WorldWideScience

Sample records for subsatellite grid scales

  1. Grid origin affects scaling of species across spatial scales.

    NARCIS (Netherlands)

    Witte, J.P.M.; He, F.; Groen, C.L.G.

    2008-01-01

    Aim: Distribution maps of species based on a grid are useful for investigating relationships between scale and the number or area of occupied grid cells. A species is scaled up simply by merging occupied grid cells on the observation grid to successively coarser cells. Scale-occupancy relationships

  2. Sub-Grid Scale Plume Modeling

    Directory of Open Access Journals (Sweden)

    Greg Yarwood

    2011-08-01

    Full Text Available Multi-pollutant chemical transport models (CTMs are being routinely used to predict the impacts of emission controls on the concentrations and deposition of primary and secondary pollutants. While these models have a fairly comprehensive treatment of the governing atmospheric processes, they are unable to correctly represent processes that occur at very fine scales, such as the near-source transport and chemistry of emissions from elevated point sources, because of their relatively coarse horizontal resolution. Several different approaches have been used to address this limitation, such as using fine grids, adaptive grids, hybrid modeling, or an embedded sub-grid scale plume model, i.e., plume-in-grid (PinG modeling. In this paper, we first discuss the relative merits of these various approaches used to resolve sub-grid scale effects in grid models, and then focus on PinG modeling which has been very effective in addressing the problems listed above. We start with a history and review of PinG modeling from its initial applications for ozone modeling in the Urban Airshed Model (UAM in the early 1980s using a relatively simple plume model, to more sophisticated and state-of-the-science plume models, that include a full treatment of gas-phase, aerosol, and cloud chemistry, embedded in contemporary models such as CMAQ, CAMx, and WRF-Chem. We present examples of some typical results from PinG modeling for a variety of applications, discuss the implications of PinG on model predictions of source attribution, and discuss possible future developments and applications for PinG modeling.

  3. Measurements of the Lunar Gravity Field using a Relay Subsatellite

    Science.gov (United States)

    Namiki, Noriyuki; Hanada, H.; Kawano, N.; Heki, K.; Iwata, T.; Ogawa, M.; Takano, T.

    1998-01-01

    Estimating spherical harmonic coefficients of the lunar gravity field has been a focus in selenodesy since the late 1960s when Doppler tracking data from lunar orbiters were first analyzed. Early analyses were limited by the low degree and order of the spherical harmonic solutions, mostly due to the slow speed and low memory of the then-available computers. However, rapid development of the computational ability has increased the resolution of the lunar gravity models significantly. Doppler tracking data from lunar orbiters 1-5 and Apollo subsatellites up to degree and order 60 (Lun60d) have been analyzed. Further, the tracking data from the Clementine spacecraft launched in 1994 has been incorporated, and a model complete to degree and order 70 (GLGM-2) has been developed. These high-resolution gravity models have been used for studies of internal structure and tectonics of the Moon. Interestingly, Lun60d and GLGM-2 show significant differences in the spherical harmonic coefficients for degree greater than 20. Because the semimajor axis of Clementine's orbit is nearly twice as large as the radius of the Moon, the contribution of the new tracking data is prevailed in the low-degree field. Methodologically, the differences in the high-degree field arise from the different weighting of the tracking data and gravity model, but, in principle, these are caused by a lack of tracking data over the farside. While the current Lunar Prospector mission is expected to improve the spatial resolution over the mid- to high-latitude regions of the nearside significantly, the absence of Doppler tracking data over the farside remains unresolved. To complete the coverage of tracking over the farside, we are developing a satellite-to-satellite (four-way) Doppler tracking experiment in SELENE (the SELenological and ENgineering Explorer) project of Japan. Outline of the Mission: The SELENE is a joint project by the National Space Development Agency of Japan (NASDA) and the Institute of

  4. Creation of geographic information database of subsatellite calibration test site

    Science.gov (United States)

    Zyelyk, Ya. I.; Semeniv, O. V.

    2014-12-01

    The prototype of geographic information database (DB) of the sub-satellite calibration test site has been created, to which user can be accessed from the free open-source geographic information system Quantum GIS (QGIS) environment. QGIS is used as an integrator of all data and applications and visualizer of the satellite imagery and vector layers of test sites in the cartographic interface. Conversion of the database from the local representation in the MS Access to the server representation in the PostgreSQL environment has been performed. Dynamic application to QGIS for user interaction from QGIS environment with the object-relational database and to display information from the database has been created. Functional-algorithmic part of these application and the interface for user interaction with the database has been developed.

  5. Optimal Wind Energy Integration in Large-Scale Electric Grids

    Science.gov (United States)

    Albaijat, Mohammad H.

    The major concern in electric grid operation is operating under the most economical and reliable fashion to ensure affordability and continuity of electricity supply. This dissertation investigates the effects of such challenges, which affect electric grid reliability and economic operations. These challenges are: 1. Congestion of transmission lines, 2. Transmission lines expansion, 3. Large-scale wind energy integration, and 4. Phaser Measurement Units (PMUs) optimal placement for highest electric grid observability. Performing congestion analysis aids in evaluating the required increase of transmission line capacity in electric grids. However, it is necessary to evaluate expansion of transmission line capacity on methods to ensure optimal electric grid operation. Therefore, the expansion of transmission line capacity must enable grid operators to provide low-cost electricity while maintaining reliable operation of the electric grid. Because congestion affects the reliability of delivering power and increases its cost, the congestion analysis in electric grid networks is an important subject. Consequently, next-generation electric grids require novel methodologies for studying and managing congestion in electric grids. We suggest a novel method of long-term congestion management in large-scale electric grids. Owing to the complication and size of transmission line systems and the competitive nature of current grid operation, it is important for electric grid operators to determine how many transmission lines capacity to add. Traditional questions requiring answers are "Where" to add, "How much of transmission line capacity" to add, and "Which voltage level". Because of electric grid deregulation, transmission lines expansion is more complicated as it is now open to investors, whose main interest is to generate revenue, to build new transmission lines. Adding a new transmission capacity will help the system to relieve the transmission system congestion, create

  6. The Cambridge CFD Grid for Large Scale Distributed CFD Applications

    OpenAIRE

    Yang, Xiaobo; Hayes, Mark; Jenkins, K.; Cant, Stewart R.

    2005-01-01

    A revised version submitted for publication in the Elsevier Journal of Future Generation Computer Systems: promotional issue on Grid Computing, originally appeared in the Proceedings of ICCS 2004, Krakow, Poland, June 2004 The Cambridge CFD (computational fluid dynamics) Grid is a distributed problem solving environment for large-scale CFD applications set up between the Cambridge eScience Centre and the CFD Lab in the Engineering Department at the University of Cambridge. A Web portal, th...

  7. Large-scale PV grid integration

    Energy Technology Data Exchange (ETDEWEB)

    Martins Souza, Hellen; Jose do Carmo, Marlon; Rocha de Oliveira, Angelo [CEFET-MG, Leopoldina (Brazil). Dept. of Control and Automation; Willer de Oliveira, Leonard [Universidade Federal de Juiz de Fora (UFJF) (Brazil). Power Systems; Ribeiro, Paulo Fernando [Technische Univ. Eindhoven (Netherlands). Electrical Energy Systems

    2012-07-01

    This paper aims to review the development of solar energy as a renewable source of electricity, which is vital to the development of a more sustainable world, pointing out challenges and technology trends. First, there will be a review of the development of photovoltaic panels, focusing on countries where the technology is in its most advanced stage, such as Germany, Netherlands, the United States and Spain as well as showing trends of this type of power generation source. Important aspects such as efficiency and production costs of photovoltaic power plants will be covered. In addition, the integration of this generation sources to the electric power system will be considered concerning their impact on system parameters as power quality, stability and protection. The existing rules and interconnection standards for large-scale integration / implementation of photovoltaic (PV) generation are reviewed and discussed. Finally, a special application case of PV in the country of Brazil is briefly mentioned considering its potential for generation and implementation in the upcoming years. (orig.)

  8. Planet-Scale grid A particle collier leads data grid developers to unprecedented dimensions

    CERN Multimedia

    Thibodeau, Patrick

    2005-01-01

    In 2007, scientists will begin smashing protons and ions together in a massive, multinational experiment to understand what the universe looked like tiny fractions of a second after the Big Bang. The particle accelerator used in this test will release a vast flood of data on a scale unlike anything seen before, and for that scientists will need a computing grid of equally great capability

  9. 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.

  10. Smart grid integration of small-scale trigeneration systems

    Science.gov (United States)

    Vacheva, Gergana; Kanchev, Hristiyan; Hinov, Nikolay

    2017-12-01

    This paper presents a study on the possibilities for implementation of local heating, air-conditioning and electricity generation (trigeneration) as distributed energy resource in the Smart Grid. By the means of microturbine-based generators and absorption chillers buildings are able to meet partially or entirely their electrical load curve or even supply power to the grid by following their heating and air-conditioning daily schedule. The principles of small-scale cooling, heating and power generation systems are presented at first, then the thermal calculations of an example building are performed: the heat losses due to thermal conductivity and the estimated daily heating and air-conditioning load curves. By considering daily power consumption curves and weather data for several winter and summer days, the heating/air-conditioning schedule is estimated and the available electrical energy from a microturbine-based cogeneration system is estimated. Simulation results confirm the potential of using cogeneration and trigeneration systems for local distributed electricity generation and grid support in the daily peaks of power consumption.

  11. Grid Integration Issues for Large Scale Wind Power Plants (WPPs)

    DEFF Research Database (Denmark)

    Wu, Qiuwei; Xu, Zhao; Østergaard, Jacob

    2010-01-01

    transmission system operators (TSOs) over the world have come up the grid codes to request the wind power plants (WPPs) to have more or less the same operating capability as the conventional power plants. The grid codes requirements from other TSOs are under development. This paper covers the steady state...... operation and low voltage ride through (LVRT) for the WPPs. The discussion of coping with the grid codes requirements is presented to come up with the grid codes complied WPPs solutions....

  12. Evapotranspiration and cloud variability at regional sub-grid scales

    Science.gov (United States)

    Vila-Guerau de Arellano, Jordi; Sikma, Martin; Pedruzo-Bagazgoitia, Xabier; van Heerwaarden, Chiel; Hartogensis, Oscar; Ouwersloot, Huug

    2017-04-01

    In regional and global models uncertainties arise due to our incomplete understanding of the coupling between biochemical and physical processes. Representing their impact depends on our ability to calculate these processes using physically sound parameterizations, since they are unresolved at scales smaller than the grid size. More specifically over land, the coupling between evapotranspiration, turbulent transport of heat and moisture, and clouds lacks a combined representation to take these sub-grid scales interactions into account. Our approach is based on understanding how radiation, surface exchange, turbulent transport and moist convection are interacting from the leaf- to the cloud scale. We therefore place special emphasis on plant stomatal aperture as the main regulator of CO2-assimilation and water transpiration, a key source of moisture source to the atmosphere. Plant functionality is critically modulated by interactions with atmospheric conditions occurring at very short spatiotemporal scales such as cloud radiation perturbations or water vapour turbulent fluctuations. By explicitly resolving these processes, the LES (large-eddy simulation) technique is enabling us to characterize and better understand the interactions between canopies and the local atmosphere. This includes the adaption time of vegetation to rapid changes in atmospheric conditions driven by turbulence or the presence of cumulus clouds. Our LES experiments are based on explicitly coupling the diurnal atmospheric dynamics to a plant physiology model. Our general hypothesis is that different partitioning of direct and diffuse radiation leads to different responses of the vegetation. As a result there are changes in the water use efficiencies and shifts in the partitioning of sensible and latent heat fluxes under the presence of clouds. Our presentation is as follows. First, we discuss the ability of LES to reproduce the surface energy balance including photosynthesis and CO2 soil

  13. Size Matters: How Scaling Affects the Interaction between Grid and Border Cells

    Directory of Open Access Journals (Sweden)

    Diogo Santos-Pata

    2017-07-01

    Full Text Available Many hippocampal cell types are characterized by a progressive increase in scale along the dorsal-to-ventral axis, such as in the cases of head-direction, grid and place cells. Also located in the medial entorhinal cortex (MEC, border cells would be expected to benefit from such scale modulations. However, this phenomenon has not been experimentally observed. Grid cells in the MEC of mammals integrate velocity related signals to map the environment with characteristic hexagonal tessellation patterns. Due to the noisy nature of these input signals, path integration processes tend to accumulate errors as animals explore the environment, leading to a loss of grid-like activity. It has been suggested that border-to-grid cells' associations minimize the accumulated grid cells' error when rodents explore enclosures. Thus, the border-grid interaction for error minimization is a suitable scenario to study the effects of border cell scaling within the context of spatial representation. In this study, we computationally address the question of (i border cells' scale from the perspective of their role in maintaining the regularity of grid cells' firing fields, as well as (ii what are the underlying mechanisms of grid-border associations relative to the scales of both grid and border cells. Our results suggest that for optimal contribution to grid cells' error minimization, border cells should express smaller firing fields relative to those of the associated grid cells, which is consistent with the hypothesis of border cells functioning as spatial anchoring signals.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-12-01

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

  15. Mastering Uncertainty and Risk at Multiple Time Scales in the Future Electrical Grid

    Energy Technology Data Exchange (ETDEWEB)

    Chertkov, Michael [Los Alamos National Laboratory; Bent, Russell W. [Los Alamos National Laboratory; Backhaus, Scott N. [Los Alamos National Laboratory

    2012-07-10

    Today's electrical grids enjoy a relatively clean separation of spatio-temporal scales yielding a compartmentalization of grid design, optimization, control and risk assessment allowing for the use of conventional mathematical tools within each area. In contrast, the future grid will incorporate time-intermittent renewable generation, operate via faster electrical markets, and tap the latent control capability at finer grid modeling scales; creating a fundamentally new set of couplings across spatiotemporal scales and requiring revolutionary advances in mathematics techniques to bridge these scales. One example is found in decade-scale grid expansion planning in which today's algorithms assume accurate load forecasts and well-controlled generation. Incorporating intermittent renewable generation creates fluctuating network flows at the hourly time scale, inherently linking the ability of a transmission line to deliver electrical power to hourly operational decisions. New operations-based planning algorithms are required, creating new mathematical challenges. Spatio-temporal scales are also crossed when the future grid's minute-scale fluctuations in network flows (due to intermittent generation) create a disordered state upon which second-scale transient grid dynamics propagate effectively invalidating today's on-line dynamic stability analyses. Addressing this challenge requires new on-line algorithms that use large data streams from new grid sensing technologies to physically aggregate across many spatial scales to create responsive, data-driven dynamic models. Here, we sketch the mathematical foundations of these problems and potential solutions.

  16. Estimation of aquifer scale proportion using equal area grids: assessment of regional scale groundwater quality

    Science.gov (United States)

    Belitz, Kenneth; Jurgens, Bryant C.; Landon, Matthew K.; Fram, Miranda S.; Johnson, Tyler D.

    2010-01-01

    The proportion of an aquifer with constituent concentrations above a specified threshold (high concentrations) is taken as a nondimensional measure of regional scale water quality. If computed on the basis of area, it can be referred to as the aquifer scale proportion. A spatially unbiased estimate of aquifer scale proportion and a confidence interval for that estimate are obtained through the use of equal area grids and the binomial distribution. Traditionally, the confidence interval for a binomial proportion is computed using either the standard interval or the exact interval. Research from the statistics literature has shown that the standard interval should not be used and that the exact interval is overly conservative. On the basis of coverage probability and interval width, the Jeffreys interval is preferred. If more than one sample per cell is available, cell declustering is used to estimate the aquifer scale proportion, and Kish's design effect may be useful for estimating an effective number of samples. The binomial distribution is also used to quantify the adequacy of a grid with a given number of cells for identifying a small target, defined as a constituent that is present at high concentrations in a small proportion of the aquifer. Case studies illustrate a consistency between approaches that use one well per grid cell and many wells per cell. The methods presented in this paper provide a quantitative basis for designing a sampling program and for utilizing existing data.

  17. 77 FR 58416 - Large Scale Networking (LSN); Middleware and Grid Interagency Coordination (MAGIC) Team

    Science.gov (United States)

    2012-09-20

    ... Large Scale Networking (LSN); Middleware and Grid Interagency Coordination (MAGIC) Team AGENCY: The Networking and Information Technology Research and Development (NITRD) National Coordination Office (NCO... to the Large Scale Networking (LSN) Coordinating Group (CG). Public Comments: The government seeks...

  18. 78 FR 7464 - Large Scale Networking (LSN)-Middleware And Grid Interagency Coordination (MAGIC) Team

    Science.gov (United States)

    2013-02-01

    ... Large Scale Networking (LSN)--Middleware And Grid Interagency Coordination (MAGIC) Team AGENCY: The Networking and Information Technology Research and Development (NITRD) National Coordination Office (NCO... Team reports to the Large Scale Networking (LSN) Coordinating Group (CG). Public Comments: The...

  19. GLAD: a system for developing and deploying large-scale bioinformatics grid.

    Science.gov (United States)

    Teo, Yong-Meng; Wang, Xianbing; Ng, Yew-Kwong

    2005-03-01

    Grid computing is used to solve large-scale bioinformatics problems with gigabytes database by distributing the computation across multiple platforms. Until now in developing bioinformatics grid applications, it is extremely tedious to design and implement the component algorithms and parallelization techniques for different classes of problems, and to access remotely located sequence database files of varying formats across the grid. In this study, we propose a grid programming toolkit, GLAD (Grid Life sciences Applications Developer), which facilitates the development and deployment of bioinformatics applications on a grid. GLAD has been developed using ALiCE (Adaptive scaLable Internet-based Computing Engine), a Java-based grid middleware, which exploits the task-based parallelism. Two bioinformatics benchmark applications, such as distributed sequence comparison and distributed progressive multiple sequence alignment, have been developed using GLAD.

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

    CERN Document Server

    Kołodziej, Joanna

    2012-01-01

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

  1. Effect of wettability on scale-up of multiphase flow from core-scale to reservoir fine-grid-scale

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Y.C.; Mani, V.; Mohanty, K.K. [Univ. of Houston, TX (United States)

    1997-08-01

    Typical field simulation grid-blocks are internally heterogeneous. The objective of this work is to study how the wettability of the rock affects its scale-up of multiphase flow properties from core-scale to fine-grid reservoir simulation scale ({approximately} 10{prime} x 10{prime} x 5{prime}). Reservoir models need another level of upscaling to coarse-grid simulation scale, which is not addressed here. Heterogeneity is modeled here as a correlated random field parameterized in terms of its variance and two-point variogram. Variogram models of both finite (spherical) and infinite (fractal) correlation length are included as special cases. Local core-scale porosity, permeability, capillary pressure function, relative permeability functions, and initial water saturation are assumed to be correlated. Water injection is simulated and effective flow properties and flow equations are calculated. For strongly water-wet media, capillarity has a stabilizing/homogenizing effect on multiphase flow. For small variance in permeability, and for small correlation length, effective relative permeability can be described by capillary equilibrium models. At higher variance and moderate correlation length, the average flow can be described by a dynamic relative permeability. As the oil wettability increases, the capillary stabilizing effect decreases and the deviation from this average flow increases. For fractal fields with large variance in permeability, effective relative permeability is not adequate in describing the flow.

  2. Prospects for investment in large-scale, grid-connected solar power in Africa

    DEFF Research Database (Denmark)

    Hansen, Ulrich Elmer; Nygaard, Ivan; Pedersen, Mathilde Brix

    Solar power in Africa is on its way to becoming a market-based commodity, thus escaping the niche for individual electricity supply that is mainly supported by international donor organisations. Significant reductions in the cost of photovoltaic (PV) panels and a 400 percent increase in oil prices......-scale investments in grid-connected solar power plants and local assembly facilities for PV panels, have exceeded even optimistic scenarios. Finally, therefore, there seem to be bright prospects for investment in large-scale grid-connected solar power in Africa....... since the 1990s have changed the competiveness of solar PV in all markets, ranging from individual households via institutions to mini-grids and grid-connected installations. In volume and investment, the market for large-scale grid-connected solar power plants is by far the most important...

  3. Integration of Large-scale Consumers in Smart Grid

    DEFF Research Database (Denmark)

    Rahnama, Samira

    A prominent feature of the smart grid is to involve the consumer side in balancing effort, rather than placing the entire burden of maintaining this balance on the producers. This thesis investigates the utilization of flexible consumers in the future smart grid. The focus of this work is on indu......A prominent feature of the smart grid is to involve the consumer side in balancing effort, rather than placing the entire burden of maintaining this balance on the producers. This thesis investigates the utilization of flexible consumers in the future smart grid. The focus of this work...... is on industrial consumers. We propose a three-level hierarchical control framework, in which a so-called “Aggregator” is located between a number of flexible industrial demands and a grid operator. The aggregator is the heart of this setup, with the task of handling the energy/power services can be derived from...... an appropriate control scenario, formulating the optimal objective function at the aggregator, modeling the flexibility of our specific case studies and determining the required information flow. This thesis also investigates different types of aggregation, when we have different types of consumers...

  4. Scale Effect Analysis of Urban Compactness Measurement Index Based On Grid

    Science.gov (United States)

    Cao, Lei

    2017-05-01

    Scale effect is one of the basic aspects of urban compactness. This paper takes the use of urban construction land as the breakthrough point, continuity degree and Gini coefficient as the indexes to analyse the scale effect of grid from the calculation through the different scales grid analysis of urban construction land extracted by ERDAS and ARCGIS respectively. The result showed that the selected indicators quantitively indicate the features of research area land, different scale effects of two indexes, big difference in continuity degree influenced by scale, and slight impact on Gini coefficient influenced by scale.

  5. Towards a Grid File System Based on a Large-Scale BLOB Management Service

    Science.gov (United States)

    Tran, Viet-Trung; Antoniu, Gabriel; Nicolae, Bogdan; Bougé, Luc; Tatebe, Osamu

    This paper addresses the problem of building a grid file system for applications that need to manipulate huge data, distributed and concurrently accessed at a very large scale. In this paper we explore how this goal could be reached through a cooperation between the Gfarm grid file system and BlobSeer, a distributed object management system specifically designed for huge data management under heavy concurrency. The resulting BLOB-based grid file system exhibits scalable file access performance in scenarios where huge files are subject to massive, concurrent, fine-grain accesses. This is demonstrated through preliminary experiments of our prototype, conducted on the Grid'5000 testbed.

  6. 78 FR 70076 - Large Scale Networking (LSN)-Middleware and Grid Interagency Coordination (MAGIC) Team

    Science.gov (United States)

    2013-11-22

    ... Large Scale Networking (LSN)--Middleware and Grid Interagency Coordination (MAGIC) Team AGENCY: The Networking and Information Technology Research and Development (NITRD) National Coordination Office (NCO... Networking (LSN) Coordinating Group (CG). Public Comments: The government seeks individual input; attendees...

  7. Grid-Scale Energy Storage Demonstration of Ancillary Services Using the UltraBattery Technology

    Energy Technology Data Exchange (ETDEWEB)

    Seasholtz, Jeff [East Penn Mfg. Co., Inc., Lyons, PA (United States)

    2015-08-20

    The collaboration described in this document is being done as part of a cooperative research agreement under the Department of Energy’s Smart Grid Demonstration Program. This document represents the Final Technical Performance Report, from July 2012 through April 2015, for the East Penn Manufacturing Smart Grid Program demonstration project. This Smart Grid Demonstration project demonstrates Distributed Energy Storage for Grid Support, in particular the economic and technical viability of a grid-scale, advanced energy storage system using UltraBattery ® technology for frequency regulation ancillary services and demand management services. This project entailed the construction of a dedicated facility on the East Penn campus in Lyon Station, PA that is being used as a working demonstration to provide regulation ancillary services to PJM and demand management services to Metropolitan Edison (Met-Ed).

  8. Towards A Grid File System Based On A Large-Scale BLOB Management Service

    OpenAIRE

    Tran, Viet-Trung; Antoniu, Gabriel; Nicolae, Bogdan; Bougé, Luc

    2009-01-01

    International audience; This paper addresses the problem of building a grid file system for applications that need to manipulate huge data, distributed and concurrently accessed at a very large scale. In this paper we explore how this goal could be reached through a cooperation between the Gfarm grid file system and BlobSeer, a distributed object management system specifically designed for huge data management under heavy concurrency. The resulting BLOB-based grid file system exhibits scalable fil...

  9. A Systematic Multi-Time Scale Solution for Regional Power Grid Operation

    Science.gov (United States)

    Zhu, W. J.; Liu, Z. G.; Cheng, T.; Hu, B. Q.; Liu, X. Z.; Zhou, Y. F.

    2017-10-01

    Many aspects need to be taken into consideration in a regional grid while making schedule plans. In this paper, a systematic multi-time scale solution for regional power grid operation considering large scale renewable energy integration and Ultra High Voltage (UHV) power transmission is proposed. In the time scale aspect, we discuss the problem from month, week, day-ahead, within-day to day-behind, and the system also contains multiple generator types including thermal units, hydro-plants, wind turbines and pumped storage stations. The 9 subsystems of the scheduling system are described, and their functions and relationships are elaborated. The proposed system has been constructed in a provincial power grid in Central China, and the operation results further verified the effectiveness of the system.

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

    Directory of Open Access Journals (Sweden)

    Sheng Jie Shao

    2010-06-01

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

  11. Bio-Inspired Computation: Clock-Free, Grid-Free, Scale-Free and Symbol Free

    Science.gov (United States)

    2015-06-11

    AFRL-AFOSR-JP-TR-2015-0002 Bio -inspired computation: clock-free, grid-free, scale-free, and symbol free Janet Wiles THE UNIVERSITY OF QUEENSLAND...SUBTITLE Bio -inspired computation: clock-free, grid-free, scale-free, and symbol free 5a. CONTRACT NUMBER FA2386-12-1-4050 5b. GRANT NUMBER 5c...SUPPLEMENTARY NOTES 14. ABSTRACT The project developed a new fundamental component for bio -inspired computing, based on a new way of modelling

  12. Vehicle-to-grid power implementation: From stabilizing the grid to supporting large-scale renewable energy

    Science.gov (United States)

    Kempton, Willett; Tomić, Jasna

    Vehicle-to-grid power (V2G) uses electric-drive vehicles (battery, fuel cell, or hybrid) to provide power for specific electric markets. This article examines the systems and processes needed to tap energy in vehicles and implement V2G. It quantitatively compares today's light vehicle fleet with the electric power system. The vehicle fleet has 20 times the power capacity, less than one-tenth the utilization, and one-tenth the capital cost per prime mover kW. Conversely, utility generators have 10-50 times longer operating life and lower operating costs per kWh. To tap V2G is to synergistically use these complementary strengths and to reconcile the complementary needs of the driver and grid manager. This article suggests strategies and business models for doing so, and the steps necessary for the implementation of V2G. After the initial high-value, V2G markets saturate and production costs drop, V2G can provide storage for renewable energy generation. Our calculations suggest that V2G could stabilize large-scale (one-half of US electricity) wind power with 3% of the fleet dedicated to regulation for wind, plus 8-38% of the fleet providing operating reserves or storage for wind. Jurisdictions more likely to take the lead in adopting V2G are identified.

  13. Implementation of Grid-computing Framework for Simulation in Multi-scale Structural Analysis

    Directory of Open Access Journals (Sweden)

    Data Iranata

    2010-05-01

    Full Text Available A new grid-computing framework for simulation in multi-scale structural analysis is presented. Two levels of parallel processing will be involved in this framework: multiple local distributed computing environments connected by local network to form a grid-based cluster-to-cluster distributed computing environment. To successfully perform the simulation, a large-scale structural system task is decomposed into the simulations of a simplified global model and several detailed component models using various scales. These correlated multi-scale structural system tasks are distributed among clusters and connected together in a multi-level hierarchy and then coordinated over the internet. The software framework for supporting the multi-scale structural simulation approach is also presented. The program architecture design allows the integration of several multi-scale models as clients and servers under a single platform. To check its feasibility, a prototype software system has been designed and implemented to perform the proposed concept. The simulation results show that the software framework can increase the speedup performance of the structural analysis. Based on this result, the proposed grid-computing framework is suitable to perform the simulation of the multi-scale structural analysis.

  14. Sub-Grid-Scale Description of Turbulent Magnetic Reconnection in Magnetohydrodynamics

    CERN Document Server

    Widmer, Fabien; Yokoi, Nobumitsu

    2015-01-01

    Magnetic reconnection requires, at least locally, a non-ideal plasma response. In collisionless space and astrophysical plasmas, turbulence could permit this instead of the too rare binary collisions. We investigated the influence of turbulence on the reconnection rate in the framework of a single fluid compressible MHD approach. The goal is to find out, whether unresolved, sub-grid for MHD simulations, turbulence can enhance the reconnection process in high Reynolds number astrophysical plasma. We solve, simultaneously with the grid-scale MHD equations, evolution equations for the sub-grid turbulent energy and cross helicity according to Yokoi's model (Yokoi (2013)) where turbulence is self-generated and -sustained through the inhomogeneities of the mean fields. Simulations of Harris and force free sheets confirm the results of Higashimori et al. (2013) and new results are obtained about the dependence on resistivity for large Reynolds number as well as guide field effects. The amount of energy transferred f...

  15. OffshoreDC DC grids for integration of large scale wind power

    DEFF Research Database (Denmark)

    Zeni, Lorenzo; Endegnanew, Atsede Gualu; Stamatiou, Georgios

    The present report summarizes the main findings of the Nordic Energy Research project “DC grids for large scale integration of offshore wind power – OffshoreDC”. The project is been funded by Nordic Energy Research through the TFI programme and was active between 2011 and 2016. The overall...... objective of the project was to drive the development of the VSC based HVDC technology for future large scale offshore grids, supporting a standardised and commercial development of the technology, and improving the opportunities for the technology to support power system integration of large scale offshore...... wind power. This was done by bringing together the key industry stakeholders and competent research organisations in the project....

  16. Improving sub-grid scale accuracy of boundary features in regional finite-difference models

    Science.gov (United States)

    Panday, Sorab; Langevin, Christian D.

    2012-01-01

    As an alternative to grid refinement, the concept of a ghost node, which was developed for nested grid applications, has been extended towards improving sub-grid scale accuracy of flow to conduits, wells, rivers or other boundary features that interact with a finite-difference groundwater flow model. The formulation is presented for correcting the regular finite-difference groundwater flow equations for confined and unconfined cases, with or without Newton Raphson linearization of the nonlinearities, to include the Ghost Node Correction (GNC) for location displacement. The correction may be applied on the right-hand side vector for a symmetric finite-difference Picard implementation, or on the left-hand side matrix for an implicit but asymmetric implementation. The finite-difference matrix connectivity structure may be maintained for an implicit implementation by only selecting contributing nodes that are a part of the finite-difference connectivity. Proof of concept example problems are provided to demonstrate the improved accuracy that may be achieved through sub-grid scale corrections using the GNC schemes.

  17. Biogas infrastructure from farm-scale to regional scale, line-pack storage in biogas grids

    NARCIS (Netherlands)

    Evert Jan Hengeveld

    2016-01-01

    The number of local and regional initiatives encouraging the production and use of regional produced energy grows. In these new developments biogas can play a role, as a producer of energy, but also in balancing the electricity grid. Collection of biogas from several digesters to a hub supports the

  18. Stochastic fields method for sub-grid scale emission heterogeneity in mesoscale atmospheric dispersion models

    OpenAIRE

    M. Cassiani; Vinuesa, J.F.; Galmarini, S.; Denby, B

    2010-01-01

    The stochastic fields method for turbulent reacting flows has been applied to the issue of sub-grid scale emission heterogeneity in a mesoscale model. This method is a solution technique for the probability density function (PDF) transport equation and can be seen as a straightforward extension of currently used mesoscale dispersion models. It has been implemented in an existing mesoscale model and the results are compared with Large-Eddy Simulation (LES) data devised to test specifically the...

  19. Stochastic fields method for sub-grid scale emission heterogeneity in mesoscale atmospheric dispersion models

    Directory of Open Access Journals (Sweden)

    M. Cassiani

    2010-01-01

    Full Text Available The stochastic fields method for turbulent reacting flows has been applied to the issue of sub-grid scale emission heterogeneity in a mesoscale model. This method is a solution technique for the probability density function (PDF transport equation and can be seen as a straightforward extension of currently used mesoscale dispersion models. It has been implemented in an existing mesoscale model and the results are compared with Large-Eddy Simulation (LES data devised to test specifically the effect of sub-grid scale emission heterogeneity on boundary layer concentration fluctuations. The sub-grid scale emission variability is assimilated in the model as a PDF of the emissions. The stochastic fields method shows excellent agreement with the LES data without adjustment of the constants used in the mesoscale model. The stochastic fields method is a stochastic solution of the transport equations for the concentration PDF of dispersing scalars, therefore it possesses the ability to handle chemistry of any complexity without the need to introduce additional closures for the high order statistics of chemical species. This study shows for the first time the feasibility of applying this method to mesoscale chemical transport models.

  20. Integrated Multi-Scale Data Analytics and Machine Learning for the Distribution Grid and Building-to-Grid Interface

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, Emma M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Hendrix, Val [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Chertkov, Michael [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Deka, Deepjyoti [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-03-16

    This white paper introduces the application of advanced data analytics to the modernized grid. In particular, we consider the field of machine learning and where it is both useful, and not useful, for the particular field of the distribution grid and buildings interface. While analytics, in general, is a growing field of interest, and often seen as the golden goose in the burgeoning distribution grid industry, its application is often limited by communications infrastructure, or lack of a focused technical application. Overall, the linkage of analytics to purposeful application in the grid space has been limited. In this paper we consider the field of machine learning as a subset of analytical techniques, and discuss its ability and limitations to enable the future distribution grid and the building-to-grid interface. To that end, we also consider the potential for mixing distributed and centralized analytics and the pros and cons of these approaches. Machine learning is a subfield of computer science that studies and constructs algorithms that can learn from data and make predictions and improve forecasts. Incorporation of machine learning in grid monitoring and analysis tools may have the potential to solve data and operational challenges that result from increasing penetration of distributed and behind-the-meter energy resources. There is an exponentially expanding volume of measured data being generated on the distribution grid, which, with appropriate application of analytics, may be transformed into intelligible, actionable information that can be provided to the right actors – such as grid and building operators, at the appropriate time to enhance grid or building resilience, efficiency, and operations against various metrics or goals – such as total carbon reduction or other economic benefit to customers. While some basic analysis into these data streams can provide a wealth of information, computational and human boundaries on performing the analysis

  1. Parallel Computational Fluid Dynamics 2007 : Implementations and Experiences on Large Scale and Grid Computing

    CERN Document Server

    2009-01-01

    At the 19th Annual Conference on Parallel Computational Fluid Dynamics held in Antalya, Turkey, in May 2007, the most recent developments and implementations of large-scale and grid computing were presented. This book, comprised of the invited and selected papers of this conference, details those advances, which are of particular interest to CFD and CFD-related communities. It also offers the results related to applications of various scientific and engineering problems involving flows and flow-related topics. Intended for CFD researchers and graduate students, this book is a state-of-the-art presentation of the relevant methodology and implementation techniques of large-scale computing.

  2. SuperGrid or SmartGrid: Competing strategies for large-scale integration of intermittent renewables?

    DEFF Research Database (Denmark)

    Blarke, Morten; M. Jenkins, Bryan

    2013-01-01

    This paper defines and compares two strategies for integrating intermittent renewables: SuperGrid and SmartGrid. While conventional energy policy suggests that these strategies may be implemented alongside each other, the paper identifies significant technological and socio-economic conflicts...... of interest between the two. The article identifies differences between a domestic strategy for the integration of intermittent renewables, vis-à-vis the SmartGrid, and a cross-system strategy, vis-à-vis the SuperGrid. Policy makers and transmission system operators must understand the need for both...... strategies to evolve in parallel, but in different territories, or with strategic integration, avoiding for one strategy to undermine the feasibility of the other. A strategic zoning strategy is introduced from which attentive societies as well as the global community stand to benefit. The analysis includes...

  3. Utility-scale grid-tied PV inverter reliability workshop summary report.

    Energy Technology Data Exchange (ETDEWEB)

    Granata, Jennifer E.; Quintana, Michael A.; Tasca, Coryne Adelle (SRA International, Inc., Fairfax, VA); Atcitty, Stanley

    2011-07-01

    A key to the long-term success of the photovoltaic (PV) industry is confidence in the reliability of PV systems. Inverters are the most commonly noted cause of PV system incidents triggered in the field. While not all of these incidents are reliability-related or even necessarily failures, they still result in a loss of generated power. With support from the U.S. Department of Energy's Solar Energy Technologies Program, Sandia National Laboratories organized a Utility-Scale Grid-Tied Inverter Reliability Workshop in Albuquerque, New Mexico, January 27-28, 2011. The workshop addressed the reliability of large (100-kilowatt+) grid-tied inverters and the implications when such inverters fail, evaluated inverter codes and standards, and provided discussion about opportunities to enhance inverter reliability. This report summarizes discussions and presentations from the workshop and identifies opportunities for future efforts.

  4. Detecting and mitigating abnormal events in large scale networks: budget constrained placement on smart grids

    Energy Technology Data Exchange (ETDEWEB)

    Santhi, Nandakishore [Los Alamos National Laboratory; Pan, Feng [Los Alamos National Laboratory

    2010-10-19

    Several scenarios exist in the modern interconnected world which call for an efficient network interdiction algorithm. Applications are varied, including various monitoring and load shedding applications on large smart energy grids, computer network security, preventing the spread of Internet worms and malware, policing international smuggling networks, and controlling the spread of diseases. In this paper we consider some natural network optimization questions related to the budget constrained interdiction problem over general graphs, specifically focusing on the sensor/switch placement problem for large-scale energy grids. Many of these questions turn out to be computationally hard to tackle. We present a particular form of the interdiction question which is practically relevant and which we show as computationally tractable. A polynomial-time algorithm will be presented for solving this problem.

  5. Calculating Soil Wetness, Evapotranspiration and Carbon Cycle Processes Over Large Grid Areas Using a New Scaling Technique

    Science.gov (United States)

    Sellers, Piers

    2012-01-01

    Soil wetness typically shows great spatial variability over the length scales of general circulation model (GCM) grid areas (approx 100 km ), and the functions relating evapotranspiration and photosynthetic rate to local-scale (approx 1 m) soil wetness are highly non-linear. Soil respiration is also highly dependent on very small-scale variations in soil wetness. We therefore expect significant inaccuracies whenever we insert a single grid area-average soil wetness value into a function to calculate any of these rates for the grid area. For the particular case of evapotranspiration., this method - use of a grid-averaged soil wetness value - can also provoke severe oscillations in the evapotranspiration rate and soil wetness under some conditions. A method is presented whereby the probability distribution timction(pdf) for soil wetness within a grid area is represented by binning. and numerical integration of the binned pdf is performed to provide a spatially-integrated wetness stress term for the whole grid area, which then permits calculation of grid area fluxes in a single operation. The method is very accurate when 10 or more bins are used, can deal realistically with spatially variable precipitation, conserves moisture exactly and allows for precise modification of the soil wetness pdf after every time step. The method could also be applied to other ecological problems where small-scale processes must be area-integrated, or upscaled, to estimate fluxes over large areas, for example in treatments of the terrestrial carbon budget or trace gas generation.

  6. Large-Scale Electrochemical Energy Storage in High Voltage Grids: Overview of the Italian Experience

    Directory of Open Access Journals (Sweden)

    Roberto Benato

    2017-01-01

    Full Text Available This paper offers a wide overview on the large-scale electrochemical energy projects installed in the high voltage Italian grid. Detailed descriptions of energy (charge/discharge times of about 8 h and power intensive (charge/discharge times ranging from 0.5 h to 4 h installations are presented with some insights into the authorization procedures, safety features, and ancillary services. These different charge/discharge times reflect the different operation uses inside the electric grid. Energy intensive storage aims at decoupling generation and utilization since, in the southern part of Italy, there has been a great growth of wind farms: these areas are characterized by a surplus of generation with respect to load absorption and to the net transport capacity of the 150 kV high voltage backbones. Power intensive storage aims at providing ancillary services inside the electric grid as primary and secondary frequency regulation, synthetic rotational inertia, and further functionalities. The return on experience of Italian installations will be able to play a key role also for other countries and other transmission system operators.

  7. Advanced Grid-Friendly Controls Demonstration Project for Utility-Scale PV Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Gevorgian, Vahan; O' Neill, Barbara

    2016-01-21

    A typical photovoltaic (PV) power plant consists of multiple power electronic inverters and can contribute to grid stability and reliability through sophisticated 'grid-friendly' controls. The availability and dissemination of actual test data showing the viability of advanced utility-scale PV controls among all industry stakeholders can leverage PV's value from being simply an energy resource to providing additional ancillary services that range from variability smoothing and frequency regulation to power quality. Strategically partnering with a selected utility and/or PV power plant operator is a key condition for a successful demonstration project. The U.S. Department of Energy's (DOE's) Solar Energy Technologies Office selected the National Renewable Energy Laboratory (NREL) to be a principal investigator in a two-year project with goals to (1) identify a potential partner(s), (2) develop a detailed scope of work and test plan for a field project to demonstrate the gird-friendly capabilities of utility-scale PV power plants, (3) facilitate conducting actual demonstration tests, and (4) disseminate test results among industry stakeholders via a joint NREL/DOE publication and participation in relevant technical conferences. The project implementation took place in FY 2014 and FY 2015. In FY14, NREL established collaborations with AES and First Solar Electric, LLC, to conduct demonstration testing on their utility-scale PV power plants in Puerto Rico and Texas, respectively, and developed test plans for each partner. Both Puerto Rico Electric Power Authority and the Electric Reliability Council of Texas expressed interest in this project because of the importance of such advanced controls for the reliable operation of their power systems under high penetration levels of variable renewable generation. During FY15, testing was completed on both plants, and a large amount of test data was produced and analyzed that demonstrates the ability of

  8. Analysis for Large Scale Integration of Electric Vehicles into Power Grids

    DEFF Research Database (Denmark)

    Hu, Weihao; Chen, Zhe; Wang, Xiaoru

    2011-01-01

    Electric Vehicles (EVs) provide a significant opportunity for reducing the consumption of fossil energies and the emission of carbon dioxide. With more and more electric vehicles integrated in the power systems, it becomes important to study the effects of EV integration on the power systems......, especially the low and middle voltage level networks. In the paper, the basic structure and characteristics of the electric vehicles are introduced. The possible impacts of large scale integration of electric vehicles on the power systems especially the advantage to the integration of the renewable energies...... are discussed. Finally, the research projects related to the large scale integration of electric vehicles into the power systems are introduced, it will provide reference for large scale integration of Electric Vehicles into power grids....

  9. Characteristic length scale of input data in distributed models: implications for modeling grid size

    Science.gov (United States)

    Artan, G. A.; Neale, C. M. U.; Tarboton, D. G.

    2000-01-01

    The appropriate spatial scale for a distributed energy balance model was investigated by: (a) determining the scale of variability associated with the remotely sensed and GIS-generated model input data; and (b) examining the effects of input data spatial aggregation on model response. The semi-variogram and the characteristic length calculated from the spatial autocorrelation were used to determine the scale of variability of the remotely sensed and GIS-generated model input data. The data were collected from two hillsides at Upper Sheep Creek, a sub-basin of the Reynolds Creek Experimental Watershed, in southwest Idaho. The data were analyzed in terms of the semivariance and the integral of the autocorrelation. The minimum characteristic length associated with the variability of the data used in the analysis was 15 m. Simulated and observed radiometric surface temperature fields at different spatial resolutions were compared. The correlation between agreement simulated and observed fields sharply declined after a 10×10 m2 modeling grid size. A modeling grid size of about 10×10 m2 was deemed to be the best compromise to achieve: (a) reduction of computation time and the size of the support data; and (b) a reproduction of the observed radiometric surface temperature.

  10. Evolution of turbulence and in-plane vortices in the near field flow behind multi-scale planar grids

    Science.gov (United States)

    Gan, L.; Krogstad, P.-Å.

    2016-08-01

    In this experimental work, we carry out detailed two-dimensional particle image velocimetry investigations for the near field wakes behind a conventional and two multi-scale planar grids, using stitched camera fields of view. Statistical independent measurements are conducted focusing on the first few mesh distances downstream of the grid. It is found that the multiple integral length scales originated from the grids loose their importance on the turbulence development after about three mesh distances downstream, much earlier than the distance where the turbulence becomes homogeneous. The largest eddy size, represented by the integral length scales, does not show clear differences in its growth rate among the three grids after an initial development of three times the largest grid size downstream. Nevertheless, when examining individual vortex behaviours using conditional averaging and filtering processes, clear differences are found. The grids are found to have different decay rates of peak vorticity and projected vortex strengths. Despite these differences, the in-plane vorticity correlation function reveals that the mean vortex shape of all the grids shows a universal near-Gaussian pattern which does not change much as the turbulence decays.

  11. Next generation molten NaI batteries for grid scale energy storage

    Science.gov (United States)

    Small, Leo J.; Eccleston, Alexis; Lamb, Joshua; Read, Andrew C.; Robins, Matthew; Meaders, Thomas; Ingersoll, David; Clem, Paul G.; Bhavaraju, Sai; Spoerke, Erik D.

    2017-08-01

    Robust, safe, and reliable grid-scale energy storage continues to be a priority for improved energy surety, expanded integration of renewable energy, and greater system agility required to meet modern dynamic and evolving electrical energy demands. We describe here a new sodium-based battery based on a molten sodium anode, a sodium iodide/aluminum chloride (NaI/AlCl3) cathode, and a high conductivity NaSICON (Na1+xZr2SixP3-xO12) ceramic separator. This NaI battery operates at intermediate temperatures (120-180 °C) and boasts an energy density of >150 Wh kg-1. The energy-dense NaI-AlCl3 ionic liquid catholyte avoids lifetime-limiting plating and intercalation reactions, and the use of earth-abundant elements minimizes materials costs and eliminates economic uncertainties associated with lithium metal. Moreover, the inherent safety of this system under internal mechanical failure is characterized by negligible heat or gas production and benign reaction products (Al, NaCl). Scalability in design is exemplified through evolution from 0.85 to 10 Ah (28 Wh) form factors, displaying lifetime average Coulombic efficiencies of 99.45% and energy efficiencies of 81.96% over dynamic testing lasting >3000 h. This demonstration promises a safe, cost-effective, and long-lifetime technology as an attractive candidate for grid scale storage.

  12. Multi-time Scale Joint Scheduling Method Considering the Grid of Renewable Energy

    Science.gov (United States)

    Zhijun, E.; Wang, Weichen; Cao, Jin; Wang, Xin; Kong, Xiangyu; Quan, Shuping

    2018-01-01

    Renewable new energy power generation prediction error like wind and light, brings difficulties to dispatch the power system. In this paper, a multi-time scale robust scheduling method is set to solve this problem. It reduces the impact of clean energy prediction bias to the power grid by using multi-time scale (day-ahead, intraday, real time) and coordinating the dispatching power output of various power supplies such as hydropower, thermal power, wind power, gas power and. The method adopts the robust scheduling method to ensure the robustness of the scheduling scheme. By calculating the cost of the abandon wind and the load, it transforms the robustness into the risk cost and optimizes the optimal uncertainty set for the smallest integrative costs. The validity of the method is verified by simulation.

  13. Gridded design rule scaling: taking the CPU toward the 16nm node

    Science.gov (United States)

    Bencher, Christopher; Dai, Huixiong; Chen, Yongmei

    2009-03-01

    The Intel 45nm PenrynTM CPU was a landmark design, not only for its implementation of high-K metal gate materials1, but also for the adoption of a nearly gridded design rule (GDR) layout architecture for the poly silicon gate layer2. One key advantage of using gridded design rules is reduction of design rules and ease of 1- dimensional scaling compared to complex random 2-dimensinal layouts. In this paper, we demonstrate the scaling capability of GDR to 16nm and 22nm logic nodes. Copying the design of published images for the Intel 45nm PenrynTM poly-silicon layer2, we created a mask set designed to duplicate those patterns targeting a final pitch of 64nm and 52nm using Sidewall Spacer Double Patterning for the extreme pitch shrinking and performed exploratory work at final pitch of 44nm. Mask sets were made in both tones to enable demonstration of both damascene (dark field) patterning and poly-silicon gate layer (clear field) GDR layouts, although the results discussed focus primarily on poly-silicon gate layer scaling. The paper discusses the line-and-cut double patterning technique for generating GDR structures, the use of sidewall spacer double patterning for scaling parallel lines and the lithographic process window (CD and alignment) for applying cut masks. Through the demonstration, we highlight process margin issues and suggest corrective actions to be implemented in future demonstrations and more advanced studies. Overall, the process window is quite large and the technique has strong manufacturing possibilities.

  14. Impact of Spatial Scale on Calibration and Model Output for a Grid-based SWAT Model

    Science.gov (United States)

    Pignotti, G.; Vema, V. K.; Rathjens, H.; Raj, C.; Her, Y.; Chaubey, I.; Crawford, M. M.

    2014-12-01

    The traditional implementation of the Soil and Water Assessment Tool (SWAT) model utilizes common landscape characteristics known as hydrologic response units (HRUs). Discretization into HRUs provides a simple, computationally efficient framework for simulation, but also represents a significant limitation of the model as spatial connectivity between HRUs is ignored. SWATgrid, a newly developed, distributed version of SWAT, provides modified landscape routing via a grid, overcoming these limitations. However, the current implementation of SWATgrid has significant computational overhead, which effectively precludes traditional calibration and limits the total number of grid cells in a given modeling scenario. Moreover, as SWATgrid is a relatively new modeling approach, it remains largely untested with little understanding of the impact of spatial resolution on model output. The objective of this study was to determine the effects of user-defined input resolution on SWATgrid predictions in the Upper Cedar Creek Watershed (near Auburn, IN, USA). Original input data, nominally at 30 m resolution, was rescaled for a range of resolutions between 30 and 4,000 m. A 30 m traditional SWAT model was developed as the baseline for model comparison. Monthly calibration was performed, and the calibrated parameter set was then transferred to all other SWAT and SWATgrid models to focus the effects of resolution on prediction uncertainty relative to the baseline. Model output was evaluated with respect to stream flow at the outlet and water quality parameters. Additionally, output of SWATgrid models were compared to output of traditional SWAT models at each resolution, utilizing the same scaled input data. A secondary objective considered the effect of scale on calibrated parameter values, where each standard SWAT model was calibrated independently, and parameters were transferred to SWATgrid models at equivalent scales. For each model, computational requirements were evaluated

  15. Investigating the Scale Dependence of SCM Simulated Clouds by Using Gridded Forcing Data at SGP

    Science.gov (United States)

    Tang, S.; Zhang, M.; Xie, S.

    2016-12-01

    Large-scale forcing data, such as vertical velocity and advective tendencies, are required to drive single-column models (SCM), cloud-resolving models and large-eddy simulations. Previous studies suggest that some model discrepancies could be attributed to the lack of horizontal inhomogeneity in the large-scale forcing data. This study investigates the spatial variability of the gridded large-scale forcing data derived from a three-dimensional constrained variational analysis (3DCVA) method and its impact on SCM simulated clouds and radiation. The analysis of March 2000 intensive operational periods at the ARM SGP site shows that the large-scale forcing data have large spatial variability especially when there are frontal systems passing through. SCM simulations are performed in each sub-column and the combination of these sub-columns captures some characteristics of the front structure. However, physical parameterizations are still the most important error source in SCM, since most model discrepancies remain in the sub-column runs. Overall, with the spatial variability of forcing, the average of sub-column SCM simulations of clouds and radiation are more consistent with the domain-averaged observations compared to the coarse column simulation

  16. Calcium-based multi-element chemistry for grid-scale electrochemical energy storage

    Science.gov (United States)

    Ouchi, Takanari; Kim, Hojong; Spatocco, Brian L.; Sadoway, Donald R.

    2016-03-01

    Calcium is an attractive material for the negative electrode in a rechargeable battery due to its low electronegativity (high cell voltage), double valence, earth abundance and low cost; however, the use of calcium has historically eluded researchers due to its high melting temperature, high reactivity and unfavorably high solubility in molten salts. Here we demonstrate a long-cycle-life calcium-metal-based rechargeable battery for grid-scale energy storage. By deploying a multi-cation binary electrolyte in concert with an alloyed negative electrode, calcium solubility in the electrolyte is suppressed and operating temperature is reduced. These chemical mitigation strategies also engage another element in energy storage reactions resulting in a multi-element battery. These initial results demonstrate how the synergistic effects of deploying multiple chemical mitigation strategies coupled with the relaxation of the requirement of a single itinerant ion can unlock calcium-based chemistries and produce a battery with enhanced performance.

  17. Optimizing Electric Vehicle Coordination Over a Heterogeneous Mesh Network in a Scaled-Down Smart Grid Testbed

    DEFF Research Database (Denmark)

    Bhattarai, Bishnu Prasad; Lévesque, Martin; Maier, Martin

    2015-01-01

    , smart grid (SG) is still at the developmental stage to address those issues. In this regard, a smart grid testbed (SGT) is desirable to develop, analyze, and demonstrate various novel SG solutions, namely demand response, real-time pricing, and congestion management. In this paper, a novel SGT...... is developed in a laboratory by scaling a 250 kVA, 0.4 kV real low-voltage distribution feeder down to 1 kVA, 0.22 kV. Information and communication technology is integrated in the scaled-down network to establish real-time monitoring and control. The novelty of the developed testbed is demonstrated...

  18. Large Scale Monte Carlo Simulation of Neutrino Interactions Using the Open Science Grid and Commercial Clouds

    Science.gov (United States)

    Norman, A.; Boyd, J.; Davies, G.; Flumerfelt, E.; Herner, K.; Mayer, N.; Mhashilhar, P.; Tamsett, M.; Timm, S.

    2015-12-01

    Modern long baseline neutrino experiments like the NOvA experiment at Fermilab, require large scale, compute intensive simulations of their neutrino beam fluxes and backgrounds induced by cosmic rays. The amount of simulation required to keep the systematic uncertainties in the simulation from dominating the final physics results is often 10x to 100x that of the actual detector exposure. For the first physics results from NOvA this has meant the simulation of more than 2 billion cosmic ray events in the far detector and more than 200 million NuMI beam spill simulations. Performing these high statistics levels of simulation have been made possible for NOvA through the use of the Open Science Grid and through large scale runs on commercial clouds like Amazon EC2. We details the challenges in performing large scale simulation in these environments and how the computing infrastructure for the NOvA experiment has been adapted to seamlessly support the running of different simulation and data processing tasks on these resources.

  19. Construction of a high resolution precipitation grid over an alpine catchment for multi-scale performance assessment of gridded daily reference data sets.

    Science.gov (United States)

    Gampe, David; Ludwig, Ralf

    2017-04-01

    Precipitation plays a key role in the hydrological cycle and thus is a crucial variable in the meteo-hydrological modeling chain. Accurate spatial and temporal assessment of precipitation is in this context of utmost importance. Gridded reference data sets for precipitation are also needed to evaluate and bias adjust climate model simulations in order to better represent current regional conditions. Uncertainties in these data sets increase when moving to higher spatial resolution, including small-scale processes, and more complex terrain. In this study a high resolution reference data set with a grid size of 1km is derived from over 150 observation stations over the mountainous Adige catchment ( 12,000 km2), located in Northern Italy with elevations up to 3800 m. This gridded product is then applied to evaluate the performance of state-of-the-art reference data sets which are available at various spatial resolutions ranging from several km to climate model scale at 2°. These global or regional data sets stem either directly from observations or re-analysis simulations, with or without assimilated precipitation, or are based remote sensing approaches. The main objective of this study is to address and quantify uncertainties of these coarser data sets. Additionally, whether they perform acceptable on catchment scale and can be applied for bias correction and model calibration, or if regional high resolution data sets outperform these data sets. Comparison is performed at various spatial resolutions corresponding to those of the applied precipitation data sets. Furthermore, an inter comparison of all of these is conducted at a the coarsest common resolution, where higher resolved data sets are aggregated to the target resolution, allowing for an analysis without penalizing data sets at coarse resolution. Performance assessment of the reference data sets is carried out on daily precipitation statistics for the period 1989 - 2008 using a multitude of indicators.

  20. Design of fast ion conducting cathode materials for grid-scale sodium-ion batteries.

    Science.gov (United States)

    Wong, Lee Loong; Chen, Haomin; Adams, Stefan

    2017-03-15

    The obvious cost advantage as well as attractive electrochemical properties, including excellent cycling stability and the potential of high rate performance, make sodium-ion batteries prime candidates in the race to technically and commercially enable large-scale electrochemical energy storage. In this work, we apply our bond valence site energy modelling method to further the understanding of rate capabilities of a wide range of potential insertion-type sodium-ion battery cathode materials. We demonstrate how a stretched exponential function permits us to systematically quantify the rate performance, which in turn reveals guidelines for the design of novel sodium-ion battery chemistries suitable for high power, grid-scale applications. Starting from a diffusion relaxation model, we establish a semi-quantitative prediction of the rate-performance of half-cells from the structure of the cathode material that factors in dimensionality of Na(+) ion migration pathways, the height of the migration barriers and the crystallite size of the active material. With the help of selected examples, we also illustrate the respective roles of unoccupied low energy sites within the pathway and temperature towards the overall rate capability of insertion-type cathode materials.

  1. Sizing and Siting of Large-Scale Batteries in Transmission Grids to Optimize the Use of Renewables

    NARCIS (Netherlands)

    Fiorini, Laura; Pagani, Giuliano; Pelacchi, P.; Poli, Davide; Aiello, Marco

    2017-01-01

    Power systems are a recent field of application of Complex Network research, which allows to perform large scale studies and evaluations. Based on this theory, a power grid is modeled as a weighted graph with several kinds of nodes and edges, and further analysis can help in investigating the

  2. Two-fluid sub-grid-scale viscosity in nonlinear simulation of ballooning modes in a heliotron device

    Science.gov (United States)

    Miura, H.; Hamba, F.; Ito, A.

    2017-07-01

    A large eddy simulation (LES) approach is introduced to enable the study of the nonlinear growth of ballooning modes in a heliotron-type device, by solving fully 3D two-fluid magnetohydrodynamic (MHD) equations numerically over a wide range of parameter space, keeping computational costs as low as possible. A model to substitute the influence of scales smaller than the grid size, at sub-grid scale (SGS), and at the scales larger than it—grid scale (GS)—has been developed for LES. The LESs of two-fluid MHD equations with SGS models have successfully reproduced the growth of the ballooning modes in the GS and nonlinear saturation. The numerical results show the importance of SGS effects on the GS components, or the effects of turbulent fluctuation at small scales in low-wavenumber unstable modes, over the course of the nonlinear saturation process. The results also show the usefulness of the LES approach in studying instability in a heliotron device. It is shown through a parameter survey over many SGS model coefficients that turbulent small-scale components in experiments can contribute to keeping the plasma core pressure from totally collapsing.

  3. Sub-grid-scale description of turbulent magnetic reconnection in magnetohydrodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Widmer, F., E-mail: widmer@mps.mpg.de [Max-Planck-Institut für Sonnensystemforschung, Justus-von-Liebig-Weg 3, 37077 Göttingen (Germany); Institut für Astrophysik, Georg-August-Universität, Friedrich-Hund-Platz 1, 37077 Göttingen (Germany); Büchner, J. [Max-Planck-Institut für Sonnensystemforschung, Justus-von-Liebig-Weg 3, 37077 Göttingen (Germany); Yokoi, N. [Institute of Industrial Science, University of Tokyo, 4-6-1 Komaba, Meguro, Tokyo 153-8505 (Japan)

    2016-04-15

    Magnetic reconnection requires, at least locally, a non-ideal plasma response. In collisionless space and astrophysical plasmas, turbulence could transport energy from large to small scales where binary particle collisions are rare. We have investigated the influence of small scale magnetohydrodynamics (MHD) turbulence on the reconnection rate in the framework of a compressible MHD approach including sub-grid-scale (SGS) turbulence. For this sake, we considered Harris-type and force-free current sheets with finite guide magnetic fields directed out of the reconnection plane. The goal is to find out whether unresolved by conventional simulations MHD turbulence can enhance the reconnection process in high-Reynolds-number astrophysical plasmas. Together with the MHD equations, we solve evolution equations for the SGS energy and cross-helicity due to turbulence according to a Reynolds-averaged turbulence model. The SGS turbulence is self-generated and -sustained through the inhomogeneities of the mean fields. By this way, the feedback of the unresolved turbulence into the MHD reconnection process is taken into account. It is shown that the turbulence controls the regimes of reconnection by its characteristic timescale τ{sub t}. The dependence on resistivity was investigated for large-Reynolds-number plasmas for Harris-type as well as force-free current sheets with guide field. We found that magnetic reconnection depends on the relation between the molecular and apparent effective turbulent resistivity. We found that the turbulence timescale τ{sub t} decides whether fast reconnection takes place or whether the stored energy is just diffused away to small scale turbulence. If the amount of energy transferred from large to small scales is enhanced, fast reconnection can take place. Energy spectra allowed us to characterize the different regimes of reconnection. It was found that reconnection is even faster for larger Reynolds numbers controlled by the molecular

  4. Trends in Mediterranean gridded temperature extremes and large-scale circulation influences

    Directory of Open Access Journals (Sweden)

    D. Efthymiadis

    2011-08-01

    Full Text Available Two recently-available daily gridded datasets are used to investigate trends in Mediterranean temperature extremes since the mid-20th century. The underlying trends are found to be generally consistent with global trends of temperature and their extremes: cold extremes decrease and warm/hot extremes increase. This consistency is better manifested in the western part of the Mediterranean where changes are most pronounced since the mid-1970s. In the eastern part, a cooling is observed, with a near reversal in the last two decades. This inter-basin discrepancy is clearer in winter, while in summer changes are more uniform and the west-east difference is restricted to the rate of increase of warm/hot extremes, which is higher in central and eastern parts of the Mediterranean over recent decades. Linear regression and correlation analysis reveals some influence of major large-scale atmospheric circulation patterns on the occurrence of these extremes – both in terms of trend and interannual variability. These relationships are not, however, able to account for the most striking features of the observations – in particular the intensification of the increasing trend in warm/hot extremes, which is most evident over the last 15–20 yr in the Central and Eastern Mediterranean.

  5. Validated real-time energy models for small-scale grid-connected PV-systems

    Energy Technology Data Exchange (ETDEWEB)

    Ayompe, L.M.; Duffy, A. [Department of Civil and Structural Engineering, School of Civil and Building Services, Dublin Institute of Technology, Bolton Street, Dublin 1 (Ireland); McCormack, S.J. [Department of Civil, Structural and Environmental Engineering, Trinity College Dublin, Dublin 2 (Ireland); Conlon, M. [School of Electrical Engineering Systems, Dublin Institute of Technology, Kevin St, Dublin 8 (Ireland)

    2010-10-15

    This paper presents validated real-time energy models for small-scale grid-connected PV-systems suitable for domestic application. The models were used to predict real-time AC power output from a PV-system in Dublin, Ireland using 30-min intervals of measured performance data between April 2009 and March 2010. Statistical analysis of the predicted results and measured data highlight possible sources of errors and the limitations and/or adequacy of existing models, to describe the temperature and efficiency of PV-cells and consequently, the accuracy of power prediction models. PV-system AC output power predictions using empirical models for PV-cell temperature and efficiency prediction showed lower percentage mean absolute errors (PMAEs) of 7.9-11.7% while non-empirical models had errors of 10.0-12.4%. Cumulative errors for PV-system AC output power predictions were 1.3% for empirical models and 3.3% for non-empirical models. The proposed models are suitable for predicting PV-system AC output power at time intervals suitable for smart metering. (author)

  6. Field Experience with and Potential for Multi-time Scale Grid Transactions from Responsive Commercial Buildings

    Energy Technology Data Exchange (ETDEWEB)

    Piette, Mary Ann; Kiliccote, Sila; Ghatikar, Girish

    2014-08-01

    The need for and concepts behind demand response are evolving. As the electric system changes with more intermittent renewable electric supply systems, there is a need to allow buildings to provide more flexible demand. This paper presents results from field studies and pilots, as well as engineering estimates of the potential capabilities of fast load responsiveness in commercial buildings. We present a sector wide analysis of flexible loads in commercial buildings, which was conducted to improve resource planning and determine which loads to evaluate in future demonstrations. These systems provide important capabilities for future transactional systems. The field analysis is based on results from California, plus projects in the northwest and east coast. End-uses considered include heating, ventilation, air conditioning and lighting. The timescales of control include day-ahead, as well as day-of, 10-minute ahead and even faster response. This technology can provide DR signals on different times scales to interact with responsive building loads. We describe the latency of the control systems in the building and the round trip communications with the wholesale grid operators.

  7. Carbon dioxide emissions effects of grid-scale electricity storage in a decarbonizing power system

    Science.gov (United States)

    Craig, Michael T.; Jaramillo, Paulina; Hodge, Bri-Mathias

    2018-01-01

    While grid-scale electricity storage (hereafter ‘storage’) could be crucial for deeply decarbonizing the electric power system, it would increase carbon dioxide (CO2) emissions in current systems across the United States. To better understand how storage transitions from increasing to decreasing system CO2 emissions, we quantify the effect of storage on operational CO2 emissions as a power system decarbonizes under a moderate and strong CO2 emission reduction target through 2045. Under each target, we compare the effect of storage on CO2 emissions when storage participates in only energy, only reserve, and energy and reserve markets. We conduct our study in the Electricity Reliability Council of Texas (ERCOT) system and use a capacity expansion model to forecast generator fleet changes and a unit commitment and economic dispatch model to quantify system CO2 emissions with and without storage. We find that storage would increase CO2 emissions in the current ERCOT system, but would decrease CO2 emissions in 2025 through 2045 under both decarbonization targets. Storage reduces CO2 emissions primarily by enabling gas-fired generation to displace coal-fired generation, but also by reducing wind and solar curtailment. We further find that the market in which storage participates drives large differences in the magnitude, but not the direction, of the effect of storage on CO2 emissions.

  8. Control of modular multilevel converters for grid integration of full-scale wind energy conversion systems

    Science.gov (United States)

    Debnath, Suman

    The growing demand for wind power generation has pushed the capacity of wind turbines towards MW power levels. Higher capacity of the wind turbines necessitates operation of the generators and power electronic conversion systems at higher voltage/power levels. The power electronic conversion system of a wind energy conversion system (WECS) needs to meet the stringent requirements in terms of reliability, efficiency, scalability and ease of maintenance, power quality, and dv/dt stress on the generator/transformer. Although the multilevel converters including the neutral point clamped (NPC) converter and the active NPC converter meet most of the requirements, they fall short in reliability and scalability. Motivated by modularity/scalability feature of the modular multilevel converter (MMC), this research is to enable the MMC to meet all of the stringent requirements of the WECS by addressing their unique control challenges. This research presents systematic modeling and control of the MMC to enable it to be a potential converter topology for grid integration of full-scale WECSs. Based on the developed models, appropriate control systems for control of circulating current and capacitor voltages under fixed- and variable-frequency operations are proposed. Using the developed MMC models, a gradient-based cosimulation algorithm to optimize the gains of the developed control systems, is proposed. Performance/effectiveness of the developed models and the proposed control systems for the back-to-back MMC-based WECS are evaluated/verified based on simulations studies in the PSCAD/EMTDC software environment and experimental case studies on a laboratory-scale hardware prototype.

  9. Demonstration of Active Power Controls by Utility-Scale PV Power Plant in an Island Grid: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Gevorgian, Vahan; O' Neill, Barbara

    2017-02-01

    The National Renewable Energy Laboratory (NREL), AES, and the Puerto Rico Electric Power Authority conducted a demonstration project on a utility-scale photovoltaic (PV) plant to test the viability of providing important ancillary services from this facility. As solar generation increases globally, there is a need for innovation and increased operational flexibility. A typical PV power plant consists of multiple power electronic inverters and can contribute to grid stability and reliability through sophisticated 'grid-friendly' controls. In this way, it may mitigate the impact of its variability on the grid and contribute to important system requirements more like traditional generators. In 2015, testing was completed on a 20-MW AES plant in Puerto Rico, and a large amount of test data was produced and analyzed that demonstrates the ability of PV power plants to provide various types of new grid-friendly controls. This data showed how active power controls can leverage PV's value from being simply an intermittent energy resource to providing additional ancillary services for an isolated island grid. Specifically, the tests conducted included PV plant participation in automatic generation control, provision of droop response, and fast frequency response.

  10. Evaluation of Aggregators for Integration of Large-scale Consumers in Smart Grid

    DEFF Research Database (Denmark)

    Rahnama, Samira; Shafiei, Seyed Ehsan; Stoustrup, Jakob

    2014-01-01

    Utilization of consumers to mitigate the impact of increasing renewable resources on power systems is one of the visions of future smart grids. Flexible consumers are consumers who can change their consumption patterns in such a way as to help the grid to tackle the balancing problem. In previous...... work, we proposed a hierarchical structure to provide regulating power to the grid by just utilizing the consumption units. The main focus of that work was on designing a centralized controller, a so-called aggregator, which is responsible for aggregating the flexibility in an optimal way...

  11. INFN, IT the GENIUS grid portal and the robot certificates to perform phylogenetic analysis on large scale: a success story from the International LIBI project

    Science.gov (United States)

    Barbera, Roberto; Donvit, Giacinto; Falzone, Alberto; Rocca, Giuseppe La; Maggi, Giorgio Pietro; Milanesi, Luciano; Vicarioicario, Saverio

    This paper depicts the solution proposed by INFN to allow users, not owning a personal digital certificate and therefore not belonging to any specific Virtual Organization (VO), to access Grid infrastructures via the GENIUS Grid portal enabled with robot certificates. Robot certificates, also known as portal certificates, are associated with a specific application that the user wants to share with the whole Grid community and have recently been introduced by the EUGridPMA (European Policy Management Authority for Grid Authentication) to perform automated tasks on Grids on behalf of users. They are proven to be extremely useful to automate grid service monitoring, data processing production, distributed data collection systems, etc. In this paper, robot certificates have been used to allow bioinformaticians involved in the Italian LIBI project to perform large scale phylogenetic analyses. The distributed environment set up in this work strongly simplify the grid access of occasional users and represents a valuable step forward to wide the communities of users.

  12. 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.

  13. Large scale rooftop photovoltaics grid connected system at Charoenphol-Rama I green building

    Energy Technology Data Exchange (ETDEWEB)

    Ketjoy, N.; Rakwichian, W. [School of Renewable Energy Technology (SERT) (Thailand); Wongchupan, V. [Panya Consultants Co., Ltd (Thailand); Sankarat, T. [Tesco Lotus, Ek-Chai Distribution System Co., Ltd. (Thailand)

    2004-07-01

    This paper presents a technical feasibility study project for the large scale rooftop photovoltaics (PV) grid connected system at Charoenphol-Rama I green building super store of TESCO LOTUS (TL) in Thailand. The objective of this project is (i) to study the technical feasibility of installation 350 kWp PV systems on the top of the roof in this site (ii) and to determine the energy produce from this system. The technical factors are examined using a computerized PVS 2000 simulation and assessment tool. This super store building located in Bangkok, with latitude 14 N, longitude 100 E and the building direction is 16 from North direction. The building roof area is 14,000 m2; with 3 degree face East and 3 degree face West pitch. Average daily solar energy in this area is approximately 5.0 kWh. The study team for this project consists of educational institution as School of Renewable Energy Technology (SERT) and private institution as Panya Consultants (PC). TL is the project owner, PC is responsible for project management, and SERT is a third party and responsible for PV system study, conceptual design and all technical process. In this feasibility studies SERT will identify the most attractive scenarios of photovoltaic cell technology (mono, poly-crystalline or thin film amorphous), system design concepts for owners (TL) and determine possibility of the energy yield of the system from different module orientation and tilt angle. The result of this study is a guide to help TL to make decision to select proper rooftop PV system option for this store with proper technology view. The economic view will not be considered in this study. (orig.)

  14. ImmunoGrid: towards agent-based simulations of the human immune system at a natural scale

    DEFF Research Database (Denmark)

    Halling-Brown, M.; Pappalardo, F.; Rapin, Nicolas

    2010-01-01

    , such as the European Virtual Physiological Human initiative. Finally, we ask a key question: How long will it take us to resolve these challenges and when can we expect to have fully functional models that will deliver health-care benefits in the form of personalized care solutions and improved disease prevention?......The ultimate aim of the EU-funded ImmunoGrid project is to develop a natural-scale model of the human immune system-that is, one that reflects both the diversity and the relative proportions of the molecules and cells that comprise it-together with the grid infrastructure necessary to apply...... resources required. In this paper, we explain the key challenges and the approaches adopted to overcome them. We also consider wider implications for the present ambitious plans to develop natural-scale, integrated models of the human body that can make contributions to personalized health care...

  15. A multi-grid framework for the extraction of large-scale vortices in Large-Eddy Simulation

    Science.gov (United States)

    Legrand, Nicolas; Lartigue, Ghislain; Moureau, Vincent

    2017-11-01

    The analysis of large-scale vortices from highly refined unsteady simulations becomes challenging as the mesh resolution increases. Beyond the large amount of data that needs to be processed, classical vortex visualization techniques based on invariants of the velocity gradient tensor fail in extracting the large-scale vortices as the velocity gradient tensor magnitude is greater for small turbulent eddies than for energy-containing vortices. This problem is even more important in highly-resolved simulations with a broad range of eddies. The methodology presented here is a geometric multi-grid high-order filtering (MGHOF) framework for on-line analysis of high-fidelity simulations. This approach relies on high-order implicit filters and enables the extraction of large-scale features from Large-Eddy Simulations (LES) on massive and distributed unstructured grids at a reduced cost. The MGHOF framework is first described and validated, then the methodology is applied to a 3D turbulent plane jet and to the LES of a 3D low-Mach number turbine blade with various mesh sizes, ranging from a few million to a few billion tetrahedra. In the latter case, the MGHOF enables to perform the dynamic mode decomposition of the velocity and temperature fields for the finer grid resolution.

  16. How entorhinal grid cells may learn multiple spatial scales from a dorsoventral gradient of cell response rates in a self-organizing map.

    Directory of Open Access Journals (Sweden)

    Stephen Grossberg

    Full Text Available Place cells in the hippocampus of higher mammals are critical for spatial navigation. Recent modeling clarifies how this may be achieved by how grid cells in the medial entorhinal cortex (MEC input to place cells. Grid cells exhibit hexagonal grid firing patterns across space in multiple spatial scales along the MEC dorsoventral axis. Signals from grid cells of multiple scales combine adaptively to activate place cells that represent much larger spaces than grid cells. But how do grid cells learn to fire at multiple positions that form a hexagonal grid, and with spatial scales that increase along the dorsoventral axis? In vitro recordings of medial entorhinal layer II stellate cells have revealed subthreshold membrane potential oscillations (MPOs whose temporal periods, and time constants of excitatory postsynaptic potentials (EPSPs, both increase along this axis. Slower (faster subthreshold MPOs and slower (faster EPSPs correlate with larger (smaller grid spacings and field widths. A self-organizing map neural model explains how the anatomical gradient of grid spatial scales can be learned by cells that respond more slowly along the gradient to their inputs from stripe cells of multiple scales, which perform linear velocity path integration. The model cells also exhibit MPO frequencies that covary with their response rates. The gradient in intrinsic rhythmicity is thus not compelling evidence for oscillatory interference as a mechanism of grid cell firing. A response rate gradient combined with input stripe cells that have normalized receptive fields can reproduce all known spatial and temporal properties of grid cells along the MEC dorsoventral axis. This spatial gradient mechanism is homologous to a gradient mechanism for temporal learning in the lateral entorhinal cortex and its hippocampal projections. Spatial and temporal representations may hereby arise from homologous mechanisms, thereby embodying a mechanistic "neural relativity" that

  17. How entorhinal grid cells may learn multiple spatial scales from a dorsoventral gradient of cell response rates in a self-organizing map.

    Science.gov (United States)

    Grossberg, Stephen; Pilly, Praveen K

    2012-01-01

    Place cells in the hippocampus of higher mammals are critical for spatial navigation. Recent modeling clarifies how this may be achieved by how grid cells in the medial entorhinal cortex (MEC) input to place cells. Grid cells exhibit hexagonal grid firing patterns across space in multiple spatial scales along the MEC dorsoventral axis. Signals from grid cells of multiple scales combine adaptively to activate place cells that represent much larger spaces than grid cells. But how do grid cells learn to fire at multiple positions that form a hexagonal grid, and with spatial scales that increase along the dorsoventral axis? In vitro recordings of medial entorhinal layer II stellate cells have revealed subthreshold membrane potential oscillations (MPOs) whose temporal periods, and time constants of excitatory postsynaptic potentials (EPSPs), both increase along this axis. Slower (faster) subthreshold MPOs and slower (faster) EPSPs correlate with larger (smaller) grid spacings and field widths. A self-organizing map neural model explains how the anatomical gradient of grid spatial scales can be learned by cells that respond more slowly along the gradient to their inputs from stripe cells of multiple scales, which perform linear velocity path integration. The model cells also exhibit MPO frequencies that covary with their response rates. The gradient in intrinsic rhythmicity is thus not compelling evidence for oscillatory interference as a mechanism of grid cell firing. A response rate gradient combined with input stripe cells that have normalized receptive fields can reproduce all known spatial and temporal properties of grid cells along the MEC dorsoventral axis. This spatial gradient mechanism is homologous to a gradient mechanism for temporal learning in the lateral entorhinal cortex and its hippocampal projections. Spatial and temporal representations may hereby arise from homologous mechanisms, thereby embodying a mechanistic "neural relativity" that may clarify how

  18. Adapting AC Lines to DC Grids for Large-Scale Renewable Power Transmission

    Directory of Open Access Journals (Sweden)

    D. Marene Larruskain

    2014-10-01

    Full Text Available All over the world, governments of different countries are nowadays promoting the use of clean energies in order to achieve sustainable energy systems. In this scenario, since the installed capacity is continuously increasing, renewable sources can play an important role. Notwithstanding that, some important problems may appear when connecting these sources to the grid, being the overload of distribution lines one of the most relevant. In fact, renewable generation is usually connected to the nearest AC grid, although this HV system may not have been designed considering distributed generation. In the particular case of large wind farms, the electrical grid has to transmit all the power generated by wind energy and, as a consequence, the AC system may get overloaded. It is therefore necessary to determine the impact of wind power transmission so that appropriate measures can be taken. Not only are these measures influenced by the amount of power transmitted, but also by the quality of the transmitted power, due to the output voltage fluctuation caused by the highly variable nature of wind. When designing a power grid, although AC systems are usually the most economical solution because of its highly proven technology, HVDC may arise in some cases (e.g. offshore wind farms as an interesting alternative, offering some added values such as lower losses and better controllability. This way, HVDC technology can solve most of the aforementioned problems and has a good potential for future use. Additionally, the fast development of power electronics based on new and powerful semiconductor devices allow the spread of innovative technologies, such as VSC-HVDC, which can be applied to create DC grids. This paper focuses on the main aspects involved in adapting the existing overhead AC lines to DC grids, with the objective of improving the transmission of distributed renewable energy to the centers of consumption.

  19. Using gridded multimedia model to simulate spatial fate of Benzo[α]pyrene on regional scale.

    Science.gov (United States)

    Liu, Shijie; Lu, Yonglong; Wang, Tieyu; Xie, Shuangwei; Jones, Kevin C; Sweetman, Andrew J

    2014-02-01

    Predicting the environmental multimedia fate is an essential step in the process of assessing the human exposure and health impacts of chemicals released into the environment. Multimedia fate models have been widely applied to calculate the fate and distribution of chemicals in the environment, which can serve as input to a human exposure model. In this study, a grid based multimedia fugacity model at regional scale was developed together with a case study modeling the fate and transfer of Benzo[α]pyrene (BaP) in Bohai coastal region, China. Based on the estimated emission and in-site survey in 2008, the BaP concentrations in air, vegetation, soil, fresh water, fresh water sediment and coastal water as well as the transfer fluxes were derived under the steady-state assumption. The model results were validated through comparison between the measured and modeled concentrations of BaP. The model results indicated that the predicted concentrations of BaP in air, fresh water, soil and sediment generally agreed with field observations. Model predictions suggest that soil was the dominant sink of BaP in terrestrial systems. Flow from air to soil, vegetation and costal water were three major pathways of BaP inter-media transport processes. Most of the BaP entering the sea was transferred by air flow, which was also the crucial driving force in the spatial distribution processes of BaP. The Yellow River, Liaohe River and Daliao River played an important role in the spatial transformation processes of BaP. Compared with advection outflow, degradation was more important in removal processes of BaP. Sensitivities of the model estimates to input parameters were tested. The result showed that emission rates, compartment dimensions, transport velocity and degradation rates of BaP were the most influential parameters for the model output. Monte Carlo simulation was carried out to determine parameter uncertainty, from which the coefficients of variation for the estimated Ba

  20. Applying 4-regular grid structures in large-scale access networks

    DEFF Research Database (Denmark)

    Pedersen, Jens Myrup; Knudsen, Thomas P.; Patel, Ahmed

    2006-01-01

    4-Regular grid structures have been used in multiprocessor systems for decades due to a number of nice properties with regard to routing, protection, and restoration, together with a straightforward planar layout. These qualities are to an increasing extent demanded also in largescale access...

  1. Solving large-scale real-world telecommunication problems using a grid-based genetic algorithm

    Science.gov (United States)

    Luna, Francisco; Nebro, Antonio; Alba, Enrique; Durillo, Juan

    2008-11-01

    This article analyses the use of a grid-based genetic algorithm (GrEA) to solve a real-world instance of a problem from the telecommunication domain. The problem, known as automatic frequency planning (AFP), is used in a global system for mobile communications (GSM) networks to assign a number of fixed frequencies to a set of GSM transceivers located in the antennae of a cellular phone network. Real data instances of the AFP are very difficult to solve owing to the NP-hard nature of the problem, so combining grid computing and metaheuristics turns out to be a way to provide satisfactory solutions in a reasonable amount of time. GrEA has been deployed on a grid with up to 300 processors to solve an AFP instance of 2612 transceivers. The results not only show that significant running time reductions are achieved, but that the search capability of GrEA clearly outperforms that of the equivalent non-grid algorithm.

  2. On Hierarchical Extensions of Large-Scale 4-regular Grid Network Structures

    DEFF Research Database (Denmark)

    Pedersen, Jens Myrup; Patel, A.; Knudsen, Thomas Phillip

    2004-01-01

    It is studied how the introduction of ordered hierarchies in 4-regular grid network structures decreases distances remarkably, while at the same time allowing for simple topological routing schemes. Both meshes and tori are considered; in both cases non-hierarchical structures have power law depe...

  3. Large Scale Solar Power Integration in Distribution Grids : PV Modelling, Voltage Support and Aggregation Studies

    NARCIS (Netherlands)

    Samadi, A.

    2014-01-01

    Long term supporting schemes for photovoltaic (PV) system installation have led to accommodating large numbers of PV systems within load pockets in distribution grids. High penetrations of PV systems can cause new technical challenges, such as voltage rise due to reverse power flow during light load

  4. Multi-scale modeling of urban air pollution: development of a Street-in-Grid model

    Science.gov (United States)

    Kim, Youngseob; Wu, You; Seigneur, Christian; Roustan, Yelva

    2016-04-01

    A new multi-scale model of urban air pollution is presented. This model combines a chemical-transport model (CTM) that includes a comprehensive treatment of atmospheric chemistry and transport at spatial scales greater than 1 km and a street-network model that describes the atmospheric concentrations of pollutants in an urban street network. The street-network model is based on the general formulation of the SIRANE model and consists of two main components: a street-canyon component and a street-intersection component. The street-canyon component calculates the mass transfer velocity at the top of the street canyon (roof top) and the mean wind velocity within the street canyon. The estimation of the mass transfer velocity depends on the intensity of the standard deviation of the vertical velocity at roof top. The effect of various formulations of this mass transfer velocity on the pollutant transport at roof-top level is examined. The street-intersection component calculates the mass transfer from a given street to other streets across the intersection. These mass transfer rates among the streets are calculated using the mean wind velocity calculated for each street and are balanced so that the total incoming flow rate is equal to the total outgoing flow rate from the intersection including the flow between the intersection and the overlying atmosphere at roof top. In the default option, the Leighton photostationary cycle among ozone (O3) and nitrogen oxides (NO and NO2) is used to represent the chemical reactions within the street network. However, the influence of volatile organic compounds (VOC) on the pollutant concentrations increases when the nitrogen oxides (NOx) concentrations are low. To account for the possible VOC influence on street-canyon chemistry, the CB05 chemical kinetic mechanism, which includes 35 VOC model species, is implemented in this street-network model. A sensitivity study is conducted to assess the uncertainties associated with the use of

  5. General Forced Oscillations in a Real Power Grid Integrated with Large Scale Wind Power

    Directory of Open Access Journals (Sweden)

    Ping Ju

    2016-07-01

    Full Text Available According to the monitoring of the wide area measurement system, inter-area oscillations happen more and more frequently in a real power grid of China, which are close to the forced oscillation. Applying the conventional forced oscillation theory, the mechanism of these oscillations cannot be explained well, because the oscillations vary with random amplitude and a narrow frequency band. To explain the mechanism of such oscillations, the general forced oscillation (GFO mechanism is taken into consideration. The GFO is the power system oscillation excited by the random excitations, such as power fluctuations from renewable power generation. Firstly, properties of the oscillations observed in the real power grid are analyzed. Using the GFO mechanism, the observed oscillations seem to be the GFO caused by some random excitation. Then the variation of the wind power measured in this power gird is found to be the random excitation which may cause the GFO phenomenon. Finally, simulations are carried out and the power spectral density of the simulated oscillation is compared to that of the observed oscillation, and they are similar with each other. The observed oscillation is thus explained well using the GFO mechanism and the GFO phenomenon has now been observed for the first time in real power grids.

  6. Analytical Assessment of the Relationship between 100MWp Large-scale Grid-connected Photovoltaic Plant Performance and Meteorological Parameters

    Science.gov (United States)

    Sheng, Jie; Zhu, Qiaoming; Cao, Shijie; You, Yang

    2017-05-01

    This paper helps in study of the relationship between the photovoltaic power generation of large scale “fishing and PV complementary” grid-tied photovoltaic system and meteorological parameters, with multi-time scale power data from the photovoltaic power station and meteorological data over the same period of a whole year. The result indicates that, the PV power generation has the most significant correlation with global solar irradiation, followed by diurnal temperature range, sunshine hours, daily maximum temperature and daily average temperature. In different months, the maximum monthly average power generation appears in August, which related to the more global solar irradiation and longer sunshine hours in this month. However, the maximum daily average power generation appears in October, this is due to the drop in temperature brings about the improvement of the efficiency of PV panels. Through the contrast of monthly average performance ratio (PR) and monthly average temperature, it is shown that, the larger values of monthly average PR appears in April and October, while it is smaller in summer with higher temperature. The results concluded that temperature has a great influence on the performance ratio of large scale grid-tied PV power system, and it is important to adopt effective measures to decrease the temperature of PV plant properly.

  7. On Hierarchical Extensions of Large-Scale 4-regular Grid Network Structures

    DEFF Research Database (Denmark)

    Pedersen, Jens Myrup; Patel, A.; Knudsen, Thomas Phillip

    It is studied how the introduction of ordered hierarchies in 4-regular grid network structures decreses distances remarkably, while at the same time allowing for simple topological routing schemes. Both meshes and tori are considered; in both cases non-hierarchical structures have power law......, and it is shown that while they allow for more flexibility in design and construction of structures supporting topological routing, their performances are comparable to the performance of the perfect square mesh. Finally suggestions for further research within the field are given....

  8. Voltage stability issues for a benchmark grid model including large scale wind power

    DEFF Research Database (Denmark)

    Eek, Jarle; Lund, Torsten; Di Marzio, Guiseppe

    2006-01-01

    The objective of the paper is to investigate how the voltage stability of a relatively weak network after a grid fault is affected by the connection of a large wind park. A theoretical discussion of the stationary and dynamic characteristics of the Short Circuit Induction Generator and the Doubly...... Fed Induction Generator is given. Further, a case study of a wind park connected to the transmission system through an existing regional 132 kV regional distribution line is presented. For the SCIG it is concluded that a stationary torque curve calculated under consideration of the impedance...

  9. Reactivation of dead sulfide species in lithium polysulfide flow battery for grid scale energy storage.

    Science.gov (United States)

    Jin, Yang; Zhou, Guangmin; Shi, Feifei; Zhuo, Denys; Zhao, Jie; Liu, Kai; Liu, Yayuan; Zu, Chenxi; Chen, Wei; Zhang, Rufan; Huang, Xuanyi; Cui, Yi

    2017-09-06

    Lithium polysulfide batteries possess several favorable attributes including low cost and high energy density for grid energy storage. However, the precipitation of insoluble and irreversible sulfide species on the surface of carbon and lithium (called "dead" sulfide species) leads to continuous capacity degradation in high mass loading cells, which represents a great challenge. To address this problem, herein we propose a strategy to reactivate dead sulfide species by reacting them with sulfur powder with stirring and heating (70 °C) to recover the cell capacity, and further demonstrate a flow battery system based on the reactivation approach. As a result, ultrahigh mass loading (0.125 g cm-3, 2 g sulfur in a single cell), high volumetric energy density (135 Wh L-1), good cycle life, and high single-cell capacity are achieved. The high volumetric energy density indicates its promising application for future grid energy storage.Lithium polysulfide batteries suffer from the precipitation of insoluble and irreversible sulfide species on the surface of carbon and lithium. Here the authors show a reactivation strategy by a reaction with cheap sulfur powder under stirring and heating to recover the cell capacity.

  10. Alignments and small scale statistics in the production region of grid turbulence

    Science.gov (United States)

    Paul, Immanuvel; Papadakis, George; Vassilicos, John Christos; Turbulence, Mixing; Flow Control Group Team

    2015-11-01

    Direct Numerical Simulation (DNS) of turbulent flow generated by a single square grid is investigated using an unstructured finite volume method. The maximum value of the Taylor length-based Reynolds number throughout the computed flow field is about 40. The main focus of this study is on the production region which lies in the lee of the grid where turbulence builds up. Statistics of vorticity and of eigenvalues (λi, where i =1,2,3) and eigenvectors (ei, where i =1,2,3) of the fluctuating strain rate tensor (Sij) are analyzed. It is observed that the PDFs of all the eigenvalues in the production region are highly non-gaussian. The PDFs of the compressive (λ3) and intermediate (λ2) eigenvalues are strongly skewed to negative and positive values respectively. The energy spectrum of the streamwise fluctuating velocity has a well-defined power law with an exponent around -2 or -5/3 over more than one decade depending on the position in the production region. It is also observed that the most extensive eigenvector (e1) and the intermediate eigenvector (e2) align significantly with vorticity vector in the production region, which in turn increases average enstrophy production.

  11. IGMS: An Integrated ISO-to-Appliance Scale Grid Modeling System

    Energy Technology Data Exchange (ETDEWEB)

    Palmintier, Bryan; Hale, Elaine; Hansen, Timothy M.; Jones, Wesley; Biagioni, David; Sorensen, Harry; Wu, Hongyu; Hodge, Bri-Mathias

    2017-05-01

    This paper describes the Integrated Grid Modeling System (IGMS), a novel electric power system modeling platform for integrated transmission-distribution analysis that co-simulates off-the-shelf tools on high performance computing (HPC) platforms to offer unprecedented resolution from ISO markets down to appliances and other end uses. Specifically, the system simultaneously models hundreds or thousands of distribution systems in co-simulation with detailed Independent System Operator (ISO) markets and AGC-level reserve deployment. IGMS uses a new MPI-based hierarchical co-simulation framework to connect existing sub-domain models. Our initial efforts integrate opensource tools for wholesale markets (FESTIV), bulk AC power flow (MATPOWER), and full-featured distribution systems including physics-based end-use and distributed generation models (many instances of GridLAB-D[TM]). The modular IGMS framework enables tool substitution and additions for multi-domain analyses. This paper describes the IGMS tool, characterizes its performance, and demonstrates the impacts of the coupled simulations for analyzing high-penetration solar PV and price responsive load scenarios.

  12. Off-grid hybrid electric power supply system, using a combination of solar cells, small scale wind turbine and batteries

    Energy Technology Data Exchange (ETDEWEB)

    Schroeter, W.

    1994-03-01

    The design of an off-grid electric power supply system consisting of a small scale wind turbine, a combination of solar cells and batteries is described. The robust, small scale FC 4000 wind turbine, which needs little maintenance, can be used under varying climatic conditions. It is equipped with a permanent-magnet generator with an output of 1.5 kW. The generator`s rotor is directly coupled with the wind turbine`s rotor and is without a gearbox, so the frequency and output varies according to wind speed. The 12 m{sup 2} solar cell system consists of round modules embedded in glass and with an efficiency of 13%. The lead acid batteries are used when power consumption exceeds production and store energy for future use. Further adjustments are necessary in order to optimize the performance of this hybrid system. (AB)

  13. Grid Support in Large Scale PV Power Plants using Active Power Reserves

    DEFF Research Database (Denmark)

    Craciun, Bogdan-Ionut

    (ENTSO-E) to continuously upgrade their Network Codes (NCs), moving their focus to grid stabilization features. Considering the technical challenges present in the nowadays power systems, the work presented in this thesis focuses on frequency and power ramp control strategies provided by LPVPPs...... active players in the power system, along with the conventional generation, and can share part of their stabilizing responsibilities. Stringent power ramping obligations imposed by TSOs such as Puerto Rico Electric Power Authority (PREPA) with increased levels of renewables, represents the second topic...... of this thesis. Power fluctuations created by the variable and intermittent nature of the irradiance, are smoothed out by a proposed power ramp limitation (PRL) control architecture, which considers LPVPP spatial distribution and minimizes the power mismatches by using optimal curtailed APRs. The proposed PRL...

  14. Spatial scale and place field stability in a grid-to-place cell model of the dorsoventral axis of the hippocampus.

    Science.gov (United States)

    Lyttle, David; Gereke, Brian; Lin, Kevin K; Fellous, Jean-Marc

    2013-08-01

    The rodent hippocampus and entorhinal cortex contain spatially modulated cells that serve as the basis for spatial coding. Both medial entorhinal grid cells and hippocampal place cells have been shown to encode spatial information across multiple spatial scales that increase along the dorsoventral axis of these structures. Place cells near the dorsal pole possess small, stable, and spatially selective firing fields, while ventral cells have larger, less stable, and less spatially selective firing fields. One possible explanation for these dorsoventral changes in place field properties is that they arise as a result of similar dorsoventral differences in the properties of the grid cell inputs to place cells. Here, we test the alternative hypothesis that dorsoventral place field differences are due to higher amounts of nonspatial inputs to ventral hippocampal cells. We use a computational model of the entorhinal-hippocampal network to assess the relative contributions of grid scale and nonspatial inputs in determining place field size and stability. In addition, we assess the consequences of grid node firing rate heterogeneity on place field stability. Our results suggest that dorsoventral differences in place cell properties can be better explained by changes in the amount of nonspatial inputs, rather than by changes in the scale of grid cell inputs, and that grid node heterogeneity may have important functional consequences. The observed gradient in field size may reflect a shift from processing primarily spatial information in the dorsal hippocampus to processing more nonspatial, contextual, and emotional information near the ventral hippocampus. Copyright © 2013 Wiley Periodicals, Inc.

  15. Economic evaluation of small-scale photovoltaic hybrid systems for mini-grid applications in far north Cameroon

    Energy Technology Data Exchange (ETDEWEB)

    Mbaka, Nfah Eustace; Godpromesse, Kenne [Laboratoire d' Automatique et d' Informatique Appliquee, I.U.T. Fotso Victor, P.O. Box 134, Bandjoun, University of Dschang (Cameroon); Mucho, Ngundam John [Automation and Control Laboratory, School of Engineering, P.O. Box 8390, University of Yaounde I (Cameroon)

    2010-10-15

    A comparison between photovoltaic hybrid systems (PVHS), standalone photovoltaic (PV) and standalone diesel generator options is performed using the net present value (NPV) technique. A typical village mini-grid energy demand of 7.08 kWh/day is considered in the computation of energy costs and breakeven grid distances. A first sensitivity analysis is conducted using remote diesel prices of 0.8 EUR/l, 0.98 EUR/l, 1.12 EUR/l, 1.28 EUR/l with a PV module cost of 7.5 EUR/Wp. A second sensitivity analysis is also done using PV module costs of 5.25 EUR/Wp, 6 EUR/Wp, 6.75 EUR/Wp, 7.5 EUR/Wp with a diesel price of 1.12 EUR/l. The energy cost for the diesel option was found to be 0.812 EUR/kWh at a diesel fuel price of 1.12 EUR/l. The sensitivity analyses showed that minimum energy costs were attained in PVHS at renewable energy fractions in the range 82.6-95.3%. In the second sensitivity analysis the energy costs and breakeven grid distances were found to be in the ranges 0.692-0.785 EUR/kWh and 5.1-5.9 km respectively. For a PV module cost of 5.25 EUR/Wp, the lowest energy cost for the PVHS option was 0.692 EUR/kWh at a final renewable energy fraction of 95.3% with the diesel generator hours being 37 h compared to 2075 h in the standalone diesel generator option. Consequently, a 30% reduction in custom duties and taxes on imported PV modules and sub-systems would increase the use of small-scale and climate friendly PV mini-grids in remote areas of far north Cameroon that have an annual insolation of at least 5.55 kWh/m{sup 2}/day. (author)

  16. Tunable Reaction Potentials in Open Framework Nanoparticle Battery Electrodes for Grid-Scale Energy Storage

    KAUST Repository

    Wessells, Colin D.

    2012-02-28

    The electrical energy grid has a growing need for energy storage to address short-term transients, frequency regulation, and load leveling. Though electrochemical energy storage devices such as batteries offer an attractive solution, current commercial battery technology cannot provide adequate power, and cycle life, and energy efficiency at a sufficiently low cost. Copper hexacyanoferrate and nickel hexacyanoferrate, two open framework materials with the Prussian Blue structure, were recently shown to offer ultralong cycle life and high-rate performance when operated as battery electrodes in safe, inexpensive aqueous sodium ion and potassium ion electrolytes. In this report, we demonstrate that the reaction potential of copper-nickel alloy hexacyanoferrate nanoparticles may be tuned by controlling the ratio of copper to nickel in these materials. X-ray diffraction, TEM energy dispersive X-ray spectroscopy, and galvanostatic electrochemical cycling of copper-nickel hexacyanoferrate reveal that copper and nickel form a fully miscible solution at particular sites in the framework without perturbing the structure. This allows copper-nickel hexacyanoferrate to reversibly intercalate sodium and potassium ions for over 2000 cycles with capacity retentions of 100% and 91%, respectively. The ability to precisely tune the reaction potential of copper-nickel hexacyanoferrate without sacrificing cycle life will allow the development of full cells that utilize the entire electrochemical stability window of aqueous sodium and potassium ion electrolytes. © 2012 American Chemical Society.

  17. Can Clouds Replace Grids? A Real-Life Exabyte-Scale Test-Case

    CERN Document Server

    Shiers, J

    2008-01-01

    The world’s largest scientific machine – comprising dual 27km circular proton accelerators cooled to 1.9oK and located some 100m underground – currently relies on major production Grid infrastructures for the offline computing needs of the 4 main experiments that will take data at this facility. After many years of sometimes difficult preparation the computing service has been declared â€ワopen” and ready to meet the challenges that will come shortly when the machine restarts in 2009. But the service is not without its problems: reliability – as seen by the experiments, as opposed to that measured by the official tools – still needs to be significantly improved. Prolonged downtimes or degradations of major services or even complete sites are still too common and the operational and coordination effort to keep the overall service running is probably not sustainable at this level. Recently â€ワCloud Computing” – in terms of pay-per-use fabric provisioning – has...

  18. Effect of reactions in small eddies on biomass gasification with eddy dissipation concept - Sub-grid scale reaction model.

    Science.gov (United States)

    Chen, Juhui; Yin, Weijie; Wang, Shuai; Meng, Cheng; Li, Jiuru; Qin, Bai; Yu, Guangbin

    2016-07-01

    Large-eddy simulation (LES) approach is used for gas turbulence, and eddy dissipation concept (EDC)-sub-grid scale (SGS) reaction model is employed for reactions in small eddies. The simulated gas molar fractions are in better agreement with experimental data with EDC-SGS reaction model. The effect of reactions in small eddies on biomass gasification is emphatically analyzed with EDC-SGS reaction model. The distributions of the SGS reaction rates which represent the reactions in small eddies with particles concentration and temperature are analyzed. The distributions of SGS reaction rates have the similar trend with those of total reactions rates and the values account for about 15% of the total reactions rates. The heterogeneous reaction rates with EDC-SGS reaction model are also improved during the biomass gasification process in bubbling fluidized bed. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Comparison of five gridded precipitation products at climatological scales over West Africa

    Science.gov (United States)

    Akinsanola, A. A.; Ogunjobi, K. O.; Ajayi, V. O.; Adefisan, E. A.; Omotosho, J. A.; Sanogo, S.

    2017-12-01

    The paper aimed at assessing the capabilities and limitations of five different precipitation products to describe rainfall over West Africa. Five gridded precipitation datasets of the Tropical Rainfall Measurement Mission (TRMM) Multi-Platform Analysis (TMPA 3B43v7); University of Delaware (UDEL version 3.01); Climatic Research Unit (CRU version 3.1); Global Precipitation Climatology Centre (GPCC version 7) and African Rainfall Climatology (ARC version 2) were compared and validated with reference ground observation data from 81 stations spanning a 19-year period, from January 1990 to December 2008. Spatial investigation of the precipitation datasets was performed, and their capability to replicate the inter-annual and intra-seasonal variability was also assessed. The ability of the products to capture the El Nino and La Nina events were also assessed. Results show that all the five datasets depicted similar spatial distribution of mean rainfall climatology, although differences exist in the total rainfall amount for each precipitation dataset. Further analysis shows that the three distinct phases of the mean annual cycle of the West Africa Monsoon precipitation were well captured by the datasets. However, CRU, GPCC and UDEL failed to capture the little dry season in the month of August while UDEL and GPCC underestimated rainfall amount in the Sahel region. Results of the inter-annual precipitation anomalies shows that ARC2 fail to capture about 46% of the observed variability while the other four datasets exhibits a greater performance ( r > 0.9). All the precipitation dataset except ARC2 were consistent with the ground observation in capturing the dry and wet conditions associated with El Nino and La Nina events, respectively. ARC2 tends to overestimate the El Nino event and failed to capture the La Nina event in all the years considered. In general GPCC, CRU and TRMM were found to be the most outstanding datasets and can, therefore, be used for precipitation

  20. A three pronged approach to community scale renewable energy: Education, incremental capital investment and smart grid technology

    Science.gov (United States)

    Demeo, Anna E.

    ; first hand exposure to technology, providing a sense of independence that strengthens communities, and developing a direct link between the energy people use and how that energy is created. Ultimately community scale renewable energy projects help bolster support for large-scale projects that are imperative to making real and lasting progress towards reducing emissions. Finally, technological advancements in renewable energy generation, energy storage and distribution systems, are imperative to replacing fossil fuels. The shift towards a higher penetration of renewable energy into the electric grid can be realized with the implementation of a more sophisticated smart grid, which uses dynamic demand response to alter demand to follow generation. Introduction of tidal power can serve to further stabilize the grid and reduce the amount of storage required. This work describes an interdisciplinary approach to addressing issues of energy, and thereby climate, through substantive efforts in three concentrations; energy literacy education, community driven renewable energy projects based on incremental capital investment and a smart, micro grid encompassing tidal power and other renewable energy source.

  1. Delta-Connected Cascaded H-Bridge Multilevel Converters for Large-Scale Photovoltaic Grid Integration

    DEFF Research Database (Denmark)

    Yu, Yifan; Konstantinou, Georgios; Townsend, Christopher D.

    2017-01-01

    The cascaded H-bridge (CHB) converter is becoming a promising candidate for use in next generation large-scale photovoltaic (PV) power plants. However, solar power generation in the three converter phase-legs can be significantly unbalanced, especially in a large geographically-dispersed plant...

  2. Impact of Sub-grid Soil Textural Properties on Simulations of Hydrological Fluxes at the Continental Scale Mississippi River Basin

    Science.gov (United States)

    Kumar, R.; Samaniego, L. E.; Livneh, B.

    2013-12-01

    Knowledge of soil hydraulic properties such as porosity and saturated hydraulic conductivity is required to accurately model the dynamics of near-surface hydrological processes (e.g. evapotranspiration and root-zone soil moisture dynamics) and provide reliable estimates of regional water and energy budgets. Soil hydraulic properties are commonly derived from pedo-transfer functions using soil textural information recorded during surveys, such as the fractions of sand and clay, bulk density, and organic matter content. Typically large scale land-surface models are parameterized using a relatively coarse soil map with little or no information on parametric sub-grid variability. In this study we analyze the impact of sub-grid soil variability on simulated hydrological fluxes over the Mississippi River Basin (≈3,240,000 km2) at multiple spatio-temporal resolutions. A set of numerical experiments were conducted with the distributed mesoscale hydrologic model (mHM) using two soil datasets: (a) the Digital General Soil Map of the United States or STATSGO2 (1:250 000) and (b) the recently collated Harmonized World Soil Database based on the FAO-UNESCO Soil Map of the World (1:5 000 000). mHM was parameterized with the multi-scale regionalization technique that derives distributed soil hydraulic properties via pedo-transfer functions and regional coefficients. Within the experimental framework, the 3-hourly model simulations were conducted at four spatial resolutions ranging from 0.125° to 1°, using meteorological datasets from the NLDAS-2 project for the time period 1980-2012. Preliminary results indicate that the model was able to capture observed streamflow behavior reasonably well with both soil datasets, in the major sub-basins (i.e. the Missouri, the Upper Mississippi, the Ohio, the Red, and the Arkansas). However, the spatio-temporal patterns of simulated water fluxes and states (e.g. soil moisture, evapotranspiration) from both simulations, showed marked

  3. An Investigation of Wavelet Bases for Grid-Based Multi-Scale Simulations Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Baty, R.S.; Burns, S.P.; Christon, M.A.; Roach, D.W.; Trucano, T.G.; Voth, T.E.; Weatherby, J.R.; Womble, D.E.

    1998-11-01

    The research summarized in this report is the result of a two-year effort that has focused on evaluating the viability of wavelet bases for the solution of partial differential equations. The primary objective for this work has been to establish a foundation for hierarchical/wavelet simulation methods based upon numerical performance, computational efficiency, and the ability to exploit the hierarchical adaptive nature of wavelets. This work has demonstrated that hierarchical bases can be effective for problems with a dominant elliptic character. However, the strict enforcement of orthogonality was found to be less desirable than weaker semi-orthogonality or bi-orthogonality for solving partial differential equations. This conclusion has led to the development of a multi-scale linear finite element based on a hierarchical change of basis. The reproducing kernel particle method has been found to yield extremely accurate phase characteristics for hyperbolic problems while providing a convenient framework for multi-scale analyses.

  4. The application of liquid air energy storage for large scale long duration solutions to grid balancing

    Directory of Open Access Journals (Sweden)

    Brett Gareth

    2014-01-01

    Full Text Available Liquid Air Energy Storage (LAES provides large scale, long duration energy storage at the point of demand in the 5 MW/20 MWh to 100 MW/1,000 MWh range. LAES combines mature components from the industrial gas and electricity industries assembled in a novel process and is one of the few storage technologies that can be delivered at large scale, with no geographical constraints. The system uses no exotic materials or scarce resources and all major components have a proven lifetime of 25+ years. The system can also integrate low grade waste heat to increase power output. Founded in 2005, Highview Power Storage, is a UK based developer of LAES. The company has taken the concept from academic analysis, through laboratory testing, and in 2011 commissioned the world's first fully integrated system at pilot plant scale (300 kW/2.5 MWh hosted at SSE's (Scottish & Southern Energy 80 MW Biomass Plant in Greater London which was partly funded by a Department of Energy and Climate Change (DECC grant. Highview is now working with commercial customers to deploy multi MW commercial reference plants in the UK and abroad.

  5. The air quality and human health effects of integrating utility-scale batteries into the New York State electricity grid

    Science.gov (United States)

    Gilmore, Elisabeth A.; Apt, Jay; Walawalkar, Rahul; Adams, Peter J.; Lave, Lester B.

    In a restructured electricity market, utility-scale energy storage technologies such as advanced batteries can generate revenue by charging at low electricity prices and discharging at high prices. This strategy changes the magnitude and distribution of air quality emissions and the total carbon dioxide (CO 2) emissions. We evaluate the social costs associated with these changes using a case study of 500 MW sodium-sulfur battery installations with 80% round-trip efficiency. The batteries displace peaking generators in New York City and charge using off-peak generation in the New York Independent System Operator (NYISO) electricity grid during the summer. We identify and map charging and displaced plant types to generators in the NYISO. We then convert the emissions into ambient concentrations with a chemical transport model, the Particulate Matter Comprehensive Air Quality Model with extensions (PMCAM x). Finally, we transform the concentrations into their equivalent human health effects and social benefits and costs. Reductions in premature mortality from fine particulate matter (PM 2.5) result in a benefit of 4.5 ¢ kWh -1 and 17 ¢ kWh -1 from displacing a natural gas and distillate fuel oil fueled peaking plant, respectively, in New York City. Ozone (O 3) concentrations increase due to decreases in nitrogen oxide (NO x) emissions, although the magnitude of the social cost is less certain. Adding the costs from charging, displacing a distillate fuel oil plant yields a net social benefit, while displacing the natural gas plant has a net social cost. With the existing base-load capacity, the upstate population experiences an increase in adverse health effects. If wind generation is charging the battery, both the upstate charging location and New York City benefit. At 20 per tonne of CO 2, the costs from CO 2 are small compared to those from air quality. We conclude that storage could be added to existing electricity grids as part of an integrated strategy from a

  6. Grid-based water quality simulation at catchment scale: Nitrogen model development and evaluation

    Science.gov (United States)

    Yang, Xiaoqiang; Jomaa, Seifeddine; Rode, Michael

    2017-04-01

    Stream water quality has been changed significantly during last few decades due to changes in human impacts. Accurate and flexible water quality models, which can properly reflect the heterogeneity and long term temporal dynamic of catchment functioning, are still needed. To this end, a new grid-based catchment water quality model was developed based on the mesoscale Hydrological Model (mHM) and the HYdrological Prediction of Environment (HYPE) model. The model structure and parameterization scheme were flexibly designed depending on the spatial heterogeneity of study sites and their specific requirements. Based on that, more detailed spatial information can be provided. Moreover, three main improvements on Nitrate sub-model were implemented: i) nitrate transport processes were conducted in physically connected river networks, allowing time-series point-source inputs added in the exact location of sewage treatment plants; ii) additional retention storage of deep groundwater was included for long term nitrate-N simulation; iii) special design for better taking into account crop rotation was implemented. Those new features can extend the model capability and facilitate the understanding of catchment mechanisms and analysis of future scenarios and measures. The newly developed model was fully verified in the Selke catchment (456 km2), central Germany. Long term discharge and water quality data have been collected at three nested gauging stations (1997-2015). The station Meisdorf, above where 72% of area is occupied by forest, represents the discharge and nutrient exports from forest area. Agricultural land dominates the lower part of the catchment (almost 96% of in-between area of the Meisdorf and the outlet station Hausneindorf) with considerable urban areas. Due to the relatively large number of model parameters, sensitivity analysis was firstly conducted. Subsequently, sensitive parameters were calibrated using stepwise and multi-variable approaches, respectively

  7. Modeling and Coordinated Control Strategy of Large Scale Grid-Connected Wind/Photovoltaic/Energy Storage Hybrid Energy Conversion System

    Directory of Open Access Journals (Sweden)

    Lingguo Kong

    2015-01-01

    Full Text Available An AC-linked large scale wind/photovoltaic (PV/energy storage (ES hybrid energy conversion system for grid-connected application was proposed in this paper. Wind energy conversion system (WECS and PV generation system are the primary power sources of the hybrid system. The ES system, including battery and fuel cell (FC, is used as a backup and a power regulation unit to ensure continuous power supply and to take care of the intermittent nature of wind and photovoltaic resources. Static synchronous compensator (STATCOM is employed to support the AC-linked bus voltage and improve low voltage ride through (LVRT capability of the proposed system. An overall power coordinated control strategy is designed to manage real-power and reactive-power flows among the different energy sources, the storage unit, and the STATCOM system in the hybrid system. A simulation case study carried out on Western System Coordinating Council (WSCC 3-machine 9-bus test system for the large scale hybrid energy conversion system has been developed using the DIgSILENT/Power Factory software platform. The hybrid system performance under different scenarios has been verified by simulation studies using practical load demand profiles and real weather data.

  8. Sub-grid scale models for discontinuous Galerkin methods based on the Mori-Zwanzig formalism

    Science.gov (United States)

    Parish, Eric; Duraisamy, Karthk

    2017-11-01

    The optimal prediction framework of Chorin et al., which is a reformulation of the Mori-Zwanzig (M-Z) formalism of non-equilibrium statistical mechanics, provides a framework for the development of mathematically-derived closure models. The M-Z formalism provides a methodology to reformulate a high-dimensional Markovian dynamical system as a lower-dimensional, non-Markovian (non-local) system. In this lower-dimensional system, the effects of the unresolved scales on the resolved scales are non-local and appear as a convolution integral. The non-Markovian system is an exact statement of the original dynamics and is used as a starting point for model development. In this work, we investigate the development of M-Z-based closures model within the context of the Variational Multiscale Method (VMS). The method relies on a decomposition of the solution space into two orthogonal subspaces. The impact of the unresolved subspace on the resolved subspace is shown to be non-local in time and is modeled through the M-Z-formalism. The models are applied to hierarchical discontinuous Galerkin discretizations. Commonalities between the M-Z closures and conventional flux schemes are explored. This work was supported in part by AFOSR under the project ''LES Modeling of Non-local effects using Statistical Coarse-graining'' with Dr. Jean-Luc Cambier as the technical monitor.

  9. PowerGrid - A Computation Engine for Large-Scale Electric Networks

    Energy Technology Data Exchange (ETDEWEB)

    Chika Nwankpa

    2011-01-31

    This Final Report discusses work on an approach for analog emulation of large scale power systems using Analog Behavioral Models (ABMs) and analog devices in PSpice design environment. ABMs are models based on sets of mathematical equations or transfer functions describing the behavior of a circuit element or an analog building block. The ABM concept provides an efficient strategy for feasibility analysis, quick insight of developing top-down design methodology of large systems and model verification prior to full structural design and implementation. Analog emulation in this report uses an electric circuit equivalent of mathematical equations and scaled relationships that describe the states and behavior of a real power system to create its solution trajectory. The speed of analog solutions is as quick as the responses of the circuit itself. Emulation therefore is the representation of desired physical characteristics of a real life object using an electric circuit equivalent. The circuit equivalent has within it, the model of a real system as well as the method of solution. This report presents a methodology of the core computation through development of ABMs for generators, transmission lines and loads. Results of ABMs used for the case of 3, 6, and 14 bus power systems are presented and compared with industrial grade numerical simulators for validation.

  10. Ecogrid EU: a large scale smart grids demonstration of real time market-based integration of numerous small der and DR

    NARCIS (Netherlands)

    Ding, Y.; Nyeng, P.; Ostergaard, J.; Trong, M.D.; Pineda, S.; Kok, K.; Huitema, G.B.; Grande, O.S.

    2012-01-01

    This paper provides an overview of the Ecogrid EU project, which is a large-scale demonstration project on the Danish island Bornholm. It provides Europe a fast track evolution towards smart grid dissemination and deployment in the distribution network. Objective of Ecogrid EU is to illustrate that

  11. One-equation sub-grid scale (SGS) modelling for Euler-Euler large eddy simulation (EELES) of dispersed bubbly flow

    NARCIS (Netherlands)

    Niceno, B.; Dhotre, M.T.; Deen, N.G.

    2008-01-01

    In this work, we have presented a one-equation model for sub-grid scale (SGS) kinetic energy and applied it for an Euler-Euler large eddy simulation (EELES) of a bubble column reactor. The one-equation model for SGS kinetic energy shows improved predictions over the state-of-the-art dynamic

  12. Information Power Grid: Distributed High-Performance Computing and Large-Scale Data Management for Science and Engineering

    Science.gov (United States)

    Johnston, William E.; Gannon, Dennis; Nitzberg, Bill

    2000-01-01

    We use the term "Grid" to refer to distributed, high performance computing and data handling infrastructure that incorporates geographically and organizationally dispersed, heterogeneous resources that are persistent and supported. This infrastructure includes: (1) Tools for constructing collaborative, application oriented Problem Solving Environments / Frameworks (the primary user interfaces for Grids); (2) Programming environments, tools, and services providing various approaches for building applications that use aggregated computing and storage resources, and federated data sources; (3) Comprehensive and consistent set of location independent tools and services for accessing and managing dynamic collections of widely distributed resources: heterogeneous computing systems, storage systems, real-time data sources and instruments, human collaborators, and communications systems; (4) Operational infrastructure including management tools for distributed systems and distributed resources, user services, accounting and auditing, strong and location independent user authentication and authorization, and overall system security services The vision for NASA's Information Power Grid - a computing and data Grid - is that it will provide significant new capabilities to scientists and engineers by facilitating routine construction of information based problem solving environments / frameworks. Such Grids will knit together widely distributed computing, data, instrument, and human resources into just-in-time systems that can address complex and large-scale computing and data analysis problems. Examples of these problems include: (1) Coupled, multidisciplinary simulations too large for single systems (e.g., multi-component NPSS turbomachine simulation); (2) Use of widely distributed, federated data archives (e.g., simultaneous access to metrological, topological, aircraft performance, and flight path scheduling databases supporting a National Air Space Simulation systems}; (3

  13. Sub-grid scale representation of vegetation in global land surface schemes: implications for estimation of the terrestrial carbon sink

    Directory of Open Access Journals (Sweden)

    J. R. Melton

    2014-02-01

    Full Text Available Terrestrial ecosystem models commonly represent vegetation in terms of plant functional types (PFTs and use their vegetation attributes in calculations of the energy and water balance as well as to investigate the terrestrial carbon cycle. Sub-grid scale variability of PFTs in these models is represented using different approaches with the "composite" and "mosaic" approaches being the two end-members. The impact of these two approaches on the global carbon balance has been investigated with the Canadian Terrestrial Ecosystem Model (CTEM v 1.2 coupled to the Canadian Land Surface Scheme (CLASS v 3.6. In the composite (single-tile approach, the vegetation attributes of different PFTs present in a grid cell are aggregated and used in calculations to determine the resulting physical environmental conditions (soil moisture, soil temperature, etc. that are common to all PFTs. In the mosaic (multi-tile approach, energy and water balance calculations are performed separately for each PFT tile and each tile's physical land surface environmental conditions evolve independently. Pre-industrial equilibrium CLASS-CTEM simulations yield global totals of vegetation biomass, net primary productivity, and soil carbon that compare reasonably well with observation-based estimates and differ by less than 5% between the mosaic and composite configurations. However, on a regional scale the two approaches can differ by > 30%, especially in areas with high heterogeneity in land cover. Simulations over the historical period (1959–2005 show different responses to evolving climate and carbon dioxide concentrations from the two approaches. The cumulative global terrestrial carbon sink estimated over the 1959–2005 period (excluding land use change (LUC effects differs by around 5% between the two approaches (96.3 and 101.3 Pg, for the mosaic and composite approaches, respectively and compares well with the observation-based estimate of 82.2 ± 35 Pg C over the same

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

    Energy Technology Data Exchange (ETDEWEB)

    Hankin, Steve

    2012-06-01

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

  15. Improving Wind Farm Dispatchability Using Model Predictive Control for Optimal Operation of Grid-Scale Energy Storage

    Directory of Open Access Journals (Sweden)

    Douglas Halamay

    2014-09-01

    Full Text Available This paper demonstrates the use of model-based predictive control for energy storage systems to improve the dispatchability of wind power plants. Large-scale wind penetration increases the variability of power flow on the grid, thus increasing reserve requirements. Large energy storage systems collocated with wind farms can improve dispatchability of the wind plant by storing energy during generation over-the-schedule and sourcing energy during generation under-the-schedule, essentially providing on-site reserves. Model predictive control (MPC provides a natural framework for this application. By utilizing an accurate energy storage system model, control actions can be planned in the context of system power and state-of-charge limitations. MPC also enables the inclusion of predicted wind farm performance over a near-term horizon that allows control actions to be planned in anticipation of fast changes, such as wind ramps. This paper demonstrates that model-based predictive control can improve system performance compared with a standard non-predictive, non-model-based control approach. It is also demonstrated that secondary objectives, such as reducing the rate of change of the wind plant output (i.e., ramps, can be considered and successfully implemented within the MPC framework. Specifically, it is shown that scheduling error can be reduced by 81%, reserve requirements can be improved by up to 37%, and the number of ramp events can be reduced by 74%.

  16. Assessment of sub-grid scale dispersion closure with regularized deconvolution method in a particle-laden turbulent jet

    Science.gov (United States)

    Wang, Qing; Zhao, Xinyu; Ihme, Matthias

    2017-11-01

    Particle-laden turbulent flows are important in numerous industrial applications, such as spray combustion engines, solar energy collectors etc. It is of interests to study this type of flows numerically, especially using large-eddy simulations (LES). However, capturing the turbulence-particle interaction in LES remains challenging due to the insufficient representation of the effect of sub-grid scale (SGS) dispersion. In the present work, a closure technique for the SGS dispersion using regularized deconvolution method (RDM) is assessed. RDM was proposed as the closure for the SGS dispersion in a counterflow spray that is studied numerically using finite difference method on a structured mesh. A presumed form of LES filter is used in the simulations. In the present study, this technique has been extended to finite volume method with an unstructured mesh, where no presumption on the filter form is required. The method is applied to a series of particle-laden turbulent jets. Parametric analyses of the model performance are conducted for flows with different Stokes numbers and Reynolds numbers. The results from LES will be compared against experiments and direct numerical simulations (DNS).

  17. Assessing Impact of Large-Scale Distributed Residential HVAC Control Optimization on Electricity Grid Operation and Renewable Energy Integration

    Science.gov (United States)

    Corbin, Charles D.

    Demand management is an important component of the emerging Smart Grid, and a potential solution to the supply-demand imbalance occurring increasingly as intermittent renewable electricity is added to the generation mix. Model predictive control (MPC) has shown great promise for controlling HVAC demand in commercial buildings, making it an ideal solution to this problem. MPC is believed to hold similar promise for residential applications, yet very few examples exist in the literature despite a growing interest in residential demand management. This work explores the potential for residential buildings to shape electric demand at the distribution feeder level in order to reduce peak demand, reduce system ramping, and increase load factor using detailed sub-hourly simulations of thousands of buildings coupled to distribution power flow software. More generally, this work develops a methodology for the directed optimization of residential HVAC operation using a distributed but directed MPC scheme that can be applied to today's programmable thermostat technologies to address the increasing variability in electric supply and demand. Case studies incorporating varying levels of renewable energy generation demonstrate the approach and highlight important considerations for large-scale residential model predictive control.

  18. Numerical aspects of drift kinetic turbulence: Ill-posedness, regularization and a priori estimates of sub-grid-scale terms

    KAUST Repository

    Samtaney, Ravi

    2012-01-01

    We present a numerical method based on an Eulerian approach to solve the Vlasov-Poisson system for 4D drift kinetic turbulence. Our numerical approach uses a conservative formulation with high-order (fourth and higher) evaluation of the numerical fluxes coupled with a fourth-order accurate Poisson solver. The fluxes are computed using a low-dissipation high-order upwind differencing method or a tuned high-resolution finite difference method with no numerical dissipation. Numerical results are presented for the case of imposed ion temperature and density gradients. Different forms of controlled regularization to achieve a well-posed system are used to obtain convergent resolved simulations. The regularization of the equations is achieved by means of a simple collisional model, by inclusion of an ad-hoc hyperviscosity or artificial viscosity term or by implicit dissipation in upwind schemes. Comparisons between the various methods and regularizations are presented. We apply a filtering formalism to the Vlasov equation and derive sub-grid-scale (SGS) terms analogous to the Reynolds stress terms in hydrodynamic turbulence. We present a priori quantifications of these SGS terms in resolved simulations of drift-kinetic turbulence by applying a sharp filter. © 2012 IOP Publishing Ltd.

  19. Influence of Sub-grid-Scale Isentropic Transports on McRAS Evaluations using ARM-CART SCM Datasets

    Science.gov (United States)

    Sud, Y. C.; Walker, G. K.; Tao, W. K.

    2004-01-01

    In GCM-physics evaluations with the currently available ARM-CART SCM datasets, McRAS produced very similar character of near surface errors of simulated temperature and humidity containing typically warm and moist biases near the surface and cold and dry biases aloft. We argued it must have a common cause presumably rooted in the model physics. Lack of vertical adjustment of horizontal transport was thought to be a plausible source. Clearly, debarring such a freedom would force the incoming air to diffuse into the grid-cell which would naturally bias the surface air to become warm and moist while the upper air becomes cold and dry, a characteristic feature of McRAS biases. Since, the errors were significantly larger in the two winter cases that contain potentially more intense episodes of cold and warm advective transports, it further reaffirmed our argument and provided additional motivation to introduce the corrections. When the horizontal advective transports were suitably modified to allow rising and/or sinking following isentropic pathways of subgrid scale motions, the outcome was to cool and dry (or warm and moisten) the lower (or upper) levels. Ever, crude approximations invoking such a correction reduced the temperature and humidity biases considerably. The tests were performed on all the available ARM-CART SCM cases with consistent outcome. With the isentropic corrections implemented through two different numerical approximations, virtually similar benefits were derived further confirming the robustness of our inferences. These results suggest the need for insentropic advective transport adjustment in a GCM due to subgrid scale motions.

  20. Modeling lightning-NOx chemistry on a sub-grid scale in a global chemical transport model

    Directory of Open Access Journals (Sweden)

    A. Gressent

    2016-05-01

    Full Text Available For the first time, a plume-in-grid approach is implemented in a chemical transport model (CTM to parameterize the effects of the nonlinear reactions occurring within high concentrated NOx plumes from lightning NOx emissions (LNOx in the upper troposphere. It is characterized by a set of parameters including the plume lifetime, the effective reaction rate constant related to NOx–O3 chemical interactions, and the fractions of NOx conversion into HNO3 within the plume. Parameter estimates were made using the Dynamical Simple Model of Atmospheric Chemical Complexity (DSMACC box model, simple plume dispersion simulations, and the 3-D Meso-NH (non-hydrostatic mesoscale atmospheric model. In order to assess the impact of the LNOx plume approach on the NOx and O3 distributions on a large scale, simulations for the year 2006 were performed using the GEOS-Chem global model with a horizontal resolution of 2° × 2.5°. The implementation of the LNOx parameterization implies an NOx and O3 decrease on a large scale over the region characterized by a strong lightning activity (up to 25 and 8 %, respectively, over central Africa in July and a relative increase downwind of LNOx emissions (up to 18 and 2 % for NOx and O3, respectively, in July. The calculated variability in NOx and O3 mixing ratios around the mean value according to the known uncertainties in the parameter estimates is at a maximum over continental tropical regions with ΔNOx [−33.1, +29.7] ppt and ΔO3 [−1.56, +2.16] ppb, in January, and ΔNOx [−14.3, +21] ppt and ΔO3 [−1.18, +1.93] ppb, in July, mainly depending on the determination of the diffusion properties of the atmosphere and the initial NO mixing ratio injected by lightning. This approach allows us (i to reproduce a more realistic lightning NOx chemistry leading to better NOx and O3 distributions on the large scale and (ii to focus on other improvements to reduce remaining uncertainties from processes

  1. Ecogrid EU - a large scale smart grids demonstration of real time market-based integration of numerous small DER and DR

    DEFF Research Database (Denmark)

    Ding, Yi; Nyeng, Preben; Ostergaard, Jacob

    2012-01-01

    This paper provides an overview of the Ecogrid EU project, which is a large-scale demonstration project on the Danish island Bornholm. It provides Europe a fast track evolution towards smart grid dissemination and deployment in the distribution network. Objective of Ecogrid EU is to illustrate th...... customers will be equipped with demand response devices with smart controllers and smart meters, allowing them to respond to real-time prices based on their pre-programmed demand-response preferences.......This paper provides an overview of the Ecogrid EU project, which is a large-scale demonstration project on the Danish island Bornholm. It provides Europe a fast track evolution towards smart grid dissemination and deployment in the distribution network. Objective of Ecogrid EU is to illustrate...

  2. Effect of Considering Sub-Grid Scale Uncertainties on the Forecasts of a High-Resolution Limited Area Ensemble Prediction System

    Science.gov (United States)

    Kim, SeHyun; Kim, Hyun Mee

    2017-05-01

    The ensemble prediction system (EPS) is widely used in research and at operation center because it can represent the uncertainty of predicted atmospheric state and provide information of probabilities. The high-resolution (so-called "convection-permitting") limited area EPS can represent the convection and turbulence related to precipitation phenomena in more detail, but it is also much sensitive to small-scale or sub-grid scale processes. The convection and turbulence are represented using physical processes in the model and model errors occur due to sub-grid scale processes that were not resolved. This study examined the effect of considering sub-grid scale uncertainties using the high-resolution limited area EPS of the Korea Meteorological Administration (KMA). The developed EPS has horizontal resolution of 3 km and 12 ensemble members. The initial and boundary conditions were provided by the global model. The Random Parameters (RP) scheme was used to represent sub-grid scale uncertainties. The EPSs with and without the RP scheme were developed and the results were compared. During the one month period of July, 2013, a significant difference was shown in the spread of 1.5 m temperature and the Root Mean Square Error and spread of 10 m zonal wind due to application of the RP scheme. For precipitation forecast, the precipitation tended to be overestimated relative to the observation when the RP scheme was applied. Moreover, the forecast became more accurate for heavy precipitations and the longer forecast lead times. For two heavy rainfall cases occurred during the research period, the higher Equitable Threat Score was observed for heavy precipitations in the system with the RP scheme compared to the one without, demonstrating consistency with the statistical results for the research period. Therefore, the predictability for heavy precipitation phenomena that affected the Korean Peninsula increases if the RP scheme is used to consider sub-grid scale uncertainties

  3. The Earth System Grid Federation (ESGF): Climate Science Infrastructure for Large-scale Data Management and Dissemination

    Science.gov (United States)

    Williams, D. N.

    2015-12-01

    Progress in understanding and predicting climate change requires advanced tools to securely store, manage, access, process, analyze, and visualize enormous and distributed data sets. Only then can climate researchers understand the effects of climate change across all scales and use this information to inform policy decisions. With the advent of major international climate modeling intercomparisons, a need emerged within the climate-change research community to develop efficient, community-based tools to obtain relevant meteorological and other observational data, develop custom computational models, and export analysis tools for climate-change simulations. While many nascent efforts to fill these gaps appeared, they were not integrated and therefore did not benefit from collaborative development. Sharing huge data sets was difficult, and the lack of data standards prevented the merger of output data from different modeling groups. Thus began one of the largest-ever collaborative data efforts in climate science, resulting in the Earth System Grid Federation (ESGF), which is now used to disseminate model, observational, and reanalysis data for research assessed by the Intergovernmental Panel on Climate Change (IPCC). Today, ESGF is an open-source petabyte-level data storage and dissemination operational code-base that manages secure resources essential for climate change study. It is designed to remain robust even as data volumes grow exponentially. The internationally distributed, peer-to-peer ESGF "data cloud" archive represents the culmination of an effort that began in the late 1990s. ESGF portals are gateways to scientific data collections hosted at sites around the globe that allow the user to register and potentially access the entire ESGF network of data and services. The growing international interest in ESGF development efforts has attracted many others who want to make their data more widely available and easy to use. For example, the World Climate

  4. 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...

  5. Performance engineering in data Grids

    CERN Document Server

    Laure, Erwin; Stockinger, Kurt

    2005-01-01

    The vision of Grid computing is to facilitate worldwide resource sharing among distributed collaborations. With the help of numerous national and international Grid projects, this vision is becoming reality and Grid systems are attracting an ever increasing user base. However, Grids are still quite complex software systems whose efficient use is a difficult and error-prone task. In this paper we present performance engineering techniques that aim to facilitate an efficient use of Grid systems, in particular systems that deal with the management of large-scale data sets in the tera- and petabyte range (also referred to as data Grids). These techniques are applicable at different layers of a Grid architecture and we discuss the tools required at each of these layers to implement them. Having discussed important performance engineering techniques, we investigate how major Grid projects deal with performance issues particularly related to data Grids and how they implement the techniques presented.

  6. Development of the Large-Scale Statistical Analysis System of Satellites Observations Data with Grid Datafarm Architecture

    Science.gov (United States)

    Yamamoto, K.; Murata, K.; Kimura, E.; Honda, R.

    2006-12-01

    In the Solar-Terrestrial Physics (STP) field, the amount of satellite observation data has been increasing every year. It is necessary to solve the following three problems to achieve large-scale statistical analyses of plenty of data. (i) More CPU power and larger memory and disk size are required. However, total powers of personal computers are not enough to analyze such amount of data. Super-computers provide a high performance CPU and rich memory area, but they are usually separated from the Internet or connected only for the purpose of programming or data file transfer. (ii) Most of the observation data files are managed at distributed data sites over the Internet. Users have to know where the data files are located. (iii) Since no common data format in the STP field is available now, users have to prepare reading program for each data by themselves. To overcome the problems (i) and (ii), we constructed a parallel and distributed data analysis environment based on the Gfarm reference implementation of the Grid Datafarm architecture. The Gfarm shares both computational resources and perform parallel distributed processings. In addition, the Gfarm provides the Gfarm filesystem which can be as virtual directory tree among nodes. The Gfarm environment is composed of three parts; a metadata server to manage distributed files information, filesystem nodes to provide computational resources and a client to throw a job into metadata server and manages data processing schedulings. In the present study, both data files and data processes are parallelized on the Gfarm with 6 file system nodes: CPU clock frequency of each node is Pentium V 1GHz, 256MB memory and40GB disk. To evaluate performances of the present Gfarm system, we scanned plenty of data files, the size of which is about 300MB for each, in three processing methods: sequential processing in one node, sequential processing by each node and parallel processing by each node. As a result, in comparison between the

  7. Impact of the use of FACTS to increase robustness of operation in grids with large scale wind generation

    Energy Technology Data Exchange (ETDEWEB)

    Franco Marques, P.J. [School of Technology and Management, Polytechnic Institute of Leiria (Portugal); Pecas Lopes, J.A. [INESC Porto, Institute for Systems and Computer Engineering of Porto (Portugal)

    2006-07-01

    Increased penetration of wind power should not jeopardize power system robustness of operation. One of the critical issues is related with the possibility of the loss of large shares of wind power following a system disturbance. The propagation of voltage reduction that results from a short circuit may provoke the disconnection of the wind generators, especially those that do not present ride through default capabilities. The use of FACTS connected to the grid, nearby the large wind parks, may attenuate such a situation. In this work the effectiveness of such technical approach is addressed and discussed. Results obtained demonstrate that the use of FACTS increases grid robustness of operation by avoided the disconnection of part of the wind generation. (orig.)

  8. Integrating land management into Earth system models: the importance of land use transitions at sub-grid-scale

    Science.gov (United States)

    Pongratz, Julia; Wilkenskjeld, Stiig; Kloster, Silvia; Reick, Christian

    2014-05-01

    Recent studies indicate that changes in surface climate and carbon fluxes caused by land management (i.e., modifications of vegetation structure without changing the type of land cover) can be as large as those caused by land cover change. Further, such effects may occur on substantial areas: while about one quarter of the land surface has undergone land cover change, another fifty percent are managed. This calls for integration of management processes in Earth system models (ESMs). This integration increases the importance of awareness and agreement on how to diagnose effects of land use in ESMs to avoid additional model spread and thus unnecessary uncertainties in carbon budget estimates. Process understanding of management effects, their model implementation, as well as data availability on management type and extent pose challenges. In this respect, a significant step forward has been done in the framework of the current IPCC's CMIP5 simulations (Coupled Model Intercomparison Project Phase 5): The climate simulations were driven with the same harmonized land use dataset that, different from most datasets commonly used before, included information on two important types of management: wood harvest and shifting cultivation. However, these new aspects were employed by only part of the CMIP5 models, while most models continued to use the associated land cover maps. Here, we explore the consequences for the carbon cycle of including subgrid-scale land transformations ("gross transitions"), such as shifting cultivation, as example of the current state of implementation of land management in ESMs. Accounting for gross transitions is expected to increase land use emissions because it represents simultaneous clearing and regrowth of natural vegetation in different parts of the grid cell, reducing standing carbon stocks. This process cannot be captured by prescribing land cover maps ("net transitions"). Using the MPI-ESM we find that ignoring gross transitions

  9. A novel partial grid search approach for handling complex multi-dimensional parameter estimation and state improvement at the catchment scale.

    Science.gov (United States)

    Miltin Mboh, Cho; Montzka, Carsten; Baatz, Roland; Vereecken, Harry

    2014-05-01

    The integration of satellite data with physically based models can enable the characterization of earth systems and lead to improved management of natural resources at the catchment and regional scales. The reliability of simulations from physically based models depends on the accuracy of the forcing data and the model parameters. Forcing data obtained from satellites or other sources are often plagued with uncertainties and the model parameters require updates to capture the ever-changing environmental conditions. Although comprehensive data assimilation schemes for dual state and parameter updating have been proposed for improving the reliability of model simulations, their computational cost is sometimes prohibitively high. In this contribution, we propose a cost-effective and efficient alternative to handling complex multi-dimensional parameter and state improvement at the catchment scale. Our approach demystifies the complex multi-dimensional parameter estimation and state improvement problem by combining 1-dimensional exhaustive gridding with sensitivity-pushing, Newton-Raphson based guided random sampling and feedback from historical inverse estimates. In a numerical case study in the joint Rur and Erft Catchments in Germany, we apply our novel partial grid search approach to the estimation of soil surface roughness and vegetation opacity from disaggregated SMOS (Soil Moisture and Ocean Salinity Satellite) brightness temperature using the Community Microwave Emission Modeling platform (CMEM). Besides plausibly good estimates of the soil surface roughness and vegetation opacity at the catchment scale, our method also leads to improvement of the system states like soil surface moisture and soil temperature profile. Our method therefore has data assimilation capabilities without the associated computational cost incurred in ensemble-based data assimilation approaches. The partial grid search approach to parameter estimation is therefore a promising tool for

  10. High Performance Reduced Order Models for Wind Turbines with Full-Scale Converters Applied on Grid Interconnection Studies

    Directory of Open Access Journals (Sweden)

    Heverton A. Pereira

    2014-11-01

    Full Text Available Wind power has achieved technological evolution, and Grid Code (GC requirements forced wind industry consolidation in the last three decades. However, more studies are necessary to understand how the dynamics inherent in this energy source interact with the power system. Traditional energy production usually contains few high power unit generators; however, Wind Power Plants (WPPs consist of dozens or hundreds of low-power units. Time domain simulations of WPPs may take too much time if detailed models are considered in such studies. This work discusses reduced order models used in interconnection studies of synchronous machines with full converter technology. The performance of all models is evaluated based on time domain simulations in the Simulink/MATLAB environment. A detailed model is described, and four reduced order models are compared using the performance index, Normalized Integral of Absolute Error (NIAE. Models are analyzed during wind speed variations and balanced voltage dip. During faults, WPPs must be able to supply reactive power to the grid, and this characteristic is analyzed. Using the proposed performance index, it is possible to conclude if a reduced order model is suitable to represent the WPPs dynamics on grid studies.

  11. Smart Dual-Mode Heat Pump With HP2Grid Functionality To Support Large-Scale Integration Of Intermittent Renewables

    DEFF Research Database (Denmark)

    Carmo, Carolina; Blarke, Morten Boje

    2013-01-01

    The transition towards a 100 % fossil-free energy system, while achieving extreme penetration levels of intermittent wind and solar power in electricity generation, requires demandside technologies that are smart (intermittency-friendly) and efficient. The interaction between electric and thermal...... materials and the ability to generate electricity back to the grid. This new concept will not only improve the residential thermal supply system efficiency by 30-40 %, but will also extend the current intra-day flexibility of heat pumps to a wider range of flexible uses. In this paper, we will investigate...

  12. Experimental static and dynamic tests on a large-scale free-form Voronoi grid shell mock-up in comparison with finite-element method results

    Science.gov (United States)

    Froli, Maurizio; Laccone, Francesco

    2017-09-01

    Grid shells supporting transparent or opaque panels are largely used to cover long-spanned spaces because of their lightness, the easy setup, and economy. This paper presents the results of experimental static and dynamic investigations carried out on a large-scale free-form grid shell mock-up, whose geometry descended from an innovative Voronoi polygonal pattern. Accompanying finite-element method (FEM) simulations followed. To these purposes, a four-step procedure was adopted: (1) a perfect FEM model was analyzed; (2) using the modal shapes scaled by measuring the mock-up, a deformed unloaded geometry was built, which took into account the defects caused by the assembly phase; (3) experimental static tests were executed by affixing weights to the mock-up, and a simplified representative FEM model was calibrated, choosing the nodes stiffness and the material properties as parameters; and (4) modal identification was performed through operational modal analysis and impulsive tests, and then, a simplified FEM dynamical model was calibrated. Due to the high deformability of the mock-up, only a symmetric load case configuration was adopted.

  13. Virtual microscopy and grid-enabled decision support for large-scale analysis of imaged pathology specimens.

    Science.gov (United States)

    Yang, Lin; Chen, Wenjin; Meer, Peter; Salaru, Gratian; Goodell, Lauri A; Berstis, Viktors; Foran, David J

    2009-07-01

    Breast cancer accounts for about 30% of all cancers and 15% of cancer deaths in women. Advances in computer-assisted analysis hold promise for classifying subtypes of disease and improving prognostic accuracy. We introduce a grid-enabled decision support system for performing automatic analysis of imaged breast tissue microarrays. To date, we have processed more than 1,00,000 digitized specimens (1200 x 1200 pixels each) on IBM's World Community Grid (WCG). As a part of the Help Defeat Cancer (HDC) project, we have analyzed that the data returned from WCG along with retrospective patient clinical profiles for a subset of 3744 breast tissue samples, and have reported the results in this paper. Texture-based features were extracted from the digitized specimens, and isometric feature mapping was applied to achieve nonlinear dimension reduction. Iterative prototyping and testing were performed to classify several major subtypes of breast cancer. Overall, the most reliable approach was gentle AdaBoost using an eight-node classification and regression tree as the weak learner. Using the proposed algorithm, a binary classification accuracy of 89% and the multiclass accuracy of 80% were achieved. Throughout the course of the experiments, only 30% of the dataset was used for training.

  14. A high-rate and long cycle life aqueous electrolyte battery for grid-scale energy storage.

    Science.gov (United States)

    Pasta, Mauro; Wessells, Colin D; Huggins, Robert A; Cui, Yi

    2012-01-01

    New types of energy storage are needed in conjunction with the deployment of solar, wind and other volatile renewable energy sources and their integration with the electric grid. No existing energy storage technology can economically provide the power, cycle life and energy efficiency needed to respond to the costly short-term transients that arise from renewables and other aspects of grid operation. Here we demonstrate a new type of safe, fast, inexpensive, long-life aqueous electrolyte battery, which relies on the insertion of potassium ions into a copper hexacyanoferrate cathode and a novel activated carbon/polypyrrole hybrid anode. The cathode reacts rapidly with very little hysteresis. The hybrid anode uses an electrochemically active additive to tune its potential. This high-rate, high-efficiency cell has a 95% round-trip energy efficiency when cycled at a 5C rate, and a 79% energy efficiency at 50C. It also has zero-capacity loss after 1,000 deep-discharge cycles.

  15. A high-rate and long cycle life aqueous electrolyte battery for grid-scale energy storage

    KAUST Repository

    Pasta, Mauro

    2012-10-23

    New types of energy storage are needed in conjunction with the deployment of solar, wind and other volatile renewable energy sources and their integration with the electric grid. No existing energy storage technology can economically provide the power, cycle life and energy efficiency needed to respond to the costly short-term transients that arise from renewables and other aspects of grid operation. Here we demonstrate a new type of safe, fast, inexpensive, long-life aqueous electrolyte battery, which relies on the insertion of potassium ions into a copper hexacyanoferrate cathode and a novel activated carbon/polypyrrole hybrid anode. The cathode reacts rapidly with very little hysteresis. The hybrid anode uses an electrochemically active additive to tune its potential. This high-rate, high-efficiency cell has a 95% round-trip energy efficiency when cycled at a 5C rate, and a 79% energy efficiency at 50C. It also has zero-capacity loss after 1,000 deep-discharge cycles. © 2012 Macmillan Publishers Limited. All rights reserved.

  16. A Design of Irregular Grid Map for Large-Scale Wi-Fi LAN Fingerprint Positioning Systems

    Directory of Open Access Journals (Sweden)

    Jae-Hoon Kim

    2014-01-01

    Full Text Available The rapid growth of mobile communication and the proliferation of smartphones have drawn significant attention to location-based services (LBSs. One of the most important factors in the vitalization of LBSs is the accurate position estimation of a mobile device. The Wi-Fi positioning system (WPS is a new positioning method that measures received signal strength indication (RSSI data from all Wi-Fi access points (APs and stores them in a large database as a form of radio fingerprint map. Because of the millions of APs in urban areas, radio fingerprints are seriously contaminated and confused. Moreover, the algorithmic advances for positioning face computational limitation. Therefore, we present a novel irregular grid structure and data analytics for efficient fingerprint map management. The usefulness of the proposed methodology is presented using the actual radio fingerprint measurements taken throughout Seoul, Korea.

  17. Sensitivity of boreal forest regional water flux and net primary production simulations to sub-grid-scale land cover complexity

    Science.gov (United States)

    Kimball, J. S.; Running, S. W.; Saatchi, S. S.

    1999-11-01

    We use a general ecosystem process model (BIOME-BGC) coupled with remote sensing information to evaluate the sensitivity of boreal forest regional evapotranspiration (ET) and net primary production (NPP) to land cover spatial scale. Simulations were conducted over a 3 year period (1994-1996) at spatial scales ranging from 30 to 50 km within the BOREAS southern modeling subarea. Simulated fluxes were spatially complex, ranging from 0.1 to 3.9 Mg C ha-1 yr-1 and from 18 to 29 cm yr-1. Biomass and leaf area index heterogeneity predominantly controlled this complexity, while biophysical differences between deciduous and coniferous vegetation were of secondary importance. Spatial aggregation of land cover characteristics resulted in mean monthly NPP estimation bias from 25 to 48% (0.11-0.20 g C m-2 d-1) and annual estimation errors from 2 to 14% (0.04-0.31 Mg C ha-1 yr-1). Error was reduced at longer time intervals because coarse scale overestimation errors during spring were partially offset by underestimation of fine scale results during summer and winter. ET was relatively insensitive to land cover spatial scale with an average bias of less than 5% (0.04 kg m-2 d-1). Factors responsible for differences in scaling behavior between ET and NPP included compensating errors for ET calculations and boreal forest spatial and temporal NPP complexity. Careful consideration of landscape spatial and temporal heterogeneity is necessary to identify and mitigate potential error sources when using plot scale information to understand regional scale patterns. Remote sensing data integrated within an ecological process model framework provides an efficient mechanism to evaluate scaling behavior, interpret patterns in coarse resolution data, and identify appropriate scales of operation for various processes.

  18. Analyzing Sustainable Energy Opportunities for a Small Scale Off-Grid Facility: A Case Study at Experimental Lakes Area (ELA), Ontario

    Science.gov (United States)

    Duggirala, Bhanu

    This thesis explored the opportunities to reduce energy demand and renewable energy feasibility at an off-grid science "community" called the Experimental Lakes Area (ELA) in Ontario. Being off-grid, ELA is completely dependent on diesel and propane fuel supply for all its electrical and heating needs, which makes ELA vulnerable to fluctuating fuel prices. As a result ELA emits a large amount of greenhouse gases (GHG) for its size. Energy efficiency and renewable energy technologies can reduce energy consumption and consequently energy cost, as well as GHG. Energy efficiency was very important to ELA due to the elevated fuel costs at this remote location. Minor upgrades to lighting, equipment and building envelope were able to reduce energy costs and reduce load. Efficient energy saving measures were recommended that save on operating and maintenance costs, namely, changing to LED lights, replacing old equipment like refrigerators and downsizing of ice makers. This resulted in a 4.8% load reduction and subsequently reduced the initial capital cost for biomass by 27,000, by 49,500 for wind power and by 136,500 for solar power. Many alternative energies show promise as potential energy sources to reduce the diesel and propane consumption at ELA including wind energy, solar heating and biomass. A biomass based CHP system using the existing diesel generators as back-up has the shortest pay back period of the technologies modeled. The biomass based CHP system has a pay back period of 4.1 years at 0.80 per liter of diesel, as diesel price approaches $2.00 per liter the pay back period reduces to 0.9 years, 50% the generation cost compared to present generation costs. Biomass has been successfully tried and tested in many off-grid communities particularly in a small-scale off-grid setting in North America and internationally. Also, the site specific solar and wind data show that ELA has potential to harvest renewable resources and produce heat and power at competitive

  19. Grid Computing

    Indian Academy of Sciences (India)

    IAS Admin

    global view and optimize the configuration and the use of all the computers, particularly high performance servers wherever they are. An enterprise grid is ... attributes: business model, architecture, resource management, security model, programming model, and applications [6]. Business Model. Grid is formed by 'not for ...

  20. 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.

  1. An Efficient Audio Coding Scheme for Quantitative and Qualitative Large Scale Acoustic Monitoring Using the Sensor Grid Approach

    Directory of Open Access Journals (Sweden)

    Félix Gontier

    2017-11-01

    Full Text Available The spreading of urban areas and the growth of human population worldwide raise societal and environmental concerns. To better address these concerns, the monitoring of the acoustic environment in urban as well as rural or wilderness areas is an important matter. Building on the recent development of low cost hardware acoustic sensors, we propose in this paper to consider a sensor grid approach to tackle this issue. In this kind of approach, the crucial question is the nature of the data that are transmitted from the sensors to the processing and archival servers. To this end, we propose an efficient audio coding scheme based on third octave band spectral representation that allows: (1 the estimation of standard acoustic indicators; and (2 the recognition of acoustic events at state-of-the-art performance rate. The former is useful to provide quantitative information about the acoustic environment, while the latter is useful to gather qualitative information and build perceptually motivated indicators using for example the emergence of a given sound source. The coding scheme is also demonstrated to transmit spectrally encoded data that, reverted to the time domain using state-of-the-art techniques, are not intelligible, thus protecting the privacy of citizens.

  2. 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.

  3. 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.

  4. Acorn: A grid computing system for constraint based modeling and visualization of the genome scale metabolic reaction networks via a web interface

    Directory of Open Access Journals (Sweden)

    Bushell Michael E

    2011-05-01

    Full Text Available Abstract Background Constraint-based approaches facilitate the prediction of cellular metabolic capabilities, based, in turn on predictions of the repertoire of enzymes encoded in the genome. Recently, genome annotations have been used to reconstruct genome scale metabolic reaction networks for numerous species, including Homo sapiens, which allow simulations that provide valuable insights into topics, including predictions of gene essentiality of pathogens, interpretation of genetic polymorphism in metabolic disease syndromes and suggestions for novel approaches to microbial metabolic engineering. These constraint-based simulations are being integrated with the functional genomics portals, an activity that requires efficient implementation of the constraint-based simulations in the web-based environment. Results Here, we present Acorn, an open source (GNU GPL grid computing system for constraint-based simulations of genome scale metabolic reaction networks within an interactive web environment. The grid-based architecture allows efficient execution of computationally intensive, iterative protocols such as Flux Variability Analysis, which can be readily scaled up as the numbers of models (and users increase. The web interface uses AJAX, which facilitates efficient model browsing and other search functions, and intuitive implementation of appropriate simulation conditions. Research groups can install Acorn locally and create user accounts. Users can also import models in the familiar SBML format and link reaction formulas to major functional genomics portals of choice. Selected models and simulation results can be shared between different users and made publically available. Users can construct pathway map layouts and import them into the server using a desktop editor integrated within the system. Pathway maps are then used to visualise numerical results within the web environment. To illustrate these features we have deployed Acorn and created a

  5. Acorn: a grid computing system for constraint based modeling and visualization of the genome scale metabolic reaction networks via a web interface.

    Science.gov (United States)

    Sroka, Jacek; Bieniasz-Krzywiec, Lukasz; Gwóźdź, Szymon; Leniowski, Dariusz; Lącki, Jakub; Markowski, Mateusz; Avignone-Rossa, Claudio; Bushell, Michael E; McFadden, Johnjoe; Kierzek, Andrzej M

    2011-05-24

    Constraint-based approaches facilitate the prediction of cellular metabolic capabilities, based, in turn on predictions of the repertoire of enzymes encoded in the genome. Recently, genome annotations have been used to reconstruct genome scale metabolic reaction networks for numerous species, including Homo sapiens, which allow simulations that provide valuable insights into topics, including predictions of gene essentiality of pathogens, interpretation of genetic polymorphism in metabolic disease syndromes and suggestions for novel approaches to microbial metabolic engineering. These constraint-based simulations are being integrated with the functional genomics portals, an activity that requires efficient implementation of the constraint-based simulations in the web-based environment. Here, we present Acorn, an open source (GNU GPL) grid computing system for constraint-based simulations of genome scale metabolic reaction networks within an interactive web environment. The grid-based architecture allows efficient execution of computationally intensive, iterative protocols such as Flux Variability Analysis, which can be readily scaled up as the numbers of models (and users) increase. The web interface uses AJAX, which facilitates efficient model browsing and other search functions, and intuitive implementation of appropriate simulation conditions. Research groups can install Acorn locally and create user accounts. Users can also import models in the familiar SBML format and link reaction formulas to major functional genomics portals of choice. Selected models and simulation results can be shared between different users and made publically available. Users can construct pathway map layouts and import them into the server using a desktop editor integrated within the system. Pathway maps are then used to visualise numerical results within the web environment. To illustrate these features we have deployed Acorn and created a web server allowing constraint based

  6. Predicting the impacts of fishing canals on Floodplain Dynamics in Northern Cameroon using a small-scale sub-grid hydraulic model

    Science.gov (United States)

    Shastry, A. R.; Durand, M. T.; Fernandez, A.; Hamilton, I.; Kari, S.; Labara, B.; Laborde, S.; Mark, B. G.; Moritz, M.; Neal, J. C.; Phang, S. C.

    2015-12-01

    Modeling Regime Shifts in the Logone floodplain (MORSL) is an ongoing interdisciplinary project at The Ohio State University studying the ecological, social and hydrological system of the region. This floodplain, located in Northern Cameroon, is part of the Lake Chad basin. Between September and October the floodplain is inundated by the overbank flow from the Logone River, which is important for agriculture and fishing. Fishermen build canals to catch fish during the flood's recession to the river by installing fishnets at the intersection of the canals and the river. Fishing canals thus connect the river to natural depressions of the terrain, which act as seasonal ponds during this part of the year. Annual increase in the number of canals affect hydraulics and hence fishing in the region. In this study, the Bara region (1 km2) of the Logone floodplain, through which Lorome Mazra flows, is modeled using LISFLOOD-FP, a raster-based model with sub-grid parameterizations of canals. The aim of the study is to find out how the small-scale, local features like canals and fishnets govern the flow, so that it can be incorporated in a large-scale model of the floodplain at a coarser spatial resolution. We will also study the effect of increasing number of canals on the flooding pattern. We use a simplified version of the hydraulic system at a grid-cell size of 30-m, using synthetic topography, parameterized fishing canals, and representing fishnets as trash screens. The inflow at Bara is obtained from a separate, lower resolution (1-km grid-cell) model run, which is forced by daily discharge records obtained from Katoa, located about 25-km to the south of Bara. The model appropriately captures the rise and recession of the annual flood, supporting use of the LISFLOOD-FP approach. Predicted water levels at specific points in the river, the canals, the depression and the floodplain will be compared to field measured heights of flood recession in Bara, November 2014.

  7. Power grid complex network evolutions for the smart grid

    NARCIS (Netherlands)

    Pagani, Giuliano Andrea; Aiello, Marco

    2014-01-01

    The shift towards an energy grid dominated by prosumers (consumers and producers of energy) will inevitably have repercussions on the electricity distribution infrastructure. Today the grid is a hierarchical one delivering energy from large scale facilities to end-users. Tomorrow it will be a

  8. 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.

  9. Reliability and Energy Loss in Full-scale Wind Power Converter Considering Grid Codes and Wind Classes

    DEFF Research Database (Denmark)

    Zhou, Dao; Blaabjerg, Frede; Franke, Toke

    2014-01-01

    With the increasing penetration of the wind power, reliable operation and cost-effective wind energy production are of more and more importance. As one of the promising configurations, the cost on reliability and production losses of permanent-magnet synchronous generator based full-scale wind...

  10. The role of large scale energy storage systems in the electricity grid of the Netherlands in 2050

    NARCIS (Netherlands)

    Velthuis, Martin

    2012-01-01

    SUMMARY The burning of the fossil fuels for electricity generation has an environmental impact on a global scale. Also, the world is going to be running out of the fossil fuels before or within the next century. This is the reason why renewable energy so

  11. New iterative load balancing scheme with multi-grid level relaxation technique toward a large scale geodynamical granular simulation

    Science.gov (United States)

    Furuichi, M.; Nishiura, D.

    2016-12-01

    The complex dynamics of granular system is an essential part of natural processes such as crystal rich magma flow, accretion prism formation or tsunami sedimentation. Numerical modeling with Discrete Element Method (DEM) is an effective approach for understanding granular dynamics especially when the contact between particles induces strongly non-linear rheology (e.g. DEM-CFD simulation for magma reservoir [Bergantz et.al., Nature geo, 2015, Furuichi and Nishiura, G-cubed, 2014]). In Moving Lagrangian particle methods like DEM, a large number of particles is required to obtain an accurate solution. Therefore, an efficient parallelization of the code is important to handle huge particles system on HPC. However, since particles move around during the simulation, the workload between the different MPI processes becomes imbalance when using static sub-domains. To overcome this limitation, we present a new dynamic load balancing algorithms applicable to particle simulation methods such as DEM and Smoothed Particle Hydrodynamics (SPH) [Furuichi and Nishiura submitted to Comput. Phys. Comm.]. Our method utilizes flexible orthogonal domain decomposition in which the domain is divided into columns, each of which independently defines rectangle sub-domains by rows. We regard the difference of the executed time between neighbor logical processes as the residual of nonlinear problem of the domain change. The load balancing is attained by minimizing the residual within the framework of the iterative non-linear solver combined with the multi-grid level technique for the local relaxation. Scalability tests attest that the algorithm demonstrates close-to-optimal strong and weak scalability on the K-computer and the Earth Simulator. This result holds for even as well as uneven particle distribution, including different types of particles and heterogeneous computer architecture. We performed a DEM simulation with over 2 billion particles for demonstrating the proposed scheme. The

  12. 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

  13. From Sub-basin to Grid Scale Soil Moisture Disaggregation in SMART, A Semi-distributed Hydrologic Modeling Framework

    Science.gov (United States)

    Ajami, H.; Sharma, A.

    2016-12-01

    A computationally efficient, semi-distributed hydrologic modeling framework is developed to simulate water balance at a catchment scale. The Soil Moisture and Runoff simulation Toolkit (SMART) is based upon the delineation of contiguous and topologically connected Hydrologic Response Units (HRUs). In SMART, HRUs are delineated using thresholds obtained from topographic and geomorphic analysis of a catchment, and simulation elements are distributed cross sections or equivalent cross sections (ECS) delineated in first order sub-basins. ECSs are formulated by aggregating topographic and physiographic properties of the part or entire first order sub-basins to further reduce computational time in SMART. Previous investigations using SMART have shown that temporal dynamics of soil moisture are well captured at a HRU level using the ECS delineation approach. However, spatial variability of soil moisture within a given HRU is ignored. Here, we examined a number of disaggregation schemes for soil moisture distribution in each HRU. The disaggregation schemes are either based on topographic based indices or a covariance matrix obtained from distributed soil moisture simulations. To assess the performance of the disaggregation schemes, soil moisture simulations from an integrated land surface-groundwater model, ParFlow.CLM in Baldry sub-catchment, Australia are used. ParFlow is a variably saturated sub-surface flow model that is coupled to the Common Land Model (CLM). Our results illustrate that the statistical disaggregation scheme performs better than the methods based on topographic data in approximating soil moisture distribution at a 60m scale. Moreover, the statistical disaggregation scheme maintains temporal correlation of simulated daily soil moisture while preserves the mean sub-basin soil moisture. Future work is focused on assessing the performance of this scheme in catchments with various topographic and climate settings.

  14. Introducing Advanced Fine-grained Security in dCache-SRM for PetaByte-scale Storage Systems on Global Data Grids: gPLAZMA `grid-aware PLuggable AuthoriZation MAnagement System'

    CERN Document Server

    Rana, A S; Kennedy, R; Bakken, J; Hesselroth, T; Fisk, I; Fuhrmann, P; Ernst, M; Lorch, M; Skow, D

    2006-01-01

    We introduce gPLAZMA (grid-aware PLuggable Authorization MAnagement) for dCache/SRM in this publication. Our work is motivated by a need for fine-grained security (Role Based Access Control or RBAC) in storage systems on global data grids, and utilizes VOMS extended X.509 certificate specification for defining extra attributes (FQANs), based on RFC3281. Our implementation, gPLAZMA in dCache, introduces storage authorization callouts for SRM and GridFTP. It allows using different authorization mechanisms simultaneously, fine-tuned with switches and priorities of mechanisms. Of the four mechanisms currently supported, one is an integration with RBAC services in the open science grid (OSG) USCMS/USATLAS Privilege Project, others are built-in as a lightweight suite of services (gPLAZMA lite authorization services suite) including the legacy dcache.kpwd file, as well as the popular grid-mapfile, augmented with a gPLAZMALite specific RBAC mechanism. Based on our current work, we also outline a list of future tasks....

  15. Systematic investigation of gridding-related scaling effects on annual statistics of daily temperature and precipitation maxima: A case study for south-east Australia

    Directory of Open Access Journals (Sweden)

    Francia B. Avila

    2015-09-01

    Full Text Available Using daily station observations over the period 1951–2013 in a region of south-east Australia, we systematically compare how the horizontal resolution, interpolation method and order of operation in generating gridded data sets affect estimates of annual extreme indices of temperature and precipitation maxima (hottest and wettest days. Three interpolation methods (natural neighbors, cubic spline and angular distance weighting are used to calculate grids at five different horizontal gridded resolutions ranging from 0.25° to 2.5°. In each case the order of operation in which the grid values of the hottest and wettest day are calculated is varied: either they are estimated from daily grids or from station points and then gridded. We find that the grid resolution-despite showing more regional detail at high resolution – has relatively limited effect when considering regional averages. However, the interpolation method and the order of operation can substantially influence the actual gridded values. And while the difference due to the order of operation is not substantial when using natural neighbor and cubic spline interpolation, it is particularly apparent for indices calculated from daily gridded estimates using the angular distance weighting method. As expected given the high spatial variability of precipitation fields, precipitation extremes are most sensitive to method, but temperature extremes also exhibit substantial differences. For the annual maximum values averaged over the study area, the differences may be up to 2.8 °C for temperature and 60 mm (about a factor 2 for precipitation. Differences are seen most prominently in return period estimates where a 1 in 100 year return value calculated using the angular distance weighting daily gridded method is equivalent to about a 1 in 5 year return value in most of the other methods. Despite substantial differences in the actual values of gridded extremes, analyses suggest that the

  16. ImmunoGrid, an integrative environment for large-scale simulation of the immune system for vaccine discovery, design and optimization

    DEFF Research Database (Denmark)

    Pappalardo, F.; Halling-Brown, M. D.; Rapin, Nicolas

    2009-01-01

    conceptual models of the immune system, models of antigen processing and presentation, system-level models of the immune system, Grid computing, and database technology to facilitate discovery, formulation and optimization of vaccines. ImmunoGrid modules share common conceptual models and ontologies...

  17. Efficient Scheduling of Scientific Workflows with Energy Reduction Using Novel Discrete Particle Swarm Optimization and Dynamic Voltage Scaling for Computational Grids

    Directory of Open Access Journals (Sweden)

    M. Christobel

    2015-01-01

    Full Text Available One of the most significant and the topmost parameters in the real world computing environment is energy. Minimizing energy imposes benefits like reduction in power consumption, decrease in cooling rates of the computing processors, provision of a green environment, and so forth. In fact, computation time and energy are directly proportional to each other and the minimization of computation time may yield a cost effective energy consumption. Proficient scheduling of Bag-of-Tasks in the grid environment ravages in minimum computation time. In this paper, a novel discrete particle swarm optimization (DPSO algorithm based on the particle’s best position (pbDPSO and global best position (gbDPSO is adopted to find the global optimal solution for higher dimensions. This novel DPSO yields better schedule with minimum computation time compared to Earliest Deadline First (EDF and First Come First Serve (FCFS algorithms which comparably reduces energy. Other scheduling parameters, such as job completion ratio and lateness, are also calculated and compared with EDF and FCFS. An energy improvement of up to 28% was obtained when Makespan Conservative Energy Reduction (MCER and Dynamic Voltage Scaling (DVS were used in the proposed DPSO algorithm.

  18. Efficient Scheduling of Scientific Workflows with Energy Reduction Using Novel Discrete Particle Swarm Optimization and Dynamic Voltage Scaling for Computational Grids.

    Science.gov (United States)

    Christobel, M; Tamil Selvi, S; Benedict, Shajulin

    2015-01-01

    One of the most significant and the topmost parameters in the real world computing environment is energy. Minimizing energy imposes benefits like reduction in power consumption, decrease in cooling rates of the computing processors, provision of a green environment, and so forth. In fact, computation time and energy are directly proportional to each other and the minimization of computation time may yield a cost effective energy consumption. Proficient scheduling of Bag-of-Tasks in the grid environment ravages in minimum computation time. In this paper, a novel discrete particle swarm optimization (DPSO) algorithm based on the particle's best position (pbDPSO) and global best position (gbDPSO) is adopted to find the global optimal solution for higher dimensions. This novel DPSO yields better schedule with minimum computation time compared to Earliest Deadline First (EDF) and First Come First Serve (FCFS) algorithms which comparably reduces energy. Other scheduling parameters, such as job completion ratio and lateness, are also calculated and compared with EDF and FCFS. An energy improvement of up to 28% was obtained when Makespan Conservative Energy Reduction (MCER) and Dynamic Voltage Scaling (DVS) were used in the proposed DPSO algorithm.

  19. 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,...

  20. The GOES-R ABI Fixed Grid Format: Overview and Case Study

    Science.gov (United States)

    Pogorzala, D.; Padula, F.; Cao, C.; Wu, X.

    2014-12-01

    The Advanced Baseline Imager (ABI) aboard the Geostationary Operational Environmental Satellite-R series (GOES-R) will image Earth in 16 spectral channels at channel-specific resolutions of 0.5, 1.0 and 2.0 km. All Level-1b and Level-2+ products created by ABI will be geometrically interpolated to a Fixed Grid; a set of static pixel locations centered on the sub-satellite point. The Fixed Grid represents a new standard in products created by the GOES series of satellites and will aid users by providing continuity in the locations of geographic features throughout mission life. However, detector-level anomalies will be impacted by the resampling process in a variety of ways. Depending on the nature of the anomaly, the proximity of the detector sample to the pixel centers, and the underlying scene phenomenology, the resampling process has the potential to both amplify and mitigate system anomalies. This work will introduce the resampling process and the Fixed Grid, as well as present a case study characterizing the radiometric impacts of detector anomalies to L1b products.

  1. 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...

  2. Grid interoperability joining grid information systems

    CERN Document Server

    Flechl, M

    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 th...

  3. Relating health and climate impacts to grid-scale emissions using adjoint sensitivity modeling for the Climate and Clean Air Coalition

    Science.gov (United States)

    Henze, D. K.; Lacey, F.; Seltzer, M.; Vallack, H.; Kuylenstierna, J.; Bowman, K. W.; Anenberg, S.; Sasser, E.; Lee, C. J.; Martin, R.

    2013-12-01

    The Climate and Clean Air Coalition (CCAC) was initiated in 2012 to develop, understand and promote measures to reduce short lived climate forcers such as aerosol, ozone and methane. The Coalition now includes over 30 nations, and as a service to these nations is committed to providing a decision support toolkit that allows member nations to explore the benefits of a range of emissions mitigation measures in terms of the combined impacts on air quality and climate and so help in the development of their National Action Plans. Here we will present recent modeling work to support the development of the CCAC National Action Plans toolkit. Adjoint sensitivity analysis is presented as a means of efficiently relating air quality, climate and crop impacts back to changes in emissions from each species, sector and location at the grid-scale resolution of typical global air quality model applications. The GEOS-Chem adjoint model is used to estimate the damages per ton of emissions of PM2.5 related mortality, the impacts of ozone precursors on crops and ozone-related health effects, and the combined impacts of these species on regional surface temperature changes. We show how the benefits-per-emission vary spatially as a function of the surrounding environment, and how this impacts the overall benefit of sector-specific control strategies. We present initial findings for Bangladesh, as well as Mexico, Ghana and Colombia, some of the first countries to join the CCAC, and discuss general issues related to adjoint-based metrics for quantifying air quality and climate co-benefits.

  4. A GIS based methodology for gridding of large-scale emission inventories: Application to carbon-monoxide emissions over Indian region

    Science.gov (United States)

    Dalvi, Mohit; Beig, Gufran; Patil, Uday; Kaginalkar, Akshara; Sharma, C.; Mitra, A. P.

    Chemical simulations in most of the atmospheric chemistry models require surface emissions in a specific form (gridded), which are often not available. Simple interpolation of broader level emissions to obtain gridded data may lead to erroneous results. An attempt has been made in this paper to develop a geographical information system (GIS) based methodology for distributing the emissions from a broader level inventory to finely gridded emission values, considering local micro-level details and activity data. Given the importance of Carbon Monoxide emissions in ozone pollution chemistry over India, an emission inventory for CO from various sources for India has been used to demonstrate the GIS-based gridding methodology. The total CO emissions over India for 2001, which are estimated to be around 69.0 Tg year -1, have been downscaled source-wise (distinguishing between rural and urban bio-fuel, vehicular traffic, coal and biomass burning) from state-level (28 points) to district level (˜500 points) before mapping through a GIS utility and finally gridded to a 1°×1° resolution with a data loss of only about 13%. The final results provide detailed information with emission "hot spots" and the relative contribution of various sources. This article focuses on usage of the GIS based statistical methodology for gridding the inventory and the results obtained thereof are discussed.

  5. 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.

  6. Grid attacks avian flu

    CERN Multimedia

    2006-01-01

    During April, a collaboration of Asian and European laboratories analysed 300,000 possible drug components against the avian flu virus H5N1 using the EGEE Grid infrastructure. Schematic presentation of the avian flu virus.The distribution of the EGEE sites in the world on which the avian flu scan was performed. The goal was to find potential compounds that can inhibit the activities of an enzyme on the surface of the influenza virus, the so-called neuraminidase, subtype N1. Using the Grid to identify the most promising leads for biological tests could speed up the development process for drugs against the influenza virus. Co-ordinated by CERN and funded by the European Commission, the EGEE project (Enabling Grids for E-sciencE) aims to set up a worldwide grid infrastructure for science. The challenge of the in silico drug discovery application is to identify those molecules which can dock on the active sites of the virus in order to inhibit its action. To study the impact of small scale mutations on drug r...

  7. Collaborating CPU and GPU for large-scale high-order CFD simulations with complex grids on the TianHe-1A supercomputer

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Chuanfu, E-mail: xuchuanfu@nudt.edu.cn [College of Computer Science, National University of Defense Technology, Changsha 410073 (China); Deng, Xiaogang; Zhang, Lilun [College of Computer Science, National University of Defense Technology, Changsha 410073 (China); Fang, Jianbin [Parallel and Distributed Systems Group, Delft University of Technology, Delft 2628CD (Netherlands); Wang, Guangxue; Jiang, Yi [State Key Laboratory of Aerodynamics, P.O. Box 211, Mianyang 621000 (China); Cao, Wei; Che, Yonggang; Wang, Yongxian; Wang, Zhenghua; Liu, Wei; Cheng, Xinghua [College of Computer Science, National University of Defense Technology, Changsha 410073 (China)

    2014-12-01

    Programming and optimizing complex, real-world CFD codes on current many-core accelerated HPC systems is very challenging, especially when collaborating CPUs and accelerators to fully tap the potential of heterogeneous systems. In this paper, with a tri-level hybrid and heterogeneous programming model using MPI + OpenMP + CUDA, we port and optimize our high-order multi-block structured CFD software HOSTA on the GPU-accelerated TianHe-1A supercomputer. HOSTA adopts two self-developed high-order compact definite difference schemes WCNS and HDCS that can simulate flows with complex geometries. We present a dual-level parallelization scheme for efficient multi-block computation on GPUs and perform particular kernel optimizations for high-order CFD schemes. The GPU-only approach achieves a speedup of about 1.3 when comparing one Tesla M2050 GPU with two Xeon X5670 CPUs. To achieve a greater speedup, we collaborate CPU and GPU for HOSTA instead of using a naive GPU-only approach. We present a novel scheme to balance the loads between the store-poor GPU and the store-rich CPU. Taking CPU and GPU load balance into account, we improve the maximum simulation problem size per TianHe-1A node for HOSTA by 2.3×, meanwhile the collaborative approach can improve the performance by around 45% compared to the GPU-only approach. Further, to scale HOSTA on TianHe-1A, we propose a gather/scatter optimization to minimize PCI-e data transfer times for ghost and singularity data of 3D grid blocks, and overlap the collaborative computation and communication as far as possible using some advanced CUDA and MPI features. Scalability tests show that HOSTA can achieve a parallel efficiency of above 60% on 1024 TianHe-1A nodes. With our method, we have successfully simulated an EET high-lift airfoil configuration containing 800M cells and China's large civil airplane configuration containing 150M cells. To our best knowledge, those are the largest-scale CPU–GPU collaborative simulations

  8. Collaborating CPU and GPU for large-scale high-order CFD simulations with complex grids on the TianHe-1A supercomputer

    Science.gov (United States)

    Xu, Chuanfu; Deng, Xiaogang; Zhang, Lilun; Fang, Jianbin; Wang, Guangxue; Jiang, Yi; Cao, Wei; Che, Yonggang; Wang, Yongxian; Wang, Zhenghua; Liu, Wei; Cheng, Xinghua

    2014-12-01

    Programming and optimizing complex, real-world CFD codes on current many-core accelerated HPC systems is very challenging, especially when collaborating CPUs and accelerators to fully tap the potential of heterogeneous systems. In this paper, with a tri-level hybrid and heterogeneous programming model using MPI + OpenMP + CUDA, we port and optimize our high-order multi-block structured CFD software HOSTA on the GPU-accelerated TianHe-1A supercomputer. HOSTA adopts two self-developed high-order compact definite difference schemes WCNS and HDCS that can simulate flows with complex geometries. We present a dual-level parallelization scheme for efficient multi-block computation on GPUs and perform particular kernel optimizations for high-order CFD schemes. The GPU-only approach achieves a speedup of about 1.3 when comparing one Tesla M2050 GPU with two Xeon X5670 CPUs. To achieve a greater speedup, we collaborate CPU and GPU for HOSTA instead of using a naive GPU-only approach. We present a novel scheme to balance the loads between the store-poor GPU and the store-rich CPU. Taking CPU and GPU load balance into account, we improve the maximum simulation problem size per TianHe-1A node for HOSTA by 2.3×, meanwhile the collaborative approach can improve the performance by around 45% compared to the GPU-only approach. Further, to scale HOSTA on TianHe-1A, we propose a gather/scatter optimization to minimize PCI-e data transfer times for ghost and singularity data of 3D grid blocks, and overlap the collaborative computation and communication as far as possible using some advanced CUDA and MPI features. Scalability tests show that HOSTA can achieve a parallel efficiency of above 60% on 1024 TianHe-1A nodes. With our method, we have successfully simulated an EET high-lift airfoil configuration containing 800M cells and China's large civil airplane configuration containing 150M cells. To our best knowledge, those are the largest-scale CPU-GPU collaborative simulations that

  9. Grid computing the European Data Grid Project

    CERN Document Server

    Segal, B; Gagliardi, F; Carminati, F

    2000-01-01

    The goal of this project is the development of a novel environment to support globally distributed scientific exploration involving multi- PetaByte datasets. The project will devise and develop middleware solutions and testbeds capable of scaling to handle many PetaBytes of distributed data, tens of thousands of resources (processors, disks, etc.), and thousands of simultaneous users. The scale of the problem and the distribution of the resources and user community preclude straightforward replication of the data at different sites, while the aim of providing a general purpose application environment precludes distributing the data using static policies. We will construct this environment by combining and extending newly emerging "Grid" technologies to manage large distributed datasets in addition to computational elements. A consequence of this project will be the emergence of fundamental new modes of scientific exploration, as access to fundamental scientific data is no longer constrained to the producer of...

  10. Computational physical oceanography -- A comprehensive approach based on generalized CFD/grid techniques for planetary scale simulations of oceanic flows. Final report, September 1, 1995--August 31, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Beddhu, M.; Jiang, M.Y.; Whitfield, D.L.; Taylor, L.K.; Arabshahi, A.

    1997-02-20

    The original intention for this work was to impart the technology that was developed in the field of computational aeronautics to the field of computational physical oceanography. This technology transfer involved grid generation techniques and solution procedures to solve the governing equations over the grids thus generated. Specifically, boundary fitting non-orthogonal grids would be generated over a sphere taking into account the topography of the ocean floor and the topography of the continents. The solution methodology to be employed involved the application of an upwind, finite volume discretization procedure that uses higher order numerical fluxes at the cell faces to discretize the governing equations and an implicit Newton relaxation technique to solve the discretized equations. This report summarizes the efforts put forth during the past three years to achieve these goals and indicates the future direction of this work as it is still an ongoing effort.

  11. Large scale and cloud-based multi-model analytics experiments on climate change data in the Earth System Grid Federation

    Science.gov (United States)

    Fiore, Sandro; Płóciennik, Marcin; Doutriaux, Charles; Blanquer, Ignacio; Barbera, Roberto; Donvito, Giacinto; Williams, Dean N.; Anantharaj, Valentine; Salomoni, Davide D.; Aloisio, Giovanni

    2017-04-01

    In many scientific domains such as climate, data is often n-dimensional and requires tools that support specialized data types and primitives to be properly stored, accessed, analysed and visualized. Moreover, new challenges arise in large-scale scenarios and eco-systems where petabytes (PB) of data can be available and data can be distributed and/or replicated, such as the Earth System Grid Federation (ESGF) serving the Coupled Model Intercomparison Project, Phase 5 (CMIP5) experiment, providing access to 2.5PB of data for the Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report (AR5). A case study on climate models intercomparison data analysis addressing several classes of multi-model experiments is being implemented in the context of the EU H2020 INDIGO-DataCloud project. Such experiments require the availability of large amount of data (multi-terabyte order) related to the output of several climate models simulations as well as the exploitation of scientific data management tools for large-scale data analytics. More specifically, the talk discusses in detail a use case on precipitation trend analysis in terms of requirements, architectural design solution, and infrastructural implementation. The experiment has been tested and validated on CMIP5 datasets, in the context of a large scale distributed testbed across EU and US involving three ESGF sites (LLNL, ORNL, and CMCC) and one central orchestrator site (PSNC). The general "environment" of the case study relates to: (i) multi-model data analysis inter-comparison challenges; (ii) addressed on CMIP5 data; and (iii) which are made available through the IS-ENES/ESGF infrastructure. The added value of the solution proposed in the INDIGO-DataCloud project are summarized in the following: (i) it implements a different paradigm (from client- to server-side); (ii) it intrinsically reduces data movement; (iii) it makes lightweight the end-user setup; (iv) it fosters re-usability (of data, final

  12. The Grid Resource Broker, A Ubiquitous Grid Computing Framework

    Directory of Open Access Journals (Sweden)

    Giovanni Aloisio

    2002-01-01

    Full Text Available Portals to computational/data grids provide the scientific community with a friendly environment in order to solve large-scale computational problems. The Grid Resource Broker (GRB is a grid portal that allows trusted users to create and handle computational/data grids on the fly exploiting a simple and friendly web-based GUI. GRB provides location-transparent secure access to Globus services, automatic discovery of resources matching the user's criteria, selection and scheduling on behalf of the user. Moreover, users are not required to learn Globus and they do not need to write specialized code or to rewrite their existing legacy codes. We describe GRB architecture, its components and current GRB features addressing the main differences between our approach and related work in the area.

  13. Analysis of Information Quality in event triggered Smart Grid Control

    DEFF Research Database (Denmark)

    Kristensen, Thomas le Fevre; Olsen, Rasmus Løvenstein; Rasmussen, Jakob Gulddahl

    2015-01-01

    The integration of renewable energy sources into the power grid requires added control intelligence which imposes new communication requirements onto the future power grid. Since large scale implementation of new communication infrastructure is infeasible, we consider methods of increasing...

  14. 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...

  15. Flow Battery Solution for Smart Grid Applications

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2014-11-30

    To address future grid requirements, a U.S. Department of Energy ARRA Storage Demonstration program was launched in 2009 to commercialize promising technologies needed for stronger and more renewables-intensive grids. Raytheon Ktech and EnerVault received a cost-share grant award from the U.S. Department of Energy to develop a grid-scale storage system based on EnerVault’s iron-chromium redox flow battery technology.

  16. Distributed intrusion detection system based on grid security model

    Science.gov (United States)

    Su, Jie; Liu, Yahui

    2008-03-01

    Grid computing has developed rapidly with the development of network technology and it can solve the problem of large-scale complex computing by sharing large-scale computing resource. In grid environment, we can realize a distributed and load balance intrusion detection system. This paper first discusses the security mechanism in grid computing and the function of PKI/CA in the grid security system, then gives the application of grid computing character in the distributed intrusion detection system (IDS) based on Artificial Immune System. Finally, it gives a distributed intrusion detection system based on grid security system that can reduce the processing delay and assure the detection rates.

  17. Bathymetric Position Index (BPI) Structures 5 m grid derived from gridded bathymetry of Kure Atoll, Hawaii, USA.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — BPI Structures are derived from two scales of a focal mean analysis on bathymetry and slope. The grid is based on gridded (5 m cell size) multibeam bathymetry,...

  18. Bathymetric Position Index (BPI) Structures 10 m grid derived from gridded bathymetry of Wake Island, West Central Pacific.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — BPI Structures are derived from two scales of a focal mean analysis on bathymetry and slope. The grid is based on gridded (10 m cell size) multibeam bathymetry,...

  19. Bathymetric Position Index (BPI) Structures 5 m grid derived from gridded bathymetry of Rose Atoll, Territory of American Samoa, USA.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — BPI Structures are derived from two scales of a focal mean analysis on bathymetry and slope. The grid is based on gridded (5 m cell size) multibeam bathymetry,...

  20. Bathymetric Position Index (BPI) Structures 5 m grid derived from gridded bathymetry of Pearl and Hermes Atoll, Hawaii, USA.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — BPI Structures are derived from two scales of a focal mean analysis on bathymetry and slope. The grid is based on gridded (5 m cell size) multibeam bathymetry,...

  1. Bathymetric Position Index (BPI) Structures 20 m grid derived from gridded bathymetry of Brooks Banks, Hawaii, USA.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — BPI Structures are derived from two scales of a focal mean analysis on bathymetry and slope. The grid is based on gridded (20 m cell size) multibeam bathymetry,...

  2. Bathymetric Position Index (BPI) Structures 60 m grid derived from gridded bathymetry of Wake Island, West Central Pacific.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — BPI Structures are derived from two scales of a focal mean analysis on bathymetry and slope. The grid is based on gridded (60 m cell size) multibeam bathymetry,...

  3. Bathymetric Position Index (BPI) Structures 5 m grid derived from gridded bathymetry of Brooks Banks, Hawaii, USA.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — BPI Structures are derived from two scales of a focal mean analysis on bathymetry and slope. The grid is based on gridded (5 m cell size) multibeam bathymetry,...

  4. Bathymetric Position Index (BPI) Structures 60 m grid derived from gridded bathymetry of Rota Island, Mariana Islands, USA

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — BPI Structures are derived from two scales of a focal mean analysis on bathymetry and slope. The grid is based on gridded (60 m cell size) multibeam bathymetry,...

  5. CRED Bathymetric Position Index (BPI) Structures grid derived from gridded bathymetry of Tutuila Island, American Samoa, South Pacific

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — BPI Structures are derived from two scales of a focal mean analysis on bathymetry; slope; and depth. The grid is based on gridded (5 m cell size) multibeam...

  6. 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

  7. Grid computing

    CERN Multimedia

    2007-01-01

    "Some of today's large-scale scientific activities - modelling climate change, Earth observation, studying the human genome and particle physics experiments - involve handling millions of bytes of data very rapidly." (1 page)

  8. Fine-scale application of WRF-CAM5 during a dust storm episode over East Asia: Sensitivity to grid resolutions and aerosol activation parameterizations

    Science.gov (United States)

    Wang, Kai; Zhang, Yang; Zhang, Xin; Fan, Jiwen; Leung, L. Ruby; Zheng, Bo; Zhang, Qiang; He, Kebin

    2018-03-01

    An advanced online-coupled meteorology and chemistry model WRF-CAM5 has been applied to East Asia using triple-nested domains at different grid resolutions (i.e., 36-, 12-, and 4-km) to simulate a severe dust storm period in spring 2010. Analyses are performed to evaluate the model performance and investigate model sensitivity to different horizontal grid sizes and aerosol activation parameterizations and to examine aerosol-cloud interactions and their impacts on the air quality. A comprehensive model evaluation of the baseline simulations using the default Abdul-Razzak and Ghan (AG) aerosol activation scheme shows that the model can well predict major meteorological variables such as 2-m temperature (T2), water vapor mixing ratio (Q2), 10-m wind speed (WS10) and wind direction (WD10), and shortwave and longwave radiation across different resolutions with domain-average normalized mean biases typically within ±15%. The baseline simulations also show moderate biases for precipitation and moderate-to-large underpredictions for other major variables associated with aerosol-cloud interactions such as cloud droplet number concentration (CDNC), cloud optical thickness (COT), and cloud liquid water path (LWP) due to uncertainties or limitations in the aerosol-cloud treatments. The model performance is sensitive to grid resolutions, especially for surface meteorological variables such as T2, Q2, WS10, and WD10, with the performance generally improving at finer grid resolutions for those variables. Comparison of the sensitivity simulations with an alternative (i.e., the Fountoukis and Nenes (FN) series scheme) and the default (i.e., AG scheme) aerosol activation scheme shows that the former predicts larger values for cloud variables such as CDNC and COT across all grid resolutions and improves the overall domain-average model performance for many cloud/radiation variables and precipitation. Sensitivity simulations using the FN series scheme also have large impacts on

  9. 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.

  10. Spatial services grid

    Science.gov (United States)

    Cao, Jian; Li, Qi; Cheng, Jicheng

    2005-10-01

    This paper discusses the concept, key technologies and main application of Spatial Services Grid. The technologies of Grid computing and Webservice is playing a revolutionary role in studying the spatial information services. The concept of the SSG (Spatial Services Grid) is put forward based on the SIG (Spatial Information Grid) and OGSA (open grid service architecture). Firstly, the grid computing is reviewed and the key technologies of SIG and their main applications are reviewed. Secondly, the grid computing and three kinds of SIG (in broad sense)--SDG (spatial data grid), SIG (spatial information grid) and SSG (spatial services grid) and their relationships are proposed. Thirdly, the key technologies of the SSG (spatial services grid) is put forward. Finally, three representative applications of SSG (spatial services grid) are discussed. The first application is urban location based services gird, which is a typical spatial services grid and can be constructed on OGSA (Open Grid Services Architecture) and digital city platform. The second application is region sustainable development grid which is the key to the urban development. The third application is Region disaster and emergency management services grid.

  11. Merging Grid Technologies

    NARCIS (Netherlands)

    Begeman, K. G.; Belikov, A. N.; Boxhoorn, D. R.; Dijkstra, F.; Valentijn, E. A.; Vriend, W. -J.; Zhao, Z.

    This paper reports the integration of the astronomical Grid solution realised in the Astro-WISE information system with the EGEE Grid and the porting of Astro-WISE applications on EGEE. We review the architecture of the Astro-WISE Grid, define the problems for the integration of the Grid

  12. Toward a Grid Work flow Formal Composition

    Energy Technology Data Exchange (ETDEWEB)

    Hlaoui, Y. B.; BenAyed, L. J.

    2007-07-01

    This paper exposes a new approach for the composition of grid work flow models. This approach proposes an abstract syntax for the UML Activity Diagrams (UML-AD) and a formal foundation for grid work flow composition in form of a work flow algebra based on UML-AD. This composition fulfils the need for collaborative model development particularly the specification and the reduction of the complexity of grid work flow model verification. This complexity has arisen with the increase in scale of grid work flow applications such as science and e-business applications since large amounts of computational resources are required and multiple parties could be involved in the development process and in the use of grid work flows. Furthermore, the proposed algebra allows the definition of work flow views which are useful to limit the access to predefined users in order to ensure the security of grid work flow applications. (Author)

  13. INITIAL APPL;ICATION OF THE ADAPTIVE GRID AIR POLLUTION MODEL

    Science.gov (United States)

    The paper discusses an adaptive-grid algorithm used in air pollution models. The algorithm reduces errors related to insufficient grid resolution by automatically refining the grid scales in regions of high interest. Meanwhile the grid scales are coarsened in other parts of the d...

  14. 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

  15. 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

  16. Virtual MHD Jets on Grids

    DEFF Research Database (Denmark)

    Lery, Thibaut; Combet, Céline; Murphy, G C

    2005-01-01

    . Many national, European and international projects have been launched during the last years trying to explore the Grid and to change the way we are doing our everyday work. In Ireland, we have started the CosmoGrid project that is a collaborative project aimed to provide high performance super-computing......As network performance has outpaced computational power and storage capacity, a new paradigm has evolved to enable the sharing of geographically distributed resources. This paradigm is known as Grid computing and aims to offer access to distributed resource irrespective of their physical location...... environments. This will help to address complex problems such as magnetohydrodynamic outflows and jets in order to model and numerically simulate them. Indeed, the numerical modeling of plasma jets requires massive computations, due to the wide range of spatial-temporal scales involved. We present here...

  17. 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.

  18. Cloud feedback studies with a physics grid

    Energy Technology Data Exchange (ETDEWEB)

    Dipankar, Anurag [Max Planck Institute for Meteorology Hamburg; Stevens, Bjorn [Max Planck Institute for Meteorology Hamburg

    2013-02-07

    During this project the investigators implemented a fully parallel version of dual-grid approach in main frame code ICON, implemented a fully conservative first-order interpolation scheme for horizontal remapping, integrated UCLA-LES micro-scale model into ICON to run parallely in selected columns, and did cloud feedback studies on aqua-planet setup to evaluate the classical parameterization on a small domain. The micro-scale model may be run in parallel with the classical parameterization, or it may be run on a "physics grid" independent of the dynamics grid.

  19. 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

  20. Understanding Spatial and Temporal Variability in Ozone Levels within a Remote-sensing Scale Grid Cell using Data Collected with Low-cost, Next Generation Monitoring Systems

    Science.gov (United States)

    Collier, A. M.; Hannigan, M.; Masson, N.; Piedrahita, R.; Gordon, J. L.; Russel, M.

    2014-12-01

    For the past several years, our research group has been developing low-cost (for reference, each unit costs under $1000) next generation air quality monitors, which utilize metal-oxide semiconductor sensors and non-dispersive infrared sensors to collect data on various gaseous pollutants. The pollutants of focus for this deployment were CO2, O3, and NO2. Additional data collected by the monitors includes temperature, humidity, wind speed and direction, and some information on hydrocarbon levels. A main focus of our research has been sensor characterization and exploring research applications of the technology. During summer 2014, the DISCOVER-AQ and FRAPPE sampling campaigns provided our group with the opportunity to deploy twenty monitors throughout the sampling region with the Boulder Atmospheric Observatory Tower in Erie CO at the center of our monitoring area. Thirteen of these monitors were located at ground-level within an approximately 10 by 10 km grid cell, and the rest were outside of this area at various distances. This placement was intended to provide information on pollutant variability, specifically ozone, within a remote-sensing sized grid cell. Additionally, the availability of reference monitors in the field provided opportunities for co-location during the deployment and hence, opportunities to quantify monitor performance. Analysis will include both an evaluation of low-cost sensor performance and a look at temporal and spatial variability. For example, land-use regression modeling will be used to explore population density, distance to roadways, and distance to oil and gas activity as covariates. Additionally, we will explore how the spatial distribution varies with time and look for temporal patterns.

  1. High-efficiency grid-connected photovoltaic module integrated converter system with high-speed communication interfaces for small-scale distribution power generation

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Woo-Young; Lai, Jih-Sheng (Jason) [Future Energy Electronics Center, Department of Electrical and Computer Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA (United States)

    2010-04-15

    This paper presents a high-efficiency grid-connected photovoltaic (PV) module integrated converter (MIC) system with reduced PV current variation. The proposed PV MIC system consists of a high-efficiency step-up DC-DC converter and a single-phase full-bridge DC-AC inverter. An active-clamping flyback converter with a voltage-doubler rectifier is proposed for the step-up DC-DC converter. The proposed step-up DC-DC converter reduces the switching losses by eliminating the reverse-recovery current of the output rectifying diodes. To reduce the PV current variation introduced by the grid-connected inverter, a PV current variation reduction method is also suggested. The suggested PV current variation reduction method reduces the PV current variation without any additional components. Moreover, for centralized power control of distributed PV MIC systems, a PV power control scheme with both a central control level and a local control level is presented. The central PV power control level controls the whole power production by sending out reference power signals to each individual PV MIC system. The proposed step-up DC-DC converter achieves a high-efficiency of 97.5% at 260 W output power to generate the DC-link voltage of 350 V from the PV voltage of 36.1 V. The PV MIC system including the DC-DC converter and the DC-AC inverter achieves a high-efficiency of 95% with the PV current ripple less than 3% variation of the rated PV current. (author)

  2. REVIEW ON GRID INTERFACING OF MULTIMEGAWATT PHOTOVOLTAIC INVERTERS

    OpenAIRE

    Mr. Vilas S. Solanke*; Mr. Naveen Kumar

    2016-01-01

    This paper presents review on the latest development of control of grid connected photovoltaic energy conversion system. Also this paper present existing systems control algorithm for three-phase and single phase grid-connected photovoltaic (PV) system. This paper focuses on one aspect of solar energy, namely grid interfacing of large-scale PV farms. This Grid-connected photovoltaic i.e. PV systems can provide a number of benefits to electric utilities, such as power loss reduction, improve...

  3. HIRENASD Solar Grids

    Data.gov (United States)

    National Aeronautics and Space Administration — These grids were generated by Markus Ritter (DLR) using Solar in TAU format netcdf.nc. The grids were converted to CGNS format by Pawel Chwalowski (NASA)

  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. RSW Modified Inflow Grid

    Data.gov (United States)

    National Aeronautics and Space Administration — After discussions by the organizing committee, and some research using the RSW grids, a modification has been made on the RSW grids. The inflow boundary has now been...

  6. RSW hexahedral grids

    Data.gov (United States)

    National Aeronautics and Space Administration — RSW hexahedral grids in CGNS (unstructured) and Plot3d (structured) formats generated by ANSYS Germany. Please see AePW_RSW_Grids.pptx below for full description of...

  7. Large Scale Explorative Oligonucleotide Probe Selection for Thousands of Genetic Groups on a Computing Grid: Application to Phylogenetic Probe Design Using a Curated Small Subunit Ribosomal RNA Gene Database

    Directory of Open Access Journals (Sweden)

    Faouzi Jaziri

    2014-01-01

    Full Text Available Phylogenetic Oligonucleotide Arrays (POAs were recently adapted for studying the huge microbial communities in a flexible and easy-to-use way. POA coupled with the use of explorative probes to detect the unknown part is now one of the most powerful approaches for a better understanding of microbial community functioning. However, the selection of probes remains a very difficult task. The rapid growth of environmental databases has led to an exponential increase of data to be managed for an efficient design. Consequently, the use of high performance computing facilities is mandatory. In this paper, we present an efficient parallelization method to select known and explorative oligonucleotide probes at large scale using computing grids. We implemented a software that generates and monitors thousands of jobs over the European Computing Grid Infrastructure (EGI. We also developed a new algorithm for the construction of a high-quality curated phylogenetic database to avoid erroneous design due to bad sequence affiliation. We present here the performance and statistics of our method on real biological datasets based on a phylogenetic prokaryotic database at the genus level and a complete design of about 20,000 probes for 2,069 genera of prokaryotes.

  8. Characterization of Slosh Damping for Ortho-Grid and Iso-Grid Internal Tank Structures

    Science.gov (United States)

    Westra, Douglas G.; Sansone, Marco D.; Eberhart, Chad J.; West, Jeffrey S.

    2016-01-01

    Grid stiffened tank structures such as Ortho-Grid and Iso-Grid are widely used in cryogenic tanks for providing stiffening to the tank while reducing mass, compared to tank walls of constant cross-section. If the structure is internal to the tank, it will positively affect the fluid dynamic behavior of the liquid propellant, in regard to fluid slosh damping. As NASA and commercial companies endeavor to explore the solar system, vehicles will by necessity become more mass efficient, and design margin will be reduced where possible. Therefore, if the damping characteristics of the Ortho-Grid and Iso-Grid structure is understood, their positive damping effect can be taken into account in the systems design process. Historically, damping by internal structures has been characterized by rules of thumb and for Ortho-Grid, empirical design tools intended for slosh baffles of much larger cross-section have been used. There is little or no information available to characterize the slosh behavior of Iso-Grid internal structure. Therefore, to take advantage of these structures for their positive damping effects, there is much need for obtaining additional data and tools to characterize them. Recently, the NASA Marshall Space Flight Center conducted both sub-scale testing and computational fluid dynamics (CFD) simulations of slosh damping for Ortho-Grid and Iso-Grid tanks for cylindrical tanks containing water. Enhanced grid meshing techniques were applied to the geometrically detailed and complex Ortho-Grid and Iso-Grid structures. The Loci-STREAM CFD program with the Volume of Fluid Method module for tracking and locating the water-air fluid interface was used to conduct the simulations. The CFD simulations were validated with the test data and new empirical models for predicting damping and frequency of Ortho-Grid and Iso-Grid structures were generated.

  9. 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 r...... signals in hybridization filters and (2) localization of knit units in textile samples....

  10. 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.

  11. 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.

  12. Grid Based Chinese Virtual Observatory System Design

    Science.gov (United States)

    Cui, Chenzhou; Zhao, Yongheng

    Chinese Virtual Observatory (China-VO) project is a consortium initiated by Chinese National Astronomical Observatory and Large Sky Area Multi-Object Fiber Spectroscopic Telescope project. A three-layer architecture of the China-VO is described which depends upon the Open Grid Services Architecture being developed by the Global Grid Forum. The fabric layer mainly consists of astronomical datasets with corresponding metadate and data access services. The resource layer includes a large scale of services for grid resource management data interoperation data mining security logical name space and so on. The application layer consists of user interfaces and other client services. In the China-VO system all the functional components are SOAP Grid service implementations. Chinese National Grid (CNGrid) will be the testbed for the China-VO. How to interact with other CNGrid components is also discussed.

  13. Environmental life cycle assessment of a large-scale grid-connected PV power plant. Case study Moura 62 MW PV power plant

    Energy Technology Data Exchange (ETDEWEB)

    Suomalainen, Kiti

    2006-01-15

    An environmental life cycle assessment has been conducted for a 62 MW grid-connected photovoltaic installation to study the role of BOS components in the total environmental load. Also the influence of the current electricity supply has been investigated. For an alternative approach a net output approach has been used, where all electricity requirements are supplied by the photovoltaic installation itself. The components taken into account are monocrystalline silicon cells in frameless modules, steel support structures in concrete foundations, inverters, transformers, cables, transports and construction of roads and buildings. For stationary inert products without intrinsic energy requirements, such as cables, inverters, support structures etc., only raw material acquisition and processing are taken into account, since they are considered the most dominant stages in the life cycle. The results confirm a minor environmental load from BOS components compared to the module life cycle, showing approximately ten to twenty percent impact of the total. Uncertainties lie in the approximations for electronic devices as well as in the emissions from silicon processing. Concerning the electricity supply, the results differ considerably depending on which system perspective is used. In the net output approach the impacts decrease with approximately ninety percent from the traditional approach. Some increases are also shown in toxicity categories due to the increased module production needed for the enlargement of the installation.

  14. Mapping of grid faults and grid codes

    DEFF Research Database (Denmark)

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

    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......’ 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...

  15. Mapping of grid faults and grid codes

    DEFF Research Database (Denmark)

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

    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......' 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...

  16. 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.

  17. Restricting 32-128 km horizontal scales hardly affects the MJO in the Superparameterized Community Atmosphere Model v.3.0 but the number of cloud-resolving grid columns constrains vertical mixing

    Science.gov (United States)

    Pritchard, Michael S.; Bretherton, Christopher S.; DeMott, Charlotte A.

    2014-09-01

    The effects of artificially restricting the 32-128 km horizontal scale regime on MJO dynamics in the Superparameterized Community Atmosphere Model v.3.0 have been explored through reducing the extent of its embedded cloud resolving model (CRM) arrays. Two and four-fold reductions in CRM extent (from 128 to 64 km and 32 km) produce statistical composite MJO signatures with spatial scale, zonal phase speed, and intrinsic wind-convection anomaly structure that are all remarkably similar to the standard SPCAM's MJO. This suggests that the physics of mesoscale convective organization on 32-128 km scales are not critical to MJO dynamics in SPCAM and that reducing CRM extent may be a viable strategy for 400% more computationally efficient analysis of superparameterized MJO dynamics. However several unexpected basic state responses caution that extreme CRM domain reduction can lead to systematic mean state issues in superparameterized models. We hypothesize that an artificial limit on the efficiency of vertical updraft mixing is set by the number of grid columns available for compensating subsidence in the embedded CRM arrays. This can lead to reduced moisture ventilation supporting too much liquid cloud and thus an overly strong cloud shortwave radiative forcing, particularly in regions of deep convection.

  18. Intrusion Detection System Inside Grid Computing Environment (IDS-IGCE)

    OpenAIRE

    Basappa B. Kodada; Ramesh Nayak; Raghavendra Prabhu; Suresha D

    2012-01-01

    Grid Computing is a kind of important information technology which enables resource sharing globally to solve the large scale problem. It is based on networks and able to enable large scale aggregation and sharing of computational, data, sensors and other resources across institutional boundaries. Integrated Globus Tool Kit with Web services is to present OGSA (Open Grid Services Architecture) as the standardservice grid architecture. In OGSA, everything is abstracted as a service, including ...

  19. 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.

  20. Scale-dependency of LiDAR derived terrain attributes in quantitative soil-landscape modeling: Effects of grid resolution vs. neighborhood extent

    Science.gov (United States)

    Quantifying the spatial distribution of soil properties is essential for ecological and environmental modeling at the landscape scale. Terrain attributes are one of the primary covariates in soil-landscape models due to their control on energy and mass fluxes, which in turn contr...

  1. An aggregate model of grid-connected, large-scale, offshore wind farm for power stability investigations-importance of windmill mechanical system

    DEFF Research Database (Denmark)

    Akhmatov, Vladislav; Knudsen, H.

    2002-01-01

    An aggregate model of a large-scale offshore wind farm, comprising 72 wind turbines of 2 MW rating each, is set up. Representation of the shaft systems of the wind turbines shall be taken into account when a simplified aggregate model of the wind farm is used in voltage stability investigations. ...

  2. Securing smart grid technology

    Science.gov (United States)

    Chaitanya Krishna, E.; Kosaleswara Reddy, T.; Reddy, M. YogaTeja; Reddy G. M., Sreerama; Madhusudhan, E.; AlMuhteb, Sulaiman

    2013-03-01

    In the developing countries electrical energy is very important for its all-round improvement by saving thousands of dollars and investing them in other sector for development. For Growing needs of power existing hierarchical, centrally controlled grid of the 20th Century is not sufficient. To produce and utilize effective power supply for industries or people we should have Smarter Electrical grids that address the challenges of the existing power grid. The Smart grid can be considered as a modern electric power grid infrastructure for enhanced efficiency and reliability through automated control, high-power converters, modern communications infrastructure along with modern IT services, sensing and metering technologies, and modern energy management techniques based on the optimization of demand, energy and network availability and so on. The main objective of this paper is to provide a contemporary look at the current state of the art in smart grid communications as well as critical issues on smart grid technologies primarily in terms of information and communication technology (ICT) issues like security, efficiency to communications layer field. In this paper we propose new model for security in Smart Grid Technology that contains Security Module(SM) along with DEM which will enhance security in Grid. It is expected that this paper will provide a better understanding of the technologies, potential advantages and research challenges of the smart grid and provoke interest among the research community to further explore this promising research area.

  3. Bathymetric Position Index (BPI) Structures 10 m grid derived from gridded bathymetry of Farallon de Pajaros (Uracas) Island, Commonwealth of the Northern Mariana Islands (CNMI), USA

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — BPI Structures are derived from two scales of a focal mean analysis on bathymetry and slope. The grid is based on gridded (10 m cell size) multibeam bathymetry,...

  4. Bathymetric Position Index (BPI) Structures 10 m grid derived from gridded bathymetry of Maug Island, Commonwealth of the Northern Mariana Islands (CNMI), USA.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — BPI Structures are derived from two scales of a focal mean analysis on bathymetry and slope. The grid is based on gridded (10 m cell size) multibeam bathymetry,...

  5. Bathymetric Position Index (BPI) Structures 5 m grid derived from gridded bathymetry of Ta'u Island, Territory of American Samoa, USA.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — BPI Structures are derived from two scales of a focal mean analysis on bathymetry and slope. The grid is based on gridded (5 m cell size) multibeam bathymetry,...

  6. Bathymetric Position Index (BPI) Structures 10 m grid derived from gridded bathymetry of Alamagan Island, Commonwealth of the Northern Mariana Islands (CNMI), USA.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — BPI Structures are derived from two scales of a focal mean analysis on bathymetry and slope. The grid is based on gridded (10 m cell size) multibeam bathymetry,...

  7. Bathymetric Position Index (BPI) Structures 40 m grid derived from gridded bathymetry of Howland Island, Pacific Remote Island Areas, Central Pacific.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — BPI Structures are derived from two scales of a focal mean analysis on bathymetry and slope. The grid is based on gridded (40 m cell size) multibeam bathymetry,...

  8. Bathymetric Position Index (BPI) Structures 10 m grid derived from gridded bathymetry of Sarigan Island, Commonwealth of the Northern Mariana Islands (CNMI), USA.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — BPI Structures are derived from two scales of a focal mean analysis on bathymetry and slope. The grid is based on gridded (10 m cell size) multibeam bathymetry,...

  9. Bathymetric Position Index (BPI) Structures 5 m grid derived from gridded bathymetry of Ofu and Olosega Islands, Territory of American Samoa, USA.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — BPI Structures are derived from two scales of a focal mean analysis on bathymetry and slope. The grid is based on gridded (5 m cell size) multibeam bathymetry,...

  10. Bathymetric Position Index (BPI) Structures 20 m grid derived from gridded bathymetry of Johnston Island, Pacific Remote Island Areas, Central Pacific.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — BPI Structures are derived from two scales of a focal mean analysis on bathymetry and slope. The grid is based on gridded (20 m cell size) multibeam bathymetry,...

  11. Bathymetric Position Index (BPI) Structures 5 m grid derived from gridded bathymetry of Galvez Bank, South Galvez Bank, and 11-Mile Reef, Territory of Guam, USA.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — BPI Structures are derived from two scales of a focal mean analysis on bathymetry and slope. The grid is based on gridded (5 m cell size) multibeam bathymetry,...

  12. Bathymetric Position Index (BPI) Structures 5 m grid derived from gridded bathymetry of Rota Island, Commonwealth of the Northern Mariana Islands (CNMI), USA.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — BPI Structures are derived from two scales of a focal mean analysis on bathymetry and slope. The grid is based on gridded (5 m cell size) multibeam bathymetry,...

  13. Bathymetric Position Index (BPI) Structures 10 m grid derived from gridded bathymetry of Pagan Island, Commonwealth of the Northern Mariana Islands (CNMI), USA.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — BPI Structures are derived from two scales of a focal mean analysis on bathymetry and slope. The grid is based on gridded (10 m cell size) multibeam bathymetry,...

  14. Bathymetric Position Index (BPI) Structures 10 m grid derived from gridded bathymetry of Supply Reef, Commonwealth of the Northern Mariana Islands (CNMI), USA.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — BPI Structures are derived from two scales of a focal mean analysis on bathymetry and slope. The grid is based on gridded (10 m cell size) multibeam bathymetry,...

  15. Bathymetric Position Index (BPI) Structures 10 m grid derived from gridded bathymetry of Agrihan Island, Commonwealth of the Northern Mariana Islands (CNMI), USA.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — BPI Structures are derived from two scales of a focal mean analysis on bathymetry and slope. The grid is based on gridded (10 m cell size) multibeam bathymetry,...

  16. Bathymetric Position Index (BPI) Structures 20 m grid derived from gridded bathymetry of Baker Island, Pacific Remote Island Areas, Central Pacific.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — BPI Structures are derived from two scales of a focal mean analysis on bathymetry and slope. The grid is based on gridded (20 m cell size) multibeam bathymetry,...

  17. Non-orthogonal version of the arbitrary polygonal C-grid and a new diamond grid

    Directory of Open Access Journals (Sweden)

    H. Weller

    2014-05-01

    Full Text Available Quasi-uniform grids of the sphere have become popular recently since they avoid parallel scaling bottlenecks associated with the poles of latitude–longitude grids. However quasi-uniform grids of the sphere are often non-orthogonal. A version of the C-grid for arbitrary non-orthogonal grids is presented which gives some of the mimetic properties of the orthogonal C-grid. Exact energy conservation is sacrificed for improved accuracy and the resulting scheme numerically conserves energy and potential enstrophy well. The non-orthogonal nature means that the scheme can be used on a cubed sphere. The advantage of the cubed sphere is that it does not admit the computational modes of the hexagonal or triangular C-grids. On various shallow-water test cases, the non-orthogonal scheme on a cubed sphere has accuracy less than or equal to the orthogonal scheme on an orthogonal hexagonal icosahedron. A new diamond grid is presented consisting of quasi-uniform quadrilaterals which is more nearly orthogonal than the equal-angle cubed sphere but with otherwise similar properties. It performs better than the cubed sphere in every way and should be used instead in codes which allow a flexible grid structure.

  18. Power grid complex network evolutions for the smart grid

    Science.gov (United States)

    Pagani, Giuliano Andrea; Aiello, Marco

    2014-02-01

    The shift towards an energy grid dominated by prosumers (consumers and producers of energy) will inevitably have repercussions on the electricity distribution infrastructure. Today the grid is a hierarchical one delivering energy from large scale facilities to end-users. Tomorrow it will be a capillary infrastructure at the medium and low voltage levels that will support local energy trading among prosumers. We investigate how different network topologies and growth models facilitate a more efficient and reliable network, and how they can facilitate the emergence of a decentralized electricity market. We show how connectivity plays an important role in improving the properties of reliability and path-cost reduction. Our results indicate that a specific type of evolution balances best the ratio between increased connectivity and costs to achieve the network growth.

  19. 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.

  20. The Grid : english version

    CERN Multimedia

    Rosy Mondardini Producer

    2003-01-01

    The Grid : . Sharing resources owned by many different organizations to access remote computers, software, and data efficiently and automatically . Secure access to establish the identity of a user or resource, after defining conditions under which sharing occurs . Bridging distance using high-speed connections between computers to create a global Grid . Open standards to allow applications designed for one Grid to run on all others

  1. 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....

  2. Challenges facing production grids

    Energy Technology Data Exchange (ETDEWEB)

    Pordes, Ruth; /Fermilab

    2007-06-01

    Today's global communities of users expect quality of service from distributed Grid systems equivalent to that their local data centers. This must be coupled to ubiquitous access to the ensemble of processing and storage resources across multiple Grid infrastructures. We are still facing significant challenges in meeting these expectations, especially in the underlying security, a sustainable and successful economic model, and smoothing the boundaries between administrative and technical domains. Using the Open Science Grid as an example, I examine the status and challenges of Grids operating in production today.

  3. Airborne Grid Sea-Ice Surveys for Comparison with Cryosat-2

    Science.gov (United States)

    Brozena, J. M.; Gardner, J. M.; Liang, R.; Hagen, R. A.; Ball, D.; Newman, T.

    2015-12-01

    The Naval Research Laboratory is studying of the changing Arctic with a focus on ice thickness and distribution variability. The goal is optimization of computer models used to predict sea ice changes. An important part of our study is to calibrate/validate Cryosat-2 ice thickness data prior to its incorporation into new ice forecast models. The footprint of the altimeter over sea-ice is a significant issue in any attempt to ground-truth the data. Along-track footprints are reduced to ~ 300 m by SAR processing of the returns. However, the cross-track footprint is determined by the topography of the surface. Further, the actual return is the sum of the returns from individual reflectors within the footprint making it difficult to interpret the return, and optimize the waveform tracker. We therefore collected a series of grids of scanning LiDAR and radar on sub-satellite tracks over sea-ice that would extend far enough cross-track to capture the illuminated area. The difficulty in the collection of such grids, which are comprised of adjacent overlapping tracks is ice motion of as much as 300 m over the duration of a single flight track (~ 20 km) of data collection. With a typical LiDAR swath width of radar. The detailed 2-d LiDAR image is the snow surface, not the underlying ice presumably illuminated by the radar. Our hope is that the 1-D radar profiles collected along the LiDAR swath centerlines will be sufficient to correct the grid for snow thickness. A total of 15 grids 5-20 km wide (cross-track) by 10-30 km long (along-track) centered on ice illuminated by CryoSat-2 were collected north of Barrow, AK. This occured over three field seasons which took place from 2013-15. Data from the grids are shown here and are being used to examine the relationship of the tracked satellite waveform data to the actual surface.

  4. Basin-scale assessment of water resource availability in climate change scenarios through a grid-based approach: an application to Sicily

    Science.gov (United States)

    Liuzzo, L.; Noto, L. V.; La Loggia, G.

    2009-04-01

    Climate change resulting from the enhanced greenhouse effect is expected to have great implications for hydrological cycle and for existing surface and groundwater resources systems. The effects of climate variability and climate change have to be fully considered in current water management and planning, since water availability, quality and streamflow are sensitive to changes in temperature and precipitation regimes. Since hydrological models are an important tool in the study and analysis of the hydrological processes and in water resources management, international literature proposes several models, that attempt to assess accurately the available water resources under stationary and changing climatic conditions at different spatial and temporal scales. In order to assess the potential impacts of climate change on surface and groundwater resources water availability in a Southern area of Italy, a conceptual model was applied to simulate the hydrological processes in the Belice river basin, located in Sicily. A trend analysis, carried out using non-parametric techniques, highlighted a decrease of precipitation and an increase of temperature for the area of study over the last 80 years. The model was applied for current conditions of precipitation and temperature as well as under the hypothesis of climate variations, as represented by scenarios consistent with the climate trend analysis. The analysis of the climatic forcing trend provided the parameters needed in order to generate synthetic climate forcing series through the use of stochastic approaches. The conceptual model, developed and applied in this study, is the TOpography based Probability Distributed Model, indicated as TOPDM, resulting from the combination and integration of TOPMODEL into a probability distributed model. Through a relationship between topographic index and storage capacity, this model reflects adequately the influence of basin topography in the hydrological process of runoff generation

  5. Gridded Species Distribution: Global Amphibian Richness Grids, 2015 Release

    Data.gov (United States)

    National Aeronautics and Space Administration — The 2015 Release of the Global Amphibian Richness Grids data set of the Gridded Species Distribution collection are aggregations of the presence grids data for the...

  6. 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...

  7. 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...

  8. 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...

  9. Gridded Species Distribution: Global Mammal Richness Grids, 2015 Release

    Data.gov (United States)

    National Aeronautics and Space Administration — The 2015 Release of the Global Mammal Richness Grids data set of the Gridded Species Distribution collection are aggregations of the presence grids data for the...

  10. Control of Wind Turbines during Symmetrical and Asymmetrical Grid Faults

    DEFF Research Database (Denmark)

    Göksu, Ömer

    grid code requirements, which are targeting to make the WPPs operate in a closer manner to the conventional power plants. Common to most of the grid codes, WPPs are required to stay connected during short-circuit grid faults, and also inject reactive current in order to support the grid voltage...... regulation. The uninterrupted operation of WPPs is required even when the grid voltage drops down to zero; and the current injection requirement is defined as positive sequence reactive current irrespective of the fault type; symmetrical or asymmetrical. In this project, the response of full-scale converter...... type wind turbines (WTs), in an AC connected WPP, is investigated and control algorithms are designed for minimum disrupted operation and improved grid support, for both symmetrical and asymmetrical grid faults. WTs’ response with conventional control algorithms is studied regarding the impact...

  11. 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

  12. 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 ...

  13. 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

  14. DataGrid

    CERN Multimedia

    Silvano de Gennaro

    2003-01-01

    DataGrid is a project funded by the European Union that aims to enable access to geographically distributed computing power and storage facilities belonging to different institutions. This will provide scientists with an unprecedented computing and data management tool. DataGrid is led by CERN, together with 20 other scientific and industrial partners.

  15. 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.

  16. Building Grid applications using Web Services

    CERN Multimedia

    CERN. Geneva

    2004-01-01

    There has been a lot of discussion within the Grid community about the use of Web Services technologies in building large-scale, loosely-coupled, cross-organisation applications. In this talk we are going to explore the principles that govern Service-Oriented Architectures and the promise of Web Services technologies for integrating applications that span administrative domains. We are going to see how existing Web Services specifications and practices could provide the necessary infrastructure for implementing Grid applications. Biography Dr. Savas Parastatidis is a Principal Research Associate at the School of Computing Science, University of Newcastle upon Tyne, UK. Savas is one of the authors of the "Grid Application Framework based on Web Services Specifications and Practices" document that was influential in the convergence between Grid and Web Services and the move away from OGSI (more information can be found at http://www.neresc.ac.uk/ws-gaf). He has done research on runtime support for distributed-m...

  17. 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...... and costs. This paper elaborates on the key stakeholders, crucial polices and general challenges in the context of the Chinese smart grid development. The paper finds that the Chinese energy market is a state monopoly and foreign companies can only become key stakeholders in the role of suppliers or service...... providers. It can be concluded that the Chinese smart grid development has still to overcome technological and political issues, such as overlapping authority structures, not installed or immature key technologies, the absence of standards and governmental market protectionism....

  18. 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.

  19. 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.

  20. Fractal Characteristics Analysis of Blackouts in Interconnected Power Grid

    DEFF Research Database (Denmark)

    Wang, Feng; Li, Lijuan; Li, Canbing

    2017-01-01

    The power failure models are a key to understand the mechanism of large scale blackouts. In this letter, the similarity of blackouts in interconnected power grids (IPGs) and their sub-grids is discovered by the fractal characteristics analysis to simplify the failure models of the IPG. The distri......The power failure models are a key to understand the mechanism of large scale blackouts. In this letter, the similarity of blackouts in interconnected power grids (IPGs) and their sub-grids is discovered by the fractal characteristics analysis to simplify the failure models of the IPG....... The distribution characteristics of blackouts in various sub-grids are demonstrated based on the Kolmogorov-Smirnov (KS) test. The fractal dimensions (FDs) of the IPG and its sub-grids are then obtained by using the KS test and the maximum likelihood estimation (MLE). The blackouts data in China were used...

  1. 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...

  2. 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...

  3. CMS Monte Carlo production in the WLCG computing grid

    CERN Document Server

    Hernández, J M; Mohapatra, A; Filippis, N D; Weirdt, S D; Hof, C; Wakefield, S; Guan, W; Khomitch, A; Fanfani, A; Evans, D; Flossdorf, A; Maes, J; van Mulders, P; Villella, I; Pompili, A; My, S; Abbrescia, M; Maggi, G; Donvito, G; Caballero, J; Sanches, J A; Kavka, C; Van Lingen, F; Bacchi, W; Codispoti, G; Elmer, P; Eulisse, G; Lazaridis, C; Kalini, S; Sarkar, S; Hammad, G

    2008-01-01

    Monte Carlo production in CMS has received a major boost in performance and scale since the past CHEP06 conference. The production system has been re-engineered in order to incorporate the experience gained in running the previous system and to integrate production with the new CMS event data model, data management system and data processing framework. The system is interfaced to the two major computing Grids used by CMS, the LHC Computing Grid (LCG) and the Open Science Grid (OSG).

  4. Automatic grid refinement criterion for lattice Boltzmann method

    OpenAIRE

    Lagrava, Daniel; Malaspinas, Orestis; Latt, Jonas; Chopard, Bastien

    2015-01-01

    In all kinds of engineering problems, and in particular in methods for computational fluid dynamics based on regular grids, local grid refinement is of crucial importance. To save on computational expense, many applications require to resolve a wide range of scales present in a numerical simulation by locally adding more mesh points. In general, the need for a higher (or a lower) resolution is not known a priori, and it is therefore difficult to locate areas for which local grid refinement is...

  5. Quality Assurance Framework for Mini-Grids

    Energy Technology Data Exchange (ETDEWEB)

    Baring-Gould, Ian [National Renewable Energy Lab. (NREL), Golden, CO (United States); Burman, Kari [National Renewable Energy Lab. (NREL), Golden, CO (United States); Singh, Mohit [National Renewable Energy Lab. (NREL), Golden, CO (United States); Esterly, Sean [National Renewable Energy Lab. (NREL), Golden, CO (United States); Mutiso, Rose [US Department of Energy, Washington, DC (United States); McGregor, Caroline [US Department of Energy, Washington, DC (United States)

    2016-11-01

    will drive investment and scale-up in this sector. The QAF implementation process also defines a set of implementation guidelines that help the deployment of mini-grids on a regional or national scale, helping to insure successful rapid deployment of these relatively new remote energy options. Note that the QAF is technology agnostic, addressing both alternating current (AC) and direct current (DC) mini-grids, and is also applicable to renewable, fossil-fuel, and hybrid systems.

  6. Decentral Smart Grid Control

    Science.gov (United States)

    Schäfer, Benjamin; Matthiae, Moritz; Timme, Marc; Witthaut, Dirk

    2015-01-01

    Stable operation of complex flow and transportation networks requires balanced supply and demand. For the operation of electric power grids—due to their increasing fraction of renewable energy sources—a pressing challenge is to fit the fluctuations in decentralized supply to the distributed and temporally varying demands. To achieve this goal, common smart grid concepts suggest to collect consumer demand data, centrally evaluate them given current supply and send price information back to customers for them to decide about usage. Besides restrictions regarding cyber security, privacy protection and large required investments, it remains unclear how such central smart grid options guarantee overall stability. Here we propose a Decentral Smart Grid Control, where the price is directly linked to the local grid frequency at each customer. The grid frequency provides all necessary information about the current power balance such that it is sufficient to match supply and demand without the need for a centralized IT infrastructure. We analyze the performance and the dynamical stability of the power grid with such a control system. Our results suggest that the proposed Decentral Smart Grid Control is feasible independent of effective measurement delays, if frequencies are averaged over sufficiently large time intervals.

  7. Transmission grid security

    CERN Document Server

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

    2011-01-01

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

  8. US National Grid

    Data.gov (United States)

    Kansas Data Access and Support Center — This is a polygon feature data layer of United States National Grid (1000m x 1000m polygons ) constructed by the Center for Interdisciplinary Geospatial Information...

  9. Lincoln Laboratory Grid

    Data.gov (United States)

    Federal Laboratory Consortium — The Lincoln Laboratory Grid (LLGrid) is an interactive, on-demand parallel computing system that uses a large computing cluster to enable Laboratory researchers to...

  10. World Wide Grid

    CERN Multimedia

    Grätzel von Grätz, Philipp

    2007-01-01

    Whether for genetic risk analysis or 3D-rekonstruktion of the cerebral vessels: the modern medicine requires more computing power. With a grid infrastructure, this one can be if necessary called by the network. (4 pages)

  11. 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

  12. Meet the Grid

    CERN Multimedia

    Yurkewicz, Katie

    2005-01-01

    Today's cutting-edge scientific projects are larger, more complex, and more expensive than ever. Grid computing provides the resources that allow researchers to share knowledge, data, and computer processing power across boundaries

  13. RSW Cell Centered Grids

    Data.gov (United States)

    National Aeronautics and Space Administration — New cell centered grids are generated to complement the node-centered ones uploaded. Six tarballs containing the coarse, medium, and fine mixed-element and pure tet....

  14. IDL Grid Web Portal

    Science.gov (United States)

    Massimino, P.; Costa, A.

    2008-08-01

    Image Data Language is a software for data analysis, visualization and cross-platform application development. The potentiality of IDL is well-known in the academic scientific world, especially in the astronomical environment where thousands of procedures are developed by using IDL. The typical use of IDL is the interactive mode but it is also possible to run IDL programs that do not require any interaction with the user, submitting them in batch or background modality. Through the interactive mode the user immediately receives images or other data produced in the running phase of the program; in batch or background mode, the user will have to wait for the end of the program, sometime for many hours or days to obtain images or data that IDL produced as output: in fact in Grid environment it is possible to access to or retrieve data only after completion of the program. The work that we present gives flexibility to IDL procedures submitted to the Grid computer infrastructure. For this purpose we have developed an IDL Grid Web Portal to allow the user to access the Grid and to submit IDL programs granting a full job control and the access to images and data generated during the running phase, without waiting for their completion. We have used the PHP technology and we have given the same level of security that Grid normally offers to its users. In this way, when the user notices that the intermediate program results are not those expected, he can stop the job, change the parameters to better satisfy the computational algorithm and resubmit the program, without consuming the CPU time and other Grid resources. The IDL Grid Web Portal allows you to obtain IDL generated images, graphics and data tables by using a normal browser. All conversations from the user and the Grid resources occur via Web, as well as authentication phases. The IDL user has not to change the program source much because the Portal will automatically introduce the appropriate modification before

  15. DC micro-grids

    OpenAIRE

    Mia, Gredelj

    2014-01-01

    The conventional electrical system in place today sees our electrical devices powered by AC mains. But as renewable technologies such as solar photovoltaic and wind power become more prevalent at a household level, DC micro-grids could be a cheaper and more efficient alternative. New lighting devices (LED) can reduce the electricity consumption substantially. Two alternatives are envisioned in this paper: A stand-alone alternative in which there is no grid connection, that would require local...

  16. Thermal Anemometry Grid Sensor

    OpenAIRE

    Martin Arlit; Eckhard Schleicher; Uwe Hampel

    2017-01-01

    A novel thermal anemometry grid sensor was developed for the simultaneous measurement of cross-sectional temperature and axial velocity distribution in a fluid flow. The sensor consists of a set of platinum resistors arranged in a regular grid. Each platinum resistor allows the simultaneous measurement of fluid temperature via electrical resistance and flow velocity via constant voltage thermal anemometry. Cross-sectional measurement was enabled by applying a special multiplexing-excitation s...

  17. Grid Computing Technology

    Directory of Open Access Journals (Sweden)

    Georgiana MARIN Romanian

    2011-09-01

    Full Text Available This paper presents the grid computing technology, the recent developments in this field. The idea of grid computing has its origins in the early development of computer networks and technologies involved, given that CPU cycle use "free" or "unused" was seen as an optimal and cost-effective way to use all capabilities of the hardware resources which were very expensive machinery.

  18. 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.

  19. Multilevel unit commitment in smart grids

    NARCIS (Netherlands)

    Bosman, M.G.C.; Molderink, Albert; Bakker, Vincent; Smit, Gerardus Johannes Maria; Hurink, Johann L.

    2012-01-01

    This paper focuses on the planning of electricity resources in the developing electricity infrastructure. First we model the existing infrastructure and extend this model to a smart grid infrastructure, where we focus on the large scale introduction of small electricity generators, leading to

  20. Methods and apparatus of analyzing electrical power grid data

    Science.gov (United States)

    Hafen, Ryan P.; Critchlow, Terence J.; Gibson, Tara D.

    2017-09-05

    Apparatus and methods of processing large-scale data regarding an electrical power grid are described. According to one aspect, a method of processing large-scale data regarding an electrical power grid includes accessing a large-scale data set comprising information regarding an electrical power grid; processing data of the large-scale data set to identify a filter which is configured to remove erroneous data from the large-scale data set; using the filter, removing erroneous data from the large-scale data set; and after the removing, processing data of the large-scale data set to identify an event detector which is configured to identify events of interest in the large-scale data set.

  1. Grid Scale Energy Storage (Symposium EE8)

    Science.gov (United States)

    2016-06-01

    ionic liquids and polymers can be used to prepare this new compound. We will describe these new synthetic routes to obtain alluaudite high -voltage... High Voltage Aqueous Li-Ion Chemistries Chunsheng Wang1, Liumin Suo1, Kang Xu2, Oleg Borodin2. 1, , Univ of Maryland, College Park, Maryland, United...density electrolyte, high selective membrane, and catalytic electrode will be reported. New redox flow battery chemistry based on soluble low-cost

  2. The two major Grid infrastructures

    CERN Multimedia

    2005-01-01

    This map shows the world's two major Grid infrastructures. The Open Science Grid (OSG) will handle data in the US, while Enabling Grids for E-sciencE (EGEE) will process data in Europe and the rest of the world. These Grids share processing power in order to process the huge amounts of information from experiments such as those at the LHC.

  3. 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

  4. The GridShare solution: a smart grid approach to improve service provision on a renewable energy mini-grid in Bhutan

    Science.gov (United States)

    Quetchenbach, T. G.; Harper, M. J.; Robinson, J., IV; Hervin, K. K.; Chase, N. A.; Dorji, C.; Jacobson, A. E.

    2013-03-01

    This letter reports on the design and pilot installation of GridShares, devices intended to alleviate brownouts caused by peak power use on isolated, village-scale mini-grids. A team consisting of the authors and partner organizations designed, built and field-tested GridShares in the village of Rukubji, Bhutan. The GridShare takes an innovative approach to reducing brownouts by using a low cost device that communicates the state of the grid to its users and regulates usage before severe brownouts occur. This demand-side solution encourages users to distribute the use of large appliances more evenly throughout the day, allowing power-limited systems to provide reliable, long-term renewable electricity to these communities. In the summer of 2011, GridShares were installed in every household and business connected to the Rukubji micro-hydro mini-grid, which serves approximately 90 households with a 40 kW nominal capacity micro-hydro system. The installation was accompanied by an extensive education program. Following the installation of the GridShares, the occurrence and average length of severe brownouts, which had been caused primarily by the use of electric cooking appliances during meal preparation, decreased by over 92%. Additionally, the majority of residents surveyed stated that now they are more certain that their rice will cook well and that they would recommend installing GridShares in other villages facing similar problems.

  5. SMART GRIDS LABORATORIES INVENTORY 2015

    OpenAIRE

    PONCELA BLANCO MARTA; PRETTICO GIUSEPPE; ANDREADOU NIKOLETA; OLARIAGA-GUARDIOLA Miguel; Fulli, Gianluca; COVRIG CATALIN-FELIX

    2015-01-01

    A smart electricity grid opens the door to a myriad of new applications aimed at enhancing security of supply, sustainability and market competitiveness. Gathering detailed information about smart grid laboratories activities represents a primary need. In order to obtain a better picture of the ongoing Smart Grid developments, after the successful smart grid project survey initiated in 2011, we recently launched a focused on-line survey addressed to organisations owning or running Smart Grid ...

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

    Directory of Open Access Journals (Sweden)

    Cheol-Hee Yoo

    2014-11-01

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

  7. A Globally Distributed Grid Monitoring System to Facilitate High-Performance Computing at D0/SAM-Grid

    Energy Technology Data Exchange (ETDEWEB)

    Rana, Abhishek S. [Texas U., Arlington

    2002-01-01

    A grid environment involves large scale sharing of resources that are distributed from a geographical or an administrative perspective. There is a need for systems that enable continuous discovery and monitoring of the components of a grid. In this work, we discuss the development and deployment of a monitoring system that has been designed as a prototype for the D0/SAM-Grid. We have developed a system that uses a layered architecture for information generation and processing, utilizes the various grid middleware tools, and implements Integration and Enquiry Protocols using existing Discovery Protocols to provide a user with a coherent view of all current activity in this grid - in the form of a web portal interface. The prototype system has been deployed for monitoring of 11 sites geographically distributed in 5 countries across 3 continents. This work focuses on the D0/SAM-Grid, and is based on the SAM system developed at Fermilab.

  8. SeGrid: A Secure Grid Framework for Sensor Networks

    Directory of Open Access Journals (Sweden)

    An Fengguang

    2006-01-01

    Full Text Available In this paper, we propose SeGrid, a secure framework for establishing grid keys in low duty cycle sensor networks, for which establishing a common key for each pair of neighboring sensors is unnecessary since most sensors remain in sleep mode at any instant of time. SeGrid intends to compute a shared key for two grids that may be multihop away. This design explores the fact that for most applications, closer grids have higher probability and desire for secure message exchange. SeGrid relies on the availability of a low-cost public cryptosystem. The query and update of the corresponding public shares are controlled by a novel management protocol such that the closer the two grids, the shorter the distance to obtain each other's public share. We instantiate SeGrid based on Blom's key establishment to illustrate the computation of a grid key.

  9. Grid and Entrepreneurship Workshop

    CERN Multimedia

    2006-01-01

    The CERN openlab is organising a special workshop about Grid opportunities for entrepreneurship. This one-day event will provide an overview of what is involved in spin-off technology, with a special reference to the context of computing and data Grids. Lectures by experienced entrepreneurs will introduce the key concepts of entrepreneurship and review, in particular, the industrial potential of EGEE (the EU co-funded Enabling Grids for E-sciencE project, led by CERN). Case studies will be given by CEOs of European start-ups already active in the Grid and computing cluster area, and regional experts will provide an overview of efforts in several European regions to stimulate entrepreneurship. This workshop is designed to encourage students and researchers involved or interested in Grid technology to consider the entrepreneurial opportunities that this technology may create in the coming years. This workshop is organized as part of the CERN openlab student programme, which is co-sponsored by CERN, HP, ...

  10. Hybrid and Monolithic Active Quasi-Optical Grids

    Science.gov (United States)

    de Lisio, Michael Peter, Jr.

    Quasi-optical grids combine the output powers of many solid state sources in free space, eliminating the conductor losses associated with traditional waveguide or transmission-line combiners. This approach shows most promise at millimeter-wave frequencies, where the outputs of thousands of devices could potentially be combined through wafer-scale integration. This thesis will detail three separate active quasi-optical grids. The first grid is a 16-element hybrid tunnel diode oscillator. This grid achieved a locked output frequency spectrum, with a peak Effective Radiated Power (ERP) of 1.3mW at 1.9GHz. This grid is a prototype for monolithic Resonant Tunneling Diode (RTD) grid oscillators, designed to operate from 200 to 500 GHz. The second grid is a 100-element hybrid pseudomorphic High Electron Mobility Transistor (pHEMT) amplifier. Modelling techniques, design procedure, and experimental results will be presented. This grid has a peak gain of 12 dB at 9 GHz, with a 15% 3-dB bandwidth. The output power, 3.7W, increases with the number of devices, while the noise figure, 3 dB, is similar to that of a single device. The third grid is a 36-element monolithic pHEMT amplifier. This grid has a peak gain of 6.5 dB at 44 GHz. By changing the positions of external polarizers and slabs, the grid can be tuned to operate up to 60 GHz with 2.5 dB gain. In addition, theoretical discussions of two topics relevant to active grids will be discussed. The first is a technique employing the method of moments and the induced emf technique to determine the electromagnetic properties of periodic grating structures. The second explores some thermal properties of quasi-optical grids.

  11. The Impact of the Topology on Cascading Failures in a Power Grid Model

    NARCIS (Netherlands)

    Koç, Y.; Warnier, M.; Van Mieghem, P.; Kooij, R.E.; Brazier, F.M.T.

    2014-01-01

    Cascading failures are one of the main reasons for large scale blackouts in power transmission grids. Secure electrical power supply requires, together with careful operation, a robust design of the electrical power grid topology. Currently, the impact of the topology on grid robustness is mainly

  12. Renewable Energy Zones: Delivering Clean Power to Meet Demand, Greening the Grid

    Energy Technology Data Exchange (ETDEWEB)

    Hurlbut, David; Chernyakhovskiy, Ilya; Cochran, Jaquelin

    2016-05-01

    Greening the Grid provides technical assistance to energy system planners, regulators, and grid operators to overcome challenges associated with integrating variable renewable energy into the grid. This document describes the renewable energy zone concept that has emerged as a transmission planning tool to help scale up the penetration of solar, wind, and other resources on the power system.

  13. AC HTS Transmission Cable for Integration into the Future EHV Grid of the Netherlands

    NARCIS (Netherlands)

    Zuijderduin, R.; Chevtchenko, O.; Smit, J.J.; Aanhaanen, G.; Melnik, I.; Geschiere, A.

    2012-01-01

    Due to increasing power demand, the electricity grid of the Netherlands is changing. The future grid must be capable to transmit all the connected power. Power generation will be more decentralized like for instance wind parks connected to the grid. Furthermore, future large scale production units

  14. How Does the Modular Organization of Entorhinal Grid Cells Develop?

    Directory of Open Access Journals (Sweden)

    Stephen eGrossberg

    2014-06-01

    Full Text Available The entorhinal-hippocampal system plays a crucial role in spatial cognition and navigation. Since the discovery of grid cells in layer II of medial entorhinal cortex (MEC, several types of models have been proposed to explain their development and operation; namely, continuous attractor network models, oscillatory interference models, and self-organizing map (SOM models. Recent experiments revealing the in vivo intracellular signatures of grid cells (Domnisoru et al., 2013; Schmidt-Heiber & Hausser, 2013, the primarily inhibitory recurrent connectivity of grid cells (Couey et al., 2013; Pastoll et al., 2013, and the topographic organization of grid cells within anatomically overlapping modules of multiple spatial scales along the dorsoventral axis of MEC (Stensola et al., 2012 provide strong constraints and challenges to existing grid cell models. This article provides a computational explanation for how MEC cells can emerge through learning with grid cell properties in modular structures. Within this SOM model, grid cells with different rates of temporal integration learn modular properties with different spatial scales. Model grid cells learn in response to inputs from multiple scales of directionally-selective stripe cells (Krupic et al., 2012; Mhatre et al., 2012 that perform path integration of the linear velocities that are experienced during navigation. Slower rates of grid cell temporal integration support learned associations with stripe cells of larger scales. The explanatory and predictive capabilities of the three types of grid cell models are comparatively analyzed in light of recent data to illustrate how the SOM model overcomes problems that other types of models have not yet handled.

  15. Smart Grid Architectures

    DEFF Research Database (Denmark)

    Dondossola, Giovanna; Terruggia, Roberta; Bessler, Sandford

    2014-01-01

    grids requiring the development of new Information and Communication Technology (ICT) solutions with various degrees of adaptation of the monitoring, communication and control technologies. The costs of ICT based solutions need however to be taken into account, hence it is desirable to work...... with existing communication networks. The objective of the European FP7 project SmartC2Net in this regard is to enable robust smart grid control utilizing heterogeneous third party communication infrastructures.......The scope of this paper is to address the evolution of distribution grid architectures following the widespread introduction of renewable energy sources. The increasing connection of distributed resources has a strong impact on the topology and the control functionality of the current distribution...

  16. Grid-Tied Photovoltaic Power System

    Science.gov (United States)

    Eichenberg, Dennis J.

    2011-01-01

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

  17. GridWise Standards Mapping Overview

    Energy Technology Data Exchange (ETDEWEB)

    Bosquet, Mia L.

    2004-04-01

    ''GridWise'' is a concept of how advanced communications, information and controls technology can transform the nation's energy system--across the spectrum of large scale, central generation to common consumer appliances and equipment--into a collaborative network, rich in the exchange of decision making information and an abundance of market-based opportunities (Widergren and Bosquet 2003) accompanying the electric transmission and distribution system fully into the information and telecommunication age. This report summarizes a broad review of standards efforts which are related to GridWise--those which could ultimately contribute significantly to advancements toward the GridWise vision, or those which represent today's current technological basis upon which this vision must build.

  18. Data Compression of Hydrocarbon Reservoir Simulation Grids

    KAUST Repository

    Chavez, Gustavo Ivan

    2015-05-28

    A dense volumetric grid coming from an oil/gas reservoir simulation output is translated into a compact representation that supports desired features such as interactive visualization, geometric continuity, color mapping and quad representation. A set of four control curves per layer results from processing the grid data, and a complete set of these 3-dimensional surfaces represents the complete volume data and can map reservoir properties of interest to analysts. The processing results yield a representation of reservoir simulation results which has reduced data storage requirements and permits quick performance interaction between reservoir analysts and the simulation data. The degree of reservoir grid compression can be selected according to the quality required, by adjusting for different thresholds, such as approximation error and level of detail. The processions results are of potential benefit in applications such as interactive rendering, data compression, and in-situ visualization of large-scale oil/gas reservoir simulations.

  19. Maturity grids as tools for change management

    DEFF Research Database (Denmark)

    Maier, Anja; Moultrie, James; Clarkson, P John

    2011-01-01

    A maturity grid is a change management tool. Levels of maturity are assigned against aspects of an area under study, thus creating a grid. Text descriptions at the resulting intersections describe the typical behaviour exhibited by a firm for each area under study and from the basis...... for the assessment scale. It is a flexible assessment technique that is used by practitioners in industry, consultants and researchers in academia for diagnostic, reflective and improvement purposes. A large number of maturity grids have been proposed to assess a range of capabilities including quality management......, software development, supplier relationships, R&D effectiveness, product development, innovation, product design, collaboration and communication. Each of these assessments focuses on a specific knowledge domain, and, as a result, is normally published in specialized journals relating to the domain...

  20. Job Scheduling in a Heterogeneous Grid Environment

    Science.gov (United States)

    Shan, Hong-Zhang; Smith, Warren; Oliker, Leonid; Biswas, Rupak

    2004-01-01

    Computational grids have the potential for solving large-scale scientific problems using heterogeneous and geographically distributed resources. However, a number of major technical hurdles must be overcome before this potential can be realized. One problem that is critical to effective utilization of computational grids is the efficient scheduling of jobs. This work addresses this problem by describing and evaluating a grid scheduling architecture and three job migration algorithms. The architecture is scalable and does not assume control of local site resources. The job migration policies use the availability and performance of computer systems, the network bandwidth available between systems, and the volume of input and output data associated with each job. An extensive performance comparison is presented using real workloads from leading computational centers. The results, based on several key metrics, demonstrate that the performance of our distributed migration algorithms is significantly greater than that of a local scheduling framework and comparable to a non-scalable global scheduling approach.

  1. Grid-added value to address malaria.

    Science.gov (United States)

    Breton, V; Jacq, N; Kasam, V; Hofmann-Apitius, M

    2008-03-01

    Through this paper, we call for a distributed, Internet-based collaboration to address one of the worst plagues of our present world, malaria. The spirit is a nonproprietary peer-production of information-embedding goods. And we propose to use the grid technology to enable such a worldwide "open-source" like collaboration. The first step toward this vision has been achieved during the summer 2005 on the enabling grids for E-scienceE (EGEE) grid infrastructure where 42 million ligands were docked for a total amount of 80 CPU years in 6 weeks in the quest for new drugs. The impact of this first deployment has significantly raised the interest of the research community so that several laboratories all around the world expressed interest to propose targets for a second large-scale deployment against malaria.

  2. Thermal Anemometry Grid Sensor

    Directory of Open Access Journals (Sweden)

    Martin Arlit

    2017-07-01

    Full Text Available A novel thermal anemometry grid sensor was developed for the simultaneous measurement of cross-sectional temperature and axial velocity distribution in a fluid flow. The sensor consists of a set of platinum resistors arranged in a regular grid. Each platinum resistor allows the simultaneous measurement of fluid temperature via electrical resistance and flow velocity via constant voltage thermal anemometry. Cross-sectional measurement was enabled by applying a special multiplexing-excitation scheme. In this paper, we present the design and characterization of a prototypical sensor for measurements in a range of very low velocities.

  3. Distributed photovoltaic grid transformers

    CERN Document Server

    Shertukde, Hemchandra Madhusudan

    2014-01-01

    The demand for alternative energy sources fuels the need for electric power and controls engineers to possess a practical understanding of transformers suitable for solar energy. Meeting that need, Distributed Photovoltaic Grid Transformers begins by explaining the basic theory behind transformers in the solar power arena, and then progresses to describe the development, manufacture, and sale of distributed photovoltaic (PV) grid transformers, which help boost the electric DC voltage (generally at 30 volts) harnessed by a PV panel to a higher level (generally at 115 volts or higher) once it is

  4. Instant jqGrid

    CERN Document Server

    Manricks, Gabriel

    2013-01-01

    Get to grips with a new technology, understand what it is and what it can do for you, and then get to work with the most important features and tasks. A step-by-step, practical Starter book, Instant jqGrid embraces you while you take your first steps, and introduces you to the content in an easy-to-follow order.This book is aimed at people who have some knowledge of HTML and JavaScript. Knowledge of PHP and SQL would also prove to be beneficial. No prior knowledge of jqGrid is expected.

  5. Grid zone drone

    OpenAIRE

    McCarthy, Clive; Cooper, Graham; Field, James; Thayne, Martyn; Vickers, Richard

    2014-01-01

    From 16th – 19th October 2014, co_LAB presented its newest creation, Grid Zone Drone, at Kinetica – an international exhibition providing a global platform for galleries, curatorial groups, design studios and artists working with new media art. 2014 marked the third consecutive year that the University of Lincoln has been represented at the global art fair. Grid Zone Drone represents a continuation of the group’s research into ‘drone culture’, and explores the detachment of the drone withi...

  6. Thermal Anemometry Grid Sensor.

    Science.gov (United States)

    Arlit, Martin; Schleicher, Eckhard; Hampel, Uwe

    2017-07-19

    A novel thermal anemometry grid sensor was developed for the simultaneous measurement of cross-sectional temperature and axial velocity distribution in a fluid flow. The sensor consists of a set of platinum resistors arranged in a regular grid. Each platinum resistor allows the simultaneous measurement of fluid temperature via electrical resistance and flow velocity via constant voltage thermal anemometry. Cross-sectional measurement was enabled by applying a special multiplexing-excitation scheme. In this paper, we present the design and characterization of a prototypical sensor for measurements in a range of very low velocities.

  7. Sustaining and Extending the Open Science Grid: Science Innovation on a PetaScale Nationwide Facility (DE-FC02-06ER41436) SciDAC-2 Closeout Report

    Energy Technology Data Exchange (ETDEWEB)

    Livny, Miron [Univ. of Wisconsin, Madison, WI (United States); Shank, James [Boston Univ., MA (United States); Ernst, Michael [Brookhaven National Lab. (BNL), Upton, NY (United States); Blackburn, Kent [California Inst. of Technology (CalTech), Pasadena, CA (United States); Goasguen, Sebastien [Clemson Univ., SC (United States); Tuts, Michael [Columbia Univ., New York, NY (United States); Gibbons, Lawrence [Cornell Univ., Ithaca, NY (United States); Pordes, Ruth [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Sliz, Piotr [Harvard Medical School, Boston, MA (United States); Deelman, Ewa [Univ. of Southern California, Los Angeles, CA (United States). Information Sciences Inst.; Barnett, William [Indiana Univ., Bloomington, IN (United States); Olson, Doug [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); McGee, John [Univ. of North Carolina, Chapel Hill, NC (United States). Renaissance Computing Inst.; Cowles, Robert [SLAC National Accelerator Lab., Menlo Park, CA (United States); Wuerthwein, Frank [Univ. of California, San Diego, CA (United States); Gardner, Robert [Univ. of Chicago, IL (United States); Avery, Paul [Univ. of Florida, Gainesville, FL (United States); Wang, Shaowen [Univ. of Illinois, Champaign, IL (United States); Univ. of Iowa, Iowa City, IA (United States); Lincoln, David Swanson [Univ. of Nebraska, Lincoln, NE (United States)

    2015-02-11

    Under this SciDAC-2 grant the project’s goal w a s t o stimulate new discoveries by providing scientists with effective and dependable access to an unprecedented national distributed computational facility: the Open Science Grid (OSG). We proposed to achieve this through the work of the Open Science Grid Consortium: a unique hands-on multi-disciplinary collaboration of scientists, software developers and providers of computing resources. Together the stakeholders in this consortium sustain and use a shared distributed computing environment that transforms simulation and experimental science in the US. The OSG consortium is an open collaboration that actively engages new research communities. We operate an open facility that brings together a broad spectrum of compute, storage, and networking resources and interfaces to other cyberinfrastructures, including the US XSEDE (previously TeraGrid), the European Grids for ESciencE (EGEE), as well as campus and regional grids. We leverage middleware provided by computer science groups, facility IT support organizations, and computing programs of application communities for the benefit of consortium members and the US national CI.

  8. Grid Computing Environment using a Beowulf Cluster

    Science.gov (United States)

    Alanis, Fransisco; Mahmood, Akhtar

    2003-10-01

    Custom-made Beowulf clusters using PCs are currently replacing expensive supercomputers to carry out complex scientific computations. At the University of Texas - Pan American, we built a 8 Gflops Beowulf Cluster for doing HEP research using RedHat Linux 7.3 and the LAM-MPI middleware. We will describe how we built and configured our Cluster, which we have named the Sphinx Beowulf Cluster. We will describe the results of our cluster benchmark studies and the run-time plots of several parallel application codes that were compiled in C on the cluster using the LAM-XMPI graphics user environment. We will demonstrate a "simple" prototype grid environment, where we will submit and run parallel jobs remotely across multiple cluster nodes over the internet from the presentation room at Texas Tech. University. The Sphinx Beowulf Cluster will be used for monte-carlo grid test-bed studies for the LHC-ATLAS high energy physics experiment. Grid is a new IT concept for the next generation of the "Super Internet" for high-performance computing. The Grid will allow scientist worldwide to view and analyze huge amounts of data flowing from the large-scale experiments in High Energy Physics. The Grid is expected to bring together geographically and organizationally dispersed computational resources, such as CPUs, storage systems, communication systems, and data sources.

  9. Essential Grid Workflow Monitoring Elements

    Energy Technology Data Exchange (ETDEWEB)

    Gunter, Daniel K.; Jackson, Keith R.; Konerding, David E.; Lee,Jason R.; Tierney, Brian L.

    2005-07-01

    Troubleshooting Grid workflows is difficult. A typicalworkflow involves a large number of components networks, middleware,hosts, etc. that can fail. Even when monitoring data from all thesecomponents is accessible, it is hard to tell whether failures andanomalies in these components are related toa given workflow. For theGrid to be truly usable, much of this uncertainty must be elim- inated.We propose two new Grid monitoring elements, Grid workflow identifiersand consistent component lifecycle events, that will make Gridtroubleshooting easier, and thus make Grids more usable, by simplifyingthe correlation of Grid monitoring data with a particular Gridworkflow.

  10. Enabling Campus Grids with Open Science Grid Technology

    Science.gov (United States)

    Weitzel, Derek; Bockelman, Brian; Fraser, Dan; Pordes, Ruth; Swanson, David

    2011-12-01

    The Open Science Grid is a recognized key component of the US national cyber-infrastructure enabling scientific discovery through advanced high throughput computing. The principles and techniques that underlie the Open Science Grid can also be applied to Campus Grids since many of the requirements are the same, even if the implementation technologies differ. We find five requirements for a campus grid: trust relationships, job submission, resource independence, accounting, and data management. The Holland Computing Center's campus grid at the University of Nebraska-Lincoln was designed to fulfill the requirements of a campus grid. A bridging daemon was designed to bring non-Condor clusters into a grid managed by Condor. Condor features which make it possible to bridge Condor sites into a multi-campus grid have been exploited at the Holland Computing Center as well.

  11. Changing from computing grid to knowledge grid in life-science grid.

    Science.gov (United States)

    Talukdar, Veera; Konar, Amit; Datta, Ayan; Choudhury, Anamika Roy

    2009-09-01

    Grid computing has a great potential to become a standard cyber infrastructure for life sciences that often require high-performance computing and large data handling, which exceeds the computing capacity of a single institution. Grid computer applies the resources of many computers in a network to a single problem at the same time. It is useful to scientific problems that require a great number of computer processing cycles or access to a large amount of data.As biologists,we are constantly discovering millions of genes and genome features, which are assembled in a library and distributed on computers around the world.This means that new, innovative methods must be developed that exploit the re-sources available for extensive calculations - for example grid computing.This survey reviews the latest grid technologies from the viewpoints of computing grid, data grid and knowledge grid. Computing grid technologies have been matured enough to solve high-throughput real-world life scientific problems. Data grid technologies are strong candidates for realizing a "resourceome" for bioinformatics. Knowledge grids should be designed not only from sharing explicit knowledge on computers but also from community formulation for sharing tacit knowledge among a community. By extending the concept of grid from computing grid to knowledge grid, it is possible to make use of a grid as not only sharable computing resources, but also as time and place in which people work together, create knowledge, and share knowledge and experiences in a community.

  12. Ten questions concerning integrating smart buildings into the smart grid

    Energy Technology Data Exchange (ETDEWEB)

    Lawrence, Thomas M.; Boudreau, Marie-Claude; Helsen, Lieve; Henze, Gregor; Mohammadpour, Javad; Noonan, Doug; Patteeuw, Dieter; Pless, Shanti; Watson, Richard T.

    2016-11-01

    Recent advances in information and communications technology (ICT) have initiated development of a smart electrical grid and smart buildings. Buildings consume a large portion of the total electricity production worldwide, and to fully develop a smart grid they must be integrated with that grid. Buildings can now be 'prosumers' on the grid (both producers and consumers), and the continued growth of distributed renewable energy generation is raising new challenges in terms of grid stability over various time scales. Buildings can contribute to grid stability by managing their overall electrical demand in response to current conditions. Facility managers must balance demand response requests by grid operators with energy needed to maintain smooth building operations. For example, maintaining thermal comfort within an occupied building requires energy and, thus an optimized solution balancing energy use with indoor environmental quality (adequate thermal comfort, lighting, etc.) is needed. Successful integration of buildings and their systems with the grid also requires interoperable data exchange. However, the adoption and integration of newer control and communication technologies into buildings can be problematic with older legacy HVAC and building control systems. Public policy and economic structures have not kept up with the technical developments that have given rise to the budding smart grid, and further developments are needed in both technical and non-technical areas.

  13. Unlocking the smart grid

    Energy Technology Data Exchange (ETDEWEB)

    Rokach, Joshua Z.

    2010-10-15

    The country has progressed in a relatively short time from rotary dial phones to computers, cell phones, and iPads. With proper planning and orderly policy implementation, the same will happen with the Smart Grid. Here are some suggestions on how to proceed. (author)

  14. Kids Enjoy Grids

    CERN Multimedia

    2007-01-01

    I want to come back and work here when I'm older,' was the spontaneous reaction of one of the children invited to CERN by the Enabling Grids for E-sciencE project for a 'Grids for Kids' day at the end of January. The EGEE project is led by CERN, and the EGEE gender action team organized the day to introduce children to grid technology at an early age. The school group included both boys and girls, aged 9 to 11. All of the presenters were women. 'In general, before this visit, the children thought that scientists always wore white coats and were usually male, with wild Einstein-like hair,' said Jackie Beaver, the class's teacher at the Institut International de Lancy, a school near Geneva. 'They were surprised and pleased to see that women became scientists, and that scientists were quite 'normal'.' The half-day event included presentations about why Grids are needed, a visit of the computer centre, some online games, and plenty of time for questions. In the end, everyone agreed that it was a big success a...

  15. Ohio Bouguer Gravity Grid

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A 2 kilometer Bouguer anomaly grid for the state of Ohio. Number of columns is 187 and number of rows is 217. The order of the data is from the lower left to the...

  16. Utah Bouguer Gravity Grid

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A 2.5 kilometer Bouguer anomaly grid for the state of Utah. Number of columns is 196 and number of rows is 245. The order of the data is from the lower left to the...

  17. Maine Bouguer Gravity Grid

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A 2 kilometer Bouguer anomaly grid for the state of Maine. Number of columns is 197 and number of rows is 292. The order of the data is from the lower left to the...

  18. Bolivian Bouguer Anomaly Grid

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A 1 kilometer Bouguer anomaly grid for the country of Bolivia.Number of columns is 550 and number of rows is 900. The order of the data is from the lower left to the...

  19. Molecular Grid Membranes

    National Research Council Canada - National Science Library

    Michl, Josef; Magnera, Thomas

    2008-01-01

    ...) porphyrin triply linked in the meso-meso, and both beta-beta positions four times by carbon-carbon bonds to each of its neighbors to form porphite sheets a grid-type material that would be an analog of graphene...

  20. Modelling Chinese Smart Grid

    DEFF Research Database (Denmark)

    Yuksel, Ender; Nielson, Hanne Riis; Nielson, Flemming

    In this document, we consider a specific Chinese Smart Grid implementation and try to address the verification problem for certain quantitative properties including performance and battery consumption. We employ stochastic model checking approach and present our modelling and analysis study using...

  1. NSTAR Smart Grid Pilot

    Energy Technology Data Exchange (ETDEWEB)

    Rabari, Anil [NSTAR Electric, Manchester, NH (United States); Fadipe, Oloruntomi [NSTAR Electric, Manchester, NH (United States)

    2014-03-31

    NSTAR Electric & Gas Corporation (“the Company”, or “NSTAR”) developed and implemented a Smart Grid pilot program beginning in 2010 to demonstrate the viability of leveraging existing automated meter reading (“AMR”) deployments to provide much of the Smart Grid functionality of advanced metering infrastructure (“AMI”), but without the large capital investment that AMI rollouts typically entail. In particular, a central objective of the Smart Energy Pilot was to enable residential dynamic pricing (time-of-use “TOU” and critical peak rates and rebates) and two-way direct load control (“DLC”) by continually capturing AMR meter data transmissions and communicating through customer-sited broadband connections in conjunction with a standardsbased home area network (“HAN”). The pilot was supported by the U.S. Department of Energy’s (“DOE”) through the Smart Grid Demonstration program. NSTAR was very pleased to not only receive the funding support from DOE, but the guidance and support of the DOE throughout the pilot. NSTAR is also pleased to report to the DOE that it was able to execute and deliver a successful pilot on time and on budget. NSTAR looks for future opportunities to work with the DOE and others in future smart grid projects.

  2. Nevada Isostatic Gravity Grid

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A 2 kilometer Isostatic anomaly grid for the state of Nevada. Number of columns is 269 and number of rows is 394. The order of the data is from the lower left to the...

  3. Grid interoperability the interoperations cookbook

    CERN Document Server

    Field, L

    2008-01-01

    Over recent years a number of grid projects have emerged which have built grid infrastructures that are now the computing backbones for various user communities. A significant number of these communities are limited to one grid infrastructure due to the different middleware and procedures used in each grid. Grid interoperation is trying to bridge these differences and enable virtual organizations to access resources independent of the grid project affiliation. This paper gives an overview of grid interoperation and describes the current methods used to bridge the differences between grids. Actual use cases encountered during the last three years are discussed and the most important interfaces required for interoperability are highlighted. A summary of the standardisation efforts in these areas is given and we argue for moving more aggressively towards standards.

  4. Allegheny County Map Index Grid

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — Map Index Sheets from Block and Lot Grid of Property Assessment and based on aerial photography, showing 1983 datum with solid line and NAD 27 with 5 second grid...

  5. HIRENASD Unstructured Grids - Centaur software

    Data.gov (United States)

    National Aeronautics and Space Administration — These grids were constructed using Centaur software at DLR in Germany. The grids designed for node based (labeled 'cv') and cell-centered solvers (labeled 'cc') are...

  6. Cloud Computing and Smart Grids

    Directory of Open Access Journals (Sweden)

    Janina POPEANGĂ

    2012-10-01

    Full Text Available Increasing concern about energy consumption is leading to infrastructure that supports real-time, two-way communication between utilities and consumers, and allows software systems at both ends to control and manage power use. To manage communications to millions of endpoints in a secure, scalable and highly-available environment and to achieve these twin goals of ‘energy conservation’ and ‘demand response’, utilities must extend the same communication network management processes and tools used in the data center to the field.This paper proposes that cloud computing technology, because of its low cost, flexible and redundant architecture and fast response time, has the functionality needed to provide the security, interoperability and performance required for large-scale smart grid applications.

  7. Communication technologies in smart grid

    Directory of Open Access Journals (Sweden)

    Miladinović Nikola

    2013-01-01

    Full Text Available The role of communication technologies in Smart Grid lies in integration of large number of devices into one telecommunication system. This paper provides an overview of the technologies currently in use in electric power grid, that are not necessarily in compliance with the Smart Grid concept. Considering that the Smart Grid is open to the flow of information in all directions, it is necessary to provide reliability, protection and security of information.

  8. Communication technologies in smart grid

    OpenAIRE

    Miladinović Nikola; Polužanski Vladimir; Milosavljević Srđan

    2013-01-01

    The role of communication technologies in Smart Grid lies in integration of large number of devices into one telecommunication system. This paper provides an overview of the technologies currently in use in electric power grid, that are not necessarily in compliance with the Smart Grid concept. Considering that the Smart Grid is open to the flow of information in all directions, it is necessary to provide reliability, protection and security of information.

  9. GridOrbit public display

    DEFF Research Database (Denmark)

    Ramos, Juan David Hincapie; Tabard, Aurélien; Bardram, Jakob

    2010-01-01

    the research taking place in the biology laboratory. This should promote contribu-tions to the grid, and thereby mediate the appropriation of the grid technology. GridOrbit visualizes the activity in the grid, shows information about the different active projects, and supports a messaging functionality where...... people comment on projects. Our work explores the usage of interactive technologies as enablers for the appropriation of an otherwise invisible infrastructure....

  10. Grid3: An Application Grid Laboratory for Science

    CERN Multimedia

    CERN. Geneva

    2004-01-01

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

  11. Two-Dimensional Vernier Scale

    Science.gov (United States)

    Juday, Richard D.

    1992-01-01

    Modified vernier scale gives accurate two-dimensional coordinates from maps, drawings, or cathode-ray-tube displays. Movable circular overlay rests on fixed rectangular-grid overlay. Pitch of circles nine-tenths that of grid and, for greatest accuracy, radii of circles large compared with pitch of grid. Scale enables user to interpolate between finest divisions of regularly spaced rule simply by observing which mark on auxiliary vernier rule aligns with mark on primary rule.

  12. Load Balancing Strategies for Multi-Block Overset Grid Applications

    Science.gov (United States)

    Djomehri, M. Jahed; Biswas, Rupak; Lopez-Benitez, Noe; Biegel, Bryan (Technical Monitor)

    2002-01-01

    The multi-block overset grid method is a powerful technique for high-fidelity computational fluid dynamics (CFD) simulations about complex aerospace configurations. The solution process uses a grid system that discretizes the problem domain by using separately generated but overlapping structured grids that periodically update and exchange boundary information through interpolation. For efficient high performance computations of large-scale realistic applications using this methodology, the individual grids must be properly partitioned among the parallel processors. Overall performance, therefore, largely depends on the quality of load balancing. In this paper, we present three different load balancing strategies far overset grids and analyze their effects on the parallel efficiency of a Navier-Stokes CFD application running on an SGI Origin2000 machine.

  13. Cognitive Radio for Smart Grid with Security Considerations

    Directory of Open Access Journals (Sweden)

    Khaled Shuaib

    2016-04-01

    Full Text Available In this paper, we investigate how Cognitive Radio as a means of communication can be utilized to serve a smart grid deployment end to end, from a home area network to power generation. We show how Cognitive Radio can be mapped to integrate the possible different communication networks within a smart grid large scale deployment. In addition, various applications in smart grid are defined and discussed showing how Cognitive Radio can be used to fulfill their communication requirements. Moreover, information security issues pertained to the use of Cognitive Radio in a smart grid environment at different levels and layers are discussed and mitigation techniques are suggested. Finally, the well-known Role-Based Access Control (RBAC is integrated with the Cognitive Radio part of a smart grid communication network to protect against unauthorized access to customer’s data and to the network at large.

  14. Smart Grid Demonstration Project

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Craig [National Rural Electric Cooperative Association, Arlington, VA (United States); Carroll, Paul [National Rural Electric Cooperative Association, Arlington, VA (United States); Bell, Abigail [National Rural Electric Cooperative Association, Arlington, VA (United States)

    2015-03-11

    The National Rural Electric Cooperative Association (NRECA) organized the NRECA-U.S. Department of Energy (DOE) Smart Grid Demonstration Project (DE-OE0000222) to install and study a broad range of advanced smart grid technologies in a demonstration that spanned 23 electric cooperatives in 12 states. More than 205,444 pieces of electronic equipment and more than 100,000 minor items (bracket, labels, mounting hardware, fiber optic cable, etc.) were installed to upgrade and enhance the efficiency, reliability, and resiliency of the power networks at the participating co-ops. The objective of this project was to build a path for other electric utilities, and particularly electrical cooperatives, to adopt emerging smart grid technology when it can improve utility operations, thus advancing the co-ops’ familiarity and comfort with such technology. Specifically, the project executed multiple subprojects employing a range of emerging smart grid technologies to test their cost-effectiveness and, where the technology demonstrated value, provided case studies that will enable other electric utilities—particularly electric cooperatives— to use these technologies. NRECA structured the project according to the following three areas: Demonstration of smart grid technology; Advancement of standards to enable the interoperability of components; and Improvement of grid cyber security. We termed these three areas Technology Deployment Study, Interoperability, and Cyber Security. Although the deployment of technology and studying the demonstration projects at coops accounted for the largest portion of the project budget by far, we see our accomplishments in each of the areas as critical to advancing the smart grid. All project deliverables have been published. Technology Deployment Study: The deliverable was a set of 11 single-topic technical reports in areas related to the listed technologies. Each of these reports has already been submitted to DOE, distributed to co-ops, and

  15. Wireless Communications in Smart Grid

    Science.gov (United States)

    Bojkovic, Zoran; Bakmaz, Bojan

    Communication networks play a crucial role in smart grid, as the intelligence of this complex system is built based on information exchange across the power grid. Wireless communications and networking are among the most economical ways to build the essential part of the scalable communication infrastructure for smart grid. In particular, wireless networks will be deployed widely in the smart grid for automatic meter reading, remote system and customer site monitoring, as well as equipment fault diagnosing. With an increasing interest from both the academic and industrial communities, this chapter systematically investigates recent advances in wireless communication technology for the smart grid.

  16. The Grid PC farm

    CERN Multimedia

    Maximilien Brice

    2006-01-01

    Housed in the CERN Computer Centre, these banks of computers process and store data produced on the CERN systems. When the LHC starts operation in 2008, it will produce enough data every year to fill a stack of CDs 20 km tall. To handle this huge amount of data, CERN has also developed the Grid, allowing processing power to be shared between computer centres around the world.

  17. Edge domination in grids

    DEFF Research Database (Denmark)

    Klostermeyer, William F.; Yeo, Anders

    2015-01-01

    It has been conjectured that the edge domination number of the m × n grid graph, denoted by γ′(Pm□Pn), is ⌊mn/3⌋, when m,n ≥ 2. Our main result gives support for this conjecture by proving that ⌊mn/3⌋ ≤ -γ′{Pm□Pn) ≤ mn/3 + n/12 + 1, when m,n ≥ 2. We furthermore show that the conjecture holds when...

  18. Grid computing for electromagnetics

    CERN Document Server

    Tarricone, Luciano

    2004-01-01

    Today, more and more practitioners, researchers, and students are utilizing the power and efficiency of grid computing for their increasingly complex electromagnetics applications. This cutting-edge book offers you the practical and comprehensive guidance you need to use this new approach to supercomputing for your challenging projects. Supported with over 110 illustrations, the book clearly describes a high-performance, low-cost method to solving huge numerical electromagnetics problems.

  19. Grid generated turbulence in the near-field

    Science.gov (United States)

    Salazar, Ricardo; Isaza, Juan; Warhaft, Zellman

    2014-11-01

    Using a conventional bi-planar turbulence-generating grid, we confirm the recent findings (Valente & Vassilicos, Phys. Rev. Lett. 108, 214503 (2012)) that show there is a turbulence decay region close to the generating grid that departs from the ``classical'' turbulence decay (Comte-Bellot & Corrsin, J. Fluid Mech. 25, 657 (1966)). In this ``near field'' region, the turbulence energy decays more rapidly than in the far field and it exhibits unusual scaling properties. Based on the velocity decay laws, we show that for our conventional grid, the near field extends from x/M ~ 6 to x/M ~ 12 where x is the downstream distance from the grid and M is the mesh size. However, other statistics (velocity derivatives and length scales ratios) indicate that the extent of the initial period depends on the grid mesh Reynolds number, RM, extending further for higher values of RM. In the near field the turbulence approaches isotropy both at the large and small scales but there still is inhomogeneity in the derivative statistics. The derivative skewness also departs from values observed at comparable Reynolds numbers in the far field decay region, and in other turbulent flows at comparable Reynolds numbers. We do not believe that the near field scaling violates Kolmogorov phenomenology, which applies to systems that are not affected by proximity to initial and boundary conditions. These conditions are not met close to the grid.

  20. A novel algorithm for incompressible flow using only a coarse grid projection

    KAUST Repository

    Lentine, Michael

    2010-07-26

    Large scale fluid simulation can be difficult using existing techniques due to the high computational cost of using large grids. We present a novel technique for simulating detailed fluids quickly. Our technique coarsens the Eulerian fluid grid during the pressure solve, allowing for a fast implicit update but still maintaining the resolution obtained with a large grid. This allows our simulations to run at a fraction of the cost of existing techniques while still providing the fine scale structure and details obtained with a full projection. Our algorithm scales well to very large grids and large numbers of processors, allowing for high fidelity simulations that would otherwise be intractable. © 2010 ACM.

  1. Resilient Grid Operational Strategies

    Energy Technology Data Exchange (ETDEWEB)

    Pasqualini, Donatella [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-03-01

    Extreme weather-related disturbances, such as hurricanes, are a leading cause of grid outages historically. Although physical asset hardening is perhaps the most common way to mitigate the impacts of severe weather, operational strategies may be deployed to limit the extent of societal and economic losses associated with weather-related physical damage.1 The purpose of this study is to examine bulk power-system operational strategies that can be deployed to mitigate the impact of severe weather disruptions caused by hurricanes, thereby increasing grid resilience to maintain continuity of critical infrastructure during extreme weather. To estimate the impacts of resilient grid operational strategies, Los Alamos National Laboratory (LANL) developed a framework for hurricane probabilistic risk analysis (PRA). The probabilistic nature of this framework allows us to estimate the probability distribution of likely impacts, as opposed to the worst-case impacts. The project scope does not include strategies that are not operations related, such as transmission system hardening (e.g., undergrounding, transmission tower reinforcement and substation flood protection) and solutions in the distribution network.

  2. Modern Grid Initiative Distribution Taxonomy Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, Kevin P.; Chen, Yousu; Chassin, David P.; Pratt, Robert G.; Engel, David W.; Thompson, Sandra E.

    2008-11-01

    This is the final report for the development of a toxonomy of prototypical electrical distribution feeders. Two of the primary goals of the Department of Energy's (DOE) Modern Grid Initiative (MGI) are 'to accelerate the modernization of our nation's electricity grid' and to 'support demonstrations of systems of key technologies that can serve as the foundation for an integrated, modern power grid'. A key component to the realization of these goals is the effective implementation of new, as well as existing, 'smart grid technologies'. Possibly the largest barrier that has been identified in the deployment of smart grid technologies is the inability to evaluate how their deployment will affect the electricity infrastructure, both locally and on a regional scale. The inability to evaluate the impacts of these technologies is primarily due to the lack of detailed electrical distribution feeder information. While detailed distribution feeder information does reside with the various distribution utilities, there is no central repository of information that can be openly accessed. The role of Pacific Northwest National Laboratory (PNNL) in the MGI for FY08 was to collect distribution feeder models, in the SynerGEE{reg_sign} format, from electric utilities around the nation so that they could be analyzed to identify regional differences in feeder design and operation. Based on this analysis PNNL developed a taxonomy of 24 prototypical feeder models in the GridLAB-D simulations environment that contain the fundamental characteristics of non-urban core, radial distribution feeders from the various regions of the U.S. Weighting factors for these feeders are also presented so that they can be used to generate a representative sample for various regions within the United States. The final product presented in this report is a toolset that enables the evaluation of new smart grid technologies, with the ability to aggregate their effects

  3. Fundamentals of grid computing theory, algorithms and technologies

    CERN Document Server

    2010-01-01

    This volume discusses how the novel technologies of semantic web and workflow have been integrated into the grid and grid services. It focuses on sharing resources, data replication, data management, fault tolerance, scheduling, broadcasting, and load balancing algorithms. The book discusses emerging developments in grid computing, including cloud computing, and explores large-scale computing in high energy physics, weather forecasting, and more. The contributors often use simulations to evaluate the performance of models and algorithms. In the appendices, they present two types of easy-to-use open source software written in Java

  4. Flames in fractal grid generated turbulence

    Energy Technology Data Exchange (ETDEWEB)

    Goh, K H H; Hampp, F; Lindstedt, R P [Department of Mechanical Engineering, Imperial College, London SW7 2AZ (United Kingdom); Geipel, P, E-mail: p.lindstedt@imperial.ac.uk [Siemens Industrial Turbomachinery AB, SE-612 83 Finspong (Sweden)

    2013-12-15

    Twin premixed turbulent opposed jet flames were stabilized for lean mixtures of air with methane and propane in fractal grid generated turbulence. A density segregation method was applied alongside particle image velocimetry to obtain velocity and scalar statistics. It is shown that the current fractal grids increase the turbulence levels by around a factor of 2. Proper orthogonal decomposition (POD) was applied to show that the fractal grids produce slightly larger turbulent structures that decay at a slower rate as compared to conventional perforated plates. Conditional POD (CPOD) was also implemented using the density segregation technique and the results show that CPOD is essential to segregate the relative structures and turbulent kinetic energy distributions in each stream. The Kolmogorov length scales were also estimated providing values {approx}0.1 and {approx}0.5 mm in the reactants and products, respectively. Resolved profiles of flame surface density indicate that a thin flame assumption leading to bimodal statistics is not perfectly valid under the current conditions and it is expected that the data obtained will be of significant value to the development of computational methods that can provide information on the conditional structure of turbulence. It is concluded that the increase in the turbulent Reynolds number is without any negative impact on other parameters and that fractal grids provide a route towards removing the classical problem of a relatively low ratio of turbulent to bulk strain associated with the opposed jet configuration. (paper)

  5. Financial Derivatives Market for Grid Computing

    CERN Document Server

    Aubert, David; Lindset, Snorre; Huuse, Henning

    2007-01-01

    This Master thesis studies the feasibility and properties of a financial derivatives market on Grid computing, a service for sharing computing resources over a network such as the Internet. For the European Organization for Nuclear Research (CERN) to perform research with the world's largest and most complex machine, the Large Hadron Collider (LHC), Grid computing was developed to handle the information created. In accordance with the mandate of CERN Technology Transfer (TT) group, this thesis is a part of CERN's dissemination of the Grid technology. The thesis gives a brief overview of the use of the Grid technology and where it is heading. IT trend analysts and large-scale IT vendors see this technology as key in transforming the world of IT. They predict that in a matter of years, IT will be bought as a service, instead of a good. Commoditization of IT, delivered as a service, is a paradigm shift that will have a broad impact on all parts of the IT market, as well as on the society as a whole. Political, e...

  6. New Science on the Open Science Grid

    CERN Document Server

    Board, The Open Science Grid Executive; Pordes, Ruth; Altunay, Mine; Avery, Paul; Bejan, Alina; Blackburn, Kent; Blatecky, Alan; Gardner, Rob; Kramer, Bill; Livny, Miron; McGee, John; Potekhin, Maxim; Quick, Rob; Olson, Doug; Roy, Alain; Sehgal, Chander; Wenaus, Torre; Wilde, Mike; Wuerthwein, Frank

    2012-01-01

    The Open Science Grid (OSG) includes work to enable new science, new scientists, and new modalities in support of computationally based research. There are frequently significant sociological and organizational changes required in transformation from the existing to the new. OSG leverages its deliverables to the large scale physics experiment member communities to benefit new communities at all scales through activities in education, engagement and the distributed facility. As a partner to the poster and tutorial at SciDAC 2008, this paper gives both a brief general description and some specific examples of new science enabled on the OSG. More information is available at the OSG web site: (http://www.opensciencegrid.org).

  7. 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.

  8. The Knowledge Grid

    CERN Document Server

    Zhuge, Hai

    2004-01-01

    The Knowledge Grid is an intelligent and sustainable interconnection environment that enables people and machines to effectively capture, publish, share and manage knowledge resources. It also provides appropriate on-demand services to support scientific research, technological innovation, cooperative teamwork, problem solving, and decision making. It incorporates epistemology and ontology to reflect human cognitive characteristics; exploits social, ecological and economic principles; and adopts techniques and standards developed during work toward the future web. This book presents its methodology, theory, models and applications systematically for the first time.

  9. Smart grids and e-mobility

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    Within the third European Conference at 17th-18th October, 2011 in Munich (Federal Republic of Germany) the following lectures and posters were presented: (1) Market and billing models for electric mobility (M. Bolczek); (2) Optimal pooling of electric vehicles for ancillary markets under consideration of uncertain parameters (T. Pollok); (3) Introducing human factors psychology to vehicle-to-grid technologies (U. Hahnel); (4) The role of smart sensor networks for voltage monitoring in smart grids (P. Stoea); (5) Evaluating the impacts of electric vehicles and micro-generation in distribution networks (F. Soares); (6) Electric cars as energy storages - case study from Nordic Country (J. Lussia); (7) Are battery electric vehicles competitive? - The development of a customer value-based model (R. Colmon); (8) Technical and commercial protocol for different bidirectional integration topologies (P. Benoit); (9) The use of electric vehicles in Greece: A case study (C. Ioakimidis); (10) Fast charging station business analysis (J. Borges); (11) Power distribution networks: Intelligent substations (S2G) (M.E. Hervas); (12) Optimal design and energy management of decentralized PV-power supply units with short-term and long-term energy storage path (T. Bocklisch); (13) Easy grid analysis method for a central observing and controlling system in the low voltage grid for E-Mobility and renewable integration (A. Schuser); (14) Smart grids and EU data protection law - What is the legal framework? (J. Hladjk); (15) Smart integration of electric vehicles (A. Niesse); (16) Smart standards for smart grid devices (G. Kaestle); (17) Driving ambition: Bridging the gap between electric vehicles and smart metering (A. Galdos); (18) Analysis of an electric vehicle agent based management model (P. Papadopoulos); (19) Assessing the potential of electric vehicles and photovoltaics in a smart-grid environment in Brazil (R. Ruether); (20) Opportunities and challenges with large scale

  10. Multiscale image processing and antiscatter grids in digital radiography.

    Science.gov (United States)

    Lo, Winnie Y; Hornof, William J; Zwingenberger, Allison L; Robertson, Ian D

    2009-01-01

    Scatter radiation is a source of noise and results in decreased signal-to-noise ratio and thus decreased image quality in digital radiography. We determined subjectively whether a digitally processed image made without a grid would be of similar quality to an image made with a grid but without image processing. Additionally the effects of exposure dose and of a using a grid with digital radiography on overall image quality were studied. Thoracic and abdominal radiographs of five dogs of various sizes were made. Four acquisition techniques were included (1) with a grid, standard exposure dose, digital image processing; (2) without a grid, standard exposure dose, digital image processing; (3) without a grid, half the exposure dose, digital image processing; and (4) with a grid, standard exposure dose, no digital image processing (to mimic a film-screen radiograph). Full-size radiographs as well as magnified images of specific anatomic regions were generated. Nine reviewers rated the overall image quality subjectively using a five-point scale. All digitally processed radiographs had higher overall scores than nondigitally processed radiographs regardless of patient size, exposure dose, or use of a grid. The images made at half the exposure dose had a slightly lower quality than those made at full dose, but this was only statistically significant in magnified images. Using a grid with digital image processing led to a slight but statistically significant increase in overall quality when compared with digitally processed images made without a grid but whether this increase in quality is clinically significant is unknown.

  11. Market aspects of smart power grids development

    Directory of Open Access Journals (Sweden)

    Maciej Makowski

    2012-03-01

    Full Text Available Smart Grids herald a revolution in the power sector. The centralized and passive power grid model known for over a century is before our very eyes assuming a completely brand new shape: of an active and dynamic network with an increasingly relevant role of consumers – prosumers, who are offered brand new products and services. Such an active development is possible due to a number of factors, such as: 1. Synergy of ICT with power engineering – these disciplines are becoming an indispensable element of the modern power grid’s operation, 2. The European Union’s regulations in the area of reduction of CO2 emission and improved energy efficiency, as well as identification of Smart Grids as one of the optimum tools, 3. Growth, thanks to continuously increasing expenditures, public awareness of the purchase and rational use of energy. However, the Smart Grid development and ICT implementation in the power sector also carry a risk in the matter of setting up system and process links between the systems of concerned energy market players, which should be mitigated by development of technical standards, methods and principles of good cooperation between the concerned parties. Mitigation of the risk, and as a consequence, effective Smart Grids development will provide conditions for dynamic development of new roles and mechanisms on the energy market. Offering modern products and services to consumers and prosumers, and effective implementation on a national scale of demand management mechanisms will be a source of multidimensional benefits of a functional and financial nature, and will also have a positive impact on the National Lower Grid’s security.

  12. High Quality Data for Grid Integration Studies

    Energy Technology Data Exchange (ETDEWEB)

    Clifton, Andrew; Draxl, Caroline; Sengupta, Manajit; Hodge, Bri-Mathias

    2017-01-22

    As variable renewable power penetration levels increase in power systems worldwide, renewable integration studies are crucial to ensure continued economic and reliable operation of the power grid. The existing electric grid infrastructure in the US in particular poses significant limitations on wind power expansion. In this presentation we will shed light on requirements for grid integration studies as far as wind and solar energy are concerned. Because wind and solar plants are strongly impacted by weather, high-resolution and high-quality weather data are required to drive power system simulations. Future data sets will have to push limits of numerical weather prediction to yield these high-resolution data sets, and wind data will have to be time-synchronized with solar data. Current wind and solar integration data sets are presented. The Wind Integration National Dataset (WIND) Toolkit is the largest and most complete grid integration data set publicly available to date. A meteorological data set, wind power production time series, and simulated forecasts created using the Weather Research and Forecasting Model run on a 2-km grid over the continental United States at a 5-min resolution is now publicly available for more than 126,000 land-based and offshore wind power production sites. The National Solar Radiation Database (NSRDB) is a similar high temporal- and spatial resolution database of 18 years of solar resource data for North America and India. The need for high-resolution weather data pushes modeling towards finer scales and closer synchronization. We also present how we anticipate such datasets developing in the future, their benefits, and the challenges with using and disseminating such large amounts of data.

  13. Compressed air energy storage in offshore grids

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, S.T.; Meibom, P. (Technical Univ. of Denmark (DTU). Risoe National Lab. for Sustainable Energy, Roskilde (Denmark)); Crotogino, F.; Donadei, S. (KBB Underground Technologies, Hanover (Germany))

    2011-05-15

    Fluctuating renewable energy sources can be rendered more reliable by massive international grid extensions and by energy storages. The latter ones are partially discussed as offshore grids to combine the grid connection of offshore wind parks with international power trading. This paper gives a first assessment of offshore energy storage possibilities. Compressed air energy storage (CAES) is a technology that has been used successfully onshore for decades and is the most economic large-scale storage option after pumped hydro. More efficient adiabatic CAES is under development. At the same time, the oil and gas offshore industry provides enough experience to state that a CAES power plant could be installed and operated offshore even though at considerable higher costs. Suitable salt formations for the salt caverns exist in and around the North Sea and to a lower extent the Baltic Sea. Offshore energy storage can facilitate several issues in an offshore grid: firstly, it can delay or even replace the necessity for building interconnectors due to additional wind or wave power. Secondly, it can balance generation deviations due to forecast errors. Depending on market design, these have a negative effect on offshore generation or interconnector operation. Balancing forecast errors could allow operating the interconnectors in a more reliable and thus, more profitable way. If the offshore grid is considered a single price zone between countries, a storage has a lowering effect on electricity price volatility. The WILMAR planning tool is used to estimate these effects. Comparing onshore and offshore CAES, it is concluded that an an offshore adiabatic CAES can participate in several markets, but that this advantage is outweighed by an onshore unit's ability to provide spinning reserves. (Author)

  14. Smart Grid Enabled EVSE

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2015-01-12

    The combined team of GE Global Research, Federal Express, National Renewable Energy Laboratory, and Consolidated Edison has successfully achieved the established goals contained within the Department of Energy’s Smart Grid Capable Electric Vehicle Supply Equipment funding opportunity. The final program product, shown charging two vehicles in Figure 1, reduces by nearly 50% the total installed system cost of the electric vehicle supply equipment (EVSE) as well as enabling a host of new Smart Grid enabled features. These include bi-directional communications, load control, utility message exchange and transaction management information. Using the new charging system, Utilities or energy service providers will now be able to monitor transportation related electrical loads on their distribution networks, send load control commands or preferences to individual systems, and then see measured responses. Installation owners will be able to authorize usage of the stations, monitor operations, and optimally control their electricity consumption. These features and cost reductions have been developed through a total system design solution.

  15. Interharmonics from Grid-Connected PV Systems

    DEFF Research Database (Denmark)

    Sangwongwanich, Ariya; Yang, Yongheng; Sera, Dezso

    2017-01-01

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

  16. From the grid to the smart grid, topologically

    Science.gov (United States)

    Pagani, Giuliano Andrea; Aiello, Marco

    2016-05-01

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

  17. Visualization of big SPH simulations via compressed octree grids

    KAUST Repository

    Reichl, Florian

    2013-10-01

    Interactive and high-quality visualization of spatially continuous 3D fields represented by scattered distributions of billions of particles is challenging. One common approach is to resample the quantities carried by the particles to a regular grid and to render the grid via volume ray-casting. In large-scale applications such as astrophysics, however, the required grid resolution can easily exceed 10K samples per spatial dimension, letting resampling approaches appear unfeasible. In this paper we demonstrate that even in these extreme cases such approaches perform surprisingly well, both in terms of memory requirement and rendering performance. We resample the particle data to a multiresolution multiblock grid, where the resolution of the blocks is dictated by the particle distribution. From this structure we build an octree grid, and we then compress each block in the hierarchy at no visual loss using wavelet-based compression. Since decompression can be performed on the GPU, it can be integrated effectively into GPU-based out-of-core volume ray-casting. We compare our approach to the perspective grid approach which resamples at run-time into a view-aligned grid. We demonstrate considerably faster rendering times at high quality, at only a moderate memory increase compared to the raw particle set. © 2013 IEEE.

  18. Non-Galerkin Coarse Grids for Algebraic Multigrid

    Energy Technology Data Exchange (ETDEWEB)

    Falgout, Robert D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Schroder, Jacob B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2014-06-26

    Algebraic multigrid (AMG) is a popular and effective solver for systems of linear equations that arise from discretized partial differential equations. And while AMG has been effectively implemented on large scale parallel machines, challenges remain, especially when moving to exascale. Particularly, stencil sizes (the number of nonzeros in a row) tend to increase further down in the coarse grid hierarchy, and this growth leads to more communication. Therefore, as problem size increases and the number of levels in the hierarchy grows, the overall efficiency of the parallel AMG method decreases, sometimes dramatically. This growth in stencil size is due to the standard Galerkin coarse grid operator, $P^T A P$, where $P$ is the prolongation (i.e., interpolation) operator. For example, the coarse grid stencil size for a simple three-dimensional (3D) seven-point finite differencing approximation to diffusion can increase into the thousands on present day machines, causing an associated increase in communication costs. We therefore consider algebraically truncating coarse grid stencils to obtain a non-Galerkin coarse grid. First, the sparsity pattern of the non-Galerkin coarse grid is determined by employing a heuristic minimal “safe” pattern together with strength-of-connection ideas. Second, the nonzero entries are determined by collapsing the stencils in the Galerkin operator using traditional AMG techniques. The result is a reduction in coarse grid stencil size, overall operator complexity, and parallel AMG solve phase times.

  19. The Grid2003 Production Grid Principles and Practice

    CERN Document Server

    Foster, I; Gose, S; Maltsev, N; May, E; Rodríguez, A; Sulakhe, D; Vaniachine, A; Shank, J; Youssef, S; Adams, D; Baker, R; Deng, W; Smith, J; Yu, D; Legrand, I; Singh, S; Steenberg, C; Xia, Y; Afaq, A; Berman, E; Annis, J; Bauerdick, L A T; Ernst, M; Fisk, I; Giacchetti, L; Graham, G; Heavey, A; Kaiser, J; Kuropatkin, N; Pordes, R; Sekhri, V; Weigand, J; Wu, Y; Baker, K; Sorrillo, L; Huth, J; Allen, M; Grundhoefer, L; Hicks, J; Luehring, F C; Peck, S; Quick, R; Simms, S; Fekete, G; Van den Berg, J; Cho, K; Kwon, K; Son, D; Park, H; Canon, S; Jackson, K; Konerding, D E; Lee, J; Olson, D; Sakrejda, I; Tierney, B; Green, M; Miller, R; Letts, J; Martin, T; Bury, D; Dumitrescu, C; Engh, D; Gardner, R; Mambelli, M; Smirnov, Y; Voeckler, J; Wilde, M; Zhao, Y; Zhao, X; Avery, P; Cavanaugh, R J; Kim, B; Prescott, C; Rodríguez, J; Zahn, A; McKee, S; Jordan, C; Prewett, J; Thomas, T; Severini, H; Clifford, B; Deelman, E; Flon, L; Kesselman, C; Mehta, G; Olomu, N; Vahi, K; De, K; McGuigan, P; Sosebee, M; Bradley, D; Couvares, P; De Smet, A; Kireyev, C; Paulson, E; Roy, A; Koranda, S; Moe, B; Brown, B; Sheldon, P

    2004-01-01

    The Grid2003 Project has deployed a multi-virtual organization, application-driven grid laboratory ("GridS") that has sustained for several months the production-level services required by physics experiments of the Large Hadron Collider at CERN (ATLAS and CMS), the Sloan Digital Sky Survey project, the gravitational wave search experiment LIGO, the BTeV experiment at Fermilab, as well as applications in molecular structure analysis and genome analysis, and computer science research projects in such areas as job and data scheduling. The deployed infrastructure has been operating since November 2003 with 27 sites, a peak of 2800 processors, work loads from 10 different applications exceeding 1300 simultaneous jobs, and data transfers among sites of greater than 2 TB/day. We describe the principles that have guided the development of this unique infrastructure and the practical experiences that have resulted from its creation and use. We discuss application requirements for grid services deployment and configur...

  20. Comparison of Gridded and Measured Rainfall Data for Basin-scale Hydrological Studies Comparación de Datos de Precipitación Grillados y Medidos para Estudios Hidrológicos a Escala de Cuenca

    Directory of Open Access Journals (Sweden)

    Enrique Muñoz

    2011-09-01

    Full Text Available Global gridded climatological (GGC datasets, including precipitation and temperature, are becoming more and more precise, accessible, and common, but the utility of these datasets and their limits for hydrological research are still not well determined. In this paper, we compare the performance of two hydrological models that are identical in structure but built with two different inputs: rainfall from rain gauge stations and from a GGC dataset. The objective is to evaluate the utility of gridded datasets in water resource availability studies mainly for hydroelectric and agricultural purposes. The Andean basin of the Laja River, located in south-central Chile, was chosen for this study. It was based on an 18-yr simulation, and it was concluded that i with gridded climatological datasets in a monthly water balance model, it is possible to reproduce the behavior of an Andean basin with good goodness-of-fit, but with worse results than when using inputs from rain gauges; ii the amount of rainfall in gridded datasets in the Andean area of the Laja basin is underestimated and damped, an effect which is transferred to the simulated flows; and iii regarding the main activities in the Laja basin, global gridded datasets are useful for hydrological studies with agricultural purposes prior to a treatment that considers the orographic effect. On the other hand, these datasets are useless for hydroelectric purposes due to the large underestimation of peak flows obtained during the rainy season.Datos grillados a escala mundial como precipitación y temperatura están siendo cada vez más precisos, accesibles y comunes, pero la utilidad de estos datos y sus limitaciones para estudios hidrológicos, todavía no están bien definidas. En este trabajo se compara el comportamiento de dos modelos hidrológicos, idénticos en estructura, pero construidos con dos entradas diferentes: la precipitación proveniente de estaciones pluviométricas y la precipitaci

  1. In silico drug discovery approaches on grid computing infrastructures.

    Science.gov (United States)

    Wolf, Antje; Shahid, Mohammad; Kasam, Vinod; Ziegler, Wolfgang; Hofmann-Apitius, Martin

    2010-02-01

    The first step in finding a "drug" is screening chemical compound databases against a protein target. In silico approaches like virtual screening by molecular docking are well established in modern drug discovery. As molecular databases of compounds and target structures are becoming larger and more and more computational screening approaches are available, there is an increased need in compute power and more complex workflows. In this regard, computational Grids are predestined and offer seamless compute and storage capacity. In recent projects related to pharmaceutical research, the high computational and data storage demands of large-scale in silico drug discovery approaches have been addressed by using Grid computing infrastructures, in both; pharmaceutical industry as well as academic research. Grid infrastructures are part of the so-called eScience paradigm, where a digital infrastructure supports collaborative processes by providing relevant resources and tools for data- and compute-intensive applications. Substantial computing resources, large data collections and services for data analysis are shared on the Grid infrastructure and can be mobilized on demand. This review gives an overview on the use of Grid computing for in silico drug discovery and tries to provide a vision of future development of more complex and integrated workflows on Grids, spanning from target identification and target validation via protein-structure and ligand dependent screenings to advanced mining of large scale in silico experiments.

  2. Thermal analysis of two-level wind power converter under symmetrical grid fault

    DEFF Research Database (Denmark)

    Zhou, Dao; Blaabjerg, Frede

    2013-01-01

    ) condition as well as the junction temperature. For the full-scale wind turbine system, the most thermal stressed power device in the grid-side converter will appear at the grid voltage below 0.5 pu, and for the partial-scale wind turbine system, the most thermal stressed power device in the rotor......In this paper, the case of symmetrical grid fault when using the multi-MW wind turbine of partial-scale and full-scale two-level power converter are designed and investigated. Firstly, the different operation behaviors of the relevant power converters under the voltage dip will be described...

  3. The Open Science Grid

    CERN Document Server

    Pordes, Ruth; Olson, Doug; Livny, Miron; Roy, Alain; Avery, Paul; Blackburn, Kent; Wenaus, Torre; Wuerthwein, Frank K.; Gardner, Rob; Wilde, Mike; Blatecky, Alan; McGee, John; Quick, Rob

    2007-01-01

    The Open Science Grid (OSG) provides a distributed facility where the Consortium members provide guaranteed and opportunistic access to shared computing and storage resources. OSG provides support for and evolution of the infrastructure through activities that cover operations, security, software, troubleshooting, addition of new capabilities, and support for existing and engagement with new communities. The OSG SciDAC-2 project provides specific activities to manage and evolve the distributed infrastructure and support it's use. The innovative aspects of the project are the maintenance and performance of a collaborative (shared & common) petascale national facility over tens of autonomous computing sites, for many hundreds of users, transferring terabytes of data a day, executing tens of thousands of jobs a day, and providing robust and usable resources for scientific groups of all types and sizes. More information can be found at the OSG web site: www.opensciencegrid.org.

  4. The Open Science Grid

    Energy Technology Data Exchange (ETDEWEB)

    Pordes, Ruth; /Fermilab; Kramer, Bill; Olson, Doug; / /LBL, Berkeley; Livny, Miron; Roy, Alain; /Wisconsin U., Madison; Avery, Paul; /Florida U.; Blackburn, Kent; /Caltech; Wenaus, Torre; /Brookhaven; Wurthwein, Frank; /UC, San Diego; Gardner, Rob; Wilde, Mike; /Chicago U. /Indiana U.

    2007-06-01

    The Open Science Grid (OSG) provides a distributed facility where the Consortium members provide guaranteed and opportunistic access to shared computing and storage resources. OSG provides support for and evolution of the infrastructure through activities that cover operations, security, software, troubleshooting, addition of new capabilities, and support for existing and engagement with new communities. The OSG SciDAC-2 project provides specific activities to manage and evolve the distributed infrastructure and support its use. The innovative aspects of the project are the maintenance and performance of a collaborative (shared & common) petascale national facility over tens of autonomous computing sites, for many hundreds of users, transferring terabytes of data a day, executing tens of thousands of jobs a day, and providing robust and usable resources for scientific groups of all types and sizes. More information can be found at the OSG web site: www.opensciencegrid.org.

  5. Review of Strategies and Technologies for Demand-Side Management on Isolated Mini-Grids

    Energy Technology Data Exchange (ETDEWEB)

    Harper, Meg [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2013-03-01

    This review provides an overview of strategies and currently available technologies used for demandside management (DSM) on mini-grids throughout the world. For the purposes of this review, mini-grids are defined as village-scale electricity distribution systems powered by small local generation sources and not connected to a main grid.1 Mini-grids range in size from less than 1 kW to several hundred kW of installed generation capacity and may utilize different generation technologies, such as micro-hydro, biomass gasification, solar, wind, diesel generators, or a hybrid combination of any of these. This review will primarily refer to AC mini-grids, though much of the discussion could apply to DC grids as well. Many mini-grids include energy storage, though some rely solely on real-time generation.

  6. Differences between downscaling with spectral and grid nudging using WRF

    Directory of Open Access Journals (Sweden)

    P. Liu

    2012-04-01

    Full Text Available Dynamical downscaling has been extensively used to study regional climate forced by large-scale global climate models. During the downscaling process, however, the simulation of regional climate models (RCMs tends to drift away from the driving fields. Developing a solution that addresses this issue, by retaining the large scale features (from the large-scale fields and the small-scale features (from the RCMs has led to the development of "nudging" techniques. Here, we examine the performance of two nudging techniques, grid and spectral nudging, in the downscaling of NCEP/NCAR data with the Weather Research and Forecasting (WRF Model. The simulations are compared against the results with North America Regional Reanalysis (NARR data set at different scales of interest using the concept of similarity. We show that with the appropriate choice of wave numbers, spectral nudging outperforms grid nudging in the capacity of balancing the performance of simulation at the large and small scales.

  7. Monitoring of Grid scientific workflows

    NARCIS (Netherlands)

    Balis, B.; Bubak, M.; Łabno, B.

    2008-01-01

    Scientific workflows are a means of conducting in silico experiments in modern computing infrastructures for e-Science, often built on top of Grids. Monitoring of Grid scientific workflows is essential not only for performance analysis but also to collect provenance data and gather feedback useful

  8. Wind Turbine Providing Grid Support

    DEFF Research Database (Denmark)

    2011-01-01

    A variable speed wind turbine is arranged to provide additional electrical power to counteract non-periodic disturbances in an electrical grid. A controller monitors events indicating a need to increase the electrical output power from the wind turbine to the electrical grid. The controller...

  9. Astro-WISE and Grid

    NARCIS (Netherlands)

    Begeman, Kor; Belikov, Andrey N.; Dijkstra, Fokke; Meyer-Zhao, Zheng; Valentijn, Edwin A.; Vriend, Willem-Jan

    The paper reviews the Astro-WISE infrastructure and demonstrates that the Astro-WISE Information System provides a Grid itself. We describe the integration of Astro-WISE with an external Grid infrastructure (BiGGrid). The integration is performed on all infrastructural layers (data storage, metadata

  10. What's New with the Grid?

    Science.gov (United States)

    Blake, Robert R.; Mouton, Jane Srygley

    1978-01-01

    Authors reexamine assumptions formulated in the early years of their Managerial Grid and test them against what is known today. Focus is on managerial motivations and industrial leadership. Includes a table which categorizes varied multi-disciplinary approaches to leadership using the Grid framework. (EM)

  11. On Robustness of Power Grids

    NARCIS (Netherlands)

    Koç, Y.

    2015-01-01

    Current and future trends in environmental, economical, and human-caused factors (such as power demand growth, over-ageing of assets in power grids, and extreme weather conditions) challenge power grid robustness in the near future, necessitating research to better analyse and understand the notion

  12. Smart Grid Communication Middleware Comparison

    DEFF Research Database (Denmark)

    Petersen, Bo Søborg; Bindner, Henrik W.; Poulsen, Bjarne

    2017-01-01

    are possible by their performance, which is limited by the middleware characteristics, primarily interchangeable serialization and the Publish-Subscribe messaging pattern. The earlier paper “Smart Grid Serialization Comparison” (Petersen et al. 2017) aids in the choice of serialization, which has a big impact...... the strongest candidates for Smart Grid distributed control, but WAMP should also be considered in the future....

  13. Smart grid: hope or hype?

    DEFF Research Database (Denmark)

    Lunde, Morten; Røpke, Inge; Heiskanen, Eva

    2016-01-01

    how their (intentional or unintentional) choices serve to create or maintain certain boundaries in smart grid development: for example, an exclusive focus on electricity within the broader context of a sustainable energy system. As serious investment starts being made in the smart grid, concepts like...

  14. 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.

  15. Increased Productivity for Emerging Grid Applications the Application Support System

    CERN Document Server

    Maier, Andrew; Mendez Lorenzo, Patricia; Moscicki, Jakub; Lamanna, Massimo; Muraru, Adrian

    2008-01-01

    Recently a growing number of various applications have been quickly and successfully enabled on the Grid by the CERN Grid application support team. This allowed the applications to achieve and publish large-scale results in a short time which otherwise would not be possible. We present the general infrastructure, support procedures and tools that have been developed. We discuss the general patterns observed in supporting new applications and porting them to the EGEE environment. The CERN Grid application support team has been working with the following real-life applications: medical and particle physics simulation (Geant4, Garfield), satellite imaging and geographic information for humanitarian relief operations (UNOSAT), telecommunications (ITU), theoretical physics (Lattice QCD, Feynman-loop evaluation), Bio-informatics (Avian Flu Data Challenge), commercial imaging processing and classification (Imense Ltd.) and physics experiments (ATLAS, LHCb, HARP). Using the EGEE Grid we created a standard infrastruct...

  16. Control and Optimization Methods for Electric Smart Grids

    CERN Document Server

    Ilić, Marija

    2012-01-01

    Control and Optimization Methods for Electric Smart Grids brings together leading experts in power, control and communication systems,and consolidates some of the most promising recent research in smart grid modeling,control and optimization in hopes of laying the foundation for future advances in this critical field of study. The contents comprise eighteen essays addressing wide varieties of control-theoretic problems for tomorrow’s power grid. Topics covered include: Control architectures for power system networks with large-scale penetration of renewable energy and plug-in vehicles Optimal demand response New modeling methods for electricity markets Control strategies for data centers Cyber-security Wide-area monitoring and control using synchronized phasor measurements. The authors present theoretical results supported by illustrative examples and practical case studies, making the material comprehensible to a wide audience. The results reflect the exponential transformation that today’s grid is going...

  17. Managing Dynamic User Communities in a Grid of Autonomous Resources

    CERN Document Server

    Alfieri, R; Gianoli, A; Spataro, F; Ciaschini, Vincenzo; dell'Agnello, L; Bonnassieux, F; Broadfoot, P; Lowe, G; Cornwall, L; Jensen, J; Kelsey, D; Frohner, A; Groep, DL; Som de Cerff, W; Steenbakkers, M; Venekamp, G; Kouril, D; McNab, A; Mulmo, O; Silander, M; Hahkala, J; Lhorentey, K

    2003-01-01

    One of the fundamental concepts in Grid computing is the creation of Virtual Organizations (VO's): a set of resource consumers and providers that join forces to solve a common problem. Typical examples of Virtual Organizations include collaborations formed around the Large Hadron Collider (LHC) experiments. To date, Grid computing has been applied on a relatively small scale, linking dozens of users to a dozen resources, and management of these VO's was a largely manual operation. With the advance of large collaboration, linking more than 10000 users with a 1000 sites in 150 counties, a comprehensive, automated management system is required. It should be simple enough not to deter users, while at the same time ensuring local site autonomy. The VO Management Service (VOMS), developed by the EU DataGrid and DataTAG projects[1, 2], is a secured system for managing authorization for users and resources in virtual organizations. It extends the existing Grid Security Infrastructure[3] architecture with embedded VO ...

  18. Smart Grid Control and Communication

    DEFF Research Database (Denmark)

    Ciontea, Catalin-Iosif; Pedersen, Rasmus; Kristensen, Thomas le Fevre

    2015-01-01

    ) and the quality of the power may become costly. In this light, Smart Grids may provide an answer towards a more active and efficient electrical network. The EU project SmartC2Net aims to enable smart grid operations over imperfect, heterogeneous general purpose networks, which poses a significant challenge...... to the reliability due to the stochastic behavior found in such networks. Therefore, key concepts are presented in this paper targeting the support of proper smart grid control in these network environments and its Real-Time Hardware-In-the Loop (HIL) verification. An overview on the required Information......The expected growth in distributed generation will significantly affect the operation and control of today's distribution grids. Being confronted with fast fluctuating power from distributed generations, the assurance of a reliable service (grid stability, avoidance of energy losses...

  19. gCube Grid services

    CERN Document Server

    Andrade, Pedro

    2008-01-01

    gCube is a service-based framework for eScience applications requiring collaboratory, on-demand, and intensive information processing. It provides to these communities Virtual Research Environments (VREs) to support their activities. gCube is build on top of standard technologies for computational Grids, namely the gLite middleware. The software was produced by the DILIGENT project and will continue to be supported and further developed by the D4Science project. gCube reflects within its name a three-sided interpretation of the Grid vision of resource sharing: sharing of computational resources, sharing of structured data, and sharing of application services. As such, gCube embodies the defining characteristics of computational Grids, data Grids, and virtual data Grids. Precisely, it builds on gLite middleware for managing distributed computations and unstructured data, includes dedicated services for managing data and metadata, provides services for distributed information retrieval, allows the orchestration...

  20. Enhanced INL Power Grid Test Bed Infrastructure – Phase I

    Energy Technology Data Exchange (ETDEWEB)

    Reid, Carol Ann [Idaho National Lab. (INL), Idaho Falls, ID (United States); West, Grayson Shawn [Idaho National Lab. (INL), Idaho Falls, ID (United States); McBride, Scott Alan [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2014-06-01

    Idaho National Laboratory (INL), a Department of Energy (DOE) laboratory, owns, operates, and maintains transmission and distribution power grid infrastructure to support the INL multi program mission. Sections of this power infrastructure, known as the INL Power Grid Test Bed, have been and are being used by government and industry to develop, demonstrate, and validate technologies for the modern grid, including smart grid, on a full scale utility test bed. INL’s power grid includes 61 miles of 140 MW, 138 kV rated electrical power transmission supplying seven main substations, each feeding a separate facility complex (or ‘city’) within the INL’s 890 square mile Site. This power grid is fed by three commercial utilities into the INL’s main control substation, but is operated independently from the commercial utility through its primary substation and command and control center. Within the INL complex, one of the seven complexes, the Critical Infrastructure Test Range Complex (CITRC), has been designated as the INL complex for supporting critical infrastructure research and testing. This complex includes its own substation and 13.8kV distribution network, all configurable and controlled by the INL research and development programs. Through investment partnership with the DOE Office of Electricity Delivery and Energy Reliability (DOE OE), INL is enhancing its existing distribution infrastructure to expand the types of testing that can be conducted and increase flexibility for testing configurations. The enhancement of the INL Power Grid Test Bed will enable development and full scale testing of smart-grid-related technologies and smart devices including testing interoperability, operational performance, reliability, and resiliency contribution at multiple distribution voltage classes, specifically 15kV, 25kV, and 35kV. The expected time frame for completion of the Phase I portion of the enhancement would be 4th quarter fiscal year (FY) 2015.

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

    DEFF Research Database (Denmark)

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

    2012-01-01

    Grid synchronization algorithms are of great importance in the control of grid-connected power converters, as fast and accurate detection of the grid voltage parameters is crucial in order to implement stable control strategies under generic grid conditions. This paper presents a new grid...... of the instantaneous symmetrical components of the grid voltage under unbalanced and distorted grid conditions. This paper analyzes the performance of the proposed synchronization method including different design issues. Moreover, the behavior of the method for synchronizing with highly unbalanced grid is proven...

  2. Sensing and Measurement Architecture for Grid Modernization

    Energy Technology Data Exchange (ETDEWEB)

    Taft, Jeffrey D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); De Martini, Paul [California Inst. of Technology (CalTech), Pasadena, CA (United States)

    2016-02-01

    This paper addresses architecture for grid sensor networks, with primary emphasis on distribution grids. It describes a forward-looking view of sensor network architecture for advanced distribution grids, and discusses key regulatory, financial, and planning issues.

  3. Global Population Density Grid Time Series Estimates

    Data.gov (United States)

    National Aeronautics and Space Administration — Global Population Density Grid Time Series Estimates provide a back-cast time series of population density grids based on the year 2000 population grid from SEDAC's...

  4. Global Population Count Grid Time Series Estimates

    Data.gov (United States)

    National Aeronautics and Space Administration — Global Population Count Grid Time Series Estimates provide a back-cast time series of population grids based on the year 2000 population grid from SEDAC's Global...

  5. BSCW Unstructured Grids - VGRID software FINAL

    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...

  6. Bathymetric Position Index (BPI) Structures derived from gridded bathymetry of Farallon de Medinilla (FDM), Commonwealth of the Northern Mariana (CNMI), USA.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — BPI Structures are derived from two scales of a focal mean analysis on bathymetry and slope. The grid is based on gridded (5 m cell size) multibeam bathymetry,...

  7. 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

    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...... 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...

  8. Smart grid security innovative solutions for a modernized grid

    CERN Document Server

    Skopik, Florian

    2015-01-01

    The Smart Grid security ecosystem is complex and multi-disciplinary, and relatively under-researched compared to the traditional information and network security disciplines. While the Smart Grid has provided increased efficiencies in monitoring power usage, directing power supplies to serve peak power needs and improving efficiency of power delivery, the Smart Grid has also opened the way for information security breaches and other types of security breaches. Potential threats range from meter manipulation to directed, high-impact attacks on critical infrastructure that could bring down regi

  9. Offshore wind farms energy injection in the electrical grid - Lithium battery to mitigate power fluctuations

    OpenAIRE

    IKNI, DJAMEL; Camara, Mamadou Baïlo; Dakyo, Brayima

    2016-01-01

    The wind farm energy injection in the electrical grid generates the economic and technical challenges which must to be solved for successful large scale wind energy integration in electrical grids. Due to wind speed variations, the wind farm output power presents the fluctuating components which are not compatible to the electrical grid requirements. Today, this problem is a major challenge with the wind farm projects increasing in the world. Large power variations cause the deviations of rms...

  10. Transmission Technologies and Operational Characteristic Analysis of Hybrid UHV AC/DC Power Grids in China

    Science.gov (United States)

    Tian, Zhang; Yanfeng, Gong

    2017-05-01

    In order to solve the contradiction between demand and distribution range of primary energy resource, Ultra High Voltage (UHV) power grids should be developed rapidly to meet development of energy bases and accessing of large-scale renewable energy. This paper reviewed the latest research processes of AC/DC transmission technologies, summarized the characteristics of AC/DC power grids, concluded that China’s power grids certainly enter a new period of large -scale hybrid UHV AC/DC power grids and characteristics of “strong DC and weak AC” becomes increasingly pro minent; possible problems in operation of AC/DC power grids was discussed, and interaction or effect between AC/DC power grids was made an intensive study of; according to above problems in operation of power grids, preliminary scheme is summarized as fo llows: strengthening backbone structures, enhancing AC/DC transmission technologies, promoting protection measures of clean energ y accessing grids, and taking actions to solve stability problems of voltage and frequency etc. It’s valuable for making hybrid UHV AC/DC power grids adapt to operating mode of large power grids, thus guaranteeing security and stability of power system.

  11. Complete coverage of space favors modularity of the grid system in the brain

    Science.gov (United States)

    Sanzeni, A.; Balasubramanian, V.; Tiana, G.; Vergassola, M.

    2016-12-01

    Grid cells in the entorhinal cortex fire when animals that are exploring a certain region of space occupy the vertices of a triangular grid that spans the environment. Different neurons feature triangular grids that differ in their properties of periodicity, orientation, and ellipticity. Taken together, these grids allow the animal to maintain an internal, mental representation of physical space. Experiments show that grid cells are modular, i.e., there are groups of neurons which have grids with similar periodicity, orientation, and ellipticity. We use statistical physics methods to derive a relation between variability of the properties of the grids within a module and the range of space that can be covered completely (i.e., without gaps) by the grid system with high probability. Larger variability shrinks the range of representation, providing a functional rationale for the experimentally observed comodularity of grid cell periodicity, orientation, and ellipticity. We obtain a scaling relation between the number of neurons and the period of a module, given the variability and coverage range. Specifically, we predict how many more neurons are required at smaller grid scales than at larger ones.

  12. Interactive volume visualization of general polyhedral grids

    KAUST Repository

    Muigg, Philipp

    2011-12-01

    This paper presents a novel framework for visualizing volumetric data specified on complex polyhedral grids, without the need to perform any kind of a priori tetrahedralization. These grids are composed of polyhedra that often are non-convex and have an arbitrary number of faces, where the faces can be non-planar with an arbitrary number of vertices. The importance of such grids in state-of-the-art simulation packages is increasing rapidly. We propose a very compact, face-based data structure for representing such meshes for visualization, called two-sided face sequence lists (TSFSL), as well as an algorithm for direct GPU-based ray-casting using this representation. The TSFSL data structure is able to represent the entire mesh topology in a 1D TSFSL data array of face records, which facilitates the use of efficient 1D texture accesses for visualization. In order to scale to large data sizes, we employ a mesh decomposition into bricks that can be handled independently, where each brick is then composed of its own TSFSL array. This bricking enables memory savings and performance improvements for large meshes. We illustrate the feasibility of our approach with real-world application results, by visualizing highly complex polyhedral data from commercial state-of-the-art simulation packages. © 2011 IEEE.

  13. Ceramic ball grid array package stress analysis

    Science.gov (United States)

    Badri, S. H. B. S.; Aziz, M. H. A.; Ong, N. R.; Sauli, Z.; Alcain, J. B.; Retnasamy, V.

    2017-09-01

    The ball grid array (BGA), a form of chip scale package (CSP), was developed as one of the most advanced surface mount devices, which may be assembled by an ordinary surface ball bumps are used instead of plated nickel and gold (Ni/Au) bumps. Assembly and reliability of the BGA's printed circuit board (PCB), which is soldered by conventional surface mount technology is considered in this study. The Ceramic Ball Grid Array (CBGA) is a rectangular ceramic package or square-shaped that will use the solder ball for external electrical connections instead of leads or wire for connections. The solder balls will be arranged in an array or grid at the bottom of the ceramic package body. In this study, ANSYS software is used to investigate the stress on the package for 2 balls and 4 balls of the CBGA package with the various force range of 1-3 Newton applied to the top of the die, top of the substrate and side of the substrate. The highest maximum stress was analyzed and the maximum equivalent stress was observed on the solder ball and the die. From the simulation result, the CBGA package with less solder balls experience higher stress compared to the package with many solder balls. Therefore, less number of solder ball on the CBGA package results higher stress and critically affect the reliability of the solder balls itself, substrate and die which can lead to the solder crack and also die crack.

  14. Distributed computing grid experiences in CMS

    CERN Document Server

    Andreeva, Julia; Barrass, T; Bonacorsi, D; Bunn, Julian; Capiluppi, P; Corvo, M; Darmenov, N; De Filippis, N; Donno, F; Donvito, G; Eulisse, G; Fanfani, A; Fanzago, F; Filine, A; Grandi, C; Hernández, J M; Innocente, V; Jan, A; Lacaprara, S; Legrand, I; Metson, S; Newbold, D; Newman, H; Pierro, A; Silvestris, L; Steenberg, C; Stockinger, H; Taylor, Lucas; Thomas, M; Tuura, L; Van Lingen, F; Wildish, Tony

    2005-01-01

    The CMS experiment is currently developing a computing system capable of serving, processing and archiving the large number of events that will be generated when the CMS detector starts taking data. During 2004 CMS undertook a large scale data challenge to demonstrate the ability of the CMS computing system to cope with a sustained data- taking rate equivalent to 25% of startup rate. Its goals were: to run CMS event reconstruction at CERN for a sustained period at 25 Hz input rate; to distribute the data to several regional centers; and enable data access at those centers for analysis. Grid middleware was utilized to help complete all aspects of the challenge. To continue to provide scalable access from anywhere in the world to the data, CMS is developing a layer of software that uses Grid tools to gain access to data and resources, and that aims to provide physicists with a user friendly interface for submitting their analysis jobs. This paper describes the data challenge experience with Grid infrastructure ...

  15. Global Data Grid Efforts for ATLAS

    CERN Multimedia

    Gardner, R.

    2001-01-01

    Over the past two years computational data grids have emerged as a promising new technology for large scale, data-intensive computing required by the LHC experiments, as outlined by the recent "Hoffman" review panel that addressed the LHC computing challenge. The problem essentially is to seamlessly link physicists to petabyte-scale data and computing resources, distributed worldwide, and connected by high-bandwidth research networks. Several new collaborative initiatives in Europe, the United States, and Asia have formed to address the problem. These projects are of great interest to ATLAS physicists and software developers since their objective is to offer tools that can be integrated into the core ATLAS application framework for distributed event reconstruction, Monte Carlo simulation, and data analysis, making it possible for individuals and groups of physicists to share information, data, and computing resources in new ways and at scales not previously attempted. In addition, much of the distributed IT...

  16. National Smart Water Grid

    Energy Technology Data Exchange (ETDEWEB)

    Beaulieu, R A

    2009-07-13

    The United States repeatedly experiences floods along the Midwest's large rivers and droughts in the arid Western States that cause traumatic environmental conditions with huge economic impact. With an integrated approach and solution these problems can be alleviated. Tapping into the Mississippi River and its tributaries, the world's third largest fresh water river system, during flood events will mitigate the damage of flooding and provide a new source of fresh water to the Western States. The trend of increased flooding on the Midwest's large rivers is supported by a growing body of scientific literature. The Colorado River Basin and the western states are experiencing a protracted multi-year drought. Fresh water can be pumped via pipelines from areas of overabundance/flood to areas of drought or high demand. Calculations document 10 to 60 million acre-feet (maf) of fresh water per flood event can be captured from the Midwest's Rivers and pumped via pipelines to the Colorado River and introduced upstream of Lake Powell, Utah, to destinations near Denver, Colorado, and used in areas along the pipelines. Water users of the Colorado River include the cities in southern Nevada, southern California, northern Arizona, Colorado, Utah, Indian Tribes, and Mexico. The proposed start and end points, and routes of the pipelines are documented, including information on right-of-ways necessary for state and federal permits. A National Smart Water Grid{trademark} (NSWG) Project will create thousands of new jobs for construction, operation, and maintenance and save billions in drought and flood damage reparations tax dollars. The socio-economic benefits of NWSG include decreased flooding in the Midwest; increased agriculture, and recreation and tourism; improved national security, transportation, and fishery and wildlife habitats; mitigated regional climate change and global warming such as increased carbon capture; decreased salinity in Colorado River water

  17. Constructing the ASCI computational grid

    Energy Technology Data Exchange (ETDEWEB)

    BEIRIGER,JUDY I.; BIVENS,HUGH P.; HUMPHREYS,STEVEN L.; JOHNSON,WILBUR R.; RHEA,RONALD E.

    2000-06-01

    The Accelerated Strategic Computing Initiative (ASCI) computational grid is being constructed to interconnect the high performance computing resources of the nuclear weapons complex. The grid will simplify access to the diverse computing, storage, network, and visualization resources, and will enable the coordinated use of shared resources regardless of location. To match existing hardware platforms, required security services, and current simulation practices, the Globus MetaComputing Toolkit was selected to provide core grid services. The ASCI grid extends Globus functionality by operating as an independent grid, incorporating Kerberos-based security, interfacing to Sandia's Cplant{trademark},and extending job monitoring services. To fully meet ASCI's needs, the architecture layers distributed work management and criteria-driven resource selection services on top of Globus. These services simplify the grid interface by allowing users to simply request ''run code X anywhere''. This paper describes the initial design and prototype of the ASCI grid.

  18. Embodied Energy and Off-Grid Lighting

    Energy Technology Data Exchange (ETDEWEB)

    Alstone, Peter; Mills, Evan; Jacobson, Arne

    2011-01-25

    The greenhouse gas (GHG) emissions from fuel-based lighting are substantial given the paltry levels of lighting service provided to users, leading to a great opportunity for GHG mitigation byencouraging the switch from fuel-based to rechargeable LED lighting. However, as with most new energy technology, switching to efficient lighting requires an up-front investment of energy(and GHGs) embedded in the manufacture of replacement components. We studied a population of off-grid lighting users in 2008-2009 in Kenya who were given the opportunity to adopt LEDlighting. Based on their use patterns with the LED lights and the levels of kerosene offset we observed, we found that the embodied energy of the LED lamp was"paid for" in only one month for grid charged products and two months for solar charged products. Furthermore, the energyreturn-on investment-ratio (energy produced or offset over the product's service life divided by energy embedded) for off-grid LED lighting ranges from 12 to 24, which is on par with on-gridsolar and large-scale wind energy. We also found that the energy embodied in the manufacture of a typical hurricane lantern is about one-half to one-sixth of that embodied in the particular LEDlights that we evaluated, indicating that the energy payback time would be moderately faster if LEDs ultimately displace the production of kerosene lanterns. As LED products improve, weanticipate longer service lives and more successful displacement of kerosene lighting, both of which will speed the already rapid recovery of embodied energy in these products. Our studyprovides a detailed appendix with embodied energy values for a variety of components used to construct off-grid LED lighting, which can be used to analyze other products.

  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. Buildings-to-Grid Technical Opportunities: From the Grid Perspective

    Energy Technology Data Exchange (ETDEWEB)

    Kropski, Ben [National Renewable Energy Lab. (NREL), Golden, CO (United States); Pratt, Rob [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2014-03-28

    This paper outlines the nature of the power grid, lists challenges and barriers to the implementation of a transactive energy ecosystem, and provides concept solutions to current technological impediments.

  1. Secondary emission monitor (SEM) grids.

    CERN Multimedia

    Patrice Loïez

    2002-01-01

    A great variety of Secondary Emission Monitors (SEM) are used all over the PS Complex. At other accelerators they are also called wire-grids, harps, etc. They are used to measure beam density profiles (from which beam size and emittance can be derived) in single-pass locations (not on circulating beams). Top left: two individual wire-planes. Top right: a combination of a horizontal and a vertical wire plane. Bottom left: a ribbon grid in its frame, with connecting wires. Bottom right: a SEM-grid with its insertion/retraction mechanism.

  2. A terahertz grid frequency doubler

    OpenAIRE

    Moussessian, Alina; Wanke, Michael C.; Li, Yongjun; Chiao, Jung-Chih; Allen, S. James; Crowe, Thomas W.; Rutledge, David B.

    1998-01-01

    We present a 144-element terahertz quasi-optical grid frequency doubler. The grid is a planar structure with bow-tie antennas as a unit cell, each loaded with a planar Schottky diode. The maximum output power measured for this grid is 24 mW at 1 THz for 3.1-μs 500-GHz input pulses with a peak input power of 47 W. An efficiency of 0.17% for an input power of 6.3 W and output power of 10.8 mW is measured. To date, this is the largest recorded output power for a multiplier at terahertz frequenci...

  3. 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).

  4. Mapping of grid faults and grid codes[Wind turbines

    Energy Technology Data Exchange (ETDEWEB)

    Iov, F. [Aalborg Univ., Inst. of Energy Technology (Denmark); Hansen, Anca D.; Soerensen, Poul; Cutululis, N.A. [Risoe National Lab. - DTU, Wind Enegy Dept., Roskilde (Denmark)

    2007-06-15

    The objective of this project is to investigate into the consequences of the new grid connection requirements for the fatigue and extreme loads of wind turbines. The goal is also to clarify and define possible new directions in the certification process of power plant wind turbines, namely wind turbines, which participate actively in the stabilisation of power systems. Practical experience shows that there is a need for such investigations. The grid connection requirements for wind turbines have increased significantly during the last 5-10 years. Especially the requirements for wind turbines to stay connected to the grid during and after voltage sags, imply potential challenges in the design of wind turbines. These requirements pose challenges for the design of both the electrical system and the mechanical structure of wind turbines. An overview over the frequency of grid faults and the grid connection requirements in different relevant countries is done in this report. The most relevant study cases for the quantification of the loads' impact on the wind turbines' lifetime are defined. The goal of this report is to present a mapping of different grid fault types and their frequency in different countries. The report provides also a detailed overview of the Low Voltage Ride-Through Capabilities for wind turbines in different relevant countries. The most relevant study cases for the quantification of the loads' impact on the wind turbines' lifetime are defined. (au)

  5. Monitoring of Grid Scientific Workflows

    Directory of Open Access Journals (Sweden)

    Bartosz Balis

    2008-01-01

    Full Text Available Scientific workflows are a means of conducting in silico experiments in modern computing infrastructures for e-Science, often built on top of Grids. Monitoring of Grid scientific workflows is essential not only for performance analysis but also to collect provenance data and gather feedback useful in future decisions, e.g., related to optimization of resource usage. In this paper, basic problems related to monitoring of Grid scientific workflows are discussed. Being highly distributed, loosely coupled in space and time, heterogeneous, and heavily using legacy codes, workflows are exceptionally challenging from the monitoring point of view. We propose a Grid monitoring architecture for scientific workflows. Monitoring data correlation problem is described and an algorithm for on-line distributed collection of monitoring data is proposed. We demonstrate a prototype implementation of the proposed workflow monitoring architecture, the GEMINI monitoring system, and its use for monitoring of a real-life scientific workflow.

  6. NASA Wingtip Code Validation Grid

    Science.gov (United States)

    Zilliac, Greg; Mariani, Jennifer Dacles

    1995-01-01

    I have been contacted by Alan Celic to request the computational fluid dynamics (CFD) grid file for the NASA Wingtip CFD validation case. Alan is currently a Ph.D. student at the University of Stuttgard in Germany and spent a year here at Ames Research Center (ARC) as an Ames Associate. This case is a standard validation case studied by many within the U.S. The case is of the flow around a rectangular wing with a rounded wing tip. The airfoil is a NACA 0012. There is nothing special or unusual about the geometry or the grid file. The grid file is a single-zone grid with 2.5 million points. This geometry is generic and is not similar to any currently flying vehicle. All of the results published by NASA, as part of this study, (completed in 1995) are currently in the public domain.

  7. U.S. Topographic Grid

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — isotop.bin - topographic data for conterminous U.S. projected on an 8 km grid. Projection is Albers, central meridian = 96 degrees West, base latitude = 0 degrees...

  8. The smart grid research network

    DEFF Research Database (Denmark)

    Troi, Anders; Jørgensen, Bo Nørregaard; Larsen, Emil Mahler

    2013-01-01

    This road map is a result of part-recommendation no. 25 in ‘MAIN REPORT – The Smart Grid Network’s recommendations’, written by the Smart Grid Network for the Danish Ministry of Climate, Energy and Building in October 2011. This part-recommendation states: “Part-recommendation 25 – A road map...... for Smart Grid research, development and demonstration It is recommended that the electricity sector invite the Ministry to participate in the creation of a road map to ensure that solutions are implemented and coordinated with related policy areas. The sector should also establish a fast-acting working...... group with representatives from universities, distribution companies and the electric industry, in order to produce a mutual, binding schedule for the RDD of the Smart Grid in Denmark. Time prioritisation of part-recommendation: 2011-2012 Responsibility for implementation of part...

  9. The Cardiovascular Research Grid (CVRG)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The CardioVascular Research Grid (CVRG) project is creating an infrastructure for sharing cardiovascular data and data analysis tools. CVRG tools are developed using...

  10. Wind energy in offshore grids

    DEFF Research Database (Denmark)

    Schröder, Sascha Thorsten

    and investment implications under different regulatory frameworks are a hitherto underrepresented research field. They are addressed by this thesis. Offshore grids between several countries combine the absorption of wind energy with international power trading. However, the inclusion into an offshore grid...... correcting its wind forecast errors in a specific onshore balancing group. An analytical approach with a transmission system operator and a wind farm as stakeholders illustrates resulting incentives for strategic behaviour. Depending on the regulatory regime, they may be inclined to announce more or less......This cumulative PhD thesis deals with wind integration in offshore grids from an economic point of view. It is composed of a generic part and eight papers. As the topic has mostly been analysed with a focus on topology and technical issues until now, market-operational questions in offshore grids...

  11. BSCW Unstructured Mixed Element Grids

    Data.gov (United States)

    National Aeronautics and Space Administration — Corase Grid: Quad Surface Faces= 9360 Tria Surface Faces= 128928 Nodes = 2869187 Total Elements = 9099201 Hex Elements = 0 Pent_5 Elements = 0 Pent_6 Elements =...

  12. Formal Aspects of Grid Brokering

    Directory of Open Access Journals (Sweden)

    Attila Kertész

    2009-12-01

    Full Text Available Coordination in distributed environments, like Grids, involves selecting the most appropriate services, resources or compositions to carry out the planned activities. Such functionalities appear at various levels of the infrastructure and in various means forming a blurry domain, where it is hard to see how the participating components are related and what their relevant properties are. In this paper we focus on a subset of these problems: resource brokering in Grid middleware. This paper aims at establishing a semantical model for brokering and related activities by defining brokering agents at three levels of the Grid middleware for resource, host and broker selection. The main contribution of this paper is the definition and decomposition of different brokering components in Grids by providing a formal model using Abstract State Machines.

  13. Governments plan data grid projects

    CERN Multimedia

    Thibodeau, Patrick

    2007-01-01

    "Some governments and not-for-profit organizations such as hospitals are beginning to look at data grid technology as a means to improve servies, lower operating costs and spur economic development." (1 page)

  14. Performance Modeling of Enterprise Grids

    Science.gov (United States)

    Hoffman, Doug L.; Apon, Amy; Dowdy, Larry; Lu, Baochuan; Hamm, Nathan; Ngo, Linh; Bui, Hung

    Modeling has long been recognized as an invaluable tool for predicting the performance behavior of computer systems. Modeling software, both commercial and open source, is widely used as a guide for the development of new systems and the upgrading of exiting ones. Tools such as queuing network models, stochastic Petri nets, and event driven simulation are in common use for stand-alone computer systems and networks. Unfortunately, no set of comprehensive tools exists for modeling complex distributed computing environments such as the ones found in emerging grid deployments. With the rapid advance of grid computing, the need for improved modeling tools specific to the grid environment has become evident. This chapter addresses concepts, methodologies, and tools that are useful when designing, implementing, and tuning the performance in grid and cluster environments

  15. Integration of HTS Cables in the Future Grid of the Netherlands

    NARCIS (Netherlands)

    Zuijderduin, R.; Chevchenko, O.; Smit, J.J.; Aanhaanen, G.; Melnik, I.; Geschiere, A.

    2012-01-01

    ue to increasing power demand, the electricity grid of the Netherlands is changing. The future transmission grid will obtain electrical power generated by decentralized renewable sources, together with large scale generation units located at the coastal region. In this way electrical power has to be

  16. GMLC Hawaii Regional Partnership: Distributed Inverter-Based Grid Frequency Support

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Austin; Hoke, Andy

    2017-05-04

    This presentation is part of a panel session at the IEEE ISGT conference on Grid Modernization Initiative projects. This segment of the panel session provides a brief overview of a Hawaii Regional Partnership project focusing grid frequency support from distributed resources on the fastest time scales.

  17. Real-Time Market Concept Architecture for EcoGrid EU—A Prototype for European Smart Grids

    DEFF Research Database (Denmark)

    Ding, Yi; Pineda Morente, Salvador; Nyeng, Preben

    2014-01-01

    ) to participate in electricity markets. Current electricity markets need to be tailored to incorporate these changes regarding how electricity will be generated and consumed in the future. The EcoGrid EU is a large-scale EU-funded project, which establishes the first prototype of the future European intelligent...... grids. In this project, small-scale DERs and small end-consumers can actively participate in a new real-time electricity market by responding to 5-min real time electricity prices. In this way, the market operator will also obtain additional balancing power to cancel out the production variation...... introduced by renewable electricity generation. The real-time market concept architecture for EcoGrid EU is introduced in this paper, which provides a market-based platform and information and communication technology (ICT) infrastructure that extends the current electricity market to a shorter time horizon...

  18. Grid Voltage Modulated Control of Grid-Connected Voltage Source Inverters under Unbalanced Grid Conditions

    DEFF Research Database (Denmark)

    Li, Mingshen; Gui, Yonghao; Quintero, Juan Carlos Vasquez

    2017-01-01

    In this paper, an improved grid voltage modulated control (GVM) with power compensation is proposed for grid-connected voltage inverters when the grid voltage is unbalanced. The objective of the proposed control is to remove the power ripple and to improve current quality. Three power compensation...... objectives are selected to eliminate the negative sequence components of currents. The modified GVM method is designed to obtain two separate second-order systems for not only the fast convergence rate of the instantaneous active and reactive powers but also the robust performance. In addition, this method...

  19. Regional Analysis of Aids and Prices for Small-scale Grid-connected Solar Photovoltaic Systems in Spain; Analisis Regional de Precios y Ayudas para Sistemas fotovoltaicos de Pequena Escala Conectados a Red Electrica en Espana

    Energy Technology Data Exchange (ETDEWEB)

    Varela, M.; Ramirez, L.; Mora, L.; Sidrach de Cardona, M.

    2002-07-01

    Electricity production from small solar photovoltaic systems in Spain obtains a premium pnce of 0,36 Euros/kWh over the electricity market price or a fix price of 0.40 Euros/kWh. The development of these small systems, in Spain clearly demonstrates that the established prime is not sufficient in the majority of locations. On the other hand, the prime revision set up by the RD 2818/98. considering the profitability of the renewable installations, demand a regional analysis of small PV systems profitability necessary in Spain. The accomplished results permit to conclude that the amount of the current prime is by itself insufficient to make profitable the small grid-connected PV systems in anywhere of the national geography. To guarantee the profitability of these systems is should be necessary to place the fix price at around 0,93 Euros/k Wh. However, if the duplication of the current price obtained by these installations was considered, this could ensure the profitability of these small systems in at least the 77% of the land. (Author) 12 refs.

  20. GRID INFORMATION SECURITY FUNCTIONAL REQUIREMENT

    OpenAIRE

    Amy Poh Ai Ling; Mukaidono Masao

    2011-01-01

    This paper describes the background of smart information infrastructure and the needs for smart grid information security. It introduces the conceptual analysis to the methodology with the application ofhermeneutic circle and information security functional requirement identification. Information security for the grid market cover matters includes automation and communications industry that affects the operation of electric power systems and the functioning of the utilities that manage them ...

  1. Smart grid applications and developments

    CERN Document Server

    Mah, Daphne; Li, Victor OK; Balme, Richard

    2014-01-01

    Meeting today's energy and climate challenges require not only technological advancement but also a good understanding of stakeholders' perceptions, political sensitivity, well-informed policy analyses and innovative interdisciplinary solutions. This book will fill this gap. This is an interdisciplinary informative book to provide a holistic and integrated understanding of the technology-stakeholder-policy interactions of smart grid technologies. The unique features of the book include the following: (a) interdisciplinary approach - by bringing in the policy dimensions to smart grid technologi

  2. Smart Grid Communication Middleware Comparison

    OpenAIRE

    Petersen, Bo Søborg; Bindner, Henrik W.; Poulsen, Bjarne; You, Shi

    2017-01-01

    Communication between Distributed Energy Resources (DERs) is necessary to efficiently solve the intermittency issues caused by renewable energy, using DER power grid auxiliary services, primarily load shifting and shedding. The middleware used for communication determines which services are possible by their performance, which is limited by the middleware characteristics, primarily interchangeable serialization and the Publish-Subscribe messaging pattern. The earlier paper “Smart Grid Seriali...

  3. The prosumers and the grid

    OpenAIRE

    Gautier, Axel; Jacqmin, Julien; Poudou, Jean-Christophe

    2017-01-01

    Prosumers are households that are both producers and consumers of electricity. A prosumer has a grid-connected decentralized production unit (DPU) and makes two types of exchanges with the grid: energy imports when the local production is insufficient to match the local consumption and energy exports when local production exceeds it. There exists two systems to measure the exchanges : a net metering system that uses a single meter to measure the balance between exports and imports and a net p...

  4. LA TITUDE-LONGITUDE GRID MAPS OF AFRICA (CCTA ...

    African Journals Online (AJOL)

    made at a CCTAjCSA specialist meeting on the Cartography of Vectors of Disease, Bukavu-. Lwiro, 1957 (see CCTAjCSA Publication No. 29, 1958). The maps are printed on a good quality cartridge paper, on the same scales and projection. (zenithal equal area) as the CCTA Climatological Atlas.· The grid and the base ...

  5. Workload characterization, modeling, and prediction in grid Computing

    NARCIS (Netherlands)

    Li, Hui

    2008-01-01

    Workloads play an important role in experimental performance studies of computer systems. This thesis presents a comprehensive characterization of real workloads on production clusters and Grids. A variety of correlation structures and rich scaling behavior are identified in workload attributes such

  6. Development of smart conductive 2D-3D textile grid

    NARCIS (Netherlands)

    Agrawal, P. (Pramod); Bottenberg, E. (Eliza); Brinks, G.J. (Ger); Gooijer, H. (Henk)

    2013-01-01

    The conductive textile grid is a large-scale (226 x 115 cm) multi-layer demonstrator exhibiting different conductive textile materials with certain outputs (such as LEDs, thermo-chromic ink and shape memory alloy) can be connected onto a base conductive fabric. Various conductive materials such as

  7. 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

  8. Resilience of Urban Smart Grids Involving Multiple Control Loops

    DEFF Research Database (Denmark)

    Madsen, Jacob Theilgaard; Pillai, Jayakrishnan Radhakrishna; Schwefel, Hans-Peter

    2016-01-01

    Intelligent control of energy distribution grids is implemented via a hierarchy of control loops with different input values and different control targets, which also work on different time-scales. This control is enabled by a bi-directional communication flow, which can be interrupted due to ICT...

  9. The cosmic web in CosmoGrid void regions

    NARCIS (Netherlands)

    Rieder, Steven; van de Weygaert, Rien; Cautun, Marius; Beygu, Burcu; Portegies Zwart, Simon

    2016-01-01

    We study the formation and evolution of the cosmic web, using the high-resolution CosmoGrid ΛCDM simulation. In particular, we investigate the evolution of the large-scale structure around void halo groups, and compare this to observations of the VGS-31 galaxy group, which consists of three

  10. Fusion energy in an inertial electrostatic confinement device using a magnetically shielded grid

    Energy Technology Data Exchange (ETDEWEB)

    Hedditch, John, E-mail: john.hedditch@sydney.edu.au; Bowden-Reid, Richard, E-mail: rbow3948@physics.usyd.edu.au; Khachan, Joe, E-mail: joe.khachan@sydney.edu.au [School of Physics, The University of Sydney, Sydney, New South Whales 2006 (Australia)

    2015-10-15

    Theory for a gridded inertial electrostatic confinement (IEC) fusion system is presented, which shows a net energy gain is possible if the grid is magnetically shielded from ion impact. A simplified grid geometry is studied, consisting of two negatively biased coaxial current-carrying rings, oriented such that their opposing magnetic fields produce a spindle cusp. Our analysis indicates that better than break-even performance is possible even in a deuterium-deuterium system at bench-top scales. The proposed device has the unusual property that it can avoid both the cusp losses of traditional magnetic fusion systems and the grid losses of traditional IEC configurations.

  11. Fusion in a magnetically-shielded-grid inertial electrostatic confinement device

    CERN Document Server

    Hedditch, John; Khachan, Joe

    2015-01-01

    Theory for a gridded inertial electrostatic confinement (IEC) fusion system is presented that shows a net energy gain is possible if the grid is magnetically shielded from ion impact. A simplified grid geometry is studied, consisting of two negatively-biased coaxial current-carrying rings, oriented such that their opposing magnetic fields produce a spindle cusp. Our analysis indicates that better than break-even performance is possible even in a deuterium-deuterium system at bench-top scales. The proposed device has the unusual property that it can avoid both the cusp losses of traditional magnetic fusion systems and the grid losses of traditional IEC configurations.

  12. Bio-Inspired Cyber Security for Smart Grid Deployments

    Energy Technology Data Exchange (ETDEWEB)

    McKinnon, Archibald D.; Thompson, Seth R.; Doroshchuk, Ruslan A.; Fink, Glenn A.; Fulp, Errin W.

    2013-05-01

    mart grid technologies are transforming the electric power grid into a grid with bi-directional flows of both power and information. Operating millions of new smart meters and smart appliances will significantly impact electric distribution systems resulting in greater efficiency. However, the scale of the grid and the new types of information transmitted will potentially introduce several security risks that cannot be addressed by traditional, centralized security techniques. We propose a new bio-inspired cyber security approach. Social insects, such as ants and bees, have developed complex-adaptive systems that emerge from the collective application of simple, light-weight behaviors. The Digital Ants framework is a bio-inspired framework that uses mobile light-weight agents. Sensors within the framework use digital pheromones to communicate with each other and to alert each other of possible cyber security issues. All communication and coordination is both localized and decentralized thereby allowing the framework to scale across the large numbers of devices that will exist in the smart grid. Furthermore, the sensors are light-weight and therefore suitable for implementation on devices with limited computational resources. This paper will provide a brief overview of the Digital Ants framework and then present results from test bed-based demonstrations that show that Digital Ants can identify a cyber attack scenario against smart meter deployments.

  13. AstroGrid-D: Grid technology for astronomical science

    Science.gov (United States)

    Enke, Harry; Steinmetz, Matthias; Adorf, Hans-Martin; Beck-Ratzka, Alexander; Breitling, Frank; Brüsemeister, Thomas; Carlson, Arthur; Ensslin, Torsten; Högqvist, Mikael; Nickelt, Iliya; Radke, Thomas; Reinefeld, Alexander; Reiser, Angelika; Scholl, Tobias; Spurzem, Rainer; Steinacker, Jürgen; Voges, Wolfgang; Wambsganß, Joachim; White, Steve

    2011-02-01

    We present status and results of AstroGrid-D, a joint effort of astrophysicists and computer scientists to employ grid technology for scientific applications. AstroGrid-D provides access to a network of distributed machines with a set of commands as well as software interfaces. It allows simple use of computer and storage facilities and to schedule or monitor compute tasks and data management. It is based on the Globus Toolkit middleware (GT4). Chapter 1 describes the context which led to the demand for advanced software solutions in Astrophysics, and we state the goals of the project. We then present characteristic astrophysical applications that have been implemented on AstroGrid-D in chapter 2. We describe simulations of different complexity, compute-intensive calculations running on multiple sites (Section 2.1), and advanced applications for specific scientific purposes (Section 2.2), such as a connection to robotic telescopes (Section 2.2.3). We can show from these examples how grid execution improves e.g. the scientific workflow. Chapter 3 explains the software tools and services that we adapted or newly developed. Section 3.1 is focused on the administrative aspects of the infrastructure, to manage users and monitor activity. Section 3.2 characterises the central components of our architecture: The AstroGrid-D information service to collect and store metadata, a file management system, the data management system, and a job manager for automatic submission of compute tasks. We summarise the successfully established infrastructure in chapter 4, concluding with our future plans to establish AstroGrid-D as a platform of modern e-Astronomy.

  14. Stability identification for grid-connected inverters with LCL filters considering grid-voltage feedforward regulator

    DEFF Research Database (Denmark)

    Lu, Minghui; Blaabjerg, Frede

    2017-01-01

    This paper identifies stable resonance frequency range for grid-connected inverter with Grid-Voltage Feedforward Regulator (GVFR). Beginning with the current loop stability analysis without GVFR, system poles distribution is analytically studied in z-domain, the critical frequency is therefore...... calculated as well as the control gain limit. Then, this paper reveals the GVFR would change the system stability in the weak power system, two frequency boundaries and three typical resonance frequency ranges are identified and compared. System poles distribution shows that GVFR can offer damping effects...... when resonance frequency is below ωs/3, in contrast, over which GVFR will destabilize the system. The theoretical analysis is validated by experimental tests based on a laboratory-scale prototype....

  15. Structural vulnerability assessment of electric power grids

    NARCIS (Netherlands)

    Koç, Y.; Warnier, M.; Kooij, R.E.; Brazier, F.

    2014-01-01

    Cascading failures are the typical reasons of blackouts in power grids. The grid topology plays an important role in determining the dynamics of cascading failures in power grids. Measures for vulnerability analysis are crucial to assure a higher level of robustness of power grids. Metrics from

  16. The performance of GridPix detectors

    NARCIS (Netherlands)

    Bilevych, Y.; Blanco Carballo, V.M.; Breur, S.; Fransen, M.; van der Graaf, H.; Hartjes, F.; Hessey, N.; Kalter, R.; Ketel, T.; Koppert, W.C.; Rogers, M.; Schmitz, Jurriaan; Timmermans, J.; Visschers, J.

    2009-01-01

    The GridPix detector is an assembly of a TimePix pixel chip, covered with a layer of silicon rich silicon nitride (SiRN) as protection against discharges, an integrated MPGD grid (InGrid), a drift gap and a cathode plane. GridPix detectors have been tested using a test beam at DESY. Measurements

  17. When social practices meet smart grids

    NARCIS (Netherlands)

    Smale, Robin; Vliet, van Bas; Spaargaren, Gert

    2017-01-01

    This article seeks to analyse recent shifts in goals concerning domestic energy uses. Drawing on two Dutch smart grid projects, we observe that in the smart grid transition the balancing of (renewable) supply and demand in energy grids becomes the key priority of grid managers. This shift becomes

  18. Grid-Optimization Program for Photovoltaic Cells

    Science.gov (United States)

    Daniel, R. E.; Lee, T. S.

    1986-01-01

    CELLOPT program developed to assist in designing grid pattern of current-conducting material on photovoltaic cell. Analyzes parasitic resistance losses and shadow loss associated with metallized grid pattern on both round and rectangular solar cells. Though performs sensitivity studies, used primarily to optimize grid design in terms of bus bar and grid lines by minimizing power loss. CELLOPT written in APL.

  19. Grid Fin Stabilization of the Orion Launch Abort Vehicle

    Science.gov (United States)

    Pruzan, Daniel A.; Mendenhall, Michael R.; Rose, William C.; Schuster, David M.

    2011-01-01

    Wind tunnel tests were conducted by Nielsen Engineering & Research (NEAR) and Rose Engineering & Research (REAR) in conjunction with the NASA Engineering & Safety Center (NESC) on a 6%-scale model of the Orion launch abort vehicle (LAV) configured with four grid fins mounted near the base of the vehicle. The objectives of these tests were to 1) quantify LAV stability augmentation provided by the grid fins from subsonic through supersonic Mach numbers, 2) assess the benefits of swept grid fins versus unswept grid fins on the LAV, 3) determine the effects of the LAV abort motors on grid fin aerodynamics, and 4) generate an aerodynamic database for use in the future application of grid fins to small length-to-diameter ratio vehicles similar to the LAV. The tests were conducted in NASA Ames Research Center's 11x11-foot transonic wind tunnel from Mach 0.5 through Mach 1.3 and in their 9x7-foot supersonic wind tunnel from Mach 1.6 through Mach 2.5. Force- and moment-coefficient data were collected for the complete vehicle and for each individual grid fin as a function of angle of attack and sideslip angle. Tests were conducted with both swept and unswept grid fins with the simulated abort motors (cold jets) off and on. The swept grid fins were designed with a 22.5deg aft sweep angle for both the frame and the internal lattice so that the frontal projection of the swept fins was the same as for the unswept fins. Data from these tests indicate that both unswept and swept grid fins provide significant improvements in pitch stability as compared to the baseline vehicle over the Mach number range investigated. The swept fins typically provide improved stability as compared to the unswept fins, but the performance gap diminished as Mach number was increased. The aerodynamic performance of the fins was not observed to degrade when the abort motors were turned on. Results from these tests indicate that grid fins can be a robust solution for stabilizing the Orion LAV over a wide

  20. Grid Representations and the Chromatic Number

    OpenAIRE

    Balko, Martin

    2012-01-01

    A grid drawing of a graph maps vertices to grid points and edges to line segments that avoid grid points representing other vertices. We show that there is a number of grid points that some line segment of an arbitrary grid drawing must intersect. This number is closely connected to the chromatic number. Second, we study how many columns we need to draw a graph in the grid, introducing some new $\\NP$-complete problems. Finally, we show that any planar graph has a planar grid drawing where eve...

  1. Performance Enhancement Strategies for Multi-Block Overset Grid CFD Applications

    Science.gov (United States)

    Djomehri, M. Jahed; Biswas, Rupak

    2003-01-01

    The overset grid methodology has significantly reduced time-to-solution of highfidelity computational fluid dynamics (CFD) simulations about complex aerospace configurations. The solution process resolves the geometrical complexity of the problem domain by using separately generated but overlapping structured discretization grids that periodically exchange information through interpolation. However, high performance computations of such large-scale realistic applications must be handled efficiently on state-of-the-art parallel supercomputers. This paper analyzes the effects of various performance enhancement strategies on the parallel efficiency of an overset grid Navier-Stokes CFD application running on an SGI Origin2000 machinc. Specifically, the role of asynchronous communication, grid splitting, and grid grouping strategies are presented and discussed. Details of a sophisticated graph partitioning technique for grid grouping are also provided. Results indicate that performance depends critically on the level of latency hiding and the quality of load balancing across the processors.

  2. 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...... model of the DFIG under recurring grid faults is verified by simulations on a 1.5-MW DFIG wind turbine system model and experiments on a 30-kW reduced scale DFIG test system....

  3. The AgMIP GRIDded Crop Modeling Initiative (AgGRID) and the Global Gridded Crop Model Intercomparison (GGCMI)

    Science.gov (United States)

    Elliott, Joshua; Muller, Christoff

    2015-01-01

    Climate change is a significant risk for agricultural production. Even under optimistic scenarios for climate mitigation action, present-day agricultural areas are likely to face significant increases in temperatures in the coming decades, in addition to changes in precipitation, cloud cover, and the frequency and duration of extreme heat, drought, and flood events (IPCC, 2013). These factors will affect the agricultural system at the global scale by impacting cultivation regimes, prices, trade, and food security (Nelson et al., 2014a). Global-scale evaluation of crop productivity is a major challenge for climate impact and adaptation assessment. Rigorous global assessments that are able to inform planning and policy will benefit from consistent use of models, input data, and assumptions across regions and time that use mutually agreed protocols designed by the modeling community. To ensure this consistency, large-scale assessments are typically performed on uniform spatial grids, with spatial resolution of typically 10 to 50 km, over specified time-periods. Many distinct crop models and model types have been applied on the global scale to assess productivity and climate impacts, often with very different results (Rosenzweig et al., 2014). These models are based to a large extent on field-scale crop process or ecosystems models and they typically require resolved data on weather, environmental, and farm management conditions that are lacking in many regions (Bondeau et al., 2007; Drewniak et al., 2013; Elliott et al., 2014b; Gueneau et al., 2012; Jones et al., 2003; Liu et al., 2007; M¨uller and Robertson, 2014; Van den Hoof et al., 2011;Waha et al., 2012; Xiong et al., 2014). Due to data limitations, the requirements of consistency, and the computational and practical limitations of running models on a large scale, a variety of simplifying assumptions must generally be made regarding prevailing management strategies on the grid scale in both the baseline and

  4. Grid-size dependence of Cauchy boundary conditions used to simulate stream-aquifer interactions

    Science.gov (United States)

    Mehl, S.; Hill, M.C.

    2010-01-01

    This work examines the simulation of stream–aquifer interactions as grids are refined vertically and horizontally and suggests that traditional methods for calculating conductance can produce inappropriate values when the grid size is changed. Instead, different grid resolutions require different estimated values. Grid refinement strategies considered include global refinement of the entire model and local refinement of part of the stream. Three methods of calculating the conductance of the Cauchy boundary conditions are investigated. Single- and multi-layer models with narrow and wide streams produced stream leakages that differ by as much as 122% as the grid is refined. Similar results occur for globally and locally refined grids, but the latter required as little as one-quarter the computer execution time and memory and thus are useful for addressing some scale issues of stream–aquifer interactions. Results suggest that existing grid-size criteria for simulating stream–aquifer interactions are useful for one-layer models, but inadequate for three-dimensional models. The grid dependence of the conductance terms suggests that values for refined models using, for example, finite difference or finite-element methods, cannot be determined from previous coarse-grid models or field measurements. Our examples demonstrate the need for a method of obtaining conductances that can be translated to different grid resolutions and provide definitive test cases for investigating alternative conductance formulations.

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

    Energy Technology Data Exchange (ETDEWEB)

    2016-04-01

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

  6. Smart Grid Information Security (IS) Functional Requirement

    OpenAIRE

    Ling, Amy Poh Ai; Masao, Mukaidono

    2011-01-01

    It is important to implement safe smart grid environment to enhance people's lives and livelihoods. This paper provides information on smart grid IS functional requirement by illustrating some discussion points to the sixteen identified requirements. This paper introduces the smart grid potential hazards that can be referred as a triggering factor to improve the system and security of the entire grid. The background of smart information infrastructure and the needs for smart grid IS is descri...

  7. The Hermann grid illusion revisited.

    Science.gov (United States)

    Schiller, Peter H; Carvey, Christina E

    2005-01-01

    The Hermann grid illusion consists of smudges perceived at the intersections of a white grid presented on a black background. In 1960 the effect was first explained by a theory advanced by Baumgartner suggesting the illusory effect is due to differences in the discharge characteristics of retinal ganglion cells when their receptive fields fall along the intersections versus when they fall along non-intersecting regions of the grid. Since then, others have claimed that this theory might not be adequate, suggesting that a model based on cortical mechanisms is necessary [Lingelbach et al, 1985 Perception 14(1) A7; Spillmann, 1994 Perception 23 691 708; Geier et al, 2004 Perception 33 Supplement, 53; Westheimer, 2004 Vision Research 44 2457 2465]. We present in this paper the following evidence to show that the retinal ganglion cell theory is untenable: (i) varying the makeup of the grid in a manner that does not materially affect the putative differential responses of the ganglion cells can reduce or eliminate the illusory effect; (ii) varying the grid such as to affect the putative differential responses of the ganglion cells does not eliminate the illusory effect; and (iii) the actual spatial layout of the retinal ganglion cell receptive fields is other than that assumed by the theory. To account for the Hermann grid illusion we propose an alternative theory according to which the illusory effect is brought about by the manner in which S1 type simple cells (as defined by Schiller et al, 1976 Journal of Neurophysiology 39 1320-1333) in primary visual cortex respond to the grid. This theory adequately handles many of the facts delineated in this paper.

  8. Subsatellite experiments in a coastal region of the Black sea

    Science.gov (United States)

    Bakhanov, V.; Bogatov, N.; Ermoshkin, A.; Kazakov, V.; Kemarskaya, O.; Lobanov, V.; Repina, I.; Titov, V.; Troitskaya, Yu.; Zuikova, E.

    2009-04-01

    The results of field experiments carried out in 2007, 2008 in a north-east part of the Black sea in region of city Gelendzhik, are given. Experiments targeted the development of a bottom topography remote (radar and optical) diagnostics. Experimental area is characterized by abrupt depth dumping (fall 50 - 1250 m), and irregularity of a bank vault (numerous canyons). Such bottom topography in the presence of alongshore current creates favorable conditions for hydrodynamic perturbations on thermocline and corresponding anomalies on sea surface and in atmospheric surface layer characteristics. The simultaneous measurement of atmospheric near-surface layer, sea surface and sea bulk parameters synchronously with reception of the radar image from the satellite ENVISAT was feature of the given experiment. The ground-based measurements were carried out simultaneously from high coast by means of X-band radar and from R/V "Aquanaut" (Institute of Oceanology RAS). The meteorological conditions during observations varied considerably. The wind velocity changed from 0 up to 10 m/c, heaving - from 0 up to 4 balls. The short-term atmospheric precipitations were observed. The bottom topography was measured by echo-sounder. Investigation of the hydrological characteristics was carried out by combined SVP-CTD probe. The current field was measured by ADCP. The surface wave characteristics in length range 4 mm - 1 m were measured by X and Ka radar and two-dimensional optical spectrum analyzer. Air temperature, relative humidity, atmospheric pressure, wind velocity and direction were measured. Sonic anemometer-thermometer for recording horizontal and vertical components of the wind and temperature fluctuations in the surface layer was used. The connection of current field heterogeneities with a bottom configuration in region of depth dumping is investigated. The correlation of radar signal with current speed in near-surface region is observed also. For example, the slicks are observed in region of the current maximal gradient, which in our experiments placed above depth dumping. Surface wave transformation, in turn, gives a variability of mesoscale component of meteorological fields in atmospheric near-surface layer. Heat and momentum turbulent fluxes above surface waves were determined by eddy correlation technique. The measurements have shown that in all cases when anomalies were present at the surface the structure of the atmospheric turbulence changed. Therefore, we may conclude that the features of bottom topography can be reflected in the surface wave and atmospheric near-surface layer. The joint processing of the satellite image (SAR signal intensity) sections along a tacks and wind, surface wave and current in sea upper layer parameters measured from the research vessel "Aquanaut", was carried out. The comparison of satellite sections to the 3 cm radar (VV polarization) data has shown their good agreement on time interval one hour. At comparison of radar panoramas received from the satellite (wave-length 5.6 cm, VV polarization) and from the vessel (wave-length 3 cm, HH polarization) was shown their similarity, in particular slick bands are mapped equally. The examples of feature comparison of the radar satellite images (slicks, wind fronts etc.) with a variability of atmospheric near-surface layer and sea bulk parameters also are considered. It was found, that the presence of features on the satellite images is always connected with variability of measured physical characteristics. This work was supported by the grant RFBR 08-05-00195, 07-05-00565, 07-05-12011, 07-05-10106, 08-05-10047.

  9. 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.

  10. Tools and Techniques for Measuring and Improving Grid Performance

    Science.gov (United States)

    Biswas, Rupak; Frumkin, M.; Smith, W.; VanderWijngaart, R.; Wong, P.; Biegel, Bryan (Technical Monitor)

    2001-01-01

    This viewgraph presentation provides information on NASA's geographically dispersed computing resources, and the various methods by which the disparate technologies are integrated within a nationwide computational grid. Many large-scale science and engineering projects are accomplished through the interaction of people, heterogeneous computing resources, information systems and instruments at different locations. The overall goal is to facilitate the routine interactions of these resources to reduce the time spent in design cycles, particularly for NASA's mission critical projects. The IPG (Information Power Grid) seeks to implement NASA's diverse computing resources in a fashion similar to the way in which electric power is made available.

  11. Industrial Demand Management Providing Ancillary Services to the Distribution Grid

    DEFF Research Database (Denmark)

    Rahnama, Samira; Green, Torben; Lyhne, Casper

    2017-01-01

    delivery. Consumers' involvement requires new entities and infrastructure. A so-called aggregator has been introduced as a new player to manage the services that are offered by the consumption units. This paper describes an industrial scale experimental setup for evaluating a particular type of aggregator......A prominent feature of the future smart grid is the active participation of the consumer side in ancillary service provision. Grid operators procure ancillary services, including regulating power, voltage control, frequency control, and so on, to ensure safe, reliable, and high-quality electricity...

  12. Smart Grid Information Clearinghouse (SGIC)

    Energy Technology Data Exchange (ETDEWEB)

    Rahman, Saifur [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States)

    2014-08-31

    Since the Energy Independence and Security Act of 2007 was enacted, there has been a large number of websites that discusses smart grid and relevant information, including those from government, academia, industry, private sector and regulatory. These websites collect information independently. Therefore, smart grid information was quite scattered and dispersed. The objective of this work was to develop, populate, manage and maintain the public Smart Grid Information Clearinghouse (SGIC) web portal. The information in the SGIC website is comprehensive that includes smart grid information, research & development, demonstration projects, technical standards, costs & benefit analyses, business cases, legislation, policy & regulation, and other information on lesson learned and best practices. The content in the SGIC website is logically grouped to allow easily browse, search and sort. In addition to providing the browse and search feature, the SGIC web portal also allow users to share their smart grid information with others though our online content submission platform. The Clearinghouse web portal, therefore, serves as the first stop shop for smart grid information that collects smart grid information in a non-bias, non-promotional manner and can provide a missing link from information sources to end users and better serve users’ needs. The web portal is available at www.sgiclearinghouse.org. This report summarizes the work performed during the course of the project (September 2009 – August 2014). Section 2.0 lists SGIC Advisory Committee and User Group members. Section 3.0 discusses SGIC information architecture and web-based database application functionalities. Section 4.0 summarizes SGIC features and functionalities, including its search, browse and sort capabilities, web portal social networking, online content submission platform and security measures implemented. Section 5.0 discusses SGIC web portal contents, including smart grid 101, smart grid projects

  13. Smoothing effect for spatially distributed renewable resources and its impact on power grid robustness

    CERN Document Server

    Nagata, Motoki; Fujiwara, Naoya; Tanaka, Gouhei; Suzuki, Hideyuki; Aihara, Kazuyuki

    2015-01-01

    In this paper, we show that spatial correlation of renewable energy outputs greatly influences the robustness of power grids. First, we propose a new index for the spatial correlation among renewable energy outputs. We find that the spatial correlation of renewable energy outputs in a short time-scale is as weak as that caused by independent random variables and that in a long time-scale is as strong as that under perfect synchronization. Then, by employing the topology of the power grid in eastern Japan, we analyze the robustness of the power grid with spatial correlation of renewable energy outputs. The analysis is performed by using a realistic differential-algebraic equations model and the result shows that the spatial correlation of the energy resources strongly degrades the robustness of the power grid. Our result suggests that the spatial correlation of the renewable energy outputs should be taken into account when estimating the stability of power grids.

  14. Building the TeraGrid.

    Science.gov (United States)

    Beckman, Peter H

    2005-08-15

    On 1 October 2004, the most ambitious high-performance Grid project in the United States-the TeraGrid-became fully operational. Resources at nine sites--the San Diego Supercomputer Center, the California Institute of Technology, the National Center for Supercomputing Applications, the University of Chicago/Argonne National Laboratory, Pittsburgh Supercomputing Center, Texas Advanced Computing Center, Purdue University, Indiana University and Oak Ridge National Laboratory-were joined via an ultra-fast optical network, unified policies and security procedures and a sophisticated distributed computing software environment. Funded by the National Science Foundation, the TeraGrid enables scientists and engineers to combine distributed, multiple data sources with computation at any of the sites or link massively parallel computer simulations to extreme-resolution visualizations at remote sites. A single shared utility lets multiple resources be easily leveraged and provides improved access to advanced computational capabilities. One of the demonstrations of this new model for using distributed resources, Teragyroid, linked the infrastructure of the TeraGrid with computing resources in the United Kingdom via a transatlantic data fibre link. Once connected, the software framework of the RealityGrid project was used to successfully explore lattice-Boltzmann simulations involving lattices of over one billion sites.

  15. Gridded Species Distribution, Version 1: Mammals of the Americas Family Richness Grids

    Data.gov (United States)

    National Aeronautics and Space Administration — The Mammals of the Americas Family Richness Grids of the Gridded Species Distribution, Version 1 are aggregations of the presence grids data at the family level....

  16. Gridded Species Distribution, Version 1: Mammals of the Americas Presence Grids

    Data.gov (United States)

    National Aeronautics and Space Administration — The Mammals of the Americas Presence Grids of the Gridded Species Distribution, Version 1 is a reclassified version of the original grids of the mammal species...

  17. Gridded Species Distribution, Version 1: Birds of the Americas Original Grids

    Data.gov (United States)

    National Aeronautics and Space Administration — The Birds of the Americas Original Grids of the Gridded Species Distribution, Version 1are converted 1- kilometer grid cell data in the Geographic Coordinate System...

  18. Gridded Species Distribution, Version 1: Birds of the Americas Presence Grids

    Data.gov (United States)

    National Aeronautics and Space Administration — The Birds of the Americas Family Presence Grids of the Gridded Species Distribution, Version 1 is a reclassified version of the original grids of the bird species...

  19. Gridded Species Distribution, Version 1: Birds of the Americas Family Richness Grids

    Data.gov (United States)

    National Aeronautics and Space Administration — The Birds of the Americas Family Richness Grids of the Gridded Species Distribution, Version 1 are the aggregations of the Presence Grids data at the family level....

  20. Gridded Population of the World, Version 3 (GPWv3): National Identifier Grid

    Data.gov (United States)

    National Aeronautics and Space Administration — Gridded Population of the World, Version 3 (GPWv3) National Identifier Grid is derived from the land area grid to create a raster surface where pixels (cells) that...

  1. Gridded Species Distribution, Version 1: Mammals of the Americas Original Grids

    Data.gov (United States)

    National Aeronautics and Space Administration — The Mammals of the Americas Original Grids of the Gridded Species Distribution, Version 1 are converted 1- kilometer grid cell data in the Geographic Coordinate...

  2. Grids: The Top Ten Questions

    Directory of Open Access Journals (Sweden)

    Jennifer M. Schopf

    2002-01-01

    Full Text Available The design and implementation of a national computing system and data grid has become a reachable goal from both the computer science and computational science point of view. A distributed infrastructure capable of sophisticated computational functions can bring many benefits to scientific work, but poses many challenges, both technical and socio-political. Technical challenges include having basic software tools, higher-level services, functioning and pervasive security, and standards, while socio-political issues include building a user community, adding incentives for sites to be part of a user-centric environment, and educating funding sources about the needs of this community. This paper details the areas relating to Grid research that we feel still need to be addressed to fully leverage the advantages of the Grid.

  3. Famed lab seeks big grid

    CERN Multimedia

    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.

  4. Earth Science Data Grid System

    Science.gov (United States)

    Chi, Y.; Yang, R.; Kafatos, M.

    2004-12-01

    The Earth Science Data Grid System (ESDGS) is a software in support of earth science data storage and access. It is built upon the Storage Resource Broker (SRB) data grid technology. We have developed a complete data grid system consistent of SRB server providing users uniform access to diverse storage resources in a heterogeneous computing environment and metadata catalog server (MCAT) managing the metadata associated with data set, users, and resources. We are also developing additional services of 1) metadata management, 2) geospatial, temporal, and content-based indexing, and 3) near/on site data processing, in response to the unique needs of Earth science applications. In this paper, we will describe the software architecture and components of the system, and use a practical example in support of storage and access of rainfall data from the Tropical Rainfall Measuring Mission (TRMM) to illustrate its functionality and features.

  5. Vortex Filaments in Grids for Scalable, Fine Smoke Simulation.

    Science.gov (United States)

    Meng, Zhang; Weixin, Si; Yinling, Qian; Hanqiu, Sun; Jing, Qin; Heng, Pheng-Ann

    2015-01-01

    Vortex modeling can produce attractive visual effects of dynamic fluids, which are widely applicable for dynamic media, computer games, special effects, and virtual reality systems. However, it is challenging to effectively simulate intensive and fine detailed fluids such as smoke with fast increasing vortex filaments and smoke particles. The authors propose a novel vortex filaments in grids scheme in which the uniform grids dynamically bridge the vortex filaments and smoke particles for scalable, fine smoke simulation with macroscopic vortex structures. Using the vortex model, their approach supports the trade-off between simulation speed and scale of details. After computing the whole velocity, external control can be easily exerted on the embedded grid to guide the vortex-based smoke motion. The experimental results demonstrate the efficiency of using the proposed scheme for a visually plausible smoke simulation with macroscopic vortex structures.

  6. Job Superscheduler Architecture and Performance in Computational Grid Environments

    Science.gov (United States)

    Shan, Hongzhang; Oliker, Leonid; Biswas, Rupak

    2003-01-01

    Computational grids hold great promise in utilizing geographically separated heterogeneous resources to solve large-scale complex scientific problems. However, a number of major technical hurdles, including distributed resource management and effective job scheduling, stand in the way of realizing these gains. In this paper, we propose a novel grid superscheduler architecture and three distributed job migration algorithms. We also model the critical interaction between the superscheduler and autonomous local schedulers. Extensive performance comparisons with ideal, central, and local schemes using real workloads from leading computational centers are conducted in a simulation environment. Additionally, synthetic workloads are used to perform a detailed sensitivity analysis of our superscheduler. Several key metrics demonstrate that substantial performance gains can be achieved via smart superscheduling in distributed computational grids.

  7. Health-e-Child a grid platform for european paediatrics

    CERN Document Server

    Skaburskas, K; Shade, J; Manset, D; Revillard, J; Rios, A; Anjum, A; Branson, A; Bloodsworth, P; Hauer, T; McClatchey, R; Rogulin, D

    2008-01-01

    The Health-e-Child (HeC) project [1], [2] is an EC Framework Programme 6 Integrated Project that aims to develop a grid-based integrated healthcare platform for paediatrics. Using this platform biomedical informaticians will integrate heterogeneous data and perform epidemiological studies across Europe. The resulting Grid enabled biomedical information platform will be supported by robust search, optimization and matching techniques for information collected in hospitals across Europe. In particular, paediatricians will be provided with decision support, knowledge discovery and disease modelling applications that will access data in hospitals in the UK, Italy and France, integrated via the Grid. For economy of scale, reusability, extensibility, and maintainability, HeC is being developed on top of an EGEE/gLite [3] based infrastructure that provides all the common data and computation management services required by the applications. This paper discusses some of the major challenges in bio-medical data integr...

  8. Effect of Under-Resolved Grids on High Order Methods

    Science.gov (United States)

    Yee, H. C.; Sjoegreen, B.; Mansour, Nagi (Technical Monitor)

    2001-01-01

    There has been much discussion on verification and validation processes for establishing the credibility of CFD simulations. Since the early 1990s, many of the aeronautical and mechanical engineering related reference journals mandated that any accepted articles in numerical simulations (without known solutions to compared with) need to perform a minimum of one level of grid refinement and time step reduction. Due to the difficulty in analysis, the effect of under-resolved grids and the nonlinear behavior of available spatial discretizations, are scarcely discussed in the literature. Here, an under-resolved numerical simulation is one where the grid spacing being used is too coarse to resolve the smallest physically relevant scales of the chosen continuum governing equations that are of interest to the numerical modeler. With the advent of new developments in fourth-order or higher spatial schemes, it has become common to regard high order schemes as more accurate, reliable and require less grid points. The danger comes when one tries to perform computations with the coarsest grid possible while still hoping to maintain numerical results sufficiently accurate for complex flows, and especially, data-limited problems. On one hand, high order methods when applies to highly coupled multidimensional complex nonlinear problems might have different stability, convergence and reliability behavior than their well studied low order counterparts, especially for nonlinear schemes such as TVD, MUSCL with limiters, ENO, WENO and discrete Galerkin. On the other hand, high order methods involve more operation counts and systematic grid convergence study can be time consuming and prohibitively expansive. At the same time it is difficult to fully understand or categorize the different nonlinear behavior of finite discretizations, especially at the limits of under-resolution when different types of bifurcation phenomena might occur, depending on the combination of grid spacings, time

  9. Hydrography-driven coarsening of grid digital elevation models

    Science.gov (United States)

    Moretti, Giovanni; Orlandini, Stefano

    2017-04-01

    Grid coarsening is commonly applied to high-resolution digital elevation models to obtain suitable meshes for distributed catchment models, especially when computational constrains inherent to large-scale and/or long-term simulations need to be satisfied. The nearest neighbor coarsening strategy is the standard method for this task. However, depitting after the nearest neighbor coarsening can yield significant alterations of land surface topography and extracted channel network. It is, therefore, relevant to seek for coarsening strategies that can better distill the information content of high-resolution digital elevation models to ultimately allow coarsened digital elevation models to yield accurate channel networks. A new grid coarsening strategy, denoted as hydrography-driven coarsening, is developed in the present study. In the hydrography-driven coarsening, (1) the high-resolution digital elevation model is depitted, (2) the obtained topographic data are used to extract a reference grid network, and (3) the Horton stream orders are assigned to each link of the extracted grid network. The elevation of the point lying along the highest-order stream within a coarse grid cell and displaying the minimum distance to the coarse grid cell center is assigned to that coarse grid cell. The capabilities of the hydrography-driven coarsening with respect to the standard nearest neighbor coarsening are evaluated over a synthetic valley and two real drainage basins located in the Italian Alps and in the Italian Apennines. The hydrography-driven coarsening method developed yields more accurate depitted digital elevation models than nearest neighbors coarsening. In addition, channels extracted after the proposed coarsening method are closer to observed channels than those extracted after standard coarsening.

  10. Grid Computing in High Energy Physics

    Science.gov (United States)

    Avery, Paul

    2004-09-01

    important area, outlining new research directions and practical experiences in deploying national and international scale Data Grids.

  11. Vehicle-to-Grid Automatic Load Sharing with Driver Preference in Micro-Grids

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yubo; Nazaripouya, Hamidreza; Chu, Chi-Cheng; Gadh, Rajit; Pota, Hemanshu R.

    2014-10-15

    Integration of Electrical Vehicles (EVs) with power grid not only brings new challenges for load management, but also opportunities for distributed storage and generation. This paper comprehensively models and analyzes distributed Vehicle-to-Grid (V2G) for automatic load sharing with driver preference. In a micro-grid with limited communications, V2G EVs need to decide load sharing based on their own power and voltage profile. A droop based controller taking into account driver preference is proposed in this paper to address the distributed control of EVs. Simulations are designed for three fundamental V2G automatic load sharing scenarios that include all system dynamics of such applications. Simulation results demonstrate that active power sharing is achieved proportionally among V2G EVs with consideration of driver preference. In additional, the results also verify the system stability and reactive power sharing analysis in system modelling, which sheds light on large scale V2G automatic load sharing in more complicated cases.

  12. Hierarchical Control for Smart Grids

    DEFF Research Database (Denmark)

    Trangbæk, K; Bendtsen, Jan Dimon; Stoustrup, Jakob

    2011-01-01

    of autonomous consumers. The control system is tasked with balancing electric power production and consumption within the smart grid, and makes active use of the flexibility of a large number of power producing and/or power consuming units. The objective is to accommodate the load variation on the grid, arising...... on one hand from varying consumption, and on the other hand by natural variations in power production e.g. from wind turbines. The high-level MPC problem is solved using quadratic optimisation, while the aggregator level can either involve quadratic optimisation or simple sorting-based min-max solutions...

  13. GENI: Grid Hardware and Software

    Energy Technology Data Exchange (ETDEWEB)

    None

    2012-01-09

    GENI Project: The 15 projects in ARPA-E’s GENI program, short for “Green Electricity Network Integration,” aim to modernize the way electricity is transmitted in the U.S. through advances in hardware and software for the electric grid. These advances will improve the efficiency and reliability of electricity transmission, increase the amount of renewable energy the grid can utilize, and provide energy suppliers and consumers with greater control over their power flows in order to better manage peak power demand and cost.

  14. Smart Regulation for Smart Grids

    OpenAIRE

    Meeus, Leonardo; Saguan, Marcelo; Glachant, Jean-Michel; Belmans, Ronnie

    2010-01-01

    QM-AI-10-001-EN-C (print)/QM-AI-10-001-EN-N (online) The European Union set ambitious objectives for the year 2020 in terms of increase of renewable generation, energy savings and reduction of GHG emissions. These objectives lead Europe towards a complete decarbonisation of the electricity system. There is a key role to be played by grids in facilitating the required transformation and this implies they need to become “smart”. In practical terms, making grids smart means deepening the ener...

  15. Grid for Earth Science Applications

    Science.gov (United States)

    Petitdidier, Monique; Schwichtenberg, Horst

    2013-04-01

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

  16. IGB grid: User's manual (A turbomachinery grid generation code)

    Science.gov (United States)

    Beach, T. A.; Hoffman, G.

    1992-01-01

    A grid generation code called IGB is presented for use in computational investigations of turbomachinery flowfields. It contains a combination of algebraic and elliptic techniques coded for use on an interactive graphics workstation. The instructions for use and a test case are included.

  17. Smart Grids. Innovators talking; Smart Grids. Innovators aan het woord

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-02-15

    Qualitative studies have been conducted of the results of completed projects focused on energy innovation, spread over the seven themes of the top sector Energy: Energy saving in industry, Energy conservation in the built environment, Gas, Bio-energy, Smart grids, Offshore Wind, Solar PV. This provides insight into the follow-up activities and lessons of some EOS (Energy Research Subsidy) completed projects with the aim to inspire, connect and strengthen the TKIs (Topconsortia for Knowledge and Innovation) and individual companies and researchers working on energy innovation. This report concerns the research on Smart Grids [Dutch] Er is een kwalitatief onderzoek uitgevoerd naar de resultaten van afgeronde projecten gericht op energie-innovatie, verdeeld over de zeven thema's van de topsector Energie: Energiebesparing in de industrie; Energiebesparing in de gebouwde omgeving; Gas; Bio-energie; Smart grids; Wind op zee; Zon-pv. Daarmee wordt inzicht gegeven in de vervolgactiviteiten en lessen van een aantal afgesloten EOS-projecten (Energie Onderzoek Subsidie) met het oog op het inspireren, verbinden en versterken van de TKI's (Topconsortia voor Kennis en Innovatie) en individuele bedrijven en onderzoekers die werken aan energie-innovatie. Dit rapport betreft het onderzoek naar Smart Grids.

  18. Production-Grid: Task-Farming in D-Grid

    NARCIS (Netherlands)

    T.A. Knoch (Tobias); Alexander Beck-Ratzka

    2010-01-01

    textabstractDie D-Grid Initiative stellt Bundesweit derzeit >30.000 Rechencores insgesamt 36 Community-Projekten zur Verfügung. Insgesamt wurden bisher in 3 „Calls“ und mehreren Infrastruktursonderinvestitionen ca. 134 Millionen Euro investiert. Auf den Resourcen laufen mehrere sogenannte

  19. A Production-Grid: Answers to WissGrid

    NARCIS (Netherlands)

    T.A. Knoch (Tobias); Alexander Beck-Ratzka

    2011-01-01

    textabstractDie D-Grid Initiative stellt Bundesweit derzeit >30.000 Rechencores insgesamt 36 Community-Projekten zur Verfügung. Insgesamt wurden bisher in 3 „Calls“ und mehreren Infrastruktursonderinvestitionen ca. 134 Millionen Euro investiert. Auf den Resourcen laufen mehrere sogenannte

  20. 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.

  1. 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)

  2. 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.

  3. ARC Cache: A solution for lightweight Grid sites in ATLAS

    CERN Document Server

    Garonne, Vincent; The ATLAS collaboration

    2016-01-01

    Many Grid sites have the need to reduce operational manpower, and running a storage element consumes a large amount of effort. In addition, setting up a new Grid site including a storage element involves a steep learning curve and large investment of time. For these reasons so-called storage-less sites are becoming more popular as a way to provide Grid computing resources with less operational overhead. ARC CE is a widely-used and mature Grid middleware which was designed from the start to be used on sites with no persistent storage element. Instead, it maintains a local self-managing cache of data which retains popular data for future jobs. As the cache is simply an area on a local posix shared filesystem with no external-facing service, it requires no extra maintenance. The cache can be scaled up as required by increasing the size of the filesystem or adding new filesystems. This paper describes how ARC CE and its cache are an ideal solution for lightweight Grid sites in the ATLAS experiment, and the integr...

  4. Gridded National Inventory of U.S. Methane Emissions

    Science.gov (United States)

    Maasakkers, Joannes D.; Jacob, Daniel J.; Sulprizio, Melissa P.; Turner, Alexander J.; Weitz, Melissa; Wirth, Tom; Hight, Cate; DeFigueiredo, Mark; Desai, Mausami; Schmeltz, Rachel; hide

    2016-01-01

    We present a gridded inventory of US anthropogenic methane emissions with 0.1 deg x 0.1 deg spatial resolution, monthly temporal resolution, and detailed scale dependent error characterization. The inventory is designed to be onsistent with the 2016 US Environmental Protection Agency (EPA) Inventory of US Greenhouse Gas Emissionsand Sinks (GHGI) for 2012. The EPA inventory is available only as national totals for different source types. We use a widerange of databases at the state, county, local, and point source level to disaggregate the inventory and allocate the spatial and temporal distribution of emissions for individual source types. Results show large differences with the EDGAR v4.2 global gridded inventory commonly used as a priori estimate in inversions of atmospheric methane observations. We derive grid-dependent error statistics for individual source types from comparison with the Environmental Defense Fund (EDF) regional inventory for Northeast Texas. These error statistics are independently verified by comparison with the California Greenhouse Gas Emissions Measurement (CALGEM) grid-resolved emission inventory. Our gridded, time-resolved inventory provides an improved basis for inversion of atmospheric methane observations to estimate US methane emissions and interpret the results in terms of the underlying processes.

  5. Protecting Intelligent Distributed Power Grids against Cyber Attacks

    Energy Technology Data Exchange (ETDEWEB)

    Dong Wei; Yan Lu; Mohsen Jafari; Paul Skare; Kenneth Rohde

    2010-12-31

    Like other industrial sectors, the electrical power industry is facing challenges involved with the increasing demand for interconnected operations and control. The electrical industry has largely been restructured due to deregulation of the electrical market and the trend of the Smart Grid. This moves new automation systems from being proprietary and closed to the current state of Information Technology (IT) being highly interconnected and open. However, while gaining all of the scale and performance benefits of IT, existing IT security challenges are acquired as well. The power grid automation network has inherent security risks due to the fact that the systems and applications for the power grid were not originally designed for the general IT environment. In this paper, we propose a conceptual layered framework for protecting power grid automation systems against cyber attacks. The following factors are taken into account: (1) integration with existing, legacy systems in a non-intrusive fashion; (2) desirable performance in terms of modularity, scalability, extendibility, and manageability; (3) alignment to the 'Roadmap to Secure Control Systems in the Energy Sector' and the future smart grid. The on-site system test of the developed prototype security system is briefly presented as well.

  6. ENHANCED HYBRID PSO – ACO ALGORITHM FOR GRID SCHEDULING

    Directory of Open Access Journals (Sweden)

    P. Mathiyalagan

    2010-07-01

    Full Text Available Grid computing is a high performance computing environment to solve larger scale computational demands. Grid computing contains resource management, task scheduling, security problems, information management and so on. Task scheduling is a fundamental issue in achieving high performance in grid computing systems. A computational GRID is typically heterogeneous in the sense that it combines clusters of varying sizes, and different clusters typically contains processing elements with different level of performance. In this, heuristic approaches based on particle swarm optimization and ant colony optimization algorithms are adopted for solving task scheduling problems in grid environment. Particle Swarm Optimization (PSO is one of the latest evolutionary optimization techniques by nature. It has the better ability of global searching and has been successfully applied to many areas such as, neural network training etc. Due to the linear decreasing of inertia weight in PSO the convergence rate becomes faster, which leads to the minimal makespan time when used for scheduling. To make the convergence rate faster, the PSO algorithm is improved by modifying the inertia parameter, such that it produces better performance and gives an optimized result. The ACO algorithm is improved by modifying the pheromone updating rule. ACO algorithm is hybridized with PSO algorithm for efficient result and better convergence in PSO algorithm.

  7. OpenMP parallelization of a gridded SWAT (SWATG)

    Science.gov (United States)

    Zhang, Ying; Hou, Jinliang; Cao, Yongpan; Gu, Juan; Huang, Chunlin

    2017-12-01

    Large-scale, long-term and high spatial resolution simulation is a common issue in environmental modeling. A Gridded Hydrologic Response Unit (HRU)-based Soil and Water Assessment Tool (SWATG) that integrates grid modeling scheme with different spatial representations also presents such problems. The time-consuming problem affects applications of very high resolution large-scale watershed modeling. The OpenMP (Open Multi-Processing) parallel application interface is integrated with SWATG (called SWATGP) to accelerate grid modeling based on the HRU level. Such parallel implementation takes better advantage of the computational power of a shared memory computer system. We conducted two experiments at multiple temporal and spatial scales of hydrological modeling using SWATG and SWATGP on a high-end server. At 500-m resolution, SWATGP was found to be up to nine times faster than SWATG in modeling over a roughly 2000 km2 watershed with 1 CPU and a 15 thread configuration. The study results demonstrate that parallel models save considerable time relative to traditional sequential simulation runs. Parallel computations of environmental models are beneficial for model applications, especially at large spatial and temporal scales and at high resolutions. The proposed SWATGP model is thus a promising tool for large-scale and high-resolution water resources research and management in addition to offering data fusion and model coupling ability.

  8. Smart grid standards specifications, requirements, and technologies

    CERN Document Server

    Sato, Takuro; Duan, Bin; Macuha, Martin; Zhou, Zhenyu; Wu, Jun; Tariq, Muhammad; Asfaw, Solomon A

    2015-01-01

    With numerous existing Smart Grid standards, it is clear that governments and industrial organizations world-wide have understood and acknowledged the critical role they play. This timely book is a useful guide for Smart Grid professionals in easily classifying fundamental Smart Grid standards, and to quickly find the building blocks they need to analyse and implement a Smart Grid system. The standards are organized in a systematic manner that aids identification, according to grid requirements. It also covers broader Smart Grid areas including, but not limited to, the following: A fully c

  9. Communication and Networking in Smart Grids

    CERN Document Server

    Xiao, Yang

    2012-01-01

    Appropriate for researchers, practitioners, and students alike, Communication and Networking in Smart Grids presents state-of-the-art approaches and novel technologies for communication networks in smart grids. It explains how contemporary grid networks are developed and deployed and presents a collection of cutting-edge advances to help improve current practice. Prominent researchers working on smart grids and in related fields around the world explain the fundamental aspects and applications of smart grids. Describing the role that communication and networking will play in future smart grids

  10. The LHCb Grid Simulation: Proof of Concept

    Science.gov (United States)

    Hushchyn, M.; Ustyuzhanin, A.; Arzymatov, K.; Roiser, S.; Baranov, A.

    2017-10-01

    The Worldwide LHC Computing Grid provides access to data and computational resources to analyze it for researchers with different geographical locations. The grid has a hierarchical topology with multiple sites distributed over the world with varying number of CPUs, amount of disk storage and connection bandwidth. Job scheduling and data distribution strategy are key elements of grid performance. Optimization of algorithms for those tasks requires their testing on real grid which is hard to achieve. Having a grid simulator might simplify this task and therefore lead to more optimal scheduling and data placement algorithms. In this paper we demonstrate a grid simulator for the LHCb distributed computing software.

  11. Electric vehicle utilization for ancillary grid services

    Science.gov (United States)

    Aziz, Muhammad

    2018-02-01

    Electric vehicle has been developed through several decades as transportation mean, without paying sufficient attention of its utilization for other purposes. Recently, the utilization of electric vehicle to support the grid electricity has been proposed and studied intensively. This utilization covers several possible services including electricity storage, spinning reserve, frequency and voltage regulation, and emergency energy supply. This study focuses on theoretical and experimental analysis of utilization of electric vehicles and their used batteries to support a small-scale energy management system. Charging rate of electric vehicle under different ambient temperature (seasonal condition) is initially analyzed to measure the correlation of charging rate, charging time, and state-of-charge. It is confirmed that charging under warmer condition (such as in summer or warmer region) shows higher charging rate than one in colder condition, therefore, shorter charging time can be achieved. In addition, in the demonstration test, each five electric vehicles and used batteries from the same electric vehicles are employed and controlled to support the electricity of the office building. The performance of the system is evaluated throughout a year to measure the load leveling effect during peak-load time. The results show that the targeted peak-load can be shaved well under certain calculated peak-shaving threshold. The finding confirms that the utilization of electric vehicle for supporting the electricity of grid or certain energy management system is feasible and deployable in the future.

  12. National Offshore Wind Energy Grid Interconnection Study

    Energy Technology Data Exchange (ETDEWEB)

    Daniel, John P. [ABB Inc; Liu, Shu [ABB Inc; Ibanez, Eduardo [National Renewable Energy Laboratory; Pennock, Ken [AWS Truepower; Reed, Greg [University of Pittsburgh; Hanes, Spencer [Duke Energy

    2014-07-30

    The National Offshore Wind Energy Grid Interconnection Study (NOWEGIS) considers the availability and potential impacts of interconnecting large amounts of offshore wind energy into the transmission system of the lower 48 contiguous United States. A total of 54GW of offshore wind was assumed to be the target for the analyses conducted. A variety of issues are considered including: the anticipated staging of offshore wind; the offshore wind resource availability; offshore wind energy power production profiles; offshore wind variability; present and potential technologies for collection and delivery of offshore wind energy to the onshore grid; potential impacts to existing utility systems most likely to receive large amounts of offshore wind; and regulatory influences on offshore wind development. The technologies considered the reliability of various high-voltage ac (HVAC) and high-voltage dc (HVDC) technology options and configurations. The utility system impacts of GW-scale integration of offshore wind are considered from an operational steady-state perspective and from a regional and national production cost perspective.

  13. Grid accounting service: state and future development

    Energy Technology Data Exchange (ETDEWEB)

    Levshina, T. [Fermilab; Sehgal, C. [Fermilab; Bockelman, B. [Nebraska U.; Weitzel, D. [Nebraska U.; Guru, A. [Nebraska U.

    2014-01-01

    During the last decade, large-scale federated distributed infrastructures have been continually developed and expanded. One of the crucial components of a cyber-infrastructure is an accounting service that collects data related to resource utilization and identity of users using resources. The accounting service is important for verifying pledged resource allocation per particular groups and users, providing reports for funding agencies and resource providers, and understanding hardware provisioning requirements. It can also be used for end-to-end troubleshooting as well as billing purposes. In this work we describe Gratia, a federated accounting service jointly developed at Fermilab and Holland Computing Center at University of Nebraska-Lincoln. The Open Science Grid, Fermilab, HCC, and several other institutions have used Gratia in production for several years. The current development activities include expanding Virtual Machines provisioning information, XSEDE allocation usage accounting, and Campus Grids resource utilization. We also identify the direction of future work: improvement and expansion of Cloud accounting, persistent and elastic storage space allocation, and the incorporation of WAN and LAN network metrics.

  14. Squid – a simple bioinformatics grid

    Directory of Open Access Journals (Sweden)

    de Miranda Antonio B

    2005-08-01

    Full Text Available Abstract Background BLAST is a widely used genetic research tool for analysis of similarity between nucleotide and protein sequences. This paper presents a software application entitled "Squid" that makes use of grid technology. The current version, as an example, is configured for BLAST applications, but adaptation for other computing intensive repetitive tasks can be easily accomplished in the open source version. This enables the allocation of remote resources to perform distributed computing, making large BLAST queries viable without the need of high-end computers. Results Most distributed computing / grid solutions have complex installation procedures requiring a computer specialist, or have limitations regarding operating systems. Squid is a multi-platform, open-source program designed to "keep things simple" while offering high-end computing power for large scale applications. Squid also has an efficient fault tolerance and crash recovery system against data loss, being able to re-route jobs upon node failure and recover even if the master machine fails. Our results show that a Squid application, working with N nodes and proper network resources, can process BLAST queries almost N times faster than if working with only one computer. Conclusion Squid offers high-end computing, even for the non-specialist, and is freely available at the project web site. Its open-source and binary Windows distributions contain detailed instructions and a "plug-n-play" instalation containing a pre-configured example.

  15. Promotional drivers for grid-connected PV

    Energy Technology Data Exchange (ETDEWEB)

    Lopez Polo, A.; Hass, R.; Suna, D.

    2009-03-15

    This report for the International Energy Agency (IEA) made by Task 10 of the Photovoltaic Power Systems (PVPS) programme takes a look at promotional measures for grid-connected photovoltaic systems. The mission of the Photovoltaic Power Systems Programme is to enhance the international collaboration efforts which accelerate the development and deployment of photovoltaic solar energy. The objective of Task 10 is stated as being to enhance the opportunities for wide-scale, solution-oriented application of photovoltaics in the urban environment. The paper discusses the core objective of this study which was to analyse the success of various governmental regulatory programs and governmental and non-governmental marketing programs for grid-connected PV systems. To meet this objective, a review of the most important past and current programs around the world was conducted. The theoretical bases of supply and demand are explained and the types of existing strategies are documented in a second Section. In Chapter 3, various programs around the world are described. Chapter 4 focuses on defining success criteria which will be used for the analysis of the programs. Finally, the major conclusions drawn complete this analysis.

  16. Adding Four- Dimensional Data Assimilation (aka grid ...

    Science.gov (United States)

    Adding four-dimensional data assimilation (a.k.a. grid nudging) to MPAS.The U.S. Environmental Protection Agency is investigating the use of MPAS as the meteorological driver for its next-generation air quality model. To function as such, MPAS needs to operate in a diagnostic mode in much the same manner as the current meteorological driver, the Weather Research and Forecasting (WRF) model. The WRF operates in diagnostic mode using Four-Dimensional Data Assimilation, also known as "grid nudging". MPAS version 4.0 has been modified with the addition of an FDDA routine to the standard physics drivers to nudge the state variables for wind, temperature and water vapor towards MPAS initialization fields defined at 6-hour intervals from GFS-derived data. The results to be shown demonstrate the ability to constrain MPAS simulations to known historical conditions and thus provide the U.S. EPA with a practical meteorological driver for global-scale air quality simulations. The National Exposure Research Laboratory (NERL) Computational Exposure Division (CED) develops and evaluates data, decision-support tools, and models to be applied to media-specific or receptor-specific problem areas. CED uses modeling-based approaches to characterize exposures, evaluate fate and transport, and support environmental diagnostics/forensics with input from multiple data sources. It also develops media- and receptor-specific models, process models, and decision support tools for use bo

  17. Privacy-Preserving Aggregation and Authentication of Multi-Source Smart Meters in a Smart Grid System

    Directory of Open Access Journals (Sweden)

    Dongyoung Koo

    2017-09-01

    Full Text Available The smart grid is a promising electrical grid paradigm for enhancing flexibility and reliability in power transmission through two-way communications among grid entities. In the smart grid system, the privacy of usage information measured by individual smart meters has gained significant attention, owing to the possibility of personal information inference. Moreover, efficient and reliable power provisioning can be seriously impeded through illicit manipulations of aggregated data under the influence of malicious adversaries. Due to such potential risks, it becomes an important requirement for the smart grid to preserve privacy of metering data by secure aggregation and to authenticate the aggregated result in an efficient manner within large scale environments. From this perspective, this paper investigates the current status of security and privacy in smart grid systems and representative state-of-the-art studies in secure aggregation and authentication of metering data for future directions of a smart grid.

  18. Application of approximate pattern matching in two dimensional spaces to grid layout for biochemical network maps.

    Science.gov (United States)

    Inoue, Kentaro; Shimozono, Shinichi; Yoshida, Hideaki; Kurata, Hiroyuki

    2012-01-01

    For visualizing large-scale biochemical network maps, it is important to calculate the coordinates of molecular nodes quickly and to enhance the understanding or traceability of them. The grid layout is effective in drawing compact, orderly, balanced network maps with node label spaces, but existing grid layout algorithms often require a high computational cost because they have to consider complicated positional constraints through the entire optimization process. We propose a hybrid grid layout algorithm that consists of a non-grid, fast layout (preprocessor) algorithm and an approximate pattern matching algorithm that distributes the resultant preprocessed nodes on square grid points. To demonstrate the feasibility of the hybrid layout algorithm, it is characterized in terms of the calculation time, numbers of edge-edge and node-edge crossings, relative edge lengths, and F-measures. The proposed algorithm achieves outstanding performances compared with other existing grid layouts. Use of an approximate pattern matching algorithm quickly redistributes the laid-out nodes by fast, non-grid algorithms on the square grid points, while preserving the topological relationships among the nodes. The proposed algorithm is a novel use of the pattern matching, thereby providing a breakthrough for grid layout. This application program can be freely downloaded from http://www.cadlive.jp/hybridlayout/hybridlayout.html.

  19. [Effects of high-strip density anti-scatter grid on image quality and radiation dose].

    Science.gov (United States)

    Wamser, G; Maier, W; Aichinger, H; Bohndorf, K

    1997-06-01

    Using a new type of a stationary high strip density grid (13/75) for plain films of the abdomen, the effect was evaluated with regard to quality and patient dose in comparison with an established moving radiographic grid (12/40). The high strip density grid (13/75) was compared with a 12/40 grid using test objects and 100 patients per each grid type for plain films of the abdomen. The examinations were carried out via the screen-film system, speed class (SC) 400. Patients' weight, age and dose measurements were recorded. The image quality was evaluated via a multi-reader study using delineation of anatomical structures and a rating scale (score 1-5 or 1-3). Both measurements with test objects and patients abdominal plain films showed a decrease in radiation dose of 17% using the 13/75 grid, and 24%, respectively. The delineation of 4 out of 7 anatomical structures was slightly reduced with the new high strip density grid (maximum score reduction: 0.4), the image contrast, as well as the radiologists' subjective rating. Apart from an acceptable loss in image quality compared with the 12/40 grid, the new high strip density grid (13/ 75) enables a clear reduction in radiation dose.

  20. FermiGrid - experience and future plans

    Energy Technology Data Exchange (ETDEWEB)

    Chadwick, K.; Berman, E.; Canal, P.; Hesselroth, T.; Garzoglio, G.; Levshina, T.; Sergeev, V.; Sfiligoi, I.; Timm, S.; Yocum, D.; /Fermilab

    2007-09-01

    Fermilab supports a scientific program that includes experiments and scientists located across the globe. In order to better serve this community, Fermilab has placed its production computer resources in a Campus Grid infrastructure called 'FermiGrid'. The FermiGrid infrastructure allows the large experiments at Fermilab to have priority access to their own resources, enables sharing of these resources in an opportunistic fashion, and movement of work (jobs, data) between the Campus Grid and National Grids such as Open Science Grid and the WLCG. FermiGrid resources support multiple Virtual Organizations (VOs), including VOs from the Open Science Grid (OSG), EGEE and the Worldwide LHC Computing Grid Collaboration (WLCG). Fermilab also makes leading contributions to the Open Science Grid in the areas of accounting, batch computing, grid security, job management, resource selection, site infrastructure, storage management, and VO services. Through the FermiGrid interfaces, authenticated and authorized VOs and individuals may access our core grid services, the 10,000+ Fermilab resident CPUs, near-petabyte (including CMS) online disk pools and the multi-petabyte Fermilab Mass Storage System. These core grid services include a site wide Globus gatekeeper, VO management services for several VOs, Fermilab site authorization services, grid user mapping services, as well as job accounting and monitoring, resource selection and data movement services. Access to these services is via standard and well-supported grid interfaces. We will report on the user experience of using the FermiGrid campus infrastructure interfaced to a national cyberinfrastructure--the successes and the problems.