Sample records for large power time

  1. DECENTRALIZED REAL-TIME MANAGEMENT LARGELY UNPREDICTABLE POWER NEEDS AND SUPPLY

    E-Print Network [OSTI]

    Wedde, Horst F.

    of unpredictable power need and supply situations. We model a representative scenario to explain variousDECENTRALIZED REAL-TIME MANAGEMENT OF LARGELY UNPREDICTABLE POWER NEEDS AND SUPPLY H. F. Wedde*, F technologies based on solar or wind power, or on renewable energy sources, is an adequate management

  2. Large power transformers

    SciTech Connect (OSTI)

    Karsai, K.; Kerenyi, D.; Kiss, L.

    1987-01-01T23:59:59.000Z

    The book deals with the following aspects of transformer engineering: general principles governing the function of transformers, iron cores, windings, stray losses caused by stray flux, the insulation of transformers, and the structural parts and accessories. This edition includes the developments in theory and practice on the basis of the authors' experience in design, manufacturing and testing of large transformers. New developments have been particularly extensive in the fields of new magnetic materials, cooling methods, dielectric strength for overvoltages of different types, and stray-load loss problems, which are presented in the book in detail. The many diagrams in the book can be used directly in the design, manufacture and testing of large transformers. In preparing their text, the authors have aimed to satisfy the demand for a work that summarizes the latest experience in development and design of large power transformers.

  3. Microsoft PowerPoint - 2-A-3-OK-Real-Time Data Infrastructure for Large Scale Wind Fleets.pptx

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHighand Retrievals fromprocess usedGELustre File Systemi di t ff tRPWGReal

  4. POWER SYSTEMS STABILITY WITH LARGE-SCALE WIND POWER PENETRATION

    E-Print Network [OSTI]

    Bak-Jensen, Birgitte

    of offshore wind farms, wind power fluctuations may introduce several challenges to reliable power system behaviour due to natural wind fluctuations. The rapid power fluctuations from the large scale wind farms Generation Control (AGC) system which includes large- scale wind farms for long-term stability simulation

  5. Laser Power Meter Large, bright, backlit LCD

    E-Print Network [OSTI]

    Woodall, Jerry M.

    Laser Power Meter FEATURES · Large, bright, backlit LCD display · Digital accuracy with analog-like movement for laser tuning · Works with thermopile and optical sensors · Intuitive button-driven user COMPATIBILITY · PowerMax® thermal sensors · Optical sensors FieldMaxII-TO Coherent Laser Measurement and Control

  6. Large power grid analysis using domain decomposition

    E-Print Network [OSTI]

    Mohanram, Kartik

    -scale linear circuits such as power distribution networks. Simulation results show that by inte- grating the proposed DD framework, existing linear circuit simulators can be extended to handle otherwise intractableLarge power grid analysis using domain decomposition Quming Zhou, Kai Sun, Kartik Mohanram, Danny C

  7. SPEAR3 LARGE DC MAGNET POWER SUPPLIES

    SciTech Connect (OSTI)

    de Lira, A

    2004-06-23T23:59:59.000Z

    The Stanford Synchrotron Radiation Laboratory (SSRL) has successfully commissioned SPEAR3, its newly upgraded 3-GeV synchrotron light source. First stored beam occurred December 15, 2003 and 100mA operation was reached on January 20, 2004. This paper describes the specification, design, and performance of the SPEAR3 DC magnet large power supplies (LGPS) that consist of tightly-regulated (better than {+-}10 ppm) current sources ranging from 100A to 225A and output powers ranging from 70kW to 135kW. A total of 6 LGPS are in successful operation and are used to power strings of quadrupoles and sextupoles. The LGPS are isolated by a delta/delta-wye 60Hz step-down transformer that provides power to 2 series-connected chopper stages operating phase-shifted at a switching frequency of 18-kHz to provide for fast output response and high efficiency. Also described are outside procurement aspects, installation, in-house testing, and operation of the power supplies.

  8. Limits to the power density of very large wind farms

    E-Print Network [OSTI]

    Nishino, Takafumi

    2013-01-01T23:59:59.000Z

    A simple analysis is presented concerning an upper limit of the power density (power per unit land area) of a very large wind farm located at the bottom of a fully developed boundary layer. The analysis suggests that the limit of the power density is about 0.38 times $\\tau_{w0}U_{F0}$, where $\\tau_{w0}$ is the natural shear stress on the ground (that is observed before constructing the wind farm) and $U_{F0}$ is the natural or undisturbed wind speed averaged across the height of the farm to be constructed. Importantly, this implies that the maximum extractable power from such a very large wind farm will not be proportional to the cubic of the wind speed at the farm height, or even the farm height itself, but be proportional to $U_{F0}$.

  9. Large-Scale Data Challenges in Future Power Grids

    SciTech Connect (OSTI)

    Yin, Jian; Sharma, Poorva; Gorton, Ian; Akyol, Bora A.

    2013-03-25T23:59:59.000Z

    This paper describes technical challenges in supporting large-scale real-time data analysis for future power grid systems and discusses various design options to address these challenges. Even though the existing U.S. power grid has served the nation remarkably well over the last 120 years, big changes are in the horizon. The widespread deployment of renewable generation, smart grid controls, energy storage, plug-in hybrids, and new conducting materials will require fundamental changes in the operational concepts and principal components. The whole system becomes highly dynamic and needs constant adjustments based on real time data. Even though millions of sensors such as phase measurement units (PMUs) and smart meters are being widely deployed, a data layer that can support this amount of data in real time is needed. Unlike the data fabric in cloud services, the data layer for smart grids must address some unique challenges. This layer must be scalable to support millions of sensors and a large number of diverse applications and still provide real time guarantees. Moreover, the system needs to be highly reliable and highly secure because the power grid is a critical piece of infrastructure. No existing systems can satisfy all the requirements at the same time. We examine various design options. In particular, we explore the special characteristics of power grid data to meet both scalability and quality of service requirements. Our initial prototype can improve performance by orders of magnitude over existing general-purpose systems. The prototype was demonstrated with several use cases from PNNL’s FPGI and was shown to be able to integrate huge amount of data from a large number of sensors and a diverse set of applications.

  10. innovati nNREL Confirms Large Potential for Grid Integration of Wind, Solar Power

    E-Print Network [OSTI]

    innovati nNREL Confirms Large Potential for Grid Integration of Wind, Solar Power To fully harvest a database of potential wind power sites and detailed, time-dependent estimates of the power that would the nation's bountiful wind and solar resources, it is critical to know how much electrical power from

  11. Powers of Ten Thousand: Navigating in Large Information Spaces

    E-Print Network [OSTI]

    Powers of Ten Thousand: Navigating in Large Information Spaces Henry Lieberman Media Laboratory large display space, for example, a street map of the entire United States? The traditional solution, on a scale of at least 1 to 10,000. Powers of ten thousand The book and film Powers of Ten [Morrison

  12. Lessons Learned: Planning and Operating Power Systems with Large

    E-Print Network [OSTI]

    Lessons Learned: Planning and Operating Power Systems with Large Amounts of Renewable Energy agency thereof. #12;Lessons Learned: Planning and Operating Power Systems with Large Amounts of Renewable to their systems powered by as-available renewable energy sources (primarily wind and solar). The Big Island also

  13. Ris-R-Report Power fluctuations from large wind farms -

    E-Print Network [OSTI]

    Abstract (max. 2000 char.): Experience from power system operation with the first large offshore wind farm acquired at the two large offshore wind farms in Denmark are applied to validate the models. FinallyRisø-R-Report Power fluctuations from large wind farms - Final report Poul Sørensen, Pierre Pinson

  14. TQuEST: Threshold Query Execution for Large Sets of Time Series

    E-Print Network [OSTI]

    Kriegel, Hans-Peter

    TQuEST: Threshold Query Execution for Large Sets of Time Series Johannes AÃ?falg, Hans-Peter Kriegel TQuEST, a powerful query processor for time series databases. TQuEST supports a novel but very useful times. 1 Introduction In this paper, we present TQuEST, a powerful analysis tool for time series

  15. QER- Comment of Large Public Power Council 2

    Broader source: Energy.gov [DOE]

    Attached please find comments by the Large Public Power Council for the record regarding the April 11th QER meeting.

  16. QER- Comment of Large Public Power Council 1

    Broader source: Energy.gov [DOE]

    Attached are the Comments of the Large Public Power Council on the QER. Please feel to contact me if you have any questions.

  17. Effect of Large Dynamic Loads on Interconnected Power Systems with Power Oscillation Damping

    E-Print Network [OSTI]

    Pota, Himanshu Roy

    Effect of Large Dynamic Loads on Interconnected Power Systems with Power Oscillation Damping.hossain and H.Pota)@adfa.edu.au Abstract--Power systems are composed of dynamic loads. In this paper presents an analysis to investigate the effects of large dynamic loads on interconnected power systems

  18. The use of real-time off-site observations as a methodology for increasing forecast skill in prediction of large wind power ramps one or more hours ahead of their impact on a wind plant.

    SciTech Connect (OSTI)

    Martin Wilde, Principal Investigator

    2012-12-31T23:59:59.000Z

    ABSTRACT Application of Real-Time Offsite Measurements in Improved Short-Term Wind Ramp Prediction Skill Improved forecasting performance immediately preceding wind ramp events is of preeminent concern to most wind energy companies, system operators, and balancing authorities. The value of near real-time hub height-level wind data and more general meteorological measurements to short-term wind power forecasting is well understood. For some sites, access to onsite measured wind data - even historical - can reduce forecast error in the short-range to medium-range horizons by as much as 50%. Unfortunately, valuable free-stream wind measurements at tall tower are not typically available at most wind plants, thereby forcing wind forecasters to rely upon wind measurements below hub height and/or turbine nacelle anemometry. Free-stream measurements can be appropriately scaled to hub-height levels, using existing empirically-derived relationships that account for surface roughness and turbulence. But there is large uncertainty in these relationships for a given time of day and state of the boundary layer. Alternatively, forecasts can rely entirely on turbine anemometry measurements, though such measurements are themselves subject to wake effects that are not stationary. The void in free-stream hub-height level measurements of wind can be filled by remote sensing (e.g., sodar, lidar, and radar). However, the expense of such equipment may not be sustainable. There is a growing market for traditional anemometry on tall tower networks, maintained by third parties to the forecasting process (i.e., independent of forecasters and the forecast users). This study examines the value of offsite tall-tower data from the WINDataNOW Technology network for short-horizon wind power predictions at a wind farm in northern Montana. The presentation shall describe successful physical and statistical techniques for its application and the practicality of its application in an operational setting. It shall be demonstrated that when used properly, the real-time offsite measurements materially improve wind ramp capture and prediction statistics, when compared to traditional wind forecasting techniques and to a simple persistence model.

  19. Large-Scale Eucalyptus Energy Farms and Power Cogeneration1

    E-Print Network [OSTI]

    Standiford, Richard B.

    Large-Scale Eucalyptus Energy Farms and Power Cogeneration1 Robert C. Noronla2 The initiation of a large-scale cogeneration project, especially one that combines construction of the power generation supplemental fuel source must be sought if the cogeneration facility will consume more fuel than

  20. Impact of Wind Shear and Tower Shadow Effects on Power System with Large Scale Wind Power

    E-Print Network [OSTI]

    Hu, Weihao

    Impact of Wind Shear and Tower Shadow Effects on Power System with Large Scale Wind Power to wind speed variations, the wind shear and the tower shadow effects. The fluctuating power may be ableSILENT/PowerFactory. In this paper, the impacts of wind shear and tower shadow effects on the small signal stability of power systems

  1. Computing GIC in large power systems

    SciTech Connect (OSTI)

    Prabhakara, F.S. (Power Technologies, Inc., Schenectady, NY (United States)); Ponder, J.Z.; Towle, J.N.

    1992-01-01T23:59:59.000Z

    On March 13, 1989, a severe geomagnetic disturbance affected power and communications systems in the North American continent. Since the geomagnetic disturbance, several other disturbances have occurred. The Pennsylvania, New Jersey, and Maryland (PJM) Interconnection system, its member companies, and some of the neighboring utilities experienced the geomagnetic induced current (GIC) effects on March 13, 1989, as well as during the subsequent geomagnetic disturbances. As a result, considerable effort is being focused on measurement, analysis, and mitigation of GIC in the PJM system. Some of the analytical and computational work completed so far is summarized in this article.

  2. SIMULATING LARGE-SCALE STRUCTURE FORMATION FOR BSI POWER SPECTRA

    E-Print Network [OSTI]

    V. Mueller

    1995-05-30T23:59:59.000Z

    A double inflationary model provides perturbation spectra with enhanced power at large scales (Broken Scale Invariant perturbations -- BSI), leading to a promising scenario for the formation of cosmic structures. We describe a series of high-resolution PM simulations with a model for the thermodynamic evolution of baryons in which we are capable of identifying 'galaxy' halos with a reasonable mass spectrum and following the genesis of large and super-large scale structures. The power spectra and correlation functions of 'galaxies' are compared with reconstructed power spectra of the CfA catalogue and the correlation functions of the Las Campanas Deep Redshift Survey.

  3. Temporal structure of aggregate power fluctuations in large-eddy simulations of extended wind-farms

    E-Print Network [OSTI]

    Stevens, Richard J A M

    2014-01-01T23:59:59.000Z

    Fluctuations represent a major challenge for the incorporation of electric power from large wind-farms into power grids. Wind farm power output fluctuates strongly in time, over various time scales. Understanding these fluctuations, especially their spatio-temporal characteristics, is particularly important for the design of backup power systems that must be readily available in conjunction with wind-farms. In this work we analyze the power fluctuations associated with the wind-input variability at scales between minutes to several hours, using large eddy simulations (LES) of extended wind-parks, interacting with the atmospheric boundary layer. LES studies enable careful control of parameters and availability of wind-velocities simultaneously across the entire wind-farm. The present study focuses on neutral atmospheric conditions and flat terrain, using actuator-disk representations of the individual wind-turbines. We consider power from various aggregates of wind-turbines such as the total average power sign...

  4. Glendale Water and Power- Large Business Energy Efficiency Program

    Broader source: Energy.gov [DOE]

    Glendale Water and Power (GWP) offers a rebate to its medium and large business customers with electric bills of more than $3000 per month (electric usage of 250,000 kWh annually ~ $36,000 per year...

  5. Power Compensation Effect of an Adjustable-Speed Rotary Condenser with a Flywheel for a Large Capacity Magnet Power Supply

    E-Print Network [OSTI]

    Akagi, H

    1999-01-01T23:59:59.000Z

    Power Compensation Effect of an Adjustable-Speed Rotary Condenser with a Flywheel for a Large Capacity Magnet Power Supply

  6. Preventive overhaul time for power transformers

    SciTech Connect (OSTI)

    Sarmadi, M. [Pennsylvania State Univ., University Park, PA (United States). Electrical Engineering Dept.; Rouhi, J. [Univ. of Mazandaran (Iran, Islamic Republic of); Fayyaz, A. [Mazandaran Power Co. (Iran, Islamic Republic of)

    1999-11-01T23:59:59.000Z

    Power transformers are the major piece of equipment in high-voltage substations. A considerable number of these transformers exist in Iran`s integrated network. Due to the climate diversity and improper usage, many of these transformers age rapidly, suffer failure and are taken out of service before half their useful life. At the present time the utility companies have no specific time-frame and plan for preventive overhaul. Detection of preventive overhaul time will increase the remaining life of transformers and improve the reliability of substations. An exact check of the remaining lifetime of transformers is not yet possible by available diagnostic techniques. In this paper, the authors present a method of identifying the right time for preventive overhaul in 63 kV power transformers. This method is developed based on 25 year transformer performance records in Northern Iran (subtropical climate) and with the utilization of studies done by electrical engineering communities world-wide.

  7. Optimal operation of large-scale power systems

    SciTech Connect (OSTI)

    Lee, K.Y.; Ortiz, J.L.; Mohtadi, M.A.; Park, Y.M.

    1988-05-01T23:59:59.000Z

    This paper presents a method for an optimal operation of large-scale power systems similar to the one utilized by the Houston Lighting and Power Company. The main objective is to minimize the system fuel costs, and maintain an acceptable system performance in terms of limits on generator real and reactive power outputs, transformer tap settings, and bus voltage levels. Minimizing the fuel costs of such large-scale systems enhances the performance of optimal real power generator allocation and of optimal power flow that results in an economic dispatch. The gradient projection method (GPM) is utilized in solving the optimization problems. It is an iterative numerical procedure for finding an extremum of a function of several variables that are required to satisfy various constraining relations without using penalty functions or Lagrange multipliers among other advantages. Mathematical models are developed to represent the sensitivity relationships between dependent and control variables for both real- and reactive-power optimization procedures; and thus eliminate the use of B-coefficients. Data provided by the Houston lighting and Power Company are used to demonstrate the effectiveness of the proposed procedures.

  8. A decomposition approach to optimal reactive power dispatch in large-scale power systems

    SciTech Connect (OSTI)

    Deeb, N.I.

    1989-01-01T23:59:59.000Z

    Power systems network operation is aimed at reducing system losses and minimizing the operational cost while satisfying performance requirements in normal and contingency situations. In this project, the procedure for the reactive power optimization has the solutions for investment and operation subproblems. The global solution is an iterative process between these two subproblems using the Bender decomposition method. In the investment subproblem decisions for the capacity and location of new reactive sources are made. These decisions are used in the optimization of the system operation. The outstanding features of the proposed method are that it does not require any matrix inversion, will save computation time and memory space, and can be implemented on very large scale power systems. The method employs a linearized objective function and constraints, and is based on adjusting control variables which are tap positions of transformers and reactive power injections. Linear programming is used to calculate voltage increments, which would minimize transmission losses, and adjustments of control variables would be obtained by a modified Jacobian matrix. This approach would greatly simplify the application of Dantzig-Wolfe decomposition method for solving the operation subproblem. According to the mathematical features of the Dantzig-Wolfe method, a multi-area approach is implemented and system equations are decomposed into a master problem and several subproblems. The master problem is formed by constraints, which represent linking transmission lines between areas. Two updated techniques are incorporated in the method to enhance the optimization process, which would save additional computation time and memory space. The proposed method is applied to the IEEE-30 bus system, a 60-bus system, a 180-bus system and a 1200-bus system, and numerical results are presented.

  9. hal-00169265,version1-3Sep2007 LARGE DEVIATION FOR RETURN TIMES IN OPEN SETS FOR

    E-Print Network [OSTI]

    Boyer, Edmond

    -times into A satisfies a LDP for the measure µ near the average. A powerful method in Large Deviation Theory is to provehal-00169265,version1-3Sep2007 LARGE DEVIATION FOR RETURN TIMES IN OPEN SETS FOR AXIOM, we prove a Large devi- ation result for the sequence of successive return times into a fixed open set

  10. Optimization of auxiliary power systems design for large generating units

    SciTech Connect (OSTI)

    Fabri, E.I.; Kang, E.K.; Dusterdick, R.W.

    1980-01-01T23:59:59.000Z

    Modern fossil and nuclear generating units require the support of a fairly large and complex electric auxiliary power system. The selection of an optimized and cost-effective auxiliary power transformer rating may be a difficult process, since the loading profile and coincident operation of the loads often cannot be firmly defined at an early stage of design. The authors believe that this important design process could be greatly aided by systematic field tests and recording of the actual auxiliary loading profiles during various modes of plant operations.

  11. Anti-Synchronization in Multiple Time Delay Power Systems

    E-Print Network [OSTI]

    E. M. Shahverdiev

    2010-08-23T23:59:59.000Z

    We investigate chaos antisynchronization between two uni-directionally coupled multiple time delay power systems.The results are of certain importance to prevent power black-out in the entire power grid.

  12. Just enough inflation: power spectrum modifications at large scales

    E-Print Network [OSTI]

    Michele Cicoli; Sean Downes; Bhaskar Dutta; Francisco G. Pedro; Alexander Westphal

    2014-07-03T23:59:59.000Z

    We show that models of `just enough' inflation, where the slow-roll evolution lasted only $50-60$ e-foldings, feature modifications of the CMB power spectrum at large angular scales. We perform a systematic and model-independent analysis of any possible non-slow-roll background evolution prior to the final stage of slow-roll inflation. We find a high degree of universality since most common backgrounds like fast-roll evolution, matter or radiation-dominance give rise to a power loss at large angular scales and a peak together with an oscillatory behaviour at scales around the value of the Hubble parameter at the beginning of slow-roll inflation. Depending on the value of the equation of state parameter, different pre-inflationary epochs lead instead to an enhancement of power at low-$\\ell$, and so seem disfavoured by recent observational hints for a lack of CMB power at $\\ell\\lesssim 40$. We also comment on the importance of initial conditions and the possibility to have multiple pre-inflationary stages.

  13. Real Time Simulation of Power Grid Disruptions

    SciTech Connect (OSTI)

    Chinthavali, Supriya [ORNL; Dimitrovski, Aleksandar D [ORNL; Fernandez, Steven J [ORNL; Groer, Christopher S [ORNL; Nutaro, James J [ORNL; Olama, Mohammed M [ORNL; Omitaomu, Olufemi A [ORNL; Shankar, Mallikarjun [ORNL; Spafford, Kyle L [ORNL; Vacaliuc, Bogdan [ORNL

    2012-11-01T23:59:59.000Z

    DOE-OE and DOE-SC workshops (Reference 1-3) identified the key power grid problem that requires insight addressable by the next generation of exascale computing is coupling of real-time data streams (1-2 TB per hour) as the streams are ingested to dynamic models. These models would then identify predicted disruptions in time (2-4 seconds) to trigger the smart grid s self healing functions. This project attempted to establish the feasibility of this approach and defined the scientific issues, and demonstrated example solutions to important smart grid simulation problems. These objectives were accomplished by 1) using the existing frequency recorders on the national grid to establish a representative and scalable real-time data stream; 2) invoking ORNL signature identification algorithms; 3) modeling dynamically a representative region of the Eastern interconnect using an institutional cluster, measuring the scalability and computational benchmarks for a national capability; and 4) constructing a prototype simulation for the system s concept of smart grid deployment. The delivered ORNL enduring capability included: 1) data processing and simulation metrics to design a national capability justifying exascale applications; 2) Software and intellectual property built around the example solutions; 3) demonstrated dynamic models to design few second self-healing.

  14. Global Wind Power Conference September 18-21, 2006, Adelaide, Australia Design and Operation of Power Systems with Large Amounts of Wind Power, first

    E-Print Network [OSTI]

    of Power Systems with Large Amounts of Wind Power, first results of IEA collaboration Hannele Holttinen1.holttinen@vtt.fi Abstract: An international forum for exchange of knowledge of power system impacts of wind power has been Systems with Large Amounts of Wind Power"will analyse existing case studies from different power systems

  15. Compact, Low-power and Precision Timing Photodetector Readout

    SciTech Connect (OSTI)

    Varner, Gary S.; Ruckman, Larry L.; /Hawaii U.; Schwiening, Jochen; Vavra, Jaroslav; /SLAC

    2011-06-14T23:59:59.000Z

    Photodetector readout for next generation high event rate particle identification and single-photon detection requires a digitizer capable of integrated recording of dense arrays of sensor elements with high analog bandwidth (precision timing) and large record depth, in a cost-effective, compact and low-power way. Simply stated, one cannot do better than having a high-fidelity 'oscilloscope on a chip' for every sensor channel. A firs version of the Buffered Large Analog Bandwidth (BLAB1) ASIC has been designed based upon the lessons learned from the development of the Large Analog Bandwidth Recorder and Digitizer with Ordered Readout (LABRADOR) ASIC. While this LABRADOR ASIC has been very successful and forms the readout basis of a generation of new, large-scale radio neutrino detectors, its limited sampling depth is a major drawback. To address this shortcoming, a prototype intended for photodetector readout has been designed and fabricated with 64k deep sampling at multi-GSa/s operation. An evaluation system has been constructed for instrumentation of Time-Of-Propagation (TOP) and focusing DIRC prototypes and test results will be reported.

  16. Vulnerability of nuclear power plant structures to large external fires

    SciTech Connect (OSTI)

    Bennett, D.E.

    1983-08-01T23:59:59.000Z

    This report examines the inherent vulnerability of nuclear power plant structures to the thermal environments arising from large, external fires. The inherent vulnerability is the capacity of the concrete safety-related structures to absorb thermal loads without exceeding the appropriate thermal and structural design criteria. The potential sources of these thermal environments are large, offsite fires arising from accidents involving the transportation or storage of large quantities of flammable gases or liquids. A realistic thermal response analysis of a concrete panel was performed using three limiting criteria: temperature at the first rebar location, erosion and ablation of the front (exterior) surface due to high heat fluxes, and temperature at the back (interior) surface. The results of this analysis yield a relationship between incident heat flux and the maximum allowable exposure duration. Example calculations for the break of a 0.91 m (3') diameter high-pressure natural gas pipeline and a 1 m/sup 2/ hole in a 2-1/2 million gallon gasoline tank show that the resulting fires do not pose a significant hazard for ranges of 500 m or greater.

  17. FUTURE POWER GRID INITIATIVE Real-time High-Performance

    E-Print Network [OSTI]

    FUTURE POWER GRID INITIATIVE Real-time High-Performance Computing Infrastructure for Next- Generation Power Grid Analysis OBJECTIVE » We are developing infrastructure, software, formal models for real Infrastructure Operations Center (EIOC), the Pacific Northwest National Laboratory's (PNNL) national electric

  18. Update to Large Power Transformers and the U.S. Electric Grid...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Update to Large Power Transformers and the U.S. Electric Grid Report Now Available Update to Large Power Transformers and the U.S. Electric Grid Report Now Available April 25, 2014...

  19. An improved voltage control on large-scale power system

    SciTech Connect (OSTI)

    Vu, H.; Pruvot, P.; Launay, C.; Harmand, Y. [Electricite de France, Clamart (France). Study and Research Div.] [Electricite de France, Clamart (France). Study and Research Div.

    1996-08-01T23:59:59.000Z

    To achieve a better voltage-var control in the electric power transmission system, different facilities are used. Generators are equipped with automatic voltage regulators to cope with sudden and random changes voltage caused by natural load fluctuations or failures. Other devices like capacitors, inductors, transformers with on load tap changers are installed on the network. Faced with the evolution of the network and operating conditions, electricity utilities are more and more interested in overall and coherent control systems, automatic or not. These systems are expected to coordinate the actions of local facilities for a better voltage control (more stable and faster reaction) inside different areas of the network in case of greater voltage and var variations. They affords besides a better use of existing reactive resources. Also, installation of new devices can be avoided allowing economy of investment. With this frame of mind, EDF has designed a system called Co-ordinated Secondary Voltage Control (CSVC). It`s an automatic closed loop system with a dynamic of a few minutes. It takes into account the network conditions (topology, loads), the voltage limits and the generator operating constraints. This paper presents recent improvements which allow the CSVC to control the voltage profile and different kinds of reactive means on a large-scale power system. Furthermore, this paper presents solution to spread out investment costs over several years, considering a deployment gradually extended.

  20. 2144 IEEE TRANSACTIONS ON POWER SYSTEMS, VOL. 22, NO. 4, NOVEMBER 2007 Fast SCUC for Large-Scale Power Systems

    E-Print Network [OSTI]

    Fu, Yong

    2144 IEEE TRANSACTIONS ON POWER SYSTEMS, VOL. 22, NO. 4, NOVEMBER 2007 Fast SCUC for Large introduces an efficient fast SCUC (F-SCUC) for large-scale power systems. Main components used-changing and phase-shifting transformers, and so on [1]. Such SCUC problem is a nonconvex, nonlinear, large

  1. Management Plan Large-Area Time-of-Flight System

    E-Print Network [OSTI]

    Llope, William J.

    Management Plan for the Large-Area Time-of-Flight System for STAR at Brookhaven National Laboratory For the U.S. Department of Energy Office of Science Office of Nuclear Physics December 1, 2005 #12;2 STAR Project Manager Timothy Hallman STAR Spokesman Brookhaven National Lab approval: Thomas Ludlam BNL Project

  2. Ferroelectric opening switches for large-scale pulsed power drivers.

    SciTech Connect (OSTI)

    Brennecka, Geoffrey L.; Rudys, Joseph Matthew; Reed, Kim Warren; Pena, Gary Edward; Tuttle, Bruce Andrew; Glover, Steven Frank

    2009-11-01T23:59:59.000Z

    Fast electrical energy storage or Voltage-Driven Technology (VDT) has dominated fast, high-voltage pulsed power systems for the past six decades. Fast magnetic energy storage or Current-Driven Technology (CDT) is characterized by 10,000 X higher energy density than VDT and has a great number of other substantial advantages, but it has all but been neglected for all of these decades. The uniform explanation for neglect of CDT technology is invariably that the industry has never been able to make an effective opening switch, which is essential for the use of CDT. Most approaches to opening switches have involved plasma of one sort or another. On a large scale, gaseous plasmas have been used as a conductor to bridge the switch electrodes that provides an opening function when the current wave front propagates through to the output end of the plasma and fully magnetizes the plasma - this is called a Plasma Opening Switch (POS). Opening can be triggered in a POS using a magnetic field to push the plasma out of the A-K gap - this is called a Magnetically Controlled Plasma Opening Switch (MCPOS). On a small scale, depletion of electron plasmas in semiconductor devices is used to affect opening switch behavior, but these devices are relatively low voltage and low current compared to the hundreds of kilo-volts and tens of kilo-amperes of interest to pulsed power. This work is an investigation into an entirely new approach to opening switch technology that utilizes new materials in new ways. The new materials are Ferroelectrics and using them as an opening switch is a stark contrast to their traditional applications in optics and transducer applications. Emphasis is on use of high performance ferroelectrics with the objective of developing an opening switch that would be suitable for large scale pulsed power applications. Over the course of exploring this new ground, we have discovered new behaviors and properties of these materials that were here to fore unknown. Some of these unexpected discoveries have lead to new research directions to address challenges.

  3. Real-Time Dispatchability of Bulk Power Systems with Volatile ...

    E-Print Network [OSTI]

    2015-03-16T23:59:59.000Z

    the concept of real-time dispatchability (RTDA) of power systems with variable energy resources .... eration control, economic dispatch and unit commitment. Ref

  4. Optimization Online - Real-Time Dispatchability of Bulk Power ...

    E-Print Network [OSTI]

    Wei Wei

    2015-03-16T23:59:59.000Z

    Mar 16, 2015 ... Real-Time Dispatchability of Bulk Power Systems with Volatile Renewable Generations. Wei Wei (wei-wei04 ***at*** mails.tsinghua.edu.cn)

  5. Model Predictive Control based Real Time Power System Protection Schemes

    E-Print Network [OSTI]

    Kumar, Ratnesh

    1 Model Predictive Control based Real Time Power System Protection Schemes Licheng Jin, Member by controlling the production, absorption as well as flow of reactive power at various locations in the system predictive control, trajectory sensitivity, voltage stabilization, switching control, power system I

  6. Ultra-Low Power Time Synchronization Using Passive Radio Receivers

    E-Print Network [OSTI]

    Amir, Yair

    Ultra-Low Power Time Synchronization Using Passive Radio Receivers Yin Chen Qiang Wang Marcus Chang. In this pa- per, we present an inexpensive and ultra-low power ( of elapsed seconds. The universal time sig- nal receiver combines an off-the-shelf radio chip with an ultra-low

  7. Models for Assessing Power Fluctuations from Large Wind Farms N. A. Cutululis1)

    E-Print Network [OSTI]

    that the active power supplied from the first large 160 MW offshore wind farm in this system, Horns Rev today). Figure 1. Power generation of Horns Rev offshore wind farm and onshore turbines, January 18 2005Models for Assessing Power Fluctuations from Large Wind Farms N. A. Cutululis1) , P. Sørensen1) , A

  8. Dynamic Response of Large Wind Power Plant Affected by Diverse Conditions at Individual Turbines

    SciTech Connect (OSTI)

    Elizondo, Marcelo A.; Lu, Shuai; Lin, Guang; Wang, Shaobu

    2014-07-31T23:59:59.000Z

    Diverse operating conditions at individual wind turbine generators (WTG) within wind power plants (WPPs) can affect the WPP dynamic response to system faults. For example, individual WTGs can experience diverse terminal voltage and power output caused by different wind direction and speed, affecting the response of protection and control limiters. In this paper, we present a study to investigate the dynamic response of a detailed WPP model under diverse power outputs of its individual WTGs. Wake effect is considered as the reason for diverse power outputs. The diverse WTG power output is evaluated in a test system where a large 168-machine test WPP is connected to the IEEE-39-bus system. The power output from each WTG is derived from a wake effect model that uses realistic statistical data for incoming wind speed and direction. The results show that diverse WTG output due to wake effect can affect the WPP dynamic response activating specialized control in some turbines. In addition, transient stability is affected by exhibiting uncertainty in critical clearing time calculation.

  9. advanced large power: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    . . . . 18 3.4.1 Heat Exchanger - Code description . . . . . . . . . . . . . . . 18 3.4.2 Simulation ResultsADVANCED POWER PLANT MODELING WITH APPLICATIONS TO THE ADVANCED BOILING...

  10. IEEE TRANSACTIONS ON POWER SYSTEMS 1 Large-Scale Integration of Deferrable

    E-Print Network [OSTI]

    Oren, Shmuel S.

    . Index Terms--Load management, power generation scheduling, wind power generation. I. INTRODUCTION on power system operations it is necessary to represent the balancing oper- ations of the remaining gridIEEE TRANSACTIONS ON POWER SYSTEMS 1 Large-Scale Integration of Deferrable Demand and Renewable

  11. Impacts of Large Amounts of Wind Power on Design and Operation...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Impacts of Large Amounts of Wind Power on Design and Operation of Power Systems; Results of IEA Collaboration B. Parsons and E. Ela National Renewable Energy Laboratory, USA H....

  12. Reactive power planning of large-scale systems

    SciTech Connect (OSTI)

    Burchett, R.C.; Happ, H.H.; Vierath, D.R.

    1983-01-01T23:59:59.000Z

    This paper discusses short-term operations planning applications in reactive power management involving existing equipment. Reactive power planning involves the sizing and siting of additional reactive support equipment in order to satisfy system voltage constraints (minimum and maximum limits) under both normal and contingency conditions. The use of the Optimal Power Flow (OPF) and the VARPLAN computer codes for operations planning are examined. The OPF software can be used to determine if reactive outputs from nearby generators are scheduled properly, and to confirm that parallel transformers have been properly set. A major benefit of the system planning software VARPLAN is the ability to simultaneously consider both normal and contingency conditions, while adding a minimal amount of new reactive power. Applications to long-term system planning of new reactive power sources are described.

  13. Volatility of Power Grids Under Real-Time Pricing

    E-Print Network [OSTI]

    Roozbehani, Mardavij

    The paper proposes a framework for modeling and analysis of the dynamics of supply, demand, and clearing prices in power systems with real-time retail pricing and information asymmetry. Characterized by passing on the ...

  14. The Large Observatory For x-ray Timing

    E-Print Network [OSTI]

    Feroci, M; Bozzo, E; Barret, D; Brandt, S; Hernanz, M; van der Klis, M; Pohl, M; Santangelo, A; Stella, L; Watts, A; Wilms, J; Zane, S; Ahangarianabhari, M; Albertus, C; Alford, M; Alpar, A; Altamirano, D; Alvarez, L; Amati, L; Amoros, C; Andersson, N; Antonelli, A; Argan, A; Artigue, R; Artigues, B; Atteia, J -L; Azzarello, P; Bakala, P; Baldazzi, G; Balman, S; Barbera, M; van Baren, C; Bhattacharyya, S; Baykal, A; Belloni, T; Bernardini, F; Bertuccio, G; Bianchi, S; Bianchini, A; Binko, P; Blay, P; Bocchino, F; Bodin, P; Bombaci, I; Bidaud, J -M Bonnet; Boutloukos, S; Bradley, L; Braga, J; Brown, E; Bucciantini, N; Burderi, L; Burgay, M; Bursa, M; Budtz-Jørgensen, C; Cackett, E; Cadoux, F R; Cais, P; Caliandro, G A; Campana, R; Campana, S; Capitanio, F; Casares, J; Casella, P; Castro-Tirado, A J; Cavazzuti, E; Cerda-Duran, P; Chakrabarty, D; Château, F; Chenevez, J; Coker, J; Cole, R; Collura, A; Cornelisse, R; Courvoisier, T; Cros, A; Cumming, A; Cusumano, G; D'Aì, A; D'Elia, V; Del Monte, E; De Luca, A; De Martino, D; Dercksen, J P C; De Pasquale, M; De Rosa, A; Del Santo, M; Di Cosimo, S; Diebold, S; Di Salvo, T; 1), I Donnarumma; (32), A Drago; (33), M Durant; (107), D Emmanoulopoulos; (135), M H Erkut; (85), P Esposito; (1, Y Evangelista; 1b),; (24), A Fabian; (34), M Falanga; (25), Y Favre; (35), C Feldman; (128), V Ferrari; (3), C Ferrigno; (133), M Finger; (36), M H Finger; (35, G W Fraser; +),; (2), M Frericks; (7), F Fuschino; (125), M Gabler; (37), D K Galloway; (6), J L Galvez Sanchez; (6), E Garcia-Berro; (10), B Gendre; (62), S Gezari; (39), A B Giles; (40), M Gilfanov; (10), P Giommi; (102), G Giovannini; (102), M Giroletti; (4), E Gogus; (105), A Goldwurm; (86), K Goluchová; (16), D Götz; (16), C Gouiffes; (56), M Grassi; (42), P Groot; (17), M Gschwender; (128), L Gualtieri; (32), C Guidorzi; (3), L Guy; (2), D Haas; (50), P Haensel; (29), M Hailey; (19), F Hansen; (42), D H Hartmann; (43), C A Haswell; (88), K Hebeler; (37), A Heger; (2), W Hermsen; (28), J Homan; (19), A Hornstrup; (23, R Hudec; 72),; (45), J Huovelin; (5), A Ingram; (2), J J M in't Zand; (27), G Israel; (20), K Iwasawa; (47), L Izzo; (2), H M Jacobs; (17), F Jetter; (118, T Johannsen; 127),; (2), H M Jacobs; (2), P Jonker; (126), J Josè; (49), P Kaaret; (123), G Kanbach; (23), V Karas; (6), D Karelin; (29), D Kataria; (49), L Keek; (29), T Kennedy; (17), D Klochkov; (50), W Kluzniak; (17), K Kokkotas; (45), S Korpela; (51), C Kouveliotou; (87), I Kreykenbohm; (2), L M Kuiper; (19), I Kuvvetli; (7), C Labanti; (52), D Lai; (53), F K Lamb; (2), P P Laubert; (105), F Lebrun; (8), D Lin; (29), D Linder; (54), G Lodato; (55), F Longo; (19), N Lund; (131), T J Maccarone; (14), D Macera; (8), S Maestre; (62), S Mahmoodifar; (17), D Maier; (56), P Malcovati; (120), I Mandel; (144), V Mangano; (50), A Manousakis; (7), M Marisaldi; (109), A Markowitz; (35), A Martindale; (59), G Matt; (107), I M McHardy; (60), A Melatos; (61), M Mendez; (85), S Mereghetti; (68), M Michalska; (20), S Migliari; (85, R Mignani; 108),; (62), M C Miller; (49), J M Miller; (57), T Mineo; (112), G Miniutti; (64), S Morsink; (65), C Motch; (13), S Motta; (66), M Mouchet; (8), G Mouret; (19), J Mula?ová; (1, F Muleri; 1b),; (140), T Muñoz-Darias; (95), I Negueruela; (28), J Neilsen; (43), A J Norton; (28), M Nowak; (35), P O'Brien; (19), P E H Olsen; (102), M Orienti; (99, M Orio; 110),; (7), M Orlandini; (68), P Orleanski; (35), J P Osborne; (69), R Osten; (70), F Ozel; (1, L Pacciani; 1b),; (119), M Paolillo; (6), A Papitto; (20), J M Paredes; (83, A Patruno; 141),; (71), B Paul; (17), E Perinati; (115), A Pellizzoni; (47), A V Penacchioni; (136), M A Perez; (72), V Petracek; (10), C Pittori; (95), J Pons; (6), J Portell; (115), A Possenti; (73), J Poutanen; (122), M Prakash; (16), P Le Provost; (70), D Psaltis; (8), D Rambaud; (8), P Ramon; (76), G Ramsay; (1, M Rapisarda; 1b),; (77), A Rachevski; (77), I Rashevskaya; (78), P S Ray; (6), N Rea; (80), S Reddy; (113, P Reig; 81),; (63), M Reina Aranda; (28), R Remillard; (62), C Reynolds; (124), L Rezzolla; (20), M Ribo; (2), R de la Rie; (115), A Riggio; (138), A Rios; (82, P Rodríguez- Gil; 104),; (16), J Rodriguez; (3), R Rohlfs; (57), P Romano; (83), E M R Rossi; (50), A Rozanska; (29), A Rousseau; (84), F Ryde; (63), L Sabau-Graziati; (6), G Sala; (85), R Salvaterra; (61), A Sanna; (134), J Sandberg; (130), S Scaringi; (16), S Schanne; (86), J Schee; (87), C Schmid; (117), S Shore; (27), R Schneider; (88), A Schwenk; (89), A D Schwope; (114), J -Y Seyler; (90), A Shearer; (29), A Smith; (58), D M Smith; (29), P J Smith; (23), V Sochora; (1), P Soffitta; (61), P Soleri; (29), A Spencer

    2014-01-01T23:59:59.000Z

    The Large Observatory For x-ray Timing (LOFT) was studied within ESA M3 Cosmic Vision framework and participated in the final down-selection for a launch slot in 2022-2024. Thanks to the unprecedented combination of effective area and spectral resolution of its main instrument, LOFT will study the behaviour of matter under extreme conditions, such as the strong gravitational field in the innermost regions of accretion flows close to black holes and neutron stars, and the supra-nuclear densities in the interior of neutron stars. The science payload is based on a Large Area Detector (LAD, 10 m 2 effective area, 2-30 keV, 240 eV spectral resolution, 1 deg collimated field of view) and a WideField Monitor (WFM, 2-50 keV, 4 steradian field of view, 1 arcmin source location accuracy, 300 eV spectral resolution). The WFM is equipped with an on-board system for bright events (e.g. GRB) localization. The trigger time and position of these events are broadcast to the ground within 30 s from discovery. In this paper we ...

  15. Large Power Transformers and the U.S. Electric Grid Report Update...

    Broader source: Energy.gov (indexed) [DOE]

    Reliability has released an update to its 2012 Large Power Transformers and the U.S. Electric Grid report. The new report includes updated information about global electrical...

  16. FACTS Devices for Large Wind Power Plants A. Adamczyk

    E-Print Network [OSTI]

    Teodorescu, Remus

    -of-the-art in FACTS for large WPPs with AC connection is given. FACTS devices (excluding HVDC) with their properties

  17. Design considerations for large space electric power systems

    SciTech Connect (OSTI)

    Renz, D.D.; Finke, R.C.; Stevens, N.J.; Triner, J.E.; Hansen, I.G.

    1983-04-01T23:59:59.000Z

    As power levels of spacecraft rise to the 50 to 100 kW range, it becomes apparent that low voltage (28 V) dc power distribution and management systems will not operate efficiently at these higher power levels. The concept of transforming a solar array voltage at 150 V dc into a 1000 V ac distribution system operating at 20 kHz is examined. The transformation is accomplished with series-resonant inverter by using a rotary transformer to isolate the solar array from the spacecraft. The power can then be distributed in any desired method such as three phase delta to delta. The distribution voltage can be easily transformed to any desired load voltage and operating frequency. The reasons for the voltage limitations on the solar array due to plasma interactions and the many advantages of a high voltage, high frequency at distribution system are discussed.

  18. Mandatory Green Power Option for Large Municipal Utilities

    Broader source: Energy.gov [DOE]

    Municipal electric utilities serving more than 40,000 customers in Colorado must offer an optional green-power program that allows retail customers the choice of supporting emerging renewable...

  19. Model Abstraction Techniques for Large-Scale Power Systems

    E-Print Network [OSTI]

    Report on System Simulation using High Performance Computing Prepared by New Mexico Tech New Mexico: Application of High Performance Computing to Electric Power System Modeling, Simulation and Analysis Task Two

  20. Aging assessment of large electric motors in nuclear power plants

    SciTech Connect (OSTI)

    Villaran, M.; Subudhi, M. [Brookhaven National Lab., Upton, NY (United States)

    1996-03-01T23:59:59.000Z

    Large electric motors serve as the prime movers to drive high capacity pumps, fans, compressors, and generators in a variety of nuclear plant systems. This study examined the stressors that cause degradation and aging in large electric motors operating in various plant locations and environments. The operating history of these machines in nuclear plant service was studied by review and analysis of failure reports in the NPRDS and LER databases. This was supplemented by a review of motor designs, and their nuclear and balance of plant applications, in order to characterize the failure mechanisms that cause degradation, aging, and failure in large electric motors. A generic failure modes and effects analysis for large squirrel cage induction motors was performed to identify the degradation and aging mechanisms affecting various components of these large motors, the failure modes that result, and their effects upon the function of the motor. The effects of large motor failures upon the systems in which they are operating, and on the plant as a whole, were analyzed from failure reports in the databases. The effectiveness of the industry`s large motor maintenance programs was assessed based upon the failure reports in the databases and reviews of plant maintenance procedures and programs.

  1. Power Minimisation for Real-time Dataflow Applications

    E-Print Network [OSTI]

    Kuzmanov, Georgi

    at lower frequencies on hardware resources thereby consuming less power. Real-time applications have for dataflow modelled real-time applications that may be mapped onto multiple hardware resources. We achieve this by using an application's static slack in order to perform DVFS while still satisfying the application

  2. A SUBSPACE APPROACH TO FAULT DIAGNOSTICS IN LARGE POWER SYSTEMS

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    and to fast detect and identify possible failures. In this article, we focus on failures in power lines which translate in sudden changes in the electric impedance. To keep track of the current flowing in the line), transmission line states are only refreshed on an hourly basis [1]. For rather static systems, the au- thors

  3. Obtaining the right large power transformer for a hydro plant

    SciTech Connect (OSTI)

    Clemen, D.M. [Harza Engineering Company, Chicago, IL (United States)

    1995-07-01T23:59:59.000Z

    Transformer efficiency and reliability are important factors in determining the productivity of a hydroelectric generating plant. A well-supervised testing program can help plant owners and engineers improve the quality of equipment installed at their plant. This paper addresses such a program as applied to the selection of the generator step-up, or main power, transformer at a hydroelectric generating station.

  4. Simulating the Power Consumption of Large-Scale Sensor Network Applications

    E-Print Network [OSTI]

    Simulating the Power Consumption of Large-Scale Sensor Network Applications Victor Shnayder, Mark of the most important as- pects of sensor application design: that of power consump- tion. While simple approximations of overall power usage can be derived from estimates of node duty cycle and com- munication rates

  5. A SPECULATIVE FRAMEWORK FOR THE APPLICATION OF ARTIFICIAL INTELLIGENCE TO LARGE SCALE INTERCONNECTED POWER SYSTEMS

    E-Print Network [OSTI]

    Hartley, Roger

    INTERCONNECTED POWER SYSTEMS By Nadipuram R. Prasad Satish J. Ranade Electrical Engineering Department New Mexico) technologies to the operation and control of large scale interconnected electric power systems. A fundamental issue discussed in this paper is the control structure of power systems. An evaluation of the control

  6. High voltage-high power components for large space power distribution systems

    SciTech Connect (OSTI)

    Renz, D.D.

    1984-08-01T23:59:59.000Z

    For over a decade, Lewis Research Center has been developing space power components. These components include a family of bi-polar power switching transistors, fast switching power diodes, heat pipe cooled high-frequency transformers and inductors, high frequency conduction cooled transformers, high powerhigh frequency capacitors, remote power controllers and rotary power transfer devices. Many of these components such as the power switching transistors, power diodes and the high frequency capacitor are commercially available. All the other components have been developed to the prototype level. Series resonant dc/dc converters have been built to the 25 kW level.

  7. Including Variability in Large-Scale Cluster Power Models

    E-Print Network [OSTI]

    Rivoire, Suzanne

    , mobile (laptop), desktop, and server processor spac- es, reflecting energy-efficient server.rivoire@sonoma.edu University of CA, Santa Cruz3 eka@soe.ucsc.edu Abstract--Studying the energy efficiency of large five-node clusters using embedded, laptop, desktop, and server processors. The variation is manifested

  8. Analysis of Wind Power and Load Data at Multiple Time Scales

    SciTech Connect (OSTI)

    Coughlin, Katie; Eto, J.H.

    2010-12-20T23:59:59.000Z

    In this study we develop and apply new methods of data analysis for high resolution wind power and system load time series, to improve our understanding of how to characterize highly variable wind power output and the correlations between wind power and load. These methods are applied to wind and load data from the ERCOT region, and wind power output from the PJM and NYISO areas. We use a wavelet transform to apply mathematically well-defined operations of smoothing and differencing to the time series data. This approach produces a set of time series of the changes in wind power and load (or ?deltas?), over a range of times scales from a few seconds to approximately one hour. A number of statistical measures of these time series are calculated. We present sample distributions, and devise a method for fitting the empirical distribution shape in the tails. We also evaluate the degree of serial correlation, and linear correlation between wind and load. Our examination of the data shows clearly that the deltas do not follow a Gaussian shape; the distribution is exponential near the center and appears to follow a power law for larger fluctuations. Gaussian distributions are frequently used in modeling studies. These are likely to over-estimate the probability of small to moderate deviations. This in turn may lead to an over-estimation of the additional reserve requirement (hence the cost) for high penetration of wind. The Gaussian assumption provides no meaningful information about the real likelihood of large fluctuations. The possibility of a power law distribution is interesting because it suggests that the distribution shape for of wind power fluctuations may become independent of system size for large enough systems.

  9. Particle contamination levels in oil-filled large power transformers

    SciTech Connect (OSTI)

    Oommen, T.V.; Petrie, E.M.

    1983-05-01T23:59:59.000Z

    A study of particle levels in transformer oil was conducted, covering about 200 samples taken from field and factory units. Factory samples were included to determine a relative base condition on which to compare field data. Particle distribution curves show size and count relationship in transformers. The particles were studied also by Atomic Absorption Spectroscopy to measure the content of iron, copper and other common metals expected. Particle analysis can supplement more standard laboratory techniques to judge the condition of oil in operating power transformers. The diagnostic value of such analysis, especially in determining pump performance problems, is illustrated with examples.

  10. Factory overload testing of a large power transformer

    SciTech Connect (OSTI)

    Douglas, D.H.; Lawrence, C.O.; Templeton, J.B.

    1985-09-01T23:59:59.000Z

    A factory overload test of up to 150% of the nameplate rating was run on a 224 MVA autotransformer. The results of this test were of great value and were used in identifying transformer overload limitations, in evaluating loading guide oil and winding equations, exponents and time constants, and in helping to perfect a factory overload test procedure.

  11. 42 IEEE TRANSACTIONS ON VERY LARGE SCALE INTEGRATION (VLSI) SYSTEMS, VOL. 12, NO. 1, JANUARY 2004 Timing Driven Gate Duplication

    E-Print Network [OSTI]

    Kastner, Ryan

    42 IEEE TRANSACTIONS ON VERY LARGE SCALE INTEGRATION (VLSI) SYSTEMS, VOL. 12, NO. 1, JANUARY 2004 of transforming a set of boolean equations into a circuit comprising of gates that implement the logic while, and power) but the present work deals with delay optimization. Many timing optimization strategies have been

  12. Fast time domain simulation for large order hybrid systems

    E-Print Network [OSTI]

    Sou, Kin Cheong, 1979-

    2002-01-01T23:59:59.000Z

    Simulation is an important tool for the analysis and design of complex systems. As the models become more and more complex, more powerful simulation methods are desired. As an attempt to address this problem, a simulation ...

  13. Resultant magnetic fields due to both windings and heavy current leads in large power transformers

    SciTech Connect (OSTI)

    Tang Renyuan; Li Yan; Lin Feng; Tian Lijian [Shenyang Polytechnic Univ. (China)] [Shenyang Polytechnic Univ. (China)

    1996-05-01T23:59:59.000Z

    The eddy current field due to both windings and heavy current leads (HCL) in large power transformers is analyzed by using the improved T-{Omega} method, in which the T and {Omega} can be solved separately in different subregions. Thus, the storage capacity and CPU time can be saved to a great extent. In addition, the local overheating on the tank wall near the magnetic shield gap is calculated and analyzed, and the improving measures are proposed. On the basis of these work, a composite shield is analyzed and optimized. The numerical results show that the eddy current losses have been reduced and the local overheating has been removed by using this composite shield.

  14. Variable timing circuit for motive power battery chargers

    SciTech Connect (OSTI)

    Lambert, F.J.; Bosack, D.J.; Johansen, D.K.

    1984-03-27T23:59:59.000Z

    A timing circuit for charging motive power batteries. The timing control circuit provides different times of charge in accordance with the time at which a predetermined voltage/current state of the battery is achieved. Control circuit cooperates with a controller in causing termination of the charging operation immediately upon reaching of the voltage/current state if this occurs in a first time slot of an initial control time period. The timing circuit provides an automatic finish time period of charge if the battery reaches the predetermined voltage/current state at some time during the initial control time period. The control includes a switch permitting the user to cause an automatic additional amount of charging upon completion of the normal charging cycle effected by the control, such as for effecting a weekend charge. The control further includes structure for terminating the charging operation in the event the battery being charged does not reach the predetermined voltage/current state at the end of a preselected maximum time. A signal light signals such a fault condition in the charging operation.

  15. POWER ELECTRONICS HARMONIC ANALYSIS BASED ON THE LINEAR TIME PERIODIC MODELING. APPLICATIONS FOR AC/DC/AC POWER

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    /Simulink simulations. Key words: power system harmonics, power electronic, linear time periodic modeling, PWM, control1 POWER ELECTRONICS HARMONIC ANALYSIS BASED ON THE LINEAR TIME PERIODIC MODELING. APPLICATIONS in power electronic systems. The considered system is described by a set of differential equations, which

  16. Gated Si nanowires for large thermoelectric power factors Neophytos Neophytou1

    E-Print Network [OSTI]

    1 Gated Si nanowires for large thermoelectric power factors Neophytos Neophytou1 and Hans Kosina2 1.Neophytou@warwick.ac.uk Abstract We investigate the effect of electrostatic gating on the thermoelectric power factor of p-type Si, coupled to linearized Boltzmann transport equation for the calculation of the thermoelectric coefficients

  17. PNNL-SA-XXXXX Ultra Large-Scale Power System Control and

    E-Print Network [OSTI]

    Low, Steven H.

    PNNL-SA-XXXXX Ultra Large-Scale Power System Control and Coordination Architecture A Strategic Institute of Technology Rick Geiger Utilities and Smart Grid Cisco Systems #12;#12;PNNL-SA-XXXXX #12;PNNL Richland, Washington 99352 #12;PNNL-SA-XXXXX #12;#12;PNNL-SA-XXXXX 1.0 Introduction Electric power grids

  18. NTL Detection of Electricity Theft and Abnormalities for Large Power Consumers In TNB Malaysia

    E-Print Network [OSTI]

    Ducatelle, Frederick

    in power utilities originating from electricity theft and other customer malfeasances are termed as Non]. Investigations are undertaken by electric utility companies to assess the impact of technical lossesNTL Detection of Electricity Theft and Abnormalities for Large Power Consumers In TNB Malaysia J

  19. Optimization and control of large power engineering systems (principal investigation results)

    SciTech Connect (OSTI)

    Belyaev, L.S.; Gorskii, Yu.M.; Krumm, L.A.; Makarov, A.A.; Merenkov, A.P.; Popyrin, L.S.; Rudenko, Yu.N.; Sher, I.A.

    1980-01-01T23:59:59.000Z

    Principal scientific and practical results of investigations in the development of theory and methods of optimization and control of large power engineering systems, conducted under the scientific and methodological management of the USSR Academy of Sciences Scientific Council on complex problems of power engineering are characterized and the investigation development tasks are formulated. 52 refs.

  20. Identification of Market Power in Large-Scale Electric Energy Markets Bernard C. Lesieutre

    E-Print Network [OSTI]

    Identification of Market Power in Large-Scale Electric Energy Markets Bernard C. Lesieutre Hyung and competitive operation of centrally- dispatched electricity markets. Traditional measures for market power demand and reserve requirements, a centrally-dispatched electricity market provides a transparent

  1. Energy Policy 35 (2007) 15841598 Public opinion about large offshore wind power: Underlying factors

    E-Print Network [OSTI]

    Firestone, Jeremy

    2007-01-01T23:59:59.000Z

    Energy Policy 35 (2007) 1584­1598 Public opinion about large offshore wind power: Underlying opinion regarding offshore wind power based on a survey of residents near a proposed development off Cape, the first offshore wind proposal in North America, in Nantucket Sound (MA, USA) has generated a strong

  2. The Power of a Few Large Blocks: A credible assumption with incredible efficiency

    E-Print Network [OSTI]

    Foster, Dean P.

    i.i.d. assumption about the error structure, the two-sample t-statistic for oil was significantThe Power of a Few Large Blocks: A credible assumption with incredible efficiency Dongyu Lin and Dean P. Foster Abstract The most powerful assumption in data analysis is that of independence. Unfortu

  3. Large time behaviour of mild solutions of Hamilton-Jacobi-Bellman equations in infinite dimension

    E-Print Network [OSTI]

    Boyer, Edmond

    Large time behaviour of mild solutions of Hamilton-Jacobi-Bellman equations in infinite dimension by a probabilistic approach Ying Hu Pierre-Yves Madec Adrien Richou June 22, 2014 Abstract We study the large time We are concerned with the large time behaviour of solutions of the Cauchy problem in an infinite

  4. An efficient algorithm for real-time network reconfiguration in large scale unbalanced distribution systems

    SciTech Connect (OSTI)

    Wang, J.C.; Chiang, H.D. [Cornell Univ., Ithaca, NY (United States). School of Electrical Engineering; Darling, G.R. [NYSEG Corp., Binghamton, NY (United States). Distribution System Dept.

    1996-02-01T23:59:59.000Z

    Real-time applications demand fast computation, this paper proposes an efficient algorithm for real-time network reconfiguration on large unbalanced distribution networks. A novel formulation of the network reconfiguration to achieve loss minimization and load balancing is given. To reduce computational requirements for the solution algorithm, well justified power flow and loss reduction formulas in terms of the on/off status of network switches are proposed for efficient system updating. The algorithm relies only on a few full power flow studies based on system states attained by explicit expressions using backward-forward sweeps for efficient computation of system`s states at the critical system operating points. The solution algorithm runs in an amount of time linearly proportional to the number of tie switches and the number of sectionalizing switches in the system. The solution algorithm has been implemented into a software package and tested on unbalanced distribution systems including a system with 292-buses, 76-laterals, 7 transformers, 45 switches and 255 lines sections under diverse system conditions.

  5. An efficient algorithm for real-time network reconfiguration in large scale unbalanced distribution systems

    SciTech Connect (OSTI)

    Wang, J.C.; Chiang, H.D. [Cornell Univ., Ithaca, NY (United States). School of Electrical Engineering; Darling, G.R. [NYSEG Corp., Binghamton, NY (United States). Distribution System Dept.

    1995-12-31T23:59:59.000Z

    Real-time applications demand fast computation, this paper proposes an efficient algorithm for real-time network reconfiguration on large unbalanced distribution networks. A novel formulation of the network reconfiguration to achieve loss minimization and load balancing is given. To reduce computational requirements for the solution algorithm, well justified power flow and loss reduction formulas in terms of the on/off status of network switches are proposed for efficient system updating. The algorithm relies only a few full power flow studies based on system states attained by explicit expressions using backward-forward sweeps for efficient computation of system`s states at the critical system operating points. The solution algorithm runs in an amount of time linearly proportional to the number of tie switches and the number of sectionalizing switches in the system. The solution algorithm has been implemented into a software package and tested on unbalanced distribution systems including a system with 292-buses, 76-laterals, 7 transformers, 45 switches and 255 lines sections under diverse system conditions.

  6. Classification of power quality disturbances using time-frequency ambiguity plane and

    E-Print Network [OSTI]

    Mamishev, Alexander

    Classification of power quality disturbances using time-frequency ambiguity plane and neural disturbances in power systems is an important task in power system monitoring and protection, This paper discussed. Keywords -- Power Quality Disturbances, Classification, Ambiguity Plane, Modified Fisher

  7. Time series modeling of autonomous hybrid power systems

    SciTech Connect (OSTI)

    Quinlan, P.J.; Beckman, W.A.; Mitchell, J.W.; Klein, S.A.; Blair, N.J. [Univ. of Wisconsin, Madison, WI (United States). Solar Energy Lab.

    1997-12-31T23:59:59.000Z

    The Solar Energy Laboratory (SEL) has developed a wind diesel PV hybrid systems simulator, UW-HYBRID 1.0, as an application of the TRNSYS 14.2 time-series simulation environment. The simulator provides a customizable user interface. The simulation provides an AC/DC buss, diesel generators, wind turbines, PV modules, a battery bank, and power converter. PV system simulations include solar angle and peak power tracking options. Diesel simulations include estimated fuel-use and waste heat output, and are dispatched using a least-cost of fuel strategy. Wind system simulations include varying air density, wind shear and wake effects. Time step duration is user-selectable. This paper provides a description of the simulation models and example output.

  8. Impacts of Large-Scale Wind Generators Penetration on the Voltage Stability of Power Systems

    E-Print Network [OSTI]

    Pota, Himanshu Roy

    development of wind energy tech- nology and the current world-wide status of grid-connected as well as standImpacts of Large-Scale Wind Generators Penetration on the Voltage Stability of Power Systems M. J systems and their dynamic behaviours to identify critical issues that limit the large-scale integration

  9. Parallel domain decomposition for simulation of large-scale power grids

    E-Print Network [OSTI]

    Mohanram, Kartik

    of large-scale linear circuits such as power grids. DD techniques that use non-overlapping and overlap that with the proposed parallel DD framework, existing linear circuit simulators can be extended to handle large- scale can be solved independently in parallel using standard techniques for linear system analysis

  10. Reliability analysis of electric power systems including time dependent sources 

    E-Print Network [OSTI]

    Kim, Younjong

    1987-01-01T23:59:59.000Z

    Chairman of Advisory Committee: Chanan Singh A method for reliability analysis of electric power systems with time dependent sources, such as photovoltaic and wind generation, is introduced. The fluctuating characteristic of unconventional generation... and active solar. wind, geothermal, and hydropower. Of all the renewable energy technologies that have been the focus of encouraging government and private R k D efforts, photovoltaic generation and wind turbine generation appear to be the leading...

  11. Solar Power in the Desert: Are the current large-scale solar developments really improving California’s environment?

    E-Print Network [OSTI]

    Allen, Michael F.; McHughen, Alan

    2011-01-01T23:59:59.000Z

    D EVELOPMENT I SSUES Solar Power in the Desert: Are the2 Most of the large-scale solar power projects utilize largethat will be affected by solar power facilities. There are

  12. Large

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn12electron 9 5 - -/e),,sand CERNLand and AssetLandscapingLarge

  13. The Use of Large Transparent Ceramics in a High Powered, Diode Pumped Solid State Laser

    SciTech Connect (OSTI)

    Yamamoto, R; Bhachu, B; Cutter, K; Fochs, S; Letts, S; Parks, C; Rotter, M; Soules, T

    2007-09-24T23:59:59.000Z

    The advent of large transparent ceramics is one of the key enabling technological advances that have shown that the development of very high average power compact solid state lasers is achievable. Large ceramic neodymium doped yttrium aluminum garnet (Nd:YAG) amplifier slabs are used in Lawrence Livermore National Laboratory's (LLNL) Solid State Heat Capacity Laser (SSHCL), which has achieved world record average output powers in excess of 67 kilowatts. We will describe the attributes of using large transparent ceramics, our present system architecture and corresponding performance; as well as describe our near term future plans.

  14. Development of Low-Voltage and Large Current DC Power Supply with High-Frequency Transformer Coupling

    E-Print Network [OSTI]

    Fujimoto, Hiroshi

    Development of Low-Voltage and Large Current DC Power Supply with High-Frequency Transformer excellent performance. Keywords DC power supply, low-voltage and large-current, high-frequency transformer Iobe (MACOHO Co., Ltd.) Abstract This paper describes low-voltage and large-current DC power supplies

  15. Transient Stability Assessment of Power System with Large Amount of Wind Power Penetration: the

    E-Print Network [OSTI]

    Bak, Claus Leth

    the transient stability. In Denmark, the onshore and offshore wind farms are connected to distribution system and transmission system respectively. The control and protection methodologies of onshore and offshore wind farms definitely affect the transient stability of power system. In this paper, the onshore and offshore wind farms

  16. Visual Analysis of Frequent Patterns In Large Time Series

    E-Print Network [OSTI]

    Ramakrishnan, Naren

    1 shows an example on how to monitor chiller efficiency in data centers using a pair of data center chiller time series in which different motifs were discovered. The illustrated process can be subdivided valued vector ti captures the data values (e.g., chiller utilization in the data center example), we

  17. Transit timing with fast cameras on large telescopes

    E-Print Network [OSTI]

    Adams, Elisabeth Rose

    2010-01-01T23:59:59.000Z

    Timing and system parameters were measured for seven transiting exoplanets: OGLETR- 56b (11 transits), OGLE-TR-132b (7), OGLE-TR-111b (6), OGLE-TR-113b (6), CoRoT-2b (3), OGLE-TR-10b (3), and XO-2b (2). Ground-based ...

  18. CLIPPER: Counter-based Low Impact Processor Power Estimation at Run-time

    E-Print Network [OSTI]

    New South Wales, University of

    -time power/energy data has been presented. Current measurement systems draw too much power to be used is dif- ficult as measurement systems for power and energy usage draw too much power themselves, making the knowledge of processor power/energy consumption at run- time. So far, no efficient method to provide run

  19. Development of a large-capacity superconducting cable for 100 kVA-class power transformers

    SciTech Connect (OSTI)

    Funaki, K.; Iwakuma, M.; Satoh, S.; Hiramatsu, M.; Takeo, M.; Yamafuji, K.; Nonaka, S. (Kyushu Univ., Fukuoka (Japan). Faculty of Engineering); Hoshino, M.; Simada, M.; Yoneda, E.S. (Toshiba Corp., Yokohama (JP))

    1992-01-01T23:59:59.000Z

    This paper reports that the authors have designed and fabricated a large-capacity superconducting cable for 1000k VA-class power transformers. The cable is a triply-stacked multi-strand (6 {times} 6 {times} 6) type. The elementary strand has 19,050 NbTi filaments of 0.63 mm thick in CuNi matrix. The test cable is installed as the secondary winding in a superconducting transformer with iron core in a room-temperature space. The primary winding is the second-level subcable of the secondary one and the turn ratio is nearly 14. The designed capacity of the test cable is 4.545 kA at the secondary voltage of 220V. The peak value of the current, 6.43kA (peak), is 78% of the critical current on the load line. The maximum current of the cable at 60Hz operation was 3.78kA (peak). The attained level of the secondary winding is 47% of the critical current. In the 60Hz operation of a small coil wound by the test cable, premature quench was initiated from the terminals of the cable connected with copper plates. It is suggested from the experimental results that the degradation in maximum current of the test cable is related to current transfer between the cable and the copper terminal plates.

  20. PowerSleep: A Smart Power-Saving Scheme with Sleep for Servers under Response Time Constraint

    E-Print Network [OSTI]

    Wang, Shengquan

    the cost of the power delivery subsystems and the cooling facility, the electricity cost is significant power consumption by 50100% [14]. Given the fact that average server utilization is only 2030PowerSleep: A Smart Power-Saving Scheme with Sleep for Servers under Response Time Constraint

  1. Development of Low-Voltage and Large-Current DC Power Supply with High-Frequency Transformer Coupling

    E-Print Network [OSTI]

    Fujimoto, Hiroshi

    Development of Low-Voltage and Large-Current DC Power Supply with High-Frequency Transformer-voltage and large-current DC power supply with a high-frequency transformer coupling. The power supply is simply·,Zü"gg"X·C~R,êC"_N^"X Keywords: DC power supply, low-voltage and large-current, high-frequency transformer, leakage inductance 1

  2. IEEE TRANSACTIONS ON POWER SYSTEMS, VOL. X, NO. Y, MONTH 2012 1 Volatility of Power Grids under Real-Time Pricing

    E-Print Network [OSTI]

    Bhatia, Sangeeta

    -shifting and storage, as well as uncertainty in consumer behavior, preferences, time-varying and private valuation THE increasing demand for energy along with growing environmental concerns have led to a national agenda for engineering modern power grids with the capacity to integrate renewable energy resources at large scale

  3. Suppression of static electrification of insulating oil for large power transformers

    SciTech Connect (OSTI)

    Yasuda, M.; Goto, K.; Ishii, T.; Masunaga, M.; Mori, E.; Okubo, H.

    1982-11-01T23:59:59.000Z

    Streaming electrification of large power transformers is discussed here from the standpoint of characteristics of insulating oils used in them. First, the relation between the thermal degradation and charging tendency of insulating oils is defined to show that suppressing the degradation of oils to be caused by long term operation of the transformers can minimize the rise in charging tendency, leading to suppressed streaming electrification within the transformer. Second, experimental results show that alkylbenzene mixture oil and benzotriazol additive oil are excellent in charging characteristics when used as insulating oils of large power transformers.

  4. Just In-Time Maintenance of Nuclear Power Plants

    SciTech Connect (OSTI)

    DR. Alexander G. Parlos

    2002-01-22T23:59:59.000Z

    The goal of this project has been to develop and demonstrate the feasibility of a new technology for maintenance engineering: a Just-In-Time Maintenance (JITM) system for rotating machines. The JITM system is based on several key developments at Texas A and M over the past ten years in emerging intelligent information technologies, which if integrated into a single system could provide a revolutionary approach in the way maintenance is performed. Rotating machines, such as induction motors, range from a few horse power (hp) to several thousand hp in size, and they are widely used in nuclear power plants and in other industries. Forced outages caused by induction motor failures are the reason for as much as 15% - 40% of production costs to be attributable to maintenance, whereas plant shutdowns caused by induction motor failures result in daily financial losses to the utility and process industries of $1 M or more. The basic components of the JITM system are the available machine sensors, that is electric current sensors and accelerometers, and the computational algorithms used in the analysis and interpretation of the occurring incipient failures. The JITM system can reduce the costs attributable to maintenance by about 40% and it can lower the maintenance budgets of power and process plants by about 35%, while requiring no additional sensor installation. As a result, the JITM system can improve the competitiveness of US nuclear utilities at minimal additional cost.

  5. Time series power flow analysis for distribution connected PV generation.

    SciTech Connect (OSTI)

    Broderick, Robert Joseph; Quiroz, Jimmy Edward; Ellis, Abraham; Reno, Matthew J. [Georgia Institute of Technology, Atlanta, GA; Smith, Jeff [Electric Power Research Institute, Knoxville, TN; Dugan, Roger [Electric Power Research Institute, Knoxville, TN

    2013-01-01T23:59:59.000Z

    Distributed photovoltaic (PV) projects must go through an interconnection study process before connecting to the distribution grid. These studies are intended to identify the likely impacts and mitigation alternatives. In the majority of the cases, system impacts can be ruled out or mitigation can be identified without an involved study, through a screening process or a simple supplemental review study. For some proposed projects, expensive and time-consuming interconnection studies are required. The challenges to performing the studies are twofold. First, every study scenario is potentially unique, as the studies are often highly specific to the amount of PV generation capacity that varies greatly from feeder to feeder and is often unevenly distributed along the same feeder. This can cause location-specific impacts and mitigations. The second challenge is the inherent variability in PV power output which can interact with feeder operation in complex ways, by affecting the operation of voltage regulation and protection devices. The typical simulation tools and methods in use today for distribution system planning are often not adequate to accurately assess these potential impacts. This report demonstrates how quasi-static time series (QSTS) simulation and high time-resolution data can be used to assess the potential impacts in a more comprehensive manner. The QSTS simulations are applied to a set of sample feeders with high PV deployment to illustrate the usefulness of the approach. The report describes methods that can help determine how PV affects distribution system operations. The simulation results are focused on enhancing the understanding of the underlying technical issues. The examples also highlight the steps needed to perform QSTS simulation and describe the data needed to drive the simulations. The goal of this report is to make the methodology of time series power flow analysis readily accessible to utilities and others responsible for evaluating potential PV impacts.

  6. Ver.2003.01.27 Development of Low-Voltage and Large-Current DC Power Supply

    E-Print Network [OSTI]

    Fujimoto, Hiroshi

    describes low-voltage and large-current DC power supplies with a high-frequency transformer coupling. Two Ver.2003.01.27 Development of Low-Voltage and Large-Current DC Power Supply-bridge inverter, an amorphous-core step down transformer and a schottky diode rectifier. One power supply operates

  7. Production cost and air emissions impacts of coal cycling in power systems with large-scale wind penetration

    E-Print Network [OSTI]

    Jaramillo, Paulina

    on dispatchable generating capacity, such as coal and natural gas power plants, which can be cycled in responseProduction cost and air emissions impacts of coal cycling in power systems with large-scale wind emissions impacts of coal cycling in power systems with large-scale wind penetration David Luke Oates

  8. Inflation that runs naturally: Gravitational waves and suppression of power at large and small scales

    E-Print Network [OSTI]

    Quinn E. Minor; Manoj Kaplinghat

    2015-03-08T23:59:59.000Z

    We point out three correlated predictions of the axion monodromy inflation model: large amplitude of gravitational waves, suppression of power on horizon scales and on scales relevant for the formation of dwarf galaxies. While these predictions are likely generic to models with oscillations in the inflaton potential, the axion monodromy model naturally accommodates the required running spectral index through Planck-scale corrections to the inflaton potential. Applying this model to a combined data set of Planck, ACT, SPT, and WMAP low-$\\ell$ polarization cosmic microwave background (CMB) data, we find a best-fit tensor-to-scalar ratio $r_{0.05} = 0.07^{+0.05}_{-0.04}$ due to gravitational waves, which may have been observed by the BICEP2 experiment. Despite the contribution of gravitational waves, the total power on large scales (CMB power spectrum at low multipoles) is lower than the standard $\\Lambda$CDM cosmology with a power-law spectrum of initial perturbations and no gravitational waves, thus mitigating some of the tension on large scales. There is also a reduction in the matter power spectrum of 20-30\\% at scales corresponding to $k = 10~{\\rm Mpc}^{-1}$, which are relevant for dwarf galaxy formation. This will alleviate some of the unsolved small-scale structure problems in the standard $\\Lambda$CDM cosmology. The inferred matter power spectrum is also found to be consistent with recent Lyman-$\\alpha$ forest data, which is in tension with the Planck-favored $\\Lambda$CDM model with power-law primordial power spectrum.

  9. A power line impedance spectrum analyzer using real-time digital signal processing

    E-Print Network [OSTI]

    Margolis, Michael G

    1993-01-01T23:59:59.000Z

    Power distribution system impedance as seen by power converters and other non-linear loads is important for the determination of harmonic current injection and propagation caused by these loads. This thesis presents a real-time power line impedance...

  10. A TWO-STAGE APPROACH TO SOLVING LARGE-SCALE OPTIMAL POWER FLOWS

    E-Print Network [OSTI]

    Gross, George

    A TWO-STAGE APPROACH TO SOLVING LARGE-SCALE OPTIMAL POWER FLOWS *F e l i x F. Wu George Gross James problem is formulated as an unconstrained minimization problem using penalty functions and i s solved ] and Sasson and Merrill [ 3 ] . The s i z e and t h e extensive amount of computation involved i n solving t h

  11. Large-scale Ocean-based or Geothermal Power Plants by Thermoelectric Effects

    E-Print Network [OSTI]

    Liu, Liping

    2012-01-01T23:59:59.000Z

    Heat resources of small temperature difference are easily accessible, free and unlimited on earth. Thermoelectric effects provide the technology for converting these heat resources directly into electricity. We present designs of electricity generators based on thermoelectric effects and using heat resources of small temperature difference, e.g., ocean water at different depths and geothermal sources, and conclude that large-scale power plants based on thermoelectric effects are feasible and economically competitive. The key observation is that the power factor of thermoelectric materials, unlike the figure of merit, can be improved by orders of magnitude upon laminating good conductors and good thermoelectric materials. The predicted large-scale power plants based on thermoelectric effects, if validated, will have a global economic and social impact for its scalability, and the renewability, free and unlimited supply of heat resources of small temperature difference on earth.

  12. Large Hybrid Energy Systems for Making Low CO2 Load-Following Power and Synthetic Fuel

    SciTech Connect (OSTI)

    Robert S. Cherry; Richard D. Boardman; Steven Aumeier

    2012-02-01T23:59:59.000Z

    Hybrid energy systems using nuclear heat sources can economically produce load-following electrical power by exploiting the surplus generation capacity available at night or seasonally to make synthetic fuel. Vehicle fuel is the only current energy use large enough to absorb all the energy capacity that might be diverted from the power industry, and its ease of storage obviates problems with discontinuous synfuel production. The potential benefits and challenges of synfuels integration are illustrated by the production of methanol from natural gas (as a source of carbon) using steam from a light water nuclear power reactor which is assumed to be available in accord with a year's worth of power demand data. Methanol's synthesis process is easily adapted to using 300 C heat from a light water reactor and this simple compound can be further processed into gasoline, biodiesel, or dimethyl ether, fuels which can be used with the current vehicle fleet. A supplemental feed to the methanol process of natural gas (for energy) allows operation at constant full rate when the nuclear heat is being used to produce electrical power. The higher capital costs of such a system are offset by a lower cost of heat and power production from a large base load type of plant and by reduced costs associated with much lower CO2 emissions. Other less tangible economic benefits of this and similar hybrid systems include better use of natural resource for fuels and greater energy services security from the domestic production of vehicle fuel.

  13. Abstract--A large share of integrated wind power causes technical and financial impacts on the operation of the existing

    E-Print Network [OSTI]

    the future wind power feed-in. But in an efficient market setting, power plant operators will take1 Abstract-- A large share of integrated wind power causes technical and financial impacts behaviour of the wind power generation and of the prediction error. It can be used for the evaluation

  14. Examining the Variability of Wind Power Output in the Regulation Time Frame: Preprint

    SciTech Connect (OSTI)

    Hodge, B. M.; Shedd, S.; Florita, A.

    2012-08-01T23:59:59.000Z

    This work examines the distribution of changes in wind power for different time scales in the regulation time frame as well as the correlation of changes in power output for individual wind turbines in a wind plant.

  15. Amplitude Noise and Timing Jitter Characterization of a High-Power

    E-Print Network [OSTI]

    Keller, Ursula

    Amplitude Noise and Timing Jitter Characterization of a High-Power Mode-Locked Integrated External and Timing Jitter Characterization of a High-Power Mode-Locked Integrated External-Cavity Surface Emitting present a timing jitter and amplitude noise characterization of a high-power mode-locked integrated

  16. Improved Structure and Fabrication of Large, High-Power KHPS Rotors - Final Scientific/Technical Report

    SciTech Connect (OSTI)

    Corren, Dean [Verdant Power, Inc.; Colby, Jonathan [Verdant Power, Inc.; Adonizio, Mary Ann [Verdant Power, Inc.

    2013-01-29T23:59:59.000Z

    Verdant Power, Inc, working in partnership with the National Renewable Energy Laboratory (NREL), Sandia National Laboratories (SNL), and the University of Minnesota St. Anthony Falls Laboratory (SAFL), among other partners, used evolving Computational Fluid Dynamics (CFD) and Finite Element Analysis (FEA) models and techniques to improve the structure and fabrication of large, high-power composite Kinetic Hydropower System (KHPS) rotor blades. The objectives of the project were to: design; analyze; develop for manufacture and fabricate; and thoroughly test, in the lab and at full scale in the water, the improved KHPS rotor blade.

  17. Study on eddy current losses and shielding measures in large power transformers

    SciTech Connect (OSTI)

    Chen Yongbin; Yu Hainian [Shenyang Transformer Research Inst. (China)] [Shenyang Transformer Research Inst. (China); Yang Junyou; Tang Renyuan [Shenyang Polytechnic Univ. (China)] [Shenyang Polytechnic Univ. (China)

    1994-09-01T23:59:59.000Z

    The improved T-{Omega} method is applied to the computation of the three dimensional eddy current field in a 360MVA/500kV large power transformer, the structure of which is complicated. The different cases of tank wall with magnetic shunt, aluminum screen or without any shield are analyzed. The relations between eddy current losses and the materials, structure and size of the tank shield are presented. Compared with a parallel magnetic shunt arrangement, the vertical magnetic shunt reduces stray losses by 63.8%. The optimal thickness or the vertical magnetic shunt Is 10mm. The magnetic shunt should be spread over 0.5mm at both ends of windings in the 360MVA/500kV large power transformer.

  18. Real-time Lighting System for Large Group Interaction Joshua Randall

    E-Print Network [OSTI]

    Real-time Lighting System for Large Group Interaction Joshua Randall Massachusetts Institute of Technology May 2002 Abstract Lighting systems have historically been controlled by an individual or small group of human operators working together in real-time. Applications for real-time lighting control

  19. Towards Real-Time High Performance Computing For Power Grid Analysis

    SciTech Connect (OSTI)

    Hui, Peter SY; Lee, Barry; Chikkagoudar, Satish

    2012-11-16T23:59:59.000Z

    Real-time computing has traditionally been considered largely in the context of single-processor and embedded systems, and indeed, the terms real-time computing, embedded systems, and control systems are often mentioned in closely related contexts. However, real-time computing in the context of multinode systems, specifically high-performance, cluster-computing systems, remains relatively unexplored. Imposing real-time constraints on a parallel (cluster) computing environment introduces a variety of challenges with respect to the formal verification of the system's timing properties. In this paper, we give a motivating example to demonstrate the need for such a system--- an application to estimate the electromechanical states of the power grid--- and we introduce a formal method for performing verification of certain temporal properties within a system of parallel processes. We describe our work towards a full real-time implementation of the target application--- namely, our progress towards extracting a key mathematical kernel from the application, the formal process by which we analyze the intricate timing behavior of the processes on the cluster, as well as timing measurements taken on our test cluster to demonstrate use of these concepts.

  20. A comparison of instrumentation for measuring the losses of large power transformers

    SciTech Connect (OSTI)

    Malewski, R.; Arseneau, R.; Moore, W.; So, E.

    1983-06-01T23:59:59.000Z

    The results of a comparison of several different types of equipment and techniques for measuring the short circuit (copper) and open circuit (iron) losses of a large power transformer are presented. The measurements were made on a 233-MVA, 735-kV, single phase, 60-Hz power transformer with a short circuit power factor of 1.3%, at currents up to rated, and open circuit voltages to 115 percent of the rating. The short circuit tests were performed using two current comparator type high-voltage capacitance bridges, a thermal wattmeter, an electro-dynamic wattmeter system with conventional instrument transformers and a new semi-automated digital wattmeter system. For the open-circuit tests only the three wattmeters were employed. The average discrepancy between the five measuring systems used in the short circuit tests was less than 1% and between the three systems in the open circuit tests less than 0.5%.

  1. 2 Large CO2 reductions via offshore wind power matched to inherent 3 storage in energy end-uses

    E-Print Network [OSTI]

    Firestone, Jeremy

    2 Large CO2 reductions via offshore wind power matched to inherent 3 storage in energy end-uses 4] We develop methods for assessing offshore wind 9 resources, using a model of the vertical structure. Dhanju, R. W. 26 Garvine, and M. Z. Jacobson (2007), Large CO2 reductions via 27 offshore wind power

  2. Power Saving Design for Servers under Response Time Constraint Shengquan Wang

    E-Print Network [OSTI]

    Wang, Shengquan

    utilization is high, where instead we use PowerIdle power-saving scheme with DVS only. By modeling the system the cost of the power delivery subsystems and the cooling facility, the electricity cost is significantPower Saving Design for Servers under Response Time Constraint Shengquan Wang Department

  3. Run-time Modeling and Estimation of Operating System Power Consumption

    E-Print Network [OSTI]

    John, Lizy Kurian

    Run-time Modeling and Estimation of Operating System Power Consumption Tao Li Department computing systems point to the need for power modeling and estimation for all components of a system software power evaluation, as well as power management (e.g. dynamic thermal control and equal energy

  4. Routine based OS-aware Microprocessor Resource Adaptation for Run-time Operating System Power Saving

    E-Print Network [OSTI]

    John, Lizy Kurian

    workloads (see section 2 for detail), making it a major power consumer. The proportion of the OS power, such as thermal sensor reading, energy accounting and power control for memory and I/O devices [2]. ClearlyRoutine based OS-aware Microprocessor Resource Adaptation for Run-time Operating System Power

  5. Efficient Power Management of Heterogeneous Soft Real-Time Clusters Leping Wang, Ying Lu

    E-Print Network [OSTI]

    Lu, Ying

    Efficient Power Management of Heterogeneous Soft Real-Time Clusters Leping Wang, Ying Lu Department}@cse.unl.edu Abstract With growing cost of electricity, the power management of server clusters has become an important for power management of heterogeneous soft real-time clusters. It is built on simple but effective

  6. An Efficient Threshold-Based Power Management Mechanism for Heterogeneous Soft Real-Time Clusters

    E-Print Network [OSTI]

    Lu, Ying

    An Efficient Threshold-Based Power Management Mechanism for Heterogeneous Soft Real-Time Clusters {lwang, ylu}@cse.unl.edu Abstract With growing cost of electricity, the power management of server proposes an efficient algorithm for power management of heterogeneous soft real-time clusters. It is built

  7. Task Merging for Dynamic Power Management of Cyclic Applications in Real-Time Multiprocessor Systems

    E-Print Network [OSTI]

    Qiu, Qinru

    Task Merging for Dynamic Power Management of Cyclic Applications in Real-Time Multiprocessor--In this paper we propose the method of task merging and idle period clustering for dynamic power management (DPM management, low power, multiprocessor, real-time I. INTRODUCTION Multiprocessor systems, which were used only

  8. Power in Knowledge Management in Late Modern Times Hamid R. Ekbia1

    E-Print Network [OSTI]

    Indiana University

    AOM-13517 1 Power in Knowledge Management in Late Modern Times Hamid R. Ekbia1 & Rob Kling2 1 will be greatly appreciated.) #12;AOM-13517 2 Power in Knowledge Management in Late Modern Times Abstract of knowledge management, especially as they relate to power relationships inside and outside organizations. We

  9. Fast Track Communication Efficiency and large deviations in time-asymmetric

    E-Print Network [OSTI]

    Geissler, Phillip

    -state engine. We find in general that the form of efficiency probability distributions is similar to those systems, molecular motors, large deviations in non-equilibrium systems 1. Introduction As engineeringFast Track Communication Efficiency and large deviations in time-asymmetric stochastic heat engines

  10. A Power Provision and Capping Architecture for Large Scale Systems Yongpeng Liu, Hong Zhu, Kai Lu and Yongyan Liu

    E-Print Network [OSTI]

    Zhu, Hong

    whole system's total power consumption under budget. Two policies are designed and implemented to select amount of energy. According to the recent TOP500 list of high performance systems [2], the average powerA Power Provision and Capping Architecture for Large Scale Systems Yongpeng Liu, Hong Zhu, Kai Lu

  11. IEEE TRANSACTIONS ON POWER SYSTEMS, VOL. 29, NO. 1, JANUARY 2014 489 Large-Scale Integration of Deferrable

    E-Print Network [OSTI]

    Oren, Shmuel S.

    scheduling, wind power generation. I. INTRODUCTION THE key disadvantage of renewable resources relative and demand response integration on power system operations it is necessary to represent the balancing operIEEE TRANSACTIONS ON POWER SYSTEMS, VOL. 29, NO. 1, JANUARY 2014 489 Large-Scale Integration

  12. Abstract--The security of modern large interconnected power systems suffers from the absence of a unique security coordinator

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1 Abstract-- The security of modern large interconnected power systems suffers from the absence interconnected power systems. In the absence of a full information exchange, the operators' alternative solution contingencies screening , control areas data exchange, multi-area electric power system security assessment. I

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

    SciTech Connect (OSTI)

    Chika Nwankpa

    2011-01-31T23:59:59.000Z

    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.

  14. Isocurvature and curvaton perturbations with red power spectrum and large hemispherical asymmetry

    SciTech Connect (OSTI)

    McDonald, John, E-mail: j.mcdonald@lancaster.ac.uk [Lancaster-Manchester-Sheffield Consortium for Fundamental Physics, Cosmology and Astroparticle Physics Group, Dept. of Physics, University of Lancaster, Lancaster LA1 4YB (United Kingdom)

    2013-07-01T23:59:59.000Z

    We calculate the power spectrum and hemispherical asymmetry of isocurvature and curvaton perturbations due to a complex field ? which is evolving along the tachyonic part of its potential. Using a semi-classical evolution of initially sub-horizon quantum fluctuations, we compute the power spectrum, mean field and hemispherical asymmetry as a function of the number of e-foldings of tachyonic growth ?N and the tachyonic mass term cH{sup 2}. We find that a large hemispherical asymmetry due to the modulation of |?| can easily be generated via the spatial modulation of |?| across the horizon, with ?|?|/|?| > 0.5 when the observed Universe exits the horizon within 10-40 e-foldings of the beginning of tachyonic evolution and c is in the range 0.1-1. The spectral index of the isocurvature and curvaton perturbations is generally negative, corresponding to a red power spectrum. Dark matter isocurvature perturbations due to an axion-like curvaton with a large hemispherical asymmetry may be able to explain the hemispherical asymmetry observed by WMAP and Planck. In this case, the red spectrum can additionally suppress the hemispherical asymmetry at small scales, which should make it easier to satisfy scale-dependence requirements on the asymmetry from quasar number counts.

  15. Large Parabolic Dish collectors with small gas-turbine, Stirling engine or photovoltaic power conversion systems

    SciTech Connect (OSTI)

    Gehlisch, K.; Heikal, H.; Mobarak, A.; Simon, M.

    1982-08-01T23:59:59.000Z

    A comparison for different solar thermal power plants is presented and demonstrates that the large parabolic dish in association with a gas turbine or a Sterling engine could be a competitive system design in the net power range of 50-1000KW. The important advantages of the Large Parabolic Dish concept compared to the Farm and Tower concept are discussed: concentration ratios up to 5000 and uniform heat flux distribution throughout the day which allow very high receiver temperatures and therefor high receiver efficiency to operate effectively Stirling motors or small gas turbines in the mentioned power range with an overall efficiency of 20 to 30%. The high focal plane concentration leads to the efficient use of ceramic materials for receivers of the next generation, applicable in temperature ranges up to 1,300 /sup 0/C for energy converters. Besides the production of electricity, the system can supply process heat in the temperature range of 100 to 400 /sup 0/C as waste heat from the gas turbo converter and heat at temperature levels from 500 to 900 /sup 0/C (1300 /sup 0/C) directly out of the receiver.

  16. Improved time response for large area microchannel plate photomultiplier tubes in fusion diagnostics

    SciTech Connect (OSTI)

    Milnes, J. S., E-mail: james.milnes@photek.co.uk; Conneely, T. M.; Howorth, J. [Photek Ltd, 26 Castleham Road, St Leonards on Sea, East Sussex, TN38 9NS (United Kingdom); Horsfield, C. J. [AWE, Aldermaston, Reading, Berkshire, RG7 4PR (United Kingdom)

    2014-11-15T23:59:59.000Z

    Fusion diagnostics that utilise high speed scintillators often need to capture a large area of light with a high degree of time accuracy. Microchannel plate (MCP) photomultiplier tubes (PMTs) are recognised as the leading device for capturing fast optical signals. However, when manufactured in their traditional proximity focused construction, the time response performance is reduced as the active area increases. This is due to two main factors: the capacitance of a large anode and the difficulty of obtaining small pore MCPs with a large area. Collaboration between Photek and AWE has produced prototype devices that combine the excellent time response of small area MCP-PMTs with a large active area by replacing the traditional proximity-gap front section with an electro-optically focused photocathode to MCP. We present results from both single and double MCP devices with a 40 mm diameter active area and show simulations for the 100 mm device being built this year.

  17. Service quality planning for freight distribution with time windows in large networks

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    as a quality factor of the service, since its nature and configuration also affects the total transportation1 Service quality planning for freight distribution with time windows in large networks Francesco introduces a methodology whose aim is to evaluate how the quality of a freight distribution service with time

  18. TetSplat: Real-Time Rendering and Volume Clipping of Large Unstructured Tetrahedral Meshes

    E-Print Network [OSTI]

    TetSplat: Real-Time Rendering and Volume Clipping of Large Unstructured Tetrahedral Meshes Ken-resolution data representations. These compact hierarchical data structures are then adaptively rendered and probed in real-time on a commodity PC. Our point-based rendering algorithm, which is inspired by QSplat

  19. Time series modeling and large scale global solar radiation forecasting from geostationary satellites data

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1 Time series modeling and large scale global solar radiation forecasting from geostationary global solar radiation. In this paper, we use geostationary satellites data to generate 2-D time series of solar radiation for the next hour. The results presented in this paper relate to a particular territory

  20. CHP: It's Time for Combined Heat and Power

    E-Print Network [OSTI]

    Herweck, R.

    of use Electricity Electricity Heat Heat Combined Heat and Power Conventional Generation Building Load Power Plant fuel (66 units of remote energy) Boiler fuel (34 units of on-site energy) CHP fuel (x units of on-site energy) Losses Losses 20 29 20... to 90% CHP DE can cut fuel consumption per unit of output to half or a third of conventional usage… especially natural gas supplies now in heavy demand Economic Development: Combined Heat and Power #0;9 Reduces the cost of new electricity T...

  1. Hazards to nuclear power plants from large liquefied natural gas (LNG) spills on water

    SciTech Connect (OSTI)

    Kot, C.A.; Eichler, T.V.; Wiedermann, A.H.; Pape, R.; Srinivasan, M.G.

    1981-11-01T23:59:59.000Z

    The hazards to nuclear power plants arising from large spills of liquefied natural gas (LNG) on water transportation routes are treated by deterministic analytical procedures. Global models, which address the salient features of the LNG spill phenomena are used in the analysis. A coupled computational model for the combined LNG spill, spreading, and fire scenario is developed. To predict the air blast environment in the vicinity of vapor clouds with pancake-like geometries, a scalable procedure using both analytical methods and hydrocode calculations is synthesized. Simple response criteria from the fire and weapons effects literature are used to characterize the susceptibility of safety-related power plant systems. The vulnerability of these systems is established either by direct comparison between the LNG threat and the susceptibility criteria or through simple response calculations. Results are analyzed.

  2. Development of a perfluorocarbon liquid immersed prototype large power transformer with compressed SF sub 6 insulation

    SciTech Connect (OSTI)

    Mukaryama, Y.; Nonaka, F.; Takagi, I. (Chubu Electric Power Co. Inc., Nagoya (Japan)); Higaki, M.; Endoo, K.; Sakamoto, T.; Hiraishi, K.; Kawashima, K. (Hitachi Ltd., Hitachi (JP))

    1991-07-01T23:59:59.000Z

    This paper reports on a prototype of three phase non-flammable, large power transformer that has been developed. It uses non-flammable perfluorocarbon liquid as both a coolant and an insulating material for windings, and compressed SF{sub 6} gas as the insulation from the outer windings to the tank. Using cooling and insulation models, the cooling and insulation characteristics of the disc windings were clarified. Stress analyses and the pressure tests of the transformer tank were carried out, to evaluate its mechanical characteristics. Finally, a prototype of 275kV 100MVA three phase transformer was developed, and its excellent performance was confirmed.

  3. EWEC 2007 conference, 7-10 May 2007, Milan, Italy State-of-the-art of Design and Operation of Power Systems with Large Amounts of

    E-Print Network [OSTI]

    Systems with Large Amounts of Wind Power, Summary of IEA Wind collaboration Hannele Holttinen1 , Peter for exchange of knowledge of power system impacts of wind power has been formed under the IEA Implementing Agreement on Wind Energy. The task "Design and Operation of Power Systems with Large Amounts of Wind Power

  4. Effective Prediction of Job Times in a Large-Scale Grid Environment Menno Dobber

    E-Print Network [OSTI]

    van der Mei, Rob

    of jobs on shared processors. To this end, we analyze several existing methods that are po- tentially processors, that share their available capacities, construct a tremendous source of processing power are that the wallclock times of the jobs are highly bursty, mainly because of the changing load, and that the set

  5. A Tutorial on Detection and Characterization of Special Behavior in Large Electric Power Systems

    SciTech Connect (OSTI)

    Hauer, John F.; DeSteese, John G.

    2004-08-20T23:59:59.000Z

    The objective of this document is to report results in the detection and characterization of special behavior in large electric power systems. Such behavior is usually dynamic in nature, but not always. This is also true for the underlying sources of special behavior. At the device level, a source of special behavior might be an automatic control system, a dynamic load, or even a manual control system that is operated according to some sharply defined policy. Other possible sources include passive system conditions, such as the state of a switched device or the amount of power carried on some critical line. Detection and characterization are based upon “signature information” that is extracted from the behavior observed. Characterization elements include the signature information itself, the nature of the behavior and its likely causes, and the associated implications for the system or for the public at large. With sufficient data and processing, this characterization may directly identify a particular condition or device at a specific location. Such conclusive results cannot always be done from just one observation, however. Information environments that are very sparse may require multiple observations, comparative model studies, and even direct testing of the system.

  6. Convergence Time of Power-Control Dynamics Johannes Dams Martin Hoefer Thomas Kesselheim

    E-Print Network [OSTI]

    Convergence Time of Power-Control Dynamics Johannes Dams Martin Hoefer Thomas Kesselheim April 20, 2011 Abstract We study two (classes of) distributed algorithms for power control in a general model for power control using regret learning algorithms and iterative discretization. While the exact convergence

  7. ROBUST CONTROL ANALYSIS USING REAL-TIME IMPLEMENTATION OF A HYBRID FUEL CELL POWER GENERATION SYSTEM

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    ROBUST CONTROL ANALYSIS USING REAL-TIME IMPLEMENTATION OF A HYBRID FUEL CELL POWER GENERATION the control of two identical boost power converters. For the closed-loop control a previously proposed proposed by the authors in former works. The control actuators are the duty cycles of the boost power

  8. Powering Up With Space-Time Wind Forecasting Amanda S. HERING and Marc G. GENTON

    E-Print Network [OSTI]

    Genton, Marc G.

    Powering Up With Space-Time Wind Forecasting Amanda S. HERING and Marc G. GENTON The technology to harvest electricity from wind energy is now advanced enough to make entire cities powered by it a reality be more realistically assessed with a loss measure that depends upon the power curve relating wind speed

  9. DEZENT: A Safety-Critical Real-Time Approach Decentralized Electric Power Management

    E-Print Network [OSTI]

    Wedde, Horst F.

    for establishing technologies based on solar or wind power, or on renewable energy sources, is an adequate- selves to the producer/ consumer problems within a balance responsibility entity, i.e. a 10 kV power areaDEZENT: A Safety-Critical Real-Time Approach for Decentralized Electric Power Management H. F

  10. Formal Analysis and Validation of Continuous-Time Markov Chain based System Level Power Management Strategies

    E-Print Network [OSTI]

    Oxford, University of

    Formal Analysis and Validation of Continuous-Time Markov Chain based System Level Power Management that competitive analysis based power management strategies can be automatically analyzed for proving competitive bounds and for validating power management strate- gies using the SMV model checker. In this paper, we

  11. Formal Analysis and Validation of ContinuousTime Markov Chain based System Level Power Management Strategies

    E-Print Network [OSTI]

    Oxford, University of

    Formal Analysis and Validation of Continuous­Time Markov Chain based System Level Power Management that competitive analysis based power management strategies can be automatically analyzed for proving competitive bounds and for validating power management strate­ gies using the SMV model checker. In this paper, we

  12. Capacitor placement and real time control in large-scale unbalanced distribution systems: Numerical studies

    SciTech Connect (OSTI)

    Wang, J.C.; Chiang, H.D.; Miu, K.N. [Cornell Univ., Ithaca, NY (United States). School of Electrical Engineering; Darling, G. [NYSEG Corp., Binghamton, NY (United States). Distribution System Dept.

    1997-04-01T23:59:59.000Z

    A novel solution algorithm for capacitor placement and real-time control in real large-scale unbalanced distribution systems is evaluated and implemented to determine the number, locations, sizes, types and control schemes of capacitors to be placed on large-scale unbalanced distribution systems. A detailed numerical study regarding the solution algorithm in large scale unbalanced distribution systems is undertaken. Promising numerical results on both 292 bus and 394 bus real unbalanced distribution systems containing unbalanced loads and phasing and various types of transformers are presented. The computational performance for the capacitor control problem under load variations is encouraging.

  13. Dense, low-power sensor network for three-dimensional thermal characterization of large-scale atria spaces

    E-Print Network [OSTI]

    Gong, Nan-Wei

    We describe the design and implementation of a dense, low-power wireless sensor network for fine-grained three-dimensional thermal characterization of a large open indoor space. To better understand the airflow dynamics ...

  14. Understanding the Impact of Large-Scale Penetration of Micro Combined Heat & Power Technologies within Energy Systems

    E-Print Network [OSTI]

    Catholic University of Chile (Universidad Católica de Chile)

    of Micro Combined Heat & Power Technologies within Energy Systems by Karen de los Ángeles Tapia-based electricity generation technologies are considered, by energy experts and also policymakers, to be essentialUnderstanding the Impact of Large-Scale Penetration of Micro Combined Heat & Power Technologies

  15. Fourth International Workshop on Large-Scale Integration of Wind Power and Transmission Networks for Offshore Wind Farms,

    E-Print Network [OSTI]

    for Offshore Wind Farms, 20-21 October 2003, Billund, Denmark C. S. Nielsen, Hans F. Ravn, Camilla Schaumburg1 Fourth International Workshop on Large-Scale Integration of Wind Power and Transmission Networks of Denmark, B. 321, DK-2800 Lyngby, Denmark, csm@imm.dtu.dk Two wind power prognosis criteria and regulating

  16. Large CO2 reductions via offshore wind power matched to inherent storage in energy end-uses

    E-Print Network [OSTI]

    Jacobson, Mark

    Large CO2 reductions via offshore wind power matched to inherent storage in energy end-uses Willett develop methods for assessing offshore wind resources, using a model of the vertical structure offshore wind power matched to inherent storage in energy end- uses, Geophys. Res. Lett., 34, L02817, doi

  17. Simulation of Efficient Real-time Scheduling and Power Optimization

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    designs. However, the most serious limitation of these devices is the battery lifetime since battery the temporal constraints of these embedded systems. Reducing energy, especially, affect not only the battery or even to decrease the conditions of cooling and the costs, in the large scale, of giant multiprocessor

  18. Time-resolved photoelectron imaging of large anionic methanol clusters: ,,Methanol...n

    E-Print Network [OSTI]

    Neumark, Daniel M.

    Time-resolved photoelectron imaging of large anionic methanol clusters: ,,Methanol...n - ,,nÈ145; published online 27 June 2007 The dynamics of an excess electron in size-selected methanol clusters electron6­11 and its cluster counterparts,12­18 water n - . The solvated electron in liquid methanol has

  19. Reliability analysis of electric power systems including time dependent sources

    E-Print Network [OSTI]

    Kim, Younjong

    1987-01-01T23:59:59.000Z

    ' the PEP S subsystem is computed by: POP, = NP POt (3. 22) where POPt = power output of the PEPS subsystem during the jth hour NP = number of PEPS units in the subsystem 25 The parameters used for designing the PEPS subsystem are taken from I5... and wind velocity data are obtained for output computation. The capacity of two unconventional subsystem is designed to be equal to each other. 5. 1 System Description Generation System For the purpose of this study, one of the EPRI reduced scenarios...

  20. The study on flow electrification of oil-cellulose insulating system in large power transformer

    SciTech Connect (OSTI)

    Zhang, J.; Cao, L.J. [Nanyang Technological Univ., Singapore (Singapore). School of Electrical and Electronic Engineering

    1995-12-31T23:59:59.000Z

    Electrical breakdown due to charge accumulation from transformer oil flow has caused many failures of large power transformers world wide. The problem is due to the entrainment of diffused electrical double layer charges into circulating transformer oil. As the charges accumulate on the surface of solid insulating materials and in volume oil, static potential builds up. If the rate of charge accumulation is greater than the rate of charge relaxation, harmful spark discharge may occur. By employing a pressboard pipe model, the present study carried out revealed the influence of higher oil flow rate and upstream charge on flow electrification. By simulating an actual transformer internal structure, it is noticed that there is a probability of partial discharge inception under higher oil circulation velocity. However, the upstream charge and dry zone can lead to a great increase of electric field strength, which may become important potential causes of partial discharge inception under the condition of relative low oil velocity.

  1. 752 IEEE TRANSACTIONS ON POWER SYSTEMS, VOL. 24, NO. 2, MAY 2009 Large-Scale Distribution Planning--Part

    E-Print Network [OSTI]

    Catholic University of Chile (Universidad Católica de Chile)

    methodology for low-voltage distribution network planning. Combined optimization of transformers, "Large-scale distribution planning--Part I: Simultaneous network and transformer optimization" [1752 IEEE TRANSACTIONS ON POWER SYSTEMS, VOL. 24, NO. 2, MAY 2009 Large-Scale Distribution Planning

  2. Equivalencing the Collector System of a Large Wind Power Plant: Preprint

    SciTech Connect (OSTI)

    Muljadi, E.; Butterfield, C. P.; Ellis, A.; Mechenbier, J.; Hochheimer, J.; Young, R.; Miller, N.; Delmerico, R.; Zavadil, R.; Smith, J. C.

    2006-01-01T23:59:59.000Z

    This paper focuses on our effort to develop an equivalent representation of a wind power plant collector system for power system planning studies.

  3. Method of Equivalencing for a Large Wind Power Plant with Multiple Turbine Representation: Preprint

    SciTech Connect (OSTI)

    Muljadi, E.; Pasupulati, S.; Ellis, A.; Kosterov, D.

    2008-07-01T23:59:59.000Z

    This paper focuses on our effort to develop an equivalent representation of a Wind Power Plant collector system for power system planning studies.

  4. Wind Power Answer In Times of Water Scarcity (Presentation)

    SciTech Connect (OSTI)

    Flowers, L.; Reategui, S.

    2010-05-25T23:59:59.000Z

    Strategic energy planning is paramount during times of dramatic population growth, global warming, increasing energy demands, and concerns over energy security, food security, and economic development. Recent concerns over water scarcity have moved the energy-water issue to the forefront of energy options discussions. This presentation describes the current water challenges in the United States and presents a case for wind energy as one way to mitigate the problem of water scarcity in several U.S. regions while providing a clean and sustainable economic future for America.

  5. Power Management for Real-Time Embedded Systems on Block-Partitioned Multicore Platforms

    E-Print Network [OSTI]

    Zhu, Dakai

    Power Management for Real-Time Embedded Systems on Block-Partitioned Multicore Platforms Xuan Qi. For the mobile and portable devices, battery is one dominant constraint with fixed energy budget. For the high, it is imperative to develop power management schemes for systems on multicore platforms. However, applying

  6. Integrating Real Time and Power Management in a Real System Martin P. Lawitzky

    E-Print Network [OSTI]

    § Stefan M. Petters§ NICTA Sydney, Australia § University of New South Wales Sydney, Australia ¶ TU M. This enables the use of the dynamic slack caused by the variability of execution time, to reduce energy and other thermal dissipation devices, a limited power supply (e.g. a solar powered system), or simply

  7. Geek-Up[09.03.10] -- Innovative Silicon Wafers, Real-Time Power...

    Broader source: Energy.gov (indexed) [DOE]

    difference. We buy power to decrease the system load or sell to increase it. Or, the hydro operator can increase or decrease generation at the dams." Learn how BPA's real-time...

  8. Stopping power measurements of He ions in Si and SiC by time...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    power measurements of He ions in Si and SiC by time-of-flight spectrometry. Abstract: Electronic energy loss is the fundamental mechanism accountable for the response of...

  9. Real-Time Pricing- A Flexible Alternative for Electrical Power Supply

    E-Print Network [OSTI]

    Reynolds, S. D.; Frye, A. O. Jr.

    REAL-TIME PRICING - A FLEXIBLE ALTERNATIVE ..OR ELECTRICAL POWER SUPPLY S. D. REYNOLDS Manager of Industrial Marketing & Services Tennessee Valley Authority Chattanooga, Tennessee ABSTRACT In an increasingly competitive operating... conditions to more tl,an 240 mills per kilo,~atthollr 78 REAL-TIME PRICING A FLEXIBLE ALTERNATIVE rOR ELECTRICAL POWER SUPPLY S. D. REYNOLDS Manager of Industrial Marketing & Services Tennessee Valley Authority Chattanooga, Tennessee ABSTRACT...

  10. Energy Storage and Reactive Power Compensator in a Large Wind Farm: Preprint

    SciTech Connect (OSTI)

    Muljadi, E.; Butterfield, C. P.; Yinger, R.; Romanowitz, H.

    2003-10-01T23:59:59.000Z

    The size of wind farm power systems is increasing, and so is the number of wind farms contributing to the power systems network. The size of wind turbines is also increasing--from less than 1 MW a few years ago to the 2- to 3-MW machines being installed today and the 5-MW machines under development. The interaction of the wind farm, energy storage, reactive power compensation, and the power system network is being investigated. Because the loads and the wind farms' output fluctuate during the day, the use of energy storage and reactive power compensation is ideal for the power system network. Energy storage and reactive power compensation can minimize real/reactive power imbalances that can affect the surrounding power system. In this paper, we will show how the contribution of wind farms affects the power distribution network and how the power distribution network, energy storage, and reactive power compensation interact when the wind changes. We will also investigate the size of the components in relation to each other and to the power system.

  11. A Discrete-Time Scheduling Model for Continuous Power-intensive Process Networks with Various Electricity Contracts

    E-Print Network [OSTI]

    Grossmann, Ignacio E.

    formulation. Assigns prices to every time period Tracks cumulative power purchases for predefined meter reading times Can accommodate discount prices that depend on the amount of power purchased Can accommodate penalties for under- and overconsumption Power Purchase Price Power Purchase Penalty Discount

  12. Modified automatic time error control and inadvertent interchange reduction for the WSCC interconnected power systems

    SciTech Connect (OSTI)

    McReynolds, W.L. (Bonneville Power Administration, Vancouver, WA (US)); Badley, D.E. (N.W. Power Pool, Coordinating Office, Portland, OR (US))

    1991-08-01T23:59:59.000Z

    This paper describes an automatic generation control (AGC) system that simultaneously reduces time error and accumulated inadvertent interchange energy in interconnected power system. This method is automatic time error and accumulated inadvertent interchange reduction (AIIR). With this method control areas help correct the system time error when doing so also tends to correct accumulated inadvertent interchange. Thus in one step accumulated inadvertent interchange and system time error are corrected.

  13. Total Cost Per MwH for all common large scale power generation...

    Open Energy Info (EERE)

    power generation soruces ? I am talking about the cost of mountain top removal for coal mined that way, the trip to the power plant, the sludge pond or ash heap, the cost of...

  14. WIRELESS HELIOSTAT AND CONTROL SYSTEM FOR LARGE SELF-POWERED HELIOSTAT FIELDS

    E-Print Network [OSTI]

    Turau, Volker

    Nodes, are deployed in the DLR Solar Tower Demonstration Plant heliostat field, controlled by a base station located individual heliostats, represent about 40% of the investment into the solar power plant. Furthermore, commercial solar power plants utilize dedicated wired links and bus systems to power and control heliostats

  15. IEEE TRANSACTIONS LARGE SCALE INTEGRATION (VLSI) SYSTEMS, MARCH Trading Off Transient Fault Tolerance and Power

    E-Print Network [OSTI]

    Tessier, Russell

    tolerance also ultra­low­power consumption limited battery In paper, a highly accurate method estimating. INTRODUCTION T RENDS CMOS technology, applications, operating conditions resulting in circuits higher power con batteries their source power. limited battery the ability of replace recharge battery, circuits used

  16. IEEE TRANSACTIONS ON VERY LARGE SCALE INTEGRATION (VLSI) SYSTEMS, VOL. 5, NO. 4, DECEMBER 1997 473 Gate-Level Power and Current Simulation of

    E-Print Network [OSTI]

    Bogliolo, Alessandro

    for design evaluation. A large number of power estimation techniques has been proposed [1]­[4] based, the large number of simulations needed to reach a significant estimate of average power dissipation further and valida- tion. When optimizing for power, several transformations are applied to a circuit to reduce its

  17. A (Smart) Real-time PMU-assisted Power Transfer Limitation Monitoring

    E-Print Network [OSTI]

    Stability Analysis (DSA) Energy Management System (EMS) Real-Time Network Information DiagnosticA (Smart) Real-time PMU-assisted Power Transfer Limitation Monitoring and Enhancement System) · PJM's On-line Available transfer capability monitoring system and (smart) enhancements (i.e. increase

  18. Linear Compositional Delay Model for the Timing Analysis of Sub-Powered Combinational Circuits

    E-Print Network [OSTI]

    Linear Compositional Delay Model for the Timing Analysis of Sub-Powered Combinational Circuits the propagation delay through nanometer CMOS circuits is highly desirable. Statistical Static Timing Analysis to accurately capture the circuit behaviour. In view of this we introduce an Inverse Gaussian Distribution (IGD

  19. 744 IEEE TRANSACTIONS ON POWER SYSTEMS, VOL. 24, NO. 2, MAY 2009 Large-Scale Distribution Planning--Part I

    E-Print Network [OSTI]

    Catholic University of Chile (Universidad Católica de Chile)

    744 IEEE TRANSACTIONS ON POWER SYSTEMS, VOL. 24, NO. 2, MAY 2009 Large-Scale Distribution Planning--Part I: Simultaneous Network and Transformer Optimization Alejandro Navarro, Member, IEEE, and Hugh-voltage distribution networks. Combined optimization of transformers and associated networks is per- formed

  20. A Bio-Inspired Multi-Agent System Framework for Real-Time Load Management in All-Electric Ship Power Systems

    E-Print Network [OSTI]

    Feng, Xianyong

    2012-07-16T23:59:59.000Z

    All-electric ship power systems have limited generation capacity and finite rotating inertia compared with large power systems. Moreover, all-electric ship power systems include large portions of nonlinear loads and dynamic loads relative...

  1. Stochastic Methods for Planning and Operating Power Systems with Large Amounts of Wind and Solar Power: Preprint

    SciTech Connect (OSTI)

    Milligan, M.; Donohoo, P.; O'Malley, M.

    2012-09-01T23:59:59.000Z

    Wind and solar generators differ in their generation characteristics than conventional generators. The variable output and imperfect predictability of these generators face a stochastic approach to plan and operate the power system without fundamentally changing the operation and planning problems. This paper overviews stochastic modeling challenges in operations, generation planning, and transmission planning, with references to current industry and academic work. Different stochastic problem formulations, including approximations, are also discussed.

  2. The constraints on power spectrum of relic gravitational waves from current observations of large-scale structure of the Universe

    E-Print Network [OSTI]

    B. Novosyadlyj; S. Apunevych

    2004-12-02T23:59:59.000Z

    We carry out the determination of the amplitude of relic gravitational waves power spectrum. Indirect best-fit technique was applied to compare observational data and theory predictions. As observations we have used data on large-scale structure (LSS) of the Universe and anisotropy of cosmic microwave background (CMB) temperature. The conventional inflationary model with 11 parameters has been investigated, all of them evaluated jointly. This approach gave us a possibility to find parameters of power spectrum of gravitational waves along with statistical errors. The main result consists in following: WMAP data on power spectrum of CMB temperature fluctuations along with LSS data prefer model with small amplitude of tensor mode power spectrum, close to zero. The upper limit for its amplitude at quadupole harmonics T/S=0.6 at 95% C.L.

  3. The power of event-driven analytics in Large Scale Data Processing

    ScienceCinema (OSTI)

    None

    2011-04-25T23:59:59.000Z

    FeedZai is a software company specialized in creating high-­-throughput low-­-latency data processing solutions. FeedZai develops a product called "FeedZai Pulse" for continuous event-­-driven analytics that makes application development easier for end users. It automatically calculates key performance indicators and baselines, showing how current performance differ from previous history, creating timely business intelligence updated to the second. The tool does predictive analytics and trend analysis, displaying data on real-­-time web-­-based graphics. In 2010 FeedZai won the European EBN Smart Entrepreneurship Competition, in the Digital Models category, being considered one of the "top-­-20 smart companies in Europe". The main objective of this seminar/workshop is to explore the topic for large-­-scale data processing using Complex Event Processing and, in particular, the possible uses of Pulse in the scope of the data processing needs of CERN. Pulse is available as open-­-source and can be licensed both for non-­-commercial and commercial applications. FeedZai is interested in exploring possible synergies with CERN in high-­-volume low-­-latency data processing applications. The seminar will be structured in two sessions, the first one being aimed to expose the general scope of FeedZai's activities, and the second focused on Pulse itself: 10:00-11:00 FeedZai and Large Scale Data Processing Introduction to FeedZai FeedZai Pulse and Complex Event Processing Demonstration Use-Cases and Applications Conclusion and Q&A 11:00-11:15 Coffee break 11:15-12:30 FeedZai Pulse Under the Hood A First FeedZai Pulse Application PulseQL overview Defining KPIs and Baselines Conclusion and Q&A About the speakers Nuno Sebastião is the CEO of FeedZai. Having worked for many years for the European Space Agency (ESA), he was responsible the overall design and development of Satellite Simulation Infrastructure of the agency. Having left ESA to found FeedZai, Nuno is currently responsible for the whole operations of the company. Nuno holds an M.Eng. in Informatics Engineering for the University of Coimbra, and an MBA from the London Business School. Paulo Marques is the CTO of FeedZai, being responsible for product development. Paulo is an Assistant Professor at the University of Coimbra, in the area of Distributed Data Processing, and an Adjunct Associated Professor at Carnegie Mellon, in the US. In the past Paulo lead a large number of projects for institutions like the ESA, Microsoft Research, SciSys, Siemens, among others, being now fully dedicated to FeedZai. Paulo holds a Ph.D. in Distributed Systems from the University of Coimbra.

  4. Evolution of Energy Efficiency Programs Over Time: The Case of Standby Power

    SciTech Connect (OSTI)

    Payne, Christopher; Chung, Iris (Hoi); Fisher, Emily

    2014-08-17T23:59:59.000Z

    Issued in 2001, Presidential Executive Order 13221 directed federal agencies to purchase products with low standby power, with the goal of 1) reducing energy consumption in federal facilities, and 2) drawing attention to the problem of high standby power consumption, with guidance provided by the Federal Energy Management Program (FEMP). At that time, standby power was newly recognized as an increasing building energy load. Since then, procurement of products with low standby power have been set in place in acquisition processes, and the purchasing power of the federal government continues to influence manufacturers design decisions related to standby power. In recent years, FEMP has shifted effort from direct manufacturer outreach for data collection, to integrating low standby requirement into broader acquisition programs including Energy Star and Electronic Product Environmental Assessment Tool (EPEAT). Another milestone has been the labeling of low standby products on the GSA Advantage website to simplify and enhance compliance. Looking forward into the program?s future, this question arises How do we design programs over time to reflect market and technology changes, by adjusting programmatic requirements while maintaining effectiveness? This paper discusses that question for the case of standby power, which transitioned from covering a single to multiple environmental attributes, both in the context of the program's past and future.

  5. Fusion Power: A Strategic Choice for the Future Energy Provision. Why is So Much Time Wasted for Decision Making?

    SciTech Connect (OSTI)

    D'haeseleer, William D

    2005-04-15T23:59:59.000Z

    From a general analysis of the world energy issue, it is argued that an affordable, clean and reliable energy supply will have to consist of a portfolio of primary energy sources, a large fraction of which will be converted to a secondary carrier in large baseload plants. Because of all future uncertainties, it would be irresponsible not to include thermonuclear fusion as one of the future possibilities for electricity generation.The author tries to understand why nuclear-fusion research is not considered of strategic importance by the major world powers. The fusion programs of the USA and Europe are taken as prime examples to illustrate the 'hesitation'. Europe is now advocating a socalled 'fast-track' approach, thereby seemingly abandoning the 'classic' time frame towards fusion that it has projected for many years. The US 'oscillatory' attitude towards ITER in relation to its domestic program is a second case study that is looked at.From the real history of the ITER design and the 'siting' issue, one can try to understand how important fusion is considered by these world powers. Not words are important, but deeds. Fast tracks are nice to talk about, but timely decisions need to be taken and sufficient money is to be provided. More fundamental understanding of fusion plasma physics is important, but in the end, real hardware devices must be constructed to move along the path of power plant implementation.The author tries to make a balance of where fusion power research is at this moment, and where, according to his views, it should be going.

  6. A multichannel, real-time MRI RF power monitor for independent SAR determination

    SciTech Connect (OSTI)

    El-Sharkawy, AbdEl-Monem M.; Qian Di; Bottomley, Paul A.; Edelstein, William A. [Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins, University School of Medicine, Baltimore, Maryland 21287 (United States); Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins, University School of Medicine, Baltimore, Maryland 21287 (United States) and Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, Maryland 21287 (United States); Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins, University School of Medicine, Baltimore, Maryland 21287 (United States)

    2012-05-15T23:59:59.000Z

    Purpose: Accurate measurements of the RF power delivered during clinical MRI are essential for safety and regulatory compliance, avoiding inappropriate restrictions on clinical MRI sequences, and for testing the MRI safety of peripheral and interventional devices at known RF exposure levels. The goal is to make independent RF power measurements to test the accuracy of scanner-reported specific absorption rate (SAR) over the extraordinary range of operating conditions routinely encountered in MRI. Methods: A six channel, high dynamic range, real-time power profiling system was designed and built for monitoring power delivery during MRI up to 440 MHz. The system was calibrated and used in two 3 T scanners to measure power applied to human subjects during MRI scans. The results were compared with the scanner-reported SAR. Results: The new power measurement system has highly linear performance over a 90 dB dynamic range and a wide range of MRI duty cycles. It has about 0.1 dB insertion loss that does not interfere with scanner operation. The measurements of whole-body SAR in volunteers showed that scanner-reported SAR was significantly overestimated by up to about 2.2 fold. Conclusions: The new power monitor system can accurately and independently measure RF power deposition over the wide range of conditions routinely encountered during MRI. Scanner-reported SAR values are not appropriate for setting exposure limits during device or pulse sequence testing.

  7. NREL Confirms Large Potential for Grid Integration of Wind, Solar Power (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2011-10-01T23:59:59.000Z

    To fully harvest the nation's bountiful wind and solar resources, it is critical to know how much electrical power from these renewable resources could be integrated reliably into the grid. To inform the discussion about the potential of such variable sources, the National Renewable Energy Laboratory (NREL) launched two key regional studies, examining the east and west sections of the U.S. power grid. The studies show that it is technically possible for U.S. power systems to integrate 20%-35% renewable electricity if infrastructure and operational improvements can be made.

  8. Spatial, temporal, and hybrid decompositions for large-scale vehicle routing with time windows

    SciTech Connect (OSTI)

    Bent, Russell W [Los Alamos National Laboratory

    2010-01-01T23:59:59.000Z

    This paper studies the use of decomposition techniques to quickly find high-quality solutions to large-scale vehicle routing problems with time windows. It considers an adaptive decomposition scheme which iteratively decouples a routing problem based on the current solution. Earlier work considered vehicle-based decompositions that partitions the vehicles across the subproblems. The subproblems can then be optimized independently and merged easily. This paper argues that vehicle-based decompositions, although very effective on various problem classes also have limitations. In particular, they do not accommodate temporal decompositions and may produce spatial decompositions that are not focused enough. This paper then proposes customer-based decompositions which generalize vehicle-based decouplings and allows for focused spatial and temporal decompositions. Experimental results on class R2 of the extended Solomon benchmarks demonstrates the benefits of the customer-based adaptive decomposition scheme and its spatial, temporal, and hybrid instantiations. In particular, they show that customer-based decompositions bring significant benefits over large neighborhood search in contrast to vehicle-based decompositions.

  9. Impacts of large quantities of wind energy on the electric power system

    E-Print Network [OSTI]

    Yao, Yuan, S.M. Massachusetts Institute of Technology

    2011-01-01T23:59:59.000Z

    Wind energy has been surging on a global scale. Significant penetration of wind energy is expected to take place in the power system, bringing new challenges because of the variability and uncertainty of this renewable ...

  10. DATA-DRIVEN ON-LINE PREDICTION OF THE AVAILABLE RECOVERY TIME IN NUCLEAR POWER PLANT FAILURE SCENARIOS

    E-Print Network [OSTI]

    Boyer, Edmond

    -XADS). Key Words: Recovery Time, Emergency Accident Management, Nuclear Power Plant, Lead- Bismuth Eutectic e1 DATA-DRIVEN ON-LINE PREDICTION OF THE AVAILABLE RECOVERY TIME IN NUCLEAR POWER PLANT FAILURE [Øwre, 2001]. Yet, the problem of what kind of decision support to provide to nuclear power plant

  11. Test Cases for Wind Power Plant Dynamic Models on Real-Time Digital Simulator: Preprint

    SciTech Connect (OSTI)

    Singh, M.; Muljadi, E.; Gevorgian, V.

    2012-06-01T23:59:59.000Z

    The objective of this paper is to present test cases for wind turbine generator and wind power plant models commonly used during commissioning of wind power plants to ensure grid integration compatibility. In this paper, different types of wind power plant models based on the Western Electricity Coordinating Council Wind Generator Modeling Group's standardization efforts are implemented on a real-time digital simulator, and different test cases are used to gauge their grid integration capability. The low-voltage ride through and reactive power support capability and limitations of wind turbine generators under different grid conditions are explored. Several types of transient events (e.g., symmetrical and unsymmetrical faults, frequency dips) are included in the test cases. The differences in responses from different types of wind turbine are discussed in detail.

  12. A multiprocessor system for real-time simulation of power electronic circuits

    E-Print Network [OSTI]

    Qawasmi, Nabil Hussein

    1988-01-01T23:59:59.000Z

    that describes it [7]. Its applications are widely distributed among many areas of technology such as process controls, aerospace, and other engineering oriented system design and analysis problems. Real-time simulation is a much favored simulation method...A MULTIPROCESSOR SYSTEM FOR REAL-TIME SIMULATION OF POWER ELECTRONIC CIRCUITS A Thesis by NABIL HUSSEIN QAWASMI Submitted to the Graduate College of Texas AkM University in partial fulfillment of the requirement for the degree of MASTER...

  13. Comparison of large central and small decentralized power generation in India

    SciTech Connect (OSTI)

    none,

    1997-05-01T23:59:59.000Z

    This reports evaluates two options for providing reliable power to rural areas in India. The benefits and costs are compared for biomass based distributed generation (DG) systems versus a 1200-MW central grid coal-fired power plant. The biomass based DG systems are examined both as alternatives to grid extension and as supplements to central grid power. The benefits are divided into three categories: those associated with providing reliable power from any source, those associated specifically with biomass based DG technology, and benefits of a central grid coal plant. The report compares the estimated delivered costs of electricity from the DG systems to those of the central plant. The analysis includes estimates for a central grid coal plant and four potential DG system technologies: Stirling engines, direct-fired combustion turbines, fuel cells, and biomass integrated gasification combined cycles. The report also discusses issues affecting India`s rural electricity demand, including economic development, power reliability, and environmental concerns. The results of the costs of electricity comparison between the biomass DG systems and the coal-fired central grid station demonstrated that the DG technologies may be able to produce very competitively priced electricity by the start of the next century. The use of DG technology may provide a practical means of addressing many rural electricity issues that India will face in the future. Biomass DG technologies in particular offer unique advantages for the environment and for economic development that will make them especially attractive. 58 refs., 31 figs.

  14. IEEE TRANSACTIONS ON VERY LARGE SCALE INTEGRATION (VLSI) SYSTEMS, VOL. 11, NO. 1, FEBRUARY 2003 129 Relative Timing

    E-Print Network [OSTI]

    Stevens, Ken

    IEEE TRANSACTIONS ON VERY LARGE SCALE INTEGRATION (VLSI) SYSTEMS, VOL. 11, NO. 1, FEBRUARY 2003 129 synthesis and veri- fication are demonstrated on three example circuits, facilitating transformations from perfor- mance, area, power, and functional testability of up to a factor of 3 in all three cases

  15. Data Fusion of Power and Time Measurements for Mobile Terminal Location

    E-Print Network [OSTI]

    Plataniotis, Konstantinos N.

    Data Fusion of Power and Time Measurements for Mobile Terminal Location Michael McGuire, Member Abstract--The location of mobile terminals in cellular networks is an important problem with applications information about mobile terminal location. This paper applies data fusion to combine the information of RSS

  16. An area and power efficient discrete-time chaos generator and V.D. Juncu**

    E-Print Network [OSTI]

    Dudek, Piotr

    of the nonlinear circuit, as well as the transfer characteristic of the buffer (typically linear). Second of the circuit, but they can be ignored in a first-order analysis. y(x) C1 C2 nonlinear xn+1 buffer xn yAn area and power efficient discrete-time chaos generator circuit P. Dudek* and V.D. Juncu

  17. Large-Signal HBT Model with Improved Collector Transit Time Formulation for GaAs and InP Technologies

    E-Print Network [OSTI]

    Asbeck, Peter M.

    mi': iaE Large-Signal HBT Model with Improved Collector Transit Time Formulation for GaAs and In large-signal HBT model which accurately accounts for the intricate hias dependence of collector delay collector delay function accounts for the variation of electron velocity with electric field

  18. A radiographic analysis of the effect of dietary fiber on transit time through the rat large intestine 

    E-Print Network [OSTI]

    Meacher, Mary Melanie

    1986-01-01T23:59:59.000Z

    A RADIOGRAPHIC ANALYSIS OF THE EFFECT OF DIETARY FIBER ON TRANSIT TIME THROUGH THE RAT LARGE INTESTINE A Thesis by MARY MELANIE MEACHER Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirements... for the degree of MASTER OF SCIENCE August 1986 Major Subject. ' Nutrition A RADIOGRAPHIC ANALYSIS OF THE EFFECT OF DIETARY FIBER ON TRANSIT TIME THROUGH THB RAT LARGE INTESTINE A Thesis by MARY MELANIE MEACHER Approved as to style and content by...

  19. Large amplitude oscillatory shear flow of gluten dough: A model power-law gel

    E-Print Network [OSTI]

    Ng, Trevor S. K.

    In a previous paper [T. S. K. Ng and G. H. McKinley, J. Rheol.52(2), 417–449 (2008)], we demonstrated that gluten gels can best be understood as a polymericnetwork with a power-law frequency response that reflects the ...

  20. Partition Based Cascaded Generator Scheduling with Constraints for Large Power Networks

    E-Print Network [OSTI]

    Kundur, Deepa

    must be revisited. In this paper, we focus on the generator scheduling problem in smart grid comprehensive view for planning in the smart grid. Given the mammoth size of the power networks, we propose]. In addition, the smart grid vision in- corporates consumer-driven and regulator-driven policies

  1. Variability of Power from Large-Scale Solar Photovoltaic Scenarios in the State of Gujarat: Preprint

    SciTech Connect (OSTI)

    Parsons, B.; Hummon, M.; Cochran, J.; Stoltenberg, B.; Batra, P.; Mehta, B.; Patel, D.

    2014-04-01T23:59:59.000Z

    India has ambitious goals for high utilization of variable renewable power from wind and solar, and deployment has been proceeding at a rapid pace. The western state of Gujarat currently has the largest amount of solar generation of any Indian state, with over 855 Megawatts direct current (MWDC). Combined with over 3,240 MW of wind, variable generation renewables comprise nearly 18% of the electric-generating capacity in the state. A new historic 10-kilometer (km) gridded solar radiation data set capturing hourly insolation values for 2002-2011 is available for India. We apply an established method for downscaling hourly irradiance data to one-minute irradiance data at potential PV power production locations for one year, 2006. The objective of this report is to characterize the intra-hour variability of existing and planned photovoltaic solar power generation in the state of Gujarat (a total of 1.9 gigawatts direct current (GWDC)), and of five possible expansion scenarios of solar generation that reflect a range of geographic diversity (each scenario totals 500-1,000 MW of additional solar capacity). The report statistically analyzes one year's worth of power variability data, applied to both the baseline and expansion scenarios, to evaluate diurnal and seasonal power fluctuations, different timescales of variability (e.g., from one to 15 minutes), the magnitude of variability (both total megawatts and relative to installed solar capacity), and the extent to which the variability can be anticipated in advance. The paper also examines how Gujarat Energy Transmission Corporation (GETCO) and the Gujarat State Load Dispatch Centre (SLDC) could make use of the solar variability profiles in grid operations and planning.

  2. Variability of Power from Large-Scale Solar Photovoltaic Scenarios in the State of Gujarat (Presentation)

    SciTech Connect (OSTI)

    Parsons, B.; Hummon, M.; Cochran, J.; Stoltenberg, B.; Batra, P.; Mehta, B.; Patel, D.

    2014-04-01T23:59:59.000Z

    India has ambitious goals for high utilization of variable renewable power from wind and solar, and deployment has been proceeding at a rapid pace. The western state of Gujarat currently has the largest amount of solar generation of any Indian state, with over 855 Megawatts direct current (MWDC). Combined with over 3,240 MW of wind, variable generation renewables comprise nearly 18% of the electric-generating capacity in the state. A new historic 10-kilometer (km) gridded solar radiation data set capturing hourly insolation values for 2002-2011 is available for India. We apply an established method for downscaling hourly irradiance data to one-minute irradiance data at potential PV power production locations for one year, 2006. The objective of this report is to characterize the intra-hour variability of existing and planned photovoltaic solar power generation in the state of Gujarat (a total of 1.9 gigawatts direct current (GWDC)), and of five possible expansion scenarios of solar generation that reflect a range of geographic diversity (each scenario totals 500-1,000 MW of additional solar capacity). The report statistically analyzes one year's worth of power variability data, applied to both the baseline and expansion scenarios, to evaluate diurnal and seasonal power fluctuations, different timescales of variability (e.g., from one to 15 minutes), the magnitude of variability (both total megawatts and relative to installed solar capacity), and the extent to which the variability can be anticipated in advance. The paper also examines how Gujarat Energy Transmission Corporation (GETCO) and the Gujarat State Load Dispatch Centre (SLDC) could make use of the solar variability profiles in grid operations and planning.

  3. This thesis applies model order reduction (MOR) techniques to large modern power systems that preserve particular dynamic characteristics of the original system. Depending upon the nature of the

    E-Print Network [OSTI]

    Kumar, M. Jagadesh

    in power systems have been explored and compared ­ Balanced truncation (BT) and Krylov subspace between the wind velocity/system frequency and the power output. These linear models, validated using DigABSTRACT This thesis applies model order reduction (MOR) techniques to large modern power systems

  4. Stochastic Modeling and Power Control of Time-Varying Wireless Communication Networks

    SciTech Connect (OSTI)

    Olama, Mohammed M [ORNL; Djouadi, Seddik M [ORNL; Charalambous, Prof. Charalambos [University of Cyprus

    2014-01-01T23:59:59.000Z

    Wireless networks are characterized by nodes mobility, which makes the propagation environment time-varying and subject to fading. As a consequence, the statistical characteristics of the received signal vary continuously, giving rise to a Doppler power spectral density (DPSD) that varies from one observation instant to the next. This paper is concerned with dynamical modeling of time-varying wireless fading channels, their estimation and parameter identification, and optimal power control from received signal measurement data. The wireless channel is characterized using a stochastic state-space form and derived by approximating the time-varying DPSD of the channel. The expected maximization and Kalman filter are employed to recursively identify and estimate the channel parameters and states, respectively, from online received signal strength measured data. Moreover, we investigate a centralized optimal power control algorithm based on predictable strategies and employing the estimated channel parameters and states. The proposed models together with the estimation and power control algorithms are tested using experimental measurement data and the results are presented.

  5. Apparatus and method for closed-loop control of reactor power in minimum time

    DOE Patents [OSTI]

    Bernard, Jr., John A. (72 Paul Revere Rd., Needham Heights, MA 02194)

    1988-11-01T23:59:59.000Z

    Closed-loop control law for altering the power level of nuclear reactors in a safe manner and without overshoot and in minimum time. Apparatus is provided for moving a fast-acting control element such as a control rod or a control drum for altering the nuclear reactor power level. A computer computes at short time intervals either the function: .rho.=(.beta.-.rho.).omega.-.lambda..sub.e '.rho.-.SIGMA..beta..sub.i (.lambda..sub.i -.lambda..sub.e ')+l* .omega.+l* [.omega..sup.2 +.lambda..sub.e '.omega.] or the function: .rho.=(.beta.-.rho.).omega.-.lambda..sub.e .rho.-(.lambda..sub.e /.lambda..sub.e)(.beta.-.rho.)+l* .omega.+l* [.omega..sup.2 +.lambda..sub.e .omega.-(.lambda..sub.e /.lambda..sub.e).omega.] These functions each specify the rate of change of reactivity that is necessary to achieve a specified rate of change of reactor power. The direction and speed of motion of the control element is altered so as to provide the rate of reactivity change calculated using either or both of these functions thereby resulting in the attainment of a new power level without overshoot and in minimum time. These functions are computed at intervals of approximately 0.01-1.0 seconds depending on the specific application.

  6. Large-scale optimal power flow: Effects of initialization, decoupling and discretization

    SciTech Connect (OSTI)

    Papalexopoulos, A.D.; Imparato, C.F.; Wu, F.F.

    1989-08-01T23:59:59.000Z

    The optimal power flow has entered a new era since the introduction of second-order methods. These methods have renewed hopes for its on-line application in Energy Management Systems. This paper reports on some of the results of tests of a second-order OPF method. The testing was conducted using a 1500 bus network, under a variety of loading conditions. Three issues were studied: Sensitivity of OPF solutions with respect to the starting points used in the solution; Accuracy of the active/reactive decoupled approach to OPF solution; Effects of discretization of transformer taps on the OPF solutions.

  7. Op%mal Scheduling of Combined Heat and Power (CHP) Plants1 under Time-sensi%ve Electricity Prices

    E-Print Network [OSTI]

    Grossmann, Ignacio E.

    1 Op%mal Scheduling of Combined Heat and Power (CHP) Plants1 under Time-sensi%ve Electricity Prices Summary In this case study, a CHP plant increases its profit%ons with the power grid 4 Power Grid CHP plant Typically mul%ple boilers and turbines

  8. IEEE TRANSACTIONS ON POWER SYSTEMS, VOL. 21, NO. 1, FEBRUARY 2006 11 A Decoupled Time-Domain Simulation

    E-Print Network [OSTI]

    are commonly used for solving power system dynamic simulation, and research effort has been done to improveIEEE TRANSACTIONS ON POWER SYSTEMS, VOL. 21, NO. 1, FEBRUARY 2006 11 A Decoupled Time-Domain Simulation Method via Invariant Subspace Partition for Power System Analysis Dan Yang, Student Member, IEEE

  9. Phosphate single mode large mode area all-solid photonic crystal fiber with multi-watt output power

    SciTech Connect (OSTI)

    Wang, Longfei; He, Dongbing; Yu, Chunlei; Hu, Lili; Chen, Danping, E-mail: dpchen2008@aliyun.com [Key Laboratory of High Power Laser Materials, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Liu, Hui [Navigation Staff Room, Anhui Bengbu Petty Officer Academy of Navy, Bengbu 233000 (China); Qiu, Jianrong [Institute of Optical Communication Materials, South China University of Technology, Guangzhou 510641 (China)

    2014-03-31T23:59:59.000Z

    An index-depressed active core, single-mode phosphate all-solid large-mode-area photonic crystal fiber (PCF) is theoretically investigated using full-vectorial finite difference approach and experimentally realized. The PCF has a maximum output power of 5.4?W and 31% slope efficiency. Single-mode operation is realized through PCFs with core diameters of 30, 35, and 40??m, respectively. The beam quality is not degraded even at maximum output power. Our simulations and experiments reveal that the laser performance is significantly affected by the center-to-center distance between the two nearest rods ?, the rod diameter d, and their ratio d/?, implying that much attention should be given in employing optimal parameters to achieve excellent laser performance.

  10. Joint Optimization of Idle and Cooling Power in Data Centers While Maintaining Response Time

    E-Print Network [OSTI]

    Vijaykumar, T. N.

    power, where the total electric power = server power + cooling power + power distribution losses. Mod). Previous server- power proposals exploit this under-utilization to reduce the server idle power by keeping service providers, data centers reduce the total cost for the service providers. However, electric power

  11. Space-time power schedule for distributed MIMO links without instantaneous channel state information at the transmitting nodes

    E-Print Network [OSTI]

    Rong, Yue; Hua, Yingbo; Swami, Ananthram; Swindlehurst, A. Lee

    2008-01-01T23:59:59.000Z

    We have proposed a space–time optimal power schedulingin [4]–[7]. In [4], a space-only (i.e. , time-invariant)are all and . Scheme A5 space-only schemes. Here, RONG et

  12. Online Monitoring Technical Basis and Analysis Framework for Large Power Transformers; Interim Report for FY 2012

    SciTech Connect (OSTI)

    Nancy J. Lybeck; Vivek Agarwal; Binh T. Pham; Heather D. Medema; Kirk Fitzgerald

    2012-09-01T23:59:59.000Z

    The Light Water Reactor Sustainability program at Idaho National Laboratory (INL) is actively conducting research to develop and demonstrate online monitoring (OLM) capabilities for active components in existing Nuclear Power Plants. A pilot project is currently underway to apply OLM to Generator Step-Up Transformers (GSUs) and Emergency Diesel Generators (EDGs). INL and the Electric Power Research Institute (EPRI) are working jointly to implement the pilot project. The EPRI Fleet-Wide Prognostic and Health Management (FW-PHM) Software Suite will be used to implement monitoring in conjunction with utility partners: the Shearon Harris Nuclear Generating Station (owned by Duke Energy for GSUs, and Braidwood Generating Station (owned by Exelon Corporation) for EDGs. This report presents monitoring techniques, fault signatures, and diagnostic and prognostic models for GSUs. GSUs are main transformers that are directly connected to generators, stepping up the voltage from the generator output voltage to the highest transmission voltages for supplying electricity to the transmission grid. Technical experts from Shearon Harris are assisting INL and EPRI in identifying critical faults and defining fault signatures associated with each fault. The resulting diagnostic models will be implemented in the FW-PHM Software Suite and tested using data from Shearon-Harris. Parallel research on EDGs is being conducted, and will be reported in an interim report during the first quarter of fiscal year 2013.

  13. Noise in Large-Signal, Time-Varying RF CMOS Circuits: Theory & Design

    E-Print Network [OSTI]

    Murphy, David Patrick

    2012-01-01T23:59:59.000Z

    mW, 70 kHz 1/f corner direct conversion CMOS receiver,” innoise for low-power direct-conversion receiver,” IEEE J.Darabi, “Analysis of direct-conversion IQ transmitters with

  14. A methodology for understanding the impacts of large-scale penetration of micro-combined heat and power

    SciTech Connect (OSTI)

    Tapia-Ahumada, K. [MIT Energy Initiative, Massachusetts Institute of Technology, Cambridge, MA (United States); Pérez-Arriaga, I. J. [Institute for Research in Technology, Comillas Pontifical University (Spain); Moniz, Ernest J. [MIT Energy Initiative, Massachusetts Institute of Technology, Cambridge, MA (United States)

    2013-10-01T23:59:59.000Z

    Co-generation at small kW-e scale has been stimulated in recent years by governments and energy regulators as one way to increasing energy efficiency and reducing CO2emissions. If a widespread adoption should be realized, their effects from a system's point of view are crucial to understand the contributions of this technology. Based on a methodology that uses long-term capacity planning expansion, this paper explores some of the implications for an electric power system of having a large number of micro-CHPs. Results show that fuel cells-based micro-CHPs have the best and most consistent performance for different residential demands from the customer and system's perspectives. As the penetration increases at important levels, gas-based technologies - particularly combined cycle units - are displaced in capacity and production, which impacts the operation of the electric system during summer peak hours. Other results suggest that the tariff design impacts the economic efficiency of the system and the operation of micro-CHPs under a price-based strategy. Finally, policies aimed at micro-CHPs should consider the suitability of the technology (in size and heat-to-power ratio) to meet individual demands, the operational complexities of a large penetration, and the adequacy of the economic signals to incentivize an efficient and sustainable operation. Highlights: Capacity displacements and daily operation of an electric power system are explored; Benefits depend on energy mix, prices, and micro-CHP technology and control scheme; Benefits are observed mostly in winter when micro-CHP heat and power are fully used; Micro-CHPs mostly displace installed capacity from natural gas combined cycle units; and, Tariff design impacts economic efficiency of the system and operation of micro-CHPs.

  15. Development of a hybrid intelligent system for on-line real-time monitoring of nuclear power plant operations

    E-Print Network [OSTI]

    Yildiz, Bilge, 1976-

    2003-01-01T23:59:59.000Z

    A nuclear power plant (NPP) has an intricate operational domain involving systems, structures and components (SSCs) that vary in scale and complexity. Many of the large scale SSCs contribute to the lost availability in the ...

  16. A Two-stage Kalman Filtering Approach for Robust and Real-time Power Systems State Tracking

    E-Print Network [OSTI]

    Welch, Greg

    A Two-stage Kalman Filtering Approach for Robust and Real-time Power Systems State Tracking Jinghe changes of system dynamics and erroneous PMU measurements. Index Terms--Power systems, real-time state- tics of loads and control devices are not included in operational models. This assumption reduces

  17. The exceptionally powerful TeV gamma-ray emitters in the Large Magellanic Cloud

    E-Print Network [OSTI]

    :,; Aharonian, F; Benkhali, F Ait; Akhperjanian, A G; Angüner, E O; Backes, M; Balenderan, S; Balzer, A; Barnacka, A; Becherini, Y; Becker-Tjus, J; Berge, D; Bernhard, S; Bernlöhr, K; Birsin, E; Biteau, J; Böttcher, M; Boisson, C; Bolmont, J; Bordas, P; Bregeon, J; Brun, F; Brun, P; Bryan, M; Bulik, T; Carrigan, S; Casanova, S; Chadwick, P M; Chakraborty, N; Chalme-Calvet, R; Chaves, R C G; Chrétien, M; Colafrancesco, S; Cologna, G; Conrad, J; Couturier, C; Cui, Y; Dalton, M; Davids, I D; Degrange, B; Deil, C; de Wilt, P; Djannati-Ataï, A; Domainko, W; Donath, A; Drury, L O'C; Dubus, G; Dutson, K; Dyks, J; Dyrda, M; Edwards, T; Egberts, K; Eger, P; Espigat, P; Farnier, C; Fegan, S; Feinstein, F; Fernandes, M V; Fernandez, D; Fiasson, A; Fontaine, G; Förster, A; ling, M Füß; Gabici, S; Gajdus, M; Gallant, Y A; Garrigoux, T; Giavitto, G; Giebels, B; Glicenstein, J F; Gottschall, D; Grondin, M -H; Grudzi?ska, M; Hadasch, D; Häffner, S; Hahn, J; Harris, J; Heinzelmann, G; Henri, G; Hermann, G; Hervet, O; Hillert, A; Hinton, J A; Hofmann, W; Hofverberg, P; Holler, M; Horns, D; Ivascenko, A; Jacholkowska, A; Jahn, C; Jamrozy, M; Janiak, M; Jankowsky, F; Jung, I; Kastendieck, M A; Katarzy?ski, K; Katz, U; Kaufmann, S; Khélifi, B; Kieffer, M; Klepser, S; Klochkov, D; Klu?niak, W; Kolitzus, D; Komin, Nu; Kosack, K; Krakau, S; Krayzel, F; Krüger, P P; Laffon, H; Lamanna, G; Lefaucheur, J; Lefranc, V; Lemière, A; Lemoine-Goumard, M; Lenain, J -P; Lohse, T; Lopatin, A; Lu, C -C; Marandon, V; Marcowith, A; Marx, R; Maurin, G; Maxted, N; Mayer, M; McComb, T J L; Méhault, J; Meintjes, P J; Menzler, U; Meyer, M; Mitchell, A M W; Moderski, R; Mohamed, M; Morå, K; Moulin, E; Murach, T; de Naurois, M; Niemiec, J; Nolan, S J; Oakes, L; Odaka, H; Ohm, S; Opitz, B; Ostrowski, M; Oya, I; Panter, M; Parsons, R D; Arribas, M Paz; Pekeur, N W; Pelletier, G; Perez, J; Petrucci, P -O; Peyaud, B; Pita, S; Poon, H; Pühlhofer, G; Punch, M; Quirrenbach, A; Raab, S; Reichardt, I; Reimer, A; Reimer, O; Renaud, M; Reyes, R de los; Rieger, F; Rob, L; Romoli, C; Rosier-Lees, S; Rowell, G; Rudak, B; Sahakian, C B Rulten V; Salek, D; Sanchez, D A; Santangelo, A; Schlickeiser, R; Schüssler, F; Schulz, A; Schwanke, U; Schwarzburg, S; Schwemmer, S; Sol, H; Spanier, F; Spengler, G; Spies, F; Stawarz, ?; Steenkamp, R; Stegmann, C; Stinzing, F; Stycz, K; Sushch, I; Tavernet, J -P; Tavernier, T; Taylor, A M; Terrier, R; Tluczykont, M; Trichard, C; Valerius, K; van Eldik, C; van Soelen, B; Vasileiadis, G; Veh, J; Venter, C; Viana, A; Vincent, P; Vink, J; Völk, H J; Volpe, F; Vorster, M; Vuillaume, T; Wagner, S J; Wagner, P; Wagner, R M; Ward, M; Weidinger, M; Weitzel, Q; White, R; Wierzcholska, A; Willmann, P; Wörnlein, A; Wouters, D; Yang, R; Zabalza, V; Zaborov, D; Zacharias, M; Zdziarski, A A; Zech, A; Zechlin, H -S

    2015-01-01T23:59:59.000Z

    The Large Magellanic Cloud, a satellite galaxy of the Milky Way, has been observed with the High Energy Stereoscopic System (H.E.S.S.) above an energy of 100 billion electron volts for a deep exposure of 210 hours. Three sources of different types were detected: the pulsar wind nebula of the most energetic pulsar known N 157B, the radio-loud supernova remnant N 132D and the largest non-thermal X-ray shell - the superbubble 30 Dor C. The unique object SN 1987A is, surprisingly, not detected, which constrains the theoretical framework of particle acceleration in very young supernova remnants. These detections reveal the most energetic tip of a gamma-ray source population in an external galaxy, and provide via 30 Dor C the unambiguous detection of gamma-ray emission from a superbubble.

  18. Optimal restoration of power supply in large distribution systems in developing countries

    SciTech Connect (OSTI)

    Devi, V.S.; Sen Gupta, D.P. [Indian Inst. of Science, Bangalore (India). Dept. of Electrical Engineering; Anandalingam, G. [Univ. of Pennsylvania, Philadelphia, PA (United States). Dept. of Systems Engineering

    1995-01-01T23:59:59.000Z

    A computer aided optimal method has been developed for the restoration of electric supply to areas isolated from the network following a fault in a distribution system. A search technique is used where the search is guided by appropriate heuristics. The optimum solution entails finding the strategy which involves the operation of minimum number of switch gear for rerouting the supply within the constraint of specified loading. This is an essential requirement in countries like India where the circuit breakers are almost always manually operated and a number of transformers and feeders operate close to their rated capacity. It pays therefore to adopt different strategies at peak load and off peak conditions since the number of breaker operations is so critical. The heuristic search that is developed is applied to a large distribution system and provides very good results.

  19. Figure 5. Wavelet time series analysis for yearly LBM outbreaks. a) The normalized time-series. b) Temporally-local wavelet power spectrum (dark red indicates the strongest

    E-Print Network [OSTI]

    SUPPLEMENT Figure 5. Wavelet time series analysis for yearly LBM outbreaks. a) The normalized time-series. b) Temporally-local wavelet power spectrum (dark red indicates the strongest periodicity while white indicates the weakest periodicity). c) Spatiotemporally-global wavelet spectrum. d) Time-series plot

  20. Generator module architecture for a large solid oxide fuel cell power plant

    DOE Patents [OSTI]

    Gillett, James E.; Zafred, Paolo R.; Riggle, Matthew W.; Litzinger, Kevin P.

    2013-06-11T23:59:59.000Z

    A solid oxide fuel cell module contains a plurality of integral bundle assemblies, the module containing a top portion with an inlet fuel plenum and a bottom portion receiving air inlet feed and containing a base support, the base supports dense, ceramic exhaust manifolds which are below and connect to air feed tubes located in a recuperator zone, the air feed tubes passing into the center of inverted, tubular, elongated, hollow electrically connected solid oxide fuel cells having an open end above a combustion zone into which the air feed tubes pass and a closed end near the inlet fuel plenum, where the fuel cells comprise a fuel cell stack bundle all surrounded within an outer module enclosure having top power leads to provide electrical output from the stack bundle, where the fuel cells operate in the fuel cell mode and where the base support and bottom ceramic air exhaust manifolds carry from 85% to all 100% of the weight of the stack, and each bundle assembly has its own control for vertical and horizontal thermal expansion control.

  1. THE SCALE-UP OF LARGE PRESSURIZED FLUIDIZED BEDS FOR ADVANCED COAL-FIRED POWER PROCESSES

    SciTech Connect (OSTI)

    Leon R. Glicksman; Michael Louge; Hesham F. Younis; Richard Tan; Mathew Hyre; Mark Torpey

    2003-11-24T23:59:59.000Z

    This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor an agency thereof, nor any of the their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, A combined-cycle High Performance Power System (HIPPS) capable of overall cycle efficiencies approaching 50% has been proposed and designed by Foster Wheeler Development Corporation (FWDC). A pyrolyzer in the first stage of the HIPPS process converts a coal feedstock into fuel gas and char at an elevated pressure of 1.4 Map. (206 psia) and elevated temperature of 930 C (1700 F). The generated char serves as the feedstock for a Pulverized Coal (PC) boiler operating at atmospheric pressure, and the fuel gas is directly fired in a gas turbine. The hydrodynamic behavior of the pyrolyzer strongly influences the quality of both the fuel gas and the generated char, the energy split between the gas turbine and the steam turbine, and hence the overall efficiency of the system. By utilizing a simplified set of scaling parameters (Glicksman et al.,1993), a 4/7th labscale cold model of the pyrolyzer operating at ambient temperature and pressure was constructed and tested. The scaling parameters matched include solid to gas density ratio, Froude number, length to diameter ratio; dimensionless superficial gas velocity and solid recycle rate, particle sphericity and particle size distribution (PSD).

  2. Converter fed synchronous generator system for medium and large power plants

    SciTech Connect (OSTI)

    Ammann, C.; Reichert, K.; Joho, R.

    1986-06-01T23:59:59.000Z

    Converter fed synchronous generators have the following advantages: The turbine can operate at any speed, independent of the frequency of the power system, the part load efficiency may be improved if the speed can be adjusted. The generator is protected and isolated. The stability is improved. This scheme is applicable to hydro, steam and wind generation. The paper gives details on a converter fed 650 MW unit with steam turbine having a synchronous generator with two 3-phase windings at 30/sup 0/ to each other which directly feeds a 12-pulse HVDC link. The usual converter transformer, var-compensators and current harmonics filters on the generator side are eliminated. The study shows the advantages and disadvantages of the system. The system stability is considerably improved compared to the conventional design. As the steam turbine can be operated only with constant speed, the improvements in the efficiency of the thermal system are limited. A cost reduction can be achieved only with a higher turbine speed. Details are given on the total system losses and the total system costs in comparison to the conventional design.

  3. Analysis of Wind Power and Load Data at Multiple Time Scales

    E-Print Network [OSTI]

    Coughlin, Katie

    2011-01-01T23:59:59.000Z

    Wan, Yih-Huei. 2004. Wind Power Plant Behaviors: Analyses ofthe output of wind power plants. In a typical studyfluctuations across wind power plants located in the same

  4. 96 IEEE TRANSACTIONS ON VERY LARGE SCALE INTEGRATION (VLSI) SYSTEMS, VOL. 12, NO. 1, JANUARY 2004 Managing Power Consumption in Networks on Chips

    E-Print Network [OSTI]

    Managing Power Consumption in Networks on Chips Tajana Simunic, Stephen P. Boyd, and Peter Glynn, Member, IEEE Abstract--In this paper, we present a new methodology for managing power consumption of networks-on-chips (NOCs). A power management problem is formulated for the first time using closed-loop control concepts

  5. Implementation of BEE: a Real-time Large-scale Hardware Emulation Engine

    E-Print Network [OSTI]

    Southern California, University of

    . Categories: I. Computing Methodologies I.6 Simulation and Modeling I.6.7 Simulation Support Systems Subject complexity and integration of digital and analog systems, the computing power required for detailed cycle verification of integrated systems with heterogeneous components very difficult. In communication systems

  6. A cyclic time-dependent Markov process to model daily patterns in wind turbine power production

    E-Print Network [OSTI]

    Scholz, Teresa; Estanqueiro, Ana

    2013-01-01T23:59:59.000Z

    Wind energy is becoming a top contributor to the renewable energy mix, which raises potential reliability issues for the grid due to the fluctuating nature of its source. To achieve adequate reserve commitment and to promote market participation, it is necessary to provide models that can capture daily patterns in wind power production. This paper presents a cyclic inhomogeneous Markov process, which is based on a three-dimensional state-space (wind power, speed and direction). Each time-dependent transition probability is expressed as a Bernstein polynomial. The model parameters are estimated by solving a constrained optimization problem: The objective function combines two maximum likelihood estimators, one to ensure that the Markov process long-term behavior reproduces the data accurately and another to capture daily fluctuations. A convex formulation for the overall optimization problem is presented and its applicability demonstrated through the analysis of a case-study. The proposed model is capable of r...

  7. Large Scale Power and Running Spectral Index in New Old Inflation

    SciTech Connect (OSTI)

    Dvali, G.

    2003-11-07T23:59:59.000Z

    We have proposed a new class of inflationary scenarios in which the first stage of expansion is driven by ''old'' false vacuum inflation. This ends by nucleation of a bubble, which then further inflates. Unlike the standard slow-roll scenarios the ''clock'' ending the second inflationary phase is not a local order parameter, but rather the average value of an oscillating scalar field, which locks the system at a saddle point of the potential in a temporary inflationary state. Inflation ends when the amplitude drops below a certain critical point and liberates the system from the false vacuum state. The second stage of inflation has only about 50 e-foldings, a number which is determined entirely by the ratio of the fundamental mass scales, such as the Planck/string scale and the supersymmetry breaking scale. The density perturbations are generated due to fluctuations of moduli-dependent Yukawa couplings. In this note we explore the observable imprints in the fluctuation spectrum of generic cross-couplings in the superpotential and in the Kaehler potential. We show that in the presence of generic non-renormalizable interactions in the superpotential between the fluctuating modulus and the oscillating inflaton, the amplitude of the density perturbations is exponentially cut-off for sufficiently large wavelengths. With reasonable choices of scales and interactions, this long wavelength cutoff can occur at approximately the current horizon size. The perturbative corrections in the Kaehler potential give non-trivial potentially observable tilt and a running of the spectral index which is different from the standard inflationary models.

  8. An Indexing Scheme for Fast Similarity Search in Large Time Series Databases Eamonn J. Keogh and Michael J. Pazzani

    E-Print Network [OSTI]

    Pazzani, Michael J.

    An Indexing Scheme for Fast Similarity Search in Large Time Series Databases Eamonn J. Keogh, California 92697 USA {eamonn,pazzani}@ics.uci.edu Abstract We address the problem of similarity search similar element of the bin. This bound allows us to search the bins in best first order, and to prune some

  9. From Dirac theories in curved space-times to a Variation of Dirac's large-number hypothesis

    E-Print Network [OSTI]

    U. D. Jentschura

    2014-05-07T23:59:59.000Z

    An overview is given of recent developments in the field of Dirac equations generalized to curved space-times. An illustrative discussion is provided. We conclude with a variation of Dirac's large-number hypothesis which relates a number of physical quantities on cosmological scales.

  10. Large Thermoelectric Power Factor in P-type Si (110)/[110] Ultra-Thin-Layers Compared to Differently Oriented Channels

    E-Print Network [OSTI]

    1 Large Thermoelectric Power Factor in P-type Si (110)/[110] Ultra-Thin-Layers Compared the thermoelectric power factor of ultra-thin-body p-type Si layers of thicknesses from W=3nm up to 10nm. We show improvement in 2D thin- layers of zincblende semiconductors. Keywords: low-dimensional thermoelectrics

  11. IEEE Transaction on Power Apparatus and Systems, Vol. PAS-103, No. 12, December 1984 EFFICIENT LARGE-SCALE HYDRO SYSTEM SCHEDULING WITH FORCED SPILL CONDITIONS

    E-Print Network [OSTI]

    Gross, George

    releases from each reservoir and through each power house so as to optimize the total benefit of the hydroIEEE Transaction on Power Apparatus and Systems, Vol. PAS-103, No. 12, December 1984 EFFICIENT LARGE-SCALE HYDRO SYSTEM SCHEDULING WITH FORCED SPILL CONDITIONS Yoshiro Ikura George Gross Systems

  12. LARGE DEVIATIONS FOR THE LOCAL TIMES OF A RANDOM WALK AMONG RANDOM CONDUCTANCES

    E-Print Network [OSTI]

    König, Wolfgang

    .1) This operator is symmetric and generates the continuous-time random walk (X t ) t#[0,#) in Z d , the random walk AND TILMAN WOLFF In some recent publications (see, e.g., [BD10]), the above walk is called variable-speed times of the walk. The speed and the rate function of our principle are explicit in terms of the lower

  13. Visualizing Frequent Patterns in Large Multivariate Time Series , M. Marwah1

    E-Print Network [OSTI]

    Ramakrishnan, Naren

    languages, detecting anomalies in patients' medical records over time [5], and chiller efficiency in data centers [14]. Figure 1 shows an example of the visual analysis of a pair of data center chiller time series in which different motifs were discovered. A chiller is a key component of the cooling

  14. Application of Entry-Time Processes in Asset Management for Nuclear Power Plants (Final Report)

    SciTech Connect (OSTI)

    Paul Nelson

    2008-01-23T23:59:59.000Z

    A mathematical model of entry-time processes was developed, and a computational method for solving that model was verified. This methodology was demonstrated via application to a succession of increasingly more complex subsystems of nuclear power plants. The effort culminated in the application to main generators that constituted the PhD dissertation of Shuwen (“Eric”) Wang. Dr. Wang is now employed by ABS Consulting, in Anaheim, CA. ABS is a principal provider to the nuclear industry of technical services related to reliability and safety.

  15. A Data Driven Framework for Real Time Power System Event Detection and Visualization

    E-Print Network [OSTI]

    McCamish, Ben; Landford, Jordan; Bass, Robert; Cotilla-Sanchez, Eduardo; Chiu, David

    2015-01-01T23:59:59.000Z

    Increased adoption and deployment of phasor measurement units (PMU) has provided valuable fine-grained data over the grid. Analysis over these data can provide real-time insight into the health of the grid, thereby improving control over operations. Realizing this data-driven control, however, requires validating, processing and storing massive amounts of PMU data. This paper describes a PMU data management system that supports input from multiple PMU data streams, features an event-detection algorithm, and provides an efficient method for retrieving archival data. The event-detection algorithm rapidly correlates multiple PMU data streams, providing details on events occurring within the power system in real-time. The event-detection algorithm feeds into a visualization component, allowing operators to recognize events as they occur. The indexing and data retrieval mechanism facilitates fast access to archived PMU data. Using this method, we achieved over 30x speedup for queries with high selectivity. With th...

  16. Studying accreting black holes and neutron stars with time series: beyond the power spectrum

    E-Print Network [OSTI]

    S. Vaughan; P. Uttley

    2008-02-04T23:59:59.000Z

    The fluctuating brightness of cosmic X-ray sources, particularly accreting black holes and neutron star systems, has enabled enormous progress in understanding the physics of turbulent accretion flows, the behaviour of matter on the surfaces of neutron stars and improving the evidence for black holes. Most of this progress has been made by analysing and modelling time series data in terms of their power and cross spectra, as will be discussed in other articles in this volume. Recently, attempts have been made to make use of other aspects of the data, by testing for non-linearity, non-Gaussianity, time asymmetry and by examination of higher order Fourier spectra. These projects, which have been made possible by the vast increase in data quality and quantity over the past decade, are the subject of this article.

  17. Transition Time Bounded Low-power Clock Tree Construction Min Pan, Chris Chong-Nuen Chu and J. Morris Chang

    E-Print Network [OSTI]

    Chu, Chris C.-N.

    Transition Time Bounded Low-power Clock Tree Construction Min Pan, Chris Chong-Nuen Chu and J is the signal with the highest frequency in the whole system, which makes the transition time bound of the clock signal extremely tight. Hence, it is necessary to have transition time bounds to construct low

  18. Optimal Reactive Power Dispatch in Real-Time S. Salamat Sharif1

    E-Print Network [OSTI]

    Taylor, James H.

    ) an improvement in the volt- age profile and voltage stability, and 2) a savings in ac- tive power loss of view. A reduction in active power loss gained from ORPD can save a significant amount of money reactive power dispatch, power loss minimization, optimization methods 1 Introduction Optimal power

  19. Modelling and Formal Verification of Timing Aspects in Large PLC Programs

    E-Print Network [OSTI]

    Fernandez Adiego, B; Blanco Vinuela, E; Tournier, J-C; Gonzalez Suarez, V M; Blech, J O

    2014-01-01T23:59:59.000Z

    One of the main obstacle that prevents model checking from being widely used in industrial control systems is the complexity of building formal models out of PLC programs, especially when timing aspects need to be integrated. This paper brings an answer to this obstacle by proposing a methodology to model and verify timing aspects of PLC programs. Two approaches are proposed to allow the users to balance the trade-off between the complexity of the model, i.e. its number of states, and the set of specifications possible to be verified. A tool supporting the methodology which allows to produce models for different model checkers directly from PLC programs has been developed. Verification of timing aspects for real-life PLC programs are presented in this paper using NuSMV.

  20. Long-time behavior and relaxation of power-law correlation in one-dimensional self-gravitating system

    E-Print Network [OSTI]

    Hiroko Koyama; Tetsuro Konishi

    2001-12-19T23:59:59.000Z

    Long-time behavior of spatial power-law correlation in one-dimensional self-gravitating system is numerically investigated. It is found that the power-law structure persists even after the system is virialized. The structure gradually disappears owing to energy exchange among particles. Energy distribution is quasi-stationary after the system is virialized.

  1. Particle Falls is a large-scale public artwork that provides a real time visualization of

    E-Print Network [OSTI]

    Maccabe, Barney

    at the same time by using particulate air pollution as a basis for a cascading waterfall flowing down the side in California. Despite the invisibility of air, modern sensors can detect tiny particulate pollution levels of particulate pollution in the San Fernando Corridor in the form of a projection on the AT&T Building in San

  2. Analysis of Wind Power and Load Data at Multiple Time Scales

    E-Print Network [OSTI]

    Coughlin, Katie

    2011-01-01T23:59:59.000Z

    Huei. 2005. Primer on Wind Power for Utility Applications.Wan, Yih-Huei. 2004. Wind Power Plant Behaviors: Analysesof Long-Term Wind Power Data. National Renewable Energy Lab

  3. Solar Power in the Desert: Are the current large-scale solar developments really improving California’s environment?

    E-Print Network [OSTI]

    Allen, Michael F.; McHughen, Alan

    2011-01-01T23:59:59.000Z

    habitat loss from solar and thermal power expansions (Photovoltaic vs Solar Thermal. In: Planetary Stewardship.of the vegetation for thermal solar power units. The net C

  4. Monitoring of Power System Topology in Real-Time Mladen Kezunovic

    E-Print Network [OSTI]

    components such as generators, power transformers, transmission lines, loads, etc. The knowledge about components such as generators, power transformers, busbars, transmission lines and loads. The interconnected

  5. Analysis of Wind Power and Load Data at Multiple Time Scales

    E-Print Network [OSTI]

    Coughlin, Katie

    2011-01-01T23:59:59.000Z

    The spectrum of power from wind turbines. Journal of PowerAWEA 2010. American Wind Energy Association ProjectsErik and Jason Kemper. 2009. Wind Plant Ramping Behavior.

  6. Agent-based Large-Scale Emergency Evacuation Using Real-Time Open Government Data

    SciTech Connect (OSTI)

    Lu, Wei [ORNL; Liu, Cheng [ORNL; Bhaduri, Budhendra L [ORNL

    2014-01-01T23:59:59.000Z

    The open government initiatives have provided tremendous data resources for the transportation system and emergency services in urban areas. This paper proposes a traffic simulation framework using high temporal resolution demographic data and real time open government data for evacuation planning and operation. A comparison study using real-world data in Seattle, Washington is conducted to evaluate the framework accuracy and evacuation efficiency. The successful simulations of selected area prove the concept to take advantage open government data, open source data, and high resolution demographic data in emergency management domain. There are two aspects of parameters considered in this study: user equilibrium (UE) conditions of traffic assignment model (simple Non-UE vs. iterative UE) and data temporal resolution (Daytime vs. Nighttime). Evacuation arrival rate, average travel time, and computation time are adopted as Measure of Effectiveness (MOE) for evacuation performance analysis. The temporal resolution of demographic data has significant impacts on urban transportation dynamics during evacuation scenarios. Better evacuation performance estimation can be approached by integrating both Non-UE and UE scenarios. The new framework shows flexibility in implementing different evacuation strategies and accuracy in evacuation performance. The use of this framework can be explored to day-to-day traffic assignment to support daily traffic operations.

  7. EMCS and time-series energy data analysis in a large government office building

    SciTech Connect (OSTI)

    Piette, Mary Ann; Kinney, Satkartar; Friedman, Hannah

    2001-04-01T23:59:59.000Z

    Energy Management Control System (EMCS) data are an underutilized source of information on the performance of commercial buildings. Newer EMCS's have the ability and storage capacity to trend large amounts of data and perform preliminary analyses; however, these features often receive little or no use, as operators are generally not trained in data management, visualization, and analysis. Whole-building hourly electric-utility data are another readily available and underutilized source of information. This paper outlines the use of EMCS and utility data to evaluate the performance of the Ronald V. Dellums Federal Building in Oakland, California, a large office building operated by the Federal General Services Administration (GSA). The project began as an exploratory effort at Lawrence Berkeley National Laboratory (LBNL) to examine the procedures operators were using to obtain information and operate their buildings. Trending capabilities were available, but in limited use by the operators. LBNL worked with the building operators to use EMCS to trend one-minute data for over one-hundred points. Hourly electricity-use data were also used to understand usage patterns and peak demand. The paper describes LBNL's key findings in the following areas: Characterization of cooling plant operations; Characterization of economizer performance; Analysis of annual energy use and peak demand operations; Techniques, strengths, and shortcomings of EMCS data analysis; Future plans at the building for web-based remote monitoring and diagnostics. These findings have helped GSA develop strategies for peak demand reduction in this and other GSA buildings. Such activities are of great interest in California and elsewhere, where electricity reliability and demand are currently problematic. Overall, though the building's energy use is fairly low, significant energy savings are available by improving the existing EMCS control strategies.

  8. Wide dynamic range neutron flux monitor having fast time response for the Large Helical Device

    SciTech Connect (OSTI)

    Isobe, M., E-mail: isobe@nifs.ac.jp; Takeiri, Y. [National Institute for Fusion Science, Toki 509-5292 (Japan); Department of Fusion Science, The Graduate University for Advanced Studies, Toki 509-5292 (Japan); Ogawa, K.; Miyake, H.; Hayashi, H.; Kobuchi, T. [National Institute for Fusion Science, Toki 509-5292 (Japan); Nakano, Y.; Watanabe, K.; Uritani, A. [Department of Materials, Physics and Energy Engineering, Nagoya University, Nagoya 464-8603 (Japan); Misawa, T. [Kyoto University Research Reactor Institute, Kumatori 590-0494 (Japan); Nishitani, T. [Japan Atomic Energy Agency, Rokkasho 039-3212 (Japan); Tomitaka, M.; Kumagai, T.; Mashiyama, Y.; Ito, D.; Kono, S. [Toshiba Corporation, Fuchu 183-8511 (Japan); Yamauchi, M. [Toshiba Nuclear Engineering Services Corporation, Yokohama 235-8523 (Japan)

    2014-11-15T23:59:59.000Z

    A fast time response, wide dynamic range neutron flux monitor has been developed toward the LHD deuterium operation by using leading-edge signal processing technologies providing maximum counting rate up to ?5 × 10{sup 9} counts/s. Because a maximum total neutron emission rate over 1 × 10{sup 16} n/s is predicted in neutral beam-heated LHD plasmas, fast response and wide dynamic range capabilities of the system are essential. Preliminary tests have demonstrated successful performance as a wide dynamic range monitor along the design.

  9. Power Saving Design for Servers under Response Time Constraint Shengquan Wang

    E-Print Network [OSTI]

    Wang, Shengquan

    the server utilization is high. Instead we use PowerIdle power-saving scheme, which uses only DVS utility bill. For example, for a high-performance server with 330 Watt power consumption, the annual that the electricity cost remains significant even if the server does not always operate with the maximum power

  10. Time series modeling and large scale global solar radiation forecasting from geostationary satellites data

    E-Print Network [OSTI]

    Voyant, Cyril; Muselli, Marc; Paoli, Christophe; Nivet, Marie Laure

    2014-01-01T23:59:59.000Z

    When a territory is poorly instrumented, geostationary satellites data can be useful to predict global solar radiation. In this paper, we use geostationary satellites data to generate 2-D time series of solar radiation for the next hour. The results presented in this paper relate to a particular territory, the Corsica Island, but as data used are available for the entire surface of the globe, our method can be easily exploited to another place. Indeed 2-D hourly time series are extracted from the HelioClim-3 surface solar irradiation database treated by the Heliosat-2 model. Each point of the map have been used as training data and inputs of artificial neural networks (ANN) and as inputs for two persistence models (scaled or not). Comparisons between these models and clear sky estimations were proceeded to evaluate the performances. We found a normalized root mean square error (nRMSE) close to 16.5% for the two best predictors (scaled persistence and ANN) equivalent to 35-45% related to ground measurements. F...

  11. LARGE SCALE SIMULATIONS OF THE MECHANCIAL PROPERTIES OF LAYERED TRANSITION METAL TERNARY COMPOUNDS FOR FOSSIL ENERGY POWER SYSTEM APPLICATIONS

    SciTech Connect (OSTI)

    Ching, Wai-Yim

    2014-12-31T23:59:59.000Z

    Advanced materials with applications in extreme conditions such as high temperature, high pressure, and corrosive environments play a critical role in the development of new technologies to significantly improve the performance of different types of power plants. Materials that are currently employed in fossil energy conversion systems are typically the Ni-based alloys and stainless steels that have already reached their ultimate performance limits. Incremental improvements are unlikely to meet the more stringent requirements aimed at increased efficiency and reduce risks while addressing environmental concerns and keeping costs low. Computational studies can lead the way in the search for novel materials or for significant improvements in existing materials that can meet such requirements. Detailed computational studies with sufficient predictive power can provide an atomistic level understanding of the key characteristics that lead to desirable properties. This project focuses on the comprehensive study of a new class of materials called MAX phases, or Mn+1AXn (M = a transition metal, A = Al or other group III, IV, and V elements, X = C or N). The MAX phases are layered transition metal carbides or nitrides with a rare combination of metallic and ceramic properties. Due to their unique structural arrangements and special types of bonding, these thermodynamically stable alloys possess some of the most outstanding properties. We used a genomic approach in screening a large number of potential MAX phases and established a database for 665 viable MAX compounds on the structure, mechanical and electronic properties and investigated the correlations between them. This database if then used as a tool for materials informatics for further exploration of this class of intermetallic compounds.

  12. Real-Time Combined Heat and Power Operational Strategy Using a Hierarchical Optimization Algorithm

    SciTech Connect (OSTI)

    Yun, Kyung Tae; Cho, Heejin; Luck, Rogelio; Mago, Pedro J.

    2011-06-01T23:59:59.000Z

    Existing attempts to optimize the operation of Combined Heat and Power (CHP) systems for building applications have two major limitations: the electrical and thermal loads are obtained from historical weather profiles; and the CHP system models ignore transient responses by using constant equipment efficiencies. This paper considers the transient response of a building combined with a hierarchical CHP optimal control algorithm to obtain a real-time integrated system that uses the most recent weather and electric load information. This is accomplished by running concurrent simulations of two transient building models. The first transient building model uses current as well as forecast input information to obtain short term predictions of the thermal and electric building loads. The predictions are then used by an optimization algorithm, i.e., a hierarchical controller, that decides the amount of fuel and of electrical energy to be allocated at the current time step. In a simulation, the actual physical building is not available and, hence, to simulate a real-time environment, a second, building model with similar but not identical input loads are used to represent the actual building. A state-variable feedback loop is completed at the beginning of each time step by copying, i.e., measuring, the state variable from the actual building and restarting the predictive model using these ?measured? values as initial conditions. The simulation environment presented in this paper features nonlinear effects such as the dependence of the heat exchanger effectiveness on their operating conditions. The results indicate that the CHP engine operation dictated by the proposed hierarchical controller with uncertain weather conditions have the potential to yield significant savings when compared to conventional systems using current values of electricity and fuel prices.

  13. A modeling and control framework for operating large-scale electric power systems under present and newly evolving competitive industry structures

    E-Print Network [OSTI]

    Ilic, Marija

    1995-01-01T23:59:59.000Z

    This paper introduces a systematic, structure-based modeling framework for analysis and control of electric power systems for processes evolving over the mid-term and long-term time horizons. Much simpler models than the ...

  14. IEEE TRANSACTIONS ON POWER SYSTEMS, VOL. 29, NO. 2, MARCH 2014 627 Impact of Data Quality on Real-Time

    E-Print Network [OSTI]

    Tong, Lang

    -Time Locational Marginal Price Liyan Jia, Jinsub Kim, Robert J. Thomas, Life Fellow, IEEE, and Lang Tong, Fellow--Bad data detection, cyber security of smart grid, locational marginal price (LMP), power system state, IEEE Abstract--The problem of characterizing impacts of data quality on real-time locational marginal

  15. Time-resolved temperature study in a high-power impulse magnetron sputtering discharge

    SciTech Connect (OSTI)

    Britun, Nikolay; Palmucci, Maria; Konstantinidis, Stephanos [Chimie des Interactions Plasma-Surface (ChIPS), CIRMAP, Universite de Mons, 23 Place du Parc, B-7000 Mons (Belgium); Gaillard, Mireille [Groupe de Recherches sur l'Energetique des Milieux Ionises (GREMI), UMR 7344, Universite d'Orleans, 14 rue d'Issoudun, B.P. 6744, 45067 Orleans Cedex 2 (France); Snyders, Rony [Chimie des Interactions Plasma-Surface (ChIPS), CIRMAP, Universite de Mons, 23 Place du Parc, B-7000 Mons (Belgium); Materia Nova Research Center, Parc Initialis, B-7000 Mons (Belgium)

    2013-07-07T23:59:59.000Z

    The gas heating dynamics is studied in a high-power impulse magnetron sputtering discharge operating in Ar-N{sub 2} gas mixtures. The time-resolved rotational temperature analysis based on the spectral transition between the B{sup 2}{Sigma}{sub u}{sup +}-X{sup 2}{Sigma}{sub g}{sup +} energy levels in molecular nitrogen ion (N{sub 2}{sup +} First Negative Band) is undertaken for this purpose. The rotational temperature in the discharge is found to increase linearly during the plasma pulse being roughly independent on the nitrogen content in the examined range. Such a temperature increase is attributed to the bulk gas heating which is the result of collisions with the sputtered species. Two sputtered materials, Ti and W, are examined during the study. In the case of W sputtering, the gas heating is found to be more pronounced than in the Ti case, which is explained by more efficient energy exchange between the sputtered W atoms and the bulk gas atoms during the plasma on-time. The obtained temperature data are compared to the laser-induced fluorescence study of Ar metastable atoms performed recently in the same discharge in our group. The particularities related to gas thermalization as well as to validity of the utilized approach for characterization of the pulsed sputtering discharges are discussed.

  16. Large-Eddy Simulation Study of Wake Propagation and Power Production in an Array of Tidal-Current Turbines: Preprint

    SciTech Connect (OSTI)

    Churchfield, M. J.; Li, Y.; Moriarty, P. J.

    2012-07-01T23:59:59.000Z

    This paper presents our initial work in performing large-eddy simulations of tidal turbine array flows. First, a horizontally-periodic precursor simulation is performed to create turbulent flow data. Then that data is used as inflow into a tidal turbine array two rows deep and infinitely wide. The turbines are modeled using rotating actuator lines, and the finite-volume method is used to solve the governing equations. In studying the wakes created by the turbines, we observed that the vertical shear of the inflow combined with wake rotation causes lateral wake asymmetry. Also, various turbine configurations are simulated, and the total power production relative to isolated turbines is examined. Staggering consecutive rows of turbines in the simulated configurations allows the greatest efficiency using the least downstream row spacing. Counter-rotating consecutive downstream turbines in a non-staggered array shows a small benefit. This work has identified areas for improvement, such as the use of a larger precursor domain to better capture elongated turbulent structures, the inclusion of salinity and temperature equations to account for density stratification and its effect on turbulence, improved wall shear stress modelling, and the examination of more array configurations.

  17. Large-Eddy Simulation Study of Wake Propagation and Power Production in an Array of Tidal-Current Turbines: Preprint

    SciTech Connect (OSTI)

    Churchfield, M. J.; Li, Y.; Moriarty, P. J.

    2011-07-01T23:59:59.000Z

    This paper presents our initial work in performing large-eddy simulations of tidal turbine array flows. First, a horizontally-periodic precursor simulation is performed to create turbulent flow data. Then that data is used to determine the inflow into a tidal turbine array two rows deep and infinitely wide. The turbines are modeled using rotating actuator lines, and the finite-volume method is used to solve the governing equations. In studying the wakes created by the turbines, we observed that the vertical shear of the inflow combined with wake rotation causes lateral wake asymmetry. Also, various turbine configurations are simulated, and the total power production relative to isolated turbines is examined. Staggering consecutive rows of turbines in the simulated configurations allows the greatest efficiency using the least downstream row spacing. Counter-rotating consecutive downstream turbines in a non-staggered array shows a small benefit. This work has identified areas for improvement, such as the use of a larger precursor domain to better capture elongated turbulent structures, the inclusion of salinity and temperature equations to account for density stratification and its effect on turbulence, improved wall shear stress modeling, and the examination of more array configurations.

  18. Thin power law film flow down an inclined plane: consistent shallow water models and stability under large scale perturbations

    E-Print Network [OSTI]

    Noble, Pascal

    2012-01-01T23:59:59.000Z

    In this paper we derive consistent shallow water equations for thin films of power law fluids down an incline. These models account for the streamwise diffusion of momentum which is important to describe accurately the full dynamic of the thin film flows when instabilities like roll-waves arise. These models are validated through a comparison with Orr Sommerfeld equations for large scale perturbations. We only consider laminar flow for which the boundary layer issued from the interaction of the flow with the bottom surface has an influence all over the transverse direction to the flow. In this case the concept itself of thin film and its relation with long wave asymptotic leads naturally to flow conditions around a uniform free surface Poiseuille flow. The apparent viscosity diverges at the free surface which, in turn, introduces a singularity in the formulation of the Orr-Sommerfeld equations and in the derivation of shallow water models. We remove this singularity by introducing a weaker formulation of Cauc...

  19. Reduced 30% scanning time 3D multiplexer integrated circuit applied to large array format 20KHZ frequency inkjet print heads

    E-Print Network [OSTI]

    Liou, J -C

    2008-01-01T23:59:59.000Z

    Enhancement of the number and array density of nozzles within an inkjet head chip is one of the keys to raise the printing speed and printing resolutions. However, traditional 2D architecture of driving circuits can not meet the requirement for high scanning speed and low data accessing points when nozzle numbers greater than 1000. This paper proposes a novel architecture of high-selection-speed three-dimensional data registration for inkjet applications. With the configuration of three-dimensional data registration, the number of data accessing points as well as the scanning lines can be greatly reduced for large array inkjet printheads with nozzles numbering more than 1000. This IC (Integrated Circuit) architecture involves three-dimensional multiplexing with the provision of a gating transistor for each ink firing resistor, where ink firing resistors are triggered only by the selection of their associated gating transistors. Three signals: selection (S), address (A), and power supply (P), are employed toge...

  20. Novel Controls for Time-Dependent Economic Dispatch of Combined Cooling Heating and Power (CCHP)

    SciTech Connect (OSTI)

    Samuelsen, Scott; Brouwer, Jack

    2013-08-31T23:59:59.000Z

    The research and development effort detailed in this report directly addresses the challenge of reducing U.S. industrial energy and carbon intensity by contributing to an increased understanding of potential CCHP technology, the CCHP market and the challenges of widespread adoption. This study developed a number of new tools, models, and approaches for the design, control, and optimal dispatch of various CCHP technologies. The UC Irvine campus served as a ‘living laboratory’ of new CCHP technologies and enabled the design and demonstration of several novel control methods. In particular, the integration of large scale thermal energy storage capable of shifting an entire day of cooling demand required a novel approach to the CCHP dispatch optimization. The thermal energy storage proved an economically viable resource which reduced both costs and emissions by enabling generators and chillers to operate under steady high efficiency conditions at all times of the day.

  1. Use of Time-Aggregated Data in Economic Screening Analyses of Combined Heat and Power Systems

    SciTech Connect (OSTI)

    Hudson II, Carl Randy [ORNL

    2004-09-01T23:59:59.000Z

    Combined heat and power (CHP) projects (also known as cogeneration projects) usually undergo a series of assessments and viability checks before any commitment is made. A screening analysis, with electrical and thermal loads characterized on an annual basis, may be performed initially to quickly determine the economic viability of the proposed project. Screening analyses using time-aggregated data do not reflect several critical cost influences, however. Seasonal and diurnal variations in electrical and thermal loads, as well as time-of-use utility pricing structures, can have a dramatic impact on the economics. A more accurate economic assessment requires additional detailed data on electrical and thermal demand (e.g., hourly load data), which may not be readily available for the specific facility under study. Recent developments in CHP evaluation tools, however, can generate the needed hourly data through the use of historical data libraries and building simulation. This article utilizes model-generated hourly load data for four potential CHP applications and compares the calculated cost savings of a CHP system when evaluated on a time-aggregated (i.e., annual) basis to the savings when evaluated on an hour-by-hour basis. It is observed that the simple, aggregated analysis forecasts much greater savings (i.e., greater economic viability) than the more detailed hourly analysis. The findings confirm that the simpler tool produces results with a much more optimistic outlook, which, if taken by itself, might lead to erroneous project decisions. The more rigorous approach, being more reflective of actual requirements and conditions, presents a more accurate economic comparison of the alternatives, which, in turn, leads to better decision risk management.

  2. A DSP based real time power quality measurement system with voltage distortion improvement capability 

    E-Print Network [OSTI]

    Gou, Jian

    1992-01-01T23:59:59.000Z

    have been established to specify the limitation on the magnitudes of both harmonic currents and harmonic voltage distortion at different frequencies. Among these the "IEEE Guide for Harmonic Control and Reactive Compensation of Static Power... by the utility and by the electricity consumer has arrived. These measurements include: current and voltage harmonics, input power 1'actor, reactive power, real power, total harmonic distortion (THD), percentage load unbalance, etc. The measured data can...

  3. Power and efficiency limits for internal combustion engines via methods of finite-time thermodynamics

    E-Print Network [OSTI]

    Berry, R. Stephen

    Power and efficiency limits for internal combustion engines via methods of finite publication 17 June 1993) Analytical expressionsfor the upper bounds of power and efficiency of an internal and expensiveto compute and analyze.2If we are interestedin maximum power output or in maximum effi- ciency

  4. A Resilient Real-Time Agent-Based System for a Reconfigurable Power Grid

    E-Print Network [OSTI]

    Tolbert, Leon M.

    grid, collaboration, fault resiliency I. INTRODUCTION T he electric power industry in the 21st Century devices. The Electric Power Research Institute (EPRI) estimates that the annual economic losses from the information technology (IT) infrastructure level and the device level. Specifically, the reformed power grid

  5. Real-Time Power Quality Waveform Recognition with a Programmable Digital

    E-Print Network [OSTI]

    Mamishev, Alexander

    quality (PQ) monitoring is an important issue to electric utilities and many industrial power customers) related disturbances in power systems by electric utilities and industrial power customers. Software, such as semiconductors, automobiles, and paper. A report by CEIDS (Consortium for Electric Infrastructure to Support

  6. Robust Power System Stabiliser Design Using Minimax Control Approach: Validation using Real-time Digital Simulation

    E-Print Network [OSTI]

    Pota, Himanshu Roy

    Robust Power System Stabiliser Design Using Minimax Control Approach: Validation using Real Ugrinovskii1 Abstract-- This paper addresses the problem of designing decentralized power system stabilisers for interconnected power systems using robust output feedback minimax control tech- niques. We have considered

  7. The wind power probability density forecast problem can be formulated as: forecast the wind power pdf at time step t for each look-ahead time step t+k of a given time-horizon

    E-Print Network [OSTI]

    Kemner, Ken

    The wind power probability density forecast problem can be formulated as: forecast the wind power ahead) knowing a set of explanatory variables (e.g. numerical weather predictions (NWPs), wind power measured values). Translating this sentence to an equation, we have: where pt+k is the wind power

  8. 7th International Workshop on Large-Scale Integration of Wind Power and on Transmission Networks for Offshore Wind Farms Models for HLI analysis of power systems with

    E-Print Network [OSTI]

    Bak-Jensen, Birgitte

    for Offshore Wind Farms 1 Models for HLI analysis of power systems with offshore wind farms and distributed power plants, distributed generation and offshore wind farms. Particular attention is paid to the latter]-[4], but there is a lack of models of offshore wind farms, which introduce new issues for their representation, due to some

  9. Using architecture information and real-time resource state to reduce power consumption and communication costs in parallel applications.

    SciTech Connect (OSTI)

    Brandt, James M.; Devine, Karen D. [Sandia National Laboratories, Albuquerque, NM; Gentile, Ann C. [Sandia National Laboratories, Albuquerque, NM; Leung, Vitus J. [Sandia National Laboratories, Albuquerque, NM; Olivier, Stephen Lecler [Sandia National Laboratories, Albuquerque, NM; Pedretti, Kevin [Sandia National Laboratories, Albuquerque, NM; Rajamanickam, Sivasankaran [Sandia National Laboratories, Albuquerque, NM; Bunde, David P. [Sandia National Laboratories, Albuquerque, NM; Deveci, Mehmet; Catalyurek, Umit V.

    2014-09-01T23:59:59.000Z

    As computer systems grow in both size and complexity, the need for applications and run-time systems to adjust to their dynamic environment also grows. The goal of the RAAMP LDRD was to combine static architecture information and real-time system state with algorithms to conserve power, reduce communication costs, and avoid network contention. We devel- oped new data collection and aggregation tools to extract static hardware information (e.g., node/core hierarchy, network routing) as well as real-time performance data (e.g., CPU uti- lization, power consumption, memory bandwidth saturation, percentage of used bandwidth, number of network stalls). We created application interfaces that allowed this data to be used easily by algorithms. Finally, we demonstrated the benefit of integrating system and application information for two use cases. The first used real-time power consumption and memory bandwidth saturation data to throttle concurrency to save power without increasing application execution time. The second used static or real-time network traffic information to reduce or avoid network congestion by remapping MPI tasks to allocated processors. Results from our work are summarized in this report; more details are available in our publications [2, 6, 14, 16, 22, 29, 38, 44, 51, 54].

  10. Submitted to IEEE Design and Test of Computers, Special Issue on Embedded Systems for Real-Time Multimedia 1 A Backlight Power Management Framework for

    E-Print Network [OSTI]

    Pedram, Massoud

    -Time Multimedia 1 A Backlight Power Management Framework for Battery-Operated Multimedia Systems Hojun Shim School techniques are based on power management during idle or slack times, and are therefore difficult to apply introduce a backlight power management framework for color TFT LCD panels, as used in battery

  11. A Power-Aware Technique to Manage Real-Time Database Transactions in Mobile Ad-Hoc Networks **

    E-Print Network [OSTI]

    Gruenwald, Le

    1 A Power-Aware Technique to Manage Real-Time Database Transactions in Mobile Ad-Hoc Networks ** Le@ou.edu; smbanik@ou.edu) ** This work is partially supported by the National Science Foundation grant No. EIA connectivity is required. Techniques that manage database transactions in MANET need to address additional

  12. Optimal Risk-aware Power Procurement for Data Centers in Day-Ahead and Real-Time Electricity Markets

    E-Print Network [OSTI]

    Mohsenian-Rad, Hamed

    Optimal Risk-aware Power Procurement for Data Centers in Day-Ahead and Real-Time Electricity Markets Mahdi Ghamkhari, Hamed Mohsenian-Rad, and Adam Wierman Department of Electrical Engineering, University of California, Riverside, CA, USA Department of Computing and Mathematical Sciences, California

  13. 4918 IEEE TRANSACTIONS ON POWER SYSTEMS, VOL. 28, NO. 4, NOVEMBER 2013 Towards Faster Solution of Large

    E-Print Network [OSTI]

    Vuik, Kees

    dictates the integrated management of power systems of continental scale. 2) Smartgrids: ICT technologies clusters (smartgrids), consisting of loads and local Manuscript received June 15, 2012; revised November 06

  14. Observer-based control of a tethered wing wind power system: indoor real-time experiment

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    . A third solution is to use power kites as renewable energy generators [3]. One can cite the "Kite Wind Generator" of Politecnico di Torino [6], [5] and the "Laddermill" of the Delft University of Technology [13

  15. PhotoVoltaic distributed generation for Lanai power grid real-time simulation and control integration scenario.

    SciTech Connect (OSTI)

    Robinett, Rush D., III; Kukolich, Keith (Opal RT Technologies, Montreal, Quebec, Canada); Wilson, David Gerald; Schenkman, Benjamin L.

    2010-06-01T23:59:59.000Z

    This paper discusses the modeling, analysis, and testing in a real-time simulation environment of the Lanai power grid system for the integration and control of PhotoVoltaic (PV) distributed generation. The Lanai Island in Hawaii is part of the Hawaii Clean Energy Initiative (HCEI) to transition to 30% renewable green energy penetration by 2030. In Lanai the primary loads come from two Castle and Cook Resorts, in addition to residential needs. The total peak load profile is 12470 V, 5.5 MW. Currently there are several diesel generators that meet these loading requirements. As part of the HCEI, Lanai has initially installed 1.2 MW of PV generation. The goal of this study has been to evaluate the impact of the PV with respect to the conventional carbon-based diesel generation in real time simulation. For intermittent PV distributed generation, the overall stability and transient responses are investigated. A simple Lanai 'like' model has been developed in the Matlab/Simulink environment (see Fig. 1) and to accommodate real-time simulation of the hybrid power grid system the Opal-RT Technologies RT-Lab environment is used. The diesel generators have been modelled using the SimPowerSystems toolbox swing equations and a custom Simulink module has been developed for the High level PV generation. All of the loads have been characterized primarily as distribution lines with series resistive load banks with one VAR load bank. Three-phase faults are implemented for each bus. Both conventional and advanced control architectures will be used to evaluate the integration of the PV onto the current power grid system. The baseline numerical results include the stable performance of the power grid during varying cloud cover (PV generation ramping up/down) scenarios. The importance of assessing the real-time scenario is included.

  16. Large-Scale Uncertainty and Error Analysis for Time-dependent Fluid/Structure Interactions in Wind Turbine Applications

    SciTech Connect (OSTI)

    Alonso, Juan J. [Stanford University; Iaccarino, Gianluca [Stanford University

    2013-08-25T23:59:59.000Z

    The following is the final report covering the entire period of this aforementioned grant, June 1, 2011 - May 31, 2013 for the portion of the effort corresponding to Stanford University (SU). SU has partnered with Sandia National Laboratories (PI: Mike S. Eldred) and Purdue University (PI: Dongbin Xiu) to complete this research project and this final report includes those contributions made by the members of the team at Stanford. Dr. Eldred is continuing his contributions to this project under a no-cost extension and his contributions to the overall effort will be detailed at a later time (once his effort has concluded) on a separate project submitted by Sandia National Laboratories. At Stanford, the team is made up of Profs. Alonso, Iaccarino, and Duraisamy, post-doctoral researcher Vinod Lakshminarayan, and graduate student Santiago Padron. At Sandia National Laboratories, the team includes Michael Eldred, Matt Barone, John Jakeman, and Stefan Domino, and at Purdue University, we have Prof. Dongbin Xiu as our main collaborator. The overall objective of this project was to develop a novel, comprehensive methodology for uncertainty quantification by combining stochastic expansions (nonintrusive polynomial chaos and stochastic collocation), the adjoint approach, and fusion with experimental data to account for aleatory and epistemic uncertainties from random variable, random field, and model form sources. The expected outcomes of this activity were detailed in the proposal and are repeated here to set the stage for the results that we have generated during the time period of execution of this project: 1. The rigorous determination of an error budget comprising numerical errors in physical space and statistical errors in stochastic space and its use for optimal allocation of resources; 2. A considerable increase in efficiency when performing uncertainty quantification with a large number of uncertain variables in complex non-linear multi-physics problems; 3. A solution to the long-time integration problem of spectral chaos approaches; 4. A rigorous methodology to account for aleatory and epistemic uncertainties, to emphasize the most important variables via dimension reduction and dimension-adaptive refinement, and to support fusion with experimental data using Bayesian inference; 5. The application of novel methodologies to time-dependent reliability studies in wind turbine applications including a number of efforts relating to the uncertainty quantification in vertical-axis wind turbine applications. In this report, we summarize all accomplishments in the project (during the time period specified) focusing on advances in UQ algorithms and deployment efforts to the wind turbine application area. Detailed publications in each of these areas have also been completed and are available from the respective conference proceedings and journals as detailed in a later section.

  17. Analysis and synthesis of the variability of irradiance and PV power time series with the wavelet transform

    SciTech Connect (OSTI)

    Perpinan, O. [Electrical Engineering Department, EUITI-UPM, Ronda de Valencia 3, 28012 Madrid (Spain); Lorenzo, E. [Instituto de Energia Solar, UPM, Ciudad Universitaria s/n, 28040 Madrid (Spain)

    2011-01-15T23:59:59.000Z

    The irradiance fluctuations and the subsequent variability of the power output of a PV system are analysed with some mathematical tools based on the wavelet transform. It can be shown that the irradiance and power time series are nonstationary process whose behaviour resembles that of a long memory process. Besides, the long memory spectral exponent {alpha} is a useful indicator of the fluctuation level of a irradiance time series. On the other side, a time series of global irradiance on the horizontal plane can be simulated by means of the wavestrapping technique on the clearness index and the fluctuation behaviour of this simulated time series correctly resembles the original series. Moreover, a time series of global irradiance on the inclined plane can be simulated with the wavestrapping procedure applied over a signal previously detrended by a partial reconstruction with a wavelet multiresolution analysis, and, once again, the fluctuation behaviour of this simulated time series is correct. This procedure is a suitable tool for the simulation of irradiance incident over a group of distant PV plants. Finally, a wavelet variance analysis and the long memory spectral exponent show that a PV plant behaves as a low-pass filter. (author)

  18. Dartmouth College Computer Science Technical Report TR2010-668 Creating Large Disturbances in the Power Grid

    E-Print Network [OSTI]

    differ from physical attacks. #12;3 Contents 1 IntroductionDartmouth College Computer Science Technical Report TR2010-668 Creating Large Disturbances on how defending against cyber attacks can differ from defending against point failures and physical

  19. Reducing the Peak Power through Real-Time Scheduling Techniques in Cyber-Physical Energy Systems

    E-Print Network [OSTI]

    Lipari, Giuseppe

    districts organized in smart grids [5]. On the other hand, the diffusion of compact, flexible and low], large networks of electric cars [4], and automated energy supply and distribution for town and city

  20. GRB 090926A AND BRIGHT LATE-TIME FERMI LARGE AREA TELESCOPE GAMMA-RAY BURST AFTERGLOWS

    SciTech Connect (OSTI)

    Swenson, C. A.; Roming, P. W. A.; Vetere, L.; Kennea, J. A. [Pennsylvania State University, 525 Davey Lab, University Park, PA 16802 (United States); Maxham, A.; Zhang, B. B.; Zhang, B. [University of Nevada, Las Vegas, Box 454002, 4505 Maryland Parkway, Las Vegas, NV 89154 (United States); Schady, P. [Max-Planck-Institut fuer extraterrestrische Physik, Garching (Germany); Holland, S. T. [Universities Space Research Association, 10227 Wincopin Circle, Suite 500, Columbia, MD 21044 (United States); Kuin, N. P. M.; Oates, S. R.; De Pasquale, M. [The UCL Mullard Space Science Laboratory, Holmbury St Mary, Surrey, RH5 6NT (United Kingdom); Page, K. L., E-mail: cswenson@astro.psu.ed [Department of Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH (United Kingdom)

    2010-07-20T23:59:59.000Z

    GRB 090926A was detected by both the Gamma-ray Burst Monitor and Large Area Telescope (LAT) instruments on board the Fermi Gamma-ray Space Telescope. Swift follow-up observations began {approx}13 hr after the initial trigger. The optical afterglow was detected for nearly 23 days post trigger, placing it in the long-lived category. The afterglow is of particular interest due to its brightness at late times, as well as the presence of optical flares at T0+10{sup 5} s and later, which may indicate late-time central engine activity. The LAT has detected a total of 16 gamma-ray bursts; nine of these bursts, including GRB 090926A, also have been observed by Swift. Of the nine Swift-observed LAT bursts, six were detected by UVOT, with five of the bursts having bright, long-lived optical afterglows. In comparison, Swift has been operating for five years and has detected nearly 500 bursts, but has only seen {approx}30% of bursts with optical afterglows that live longer than 10{sup 5} s. We have calculated the predicted gamma-ray fluence, as would have been seen by the Burst Alert Telescope (BAT) on board Swift, of the LAT bursts to determine whether this high percentage of long-lived optical afterglows is unique, when compared to BAT-triggered bursts. We find that, with the exception of the short burst GRB 090510A, the predicted BAT fluences indicate that the LAT bursts are more energetic than 88% of all Swift bursts and also have brighter than average X-ray and optical afterglows.

  1. High-Speed Real-Time Digital Emulation for Hardware-in-the-Loop Testing of Power Electronics: A New Paradigm in the Field of Electronic Design Automation (EDA) for Power Electronics Systems

    E-Print Network [OSTI]

    Kinsy, Michel A.

    This paper details the design and application of a new ultra-high speed real-time simulation for Hardware-in-the-Loop (HiL) testing and design of high-power power electronics systems. Our real-time hardware emulation for ...

  2. Accepted for publication at IEEE Trans. Power Systems, July 2000, paper No. PE-006PRS (08-2000). Time Dependence of Controls to Avoid Voltage Collapse

    E-Print Network [OSTI]

    Cañizares, Claudio A.

    system model. Keywords: Power system control, voltage stability, voltage collapse, reactive power1 Accepted for publication at IEEE Trans. Power Systems, July 2000, paper No. PE-006PRS (08 is first presented with the help of a simple test system. The time dependence of the control actions

  3. Abstract--The issue of controlled and reliable integration of distributed energy resources into microgrids and large power

    E-Print Network [OSTI]

    Cañizares, Claudio A.

    resources (DER), many of them based on renewable energies, have experimented an unprecedented growth of the renewable energy sources, and its integration into power systems. One of the main technical issues1 Abstract-- The issue of controlled and reliable integration of distributed energy resources

  4. Real-Time Power Balancing in Electric Grids with Distributed Storage

    E-Print Network [OSTI]

    Liang, Ben

    is frequency regulation, which operates every few seconds to maintain the frequency of a power grid at its and the need to reduce greenhouse gas emissions, more and more renewable energy resources, such as wind battery size constraints, cost of using external energy sources, and battery degradation. We develop

  5. Real-Time Power Control of Data Centers for Providing Regulation Service

    E-Print Network [OSTI]

    Caramanis, Michael

    to select optimal RS reserve and average energy consumption levels that allow data centers to both deliver in the the hour-ahead power markets. I. INTRODUCTION The unabating increase in data center energy consumption in data center energy consumption from renewables, and also provide additional reserves to accommodate

  6. Some properties of zero power neutron noise in a time-varying medium with delayed neutrons

    E-Print Network [OSTI]

    Pázsit, Imre

    material parameters was treated with the master equation technique, which is a probability balance equation and discussed. Ã? 2008 Elsevier Ltd. All rights reserved. 1. Introduction In the neutron noise literature power systems constituted a separate case. In such systems the material parameters, and hence also

  7. Analysis of Wind Power and Load Data at Multiple Time Scales

    E-Print Network [OSTI]

    Coughlin, Katie

    2011-01-01T23:59:59.000Z

    29   Appendix A. PJM Windat Multiple Time Scales Appendix A. PJM Wind Data The windpower data for the PJM control area cover the period January

  8. Heavy duty insulator assemblies for 500-kV bulk power transmission line with large diameter octagonalbundled conductor

    SciTech Connect (OSTI)

    Tsujimoto, K.; Hayase, I.; Hirai, J.; Inove, M.; Naito, K.; Yukino, T.

    1982-11-01T23:59:59.000Z

    This paper describes the design procedure and the results of field tests on mechanical performances of insulator assemblies newly developed to support octagonal-bundled conductors for 500-kV bulk power transmission. Taking account of conductor-motion-induced peak tensile load, fatigue, torsional torque and others, a successful design has been achieved in two prototype assemblies for such heavy mechanical duties as encountered during conductor galloping or swing. This has been proved throughout three years of the field tests.

  9. Understanding the impact of large-scale penetration of micro combined heat & power technologies within energy systems/

    E-Print Network [OSTI]

    Tapia-Ahumada, Karen de los Ángeles

    2011-01-01T23:59:59.000Z

    Significant energy challenges today come from security of supply and environmental concerns. Those surpass the quest for economic efficiency that has been the primary objective until recent times. In an intensive fossil-fuel ...

  10. Development of an Optimum Tracer Set for Apportioning Emissions of Individual Power Plants Using Highly Time-Resolved Measurements and Advanced Receptor Modeling

    SciTech Connect (OSTI)

    John Ondov; Gregory Beachley

    2007-07-05T23:59:59.000Z

    In previous studies, 11 elements (Al, As, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Se, and Zn) were determined in 30-minute aerosol samples collected with the University of Maryland Semicontinuous Elements in Aerosol Sampler (SEAS; Kidwell and Ondov, 2001, 2004; SEAS-II) in several locations in which air quality is influenced by emissions from coal- or oil-fired power plants. At this time resolution, plumes from stationary high temperature combustion sources are readily detected as large excursions in ambient concentrations of elements emitted by these sources (Pancras et al. ). Moreover, the time-series data contain intrinsic information on the lateral diffusion of the plume (e.g., {sigma}{sub y}), which Park et al. (2005 and 2006) have exploited in their Pseudo-Deterministic Receptor Model (PDRM), to calculate emission rates of SO{sub 2} and 11 elements (mentioned above) from four individual coal- and oil-fired power plants in the Tampa Bay area. In the current project, we proposed that the resolving power of source apportionment methods might be improved by expanding the set of maker species and that there exist some optimum set of marker species that could be used. The ultimate goal was to determine the utility of using additional elements to better identify and isolate contributions of individual power plants to ambient levels of PM and its constituents. And, having achieved better resolution, achieve, also, better emission rate estimates. In this study, we optimized sample preparation and instrumental protocols for simultaneous analysis of 28 elements in dilute slurry samples collected with the SEAS with a new state-of-the-art Thermo-Systems, Inc., X-series II, Inductively Coupled Plasma Mass Spectroscopy (ICP-MS), and reanalyzed the samples previously collected in Tampa during the modeling period studied by Park et al. (2005) in which emission rates from four coal- and oil-fired power plants affected air quality at the sampling site. In the original model, Park et al. (2005), included 6 sources. Herein, we reassessed the number of contributing sources in light of the new data. A comprehensive list of sources was prepared and both our Gaussian Plume model and PMF were used to identify and predict the relative strengths of source contributions at the receptor sites. Additionally, PDRM was modified to apply National Inventory Emissions, Toxic Release Inventory, and Chemical Mass Balance source profile data to further constrain solutions. Both the original Tampa data set (SO{sub 2} plus 11 elements) and the new expanded data set (SO{sub 2} plus 23 elements) were used to resolve the contributions of particle constituents and PM to sources using Positive Matrix Factorization (PMF) and PDRM.

  11. Maximizing Power Output in Homogeneous Charge Compression Ignition (HCCI) Engines and Enabling Effective Control of Combustion Timing

    E-Print Network [OSTI]

    Saxena, Samveg

    2011-01-01T23:59:59.000Z

    HCCI Engine for Power Generation, ASME IC Engine Conference,Engines for Power Generation , ASME IC Engine Conference,Engine for Power Generation”, ASME IC Engine Conference,

  12. Large-Scale Offshore Wind Power in the United States: Assessment of Opportunities and Barriers, NREL (National Renewable Energy Laboratory)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn12electron 9 5 - -/e),,sand CERNLandLargefor High Offshore

  13. Statistical static timing analysis considering the impact of power supply noise in VLSI circuits

    E-Print Network [OSTI]

    Kim, Hyun Sung

    2009-06-02T23:59:59.000Z

    less random than between the gates within a module. 32 REFERENCES [1] Y. M. Jiang and K. T. Cheng, ?Analysis of Performance Impact Caused by Power Supply Noise in Deep Submicron Devices,? ACM/IEEE Design Automation Conf., New... Orleans, LA, June 1999, pp. 760-765. [2] S. Pant, D. Blaauw, V. Zolotov, S. Sundareswaran and R. Panda, ?Vectorless Analysis of Supply Noise Induced Delay Variation,? IEEE/ACM Int?l Conf. Computer Aided Design, San Jose, CA, Nov. 2003, pp. 184-191. [3...

  14. Statistical static timing analysis considering the impact of power supply noise in VLSI circuits 

    E-Print Network [OSTI]

    Kim, Hyun Sung

    2009-06-02T23:59:59.000Z

    less random than between the gates within a module. 32 REFERENCES [1] Y. M. Jiang and K. T. Cheng, ?Analysis of Performance Impact Caused by Power Supply Noise in Deep Submicron Devices,? ACM/IEEE Design Automation Conf., New... Orleans, LA, June 1999, pp. 760-765. [2] S. Pant, D. Blaauw, V. Zolotov, S. Sundareswaran and R. Panda, ?Vectorless Analysis of Supply Noise Induced Delay Variation,? IEEE/ACM Int?l Conf. Computer Aided Design, San Jose, CA, Nov. 2003, pp. 184-191. [3...

  15. Real-time dynamic simulator for the Topaz II reactor power system

    SciTech Connect (OSTI)

    Kwok, K.S.

    1994-10-01T23:59:59.000Z

    A dynamic simulator of the TOPAZ II reactor system has been developed for the Nuclear Electric Propulsion Space Test Program. The simulator is a self-contained IBM-PC compatible based system that executes at a speed faster than real-time. The simulator combines first-principle modeling and empirical correlations in its algorithm to attain the modeling accuracy and computational through-put that are required for real-time execution. The overall execution time of the simulator for each time step is 15 ms when no data is written to the disk, and 18 ms when nine double precision data points are written to the disk once in every time step. The simulation program has been tested and it is able to handle a step decrease of $8 worth of reactivity. It also provides simulation of fuel, emitter, collector, stainless steel, and ZrH moderator failures. Presented in this paper are the models used in the calculations, a sample simulation session, and a discussion of the performance and limitations of the simulator. The simulator has been found to provide realistic real-time dynamic response of the TOPAZ II reactor system under both normal and causality conditions.

  16. Time Variations of the Superkamiokande Solar Neutrino Flux Data by Rayleigh Power Spectrum Analysis

    E-Print Network [OSTI]

    Koushik Ghosh; Probhas Raychaudhuri

    2006-06-05T23:59:59.000Z

    We have used the Rayleigh Power Spectrum Analysis of the solar neutrino flux data from 1) 5-day-long samples from Super-Kamiokande-I detector during the period from June, 1996 to July, 2001; 2) 10 -day-long samples from the same detector during the same period and (3) 45-day long from the same detector during the same period. According to our analysis (1) gives periodicities around 0.25, 23.33, 33.75 and 42.75 months; (2) exhibits periodicities around 0.5, 1.0, 28.17, 40.67 and 52.5 months and (3) shows periodicities around 16.5 and 28.5 months. We have found almost similar periods in the solar flares, sunspot data, solar proton data.

  17. Dynamic reliability using entry-time approach for maintenance of nuclear power plants

    E-Print Network [OSTI]

    Wang, Shuwen

    2009-05-15T23:59:59.000Z

    V APPLICATION OF ENTRY-TIME MODEL TO NPP APPLICATIONS .......................................................................................116 5.1 Introduction to the Main Generator System...................................... 117 vii... of methods such as Probabilistic Risk Assessment (PRA), Markov models (cf. [1]), simulation [13] and other methods for risk assessment of dynamic systems [14] have been used to evaluate SSC (System, Structure and Component) reliability in NPP (Nuclear...

  18. Interaction-powered supernovae: rise-time versus peak-luminosity correlation and the shock-breakout velocity

    SciTech Connect (OSTI)

    Ofek, Eran O.; Arcavi, Iair; Tal, David; Gal-Yam, Avishay; Ben-Ami, Sagi; De Cia, Annalisa; Yaron, Ofer [Benoziyo Center for Astrophysics, Weizmann Institute of Science, 76100 Rehovot (Israel); Sullivan, Mark [School of Physics and Astronomy, University of Southampton, Southampton SO17 1BJ (United Kingdom); Kulkarni, Shrinivas R.; Cao, Yi [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States); Nugent, Peter E. [Computational Cosmology Center, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Bersier, David [Astrophysics Research Institute, Liverpool John Moores University, Liverpool L3 5RF (United Kingdom); Cenko, S. Bradley [Astrophysics Science Division, NASA Goddard Space Flight Center, Mail Code 661, Greenbelt, MD 20771 (United States); Filippenko, Alexei V. [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Fransson, Claes [Department of Astronomy, The Oskar Klein Centre, Stockholm University, AlbaNova University Centre, SE-106 91 Stockholm (Sweden); Kasliwal, Mansi M. [Observatories of the Carnegie Institution for Science, 813 Santa Barbara St, Pasadena, CA 91101 (United States); Laher, Russ; Surace, Jason [Spitzer Science Center, MS 314-6, California Institute of Technology, Pasadena, CA 91125 (United States); Quimby, Robert [Kavli IPMU (WPI), The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba 277-8583 (Japan)

    2014-06-20T23:59:59.000Z

    Interaction of supernova (SN) ejecta with the optically thick circumstellar medium (CSM) of a progenitor star can result in a bright, long-lived shock-breakout event. Candidates for such SNe include Type IIn and superluminous SNe. If some of these SNe are powered by interaction, then there should be a specific relation between their peak luminosity, bolometric light-curve rise time, and shock-breakout velocity. Given that the shock velocity during shock breakout is not measured, we expect a correlation, with a significant spread, between the rise time and the peak luminosity of these SNe. Here, we present a sample of 15 SNe IIn for which we have good constraints on their rise time and peak luminosity from observations obtained using the Palomar Transient Factory. We report on a possible correlation between the R-band rise time and peak luminosity of these SNe, with a false-alarm probability of 3%. Assuming that these SNe are powered by interaction, combining these observables and theory allows us to deduce lower limits on the shock-breakout velocity. The lower limits on the shock velocity we find are consistent with what is expected for SNe (i.e., ?10{sup 4} km s{sup –1}). This supports the suggestion that the early-time light curves of SNe IIn are caused by shock breakout in a dense CSM. We note that such a correlation can arise from other physical mechanisms. Performing such a test on other classes of SNe (e.g., superluminous SNe) can be used to rule out the interaction model for a class of events.

  19. CERN-PS Main Power Converter Renovation How to Provide and Control the Large Flow of Energy for a Rapid Cyclic Machine?

    E-Print Network [OSTI]

    Bordry, Frederick; Völker, F V

    2005-01-01T23:59:59.000Z

    The PS accelerator (Proton-Synchrotron) at CERN, which is part of the LHC injector chain, is composed of one hundred magnets connected in series. During a typical acceleration cycle (taking 2.4 seconds), the active power at the magnet terminals varies from plus to minus 40 MW. As this large active power variation was not acceptable to the electrical network, a motor-generator set (M-G) was inserted between the grid and the load. The M-G set (of 1968) acts as a fly-wheel with a stored kinetic energy of 233 MJ and the magnets are fed via two 12-pulse thyristor rectifiers. A renovation or replacement of the installation is planned in the near future as part of the consolidation of the LHC injectors to avoid any major breakdown, to improve overall availability and to reduce operation and maintenance costs. This paper presents a first comparison of technical solutions available to build such a power system and the strategy that will be applied for the up-grade of the system.

  20. A finite-difference time-domain simulation of high power microwave generated plasma at atmospheric pressures

    SciTech Connect (OSTI)

    Ford, Patrick J.; Beeson, Sterling R.; Krompholz, Hermann G.; Neuber, Andreas A. [Department of Electrical and Computer Engineering, Center for Pulsed Power and Power Electronics, Texas Tech University, Lubbock, Texas 79409-3102 (United States)

    2012-07-15T23:59:59.000Z

    A finite-difference algorithm was developed to calculate several RF breakdown parameters, for example, the formative delay time that is observed between the initial application of a RF field to a dielectric surface and the formation of field-induced plasma interrupting the RF power flow. The analysis is focused on the surface being exposed to a background gas pressure above 50 Torr. The finite-difference algorithm provides numerical solutions to partial differential equations with high resolution in the time domain, making it suitable for simulating the time evolving interaction of microwaves with plasma; in lieu of direct particle tracking, a macroscopic electron density is used to model growth and transport. This approach is presented as an alternative to particle-in-cell methods due to its low complexity and runtime leading to more efficient analysis for a simulation of a microsecond scale pulse. The effect and development of the plasma is modeled in the simulation using scaling laws for ionization rates, momentum transfer collision rates, and diffusion coefficients, as a function of electric field, gas type and pressure. The incorporation of plasma material into the simulation involves using the Z-transform to derive a time-domain algorithm from the complex frequency-dependent permittivity of plasma. Therefore, the effect of the developing plasma on the instantaneous microwave field is calculated. Simulation results are compared with power measurements using an apparatus designed to facilitate surface flashover across a polycarbonate boundary in a controlled N{sub 2}, air, or argon environment at pressures exceeding 50 Torr.

  1. INITIAL ANALYSIS OF TRANSIENT POWER TIME LAG DUE TO HETEROGENEITY WITHIN THE TREAT FUEL MATRIX.

    SciTech Connect (OSTI)

    D.M. Wachs; A.X. Zabriskie, W.R. Marcum

    2014-06-01T23:59:59.000Z

    The topic Nuclear Safety encompasses a broad spectrum of focal areas within the nuclear industry; one specific aspect centers on the performance and integrity of nuclear fuel during a reactivity insertion accident (RIA). This specific accident has proven to be fundamentally difficult to theoretically characterize due to the numerous empirically driven characteristics that quantify the fuel and reactor performance. The Transient Reactor Test (TREAT) facility was designed and operated to better understand fuel behavior under extreme (i.e. accident) conditions; it was shutdown in 1994. Recently, efforts have been underway to commission the TREAT facility to continue testing of advanced accident tolerant fuels (i.e. recently developed fuel concepts). To aid in the restart effort, new simulation tools are being used to investigate the behavior of nuclear fuels during facility’s transient events. This study focuses specifically on the characterizing modeled effects of fuel particles within the fuel matrix of the TREAT. The objective of this study was to (1) identify the impact of modeled heterogeneity within the fuel matrix during a transient event, and (2) demonstrate acceptable modeling processes for the purpose of TREAT safety analyses, specific to fuel matrix and particle size. Hypothetically, a fuel that is dominantly heterogeneous will demonstrate a clearly different temporal heating response to that of a modeled homogeneous fuel. This time difference is a result of the uniqueness of the thermal diffusivity within the fuel particle and fuel matrix. Using MOOSE/BISON to simulate the temperature time-lag effect of fuel particle diameter during a transient event, a comparison of the average graphite moderator temperature surrounding a spherical particle of fuel was made for both types of fuel simulations. This comparison showed that at a given time and with a specific fuel particle diameter, the fuel particle (heterogeneous) simulation and the homogeneous simulation were related by a multiplier relative to the average moderator temperature. As time increases the multiplier is comparable to the factor found in a previous analytical study from literature. The implementation of this multiplier and the method of analysis may be employed to remove assumptions and increase fidelity for future research on the effect of fuel particles during transient events.

  2. Insights into the Charge Carrier Terahertz Mobility in Polyfluorenes from Large-Scale Atomistic Simulations and Time-Resolved Terahertz

    E-Print Network [OSTI]

    Ku?el, Petr

    , University of Belgrade, Pregrevica 118, 11080 Belgrade, Serbia Division of Chemical Physics, Lund University frequencies is thermally activated but with a much smaller activation energy compared to the dc case, the dc transport is thermally activated with activation energies which can be as large as 350 me

  3. 100 IEEE TRANSACTIONS ON VERY LARGE SCALE INTEGRATION SYSTEMS, VOL. XX, NO. Y, MONTH 2004 A Framework for Energy and Transient Power

    E-Print Network [OSTI]

    Mohanty, Saraju P.

    A Framework for Energy and Transient Power Reduction during Behavioral Synthesis Saraju P. Mohanty, Student applications, the mini- mization of energy, average power, peak power, and peak power differential are equally reduction of the energy and transient power during behavioral synthesis. A new metric called "Cycle Power

  4. Time Domain Characterizationof PowerAmplifiers with Memory Effects P. Draxler*, I. Langmore, T.P. Hung, and P.M. Asbeck

    E-Print Network [OSTI]

    Asbeck, Peter M.

    are characterized via time domain measurements, with waveforms including steps, triangular waveforms and CDMA response associated with the memory effects. I. ~NTRODUCTION Requirements for extended battery life been driving the need for improved power amplifier perfonnance. Accurate amplifier characterization

  5. VLA, Very Large Array AreciboArecibo TelescopeTelescope...... in Puerto Rico

    E-Print Network [OSTI]

    Briggs, Frank H.

    " .... time series Fourier transform Frequency Time V(t) #12;...want "Noise Power" ... from voltage time series => V(t)2 Fourier transform Frequency Time V(t) then average power samples "integration" #12Parkes "The Dish" #12;19' M83 #12;Parkes "The Dish" #12;VLA, Very Large Array New Mexico #12

  6. Improving the AGR Fuel Testing Power Density Profile Versus Irradiation-Time in the Advanced Test Reactor

    SciTech Connect (OSTI)

    Gray S. Chang; David A. Petti; John T. Maki; Misti A. Lillo

    2009-05-01T23:59:59.000Z

    The Very High Temperature gas-cooled Reactor (VHTR), which is currently being developed, achieves simplification of safety through reliance on ceramic-coated fuel particles. Each TRISO-coated fuel particle has its own containment which serves as the principal barrier against radionuclide release under normal operating and accident conditions. These fuel particles, in the form of graphite fuel compacts, are currently undergoing a series of irradiation tests in the Advanced Test Reactor (ATR) at the Idaho National Laboratory (INL) to support the Advanced Gas-Cooled Reactor (AGR) fuel qualification program. A representive coated fuel particle with an 235U enrichment of 19.8 wt% was used in this analysis. The fuel burnup analysis tool used to perform the neutronics study reported herein, couples the Monte Carlo transport code MCNP, with the radioactive decay and burnup code ORIGEN2. The fuel burnup methodology known as Monte-Carlo with ORIGEN2 (MCWO) was used to evaluate the AGR experiment assembly and demonstrate compliance with ATR safety requirements. For the AGR graphite fuel compacts, the MCWO-calculated fission power density (FPD) due to neutron fission in 235U is an important design parameter. One of the more important AGR fuel testing requirements is to maintain the peak fuel compact temperature close to 1250°C throughout the proposed irradiation campaign of 550 effective full power days (EFPDs). Based on the MCWO-calculated FPD, a fixed gas gap size was designed to allow regulation of the fuel compact temperatures throughout the entire fuel irradiation campaign by filling the gap with a mixture of helium and neon gases. The chosen fixed gas gap can only regulate the peak fuel compact temperature in the desired range during the irradiation test if the ratio of the peak power density to the time-dependent low power density (P/T) at 550 EFPDs is less than 2.5. However, given the near constant neutron flux within the ATR driver core and the depletion of 235U in the graphite fuel compacts versus EFPD, the P/T ratio was calculated to be 5.3, which is unacceptable given the fuel compact temperature control requirement. To flatten the FPD profile versus EFPDs, two proposed options are – (a) add fertile (232Th) particles to the fuel compact and (b) add burnable absorber (B4C) to the graphite holder. The effectiveness of these two proposed options to flatten the FPD profile versus EFPDs were investigated and the results are compared in this study.

  7. POWER GRID RELIABILITY AND SECURITY

    SciTech Connect (OSTI)

    Bose, Anjan; Venkatasubramanian, Vaithianathan; Hauser, Carl; Bakken, David; Anderson, David; Zhao, Chuanlin; Liu, Dong; Yang, Tao; Meng, Ming; Zhang, Lin; Ning, Jiawei; Tashman, Zaid

    2014-09-30T23:59:59.000Z

    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.

  8. The Association of Large-Scale Climate Variability and Teleconnections on Wind Energy Resource over Europe and its Intermittency

    E-Print Network [OSTI]

    Kriesche, Pascal

    In times of increasing importance of wind power in the world’s energy mix, this study focuses on a better understanding of the influences of large-scale climate variability on wind power resource over Europe. The impact ...

  9. Cone-Beam Computed Tomography–Guided Positioning of Laryngeal Cancer Patients with Large Interfraction Time Trends in Setup and Nonrigid Anatomy Variations

    SciTech Connect (OSTI)

    Gangsaas, Anne, E-mail: a.gangsaas@erasmusmc.nl; Astreinidou, Eleftheria; Quint, Sandra; Levendag, Peter C.; Heijmen, Ben

    2013-10-01T23:59:59.000Z

    Purpose: To investigate interfraction setup variations of the primary tumor, elective nodes, and vertebrae in laryngeal cancer patients and to validate protocols for cone beam computed tomography (CBCT)-guided correction. Methods and Materials: For 30 patients, CBCT-measured displacements in fractionated treatments were used to investigate population setup errors and to simulate residual setup errors for the no action level (NAL) offline protocol, the extended NAL (eNAL) protocol, and daily CBCT acquisition with online analysis and repositioning. Results: Without corrections, 12 of 26 patients treated with radical radiation therapy would have experienced a gradual change (time trend) in primary tumor setup ?4 mm in the craniocaudal (CC) direction during the fractionated treatment (11/12 in caudal direction, maximum 11 mm). Due to these trends, correction of primary tumor displacements with NAL resulted in large residual CC errors (required margin 6.7 mm). With the weekly correction vector adjustments in eNAL, the trends could be largely compensated (CC margin 3.5 mm). Correlation between movements of the primary and nodal clinical target volumes (CTVs) in the CC direction was poor (r{sup 2}=0.15). Therefore, even with online setup corrections of the primary CTV, the required CC margin for the nodal CTV was as large as 6.8 mm. Also for the vertebrae, large time trends were observed for some patients. Because of poor CC correlation (r{sup 2}=0.19) between displacements of the primary CTV and the vertebrae, even with daily online repositioning of the vertebrae, the required CC margin around the primary CTV was 6.9 mm. Conclusions: Laryngeal cancer patients showed substantial interfraction setup variations, including large time trends, and poor CC correlation between primary tumor displacements and motion of the nodes and vertebrae (internal tumor motion). These trends and nonrigid anatomy variations have to be considered in the choice of setup verification protocol and planning target volume margins. eNAL could largely compensate time trends with minor prolongation of fraction time.

  10. A radiographic analysis of the effect of dietary fiber on transit time through the rat large intestine

    E-Print Network [OSTI]

    Meacher, Mary Melanie

    1986-01-01T23:59:59.000Z

    excretion of the first radiopaque pellet. Prior to radiography, each animal was intubated with a radiopaque substance that traversed with the gastrointestinal contents. Results showed transit times, between designated markers, differed from each dietary.... RESULTS. . . . 19 . 19 . . . 25 . . . 25 . 26 . 28 . . . 28 . 29 . 31 Effect of dietary fiber on food and energy intake. . . Effect of dietary fiber on body weights. . . . . . . . . . . . . Effect of dietary fiber on weight gain from first...

  11. Local Recurrence in Women With Stage I Breast Cancer: Declining Rates Over Time in a Large, Population-Based Cohort

    SciTech Connect (OSTI)

    Canavan, Joycelin, E-mail: canavanjoycelin@gmail.com [Radiation Therapy Program and Breast Cancer Outcomes Unit, British Columbia Cancer Agency, Vancouver Island Centre, University of British Columbia, Victoria, British Columbia (Canada); Truong, Pauline T.; Smith, Sally L. [Radiation Therapy Program and Breast Cancer Outcomes Unit, British Columbia Cancer Agency, Vancouver Island Centre, University of British Columbia, Victoria, British Columbia (Canada); Lu, Linghong; Lesperance, Mary [Department of Mathematics and Statistics, University of Victoria, British Columbia (Canada); Olivotto, Ivo A. [Department of Radiation Oncology, Tom Baker Cancer Centre, University of Calgary (Canada)

    2014-01-01T23:59:59.000Z

    Purpose: To evaluate whether local recurrence (LR) risk has changed over time among women with stage I breast cancer treated with breast-conserving therapy. Methods and Materials: Subjects were 5974 women aged ?50 years diagnosis with pT1N0 breast cancer from 1989 to 2006, treated with breast-conserving surgery and radiation therapy. Clinicopathologic characteristics, treatment, and LR outcomes were compared among 4 cohorts stratified by year of diagnosis: 1989 to 1993 (n=1077), 1994 to 1998 (n=1633), 1999 to 2002 (n=1622), and 2003 to 2006 (n=1642). Multivariable analysis was performed, with year of diagnosis as a continuous variable. Results: Median follow-up time was 8.6 years. Among patients diagnosed in 1989 to 1993, 1994 to 1998, 1999 to 2002, and 2003 to 2006, the proportions of grade 1 tumors increased (16% vs 29% vs 40% vs 39%, respectively, P<.001). Surgical margin clearance rates increased from 82% to 93% to 95% and 88%, respectively (P<.001). Over time, the proportions of unknown estrogen receptor (ER) status decreased (29% vs 10% vs 1.2% vs 0.5%, respectively, P<.001), whereas ER-positive tumors increased (56% vs 77% vs 86% vs 86%, respectively, P<.001). Hormone therapy use increased (23% vs 23% vs 62% vs 73%, respectively, P<.001), and chemotherapy use increased (2% vs 5% vs 10% vs 13%, respectively, P<.001). The 5-year cumulative incidence rates of LR over the 4 time periods were 2.8% vs 1.7% vs 0.9% vs 0.8%, respectively (Gray's test, P<.001). On competing risk multivariable analysis, year of diagnosis was significantly associated with decreased LR (hazard ratio, 0.92 per year, P=.0003). Relative to grade 1 histology, grades 2, 3, and unknown were associated with increased LR. Hormone therapy use was associated with reduced LR. Conclusion: Significant changes in the multimodality management of stage I breast cancer have occurred over the past 2 decades. More favorable-risk tumors were diagnosed, and margin clearance and systemic therapy use increased. These changes contributed to the observed declining LR rates among patients treated with breast-conserving therapy.

  12. Maximizing Power Output in Homogeneous Charge Compression Ignition (HCCI) Engines and Enabling Effective Control of Combustion Timing

    E-Print Network [OSTI]

    Saxena, Samveg

    2011-01-01T23:59:59.000Z

    and Yang, Y. , “Boosted HCCI for High Power Output withoutand emissions in a HCCI engine for power generation”, Energythe synergy with a gasoline HCCI engine”, SAE Paper 2011-01-

  13. Power gating is usually driven by a predictive control, and frequent mispredictions can counter-productively lead to a large increase in

    E-Print Network [OSTI]

    Sorin, Daniel J.

    frames it can consume 70% more energy than a system without power gating. When adding a feature of the most promising mechanisms for reducing leakage energy is power gating, whereby leakage energy is saved is power gated off, some energy is needed for turning the component off and then on again. If the power

  14. IEEE TRANSACTIONS ON POWER SYSTEMS, VOL. 8, NO. 1, FEBRUARY 1993, PP. 1 8. POINT OF COLLAPSE AND CONTINUATION METHODS FOR LARGE

    E-Print Network [OSTI]

    Cañizares, Claudio A.

    HVDC transmission, area interchange power control, regulating transformers, and voltage and reactive

  15. NIHAO project I: Reproducing the inefficiency of galaxy formation across cosmic time with a large sample of cosmological hydrodynamical simulations

    E-Print Network [OSTI]

    Wang, Liang; Stinson, Gregory S; Macciò, Andrea V; Penzo, Camilla; Kang, Xi; Keller, Ben W; Wadsley, James

    2015-01-01T23:59:59.000Z

    We introduce project NIHAO (Numerical Investigation of a Hundred Astrophysical Objects), a set of 100 cosmological zoom-in hydrodynamical simulations performed using the GASOLINE code, with an improved implementation of the SPH algorithm. The haloes in our study range from dwarf to Milky Way masses, and represent an unbiased sampling of merger histories, concentrations and spin parameters. The particle masses and force softenings are chosen to resolve the mass profile to below 1% of the virial radius at all masses, ensuring that galaxy half-light radii are well resolved. Using the same treatment of star formation and stellar feedback for every object, the simulated galaxies reproduce the observed inefficiency of galaxy formation across cosmic time as expressed through the stellar mass vs halo mass relation, and the star formation rate vs stellar mass relation. We thus conclude that stellar feedback is the chief piece of physics required to limit the efficiency of star formation in galaxies less massive than t...

  16. A New Approach for Line Recognition in Large-size Images Using Hough Transform

    E-Print Network [OSTI]

    Lyu, Michael R.

    is very time- efficient for large-size images. 1. Introduction Hough Transform (HT) is a powerful toolA New Approach for Line Recognition in Large-size Images Using Hough Transform Jiqiang Song, Min Transform (HT) has been limited to small-size images for a long time. For large-size images, the peak

  17. A Two-Stage Kalman Filter Approach for Robust and Real-Time Power System State Estimation

    SciTech Connect (OSTI)

    Zhang, Jinghe; Welch, Greg; Bishop, Gary; Huang, Zhenyu

    2014-04-01T23:59:59.000Z

    As electricity demand continues to grow and renewable energy increases its penetration in the power grid, realtime state estimation becomes essential for system monitoring and control. Recent development in phasor technology makes it possible with high-speed time-synchronized data provided by Phasor Measurement Units (PMU). In this paper we present a two-stage Kalman filter approach to estimate the static state of voltage magnitudes and phase angles, as well as the dynamic state of generator rotor angles and speeds. Kalman filters achieve optimal performance only when the system noise characteristics have known statistical properties (zero-mean, Gaussian, and spectrally white). However in practice the process and measurement noise models are usually difficult to obtain. Thus we have developed the Adaptive Kalman Filter with Inflatable Noise Variances (AKF with InNoVa), an algorithm that can efficiently identify and reduce the impact of incorrect system modeling and/or erroneous measurements. In stage one, we estimate the static state from raw PMU measurements using the AKF with InNoVa; then in stage two, the estimated static state is fed into an extended Kalman filter to estimate the dynamic state. Simulations demonstrate its robustness to sudden changes of system dynamics and erroneous measurements.

  18. Time evolution of the luminosity of colliding heavy-ion beams in BNL Relativistic Heavy Ion Collider and CERN Large Hadron Collider

    E-Print Network [OSTI]

    Bruce, R; Fischer, W; Jowett, J M

    2010-01-01T23:59:59.000Z

    We have studied the time evolution of the heavy ion luminosity and bunch intensities in the Relativistic Heavy Ion Collider (RHIC), at BNL, and in the Large Hadron Collider (LHC), at CERN. First, we present measurements from a large number of RHIC stores (from Run 7), colliding 100 GeV/nucleon 197Au79+ beams without stochastic cooling. These are compared with two different calculation methods. The first is a simulation based on multi-particle tracking taking into account collisions, intrabeam scattering, radiation damping, and synchrotron and betatron motion. In the second, faster, method, a system of ordinary differential equations with terms describing the corresponding effects on emittances and bunch populations is solved numerically. Results of the tracking method agree very well with the RHIC data. With the faster method, significant discrepancies are found since the losses of particles diffusing out of the RF bucket due to intrabeam scattering are not modeled accurately enough. Finally, we use both meth...

  19. Time-resolved electron thermal conduction by probing of plasma formation in transparent solids with high power subpicosecond laser pulses

    SciTech Connect (OSTI)

    Vu, B.T.V.

    1994-02-01T23:59:59.000Z

    This dissertation work includes a series of experimental measurements in a search for better understanding of high temperature (10{sup 4}-10{sup 6}K) and high density plasmas (10{sup 22}-10{sup 24}cm{sup {minus}3}) produced by irradiating a transparent solid target with high intensity (10{sup 13} - 10{sup 15}W/cm{sup 2}) and subpicosecond (10{sup {minus}12}-10{sup {minus}13}s) laser pulses. Experimentally, pump and probe schemes with both frontside (vacuum-plasma side) and backside (plasma-bulk material side) probes are used to excite and interrogate or probe the plasma evolution, thereby providing useful insights into the plasma formation mechanisms. A series of different experiments has been carried out so as to characterize plasma parameters and the importance of various nonlinear processes. Experimental evidence shows that electron thermal conduction is supersonic in a time scale of the first picosecond after laser irradiation, so fast that it was often left unresolved in the past. The experimental results from frontside probing demonstrate that upon irradiation with a strong (pump) laser pulse, a thin high temperature ({approximately}40eV) super-critical density ({approximately}10{sup 23}/cm{sup 3}) plasma layer is quickly formed at the target surface which in turn becomes strongly reflective and prevents further transmission of the remainder of the laser pulse. In the bulk region behind the surface, it is also found that a large sub-critical ({approximately}10{sup 18}/cm{sup 3}) plasma is produced by inverse Bremsstrahlung absorption and collisional ionization. The bulk underdense plasma is evidenced by large absorption of the backside probe light. A simple and analytical model, modified from the avalanche model, for plasma evolution in transparent materials is proposed to explain the experimental results. Elimination of the bulk plasma is then experimentally illustrated by using targets overcoated with highly absorptive films.

  20. Statistical searches for microlensing events in large, non-uniformly sampled time-domain surveys: A test using palomar transient factory data

    SciTech Connect (OSTI)

    Price-Whelan, Adrian M.; Agüeros, Marcel A. [Department of Astronomy, Columbia University, 550 W 120th Street, New York, NY 10027 (United States); Fournier, Amanda P. [Department of Physics, Broida Hall, University of California, Santa Barbara, CA 93106 (United States); Street, Rachel [Las Cumbres Observatory Global Telescope Network, Inc., 6740 Cortona Drive, Suite 102, Santa Barbara, CA 93117 (United States); Ofek, Eran O. [Benoziyo Center for Astrophysics, Weizmann Institute of Science, 76100 Rehovot (Israel); Covey, Kevin R. [Lowell Observatory, 1400 West Mars Hill Road, Flagstaff, AZ 86001 (United States); Levitan, David; Sesar, Branimir [Division of Physics, Mathematics, and Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States); Laher, Russ R.; Surace, Jason, E-mail: adrn@astro.columbia.edu [Spitzer Science Center, California Institute of Technology, Mail Stop 314-6, Pasadena, CA 91125 (United States)

    2014-01-20T23:59:59.000Z

    Many photometric time-domain surveys are driven by specific goals, such as searches for supernovae or transiting exoplanets, which set the cadence with which fields are re-imaged. In the case of the Palomar Transient Factory (PTF), several sub-surveys are conducted in parallel, leading to non-uniform sampling over its ?20,000 deg{sup 2} footprint. While the median 7.26 deg{sup 2} PTF field has been imaged ?40 times in the R band, ?2300 deg{sup 2} have been observed >100 times. We use PTF data to study the trade off between searching for microlensing events in a survey whose footprint is much larger than that of typical microlensing searches, but with far-from-optimal time sampling. To examine the probability that microlensing events can be recovered in these data, we test statistics used on uniformly sampled data to identify variables and transients. We find that the von Neumann ratio performs best for identifying simulated microlensing events in our data. We develop a selection method using this statistic and apply it to data from fields with >10 R-band observations, 1.1 × 10{sup 9} light curves, uncovering three candidate microlensing events. We lack simultaneous, multi-color photometry to confirm these as microlensing events. However, their number is consistent with predictions for the event rate in the PTF footprint over the survey's three years of operations, as estimated from near-field microlensing models. This work can help constrain all-sky event rate predictions and tests microlensing signal recovery in large data sets, which will be useful to future time-domain surveys, such as that planned with the Large Synoptic Survey Telescope.

  1. Low-rank approximations for large stationary covariance matrices, as used in the Bayesian and generalized-least-squares analysis of pulsar-timing data

    E-Print Network [OSTI]

    Rutger van Haasteren; Michele Vallisneri

    2014-07-24T23:59:59.000Z

    Many data-analysis problems involve large dense matrices that describe the covariance of stationary noise processes; the computational cost of inverting these matrices, or equivalently of solving linear systems that contain them, is often a practical limit for the analysis. We describe two general, practical, and accurate methods to approximate stationary covariance matrices as low-rank matrix products featuring carefully chosen spectral components. These methods can be used to greatly accelerate data-analysis methods in many contexts, such as the Bayesian and generalized-least-squares analysis of pulsar-timing residuals.

  2. Maximizing Power Output in Homogeneous Charge Compression Ignition (HCCI) Engines and Enabling Effective Control of Combustion Timing

    E-Print Network [OSTI]

    Saxena, Samveg

    2011-01-01T23:59:59.000Z

    Experimental study of biogas combustion characteristics andthe operation range of a biogas HCCI engine for powerOperating Conditions in a Biogas Fueled HCCI Engine for

  3. Maximizing Power Output in Homogeneous Charge Compression Ignition (HCCI) Engines and Enabling Effective Control of Combustion Timing

    E-Print Network [OSTI]

    Saxena, Samveg

    2011-01-01T23:59:59.000Z

    Ford Motor Company, “Diesel Engine Aftertreatment: How FordNational Laboratory, “Engine Combustion Network”, http://High Power Output without Engine Knock and with Ultra-Low

  4. IEEE TRANSACTIONS ON VERY LARGE SCALE INTEGRATION (VLSI) SYSTEMS, VOL. 6, NO. 4, DECEMBER 1998 707 Algorithm-Based Low-Power Transform Coding

    E-Print Network [OSTI]

    Hung, Shih-Hao

    Algorithm-Based Low-Power Transform Coding Architectures: The Multirate Approach An-Yeu Wu, Member, IEEE to design low-power transform coding architectures, in which the transform coefficients are computed through at the architectural level. We start with the design of low- power multirate discrete cosine transform (DCT

  5. Time evolution of the luminosity of colliding heavy-ion beams in BNL Relativistic Heavy Ion Collider and CERN Large Hadron Collider

    E-Print Network [OSTI]

    R. Bruce; M. Blaskiewicz; W. Fischer; J. M. Jowett

    2010-09-08T23:59:59.000Z

    We have studied the time evolution of the heavy ion luminosity and bunch intensities in the Relativistic Heavy Ion Collider (RHIC), at BNL, and in the Large Hadron Collider (LHC), at CERN. First, we present measurements from a large number of RHIC stores (from Run 7), colliding 100 GeV/nucleon Au beams without stochastic cooling. These are compared with two different calculation methods. The first is a simulation based on multi-particle tracking taking into account collisions, intrabeam scattering, radiation damping, and synchrotron and betatron motion. In the second, faster, method, a system of ordinary differential equations with terms describing the corresponding effects on emittances and bunch populations is solved numerically. Results of the tracking method agree very well with the RHIC data. With the faster method, significant discrepancies are found since the losses of particles diffusing out of the RF bucket due to intrabeam scattering are not modeled accurately enough. Finally, we use both methods to make predictions of the time evolution of the future Pb beams in the LHC at injection and collision energy. For this machine, the two methods agree well.

  6. NREL is a national laboratory of the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, operated by the Alliance for Sustainable Energy, LLC. Variability of Power from Large

    E-Print Network [OSTI]

    and Renewable Energy, operated by the Alliance for Sustainable Energy, LLC. Variability of Power from Large Scale Solar Photovoltaic Scenarios in the State of Gujarat Renewable Energy World India Brian ParsonsNREL is a national laboratory of the U.S. Department of Energy, Office of Energy Efficiency

  7. Wind Power Integration via Aggregator-Consumer Coordination: A Game Theoretic Approach

    E-Print Network [OSTI]

    Mohsenian-Rad, Hamed

    the balance between load and generation in the power grid at all times [2]. Moreover, wind generation is nonWind Power Integration via Aggregator-Consumer Coordination: A Game Theoretic Approach Chenye Wu@ie.cuhk.edu.hk Abstract--Due to the stochastic nature of wind power, its large-scale integration into the power grid

  8. Method for large and rapid terahertz imaging

    DOE Patents [OSTI]

    Williams, Gwyn P.; Neil, George R.

    2013-01-29T23:59:59.000Z

    A method of large-scale active THz imaging using a combination of a compact high power THz source (>1 watt), an optional optical system, and a camera for the detection of reflected or transmitted THz radiation, without the need for the burdensome power source or detector cooling systems required by similar prior art such devices. With such a system, one is able to image, for example, a whole person in seconds or less, whereas at present, using low power sources and scanning techniques, it takes several minutes or even hours to image even a 1 cm.times.1 cm area of skin.

  9. Abstract--Current grid standards seem to largely require low power (e.g. several kilowatts) single-phase photovoltaic (PV)

    E-Print Network [OSTI]

    Berning, Torsten

    --Grid requirements; photovoltaic systems; low voltage ride through; ancillary services; grid support; reliability I-phase photovoltaic (PV) systems to operate at unity power factor with maximum power point tracking, and disconnect. INTRODUCTION Due to the declining photovoltaic (PV) module price and the strong feed-in tariff policies

  10. A Completely Modular Power Converter for High-Power High-Current DC Applications

    E-Print Network [OSTI]

    Paderborn, Universität

    and filter components. Reliability and availability are other important requirements from the power converter connection of semiconductor devices, however, several centralized components (filters, transformer etc.) are used, which lead to multiple failure modes. Replacement of these large power components is both time

  11. High power impulse magnetron sputtering: Current-voltage-time characteristics indicate the onset of sustained self-sputtering

    E-Print Network [OSTI]

    Anders, Andre; Andersson, Joakim; Ehiasarian, Arutiun

    2008-01-01T23:59:59.000Z

    target voltage starts to slightly droop for higher voltages,1000 V, the actual voltage droops and shows less stability.see a large voltage droop, especially at high current). We

  12. Air pollution: Coal based power plants major culprit : HindustanTimes.com http://www.hindustantimes.com/news/5922_1646830,001500250000000... 1 of 2 3/10/2006 7:45 AM

    E-Print Network [OSTI]

    Singh, Ramesh P.

    Air pollution: Coal based power plants major culprit : HindustanTimes.com http 1 Front » Story Air pollution: Coal based power plants major culprit HT Correspondent Kanpur, March that coal based thermal power plants are the main source for air pollution. The fact came to the fore during

  13. The maximum potential to generate wind power in the contiguous United States is more than three times

    E-Print Network [OSTI]

    The maximum potential to generate wind power in the contiguous United States is more than three) study. The new analysis is based on the latest computer models and examines the wind potential at wind responsible for the increased wind potential in the study. Developed in collaboration with renewable energy

  14. A Reachability-Based Method for Large-Signal Behavior Verification of DC-DC Converters

    E-Print Network [OSTI]

    Liberzon, Daniel

    -loop, large-signal system behavior verification, and iv) switching detail modeling. In open-loop, large´inguez-Garc´ia, Member, IEEE Abstract--A method for large-signal behavior verification of power electronics DC behavior verification, lengthy time-domain simula- tions are conducted to analyze the system response

  15. Power Challenges of Large Scale Research Infrastructures: the Square Kilometer Array and Solar Energy Integration; Towards a zero-carbon footprint next generation telescope

    E-Print Network [OSTI]

    Barbosa, Domingos; Ruiz, Valeriano; Silva, Manuel; Verdes-Montenegro, Lourdes; Santander-Vela, Juande; Maia, Dalmiro; Antón, Sonia; van Ardenne, Arnold; Vetter, Matthias; Kramer, Michael; Keller, Reinhard; Pereira, Nuno; Silva, Vitor

    2012-01-01T23:59:59.000Z

    The Square Kilometer Array (SKA) will be the largest Global science project of the next two decades. It will encompass a sensor network dedicated to radioastronomy, covering two continents. It will be constructed in remote areas of South Africa and Australia, spreading over 3000Km, in high solar irradiance latitudes. Solar Power supply is therefore an option to power supply the SKA and contribute to a zero carbon footprint next generation telescope. Here we outline the major characteristics of the SKA and some innovation approaches on thermal solar energy Integration with SKA prototypes.

  16. Large-dimension, high-ZT Thermoelectric Nanocomposites for High-Power High-efficiency Waste Heat Recovery for Electricity Generation

    Broader source: Energy.gov [DOE]

    Large-dimension, high-ZT BiTe and Pb-based nanocomposites produced with a low-cost scalable process were used for development and testing of TE module prototypes, and demonstration of a waste heat recovery system

  17. Methodology for developing and implementing alternative temperature-time curves for testing the fire resistance of barriers for nuclear power plant applications

    SciTech Connect (OSTI)

    Cooper, L.Y.; Steckler, K.D.

    1996-08-01T23:59:59.000Z

    Advances in fire science over the past 40 years have offered the potential for developing technically sound alternative temperature-time curves for use in evaluating fire barriers for areas where fire exposures can be expected to be significantly different than the ASTM E-119 standard temperature-time exposure. This report summarizes the development of the ASTM E-119, standard temperature-time curve, and the efforts by the federal government and the petrochemical industry to develop alternative fire endurance curves for specific applications. The report also provides a framework for the development of alternative curves for application at nuclear power plants. The staff has concluded that in view of the effort necessary for the development of nuclear power plant specific temperature-time curves, such curves are not a viable approach for resolving the issues concerning Thermo-Lag fire barriers. However, the approach may be useful to licensees in the development of performance-based fire protection methods in the future.

  18. Maximizing Power Output in Homogeneous Charge Compression Ignition (HCCI) Engines and Enabling Effective Control of Combustion Timing

    E-Print Network [OSTI]

    Saxena, Samveg

    2011-01-01T23:59:59.000Z

    fluid region near the center of the combustion chamber is the hottest and the fuel-fuels like gasoline) requires a great deal of computing time. The calculation of detailed fluid

  19. "If performance per watt is to remain constant over the next few years, power costs could easily overtake hardware costs, possibly by a large margin." and "...one could

    E-Print Network [OSTI]

    Todorovich, Elías

    -power operation, consumes about 40 W. For 10 hours of operation between recharges, with a Lithium-Ion battery with 100 Wh/kg of energy density1 , it will require 4 kg of batteries. Energy density and weight is displayed at Table 1.1 for several battery technologies, including the Lithium-Polymer-Potential technology

  20. IEEE TRANSACTIONS ON VERY LARGE SCALE INTEGRATION (VLSI) SYSTEMS, VOL. 6, NO. 4, DECEMBER 1998 707 Algorithm-Based Low-Power Transform Coding

    E-Print Network [OSTI]

    Liu, K. J. Ray

    processing. I. INTRODUCTION DUE to the limited power-supply capability of current battery technology voltage goes down. In [1], the techniques of "parallel processing" and "pipelining" were suggested to compensate the speed penalty, in which a simple comparator circuit was used to demonstrate how parallel

  1. Reliability Estimates for Power Supplies

    SciTech Connect (OSTI)

    Lee C. Cadwallader; Peter I. Petersen

    2005-09-01T23:59:59.000Z

    Failure rates for large power supplies at a fusion facility are critical knowledge needed to estimate availability of the facility or to set priorties for repairs and spare components. A study of the "failure to operate on demand" and "failure to continue to operate" failure rates has been performed for the large power supplies at DIII-D, which provide power to the magnet coils, the neutral beam injectors, the electron cyclotron heating systems, and the fast wave systems. When one of the power supplies fails to operate, the research program has to be either temporarily changed or halted. If one of the power supplies for the toroidal or ohmic heating coils fails, the operations have to be suspended or the research is continued at de-rated parameters until a repair is completed. If one of the power supplies used in the auxiliary plasma heating systems fails the research is often temporarily changed until a repair is completed. The power supplies are operated remotely and repairs are only performed when the power supplies are off line, so that failure of a power supply does not cause any risk to personnel. The DIII-D Trouble Report database was used to determine the number of power supply faults (over 1,700 reports), and tokamak annual operations data supplied the number of shots, operating times, and power supply usage for the DIII-D operating campaigns between mid-1987 and 2004. Where possible, these power supply failure rates from DIII-D will be compared to similar work that has been performed for the Joint European Torus equipment. These independent data sets support validation of the fusion-specific failure rate values.

  2. Wave Power Demonstration Project at Reedsport, Oregon

    SciTech Connect (OSTI)

    Mekhiche, Mike [Principal Investigator] [Principal Investigator; Downie, Bruce [Project Manager] [Project Manager

    2013-10-21T23:59:59.000Z

    Ocean wave power can be a significant source of large?scale, renewable energy for the US electrical grid. The Electrical Power Research Institute (EPRI) conservatively estimated that 20% of all US electricity could be generated by wave energy. Ocean Power Technologies, Inc. (OPT), with funding from private sources and the US Navy, developed the PowerBuoy? to generate renewable energy from the readily available power in ocean waves. OPT's PowerBuoy converts the energy in ocean waves to electricity using the rise and fall of waves to move the buoy up and down (mechanical stroking) which drives an electric generator. This electricity is then conditioned and transmitted ashore as high?voltage power via underwater cable. OPT's wave power generation system includes sophisticated techniques to automatically tune the system for efficient conversion of random wave energy into low cost green electricity, for disconnecting the system in large waves for hardware safety and protection, and for automatically restoring operation when wave conditions normalize. As the first utility scale wave power project in the US, the Wave Power Demonstration Project at Reedsport, OR, will consist of 10 PowerBuoys located 2.5 miles off the coast. This U.S. Department of Energy Grant funding along with funding from PNGC Power, an Oregon?based electric power cooperative, was utilized for the design completion, fabrication, assembly and factory testing of the first PowerBuoy for the Reedsport project. At this time, the design and fabrication of this first PowerBuoy and factory testing of the power take?off subsystem are complete; additionally the power take?off subsystem has been successfully integrated into the spar.

  3. Current-voltage-time characteristics of the reactive Ar/N{sub 2} high power impulse magnetron sputtering discharge

    SciTech Connect (OSTI)

    Magnus, F.; Sveinsson, O. B.; Olafsson, S. [Science Institute, University of Iceland, Dunhaga 3, Reykjavik IS-107 (Iceland); Gudmundsson, J. T. [Science Institute, University of Iceland, Dunhaga 3, Reykjavik IS-107 (Iceland); University of Michigan-Shanghai Jiao Tong University Joint Institute, Shanghai Jiao Tong University, 800 Dong Chuan Road, Shanghai 200240 (China)

    2011-10-15T23:59:59.000Z

    The discharge current and voltage waveforms have been measured in a reactive high power impulse magnetron sputtering (HiPIMS) Ar/N{sub 2} discharge with a Ti target for 400 {mu}s long pulses. We observe that the current waveform in the reactive Ar/N{sub 2} HiPIMS discharge is highly dependent on the pulse repetition frequency, unlike the non-reactive Ar discharge. The current is found to increase significantly as the frequency is lowered. This is attributed to an increase in the secondary electron emission yield during the self-sputtering phase, when the nitride forms on the target at low frequencies. In addition, self-sputtering runaway occurs at lower discharge voltages when nitrogen is added to the discharge. This illustrates the crucial role of self-sputtering in the behavior of the reactive HiPIMS discharge.

  4. Time resolved measurement of film growth during reactive high power pulsed magnetron sputtering (HIPIMS) of titanium nitride

    E-Print Network [OSTI]

    Mitschker, Felix; Benedikt, Jan; Maszl, Christian; von Keudell, Achim

    2013-01-01T23:59:59.000Z

    The growth rate during reactive high power pulsed magnetron sputtering (HIPIMS) of titanium nitride is measured with a temporal resolution of up to 25 us using a rotating shutter concept. According to that concept a 200 um slit is rotated in front of the substrate synchronous with the HIPIMS pulses. Thereby, the growth flux is laterally distributed over the substrate. By measuring the resulting deposition profile with profilometry and with x-ray photoelectron spectroscopy, the temporal variation of the titanium and nitrogen growth flux per pulse is deduced. The analysis reveals that film growth occurs mainly during a HIPIMS pulse, with the growth rate following the HIPIMS phases ignition, current rise, gas rarefaction, plateau and afterglow. The growth fluxes of titanium and nitrogen follow slightly different behaviors with titanium dominating at the beginning of the HIPIMS pulse and nitrogen at the end of the pulse. This is explained by the gas rarefaction effect resulting in a dense initial metal plasma and...

  5. Means and method for characterizing high power, ultra short laser pulses in a real time, on line manner

    DOE Patents [OSTI]

    Veligdan, James T. (Manorville, NY)

    1994-01-01T23:59:59.000Z

    An ultra short (<10 ps), high power laser pulse is temporally characterized by a system that uses a physical measurement of a wavefront that has been altered in a known manner. The system includes a first reflection switch to remove a portion of a pulse from a beam of pulses, then includes a second reflection switch, operating in a mode that is opposite to the first reflection switch, to slice off a portion of that removed portion. The sliced portion is then directed to a measuring device for physical measurement. The two reflection switches are arranged with respect to each other and with respect to the beam of ultra short pulses such that physical measurement of the sliced portion is related to the temporal measurement of the ultra short pulse by a geometric or trigonometric relationship. The reflection switches are operated by a control pulse that is directed to impinge on each of the reflection switches at a 90.degree. angle of incidence.

  6. Abstract--Circuit breakers are crucial components for power system operation. The currently adapted time-directed

    E-Print Network [OSTI]

    inspection and preventive maintenance are typically performed. The maintenance schedules and routines usually adapted time-directed maintenance strategy and the emerging new condition-based strategy require has been applied in implementing circuit breaker maintenance and repair tasks. Several potential

  7. Unmanned Aerial Vehicle (UAV) Dynamic-Tracking Directional Wireless Antennas for Low Powered Applications that Require Reliable Extended Range Operations in Time Critical Scenarios

    SciTech Connect (OSTI)

    Scott G. Bauer; Matthew O. Anderson; James R. Hanneman

    2005-10-01T23:59:59.000Z

    The proven value of DOD Unmanned Aerial Vehicles (UAVs) will ultimately transition to National and Homeland Security missions that require real-time aerial surveillance, situation awareness, force protection, and sensor placement. Public services first responders who routinely risk personal safety to assess and report a situation for emergency actions will likely be the first to benefit from these new unmanned technologies. ‘Packable’ or ‘Portable’ small class UAVs will be particularly useful to the first responder. They require the least amount of training, no fixed infrastructure, and are capable of being launched and recovered from the point of emergency. All UAVs require wireless communication technologies for real- time applications. Typically on a small UAV, a low bandwidth telemetry link is required for command and control (C2), and systems health monitoring. If the UAV is equipped with a real-time Electro-Optical or Infrared (EO/Ir) video camera payload, a dedicated high bandwidth analog/digital link is usually required for reliable high-resolution imagery. In most cases, both the wireless telemetry and real-time video links will be integrated into the UAV with unity gain omni-directional antennas. With limited on-board power and payload capacity, a small UAV will be limited with the amount of radio-frequency (RF) energy it transmits to the users. Therefore, ‘packable’ and ‘portable’ UAVs will have limited useful operational ranges for first responders. This paper will discuss the limitations of small UAV wireless communications. The discussion will present an approach of utilizing a dynamic ground based real-time tracking high gain directional antenna to provide extend range stand-off operation, potential RF channel reuse, and assured telemetry and data communications from low-powered UAV deployed wireless assets.

  8. Power Factor Reactive Power

    E-Print Network [OSTI]

    motor power: 117.7 V x 5.1 A = 600 W? = 0.6 kW? NOT the power measured by meter #12;Page 9 PSERC: displacement power factor: angle between voltage and current = 0 degrees pf = cos(0 degrees) = 1.0 true powerPage 1 PSERC Power Factor and Reactive Power Ward Jewell Wichita State University Power Systems

  9. Means and method for characterizing high power, ultra short laser pulses in a real time, on line manner

    DOE Patents [OSTI]

    Veligdan, J.T.

    1994-03-08T23:59:59.000Z

    An ultra short (<10 ps), high power laser pulse is temporally characterized by a system that uses a physical measurement of a wavefront that has been altered in a known manner. The system includes a first reflection switch to remove a portion of a pulse from a beam of pulses, then includes a second reflection switch, operating in a mode that is opposite to the first reflection switch, to slice off a portion of that removed portion. The sliced portion is then directed to a measuring device for physical measurement. The two reflection switches are arranged with respect to each other and with respect to the beam of ultra short pulses such that physical measurement of the sliced portion is related to the temporal measurement of the ultra short pulse by a geometric or trigonometric relationship. The reflection switches are operated by a control pulse that is directed to impinge on each of the reflection switches at a 90[degree] angle of incidence. 8 figures.

  10. Recovery and Resilience After a Nuclear Power Plant Disaster: A Medical Decision model for Managing an Effective, Timely, and Balanced Response

    SciTech Connect (OSTI)

    Coleman, C. Norman [National Cancer Institute, NIH; Blumenthal, Daniel J. [National Nuclear Security Administration (NNSA), Department of Energy

    2013-05-01T23:59:59.000Z

    Based on experiences in Tokyo responding to the Fukushima Daiichi nuclear power plant crisis, a real-time, medical decision model is presented by which to make key health-related decisions given the central role of health and medical issues in such disasters. Focus is on response and recovery activities that are safe, timely, effective, and well-organized. This approach empowers on-site decision makers to make interim decisions without undue delay using readily available and high-level scientific, medical, communication, and policy expertise. Key features of this approach include ongoing assessment, consultation, information, and adaption to the changing conditions. This medical decision model presented is compatible with the existing US National Response Framework structure.

  11. Using Soir Lucene for Large-Scale Metagenomics Data Retrieval and Analysis (MICW - Metagenomics Informatics Challenges Workshop: 10K Genomes at a Time)

    ScienceCinema (OSTI)

    Goll, Johannes [JCVI

    2013-01-22T23:59:59.000Z

    JCVI's Johannes Goll on "Using Solr/Lucene for Large-Scale Metagenomics Data Retrieval and Analysis" at the Metagenomics Informatics Challenges Workshop held at the DOE JGI on October 12-13, 2011.

  12. Using Soir Lucene for Large-Scale Metagenomics Data Retrieval and Analysis (MICW - Metagenomics Informatics Challenges Workshop: 10K Genomes at a Time)

    SciTech Connect (OSTI)

    Goll, Johannes [JCVI] [JCVI

    2011-10-12T23:59:59.000Z

    JCVI's Johannes Goll on "Using Solr/Lucene for Large-Scale Metagenomics Data Retrieval and Analysis" at the Metagenomics Informatics Challenges Workshop held at the DOE JGI on October 12-13, 2011.

  13. Power and Frequency Control as it Relates to Wind-Powered Generation

    E-Print Network [OSTI]

    Lacommare, Kristina S H

    2011-01-01T23:59:59.000Z

    of large amounts of wind power production might requirewill be satisfactory as wind power provides an increasing64   7.2   Wind Power in Relation to System

  14. Gravitational Collapse In Husain Space-time For Brans-Dicke Gravity Theory with Power-law Potential

    E-Print Network [OSTI]

    Prabir Rudra; Ritabrata Biswas; Ujjal Debnath

    2014-08-18T23:59:59.000Z

    The motive of this work is to study gravitational collapse in Husain space-time in Brans-Dicke gravity theory. Among many scalar-tensor theories of gravity, Brans-Dicke is the simplest and the impact of it can be regulated by two parameters associated with it, namely, the Brans-Dicke parameter, $\\omega$, and the potential-scalar field dependency parameter $n$ respectively. V. Husain's work on exact solution for null fluid collapse in 1996 has influenced many authors to follow his way to find the end-state of the homogeneous/in-homogeneous dust cloud. Vaidya's metric is used all over to follow the nature of future outgoing radial null geodesics. Detecting whether the central singularity is naked or wrapped by an event horizon, by the existence of future directed radial null geodesic emitted in past from the singularity is the basic objective. To point out the existence of positive trajectory tangent solution, both particular parametric cases(through tabular forms) and wide range contouring process have been applied. Precisely, perfect fluid's EoS satisfies a wide range of phenomena : from dust to exotic fluid like dark energy. We have used the EoS parameter $k$ to determine the end state of collapse in different cosmological era. Our main target is to check low $\\omega$ (more deviations from Einstein gravity-more Brans Dicke effect) and negative $k$ zones. This particularly throws light on the nature of the end-state of collapse in accelerated expansion in Brans Dicke gravity. It is seen that for positive values of EoS parameter $k$, the collapse results in a black hole, whereas for negative values of $k$, naked singularity is the only outcome. It is also to be noted that "low $\\omega$" leads to the possibility of getting more naked singularities even for a non-accelerating universe.

  15. U.S. Forward Operating Base Applications of Nuclear Power

    SciTech Connect (OSTI)

    Dr. George Griffith

    2015-01-01T23:59:59.000Z

    Nuclear power was demonstrated and made practical so that it could support the military mission of powering ships and submarines. The critical mission benefits of almost unlimited air and fuel-independent power on submarines helped spur development of the nuclear power technology that still forms the basis for the modern nuclear power industry.i Potential production of large amounts of power with low-fuel volume inputs attracted military interest shortly after nuclear power was proven to be viable.ii The expected benefit of nuclear power plants at a forward operating base (FOB) is a significant reduction in the operational and transportation risks and cost required to power FOBs. The reduction in fuel and water volumes that need to be transported is viewed as particularly valuable during war time, when mission capability and reducing enemy exposure is considered much more important than cost. Paper reviews current reactor experience and previous small military reactor applications.

  16. Continuous-Time Digital Signal Processing Based Controller for High-Frequency DC-DC Converters

    E-Print Network [OSTI]

    Prodiæ, Aleksandar

    control have been recognized (flexibility, design portability, simple implementation of power management power switch on/off time is calculated from capacitor charge balance to prevent large overshoots's College Road, Toronto, ON, M5S 3G4, CANADA E-mail: Zhenyu @ power.utoronto.ca, vsmolyakov@ hotmail

  17. Jin Yu, Ehud Reiter, Jim Hunter and Chris Mellish Choosing the content of textual summaries of large time-series data sets

    E-Print Network [OSTI]

    Sripada, Yaji

    generates summaries of sensor data from a gas turbine. Table 1. Part of a sample of time series data describe and evaluate SumTime-Turbine, a prototype system which uses this architecture to generate textual summaries of sensor data from gas turbines. 1 Introduction It is often said in the NLP community

  18. IEEE TRANSACTIONS ON VERY LARGE SCALE INTEGRATION (VLSI) SYSTEMS, VOL. 19, NO. 8, AUGUST 2011 1357 A Time-Aware Fault Tolerance Scheme to Improve

    E-Print Network [OSTI]

    Zhang, Tong

    effect makes the resistance of phase-change material drift over the time, which can severely degrade A Time-Aware Fault Tolerance Scheme to Improve Reliability of Multilevel Phase-Change Memory--Because of its promising scalability potential and support of multilevel per cell storage, phase-change memory

  19. Time-resolved x-ray imaging of high-power laser-irradiated under-dense silica aerogels and agar foams

    SciTech Connect (OSTI)

    Koch, J.A.; Estabrook, K.G.; Bauer, J.D. [and others

    1995-08-01T23:59:59.000Z

    This paper presents the results of experiments in which a high-power laser was used to irradiate low density (4 - 9 mg/cm{sup 3}) silica aerogel and agar foam targets. The laser-solid interaction and energy transport through the material were monitored with time-resolved imaging diagnostics, and the data show the production and propagation of an x-ray emission front in the plasma. The emission-front trajectory data are found to be in significant disagreement with detailed simulations, which predict a much more rapid heating of the cold material, and the data suggest that this discrepancy is not explainable by target inhomogeneities. Evidence suggests that energy transport into the cold material may be dominated by thermal conduction; however, no completely satisfactory explanation for the discrepancies is identified, and further experimental and theoretical research is necessary in order to resolve this important problem in laser-plasma interaction physics.

  20. Multi-area power system state estimation utilizing boundary measurements and phasor measurement units ( PMUs)

    E-Print Network [OSTI]

    Freeman, Matthew A

    2006-10-30T23:59:59.000Z

    investigates the benefits that stem from utilizing a multi-area state estimator instead of a serial state estimator. These benefits are largely in the form of increased accuracy and decreased processing time. First, the theory behind power system state...

  1. E cient Retiming of Large Circuits Naresh Maheshwari, Student Member, IEEE, and Sachin Sapatnekar, Member, IEEE

    E-Print Network [OSTI]

    Sapatnekar, Sachin

    , Member, IEEE Abstract| Retiming, introduced by Leiserson and Saxe, is a powerful transformation1 E cient Retiming of Large Circuits Naresh Maheshwari, Student Member, IEEE, and Sachin Sapatnekar not capable of handling large circuits in a reasonable time. This work de nes the relationship be- tween

  2. Power Plant Power Plant

    E-Print Network [OSTI]

    Tingley, Joseph V.

    Basin Center for Geothermal Energy at University of Nevada, Reno (UNR) 2 Nevada Geodetic LaboratoryStillwater Power Plant Wabuska Power Plant Casa Diablo Power Plant Glass Mountain Geothermal Area Lassen Geothermal Area Coso Hot Springs Power Plants Lake City Geothermal Area Thermo Geothermal Area

  3. LIFE Power Plant Fusion Power Associates

    E-Print Network [OSTI]

    LIFE Power Plant Fusion Power Associates December 14, 2011 Mike Dunne LLNL #12;NIf-1111-23714.ppt LIFE power plant 2 #12;LIFE delivery timescale NIf-1111-23714.ppt 3 #12;Timely delivery is enabled dpa) § Removes ion threat and mitigates x-ray threat ­ allows simple steel piping § No need

  4. Implementing a Time-and Location-Differentiated Cap-and-Trade Program: Flexible Nitrogen Oxide Abatement from Power Plants in the Eastern United States

    E-Print Network [OSTI]

    de Weck, Olivier L.

    Abatement from Power Plants in the Eastern United States by Katherine C. Martin B.A., Physics Reed College Oxide Abatement from Power Plants in the Eastern United States by Katherine C. Martin Submitted, this work examines compliance data from coal power plants in 2002 and 2005 to estimate the effectiveness

  5. Time Evolution of the Mutual Fund Size Distribution Yonathan Schwarzkopf1,2

    E-Print Network [OSTI]

    empirically and theoreti- cally. The size of large mutual funds has a heavy tailed distribution that has been into a power law only over long time scales, suggesting that log-normality comes about because the industry

  6. Large-scale optimal power flow

    SciTech Connect (OSTI)

    Papalexopoulos, A.D.; Imparato, C.F.; Wu, F.F.

    1989-05-01T23:59:59.000Z

    Extensive numerical testing of a second-order OPF solution method was conducted using a 1500 bus network under various loading conditions. The results show that (i) properly implemented second-order OPF solution methods are robust with respect to different starting points, (ii) the decoupled OPF solution is expected to be close to the full OPF solution, and (iii) the effects of discretization of load tap changing (LTC) transformer taps are very small and usually negligible.

  7. Survivable pulse power space radiator

    DOE Patents [OSTI]

    Mims, J.; Buden, D.; Williams, K.

    1988-03-11T23:59:59.000Z

    A thermal radiator system is described for use on an outer space vehicle, which must survive a long period of nonuse and then radiate large amounts of heat for a limited period of time. The radiator includes groups of radiator panels that are pivotally connected in tandem, so that they can be moved to deployed configuration wherein the panels lie largely coplanar, and to a stowed configuration wherein the panels lie in a stack to resist micrometerorite damage. The panels are mounted on a boom which separates a hot power source from a payload. While the panels are stowed, warm fluid passes through their arteries to keep them warm enough to maintain the coolant in a liquid state and avoid embrittlement of material. The panels can be stored in a largely cylindrical shell, with panels progressively further from the boom being of progressively shorter length. 5 figs.

  8. Analysis of Variability and Uncertainty in Wind Power Forecasting: An International Comparison (Presentation)

    SciTech Connect (OSTI)

    Zhang, J.; Hodge, B.; Miettinen, J.; Holttinen, H.; Gomez-Lozaro, E.; Cutululis, N.; Litong-Palima, M.; Sorensen, P.; Lovholm, A.; Berge, E.; Dobschinski, J.

    2013-10-01T23:59:59.000Z

    This presentation summarizes the work to investigate the uncertainty in wind forecasting at different times of year and compare wind forecast errors in different power systems using large-scale wind power prediction data from six countries: the United States, Finland, Spain, Denmark, Norway, and Germany.

  9. Large-dimension, high-ZT Thermoelectric Nanocomposites for High...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Large-dimension, high-ZT Thermoelectric Nanocomposites for High-Power High-efficiency Waste Heat Recovery for Electricity Generation Large-dimension, high-ZT Thermoelectric...

  10. Wireless Power Transfer

    ScienceCinema (OSTI)

    None

    2013-11-19T23:59:59.000Z

    Wireless Power Transfer is an innovative approach using magnetic resonance coupling of air core transformers designed for today's growing plug-in electric vehicle market. This technology can provide a convenient, safe and flexible means to charge electric vehicles under stationary and dynamic conditions. Plug-in Electric Vehicles (PEV) are burdened by the need for cable and plug charger, galvanic isolation of the on-board electronics, bulk and cost of this charger and the large energy storage system (ESS) packs needed. With a system where you have to physically plug in there are a number of occasions where the owner could very well forget to charge the vehicle. For stationary applications (like charging of a PHEV at home), ORNL's innovative wireless power transfer technology adds a convenience factor compared to actually plugging in which will mean that the vehicle will have a full charge every morning. Electric vehicle charging must be safe, compact and efficient in order to be convenient for customers. By reconfiguring the transformer and altering the resonance frequency, energy is transferred to the battery with lower energy losses and with fewer demands on the primary circuit by the rest of the transformer system. The ORNL discovery shows that sufficient power for the battery can be transferred from the primary to secondary circuits without significant energy losses if the operating frequency is set at 50% to 95% of the resonance frequency of the circuit. The electrical power is then transmitted to the chargeable battery, which is electrically coupled to the secondary circuit through the air core transformer. Some advantages include: Reduced energy losses during transfer of energy to the battery; A charge potential that is relatively unaffected by up to 25% misalignment of vehicle; and Other receiving components draw less power from the primary circuit. These advantages allow wireless power technology applications to expand at the workplace and beyond as the demand for EV rises. For vehicles that operate over a fixed route such as busses and shuttle vehicles, Wireless Power Transfer (WPT) means that a smaller battery pack can be used. In the traditional system, the battery pack is designed to accommodate the needs of the entire route or shift. With WPT the battery can be downsized because it can be charged when the vehicle stops on its route (a rental car shuttle bus, for example, can charge when it waits in the terminal and again when it waits at the rental car place. Thus the battery only needs enough charge to get to the next stop. This decrease in battery size means significant cost savings to electrify the vehicle. This technology enables efficient "opportunity charging stations" for predefined routes and planned stops reducing down time. Charging can occur in minutes. This improvement also eliminates the harmful emissions that occur in garages while buses are at idle during charging. In larger cities, dynamic charging offers an even greater impact utilizing existing infrastructure. As vehicles travel along busy freeways and interstate systems, wireless charging can occur while the vehicle is in motion. With this technology a vehicle essentially has unlimited electric range while using a relatively small battery pack. In-motion charging stations use vehicle sensors to alert the driver. Traveling at normal speeds, sensors establish in-motion charging. WPT transmit pads sequentially energize to the negotiated power level based on vehicle speed and its requested charging energy. Lower power when vehicle speed is slow and much higher power for faster moving vehicles. Vehicle to Infrastructure communications (V2I) coordinates WPT charging level according to on-board battery pack state-of-charge. V2I activates the roadway transmit pads placing them in standby mode and negotiates charging fee based on prevailing grid rate and vehicle energy demand. Dynamic charging would allow electricity to supply a very large fraction of the energy for the transportation sector and reduce greatly petroleum consump

  11. Wireless Power Transfer

    SciTech Connect (OSTI)

    None

    2013-07-22T23:59:59.000Z

    Wireless Power Transfer is an innovative approach using magnetic resonance coupling of air core transformers designed for today's growing plug-in electric vehicle market. This technology can provide a convenient, safe and flexible means to charge electric vehicles under stationary and dynamic conditions. Plug-in Electric Vehicles (PEV) are burdened by the need for cable and plug charger, galvanic isolation of the on-board electronics, bulk and cost of this charger and the large energy storage system (ESS) packs needed. With a system where you have to physically plug in there are a number of occasions where the owner could very well forget to charge the vehicle. For stationary applications (like charging of a PHEV at home), ORNL's innovative wireless power transfer technology adds a convenience factor compared to actually plugging in which will mean that the vehicle will have a full charge every morning. Electric vehicle charging must be safe, compact and efficient in order to be convenient for customers. By reconfiguring the transformer and altering the resonance frequency, energy is transferred to the battery with lower energy losses and with fewer demands on the primary circuit by the rest of the transformer system. The ORNL discovery shows that sufficient power for the battery can be transferred from the primary to secondary circuits without significant energy losses if the operating frequency is set at 50% to 95% of the resonance frequency of the circuit. The electrical power is then transmitted to the chargeable battery, which is electrically coupled to the secondary circuit through the air core transformer. Some advantages include: Reduced energy losses during transfer of energy to the battery; A charge potential that is relatively unaffected by up to 25% misalignment of vehicle; and Other receiving components draw less power from the primary circuit. These advantages allow wireless power technology applications to expand at the workplace and beyond as the demand for EV rises. For vehicles that operate over a fixed route such as busses and shuttle vehicles, Wireless Power Transfer (WPT) means that a smaller battery pack can be used. In the traditional system, the battery pack is designed to accommodate the needs of the entire route or shift. With WPT the battery can be downsized because it can be charged when the vehicle stops on its route (a rental car shuttle bus, for example, can charge when it waits in the terminal and again when it waits at the rental car place. Thus the battery only needs enough charge to get to the next stop. This decrease in battery size means significant cost savings to electrify the vehicle. This technology enables efficient "opportunity charging stations" for predefined routes and planned stops reducing down time. Charging can occur in minutes. This improvement also eliminates the harmful emissions that occur in garages while buses are at idle during charging. In larger cities, dynamic charging offers an even greater impact utilizing existing infrastructure. As vehicles travel along busy freeways and interstate systems, wireless charging can occur while the vehicle is in motion. With this technology a vehicle essentially has unlimited electric range while using a relatively small battery pack. In-motion charging stations use vehicle sensors to alert the driver. Traveling at normal speeds, sensors establish in-motion charging. WPT transmit pads sequentially energize to the negotiated power level based on vehicle speed and its requested charging energy. Lower power when vehicle speed is slow and much higher power for faster moving vehicles. Vehicle to Infrastructure communications (V2I) coordinates WPT charging level according to on-board battery pack state-of-charge. V2I activates the roadway transmit pads placing them in standby mode and negotiates charging fee based on prevailing grid rate and vehicle energy demand. Dynamic charging would allow electricity to supply a very large fraction of the energy for the transportation sector and reduce greatly petroleum consump

  12. High-Speed Real-Time Digital Emulation for Hardware-in-the-Loop Testing of Power Electronics: A New Paradigm in the Field of

    E-Print Network [OSTI]

    Sanders, Seth

    , Novi Sad, Serbia. Abstract This paper details the design and application of a new ultra-high speed real wider proliferation of renewable energy gener- ation and realization of the smart grid vision. Power

  13. Multimegawatt space power reactors

    SciTech Connect (OSTI)

    Dearien, J.A.; Whitbeck, J.F.

    1989-01-01T23:59:59.000Z

    In response to the need of the Strategic Defense Initiative (SDI) and long range space exploration and extra-terrestrial basing by the National Air and Space Administration (NASA), concepts for nuclear power systems in the multi-megawatt levels are being designed and evaluated. The requirements for these power systems are being driven primarily by the need to minimize weight and maximize safety and reliability. This paper will discuss the present requirements for space based advanced power systems, technological issues associated with the development of these advanced nuclear power systems, and some of the concepts proposed for generating large amounts of power in space. 31 figs.

  14. Mesofluidic magnetohydrodynamic power generation

    E-Print Network [OSTI]

    Fucetola, Jay J

    2012-01-01T23:59:59.000Z

    Much of the previous research into magnetohydrodynamics has involved large-scale systems. This thesis explores the miniaturization and use of devices to convert the power dissipated within an expanding gas flow into ...

  15. Crowd-powered systems

    E-Print Network [OSTI]

    Bernstein, Michael Scott

    2012-01-01T23:59:59.000Z

    Crowd-powered systems combine computation with human intelligence, drawn from large groups of people connecting and coordinating online. These hybrid systems enable applications and experiences that neither crowds nor ...

  16. Power and Frequency Control as it Relates to Wind-Powered Generation

    SciTech Connect (OSTI)

    Lacommare, Kristina S H

    2010-12-20T23:59:59.000Z

    This report is a part of an investigation of the ability of the U.S. power system to accommodate large scale additions of wind generation. The objectives of this report are to describe principles by which large multi-area power systems are controlled and to anticipate how the introduction of large amounts of wind power production might require control protocols to be changed. The operation of a power system is described in terms of primary and secondary control actions. Primary control is fast, autonomous, and provides the first-line corrective action in disturbances; secondary control takes place on a follow-up time scale and manages the deployment of resources to ensure reliable and economic operation. This report anticipates that the present fundamental primary and secondary control protocols will be satisfactory as wind power provides an increasing fraction of the total production, provided that appropriate attention is paid to the timing of primary control response, to short term wind forecasting, and to management of reserves for control action.

  17. Analysis for robotic assembly of large flexible space structures

    E-Print Network [OSTI]

    Mangalgiri, Vickram S. (Vickram Suresh), 1979-

    2004-01-01T23:59:59.000Z

    Space solar power is a renewable, environment-friendly alternative to satisfy future terrestrial power needs. Space solar power stations will need to have large dimensions (on the order of hundreds of meters) to be able ...

  18. High-Efficiency and High-Power CMOS Power Amplifiers for Millimeter-Wave Applications /

    E-Print Network [OSTI]

    Agah, Amir

    2013-01-01T23:59:59.000Z

    large output powers at the millimeter-wave regime has been mainly focused on power combining techniques, using Wilkinson combiners and transformer-

  19. Distributed vs. Centralized Power Systems Frequency Control

    E-Print Network [OSTI]

    Dimarogonas, Dimos

    Distributed vs. Centralized Power Systems Frequency Control Martin Andreasson12 , Dimos V control of electrical power systems. We propose a distributed controller which retains the reference class of large- scale systems are electrical power systems, which employ automatic generation control

  20. Efficient Time Series Matching by Wavelets Kinpong Chan and Ada Waichee Fu

    E-Print Network [OSTI]

    Fu, Ada Waichee

    since the effectiveness of power concentration of a partic­ ular transformation depends on the nature to other problems. While large pieces reduce the power of multi­resolution, small pieces has weakness­Trees for fast retrieval. Due to the dimensionality curse problem, transformations are applied to time series

  1. Power Grid Data Analysis with R and Hadoop

    SciTech Connect (OSTI)

    Hafen, Ryan P.; Gibson, Tara D.; Kleese van Dam, Kerstin; Critchlow, Terence J.

    2014-01-01T23:59:59.000Z

    This book chapter presents an approach to analysis of large-scale time-series sensor information based on our experience with power grid data. We use the R-Hadoop Integrated Programming Environment (RHIPE) to analyze a 2TB data set and present code and results for this analysis.

  2. Active Power Control from Wind Power (Presentation)

    SciTech Connect (OSTI)

    Ela, E.; Brooks, D.

    2011-04-01T23:59:59.000Z

    In order to keep the electricity grid stable and the lights on, the power system relies on certain responses from its generating fleet. This presentation evaluates the potential for wind turbines and wind power plants to provide these services and assist the grid during critical times.

  3. Ramp Forecasting Performance from Improved Short-Term Wind Power Forecasting: Preprint

    SciTech Connect (OSTI)

    Zhang, J.; Florita, A.; Hodge, B. M.; Freedman, J.

    2014-05-01T23:59:59.000Z

    The variable and uncertain nature of wind generation presents a new concern to power system operators. One of the biggest concerns associated with integrating a large amount of wind power into the grid is the ability to handle large ramps in wind power output. Large ramps can significantly influence system economics and reliability, on which power system operators place primary emphasis. The Wind Forecasting Improvement Project (WFIP) was performed to improve wind power forecasts and determine the value of these improvements to grid operators. This paper evaluates the performance of improved short-term wind power ramp forecasting. The study is performed for the Electric Reliability Council of Texas (ERCOT) by comparing the experimental WFIP forecast to the current short-term wind power forecast (STWPF). Four types of significant wind power ramps are employed in the study; these are based on the power change magnitude, direction, and duration. The swinging door algorithm is adopted to extract ramp events from actual and forecasted wind power time series. The results show that the experimental short-term wind power forecasts improve the accuracy of the wind power ramp forecasting, especially during the summer.

  4. Tidal power

    SciTech Connect (OSTI)

    Hammons, T.J. (Glasgow Univ., Scotland (United Kingdom))

    1993-03-01T23:59:59.000Z

    The paper reviews the physics of tidal power considering gravitational effects of moon and sun; semidiurnal, diurnal, and mixed tides; and major periodic components that affect the tidal range. Shelving, funneling, reflection, and resonance phenomena that have a significant effect on tidal range are also discussed. The paper then examines tidal energy resource for principal developments estimated from parametric modeling in Europe and worldwide. Basic parameters that govern the design of tidal power schemes in terms of mean tidal range and surface area of the enclosed basin are identified. While energy extracted is proportional to the tidal amplitude squared, requisite sluicing are is proportional to the square root of the tidal amplitude. Sites with large tidal amplitudes are therefore best suited for tidal power developments, whereas sites with low tidal amplitudes have sluicing that may be prohibitive. It is shown that 48% of the European tidal resource is in the United Kingdom, 42% in France and 8% in Ireland, other countries having negligible potential. Worldwide tidal resource is identified. Tidal barrage design and construction using caissons is examined, as are alternative operating modes (single-action generation, outflow generation, flood generation, two-way generation, twin basin generation, pumping, etc), development trends and possibilities, generation cost at the barrage boundary, sensitivity to discount rates, general economics, and markets. Environmental effects, and institutional constraints to the development of tidal barrage schemes are also discussed.

  5. Near-Core and In-Core Neutron Radiation Monitors for Real Time Neutron Flux Monitoring and Reactor Power Level Measurements

    SciTech Connect (OSTI)

    Douglas S. McGregor; Marvin L. Adams; Igor Carron; Paul Nelson

    2006-06-12T23:59:59.000Z

    MPFDs are a new class of detectors that utilize properties from existing radiation detector designs. A majority of these characteristics come from fission chamber designs. These include radiation hardness, gamma-ray background insensitivity, and large signal output.

  6. IEEE TRANSACTIONS ON VERY LARGE SCALE INTEGRATION (VLSI) SYSTEMS, VOL. XX, NO. Y, MONTH 2002 1 Techniques for Energy-Efficient Communication

    E-Print Network [OSTI]

    Potkonjak, Miodrag

    IEEE TRANSACTIONS ON VERY LARGE SCALE INTEGRATION (VLSI) SYSTEMS, VOL. XX, NO. Y, MONTH 2002 1 of communication pipelines. At the same time, power/energy consumption is often another limiting factor in many portable systems. We address the problem of how to mini- mize the power consumption in system

  7. Initial Blackbeard power survey results

    SciTech Connect (OSTI)

    Murphy, T.; Devenport, J.; Holden, D.

    1996-06-01T23:59:59.000Z

    The Blackbeard broadband VHF radio receiver is in low-earth orbit aboard the ALEXIS satellite. The receiver has been used to measure the transmitted power in four VHF bands (55.2-75.8, 28.0-94.8, 132.3-152.2, and 107.7-166.0 MHz) over quiet and noisy parts of the earth. The authors present the results of the survey and discuss their implications. They find that there are remote ocean areas over which the observed spectrum is largely free of man-made interference, but that the spectrum over most of the earth is dominated by broadcast VHF signals. The signal characteristics observed over a given area are quite constant when observed at different times of day and at intervals of several weeks to months. It appears that in many cases the bulk of the signal power is coming from a small number of sources.

  8. Comparison of Time-Based Non-Active Power Definitions for Active Filtering Leon M. Tolbert, Senior Member, IEEE Thomas G. Habetler, Senior Member, IEEE

    E-Print Network [OSTI]

    Tolbert, Leon M.

    energy that causes increased line losses and greater generation requirements for utilities. Because non]. Because the vast majority of the generation and use of electrical energy at that time involved periodic p(t) is defined as the time rate of energy transfer or energy utilization. It is a physical quantity

  9. Interline Photovoltaic (I-PV) power system - A novel concept of power flow control and management

    E-Print Network [OSTI]

    Khadkikar, Vinod

    This paper presents a new system configuration for a large-scale Photovoltaic (PV) power system with multi-line transmission/distribution networks. A PV power plant is reconfigured in a way that two adjacent power system ...

  10. Performance Analysis of XCPC Powered Solar Cooling Demonstration Project

    E-Print Network [OSTI]

    Widyolar, Bennett

    2013-01-01T23:59:59.000Z

    is the fraction of available solar power incident on theoutput per available solar power and characterizes theintegral of available solar power over the operational time

  11. Implementing a time- and location-differentiated cap-and-trade program : flexible nitrogen oxide abatement from power plants in the eastern United States

    E-Print Network [OSTI]

    Martin, Katherine C

    2007-01-01T23:59:59.000Z

    Studies suggest that timing and location of emissions can change the amount of ozone formed from a given amount of nitrogen oxide (NOx) by a factor of five (Mauzerall et al. 2005). Yet existing NOx cap-and-trade programs ...

  12. Real Time Grid Reliability Management 2005

    E-Print Network [OSTI]

    Eto, Joe

    2008-01-01T23:59:59.000Z

    Modeling of power system components at severe disturbances,” in Proceedings of the International Conference on Large High Voltage Electric Systems (System Electric Power Group Electric Power Research Institute Lawrence Berkeley National Laboratory Locational Marginal Pricing Load Modeling

  13. Development of a RELAP5-3D three-dimensional model of a VVER-1000 Nuclear Power Plant for analysis of a large-break loss-of-coolant accident 

    E-Print Network [OSTI]

    Clarno, Kevin Taylor

    2001-01-01T23:59:59.000Z

    of the three-dimensional sections of the reactor vessel consisted of ensuring geometrical fidelity with the design of the modeled plant, the Balacovo Unit 4, Nuclear Power Plant in Saratov, Russia. A stable operational steady-state was obtained...

  14. Modeling Power System Operation with Intermittent Resources

    SciTech Connect (OSTI)

    Marinovici, Maria C.; Kirkham, Harold; Glass, Kevin A.; Carlsen, Leif C.

    2013-02-27T23:59:59.000Z

    Electricity generating companies and power system operators face the need to minimize total fuel cost or maximize total profit over a given time period. These issues become optimization problems subject to a large number of constraints that must be satisfied simultaneously. The grid updates due to smart-grid technologies plus the penetration of intermittent re- sources in electrical grid introduce additional complexity to the optimization problem. The Renewable Integration Model (RIM) is a computer model of interconnected power system. It is intended to provide insight and advice on complex power systems management, as well as answers to integration of renewable energy questions. This paper describes RIM basic design concept, solution method, and the initial suite of modules that it supports.

  15. Power Density Spectra of Gamma-Ray Bursts

    E-Print Network [OSTI]

    Andrei M. Beloborodov

    1999-11-08T23:59:59.000Z

    Power density spectra (PDSs) of long gamma-ray bursts provide useful information on GRBs, indicating their self-similar temporal structure. The best power-law PDSs are displayed by the longest bursts (T_90 > 100 s) in which the range of self-similar time scales covers more than 2 decades. Shorter bursts have apparent PDS slopes more strongly affected by statistical fluctuations. The underlying power law can then be reproduced with high accuracy by averaging the PDSs for a large sample of bursts. This power-law has a slope alpha\\approx -5/3 and a sharp break at 1 Hz. The power-law PDS provides a new sensitive tool for studies of gamma-ray bursts. In particular, we calculate the PDSs of bright bursts in separate energy channels. The PDS flattens in the hard channel (h\

  16. Naturalistic Decision Making For Power System Operators

    SciTech Connect (OSTI)

    Greitzer, Frank L.; Podmore, Robin; Robinson, Marck; Ey, Pamela

    2009-06-23T23:59:59.000Z

    Abstract: Motivation -- As indicated by the Blackout of 2003, the North American interconnected electric system is vulnerable to cascading outages and widespread blackouts. Investigations of large scale outages often attribute the causes to the three T’s: Trees, Training and Tools. A systematic approach has been developed to document and understand the mental processes that an expert power system operator uses when making critical decisions. The approach has been developed and refined as part of a capability demonstration of a high-fidelity real-time power system simulator under normal and emergency conditions. To examine naturalistic decision making (NDM) processes, transcripts of operator-to-operator conversations are analyzed to reveal and assess NDM-based performance criteria. Findings/Design -- The results of the study indicate that we can map the Situation Awareness Level of the operators at each point in the scenario. We can also identify clearly what mental models and mental simulations are being performed at different points in the scenario. As a result of this research we expect that we can identify improved training methods and improved analytical and visualization tools for power system operators. Originality/Value -- The research applies for the first time, the concepts of Recognition Primed Decision Making, Situation Awareness Levels and Cognitive Task Analysis to training of electric power system operators. Take away message -- The NDM approach provides an ideal framework for systematic training management and mitigation to accelerate learning in team-based training scenarios with high-fidelity power grid simulators.

  17. Utility Accrual Real-Time Scheduling with Energy Bounds In this paper, we consider timeliness and energy optimization in battery-powered, dynamic

    E-Print Network [OSTI]

    Ravindran, Binoy

    . An important technique used for optimizing the energy consumption of real-time embedded systems is dynamic in the physical world). Further, they are energy-critical, as they must operate on battery, with finite energy and minimizing the system's energy consumption, and not just the CPU's energy consumption. Moreover, such systems

  18. Version control Version control is a powerful tool for many kinds of work done over a period of time, including writing

    E-Print Network [OSTI]

    Alavi, Ali

    is a good idea are: · efficient development practices. It is very easy to try things out and experiment of time, including writing papers and theses as well as writing code. This session gives a introduction communication via a central server which stores the repository whereas a DVCS is completely distributed and each

  19. Analysis of Wind Power Ramping Behavior in ERCOT

    SciTech Connect (OSTI)

    Wan, Y. H.

    2011-03-01T23:59:59.000Z

    This report analyzes the wind power ramping behavior using 10-minute and hourly average wind power data from ERCOT and presents statistical properties of the large ramp events.

  20. Critical pulse power components

    SciTech Connect (OSTI)

    Sarjeant, W.J.; Rohwein, G.J.

    1981-01-01T23:59:59.000Z

    Critical components for pulsed power conditioning systems will be reviewed. Particular emphasis will be placed on those components requiring significant development efforts. Capacitors, for example, are one of the weakest elements in high-power pulsed systems, especially when operation at high-repetition frequencies for extended periods of time are necessary. Switches are by far the weakest active components of pulse power systems. In particular, opening switches are essentially nonexistent for most applications. Insulaton in all systems and components requires development and improvement. Efforts under way in technology base development of pulse power components will be discussed.

  1. Time Variations of the Solar Neutrino Flux Data from Sage and Gallex-Gno Detectors Obtained by Rayleigh Power Spectrum Analysis

    E-Print Network [OSTI]

    Koushik Ghosh; Probhas Raychaudhuri

    2006-06-05T23:59:59.000Z

    We have used Rayleigh power spectrum analysis of the monthly solar neutrino flux data from (1) SAGE detector during the period from 1st January 1990 to 31st December 2000; (2) SAGE detector during the period from April 1998 to December 2001; (3) GALLEX detector during the period from May 1991 to January 1997; (4) GNO detector during the period from May 1998 to December 2001; (5) GALLEX-GNO detector (combined data) from May 1991 to December 2001 and (6) average of the data from GNO and SAGE detectors during the period from May 1998 to December 2001. (1) exhibits periodicity around 1.3, 4.3, 5.5, 6.3, 7.9, 8.7, 15.9, 18.7, 23.9, 32.9 and 48.7 months. (2) shows periodicity around 1.5, 2.9, 4.5, 10.1 months. For (3) we observe periodicity around 1.7, 18.7 and 26.9 months. For (4) periodicity is seen around 3.5, 5.5, 7.7 and 10.5 months. (5) gives periodicity around 1.7, 18.5, 28.5 and 42.1 months while (6) shows periodicity around 4.3, 6.9, 10.3 and 18.1 months. We have found almost similar periods in the solar flares, sunspot data, solar proton data which indicates that the solar activity cycle may be due to the variable character of nuclear energy generation inside the sun.

  2. NRC Job Code V6060: Extended in-situ and real time monitoring. Task 4: Detection and monitoring of leaks at nuclear power plants external to structures

    SciTech Connect (OSTI)

    Sheen, S. H. (Nuclear Engineering Division)

    2012-08-01T23:59:59.000Z

    In support of Task 4 of the NRC study on compliance with 10 CFR part 20.1406, minimization of contamination, Argonne National Laboratory (ANL) conducted a one-year scoping study, in concert with a parallel study performed by NRC/NRR staff, on monitoring for leaks at nuclear power plants (NPPs) external to structures. The objective of this task-4 study is to identify and assess those sensors and monitoring techniques for early detection of abnormal radioactive releases from the engineered facility structures, systems and components (SSCs) to the surrounding underground environment in existing NPPs and planned new reactors. As such, methods of interest include: (1) detection of anomalous water content of soils surrounding SSCs, (2) radionuclides contained in the leaking water, and (3) secondary signals such as temperature. ANL work scope includes mainly to (1) identify, in concert with the nuclear industry, the sensors and techniques that have most promise to detect radionuclides and/or associated chemical releases from SSCs of existing NPPs and (2) review and provide comments on the results of the NRC/NRR staff scoping study to identify candidate technologies. This report constitutes the ANL deliverable of the task-4 study. It covers a survey of sensor technologies and leak detection methods currently applied to leak monitoring at NPPs. The survey also provides a technology evaluation that identifies their strength and deficiency based on their detection speed, sensitivity, range and reliability. Emerging advanced technologies that are potentially capable of locating releases, identifying the radionuclides, and estimating their concentrations and distributions are also included in the report along with suggestions of required further research and development.

  3. Visual Analytics for Power Grid Contingency Analysis

    SciTech Connect (OSTI)

    Wong, Pak C.; Huang, Zhenyu; Chen, Yousu; Mackey, Patrick S.; Jin, Shuangshuang

    2014-01-20T23:59:59.000Z

    Contingency analysis is the process of employing different measures to model scenarios, analyze them, and then derive the best response to remove the threats. This application paper focuses on a class of contingency analysis problems found in the power grid management system. A power grid is a geographically distributed interconnected transmission network that transmits and delivers electricity from generators to end users. The power grid contingency analysis problem is increasingly important because of both the growing size of the underlying raw data that need to be analyzed and the urgency to deliver working solutions in an aggressive timeframe. Failure to do so may bring significant financial, economic, and security impacts to all parties involved and the society at large. The paper presents a scalable visual analytics pipeline that transforms about 100 million contingency scenarios to a manageable size and form for grid operators to examine different scenarios and come up with preventive or mitigation strategies to address the problems in a predictive and timely manner. Great attention is given to the computational scalability, information scalability, visual scalability, and display scalability issues surrounding the data analytics pipeline. Most of the large-scale computation requirements of our work are conducted on a Cray XMT multi-threaded parallel computer. The paper demonstrates a number of examples using western North American power grid models and data.

  4. Analysis of Power System Dynamics Subject to Stochastic Power Injections

    E-Print Network [OSTI]

    Liberzon, Daniel

    Abstract--We propose a framework to study the impact of stochastic active/reactive power injections. In this framework the active/reactive power injections evolve according to a continuous-time Markov chain (CTMC) model. The DAE model is linearized around a nominal set of active/reactive power injections

  5. Computing High Accuracy Power Spectra with Pico

    E-Print Network [OSTI]

    William A. Fendt; Benjamin D. Wandelt

    2007-12-02T23:59:59.000Z

    This paper presents the second release of Pico (Parameters for the Impatient COsmologist). Pico is a general purpose machine learning code which we have applied to computing the CMB power spectra and the WMAP likelihood. For this release, we have made improvements to the algorithm as well as the data sets used to train Pico, leading to a significant improvement in accuracy. For the 9 parameter nonflat case presented here Pico can on average compute the TT, TE and EE spectra to better than 1% of cosmic standard deviation for nearly all $\\ell$ values over a large region of parameter space. Performing a cosmological parameter analysis of current CMB and large scale structure data, we show that these power spectra give very accurate 1 and 2 dimensional parameter posteriors. We have extended Pico to allow computation of the tensor power spectrum and the matter transfer function. Pico runs about 1500 times faster than CAMB at the default accuracy and about 250,000 times faster at high accuracy. Training Pico can be done using massively parallel computing resources, including distributed computing projects such as Cosmology@Home. On the homepage for Pico, located at http://cosmos.astro.uiuc.edu/pico, we provide new sets of regression coefficients and make the training code available for public use.

  6. The Eval that Men Do A Large-scale Study of the Use of Eval in JavaScript Applications

    E-Print Network [OSTI]

    Vitek, Jan

    The Eval that Men Do A Large-scale Study of the Use of Eval in JavaScript Applications Gregor. Transforming text into executable code with a function such as Java- Script's eval endows programmers with the ability to extend applications, at any time, and in almost any way they choose. But, this expressive power

  7. Wind Speed Forecasting for Power System Operation 

    E-Print Network [OSTI]

    Zhu, Xinxin

    2013-07-22T23:59:59.000Z

    In order to support large-scale integration of wind power into current electric energy system, accurate wind speed forecasting is essential, because the high variation and limited predictability of wind pose profound challenges to the power system...

  8. Florida Electrical Power Plant Siting Act (Florida)

    Broader source: Energy.gov [DOE]

    The Power Plant Siting Act (PPSA) is the state’s centralized process for licensing large power plants. One license—a certification— replaces local and state permits. Local governments and state...

  9. Conic optimization of electric power systems

    E-Print Network [OSTI]

    Taylor, Joshua Adam

    2011-01-01T23:59:59.000Z

    The electric power grid is recognized as an essential modern infrastructure that poses numerous canonical design and operational problems. Perhaps most critically, the inherently large scale of the power grid and similar ...

  10. Wind Speed Forecasting for Power System Operation

    E-Print Network [OSTI]

    Zhu, Xinxin

    2013-07-22T23:59:59.000Z

    In order to support large-scale integration of wind power into current electric energy system, accurate wind speed forecasting is essential, because the high variation and limited predictability of wind pose profound challenges to the power system...

  11. levels, the large change in the carrier density results in both large linear as well as large nonlinear chirp. If an appropriate

    E-Print Network [OSTI]

    Baker, R. Jacob

    below its threshold whereas for achieving nearly transform-limited pulses with high peak power, biaslevels, the large change in the carrier density results in both large linear as well as large compensate for this large linear chirp, a relatively shorter compressed pulse will be realised (at 1·5 m

  12. A systems engineering approach to the analysis of Wireless Power Transmission Systems

    E-Print Network [OSTI]

    Brown, Alan Madden

    1993-01-01T23:59:59.000Z

    , the Soviet Union was given credit for fundmg a large development program, with a Solar Power Satellite (SPS) being the eventual goal A 1987 London Times Article presented evidence of such a program, with quotes from Soviet officials indicating... detailed feasibility studies of Solar Power Satellites and other apphcations of WPT technology [(61. The United States has several programs under consideration, although few are being funded at levels needed for technology development A terrestrial...

  13. Measuring and tuning energy efficiency on large scale high performance computing platforms.

    SciTech Connect (OSTI)

    Laros, James H., III

    2011-08-01T23:59:59.000Z

    Recognition of the importance of power in the field of High Performance Computing, whether it be as an obstacle, expense or design consideration, has never been greater and more pervasive. While research has been conducted on many related aspects, there is a stark absence of work focused on large scale High Performance Computing. Part of the reason is the lack of measurement capability currently available on small or large platforms. Typically, research is conducted using coarse methods of measurement such as inserting a power meter between the power source and the platform, or fine grained measurements using custom instrumented boards (with obvious limitations in scale). To collect the measurements necessary to analyze real scientific computing applications at large scale, an in-situ measurement capability must exist on a large scale capability class platform. In response to this challenge, we exploit the unique power measurement capabilities of the Cray XT architecture to gain an understanding of power use and the effects of tuning. We apply these capabilities at the operating system level by deterministically halting cores when idle. At the application level, we gain an understanding of the power requirements of a range of important DOE/NNSA production scientific computing applications running at large scale (thousands of nodes), while simultaneously collecting current and voltage measurements on the hosting nodes. We examine the effects of both CPU and network bandwidth tuning and demonstrate energy savings opportunities of up to 39% with little or no impact on run-time performance. Capturing scale effects in our experimental results was key. Our results provide strong evidence that next generation large-scale platforms should not only approach CPU frequency scaling differently, but could also benefit from the capability to tune other platform components, such as the network, to achieve energy efficient performance.

  14. Large Magnetization at Carbon Surfaces

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn12electron 9 5 - -/e),,sand CERNLand andComputingLargeLarge

  15. Solar irradiance forecasting at multiple time horizons and novel methods to evaluate uncertainty

    E-Print Network [OSTI]

    Marquez, Ricardo

    2012-01-01T23:59:59.000Z

    114 Solar Irradiance And Power Output Variabilitytechniques for solar power output with no exogenous inputs.and their effect on solar power output. For large scale

  16. Energy Storage for the Power Grid

    SciTech Connect (OSTI)

    Wang, Wei; Imhoff, Carl; Vaishnav, Dave

    2014-04-23T23:59:59.000Z

    The iron vanadium redox flow battery was developed by researchers at Pacific Northwest National Laboratory as a solution to large-scale energy storage for the power grid.

  17. Energy Storage for the Power Grid

    ScienceCinema (OSTI)

    Wang, Wei; Imhoff, Carl; Vaishnav, Dave

    2014-06-12T23:59:59.000Z

    The iron vanadium redox flow battery was developed by researchers at Pacific Northwest National Laboratory as a solution to large-scale energy storage for the power grid.

  18. BONNEVILLE POWER ADMINISTRATION FOR IMMEDIATE RELEASE

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    energy savings in all sectors of the economy and together they have saved enough electricity through energy efficiency projects to power four large American cities....

  19. Electrical Power Supply Applications Engineer | Princeton Plasma...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    the services of an Electrical Engineer with experience in the design, procurement, commissioning, and operation of large electrical power systems and associated equipment for use...

  20. Carnot Cycle at Finite Power: Attainability of Maximal Efficiency

    E-Print Network [OSTI]

    Armen E. Allahverdyan; Karen V. Hovhannisyan; Alexey V. Melkikh; Sasun G. Gevorkian

    2013-12-12T23:59:59.000Z

    We want to understand whether and to which extent the maximal (Carnot) efficiency for heat engines can be reached at a finite power. To this end we generalize the Carnot cycle so that it is not restricted to slow processes. We show that for realistic (i.e. not purposefully-designed) engine-bath interactions, the work-optimal engine performing the generalized cycle close to the maximal efficiency has a long cycle time and hence vanishing power. This aspect is shown to relate to the theory of computational complexity. A physical manifestation of the same effect is the Levinthal's paradox in the protein folding problem. The resolution of this paradox for realistic proteins allows to construct engines that can extract at a finite power 40% of the maximally possible work reaching 90% of the maximal efficiency. For purposefully designed engine-bath interactions, the Carnot efficiency is achievable at a large power.

  1. Chamber dynamic research with pulsed power

    SciTech Connect (OSTI)

    PETERSON,ROBERT R.; OLSON,CRAIG L.; RENK,TIMOTHY J.; ROCHAU,GARY E.; SWEENEY,MARY ANN

    2000-05-15T23:59:59.000Z

    In Inertial Fusion Energy (IFE), Target Chamber Dynamics (TCD) is an integral part of the target chamber design and performance. TCD includes target output deposition of target x-rays, ions and neutrons in target chamber gases and structures, vaporization and melting of target chamber materials, radiation-hydrodynamics in target chamber vapors and gases, and chamber conditions at the time of target and beam injections. Pulsed power provides a unique environment for IFE-TCD validation experiments in two important ways: they do not require the very clean conditions which lasers need and they currently provide large x-ray and ion energies.

  2. Wind Power: How Much, How Soon, and At What Cost?

    E-Print Network [OSTI]

    Wiser, Ryan H

    2010-01-01T23:59:59.000Z

    Evaluation of Global Wind Power." Journal of Geophysical2008. "The Economics of Wind Power with Energy Storage."Economics of Large-Scale Wind Power in a Carbon Constrained

  3. Sandia Energy - Offshore Wind RD&D: Large Offshore Rotor Development

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Offshore Wind RD&D: Large Offshore Rotor Development Home Stationary Power Energy Conversion Efficiency Wind Energy Offshore Wind Offshore Wind RD&D: Large Offshore Rotor...

  4. High-Power Zinc-Air Energy Storage: Enhanced Metal-Air Energy Storage System with Advanced Grid-Interoperable Power Electronics Enabling Scalability and Ultra-Low Cost

    SciTech Connect (OSTI)

    None

    2010-10-01T23:59:59.000Z

    GRIDS Project: Fluidic is developing a low-cost, rechargeable, high-power module for Zinc-air batteries that will be used to store renewable energy. Zinc-air batteries are traditionally found in small, non-rechargeable devices like hearing aids because they are well-suited to delivering low levels of power for long periods of time. Historically, Zinc-air batteries have not been as useful for applications which require periodic bursts of power, like on the electrical grid. Fluidic hopes to fill this need by combining the high energy, low cost, and long run-time of a Zinc-air battery with new chemistry providing high power, high efficiency, and fast response. The battery module could allow large grid-storage batteries to provide much more power on very short demand—the most costly kind of power for utilities—and with much more versatile performance.

  5. Electromagnetic pulse research on electric power systems: Program summary and recommendations. Power Systems Technology Program

    SciTech Connect (OSTI)

    Barnes, P.R.; McConnell, B.W.; Van Dyke, J.W. [Oak Ridge National Lab., TN (United States); Tesche, F.M. [Tesche (F.M.), Dallas, TX (United States); Vance, E.F. [Vance (E.F.), Fort Worth, TX (United States)

    1993-01-01T23:59:59.000Z

    A single nuclear detonation several hundred kilometers above the central United States will subject much of the nation to a high-altitude electromagnetic pulse (BENT). This pulse consists of an intense steep-front, short-duration transient electromagnetic field, followed by a geomagnetic disturbance with tens of seconds duration. This latter environment is referred to as the magnetohydrodynamic electromagnetic pulse (NMENT). Both the early-time transient and the geomagnetic disturbance could impact the operation of the nation`s power systems. Since 1983, the US Department of Energy has been actively pursuing a research program to assess the potential impacts of one or more BENT events on the nation`s electric energy supply. This report summarizes the results of that program and provides recommendations for enhancing power system reliability under HENT conditions. A nominal HENP environment suitable for assessing geographically large systems was developed during the program and is briefly described in this report. This environment was used to provide a realistic indication of BEMP impacts on electric power systems. It was found that a single high-altitude burst, which could significantly disturb the geomagnetic field, may cause the interconnected power network to break up into utility islands with massive power failures in some areas. However, permanent damage would be isolated, and restoration should be possible within a few hours. Multiple bursts would likely increase the blackout areas, component failures, and restoration time. However, a long-term blackout of many months is unlikely because major power system components, such as transformers, are not likely to be damaged by the nominal HEND environment. Moreover, power system reliability, under both HENT and normal operating conditions, can be enhanced by simple, and often low cost, modifications to current utility practices.

  6. Gradient Flow of O(N) nonlinear sigma model at large N

    E-Print Network [OSTI]

    Sinya Aoki; Kengo Kikuchi; Tetsuya Onogi

    2015-05-03T23:59:59.000Z

    We study the gradient flow equation for the O(N) nonlinear sigma model in two dimensions at large N. We parameterize solution of the field at flow time t in powers of bare fields by introducing the coefficient function X_n for the n-th power term (n=1,3,...). Reducing the flow equation by keeping only the contributions at leading order in large N, we obtain a set of equations for X_n's, which can be solved iteratively starting from n=1. For n=1 case, we find an explicit form of the exact solution. Using this solution, we show that the two point function at finite flow time t is finite. As an application, we obtain the non-perturbative running coupling defined from the energy density. We also discuss the solution for n=3 case.

  7. Active Power Controls from Wind Power: Bridging the Gaps

    SciTech Connect (OSTI)

    Ela, E.; Gevorgian, V.; Fleming, P.; Zhang, Y. C.; Singh, M.; Muljadi, E.; Scholbrook, A.; Aho, J.; Buckspan, A.; Pao, L.; Singhvi, V.; Tuohy, A.; Pourbeik, P.; Brooks, D.; Bhatt, N.

    2014-01-01T23:59:59.000Z

    This paper details a comprehensive study undertaken by the National Renewable Energy Laboratory, Electric Power Research Institute, and the University of Colorado to understand how the contribution of wind power providing active power control (APC) can benefit the total power system economics, increase revenue streams, improve the reliability and security of the power system, and provide superior and efficient response while reducing any structural and loading impacts that may reduce the life of the wind turbine or its components. The study includes power system simulations, control simulations, and actual field tests using turbines at NREL's National Wind Technology Center (NWTC). The study focuses on synthetic inertial control, primary frequency control, and automatic generation control, and analyzes timeframes ranging from milliseconds to minutes to the lifetime of wind turbines, locational scope ranging from components of turbines to large wind plants to entire synchronous interconnections, and additional topics ranging from economics to power system engineering to control design.

  8. Naturalistic Decision Making for Power System Operators

    SciTech Connect (OSTI)

    Greitzer, Frank L.; Podmore, Robin; Robinson, Marck; Ey, Pamela

    2010-02-01T23:59:59.000Z

    Motivation – Investigations of large-scale outages in the North American interconnected electric system often attribute the causes to three T’s: Trees, Training and Tools. To document and understand the mental processes used by expert operators when making critical decisions, a naturalistic decision making (NDM) model was developed. Transcripts of conversations were analyzed to reveal and assess NDM-based performance criteria. Findings/Design – An item analysis indicated that the operators’ Situation Awareness Levels, mental models, and mental simulations can be mapped at different points in the training scenario. This may identify improved training methods or analytical/ visualization tools. Originality/Value – This study applies for the first time, the concepts of Recognition Primed Decision Making, Situation Awareness Levels and Cognitive Task Analysis to training of electric power system operators. Take away message – The NDM approach provides a viable framework for systematic training management to accelerate learning in simulator-based training scenarios for power system operators and teams.

  9. Numerical methods for the solution of large and very large, sparse Lyapunov equations

    SciTech Connect (OSTI)

    Hodel, A.S.

    1989-01-01T23:59:59.000Z

    In this dissertation the author considers the numerical solution of large (100 {le} n {le} 1000) and very large (n {ge} 1000), sparse Lyapunov equations AX-+ XA' + Q = 0. The author first presents a parallel version of the Hammarling algorithm for the solution of Lyapunov equations where the coefficient matrix A is large and dense. The author then presents a novel parallel algorithm for the solution of Lyapunov equations where A is large and banded. A detailed analysis of the computational requirements in tandem with the results of numerical experiments with these algorithms on an Alliant FX-8 multiprocessor is provided. In the second half of this dissertation, the author considers the numerical solution of Lyapunov equations where the coefficient matrix A is very large and sparse. Under these conditions, the solution X of the Lyapunov equation is typically full rank and dense. The associated excessive storage requirements compel us to compute low rank approximations of the solution X of the Lyapunov equation. The author presents in detail two methods for the low rank approximate solution of the Lyapunov equation. The first method, Trace Maximization, computes an orthogonal matrix V {element of}{Re}{sup n{times}k} that maximizes the trace of the solution {Sigma}{sub V} of the associated reduced order Lyapunov equation (V'AV){Sigma}{sub V} + {Sigma}{sub V}(V'A'V) + V'QV = 0. While Trace Maximization is an effective method for low rank approximation of explicitly specified Hermitian matrices, the author shows that Trace Maximization is not an effective strategy for low rank approximation of positive semidefinite Hermitian matrices X that are implicitly specified as the solution of a Lyapunov equation. Our second algorithm for low rank approximate solution of Lyapunov equations, Approximate Power Iteration, attempts to directly compute an orthogonal basis of the dominant eigenspace of the solution X.

  10. StochasticStochasticStochasticStochasticStochasticStochasticStochasticStochastic Modeling of a PowerModeling of a PowerModeling of a PowerModeling of a PowerModeling of a PowerModeling of a PowerModeling of a PowerModeling of a Power--------Managed System

    E-Print Network [OSTI]

    Pedram, Massoud

    Modeling of a PowerModeling of a Power-------- Managed System: Construction andManaged System: Construction andManaged managementDynamic power management !! Simple systemsSimple systems "" Continuous Time Markov Decision Process designaware compiler and architecture design !! Power control and management techniquesPower control

  11. The Impact of Wind Power Projects on Residential Property Values in the United States: A Multi-Site Hedonic Analysis

    E-Print Network [OSTI]

    Hoen, Ben

    2010-01-01T23:59:59.000Z

    2002) Economic Impacts of Wind Power in Kittitas County, WA.about Large Offshore Wind Power: Underlying Factors. EnergyOpinion on Offshore Wind Power - Interim Report. University

  12. Nuclear Power

    E-Print Network [OSTI]

    Vilhena and Bardo E.J. Bodmann Carbon-#1;? in Terrestrial and Aquatic Environment of Ignalina Nuclear Power Plant: Sources of Production, Releases and Dose Estimates #3;?? Jonas Mazeika Impact of radionuclide discharges from Temel?n Nuclear Power... (chapter 5), ? Instrumentation and control (chapter 6), ? Diagnostics (chapter 7), ? Safety evaluation methods (chapters 6, 8, 9 and 10), ? Environment and nuclear power plants (chapters 11 - 15), ? Human factors (chapter 16), ? Software development...

  13. Power LCAT

    ScienceCinema (OSTI)

    Drennen, Thomas

    2014-06-27T23:59:59.000Z

    POWER LCAT is a software tool used to compare elements of efficiency, cost, and environmental effects between different sources of energy.

  14. Power LCAT

    SciTech Connect (OSTI)

    Drennen, Thomas

    2012-08-15T23:59:59.000Z

    POWER LCAT is a software tool used to compare elements of efficiency, cost, and environmental effects between different sources of energy.

  15. Wind Power in Norway -Innovation strategy -

    E-Print Network [OSTI]

    Müller, Ralf R.

    Wind Power in Norway - Innovation strategy - Liana Müller #12;2 Introduction The existing energy and, at the same time, not to irreversibly damage the life on Earth. The use of waterpower, wind power, the growth of the wind power industry in Norway. In the sequel, a brief history of wind power energy

  16. Simulation of the Visual Effects of Power Plant Plumes1

    E-Print Network [OSTI]

    Standiford, Richard B.

    -fired power plant with six 500 MW coal-fired power plants located at hypothetical sites in southeastern Utah coal-fired power plants are greater than those from oil or natural gas. If we must use more coal, how in a comparison of large and small coal-fired power plants in the West. Using hypothetical power plants

  17. Wiedenhfer et al. Inter-Organizational Crisis Management Infrastructure for Electrical Power Breakdowns

    E-Print Network [OSTI]

    Wiedenhöfer et al. Inter-Organizational Crisis Management Infrastructure for Electrical Power Breakdowns Inter-Organizational Crisis Management Infrastructures for Electrical Power Breakdowns Torben-Organizational Crisis Management Infrastructure for Electrical Power Breakdowns medium to large power outages among

  18. Power system

    DOE Patents [OSTI]

    Hickam, Christopher Dale (Glasford, IL)

    2008-03-18T23:59:59.000Z

    A power system includes a prime mover, a transmission, and a fluid coupler having a selectively engageable lockup clutch. The fluid coupler may be drivingly connected between the prime mover and the transmission. Additionally, the power system may include a motor/generator drivingly connected to at least one of the prime mover and the transmission. The power-system may also include power-system controls configured to execute a control method. The control method may include selecting one of a plurality of modes of operation of the power system. Additionally, the control method may include controlling the operating state of the lockup clutch dependent upon the mode of operation selected. The control method may also include controlling the operating state of the motor/generator dependent upon the mode of operation selected.

  19. Abstract--This paper introduces the power quality issues of wind power installations in a historic perspective, as the

    E-Print Network [OSTI]

    1 Abstract--This paper introduces the power quality issues of wind power installations large offshore wind farms connected at transmission level. In this perspective, the power quality issues and global issues related to the power system control and stability. Power quality characteristics of wind

  20. SLH Timing Belt Powertrain

    SciTech Connect (OSTI)

    Schneider, Abe

    2014-04-09T23:59:59.000Z

    The main goal of this proposal was to develop and test a novel powertrain solution for the SLH hydroEngine?, a low-cost, efficient low-head hydropower technology. Nearly two-thirds of U.S. renewable electricity is produced by hydropower (EIA 2010). According to the U.S. Department of Energy; this amount could be increased by 50% with small hydropower plants, often using already-existing dams (Hall 2004). There are more than 80,000 existing dams, and of these, less than 4% generate power (Blankinship 2009). In addition, there are over 800 irrigation districts in the U.S., many with multiple, non-power, low-head drops. These existing, non-power dams and irrigation drops could be retrofitted to produce distributed, baseload, renewable energy with appropriate technology. The problem is that most existing dams are low-head, or less than 30 feet in height (Ragon 2009). Only about 2% of the available low-head hydropower resource in the U.S. has been developed, leaving more than 70 GW of annual mean potential low-head capacity untapped (Hall 2004). Natel Energy, Inc. is developing a low-head hydropower turbine that operates efficiently at heads less than 6 meters and is cost-effective for deployment across multiple low-head structures. Because of the unique racetrack-like path taken by the prime-movers in the SLH, a flexible powertrain is required. Historically, the only viable technological solution was roller chain. Despite the having the ability to easily attach blades, roller chain is characterized by significant drawbacks, including high cost, wear, and vibration from chordal action. Advanced carbon-#12;fiber-reinforced timing belts have been recently developed which, coupled with a novel belt attachment system developed by Natel Energy, result in a large reduction in moving parts, reduced mass and cost, and elimination of chordal action for increased fatigue life. The work done in this project affirmatively addressed each of the following 3 major uncertainties concerning a timing-belt based hydroEngine ?powertrain: 1. Can a belt handle the high torques and power loads demanded by the SLH? (Yes.) 2. Can the SLH blades be mounted to belt with a connection that can withstand the loads encountered in operation? (Yes.) 3. Can the belt, with blade attachments, live through the required cyclic loading? (Yes.) The research adds to the general understanding of sustainable small hydropower systems by using innovative system testing to develop and demonstrate performance of a novel powertrain solution, enabling a new type of hydroelectric turbine to be commercially developed. The technical effectiveness of the methods investigated has been shown to be positive through an extensive design and testing process accommodating many constraints and goals, with a major emphasis on high cycle fatigue life. Economic feasibility of the innovations has been demonstrated through many iterations of design for manufacturability and cost reduction. The project is of benefit to the public because it has helped to develop a solution to a major problem -- despite the large available potential for new low-head hydropower, high capital costs and high levelized cost of electricity (LCOE) continue to be major barriers to project development. The hydroEngine? represents a significant innovation, leveraging novel fluid mechanics and mechanical configuration to allow lower-cost turbine manufacture and development of low head hydropower resources.

  1. ASSESSING POWER PLANT COOLING WATER INTAKE SYSTEM

    E-Print Network [OSTI]

    ASSESSING POWER PLANT COOLING WATER INTAKE SYSTEM ENTRAINMENT IMPACTS Prepared For: California be obvious that large studies like these require the coordinated work of many people. We would first like from the Duke Energy South Bay and Morro Bay power plants and the PG&E Diablo Canyon Power Plant

  2. Combustion powered linear actuator

    DOE Patents [OSTI]

    Fischer, Gary J. (Albuquerque, NM)

    2007-09-04T23:59:59.000Z

    The present invention provides robotic vehicles having wheeled and hopping mobilities that are capable of traversing (e.g. by hopping over) obstacles that are large in size relative to the robot and, are capable of operation in unpredictable terrain over long range. The present invention further provides combustion powered linear actuators, which can include latching mechanisms to facilitate pressurized fueling of the actuators, as can be used to provide wheeled vehicles with a hopping mobility.

  3. Strathclyde powerS ahead

    E-Print Network [OSTI]

    Mottram, Nigel

    Strathclyde powerS ahead the future of renewable energy SHARING AND ENHANCING RESEARCH Discover the vision of Principal Professor Jim McDonald THE FUTURE OF ENERGY Strathclyde pioneers renewableEdicinE Snapshot the reSearcher Following a decade of environmental research in her native egypt, nabila saleem

  4. Reactive power compensating system

    DOE Patents [OSTI]

    Williams, Timothy J. (Redondo Beach, CA); El-Sharkawi, Mohamed A. (Renton, WA); Venkata, Subrahmanyam S. (Seattle, WA)

    1987-01-01T23:59:59.000Z

    The reactive power of an induction machine is compensated by providing fixed capacitors on each phase line for the minimum compensation required, sensing the current on one line at the time its voltage crosses zero to determine the actual compensation required for each phase, and selecting switched capacitors on each line to provide the balance of the compensation required.

  5. ac power source: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    and Information Sciences Websites Summary: source. Al- ternative power sources such as fuel cells (FCs) have substantially different power-time systems and embedded systems...

  6. New Siemens Research Turbine - time lapse

    SciTech Connect (OSTI)

    None

    2009-01-01T23:59:59.000Z

    The National Renewable Energy Laboratory (NREL) and Siemens Energy Inc. recently commissioned a new 2.3 megawatt Siemens wind turbine at NREL's National Wind Technology Center. This video shows a time lapse of the installation. The turbine is the centerpiece of a multi-year project to study the performance and aerodynamics of a new class of large, land-based machines — in what will be the biggest government-industry research partnership for wind power generation ever undertaken in the U.S.

  7. Large Magnetization at Carbon Surfaces

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn12electron 9 5 - -/e),,sand CERNLand andComputingLarge

  8. Large Magnetization at Carbon Surfaces

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn12electron 9 5 - -/e),,sand CERNLandLarge Magnetization at

  9. Large Magnetization at Carbon Surfaces

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn12electron 9 5 - -/e),,sand CERNLandLarge Magnetization

  10. Power combiner

    DOE Patents [OSTI]

    Arnold, Mobius; Ives, Robert Lawrence

    2006-09-05T23:59:59.000Z

    A power combiner for the combining of symmetric and asymmetric traveling wave energy comprises a feed waveguide having an input port and a launching port, a reflector for reflecting launched wave energy, and a final waveguide for the collection and transport of launched wave energy. The power combiner has a launching port for symmetrical waves which comprises a cylindrical section coaxial to the feed waveguide, and a launching port for asymmetric waves which comprises a sawtooth rotated about a central axis.

  11. The ARIES-RS power core -- Recent development in Li/V designs

    SciTech Connect (OSTI)

    Sze, D.K.; Billone, M.C.; Hua, T.Q. [and others

    1997-04-01T23:59:59.000Z

    The ARIES-RS fusion power plant design study is based on reversed-shear (RS) physics with a Li/V (lithium breeder and vanadium structure) blanket. The reversed-shear discharge has been documented in many large tokamak experiments. The plasma in the RS mode has a high beta, low current, and low current drive requirements. Therefore, it is an attractive physics regime for a fusion power plant. The blanket system based on a Li/V has high temperature operating capability, good tritium breeding, excellent high heat flux removal capability, long structural life time, low activation, low after heat and good safety characteristics. For these reasons, the ARIES-RS reactor study selected Li/V as the reference blanket. The combination of attractive physics and attractive blanket engineering is expected to result in a superior power plant design. This paper summarizes the power core design of the ARIES-RS power plant study.

  12. Cleco Power- Power Miser New Home Program

    Broader source: Energy.gov [DOE]

    Louisiana's Cleco Power offers energy efficiency incentives to eligible customers. Cleco Power offers a rate discount for residential customers building homes that meet the Power Miser Program...

  13. Cortical Hemisphere Registration Via Large Deformation Diffeomorphic Metric Curve

    E-Print Network [OSTI]

    Qiu, Anqi

    on the relation between individual brains and the atlas. This is a powerful approach allowing us to study a largeCortical Hemisphere Registration Via Large Deformation Diffeomorphic Metric Curve Mapping Anqi Qiu1 Science, Johns Hopkins University Abstract. We present large deformation diffeomorphic metric curve

  14. Long-Term Wind Power Variability

    SciTech Connect (OSTI)

    Wan, Y. H.

    2012-01-01T23:59:59.000Z

    The National Renewable Energy Laboratory started collecting wind power data from large commercial wind power plants (WPPs) in southwest Minnesota with dedicated dataloggers and communication links in the spring of 2000. Over the years, additional WPPs in other areas were added to and removed from the data collection effort. The longest data stream of actual wind plant output is more than 10 years. The resulting data have been used to analyze wind power fluctuations, frequency distribution of changes, the effects of spatial diversity, and wind power ancillary services. This report uses the multi-year wind power data to examine long-term wind power variability.

  15. Studies on the switching speed effect of the phase shift keying in SLED for generating high power microwave

    E-Print Network [OSTI]

    Zhengfeng, Xiong; Jian, Yu; Huaibi, Chen; Hui, Ning

    2015-01-01T23:59:59.000Z

    SLAC energy doubler (SLED) type radio-frequency pulse compressors are widely used in large-scale particle accelerators for converting long-duration moderate-power input pulse into short-duration high-power output pulse. The phase shift keying (PSK) is one of the key components in SLED pulse compression systems. Performance of the PSK will influence the output characteristics of SLED, such as rise-time of the output pulse, the maximal peak power gain, and the energy efficiency. In this paper, high power microwave source based on power combining and pulse compression of conventional klystrons was introduced, the nonideal PSK with slow switching speed and without power output during the switching process were investigated, the experimental results with nonideal PSK agreed well with the analytical results.

  16. Solar irradiance forecasting at multiple time horizons and novel methods to evaluate uncertainty

    E-Print Network [OSTI]

    Marquez, Ricardo

    2012-01-01T23:59:59.000Z

    119 Battery Storage System Applied To Mitigate Large Pvgenerated and battery power and actual PV power output for agenerated and battery power and actual PV power output for a

  17. Primer on Wind Power for Utility Applications

    SciTech Connect (OSTI)

    Wan, Y.

    2005-12-01T23:59:59.000Z

    The wind industry still faces many market barriers, some of which stem from utilities' lack of experience with the technology. Utility system operators and planners need to understand the effects of fluctuating wind power on system regulation and stability. Without high-frequency wind power data and realistic wind power plant models to analyze the problem, utilities often rely on conservative assumptions and worst-case scenarios to make engineering decisions. To remedy the situation, the National Renewable Energy Laboratory (NREL) has undertaken a project to record long-term, high-resolution (1-hertz [Hz]) wind power output data from large wind power plants in various regions. The objective is to systematically collect actual wind power data from large commercial wind power plants so that wind power fluctuations, their frequency distribution, the effects of spatial diversity, and the ancillary services of large commercial wind power plants can be analyzed. It also aims to provide the industry with nonproprietary wind power data in different wind regimes for system planning and operating impact studies. This report will summarize the results of data analysis performed at NREL and discuss the wind power characteristics related to power system operation and planning.

  18. Reactive Power Compensator.

    DOE Patents [OSTI]

    El-Sharkawi, M.A.; Venkata, S.S.; Chen, M.; Andexler, G.; Huang, T.

    1992-07-28T23:59:59.000Z

    A system and method for determining and providing reactive power compensation for an inductive load. A reactive power compensator (50,50') monitors the voltage and current flowing through each of three distribution lines (52a, 52b, 52c), which are supplying three-phase power to one or more inductive loads. Using signals indicative of the current on each of these lines when the voltage waveform on the line crosses zero, the reactive power compensator determines a reactive power compensator capacitance that must be connected to the lines to maintain a desired VAR level, power factor, or line voltage. Alternatively, an operator can manually select a specific capacitance for connection to each line, or the capacitance can be selected based on a time schedule. The reactive power compensator produces control signals, which are coupled through optical fibers (102/106) to a switch driver (110, 110') to select specific compensation capacitors (112) for connections to each line. The switch driver develops triggering signals that are supplied to a plurality of series-connected solid state switches (350), which control charge current in one direction in respect to ground for each compensation capacitor. During each cycle, current flows from ground to charge the capacitors as the voltage on the line begins to go negative from its positive peak value. The triggering signals are applied to gate the solid state switches into a conducting state when the potential on the lines and on the capacitors reaches a negative peak value, thereby minimizing both the potential difference and across the charge current through the switches when they begin to conduct. Any harmonic distortion on the potential and current carried by the lines is filtered out from the current and potential signals used by the reactive power compensator so that it does not affect the determination of the required reactive compensation. 26 figs.

  19. Reactive power compensator

    DOE Patents [OSTI]

    El-Sharkawi, Mohamed A. (Renton, WA); Venkata, Subrahmanyam S. (Woodinville, WA); Chen, Mingliang (Kirkland, WA); Andexler, George (Everett, WA); Huang, Tony (Seattle, WA)

    1992-01-01T23:59:59.000Z

    A system and method for determining and providing reactive power compensation for an inductive load. A reactive power compensator (50,50') monitors the voltage and current flowing through each of three distribution lines (52a, 52b, 52c), which are supplying three-phase power to one or more inductive loads. Using signals indicative of the current on each of these lines when the voltage waveform on the line crosses zero, the reactive power compensator determines a reactive power compensator capacitance that must be connected to the lines to maintain a desired VAR level, power factor, or line voltage. Alternatively, an operator can manually select a specific capacitance for connection to each line, or the capacitance can be selected based on a time schedule. The reactive power compensator produces control signals, which are coupled through optical fibers (102/106) to a switch driver (110, 110') to select specific compensation capacitors (112) for connections to each line. The switch driver develops triggering signals that are supplied to a plurality of series-connected solid state switches (350), which control charge current in one direction in respect to ground for each compensation capacitor. During each cycle, current flows from ground to charge the capacitors as the voltage on the line begins to go negative from its positive peak value. The triggering signals are applied to gate the solid state switches into a conducting state when the potential on the lines and on the capacitors reaches a negative peak value, thereby minimizing both the potential difference and across the charge current through the switches when they begin to conduct. Any harmonic distortion on the potential and current carried by the lines is filtered out from the current and potential signals used by the reactive power compensator so that it does not affect the determination of the required reactive compensation.

  20. Grid-scale Fluctuations and Forecast Error in Wind Power

    E-Print Network [OSTI]

    G. Bel; C. P. Connaughton; M. Toots; M. M. Bandi

    2015-03-29T23:59:59.000Z

    The fluctuations in wind power entering an electrical grid (Irish grid) were analyzed and found to exhibit correlated fluctuations with a self-similar structure, a signature of large-scale correlations in atmospheric turbulence. The statistical structure of temporal correlations for fluctuations in generated and forecast time series was used to quantify two types of forecast error: a timescale error ($e_{\\tau}$) that quantifies the deviations between the high frequency components of the forecast and the generated time series, and a scaling error ($e_{\\zeta}$) that quantifies the degree to which the models fail to predict temporal correlations in the fluctuations of the generated power. With no $a$ $priori$ knowledge of the forecast models, we suggest a simple memory kernel that reduces both the timescale error ($e_{\\tau}$) and the scaling error ($e_{\\zeta}$).

  1. Grid-scale Fluctuations and Forecast Error in Wind Power

    E-Print Network [OSTI]

    Bel, G; Toots, M; Bandi, M M

    2015-01-01T23:59:59.000Z

    The fluctuations in wind power entering an electrical grid (Irish grid) were analyzed and found to exhibit correlated fluctuations with a self-similar structure, a signature of large-scale correlations in atmospheric turbulence. The statistical structure of temporal correlations for fluctuations in generated and forecast time series was used to quantify two types of forecast error: a timescale error ($e_{\\tau}$) that quantifies the deviations between the high frequency components of the forecast and the generated time series, and a scaling error ($e_{\\zeta}$) that quantifies the degree to which the models fail to predict temporal correlations in the fluctuations of the generated power. With no $a$ $priori$ knowledge of the forecast models, we suggest a simple memory kernel that reduces both the timescale error ($e_{\\tau}$) and the scaling error ($e_{\\zeta}$).

  2. Real-Time Building Energy Simulation Using EnergyPlus and the Building Controls Test Bed

    E-Print Network [OSTI]

    Pang, Xiufeng

    2013-01-01T23:59:59.000Z

    Figure 9 Lighting electric power comparison between real-measurement Lighting Electric Power Comparison kW real-time

  3. High-power-density spot cooling using bulk thermoelectrics

    E-Print Network [OSTI]

    Zhang, Y; Shakouri, A; Zeng, G H

    2004-01-01T23:59:59.000Z

    model, the cooling power densities of the devices can alsothe cooling power densities 2–24 times. Experimentally, the14 4 OCTOBER 2004 High-power-density spot cooling using bulk

  4. Wireless power transfer for scaled electronic biomedical implants

    E-Print Network [OSTI]

    Theilmann, Paul Thomas

    2012-01-01T23:59:59.000Z

    S   67 Figure 2.16: Power loss due to induced eddyFigure 4.9: Instantaneous power loss in branch 1 versus time6 slope which describes power loss versus distance for an

  5. Dynamic Power Management of High Performance Network on Chip

    E-Print Network [OSTI]

    Mandal, Suman Kalyan

    2012-02-14T23:59:59.000Z

    . The addition of intelligent networking on the chip adds to the chip’s power consumption thus making management of communication power an interesting and challenging research problem. While VLSI techniques have evolved over time to enable power reduction...

  6. Wind Power Variability, Its Cost, and Effect on Power Plant Emissions

    E-Print Network [OSTI]

    Wind Power Variability, Its Cost, and Effect on Power Plant Emissions A Dissertation Submitted The recent growth in wind power is transforming the operation of electricity systems by introducing. As a result, system operators are learning in real-time how to incorporate wind power and its variability

  7. CARIBBEAN COLLOQUIUM ON POWER QUALITY (CCPQ), JUNE 2003 100 Defining Reactive Power in Circuit Transients via

    E-Print Network [OSTI]

    Stankoviæ, Aleksandar

    CARIBBEAN COLLOQUIUM ON POWER QUALITY (CCPQ), JUNE 2003 100 Defining Reactive Power in Circuit the notion of reactive power during circuit transients. The definition we propose is based on the concept, namely Short- Time Fourier Coefficients and Haar Wavelets. We illustrate this "dynamic" reactive power

  8. Multiphoton ionization of large water clusters

    SciTech Connect (OSTI)

    Apicella, B., E-mail: apicella@irc.cnr.it [Combustion Research Institute, IRC–C.N.R., P.le Tecchio 80, 80125 Napoli (Italy); Li, X. [Key Laboratory of Power Machinery and Engineering, Ministry of Education, Shanghai Jiao Tong University, Shanghai 200240 (China); Passaro, M. [CNISM and Chemical Engineering, Materials and Industrial Production Department, University of Naples “Federico II,” P.le Tecchio 80, 80125 Napoli (Italy); Spinelli, N. [CNISM and Physics Department, University of Naples “Federico II,” Via Cintia, 80124 Napoli (Italy); Wang, X. [SPIN–C.N.R., Via Cintia, 80124 Napoli (Italy)

    2014-05-28T23:59:59.000Z

    Water clusters are multimers of water molecules held together by hydrogen bonds. In the present work, multiphoton ionization in the UV range coupled with time of flight mass spectrometry has been applied to water clusters with up to 160 molecules in order to obtain information on the electronic states of clusters of different sizes up to dimensions that can approximate the bulk phase. The dependence of ion intensities of water clusters and their metastable fragments produced by laser ionization at 355 nm on laser power density indicates a (3+1)-photon resonance-enhanced multiphoton ionization process. It also explains the large increase of ionization efficiency at 355 nm compared to that at 266 nm. Indeed, it was found, by applying both nanosecond and picosecond laser ionization with the two different UV wavelengths, that no water cluster sequences after n = 9 could be observed at 266 nm, whereas water clusters up to m/z 2000 Th in reflectron mode and m/z 3000 Th in linear mode were detected at 355 nm. The agreement between our findings on clusters of water, especially true in the range with n > 10, and reported data for liquid water supports the hypothesis that clusters above a critical dimension can approximate the liquid phase. It should thus be possible to study clusters just above 10 water molecules, for getting information on the bulk phase structure.

  9. Power electronics reliability.

    SciTech Connect (OSTI)

    Kaplar, Robert James; Brock, Reinhard C.; Marinella, Matthew; King, Michael Patrick; Stanley, James K.; Smith, Mark A.; Atcitty, Stanley

    2010-10-01T23:59:59.000Z

    The project's goals are: (1) use experiments and modeling to investigate and characterize stress-related failure modes of post-silicon power electronic (PE) devices such as silicon carbide (SiC) and gallium nitride (GaN) switches; and (2) seek opportunities for condition monitoring (CM) and prognostics and health management (PHM) to further enhance the reliability of power electronics devices and equipment. CM - detect anomalies and diagnose problems that require maintenance. PHM - track damage growth, predict time to failure, and manage subsequent maintenance and operations in such a way to optimize overall system utility against cost. The benefits of CM/PHM are: (1) operate power conversion systems in ways that will preclude predicted failures; (2) reduce unscheduled downtime and thereby reduce costs; and (3) pioneering reliability in SiC and GaN.

  10. A High Performance Computing Network and System Simulator for the Power Grid: NGNS^2

    SciTech Connect (OSTI)

    Villa, Oreste; Tumeo, Antonino; Ciraci, Selim; Daily, Jeffrey A.; Fuller, Jason C.

    2012-11-11T23:59:59.000Z

    Designing and planing next generation power grid sys- tems composed of large power distribution networks, monitoring and control networks, autonomous generators and consumers of power requires advanced simulation infrastructures. The objective is to predict and analyze in time the behavior of networks of systems for unexpected events such as loss of connectivity, malicious attacks and power loss scenarios. This ultimately allows one to answer questions such as: “What could happen to the power grid if ...”. We want to be able to answer as many questions as possible in the shortest possible time for the largest possible systems. In this paper we present a new High Performance Computing (HPC) oriented simulation infrastructure named Next Generation Network and System Simulator (NGNS2 ). NGNS2 allows for the distribution of a single simulation among multiple computing elements by using MPI and OpenMP threads. NGNS2 provides extensive configuration, fault tolerant and load balancing capabilities needed to simulate large and dynamic systems for long periods of time. We show the preliminary results of the simulator running approximately two million simulated entities both on a 64-node commodity Infiniband cluster and a 48-core SMP workstation.

  11. Power Factor Compensation (PFC) Power Factor Compensation

    E-Print Network [OSTI]

    Knobloch,Jürgen

    Power Factor Compensation (PFC) Power Factor Compensation The power factor (PF) is defined as the ratio between the active power and the apparent power of a system. If the current and voltage are periodic with period , and [ ), then the active power is defined by ( ) ( ) (their inner product

  12. Star Power

    ScienceCinema (OSTI)

    None

    2014-11-18T23:59:59.000Z

    The U.S. Department of Energy's Princeton Plasma Physics Laboratory has released ''Star Power,'' a new informational video that uses dramatic and beautiful images and thought-provoking interviews to highlight the importance of the Laboratory's research into magnetic fusion.

  13. Star Power

    SciTech Connect (OSTI)

    None

    2014-10-17T23:59:59.000Z

    The U.S. Department of Energy's Princeton Plasma Physics Laboratory has released ''Star Power,'' a new informational video that uses dramatic and beautiful images and thought-provoking interviews to highlight the importance of the Laboratory's research into magnetic fusion.

  14. Power Systems Integration Laboratory (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2011-10-01T23:59:59.000Z

    This fact sheet describes the purpose, lab specifications, applications scenarios, and information on how to partner with NREL's Power Systems Integration Laboratory at the Energy Systems Integration Facility. At NREL's Power Systems Integration Laboratory in the Energy Systems Integration Facility (ESIF), research focuses on developing and testing large-scale distributed energy systems for grid-connected, stand-alone, and microgrid applications. The laboratory can accommodate large power system components such as inverters for photovoltaic (PV) and wind systems, diesel and natural gas generators, battery packs, microgrid interconnection switchgear, and vehicles. Closely coupled with the research electrical distribution bus at the ESIF, the Power Systems Integration Laboratory will offer power testing capability of megawatt-scale DC and AC power systems, as well as advanced hardware-in-the-loop and model-in-the-loop simulation capabilities. Thermal heating and cooling loops and fuel also allow testing of combined heating/cooling and power systems (CHP).

  15. POWER ANISOTROPY IN THE MAGNETIC FIELD POWER SPECTRAL TENSOR OF SOLAR WIND TURBULENCE

    SciTech Connect (OSTI)

    Wicks, R. T.; Horbury, T. S. [Physics Department, Imperial College London, London SW7 2AZ (United Kingdom); Forman, M. A. [Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY 11790-3800 (United States); Oughton, S., E-mail: r.wicks@imperial.ac.uk [Department of Mathematics, University of Waikato, Hamilton (New Zealand)

    2012-02-10T23:59:59.000Z

    We observe the anisotropy of the power spectral tensor of magnetic field fluctuations in the fast solar wind for the first time. In heliocentric RTN coordinates, the power in each element of the tensor has a unique dependence on the angle between the magnetic field and velocity of the solar wind ({theta}{sub B}) and the angle of the vector in the plane perpendicular to the velocity ({phi}{sub B}). We derive the geometrical effect of the high speed flow of the solar wind past the spacecraft on the power spectrum in the frame of the plasma P(k) to arrive at the observed power spectrum P(f, {theta}{sub B}, {phi}{sub B}) based on a scalar field description of turbulence theory. This allows us to predict the variation in the {phi}{sub B} direction and compare it to the data. We then transform the observations from RTN coordinates to magnetic-field-aligned coordinates. The observed reduced power spectral tensor matches the theoretical predictions we derive in both RTN and field-aligned coordinates, which means that the local magnetic field we calculate with wavelet envelope functions is an accurate representation of the physical axis of symmetry for the turbulence and implies that on average the turbulence is axisymmetric. We also show that we can separate the dominant toroidal component of the turbulence from the smaller but significant poloidal component and that these have different power anisotropy. We also conclude that the magnetic helicity is anisotropic and mostly two dimensional, arising from wavevectors largely confined to the plane perpendicular to B .

  16. Smart Power Laboratory (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2011-10-01T23:59:59.000Z

    This fact sheet describes the purpose, lab specifications, applications scenarios, and information on how to partner with NREL's Smart Power Laboratory at the Energy Systems Integration Facility. Research at NREL's Smart Power Laboratory in the Energy Systems Integration Facility (ESIF) focuses on the development and integration of smart technologies including the integration of distributed and renewable energy resources through power electronics and smart energy management for building applications. The 5,300 sq. ft. laboratory is designed to be highly flexible and configurable, essential for a large variety of smart power applications that range from developing advanced inverters and power converters to testing residential and commercial scale meters and control technologies. Some application scenarios are: (1) Development of power converters for integration of distributed and renewable energy resources; (2) Development of advanced controls for smart power electronics; (3) Testing prototype and commercially available power converters for electrical interconnection and performance, advanced functionality, long duration reliability and safety; and (4) Hardware-in-loop development and testing of power electronics systems in smart distribution grid models.

  17. A knowledge-based system for control of xenon-induced spatial power oscillations during load-follow operations

    SciTech Connect (OSTI)

    Chung, Sun-Kyo; Danofsky, R.A.; Spinrad, B.I.

    1988-01-01T23:59:59.000Z

    As is well known, large pressurized water reactors (PWRs) are subject to xenon-induced axial power oscillations at some time during a given cycle. Attention to this behavior is required during load-follow operations. A knowledge-based system for controlling xenon-induced spatial power oscillations is described. Experience with a limited set of load-follow patterns has demonstrated that the system is capable of providing advice on appropriate control actions. A simulation model, coupled with a rule-learning process, has been found to be a useful way for determining appropriate weights for the rules that relate power patterns and control actions.

  18. Probing Signal Design for Power System Identification

    SciTech Connect (OSTI)

    Pierre, John W.; Zhou, Ning; Tuffner, Francis K.; Hauer, John F.; Trudnowski, Daniel J.; Mittelstadt, William

    2010-05-31T23:59:59.000Z

    This paper investigates the design of effective input signals for low-level probing of power systems. In 2005, 2006, and 2008 the Western Electricity Coordinating Council (WECC) conducted four large-scale system wide tests of the western interconnected power system where probing signals were injected by modulating the control signal at the Celilo end of the Pacific DC intertie. A major objective of these tests is the accurate estimation of the inter-area electromechanical modes. A key aspect of any such test is the design of an effective probing signal that leads to measured outputs rich in information about the modes. This paper specifically studies low-level probing signal design for power-system identification. The paper describes the design methodology and the advantages of this new probing signal which was successfully applied during these tests. This probing input is a multi-sine signal with its frequency content focused in the range of the inter-area modes. The period of the signal is over two minutes providing high-frequency resolution. Up to 15 cycles of the signal are injected resulting in a processing gain of 15. The resulting system response is studied in the time and frequency domains. Because of the new probing signal characteristics, these results show significant improvement in the output SNR compared to previous tests.

  19. Prospective Climate Change Impact on Large Rivers

    E-Print Network [OSTI]

    Julien, Pierre Y.

    1 Prospective Climate Change Impact on Large Rivers in the US and South Korea Pierre Y. Julien Dept. of Civil and Environ. Eng. Colorado State University Seoul, South Korea August 11, 2009 Climate Change and Large Rivers 1. Climatic changes have been on-going for some time; 2. Climate changes usually predict

  20. Large Power Transformers and the U.S. Electric Grid

    Energy Savers [EERE]

    ISER June 2012 13 electrical steel, the major manufacturing countries being Japan, Germany, United States, France, Korea, and China (see Figure 5). 50 The technology for...

  1. Advanced Electro-thermal SPICE Modelling of Large Power IGBTs

    E-Print Network [OSTI]

    Ng, Wai Tung

    self-heating and latchup. A thermal circuit representing the characteristics of the IGBT package junction temperature variations due to self-heating. The resulting electro-thermal model is validated] is developed here for the study of dynamic performance variations due to self-heating effects

  2. Advanced electrothermal Spice modelling of large power IGBTs

    E-Print Network [OSTI]

    Ng, Wai Tung

    operation including self- heating and latchup. A thermal circuit representing the characteristics of instantaneous junction temperature variations owing to self-heating. The resulting electrothermal model developed for the study of dynamic performance variations due to self-heating effects and prediction

  3. Oxide based thermoelectric materials for large scale power generation

    E-Print Network [OSTI]

    Song, Yang, M. Eng. Massachusetts Institute of Technology

    2008-01-01T23:59:59.000Z

    The thermoelectric (TE) devices are based on the Seebeck and Peltier effects, which describe the conversion between temperature gradient and electricity. The effectiveness of the material performance can be described by ...

  4. Online Monitoring Technical Basis and Analysis Framework for Large Power

    Energy Savers [EERE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directed offOCHCO2:Introduction toManagementOPAM PolicyOfEnergy Online Classified or

  5. Idaho Power - Large Commercial Custom Efficiency Program | Department of

    Broader source: Energy.gov (indexed) [DOE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742Energy ChinaofSchaefer To:Department ofOralGovernmentStandards forandDepartmentEnergy

  6. Robust, Multifunctional Joint for Large Scale Power Production Stacks -

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's PossibleRadiation Protection TechnicalResonantNovember 15 toAdvances

  7. Large Component Removal/Disposal

    SciTech Connect (OSTI)

    Wheeler, D. M.

    2002-02-27T23:59:59.000Z

    This paper describes the removal and disposal of the large components from Maine Yankee Atomic Power Plant. The large components discussed include the three steam generators, pressurizer, and reactor pressure vessel. Two separate Exemption Requests, which included radiological characterizations, shielding evaluations, structural evaluations and transportation plans, were prepared and issued to the DOT for approval to ship these components; the first was for the three steam generators and one pressurizer, the second was for the reactor pressure vessel. Both Exemption Requests were submitted to the DOT in November 1999. The DOT approved the Exemption Requests in May and July of 2000, respectively. The steam generators and pressurizer have been removed from Maine Yankee and shipped to the processing facility. They were removed from Maine Yankee's Containment Building, loaded onto specially designed skid assemblies, transported onto two separate barges, tied down to the barges, th en shipped 2750 miles to Memphis, Tennessee for processing. The Reactor Pressure Vessel Removal Project is currently under way and scheduled to be completed by Fall of 2002. The planning, preparation and removal of these large components has required extensive efforts in planning and implementation on the part of all parties involved.

  8. ACCURATE MODELS FOR ESTIMATING AREA AND POWER OF FPGA IMPLEMENTATIONS

    E-Print Network [OSTI]

    Kambhampati, Subbarao

    -circuit power and leak- age power. Models for large parametrized IP cores have been pre- sented in [6], [7]; [6] presents area models and detailed power model for fast Hadamard transform, and [7] presents area modelsACCURATE MODELS FOR ESTIMATING AREA AND POWER OF FPGA IMPLEMENTATIONS Lanping Deng, Kanwaldeep

  9. NONLINEAR CONTROL OF POWER NETWORK MODELS USING FEEDBACK LINEARIZATION

    E-Print Network [OSTI]

    Wedeward, Kevin

    network can affect each other. We consider a simple model of a power system derived from singular analysis of large electric power networks is in- creasingly important as power systems become larger construct minimally complicated dynamical models of power networks as affine nonlinear control systems

  10. A Tariff for Reactive Power

    SciTech Connect (OSTI)

    Kueck, John D [ORNL; Kirby, Brendan J [ORNL; Li, Fangxing [ORNL; Tufon, Christopher [Pacific Gas and Electric Company; Isemonger, Alan [California Independent System Operator

    2008-07-01T23:59:59.000Z

    Two kinds of power are required to operate an electric power system: real power, measured in watts, and reactive power, measured in volt-amperes reactive or VARs. Reactive power supply is one of a class of power system reliability services collectively known as ancillary services, and is essential for the reliable operation of the bulk power system. Reactive power flows when current leads or lags behind voltage. Typically, the current in a distribution system lags behind voltage because of inductive loads such as motors. Reactive power flow wastes energy and capacity and causes voltage droop. To correct lagging power flow, leading reactive power (current leading voltage) is supplied to bring the current into phase with voltage. When the current is in phase with voltage, there is a reduction in system losses, an increase in system capacity, and a rise in voltage. Reactive power can be supplied from either static or dynamic VAR sources. Static sources are typically transmission and distribution equipment, such as capacitors at substations, and their cost has historically been included in the revenue requirement of the transmission operator (TO), and recovered through cost-of-service rates. By contrast, dynamic sources are typically generators capable of producing variable levels of reactive power by automatically controlling the generator to regulate voltage. Transmission system devices such as synchronous condensers can also provide dynamic reactive power. A class of solid state devices (called flexible AC transmission system devices or FACTs) can provide dynamic reactive power. One specific device has the unfortunate name of static VAR compensator (SVC), where 'static' refers to the solid state nature of the device (it does not include rotating equipment) and not to the production of static reactive power. Dynamic sources at the distribution level, while more costly would be very useful in helping to regulate local voltage. Local voltage regulation would reduce system losses, increase circuit capacity, increase reliability, and improve efficiency. Reactive power is theoretically available from any inverter-based equipment such as photovoltaic (PV) systems, fuel cells, microturbines, and adjustable-speed drives. However, the installation is usually only economical if reactive power supply is considered during the design and construction phase. In this report, we find that if the inverters of PV systems or the generators of combined heat and power (CHP) systems were designed with capability to supply dynamic reactive power, they could do this quite economically. In fact, on an annualized basis, these inverters and generators may be able to supply dynamic reactive power for about $5 or $6 per kVAR. The savings from the local supply of dynamic reactive power would be in reduced losses, increased capacity, and decreased transmission congestion. The net savings are estimated to be about $7 per kVAR on an annualized basis for a hypothetical circuit. Thus the distribution company could economically purchase a dynamic reactive power service from customers for perhaps $6/kVAR. This practice would provide for better voltage regulation in the distribution system and would provide an alternate revenue source to help amortize the cost of PV and CHP installations. As distribution and transmission systems are operated under rising levels of stress, the value of local dynamic reactive supply is expected to grow. Also, large power inverters, in the range of 500 kW to 1 MW, are expected to decrease in cost as they become mass produced. This report provides one data point which shows that the local supply of dynamic reactive power is marginally profitable at present for a hypothetical circuit. We expect that the trends of growing power flow on the existing system and mass production of inverters for distributed energy devices will make the dynamic supply of reactive power from customers an integral component of economical and reliable system operation in the future.

  11. Large mode-volume, large beta, photonic crystal laser resonator

    SciTech Connect (OSTI)

    Dezfouli, Mohsen Kamandar; Dignam, Marc M. [Department of Physics, Engineering Physics and Astronomy, Queen’s University, Kingston, ON K7L 3N6 (Canada)

    2014-12-15T23:59:59.000Z

    We propose an optical resonator formed from the coupling of 13, L2 defects in a triangular-lattice photonic crystal slab. Using a tight-binding formalism, we optimized the coupled-defect cavity design to obtain a resonator with predicted single-mode operation, a mode volume five times that of an L2-cavity mode and a beta factor of 0.39. The results are confirmed using finite-difference time domain simulations. This resonator is very promising for use as a single mode photonic crystal vertical-cavity surface-emitting laser with high saturation output power compared to a laser consisting of one of the single-defect cavities.

  12. Power superconducting power transmission cable

    DOE Patents [OSTI]

    Ashworth, Stephen P. (Cambridge, GB)

    2003-01-01T23:59:59.000Z

    The present invention is for a compact superconducting power transmission cable operating at distribution level voltages. The superconducting cable is a conductor with a number of tapes assembled into a subconductor. These conductors are then mounted co-planarly in an elongated dielectric to produce a 3-phase cable. The arrangement increases the magnetic field parallel to the tapes thereby reducing ac losses.

  13. COMMISSIONDECISION Small Power Plant Exemption (06-SPPE-2)

    E-Print Network [OSTI]

    ............................................................................. 14 Transmission Line Safety & Nuisance...................................................... 15 to review and license proposals to construct and operate large electric power plants, includingCOMMISSIONDECISION Small Power Plant Exemption (06-SPPE-2) Imperial County Order No: 07

  14. Can New Nuclear Power Plants be Project Financed?

    E-Print Network [OSTI]

    Taylor, Simon

    This paper considers the prospects for financing a wave of new nuclear power plants (NPP) using project financing, which is used widely in large capital intensive infrastructure investments, including the power and gas sectors, but has...

  15. SENSIBLE HEAT STORAGE FOR A SOLAR THERMAL POWER PLANT

    E-Print Network [OSTI]

    Baldwin, Thomas F.

    2011-01-01T23:59:59.000Z

    for concentrating solar-thermal energy use a large number ofBoth solar power plants absorb thermal energy in high-of a solar power plant that converts thermal energy into

  16. High-density thermoelectric power generation and nanoscale thermal metrology

    E-Print Network [OSTI]

    Mayer, Peter (Peter Matthew), 1978-

    2007-01-01T23:59:59.000Z

    Thermoelectric power generation has been around for over 50 years but has seen very little large scale implementation due to the inherently low efficiencies and powers available from known materials. Recent material advances ...

  17. Optimization of the axial power shape in pressurized water reactors

    E-Print Network [OSTI]

    Melik, M. A.

    1981-01-01T23:59:59.000Z

    Analytical and numerical methods have been applied to find the optimum axial power profile in a PWR with respect to uranium utilization. The preferred shape was found to have a large central region of uniform power density, ...

  18. Power Right. Power Smart. Efficient Computer Power Supplies and...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AC power that you get from your electric company into the DC power consumed by most electronics, including your computer. We expect our power supplies to be safe, reliable, and...

  19. IEEE TRANSACTIONS ON POWER SYSTEMS, VOL. 20, NO. 1, FEBRUARY 2005 43 Power Transmission Network Design by Greedy

    E-Print Network [OSTI]

    Resende, Mauricio G. C.

    IEEE TRANSACTIONS ON POWER SYSTEMS, VOL. 20, NO. 1, FEBRUARY 2005 43 Power Transmission Network these different trajectories. The electric power system expansion planning task is a large- scale optimization), applied to solve static power transmission network design problems. This new approach uses generalized

  20. Silicon Valley Power and Oklahoma Municipal Power Authority Win...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Silicon Valley Power and Oklahoma Municipal Power Authority Win 2014 Public Power Wind Awards Silicon Valley Power and Oklahoma Municipal Power Authority Win 2014 Public Power Wind...