency, coding complexity, and performance-cost ratio were discussed for the comparison. The results demonstrate that the algorithm's speed depends on size of point set and density of DEM grid, and the non-Hadoop implementation can achieve a high performance when memory is big enough, but the multiple Hadoop implementation can achieve a higher performance-cost ratio, while point set is of vast quantities on the other hand.

  2. Power quality improvement by using STATCOM control scheme in wind energy generation interface to grid

    Science.gov (United States)

    Kirmani, Sheeraz; Kumar, Brijesh

    2018-01-01

    “Electric Power Quality (EPQ) is a term that refers to maintaining the near sinusoidal waveform of power distribution bus voltages and currents at rated magnitude and frequency”. Today customers are more aware of the seriousness that the power quality possesses, this prompt the utilities to assure good quality of power to their customer. The power quality is basically customer centric. Increased focus of utilities toward maintaining reliable power supply by employing power quality improvement tools has reduced the power outages and black out considerably. Good power quality is the characteristic of reliable power supply. Low power factor, harmonic pollution, load imbalance, fast voltage variations are some common parameters which are used to define the power quality. If the power quality issues are not checked i.e. the parameters that define power quality doesn't fall within the predefined standards than it will lead into high electricity bill, high running cost in industries, malfunctioning of equipments, challenges in connecting renewable. Capacitor banks, FACTS devices, harmonic filters, SVC’s (static voltage compensators), STATCOM (Static-Compensator) are the solutions to achieve the power quality. The performance of Wind turbine generators is affected by poor quality power, at the same time these wind power generating plant affects the power quality negatively. This paper presents the STATCOM-BESS (battery energy storage system) system and studies its impact on the power quality in a system which consists of wind turbine generator, non linear load, hysteresis controller for controlling the operation of STATCOM and grid. The model is simulated in the MATLAB/Simulink. This scheme mitigates the power quality issues, improves voltage profile and also reduces harmonic distortion of the waveforms. BESS level out the imbalances caused in real power due to intermittent nature of wind power available due to varying wind speeds.

  3. Daily Plasmodium yoelii infective mosquito bites do not generate protection or suppress previous immunity against the liver stage

    Directory of Open Access Journals (Sweden)

    Wong Kurt A

    2011-04-01

    Full Text Available Abstract Background Human populations that are naturally subjected to Plasmodium infection do not acquire complete protection against the liver stage of this parasite despite prolonged and frequent exposure. However, sterile immunity against Plasmodium liver stage can be achieved after repeated exposure to radiation attenuated sporozoites. The reasons for this different response remain largely unknown, but a suppressive effect of blood stage Plasmodium infection has been proposed as a cause for the lack of liver stage protection. Methods Using Plasmodium yoelii 17XNL, the response generated in mice subjected to daily infective bites from normal or irradiated mosquitoes was compared. The effect of daily-infected mosquito bites on mice that were previously immunized against P. yoelii liver stage was also studied. Results It was observed that while the bites of normal infected mosquitoes do not generate strong antibody responses and protection, the bites of irradiated mosquitoes result in high levels of anti-sporozoite antibodies and protection against liver stage Plasmodium infection. Exposure to daily infected mosquito bites did not eliminate the protection acquired previously with a experimental liver stage vaccine. Conclusions Liver stage immunity generated by irradiated versus normal P. yoelii infected mosquitoes is essentially different, probably because of the blood stage infection that follows normal mosquito bites, but not irradiated. While infective mosquito bites do not induce a protective liver stage response, they also do not interfere with previously acquired liver stage protective responses, even if they induce a complete blood stage infection. Considering that the recently generated anti-malaria vaccines induce only partial protection against infection, it is encouraging that, at least in mouse models, immunity is not negatively affected by subsequent exposure and infection with the parasite.

  4. MFE revisited : part 1: adaptive grid-generation using the heat equation

    NARCIS (Netherlands)

    Zegeling, P.A.

    1996-01-01

    In this paper the moving-nite-element method (MFE) is used to solve the heat equation, with an articial time component, to give a non-uniform (steady-state) grid that is adapted to a given prole. It is known from theory and experiments that MFE, applied to parabolic PDEs, gives adaptive grids which

  5. Grids for Kids gives next-generation IT an early start

    CERN Multimedia

    2008-01-01

    Last week, the third in a growing series of Grids for Kids days was held at CERN, the European Organisation for Nuclear Research, involving children aged ten to twelve in games, tours and interactive presentations that introduced grid computing as a tool for researchers in everything from high energy physics to climate studies and genomics.

  6. Control of STATCOM in wind power plants based on induction generators during asymmetrical grid faults

    DEFF Research Database (Denmark)

    Rodriguez, Pedro; Luna, Alvaro; Medeiros, G.

    2010-01-01

    This paper explores different strategies to set the reference current of a STATCOM under unbalanced grid voltage conditions. The aim of the proposed control strategies is to provide a set of reactive current references to be injected by the STATCOM under unbalanced grid faults. Their performance,...

  7. Streamline integration as a method for two-dimensional elliptic grid generation

    Science.gov (United States)

    Wiesenberger, M.; Held, M.; Einkemmer, L.

    2017-07-01

    We propose a new numerical algorithm to construct a structured numerical elliptic grid of a doubly connected domain. Our method is applicable to domains with boundaries defined by two contour lines of a two-dimensional function. Furthermore, we can adapt any analytically given boundary aligned structured grid, which specifically includes polar and Cartesian grids. The resulting coordinate lines are orthogonal to the boundary. Grid points as well as the elements of the Jacobian matrix can be computed efficiently and up to machine precision. In the simplest case we construct conformal grids, yet with the help of weight functions and monitor metrics we can control the distribution of cells across the domain. Our algorithm is parallelizable and easy to implement with elementary numerical methods. We assess the quality of grids by considering both the distribution of cell sizes and the accuracy of the solution to elliptic problems. Among the tested grids these key properties are best fulfilled by the grid constructed with the monitor metric approach.

  8. The generation of monthly gridded datasets for a range of climatic variables over the UK

    Science.gov (United States)

    Perry, Matthew; Hollis, Daniel

    2005-06-01

    Monthly or annual 5 km × 5 km gridded datasets covering the UK are generated for the 1961-2000 period, for 36 climatic parameters. As well as the usual elements of temperature, rainfall, sunshine, cloud, wind speed, and pressure, derived temperature variables (such as growing-season length, heating degree days, and heat and cold wave durations) and further precipitation variables (such as rainfall intensity, maximum consecutive dry days, and days of snow, hail and thunder) are analysed.The analysis process uses geographical information system capabilities to combine multiple regression with inverse-distance-weighted interpolation. Geographic and topographic factors, such as easting and northing, terrain height and shape, and urban and coastal effects, are incorporated either through normalization with regard to the 1961-90 average climate, or as independent variables in the regression. Local variations are then incorporated through the spatial interpolation of regression residuals.For each of the climatic parameters, the choice of model is based on verification statistics produced by excluding a random set of stations from the analysis for a selection of months, and comparing the observed values with the estimated values at each point. This gives some insight into the significance, direction, and seasonality of factors affecting different climate elements. It also gives a measure of the accuracy of the method at predicting values between station locations.The datasets are being used for the verification of climate modelling scenarios and are available via the Internet. © Crown

  9. Research on DC Micro-grid system of photovoltaic power generation

    Science.gov (United States)

    Zheng, Yiming; Wang, Xiaohui

    2018-01-01

    The use of energy has become a topic of concern, the demand of people for power grows in number or quantity with the development of economy. It is necessary to consider using new forms of power supply-microgrid system for distributed power supply. The power supply mode can not only effectively solve the problem of excessive line loss in the large power grid, but also can increase the reliability of the power supply, and is economical and environmental friendly. With the increasing of DC loads, in order to improve the utilization efficiency, the DC microgrid power supply problems are begin to be researched and integrated with the renewable energy sources. This paper researched the development of microgrid, compared AC microgrid with DC microgrid, summarized the distribution of DC bus voltage level, the DC microgrid network form, the control mode and the main power electronics elements of DC microgrid of photovoltaic power generation system. Today, the DC microgrid system is still in the development stage without uniform voltage level standard, however, it will come into service in the future.

  10. Voltage Control Scheme with Distributed Generation and Grid Connected Converter in a DC Microgrid

    Directory of Open Access Journals (Sweden)

    Jong-Chan Choi

    2014-10-01

    Full Text Available Direct Current (DC microgrids are expected to become larger due to the rapid growth of DC energy sources and power loads. As the scale of the system expends, the importance of voltage control will be increased to operate power systems stably. Many studies have been performed on voltage control methods in a DC microgrid, but most of them focused only on a small scale microgrid, such as a building microgrid. Therefore, a new control method is needed for a middle or large scale DC microgrid. This paper analyzes voltage drop problems in a large DC microgrid and proposes a cooperative voltage control scheme with a distributed generator (DG and a grid connected converter (GCC. For the voltage control with DGs, their location and capacity should be considered for economic operation in the systems. Accordingly, an optimal DG allocation algorithm is proposed to minimize the capacity of a DG for voltage control in DC microgrids. The proposed methods are verified with typical load types by a simulation using MATLAB and PSCAD/EMTDC.

  11. Stability of interconnecting system between commercial scale He-Cs MHD combined generation plant and power grid

    International Nuclear Information System (INIS)

    Inui, Y.; Kadono, T.; Ishida, T.

    2003-01-01

    The authors suppose an interconnecting system between a commercial scale closed cycle MHD combined generation plant and power grid, in which a disk MHD generator using cesium seeded helium plasma and a synchronous generator are connected in parallel to an infinite bus through a common power transmission line, and perform detailed numerical simulations of the transient behavior of the whole system. It is made clear that the transient stability of the closed cycle disk MHD generator using cesium seeded helium plasma is excellent under the power line fault condition, even in the case where the generator is commercial scale and is connected to the power grid in parallel with a synchronous generator. It is also made clear that the effectiveness of the control method for power system stabilization using the fast power control of the MHD generator recently proposed by the authors is sufficient in the case where the working plasma of the MHD generator is cesium seeded helium because the transient stability of the MHD generator is always maintained and the transient rotor angle swing of the synchronous generator is notably suppressed

  12. Improved Control Strategies for a DFIG-Based Wind-Power Generation System with SGSC under Unbalanced and Distorted Grid Voltage Conditions

    DEFF Research Database (Denmark)

    Yao, Jun; Yu, Mengting; Hu, Weihao

    2016-01-01

    This paper investigates an improved control strategy for a doubly-fed induction generator (DFIG) based wind-power generation system with series grid-side converter (SGSC) under network unbalance and harmonic grid voltage distortion conditions. The integrated mathematical modeling of the DFIG syst...

  13. New Generation GridPix: Development and characterisation of pixelated gaseous detectors based on the Timepix3 chip

    CERN Document Server

    AUTHOR|(CDS)2082958; Hessey, Nigel

    Due to the increasing demands of high energy physics experiments there is a need for particle detectors which enable high precision measurements. In this regard, the GridPix detector is a novel detector concept which combines the benefits of a pixel chip with an integrated gas amplification structure. The resulting unit is a detector sensitive to single electrons with a great potential for particle tracking and energy loss measurements. This thesis is focusing on the development of a new generation of GridPix detectors based on the Timepix3 chip, which implements a high resolution Time to Digital Converter (TDC) in each pixel. After an introductory chapter describing the motivation behind GridPix, the manuscript presents the physics of gaseous detectors in chapter 2 along with the gaseous detectors used for particle tracking in chapter 3. Chapters 4 and 5 are focusing on the tracking performance of GridPix detectors. Chapter 4 presents results obtained with a GridPix detector based on a small scale prototy...

  14. Modelling and analysis of transient state during improved coupling procedure with the grid for DFIG based wind turbine generator

    Science.gov (United States)

    Kammoun, Soulaymen; Sallem, Souhir; Ben Ali Kammoun, Mohamed

    2017-11-01

    The aim of this study is to enhance DFIG based Wind Energy Conversion Systems (WECS) dynamics during grid coupling. In this paper, a system modelling and a starting/coupling procedure for this generator to the grid are proposed. The proposed non-linear system is a variable structure system (VSS) and has two different states, before and after coupling. So, two different state models are given to the system to analyse transient stability during the coupling. The given model represents well the transient state of the machine, through which, a behaviour assessment of the generator before, during and after connection is given based on simulation results. For this, a 300 kW DFIG based wind generation system model was simulated on the Matlab/SIMULINK environment. We judge the proposed procedure to be practical, smooth and stability improved.

  15. Integration of Hybrid PV/Wind Generation System Using Fuzzy MPPT in Grid Connected System for Remote Area

    Directory of Open Access Journals (Sweden)

    Soedibyo

    2016-01-01

    Full Text Available Photovoltaic and wind are renewable energy resources that widely used and grow rapidly in fulfilling electricity demand. Powers from both technologies depend on sunlight intensity and wind speed. For small scale power generation, DC voltage from both technologies is low and requires step-up converter to raise DC voltage ratio before converted into AC voltage. To optimize this system, step-up converter must have high ratio and efficiency to a distance of wide voltage input. This paper proposed an operation simulation and arrangement of DC-DC converter along with DC-AC from hybrid source PV-Wind which integrated to grid utilities without using storage device. High Gain Integrated Cascade Boost (HGICB is DC-DC converter that has quadratic voltage ratio and used in this research. Then DC link connected to Voltage Source Inverter (VSI which interconnected with utility grid and controlled by current control method. The total installed capacity of hybrid source is 4.4 kW. Wind turbine uses PMSG along with full bridge rectifier. To maximize and stabilize the generated power, MPPT fuzzy is used. Result from the simulation shows that converter capable to maintain maximum power whether from PV and wind turbine which canalized to utility grid in various irradiation condition, wind speed, and grid load alteration.

  16. Analysis of Energy and Power Generation in a Photovoltaic Micro installation Interconnected with a Low Voltage Grid

    Directory of Open Access Journals (Sweden)

    Marian Sobierajski

    2015-12-01

    Full Text Available The paper discusses the performance of the 15 kW photovoltaic micro installation located on the roof of building D-1 of the Faculty of Electrical Engineering at Wroclaw University of Technology. The micro installation is connected to the low voltage grid, which supplies the new, air-conditioned building D-20. The paper discusses the energy and power generation output in yearly, monthly, and daily intervals. The micro installation’s output in the summer morning peaks is compared with the daily wind generation against the background of the demand, generation, regulation reserve, and overhauls in the National Power System.

  17. A Method for a Multi-Platform Approach to Generate Gridded Surface Evaporation

    Science.gov (United States)

    Badger, A.; Livneh, B.; Small, E. E.; Abolafia-Rosenzweig, R.

    2017-12-01

    Evapotranspiration is an integral component of the surface water balance. While there are many estimates of evapotranspiration, there are fewer estimates that partition evapotranspiration into evaporation and transpiration components. This study aims to generate a CONUS-scale, observationally-based soil evaporation dataset by using the time difference of surface soil moisture by Soil Moisture Active Passive (SMAP) satellite with adjustments for transpiration and a bottom flux out of the surface layer. In concert with SMAP, the Moderate-Resolution Imaging Spectroradiometer (MODIS) satellite, North American Land Data Assimilation Systems (NLDAS) and the Hydrus-1D model are used to fully analyze the surface water balance. A biome specific estimate of the total terrestrial ET is calculated through a variation of the Penman-Monteith equation with NLDAS forcing and NLDAS Noah Model output for meteorological variables. A root density restriction and SMAP-based soil moisture restriction are applied to obtain terrestrial transpiration estimates. By forcing Hydrus-1D with NLDAS meteorology and our terrestrial transpiration estimates, an estimate of the flux between the soil surface and root zone layers (qbot) will dictate the proportion of water that is available for soil evaporation. After constraining transpiration and the bottom flux from the surface layer, we estimate soil evaporation as the residual of the surface water balance. Application of this method at Fluxnet sites shows soil evaporation estimates of approximately 0­3 mm/day and less than ET estimates. Expanding this methodology to produce a gridded product for CONUS, and eventually a global-scale product, will enable a better understanding of water balance processes and contribute a dataset to validate land-surface model's surface flux processes.

  18. Presenting a multi-objective generation scheduling model for pricing demand response rate in micro-grid energy management

    International Nuclear Information System (INIS)

    Aghajani, G.R.; Shayanfar, H.A.; Shayeghi, H.

    2015-01-01

    Highlights: • Using DRPs to cover the uncertainties resulted from power generation by WT and PV. • Proposing the use of price-offer packages and amount of DR for implement DRPs. • Considering a multi-objective scheduling model and use of MOPSO algorithm. - Abstract: In this paper, a multi-objective energy management system is proposed in order to optimize micro-grid (MG) performance in a short-term in the presence of Renewable Energy Sources (RESs) for wind and solar energy generation with a randomized natural behavior. Considering the existence of different types of customers including residential, commercial, and industrial consumers can participate in demand response programs. As with declare their interruptible/curtailable demand rate or select from among different proposed prices so as to assist the central micro-grid control in terms of optimizing micro-grid operation and covering energy generation uncertainty from the renewable sources. In this paper, to implement Demand Response (DR) schedules, incentive-based payment in the form of offered packages of price and DR quantity collected by Demand Response Providers (DRPs) is used. In the typical micro-grid, different technologies including Wind Turbine (WT), PhotoVoltaic (PV) cell, Micro-Turbine (MT), Full Cell (FC), battery hybrid power source and responsive loads are used. The simulation results are considered in six different cases in order to optimize operation cost and emission with/without DR. Considering the complexity and non-linearity of the proposed problem, Multi-Objective Particle Swarm Optimization (MOPSO) is utilized. Also, fuzzy-based mechanism and non-linear sorting system are applied to determine the best compromise considering the set of solutions from Pareto-front space. The numerical results represented the effect of the proposed Demand Side Management (DSM) scheduling model on reducing the effect of uncertainty obtained from generation power and predicted by WT and PV in a MG.

  19. Grid generation and adaptation for the Direct Simulation Monte Carlo Method. [for complex flows past wedges and cones

    Science.gov (United States)

    Olynick, David P.; Hassan, H. A.; Moss, James N.

    1988-01-01

    A grid generation and adaptation procedure based on the method of transfinite interpolation is incorporated into the Direct Simulation Monte Carlo Method of Bird. In addition, time is advanced based on a local criterion. The resulting procedure is used to calculate steady flows past wedges and cones. Five chemical species are considered. In general, the modifications result in a reduced computational effort. Moreover, preliminary results suggest that the simulation method is time step dependent if requirements on cell sizes are not met.

  20. Enhanced Control for a Direct-driven Permanent Synchronous Generator Wind-power Generation System with Flywheel Energy Storage Unit Under Unbalanced Grid Fault

    DEFF Research Database (Denmark)

    Yao, Jun; Zhou, Te; Hu, Weihao

    2015-01-01

    This article presents an enhanced control strategy for a direct-driven permanent synchronous generator based wind-power generation system with a flywheel energy storage unit. The behaviors of the direct-driven permanent magnet synchronous generator system with a flywheel energy storage unit under......, the DC-link voltage oscillations can be effectively suppressed during the unbalanced grid fault by controlling the flywheel energy storage unit. Furthermore, a proportional–integral-resonant controller is designed for the flywheel motor to eliminate the oscillations in the DC-link voltage. Finally......, the proposed coordinated control strategy for the direct-driven permanent magnet synchronous generator system with a flywheel energy storage unit has been validated by the simulation results of a 1-MW direct-driven permanent magnet synchronous generator wind power generation system with a flywheel energy...

  1. 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...... strategies based on: 1) a power control (P-CPG), 2) a current limit method (I-CPG) and 3) the Perturb and Observe algorithm (P&O-CPG). However, the operational mode changes (e.g., from the maximum power point tracking to a CPG operation) will affect the entire system performance. Thus, a benchmarking...... of the proposed CPG strategies is also conducted on a 3-kW single-phase grid-connected PV system. Comparisons reveal that either the P-CPG or I-CPG strategies can achieve fast dynamics and satisfactory steady-state performance. In contrast, the P&OCPG algorithm is the most suitable solution in terms of high...

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

    DEFF Research Database (Denmark)

    Sangwongwanich, Ariya; Yang, Yongheng; Blaabjerg, Frede

    2018-01-01

    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...... strategies based on: 1) a power control method (P-CPG), 2) a current limit method (I-CPG) and 3) the Perturb and Observe algorithm (P&O-CPG). However, the operational mode changes (e.g., from the maximum power point tracking to a CPG operation) will affect the entire system performance. Thus, a benchmarking...... of the presented CPG strategies is also conducted on a 3-kW single-phase grid-connected PV system. Comparisons reveal that either the P-CPG or I-CPG strategies can achieve fast dynamics and satisfactory steady-state performance. In contrast, the P&O-CPG algorithm is the most suitable solution in terms of high...

  3. The GLOBE-Consortium: The Erasmus Computing Grid and The Next Generation Genome Viewer

    NARCIS (Netherlands)

    T.A. Knoch (Tobias)

    2005-01-01

    markdownabstractThe Set-Up of the 20 Teraflop Erasmus Computing Grid: To meet the enormous computational needs of live-science research as well as clinical diagnostics and treatment the Hogeschool Rotterdam and the Erasmus Medical Center are currently setting up one of the largest desktop

  4. Enhanced Local Grid Voltage Support Method for High Penetration of Distributed Generators

    DEFF Research Database (Denmark)

    Demirok, Erhan; Sera, Dezso; Rodriguez, Pedro

    2011-01-01

    unbalance, flicker etc.) and network protection mechanisms can be figured out once the maximum DG connection capacity of the network is reached. In this paper, additional reactive power reserve of inverter interfaced DGs is exploited to lower the grid voltage level by means of location-adaptive Q(U) droop...

  5. Three-Phase Grid-Connected of Photovoltaic Generator Using Nonlinear Control

    DEFF Research Database (Denmark)

    Yahya, A.; El Fadil, H.; Guerrero, Josep M.

    2014-01-01

    of PV panels, ii) guaranteeing a power factor unit in the side of the grid, iii) ensuring the global asymptotic stability of the closed loop system. Based on the nonlinear model of the whole system, the controller is carried out using a Lyapunov approach. It is formally shown, using a theoretical...

  6. Thermal Behavior of Doubly-Fed Induction Generator Wind Turbine System during Balanced Grid Fault

    DEFF Research Database (Denmark)

    Zhou, Dao; Blaabjerg, Frede; Lau, Mogens

    2014-01-01

    current to the damping time of the stator flux and rotor terminal voltage during the symmetrical grid fault is firstly evaluated. Then, the theoretical analysis for the safety operation area of the power device is given in terms of the various voltage dips and various rotor speeds, in which simulation...

  7. ICT Requirements and Challenges for Provision of Grid Services from Renewable Generation Plants

    DEFF Research Database (Denmark)

    Shahid, Kamal; Olsen, Rasmus Løvenstein; Petersen, Lennart

    2018-01-01

    and to coordinate their grid support services (GSS) as well. Among other requirements, the coordination of GSS will highly depend on the communication between renewable plants and system operators’ control rooms, thereby imposing high responsibility on the under lying communication infrastructure. Despite...

  8. Prospect of solar-PV/biogas/diesel generator hybrid energy system of an off-grid area in Bangladesh

    Science.gov (United States)

    Mandal, Soumya; Yasmin, Hosna; Sarker, M. R. I.; Beg, M. R. A.

    2017-12-01

    The study presents an analysis and suggests about how renewable sources of energy can be an alternative option to produce electricity in an off-grid area. A case study is done by surveying 235 households in an off-grid area. Techno-economic analysis of the hybrid energy system is employed by using Hybrid Optimization of Multiple Energy Resources (HOMER) software. Four solar-PV modules (each of 1kW), two biogas generators (each of 3kW), three diesel generators (each of 5kW), five batteries (each of 160 Ah) and 5kW converter is found to be the best configuration in terms of Cost of Energy (COE), environmental conditions and Renewable Fraction (RF). The Cost of Energy (COE), Net Present Cost (NPC), capital cost of this configuration is found BDT15.382, BDT10007224, and BDT2582433 respectively. The renewable fraction of this system is found 75% which indicates a lower emission compared with thegrid based system and stand-alone diesel system. Although the COE is higher than grid electricity, this system offers a cheaper option than using kerosene oil and solar home systems (SHSs).

  9. Real time hardware implementation of power converters for grid integration of distributed generation and STATCOM systems

    Science.gov (United States)

    Jaithwa, Ishan

    Deployment of smart grid technologies is accelerating. Smart grid enables bidirectional flows of energy and energy-related communications. The future electricity grid will look very different from today's power system. Large variable renewable energy sources will provide a greater portion of electricity, small DERs and energy storage systems will become more common, and utilities will operate many different kinds of energy efficiency. All of these changes will add complexity to the grid and require operators to be able to respond to fast dynamic changes to maintain system stability and security. This thesis investigates advanced control technology for grid integration of renewable energy sources and STATCOM systems by verifying them on real time hardware experiments using two different systems: d SPACE and OPAL RT. Three controls: conventional, direct vector control and the intelligent Neural network control were first simulated using Matlab to check the stability and safety of the system and were then implemented on real time hardware using the d SPACE and OPAL RT systems. The thesis then shows how dynamic-programming (DP) methods employed to train the neural networks are better than any other controllers where, an optimal control strategy is developed to ensure effective power delivery and to improve system stability. Through real time hardware implementation it is proved that the neural vector control approach produces the fastest response time, low overshoot, and, the best performance compared to the conventional standard vector control method and DCC vector control technique. Finally the entrepreneurial approach taken to drive the technologies from the lab to market via ORANGE ELECTRIC is discussed in brief.

  10. RF generator interlock by plasma grid bias current - An alternate to Hα interlock

    Science.gov (United States)

    Bandyopadhyay, M.; Gahlaut, A.; Yadav, R. K.; Pandya, K.; Tyagi, H.; Vupugalla, M.; Bhuyan, M.; Bhagora, J.; Chakraborty, A.

    2017-08-01

    ROBIN is inductively coupled plasma (ICP) based negative hydrogen ion source, operated with a 100kW, 1MHz Tetrode based RF generator (RFG). Inductive plasma ignition by the RFG in ROBIN is associated with electron seeding by a hot filament and a gas puff. RFG is triggered by the control system to deliver power just at the peak pressure of the gas puff. Once plasma is ignited due to proper impedance matching, a bright light, dominated by Hα (˜656nm wavelength) radiation is available inside RF driver which is used as a feedback signal to the RFG to continue its operation. If impedance matching is not correct, plasma is not produced due to lack of power coupling and bright light is not available. During such condition, reflected RF power may damage the RFG. Therefore, to protect the RFG, it needs to be switched off automatically within 200ms by the control system in such cases. This plasma light based RFG interlock is adopted from BATMAN ion source. However, in case of vacuum immersed RF ion source in reactor grade NBI system, such plasma light based interlock may not be feasible due to lack of adequate optical fiber interfaces. In reactor grade NBI system, neutron and gamma radiations have impact on materials which may lead to frequent maintenance and machine down time. The present demonstration of RFG interlock by Bias Current (BC) in ROBIN testbed gives an alternate option in this regard. In ROBIN, a bias plate (BP) is placed in the plasma chamber near the plasma grid (PG). BP is electrically connected to the plasma chamber wall of the ion source and PG is isolated from the wall. A high current ˜85 A direct current (DC) power supply of voltage in the range of 0 - 33V is connected between the PG and the BP in such a way that PG can be biased positively with respect to the BP or plasma chamber. This arrangement is actually made to absorb electrons and correspondingly reduce co-extracted electron current during beam extraction. However, in case of normal plasma

  11. Investigation of Advanced Counterrotation Blade Configuration Concepts for High Speed Turboprop Systems. Task 3: Advanced Fan Section Grid Generator Final Report and Computer Program User's Manual

    Science.gov (United States)

    Crook, Andrew J.; Delaney, Robert A.

    1991-01-01

    A procedure is studied for generating three-dimensional grids for advanced turbofan engine fan section geometries. The procedure constructs a discrete mesh about engine sections containing the fan stage, an arbitrary number of axisymmetric radial flow splitters, a booster stage, and a bifurcated core/bypass flow duct with guide vanes. The mesh is an h-type grid system, the points being distributed with a transfinite interpolation scheme with axial and radial spacing being user specified. Elliptic smoothing of the grid in the meridional plane is a post-process option. The grid generation scheme is consistent with aerodynamic analyses utilizing the average-passage equation system developed by Dr. John Adamczyk of NASA Lewis. This flow solution scheme requires a series of blade specific grids each having a common axisymmetric mesh, but varying in the circumferential direction according to the geometry of the specific blade row.

  12. Control strategies of grid-side PWM inverter for distributed power generation systems

    DEFF Research Database (Denmark)

    Lar, I.; Radulescu, M. M.; Ritchie, Ewen

    2011-01-01

    A comparison between two predictive control methods of grid side inverter, Robust Dead Beat control and Robust Forward control is made. The report contains both simulations and experimental test wich were made at a reduced scale (2.2 kW). The harmonic monitoring has shown that Dead Beat control p...... presents less harmonic contents, while Forward control recovery time looks better due to any reference changes....

  13. A solar PV augmented hybrid scheme for enhanced wind power generation through improved control strategy for grid connected doubly fed induction generator

    Directory of Open Access Journals (Sweden)

    Adikanda Parida

    2016-12-01

    Full Text Available In this paper, a wind power generation scheme using a grid connected doubly fed induction generator (DFIG augmented with solar PV has been proposed. A reactive power-based rotor speed and position estimation technique with reduced machine parameter sensitivity is also proposed to improve the performance of the DFIG controller. The estimation algorithm is based on model reference adaptive system (MRAS, which uses the air gap reactive power as the adjustable variable. The overall generation reliability of the wind energy conversion system can be considerably improved as both solar and wind energy can supplement each other during lean periods of either of the sources. The rotor-side DC-link voltage and active power generation at the stator terminals of the DFIG are maintained constant with minimum storage battery capacity using single converter arrangement without grid-side converter (GSC. The proposed scheme has been simulated and experimentally validated with a practical 2.5 kW DFIG using dSPACE CP1104 module which produced satisfactory results.

  14. Smart grids: A paradigm shift on energy generation and distribution with the emergence of a new energy management business model

    Science.gov (United States)

    Cardenas, Jesus Alvaro

    An energy and environmental crisis will emerge throughout the world if we continue with our current practices of generation and distribution of electricity. A possible solution to this problem is based on the Smart grid concept, which is heavily influenced by Information and Communication Technology (ICT). Although the electricity industry is mostly regulated, there are global models used as roadmaps for Smart Grids' implementation focusing on technologies and the basic generation-distribution-transmission model. This project aims to further enhance a business model for a future global deployment. It takes into consideration the many factors interacting in this energy provision process, based on the diffusion of technologies and literature surveys on the available documents in the Internet as well as peer-reviewed publications. Tariffs and regulations, distributed energy generation, integration of service providers, consumers becoming producers, self-healing devices, and many other elements are shifting this industry into a major change towards liberalization and deregulation of this sector, which has been heavily protected by the government due to the importance of electricity for consumers. We propose an Energy Management Business Model composed by four basic elements: Supply Chain, Information and Communication Technology (ICT), Stakeholders Response, and the resulting Green Efficient Energy (GEE). We support the developed model based on the literature survey, we support it with the diffusion analysis of these elements, and support the overall model with two surveys: one for peers and professionals, and other for experts in the field, based on the Smart Grid Carnegie Melon Maturity Model (CMU SEI SGMM). The contribution of this model is a simple path to follow for entities that want to achieve environmental friendly energy with the involvement of technology and all stakeholders.

  15. A Comparison of Off-Grid-Pumped Hydro Storage and Grid-Tied Options for an IRSOFC-HAWT Power Generator

    Directory of Open Access Journals (Sweden)

    Mahdi Majidniya

    2017-01-01

    Full Text Available An Internal Reforming Solid Oxide Fuel Cell (IRSOFC is modeled thermodynamically; a Horizontal Axis Wind Turbine (HAWT is designed; the combined IRSOFC-HAWT system should create a reliable source of electricity for the demand of a village located in Manjil, Iran. The output power of HAWT is unstable, but by controlling the fuel rate for the IRSOFC it is possible to have a stable power output from the combined system. When the electricity demand is over the peak or the wind speed is low/unstable/significantly high, the generated power may not be sufficient. To solve this problem, two scenarios are considered: connecting to the grid or using a Pumped Hydro Storage (PHS. For the second scenario, the extra produced electricity is saved when the production is more than demand and can be used when the extra power is needed. The economic analysis is done based on the economic conditions in Iran. The results will show a period of return about 9.5 and 13 years with the levelized cost of electricity about 0.0747 and 0.0882 $/kWh for the first and second scenarios, respectively. Furthermore, effects of some parameters such as the electricity price and the real interest rate are discussed.

  16. Literature Review on Reasons and Countermeasures on Large-scale Off-grid of Wind Turbine Generator System

    Directory of Open Access Journals (Sweden)

    Zhu Jun

    2015-01-01

    Full Text Available This paper reviews the present situation of the application of wind turbines generator system(WTGS at home and abroad, describes the strategic significance and the value of sustainable development of the wind power in the country, illustrates the problems, a variety of reasons and responses on large-scale off-grid of WTGS, compares the advantages and disadvantages of various methods, gives full consideration to the actual demand for WTGS works and characteristics and points out the further research.

  17. Research on the Control Strategy for Grid-side Converter of PWM Doubly Fed Induction Wind Power Generators

    Science.gov (United States)

    Liu, Yifang; Wang, Zhijie; Li, Renfu; Jiang, Xiuchen; Sheng, Gehao; Liu, Tianyu; Liu, Sanming

    2017-05-01

    When the grid voltage drop, over current of transient rotor and over voltage may damage the power electronic devices. The attenuation of electromagnetic torque will lead to speed up. This paper proposes an improved feed-forward control strategy and its application in the PWM converter. When the PWM converter on voltage drops, bus voltage will be more stable. So over current problems of the DFIG rotor side can be reduced, and it also can improve voltage regulation speed of the DC bus voltage and reduce the oscillation amplitude. Furthermore, the stability of doubly fed wind generator system can be improved. The simulation results verify the validity of the modified control strategy.

  18. Generation of Domestic Hot Water, Space Heating and Driving Pattern Profiles for Integration Analysis of Active Loads in Low Voltage Grids

    DEFF Research Database (Denmark)

    Diaz de Cerio Mendaza, Iker; Pigazo, Alberto; Bak-Jensen, Birgitte

    2013-01-01

    The changes in the Danish energy sector, consequence of political agreements, are expected to have direct impact in the actual power distribution systems. Large number of electric boiler, heat pumps and electric vehicles are planned and will cope large percentage of the future power consumption...... demand and electric vehicle driving profiles, to be used for power grid calculations. The generated thermal profiles relied on a statistical analysis made from real domestic hot water and space heating data from 25 households of a typical Danish residential area. The driving profiles instead were formed...... based on conclusions derived from previous analysis on Danish driving patterns and the driving cycles extracted from the European project ARTEMIS. The obtained random profiles will allow electrical networks in Denmark to be analyzed while maintaining the probability of the original data set....

  19. Evaluation of Representative Smart Grid Investment Grant Project Technologies: Distributed Generation

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Ruchi; Vyakaranam, Bharat GNVSR

    2012-02-14

    This document is one of a series of reports estimating the benefits of deploying technologies similar to those implemented on the Smart Grid Investment Grant (SGIG) projects. Four technical reports cover the various types of technologies deployed in the SGIG projects, distribution automation, demand response, energy storage, and renewables integration. A fifth report in the series examines the benefits of deploying these technologies on a national level. This technical report examines the impacts of addition of renewable resources- solar and wind in the distribution system as deployed in the SGIG projects.

  20. Energy Cost of an Independent Micro-grid with Control of Power Output Sharing of a Distributed Engine Generator

    Science.gov (United States)

    Obara, Shin'ya

    Small kerosene diesel-engine power generators are introduced into an independent micro-grid (IMG) that connects 20 houses, and power and heat are supplied to them. A 3 kW engine generator is installed in six houses, and a boiler and a heat storage tank are also installed, and exhaust heat to make up for insufficiency is supplied. The boiler is installed in the house that does not install the engine generator, and heat is supplied to the demand side. Partial load operation of the engine generator has a large influence on power generation efficiency. Therefore, this paper discusses the system that controls the power of the engine generator by the power distribution control system using the genetic algorithm (GA), and the control system that changes the number of operations of the engine generators according to the magnitude of the power load. As a case study, the energy-demand model of the 20 houses in Sapporo was analyzed. As a result, the annual energy cost of the number of operations system and the power distribution control system is reducible with 16% and 8% compared with the conventional method, respectively. However, it depends for this cutback effect on the heat demand characteristic greatly, and when the proposed system is introduced into a community with little heat demand, effectiveness will decrease greatly.

  1. Experience in Developing a Single-Phase Two Winding 5 kW Self-excited Induction Generator for Off-Grid Renewable Energy Based Power Generation

    Science.gov (United States)

    Murthy, S. S.; Singh, Bhim; Sandeep, Vuddanti

    2016-06-01

    This paper deals with the design and development of a novel single-phase two winding self-excited squirrel cage induction generator (SEIG) for off-grid renewable energy based power generation. The principles underlying the design process and experience with SPEED design tool are described to design a 5 kW, 50 Hz, 230 V, 4 pole single phase AC generator. All possible configurations to reduce harmonic components of induced e.m.f. are attempted for desired performance and to get an optimum design keeping in view the manufacturing constraints. The development of a prototype based on this design has been completed with the help of an industry. Typical test results on the prototype are presented to demonstrate its performance. Computed results are obtained with a design based computational procedure for performance analysis and a critical comparison is made with test results.

  2. Dynamic Modeling and Grid Interaction of a Tidal and River Generator

    Energy Technology Data Exchange (ETDEWEB)

    Muljadi, Eduard; Gevorgian, Vahan; Donegan, James; Marnagh, Cian; McEntee, Jarlath

    2017-07-13

    This presentation provides a high-level overview of the deployment of a river generator installed in a small system. The turbine dynamics of a river generator, electrical generator, and power converter are modeled in detail. Various simulations can be exercised, and the impact of different control algorithms, failures of power switches, and corresponding impacts can be examined.

  3. Technical Evaluation of Superconducting Fault Current Limiters Used in a Micro-Grid by Considering the Fault Characteristics of Distributed Generation, Energy Storage and Power Loads

    Directory of Open Access Journals (Sweden)

    Lei Chen

    2016-09-01

    Full Text Available Concerning the development of a micro-grid integrated with multiple intermittent renewable energy resources, one of the main issues is related to the improvement of its robustness against short-circuit faults. In a sense, the superconducting fault current limiter (SFCL can be regarded as a feasible approach to enhance the transient performance of a micro-grid under fault conditions. In this paper, the fault transient analysis of a micro-grid, including distributed generation, energy storage and power loads, is conducted, and regarding the application of one or more flux-coupling-type SFCLs in the micro-grid, an integrated technical evaluation method considering current-limiting performance, bus voltage stability and device cost is proposed. In order to assess the performance of the SFCLs and verify the effectiveness of the evaluation method, different fault cases of a 10-kV micro-grid with photovoltaic (PV, wind generator and energy storage are simulated in the MATLAB software. The results show that, the efficient use of the SFCLs for the micro-grid can contribute to reducing the fault current, improving the voltage sags and suppressing the frequency fluctuations. Moreover, there will be a compromise design to fully take advantage of the SFCL parameters, and thus, the transient performance of the micro-grid can be guaranteed.

  4. Forecasting Wind and Solar Generation: Improving System Operations, Greening the Grid

    Energy Technology Data Exchange (ETDEWEB)

    Tian; Tian; Chernyakhovskiy, Ilya

    2016-01-01

    This document discusses improving system operations with forecasting and solar generation. By integrating variable renewable energy (VRE) forecasts into system operations, power system operators can anticipate up- and down-ramps in VRE generation in order to cost-effectively balance load and generation in intra-day and day-ahead scheduling. This leads to reduced fuel costs, improved system reliability, and maximum use of renewable resources.

  5. Incorporation of wind generation to the Mexican power grid: Steady state analysis

    Energy Technology Data Exchange (ETDEWEB)

    Tovar, J.H.; Guardado, J.L.; Cisneros, F. [Inst. Tecnologico de Morelia (Mexico); Cadenas, R.; Lopez, S. [Comision Federal de Electricidad, Morelia (Mexico)

    1997-09-01

    This paper describes a steady state analysis related with the incorporation of large amounts of eolic generation into the Mexican power system. An equivalent node is used to represent individual eolic generators in the wind farm. Possible overloads, losses, voltage and reactive profiles and estimated severe contingencies are analyzed. Finally, the conclusions of this study are presented.

  6. A dynamic power management strategy of a grid connected hybrid generation system using wind, photovoltaic and Flywheel Energy Storage System in residential applications

    International Nuclear Information System (INIS)

    Boukettaya, Ghada; Krichen, Lotfi

    2014-01-01

    A global supervisory strategy for a micro-grid power generation system that comprises wind and photovoltaic generation subsystems, a flywheel storage system, and domestic loads connected both to the hybrid power generators and to the grid, is developed in this paper. The objectives of the supervisor control are, firstly, to satisfy in most cases the load power demand and, secondly, to check storage and grid constraints to prevent blackout, to reduce energy costs and greenhouse gas emissions, and to extend the life of the flywheel. For these purposes, the supervisor determines online the operation mode of the different generation subsystems, switching from maximum power conversion to power regulation. Decision criteria for the supervisor based on actual variables are presented. Finally, the performance of the supervisor is extensively assessed through computer simulation using a comprehensive nonlinear model of the studied system. - Highlights: • We supervise a micro-grid power generation system with an objective to produce clipping grid consumption. • The supervisor switch online from maximum power conversion to power regulation. • We provide services both for domestic users and for the distribution network manager. • The developed algorithm is tested and validated for different scenarios

  7. Improved direct torque control of an induction generator used in a wind conversion system connected to the grid.

    Science.gov (United States)

    Abdelli, Radia; Rekioua, Djamila; Rekioua, Toufik; Tounzi, Abdelmounaïm

    2013-07-01

    This paper presents a modulated hysteresis direct torque control (MHDTC) applied to an induction generator (IG) used in wind energy conversion systems (WECs) connected to the electrical grid through a back-to-back converter. The principle of this strategy consists in superposing to the torque reference a triangular signal, as in the PWM strategy, with the desired switching frequency. This new modulated reference is compared to the estimated torque by using a hysteresis controller as in the classical direct torque control (DTC). The aim of this new approach is to lead to a constant frequency and low THD in grid current with a unit power factor and a minimum voltage variation despite the wind variation. To highlight the effectiveness of the proposed method, a comparison was made with classical DTC and field oriented control method (FOC). The obtained simulation results, with a variable wind profile, show an adequate dynamic of the conversion system using the proposed method compared to the classical approaches. Copyright © 2013 ISA. Published by Elsevier Ltd. All rights reserved.

  8. Wind Energy Management System EMS Integration Project: Incorporating Wind Generation and Load Forecast Uncertainties into Power Grid Operations

    Energy Technology Data Exchange (ETDEWEB)

    Makarov, Yuri V.; Huang, Zhenyu; Etingov, Pavel V.; Ma, Jian; Guttromson, Ross T.; Subbarao, Krishnappa; Chakrabarti, Bhujanga B.

    2010-01-01

    unique features make this work a significant step forward toward the objective of incorporating of wind, solar, load, and other uncertainties into power system operations. Currently, uncertainties associated with wind and load forecasts, as well as uncertainties associated with random generator outages and unexpected disconnection of supply lines, are not taken into account in power grid operation. Thus, operators have little means to weigh the likelihood and magnitude of upcoming events of power imbalance. In this project, funded by the U.S. Department of Energy (DOE), a framework has been developed for incorporating uncertainties associated with wind and load forecast errors, unpredicted ramps, and forced generation disconnections into the energy management system (EMS) as well as generation dispatch and commitment applications. A new approach to evaluate the uncertainty ranges for the required generation performance envelope including balancing capacity, ramping capability, and ramp duration has been proposed. The approach includes three stages: forecast and actual data acquisition, statistical analysis of retrospective information, and prediction of future grid balancing requirements for specified time horizons and confidence levels. Assessment of the capacity and ramping requirements is performed using a specially developed probabilistic algorithm based on a histogram analysis, incorporating all sources of uncertainties of both continuous (wind and load forecast errors) and discrete (forced generator outages and start-up failures) nature. A new method called the “flying brick” technique has been developed to evaluate the look-ahead required generation performance envelope for the worst case scenario within a user-specified confidence level. A self-validation algorithm has been developed to validate the accuracy of the confidence intervals.

  9. An Efficient Mesh Generation Method for Fractured Network System Based on Dynamic Grid Deformation

    Directory of Open Access Journals (Sweden)

    Shuli Sun

    2013-01-01

    Full Text Available Meshing quality of the discrete model influences the accuracy, convergence, and efficiency of the solution for fractured network system in geological problem. However, modeling and meshing of such a fractured network system are usually tedious and difficult due to geometric complexity of the computational domain induced by existence and extension of fractures. The traditional meshing method to deal with fractures usually involves boundary recovery operation based on topological transformation, which relies on many complicated techniques and skills. This paper presents an alternative and efficient approach for meshing fractured network system. The method firstly presets points on fractures and then performs Delaunay triangulation to obtain preliminary mesh by point-by-point centroid insertion algorithm. Then the fractures are exactly recovered by local correction with revised dynamic grid deformation approach. Smoothing algorithm is finally applied to improve the quality of mesh. The proposed approach is efficient, easy to implement, and applicable to the cases of initial existing fractures and extension of fractures. The method is successfully applied to modeling of two- and three-dimensional discrete fractured network (DFN system in geological problems to demonstrate its effectiveness and high efficiency.

  10. Control strategy of grid-connected photovoltaic generation system based on GMPPT method

    Science.gov (United States)

    Wang, Zhongfeng; Zhang, Xuyang; Hu, Bo; Liu, Jun; Li, Ligang; Gu, Yongqiang; Zhou, Bowen

    2018-02-01

    There are multiple local maximum power points when photovoltaic (PV) array runs under partial shading condition (PSC).However, the traditional maximum power point tracking (MPPT) algorithm might be easily trapped in local maximum power points (MPPs) and cannot find the global maximum power point (GMPP). To solve such problem, a global maximum power point tracking method (GMPPT) is improved, combined with traditional MPPT method and particle swarm optimization (PSO) algorithm. Under different operating conditions of PV cells, different tracking algorithms are used. When the environment changes, the improved PSO algorithm is adopted to realize the global optimal search, and the variable step incremental conductance (INC) method is adopted to achieve MPPT in optimal local location. Based on the simulation model of the PV grid system built in Matlab/Simulink, comparative analysis of the tracking effect of MPPT by the proposed control algorithm and the traditional MPPT method under the uniform solar condition and PSC, validate the correctness, feasibility and effectiveness of the proposed control strategy.

  11. A simple mathematical description of an off-grid hybrid solar-wind power generating system

    Science.gov (United States)

    Blasone, M.; Dell'Anno, F.; De Luca, R.; Torre, G.

    2013-05-01

    We give a detailed description of the energy balance equation for a stand-alone hybrid solar-wind power generating system. The dimensions of the power generator and the energy capacity of a buffer battery (used as an energy storage system) are chosen to suit a known consumer's profile. Future applications of the mathematical model developed and analogies with a similar hydrodynamic problem are discussed.

  12. A simple mathematical description of an off-grid hybrid solar–wind power generating system

    International Nuclear Information System (INIS)

    Blasone, M; Dell'Anno, F; De Luca, R; Torre, G

    2013-01-01

    We give a detailed description of the energy balance equation for a stand-alone hybrid solar–wind power generating system. The dimensions of the power generator and the energy capacity of a buffer battery (used as an energy storage system) are chosen to suit a known consumer's profile. Future applications of the mathematical model developed and analogies with a similar hydrodynamic problem are discussed. (paper)

  13. DESIGN AND ANALYSIS OF A GRID CONNECTED PHOTOVOLTAIC GENERATION SYSTEM WITH ACTIVE FILTERING FUNCTION.

    OpenAIRE

    Leslie, Jr., Leonard Gene

    2003-01-01

    In recent years there has been a growing interest in moving away from large centralized power generation toward distributed energy resources. Solar energy generation presents several benefits for use as a distributed energy resource, especially as a peaking power source. One drawback of solar energy sources is the need for energy storage for the system to be utilized for a significant percentage of the day. One way of avoiding adding energy storage to a solar gener...

  14. An Adaptive Quadrature Signal Generation Based Single-Phase Phase-Locked Loop for Grid-Connected Applications

    DEFF Research Database (Denmark)

    Golestan, Saeed; Guerrero, Josep M.; Abusorrah, Abdullah

    2017-01-01

    The quadrature signal generation based phase-locked loops (QSG-PLLs) are highly popular for synchronization purposes in single-phase systems. The main difference among these PLLs often lies in the technique they use for creating the fictitious quadrature component. One of the easiest QSG approaches...... is delaying the original single-phase signal by a quarter of a cycle. The PLL with such QSG technique is often called the transfer delay based PLL (TD-PLL). The TD-PLL benefits from a simple structure, rather fast dynamic response, and a good detection accuracy when the grid frequency is at its nominal value......, but it suffers from a phase offset error and double frequency oscillatory error in the estimated phase and frequency in the presence of frequency drifts. In this paper, a simple yet effective approach to remove the aforementioned errors of the TD-PLL is proposed. The resultant PLL structure is called...

  15. Generation and Demand Scheduling for a Grid-Connected Hybrid Microgrid Considering Price-based Incentives

    DEFF Research Database (Denmark)

    Hernández, Adriana Carolina Luna; Aldana, Nelson Leonardo Diaz; Savaghebi, Mehdi

    2017-01-01

    Microgrids rely on energy management levels to optimally schedule their components. Conventionally, the research in this field has been focused on the optimal formulation of the generation or the demand side management separately without considering real case scenarios and validated only...... by simulation. This paper presents the power scheduling of a real site microgrid under a price-based demand response program defined in Shanghai, China managing generation and demand simultaneously. The proposed optimization problem aims to minimize operating cost by managing renewable energy sources as well...

  16. Particularities of the distributed generation with photovoltaic systems and the interaction of electric grid; Particularidades da geracao distribuida com sistemas fotovoltaicos e sua integracao com a rede eletrica

    Energy Technology Data Exchange (ETDEWEB)

    Macedo, Wilson Negrao; Ziles, Roberto [Universidade de Sao Paulo (USP), SP (Brazil). Programa Interunidades de Pos-Graduacao em Energia. Lab. de Sistemas Fotovoltaicos], e-mail: wnmacedo@iee.usp.br, e-mail: Zilles@iee.usp.br

    2004-07-01

    In this work an approach of the particularities of the distributed generation with photovoltaic systems as well as the interaction of these systems with the electric grid is done, base aspects related to your operation and the several forms of conceive a grid connected photovoltaic system (SFCR) are taking into accounted. It shows through the different forms of consolidate the connection with the electric grid, which besides the inverter be the key element of this kind system, SFCRs' Interaction with the electric grid is enough influenced by the incentive policies or given treatment for this application in each place in particular. That aspect can influence in the demand by the owner of the installation, mostly if this is a captive consumer that now becomes an electric power producer. (author)

  17. Scenario analysis to account for photovoltaic generation uncertainty in distribution grid reconfiguration

    DEFF Research Database (Denmark)

    Chittur Ramaswamy, Parvathy; Deconinck, Geert; Pillai, Jayakrishnan Radhakrishna

    2013-01-01

    This paper considers hourly reconfiguration of a low voltage distribution network with the objectives of minimizing power loss and voltage deviation. The uncertainty in photovoltaic (PV) generation which in turn will affect the optimum configuration is tackled with the help of scenario analysis. ......-dominated solutions, demonstrating their trade-offs. Finally, the best compromise solution can be selected depending on the decision maker's requirement....

  18. Robust Current Control of Doubly Fed Wind Turbine Generator under Unbalanced Grid Voltage Conditions

    DEFF Research Database (Denmark)

    Wang, Yun; Gong, Wenming; Wu, Qiuwei

    2014-01-01

    This paper presents the design of a H ∞ current controller for doubly fed induction generators (DFIGs) in order to maintain stable operation under unbalanced voltage conditions. The H ∞ current controller has a multi-input and multi-output (MIMO) structure and is designed using the loop shaping...

  19. Rotor Voltage Dynamics in the Doubly Fed Induction Generator During Grid Faults

    DEFF Research Database (Denmark)

    Lima, Francisco K. A.; Luna, Alvaro; Rodriguez, Pedro

    2010-01-01

    This paper presents a new control strategy for the rotor-side converter (RSC) of wind turbines (WTs) based on doubly fed induction generators (DFIG) that intends to improve its low-voltage ride through capability. The main objective of this work is to design an algorithm that would enable the sys...

  20. Advanced structures for grid Synchronization of power converters in distributed generation applications

    DEFF Research Database (Denmark)

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

    2012-01-01

    The Transmission System Operators are specially concerned about the Low Voltage Ride Through requirements of distributed generation power plants. Solutions based on the installation of STATCOMs and DVRs, as well as on advanced control functionalities for the existing power converters have contrib...

  1. Optimization of Electricity Generation Schemes in the Java-Bali Grid System with Co2 Reduction Consideration

    Directory of Open Access Journals (Sweden)

    Farizal Farizal

    2016-08-01

    Full Text Available This research considers the problem of reducing CO2 emissions from the Java-Bali power grid system that consists of a variety of power-generating plants: coal-fired, natural gas, oil, and renewable energy (PV, geothermal, hydroelectric, wind, and landfill gas. The problem is formulated as linear programming and solved using LINGO 10. The model was developed for a nation to meet a specified CO2 emission target. Two carbon dioxide mitigation options are considered in this study, i.e. fuel balancing and fuel switching. In order to reduce the CO2 emissions by 26% in 2021, State Electric Supply Company (PLN has to generate up to 30% of electricity from renewable energy (RE, and the cost of electricity (COE is expected to increase to 617.77 IDR per kWh for a fuel balancing option, while for fuel switching option, PLN has to generate 29% of electricity from RE, and the COE is expected to increase to 535.85 IDR per kWh.

  2. Parallel grid population

    Science.gov (United States)

    Wald, Ingo; Ize, Santiago

    2015-07-28

    Parallel population of a grid with a plurality of objects using a plurality of processors. One example embodiment is a method for parallel population of a grid with a plurality of objects using a plurality of processors. The method includes a first act of dividing a grid into n distinct grid portions, where n is the number of processors available for populating the grid. The method also includes acts of dividing a plurality of objects into n distinct sets of objects, assigning a distinct set of objects to each processor such that each processor determines by which distinct grid portion(s) each object in its distinct set of objects is at least partially bounded, and assigning a distinct grid portion to each processor such that each processor populates its distinct grid portion with any objects that were previously determined to be at least partially bounded by its distinct grid portion.

  3. Investment coordination in network industries. The case of electricity grid and electricity generation

    Energy Technology Data Exchange (ETDEWEB)

    Hoeffler, Felix [Koeln Univ. (Germany). Energiewirtschaftliches Inst.; Max-Planck-Institute for Research on Collective Goods, Bonn (Germany); Wambach, Achim [Cologne Univ. (Germany). Dept. of Economics

    2013-06-15

    Liberalization of network industries frequently separates the network from the other parts of the industry. This is important in particular for the elec- tricity industry where private firms invest into generation facilities, while network investments usually are controlled by regulators. We discuss two regulatory regimes. First, the regulator can only decide on the network extension. Second, she can additionally use a ''capacity market'' with payments contingent on private generation investment. For the first case, we find that even absent asymmetric information, a lack of regulatory commitment can cause inefficiently high or inefficiently low investments. For the second case, we develop a standard handicap auction which implements the first best under asymmetric information, if there are no shadow costs of public funds. With shadow costs, no simple mechanism can implement the second best outcome.

  4. Sustainable electricity generation by solar pv/diesel hybrid system without storage for off grids areas

    Science.gov (United States)

    Azoumah, Y.; Yamegueu, D.; Py, X.

    2012-02-01

    Access to energy is known as a key issue for poverty reduction. The electrification rate of sub Saharan countries is one of the lowest among the developing countries. However this part of the world has natural energy resources that could help raising its access to energy, then its economic development. An original "flexy energy" concept of hybrid solar pv/diesel/biofuel power plant, without battery storage, is developed in order to not only make access to energy possible for rural and peri-urban populations in Africa (by reducing the electricity generation cost) but also to make the electricity production sustainable in these areas. Some experimental results conducted on this concept prototype show that the sizing of a pv/diesel hybrid system by taking into account the solar radiation and the load/demand profile of a typical area may lead the diesel generator to operate near its optimal point (70-90 % of its nominal power). Results also show that for a reliability of a PV/diesel hybrid system, the rated power of the diesel generator should be equal to the peak load. By the way, it has been verified through this study that the functioning of a pv/Diesel hybrid system is efficient for higher load and higher solar radiation.

  5. Sustainable electricity generation by solar pv/diesel hybrid system without storage for off grids areas

    International Nuclear Information System (INIS)

    Azoumah, Y; Yamegueu, D; Py, X

    2012-01-01

    Access to energy is known as a key issue for poverty reduction. The electrification rate of sub Saharan countries is one of the lowest among the developing countries. However this part of the world has natural energy resources that could help raising its access to energy, then its economic development. An original 'flexy energy' concept of hybrid solar pv/diesel/biofuel power plant, without battery storage, is developed in order to not only make access to energy possible for rural and peri-urban populations in Africa (by reducing the electricity generation cost) but also to make the electricity production sustainable in these areas. Some experimental results conducted on this concept prototype show that the sizing of a pv/diesel hybrid system by taking into account the solar radiation and the load/demand profile of a typical area may lead the diesel generator to operate near its optimal point (70-90 % of its nominal power). Results also show that for a reliability of a PV/diesel hybrid system, the rated power of the diesel generator should be equal to the peak load. By the way, it has been verified through this study that the functioning of a pv/Diesel hybrid system is efficient for higher load and higher solar radiation.

  6. Grid pulser

    International Nuclear Information System (INIS)

    Jansweijer, P.P.M.; Es, J.T. van.

    1990-01-01

    This report describes a fast pulse generator. This generator delivers a high-voltage pulse of at most 6000 V with a rise time being smaller than 50 nS. this results in a slew rate of more than 120.000 volts per μS. The pulse generator is used to control the grid of the injector of the electron accelerator MEA. The capacity of this grid is about 60 pF. In order to charge this capacity up to 6000 volts in 50 nS a current of 8 ampere is needed. The maximal pulse length is 50 μS with a repeat frequency of 500 Hz. During this 50 μS the stability of the pulse amplitude is better than 0.1%. (author). 20 figs

  7. Multi-Fluid Geothermal Energy Systems: Using CO2 for Dispatchable Renewable Power Generation and Grid Stabilization

    Science.gov (United States)

    Buscheck, T. A.; Bielicki, J. M.; Randolph, J.; Chen, M.; Hao, Y.; Sun, Y.

    2013-12-01

    Abstract We present an approach to use CO2 to (1) generate dispatchable renewable power that can quickly respond to grid fluctuations and be cost-competitive with natural gas, (2) stabilize the grid by efficiently storing large quantities of energy, (3) enable seasonal storage of solar thermal energy for grid integration, (4) produce brine for power-plant cooling, all which (5) increase CO2 value, rendering CO2 capture to be commerically viable, while (6) sequestering huge quantities of CO2. These attributes reduce carbon intensity of electric power, and enable cost-competitive, dispatchable power from major sources of renewable energy: wind, solar, and geothermal. Conventional geothermal power systems circulate brine as the working fluid to extract heat, but the parasitic power load for this circulation can consume a large portion of gross power output. Recently, CO2 has been considered as a working fluid because its advantageous properties reduce this parasitic loss. We expand on this idea by using multiple working fluids: brine, CO2, and N2. N2 can be separated from air at lower cost than captured CO2, it is not corrosive, and it will not react with the formation. N2 also can improve the economics of energy production and enable energy storage, while reducing operational risk. Extracting heat from geothermal reservoirs often requires submersible pumps to lift brine, but these pumps consume much of the generated electricity. In contrast, our approach drives fluid circulation by injecting supplemental, compressible fluids (CO2, and N2) with high coefficients of thermal expansion. These fluids augment reservoir pressure, produce artesian flow at the producers, and reduce the parasitic load. Pressure augmentation is improved by the thermosiphon effect that results from injecting cold/dense CO2 and N2. These fluids are heated to reservoir temperature, greatly expand, and increase the artesian flow of brine and supplemental fluid at the producers. Rather than using

  8. High-Performance Constant Power Generation in Grid-Connected PV Systems

    DEFF Research Database (Denmark)

    Sangwongwanich, Ariya; Yang, Yongheng; Blaabjerg, Frede

    2016-01-01

    An advanced power control strategy by limiting the maximum feed-in power of PV systems has been proposed, which can ensure a fast and smooth transition between maximum power point tracking and Constant Power Generation (CPG). Regardless of the solar irradiance levels, high-performance and stable...... operation are always achieved by the proposed control strategy. It can regulate the PV output power according to any set-point, and force the PV systems to operate at the left side of the maximum power point without stability problems. Experimental results have verified the effectiveness of the proposed CPG...

  9. Optimal Sizing Of An Off-Grid Small Hydro-Photovoltaic-Diesel Generator Hybrid Power System For A Distant Village

    Directory of Open Access Journals (Sweden)

    Adebanji B.

    2017-08-01

    Full Text Available This paper presented an optimal sizing technique for an off-grid hybrid system consisting of Small Hydro SHP system Photovoltaic PV modules Battery BATT banks and Diesel Generator DG. The objective cost function Annualized Cost System and the Loss of Power Supply Probability LPSP were minimized with application of Genetic Algorithm GA in order to reduce the Cost of Energy COE generation. GA compared to other convectional optimization methods has the ability to attain global optimum easily. The decision variables are the number of small hydro turbines NSHP number of solar panels NPV number of battery banks NBATT and the capacity of DG PDG. The proposed method was applied to a typical rural village Itapaji-Ekiti in Nigeria. The monthly average solar irradiance data were converted into hourly solar irradiance data for uniformity. Sensitivity analysis was also performed to identify the most important parameter influencing the optimized hybrid system. The optimal sizing result of the HPS is 954 kW of SHP 290 kW of PV panels 9500 sets of 600Ah battery strings and 350 kW of DG. The optimal Loss of Power Supply Probability LPSP is 0.0054 and the Renewable Fraction RF is 0.62 which is indeed a significant improvement on the environment and comparatively better than any other combinations in the system.

  10. Power Quality Improvement Of Grid Integrated Type I Wind Turbine Generation System Operating as DSTATCOM by d-q Control Method

    Directory of Open Access Journals (Sweden)

    S V S Phani Kumar.Ch

    2016-06-01

    Full Text Available In recent years with the excessive consumption of electrical energy, the incongruity between generation and demand, the irrational structure of World’s energy as well as the environmental pollution have become progressively more evident. It has become crucial for ecological development to reduce the consumption of conventional energy and to enhance the development and utilization of renewable energy. Wind energy and Solar are unlimited supply of renewable energy and it has no pollution. But this concept suffer from the power quality issues from grid and generator side, this paper presents a control strategy for achieving maximum benefits from these grid-interfacing inverter when installed in 3-phase 4-wire distribution systems. The inverter can be controlled to perform as a multi-function device by incorporating active power filter functionality. The inverter can thus be utilized as: 1 power converter to inject power generated from RES to the grid and 2 shunt APF (Active Power Filter to compensate current unbalance, load current harmonics, load reactive power demand and load neutral current. All of these functions may be accomplished either individually or simultaneously. With such a control, the combination of grid-interfacing inverter and the 3-phase 4-wire linear/non-linear unbalanced load at point of common coupling appears as balanced linear load to the grid. The Paper propose design of 500kW Type I Wind Generation System 250kW each with Four Leg Inverter Controlled by d-q technique operated as DSTATCOM connected to 415V 4 wire Grid and also the results are compared with conventional Unit Vector Control. The proposed d-q method reduces the %THD of system to 1.97% from 24.12% where Unit Vector Control is of 3.94% which was on higher side , this is simulated in MATLAB/SIMULINK.

  11. The PWM strategies of grid-connected distributed generation active NPC inverters

    DEFF Research Database (Denmark)

    Ma, Lin; Xinmin, Jin; Kerekes, Tamas

    2009-01-01

    The Neutral Point Clamped topology due to high efficiency, low leakage current and EMI, its integration is widely used in the distributed generation (DG) systems. However the main disadvantage of the NPC inverter is given by an unequal distribution of the losses in the semiconductor devices, which...... leads to an unequal distribution of temperature. By using the Active NPC topology, the power losses distribution problem is alleviated. The modulation strategy is a key issue for losses distribution in this topology. In this paper two known strategies are discussed and a new proposed PWM strategy......, namely the Adjustable Losses Distribution (ALD) PWM strategy is proposed for better losses distribution in the Active NPC (ANPC) topology. Simulations using Simulink and the PLECS toolbox have been done for evaluating efficiency of different NPC topologies and some experimental results are presented...

  12. Control and Protection in Low Voltage Grid with Large Scale Renewable Electricity Generation

    DEFF Research Database (Denmark)

    Mustafa, Ghullam

    of renewable energy based DGs are reduced CO2 emission, reduced operational cost as almost no fuel is used for their operation and less transmission and distribution losses as these units are normally built near to the load centers. This has also resulted in some operational challenges due to the unpredictable...... nature of such power generation sources. Some of the operational challenges include voltage variations due to power fluctuations coming from the DG units. On the other hand, it has also opened up some opportunities. One of the opportunities is islanding operation of the distribution system with DG unit(s......). Islanding is a situation where electrical system becomes electrically isolated from the rest of the power network and yet continues to be energized by the DG units connected to it. With the increased penetration of DG units, islanded operation of the distribution network is used to improve the reliability...

  13. Wind Energy Management System Integration Project Incorporating Wind Generation and Load Forecast Uncertainties into Power Grid Operations

    Energy Technology Data Exchange (ETDEWEB)

    Makarov, Yuri V.; Huang, Zhenyu; Etingov, Pavel V.; Ma, Jian; Guttromson, Ross T.; Subbarao, Krishnappa; Chakrabarti, Bhujanga B.

    2010-09-01

    features make this work a significant step forward toward the objective of incorporating of wind, solar, load, and other uncertainties into power system operations. In this report, a new methodology to predict the uncertainty ranges for the required balancing capacity, ramping capability and ramp duration is presented. Uncertainties created by system load forecast errors, wind and solar forecast errors, generation forced outages are taken into account. The uncertainty ranges are evaluated for different confidence levels of having the actual generation requirements within the corresponding limits. The methodology helps to identify system balancing reserve requirement based on a desired system performance levels, identify system “breaking points”, where the generation system becomes unable to follow the generation requirement curve with the user-specified probability level, and determine the time remaining to these potential events. The approach includes three stages: statistical and actual data acquisition, statistical analysis of retrospective information, and prediction of future grid balancing requirements for specified time horizons and confidence intervals. Assessment of the capacity and ramping requirements is performed using a specially developed probabilistic algorithm based on a histogram analysis incorporating all sources of uncertainty and parameters of a continuous (wind forecast and load forecast errors) and discrete (forced generator outages and failures to start up) nature. Preliminary simulations using California Independent System Operator (California ISO) real life data have shown the effectiveness of the proposed approach. A tool developed based on the new methodology described in this report will be integrated with the California ISO systems. Contractual work is currently in place to integrate the tool with the AREVA EMS system.

  14. Design and Implementation of a C++ Multithreaded Operational Tool for the Generation of Detection Time Grids in 2D for P- and S-waves taking into Consideration Seismic Network Topology and Data Latency

    Science.gov (United States)

    Sardina, V.

    2017-12-01

    seconds. Under the same initial conditions, generation of a 2D grid at 0.1 degree resolution (2.6 million grid points) takes no more than 22 minutes. This preliminary results show a significant gain in grid generation speed when compared to other implementation via either scripts, or previous versions of the C++ code that did not implement multithreading.

  15. Second Order Generalized Integrator Based Reference Current Generation Method for Single-Phase Shunt Active Power Filters Under Adverse Grid Conditions

    DEFF Research Database (Denmark)

    Golestan, Saeed; Monfared, Mohammad; Guerrero, Josep M.

    2013-01-01

    The reference current generation (RCG) is a crucial part in the control of a shunt active power filter (APF). A variety of RCG techniques have been proposed in literature. Among these, the instantaneous reactive power theory, called pq theory, is probably the most widely used technique. The pq...... design procedure based on the pole-zero cancellation, and the extended symmetrical optimum theory is proposed. During the design procedure, the effects of grid frequency variations and the presence of distortion in the grid voltage are taken into account. Finally, to confirm the effectiveness...

  16. Active and Reactive Power Control Strategy for Grid-Connected Six-Phase Generator by Using Multi-Modular Matrix Converters

    Directory of Open Access Journals (Sweden)

    David Caballero

    2016-12-01

    Full Text Available This paper proposes an active and reactive power control strategy based on predictive control approaches applied to gridconnected renewable energy systems. To accomplish this a multi-modular matrix converter topologies are used in combination with a simple but efficient grid synchronization strategy. The theoretical performance analysis is performed considering a six-phase wind energy generator system interconnected with the grid. Results based on a MATLAB/Simulink simulation environment are discussed and the most relevant characteristics of the proposed control technique are highlighted considering the total harmonic distortion and the mean squared error as a parameters of performance.

  17. The research agenda on social acceptance of distributed generation in smart grids: renewable as common pool resources

    NARCIS (Netherlands)

    Wolsink, M.

    2012-01-01

    The rapid developing literature on ‘smart grids’ suggests that these will facilitate ‘distributed generation’ (DG) preferably from renewable sources. However, the current development of smart (micro)grids with substantial amount of DG ("DisGenMiGrids") suffers from a focus on mere ‘technology’.

  18. System efficiency of a tap transformer based grid connection topology applied on a direct driven generator for wind power.

    Science.gov (United States)

    Apelfröjd, Senad; Eriksson, Sandra

    2014-01-01

    Results from experiments on a tap transformer based grid connection system for a variable speed vertical axis wind turbine are presented. The tap transformer based system topology consists of a passive diode rectifier, DC-link, IGBT inverter, LCL-filter, and tap transformer. Full range variable speed operation is enabled by using the different step-up ratios of a tap transformer. Simulations using MATLAB/Simulink have been performed in order to study the behavior of the system. A full experimental set up of the system has been used in the laboratory study, where a clone of the on-site generator was driven by an induction motor and the system was connected to a resistive load to better evaluate the performance. Furthermore, the system is run and evaluated for realistic wind speeds and variable speed operation. For a more complete picture of the system performance, a case study using real site Weibull parameters is done, comparing different tap selection options. The results show high system efficiency at nominal power and an increase in overall power output for full tap operation in comparison with the base case, a standard transformer. In addition, the loss distribution at different wind speeds is shown, which highlights the dominant losses at low and high wind speeds. Finally, means for further increasing the overall system efficiency are proposed.

  19. System Efficiency of a Tap Transformer Based Grid Connection Topology Applied on a Direct Driven Generator for Wind Power

    Science.gov (United States)

    2014-01-01

    Results from experiments on a tap transformer based grid connection system for a variable speed vertical axis wind turbine are presented. The tap transformer based system topology consists of a passive diode rectifier, DC-link, IGBT inverter, LCL-filter, and tap transformer. Full range variable speed operation is enabled by using the different step-up ratios of a tap transformer. Simulations using MATLAB/Simulink have been performed in order to study the behavior of the system. A full experimental set up of the system has been used in the laboratory study, where a clone of the on-site generator was driven by an induction motor and the system was connected to a resistive load to better evaluate the performance. Furthermore, the system is run and evaluated for realistic wind speeds and variable speed operation. For a more complete picture of the system performance, a case study using real site Weibull parameters is done, comparing different tap selection options. The results show high system efficiency at nominal power and an increase in overall power output for full tap operation in comparison with the base case, a standard transformer. In addition, the loss distribution at different wind speeds is shown, which highlights the dominant losses at low and high wind speeds. Finally, means for further increasing the overall system efficiency are proposed. PMID:25258733

  20. System Efficiency of a Tap Transformer Based Grid Connection Topology Applied on a Direct Driven Generator for Wind Power

    Directory of Open Access Journals (Sweden)

    Senad Apelfröjd

    2014-01-01

    Full Text Available Results from experiments on a tap transformer based grid connection system for a variable speed vertical axis wind turbine are presented. The tap transformer based system topology consists of a passive diode rectifier, DC-link, IGBT inverter, LCL-filter, and tap transformer. Full range variable speed operation is enabled by using the different step-up ratios of a tap transformer. Simulations using MATLAB/Simulink have been performed in order to study the behavior of the system. A full experimental set up of the system has been used in the laboratory study, where a clone of the on-site generator was driven by an induction motor and the system was connected to a resistive load to better evaluate the performance. Furthermore, the system is run and evaluated for realistic wind speeds and variable speed operation. For a more complete picture of the system performance, a case study using real site Weibull parameters is done, comparing different tap selection options. The results show high system efficiency at nominal power and an increase in overall power output for full tap operation in comparison with the base case, a standard transformer. In addition, the loss distribution at different wind speeds is shown, which highlights the dominant losses at low and high wind speeds. Finally, means for further increasing the overall system efficiency are proposed.

  1. An Examination of AC/HVDC Power Circuits for Interconnecting Bulk Wind Generation with the Electric Grid

    Directory of Open Access Journals (Sweden)

    Daniel Ludois

    2010-06-01

    Full Text Available The application of high voltage dc (HVDC transmission for integrating large scale and/or off-shore wind generation systems with the electric grid is attractive in comparison to extra high voltage (EHV ac transmission due to a variety of reasons. While the technology of classical current sourced converters (CSC using thyristors is well established for realization of large HVDC systems, the technology of voltage sourced converters (VSC is emerging to be an alternative approach, particularly suitable for multi-terminal interconnections. More recently, a more modular scheme that may be termed ‘bridge of bridge’ converters (BoBC has been introduced to realize HVDC systems. While all these three approaches are functionally capable of realizing HVDC systems, the converter power circuit design trade-offs between these alternatives are not readily apparent. This paper presents an examination of these topologies from the point of view of power semiconductor requirements, reactive component requirements, operating losses, fault tolerance, multi-terminal operation, modularity, complexity, etc. Detailed analytical models will be used along with a benchmark application to develop a comparative evaluation of the alternatives that maybe used by wind energy/bulk transmission developers for performing engineering trade-off studies.

  2. Final Technical Report: Sparse Grid Scenario Generation and Interior Algorithms for Stochastic Optimization in a Parallel Computing Environment

    Energy Technology Data Exchange (ETDEWEB)

    Mehrotra, Sanjay [Northwestern Univ., Evanston, IL (United States)

    2016-09-07

    The support from this grant resulted in seven published papers and a technical report. Two papers are published in SIAM J. on Optimization [87, 88]; two papers are published in IEEE Transactions on Power Systems [77, 78]; one paper is published in Smart Grid [79]; one paper is published in Computational Optimization and Applications [44] and one in INFORMS J. on Computing [67]). The works in [44, 67, 87, 88] were funded primarily by this DOE grant. The applied papers in [77, 78, 79] were also supported through a subcontract from the Argonne National Lab. We start by presenting our main research results on the scenario generation problem in Sections 1–2. We present our algorithmic results on interior point methods for convex optimization problems in Section 3. We describe a new ‘central’ cutting surface algorithm developed for solving large scale convex programming problems (as is the case with our proposed research) with semi-infinite number of constraints in Section 4. In Sections 5–6 we present our work on two application problems of interest to DOE.

  3. Maximum power extraction under different vector-control schemes and grid-synchronization strategy of a wind-driven Brushless Doubly-Fed Reluctance Generator.

    Science.gov (United States)

    Mousa, Mohamed G; Allam, S M; Rashad, Essam M

    2018-01-01

    This paper proposes an advanced strategy to synchronize the wind-driven Brushless Doubly-Fed Reluctance Generator (BDFRG) to the grid-side terminals. The proposed strategy depends mainly upon determining the electrical angle of the grid voltage, θ v and using the same transformation matrix of both the power winding and grid sides to ensure that the generated power-winding voltage has the same phase-sequence of the grid-side voltage. On the other hand, the paper proposes a vector-control (power-winding flux orientation) technique for maximum wind-power extraction under two schemes summarized as; unity power-factor operation and minimum converter-current. Moreover, a soft-starting method is suggested to avoid the employed converter over-current. The first control scheme is achieved by adjusting the command power-winding reactive power at zero for a unity power-factor operation. However, the second scheme depends on setting the command d-axis control-winding current at zero to maximize the ratio of the generator electromagnetic-torque per the converter current. This enables the system to get a certain command torque under minimum converter current. A sample of the obtained simulation and experimental results is presented to check the effectiveness of the proposed control strategies. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  4. Time value of emission and technology discounting rate for off-grid electricity generation in India using intermediate pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Patel, Amit, E-mail: amitrp@iitrpr.ac.in [Indian Institute of Technology Ropar, Nangal Road, Rupnagar 140001, Punjab (India); Faculty of Technology and Engineering, The Maharaja Sayajirao University of Baroda, Vadodara 390001, Gujarat (India); Sarkar, Prabir; Tyagi, Himanshu; Singh, Harpreet [Indian Institute of Technology Ropar, Nangal Road, Rupnagar 140001, Punjab (India)

    2016-07-15

    The environmental impact assessment of a process over its entire operational lifespan is an important issue. Estimation of life cycle emission helps in predicting the contribution of a given process to abate (or to pollute) the environmental emission scenario. Considering diminishing and time-dependent effect of emission, assessment of the overall effect of emissions is very complex. The paper presents a generalized methodology for arriving at a single emission discounting number for a process option, using the concept of time value of carbon emission flow. This number incorporates the effect of the emission resulting from the process over the entire operational lifespan. The advantage of this method is its quantitative aspect as well as its flexible nature. It can be applied to any process. The method is demonstrated with the help of an Intermediate Pyrolysis process when used to generate off-grid electricity and opting biochar route for disposing straw residue. The scenarios of very high net emission to very high net carbon sequestration is generated using process by careful selection of process parameters for different scenarios. For these different scenarios, the process discounting rate was determined and its outcome is discussed. The paper also proposes a process specific eco-label that mentions the discounting rates. - Highlight: • Methodology to obtain emission discounting rate for a process is proposed. • The method includes all components of life cycle emission converts into a time dependent discounting number. • A case study of Intermediate Pyrolysis is used to obtain such number for a range of processes. • The method is useful to determine if the effect from the operation of a process will lead to a net absorption of emission or net accumulation of emission in the environment.

  5. Time value of emission and technology discounting rate for off-grid electricity generation in India using intermediate pyrolysis

    International Nuclear Information System (INIS)

    Patel, Amit; Sarkar, Prabir; Tyagi, Himanshu; Singh, Harpreet

    2016-01-01

    The environmental impact assessment of a process over its entire operational lifespan is an important issue. Estimation of life cycle emission helps in predicting the contribution of a given process to abate (or to pollute) the environmental emission scenario. Considering diminishing and time-dependent effect of emission, assessment of the overall effect of emissions is very complex. The paper presents a generalized methodology for arriving at a single emission discounting number for a process option, using the concept of time value of carbon emission flow. This number incorporates the effect of the emission resulting from the process over the entire operational lifespan. The advantage of this method is its quantitative aspect as well as its flexible nature. It can be applied to any process. The method is demonstrated with the help of an Intermediate Pyrolysis process when used to generate off-grid electricity and opting biochar route for disposing straw residue. The scenarios of very high net emission to very high net carbon sequestration is generated using process by careful selection of process parameters for different scenarios. For these different scenarios, the process discounting rate was determined and its outcome is discussed. The paper also proposes a process specific eco-label that mentions the discounting rates. - Highlight: • Methodology to obtain emission discounting rate for a process is proposed. • The method includes all components of life cycle emission converts into a time dependent discounting number. • A case study of Intermediate Pyrolysis is used to obtain such number for a range of processes. • The method is useful to determine if the effect from the operation of a process will lead to a net absorption of emission or net accumulation of emission in the environment.

  6. Resolving high-frequency internal waves generated at an isolated coral atoll using an unstructured grid ocean model

    Science.gov (United States)

    Rayson, Matthew D.; Ivey, Gregory N.; Jones, Nicole L.; Fringer, Oliver B.

    2018-02-01

    We apply the unstructured grid hydrodynamic model SUNTANS to investigate the internal wave dynamics around Scott Reef, Western Australia, an isolated coral reef atoll located on the edge of the continental shelf in water depths of 500,m and more. The atoll is subject to strong semi-diurnal tidal forcing and consists of two relatively shallow lagoons separated by a 500 m deep, 2 km wide and 15 km long channel. We focus on the dynamics in this channel as the internal tide-driven flow and resulting mixing is thought to be a key mechanism controlling heat and nutrient fluxes into the reef lagoons. We use an unstructured grid to discretise the domain and capture both the complex topography and the range of internal wave length scales in the channel flow. The model internal wave field shows super-tidal frequency lee waves generated by the combination of the steep channel topography and strong tidal flow. We evaluate the model performance using observations of velocity and temperature from two through water-column moorings in the channel separating the two reefs. Three different global ocean state estimate datasets (global HYCOM, CSIRO Bluelink, CSIRO climatology atlas) were used to provide the model initial and boundary conditions, and the model outputs from each were evaluated against the field observations. The scenario incorporating the CSIRO Bluelink data performed best in terms of through-water column Murphy skill scores of water temperature and eastward velocity variability in the channel. The model captures the observed vertical structure of the tidal (M2) and super-tidal (M4) frequency temperature and velocity oscillations. The model also predicts the direction and magnitude of the M2 internal tide energy flux. An energy analysis reveals a net convergence of the M2 energy flux and a divergence of the M4 energy flux in the channel, indicating the channel is a region of either energy transfer to higher frequencies or energy loss to dissipation. This conclusion is

  7. Planning in Smart Grids

    NARCIS (Netherlands)

    Bosman, M.G.C.

    2012-01-01

    The electricity supply chain is changing, due to increasing awareness for sustainability and an improved energy efficiency. The traditional infrastructure where demand is supplied by centralized generation is subject to a transition towards a Smart Grid. In this Smart Grid, sustainable generation

  8. Current control methods for grid-side three-phase PWM voltage-source inverter in distributed generation systems

    DEFF Research Database (Denmark)

    Lar, Ionut Andrei; Radulescu, Mircea; Ritchie, Ewen

    2012-01-01

    A comparison between two current control methods of grid side inverter, PI current control and Robust Forward control is made. PI control is implemented in d-q synchronous frame while Forward is implemented in abc stationary frames.The report contains both simulations and experimental test wich...... were made at a reduced scale ( 2.2 kW). The constant power test showed that both method have good results which can respect existing grid codes. The constant power test showed that both method have good results which can respect existing grid codes....

  9. Grid Computing

    CERN Document Server

    Yen, Eric

    2008-01-01

    Based on the Grid Computing: International Symposium on Grid Computing (ISGC) 2007, held in Taipei, Taiwan in March of 2007, this title presents the grid solutions and research results in grid operations, grid middleware, biomedical operations, and e-science applications. It is suitable for graduate-level students in computer science.

  10. 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)

    Energy Technology Data Exchange (ETDEWEB)

    Ibrik, Imad [An-Najah National Univ., Nablus (PS). Energy Research Centre; Lecumberri, Marta

    2010-07-01

    The energy situation in Palestine is somewhat unique when compared to other countries in the Middle East. There are virtually no available natural resources, and due to the ongoing political situation, the Palestinians rely (or have to rely) almost totally on Israel for their energy needs. This paper presents three energy supply alternatives for a remote village represented in PV system, diesel generator and electric grid. Design of these systems and the associated costs of their utilization are illustrated. Economic evaluation methods are used to compare the economic-effectiveness of these energy systems. The results show that, utilizing of PV systems for rural electrification in Palestine is economically more useful than using diesel generators or extension of the high voltage electric grid. The obtained results represents also a helpful reference for energy planers in Palestine and justify the consideration of PV systems more seriously. (orig.)

  11. Fault ride-through and grid support of permanent magnet synchronous generator-based wind farms with HVAC and VSC-HVDC transmission systems

    DEFF Research Database (Denmark)

    Liu, Hongzhi; Chen, Zhe

    2012-01-01

    This paper describes fault ride-through and grid support of offshore wind farms based on permanent magnet synchronous generator (PMSG) wind turbines connected to the onshore AC network through two alternative transmission systems: high voltage AC (HVAC) or high voltage DC (HVDC) based on voltage ......-HVDC for comparison. DIgSILENT simulations are presented to demonstrate the performance of the proposed systems during a severe onshore AC fault at the point of common coupling (PCC)....

  12. 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.

  13. Increase in the number of distributed power generation installations in electricity distribution grids - Storage technologies; Zunahme der dezentralen Energieerzeugungsanlagen in elektrischen Verteilnetzen: Grundlagen der Speicher

    Energy Technology Data Exchange (ETDEWEB)

    Luechinger, P.

    2003-07-01

    This is the fifth part of a ten-part final report for the Swiss Federal Office of Energy (SFOE) on a project that looked into potential problems relating to the Swiss electricity distribution grid with respect to the increasing number of distributed power generation facilities being put into service. The identification of special conditions for the grid's operation and future development that take increasing decentralised power production into account are discussed. The results of the project activities encompass the analysis and evaluation of various problem areas associated with planning and management of the grid during normal operation and periods of malfunction, as well as required modifications to safety systems and grid configurations. This fourth appendix to the main report describes six ways of storing electricity, including accumulators, super caps, super-conducting magnetic and flywheel energy storage units. The accumulator technologies discussed include lead-acid, nickel-cadmium and sodium-sulphur batteries. Each of these types of power storage technologies is briefly described. The characteristics of these various types of storage are compared.

  14. 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.

  15. Biomass and bio-fuel based poly-generation for off-grid and grid-connected operation. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    2012-07-01

    The overall objective of this project was to design and build a combined heat and power plant based on an updraft gasifier and a 35 kW electrical output Stirling engine and further to test the flexibility of the plant with regards to fuel and application. In the project a containerized combined heat and power plant including a 200 kW updraft gasifier and a 35 kW electrical output Stirling engine was designed, the specified components were procured, the plant was installed in the three containers and the plant was erected at Amagerforbraendingen ready for the COP15 in November 2009. The potential of operating the Stirling engine in island-mode (without grid connection) was investigated by mathematical modelling. Using an absorption cooling plant connected to the Stirling CHP plant was also investigated. A technical feasibility study was undertaken and it was concluded that from the two available technologies (water/LiBr and Ammonia/water) the appropriate choice is depending on the required cooling temperature. Test runs focussed on investigating the fuel flexibility of two different configurations of Stirling engine CHP plants were carried out - respectively the updraft gasifier plant (the containerized plant and the DTU plant) and the pyrolysis plant (the plant situated at Barritskov). In order to perform these test runs a stable operation is required. On both the containerized plant and the pyrolysis plant this proved to be more challenging than expected and therefore the number of fuels tested was limited to willow chips at the containerized plant and dry wood residues, wood pellets and straw pellets on the pyrolysis plant. For all tested fuels it was possible to operate the plants, however different issues mainly related to the quality of the fuels were encountered. And so it can be concluded that the quality of the fuel is critical for the operation of both the updraft gasifier plant and the pyrolysis plant. A comprehensive desktop evaluation of the feasibility

  16. 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.

  17. Grid Integration of Wind Farms

    Science.gov (United States)

    Giæver Tande, John Olav

    2003-07-01

    This article gives an overview of grid integration of wind farms with respect to impact on voltage quality and power system stability. The recommended procedure for assessing the impact of wind turbines on voltage quality in distribution grids is presented. The procedure uses the power quality characteristic data of wind turbines to determine the impact on slow voltage variations, flicker, voltage dips and harmonics. The detailed assessment allows for substantially more wind power in distribution grids compared with previously used rule-of-thumb guidelines. Power system stability is a concern in conjunction with large wind farms or very weak grids. Assessment requires the use of power system simulation tools, and wind farm models for inclusion in such tools are presently being developed. A fixed-speed wind turbine model is described. The model may be considered a good starting point for development of more advanced models, hereunder the concept of variable-speed wind turbines with a doubly fed induction generator is briefly explained. The use of dynamic wind farm models as part of power system simulation tools allows for detailed studies and development of innovative grid integration techniques. It is demonstrated that the use of reactive compensation may relax the short-term voltage stability limit and allow integration of significantly more wind power, and that application of automatic generation control technology may be an efficient means to circumvent thermal transmission capacity constraints. The continuous development of analysis tools and technology for cost-effective and secure grid integration is an important aid to ensure the increasing use of wind energy. A key factor for success, however, is the communication of results and gained experience, and in this regard it is hoped that this article may contribute.

  18. 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

    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...

  19. A New Robust Decoupled Control of the Stator Active and Reactive Currents for Grid-Connected Doubly-Fed Induction Generators

    Directory of Open Access Journals (Sweden)

    Ahmad Bashar Ataji

    2016-03-01

    Full Text Available This paper addresses the grid-connected variable speed doubly-fed induction generator, and proposes a new decoupled control to replace the conventional decoupled active and reactive powers (P-Q control. The proposed decoupled control is based on decoupling the stator active and reactive currents, in contrast with the conventional decoupled P-Q control, which is based on decoupling the stator active and reactive powers by forcing the stator d- or q-voltage to zero. The proposed decoupled control has all the advantages of the conventional decoupled P-Q control such as constant switching frequency and robustness against slip angle inaccuracy, and it has some additional advantages: The proposed control requires less machine parameters; for the controller design, it requires the stator-to-rotor turns ratio only; for the online calculation, it does not requires any machine parameter. The proposed decoupled control is more flexible and robust since the control is independent of the grid voltage orientation. It is robust against variation in the grid voltage amplitude. Several experiments are carried out using a 1.1 kW doubly-fed induction generator (DFIG, and the results support the proposed decoupled control and demonstrate some of its advantages.

  20. Final report for %22High performance computing for advanced national electric power grid modeling and integration of solar generation resources%22, LDRD Project No. 149016.

    Energy Technology Data Exchange (ETDEWEB)

    Reno, Matthew J.; Riehm, Andrew Charles; Hoekstra, Robert John; Munoz-Ramirez, Karina; Stamp, Jason Edwin; Phillips, Laurence R.; Adams, Brian M.; Russo, Thomas V.; Oldfield, Ron A.; McLendon, William Clarence, III; Nelson, Jeffrey Scott; Hansen, Clifford W.; Richardson, Bryan T.; Stein, Joshua S.; Schoenwald, David Alan; Wolfenbarger, Paul R.

    2011-02-01

    Design and operation of the electric power grid (EPG) relies heavily on computational models. High-fidelity, full-order models are used to study transient phenomena on only a small part of the network. Reduced-order dynamic and power flow models are used when analysis involving thousands of nodes are required due to the computational demands when simulating large numbers of nodes. The level of complexity of the future EPG will dramatically increase due to large-scale deployment of variable renewable generation, active load and distributed generation resources, adaptive protection and control systems, and price-responsive demand. High-fidelity modeling of this future grid will require significant advances in coupled, multi-scale tools and their use on high performance computing (HPC) platforms. This LDRD report demonstrates SNL's capability to apply HPC resources to these 3 tasks: (1) High-fidelity, large-scale modeling of power system dynamics; (2) Statistical assessment of grid security via Monte-Carlo simulations of cyber attacks; and (3) Development of models to predict variability of solar resources at locations where little or no ground-based measurements are available.

  1. A new approach to: (a) grid generation for numerical optimization, and (b) interconnect networks for beowulf clusters, leveraging n-dimensional sphere-packings

    Science.gov (United States)

    Bewley, Thomas; Cessna, Joseph; Belitz, Paul

    2008-11-01

    The abstract field of n-dimensional sphere packing theory is well developed (for a comprehensive review, see Sphere Packings, Lattices and Groups by Conway and Sloane). This theory forms the theoretical underpinning of the error-correcting codes used in both deep space communications and in computer memory. The present work extends this elegant theory to two important and immensely practical problems in computational fluid dynamics: (a) the generation of efficient grids for the coordination of grid-based derivative-free optimization algorithms in n dimensions, and (b) the effective n-dimensional interconnection of massively-parallel clusters of computational nodes. As we will illustrate and quantify, the first problem benefits tremendously from dense sphere packings with large kissing numbers >> 2n, whereas the latter problem benefits tremendously from rare sphere packings with kissing number = n+1.

  2. Compensation of negative sequence stator flux of doubly-fed induction generator using polar voltage control-based direct torque control under unbalanced grid voltage condition

    Directory of Open Access Journals (Sweden)

    Badrinarayan Bansilal Pimple

    2015-02-01

    Full Text Available This study proposes a polar voltage control-based direct torque control method to reduce the effects of unbalanced grid voltage on doubly-fed induction generator (DFIG-based wind turbine system. Under unbalanced grid voltage, the stator flux has a negative sequence component which leads to second harmonic pulsation in torque, stator active power, stator reactive power, stator current and rotor current. In the control scheme, the negative sequence rotor voltage vector is controlled to compensate the negative sequence stator flux by negative sequence rotor flux. Simulation study is carried out on a 2 MW DFIG system using MATLAB/SIMULINK. Feasibility of the proposed control strategy is experimentally verified on a 1.5 kW DFIG system.

  3. Optimal operation control of low-voltage grids with a high share of distributed power generation[Dissertation 17063]; Optimierte Betriebsfuehrung von Niederspannungsnetzen mit einem hohen Anteil an dezentraler Erzeugung

    Energy Technology Data Exchange (ETDEWEB)

    Malte, C. T.

    2007-07-01

    The importance of renewable energy sources and combined heat and power generation for electricity production will further increase in the next years, not only in Germany but all over Europe. Beside the conventional more or less centrally organised generation and distribution structure, more and more distributed generation (DG) units of different technologies will come to the forefront. Today's centrally organised electricity supply structure is comparatively stable, relatively simple to control and guarantees a high degree of supply quality. But it requests large investments with a long commitment, is less flexible and can barely use efficiency potentials. Distribution grids (low and medium voltage) are essentially passive; this means that the network management is carried out at the higher voltage levels. As more and more DG units feed in the grid, the distribution grids have to become more 'active'. With a high share of wind power, combined heat and power as well as photovoltaic generation, more duties of grid management have to be carried out at the point of common coupling of DG units. This requests for more communication und new control strategies in the distribution grids. At the same time grids with DG have in the mid-term the potential to reduce the susceptibility for large scale black-outs, because, on one hand, with a high number of smaller and individually controlled DG units the breakdown of one unit does not have a major impact and, on the other hand, with a specific grid management the option exists to build up islanded grids during interruptions on the higher voltage levels and to continue to supply the connected customers. In the European research project 'DISPOWER' 38 institutions from all over Europe dealt these topics. In this context a new kind of energy management system for low voltage grids was developed: 'PoMS'. PoMS is the acronym for 'Power Flow and Power Quality Management System'. Major

  4. Dynamic Programming Algorithm for Generation of Optimal Elimination Trees for Multi-frontal Direct Solver Over H-refined Grids

    KAUST Repository

    AbouEisha, Hassan M.

    2014-06-06

    In this paper we present a dynamic programming algorithm for finding optimal elimination trees for computational grids refined towards point or edge singularities. The elimination tree is utilized to guide the multi-frontal direct solver algorithm. Thus, the criterion for the optimization of the elimination tree is the computational cost associated with the multi-frontal solver algorithm executed over such tree. We illustrate the paper with several examples of optimal trees found for grids with point, isotropic edge and anisotropic edge mixed with point singularity. We show the comparison of the execution time of the multi-frontal solver algorithm with results of MUMPS solver with METIS library, implementing the nested dissection algorithm.

  5. Does basic energy access generate socioeconomic benefits? A field experiment with off-grid solar power in India.

    Science.gov (United States)

    Aklin, Michaël; Bayer, Patrick; Harish, S P; Urpelainen, Johannes

    2017-05-01

    This article assesses the socioeconomic effects of solar microgrids. The lack of access to electricity is a major obstacle to the socioeconomic development of more than a billion people. Off-grid solar technologies hold potential as an affordable and clean solution to satisfy basic electricity needs. We conducted a randomized field experiment in India to estimate the causal effect of off-grid solar power on electricity access and broader socioeconomic development of 1281 rural households. Within a year, electrification rates in the treatment group increased by 29 to 36 percentage points. Daily hours of access to electricity increased only by 0.99 to 1.42 hours, and the confidence intervals are wide. Kerosene expenditure on the black market decreased by 47 to 49 rupees per month. Despite these strong electrification and expenditure effects, we found no systematic evidence for changes in savings, spending, business creation, time spent working or studying, or other broader indicators of socioeconomic development.

  6. Controlling smart grid adaptivity

    NARCIS (Netherlands)

    Toersche, Hermen; Nykamp, Stefan; Molderink, Albert; Hurink, Johann L.; Smit, Gerardus Johannes Maria

    2012-01-01

    Methods are discussed for planning oriented smart grid control to cope with scenarios with limited predictability, supporting an increasing penetration of stochastic renewable resources. The performance of these methods is evaluated with simulations using measured wind generation and consumption

  7. Numerical Grid Generation. Proceedings of a Symposium on the Numerical Generation of Curvilinear Coordinate Systems and their Use in the Numerical Solution of Partial Differential Equations, held April 1982, Nashville, Tennessee

    Science.gov (United States)

    1982-04-01

    16. Ives, D.C. and Menor , W.A. (1981) "Grid Generation for Inlet and Inlet- Centerbody Configurations Using Conformal Mapping and Stretching," Paper...and Hawkins.53 Aircraft inlet configurations including centerbodies have been treated by Ives and Menor .54 NE- A double conformal mapping procedure was...shocks and the reflection of a constant speed shock from a solid boundary at nor- mal incidence. The second set of calculations is for oblique shock

  8. Bidirectional energy management of loads and decentralized generators in the low voltage grid. Field tests and applications; Bidirektionales Energiemanagement fuer Lasten und dezentrale Erzeuger im Niederspannungsnetz. Feldtest und Anwendungen

    Energy Technology Data Exchange (ETDEWEB)

    Bendel, C.; Dallinger, D.; Nestle, D.; Ringelstein, J. [ISET e.V., Kassel (Germany)

    2008-07-01

    In the context of growing installation of decentralized and fluctuating generation in the low voltage grid, energy management in this grid level becomes more and more important. In the research project DINAR, an approach therefor was developed and implemented. This approach combines automatic management of loads and decentralized generators by decentral decision, customer information and interaction, meter reading and low voltage grid measurement. This paper covers the developed concept and results from the field test in project DINAR as well as currently ongoing research activity on possible applications. (orig.)

  9. A Web Service Tool (SOAR) for the Dynamic Generation of L1 Grids of Coincident AIRS, AMSU and MODIS Satellite Sounding Radiance Data for Climate Studies

    Science.gov (United States)

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

    2007-05-01

    Three decades of Earth remote sensing from NASA, NOAA and DOD operational and research satellites carrying successive generations of improved atmospheric sounder instruments have resulted in petabytes of radiance data with varying spatial and spectral resolutions being stored at different data archives in various data formats by the respective agencies. This evolution of sounders and the diversities of these archived data sets have led to data processing obstacles limiting the science community from readily accessing and analyzing such long-term climate data records. We address this problem by the development of a web based Service Oriented Atmospheric Radiance (SOAR) system built on the SOA paradigm that makes it practical for the science community to dynamically access, manipulate and generate long term records of L1 pre-gridded sounding radiances of coincident multi-sensor data for regions specified according to user chosen criteria. SOAR employs a modification of the standard Client Server interactions that allows users to represent themselves directly to the Process Server through their own web browsers. The browser uses AJAX to request Javascript libraries and DHTML interfaces that define the possible client interactions and communicates the SOAP messages to the Process server allowing for dynamic web dialogs with the user to take place on the fly. The Process Server is also connected to an underlying high performance compute cluster and storage system which provides much of the data processing capabilities required to service the client requests. The compute cluster employs optical communications to NOAA and NASA for accessing the data and under the governance of the Process Server invokes algorithms for on-demand spatial, temporal, and spectral gridding. Scientists can choose from a variety of statistical averaging techniques for compositing satellite observed sounder radiances from the AIRS, AMSU or MODIS instruments to form spatial-temporal grids for

  10. A reduced switch count UPF power conditioner for grid connected variable speed wind energy conversion system employing PM generators: a simulation study

    Energy Technology Data Exchange (ETDEWEB)

    Raju, A.B.; Fernandes, B.G.; Chatterjee, K. [Indian Institute of Technology, Mumbai (India). Dept. of Electrical Engineering

    2004-07-01

    In this paper, modelling and simulation of a grid connected variable speed wind energy conversion system (VSWECS) with reduced switch count power converter is presented. The system consists of a permanent magnet synchronous generator (PMSG), two-pulse width modulated B-4 power converters and a maximum power point tracker (MPPT). Mathematical models of each element of the system are developed separately and are then integrated to simulate the whole system for various wind velocities. The complete system is simulated using MATLAB/SIMULINK and simulation results are presented. (author)

  11. 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.

  12. Feasibility study for power generation using off- grid energy system from micro hydro-PV-diesel generator-battery for rural area of Ethiopia: The case of Melkey Hera village, Western Ethiopia

    Directory of Open Access Journals (Sweden)

    Tilahun Nigussie

    2017-07-01

    Full Text Available Electricity supply in Ethiopia is extremely antiquated. Most of the remote rural areas of Ethiopia are not yet electrified. Electrifying these remote areas by extending grid system is difficult and costly. Melkey Hera village is one of a rural community situated in western Ethiopia. In this village, extension of the grid is not yet practical. As the current international trend in rural electrification is to utilize renewable energy resources; solar, wind, biomass, and micro hydro power systems can be seen as alternatives. Therefore, the target of this paper is to investigate the viability of a micro hydro, Photo Voltaic (PV and Diesel Generator-battery hybrid power system options to come up with the best techno-economic and optimum configuration for supplying electricity to this village. The study was performed by an assessment of the predicted village energy demand, the available renewable energy resources, and then using the software called HOMER. The best hybrid system type was described and the optimization of the system configuration was also done. Furthermore, through the simulation of different configuration of the supply system, the optimal mini-grid hybrid system design was established to combine hydro, solar PV, battery energy storage and diesel generator. This system demonstrated to be more reliable in operation, and the most cost-effective for the required level of service. The role of energy storage in system operation also demonstrated to offer additional operational advantages in-terms of reliability and cost savings. Overall, the design results show that the majority of energy obtained from hydropower, which accounts 79%, the PV module covers 20%, and diesel generator is only 1% of the total load consumption. The obtained hybrid system is cost competitive with $\\$$0.133/kWh, which is somewhat good to satisfy the community needs. However, this is more than current energy price in Ethiopia which $\\$$0.06/kWh. If due-merit given

  13. Homogeneity and EPR metrics for assessment of regular grids used in CW EPR powder simulations

    Science.gov (United States)

    Crăciun, Cora

    2014-08-01

    CW EPR powder spectra may be approximated numerically using a spherical grid and a Voronoi tessellation-based cubature. For a given spin system, the quality of simulated EPR spectra depends on the grid type, size, and orientation in the molecular frame. In previous work, the grids used in CW EPR powder simulations have been compared mainly from geometric perspective. However, some grids with similar homogeneity degree generate different quality simulated spectra. This paper evaluates the grids from EPR perspective, by defining two metrics depending on the spin system characteristics and the grid Voronoi tessellation. The first metric determines if the grid points are EPR-centred in their Voronoi cells, based on the resonance magnetic field variations inside these cells. The second metric verifies if the adjacent Voronoi cells of the tessellation are EPR-overlapping, by computing the common range of their resonance magnetic field intervals. Beside a series of well known regular grids, the paper investigates a modified ZCW grid and a Fibonacci spherical code, which are new in the context of EPR simulations. For the investigated grids, the EPR metrics bring more information than the homogeneity quantities and are better related to the grids’ EPR behaviour, for different spin system symmetries. The metrics’ efficiency and limits are finally verified for grids generated from the initial ones, by using the original or magnetic field-constraint variants of the Spherical Centroidal Voronoi Tessellation method.

  14. Study on Power Loss Reduction Considering Load Variation with Large Penetration of Distributed Generation in Smart Grid

    Science.gov (United States)

    Liu, Chang; Lv, Xiangyu; Guo, Li; Cai, Lixia; Jie, Jinxing; Su, Kuo

    2017-05-01

    With the increasing of penetration of distributed in the smart grid, the problems that the power loss increasing and short circuit capacity beyond the rated capicity of circuit breaker will become more serious. In this paper, a methodology (Modified BPSO) is presented for network reconfiguration which is based on hybrid approach of Tabu Search and BPSO algorithms to prevent the local convergence and to decrease the calculation time using double fitnesses to consider the constraints. Moreover, an average load simulated method (ALS method) load variation considered is proposed that the average load value is used to instead of the actual load to calculation. Finally, from a case study, the results of simulation certify the approaches will decrease drastically the losses and improve the voltage profiles obviously, at the same time, the short circuit capacity is also decreased into less the shut-off capacity of circuit breaker. The power losses won’t be increased too much even if the short circuit capacity constraint is considered; voltage profiles are better with the constraint of short circuit capacity considering. The ALS method is simple and calculated time is speed.

  15. An Algorithmic Game Approach for Demand Side Management in Smart Grid with Distributed Renewable Power Generation and Storage

    Directory of Open Access Journals (Sweden)

    Ren-Shiou Liu

    2016-08-01

    Full Text Available In this paper, the problem of minimizing electricity cost and the peak system load in smart grids with distributed renewable energy resources is studied. Unlike prior research works that either assume all of the jobs are interruptible or power-shiftable, this paper focuses on more challenging scenarios in which jobs are non-interruptible and non-power-shiftable. In addition, as more and more newly-built homes have rooftop solar arrays, it is assumed that all users are equipped with a solar-plus-battery system in this paper. Thus, power can be drawn from the battery as needed to reduce the cost of electricity or to lower the overall system load. With a quadratic load-dependent cost function, this paper first shows that the electricity cost minimization problem in such a setting is NP-hard and presents a distributed demand-side management algorithm, called DDSM, to solve this. Experimental results show that the proposed DDSM algorithm is effective, scalable and converges to a Nash equilibrium in finite rounds.

  16. A novel multi-agent decentralized win or learn fast policy hill-climbing with eligibility trace algorithm for smart generation control of interconnected complex power grids

    International Nuclear Information System (INIS)

    Xi, Lei; Yu, Tao; Yang, Bo; Zhang, Xiaoshun

    2015-01-01

    Highlights: • Proposing a decentralized smart generation control scheme for the automatic generation control coordination. • A novel multi-agent learning algorithm is developed to resolve stochastic control problems in power systems. • A variable learning rate are introduced base on the framework of stochastic games. • A simulation platform is developed to test the performance of different algorithms. - Abstract: This paper proposes a multi-agent smart generation control scheme for the automatic generation control coordination in interconnected complex power systems. A novel multi-agent decentralized win or learn fast policy hill-climbing with eligibility trace algorithm is developed, which can effectively identify the optimal average policies via a variable learning rate under various operation conditions. Based on control performance standards, the proposed approach is implemented in a flexible multi-agent stochastic dynamic game-based smart generation control simulation platform. Based on the mixed strategy and average policy, it is highly adaptive in stochastic non-Markov environments and large time-delay systems, which can fulfill automatic generation control coordination in interconnected complex power systems in the presence of increasing penetration of decentralized renewable energy. Two case studies on both a two-area load–frequency control power system and the China Southern Power Grid model have been done. Simulation results verify that multi-agent smart generation control scheme based on the proposed approach can obtain optimal average policies thus improve the closed-loop system performances, and can achieve a fast convergence rate with significant robustness compared with other methods

  17. The role of grid-connected, building-integrated photovoltaic generation in commercial building energy and power loads in a warm and sunny climate

    International Nuclear Information System (INIS)

    Braun, P.; Ruether, R.

    2010-01-01

    For large commercial buildings, power load delivery limits are contracted with the local electricity distribution utility, and are usually fixed at one or more levels over the year, according to the seasonal building loads, and depending on the specific country regulations. Especially in warm and sunny climates, solar electricity generation using building-integrated photovoltaics (BIPV) can assist in reducing commercial building loads, offering peak-shaving (power) benefits on top of the on-site generation of electricity (energy). This on-site power delivery capability gives these consumers the possibility of renegotiating demand contracts with their distribution utility. Commercial buildings that operate during daytime quite often have an energy consumption profile that is well matched by solar radiation availability, and depending on the building's available surface areas, BIPV can generate considerable portions of the energy requirements. In this work we present the role of grid-connected BIPV in reducing the load demands of a large and urban commercial building located in a warm climate in Brazil. The building and adjacent car parking lots can accommodate a 1 MWp BIPV generator, which closely matches the building's typical maximum power demands. Based on real solar radiation data and simultaneous building electricity demands for the year 2007, simulation of the annual solar generation profile of this on-site generator showed that the 1 MWp BIPV system could account for around 30% of the total building's energy consumption. In addition to the energy benefit, maximum power demands were reduced due to a good match between midday air-conditioning cooling loads and solar radiation availability on both a daily and seasonal basis. Furthermore, we have simulated the effect of this considerably large urban-sited generator on the local distribution network load, and have shown that the 1 MWp BIPV installation can also offer considerable benefits to the local utility in

  18. Multi-Megawatt-Scale Power-Hardware-in-the-Loop Interface for Testing Ancillary Grid Services by Converter-Coupled Generation

    Energy Technology Data Exchange (ETDEWEB)

    Koralewicz, Przemyslaw J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Gevorgian, Vahan [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Wallen, Robert B [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-08-21

    Power-hardware-in-the-loop (PHIL) is a simulation tool that can support electrical systems engineers in the development and experimental validation of novel, advanced control schemes that ensure the robustness and resiliency of electrical grids that have high penetrations of low-inertia variable renewable resources. With PHIL, the impact of the device under test on a generation or distribution system can be analyzed using a real-time simulator (RTS). PHIL allows for the interconnection of the RTS with a 7 megavolt ampere (MVA) power amplifier to test multi-megawatt renewable assets available at the National Wind Technology Center (NWTC). This paper addresses issues related to the development of a PHIL interface that allows testing hardware devices at actual scale. In particular, the novel PHIL interface algorithm and high-speed digital interface, which minimize the critical loop delay, are discussed.

  19. Multi-Megawatt-Scale Power-Hardware-in-the-Loop Interface for Testing Ancillary Grid Services by Converter-Coupled Generation: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Koralewicz, Przemyslaw J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Gevorgian, Vahan [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Wallen, Robert B [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-07-26

    Power-hardware-in-the-loop (PHIL) is a simulation tool that can support electrical systems engineers in the development and experimental validation of novel, advanced control schemes that ensure the robustness and resiliency of electrical grids that have high penetrations of low-inertia variable renewable resources. With PHIL, the impact of the device under test on a generation or distribution system can be analyzed using a real-time simulator (RTS). PHIL allows for the interconnection of the RTS with a 7 megavolt ampere (MVA) power amplifier to test multi-megawatt renewable assets available at the National Wind Technology Center (NWTC). This paper addresses issues related to the development of a PHIL interface that allows testing hardware devices at actual scale. In particular, the novel PHIL interface algorithm and high-speed digital interface, which minimize the critical loop delay, are discussed.

  20. Contribution to the control of doubly-fed induction generators in wind power plants with particular consideration of asymmetrical grid conditions

    Energy Technology Data Exchange (ETDEWEB)

    Richter, Marlies

    2012-06-21

    In the study presented here, four different control strategies for the control of the inverter currents of a doubly-fed induction generator (DFIG) system are analysed and evaluated by means of simulation using Matlab/Simulink registered. Special attention is paid to the behaviour of the generator during asymmetrical grid voltage dips. Different control schemes are employed to reduce torque and DC-link voltage oscillations and the resulting additional loads on the system during such dips. The field-oriented control (FOC) scheme is the one usually deployed for the control of DFIGs in wind power plants and is used as the reference system within this study. The inverter currents (of the rotor-side inverter and the grid-side inverter) are regulated by proportional-integral controllers (PI) in a rotating coordinate system in which they are represented by dq-components. These components are direct quantities. A positive-negative-sequence current control (PNC) strategy is used to control the positive-sequence currents and the negative-sequence currents separately in two contra-rotating coordinate systems using PI-controllers. In contrast to the first two control strategies, frequency-selective current controllers (FSC) serve to regulate the currents in a static coordinate system. In this case the currents are represented by {alpha}{beta}-components which are alternating quantities. Combining the FSC and PNC strategies will produce frequencyselective positive-negative-sequence current controllers (FSC(PN)). These control the currents in a static coordinate system. The currents are represented by alternating {alpha}{beta}-components as in frequency-selective control but separate reference values for the negative-sequence currents are provided as in positive-negative-sequence control. Theoretical reasoning suggests and simulations prove that the three proposed alternative control strategies can improve the behaviour of DFIG-systems during slight asymmetries in the grid

  1. Design of reactive power regulator of synchronous generators by considering grid impedance angle for characteristic index objectives

    DEFF Research Database (Denmark)

    Raboni, Pietro; Chaudhary, Sanjay K.; Chen, Zhe

    2016-01-01

    Effects of low reactance to resistance ratio in distribution networks are widely studied but little work dealing with the tuning of voltage and reactive power regulators of small synchronous generators has been reported. This study endeavours the design of a proportional integral controller...... functions are formulated on the basis of the integral of an error. This difference makes them suitable for the cases where the entire step-response data series are unavailable. The performances of differently tuned regulators are compared considering a test system including a 100 kW Diesel Generator Set...

  2. Lead grids

    CERN Multimedia

    1974-01-01

    One of the 150 lead grids used in the multiwire proportional chamber g-ray detector. The 0.75 mm diameter holes are spaced 1 mm centre to centre. The grids were made by chemical cutting techniques in the Godet Workshop of the SB Physics.

  3. Acceleration grid

    International Nuclear Information System (INIS)

    Hemmerich, J.; Kupschus, P.; Fraenkle, H.

    1983-01-01

    The acceleration grid is used in nuclear fusion technique as an ion beam grid. It consists of perforated plates at different potentials situated behind one another in the axial movement direction of their through holes. In order to prevent interference in the perforated hole area due to thermal expansion, the perforated plates are fixed with elastic springiness (plate fields) at their edges. (DG) [de

  4. Grid Computing

    Indian Academy of Sciences (India)

    IAS Admin

    ate, quote the cost for using the resources. Give time estimate for completing the job. (This may be one of the QoS parameters). Schedule user's job in .... availability of Globus software tools motivated large enterprises to mobilize their resources to create an enterprise grid. An enterprise grid is designed to interconnect all ...

  5. On-Grid Solar PV versus Diesel Electricity Generation in Sub-Saharan Africa: Economics and GHG Emissions

    Directory of Open Access Journals (Sweden)

    Saule Baurzhan

    2017-03-01

    Full Text Available Many power utilities in sub-Saharan Africa (SSA have inadequate generation capacity, unreliable services, and high costs. They also face capital constraints that restrict them from making the investments necessary for capacity expansion. Capacity shortages have compelled power utilities to use leased emergency power-generating units, mainly oil-fired diesel generators, as a short-term solution. An economic analysis is carried out to compare the economic net present value (ENPV of fuel savings, as well as the greenhouse gas (GHG savings, from investing capital in a solar PV power-generation plant with those from investing the same amount of funds into a diesel power plant. The results show that ENPV is negative for the solar PV plant, whereas it has a large positive value for the diesel plant. In addition, the diesel plant would be almost three times as effective in reducing GHG emissions as the same value of investment in the solar PV plant. Even with solar investment costs falling, it will take 12 to 24 years of continuous decline before solar PV becomes cost-effective for SSA. The capital cost of solar PV would need to drop to US$1058.4 per kW to yield the same level of ENPV as the diesel plant.

  6. 40 CFR 761.308 - Sample selection by random number generation on any two-dimensional square grid.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Sample selection by random number... § 761.79(b)(3) § 761.308 Sample selection by random number generation on any two-dimensional square... area created in accordance with paragraph (a) of this section, select two random numbers: one each for...

  7. Maintaining stability of standalone Micro-Grid by employing electrical and mechanical fault ride through techniques upon fixed speed wind generation systems

    International Nuclear Information System (INIS)

    Kamel, Rashad M.

    2013-01-01

    Highlights: • This paper presented two fault ride through techniques for fixed speed wind systems. • The first technique is implemented by inserting a series resistance with the terminals of wind generator. • Second technique is performed by adapting the gear ratio to spill some mechanical power. - Abstract: This study presents two different Fault Ride Through (FRT) techniques to keep and restore stability of Fixed Speed Wind Generation system (FSWGs) installed in standalone Micro-Grid (MG). The first technique is an electrical FRT and is implemented by inserting a series resistance with the terminals of FSWGs during fault to maintain reasonable value of terminal voltage and consequently help stability restoration. The second controller is a mechanical FRT controller and is performed by change the gear ratio of wind generation systems to spill part of extracted mechanical power and consequently improving stability issue. Obtained results proved that each controller able to maintain the stability of FSWGs under the most severe disturbance conditions (400 ms three phase fault at FSWGs terminals). The first controller is faster than the second controller in restoring FSWGs stability. Superior results and performances are obtained when the two FRT techniques are employed simultaneously. Without employing any one of the two FRT techniques, FSWGs is not able to maintain or restore its stability after fault clearing. Consequently, MG will lose one of its micro-sources and cannot keep its stability during the standalone mode, unless load shedding strategy is activated. The two proposed controllers are simple, effective, and economical attractive

  8. Coordinated Control of Superconducting Fault Current Limiter and Superconducting Magnetic Energy Storage for Transient Performance Enhancement of Grid-Connected Photovoltaic Generation System

    Directory of Open Access Journals (Sweden)

    Lei Chen

    2017-01-01

    Full Text Available In regard to the rapid development of renewable energy sources, more and more photovoltaic (PV generation systems have been connected to main power networks, and it is critical to enhance their transient performance under short-circuit faults conditions. This paper proposes and studies the coordinated control of a flux-coupling-type superconducting fault current limiter (SFCL and a superconducting magnetic energy storage (SMES, to improve the fault ride through (FRT capability and smooth the power fluctuation of a grid-connected PV generation system. Theoretical analyses of the device structure, operating principle and control strategy are conducted, and a detailed simulation model of 100 kW class PV generation system is built in MATLAB/SIMULINK. During the simulations of the symmetrical and asymmetrical faults, the maximum power point tracking (MPPT control is disabled, and four different cases including without auxiliary, with SFCL, with SMES, and with SFCL-SMES, are compared. From the demonstrated results, the combination of without MPPT and with SFCL-SMES can more efficiently improve the point of common coupling (PCC voltage sag, inhibit the DC-link overvoltage and alleviate the power fluctuation. Finally, a preliminary parameter optimization method is suggested for the SFCL and the SMES, and it is helpful to promote their future application in the real PV projects.

  9. Technology Roadmaps: Smart Grids

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    The development of Technology Roadmaps: Smart Grids -- which the IEA defines as an electricity network that uses digital and other advanced technologies to monitor and manage the transport of electricity from all generation sources to meet the varying electricity demands of end users -- is essential if the global community is to achieve shared goals for energy security, economic development and climate change mitigation. Unfortunately, existing misunderstandings of exactly what smart grids are and the physical and institutional complexity of electricity systems make it difficult to implement smart grids on the scale that is needed. This roadmap sets out specific steps needed over the coming years to achieve milestones that will allow smart grids to deliver a clean energy future.

  10. Application of Fractal Grids in Industrial Low-Swirl combustion

    NARCIS (Netherlands)

    ten Thij, G.D.; Verbeek, Antonie Alex; van der Meer, Theodorus H.

    2016-01-01

    Fractal-grid-generated turbulence is a successful technique to significantly increase the reaction rate in the center of a low-swirl flame. Previous results (Verbeek et al. Combust. Flame 162(1), 129–143, 2015) are promising, but the experiments are only performed using natural gas at a single

  11. caGrid 1.0: A Grid Enterprise Architecture for Cancer Research

    Science.gov (United States)

    Oster, Scott; Langella, Stephen; Hastings, Shannon; Ervin, David; Madduri, Ravi; Kurc, Tahsin; Siebenlist, Frank; Covitz, Peter; Shanbhag, Krishnakant; Foster, Ian; Saltz, Joel

    2007-01-01

    caGrid is the core Grid architecture of the NCI-sponsored cancer Biomedical Informatics Grid (caBIGTM) program. The current release, caGrid version 1.0, is developed as the production Grid software infrastructure of caBIGTM. Based on feedback from adopters of the previous version (caGrid 0.5), it has been significantly enhanced with new features and improvements to existing components. This paper presents an overview of caGrid 1.0, its main components, and enhancements over caGrid 0.5. PMID:18693901

  12. caGrid 1.0: a Grid enterprise architecture for cancer research.

    Science.gov (United States)

    Oster, Scott; Langella, Stephen; Hastings, Shannon; Ervin, David; Madduri, Ravi; Kurc, Tahsin; Siebenlist, Frank; Covitz, Peter; Shanbhag, Krishnakant; Foster, Ian; Saltz, Joel

    2007-10-11

    caGrid is the core Grid architecture of the NCI-sponsored cancer Biomedical Informatics Grid (caBIG) program. The current release, caGrid version 1.0, is developed as the production Grid software infrastructure of caBIG. Based on feedback from adopters of the previous version (caGrid 0.5), it has been significantly enhanced with new features and improvements to existing components. This paper presents an overview of caGrid 1.0, its main components, and enhancements over caGrid 0.5.

  13. Electric Power Grids Distribution Generation System for Optimal Location and Sizing—A Case Study Investigation by Various Optimization Algorithms

    Directory of Open Access Journals (Sweden)

    Ahmed Ali

    2017-07-01

    Full Text Available In this paper, the approach focused on the variables involved in assessing the quality of a distributed generation system are reviewed in detail, for its investigation and research contribution. The aim to minimize the electric power losses (unused power consumption and optimize the voltage profile for the power system under investigation. To provide this assessment, several experiments have been made to the IEEE 34-bus test case and various actual test cases with the respect of multiple Distribution Generation DG units. The possibility and effectiveness of the proposed algorithm for optimal placement and sizing of DG in distribution systems have been verified. Finally, four algorithms were trailed: simulated annealing (SA, hybrid genetic algorithm (HGA, genetic algorithm (GA, and variable neighbourhood search. The HGA algorithm was found to produce the best solution at a cost of a longer processing time.

  14. HOMER Based Feasibility Study of Off-Grid Biogas Power Generation Model Using Poultry Litter for Rural Bangladesh

    OpenAIRE

    Sharmin Sobhan; Tanvir Ahmad; Md. Jakaria Rahimi; Md. Habib Ullah; Shaila Arif

    2016-01-01

    Lack of access to electricity is one of the major impediments to the economic growth and development for any developing country. As well as limited reserve of conventional fuel and geo-location of Bangladesh arise the demand to find an effective alternative energy source for rural electrification. This document approaches a poultry-home based power generation model for rural Bangladesh and diagnosis its feasibility through HOMER, a micro power modelling and optimization software. The introduc...

  15. Research report for fiscal 1997 on analysis and evaluation of demonstration tests for establishment of residential photovoltaic power generation load leveling technology. Evaluation on durability of device installed with inverter to protect grid connection; 1997 nendo kenkyu hokokusho. Jutaku you taiyoko hatsuden fuka heijunka gijutsu tou kakuritsu jissho shiken ni kansuru kaiseki hyoka - Inbata tsuki keito renkei hogo sochi no taikyusei hyoka

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    Tests and discussions have been performed on the safety and durability of the device installed with inverter to protect grid connection, being an important device in the photovoltaic power generation system. The particularly important requirements demanded in the device were specified as maintenance of electric power quality, coordination with the protection system in the grid side, and assurance of safety of personnel and facilities. The current fiscal year has performed operation corresponding to that in the actual field for 20 years in total, and the evaluation tests on electrical characteristics and electric power quality. This paper summarizes the achievements in four years including the results available up to the previous fiscal year. Although no large change has been identified in the electrical characteristics, variance has been found in the detection time of overvoltage in the grid side. With regard to the electric power quality, the value has exceeded 89 dB as the determining condition for the certification test in the conduction interfering waves of 5 kHz to 10 kHz. In addition, it was confirmed that the conductive high-frequency noise terminal voltage in the grid side after the repetition of operations and shutdowns tends to increase according to the operation lapse time. (NEDO)

  16. Grid Security

    CERN Multimedia

    CERN. Geneva

    2004-01-01

    The aim of Grid computing is to enable the easy and open sharing of resources between large and highly distributed communities of scientists and institutes across many independent administrative domains. Convincing site security officers and computer centre managers to allow this to happen in view of today's ever-increasing Internet security problems is a major challenge. Convincing users and application developers to take security seriously is equally difficult. This paper will describe the main Grid security issues, both in terms of technology and policy, that have been tackled over recent years in LCG and related Grid projects. Achievements to date will be described and opportunities for future improvements will be addressed.

  17. 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

  18. Equivalent Simplification Method of Micro-Grid

    OpenAIRE

    Cai Changchun; Cao Xiangqin

    2013-01-01

    The paper concentrates on the equivalent simplification method for the micro-grid system connection into distributed network. The equivalent simplification method proposed for interaction study between micro-grid and distributed network. Micro-grid network, composite load, gas turbine synchronous generation, wind generation are equivalent simplification and parallel connect into the point of common coupling. A micro-grid system is built and three phase and single phase grounded faults are per...

  19. Grid Computing

    Indian Academy of Sciences (India)

    A computing grid interconnects resources such as high performancecomputers, scientific databases, and computercontrolledscientific instruments of cooperating organizationseach of which is autonomous. It precedes and is quitedifferent from cloud computing, which provides computingresources by vendors to customers ...

  20. 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.

  1. Control of Power Electronic Converters in Distributed Power Generation Systems: Evaluation of Current Control Structures for Voltage Source Converters operating under Weak Grid Conditions

    OpenAIRE

    Midtsund, Tarjei

    2010-01-01

    The performance of different current controller structures for Voltage Source Converters (VSC) under weak grid conditions caused by large grid impedance is investigated. The VSC is synchronized to the grid by a Phase Locked Loop (PLL). Current control techniques and PLL techniques for handling both symmetrical and asymmetrical conditions are presented and discussed. The investigated current control structures are; the conventional Proportional Integral (PI)-controller in the synchronous rotat...

  2. Grid Computing

    Science.gov (United States)

    Foster, Ian

    2001-08-01

    The term "Grid Computing" refers to the use, for computational purposes, of emerging distributed Grid infrastructures: that is, network and middleware services designed to provide on-demand and high-performance access to all important computational resources within an organization or community. Grid computing promises to enable both evolutionary and revolutionary changes in the practice of computational science and engineering based on new application modalities such as high-speed distributed analysis of large datasets, collaborative engineering and visualization, desktop access to computation via "science portals," rapid parameter studies and Monte Carlo simulations that use all available resources within an organization, and online analysis of data from scientific instruments. In this article, I examine the status of Grid computing circa 2000, briefly reviewing some relevant history, outlining major current Grid research and development activities, and pointing out likely directions for future work. I also present a number of case studies, selected to illustrate the potential of Grid computing in various areas of science.

  3. The Volume Grid Manipulator (VGM): A Grid Reusability Tool

    Science.gov (United States)

    Alter, Stephen J.

    1997-01-01

    This document is a manual describing how to use the Volume Grid Manipulation (VGM) software. The code is specifically designed to alter or manipulate existing surface and volume structured grids to improve grid quality through the reduction of grid line skewness, removal of negative volumes, and adaption of surface and volume grids to flow field gradients. The software uses a command language to perform all manipulations thereby offering the capability of executing multiple manipulations on a single grid during an execution of the code. The command language can be input to the VGM code by a UNIX style redirected file, or interactively while the code is executing. The manual consists of 14 sections. The first is an introduction to grid manipulation; where it is most applicable and where the strengths of such software can be utilized. The next two sections describe the memory management and the manipulation command language. The following 8 sections describe simple and complex manipulations that can be used in conjunction with one another to smooth, adapt, and reuse existing grids for various computations. These are accompanied by a tutorial section that describes how to use the commands and manipulations to solve actual grid generation problems. The last two sections are a command reference guide and trouble shooting sections to aid in the use of the code as well as describe problems associated with generated scripts for manipulation control.

  4. Mode of Strong Earthquake Recurrence In Central Ionian Islands (greece). Possible Triggering Due To Coulomb Stress Changes Generated By The Occurrence of Previous Strong Shocks

    Science.gov (United States)

    Papadimitriou, E.

    The spatial-temporal distribution of shallow strong (M>6.3) earthquakes occurring in the area of central Ionian Islands is analyzed. These shocks generated on two adja- cent fault segments with different strike, but both associated with strike-slip faulting, constituting the boundary between continental collision to the north and oceanic sub- duction to the south. Seismic activity is confined in short time intervals alternating by much longer relatively quiescent periods. Each active period consists of a relatively large event or series (two to four) of events occurring closely both in space and time. This alteration was observed to happen four times since 1867, from when complete data exist for the study area. Since the phenomenon is not strictly periodic and during each active period multiple events occurred, it is attempted to interpret the seismic behavior on the basis of possible triggering. It is then investigated how changes in Coulomb Failure Function (DCFF) associated with one or more earthquakes may trig- ger subsequent events. Both the coseismic slip due to the generation of the strong earthquakes and stress build up associated with the two major fault segments were taken into account for the DCFF calculation. Earthquakes can be modeled as static dislocations in elastic half-space, and the stress pattern has been inverted according to the geometry and slip of each of the faults that ruptured in the chain of events. These calculations show that 13 out of 14 earthquakes with M>6.3 were preceded by a static stress change that encouraged failure. The magnitude of the stress increases transferred from one earthquake to another ranged from 0.01 MPa (0.1 bar) to over 0.1 MPa (1 bar). Maps of current DCFF provide additional information to long-term earthquake prediction. Areas of positive DCFF have been identified at two sites in Ke- falonia and Lefkada faults, respectively, where the next strong events are expected to occur.

  5. Investigation of the electromagnetic properties of solar generators in grid-coupled photovoltaic power systems. Final report; Untersuchung der elektromagnetischen Eigenschaften des Solargenerators in netzgekoppelten photovoltaischen Stromversorgungsanlagen. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Erge, T.; Bohnenstengel, J.; Bopp, G.; Dornburg, H.; Reimelt, R.; Roessler, E.; Schaetzle, R.; Wimmer, D.; Wittek, I.

    1997-12-31

    This BMBF-sponsored project, which was carried out from August 1994 to April 1997, has achieved its goal of characterizing the electromagnetic properties of solar generators of grid-coupled photovoltaic power systems. The focus of the study was on systems and components that are typically used in the household sector (range of power output 1-10 kW{sub p}), and which have become widely distributed, especially also among private house-owners and builders, not lastly by the 1000-roofs photovoltaics programme. As far as time permitted within the framework of this project, current trends in inverter technology (string-type inverters and modular inverters) were also taken into account.- The main conclusion from the project is as follows: Photovoltaic plants are principally capable of generating higher-frequency electromagnetic disturbances (both in line-transmitted and radiated form). Moreover, given certain boundary conditions, these disturbances may be emitted to the environment both via the AC side and via the DC side/solar generator. (orig./AKF) [Deutsch] In dem seit August 1994 bis April 1997 laufenden BMBF-Projekt wurde das Ziel einer Charakterisierung der elektromagnetischen Eigenschaften des Solargenerators netzgekoppelter photovoltaischer Stromversorgungsanlagen erreicht. Schwerpunkt der Untersuchungen waren dabei Anlagen und Komponenten, die typischerweise im Hausbereich eingesetzt werden (Leistungsbereich 1-10 kW{sub p}) und die nicht zuletzt durch das 1000 Daecher-Photovoltaikprogramm weite Verbreitung gerade auch bei privaten Hauseigentuemern und Bauherren gefunden haben. Soweit im Rahmen der Projektlaufzeit noch moeglich, wurden auch aktuelle Tendenzen der Wechselrichtertechnik (String- und Modulwechselrichter) beruecksichtigt. Wesentlichstes Ergebnis der Projektarbeiten ist die Aussage, dass photovoltaische Anlagen grundsaetzlich in der Lage sind, hoeherfrequente elektromagnetische Stoerungen (sowohl leitungsgebunden als auch gestrahlt) zu erzeugen, und

  6. Recent trends in grid computing

    International Nuclear Information System (INIS)

    Miura, Kenichi

    2004-01-01

    Grid computing is a technology which allows uniform and transparent access to geographically dispersed computational resources, such as computers, databases, experimental and observational equipment etc. via high-speed, high-bandwidth networking. The commonly used analogy is that of electrical power grid, whereby the household electricity is made available from outlets on the wall, and little thought need to be given to where the electricity is generated and how it is transmitted. The usage of grid also includes distributed parallel computing, high through-put computing, data intensive computing (data grid) and collaborative computing. This paper reviews the historical background, software structure, current status and on-going grid projects, including applications of grid technology to nuclear fusion research. (author)

  7. 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

  8. Spatial mapping of wind parks in Republic of Macedonia from aspect of power generation and connection to power grid

    International Nuclear Information System (INIS)

    Janchevska, Melita

    2012-01-01

    The master thesis “Spatial mapping of wind parks in Republic of Macedonia from aspect of power generation and connection to power grid” presents spatial aspects for setting of wind parks at favourable locations. The thesis presents a comprehensive analysis how to carry out the administrative procedures that are in force in Republic of Macedonia, a range of minimum allowed distances in setting of each of the wind plants within a wind parks, but also requirements for fulfilling the basic human rights in preserving quality of life of the people in rural areas where the wind parks are build. As a result, a compromise in setting of wind parks and a suitable solution of sustainable development should be reached. Therefore, the decision making process should be based on the following key factors: environmental, social and economic development of the area of concern. The production of wind power is strongly influenced by meteorological conditions and has an average factor of utilization of up to 30%. This low factor of utilization cannot be used for planning of the basic energy needs of the country, but it can contribute certainly towards the reduction of the participation of conventional power plants. Republic of Macedonia introduced feed-in tariffs as a subsiding mechanism for building and strong penetration of wind parks. Additional funding mechanisms include carbon financing and green-field credits, through development of projects in the framework of Clean Development Mechanism, which improves the economic feasibility of the project and increases the interest of the investors. The analysis of the relevant spatial aspects of setting wind parks in Republic of Macedonia based on balanced and sustainable spatial development is made with regards to the following thematic areas: exploiting the potential of wind energy, climate issues, geo morphological and geo seismically aspects, rational use of land, protection of agricultural land and forests, spatial allocation of

  9. Application of synchronous grid-connected controller in the wind-solar-storage micro grid

    OpenAIRE

    Li, Hua; Ren, Yongfeng; Li, Le; Luo, Zhenpeng

    2016-01-01

    Recently, there has been an increasing interest in using distributed generators (DG) not only to inject power into the grid, but also to enhance the power quality. In this study, a space voltage pulse width modulation (SVPWM) control method is proposed for a synchronous grid-connected controller in a wind-solar-storage micro grid. This method is based on the appropriate topology of the synchronous controller. The wind-solar-storage micro grid is controlled to reconnect to the grid synchronous...

  10. An Improved Current Control Strategy for a Grid-Connected Inverter under Distorted Grid Conditions

    OpenAIRE

    Ngoc Bao Lai; Kyeong-Hwa Kim

    2016-01-01

    This paper presents an improved current control strategy for a three-phase grid-connected inverter under distorted grid conditions. The main challenge associated with the grid-connected inverter in distributed generation (DG) systems is to maintain the harmonic contents in output current below the specified values even when the grid is subject to uncertain disturbances such as harmonic distortion. To overcome such a challenge, an improved current control scheme is proposed for a grid-connecte...

  11. Increase in the number of distributed power generation installations in electricity distribution grids - Basic technologies for decentralised production; Zunahme der dezentralen Energieerzeugungsanlagen in elektrischen Verteilnetzen: Grundlagen der dezentralen Energieerzeugungsanlagen

    Energy Technology Data Exchange (ETDEWEB)

    Hoeckel, M.; Haldi, R.

    2003-07-01

    This is the fourth part of a ten-part final report for the Swiss Federal Office of Energy (SFOE) on a project that looked into potential problems relating to the Swiss electricity distribution grid with respect to the increasing number of distributed power generation facilities being put into service. The identification of special conditions for the grid's operation and future development that take increasing decentralised power production into account are discussed. The results of the project activities encompass the analysis and evaluation of various problem areas associated with planning and management of the grid during normal operation and periods of malfunction, as well as required modifications to safety systems and grid configurations. This third appendix to the main report describes five types of distributed production facilities - photovoltaics (PV), wind power, hydropower, combined heat and power units and fuel-cell-based power generation. Each of these types of power generation equipment is briefly described and its particular characteristics are discussed. In particular, the effects of PV inverters on the mains is examined, as are the active and reactive power aspects of hydropower installations. Also the state-of-the-art of wind technologies are looked at and the various types of combined heat and power units and fuel cells are described.

  12. Impact of Investments in Generating Units and Transmission and Distribution Power Grids by 2025 on Voltage Stability and Branches Load in ENERGA SA Operational Territory – Main Findings of Research Project

    Directory of Open Access Journals (Sweden)

    Dominik Falkowski

    2013-03-01

    Full Text Available The article summarizes a research project which was conducted in order to ensure what will be the influence of future investments and changes in the Polish Power System on the stability and functionality of the ENERGA SA distribution grid system. Development of the ENERGA SA distribution grid system was also included. Only stable states were tested for various cases of system load and generation in power plants (the Nuclear Power Plant in Żarnowiec was taken into account and also in wind farms. The system was also tested in N-1 and N-2 states. The result of this study is an overall evaluation of the ENERGA SA distribution grid condition, as well as the identification of potential weak points inside this structure.

  13. Grid Computing

    Indian Academy of Sciences (India)

    IAS Admin

    A computing grid interconnects resources such as high per- formance computers, scientific databases, and computer- controlled scientific instruments of cooperating organiza- tions each of which is autonomous. It precedes and is quite different from cloud computing, which provides computing resources by vendors to ...

  14. Index Grids - MDC_USNationalGrid

    Data.gov (United States)

    NSGIC Local Govt | GIS Inventory — The U.S. National Grid is based on universally defined coordinate and grid systems and can, therefore, be easily extended for use world-wide as a universal grid...

  15. HIRENASD NLR grid

    Data.gov (United States)

    National Aeronautics and Space Administration — Structured multiblock grid of HIRENASD wing with medium grid density, about 10 mill grid points, 9.5 mill cells. Starting from coarse AIAA AEPW structured grid,...

  16. A disruptive approach for a green field smart grid installation

    Energy Technology Data Exchange (ETDEWEB)

    Bishnoi, Peeush [Siemens Technology and Services Pvt. Ltd., Bangalore (India); Klein, Wolfram; Kuntschke, Richard; Speh, Rainer; Waszak, Michal-Wolfgang [Siemens AG, Muenchen (Germany)

    2012-07-01

    The current trend towards increasingly decentralized power generation including renewable generation such as photovoltaic or wind power calls for a new concept for future power supply systems. The future power grid has to incorporate numerous distributed and comparatively small-sized generation facilities in addition to the larger centralized power plants currently in operation. Consumers will turn into prosumers that consume as well as produce electrical power. Thus, power will no longer flow exclusively from power plants to consumers such as households and industrial plants, but also between consumers, requiring new solutions, e.g., for protection within the power grid. In this paper, we propose a disruptive approach for a green field smart grid installation solving the issues arising from the increasing use of decentralized power generation. The new power supply system proposed can handle up to 100 % of volatile renewable generation and allows dynamic growth of the power grid with little effort. It is therefore suitable for building up new power supply systems in previously non-electrified regions, e.g., in rural areas in developing countries. At the same time, the system also offers solutions for the issues arising from the advent of the new energy age in developed countries. (orig.)

  17. The grid

    OpenAIRE

    Morrad, Annie; McArthur, Ian

    2018-01-01

    Project Anywhere Project title: The Grid   Artists: Annie Morrad: Artist/Senior Lecturer, University of Lincoln, School of Film and Media, Lincoln, UK   Dr Ian McArthur: Hybrid Practitioner/Senior Lecturer, UNSW Art & Design, UNSW Australia, Sydney, Australia   Annie Morrad is a London-based artist and musician and senior lecturer at the University of Lincoln, UK. Dr Ian McArthur is a Sydney-based hybrid practitione...

  18. Grid reliability

    CERN Document Server

    Saiz, P; Rocha, R; Andreeva, J

    2007-01-01

    We are offering a system to track the efficiency of different components of the GRID. We can study the performance of both the WMS and the data transfers At the moment, we have set different parts of the system for ALICE, ATLAS, CMS and LHCb. None of the components that we have developed are VO specific, therefore it would be very easy to deploy them for any other VO. Our main goal is basically to improve the reliability of the GRID. The main idea is to discover as soon as possible the different problems that have happened, and inform the responsible. Since we study the jobs and transfers issued by real users, we see the same problems that users see. As a matter of fact, we see even more problems than the end user does, since we are also interested in following up the errors that GRID components can overcome by themselves (like for instance, in case of a job failure, resubmitting the job to a different site). This kind of information is very useful to site and VO administrators. They can find out the efficien...

  19. Economic evaluation of photovoltaic electric power generation connected to the grid in deregulated electric power markets; Avaliacao economica da geracao de energia eletrica fotovoltaica conectada a rede em mercados eletricos desregulados

    Energy Technology Data Exchange (ETDEWEB)

    Zumaran, David Richard Orosco

    2000-12-01

    This work presents an analysis of economic, tariff and regulating issues related to the introduction of Grid Connected Photovoltaic Systems in a deregulated electric market context; a case study for the peruvian electric market is realized. Based on the pricing system of the electric market, it is developed an economic assessment model that can be used by institutions interested in promoting this technology for generating electricity. (author)

  20. Life-Cycle Cost Modeling to Determine Whether Vehicle-to-Grid (V2G) Integration and Ancillary Service Revenue Can Generate a Viable Case for Plug-In Electric Drive Vehicles

    Science.gov (United States)

    2013-09-01

    Bidirectional Charger My analysis compares the LCCs of two base case internal combustion engine (ICE) vehicles with those of a non–plug-in hybrid electric ...MODELING TO DETERMINE WHETHER VEHICLE -TO-GRID (V2G) INTEGRATION AND ANCILLARY SERVICE REVENUE CAN GENERATE A VIABLE CASE FOR PLUG-IN ELECTRIC DRIVE...VIABLE CASE FOR PLUG-IN ELECTRIC DRIVE VEHICLES 5. FUNDING NUMBERS 6. AUTHOR(S) Joseph Monahan 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES

  1. 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

  2. Safe Grid

    Science.gov (United States)

    Chow, Edward T.; Stewart, Helen; Korsmeyer, David (Technical Monitor)

    2003-01-01

    The biggest users of GRID technologies came from the science and technology communities. These consist of government, industry and academia (national and international). The NASA GRID is moving into a higher technology readiness level (TRL) today; and as a joint effort among these leaders within government, academia, and industry, the NASA GRID plans to extend availability to enable scientists and engineers across these geographical boundaries collaborate to solve important problems facing the world in the 21 st century. In order to enable NASA programs and missions to use IPG resources for program and mission design, the IPG capabilities needs to be accessible from inside the NASA center networks. However, because different NASA centers maintain different security domains, the GRID penetration across different firewalls is a concern for center security people. This is the reason why some IPG resources are been separated from the NASA center network. Also, because of the center network security and ITAR concerns, the NASA IPG resource owner may not have full control over who can access remotely from outside the NASA center. In order to obtain organizational approval for secured remote access, the IPG infrastructure needs to be adapted to work with the NASA business process. Improvements need to be made before the IPG can be used for NASA program and mission development. The Secured Advanced Federated Environment (SAFE) technology is designed to provide federated security across NASA center and NASA partner's security domains. Instead of one giant center firewall which can be difficult to modify for different GRID applications, the SAFE "micro security domain" provide large number of professionally managed "micro firewalls" that can allow NASA centers to accept remote IPG access without the worry of damaging other center resources. The SAFE policy-driven capability-based federated security mechanism can enable joint organizational and resource owner approved remote

  3. Grid simulator for power quality assessment of micro-grids

    DEFF Research Database (Denmark)

    Carrasco, Joaquin Eloy Garcia; Vasquez, Juan Carlos; Guerrero, Josep M.

    2013-01-01

    voltages, low-order harmonics and flicker. The aim of this equipment is to test the performance of a given system under such distorted voltages. A prototype of the simulator, consisting of two inverters connected back-to-back to a 380 V three-phase grid and feeding a micro-grid composed of two......-inverter interfaced distributed generators and a critical load was built and tested. A set of experimental results for linear purely resistive loads, non-linear loads and current-controlled inverters is presented to prove the capabilities of the simulator. Finally, a case study is presented by testing a micro-grid.......In this study, a grid simulator based on a back-to-back inverter topology with resonant controllers is presented. The simulator is able to generate three-phase voltages for a range of amplitudes and frequencies with different types of perturbations, such as voltage sags, steady-state unbalanced...

  4. Grid Integration Studies: Data Requirements, Greening the Grid

    Energy Technology Data Exchange (ETDEWEB)

    Katz, Jessica

    2015-06-01

    A grid integration study is an analytical framework used to evaluate a power system with high penetration levels of variable renewable energy (VRE). A grid integration study simulates the operation of the power system under different VRE scenarios, identifying reliability constraints and evaluating the cost of actions to alleviate those constraints. These VRE scenarios establish where, how much, and over what timeframe to build generation and transmission capacity, ideally capturing the spatial diversity benefits of wind and solar resources. The results help build confidence among policymakers, system operators, and investors to move forward with plans to increase the amount of VRE on the grid.

  5. Performance Analysis of a Four-Switch Three-Phase Grid-Side Converter with Modulation Simplification in a Doubly-Fed Induction Generator-Based Wind Turbine (DFIG-WT with Different External Disturbances

    Directory of Open Access Journals (Sweden)

    Kai Ni

    2017-05-01

    Full Text Available This paper investigates the performance of a fault-tolerant four-switch three-phase (FSTP grid-side converter (GSC in a doubly-fed induction generator-based wind turbine (DFIG-WT. The space vector pulse width modulation (SVPWM technique is simplified and unified duty ratios are used for controlling the FSTP GSC. Steady DC-bus voltage, sinusoidal three-phase grid currents and unity power factor are obtained. In addition, the balance of capacitor voltages is accomplished based on the analysis of current flows at the midpoint of DC bus in different operational modes. Besides, external disturbances such as fluctuating wind speed and grid voltage sag are considered to test its fault-tolerant ability. Furthermore, the effects of fluctuating wind speed on the performance of DFIG-WT system are explained according to an approximate expression of the turbine torque. The performance of the proposed FSTP GSC is simulated in Matlab/Simulink 2016a based on a detailed 1.5 MW DFIG-WT Simulink model. Experiments are carried out on a 2 kW platform by using a discrete signal processor (DSP TMS320F28335 controller to validate the reliability of DFIG-WT for the cases with step change of the stator active power and grid voltage sag, respectively.

  6. Grid synchronization structure for wind converters under grid fault conditions

    OpenAIRE

    Garcia, Jose Ignacio; Candela García, José Ignacio; Luna Alloza, Álvaro; Catalan, Pedro

    2016-01-01

    This paper presents a grid synchronization structure for three-phase electric power systems based on the use of a filtered quadrature signal generator (FQSG) and a phase-locked loop (PLL) structure, named Adaptive Vector Grid Synchronization system (AVGS). This system estimates the magnitude, frequency and phase of a signal, specially three-phase voltages and currents, and allows fast and accurate detection of the symmetrical components meet with the transient operating requirements imposed b...

  7. Autonomous Energy Grids: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Kroposki, Benjamin D [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Dall-Anese, Emiliano [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Bernstein, Andrey [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Zhang, Yingchen [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Hodge, Brian S [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-10-04

    With much higher levels of distributed energy resources - variable generation, energy storage, and controllable loads just to mention a few - being deployed into power systems, the data deluge from pervasive metering of energy grids, and the shaping of multi-level ancillary-service markets, current frameworks to monitoring, controlling, and optimizing large-scale energy systems are becoming increasingly inadequate. This position paper outlines the concept of 'Autonomous Energy Grids' (AEGs) - systems that are supported by a scalable, reconfigurable, and self-organizing information and control infrastructure, can be extremely secure and resilient (self-healing), and self-optimize themselves in real-time for economic and reliable performance while systematically integrating energy in all forms. AEGs rely on scalable, self-configuring cellular building blocks that ensure that each 'cell' can self-optimize when isolated from a larger grid as well as partaking in the optimal operation of a larger grid when interconnected. To realize this vision, this paper describes the concepts and key research directions in the broad domains of optimization theory, control theory, big-data analytics, and complex system modeling that will be necessary to realize the AEG vision.

  8. Neutron Science TeraGrid Gateway

    International Nuclear Information System (INIS)

    Lynch, Vickie E.; Chen, Meili; Cobb, John W.; Kohl, James Arthur; Miller, Stephen D.; Speirs, David A.; Vazhkudai, Sudharshan S.

    2010-01-01

    The unique contributions of the Neutron Science TeraGrid Gateway (NSTG) are the connection of national user facility instrument data sources to the integrated cyberinfrastructure of the National Science FoundationTeraGrid and the development of a neutron science gateway that allows neutron scientists to use TeraGrid resources to analyze their data, including comparison of experiment with simulation. The NSTG is working in close collaboration with the Spallation Neutron Source (SNS) at Oak Ridge as their principal facility partner. The SNS is a next-generation neutron source. It has completed construction at a cost of $1.4 billion and is ramping up operations. The SNS will provide an order of magnitude greater flux than any previous facility in the world and will be available to all of the nation's scientists, independent of funding source, on a peer-reviewed merit basis. With this new capability, the neutron science community is facing orders of magnitude larger data sets and is at a critical point for data analysis and simulation. There is a recognized need for new ways to manage and analyze data to optimize both beam time and scientific output. The TeraGrid is providing new capabilities in the gateway for simulations using McStas and a fitting service on distributed TeraGrid resources to improved turnaround. NSTG staff are also exploring replicating experimental data in archival storage. As part of the SNS partnership, the NSTG provides access to gateway support, cyberinfrastructure outreach, community development, and user support for the neutron science community. This community includes not only SNS staff and users but extends to all the major worldwide neutron scattering centers.

  9. Making the Grid "Smart" Through "Smart" Microgrids: Real-Time Power Management of Microgrids with Multiple Distributed Generation Sources Using Intelligent Control

    Energy Technology Data Exchange (ETDEWEB)

    Nehrir, M. Hashem [Montana State Univ., Bozeman, MT (United States)

    2016-10-20

    investigated the following: • Intelligent load control - demand response (DR) - for frequency stabilization in islanded MGs (partially supported by PNNL). • The impact of high penetration of solar photovoltaic (PV)-generated power at the distribution level (partially supported by PNNL). • The application of AI approaches to renewable (wind, PV) power forecasting (proposed by the reviewers of our proposal). • Application of AI approaches and DR for real-time MG power management (partially supported by NEC Labs-America) • Application of DR in dealing with the variability of wind power • Real-time MG power management using DR and storage (partially supported by NEC Labs-America) • Application of DR in enhancing the performance of load-frequency controller • MAS-based whole-sale and retail power market design for smart grid A

  10. Future electrical distribution grids: Smart Grids

    International Nuclear Information System (INIS)

    Hadjsaid, N.; Sabonnadiere, J.C.; Angelier, J.P.

    2010-01-01

    The new energy paradigm faced by distribution network represents a real scientific challenge. Thus, national and EU objectives in terms of environment and energy efficiency with resulted regulatory incentives for renewable energies, the deployment of smart meters and the need to respond to changing needs including new uses related to electric and plug-in hybrid vehicles introduce more complexity and favour the evolution towards a smarter grid. The economic interest group in Grenoble IDEA in connection with the power laboratory G2ELab at Grenoble Institute of technology, EDF and Schneider Electric are conducting research on the electrical distribution of the future in presence of distributed generation for ten years.Thus, several innovations emerged in terms of flexibility and intelligence of the distribution network. One can notice the intelligence solutions for voltage control, the tools of network optimization, the self-healing techniques, the innovative strategies for connecting distributed and intermittent generation or load control possibilities for the distributor. All these innovations are firmly in the context of intelligent networks of tomorrow 'Smart Grids'. (authors)

  11. Power Quality of Grid-Connected Wind Turbines with DFIG and Their Interaction with the Grid

    DEFF Research Database (Denmark)

    Sun, Tao

    quality issues of grid-connected wind turbines and the interaction between wind turbines and the grid. The specific goal of the research has been to investigate flicker emission and mitigation of grid-connected wind turbines with doubly fed induction generators (DFIG) during continuous operation......, and voltage recovery of such kind of grid-connected wind turbines after the clearance of a short circuit fault in the grid. As a basis of the research, a model of grid-connected wind turbines with DFIG is developed in the dedicated power system analysis tool PSCAD/EMTDC, which simulates the dynamics...... of the system from the turbine rotor, where the kinetic wind energy is converted to mechanical energy, to the grid connection point where the electric power is fed into the grid. The complete grid-connected wind turbine model includes the wind speed model, the aerodynamic model of the wind turbine...

  12. Almighty grid promises a shortcut to knowledge

    CERN Multimedia

    Cookson, C

    2000-01-01

    PPARC is working with scientists from CERN to build the next generation internet - 'The Grid'. The LHC will generate vast quantities of data that will need to be analysed by scientists working in 150 universities worldwide. To do this successfully a new approach is needed. The aim of the grid is to make the location of information irrelevant (1 p).

  13. Research report for fiscal 1995 on analysis and evaluation of demonstration tests for establishment of residential photovoltaic power generation load leveling technology. Evaluation on durability of device installed with inverter to protect grid connection; 1995 nendo kenkyu hokokusho. Jutaku you taiyoko hatsuden fuka heijunka gijutsu tou kakuritsu jissho shiken ni kansuru kaiseki hyoka - Inbata tsuki keito renkei hogo sochi no taikyusei hyoka

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    Discussions and evaluations have been performed on the safety and durability of the device installed with inverter to protect grid connection being an important device in the photovoltaic power generation system. In discussing the durability test items, electrical property changes were observed on AC overvoltage, AC undervoltage, frequency rise, and frequency fall, as the continuation from the previous fiscal year, in order to evaluate temperature rise in different parts due to lapse of operation time and the effects of thermal stress in each component on the stress of the entire product. Furthermore, verification of single operation detecting function, tests on sudden input power change, sudden grid voltage change, and measurement of conductive high frequency terminal voltage were conducted in addition to the above observations. In discussing the durability test methods, repetition of operation and shutdown during the rated operation was adopted in place of the simulated operation using variation in the insolation having been discussed in the previous year. As a result of the tests, no noticeable changes were recognized from the evaluation result after a lapse of 5,000 hours from the start of the operation, as compared to those after the aging operation. (NEDO)

  14. Research report for fiscal 1996 on analysis and evaluation of demonstration tests for establishment of residential photovoltaic power generation load leveling technology. Evaluation on durability of device installed with inverter to protect grid connection; 1996 nendo kenkyu hokokusho. Jutaku you taiyoko hatsuden fuka heijunka gijutsu tou kakuritsu jissho shiken ni kansuru kaiseki hyoka - Inbata tsuki keito renkei hogo sochi no taikyusei hyoka

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    Discussions and evaluations have been performed on the safety and durability of the device installed with inverter to protect grid connection being an important device in the photovoltaic power generation system. This paper summarizes the achievements in fiscal 1996. The current fiscal year performed data collection and long-term continuous operation according to the durability test program for the device installed with inverter to protect grid connection, as the continuation from the previous fiscal year. In the electrical characteristics, although no large changes have been found in AC overvoltage and AC undervoltage, instability was observed in the detection level. With regard to temperatures in different components, the temperature rise has become nearly the same as in the maximum output continuous operation as a result of the repetition of the operation and shutdown, whereas the influence on the electrical and thermal stresses have increased. Particularly, when temperature rise in the AC side noise filter was given observation, the measurement of conductive high-frequency terminal voltage showed a value higher by several ten dB than in the previous fiscal year. The current fiscal year has gone farther to starting the measurement of noise electric field intensity as the base of electromagnetic interference. (NEDO)

  15. Grids, Clouds, and Virtualization

    Science.gov (United States)

    Cafaro, Massimo; Aloisio, Giovanni

    This chapter introduces and puts in context Grids, Clouds, and Virtualization. Grids promised to deliver computing power on demand. However, despite a decade of active research, no viable commercial grid computing provider has emerged. On the other hand, it is widely believed - especially in the Business World - that HPC will eventually become a commodity. Just as some commercial consumers of electricity have mission requirements that necessitate they generate their own power, some consumers of computational resources will continue to need to provision their own supercomputers. Clouds are a recent business-oriented development with the potential to render this eventually as rare as organizations that generate their own electricity today, even among institutions who currently consider themselves the unassailable elite of the HPC business. Finally, Virtualization is one of the key technologies enabling many different Clouds. We begin with a brief history in order to put them in context, and recall the basic principles and concepts underlying and clearly differentiating them. A thorough overview and survey of existing technologies provides the basis to delve into details as the reader progresses through the book.

  16. Development of a smart DC grid model

    Energy Technology Data Exchange (ETDEWEB)

    Dalimunthe, Amty Ma’rufah Ardhiyah; Mindara, Jajat Yuda; Panatarani, Camellia; Joni, I. Made, E-mail: imadejoni@phys.unpad.ac.id [Lab. of Instrumentation System and Functional Material Processing, Physics Department, Faculty of Mathematics and Natural Sciences, Padjadjaran University, Jl. Raya Bandung-Sumedang KM21, Jatinangor 45363, Jawa Barat (Indonesia)

    2016-03-11

    Smart grid and distributed generation should be the solution of the global climate change and the crisis energy of the main source of electrical power generation which is fossil fuel. In order to meet the rising electrical power demand and increasing service quality demands, as well as reduce pollution, the existing power grid infrastructure should be developed into a smart grid and distributed power generation which provide a great opportunity to address issues related to energy efficiency, energy security, power quality and aging infrastructure systems. The conventional of the existing distributed generation system is an AC grid while for a renewable resources requires a DC grid system. This paper explores the model of smart DC grid by introducing a model of smart DC grid with the stable power generation give a minimal and compressed circuitry that can be implemented very cost-effectively with simple components. The PC based application software for controlling was developed to show the condition of the grid and to control the grid become ‘smart’. The model is then subjected to a severe system perturbation, such as incremental change in loads to test the performance of the system again stability. It is concluded that the system able to detect and controlled the voltage stability which indicating the ability of power system to maintain steady voltage within permissible rangers in normal condition.

  17. Development of a smart DC grid model

    Science.gov (United States)

    Dalimunthe, Amty Ma'rufah Ardhiyah; Mindara, Jajat Yuda; Panatarani, Camellia; Joni, I. Made

    2016-03-01

    Smart grid and distributed generation should be the solution of the global climate change and the crisis energy of the main source of electrical power generation which is fossil fuel. In order to meet the rising electrical power demand and increasing service quality demands, as well as reduce pollution, the existing power grid infrastructure should be developed into a smart grid and distributed power generation which provide a great opportunity to address issues related to energy efficiency, energy security, power quality and aging infrastructure systems. The conventional of the existing distributed generation system is an AC grid while for a renewable resources requires a DC grid system. This paper explores the model of smart DC grid by introducing a model of smart DC grid with the stable power generation give a minimal and compressed circuitry that can be implemented very cost-effectively with simple components. The PC based application software for controlling was developed to show the condition of the grid and to control the grid become `smart'. The model is then subjected to a severe system perturbation, such as incremental change in loads to test the performance of the system again stability. It is concluded that the system able to detect and controlled the voltage stability which indicating the ability of power system to maintain steady voltage within permissible rangers in normal condition.

  18. 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.

  19. 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.

  20. High energy physics and grid computing

    International Nuclear Information System (INIS)

    Yu Chuansong

    2004-01-01

    The status of the new generation computing environment of the high energy physics experiments is introduced briefly in this paper. The development of the high energy physics experiments and the new computing requirements by the experiments are presented. The blueprint of the new generation computing environment of the LHC experiments, the history of the Grid computing, the R and D status of the high energy physics grid computing technology, the network bandwidth needed by the high energy physics grid and its development are described. The grid computing research in Chinese high energy physics community is introduced at last. (authors)

  1. PREVIOUS SECOND TRIMESTER ABORTION

    African Journals Online (AJOL)

    PNLC

    PREVIOUS SECOND TRIMESTER ABORTION: A risk factor for third trimester uterine rupture in three ... for accurate diagnosis of uterine rupture. KEY WORDS: Induced second trimester abortion - Previous uterine surgery - Uterine rupture. ..... scarred uterus during second trimester misoprostol- induced labour for a missed ...

  2. Unlocking the potential of the smart grid

    Science.gov (United States)

    Konopko, Joanna

    2015-12-01

    The smart grid refers to describe a next-generation electrical power system that is typified by the increased use of Information and Communication Technologies (ICT) in the whole delivery electrical energy process. The generation, delivery and consumption energy, all the steps for power transmission and distribution make the smart grid a complex system. The question is if the amount, diversity, and uses of such data put the smart grid in the category of Big Data applications, followed by the natural question of what is the true value of such data. In this paper an initial answer to this question is provided, the current state of data generation of the Polish grid is analyzed, and a future realistic scenario is illustrated. The analysis shows that the amount of data generated in smart grid is comparable to some of Big Data system examples.

  3. Calculation approaches for grid usage fees to influence the load curve in the distribution grid level

    International Nuclear Information System (INIS)

    Illing, Bjoern

    2014-01-01

    Dominated by the energy policy the decentralized German energy market is changing. One mature target of the government is to increase the contribution of renewable generation to the gross electricity consumption. In order to achieve this target disadvantages like an increased need for capacity management occurs. Load reduction and variable grid fees offer the grid operator solutions to realize capacity management by influencing the load profile. The evolution of the current grid fees towards more causality is required to adapt these approaches. Two calculation approaches are developed in this assignment. On the one hand multivariable grid fees keeping the current components demand and energy charge. Additional to the grid costs grid load dependent parameters like the amount of decentralized feed-ins, time and local circumstances as well as grid capacities are considered. On the other hand the grid fee flat-rate which represents a demand based model on a monthly level. Both approaches are designed to meet the criteria for future grid fees. By means of a case study the effects of the grid fees on the load profile at the low voltage grid is simulated. Thereby the consumption is represented by different behaviour models and the results are scaled at the benchmark grid area. The resulting load curve is analyzed concerning the effects of peak load reduction as well as the integration of renewable energy sources. Additionally the combined effect of grid fees and electricity tariffs is evaluated. Finally the work discusses the launching of grid fees in the tense atmosphere of politics, legislation and grid operation. Results of this work are two calculation approaches designed for grid operators to define the grid fees. Multivariable grid fees are based on the current calculation scheme. Hereby demand and energy charges are weighted by time, locational and load related dependencies. The grid fee flat-rate defines a limitation in demand extraction. Different demand levels

  4. Assessing power grid reliability using rare event simulation

    NARCIS (Netherlands)

    Wadman, W.S.

    2015-01-01

    Renewable energy generators such as wind turbines and solar panels supply more and more power in modern electrical grids. Although the transition to a sustainable power supply is desirable, considerable implementation of distributed and intermittent generators may strain the power grid. Since grid

  5. The MammoGrid Project Grids Architecture

    CERN Document Server

    McClatchey, Richard; Hauer, Tamas; Estrella, Florida; Saiz, Pablo; Rogulin, Dmitri; Buncic, Predrag; Clatchey, Richard Mc; Buncic, Predrag; Manset, David; Hauer, Tamas; Estrella, Florida; Saiz, Pablo; Rogulin, Dmitri

    2003-01-01

    The aim of the recently EU-funded MammoGrid project is, in the light of emerging Grid technology, to develop a European-wide database of mammograms that will be used to develop a set of important healthcare applications and investigate the potential of this Grid to support effective co-working between healthcare professionals throughout the EU. The MammoGrid consortium intends to use a Grid model to enable distributed computing that spans national borders. This Grid infrastructure will be used for deploying novel algorithms as software directly developed or enhanced within the project. Using the MammoGrid clinicians will be able to harness the use of massive amounts of medical image data to perform epidemiological studies, advanced image processing, radiographic education and ultimately, tele-diagnosis over communities of medical "virtual organisations". This is achieved through the use of Grid-compliant services [1] for managing (versions of) massively distributed files of mammograms, for handling the distri...

  6. Technical-evaluation report on the proposed technical-specification changes on degraded grid-voltage protection for the Rancho Seco Nuclear Generating Plant (Docket No. 50-312)

    International Nuclear Information System (INIS)

    Selan, J.C.

    1983-01-01

    This Technical Evaluation Report is a revision and contains supplemental information to the Technical Evaluations documented in previous LLNL reports dated October 1980 (UCID-18690), November 10, 1981 (UCID-19113), and July 15, 1983 (UCID-19708). These reports encompass the NRC requirements on Degraded Grid Voltage Protection and Adequacy of Station Electric Distribution System Voltages. The evaluation finds that the proposed Technical Specification changes on the undervoltage/overvoltage trip setpoints and Limiting Conditions for Operation provide the required protection to the Class 1E Equipment from sustained abnormal voltages

  7. Smart power grids 2011

    CERN Document Server

    Keyhani, Ali

    2012-01-01

    Electric power systems are experiencing significant changes at the worldwide scale in order to become cleaner, smarter, and more reliable. This edited book examines a wide range of topics related to these changes, which are primarily caused by the introduction of information technologies, renewable energy penetration, digitalized equipment, new operational strategies, and so forth. The emphasis will be put on the modeling and control of smart grid systems. This book addresses research topics such as high efficiency transforrmers, wind turbines and generators, fuel cells, or high speed turbines

  8. The impact of model detail on power grid resilience measures

    Science.gov (United States)

    Auer, S.; Kleis, K.; Schultz, P.; Kurths, J.; Hellmann, F.

    2016-05-01

    Extreme events are a challenge to natural as well as man-made systems. For critical infrastructure like power grids, we need to understand their resilience against large disturbances. Recently, new measures of the resilience of dynamical systems have been developed in the complex system literature. Basin stability and survivability respectively assess the asymptotic and transient behavior of a system when subjected to arbitrary, localized but large perturbations in frequency and phase. To employ these methods that assess power grid resilience, we need to choose a certain model detail of the power grid. For the grid topology we considered the Scandinavian grid and an ensemble of power grids generated with a random growth model. So far the most popular model that has been studied is the classical swing equation model for the frequency response of generators and motors. In this paper we study a more sophisticated model of synchronous machines that also takes voltage dynamics into account, and compare it to the previously studied model. This model has been found to give an accurate picture of the long term evolution of synchronous machines in the engineering literature for post fault studies. We find evidence that some stable fix points of the swing equation become unstable when we add voltage dynamics. If this occurs the asymptotic behavior of the system can be dramatically altered, and basin stability estimates obtained with the swing equation can be dramatically wrong. We also find that the survivability does not change significantly when taking the voltage dynamics into account. Further, the limit cycle type asymptotic behaviour is strongly correlated with transient voltages that violate typical operational voltage bounds. Thus, transient voltage bounds are dominated by transient frequency bounds and play no large role for realistic parameters.

  9. Performance of LTE for smart grid communications

    NARCIS (Netherlands)

    Karagiannis, Georgios; Pham, G.T.; Nguyen, A.D.; Heijenk, Geert; Haverkort, Boudewijn R.H.M.; Campfens, F.; Fischbach, K.; Krieger, U.R.

    The next generation power grid (the “Smart Grid‿) aims to minimize environmental impact, enhance markets, improve reliability and service, and reduce costs and improve efficiency of electricity distribution. One of the main protocol frameworks used in Smart Grids is IEC 61850. Together with the

  10. Control Structures for Smart Grid Balancing

    DEFF Research Database (Denmark)

    Juelsgaard, Morten; Totu, Luminita Cristiana; Shafiei, Seyed Ehsan

    2013-01-01

    This work addresses the problem of maintaining the balance between consumption and production in the electricity grid when volatile resources, such as wind and sun, account for a large percentage of the power generation. We present control structures for Smart Grid balancing services on three dif...

  11. Voltage Quality of Grid Connected Wind Turbines

    DEFF Research Database (Denmark)

    Chen, Zhe; Blaabjerg, Frede; Sun, Tao

    2004-01-01

    Grid connected wind turbines may cause quality problems, such as voltage variation and flicker. This paper discusses the voltage variation and flicker emission of grid connected wind turbines with doubly-fed induction generators. A method to compensate flicker by using a voltage source converter...

  12. Laparoscopy After Previous Laparotomy

    Directory of Open Access Journals (Sweden)

    Zulfo Godinjak

    2006-11-01

    Full Text Available Following the abdominal surgery, extensive adhesions often occur and they can cause difficulties during laparoscopic operations. However, previous laparotomy is not considered to be a contraindication for laparoscopy. The aim of this study is to present that an insertion of Veres needle in the region of umbilicus is a safe method for creating a pneumoperitoneum for laparoscopic operations after previous laparotomy. In the last three years, we have performed 144 laparoscopic operations in patients that previously underwent one or two laparotomies. Pathology of digestive system, genital organs, Cesarean Section or abdominal war injuries were the most common causes of previouslaparotomy. During those operations or during entering into abdominal cavity we have not experienced any complications, while in 7 patients we performed conversion to laparotomy following the diagnostic laparoscopy. In all patients an insertion of Veres needle and trocar insertion in the umbilical region was performed, namely a technique of closed laparoscopy. Not even in one patient adhesions in the region of umbilicus were found, and no abdominal organs were injured.

  13. Smart Grid Risk Management

    Science.gov (United States)

    Abad Lopez, Carlos Adrian

    Current electricity infrastructure is being stressed from several directions -- high demand, unreliable supply, extreme weather conditions, accidents, among others. Infrastructure planners have, traditionally, focused on only the cost of the system; today, resilience and sustainability are increasingly becoming more important. In this dissertation, we develop computational tools for efficiently managing electricity resources to help create a more reliable and sustainable electrical grid. The tools we present in this work will help electric utilities coordinate demand to allow the smooth and large scale integration of renewable sources of energy into traditional grids, as well as provide infrastructure planners and operators in developing countries a framework for making informed planning and control decisions in the presence of uncertainty. Demand-side management is considered as the most viable solution for maintaining grid stability as generation from intermittent renewable sources increases. Demand-side management, particularly demand response (DR) programs that attempt to alter the energy consumption of customers either by using price-based incentives or up-front power interruption contracts, is more cost-effective and sustainable in addressing short-term supply-demand imbalances when compared with the alternative that involves increasing fossil fuel-based fast spinning reserves. An essential step in compensating participating customers and benchmarking the effectiveness of DR programs is to be able to independently detect the load reduction from observed meter data. Electric utilities implementing automated DR programs through direct load control switches are also interested in detecting the reduction in demand to efficiently pinpoint non-functioning devices to reduce maintenance costs. We develop sparse optimization methods for detecting a small change in the demand for electricity of a customer in response to a price change or signal from the utility

  14. Efficacy and safety of afatinib in Chinese patients with EGFR-mutated metastatic non-small-cell lung cancer (NSCLC) previously responsive to first-generation tyrosine-kinase inhibitors (TKI) and chemotherapy: comparison with historical cohort using erlotinib

    International Nuclear Information System (INIS)

    Lee, Victor H. F.; Leung, Dennis K. C.; Choy, Tim-Shing; Lam, Ka-On; Lam, Pui-Mei; Leung, To-Wai; Kwong, Dora L. W.

    2016-01-01

    Afaitnib has shown anti-tumor activity against metastatic EGFR-mutated NSCLC after prior failure to first generation EGFR-TKI and chemotherapy. We prospectively evaluated the efficacy and safety of afatinib in Chinese patients who previously failed first-generation TKI and chemotherapy under a compassionate use program (CUP) and compared to the erlotinib cohort. Patients who suffered from metastatic EGFR-mutated NSCLC previously responsive to first-generation TKI and chemotherapy received afatinib until progression, loss of clinical benefits or intolerable toxicity. Treatment response, survival and safety were evaluated and compared to the erlotinib cohort. Twenty-five and 28 patients received afatinib and erlotinib respectively. More patients in the afatinib group had worse performance status (ECOG 2) than the erlotinib group (p = 0.008). After a median follow-up of 12.1 months, afatinib demonstrated comparable objective response rate (ORR) (20.0 % vs. 7.1 %, p = 0.17) but significantly higher disease control rate (DCR) (68.0 % vs. 39.3 %, p = 0.04) compared to erlotinib. Median progression-free survival (PFS) (4.1 months [95 % CI, 2.7–5.5 months] vs. 3.3 months [95 % CI, 2.2–4.3 months], p = 0.97) and overall survival (OS) were not different between the two groups (10.3 months [95 % CI, 7.5–13.0 months] vs. 10.8 months [95 % CI, 7.4–14.2 months], p = 0.51). Multivariate analyses revealed that age ≤70 years and time to progression (TTP) ≥18 months for the 1 st TKI therapy were prognostic of PFS (p = 0.006 and p = 0.008 respectively). Afatinib caused less rash (60.0 % vs. 67.9 %, p = 0.04) but more diarrhea (60.0 % vs. 10.7 %, p = 0.002) compared to erlotinib. Afatinib produced encouraging clinical efficacy as 2 nd TKI therapy with manageable safety profiles in our Chinese patients after failure to another TKI and systemic chemotherapy. This study was registered at ClinicalTrials.gov (NCT02625168) on 3 December 2015

  15. Impact of Considering 110 kV Grid Structures on the Congestion Management in the German Transmission Grid

    Science.gov (United States)

    Hoffrichter, André; Barrios, Hans; Massmann, Janek; Venkataramanachar, Bhavasagar; Schnettler, Armin

    2018-02-01

    The structural changes in the European energy system lead to an increase of renewable energy sources that are primarily connected to the distribution grid. Hence the stationary analysis of the transmission grid and the regionalization of generation capacities are strongly influenced by subordinate grid structures. To quantify the impact on the congestion management in the German transmission grid, a 110 kV grid model is derived using publicly available data delivered by Open Street Map and integrated into an existing model of the European transmission grid. Power flow and redispatch simulations are performed for three different regionalization methods and grid configurations. The results show a significant impact of the 110 kV system and prove an overestimation of power flows in the transmission grid when neglecting subordinate grids. Thus, the redispatch volume in Germany to dissolve bottlenecks in case of N-1 contingencies decreases by 38 % when considering the 110 kV grid.

  16. SoilGrids250m: Global gridded soil information based on machine learning.

    Directory of Open Access Journals (Sweden)

    Tomislav Hengl

    Full Text Available This paper describes the technical development and accuracy assessment of the most recent and improved version of the SoilGrids system at 250m resolution (June 2016 update. SoilGrids provides global predictions for standard numeric soil properties (organic carbon, bulk density, Cation Exchange Capacity (CEC, pH, soil texture fractions and coarse fragments at seven standard depths (0, 5, 15, 30, 60, 100 and 200 cm, in addition to predictions of depth to bedrock and distribution of soil classes based on the World Reference Base (WRB and USDA classification systems (ca. 280 raster layers in total. Predictions were based on ca. 150,000 soil profiles used for training and a stack of 158 remote sensing-based soil covariates (primarily derived from MODIS land products, SRTM DEM derivatives, climatic images and global landform and lithology maps, which were used to fit an ensemble of machine learning methods-random forest and gradient boosting and/or multinomial logistic regression-as implemented in the R packages ranger, xgboost, nnet and caret. The results of 10-fold cross-validation show that the ensemble models explain between 56% (coarse fragments and 83% (pH of variation with an overall average of 61%. Improvements in the relative accuracy considering the amount of variation explained, in comparison to the previous version of SoilGrids at 1 km spatial resolution, range from 60 to 230%. Improvements can be attributed to: (1 the use of machine learning instead of linear regression, (2 to considerable investments in preparing finer resolution covariate layers and (3 to insertion of additional soil profiles. Further development of SoilGrids could include refinement of methods to incorporate input uncertainties and derivation of posterior probability distributions (per pixel, and further automation of spatial modeling so that soil maps can be generated for potentially hundreds of soil variables. Another area of future research is the development of

  17. Application Note: Power Grid Modeling With Xyce.

    Energy Technology Data Exchange (ETDEWEB)

    Sholander, Peter E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-06-01

    This application note describes how to model steady-state power flows and transient events in electric power grids with the SPICE-compatible Xyce TM Parallel Electronic Simulator developed at Sandia National Labs. This application notes provides a brief tutorial on the basic devices (branches, bus shunts, transformers and generators) found in power grids. The focus is on the features supported and assumptions made by the Xyce models for power grid elements. It then provides a detailed explanation, including working Xyce netlists, for simulating some simple power grid examples such as the IEEE 14-bus test case.

  18. Bayesian grid matching

    DEFF Research Database (Denmark)

    Hartelius, Karsten; Carstensen, Jens Michael

    2003-01-01

    A method for locating distorted grid structures in images is presented. The method is based on the theories of template matching and Bayesian image restoration. The grid is modeled as a deformable template. Prior knowledge of the grid is described through a Markov random field (MRF) model which...... represents the spatial coordinates of the grid nodes. Knowledge of how grid nodes are depicted in the observed image is described through the observation model. The prior consists of a node prior and an arc (edge) prior, both modeled as Gaussian MRFs. The node prior models variations in the positions of grid...... nodes and the arc prior models variations in row and column spacing across the grid. Grid matching is done by placing an initial rough grid over the image and applying an ensemble annealing scheme to maximize the posterior distribution of the grid. The method can be applied to noisy images with missing...

  19. TIGER: A graphically interactive grid system for turbomachinery applications

    Science.gov (United States)

    Shih, Ming-Hsin; Soni, Bharat K.

    1992-01-01

    Numerical grid generation algorithm associated with the flow field about turbomachinery geometries is presented. Graphical user interface is developed with FORMS Library to create an interactive, user-friendly working environment. This customized algorithm reduces the man-hours required to generate a grid associated with turbomachinery geometry, as compared to the use of general-purpose grid generation softwares. Bezier curves are utilized both interactively and automatically to accomplish grid line smoothness and orthogonality. Graphical User Interactions are provided in the algorithm, allowing the user to design and manipulate the grid lines with a mouse.

  20. Conference on wind energy and grid integration

    International Nuclear Information System (INIS)

    Laffaille, Didier; Boemer, Jens; Fraisse, Jean-Luc; Mignon, Herve; Gonot, Jean-Pierre; Rohrig, Kurt; Lange, Matthias; Bagusche, Daniel; Wagner, Stefan; Schiel, Johannes

    2008-01-01

    The French-German office for Renewable energies (OFAEnR) organised a conference on the grid integration of wind farms. In the framework of this French-German exchange of experience, more than 80 participants exchanged views on the evolutions of tariffs and licensing procedures, and on grid capacity improvements and production forecasts. This document brings together the available presentations (slides) made during this event: 1 - The necessary evolution of billing and procedures for wind turbines connection to the grid in France (Didier Laffaille); 2 - Improvement of wind turbines integration to the grid in the framework of the EEG 2009 law (Jens Boemer); 3 - Decentralized power generation on the French power grids - 15, 20 kV and low voltage (Jean-Luc Fraisse); 4 - GOTTESWIND? Solution for the future: towards a grid evolution (Herve Mignon); 5 - Production forecasts in Germany - State-of-the-art and challenges for the grid exploitation (Kurt Rohrig); 6 - High-voltage lines capacity evaluation in meteorological situations with high wind energy production (Matthias Lange); 7 - The IPES project for the integration of wind energy production in the exploitation of the French power system (Jean-Pierre Gonot); 8 - Experience feedback from a wind turbine manufacturer in France and in Germany (Daniel Bagusche); 9 - Solutions for grid security improvement and capacity enhancement: cooperation between grid and power plant operators (Stefan Wagner); 10 - Open questions on wind energy integration to French and German grids (Johannes Schiel)

  1. Development of Numerical Grids for UZ Flow and Transport Modeling

    International Nuclear Information System (INIS)

    P. Dobson

    2003-01-01

    This Scientific Analysis report describes the methods used to develop numerical grids of the unsaturated hydrogeologic system beneath Yucca Mountain. Numerical grid generation is an integral part of the development of the Unsaturated Zone Flow and Transport Model (UZ Model), a complex, three-dimensional (3-D) model of Yucca Mountain. This revision incorporates changes made to both the geologic framework model and the proposed repository layout. The resulting numerical grids, developed using current geologic, hydrogeologic, and mineralogic data, provide the necessary framework to: (1) develop calibrated hydrogeologic property sets and flow fields, (2) test conceptual hypotheses of flow and transport, and (3) predict flow and transport behavior under a variety of climatic and thermal-loading conditions. The technical scope, content, and management of this Scientific Analysis report was initially controlled by the planning document, ''Technical Work Plan (TWP) for: Unsaturated Zone Sections of License Application Chapters 8 and 12'' (BSC 2002 [159051], Section 1.6.4). This TWP was later superseded by ''Technical Work Plan for: Performance Assessment Unsaturated Zone'' (BSC 2002 [160819]), which contains the Data Qualification Plan used to qualify the DTN: MO0212GWLSSPAX.000 [161271] (See Attachment IV). Grids generated and documented in this report supersede those documented in previous versions of this report (BSC 2001 [159356]). The constraints, assumptions, and limitations associated with this report are discussed in the appropriate sections that follow. There were no deviations from the TWP scope of work in this report. Two software packages not listed in Table IV-2 of the TWP (BSC 2002 [159051]), ARCINFO V7.2.1 (CRWMS M and O 2000 [157019]; USGS 2000 [148304]) and 2kgrid8.for V1.0 (LBNL 2002 [154787]), were utilized in the development of the numerical grids; the use of additional software is accounted for in the TWP (BSC 2002 [159051], Section 13). The use of

  2. First Thuesday - CERN, The Grid gets real

    CERN Multimedia

    Robertson, Leslie

    2003-01-01

    A few years ago, "the Grid" was just a vision dreamt up by some computer scientists who wanted to share processor power and data storage capacity between computers around the world - in much the same way as today's Web shares information seamlessly between millions of computers. Today, Grid technology is a huge enterprise, involving hundreds of software engineers, and generating exciting opportunities for industry. "Computing on demand", "utility computing", "web services", and "virtualisation" are just a few of the buzzwords in the IT industry today that are intimately connected to the development of Grid technology. For this third First Tuesday @CERN, the panel will survey some of the latest major breakthroughs in building international computer Grids for science. It will also provide a snapshot of Grid-related industrial activities, with contributions from both major players in the IT sector as well as emerging Grid technology start-ups.

  3. Mapping of grid faults and grid codes

    DEFF Research Database (Denmark)

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

    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...... 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...

  4. Stability of Grid-Connected PV Inverters with Large Grid Impedance Variation

    DEFF Research Database (Denmark)

    Liserre, Marco; Teodorescu, Remus; Blaabjerg, Frede

    2004-01-01

    suited for loads connected in a great distance to the transformer (long wires) and the situation becomes even more difficult in low-developed remote areas characterized by low power transformers and long distribution wires with high grid impedance. Hence a theoretical analysis is needed because the grid......Photovoltaic (PV) inverters used in dispersed power generation of houses in the range of 1-5 kW are currently available from several manufactures. However, large grid impedance variation is challenging the control and the grid filter design in terms of stability. In fact the PV systems are well...... the design of resonant controllers adopted to mitigate the effect of the grid harmonic distortion on the grid current. In the high frequency range the grid impedance influence the frequency characteristic of the filter and the design of passive or active damping (to ensure stability) becomes more difficult...

  5. 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...... capability. The control methods, together with grid synchronization techniques, are responsible for the generation of appropriate reference signals in order to handle ride-through grid faults. Thus, it is necessary to evaluate the behaviors of grid synchronization methods and control possibilities in single...... 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 detection and control strategies are discussed. Some faulty modes are studied experimentally...

  6. 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...... capability. The control methods, together with grid synchronization techniques, are responsible for the generation of appropriate reference signals in order to handle ride-through grid faults. Thus, it is necessary to evaluate the behaviors of grid synchronization methods and control possibilities in single...... 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...

  7. Grid Database - Management, OGSA and Integration

    Directory of Open Access Journals (Sweden)

    Florentina Ramona PAVEL (EL BAABOUA

    2011-06-01

    Full Text Available The problem description of data models and types of databases has generated and gives rise to extensive controversy generated by their complexity, the many factors involved in the actual process of implementation. Grids encourage and promote the publication, sharing and integration of scientific data, distributed across Virtual Organizations. Scientists and researchers work on huge, complex and growing datasets. The complexity of data management within a grid environment comes from the distribution, heterogeneity and number of data sources.Early Grid applications focused principally on the storage, replication and movement of file-based data.. Many Grid applications already use databases for managing metadata, but increasingly many are associated with large databases of domain-specific information. In this paper we will talk about the fundamental concepts related to grid-database access, management, OGSA and integration.

  8. Smart Grid Status and Metrics Report Appendices

    Energy Technology Data Exchange (ETDEWEB)

    Balducci, Patrick J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Antonopoulos, Chrissi A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Clements, Samuel L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Gorrissen, Willy J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kirkham, Harold [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Ruiz, Kathleen A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Smith, David L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Weimar, Mark R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Gardner, Chris [APQC, Houston, TX (United States); Varney, Jeff [APQC, Houston, TX (United States)

    2014-07-01

    A smart grid uses digital power control and communication technology to improve the reliability, security, flexibility, and efficiency of the electric system, from large generation through the delivery systems to electricity consumers and a growing number of distributed generation and storage resources. To convey progress made in achieving the vision of a smart grid, this report uses a set of six characteristics derived from the National Energy Technology Laboratory Modern Grid Strategy. The Smart Grid Status and Metrics Report defines and examines 21 metrics that collectively provide insight into the grid’s capacity to embody these characteristics. This appendix presents papers covering each of the 21 metrics identified in Section 2.1 of the Smart Grid Status and Metrics Report. These metric papers were prepared in advance of the main body of the report and collectively form its informational backbone.

  9. Distributed generation of sustainable energy as a common pool resource: social acceptance in rural setting of smart (micro-)grid configurations

    NARCIS (Netherlands)

    Wolsink, M.; Frantál, B.; Martinát, S.

    2014-01-01

    According to the major trend in the literature on distributed generation adoption of composite multi-generation systems may yield significant benefits in terms of energy efficiency and reduced carbon emissions. The microgrid is a cluster of loads of electricity users and micro-sources that operate

  10. Grid-based Visualization Framework

    Science.gov (United States)

    Thiebaux, M.; Tangmunarunkit, H.; Kesselman, C.

    2003-12-01

    Advances in science and engineering have put high demands on tools for high-performance large-scale visual data exploration and analysis. For example, earthquake scientists can now study earthquake phenomena from first principle physics-based simulations. These simulations can generate large amounts of data, possibly high spatial resolution, and long time series. Single-system visualization software running on commodity machines cannot scale up to the large amounts of data generated by these simulations. To address this problem, we propose a flexible and extensible Grid-based visualization framework for time-critical, interactively controlled visual browsing of spatially and temporally large datasets in a Grid environment. Our framework leverages Grid resources for scalable computation and data storage to maintain performance and interactivity with large visualization jobs. Our framework utilizes Globus Toolkit 2.4 components for security (i.e., GSI), resource allocation and management (i.e., DUROC, GRAM) and communication (i.e., Globus-IO) to couple commodity desktops with remote, scalable storage and computational resources in a Grid for interactive data exploration. There are two major components in this framework---Grid Data Transport (GDT) and the Grid Visualization Utility (GVU). GDT provides libraries for performing parallel data filtering and parallel data exchange among Grid resources. GDT allows arbitrary data filtering to be integrated into the system. It also facilitates multi-tiered pipeline topology construction of compute resources and displays. In addition to scientific visualization applications, GDT can be used to support other applications that require parallel processing and parallel transfer of partial ordered independent files, such as file-set transfer. On top of GDT, we have developed the Grid Visualization Utility (GVU), which is designed to assist visualization dataset management, including file formatting, data transport and automatic

  11. Famed lab seeks big grid

    CERN Document Server

    Lillington, K

    2001-01-01

    DUBLIN, Ireland -- CERN, the famed Swiss high-energy particle physics lab, has a problem. It's about to start generating more data than any computer or network anywhere in the world is able to analyze. That prospect has led CERN to drive a major European project to create a vast "grid" research network of computers across Europe. When completed, the 10 million euro, Linux-based endeavor called DataGRID, will become a principal European computing resource for researchers of many disciplines. "I believe grid computing will revolutionize the way we compute, in much the same way as the World Wide Web and Internet changed the way we communicate," said John Ellis, a theoretical physicist and adviser to the director general of CERN.

  12. Smart grid security

    CERN Document Server

    Goel, Sanjay; Papakonstantinou, Vagelis; Kloza, Dariusz

    2015-01-01

    This book on smart grid security is meant for a broad audience from managers to technical experts. It highlights security challenges that are faced in the smart grid as we widely deploy it across the landscape. It starts with a brief overview of the smart grid and then discusses some of the reported attacks on the grid. It covers network threats, cyber physical threats, smart metering threats, as well as privacy issues in the smart grid. Along with the threats the book discusses the means to improve smart grid security and the standards that are emerging in the field. The second part of the b

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

    Indian Academy of Sciences (India)

    during light load condition the excess energy generated from the PV inverter is fed to the grid and; during an overload condition or in case of unfavorable atmospheric conditions the load demand is met by both PV inverter and the grid. In order to synchronize the PV inverter with the grid a dual transport delay based phase ...

  14. Economics of Wind Power when National Grids are Unreliable

    NARCIS (Netherlands)

    Kooten, van G.C.; Wong, L.

    2010-01-01

    Power interruptions are a typical characteristic of national grids in developing countries. Manufacturing, processing, refrigeration and other facilities that require a dependable supply of power, and might be considered a small grid within the larger national grid, employ diesel generators for

  15. Development of an ice crystal scattering database for the global change observation mission/second generation global imager satellite mission: investigating the refractive index grid system and potential retrieval error.

    Science.gov (United States)

    Letu, Husi; Nakajima, Takashi Y; Matsui, Takashi N

    2012-09-01

    Computing time and retrieval error of the effective particle radius are important considerations when developing an ice crystal scattering database to be used in radiative transfer simulation and satellite remote sensing retrieval. Therefore, the light scattering database should be optimized based on the specifications of the satellite sensor. In this study, the grid system of the complex refractive index in the 1.6 μm (SW3) channel of the Global Change Observation Mission/Second Generation Global Imager satellite sensor is investigated for optimizing the ice crystal scattering database. This grid system is separated into twelve patterns according to the step size of the real and imaginary parts of the refractive index. Specifically, the LIght Scattering solver Applicable to particles of arbitrary Shape/Geometrical-Optics Approximation technique is used to simulate the scattering of light by randomly oriented large hexagonal ice crystals. The difference of radiance with different step size of the refractive index is calculated from the developed light scattering database using the radiative transfer (R-STAR) solver. The results indicated that the step size of the real part is a significant factor in difference of radiance.

  16. Power grid reliability and security

    Energy Technology Data Exchange (ETDEWEB)

    Bose, Anjan [Washington State Univ., Pullman, WA (United States); Venkatasubramanian, Vaithianathan [Washington State Univ., Pullman, WA (United States); Hauser, Carl [Washington State Univ., Pullman, WA (United States); Bakken, David [Washington State Univ., Pullman, WA (United States); Anderson, David [Washington State Univ., Pullman, WA (United States); Zhao, Chuanlin [Washington State Univ., Pullman, WA (United States); Liu, Dong [Washington State Univ., Pullman, WA (United States); Yang, Tao [Washington State Univ., Pullman, WA (United States); Meng, Ming [Washington State Univ., Pullman, WA (United States); Zhang, Lin [Washington State Univ., Pullman, WA (United States); Ning, Jiawei [Washington State Univ., Pullman, WA (United States); Tashman, Zaid [Washington State Univ., Pullman, WA (United States)

    2015-01-31

    This project has led to the development of a real-time simulation platform for electric power grids called Grid Simulator or GridSim for simulating the dynamic and information network interactions of large- scale power systems. The platform consists of physical models of power system components including synchronous generators, loads and control, which are simulated using a modified commercial power simulator namely Transient Stability Analysis Tool (TSAT) [1] together with data cleanup components, as well as an emulated substation level and wide-area power analysis components. The platform also includes realistic representations of communication network middleware that can emulate the real-time information flow back and forth between substations and control centers in wide-area power systems. The platform has been validated on a realistic 6000-bus model of the western American power system. The simulator GridSim developed in this project is the first of its kind in its ability to simulate real-time response of large-scale power grids, and serves as a cost effective real-time stability and control simulation platform for power industry.

  17. Stability analysis of grid-connected PV systems based on impedance frequency response

    OpenAIRE

    Rodríguez Villarreal, José Raúl; Biel Solé, Domingo; Guinjoan Gispert, Francisco

    2011-01-01

    The increase of distributed generation on electric networks has raised the concern of grid stability, among other issues. The PV generators connected to the grid have to deal with varying consumption and generation scenarios, however, this may affect the performance and stability of the generators themselves, as well as the grid. This document presents an analytical stability method to maintain the grid stability by adjusting the generator control parameters based on the ...

  18. Grid-Enabled Measures

    Science.gov (United States)

    Moser, Richard P.; Hesse, Bradford W.; Shaikh, Abdul R.; Courtney, Paul; Morgan, Glen; Augustson, Erik; Kobrin, Sarah; Levin, Kerry; Helba, Cynthia; Garner, David; Dunn, Marsha; Coa, Kisha

    2011-01-01

    Scientists are taking advantage of the Internet and collaborative web technology to accelerate discovery in a massively connected, participative environment —a phenomenon referred to by some as Science 2.0. As a new way of doing science, this phenomenon has the potential to push science forward in a more efficient manner than was previously possible. The Grid-Enabled Measures (GEM) database has been conceptualized as an instantiation of Science 2.0 principles by the National Cancer Institute with two overarching goals: (1) Promote the use of standardized measures, which are tied to theoretically based constructs; and (2) Facilitate the ability to share harmonized data resulting from the use of standardized measures. This is done by creating an online venue connected to the Cancer Biomedical Informatics Grid (caBIG®) where a virtual community of researchers can collaborate together and come to consensus on measures by rating, commenting and viewing meta-data about the measures and associated constructs. This paper will describe the web 2.0 principles on which the GEM database is based, describe its functionality, and discuss some of the important issues involved with creating the GEM database, such as the role of mutually agreed-on ontologies (i.e., knowledge categories and the relationships among these categories— for data sharing). PMID:21521586

  19. Grid resilience governance of the future: analyzing the role of associations in experimental smart grid projects in the Netherlands

    NARCIS (Netherlands)

    Lammers, Imke; Vasenev, Alexandr

    2017-01-01

    Local generation decentralizes urban grids. Soon new actors, such as associations, might enter the traditional energy domain. As electrical grids are critical for society, new actors will need to collaborate with other city-level stakeholders to ensure proper grid functioning in times of crisis.

  20. Mapping of grid faults and grid codes

    DEFF Research Database (Denmark)

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

    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...... 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...

  1. Performance evaluation of a stand-alone solar dish Stirling system for power generation suitable for off-grid rural electrification

    International Nuclear Information System (INIS)

    Kadri, Y.; Hadj Abdallah, H.

    2016-01-01

    Highlights: • Estimation of the output temperature reached by 2 m parabolic dish. • Output power estimation for uncontrollable load was done using Matlab®. • Validation of the proposed system under Tunisian conditions for rural electrification. - Abstract: The development of green power generation such as solar systems that have become a great interest for several countries especially for Tunisia as it presents a significant solar potential. For this purpose, this research has investigated the feasibility and the performance of standalone solar dish/Stirling micro generation plant for rural electrification. The considered hybrid system includes solar dish/Stirling engine, permanent magnet synchronous generator and a storage battery. To start with, thermal modeling and simulation have been carried out using Matlab® for the solar-driven Stirling heat engine system composed of an Alpha Stirling engine, a solar collector and a receiver, in which the radiation, convection, conduction and radiation heat loss have been taken into consideration for the selected design. For numerical validation of the receiver’s thermal model, simulation results were compared with experimental measurements reported for the EURODISH system with a reasonable degree of agreement. Second, the generated torque driving the generator has been estimated by the Adiabatic model of URIELI based on the classical fourth-order Runge-Kutta. In order for an autonomous control, the dish generator is connected to the load via power electronic converters where the bidirectional power flow is possible by the use of two voltage source converters in a back-to-back configuration. They are referred to as Stirling/generator side converter and load side inverter, both are oriented control by space vector pulse width modulation. In this context, the Stirling side converter is used to adjust the synchronous generator while the inverter controls the power flow between the direct current bus and the

  2. A Brief Survey on the Advancement of Smart Grid

    OpenAIRE

    Chandra Mukherjee,; Pratibha Bharti

    2014-01-01

    The Smart Grid, regarded as the next generation power grid, uses two-way communication of electricity and information to create a widely distributed automated energy delivery network. In this article, a review work on different aspects on the enabling technologies for the Smart Grid is being presented. Infrastructure of Smart Grid can be broadly classified into three terms namely the smart infrastructure system, the smart management system, and the smart protection system. We ...

  3. Production of single-walled carbon nanotube grids

    Science.gov (United States)

    Hauge, Robert H; Xu, Ya-Qiong; Pheasant, Sean

    2013-12-03

    A method of forming a nanotube grid includes placing a plurality of catalyst nanoparticles on a grid framework, contacting the catalyst nanoparticles with a gas mixture that includes hydrogen and a carbon source in a reaction chamber, forming an activated gas from the gas mixture, heating the grid framework and activated gas, and controlling a growth time to generate a single-wall carbon nanotube array radially about the grid framework. A filter membrane may be produced by this method.

  4. HIRENASD coarse structured grid

    Data.gov (United States)

    National Aeronautics and Space Administration — blockstructured hexahedral grid, 6.7 mio elements, 24 degree minimum grid angle, CGNS format version 2.4, double precision Binary, Plot3D file Please contact...

  5. Influence of grid resolution in fluid-model simulation of nanosecond dielectric barrier discharge plasma actuator

    Science.gov (United States)

    Hua, Weizhuo; Fukagata, Koji

    2018-04-01

    Two-dimensional numerical simulation of a surface dielectric barrier discharge (SDBD) plasma actuator, driven by a nanosecond voltage pulse, is conducted. A special focus is laid upon the influence of grid resolution on the computational result. It is found that the computational result is not very sensitive to the streamwise grid spacing, whereas the wall-normal grid spacing has a critical influence. In particular, the computed propagation velocity changes discontinuously around the wall-normal grid spacing about 2 μm due to a qualitative change of discharge structure. The present result suggests that a computational grid finer than that was used in most of previous studies is required to correctly capture the structure and dynamics of streamer: when a positive nanosecond voltage pulse is applied to the upper electrode, a streamer forms in the vicinity of upper electrode and propagates along the dielectric surface with a maximum propagation velocity of 2 × 108 cm/s, and a gap with low electron and ion density (i.e., plasma sheath) exists between the streamer and dielectric surface. Difference between the results obtained using the finer and the coarser grid is discussed in detail in terms of the electron transport at a position near the surface. When the finer grid is used, the low electron density near the surface is caused by the absence of ionization avalanche: in that region, the electrons generated by ionization is compensated by drift-diffusion flux. In contrast, when the coarser grid is used, underestimated drift-diffusion flux cannot compensate the electrons generated by ionization, and it leads to an incorrect increase of electron density.

  6. Smart grid in China

    DEFF Research Database (Denmark)

    Sommer, Simon; Ma, Zheng; Jørgensen, Bo Nørregaard

    2015-01-01

    China is planning to transform its traditional power grid in favour of a smart grid, since it allows a more economically efficient and a more environmentally friendly transmission and distribution of electricity. Thus, a nationwide smart grid is likely to save tremendous amounts of resources...

  7. Determining Maximum Photovoltaic Penetration in a Distribution Grid considering Grid Operation Limits

    DEFF Research Database (Denmark)

    Kordheili, Reza Ahmadi; Bak-Jensen, Birgitte; Pillai, Jayakrishnan Radhakrishna

    2014-01-01

    High penetration of photovoltaic panels in distribution grid can bring the grid to its operation limits. The main focus of the paper is to determine maximum photovoltaic penetration level in the grid. Three main criteria were investigated for determining maximum penetration level of PV panels...... for this grid: even distribution of PV panels, aggregation of panels at the beginning of each feeder, and aggregation of panels at the end of each feeder. Load modeling is done using Velander formula. Since PV generation is highest in the summer due to irradiation, a summer day was chosen to determine maximum...

  8. Grid Architecture 2

    Energy Technology Data Exchange (ETDEWEB)

    Taft, Jeffrey D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-01-01

    The report describes work done on Grid Architecture under the auspices of the Department of Electricity Office of Electricity Delivery and Reliability in 2015. As described in the first Grid Architecture report, the primary purpose of this work is to provide stakeholder insight about grid issues so as to enable superior decision making on their part. Doing this requires the creation of various work products, including oft-times complex diagrams, analyses, and explanations. This report provides architectural insights into several important grid topics and also describes work done to advance the science of Grid Architecture as well.

  9. Security on the US fusion grid

    International Nuclear Information System (INIS)

    Burruss, J.R.; Fredian, T.W.; Thompson, M.R.

    2006-01-01

    The National Fusion Collaboratory project is developing and deploying new distributed computing and remote collaboration technologies with the goal of advancing magnetic fusion energy research. This has led to the development of the U.S. fusion grid (FusionGrid), a computational grid composed of collaborative, compute, and data resources from the three large U.S. fusion research facilities and with users both in the U.S. and in Europe. Critical to the development of FusionGrid was the creation and deployment of technologies to ensure security in a heterogeneous environment. These solutions to the problems of authentication, authorization, data transfer, and secure data storage, as well as the lessons learned during the development of these solutions, may be applied outside of FusionGrid and scale to future computing infrastructures such as those for next-generation devices like ITER

  10. Security on the US Fusion Grid

    International Nuclear Information System (INIS)

    Burruss, Justin R.; Fredian, Tom W.; Thompson, Mary R.

    2005-01-01

    The National Fusion Collaboratory project is developing and deploying new distributed computing and remote collaboration technologies with the goal of advancing magnetic fusion energy research. This work has led to the development of the US Fusion Grid (FusionGrid), a computational grid composed of collaborative, compute, and data resources from the three large US fusion research facilities and with users both in the US and in Europe. Critical to the development of FusionGrid was the creation and deployment of technologies to ensure security in a heterogeneous environment. These solutions to the problems of authentication, authorization, data transfer, and secure data storage, as well as the lessons learned during the development of these solutions, may be applied outside of FusionGrid and scale to future computing infrastructures such as those for next-generation devices like ITER

  11. Data security on the national fusion grid

    International Nuclear Information System (INIS)

    Burruss, Justine R.; Fredian, Tom W.; Thompson, Mary R.

    2005-01-01

    The National Fusion Collaboratory project is developing and deploying new distributed computing and remote collaboration technologies with the goal of advancing magnetic fusion energy research. This work has led to the development of the US Fusion Grid (FusionGrid), a computational grid composed of collaborative, compute, and data resources from the three large US fusion research facilities and with users both in the US and in Europe. Critical to the development of FusionGrid was the creation and deployment of technologies to ensure security in a heterogeneous environment. These solutions to the problems of authentication, authorization, data transfer, and secure data storage, as well as the lessons learned during the development of these solutions, may be applied outside of FusionGrid and scale to future computing infrastructures such as those for next-generation devices like ITER

  12. Conducted Electromagnetic Interference (EMI) in Smart Grids

    CERN Document Server

    Smolenski, Robert

    2012-01-01

    As power systems develop to incorporate renewable energy sources, the delivery systems may be disrupted by the changes involved. The grid’s technology and management must be developed to form Smart Grids between consumers, suppliers and producers. Conducted Electromagnetic Interference (EMI) in Smart Grids considers the specific side effects related to electromagnetic interference (EMI) generated by the application of these Smart Grids. Conducted Electromagnetic Interference (EMI) in Smart Grids presents specific EMI conducted phenomena as well as effective methods to filter and handle them once identified. After introduction to Smart Grids, the following sections cover dedicated methods for EMI reduction and potential avenues for future development including chapters dedicated to: •potential system services, •descriptions of the EMI spectra shaping methods, •methods of interference voltage compensation, and theoretical analysis of experimental results.  By focusing on these key aspects, Conducted El...

  13. Security on the US Fusion Grid

    Energy Technology Data Exchange (ETDEWEB)

    Burruss, Justin R.; Fredian, Tom W.; Thompson, Mary R.

    2005-06-01

    The National Fusion Collaboratory project is developing and deploying new distributed computing and remote collaboration technologies with the goal of advancing magnetic fusion energy research. This work has led to the development of the US Fusion Grid (FusionGrid), a computational grid composed of collaborative, compute, and data resources from the three large US fusion research facilities and with users both in the US and in Europe. Critical to the development of FusionGrid was the creation and deployment of technologies to ensure security in a heterogeneous environment. These solutions to the problems of authentication, authorization, data transfer, and secure data storage, as well as the lessons learned during the development of these solutions, may be applied outside of FusionGrid and scale to future computing infrastructures such as those for next-generation devices like ITER.

  14. Data security on the national fusion grid

    Energy Technology Data Exchange (ETDEWEB)

    Burruss, Justine R.; Fredian, Tom W.; Thompson, Mary R.

    2005-06-01

    The National Fusion Collaboratory project is developing and deploying new distributed computing and remote collaboration technologies with the goal of advancing magnetic fusion energy research. This work has led to the development of the US Fusion Grid (FusionGrid), a computational grid composed of collaborative, compute, and data resources from the three large US fusion research facilities and with users both in the US and in Europe. Critical to the development of FusionGrid was the creation and deployment of technologies to ensure security in a heterogeneous environment. These solutions to the problems of authentication, authorization, data transfer, and secure data storage, as well as the lessons learned during the development of these solutions, may be applied outside of FusionGrid and scale to future computing infrastructures such as those for next-generation devices like ITER.

  15. A unified grid current control for grid-interactive DG inverters in microgrids

    DEFF Research Database (Denmark)

    Wang, Xiongfei; Loh, Poh Chiang; Blaabjerg, Frede

    2015-01-01

    This paper proposes a unified grid current control for grid-interactive distributed generation inverters. In the approach, the grid-side current, instead of inverter-side current, is controlled as an inner loop, while the filter capacitor voltage is indirectly regulated through a virtual admittan...... locus analyses in the discrete z-domain are performed for elaborating the controller design. Simulations and experimental results demonstrate the performances of the proposed approach.......This paper proposes a unified grid current control for grid-interactive distributed generation inverters. In the approach, the grid-side current, instead of inverter-side current, is controlled as an inner loop, while the filter capacitor voltage is indirectly regulated through a virtual admittance...... in the outer loop. It, therefore, provides several superior features over traditional control schemes: 1) high-quality grid current in the grid-connected mode, 2) inherent derivative-less virtual output impedance control, and 3) the unified active damping for both grid-connected and islanded operations. Root...

  16. Grid Collector: Facilitating Efficient Selective Access from DataGrids

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Kesheng; Gu, Junmin; Lauret, Jerome; Poskanzer, Arthur M.; Shoshani, Arie; Sim, Alexander; Zhang, Wei-Ming

    2005-05-17

    The Grid Collector is a system that facilitates the effective analysis and spontaneous exploration of scientific data. It combines an efficient indexing technology with a Grid file management technology to speed up common analysis jobs on high-energy physics data and to enable some previously impractical analysis jobs. To analyze a set of high-energy collision events, one typically specifies the files containing the events of interest, reads all the events in the files, and filters out unwanted ones. Since most analysis jobs filter out significant number of events, a considerable amount of time is wasted by reading the unwanted events. The Grid Collector removes this inefficiency by allowing users to specify more precisely what events are of interest and to read only the selected events. This speeds up most analysis jobs. In existing analysis frameworks, the responsibility of bringing files from tertiary storages or remote sites to local disks falls on the users. This forces most of analysis jobs to be performed at centralized computer facilities where commonly used files are kept on large shared file systems. The Grid Collector automates file management tasks and eliminates the labor-intensive manual file transfers. This makes it much easier to perform analyses that require data files on tertiary storages and remote sites. It also makes more computer resources available for analysis jobs since they are no longer bound to the centralized facilities.

  17. European electricity grid. Status and perspective

    International Nuclear Information System (INIS)

    Maillard, Dominique

    2010-01-01

    There is no doubt about the need to expand and modernize the European electricity grid, especially in order to allow renewable energies to be fed stochastically into existing systems. As it is hardly possible at the present time and also in the near future to store electricity on a major scale and at adequate prices, electricity must be transmitted from the point of generation to the point of consumption directly and in real time. The development of grid systems, including cross-border transmission systems, is still behind expectations. This is not due to a shortage of projects or a lack of interest on the part of grid operators; the necessary political support is available as well, and investments at present are covered by the feed tariffs. The problem is the lack of acceptance. It is difficult to obtain new permits or commission new grids. This problem of the licensing authorities often results in considerable delays. Consequently, it is up to the grid operators to handle this situation and promote new, intelligent grid systems in an effort to achieve acceptance of a technical-scale infrastructure. This includes transparency in grid expansion, exchange with the public in order to reach mutual understanding and trust and also find compromises as well as the willingness to discuss various approaches to solutions (underground routing, upgrading of existing grid systems, smart systems, and intelligent designs) so as to optimize the use of the existing infrastructure. (orig.)

  18. Models for the modern power grid

    Science.gov (United States)

    Nardelli, Pedro H. J.; Rubido, Nicolas; Wang, Chengwei; Baptista, Murilo S.; Pomalaza-Raez, Carlos; Cardieri, Paulo; Latva-aho, Matti

    2014-10-01

    This article reviews different kinds of models for the electric power grid that can be used to understand the modern power system, the smart grid. From the physical network to abstract energy markets, we identify in the literature different aspects that co-determine the spatio-temporal multilayer dynamics of power system. We start our review by showing how the generation, transmission and distribution characteristics of the traditional power grids are already subject to complex behaviour appearing as a result of the the interplay between dynamics of the nodes and topology, namely synchronisation and cascade effects. When dealing with smart grids, the system complexity increases even more: on top of the physical network of power lines and controllable sources of electricity, the modernisation brings information networks, renewable intermittent generation, market liberalisation, prosumers, among other aspects. In this case, we forecast a dynamical co-evolution of the smart grid and other kind of networked systems that cannot be understood isolated. This review compiles recent results that model electric power grids as complex systems, going beyond pure technological aspects. From this perspective, we then indicate possible ways to incorporate the diverse co-evolving systems into the smart grid model using, for example, network theory and multi-agent simulation.

  19. Finite volume methods for the incompressible Navier-Stokes equations on unstructured grids

    Energy Technology Data Exchange (ETDEWEB)

    Meese, Ernst Arne

    1998-07-01

    Most solution methods of computational fluid dynamics (CFD) use structured grids based on curvilinear coordinates for compliance with complex geometries. In a typical industry application, about 80% of the time used to produce the results is spent constructing computational grids. Recently the use of unstructured grids has been strongly advocated. For unstructured grids there are methods for generating them automatically on quite complex domains. This thesis focuses on the design of Navier-Stokes solvers that can cope with unstructured grids and ''low quality grids'', thus reducing the need for human intervention in the grid generation.

  20. Environmental report 2001 - Verbund Austria Power Grid

    International Nuclear Information System (INIS)

    2002-01-01

    A balance of the environmental activities performed by Verbund Austria Power Grid during 2001 is presented. It comprises which measures were taken to reach their environmental objectives: certification of an environmental management system according to ISO 14001 and EMAS, environmental protection, policies, water and thermoelectric power generation status ( CO 2 , SO 2 , NO x emission monitoring, energy efficiency, replacement of old equipment), reduction of the greenhouse gases emissions and nature conservation. The report is divided in 8 sections: power grid, environmental policy, environmental management, power grid layout, environmental status of the system, introduction of new technologies for environmental monitoring, environmental objectives 2001 - 2002, and data and facts 2001. (nevyjel)

  1. Grid portal-based data management for lattice QCD data

    International Nuclear Information System (INIS)

    Andronico, G.; Barbera, R.; Falzone, A.

    2004-01-01

    We describe here a case of the European Union DataGrid Project data management services by a Lattice Quantum ChromoDynamics (LQCD) application to share the large amount of configurations generated and based on a solution developed from the International Lattice Data Grid Project using a XML dialect called QCDML. In order to allow the user to store, search and browse the lattice configurations described by QCDML in an uniform and transparent way, we have exploited the functionalities of the GENIUS Grid portal, jointly developed by INFN and NICE srl in the context of the Italian INFN Grid and EU DataGrid Projects

  2. Grid portal-based data management for lattice QCD data

    Energy Technology Data Exchange (ETDEWEB)

    Andronico, G. [Istituto Nazionale di Fisica Nucleare, Sezione di Catania, via S. Sofia 64, 95123 Catania (Italy)]. E-mail: giuseppe.andronico@ct.infn.it; Barbera, R. [Istituto Nazionale di Fisica Nucleare, Sezione di Catania, via S. Sofia 64, 95123 Catania (Italy); Dipartimento di Fisica e Astronomia dell' Universita di Catania, via S. Sofia 64, 95123 Catania (Italy); Falzone, A. [NICE SRL, via Marchesi di Roero 1, 14020 Cortanze (Italy)

    2004-11-21

    We describe here a case of the European Union DataGrid Project data management services by a Lattice Quantum ChromoDynamics (LQCD) application to share the large amount of configurations generated and based on a solution developed from the International Lattice Data Grid Project using a XML dialect called QCDML. In order to allow the user to store, search and browse the lattice configurations described by QCDML in an uniform and transparent way, we have exploited the functionalities of the GENIUS Grid portal, jointly developed by INFN and NICE srl in the context of the Italian INFN Grid and EU DataGrid Projects.

  3. Smart Control of Energy Distribution Grids over Heterogeneous Communication Networks

    DEFF Research Database (Denmark)

    Olsen, Rasmus Løvenstein; Iov, Florin; Hägerling, Christian

    2014-01-01

    The expected growth in distributed generation will significantly affect the operation and control of todays distribution grids. Being confronted with short time power variations of distributed generations, the assurance of a reliable service (grid stability, avoidance of energy losses) and the qu...

  4. F-16XL Geometry and Grids. Chapter 4

    Science.gov (United States)

    Boelens, Okko J.; Goertz,Stefan; Fritz, Willy; Karman, Steve L., Jr.; Michal, Todd R.; Lamar, John E.

    2009-01-01

    The objective of the Cranked-Arrow Wing Aerodynamics Project International (CAWAPI) was to allow a comprehensive validation of Computational Fluid Dynamics methods against the CAWAP flight database. A major part of this work involved the generation of high-quality computational grids. Prior to the grid generation an IGES file containing the air-tight geometry of the F-16XL aircraft was generated by a cooperation of some of the CAWAPI partners. Based on this geometry description both structured and unstructured grids have been generated. The baseline structured (multi-block) grid (and a family of derived grids) has been generated by the National Aerospace Laboratory (NLR). The baseline all-tetrahedral and hybrid unstructured grids were generated at the NASA Langley Research Center and the U.S. Air Force Academy, respectively. To provide more geometrical resolution, additional unstructured grids were generated at EADS-MAS, the UTSimCenter, and Boeing Phantom Works. All the grids generated within the framework of CAWAPI will be discussed.

  5. Communication, control and security challenges for the smart grid

    CERN Document Server

    Muyeen, SM

    2017-01-01

    The Smart Grid is a modern electricity grid allowing for distributed, renewable intermittent generation, partly owned by consumers. This requires advanced control and communication technologies in order to provide high quality power supply and secure generation, transmission and distribution. This book outlines these emerging technologies.

  6. High density grids

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, Aina E.; Baxter, Elizabeth L.

    2018-01-16

    An X-ray data collection grid device is provided that includes a magnetic base that is compatible with robotic sample mounting systems used at synchrotron beamlines, a grid element fixedly attached to the magnetic base, where the grid element includes at least one sealable sample window disposed through a planar synchrotron-compatible material, where the planar synchrotron-compatible material includes at least one automated X-ray positioning and fluid handling robot fiducial mark.

  7. LHC computing grid

    International Nuclear Information System (INIS)

    Novaes, Sergio

    2011-01-01

    Full text: We give an overview of the grid computing initiatives in the Americas. High-Energy Physics has played a very important role in the development of grid computing in the world and in Latin America it has not been different. Lately, the grid concept has expanded its reach across all branches of e-Science, and we have witnessed the birth of the first nationwide infrastructures and its use in the private sector. (author)

  8. 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

  9. Frequency Response Assessment and Enhancement of the U.S. Power Grids towards Extra-High Photovoltaic Generation Penetrations – an Industry Perspective

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yong; You, Shutang; Tan, Jin; Zhang, Yingchen; Liu, Yilu

    2018-01-01

    Nonsynchronous generations such as photovoltaics (PVs) are expected to undermine bulk power systems (BPSs)' frequency response at high penetration levels. Though the underlying mechanism has been relatively well understood, the accurate assessment and effective enhancement of the U.S. interconnections, frequency response under extra-high PV penetration conditions remains an issue. In this paper, the industry-provided full-detail interconnection models were further validated by synchrophasor frequency measurements and realistically-projected PV geographic distribution information were used to develop extra-high PV penetration scenarios and dynamic models for the three main U.S. interconnections, including Eastern Interconnection (EI), Western Electricity Coordinating Council (WECC), and Electric Reliability Council of Texas (ERCOT). Up to 65% instantaneous PV and 15% wind penetration were simulated and the frequency response change trend of each U.S. interconnection due to the increasing PV penetration level were examined. Most importantly, the practical solutions to address the declining frequency response were discussed. This paper will provide valuable guidance for policy makers, utility operators and academic researchers not only in the U.S. but also other countries in the world.

  10. Accurate path integration in continuous attractor network models of grid cells.

    Directory of Open Access Journals (Sweden)

    Yoram Burak

    2009-02-01

    Full Text Available Grid cells in the rat entorhinal cortex display strikingly regular firing responses to the animal's position in 2-D space and have been hypothesized to form the neural substrate for dead-reckoning. However, errors accumulate rapidly when velocity inputs are integrated in existing models of grid cell activity. To produce grid-cell-like responses, these models would require frequent resets triggered by external sensory cues. Such inadequacies, shared by various models, cast doubt on the dead-reckoning potential of the grid cell system. Here we focus on the question of accurate path integration, specifically in continuous attractor models of grid cell activity. We show, in contrast to previous models, that continuous attractor models can generate regular triangular grid responses, based on inputs that encode only the rat's velocity and heading direction. We consider the role of the network boundary in the integration performance of the network and show that both periodic and aperiodic networks are capable of accurate path integration, despite important differences in their attractor manifolds. We quantify the rate at which errors in the velocity integration accumulate as a function of network size and intrinsic noise within the network. With a plausible range of parameters and the inclusion of spike variability, our model networks can accurately integrate velocity inputs over a maximum of approximately 10-100 meters and approximately 1-10 minutes. These findings form a proof-of-concept that continuous attractor dynamics may underlie velocity integration in the dorsolateral medial entorhinal cortex. The simulations also generate pertinent upper bounds on the accuracy of integration that may be achieved by continuous attractor dynamics in the grid cell network. We suggest experiments to test the continuous attractor model and differentiate it from models in which single cells establish their responses independently of each other.

  11. 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.

  12. The play grid

    DEFF Research Database (Denmark)

    Fogh, Rune; Johansen, Asger

    2013-01-01

    In this paper we propose The Play Grid, a model for systemizing different play types. The approach is psychological by nature and the actual Play Grid is based, therefore, on two pairs of fundamental and widely acknowledged distinguishing characteristics of the ego, namely: extraversion vs...... at the Play Grid. Thus, the model has four quadrants, each of them describing one of four play types: the Assembler, the Director, the Explorer, and the Improviser. It is our hope that the Play Grid can be a useful design tool for making entertainment products for children....

  13. Greenhouse gas emission factors of purchased electricity from interconnected grids

    International Nuclear Information System (INIS)

    Ji, Ling; Liang, Sai; Qu, Shen; Zhang, Yanxia; Xu, Ming; Jia, Xiaoping; Jia, Yingtao; Niu, Dongxiao; Yuan, Jiahai; Hou, Yong; Wang, Haikun; Chiu, Anthony S.F.; Hu, Xiaojun

    2016-01-01

    Highlights: • A new accounting framework is proposed for GHG emission factors of power grids. • Three cases are used to demonstrate the proposed framework. • Comparisons with previous system boundaries approve the necessity. - Abstract: Electricity trade among power grids leads to difficulties in measuring greenhouse gas (GHG) emission factors of purchased electricity. Traditional methods assume either electricity purchased from a grid is entirely produced locally (Boundary I) or imported electricity is entirely produced by the exporting grid (Boundary II) (in fact a blend of electricity produced by many grids). Both methods ignore the fact that electricity can be indirectly traded between grids. Failing to capture such indirect electricity trade can underestimate or overestimate GHG emissions of purchased electricity in interconnected grid networks, potentially leading to incorrectly accounting for the effects of emission reduction policies involving purchased electricity. We propose a “Boundary III” framework to account for emissions both directly and indirectly caused by purchased electricity in interconnected gird networks. We use three case studies on a national grid network, an Eurasian Continent grid network, and North Europe grid network to demonstrate the proposed Boundary III emission factors. We found that the difference on GHG emissions of purchased electricity estimated using different emission factors can be considerably large. We suggest to standardize the choice of different emission factors based on how interconnected the local grid is with other grids.

  14. Grid for Meso american Archaeology

    International Nuclear Information System (INIS)

    Lucet, G.

    2007-01-01

    Meso american archaeology works with large amounts of disperse and diverse information, thus the importance of including new methods that optimise the acquisition, conservation, retrieval, and analysis of data to generate knowledge more efficiently and create a better understanding of history. Further, this information --which includes texts, coordinates, raster graphs, and vector graphs-- comes from a considerable geographical area --parts of Mexico, Nicaragua, Honduras and Costa Rica as well as Guatemala, El Salvador and Belize-- is constantly expanding. This information includes elements like shards, buildings, mural paintings, high and low reliefs, topography, maps, and information about the fauna and soil. Grid computing offers a solution to handle all this information: it respects researchers' need for independence while supplying a platform to share, process and compare the data obtained. Additionally, the Grid can enhance space-time analyses with remote visualisation techniques that can, in turn, incorporate geographical information systems and virtual reality. (Author)

  15. Electricity for development: Mini-grid solution for rural electrification in South Africa

    International Nuclear Information System (INIS)

    Azimoh, Chukwuma Leonard; Klintenberg, Patrik; Wallin, Fredrik; Karlsson, Björn; Mbohwa, Charles

    2016-01-01

    Highlights: • The use of hybrid mini-grid electricity for rural development is investigated. • Solar home system electricity has limited development impact on rural households in South Africa. • Mini-grid-solution for rural electrification is able to sustain and initiate small scale businesses. • Hydro based hybrid mini-grids have more potential to meet the energy needs of rural households. - Abstract: The objective of most rural electrification programs in the developing world is to bring about socio-economic development to households. Governments have put in place a number of measures to achieve this goal. Previous studies on rural electrification programs in developing countries show that solar home systems and mini-grid systems are the dominant technologies. Assessments of a pilot hybrid mini-grid project at Lucingweni village have concluded that mini-grid projects are not feasible due to high electricity production costs. As a result efforts toward rural electrification have been focused on the solar home system. Nevertheless, previous studies of the South African solar home system program have shown that the development objectives of the program are yet to be met more than a decade after commissioning. Therefore, this study investigates the viability of a hybrid mini-grid as a solution for rural development in South Africa. Investigations were based on Lucingweni and Thlatlaganya, two rural Villages where the mini-grid and solar home system have been introduced. The mini-grid systems were designed taking into consideration available natural resources and existing load profiles. The results show that a village of 300 households needs about 2.4 kW h/household/day of electricity to initiate and sustain income generating activities and that the solar home system is not capable of supporting this level of demand. We also show that in locations with hydro resources, a hybrid mini-grid system has the most potential for meeting the energy needs of the

  16. Gridded Species Distribution, Version 1: Global Amphibians Presence Grids

    Data.gov (United States)

    National Aeronautics and Space Administration — The Global Amphibians Presence Grids of the Gridded Species Distribution, Version 1 is a reclassified version of the original grids of amphibian species distribution...

  17. Gridded Species Distribution, Version 1: Global Amphibians Original Grids

    Data.gov (United States)

    National Aeronautics and Space Administration — The Global Amphibians Original Grids of the Gridded Species Distribution, Version 1 are converted 1- kilometer grid cell data available in the Geographic Coordinate...

  18. Gridded Species Distribution, Version 1: Global Amphibians Family Richness Grids

    Data.gov (United States)

    National Aeronautics and Space Administration — Global Amphibians Family Richness Grids of the Gridded Species Distribution, Version 1 are aggregations of the presence grids data at the family level. They are...

  19. Index Grids - MDC_USNationalGrid1K

    Data.gov (United States)

    NSGIC Local Govt | GIS Inventory — The U.S. National Grid is based on universally defined coordinate and grid systems and can, therefore, be easily extended for use world-wide as a universal grid...

  20. Security for grids

    Energy Technology Data Exchange (ETDEWEB)

    Humphrey, Marty; Thompson, Mary R.; Jackson, Keith R.

    2005-08-14

    Securing a Grid environment presents a distinctive set of challenges. This paper groups the activities that need to be secured into four categories: naming and authentication; secure communication; trust, policy, and authorization; and enforcement of access control. It examines the current state of the art in securing these processes and introduces new technologies that promise to meet the security requirements of Grids more completely.

  1. Getting grid users together

    CERN Multimedia

    Appleton, Owen

    2007-01-01

    "While Grid conferences are becoming ever more popular, many of them remain primarily IT events, with few if any users attending. Not so the second EGEE User Forum, an event specifically designed to bring together the diverse user community that makes use of the EGEE grid infrastructure." (1 page)

  2. The LHCb Grid Simulation

    CERN Multimedia

    Baranov, Alexander

    2016-01-01

    The LHCb Grid access if based on the LHCbDirac system. It provides access to data and computational resources to researchers with different geographical locations. The Grid has a hierarchical topology with multiple sites distributed over the world. The sites differ from each other by their number of CPUs, amount of disk storage and connection bandwidth. These parameters are essential for the Grid work. Moreover, job scheduling and data distribution strategy have a great impact on the grid performance. However, it is hard to choose an appropriate algorithm and strategies as they need a lot of time to be tested on the real grid. In this study, we describe the LHCb Grid simulator. The simulator reproduces the LHCb Grid structure with its sites and their number of CPUs, amount of disk storage and bandwidth connection. We demonstrate how well the simulator reproduces the grid work, show its advantages and limitations. We show how well the simulator reproduces job scheduling and network anomalies, consider methods ...

  3. Perspectives on grid computing

    NARCIS (Netherlands)

    Schwiegelshohn, U.; Badia, R.M.; Bubak, M.T.; Danelutto, M.; Dustdar, S.; Gagliardi, F.; Geiger, A.; Hluchy, L.; Kranzlmüller, D.; Laure, E.; Priol, T.; Reinefeld, A.; Resch, M.; Reuter, A.; Rienhoff, O.; Rüter, T.; Sloot, P.; Talia, D.; Ullmann, K.; Yahyapour, R.; von Voigt, G.

    2010-01-01

    Grid computing has been the subject of many large national and international IT projects. However, not all goals of these projects have been achieved. In particular, the number of users lags behind the initial forecasts laid out by proponents of grid technologies. This underachievement may have led

  4. 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.

  5. Wind and Solar on the Power Grid: Myths and Misperceptions, Greening the Grid (Spanish Version)

    Energy Technology Data Exchange (ETDEWEB)

    Authors: Denholm, Paul; Cochran, Jaquelin; Brancucci Martinez-Anido, Carlo

    2016-04-01

    This is the Spanish version of the 'Greening the Grid - Wind and Solar on the Power Grid: Myths and Misperceptions'. Wind and solar are inherently more variable and uncertain than the traditional dispatchable thermal and hydro generators that have historically provided a majority of grid-supplied electricity. The unique characteristics of variable renewable energy (VRE) resources have resulted in many misperceptions regarding their contribution to a low-cost and reliable power grid. Common areas of concern include: 1) The potential need for increased operating reserves, 2) The impact of variability and uncertainty on operating costs and pollutant emissions of thermal plants, and 3) The technical limits of VRE penetration rates to maintain grid stability and reliability. This fact sheet corrects misperceptions in these areas.

  6. Emergency and post-emergency control in the formation of micro-grids

    Directory of Open Access Journals (Sweden)

    Ilyushin Pavel

    2017-01-01

    Full Text Available At the present time, there is a worldwide tendency to clustering the electrical power systems at LV and MV levels – creating the micro-grids. In this connection, numerous of technical issues appear in control approaches in general and in particular in emergency and post-emergency control. As micro-grids are meant to operate both in interconnected and islanded modes, the ability to steadily island and backward synchronize with an upper grid provides reduction of the negative impact of failure rate of electrical power system’s elements, as well as power quality parameters influence toward operation regime of the loads. The consequence of previously described features is particular requirements for the following emergency automatics: overload-preventing automatics for overhead lines, cables and transformers; out-of-step automatics and under-frequency load shedding. Low inertia constants of some distributed generation units and low time constants of electromagnetic transients of generating units and ESS, interconnected with a grid by means of power-electronics, provide an ability to realize additional (fast control signals in overload-preventing automatics, dispatching generating units and ESS with an aim to prevent considered elements tripping.

  7. National transmission grid study

    Energy Technology Data Exchange (ETDEWEB)

    Abraham, Spencer [USDOE Office of the Secretary of Energy, Washington, DC (United States)

    2003-05-31

    The National Energy Policy Plan directed the U.S. Department of Energy (DOE) to conduct a study to examine the benefits of establishing a national electricity transmission grid and to identify transmission bottlenecks and measures to address them. DOE began by conducting an independent analysis of U.S. electricity markets and identifying transmission system bottlenecks using DOE’s Policy Office Electricity Modeling System (POEMS). DOE’s analysis, presented in Section 2, confirms the central role of the nation’s transmission system in lowering costs to consumers through increased trade. More importantly, DOE’s analysis also confirms the results of previous studies, which show that transmission bottlenecks and related transmission system market practices are adding hundreds of millions of dollars to consumers’ electricity bills each year. A more detailed technical overview of the use of POEMS is provided in Appendix A. DOE led an extensive, open, public input process and heard a wide range of comments and recommendations that have all been considered.1 More than 150 participants registered for three public workshops held in Detroit, MI (September 24, 2001); Atlanta, GA (September 26, 2001); and Phoenix, AZ (September 28, 2001).

  8. The GRID seminar

    CERN Multimedia

    CERN. Geneva HR-RFA

    2006-01-01

    The Grid infrastructure is a key part of the computing environment for the simulation, processing and analysis of the data of the LHC experiments. These experiments depend on the availability of a worldwide Grid infrastructure in several aspects of their computing model. The Grid middleware will hide much of the complexity of this environment to the user, organizing all the resources in a coherent virtual computer center. The general description of the elements of the Grid, their interconnections and their use by the experiments will be exposed in this talk. The computational and storage capability of the Grid is attracting other research communities beyond the high energy physics. Examples of these applications will be also exposed during the presentation.

  9. Fast Gridding on Commodity Graphics Hardware

    DEFF Research Database (Denmark)

    Sørensen, Thomas Sangild; Schaeffter, Tobias; Noe, Karsten Østergaard

    2007-01-01

    is the far most time consuming of the three steps (Table 1). Modern graphics cards (GPUs) can be utilised as a fast parallel processor provided that algorithms are reformulated in a parallel solution. The purpose of this work is to test the hypothesis, that a non-cartesian reconstruction can be efficiently......The most commonly used algorithm for non-cartesian MRI reconstruction is the gridding algorithm [1]. It consists of three steps:                    1) convolution with a gridding kernel and resampling on a cartesian grid, 2) inverse FFT, and 3) deapodization. On the CPU the convolution step...... implemented on graphics hardware giving a significant speedup compared to CPU based alternatives. We present a novel GPU implementation of the convolution step that overcomes the problems of memory bandwidth that has limited the speed of previous GPU gridding algorithms [2]....

  10. First Tuesday@CERN - THE GRID GETS REAL !

    CERN Multimedia

    2003-01-01

    A few years ago, "the Grid" was just a vision dreamt up by some computer scientists who wanted to share processor power and data storage capacity between computers around the world - in much the same way as today's Web shares information seamlessly between millions of computers. Today, Grid technology is a huge enterprise, involving hundreds of software engineers, and generating exciting opportunities for industry. "Computing on demand", "utility computing", "web services", and "virtualisation" are just a few of the buzzwords in the IT industry today that are intimately connected to the development of Grid technology. For this third First Tuesday @CERN, the panel will survey some of the latest major breakthroughs in building international computer Grids for science. It will also provide a snapshot of Grid-related industrial activities, with contributions from both major players in the IT sector as well as emerging Grid technology start-ups. Panel: - Les Robertson, Head of the LHC Computing Grid Project, IT ...

  11. ITIL and Grid services at GridKa

    Science.gov (United States)

    Marten, H.; Koenig, T.

    2010-04-01

    The Steinbuch Centre for Computing (SCC) is a new organizational unit of the Karlsruhe Institute of Technology (KIT). Founded in February 2008 as a merger of the previous Institute for Scientific Computing of Forschungszentrum Karlsruhe and the Computing Centre of the Technical University Karlsruhe, SCC provides a broad spectrum of IT services for 8.000 employees and 18.000 students and carries out research and development in key areas of information technology under the same roof. SCC is also known to host the German WLCG [1] Tier-1 centre GridKa. In order to accompany the merging of the two existing computing centres located at a distance of about 10 km and to provide common first class services for science, SCC has selected the IT service management according to the industrial quasi-standard "IT Infrastructure Library (ITIL)" [3] as a strategic element. The paper discusses the implementation of a few ITIL key components from the perspective of a Scientific Computing Centre using examples of Grid services at GridKa.

  12. ITIL and Grid services at GridKa

    Energy Technology Data Exchange (ETDEWEB)

    Marten, H; Koenig, T, E-mail: holger.marten@kit.ed, E-mail: tobias.koenig@kit.ed [Karlsruhe Institute of Technology, Forschungszentrum Karlsruhe GmbH Steinbuch Centre for Computing Herman-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany)

    2010-04-01

    The Steinbuch Centre for Computing (SCC) is a new organizational unit of the Karlsruhe Institute of Technology (KIT). Founded in February 2008 as a merger of the previous Institute for Scientific Computing of Forschungszentrum Karlsruhe and the Computing Centre of the Technical University Karlsruhe, SCC provides a broad spectrum of IT services for 8.000 employees and 18.000 students and carries out research and development in key areas of information technology under the same roof. SCC is also known to host the German WLCG [1] Tier-1 centre GridKa. In order to accompany the merging of the two existing computing centres located at a distance of about 10 km and to provide common first class services for science, SCC has selected the IT service management according to the industrial quasi-standard 'IT Infrastructure Library (ITIL)' [3] as a strategic element. The paper discusses the implementation of a few ITIL key components from the perspective of a Scientific Computing Centre using examples of Grid services at GridKa.

  13. ITIL and Grid services at GridKa

    International Nuclear Information System (INIS)

    Marten, H; Koenig, T

    2010-01-01

    The Steinbuch Centre for Computing (SCC) is a new organizational unit of the Karlsruhe Institute of Technology (KIT). Founded in February 2008 as a merger of the previous Institute for Scientific Computing of Forschungszentrum Karlsruhe and the Computing Centre of the Technical University Karlsruhe, SCC provides a broad spectrum of IT services for 8.000 employees and 18.000 students and carries out research and development in key areas of information technology under the same roof. SCC is also known to host the German WLCG [1] Tier-1 centre GridKa. In order to accompany the merging of the two existing computing centres located at a distance of about 10 km and to provide common first class services for science, SCC has selected the IT service management according to the industrial quasi-standard 'IT Infrastructure Library (ITIL)' [3] as a strategic element. The paper discusses the implementation of a few ITIL key components from the perspective of a Scientific Computing Centre using examples of Grid services at GridKa.

  14. A Cloud Associated Smart Grid Admin Dashboard

    Directory of Open Access Journals (Sweden)

    P. Naveen

    2018-02-01

    Full Text Available Intelligent smart grid system undertakes electricity demand in a sustainable, reliable, economical and environmentally friendly manner. As smart grid involves, it has the liability of meeting the changing consumer needs on the day-to-day basis. Modern energy consumers like to vivaciously regulate their consumption patterns more competently and intelligently than current provided ways. To fulfill the consumers’ needs, smart meters and sensors make the grid infrastructure more efficient and resilient in energy data collection and management even with the ever-changing renewable power generation. Though cloud acts as an outlet for the energy consumers to retrieve energy data from the grid, the information systems available are technically constrained and not user-friendly. Hence, a simple technology enabled utility-consumer interactive information system in the form of a dashboard is presented to cater the electric consumer needs.

  15. Player Types, Play Styles, and Play Complexity: Updating the Entertainment Grid

    Science.gov (United States)

    Rademacher Mena, Ricardo Javier

    2012-01-01

    In a previous work the author created the Education and Entertainment Grid by combining various taxonomies from the fields of play and learning. In this paper, a section of this grid known as the Entertainment Grid will be extended by including previously unused elements of Richard Bartle's online player types and Robert Caillois' play complexity.…

  16. Distributed Semantic Architecture for Smart Grids 

    Directory of Open Access Journals (Sweden)

    Mariano Ortega

    2012-11-01

    Full Text Available The smart grid revolution demands a huge effort in redesigning and enhancing current power networks, as well as integrating emerging scenarios such as distributed generation, renewable energies or the electric vehicle. This novel situation will cause a huge flood of data that can only be handled, processed and exploited in real-time with the help of cutting-edge ICT (Information and Communication Technologies. We present here a new architecture that, contrary to the previous centralised and static model, distributes the intelligence all over the grid by means of individual intelligent nodes controlling a number of electric assets. The nodes own a profile of the standard smart grid ontology stored in the knowledge base with the inferred information about their environment in RDF triples. Since the system does not have a central registry or a service directory, the connectivity emerges from the view of the world semantically encoded by each individual intelligent node (i.e., profile + inferred information. We have described a use-case both with and without real-time requirements to illustrate and validate this novel approach.

  17. Analysis of Electric Power Board of Chattanooga Smart Grid Investment

    Energy Technology Data Exchange (ETDEWEB)

    Starke, Michael [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ollis, Ben [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Glass, Jim [EPB Electric Power, Chattanooga, TN (United States); Melin, Alex [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Liu, Guodong [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Sharma, Isha [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-06-01

    The deployment of a Smart Grid within the EPB electrical system has brought significant value to EPB customers and to EPB operations. The Smart Grid implementation has permitted the capability to automate many of the existing systems, increasing the overall efficiency and decreasing round trip time for many required operation functions. This has both reduced the cost of operations and increased the reliability of customer service. This boost in performance can be primarily linked to two main components: the communication network and the availability of data. The existence of a fiber communication backbone has opened numerous opportunities for EPB. Large data sets from remote devices can be continuously polled and used to compute numerous metrics. The speed of communication has provided a pathway to sophisticated distribution automation that would not otherwise be possible. The data have been shown to provide a much broader view of the actual electrical system that was not previously available, opening many new opportunities in data analytics. This report documents many of the existing systems and operational features of the EPB system. Many of these systems have seen significant improvement with the deployment of Smart Grid technologies. The research behind this report found that in some cases, the value was directly computable or estimable for these enhancements. Currently, several ongoing research topics are under investigation within EPB. Through a grant from TVA, EPB is currently installing a 1.3MW solar photovoltaic system, which will be the first-generation asset owned by EPB.

  18. BSCW Unstructured Grids - VGRID software

    Data.gov (United States)

    National Aeronautics and Space Administration — These grids were constructed using VGRID software from NASA Langley. The grids designed for node based (labeled 'nc') and cell-centered solvers are supplied. Grids...

  19. HIRENASD Unstructured Grids - VGRID software

    Data.gov (United States)

    National Aeronautics and Space Administration — These grids were constructed using VGRID software from NASA Langley. The grids designed for node based (labeled 'nc') and cell-centered solvers are supplied. Grids...

  20. Transient stability with grid connection and wind turbine drive-train effects

    DEFF Research Database (Denmark)

    Fajardo-R, Luis A.; Medina, Aurelio; Iov, Florin

    2009-01-01

    This paper assesses transient stability of grid-connected wind turbines, combining grid-connection, wind turbine flexibility, and induction generator stability features. Through a grid-connected 2 MW wind turbine cage-generator, the investigation is conducted to identify the critical clearing time...