Sample records for ac power distribution

  1. High-frequency ac power distribution in space stations

    SciTech Connect

    Tsai, F.S.; Lee, F.C.Y. (Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (USA))

    1990-03-01

    A utility-type, 20 kHz, ac power distribution system for space station employing resonant power-conversion techniques is presented. The system converts raw dc voltage from photovoltaic cells or three-phase, low-frequency ac voltage from a solar dynamic generator into a regulated, 20 kHz, ac voltage for distribution among various loads. Operations of the components of the system such as driver invertor, dc receiver, bidirectional receiver, and three-phase ac receiver are discussed. EASY5 computer modeling and simulations are performed to study the local and global performances of the system.

  2. High-Frequency ac Power-Distribution System

    NASA Technical Reports Server (NTRS)

    Hansen, Irving G.; Mildice, James

    1987-01-01

    Loads managed automatically under cycle-by-cycle control. 440-V rms, 20-kHz ac power system developed. System flexible, versatile, and "transparent" to user equipment, while maintaining high efficiency and low weight. Electrical source, from dc to 2,200-Hz ac converted to 440-V rms, 20-kHz, single-phase ac. Power distributed through low-inductance cables. Output power either dc or variable ac. Energy transferred per cycle reduced by factor of 50. Number of parts reduced by factor of about 5 and power loss reduced by two-thirds. Factors result in increased reliability and reduced costs. Used in any power-distribution system requiring high efficiency, high reliability, low weight, and flexibility to handle variety of sources and loads.

  3. Investigation of CandidateTechniquesfor High-Frequency AC Distributed Power Systems'

    E-print Network

    Wu, Shin-Tson

    Investigation of CandidateTechniquesfor High-Frequency AC Distributed Power Systems' Shiguo Luo clock rates. Distributed power systems meet this new need because it provides better point- of years, DC distributed power systems @PSs) have been used extensively in mainframe computer systems

  4. A High Efficiency High Frequency Resonant Inverter for High Frequency AC Power Distribution Architectures

    Microsoft Academic Search

    Ye Zhongming; Jain Praveen; Sen Paresh

    2006-01-01

    A high efficiency two-stage resonant inverter with effective control of both the magnitude and phase angle of the output voltage was proposed in this paper for high frequency AC (HFAC) power distribution applications, where a number of resonant inverters need to be paralleled. In order to parallel multiple resonant inverters of the same operation frequency, each inverter module need independent

  5. Analysis and modeling of high frequency ac power distribution systems

    Microsoft Academic Search

    Zhongming Ye; Zhixiang Liang

    2008-01-01

    Small signal modeling of power converters is important for analysis, fast simulation and control design. The small signal modeling based on state-space averaging method has been widely used for PWM converters since the ripples are small in the inductor current or capacitor voltage. The model becomes less accurate from the real circuit if the ripple is not ignorable. In a

  6. Power conversion distribution system using a resonant high-frequency AC link

    NASA Technical Reports Server (NTRS)

    Sood, P. K.; Lipo, T. A.

    1986-01-01

    Static power conversion systems based on a resonant high frequency (HF) link offers a significant reduction in the size and weight of the equipment over that achieved with conventional approaches, especially when multiple sources and loads are to be integrated. A faster system response and absence of audible noise are the other principal characteristics of such systems. A conversion configuration based on a HF link which is suitable for applications requiring distributed power is proposed.

  7. Phasor-Domain Modeling of Resonant Inverters for High-Frequency AC Power Distribution Systems

    Microsoft Academic Search

    Zhongming Ye; Praveen K. Jain; Paresh C. Sen

    2009-01-01

    The circuit modeling and analysis of resonant inverters is complex because the state variables such as inductor currents and capacitor voltages are AC dominant. The phasor dynamic modeling method maps the periodical time-varying state variables into stationary frame for each harmonic of interest. Correspondingly, the circuit is decomposed into two DC subcircuits, the state variables of which are the time-varying

  8. AC power system breadboard

    NASA Technical Reports Server (NTRS)

    Wappes, Loran J.; Sundberg, R.; Mildice, J.; Peterson, D.; Hushing, S.

    1987-01-01

    The object of this program was to design, build, test, and deliver a high-frequency (20-kHz) Power System Breadboard which would electrically approximate a pair of dual redundant power channels of an IOC Space Station. This report describes that program, including the technical background, and discusses the results, showing that the major assumptions about the characteristics of this class of hardware (size, mass, efficiency, control, etc.) were substantially correct. This testbed equipment has been completed and delivered to LeRC, where it is operating as a part of the Space Station Power System Test Facility.

  9. AC power conditioners

    SciTech Connect

    Clark, J.W.

    1990-01-01

    This book contains chapters devoted to the following topics: RFI Noise Reduction, Surge Reduction, Line Isolation, Thyristor Regulator, Constant-Voltage Transformer, Tap Changer, Power and Control Elements, Regulators, Switching Converter, Thermal Management, Filter Design, Feedback and Control Circuity, System Configuration.

  10. 21 CFR 886.4440 - AC-powered magnet.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...AC-powered magnet. (a) Identification. An AC-powered magnet is an AC-powered device that generates a magnetic field intended to find and remove metallic foreign bodies from eye tissue. (b) Classification. Class...

  11. 21 CFR 886.4440 - AC-powered magnet.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...AC-powered magnet. (a) Identification. An AC-powered magnet is an AC-powered device that generates a magnetic field intended to find and remove metallic foreign bodies from eye tissue. (b) Classification. Class...

  12. 21 CFR 886.4440 - AC-powered magnet.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...AC-powered magnet. (a) Identification. An AC-powered magnet is an AC-powered device that generates a magnetic field intended to find and remove metallic foreign bodies from eye tissue. (b) Classification. Class...

  13. 21 CFR 886.4440 - AC-powered magnet.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...AC-powered magnet. (a) Identification. An AC-powered magnet is an AC-powered device that generates a magnetic field intended to find and remove metallic foreign bodies from eye tissue. (b) Classification. Class...

  14. 21 CFR 886.4440 - AC-powered magnet.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...AC-powered magnet. (a) Identification. An AC-powered magnet is an AC-powered device that generates a magnetic field intended to find and remove metallic foreign bodies from eye tissue. (b) Classification. Class...

  15. Distributed energy resources in grid interactive AC microgrids

    Microsoft Academic Search

    Xiongfei Wang; Josep M. Guerrero; Zhe Chen; Frede Blaabjerg

    2010-01-01

    Increased penetration of distributed energy resources (DER) and large-scale deployment of renewable energy sources are challenging the entire architecture of traditional power system. Microgrid, featuring higher flexibility and reliability, becomes an attractive candidate for the configuration of future electrical power system. This paper gives an overview of DER units in the grid interactive ac microgrid. The options in structures and

  16. An AC-AC inverter with build-in power factor correction soft-switching and a unified controller

    Microsoft Academic Search

    Wennan Guo; Praveen K. Jain

    2001-01-01

    This paper presents a full bridge AC-AC inverter for high frequency power distribution system with power factor correction stage controlled by a unified controller. The proposed inverter has the following features: (1) load independent output voltage with constant frequency and very low total harmonic distortion; (2) soft switching of the full bridge switches for a wide range of input voltage

  17. AC and DC power transmission

    SciTech Connect

    Not Available

    1985-01-01

    The technical and economic assessment of AC and DC transmission systems; long distance transmission, cable transmission, system inter-connection, voltage support, reactive compensation, stabilisation of systems; parallel operation of DC links with AC systems; comparison between alternatives for particular schemes. Design and application equipment: design, testing and application of equipment for HVDC, series and shunt static compensated AC schemes, including associated controls. Installations: overall design of stations and conductor arrangements for HVDC, series and shunt static AC schemes including insulation co-ordination. System analysis and modelling.

  18. Wide band AC power line characterization

    Microsoft Academic Search

    D. Liu; E. Flint; B. Gaucher; Y. Kwark

    1999-01-01

    This paper presents data characterizing the household AC power line in the 1-60 MHz band. Two types of measurements were performed: transmission and noise sampling. The transmission measurements were done by using the impulse channel sounding method, so both the line attenuation and the delay spread were obtained. The noise measurements include: power line background noise, appliance noise, and noise

  19. Combined Operation of AC and DC Distribution System with Distributed Generation Units

    NASA Astrophysics Data System (ADS)

    Noroozian, Reza; Abedi, Mehrdad; Gharehpetian, Gevorg

    2010-07-01

    This paper presents a DC distribution system which has been supplied by external AC systems as well as local DG units in order to demonstrate an overall solution to power quality issue. In this paper, the proposed operation method is demonstrated by simulation of power transfer between external AC systems, DG units, AC and DC loads. The power flow control in DC distribution system has been achieved by network converters and DG converters. Also, the mathematical model of the network, DG and load converters are obtained by using the average technique, which allows converter systems accurately simulated and control strategies for this converters is achieved. A suitable control strategy for network converters has been proposed that involves DC voltage droop regulator and novel instantaneous power regulation scheme. Also, a novel control technique has been proposed for DG converters. In this paper, a novel control system based on stationary and synchronously rotating reference frame has been proposed for load converters for supplying AC loads connected to the DC bus by balanced voltages. The several case studies have been studied based on proposed methods. The simulation results show that DC distribution systems including DG units can improve the power quality at the point of common coupling (PCC) in the power distribution system or industrial power system.

  20. Reliability of emergency ac power systems at nuclear power plants

    SciTech Connect

    Battle, R E; Campbell, D J

    1983-07-01

    Reliability of emergency onsite ac power systems at nuclear power plants has been questioned within the Nuclear Regulatory Commission (NRC) because of the number of diesel generator failures reported by nuclear plant licensees and the reactor core damage that could result from diesel failure during an emergency. This report contains the results of a reliability analysis of the onsite ac power system, and it uses the results of a separate analysis of offsite power systems to calculate the expected frequency of station blackout. Included is a design and operating experience review. Eighteen plants representative of typical onsite ac power systems and ten generic designs were selected to be modeled by fault trees. Operating experience data were collected from the NRC files and from nuclear plant licensee responses to a questionnaire sent out for this project.

  1. 21 CFR 888.1240 - AC-powered dynamometer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... An AC-powered dynamometer is an AC-powered device intended for medical purposes to assess neuromuscular function or degree of neuromuscular blockage by measuring, with a force transducer (a device that translates force into...

  2. 21 CFR 886.1850 - AC-powered slitlamp biomicroscope.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...slitlamp biomicroscope. (a) Identification. An AC-powered slitlamp biomicroscope is an AC-powered device that is a microscope intended for use in eye examination that projects into a patient's eye through a control diaphragm a thin, intense...

  3. 21 CFR 886.1850 - AC-powered slitlamp biomicroscope.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...slitlamp biomicroscope. (a) Identification. An AC-powered slitlamp biomicroscope is an AC-powered device that is a microscope intended for use in eye examination that projects into a patient's eye through a control diaphragm a thin, intense...

  4. 21 CFR 886.1850 - AC-powered slitlamp biomicroscope.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...slitlamp biomicroscope. (a) Identification. An AC-powered slitlamp biomicroscope is an AC-powered device that is a microscope intended for use in eye examination that projects into a patient's eye through a control diaphragm a thin, intense...

  5. 21 CFR 886.1850 - AC-powered slitlamp biomicroscope.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...slitlamp biomicroscope. (a) Identification. An AC-powered slitlamp biomicroscope is an AC-powered device that is a microscope intended for use in eye examination that projects into a patient's eye through a control diaphragm a thin, intense...

  6. 21 CFR 886.1850 - AC-powered slitlamp biomicroscope.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...slitlamp biomicroscope. (a) Identification. An AC-powered slitlamp biomicroscope is an AC-powered device that is a microscope intended for use in eye examination that projects into a patient's eye through a control diaphragm a thin, intense...

  7. A comparative study of electric power distribution systems for spacecraft

    NASA Technical Reports Server (NTRS)

    Stuart, Thomas A.; King, Roger J.

    1990-01-01

    The electric power distribution systems for spacecraft are compared concentrating on two interrelated issues: the choice between dc and high frequency ac, and the converter/inverter topology to be used at the power source. The relative merits of dc and ac distribution are discussed. Specific converter and inverter topologies are identified and analyzed in detail for the purpose of detailed comparison. Finally, specific topologies are recommended for use in dc and ac systems.

  8. Thermoelectric AC power sensor by CMOS technology

    Microsoft Academic Search

    Dominik Jaeggi; Henry Baltes; David Moser

    1992-01-01

    The authors report the development of a thermoelectric AC power sensor (thermoconverter) realized by industrial CMOS IC technology in combination with postprocessing micromachining. The sensor is based on a polysilicon heating resistor and a polysilicon\\/aluminum thermopile integrated on an oxide microbridge. The thermopile sensitivity is 9.9 mV\\/mW and the burn-out power of the sensor is 50 mW. The time constant

  9. The ac power system testbed

    NASA Technical Reports Server (NTRS)

    Mildice, J.; Sundberg, R.

    1987-01-01

    The object of this program was to design, build, test, and deliver a high frequency (20 kHz) Power System Testbed which would electrically approximate a single, separable power channel of an IOC Space Station. That program is described, including the technical background, and the results are discussed showing that the major assumptions about the characteristics of this class of hardware (size, mass, efficiency, control, etc.) were substantially correct. This testbed equipment was completed and delivered and is being operated as part of the Space Station Power System Test Facility.

  10. STATE OF CALIFORNIA DISTRIBUTED ENERGY STORAGE DX AC SYSTEMES ACCEPTANCE

    E-print Network

    STATE OF CALIFORNIA DISTRIBUTED ENERGY STORAGE DX AC SYSTEMES ACCEPTANCE CEC-MECH-14A (Revised 08 DISTRIBUTED ENERGY STORAGE DX AC SYSTEMES ACCEPTANCE CEC-MECH-14A (Revised 08/09) CALIFORNIA ENERGY COMMISSION CERTIFICATE OF ACCEPTANCE MECH-14A NA7.5.13 Distributed Energy Storage DX AC Systems Acceptance (Page 2 of 3

  11. AC\\/AC power conversion based on matrix converter topology with unidirectional switches

    Microsoft Academic Search

    Siyoung Kim; Seung-Ki Sul; Thomas A. Lipo

    2000-01-01

    In this paper, a new type of AC\\/AC power converter is proposed. The proposed converter is capable of direct AC\\/AC power conversion and, except for a few small snubber elements, it does not require the use of any input inductors or a DC-link capacitor. In contrast to the matrix converter, which requires bidirectional switches, the proposed converter consists of only

  12. Automated power distribution system hardware. [for space station power supplies

    NASA Technical Reports Server (NTRS)

    Anderson, Paul M.; Martin, James A.; Thomason, Cindy

    1989-01-01

    An automated power distribution system testbed for the space station common modules has been developed. It incorporates automated control and monitoring of a utility-type power system. Automated power system switchgear, control and sensor hardware requirements, hardware design, test results, and potential applications are discussed. The system is designed so that the automated control and monitoring of the power system is compatible with both a 208-V, 20-kHz single-phase AC system and a high-voltage (120 to 150 V) DC system.

  13. Distributed cooperative control of AC microgrids

    NASA Astrophysics Data System (ADS)

    Bidram, Ali

    In this dissertation, the comprehensive secondary control of electric power microgrids is of concern. Microgrid technical challenges are mainly realized through the hierarchical control structure, including primary, secondary, and tertiary control levels. Primary control level is locally implemented at each distributed generator (DG), while the secondary and tertiary control levels are conventionally implemented through a centralized control structure. The centralized structure requires a central controller which increases the reliability concerns by posing the single point of failure. In this dissertation, the distributed control structure using the distributed cooperative control of multi-agent systems is exploited to increase the secondary control reliability. The secondary control objectives are microgrid voltage and frequency, and distributed generators (DGs) active and reactive powers. Fully distributed control protocols are implemented through distributed communication networks. In the distributed control structure, each DG only requires its own information and the information of its neighbors on the communication network. The distributed structure obviates the requirements for a central controller and complex communication network which, in turn, improves the system reliability. Since the DG dynamics are nonlinear and non-identical, input-output feedback linearization is used to transform the nonlinear dynamics of DGs to linear dynamics. Proposed control frameworks cover the control of microgrids containing inverter-based DGs. Typical microgrid test systems are used to verify the effectiveness of the proposed control protocols.

  14. Industrial power distribution

    SciTech Connect

    Sorrells, M.A.

    1990-01-01

    This paper is a broad overview of industrial power distribution. Primary focus will be on selection of the various low voltage components to achieve the end product. Emphasis will be on the use of national standards to ensure a safe and well designed installation.

  15. A Distributed Generation Control Architecture for Islanded AC Microgrids

    E-print Network

    Dominguez-Garcia, Alejandro

    1 A Distributed Generation Control Architecture for Islanded AC Microgrids Stanton T. Cady, Student architecture for generation control in islanded microgrids, and illustrate the performance Member, IEEE Abstract In this paper, we propose a distributed architecture for generation control

  16. AC Bipolar Pulsed Power Supply for Reactive Magnetron Sputtering

    Microsoft Academic Search

    J. Garcia-Garcia; J. Pacheco-Sotelo; R. Valdivia-Barrientos; Carlos Rivera-Rodriguez; M. Pacheco-Pacheco; Jean Jacques Gonzalez; M. Nieto-Perez

    2011-01-01

    This paper presents an ac bipolar pulsed power sup- ply, which is used to drive a magnetron sputtering reactor operat- ing under reactive atmosphere. The power supply was tested for the deposition of thin films of ZnO:Al on glass and plastic sub- strates. Voltage, current, and optical spectroscopy measurements were performed during the discharge. The electrical aspects of the ac

  17. Modeling of an AC Power System for High Power Spacecraft

    NASA Astrophysics Data System (ADS)

    Stankovic, A. V.; Birchenough, A. G.; Kenny, B.; Kimnach, G.

    2004-02-01

    This paper presents an analysis and simulation of an AC power system for a high power spacecraft that primarily supplies rectified loads. Two different configurations consisting of a three-phase PM synchronous generator and an associated power electronics converter are compared and analyzed. The first configuration consists of a three-phase PM synchronous generator and a three-phase diode bridge supplying a DC load. The second configuration consists of a three-phase PM synchronous generator and a three-phase PWM rectifier supplying the DC load. The modeling equations for both systems are derived. The comparisons between the two different configurations are summarized in a table in terms of efficiency, harmonic content and DC voltage ripple. The simulation results obtained by using SIMULINK are presented.

  18. Inverter design for high frequency power distribution

    NASA Technical Reports Server (NTRS)

    King, R. J.

    1985-01-01

    A class of simple resonantly commutated inverters are investigated for use in a high power (100 KW - 1000 KW) high frequency (10 KHz - 20 KHz) AC power distribution system. The Mapham inverter is found to provide a unique combination of large thyristor turn-off angle and good utilization factor, much better than an alternate 'current-fed' inverter. The effects of loading the Mapham inverter entirely with rectifier loads are investigated by simulation and with an experimental 3 KW 20 KHz inverter. This inverter is found to be well suited to a power system with heavy rectifier loading.

  19. Automated Power-Distribution System

    NASA Technical Reports Server (NTRS)

    Thomason, Cindy; Anderson, Paul M.; Martin, James A.

    1990-01-01

    Automated power-distribution system monitors and controls electrical power to modules in network. Handles both 208-V, 20-kHz single-phase alternating current and 120- to 150-V direct current. Power distributed to load modules from power-distribution control units (PDCU's) via subsystem distributors. Ring busses carry power to PDCU's from power source. Needs minimal attention. Detects faults and also protects against them. Potential applications include autonomous land vehicles and automated industrial process systems.

  20. Controlled power interface between solar cells and AC source

    Microsoft Academic Search

    Koosuke Harada; Gen Zhao

    1993-01-01

    A novel interface circuit between solar cells and a commercial AC source using Van Allen's multivibrator is presented. In this circuit, the AC source is used as a backup for solar cells, and the source and load power flow is automatically balanced by the circuit itself without any external phase control. Based on the analysis of the characteristics of solar

  1. Automated Power-Distribution System

    NASA Technical Reports Server (NTRS)

    Ashworth, Barry; Riedesel, Joel; Myers, Chris; Miller, William; Jones, Ellen F.; Freeman, Kenneth; Walsh, Richard; Walls, Bryan K.; Weeks, David J.; Bechtel, Robert T.

    1992-01-01

    Autonomous power-distribution system includes power-control equipment and automation equipment. System automatically schedules connection of power to loads and reconfigures itself when it detects fault. Potential terrestrial applications include optimization of consumption of power in homes, power supplies for autonomous land vehicles and vessels, and power supplies for automated industrial processes.

  2. SSP Power Management and Distribution

    NASA Technical Reports Server (NTRS)

    Lynch, Thomas H.; Roth, A. (Technical Monitor)

    2000-01-01

    Space Solar Power is a NASA program sponsored by Marshall Space Flight Center. The Paper presented here represents the architectural study of a large power management and distribution (PMAD) system. The PMAD supplies power to a microwave array for power beaming to an earth rectenna (Rectifier Antenna). The power is in the GW level.

  3. Topologies of single-phase inverters for small distributed power generators: an overview

    Microsoft Academic Search

    Yaosuo Xue; Liuchen Chang; Sren Baekhj Kjaer; J. Bordonau; T. Shimizu

    2004-01-01

    This paper presents an overview of single-phase inverters developed for small distributed power generators. The functions of inverters in distributed power generation (DG) systems include dc-ac conversion, output power quality assurance, various protection mechanisms, and system controls. Unique requirements for small distributed power generation systems include low cost, high efficiency and tolerance for an extremely wide range of input voltage

  4. Reactive Power from Distributed Energy

    SciTech Connect

    Kueck, John; Kirby, Brendan; Rizy, Tom; Li, Fangxing; Fall, Ndeye

    2006-12-15

    Distributed energy is an attractive option for solving reactive power and distribution system voltage problems because of its proximity to load. But the cost of retrofitting DE devices to absorb or produce reactive power needs to be reduced. There also needs to be a market mechanism in place for ISOs, RTOs, and transmission operators to procure reactive power from the customer side of the meter where DE usually resides. (author)

  5. Resistojet control and power for high frequency ac buses

    NASA Technical Reports Server (NTRS)

    Gruber, Robert P.

    1987-01-01

    Resistojets are operational on many geosynchronous communication satellites which all use dc power buses. Multipropellant resistojets were selected for the Initial Operating Capability (IOC) Space Station which will supply 208 V, 20 kHz power. This paper discusses resistojet heater temperature controllers and passive power regulation methods for ac power systems. A simple passive power regulation method suitable for use with regulated sinusoidal or square wave power was designed and tested using the Space Station multipropellant resistojet. The breadboard delivered 20 kHz power to the resistojet heater. Cold start surge current limiting, a power efficiency of 95 percent, and power regulation of better than 2 percent were demonstrated with a two component, 500 W breadboard power controller having a mass of 0.6 kg.

  6. Power management and distribution technology

    NASA Technical Reports Server (NTRS)

    Dickman, John Ellis

    1993-01-01

    Power management and distribution (PMAD) technology is discussed in the context of developing working systems for a piloted Mars nuclear electric propulsion (NEP) vehicle. The discussion is presented in vugraph form. The following topics are covered: applications and systems definitions; high performance components; the Civilian Space Technology Initiative (CSTI) high capacity power program; fiber optic sensors for power diagnostics; high temperature power electronics; 200 C baseplate electronics; high temperature component characterization; a high temperature coaxial transformer; and a silicon carbide mosfet.

  7. Control Design of a Three-Phase Matrix-Converter-Based AC–AC Mobile Utility Power Supply

    Microsoft Academic Search

    Pericle Zanchetta; Patrick W. Wheeler; Jon C. Clare; Michael Bland; Lee Empringham; Dimosthenis Katsis

    2008-01-01

    This paper describes the control analysis and design of an ac-to-ac three-phase mobile utility power supply using a matrix converter capable of high-quality 50-, 60-, and 400-Hz output voltage and reduced input harmonic distortion. Instead of the traditional structure employing a diode bridge rectifier, a dc link and a pulsewidth-modulated inverter, a three-phase-to-three-phase direct ac-ac (matrix) converter has been used

  8. Distributed Space Solar Power

    NASA Technical Reports Server (NTRS)

    Fork, Richard L.

    2001-01-01

    The objective was to assess the feasibility of safely collecting solar power at geostationary orbit and delivering it to earth. A strategy which could harness a small fraction of the millions of gigawatts of sunlight passing near earth could adequately supply the power needs of earth and those of space exploration far into the future. Light collected and enhanced both spatially and temporally in space and beamed to earth provides probably the only practical means of safe and efficient delivery of this space solar power to earth. In particular, we analyzed the feasibility of delivering power to sites on earth at a comparable intensity, after conversion to a usable form, to existing power needs. Two major obstacles in the delivery of space solar power to earth are safety and the development of a source suitable for space. We focused our approach on: (1) identifying system requirements and designing a strategy satisfying current eye and skin safety requirements; and (2) identifying a concept for a potential space-based source for producing the enhanced light.

  9. ePOWER Seminar AC solar cells: A new breed of PV power generation

    E-print Network

    Abolmaesumi, Purang

    ePOWER Seminar AC solar cells: A new breed of PV power generation Professor Faisal Khan Assistant will provide a guideline for solar cell designers to fabricate various discrete components in a power converter-junction solar cells. Prof. Khan is the founder of the Power Engineering and Automation Research Lab (PEARL

  10. Watts Up? Pro AC Power Meter for Automated Energy Recording

    PubMed Central

    Hirst, Jason M.; Miller, Jonathan R.; Kaplan, Brent A.; Reed, Derek D.

    2013-01-01

    The purpose of the present paper is to review the Watts up? Pro AC power meter. Evaluations of the meter's reliability for measuring energy consumption by consumer electronics yielded acceptable levels of reliability. Implications and limitations for the use of this product in behavior analytic research and practice are discussed.

  11. ac power control in the Core Flow Test Loop

    SciTech Connect

    McDonald, D.W.

    1980-01-01

    This work represents a status report on a development effort to design an ac power controller for the Core Flow Test Loop. The Core Flow Test Loop will be an engineering test facility which will simulate the thermal environment of a gas-cooled fast-breeder reactor. The problems and limitations of using sinusoidal ac power to simulate the power generated within a nuclear reactor are addressed. The transformer-thyristor configuration chosen for the Core Flow Test Loop power supply is presented. The initial considerations, design, and analysis of a closed-loop controller prototype are detailed. The design is then analyzed for improved performance possibilities and failure modes are investigated at length. A summary of the work completed to date and a proposed outline for continued development completes the report.

  12. New techniques in the design of distributed power systems

    NASA Astrophysics Data System (ADS)

    Watson, Robert Goah

    Power conversion system design issues are expanding their role in information technology equipment design philosophies. These issues include not only improving power conversion efficiency, but also increased concerns regarding the cost and complexity of the power conversion design techniques utilized to satisfy the host system's total performance requirements. In particular, in computer system (personal computers, workstations, and servers) designs, the power "supplies" are rapidly becoming a limiting factor in meeting overall design objectives. This dissertation addresses the issue of simplifying the architecture of distributed power systems incorporated into computing equipment. In the dissertation's first half, the subject of the design of the distributed power system's front-end converter is investigated from the perspective of simplifying the conversion process while simultaneously improving efficiency. This is initially accomplished by simplifying the second-stage DC/DC converter in the standard two-stage front-end design (PFC followed by DC/DC conversion) through the incorporation of secondary-side control. Unique modifications are then made to two basic topologies (the flyback and boost converter topologies) that enable the two-stage front-end design to be reduced to an isolated PFC conversion stage, resulting in a front-end design that features reduced complexity and higher efficiency. In the dissertation's second half, the overall DC distributed power system design concept is simplified through the elimination of power processing conversion steps--the result being the creation of a high-frequency (HF) AC distributed power system. Design techniques for generating, distributing, and processing HF AC power in this new system are developed and experimentally verified. Also, an experimental comparison between both DC and AC distributed power systems is performed, illustrating in a succinct fashion the merits and limitations of both approaches.

  13. 21 CFR 880.6320 - AC-powered medical examination light.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...Identification. An AC-powered medical examination light is an AC-powered device intended for medical purposes that is used to illuminate body surfaces and cavities during a medical examination. (b) Classification. Class I (general controls)....

  14. 21 CFR 880.6320 - AC-powered medical examination light.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...Identification. An AC-powered medical examination light is an AC-powered device intended for medical purposes that is used to illuminate body surfaces and cavities during a medical examination. (b) Classification. Class I (general controls)....

  15. 21 CFR 880.6320 - AC-powered medical examination light.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...Identification. An AC-powered medical examination light is an AC-powered device intended for medical purposes that is used to illuminate body surfaces and cavities during a medical examination. (b) Classification. Class I (general controls)....

  16. 21 CFR 880.6320 - AC-powered medical examination light.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...Identification. An AC-powered medical examination light is an AC-powered device intended for medical purposes that is used to illuminate body surfaces and cavities during a medical examination. (b) Classification. Class I (general controls)....

  17. 21 CFR 880.6320 - AC-powered medical examination light.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...Identification. An AC-powered medical examination light is an AC-powered device intended for medical purposes that is used to illuminate body surfaces and cavities during a medical examination. (b) Classification. Class I (general controls)....

  18. DC Power Distribution Systems 

    E-print Network

    Savage, P.

    2012-01-01

    Low capital cost and ample low-cost natural gas supplies will make natural gas-fired combustion turbine systems the power generation technology of choice over the next decade. Against the background of earlier use by electric utilities, this paper...

  19. An experimental switched-reluctance generator based distributed power system

    Microsoft Academic Search

    Y. C. Chang; C. H. Cheng; L. Y. Lu; C. M. Liaw

    2010-01-01

    This paper presents an experimental switched-reluctance generator (SRG) based distributed power system with common DC grid and single-phase AC 220\\/110V 60Hz outputs. First, a SRG with suitably designed power converter and control scheme is constructed to generate robust DC 48V output. Then it is boosted to establish a 400V common DC grid by a current-fed push-pull (CFPP) DC\\/DC converter. Well-regulated

  20. Development of an analytical tool to study power quality of AC power systems for large spacecraft

    NASA Technical Reports Server (NTRS)

    Kraft, L. Alan; Kankam, M. David

    1991-01-01

    A harmonic power flow program applicable to space power systems with sources of harmonic distortion is described. The algorithm is a modification of the Electric Power Research Institute's HARMFLO program which assumes a three phase, balanced, AC system with loads of harmonic distortion. The modified power flow program can be used with single phase, AC systems. Early results indicate that the required modifications and the models developed are quite adequate for the analysis of a 20 kHz testbed built by General Dynamics Corporation. This is demonstrated by the acceptable correlation of present results with published data. Although the results are not exact, the discrepancies are relatively small.

  1. Development of an analytical tool to study power quality of ac power systems for large spacecraft

    NASA Technical Reports Server (NTRS)

    Kraft, L. A.; Kankam, M. D.

    1991-01-01

    A harmonic power flow program applicable to space power systems with sources of harmonic distortion is described. The algorithm is a modification of Electric Power Research Institute's HARMFLO program which assumes a three-phase, balanced, ac system with loads of harmonic distortion. The modified power flow program can be used with single phase, ac systems. Early results indicate that the required modifications and the models developed are quite adequate for the analysis of a 20-kHz testbed built by General Dynamics Corporation. This is demonstrated by the acceptable correlation of the present results with published data. Although the results are not exact, the discrepancies are relatively small.

  2. Forty-eighth annual power distribution conference

    SciTech Connect

    NONE

    1995-12-31

    This book contains papers presented at the Forty-eighth Annual Power Distribution Conference held in 1995 at Austin, Texas. The topics of the papers include power quality in power distribution systems, methods to improve power quality, power system communications, automation of distribution systems, distributed data acquisition, energy efficiency in industrial plants, weather data in operation of distribution systems, detection and location of failed or failing equipment in power distribution systems, lightning and overvoltage protection, distribution cable research update, and equipment protection devices for residential power distribution systems.

  3. Low-power Clock Synchronization using Electromagnetic Energy Radiating from AC Power Lines

    E-print Network

    Rajkumar, Ragunathan "Raj"

    of meters away. In contrast to systems like the WWVB atomic clock broadcast and GPS time receiver, our to receive a stable global clock tick by tuning to the elec- tromagnetic energy (EM) radiating from existingLow-power Clock Synchronization using Electromagnetic Energy Radiating from AC Power Lines Anthony

  4. Improved dynamic security assessment for AC\\/DC power systems using energy functions

    Microsoft Academic Search

    Nilkamal Fernandopulle; Robert T. H. Alden

    2003-01-01

    A method is presented to integrate the dynamics of DC power flow into calculations of transient energy functions of AC\\/DC power systems. This method treats the generator input power as a function of the parameters and the input, output variables of the DC damping power controller. By using this transient energy function, the accuracy of the stability prediction of AC\\/DC

  5. Improved dynamic security assessment for AC\\/DC power systems using energy functions

    Microsoft Academic Search

    N. Fernandopulle; R. T. H. Alden

    2004-01-01

    A method is presented to integrate the dynamics of DC power flow into calculations of transient energy functions of AC\\/DC power systems. This method treats the generator input power as a function of the parameters and the input, output variables of the DC control system. By using this transient energy function, the accuracy of the stability prediction of AC\\/DC power

  6. Comparison of conducted RFI emission from different unity power factor AC\\/DC converters

    Microsoft Academic Search

    J. Mahdavi; M. Tabandeh; A. K. Shahriari

    1996-01-01

    Low frequency harmonics injection into AC power supply and small power factor are the main disadvantages of conventional AC\\/DC converters. By using current mode control, the converter can be designed such that its input current have a sinusoidal form and in phase with the power supply voltage. By solving the problem of power factor with high frequency switching current mode

  7. Input - output linearization control for a three - phase AC\\/DC\\/AC voltage source converter for bidirectional power flow

    Microsoft Academic Search

    Janeth Alcalá; Víctor Cárdenas; Nancy Visairo

    2010-01-01

    In this paper the bidirectional power capability of a three-phase AC\\/DC\\/AC voltage-source converter is studied; based on the input-output linearization control theory, which is applied to the inner current loops that are connected in cascade with the outer loops. Both loops (inner and outer) allow a suitable control of the power flow. The controlled system is linearized and decoupled; based

  8. Distributed interleaving of paralleled power converters

    E-print Network

    Kassakian, J.G.

    This paper introduces a distributed approach to interleaving paralleled power converter cells. Unlike conventional methods, the distributed approach requires no centralized control, automatically accommodates varying numbers ...

  9. Load characteristics analysis of AC and DC arc furnaces using various power definitions and statistic method

    Microsoft Academic Search

    Tsu-Hsun Fu; Chi-Jui Wu

    2002-01-01

    Various power definitions and statistics are used to investigate the load characteristics of AC and DC electric arc furnaces, which occupy a major percentage of the Taiwan power system. It is very important to note their effects on power quality. It is also desirable to have an alternative way to study their load behaviors. Since AC and DC arc furnaces

  10. Load Characteristics Analysis of AC and DC Arc Furnaces Using Various Power Definitions and Statistic Method

    Microsoft Academic Search

    T. H. Fu; C. J. Wu

    2002-01-01

    Various power definitions and statistics are used to investigate the load characteristics of ac and dc electric arc furnaces, which occupy a major percentage of the Taiwan power system. It is very important to note their effect on power quality. It is also desired to have an alternative way to study their load behaviors. Since ac and dc arc furnaces

  11. A nonlinear robust HVDC control for a parallel AC/DC power system

    E-print Network

    Qu, Zhihua

    recognized that, through an HVDC transmission line, fast electronic control can be applied on the DC power, controlling DC line transmission power can improve stability of the AC system after a major disturbanceA nonlinear robust HVDC control for a parallel AC/DC power system Hongzhi Cai a , Zhihua Qu b

  12. AC and DC arc furnaces: a comparison on some power quality aspects

    Microsoft Academic Search

    G. Carpinelli; M. DiManno; P. Verde; E. Tironi; D. Zaninelli

    1999-01-01

    The paper deals with a comparison between AC and DC arc furnaces taking into account power quality indices. The study is performed using computer simulation based on the ATP program, assuming as reference a real AC arc furnace plant. Flicker phenomenon, harmonic and interharmonic distortion are evaluated for both DC and AC arc furnaces

  13. Point of collapse methods applied to AC\\/DC power systems

    Microsoft Academic Search

    C. A. Canizares; Fernando L. Alvarado; Christopher L. DeMarco; Ian Dobson; Willis F. Long

    1992-01-01

    The authors describe an extension of the point of collapse method developed for studies of AC systems to the determination of saddle-node bifurcations in power systems including high voltage direct current (HVDC) transmission. Bus voltage profiles are illustrated for an AC\\/DC test system. They significantly differ from the profiles of pure AC systems for typical system models. In particular, voltage

  14. Description of a 20 Kilohertz power distribution system

    NASA Technical Reports Server (NTRS)

    Hansen, I. G.

    1986-01-01

    A single phase, 440 VRMS, 20 kHz power distribution system with a regulated sinusoidal wave form is discussed. A single phase power system minimizes the wiring, sensing, and control complexities required in a multi-sourced redundantly distributed power system. The single phase addresses only the distribution link; mulitphase lower frequency inputs and outputs accommodation techniques are described. While the 440 V operating potential was initially selected for aircraft operating below 50,000 ft, this potential also appears suitable for space power systems. This voltage choice recognizes a reasonable upper limit for semiconductor ratings, yet will direct synthesis of 220 V, 3 power. A 20 kHz operating frequency was selected to be above the range of audibility, minimize the weight of reactive components, yet allow the construction of single power stages of 25 to 30 kW. The regulated sinusoidal distribution system has several advantages. With a regulated voltage, most ac/dc conversions involve rather simple transformer rectifier applications. A sinusoidal distribution system, when used in conjunction with zero crossing switching, represents a minimal source of EMI. The present state of 20 kHz power technology includes computer controls of voltage and/or frequency, low inductance cable, current limiting circuit protection, bi-directional power flow, and motor/generator operating using standard induction machines. A status update and description of each of these items and their significance is presented.

  15. Description of a 20 kilohertz power distribution system

    NASA Technical Reports Server (NTRS)

    Hansen, I. G.

    1986-01-01

    A single phase, 440 VRMS, 20 kHz power distribution system with a regulated sinusoidal wave form is discussed. A single phase power system minimizes the wiring, sensing, and control complexities required in a multi-sourced redundantly distributed power system. The single phase addresses only the distribution links multiphase lower frequency inputs and outputs accommodation techniques are described. While the 440 V operating potential was initially selected for aircraft operating below 50,000 ft, this potential also appears suitable for space power systems. This voltage choice recognizes a reasonable upper limit for semiconductor ratings, yet will direct synthesis of 220 V, 3 power. A 20 kHz operating frequency was selected to be above the range of audibility, minimize the weight of reactive components, yet allow the construction of single power stages of 25 to 30 kW. The regulated sinusoidal distribution system has several advantages. With a regulated voltage, most ac/dc conversions involve rather simple transformer rectifier applications. A sinusoidal distribution system, when used in conjunction with zero crossing switching, represents a minimal source of EMI. The present state of 20 kHz power technology includes computer controls of voltage and/or frequency, low inductance cable, current limiting circuit protection, bi-directional power flow, and motor/generator operating using standard induction machines. A status update and description of each of these items and their significance is presented.

  16. Measurement Of Spectral Power Distribution

    NASA Astrophysics Data System (ADS)

    Moore, J. R.

    1980-11-01

    The majority of spectroradiometers make measurements at a number of discrete wavelength settings spaced evenly across the spectrum. Many modern light sources such as fluorescent or metal halide lamps have complex line spectra which may not be properly evaluated by this method. An automated spectroradiometer system involving a non-stop spectral scan with continuous integration of the output signal from the detector is described. The method is designed to make accurate measurements of all types of spectral power distribution whether made up of lines or continuum or any mixture of the two.

  17. Airline requirements on aircraft electrical power generation and distribution

    NASA Astrophysics Data System (ADS)

    Glashagen, Claus

    Attention is given to airline requirements to aircraft electrical power generation and distribution, such as electrical power generation, namely, basic consideration of conventional AC generator, the Integrated Drive Generator, and the Variable Frequency Generator, including quality of regulation and mechanical mounting; airworthiness requirements to achieve redundancy for normal, stand-by, and emergency systems; maintainability of components and interconnecting systems; and access to internal subcomponents. Another requirement is interconnection and installation, which involve undervalued efforts required for the maintenance and repair of interconnecting and installation components. This includes hardware selection of cables, clamps, connectors, and terminals. Environmental considerations. Also discussed are electrical power distribution components, involving electro-mechanical switches and remote controlled circuit breakers in a cost-effective distribution system.

  18. Multipulse AC–DC Converters for Improving Power Quality: A Review

    Microsoft Academic Search

    Bhim Singh; Sanjay Gairola; Brij N. Singh; Ambrish Chandra; Kamal Al-Haddad

    2008-01-01

    Three-phase multipulse AC-DC converters (MPC) are developed for improving power quality to reduce harmonics in AC mains and ripples in DC output. This paper deals with the multipulse AC-DC converter configurations, state of art, their performance, power quality aspects, components selection considerations, latest trends, future developments, and potential applications. It is targeted to provide broad perspective on multipulse converter technology

  19. Soft-Switching High-Frequency AC-Link Universal Power Converters with Galvanic Isolation 

    E-print Network

    Amirabadi, Mahshid

    2013-08-07

    In this dissertation the ac-link universal power converters, which are a new class of power converters, are introduced and studied in detail. The inputs and outputs of these converters may be dc, ac, single phase, or multi-phase. Therefore, they can...

  20. Applying distributed power modules in telecom systems

    Microsoft Academic Search

    Per Lindman; L. Thorsell

    1996-01-01

    The design of modern decentralized power systems in telecommunication applications are increasingly realized by using distributed DC\\/DC power modules. Power modules are usually characterized by high switching frequencies, which enable the use of small ferrite magnetics and ceramic capacitors to enhance the reliability, the power density, and the possibility of live insertion, all desired features in new power system designs.

  1. Efficient two-level cryogenic power distribution system

    NASA Astrophysics Data System (ADS)

    Mueller, O. M.; Mueller, E. K.

    2002-05-01

    The availability of new technologies such as high-temperature superconducting (HTS) cables, high-voltage, high-speed semiconductor switches, and cryogenic power conversion suggests that one considers how these technologies can be combined and applied effectively to provide a more efficient energy distribution system. The present-day 60 Hz concept is, after all, a century old. Advantages can be obtained by combining DC and high-frequency AC technologies. DC transmission solves the problem of AC losses in HTS cables and high-frequency switching techniques reduce size, weight and cost. This paper proposes and discusses a distribution system based on two DC voltage levels (˜4 kVDC/650 VDC) interconnected with DC/DC converters using high-voltage insulated-gate bipolar transistors (HV-IGBT's), integrated gate-commutated thyristors (IGCT's), or MOS-controlled turn-off thyristors (MTO's) operated at cryogenic temperatures. Cryo-MOSFET DC/AC inverters provide the 60 Hz, 240/120 VAC user voltages. HTS cables supply power as well as the cooling fluid liquid nitrogen (LN2). The load shedding properties of such a system based on the use of LN2 are evaluated. The proposed concept is suitable for city blocks with many high-rise buildings. It provides an increase in efficiency and therefore contributes to the reduction of global warming.

  2. Phosphor-in-glass for high-powered remote-type white AC-LED.

    PubMed

    Lin, Hang; Wang, Bo; Xu, Ju; Zhang, Rui; Chen, Hui; Yu, Yunlong; Wang, Yuansheng

    2014-12-10

    The high-powered alternating current (AC) light-emitting diode (LED) (AC-LED), featuring low cost, high energy utilization efficiency, and long service life, will become a new economic growth point in the field of semiconductor lighting. However, flicker of AC-LED in the AC cycles is not healthy for human eyes, and therefore need to be restrained. Herein we report an innovation of persistent "phosphor-in-glass" (PiG) for the remote-type AC-LED, whose afterglow can be efficiently activated by the blue light. It is experimentally demonstrated that the afterglow decay of PiG in the microsecond range can partly compensate the AC time gap. Moreover, the substitution of inorganic glass for organic resins or silicones as the encapsulants would bring out several technological benefits to AC-LED, such as good heat-dissipation, low glare, and excellent physical/chemical stability. PMID:25329651

  3. Hybrid power system intelligent operation and protection involving distributed architectures and pulsed loads

    NASA Astrophysics Data System (ADS)

    Mohamed, Ahmed

    Efficient and reliable techniques for power delivery and utilization are needed to account for the increased penetration of renewable energy sources in electric power systems. Such methods are also required for current and future demands of plug-in electric vehicles and high-power electronic loads. Distributed control and optimal power network architectures will lead to viable solutions to the energy management issue with high level of reliability and security. This dissertation is aimed at developing and verifying new techniques for distributed control by deploying DC microgrids, involving distributed renewable generation and energy storage, through the operating AC power system. To achieve the findings of this dissertation, an energy system architecture was developed involving AC and DC networks, both with distributed generations and demands. The various components of the DC microgrid were designed and built including DC-DC converters, voltage source inverters (VSI) and AC-DC rectifiers featuring novel designs developed by the candidate. New control techniques were developed and implemented to maximize the operating range of the power conditioning units used for integrating renewable energy into the DC bus. The control and operation of the DC microgrids in the hybrid AC/DC system involve intelligent energy management. Real-time energy management algorithms were developed and experimentally verified. These algorithms are based on intelligent decision-making elements along with an optimization process. This was aimed at enhancing the overall performance of the power system and mitigating the effect of heavy non-linear loads with variable intensity and duration. The developed algorithms were also used for managing the charging/discharging process of plug-in electric vehicle emulators. The protection of the proposed hybrid AC/DC power system was studied. Fault analysis and protection scheme and coordination, in addition to ideas on how to retrofit currently available protection concepts and devices for AC systems in a DC network, were presented. A study was also conducted on the effect of changing the distribution architecture and distributing the storage assets on the various zones of the network on the system's dynamic security and stability. A practical shipboard power system was studied as an example of a hybrid AC/DC power system involving pulsed loads. Generally, the proposed hybrid AC/DC power system, besides most of the ideas, controls and algorithms presented in this dissertation, were experimentally verified at the Smart Grid Testbed, Energy Systems Research Laboratory. All the developments in this dissertation were experimentally verified at the Smart Grid Testbed.

  4. Power scalable processing using distributed arithmetic

    Microsoft Academic Search

    Rajeevan Amirtharajah; Thucydides Xanthopoulos; Anantha Chandrakasan

    1999-01-01

    A recent trend in low power design has been the employment of reduced precision processing methods for decreasing arithmetic activity and average power dissipation. Such designs can trade off power and arithmetic precision as system requirements change. This work explores the potential of Distributed Arithmetic (DA) computation structures for low power precisionon-demand computation. We present two proof-ofconcept VLSI implementations whose

  5. Wide bandwidth, large AC current probe for power electronics and EMI measurements

    Microsoft Academic Search

    Francois Costa; E. Laboure; F. Forest; C. Gautier

    1997-01-01

    Current measurements in power electronics or in EMI domains require high-performance probes. These probes must have a very wide bandwidth, be insensitive to electromagnetic interferences, and be able to measure large direct and alternating currents (AC-DC) without distortion. This paper is limited to AC current probes. Various principles are reviewed, in particular those based on the current transformer (CT); their

  6. Transient stability analysis of AC\\/DC power system based on transient energy function

    Microsoft Academic Search

    Y. Z. Lin; Z. X. Cai; Q. Mo

    2008-01-01

    In this paper, a transient energy function for AC\\/DC power systems is used to evaluate critical clearing times with consideration of the DC dynamics. The generator angular speeds, rotor angles and voltages at the HVDC link's AC buses are explicit variables in the transient energy function. A method for computing the transient energy function numerically is proposed. In the method,

  7. A self-powered AC magnetic sensor based on piezoelectric nanogenerator.

    PubMed

    Yu, Aifang; Song, Ming; Zhang, Yan; Kou, Jinzong; Zhai, Junyi; Lin Wang, Zhong

    2014-11-14

    An AC magnetic field, which is a carrier of information, is distributed everywhere and is continuous. How to use and detect this field has been an ongoing topic over the past few decades. Conventional magnetic sensors are usually based on the Hall Effect, the fluxgate, a superconductor quantum interface or magnetoelectric or magnetoresistive sensing. Here, a flexible, simple, low-cost and self-powered active piezoelectric nanogenerator (NG) is successfully demonstrated as an AC magnetic field sensor at room temperature. The amplitude and frequency of a magnetic field can both be accurately sensed by the NG. The output voltage of the NG has a good linearity with a measured magnetic field. The detected minute magnetic field is as low as 1.2 × 10(-7) tesla, which is 400 times greater than a commercial magnetic sensor that uses the Hall Effect. In comparison to the existing technologies, an NG is a room-temperature self-powered active sensor that is very simple and very cheap for practical applications. PMID:25333328

  8. A self-powered AC magnetic sensor based on piezoelectric nanogenerator

    NASA Astrophysics Data System (ADS)

    Yu, Aifang; Song, Ming; Zhang, Yan; Kou, Jinzong; Zhai, Junyi; Wang, Zhong Lin

    2014-11-01

    An AC magnetic field, which is a carrier of information, is distributed everywhere and is continuous. How to use and detect this field has been an ongoing topic over the past few decades. Conventional magnetic sensors are usually based on the Hall Effect, the fluxgate, a superconductor quantum interface or magnetoelectric or magnetoresistive sensing. Here, a flexible, simple, low-cost and self-powered active piezoelectric nanogenerator (NG) is successfully demonstrated as an AC magnetic field sensor at room temperature. The amplitude and frequency of a magnetic field can both be accurately sensed by the NG. The output voltage of the NG has a good linearity with a measured magnetic field. The detected minute magnetic field is as low as 1.2 × 10?7 tesla, which is 400 times greater than a commercial magnetic sensor that uses the Hall Effect. In comparison to the existing technologies, an NG is a room-temperature self-powered active sensor that is very simple and very cheap for practical applications.

  9. Hierarchical analysis of power distribution networks

    Microsoft Academic Search

    Min Zhao; Rajendran V. Panda; Sachin S. Sapatnekar; David T. Blaauw

    2002-01-01

    Careful design and verification of the power distribution network of a chip are of critical importance to ensure its reliable performance. With the increasing number of transistors on a chip, the size of the power network has grown so large as to make the verification task very challenging. The available computational power and memory resources impose limitations on the size

  10. Hierarchical analysis of power distribution networks

    Microsoft Academic Search

    Min Zhao; Rajendran V. Panda; Sachin S. Sapatnekar; Tim Edwards; Rajat Chaudhry; David Blaauw

    2000-01-01

    Careful design and verification of the power distribution network of a chip are of critical importance to ensure its reliable performance. With the increasing number of transistors on a chip, the size of the power network has grown so large as to make the verification task very challenging. The available computational power and memory resources impose limitations on the size

  11. A Partitioning Approach for Parallel Simulation of AC-Radial Shipboard Power Systems 

    E-print Network

    Uriarte, Fabian Marcel

    2011-08-08

    An approach to parallelize the simulation of AC-Radial Shipboard Power Systems (SPSs) using multicore computers is presented. Time domain simulations of SPSs are notoriously slow, due principally to the number of components, and the time...

  12. A sensor to detect the DC bias of distribution power transformers

    Microsoft Academic Search

    Giampaolo Buticchi; Emilio Lorenzani

    2011-01-01

    The widespread use of power converters in low- voltage distribution grids has given rise to issues regarding the power quality. In fact, non-linear loads such as AC Drives, switching-mode power supplies and grid-connected converters can cause, besides the generation of several current harmonics, also a DC current component injection into the grid. This DC current component can lead to magnetic

  13. Commercial utility frequency AC to high frequency AC soft switching power conversion circuit with non smoothing DC link for IH dual packs heater

    Microsoft Academic Search

    Hisayuki Sugimura; Tarek Ahmed; Mohamed Orabi; Hyun-Woo Lee; Mutsuo Nakaoka

    2004-01-01

    In this paper, a novel topology of soft switching PWM high frequency AC power conversion conditioning and processing circuit without DC smoothing capacitor filter link from the voltage grid of utility frequency AC power supply source with 60 Hz-100 V or 60 Hz-200 V is proposed and introduced for innovative consumer induction heating (IH) boiler applications as a hot water

  14. Soft-switched, high frequency resonant AC-to-DC rectifier with high power factor

    Microsoft Academic Search

    HYUN CHIL CHOI; JAE WON HAN; MYUNG JOONG YOUN

    1993-01-01

    A high frequency and soft-switched AC-to-DC rectifier employing a series-type resonant circuit is proposed to overcome the disadvantages of the conventional peak-rectifying circuit. Using the proposed rectifier, a high power factor and low harmonic currents are obtained in the AC line. Furthermore, several advantages such as high power density and wide output voltage range can also be available. Through simulation

  15. A Robust One-Cycle Controlled Full-Bridge Series-Parallel Resonant Inverter for a High-Frequency AC (HFAC) Distribution System

    Microsoft Academic Search

    Zhongming Ye; John C. W. Lam; Praveen K. Jain; Paresh C. Sen

    2007-01-01

    Resonant inverters are connected to a high-frequency AC (HFAC) bus, where power is delivered to different locations for points-of-use power management. Such a power distribution system subjects to more perturbations and load uncertainties than inverters operating with single load. A novel voltage control method is proposed in this paper for a high-frequency full-bridge resonant inverter with series-parallel resonant tank. A

  16. Network Partition for Distributed Reactive Power Optimization in Power Systems

    Microsoft Academic Search

    Zhongxu Li; Yutian Liu; Rushui Liu; Xinsheng Niu

    2008-01-01

    Reactive power optimization is an important measure to improve the secure and economic performance of power systems. To reduce the dimension of solution space and solve the time-consuming problem more effectively, a network partition method for distributed reactive power optimization is introduced to divide a large-scale power system into several small-scale subsystems. The voltage response of nodes to the perturbation

  17. Study of Impurity Distributions (Mainly Lithium in Silicon) Using ac Hopping Conduction

    Microsoft Academic Search

    M. Pollak; D. H. Watt

    1965-01-01

    The results of previous studies on ac impurity conduction are applied in an attempt to study the distribution of impurities when this is not random. The present study applies mostly to the distribution of lithium in silicon, but a few other situations are also examined. A possibility is presented, on a theoretical basis, to determine experimentally the complete distribution function

  18. Power scalable processing using distributed arithmetic

    Microsoft Academic Search

    Rajeevan Amirtharajah; Thucydides Xanthopoulos; Anantha Chandrakasan

    1999-01-01

    A recent trend in low power design has been the employment of reduced precision processing methods for decreasing arithmetic activity and average power dissipation. Such designs can trade off power and arithmetic precision as system requirements change. This work explores the potential of Distributed Arithmetic (DA) computation structures for low power precision-on-demand computation. We present two proof-of-concept VLSI implementations whose

  19. Electric power distribution and load transfer system

    NASA Technical Reports Server (NTRS)

    Bradford, Michael P. (Inventor); Parkinson, Gerald W. (Inventor); Grant, Ross M. (Inventor)

    1989-01-01

    A power distribution system includes a plurality of power sources and load transfer units including transistors and diodes connected in series and leading to a common power output, each of the transistors being controller switchable subject to voltage levels of the respective input and output sides of said transistors, and the voltage and current level of said common power output. The system is part of an interconnection scheme in which all but one of the power sources is connected to a single load transfer unit, enabling the survival of at least a single power source with the failure of one of the load transfer units.

  20. Electric power distribution and load transfer system

    NASA Technical Reports Server (NTRS)

    Bradford, Michael P. (Inventor); Parkinson, Gerald W. (Inventor); Grant, Ross M. (Inventor)

    1987-01-01

    A power distribution system includes a plurality of power sources and load transfer units including transistors and diodes connected in series and leading to a common power output, each of the transistors being controller switchable subject to voltage levels of the respective input and output sides of said transistors, and the voltage and current level of said common power output. The system is part of an interconnection scheme in which all but one of the power sources is connected to a single load transfer unit, enabling the survival of at least a single power source with the failure of one of the load transfer units.

  1. Cathode power distribution system and method of using the same for power distribution

    DOEpatents

    Williamson, Mark A; Wiedmeyer, Stanley G; Koehl, Eugene R; Bailey, James L; Willit, James L; Barnes, Laurel A; Blaskovitz, Robert J

    2014-11-11

    Embodiments include a cathode power distribution system and/or method of using the same for power distribution. The cathode power distribution system includes a plurality of cathode assemblies. Each cathode assembly of the plurality of cathode assemblies includes a plurality of cathode rods. The system also includes a plurality of bus bars configured to distribute current to each of the plurality of cathode assemblies. The plurality of bus bars include a first bus bar configured to distribute the current to first ends of the plurality of cathode assemblies and a second bus bar configured to distribute the current to second ends of the plurality of cathode assemblies.

  2. Spacecraft solid state power distribution switch

    NASA Technical Reports Server (NTRS)

    Praver, G. A.; Theisinger, P. C.

    1986-01-01

    As a spacecraft performs its mission, various loads are connected to the spacecraft power bus in response to commands from an on board computer, a function called power distribution. For the Mariner Mark II set of planetary missions, the power bus is 30 volts dc and when loads are connected or disconnected, both the bus and power return side must be switched. In addition, the power distribution function must be immune to single point failures and, when power is first applied, all switches must be in a known state. Traditionally, these requirements have been met by electromechanical latching relays. This paper describes a solid state switch which not only satisfies the requirements but incorporates several additional features including soft turn on, programmable current trip point with noise immunity, instantaneous current limiting, and direct telemetry of load currents and switch status. A breadboard of the design has been constructed and some initial test results are included.

  3. Globally Integrated Power and Clock Distribution Network

    E-print Network

    Friedman, Eby G.

    Globally Integrated Power and Clock Distribution Network Renatas Jakushokas and Eby G. Friedman [jakushok, friedman]@ece.rochester.edu Abstract-- The global networks within a conventional inte- grated circuits (IC) consists of three major types: power, ground, and clock networks. These three networks

  4. Expert System Detects Power-Distribution Faults

    NASA Technical Reports Server (NTRS)

    Walters, Jerry L.; Quinn, Todd M.

    1994-01-01

    Autonomous Power Expert (APEX) computer program is prototype expert-system program detecting faults in electrical-power-distribution system. Assists human operators in diagnosing faults and deciding what adjustments or repairs needed for immediate recovery from faults or for maintenance to correct initially nonthreatening conditions that could develop into faults. Written in Lisp.

  5. High frequency power distribution system

    NASA Technical Reports Server (NTRS)

    Patel, Mikund R.

    1986-01-01

    The objective of this project was to provide the technology of high frequency, high power transmission lines to the 100 kW power range at 20 kHz frequency. In addition to the necessary design studies, a 150 m long, 600 V, 60 A transmission line was built, tested and delivered for full vacuum tests. The configuration analysis on five alternative configurations resulted in the final selection of the three parallel Litz straps configuration, which gave a virtually concentric design in the electromagnetic sense. Low inductance, low EMI and flexibility in handling are the key features of this configuration. The final design was made after a parametric study to minimize the losses, weight and inductance. The construction of the cable was completed with no major difficulties. The R,L,C parameters measured on the cable agreed well with the calculated values. The corona tests on insulation samples showed a safety factor of 3.

  6. Discrete-time modeling of AC motors for high power AC drives control

    Microsoft Academic Search

    S. Poullain; J. L. Thomas; A. Benchaib

    2003-01-01

    This paper proposes a new discrete-time formulation of state-space model for voltage source inverter (VSI) fed AC motors, introducing the free evolution of the motor state and characterized by both the simplification of torque and flux output equations and the definition of a predictive reference frame oriented on the rotor free evolution vector. The potential of the proposed model for

  7. Intelligent Systems for Power Management and Distribution

    NASA Technical Reports Server (NTRS)

    Button, Robert M.

    2002-01-01

    The motivation behind an advanced technology program to develop intelligent power management and distribution (PMAD) systems is described. The program concentrates on developing digital control and distributed processing algorithms for PMAD components and systems to improve their size, weight, efficiency, and reliability. Specific areas of research in developing intelligent DC-DC converters and distributed switchgear are described. Results from recent development efforts are presented along with expected future benefits to the overall PMAD system performance.

  8. Computer modeling and simulation of a 20kHz ac distribution system for Space Station

    NASA Technical Reports Server (NTRS)

    Tsai, Fu-Sheng; Lee, Fred C.

    1987-01-01

    A computer model of a 20 kHz, ac distribution testbed for Space Station is presented. The system consists of six resonant inverters, a one-hundred-meter transmission line, and three load receivers: a dc receiver, a bidirectional receiver, and an ac receiver. A model library is generated characterizing all system components. The system's local and global behaviors are investigated using the EASY5 dynamic analysis program.

  9. Measurement of klystron phase modulation due to ac-powered filaments

    NASA Technical Reports Server (NTRS)

    Finnegan, E. J.

    1977-01-01

    A technique for determining the intermodulation components in the RF spectrum of the S-band radar transmitter generated by having the klystron filaments heated by 400-Hz ac power is described. When the klystron is being operated with 400-Hz (ac) on the filament, the IPM is buried in the 400-Hz equipment interference noise. The modulation sidebands were separated and identified and found to be-67 db below the main carrier. This is well below the transmitter specifications, and operating the filaments on ac would not degrade the spectrum to where it would be detrimental to the radiated RF.

  10. Hierarchical distributed stabilization of power networks

    NASA Astrophysics Data System (ADS)

    Ishizaki, Takayuki; Sadamoto, Tomonori; Imura, Jun-ichi

    2014-09-01

    Large fluctuation of electric power due to high penetration of renewable energy sources such as photovoltaic and wind power generation increases the risk to make the whole power network system unstable. The conventional frequency control called load frequency control is based on PID (proportional-integral-derivative) control or more advanced centralized and decentralized/distributed control. If we could more effectively use information on the state of the other neighbor generators, we can expect to make the whole system more robust against the large frequency fluctuation. This paper proposes a fundamental framework towards the design of hierarchical distributed stabilizing controllers for a network of power generators and loads. This novel type of distributed controller, composed of a global controller and a set of local controllers, takes into account the effect of the interaction among the generators and loads to improve robustness for the variation of locally stabilizing controllers.

  11. Hierarchical distributed stabilization of power networks

    NASA Astrophysics Data System (ADS)

    Ishizaki, Takayuki; Sadamoto, Tomonori; Imura, Jun-ichi

    2014-10-01

    Large fluctuation of electric power due to high penetration of renewable energy sources such as photovoltaic and wind power generation increases the risk to make the whole power network system unstable. The conventional frequency control called load frequency control is based on PID (proportional-integral-derivative) control or more advanced centralized and decentralized/distributed control. If we could more effectively use information on the state of the other neighbor generators, we can expect to make the whole system more robust against the large frequency fluctuation. This paper proposes a fundamental framework towards the design of hierarchical distributed stabilizing controllers for a network of power generators and loads. This novel type of distributed controller, composed of a global controller and a set of local controllers, takes into account the effect of the interaction among the generators and loads to improve robustness for the variation of locally stabilizing controllers.

  12. A power electronic transformer-based three-phase PWM ac drive with lossless commutation of leakage energy

    Microsoft Academic Search

    Kaushik Basu; Apurva Somani; Krushna K Mohapatra; N. Mohan

    2010-01-01

    This paper proposes a novel dc\\/ac converter topology with a high frequency ac-link for three-phase adjustable speed PWM ac drives. Such drives find applications in UPS systems and renewable energy sources like solar and fuel cells. This topology provides single-stage power conversion with bidirectional power flow capability. The high frequency transformer offers the benefits of galvanic isolation and high power

  13. Soft switched capacitively coupled DC-AC converter for high power

    Microsoft Academic Search

    M. Ehsani; T. S. Wu

    1993-01-01

    A capacitively coupled DC-AC power converter which is capable of zero current soft switching is presented. A form of amplitude modulation is introduced to provide a sinusoidal output waveform. Due to its favorable current stresses on the switches, this converter is suitable for high current high power inductive load applications. With this technique, switching losses can be reduced. The soft

  14. Development of software to improve AC power quality on large spacecraft

    NASA Technical Reports Server (NTRS)

    Kraft, L. Alan

    1991-01-01

    To insure the reliability of a 20 kHz, alternating current (AC) power system on spacecraft, it is essential to analyze its behavior under many adverse operating conditions. Some of these conditions include overloads, short circuits, switching surges, and harmonic distortions. Harmonic distortions can become a serious problem. It can cause malfunctions in equipment that the power system is supplying, and, during distortions such as voltage resonance, it can cause equipment and insulation failures due to the extreme peak voltages. To address the harmonic distortion issue, work was begun under the 1990 NASA-ASEE Summer Faculty Fellowship Program. Software, originally developed by EPRI, called HARMFLO, a power flow program capable of analyzing harmonic conditions on three phase, balanced, 60 Hz AC power systems, was modified to analyze single phase, 20 kHz, AC power systems. Since almost all of the equipment used on spacecraft power systems is electrically different from equipment used on terrestrial power systems, it was also necessary to develop mathematical models for the equipment to be used on the spacecraft. The modelling was also started under the same fellowship work period. Details of the modifications and models completed during the 1990 NASA-ASEE Summer Faculty Fellowship Program can be found in a project report. As a continuation of the work to develop a complete package necessary for the full analysis of spacecraft AC power system behavior, deployment work has continued through NASA Grant NAG3-1254. This report details the work covered by the above mentioned grant.

  15. About the kinetic power induced by AC and DC discharges

    Microsoft Academic Search

    E. Moreau; G. Touchard

    2005-01-01

    This paper deals with experimental measurements of the ionic wind velocity of 3 types of corona discharges in air at atmospheric pressure: a DC surface discharge established between two wires flush mounted on the wall of a dielectric, a DC volume discharge in a point-to-grid geometry and an AC surface barrier discharge generated by application of a sine HV between

  16. A general approach for analyzing power busbar under AC conditions

    Microsoft Academic Search

    Mario Chiampi; Daniela Chiarabaglio; Michele Tartaglia

    1993-01-01

    A procedure for the analysis of multiconductor busbar systems under steady-state AC conditions is presented. The method is based on a lumped parameter approach under the hypothesis of magnetic linearity. The model involves a matrix of self and mutual impedances deduced from electromagnetic field solutions including eddy current effects. The matrix, inserted into circuit equations, leads to current sharing evaluation

  17. Improved transistorized AC motor controller for battery powered urban electric passenger vehicles

    NASA Technical Reports Server (NTRS)

    Peak, S. C.

    1982-01-01

    An ac motor controller for an induction motor electric vehicle drive system was designed, fabricated, tested, evaluated, and cost analyzed. A vehicle performance analysis was done to establish the vehicle tractive effort-speed requirements. These requirements were then converted into a set of ac motor and ac controller requirements. The power inverter is a three-phase bridge using power Darlington transistors. The induction motor was optimized for use with an inverter power source. The drive system has a constant torque output to base motor speed and a constant horsepower output to maximum speed. A gear shifting transmission is not required. The ac controller was scaled from the base 20 hp (41 hp peak) at 108 volts dec to an expanded horsepower and battery voltage range. Motor reversal was accomplished by electronic reversal of the inverter phase sequence. The ac controller can also be used as a boost chopper battery charger. The drive system was tested on a dynamometer and results are presented. The current-controlled pulse width modulation control scheme yielded improved motor current waveforms. The ac controller favors a higher system voltage.

  18. Improved transistorized AC motor controller for battery powered urban electric passenger vehicles

    NASA Astrophysics Data System (ADS)

    Peak, S. C.

    1982-09-01

    An ac motor controller for an induction motor electric vehicle drive system was designed, fabricated, tested, evaluated, and cost analyzed. A vehicle performance analysis was done to establish the vehicle tractive effort-speed requirements. These requirements were then converted into a set of ac motor and ac controller requirements. The power inverter is a three-phase bridge using power Darlington transistors. The induction motor was optimized for use with an inverter power source. The drive system has a constant torque output to base motor speed and a constant horsepower output to maximum speed. A gear shifting transmission is not required. The ac controller was scaled from the base 20 hp (41 hp peak) at 108 volts dec to an expanded horsepower and battery voltage range. Motor reversal was accomplished by electronic reversal of the inverter phase sequence. The ac controller can also be used as a boost chopper battery charger. The drive system was tested on a dynamometer and results are presented. The current-controlled pulse width modulation control scheme yielded improved motor current waveforms. The ac controller favors a higher system voltage.

  19. Coupling an induction motor type generator to ac power lines. [making windmill generators compatible with public power lines

    NASA Technical Reports Server (NTRS)

    Nola, F. J. (inventor)

    1984-01-01

    A system for coupling an induction motor type generator to an A.C. power line includes an electronic switch means that is controlled by a control system and is regulated to turn on at a relatively late point in each half cycle of its operation. The energizing power supplied by the line to the induction motor type generator is decreased and the net power delivered to the line is increased.

  20. Vibration Monitoring of Power Distribution Poles

    SciTech Connect

    Clark Scott; Gail Heath; John Svoboda

    2006-04-01

    Some of the most visible and least monitored elements of our national security infrastructure are the poles and towers used for the distribution of our nation’s electrical power. Issues surrounding these elements within the United States include safety such as unauthorized climbing and access, vandalism such as nut/bolt removal or destructive small arms fire, and major vandalism such as the downing of power poles and towers by the cutting of the poles with a chainsaw or torches. The Idaho National Laboratory (INL) has an ongoing research program working to develop inexpensive and sensitive sensor platforms for the monitoring and characterization of damage to the power distribution infrastructure. This presentation covers the results from the instrumentation of a variety of power poles and wires with geophone assemblies and the recording of vibration data when power poles were subjected to a variety of stimuli. Initial results indicate that, for the majority of attacks against power poles, the resulting signal can be seen not only on the targeted pole but on sensors several poles away in the distribution network and a distributed sensor system can be used to monitor remote and critical structures.

  1. Optical power distributions through fractal routing

    NASA Astrophysics Data System (ADS)

    Jansen, Roelof; Claes, Tom; Neutens, Pieter; Du Bois, Bert; Helin, Philippe; Severi, Simone; Van Dorpe, Pol; Deshpande, Paru; Rottenberg, Xavier

    2014-05-01

    Several applications in integrated optics require an equal distribution of power from a single input port among many photonic components, whether they be projection components or sensors. One method of achieving such a system is through using progressively more tightly coupled evanescent couplers to route power from a single feeding line [1]. While very compact, this approach requires careful design and characterization of evanescent couplers, and is vulnerable to process variations as the ratio of coupling has a non-linear relation to the couplers' gap size. Fractals, widely present in nature, are recursive objects where each section is geometrically similar to its parent. They find applications in various fields [2], including RF antenna design and feeding [3]. In this paper we propose to use the fractal approach for spreading power evenly over an area using micro-machined photonic waveguides. In the fractal routing demonstrated in this work, an 1×2 multimode interference (MMI) coupler splits the power at each fractal stage. This provides several advantages. First, only one power splitter design is needed. Second, MMI couplers are well known, and more robust to process tolerances than evanescent couplers [3]. Third, they are symmetrical, and therefore provide a theoretically perfect power distribution independent of the fractal depth. We therefore demonstrate that a fractal routing provides a way to evenly and efficiently distribute power over a large area.

  2. AC power quality improvement for line-commutated inverters in photovoltaic applications

    NASA Astrophysics Data System (ADS)

    Pautzke, A. W.

    The optimization and testing of a line-commutated inverter (LCI) for linking photovoltaic arrays to utility ac systems are reported. A parity simulator is used to optimize both the basic LCI circuit and the prototype device at the operating parameters, ac line = 240 V ac, single phase; dc voltage = 200 V; dc current = 40 A; and firing angle = 160 deg. The design of the harmonic filter and power-factor-compensation network (using the parity simulator to determine the component values) is explained, and the waveforms obtained with the basic, improved-simulation, and improved-prototype LCIs are shown. Although a power-quality standard has not yet been established, the OEM selling price (in quantities of 1000) of a production LCI with power factor 0.88, ITHD 12 percent, and efficiency 93 percent, is estimated at 25 cents/watt, including the required isolation transformer.

  3. Fault-tolerant power distribution system

    NASA Technical Reports Server (NTRS)

    Volp, Jeffrey A. (Inventor)

    1987-01-01

    A fault-tolerant power distribution system which includes a plurality of power sources and a plurality of nodes responsive thereto for supplying power to one or more loads associated with each node. Each node includes a plurality of switching circuits, each of which preferably uses a power field effect transistor which provides a diode operation when power is first applied to the nodes and which thereafter provides bi-directional current flow through the switching circuit in a manner such that a low voltage drop is produced in each direction. Each switching circuit includes circuitry for disabling the power field effect transistor when the current in the switching circuit exceeds a preselected value.

  4. Modelling HTc superconductors for AC power loss estimation

    SciTech Connect

    Sykulski, J.K.; Stoll, R.L.; Mahdi, A.E.; Please, C.P. [Univ. of Southampton (United Kingdom)] [Univ. of Southampton (United Kingdom)

    1997-03-01

    AC losses in high-temperature superconductors are modelled as a highly non-linear diffusion process. Two empirical expressions for modelling effective resistivity of the conductor are used. Formulations in terms of both H and E are presented and it is argued, using dimensional analysis, that working with E is numerically more efficient. Typical results calculated using a finite-difference scheme are shown.

  5. Electron energy distribution at the insulator-semiconductor interface in ac thin film electroluminescent display devices

    SciTech Connect

    Aguilera, A.; Singh, V.P. (Univ. of Texas, El Paso, TX (United States). Electrical Engineering Dept.); Morton, D.C. (Army Research Lab., Fort Monmouth, NJ (United States). Electronics and Power Sources Directorate)

    1994-08-01

    Electron emission from insulator-semiconductor interface in ZnS:Mn ac thin film electroluminescent (ACTFEL) display devices was investigated by studying the current and field waveforms. A new technique for measuring the interface electron energy distribution at insulator-semiconductor interfaces was developed. The technique involves the measurement of tunnel current transients and can be used to study the interface electron energy distribution between any insulator-semiconductor pair with which an ac thin film test structure can be fabricated. It was applied to a ZnS:Mn display device at two temperature of 10 K and 300 K and to a metal interface device structure.

  6. AC\\/DC pulse power conversion from high voltage network to JET loads

    Microsoft Academic Search

    D. Ciscato; E. Coccorese; K. I. Selin

    1977-01-01

    The ac-dc pulse power conversion equipment for the Joint European Torus is described; the 1-GW pulse power rating of the conversion equipment is made possible by a flywheel-motor-generator set for the poloidal field load. A power of 500 MW is supplied by a 400-kV interconnected network of large generating capacity. The step-down and rectifier transformers and the filters for current

  7. Point of collapse methods applied to ac/dc power systems

    SciTech Connect

    Canizares, C.A.; Alvarado, F.L.; DeMarco, C.L.; Dobson, I.; Long, W.F. (Wisconsin Univ., Madison, WI (United States))

    1992-05-01

    This paper describes an extension of the Point of Collapse method developed for ac systems studies to the determination of saddle-node bifurcations in power systems including high voltage direct current (HVDC) transmission. Bus voltage profiles are illustrated for an ac/dc test system, which significantly differ from the profiles of pure ac systems for typical system models. In particular, voltage dependent current order limits (VDCOLs) are shown to affect the voltage profiles (nose curves) and the loadability margin of the system. It is also shown that Hopf bifurcations, which are not possible in purely ac lossless systems with second-order generator models, become plausible when the dynamics for the HVDC system are included.

  8. Non-oxidized porous silicon-based power AC switch peripheries

    PubMed Central

    2012-01-01

    We present in this paper a novel application of porous silicon (PS) for low-power alternating current (AC) switches such as triode alternating current devices (TRIACs) frequently used to control small appliances (fridge, vacuum cleaner, washing machine, coffee makers, etc.). More precisely, it seems possible to benefit from the PS electrical insulation properties to ensure the OFF state of the device. Based on the technological aspects of the most commonly used AC switch peripheries physically responsible of the TRIAC blocking performances (leakage current and breakdown voltage), we suggest to isolate upper and lower junctions through the addition of a PS layer anodically etched from existing AC switch diffusion profiles. Then, we comment the voltage capability of practical samples emanating from the proposed architecture. Thanks to the characterization results of simple Al-PS-Si(P) structures, the experimental observations are interpreted, thus opening new outlooks in the field of AC switch peripheries. PMID:23057856

  9. Galileo spacecraft power management and distribution system

    NASA Technical Reports Server (NTRS)

    Detwiler, R. C.; Smith, R. L.

    1990-01-01

    The Galileo PMAD (power management and distribution system) is described, and the design drivers that established the final as-built hardware are discussed. The spacecraft is powered by two general-purpose heat-source-radioisotope thermoelectric generators. Power bus regulation is provided by a shunt regulator. Galileo PMAD distributes a 570-W beginning of mission (BOM) power source to a user complement of some 137 load elements. Extensive use of pyrotechnics requires two pyro switching subassemblies. They initiate 148 squibs which operate the 47 pyro devices on the spacecraft. Detection and correction of faults in the Galileo PMAD is an autonomous feature dictated by requirements for long life and reliability in the absence of ground-based support. Volatile computer memories in the spacecraft command and data system and attitude control system require a continuous source of backup power during all anticipated power bus fault scenarios. Power for the Jupiter Probe is conditioned, isolated, and controlled by a Probe interface subassembly. Flight performance of the spacecraft and the PMAD has been successful to date, with no major anomalies.

  10. Modeling and Analysis of Power Distribution Networks for Gigabit Applications

    E-print Network

    Swaminathan, Madhavan

    Modeling and Analysis of Power Distribution Networks for Gigabit Applications Jinwoo Choi, Student and coupling. To minimize such noise behavior, prelayout analysis and postlayout verification of the power and analysis of the power distribution network. The power distribution network supplies power to core logic

  11. Development of software to improve AC power quality on large spacecraft

    NASA Technical Reports Server (NTRS)

    Kraft, L. Alan

    1991-01-01

    To insure the reliability of a 20 kHz, AC power system on spacecraft, it is essential to analyze its behavior under many adverse operating conditions. Some of these conditions include overloads, short circuits, switching surges, and harmonic distortions. Harmonic distortions can cause malfunctions in equipment that the power system is supplying, and during extreme distortions such as voltage resonance, it can cause equipment and insulation failures due to the extreme peak voltages. HARMFLO, a power flow computer program, which was capable of analyzing harmonic conditions on three phase, balanced, 60 Hz, AC power systems, was modified to analyze single phase, 20 kHz, AC power systems. Since almost all of the equipment used on spacecraft power systems is electrically different from equipment used on terrestrial power systems, it was also necessary to develop mathematical models for the equipment to be used on the spacecraft. The results are that (1) the harmonic power now has a model of a single phase, voltage controlled, full wave rectifier; and (2) HARMFLO was ported to the SUN workstation platform.

  12. Hardware model of a shipboard zonal electrical distribution system (ZEDS) : alternating current/direct current (AC/DC)

    E-print Network

    Tidd, Chad N. (Chad Norman)

    2010-01-01

    A hardware model of a shipboard electrical distribution system based on aspects of the DDG 51 Flight IIA, Arleigh Burke class, 60Hz Alternating Current (AC) and the future direct current (DC), zonal electrical distribution ...

  13. http://power.itp.ac.cn/~suncp/quantum.htm over 95% (Pullerits et. al 1995)

    E-print Network

    Sun, Chang-Pu

    http://power.itp.ac.cn/~suncp/quantum.htm #12; #12; over 95% (Pullerits et. al 1995) Commercial solar cell (~15%) Germanium multijunction photovoltaic (~35%) VHESC Solar Cell (~42.1%) #12;LH2 #12; Energy transfer efficiency Average transfer time #12; Master equation Lindblad #12;k #12

  14. Parallel Processing Implementation of the Unit Commitment Problem with Full AC Power Flow Constraints

    E-print Network

    Parallel Processing Implementation of the Unit Commitment Problem with Full AC Power Flow (OPF'S) as there are time slices in the planning horizon. Without resorting to a parallel the experiences of the authors obtained in the pro- cess of implementing the parallel algorithm. Section 1

  15. A Comparison of the AC and DC Power Flow Models for LMP Calculations

    Microsoft Academic Search

    Thomas J. Overbye; Xu Cheng; Yan Sun

    2004-01-01

    The paper examines the tradeoffs between using a full ac model versus the less exact, but much faster, dc power flow model for LMP-based market calculations. The paper first provides a general discussion of the approximations associated with using a dc model, with an emphasis on the impact these approximations will have on security constrained OPF (SCOPF) results and LMP

  16. Environmental testing of class IE AC motor control center for nuclear power plants

    Microsoft Academic Search

    S. K. Aggarwal; M. Husain; J. A. Maxwell

    1977-01-01

    This paper reports the testing of a Class IE AC Motor Control Center, which was subjected to high temperature\\/humidity environment and pressure pulses. The test programs, simulating the effects of a high-energy steam line break in a BWR Mark I Containment nuclear power plant, are described. The motor control center functioned satisfactorily during and after the test.

  17. Measurement of AC electric power based on dual transverse Pockels effect

    Microsoft Academic Search

    Changsheng Li; Xiang Cui; Toshihiko Yoshino

    2001-01-01

    A novel optical method for the measurement of ac electric power has been developed. It is mainly based on the electrooptic crystal multiplier, which is designed according to the dual transverse Pockels effect. By using this electro-optic device, the polarized light propagating along the threefold axis of the crystal can be modulated by the product signal of two orthogonal electric

  18. Development of AC and DC Power Supply Direct Interface Converter

    NASA Astrophysics Data System (ADS)

    Kato, Koji; Itoh, Jun-Ichi

    This paper proposes a novel control method for a direct interface converter for management of the energy flow in either an AC or DC supply. The proposed converter is constructed based on an indirect matrix converter. Therefore a proposed control strategy is based on an indirect control method with a triangular carrier wave. The basic operation of the proposed control method is confirmed by experimental results. In addition, this paper also proposes a commutation error compensation method of an output voltage error and an input current error for an indirect matrix converter. In the proposed method, the output voltage and input current error by the commutation can be compensated at the same time, because the PWM pulse of each switch is directly compensated. The validity of the proposed method is confirmed by experimental results. Those results prove that the proposed compensation method can decrease total harmonic distortion (THD) of the input and output current.

  19. Static state estimation of multiterminal DC/AC power system in rectangular co-ordinates

    SciTech Connect

    Roy, L.; Sinha, A.K. (Dept. of Electrical Engineering, IIT, Kharagpur 721 302 (IN)); Srivastava, H.N.P. (Dept. of Electrical Engineering, Bhagalpur College of Engineering (IN))

    1991-01-01

    This paper describes a simple, efficient and reliable method for estimating the state of an integrated multiterminal HVDC/AC power system in the rectangular coordinate form. A six variable model is used to represent the converter system. The proposed algorithm performs successfully in obtaining the state of an AC system with a DC link or a multiterminal DC network. It is possible to implement it for an on-line state estimation. Simulation results of a 30-busbar system are presented for illustration.

  20. AC system stability analysis and assessment for Shipboard Power Systems 

    E-print Network

    Qi, Li

    2006-04-12

    algorithm, in which time step size varies automatically due to the truncation error of the former step [14]- [17]. EUROSTAG allows the simulation of all dynamics with one invariant complete model except for fast electromagnetic transients [14]. In many... [2]. According to the time frames of dynamics, power system stability can be divided into steady-state, dynamic, or small signal and transient and long-term stability. The main physical nature of instability in power systems could be angle...

  1. Applying laminated busbars to enhance DC power distribution systems

    Microsoft Academic Search

    M. Stibgen

    2004-01-01

    The intent of this paper will be an overview of how to design and implement laminated busbars into DC power distribution systems. It will include; electrical, physical and thermal characteristics obtained by utilizing a laminated busbar for DC power distribution. The power density of today's technology requires the power distribution system to play an active role in compacting size while

  2. Relativity, nonextensivity, and extended power law distributions.

    PubMed

    Silva, R; Lima, J A S

    2005-11-01

    A proof of the relativistic theorem by including nonextensive effects is given. As it happens in the nonrelativistic limit, the molecular chaos hypothesis advanced by Boltzmann does not remain valid, and the second law of thermodynamics combined with a duality transformation implies that the parameter lies on the interval [0,2]. It is also proven that the collisional equilibrium states (null entropy source term) are described by the relativistic power law extension of the exponential Juttner distribution which reduces, in the nonrelativistic domain, to the Tsallis power law function. As a simple illustration of the basic approach, we derive the relativistic nonextensive equilibrium distribution for a dilute charged gas under the action of an electromagnetic field . Such results reduce to the standard ones in the extensive limit, thereby showing that the nonextensive entropic framework can be harmonized with the space-time ideas contained in the special relativity theory. PMID:16383791

  3. Independent Orbiter Assessment (IOA): Analysis of the Electrical Power Distribution and Control Subsystem, Volume 2

    NASA Technical Reports Server (NTRS)

    Schmeckpeper, K. R.

    1987-01-01

    The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA approach features a top-down analysis of the hardware to determine failure modes, criticality, and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. This report documents the independent analysis results corresponding to the Orbiter Electrical Power Distribution and Control (EPD and C) hardware. The EPD and C hardware performs the functions of distributing, sensing, and controlling 28 volt DC power and of inverting, distributing, sensing, and controlling 117 volt 400 Hz AC power to all Orbiter subsystems from the three fuel cells in the Electrical Power Generation (EPG) subsystem. Volume 2 continues the presentation of IOA analysis worksheets and contains the potential critical items list.

  4. A distributed control approach for power and energy management in a notional shipboard power system

    NASA Astrophysics Data System (ADS)

    Shen, Qunying

    The main goal of this thesis is to present a power control module (PCON) based approach for power and energy management and to examine its control capability in shipboard power system (SPS). The proposed control scheme is implemented in a notional medium voltage direct current (MVDC) integrated power system (IPS) for electric ship. To realize the control functions such as ship mode selection, generator launch schedule, blackout monitoring, and fault ride-through, a PCON based distributed power and energy management system (PEMS) is developed. The control scheme is proposed as two-layer hierarchical architecture with system level on the top as the supervisory control and zonal level on the bottom as the decentralized control, which is based on the zonal distribution characteristic of the notional MVDC IPS that was proposed as one of the approaches for Next Generation Integrated Power System (NGIPS) by Norbert Doerry. Several types of modules with different functionalities are used to derive the control scheme in detail for the notional MVDC IPS. Those modules include the power generation module (PGM) that controls the function of generators, the power conversion module (PCM) that controls the functions of DC/DC or DC/AC converters, etc. Among them, the power control module (PCON) plays a critical role in the PEMS. It is the core of the control process. PCONs in the PEMS interact with all the other modules, such as power propulsion module (PPM), energy storage module (ESM), load shedding module (LSHED), and human machine interface (HMI) to realize the control algorithm in PEMS. The proposed control scheme is implemented in real time using the real time digital simulator (RTDS) to verify its validity. To achieve this, a system level energy storage module (SESM) and a zonal level energy storage module (ZESM) are developed in RTDS to cooperate with PCONs to realize the control functionalities. In addition, a load shedding module which takes into account the reliability of power supply (in terms of quality of service) is developed. This module can supply uninterruptible power to the mission critical loads. In addition, a multi-agent system (MAS) based framework is proposed to implement the PCON based PEMS through a hardware setup that is composed of MAMBA boards and FPGA interface. Agents are implemented using Java Agent DEvelopment Framework (JADE). Various test scenarios were tested to validate the approach.

  5. Development of a 10 kW High Temperature High Power Density Three-Phase AC-DC-AC SiC Converter

    SciTech Connect

    Ning, Puqi [ORNL

    2012-01-01

    This paper presents the development and experimental performance of a 10 kW, all SiC, 250 C junction temperature high-power-density three-phase ac-dc-ac converter. The electromagnetic interference filter, thermal system, high temperature package, and gate drive design are discussed in detail. Finally, tests confirming the feasibility and validating the theoretical basis of the prototype converter system are described.

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

    E-print Network

    Paris-Sud XI, Université de

    1 POWER ELECTRONICS HARMONIC ANALYSIS BASED ON THE LINEAR TIME PERIODIC MODELING. APPLICATIONS harmonics can not be expressed. In the frequency domain, several methods for power network harmonic analysis methods are the most often used in the network harmonic analysis. They are simple, but not accurate

  7. Development of ceramic partitioned Bi-2223 wires for AC power cable

    NASA Astrophysics Data System (ADS)

    Ayai, Naoki; Hayashi, Kazuhiko; Takei, Hiromi; Sato, Ken-ichi; Ozawa, Yasuo

    2002-10-01

    AC losses were estimated on large current capacity cable conductors on the assumption that current was distributed to each layer uniformly. The estimation clarified wire characteristics and structure for a required large capacity and small loss conductor. From the point of those researches on conductor design, the honeycomb partition structure was chosen. We adapted evacuated extrusion method to making ceramic partition and found 31 A of critical current and 3800 A/cm 2 of engineering current density in a calcium carbonate partitioned seven-core wire. AC losses of a strontium carbonate partitioned nineteen-core wire were evaluated. In parallel field, which is a main component in multi-layered cable conductor, some loss reduction was found. The AC losses were also found evident advantages in perpendicular field.

  8. AC losses in multilayer power transmission cables comprised of YBCO tapes

    NASA Astrophysics Data System (ADS)

    Noji, H.

    2011-11-01

    AC losses in multilayer power transmission cables can be reduced by adjusting the helical winding pitch of each layer to make the layer’s current distribution uniform. The optimum helical pitch can be estimated using an electric circuit (EC) model based on the expression that calculates the losses in the superconducting tapes composing the cable. It is known that the losses in a monolayer cable depend on the cable parameters (i.e., the gap between neighboring tapes, number of tapes N, diameter of the cable former and width of the tape). However, regarding Amemiya et al.’s measurement on the losses in monolayer cables, the numerical results of the losses calculated using the Norris formula for an isolated thin strip N times are close to the experimental results. Then, to determine the losses in a three-layer cable that Mukoyama et al. have reported, the losses are calculated by the EC model based on the Norris formula. The helical pitch of each layer is adjusted to make the layer’s current distribution uniform in the cable reported by Mukoyama et al. The optimum helical pitches are calculated using the condition where the standard deviation of the layer currents is minimum, and the losses of the cable at the optimum helical pitches are calculated at 1 kA rms. By comparing the results of these calculations with the previously measured results, it was found that the mean error of the calculated values relative to the measured values is 23.7%, which indicates that the calculation using the EC model is useful as a first approximation.

  9. Power quality indices and AC electric machines (review of \\

    Microsoft Academic Search

    Kazmierkowski; F. da Silva

    2010-01-01

    This textbook contains a comprehensive overview of both the traditional PQ indices to quantify PQ disturbances and proposes new indices for future use. It is a valuable resource for students, final year undergraduate courses, or for graduated courses of PQ, reliability, and electrical power systems. It is also useful for practicing designers and researchers\\/engineers involved in solving PQ problems in

  10. Two stage resonant inverter for AC distributed power supply

    Microsoft Academic Search

    Z. M. Ye; P. K. Jain; P. C. Sen

    2004-01-01

    This paper describes the topology aspects of a two-stage high frequency resonant inverter consisting of a buck converter and a half bridge series\\/parallel resonant inverter. The resonant inverter has the advantages of better waveform quality, zero voltage switching adaptability to both inductive and capacitive load, and high efficiency. Most importantly, the phase angle of this resonant inverter can be controlled

  11. Power spectrum of hadronic multiparticle rapidity distributions

    NASA Astrophysics Data System (ADS)

    Carruthers, P.; Hakiog¯lu, T.

    1992-06-01

    We discuss issues that arise in studying the power spectrum of rapidity histograms. These questions exist because the correlation functions are typically nontranslation invariant and confined to a finite kinematical interval. It is noted that the event density ?^ referred and normalized to the average single-particle density ?1, leads to (normalized) factorial cumulant bin moments dependent only on the k parameter appearing in the special case of the negative-binomial distribution. An averaged two-particle correlation function is proposed to implement the purpose of the usual Wiener-Khinchin theorem. We then generalize the bin-averaged factorial-moment technique and strip-domain moment approaches to encompass power-spectra methods. The latter connect naturally to the correlation dimensions of fractal sets and evade the problems of nonstationarity at the price of increased computational complexity. Numerical examples of chaotic time series are used to generate data. Their power spectra possess distinct properties in Gaussian and intermittent dynamics. Event averaging smooths out the power spectrum of the Gaussian dynamics, whereas the nontrivial dynamical fluctuations survive the same averaging. We argue that statistically independent events can be generated by uniformly reshuffling the rapidity histograms only if fluctuations themselves are dominantly statistical. In the presence of strongly intermittent dynamical fluctuations, correlations may exist between different events when the event points are generated by a deterministic map. In the Appendix we give the recipe for generalizing the Wiener-Khinchin theorem to calculate the power spectrum of higher-order correlations.

  12. Reactive Power Dispatch scheme evaluation for synchronous based distributed generators to reduce real power loss in distribution systems

    Microsoft Academic Search

    Komson Daroj; W. Limpananwadi

    2008-01-01

    The enhance benefit use of reactive power additional supplied by synchronous based distributed generators to reduce real power loss in distribution system is studied in this paper. Objective is to compare the amount of loss reduced between the constant power factor (CPF) and the optimal reactive power dispatch (ORPD) schemes. The former is a traditional scheme of controlling reactive power

  13. Improved SCR ac Motor Controller for Battery Powered Urban Electric Vehicles

    NASA Technical Reports Server (NTRS)

    Latos, T. S.

    1982-01-01

    An improved ac motor controller, which when coupled to a standard ac induction motor and a dc propulsion battery would provide a complete electric vehicle power train with the exception of the mechanical transmission and drive wheels was designed. In such a system, the motor controller converts the dc electrical power available at the battery terminals to ac electrical power for the induction motor in response to the drivers commands. The performance requirements of a hypothetical electric vehicle with an upper weight bound of 1590 kg (3500 lb) were used to determine the power rating of the controller. Vehicle acceleration capability, top speed, and gradeability requisites were contained in the Society of Automotive Engineers (SAE) Schedule 227a(d) driving cycle. The important capabilities contained in this driving cycle are a vehicle acceleration requirement of 0 to 72.4 kmph (0 to 45 mph) in 28 seconds a top speed of 88.5 kmph (55 mph), and the ability to negotiate a 10% grade at 48 kmph (30 mph). A 10% grade is defined as one foot of vertical rise per 10 feet of horizontal distance.

  14. AC current distribution and losses in multifilamentary superconductors exposed to longitudinal magnetic field

    SciTech Connect

    Le Naour, S. [CREEBEL, Belfort (France)] [CREEBEL, Belfort (France); Lacaze, A.; Laumond, Y. [GEC Alsthom-DEA, Belfort (France)] [GEC Alsthom-DEA, Belfort (France); Estop, P.; Verhaege, T. [Alcatel Alsthom Recherche, Marcoussis (France)] [Alcatel Alsthom Recherche, Marcoussis (France)

    1996-07-01

    The current distribution and also AC losses, in a multifilamentary superconductor carrying a transport current, are influenced by the self and the external magnetic field. By using the Maxwell equations, a model has been developed in order to calculate the temporal evolution of current distribution in a single wire exposed or not to external magnetic field. This model is based on the actual relationship of electrical field E with current density J and takes into account the twist pitch of the wire. AC losses are calculated by adding all local losses through the cross section. This paper presents calculations of the influence of the cable twist coupled with the longitudinal magnetic field, and also gives some ideas how to decrease losses.

  15. Alpha Power Increase After Transcranial Alternating Current Stimulation at Alpha Frequency (?-tACS) Reflects Plastic Changes Rather Than Entrainment

    PubMed Central

    Vossen, Alexandra; Gross, Joachim; Thut, Gregor

    2015-01-01

    Background Periodic stimulation of occipital areas using transcranial alternating current stimulation (tACS) at alpha (?) frequency (8–12 Hz) enhances electroencephalographic (EEG) ?-oscillation long after tACS-offset. Two mechanisms have been suggested to underlie these changes in oscillatory EEG activity: tACS-induced entrainment of brain oscillations and/or tACS-induced changes in oscillatory circuits by spike-timing dependent plasticity. Objective We tested to what extent plasticity can account for tACS-aftereffects when controlling for entrainment “echoes.” To this end, we used a novel, intermittent tACS protocol and investigated the strength of the aftereffect as a function of phase continuity between successive tACS episodes, as well as the match between stimulation frequency and endogenous ?-frequency. Methods 12 healthy participants were stimulated at around individual ?-frequency for 11–15 min in four sessions using intermittent tACS or sham. Successive tACS events were either phase-continuous or phase-discontinuous, and either 3 or 8 s long. EEG ?-phase and power changes were compared after and between episodes of ?-tACS across conditions and against sham. Results ?-aftereffects were successfully replicated after intermittent stimulation using 8-s but not 3-s trains. These aftereffects did not reveal any of the characteristics of entrainment echoes in that they were independent of tACS phase-continuity and showed neither prolonged phase alignment nor frequency synchronization to the exact stimulation frequency. Conclusion Our results indicate that plasticity mechanisms are sufficient to explain ?-aftereffects in response to ?-tACS, and inform models of tACS-induced plasticity in oscillatory circuits. Modifying brain oscillations with tACS holds promise for clinical applications in disorders involving abnormal neural synchrony. PMID:25648377

  16. Electric power processing, distribution, management and energy storage

    NASA Technical Reports Server (NTRS)

    Giudici, R. J.

    1980-01-01

    Power distribution subsystems are required for three elements of the SPS program: (1) orbiting satellite, (2) ground rectenna, and (3) Electric Orbiting Transfer Vehicle (EOTV). Power distribution subsystems receive electrical power from the energy conversion subsystem and provide the power busses rotary power transfer devices, switchgear, power processing, energy storage, and power management required to deliver control, high voltage plasma interactions, electric thruster interactions, and spacecraft charging of the SPS and the EOTV are also included as part of the power distribution subsystem design.

  17. DC Micro-grid for Super High Quality Electric Power Distribution

    NASA Astrophysics Data System (ADS)

    Kakigano, Hiroaki; Miura, Yushi; Ise, Toshifumi; Uchida, Ryohei

    “DC Micro-grid" is a novel power system using dc distribution in order to provide a super high quality electric power. The dc distribution system is suitable for dc output type distributed generations such as photovoltaic and fuel cells, and energy storages such as batteries and electric double layer capacitors. Power is distributed through dc distribution line and converted to required ac or dc voltage by converters placed near loads. The load side converters do not need transformers by choosing proper distributed dc voltage. The spread scheme of converters contributes to provide a high quality power supplying. Even if a short circuit occurs at one load side, it does not effect other loads. In this paper, we propose a configuration of DC micro-grid and control methods of converters for generations and energy storages. Computer simulation results demonstrated the seamless operation during turn-on and turn-off of a distributed generation, the transient of connecting and disconnecting operation with bulk power system, and the stability against a sudden large load variation.

  18. AC 2009-1451: A FRAMEWORK FOR DEVELOPING A COHESIVE SET OF REMOTE LABORATORIES FOR DISTRIBUTED DISTANCE LEARNING

    E-print Network

    AC 2009-1451: A FRAMEWORK FOR DEVELOPING A COHESIVE SET OF REMOTE LABORATORIES FOR DISTRIBUTED Engineers (ASME), The Institute of Electrical & Electronics Engineers (IEEE), The Association for Computing

  19. Smart grid power system control in distributed generation environment

    Microsoft Academic Search

    Pertti Järventausta; Sami Repo; Antti Rautiainen; Jarmo Partanen

    2010-01-01

    This paper discusses the general aspects of smart grids and focuses on some distribution level smart grid features, such as interconnection of distributed generation and active distribution management, using automated meter reading (AMR) systems in network management and power quality monitoring, application of power electronics in electricity distribution, plug-in vehicles as part of smart grids, and frequency based load control

  20. Power System Concepts for the Lunar Outpost: A Review of the Power Generation, Energy Storage, Power Management and Distribution (PMAD) System Requirements and Potential Technologies for Development of the Lunar Outpost

    NASA Astrophysics Data System (ADS)

    Khan, Z.; Vranis, A.; Zavoico, A.; Freid, S.; Manners, B.

    2006-01-01

    This paper will review potential power system concepts for the development of the lunar outpost including power generation, energy storage and power management and distribution (PMAD). In particular, the requirements of the initial robotic missions will be discussed and the technologies considered will include cryogenics and regenerative fuel cells (RFC), AC and DC transmission line technology, high voltage and low voltage power transmission, conductor materials of construction and power beaming concepts for transmitting power to difficult to access locations such as at the bottom of craters. Operating conditions, component characteristics, reliability, maintainability, constructability, system safety, technology gaps / risk and adaptability for future lunar missions will be discussed for the technologies considered.

  1. Power spectrum of hadronic multiparticle rapidity distributions

    SciTech Connect

    Carruthers, P.; Hakioglu, T. (Department of Physics, University of Arizona, Tucson, Arizona 85721 (United States))

    1992-06-01

    We discuss issues that arise in studying the power spectrum of rapidity histograms. These questions exist because the correlation functions are typically nontranslation invariant and confined to a finite kinematical interval. It is noted that the event density {cflx {rho}} referred and normalized to the average single-particle density {rho}{sub 1}, leads to (normalized) factorial cumulant bin moments dependent only on the {ital k} parameter appearing in the special case of the negative-binomial distribution. An averaged two-particle correlation function is proposed to implement the purpose of the usual Wiener-Khinchin theorem. We then generalize the bin-averaged factorial-moment technique and strip-domain moment approaches to encompass power-spectra methods. The latter connect naturally to the correlation dimensions of fractal sets and evade the problems of nonstationarity at the price of increased computational complexity. Numerical examples of chaotic time series are used to generate data. Their power spectra possess distinct properties in Gaussian and intermittent dynamics. Event averaging smooths out the power spectrum of the Gaussian dynamics, whereas the nontrivial dynamical fluctuations survive the same averaging. We argue that statistically independent events can be generated by uniformly reshuffling the rapidity histograms only if fluctuations themselves are dominantly statistical. In the presence of strongly intermittent dynamical fluctuations, correlations may exist {ital between} different events when the event points are generated by a deterministic map. In the Appendix we give the recipe for generalizing the Wiener-Khinchin theorem to calculate the power spectrum of higher-order correlations.

  2. A Control Strategy for a Distributed Power Generation Microgrid Application With Voltage and Current-Controlled Source Converter

    Microsoft Academic Search

    Emanuel Serban; Helmine Serban

    2010-01-01

    This paper presents a pseudodroop control structure integrated within a microgrid system through distributed power generation (DPG) modules capable to function in off-grid islanded, genset-connected, and grid-connected modes of operation. System efficiency has an important role in order to harvest the maximum available renewable energy from dc or ac sources while providing power backup capability. A control strategy is proposed

  3. Input/output harmonic free current link three-phase AC power supply

    NASA Astrophysics Data System (ADS)

    Karshenas, Hamid Reza

    The three-phase current link AC to AC power supply, a relatively new topology for AC power supply application, has several potential advantages such as smaller number of magnetic components, lower switching frequency and more rugged operation. Despite this, it has received very little attention by the researchers, and the majority of work found in the literature is confined to the application of voltage type converters in this area. This thesis presents a comprehensive systematic approach for steady state/dynamic analysis and design of three-phase current link AC to AC power supplies. Concept of PWM methods in three-phase current type converters (CTC) is explained and the associated constraints in PWM pattern generation are addressed. Several PWM techniques are described and their performance from different aspects are compared. A steady state analysis is presented based on the Fourier representation of PWM waveforms which allows an accurate prediction of the relationships between the fundamental/harmonic components of the waveforms and other system parameters. Expressions governing various steady state characteristics of the system are derived. A dynamic model using the concept of local average of signals is established. The agreement between the dynamic behavior of switching system and derived model is illustrated. Phenomenon of multiple crossing is explained and the necessary requirement for avoiding such a phenomenon is obtained. The concept of internal model controllers is introduced and its application in the inverter control system for achieving zero steady state error is described. A detailed design procedure is presented. Root-locus method is used to design the system controllers. The applicability of different models in different design problems is discussed. All s-domain designs are verified by time-domain simulations. Experiments are conducted on a 2 KVA, 60 Hz to 50 Hz power supply. A 32 bit DSP-base high performance controller is used to implement the control system. The predicted steady state and dynamic results as well as the time-domain simulations are experimentally verified.

  4. Satellite control of electric power distribution

    NASA Technical Reports Server (NTRS)

    Bergen, L.

    1981-01-01

    An L-band frequencies satellite link providing the medium for direct control of electrical loads at individual customer sites from remote central locations is described. All loads supplied under interruptible-service contracts are likely condidates for such control, and they can be cycled or switched off to reduce system loads. For every kW of load eliminated or deferred to off-peak hours, the power company reduces its need for additional generating capacity. In addition, the satellite could switch meter registers so that their readings automatically reflected the time of consumption. The system would perform load-shedding operations during emergencies, disconnecting large blocks of load according to predetermined priorities. Among the distribution operations conducted by the satellite in real time would be: load reconfiguration, voltage regulation, fault isolation, and capacitor and feeder load control.

  5. An overview of power electronics applications in fuel cell systems: DC and AC converters.

    PubMed

    Ali, M S; Kamarudin, S K; Masdar, M S; Mohamed, A

    2014-01-01

    Power electronics and fuel cell technologies play an important role in the field of renewable energy. The demand for fuel cells will increase as fuel cells become the main power source for portable applications. In this application, a high-efficiency converter is an essential requirement and a key parameter of the overall system. This is because the size, cost, efficiency, and reliability of the overall system for portable applications primarily depend on the converter. Therefore, the selection of an appropriate converter topology is an important and fundamental aspect of designing a fuel cell system for portable applications as the converter alone plays a major role in determining the overall performance of the system. This paper presents a review of power electronics applications in fuel cell systems, which include various topology combinations of DC converters and AC inverters and which are primarily used in fuel cell systems for portable or stand-alone applications. This paper also reviews the switching techniques used in power conditioning for fuel cell systems. Finally, this paper addresses the current problem encountered with DC converters and AC inverter. PMID:25478581

  6. An improved fault analysis algorithm for unbalanced multi-phase power distribution systems

    SciTech Connect

    Halpin, S.M. (Mississippi State Univ., Mississippi State, MS (United States). Dept. of Electrical and Computer Engineering); Grigsby, L.L.; Gross, C.A.; Nelms, R.M. (Auburn Univ., AL (United States). Dept. of Electrical Engineering)

    1994-07-01

    The results of an improved method for fault calculations in unbalanced multi-phase power distribution systems containing non-utility generators and large induction motor loads are presented in this paper. The method utilizes a combined time- and frequency-domain analysis approach to produce results that are superior to those obtained in classical fault analysis without demanding the large increase in computer time associated with complete time-domain solutions. Sources and loads can be represented by either classical frequency-domain models or detailed differential equation models. The potentially unbalanced power distribution system is represented by an admittance matrix formed using a linear graph-based application of ac circuit theory. The time-domain differential equation source and load models are interfaced with the frequency-domain distribution system model using time series analyses to estimate equivalent voltage and current phasors from discrete data sets.

  7. Power Distributions of the APS Bending Magnets and Insertion Devices

    E-print Network

    Kemner, Ken

    are used to approximate the ID and BM power distributions. The accuracy of such analytical forms depends] at a vertical angle y into a one mrad2 "solid" angle with a charged particle beam current of one mA. Although 3.1 Analytical Curve Fits to the Bending Magnet Power Profile 4.0 ID Power Distribution 4

  8. Distributed Battery Control for Peak Power Shaving in Datacenters

    E-print Network

    Simunic, Tajana

    Distributed Battery Control for Peak Power Shaving in Datacenters Baris Aksanli and Tajana Rosing to shave peak power demands. Our novel distributed battery control design has no performance impact, reduces the peak power needs, and accurately estimates and maximizes the battery lifetime. We demonstrate

  9. A unified index for power distribution reliability\\/power quality indices

    Microsoft Academic Search

    Thomas Ortmeyer

    2010-01-01

    There is much current interest in electric power distribution system reliability and power quality. Reliability is increasingly assessed using the indices SAIFI, SAIDI, and CAIDI. More recently, a similar index, MAIFI, has been proposed to assess the level of momentary interruptions on a distribution system. Power distribution companies are being asked to improve their performance by lowering these indices. The

  10. Electroluminescence and space charge distribution in XLPE subjected to ac fields at various frequencies

    Microsoft Academic Search

    A. Fujita; S. S. Bamji; M. Abou-Dakka; A. T. Bulinski

    2007-01-01

    Crosslinked Polyethylene (XLPE) has been extensively used as an insulating material in underground distribution and transmission class high voltage cables. During service, diagnostic techniques are often employed to determine the operating condition of the insulation. Some techniques use frequencies much lower than the power frequency because the required high voltage power supplies are much smaller and it is assumed that

  11. Point-Focusing Solar-Power Distributed Receivers

    NASA Technical Reports Server (NTRS)

    Lucas, J. W.

    1985-01-01

    Two-volume annual report describes development work aimed at achieving large-scale production of modular, point-focusing distributed receivers (PFDR's) for solar-powered generation of electricity or thermal power for industrial use.

  12. Applications of an electronic transformer in a power distribution system 

    E-print Network

    Ratanapanachote, Somnida

    2005-11-01

    In electrical power distribution and power electronic applications, a transformer is an indispensable component which performs many functions. At its operating frequency (60/50 Hz), it is one of the most bulky and expensive ...

  13. Power-quality improvements in vector-controlled induction motor drive employing pulse multiplication in AC-DC converters

    Microsoft Academic Search

    Bhim Singh; G. Bhuvaneswari; Vipin Garg

    2006-01-01

    This paper deals with the pulse doubling in a 12-pulse ac-dc converter for improving power quality in vector-controlled induction motor drives (VCIMDs). The design of proposed magnetics shows the flexibility in varying the voltage ratio of the autotransformer for making it suitable for retrofit applications, where presently a six-pulse diode bridge rectifier is being used. The proposed ac-dc converter is

  14. Transient Stability Analysis of Multi-Machine AC\\/DC Power Systems Via Energy-Function Method

    Microsoft Academic Search

    M. A. Pai; K. R. Padiyar; C. Radhakrishna

    1981-01-01

    In this paper, the direct method of stability analysis using energy functions is applied for single and multi-machine AC\\/DC power systems. The system loads including the terminal characteristics of the DC link are represented as constant current type loads, and their effects on the generators at the internal nodes are obtained as additional bus power injections using the method of

  15. Cascade Failures in Power Grids with Distributed Generation

    NASA Astrophysics Data System (ADS)

    Scala, Antonio; Pahwa, Sakshi; Scoglio, Caterina; ISC Institute for Complex Systems Team; Department of Electrical and Computer Engineering Team

    2013-03-01

    Power grids are nowadays experiencing a transformation due to the introduction of Distributed Generation based on Renewable Sources. At difference with classical Distributed Generation, where local power sources mitigate anomalous user consumption peaks, Renewable Sources introduce in the grid intrinsically erratic power inputs. By introducing a simple schematic (but realistic) model for power grids with stochastic distributed generation, we study the effects of erratic sources on the robustness of several IEEE power grid test networks with up to 2 ×103 buses. We find that increasing the penetration of erratic sources causes the grid to fail with a sharp transition. We compare such results with the case of failures caused by the natural increasing power demand. Power grids are nowadays experiencing a transformation due to the introduction of Distributed Generation based on Renewable Sources. At difference with classical Distributed Generation, where local power sources mitigate anomalous user consumption peaks, Renewable Sources introduce in the grid intrinsically erratic power inputs. By introducing a simple schematic (but realistic) model for power grids with stochastic distributed generation, we study the effects of erratic sources on the robustness of several IEEE power grid test networks with up to 2 ×103 buses. We find that increasing the penetration of erratic sources causes the grid to fail with a sharp transition. We compare such results with the case of failures caused by the natural increasing power demand. US grant HDTRA1-11-1-0048, CNR-PNR National Project Crisis-Lab, US Department of Energy grant EE-0003812

  16. Power Management and Distribution Trades Studies for a Deep-Space Mission Scientific Spacecraft

    NASA Technical Reports Server (NTRS)

    Kimnach, Greg L.; Soltis, James V.

    2004-01-01

    As part of NASA's Project Prometheus, the Nuclear Systems Program, NASA GRC performed trade studies on the various Power Management and Distribution (PMAD) options for a deep-space scientific spacecraft which would have a nominal electrical power requirement of 100 kWe. These options included AC (1000Hz and 1500Hz and DC primary distribution at various voltages. The distribution system efficiency, reliability, mass, thermal, corona, space radiation levels and technology readiness of devices and components were considered. The final proposed system consisted of two independent power distribution channels, sourced by two 3-phase, 110 kVA alternators nominally operating at half-rated power. Each alternator nominally supplies 50kWe to one half of the ion thrusters and science modules but is capable of supplying the total power re3quirements in the event of loss of one alternator. This paper is an introduction to the methodology for the trades done to arrive at the proposed PMAD architecture. Any opinions expressed are those of the author(s) and do not necessarily reflect the views of Project Prometheus.

  17. Distributed Power Balancing for the FREEDM System

    Microsoft Academic Search

    Ravi Akella; Fanjun Meng; Derek Ditch; Bruce McMillin; Mariesa Crow

    2010-01-01

    The FREEDM microgrid is a test bed for a smart grid integrated with Distributed Grid Intelligence (DGI) to efficiently manage the distribution and storage of renewable energy. Within the FREEDM system, DGI applies distributed algorithms in a unique way to achieve economically feasible utilization and storage of alternative energy sources in a distributed fashion. The FREEDM microgrid consists of residential

  18. Power Quality Improvement in Bridgeless Ac-Dc Converter Based Multi-output Switched Mode Power Supply

    NASA Astrophysics Data System (ADS)

    Singh, Shihka; Singh, Bhim; Bhuvaneswari, G.; Bist, Vashist

    2014-12-01

    Computer power supplies are required to have multiple isolated regulated dc voltages with low ripple content and high input power factor at the utility interface. A dc-dc converter is used for obtaining these isolated multi-output dc voltages with excellent regulation. In this paper, a non-isolated ac-dc converter is proposed as the first stage converter to obtain a regulated dc output rather than using a simple uncontrolled diode bridge rectifier at the front end. A dc-dc converter is used at the second stage that has a high frequency transformer with multiple secondary windings to obtain different dc voltage levels at the output. The proposed bridgeless converter based power supply is designed using fundamental design equations, and different component values are calculated. Extensive simulations are carried out to demonstrate the improved performance of the proposed bridgeless converter based multi-output computer power supply at varying source voltages and load conditions. Experimental validation of the power supply is carried on a developed hardware prototype, and the test results are compared with the simulated performance for design verification.

  19. Space Power Management and Distribution Status and Trends

    NASA Technical Reports Server (NTRS)

    Reppucci, G. M.; Biess, J. J.; Inouye, L.

    1984-01-01

    An overview of space power management and distribution (PMAD) is provided which encompasses historical and current technology trends. The PMAD components discussed include power source control, energy storage control, and load power processing electronic equipment. The status of distribution equipment comprised of rotary joints and power switchgear is evaluated based on power level trends in the public, military, and commercial sectors. Component level technology thrusts, as driven by perceived system level trends, are compared to technology status of piece-parts such as power semiconductors, capacitors, and magnetics to determine critical barriers.

  20. Effect of AC target power on AlN film quality

    SciTech Connect

    Knisely, Katherine, E-mail: kknisely@umich.edu; Grosh, Karl [Department of Mechanical Engineering, University of Michigan, 2026 GG Brown—2350 Hayward St., Ann Arbor, Michigan 48109 (United States)

    2014-09-01

    The influence of alternating current (AC) target power on film stress, roughness, and x-ray diffraction rocking curve full width half maximum (FWHM) was examined for AlN films deposited using S-gun magnetron sputtering on insulative substrates consisting of Si wafers with 575?nm thermal oxide. As the AC target power was increased from 5 to 8?kW, the deposition rate increased from 9.3 to 15.9?A/s, film stress decreased from 81 to ?170?MPa, and the rocking curve FWHM increased from 0.98 to 1.03°. AlN film behavior is observed to change with target life; films deposited at 200?kWh target life were approximately 40?MPa more compressive and had 0.02° degree higher rocking curve FWHM values than films deposited at 130?kWh. AlN films deposited in two depositions were compared with films deposited in a single deposition, in order to better characterize the growth behavior and properties of AlN films deposited on an existing AlN film, which is not well understood. Two deposition films, when compared with single deposition films, showed no variation in residual stress trends or grain size behavior, but the average film roughness increased from 0.7 to 1.4?nm and rocking curve FWHM values increased by more than 0.25°.

  1. AC Resonant charger with charge rate unrelated to primary power frequency

    DOEpatents

    Watson, Harold (Torrance, CA)

    1982-01-01

    An AC resonant charger for a capacitive load, such as a PFN, is provided with a variable repetition rate unrelated to the frequency of a multi-phase AC power source by using a control unit to select and couple the phase of the power source to the resonant charger in order to charge the capacitive load with a phase that is the next to begin a half cycle. For optimum range in repetition rate and increased charging voltage, the resonant charger includes a step-up transformer and full-wave rectifier. The next phase selected may then be of either polarity, but is always selected to be of a polarity opposite the polarity of the last phase selected so that the transformer core does not saturate. Thyristors are used to select and couple the correct phase just after its zero crossover in response to a sharp pulse generated by a zero-crossover detector. The thyristor that is turned on then automatically turns off after a full half cycle of its associated phase input. A full-wave rectifier couples the secondary winding of the transformer to the load so that the load capacitance is always charged with the same polarity.

  2. A Kalman filtering based control scheme for the improvement of dynamic performance of an AC/DC power system

    NASA Astrophysics Data System (ADS)

    Pecen, Recayi

    In this dissertation, two major accomplishments are achieved. First, the feasibility of a proposed Wyoming to California HVDC system having the ratings of 1000 MW, ±500 kV, 2 kA, 860 miles and 12-pulse bipolar lines is shown for exporting Wyoming's electrical power resources to the heavy loaded western states. The second and the main objective of this dissertation is the development of a Kalman filtering (KF) based control scheme applied to an ac/dc power system. It is shown that the use KF algorithm to estimate some of the system states and utilizing them in a proportional Integral (PI) controller which has a better performance for this specific control scheme have resulted in a better dynamic performance of the proposed system. A set of case studies has shown that the system dynamic performance is improved for most of the contingencies. Ac and dc noisy voltage and current measurements received from the simulated ac/dc power system are sent to the KF estimation algorithm. The noise-separated best estimates of measurable states are computed and sent to a PI controller-based current and firing angle control subsections in order to provide a set of optimum thyristor firing angles for both converter stations during and after contingencies until the normal operation is reached. To evaluate the dynamic performance of the system with the KF algorithm, the model is simulated by a well-known digital simulation package, Electromagnetic Transients DC Program (PSCAD/EMTDC) of Manitoba HVDC Research Center. To apply the KF algorithm, a general, linearized, state-space model of the proposed ac/dc system, appropriate for analyzing both the KF and the electromagnetics transients, is derived first. The derived model enables the representation of an ac power system with two ac sources and one HVDC line with a parallel ac line connecting the two systems. It is shown that system eigenvalues of the discretized system model for a normal operating point are inside the unit circle that enables a stable operation. It is also shown that the system is controllable and observable for that specific point. The severity of a three-phase short circuit in the proposed ac/dc system is greatly reduced due to the HVDC link. One of the aims of this dissertation was to show that the addition of a parallel dc tie into an existing ac line resulted in dynamic performance improvement of the entire ac system, particularly during and after contingencies. It is also shown that a combination of the KF algorithm and PI control provides a stable recovery of the ac/dc system after a set of contingencies.

  3. Communication Using Pseudonoise Modulation on Electric Power Distribution Circuits

    Microsoft Academic Search

    P. van der Gracht; R. W. Donaldson

    1985-01-01

    Localized communication networks for office automation, security monitoring, environmental management of buildings, computer communications, and other applications enjoy every increasing demand. This paper considers communication of data and analog message signals over electric power distribution circuits for such applications, using pseudonoise (PN) modulation. Advantages of power distribution circuits include reasonably universal coverage and easy access via a standard wall plug.

  4. Decision Support The distribution of power in the European Constitution

    E-print Network

    Bilbao Arrese, Jesús Mario

    of the permanent nations (the United States, Russia, China, the United Kingdom and France) has seven votes and eachDecision Support The distribution of power in the European Constitution E. Algaba, J.M. Bilbao *, J Abstract The aim of this paper is to analyze the distribution of voting power in the Constitution

  5. Thermodynamically self consistent radial distribution functions for inverse power potentials

    Microsoft Academic Search

    P. Hutchinson; W. R. Conkie

    1972-01-01

    A previously reported self consistent approximation for the pair distribution function is applied to inverse power potentials. Results are reported for the first six virial coefficients over the full range of such potentials. The thermodynamic properties and pair distributions functions are presented for the inverse sixth and twelfth power potentials and are shown to be in close agreement with the

  6. Low-cost distributed solar-thermal-electric power generation

    E-print Network

    Sanders, Seth

    Low-cost distributed solar-thermal-electric power generation A. Der Minassians, K. H. Aschenbach discuss the technical and economic feasibility of a low-cost distributed solar-thermal-electric power relative cost, solar electric energy systems have yet to be exploited on a widespread basis. It is believed

  7. CRRES Electric Field Power Spectral Distributions

    NASA Astrophysics Data System (ADS)

    Brautigam, D. H.; Bass, J.; Wygant, J.

    2001-12-01

    The ULF wave power during the CRRES mission is investigated using the CRRES electric field instrument. The wave power spectral characteristics are examined as a function of L in terms of long-term averages, and in terms of magnetic activity (Kp). Previous work has fit the power spectral density to activity-dependent power law spectra [Holzworth and Mozer, 1979]. Results from the current study are compared with these earlier results. There are a significant number of cases where the observed spectra deviate from a power law, exhibiting a secondary peak around 8 mHz . The regularity and nature of these spectra are examined as well.

  8. Automated distribution system management for multichannel space power systems

    NASA Technical Reports Server (NTRS)

    Fleck, G. W.; Decker, D. K.; Graves, J.

    1983-01-01

    A NASA sponsored study of space power distribution system technology is in progress to develop an autonomously managed power system (AMPS) for large space power platforms. The multichannel, multikilowatt, utility-type power subsystem proposed presents new survivability requirements and increased subsystem complexity. The computer controls under development for the power management system must optimize the power subsystem performance and minimize the life cycle cost of the platform. A distribution system management philosophy has been formulated which incorporates these constraints. Its implementation using a TI9900 microprocessor and FORTH as the programming language is presented. The approach offers a novel solution to the perplexing problem of determining the optimal combination of loads which should be connected to each power channel for a versatile electrical distribution concept.

  9. Automation of Space Station module power management and distribution system

    Microsoft Academic Search

    Robert Bechtel; Bryan Walls

    1990-01-01

    Viewgraphs on automation of space station module (SSM) power management and distribution (PMAD) system are presented. Topics covered include: reasons for power system automation; SSM\\/PMAD approach to automation; SSM\\/PMAD test bed; SSM\\/PMAD topology; functional partitioning; SSM\\/PMAD control; rack level autonomy; FRAMES AI system; and future technology needs for power system automation.

  10. Automation of Space Station module power management and distribution system

    NASA Technical Reports Server (NTRS)

    Bechtel, Robert; Weeks, Dave; Walls, Bryan

    1990-01-01

    Viewgraphs on automation of space station module (SSM) power management and distribution (PMAD) system are presented. Topics covered include: reasons for power system automation; SSM/PMAD approach to automation; SSM/PMAD test bed; SSM/PMAD topology; functional partitioning; SSM/PMAD control; rack level autonomy; FRAMES AI system; and future technology needs for power system automation.

  11. Benefits of Power Electronic Interfaces for Distributed Energy Systems

    Microsoft Academic Search

    Benjamin Kroposki; Christopher Pink; Richard DeBlasio; Holly Thomas; Marcelo Simões; Pankaj K. Sen

    2010-01-01

    With the increasing use of distributed energy (DE) systems in industry and its technological advancement, it is becoming more important to understand the integration of these systems with the electric power systems. New markets and benefits for DE applications include the ability to provide ancillary services, improve energy efficiency, enhance power system reliability, and allow customer choice. Advanced power electronic

  12. LIMITED POWER BURSTS IN DISTRIBUTED MODELS OF NUCLEAR REACTORS

    E-print Network

    Bazhenov, Maxim

    LIMITED POWER BURSTS IN DISTRIBUTED MODELS OF NUCLEAR REACTORS M. V. Bazhenov and E. F. Sabaev UDC employed for analyzing reactor dynamics. Equations of this type are used for analyzing the stability of the reactor power, etc. Among these problems the question of the boundedness of reactor power bursts

  13. Local control of reactive power by distributed photovoltaic generators

    SciTech Connect

    Chertkov, Michael [Los Alamos National Laboratory; Turitsyn, Konstantin [Los Alamos National Laboratory; Sulc, Petr [Los Alamos National Laboratory; Backhaus, Scott [Los Alamos National Laboratory

    2010-01-01

    High penetration levels of distributed photovoltaic (PV) generation on an electrical distribution circuit may severely degrade power quality due to voltage sags and swells caused by rapidly varying PV generation during cloud transients coupled with the slow response of existing utility compensation and regulation equipment. Although not permitted under current standards for interconnection of distributed generation, fast-reacting, VAR-capable PV inverters may provide the necessary reactive power injection or consumption to maintain voltage regulation under difficult transient conditions. As side benefit, the control of reactive power injection at each PV inverter provides an opportunity and a new tool for distribution utilities to optimize the performance of distribution circuits, e.g. by minimizing thermal losses. We suggest a local control scheme that dispatches reactive power from each PV inverter based on local instantaneous measurements of the real and reactive components of the consumed power and the real power generated by the PVs. Using one adjustable parameter per circuit, we balance the requirements on power quality and desire to minimize thermal losses. Numerical analysis of two exemplary systems, with comparable total PV generation albeit a different spatial distribution, show how to adjust the optimization parameter depending on the goal. Overall, this local scheme shows excellent performance; it's capable of guaranteeing acceptable power quality and achieving significant saving in thermal losses in various situations even when the renewable generation in excess of the circuit own load, i.e. feeding power back to the higher-level system.

  14. A voltage-multiplying self-powered ac\\/dc converter with 0.35 V minimum input voltage for energy harvesting applications

    Microsoft Academic Search

    Shuo Cheng; Rutvik Sathe; Raj D. Natarajan; David P. Arnold

    2011-01-01

    This paper demonstrates a highly efficient, low- voltage ac\\/dc converter using a voltage multiplier (octupler) circuit architecture intended for vibrational energy harvesting applications where a low-voltage ac waveform is used to charge a battery. The circuit employs output-powered active diodes and does not require any external power supply or startup circuitry. The circuit rectifies and boosts input ac voltages in

  15. A Voltage-Multiplying Self-Powered AC\\/DC Converter with 0.35-V Minimum Input Voltage for Energy Harvesting Applications

    Microsoft Academic Search

    Shuo Cheng; Rutvik Sathe; Raj Dayal Natarajan; David P. Arnold

    2011-01-01

    This paper demonstrates a highly efficient, low- voltage ac\\/dc converter using a voltage multiplier (octupler) circuit architecture intended for vibrational energy harvesting applica- tions where a low-voltage ac waveform is used to charge a battery. The circuit employs output-powered active diodes and does not require any external power supply or startup circuitry. The circuit rectifies and boosts input ac voltages

  16. Distribution power flow for smart grid technologies

    Microsoft Academic Search

    Kevin P. Schneider; David P. Chassin; Yousu Chen; Jason C. Fuller

    2009-01-01

    Smart Grid technologies hold the promise of being able to solve many of the problems currently facing in the electric power industry. However, the large scale deployment of these new technologies has been limited due to an inability to accurately model their effects or to quantify their potential benefits. GridLAB-D is a new open source power system modeling and simulation

  17. Air ion mobility spectra and concentrations upwind and downwind of overhead AC high voltage power lines

    NASA Astrophysics Data System (ADS)

    Wright, Matthew D.; Buckley, Alison J.; Matthews, James C.; Shallcross, Dudley E.; Henshaw, Denis L.

    2014-10-01

    Corona ions produced by high-voltage power lines (HVPLs) can alter the nearby electrical environment, potentially increasing aerosol charge levels downwind. However, there is a lack of knowledge concerning the concentration and mobility of ions from AC HVPLs and their dispersion away from the line. We present ion concentration and mobility measurements made near AC HVPLs in South-West England. Examples of typical mobility spectra are shown highlighting features commonly observed. Corona was observed during 33 of 46 measurements, at 9 of 11 sites, with positive or ‘bipolar' (both polarities) ion production commonly seen. Ion production usually increases atmospheric concentrations by only a modest amount, but extreme cases can enhance concentration by an order of magnitude or more. A polarity imbalance is required to increase aerosol charge via ion attachment; this was observed on 15 of 24 days when positive corona was observed, but was not seen for negative ions. Ion mobility was higher downwind compared with upwind for both ion polarities, but the increase was not statistically significant. Future work should focus on identifying and characterising ‘heavy-producing' HVPLs, and obtaining results in conditions which may favour negative ion production e.g. high humidity, inclement weather or during nighttime.

  18. Single stage AC-DC converter for Galfenol-based micro-power energy harvesters

    NASA Astrophysics Data System (ADS)

    Cavaroc, Peyton; Curtis, Chandra; Naik, Suketu; Cooper, James

    2014-06-01

    Military based sensor systems are often hindered in operational deployment and/or other capabilities due to limitations in their energy storage elements. Typically operating from lithium based batteries, there is a finite amount of stored energy which the sensor can use to collect and transmit data. As a result, the sensors have reduced sensing and transmission rates. However, coupled with the latest advancements in energy harvesting, these sensors could potentially operate at standard sensing and transition rates as well as dramatically extend lifetimes. Working with the magnetostrictive material Galfenol, we demonstrate the production of enough energy to supplement and recharge a solid state battery thereby overcoming the deficiencies faced by unattended sensors. As with any vibration-based energy harvester, this solution produces an alternating current which needs to be rectified and boosted to a level conducive to recharge the storage element. This paper presents a power converter capable of efficiently converting an ultra-low AC voltage to a solid state charging voltage of 4.1VDC. While we are working with Galfenol transducers as our energy source, this converter may also be applied with any AC producing energy harvester, particularly at operating levels less than 2mW and 200mVAC.

  19. Hierarchical power distribution and power management scheme for a single chip mobile processor

    Microsoft Academic Search

    Toshihiro Hattori; Takahiro Irita; Masayuki Ito; Eiji Yamamoto; Hisashi Kato; Go Sado; Tetsuhiro Yamada; Kunihiko Nishiyama; Hiroshi Yagi; Takao Koike; Yoshihiko Tsuchihashi; Motoki Higashida; Hiroyuki Asano; Izumi Hayashibara; Ken Tatezawa; Yasuhisa Shimazaki; Naozumi Morino; Yoshihiko Yasu; Tadashi Hoshi; Yujiro Miyairi; Kazumasa Yanagisawa; Kenji Hirose; Saneaki Tamaki; Shinichi Yoshioka; Toshifumi Ishii; Yusuke Kanno; Hiroyuki Mizuno; Tetsuya Yamada; Naohiko Irie; Reiko Tsuchihashi; Nobuto Arai; Tomohiro Akiyama; Koji Ohno

    2006-01-01

    A hierarchical power distribution methodology that enables more than dozen power domains in a chip and a power management scheme using 20 power domains are described. This method can achieve very low leakage current in the partial active mode of a single chip mobile processor. The single chip mobile processor embedded three CPU's that is baseband processor, application processor, and

  20. Distributed Power Network Co-Design with On-Chip Power Supplies and Decoupling Capacitors

    E-print Network

    Friedman, Eby G.

    Distributed Power Network Co-Design with On-Chip Power Supplies and Decoupling Capacitors Selc¸uk K computationally complex. The rising number of on-chip power supplies and intentional decoupling capacitors network. Inter- actions among the on-chip power supplies, decoupling capacitors, and load circuitry

  1. Statistical analyses support power law distributions found in neuronal avalanches.

    PubMed

    Klaus, Andreas; Yu, Shan; Plenz, Dietmar

    2011-01-01

    The size distribution of neuronal avalanches in cortical networks has been reported to follow a power law distribution with exponent close to -1.5, which is a reflection of long-range spatial correlations in spontaneous neuronal activity. However, identifying power law scaling in empirical data can be difficult and sometimes controversial. In the present study, we tested the power law hypothesis for neuronal avalanches by using more stringent statistical analyses. In particular, we performed the following steps: (i) analysis of finite-size scaling to identify scale-free dynamics in neuronal avalanches, (ii) model parameter estimation to determine the specific exponent of the power law, and (iii) comparison of the power law to alternative model distributions. Consistent with critical state dynamics, avalanche size distributions exhibited robust scaling behavior in which the maximum avalanche size was limited only by the spatial extent of sampling ("finite size" effect). This scale-free dynamics suggests the power law as a model for the distribution of avalanche sizes. Using both the Kolmogorov-Smirnov statistic and a maximum likelihood approach, we found the slope to be close to -1.5, which is in line with previous reports. Finally, the power law model for neuronal avalanches was compared to the exponential and to various heavy-tail distributions based on the Kolmogorov-Smirnov distance and by using a log-likelihood ratio test. Both the power law distribution without and with exponential cut-off provided significantly better fits to the cluster size distributions in neuronal avalanches than the exponential, the lognormal and the gamma distribution. In summary, our findings strongly support the power law scaling in neuronal avalanches, providing further evidence for critical state dynamics in superficial layers of cortex. PMID:21720544

  2. Cascade Failures from Distributed Generation in Power Grids

    E-print Network

    Scala, Antonio; Scoglio, Caterina

    2012-01-01

    Power grids are nowadays experiencing a transformation due to the introduction of Distributed Generation based on Renewable Sources. At difference with classical Distributed Generation, where local power sources mitigate anomalous user consumption peaks, Renewable Sources introduce in the grid intrinsically erratic power inputs. By introducing a simple schematic (but realistic) model for power grids with stochastic distributed generation, we study the effects of erratic sources on the robustness of several IEEE power grid test networks with up to 2000 buses. We find that increasing the penetration of erratic sources causes the grid to fail with a sharp transition. We compare such results with the case of failures caused by the natural increasing power demand.

  3. Resonant AC power system proof-of-concept test program, volume 2, appendix 1

    NASA Technical Reports Server (NTRS)

    1986-01-01

    This report contains two volumes. The main text (Volume 1) summarizes the tests results and gives a detailed discussion of the response of three early, first generation configurations of ac power system IRAD breadboards to the contracted tests imposed on them. It explains photographs, measurements, and data calculations, as well as any observed anomalies or lessons learned. This volume (No 2, Appendix 1, Test Results and Data), published under separate cover, includes all of the data taken on the 1.0 kW single-phase; 5.0 kW three-phase; and 25.0-kW three-phase system breadboards. The format of this data is raw, i.e., it is a direct copy of the data sheets for the test data notebook.

  4. Voltage source ac-to-dc converters for high-power transmitters

    NASA Technical Reports Server (NTRS)

    Cormier, R.

    1990-01-01

    This work was done to optimize the design of the components used for the beam power supply, which is a component of the transmitters in the Deep Space Network (DSN). The major findings are: (1) the difference in regulation between a six-pulse and a twelve-pulse converter is at most 7 percent worse for the twelve-pulse converter; (2) the commutation overlap angle of a current source converter equals that of a voltage source converter with continuous line currents; (3) the sources of uncharacteristic harmonics are identified with SPICE simulation; (4) the use of an imperfect phase-shifting transformer for the twelve-pulse converter generates a harmonic at six times the line frequency; and (5) the assumptions usually made in analyzing converters can be relaxed with SPICE simulation. The results demonstrate the suitability of using SPICE simulation to obtain detailed performance predictions of ac-to-dc converters.

  5. Distribution Power Flow for Smart Grid Technologies

    SciTech Connect

    Schneider, Kevin P.; Chassin, David P.; Chen, Yousu; Fuller, Jason C.

    2009-03-18

    Smart Grid technologies hold the promise of being able to solve many of the problems currently facing in the electric power industry. However, the large scale deployment of these new technologies has been limited due to an inability to accurately model their effects or to quantify their potential benefits. GridLAB-D is a new open source power system modeling and simulation environment developed by the United States Department of Energy specifically to integrate detailed power systems and end-use models. In order to effectively model the vast array of possible smart grid technologies GridLAB-D was developed as a general simulation environment. This paper describes the basic design concept, the power flow solutions implemented, and a detailed example of the type of analysis that can be performed within the simulation environment in order to support the evaluation of smart grid technologies.

  6. Ripple Reduction Characteristics in the Parallel-Connected DC Power Distribution System Constructed by New Terminals for Wire Communication

    NASA Astrophysics Data System (ADS)

    Katsuki, Akihiko; Matsumoto, Tadashi; Watanabe, Shogo; Fukunaga, Masaichi

    Powering terminal should prevent signal inflow from the communication lines. Powered terminal in most wire communication systems needs to separate ac signals and dc supply power in its input part connected to the communication lines. Our original communication system consists of low-power dc-dc converters. In our system, the direction of dc power is opposite in powering terminal at reception and powered terminal. Therefore, to use the same electronic choke for powering terminal and powered terminal, it is preferable that the electronic choke be bidirectional. So, we have proposed new electronic choke by the use of small inductors and an amplifier. From the viewpoint of power distribution, this system contains a parallel-connected dc power supply. In this paper, voltage-ripple attenuation characteristics at reception are presented on the dc power distribution system using buck-type converters and new electronic chokes. New electronic choke has an ability of good attenuation against signals. Even though switching frequencies are different, no beat is observed in the output dc voltage waveform of powered terminal. New electronic choke effectively removes circulation or interference by the ripple.

  7. Connecting an alternative energy source to the power grid by a DSP controlled DC\\/AC inverter

    Microsoft Academic Search

    Yuval Beck; Bishara Bishara; Dror Medini

    2005-01-01

    In times when environmental issues such as global warming and air pollution are in focus, there are more objections to the use of conventional and nuclear power stations. The use of alternative energy sources such as water turbines, solar cells and wind turbines becomes essential for producing clean energy. In this paper, a novel design of a 1 kW DC\\/AC

  8. Shuttle Electrical Power Analysis Program (SEPAP) distribution circuit analysis report

    NASA Technical Reports Server (NTRS)

    Torina, E. M.

    1975-01-01

    An analysis and evaluation was made of the operating parameters of the shuttle electrical power distribution circuit under load conditions encountered during a normal Sortie 2 Mission with emphasis on main periods of liftoff and landing.

  9. Space Station Freedom power management and distribution system design

    NASA Technical Reports Server (NTRS)

    Teren, Fred

    1989-01-01

    The design is described of the Space Station Freedom Power Management and Distribution (PMAD) System. In addition, the significant trade studies which were conducted are described, which led to the current PMAD system configuration.

  10. Modeling the Effect of Hurricanes on Power Distribution Systems

    E-print Network

    Chanda, Suraj

    2012-10-19

    There are many calamitous events such as earthquakes, hurricanes, tsunamis etc. that occur suddenly and cause great loss of life, damage, or hardship. Hurricanes cause significant damage to power distribution systems, resulting in prolonged customer...

  11. Do wealth distributions follow power laws? Evidence from ‘rich lists’

    NASA Astrophysics Data System (ADS)

    Brzezinski, Michal

    2014-07-01

    We use data on the wealth of the richest persons taken from the ‘rich lists’ provided by business magazines like Forbes to verify if the upper tails of wealth distributions follow, as often claimed, a power-law behaviour. The data sets used cover the world’s richest persons over 1996-2012, the richest Americans over 1988-2012, the richest Chinese over 2006-2012, and the richest Russians over 2004-2011. Using a recently introduced comprehensive empirical methodology for detecting power laws, which allows for testing the goodness of fit as well as for comparing the power-law model with rival distributions, we find that a power-law model is consistent with data only in 35% of the analysed data sets. Moreover, even if wealth data are consistent with the power-law model, they are usually also consistent with some rivals like the log-normal or stretched exponential distributions.

  12. Oxygen distributions within R3230Ac tumors growing in dorsal flap window chambers in rats.

    PubMed

    Wilson, D F; Evans, S M; Jenkins, W T; Vinogradov, S A; Ong, E; Dewhirst, M W

    1998-01-01

    R3230Ac mammary tumors were grown in transparent window chambers implanted into the dorsal skin flap of 250 g Fischer 344 rats (see Dewhirst et al, 1992). The oxygen pressure distributions in the tumor and host tissue were measured by the oxygen dependent quenching of phosphorescence (see Vinogradov et al, 1996) after injection of Oxyphor R2 (7 mg, 0.3 ml) into the tail vein. The oxygen pressure maps show the R3230Ac tumors to be hypoxic relative to the surrounding tissue. The excitation spectrum for the phosphor has peaks at 419 nm (blue light) and at 524 nm (green light), and the emitted phosphorescence spectrum and lifetime are independent of the wavelength at which the phosphor is excited. The absorption by tissue is much greater for blue light than green light, due to intrinsic chromophores such as cytochromes, hemoglobin, myoglobin etc. Thus, blue excitation measures the oxygen pressures in a much thinner, superficial, surface layer (< 50 microns) than does green excitation, allowing "optical sectioning" of tissue oxygenation. The tissue can be further optically sectioned by making measurements from both sides of the window. Viewed from the tumor side, the superficial layers (blue excitation) of these tumors were hypoxic whereas the host tissue was well oxygenated. The oxygen pressures in the growing edge of the tumors are lower than those in the central core of the tumor, and much lower than those of the host tissue. This result is in agreement with the micro-oxygen electrode measurements of perivascular oxygen pressures reported by Dewhirst and coworkers (1992). PMID:9889940

  13. Mecomtronics Module J: Electrical Power Distribution and Loading

    NSDL National Science Digital Library

    Initially developed by NJCATE and a team of math, science, communications and technology faculty, this learning module employs the NJCATE Integrated Curriculum Model to integrate core and technical material. Accessing just-in-time learning concepts in which instructors function as coach/facilitators, the module guides students through core and technical activities built around a main project. Module activities present students with hands-on situations which simulate the workplace both in terms of the knowledge and skills required as well as the ethical concerns they will inevitably address. Specifically, Module J's End Cut Saw Machine Station project focuses on electrical power distribution and loading. Students will design a new power distribution system to support the needs of the saw motors and related equipment. The system will consist of a 480-volt feeder and motor control center. A step-down transformer will be provided to supply 120-Volt convenience outlets and general lighting to the area. Using their knowledge of power source, primary Distribution, motors, wiring, and lighting, students will: Design a power distribution system configuration Select, size and specify required power distribution equipment Size and specify required power distribution conduit and cable Size and specify heat tracing cable Produce equipment installation layout drawings Develop project manual and present a project report Target Audience 2-4 Year College Students Self Evaluation DataExcellent instructional module to support a new or existing Engineering Technology course or program.

  14. Independent Orbiter Assessment (IOA): Analysis of the electrical power distribution and control subsystem, volume 1

    NASA Technical Reports Server (NTRS)

    Schmeckpeper, K. R.

    1987-01-01

    The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA approach features a top-down analysis of the hardware to determine failure modes, criticality, and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. This report documents the independent analysis results corresponding to the Orbiter Electrical Power Distribution and Control (EPD and C) hardware. The EPD and C hardware performs the functions of distributing, sensing, and controlling 28 volt DC power and of inverting, distributing, sensing, and controlling 117 volt 400 Hz AC power to all Orbiter subsystems from the three fuel cells in the Electrical Power Generation (EPG) subsystem. Each level of hardware was evaluated and analyzed for possible failure modes and effects. Criticality was assigned based upon the severity of the effect for each failure mode. Of the 1671 failure modes analyzed, 9 single failures were determined to result in loss of crew or vehicle. Three single failures unique to intact abort were determined to result in possible loss of the crew or vehicle. A possible loss of mission could result if any of 136 single failures occurred. Six of the criticality 1/1 failures are in two rotary and two pushbutton switches that control External Tank and Solid Rocket Booster separation. The other 6 criticality 1/1 failures are fuses, one each per Aft Power Control Assembly (APCA) 4, 5, and 6 and one each per Forward Power Control Assembly (FPCA) 1, 2, and 3, that supply power to certain Main Propulsion System (MPS) valves and Forward Reaction Control System (RCS) circuits.

  15. Superconducting power delivery systems for transmission and distribution applications

    SciTech Connect

    Kral, S.F.; Aslam, M.; Ribeiro, P.F.; Huang, X.; Xu, M. [Babcock and Wilcox, Lynchburg, VA (United States)

    1995-10-01

    Transmission and distribution power systems are presently experiencing tremendous changes in both load requirements and system operation. End-users demand increased reliability and power quality. System operations change to optimize the distribution and number of generation sources to take advantage of load diversity and fuel availability. Superconducting Magnetic Energy Storage (SMES) and modern power electronics systems emerge as technologies enabling power utility systems to adapt to these changes. These systems deliver services unique and previously unavailable and the authors suggest the term Superconducting Power Systems to describe them. Babcock and Wilcox (B and W) is working with Anchorage Municipal Light and Power (ML and P) to design, manufacture and install a 50 MW, 1,800 MJ system in Anchorage, Alaska. The system will be commissioned in early 1998.

  16. PAD: Power-Aware Directory Placement in Distributed Caches

    E-print Network

    Shahriar, Selim

    PAD: Power-Aware Directory Placement in Distributed Caches Technical Report NWU-EECS-10 structures (i.e., directories) for the purpose of maintaining data coherence in the presence of conflicting and data-access-oblivious placement of the directory structures on chip. In this paper, we propose Power

  17. Proposed Recommended Practices for Cement Plant Power Distribution

    Microsoft Academic Search

    1966-01-01

    The continuing expansion and modernization program in the cement industry has placed an increasing importance on the cement plant power distribution system. The use of fewer larger production units and the increased use of automatic controls has placed greater stress on the adequacy and reliability of the power system. Safety, capacity, reliability, and low maintenance, all at a reasonable cost,

  18. Power distribution for a cement plant expansion project

    Microsoft Academic Search

    G. Costantiello; B. Kandoth

    2003-01-01

    The power distribution requirements and the selection of drives for a cement plant expansion project are defined by the new process, the equipment features and ratings, the plant layout and the electric utility characteristics and requirements. These factors are considered in pre-feasibility studies, feasibility studies and basic engineering, prior to starting the final project phase of detail engineering. Power system

  19. Distributed Beamforming and Power Allocation for Cooperative Networks

    E-print Network

    Leung, Kin K.

    and power allocation algorithm which substantially improves the diversity of the system with only veryDistributed Beamforming and Power Allocation for Cooperative Networks Zhiguo Ding, Member, IEEE of communications between two nodes was proposed in [2], [3]. Such systems are able to introduce diversity

  20. An algorithm for partial discharge location in distribution power transformers

    Microsoft Academic Search

    Z. D. WanPo; P. A. Crossley; K. J. Cornick; D. H. Zhu

    2000-01-01

    Partial discharges (PDs) are a major source of insulation failure in power transformers. Techniques for locating a PD source are of major importance in both the maintenance and repair of a transformer. A technique is described for locating a PD in a distribution power transformer. To study the propagation characteristics of a PD, a simulation model was developed for the

  1. 62. View of amplifiermodulator control system with power distribution panel ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    62. View of amplifier-modulator control system with power distribution panel on left, control power supply in middle, and amplifier modulator on right, second floor in transmitter building no. 102. - Clear Air Force Station, Ballistic Missile Early Warning System Site II, One mile west of mile marker 293.5 on Parks Highway, 5 miles southwest of Anderson, Anderson, Denali Borough, AK

  2. Suppression of AC railway power-line interference in ECG signals recorded by public access defibrillators

    PubMed Central

    Dotsinsky, Ivan

    2005-01-01

    Background Public access defibrillators (PADs) are now available for more efficient and rapid treatment of out-of-hospital sudden cardiac arrest. PADs are used normally by untrained people on the streets and in sports centers, airports, and other public areas. Therefore, automated detection of ventricular fibrillation, or its exclusion, is of high importance. A special case exists at railway stations, where electric power-line frequency interference is significant. Many countries, especially in Europe, use 16.7 Hz AC power, which introduces high level frequency-varying interference that may compromise fibrillation detection. Method Moving signal averaging is often used for 50/60 Hz interference suppression if its effect on the ECG spectrum has little importance (no morphological analysis is performed). This approach may be also applied to the railway situation, if the interference frequency is continuously detected so as to synchronize the analog-to-digital conversion (ADC) for introducing variable inter-sample intervals. A better solution consists of rated ADC, software frequency measuring, internal irregular re-sampling according to the interference frequency, and a moving average over a constant sample number, followed by regular back re-sampling. Results The proposed method leads to a total railway interference cancellation, together with suppression of inherent noise, while the peak amplitudes of some sharp complexes are reduced. This reduction has negligible effect on accurate fibrillation detection. Conclusion The method is developed in the MATLAB environment and represents a useful tool for real time railway interference suppression. PMID:16309558

  3. Power Distribution System Planning with GIS Consideration

    NASA Astrophysics Data System (ADS)

    Wattanasophon, Sirichai; Eua-Arporn, Bundhit

    This paper proposes a method for solving radial distribution system planning problems taking into account geographical information. The proposed method can automatically determine appropriate location and size of a substation, routing of feeders, and sizes of conductors while satisfying all constraints, i.e. technical constraints (voltage drop and thermal limit) and geographical constraints (obstacle, existing infrastructure, and high-cost passages). Sequential quadratic programming (SQP) and minimum path algorithm (MPA) are applied to solve the planning problem based on net price value (NPV) consideration. In addition this method integrates planner's experience and optimization process to achieve an appropriate practical solution. The proposed method has been tested with an actual distribution system, from which the results indicate that it can provide satisfactory plans.

  4. A study of power conditioning and power distribution and components

    NASA Technical Reports Server (NTRS)

    Horton, H. M.; Honnell, M. A.

    1973-01-01

    A comprehensive simulation and analysis performed on the operation of the regulator part of the Charger/Battery/Regulator Module (CBRM) are detailed. The CBRM is utilized as an integral component of the Skylab/Apollo Telescope Mount (ATM) electrical power system and contains a switching mode electronic regulator. Implementing circuit analysis techniques, pertinent voltages and currents are calculated; these, in turn, are incorporated into the regulator system study. Investigation of the turn-on and turn-off times associated with the switching circuitry is performed and an examination is made on these calculations. A simulation model computer program is utilized to generate graphs that relate various CBRM parameters to one another.

  5. Distribution system power flow analysis; A rigid approach

    Microsoft Academic Search

    T.-H. Chen; M.-S. Chen; K.-J. Hwang; P. Kotas; E. A. Chebli

    1991-01-01

    This paper introduces a rigid approach to three-phase distribution power flow analysis for large-scale distribution systems. This approach is oriented toward applications in distribution system operational analysis rather than planning analysis. This difference should be properly emphasized, otherwise, the misuse of the planning-type method to analyze the operational behavior of the system will distort the explanation of the calculated results

  6. Hysteresis, phase transitions, and dangerous transients in electrical power distribution systems

    NASA Astrophysics Data System (ADS)

    Duclut, Charlie; Backhaus, Scott; Chertkov, Michael

    2013-06-01

    The majority of dynamical studies in power systems focus on the high-voltage transmission grids where models consider large generators interacting with crude aggregations of individual small loads. However, new phenomena have been observed indicating that the spatial distribution of collective, nonlinear contribution of these small loads in the low-voltage distribution grid is crucial to the outcome of these dynamical transients. To elucidate the phenomenon, we study the dynamics of voltage and power flows in a spatially extended distribution feeder (circuit) connecting many asynchronous induction motors and discover that this relatively simple 1+1 (space+time) dimensional system exhibits a plethora of nontrivial spatiotemporal effects, some of which may be dangerous for power system stability. Long-range motor-motor interactions mediated by circuit voltage and electrical power flows result in coexistence and segregation of spatially extended phases defined by individual motor states, a “normal” state where the motors’ mechanical (rotation) frequency is slightly smaller than the nominal frequency of the basic ac flows and a “stalled” state where the mechanical frequency is small. Transitions between the two states can be initiated by a perturbation of the voltage or base frequency at the head of the distribution feeder. Such behavior is typical of first-order phase transitions in physics, and this 1+1 dimensional model shows many other properties of a first-order phase transition with the spatial distribution of the motors’ mechanical frequency playing the role of the order parameter. In particular, we observe (a) propagation of the phase-transition front with the constant speed (in very long feeders) and (b) hysteresis in transitions between the normal and stalled (or partially stalled) phases.

  7. Industrial Power Distribution System Reliability Assessment utilizing Markov Approach

    NASA Astrophysics Data System (ADS)

    Guzman-Rivera, Oscar R.

    A method to perform power system reliability analysis using Markov Approach, Reliability Block Diagrams and Fault Tree analysis has been presented. The Markov method we use is a state space model and is based on state diagrams generated for a one line industrial power distribution system. The Reliability block diagram (RBD) method is a graphical and calculation tool used to model the distribution power system of an industrial facility. Quantitative reliability estimations on this work are based on CARMS and Block Sim simulations as well as state space, RBD's and Failure Mode analyses. The power system reliability was assessed and the main contributors to power system reliability have been identified, both qualitatively and quantitatively. Methods to improve reliability have also been provided including redundancies and protection systems that might be added to the system in order to improve reliability.

  8. Advanced Power Electronic Interfaces for Distributed Energy Systems, Part 2: Modeling, Development, and Experimental Evaluation of Advanced Control Functions for Single-Phase Utility-Connected Inverter

    Microsoft Academic Search

    S. Chakraborty; B. Kroposki; W. Kramer

    2008-01-01

    Integrating renewable energy and distributed generations into the Smart Grid architecture requires power electronic (PE) for energy conversion. The key to reaching successful Smart Grid implementation is to develop interoperable, intelligent, and advanced PE technology that improves and accelerates the use of distributed energy resource systems. This report describes the simulation, design, and testing of a single-phase DC-to-AC inverter developed

  9. Power Law Distributions of Seismic Rates

    E-print Network

    A. Saichev; D. Sornette

    2004-12-09

    We report an empirical determination of the probability density functions $P_{\\text{data}}(r)$ of the number $r$ of earthquakes in finite space-time windows for the California catalog. We find a stable power law tail $P_{\\text{data}}(r) \\sim 1/r^{1+\\mu}$ with exponent $\\mu \\approx 1.6$ for all space ($5 \\times 5$ to $20 \\times 20$ km$^2$) and time intervals (0.1 to 1000 days). These observations, as well as the non-universal dependence on space-time windows for all different space-time windows simultaneously, are explained by solving one of the most used reference model in seismology (ETAS), which assumes that each earthquake can trigger other earthquakes. The data imposes that active seismic regions are Cauchy-like fractals, whose exponent $\\delta =0.1 \\pm 0.1$ is well-constrained by the seismic rate data.

  10. The system for testing electrical performance of power generating sets based on technique of AC sampling

    Microsoft Academic Search

    Lu Wang; Wusong Wen

    2010-01-01

    A multilevel distributed system for testing electrical performance of power generating sets based on CAN bus is presented. Sampling and control for electrical parameters are realized utilizing Digital Signal Processor (DSP) and sixteen-bit Microcontroller Unit (MCU) that M16C\\/6N of renesas, an intelligent load based on the MCU of AT89S52 is designed, of which value can change automatically according to the

  11. Pulse doubling in zigzag-connected autotransformer-based 12-pulse ac-dc converter for power quality improvement

    NASA Astrophysics Data System (ADS)

    Abdollahi, Rohollah

    2012-12-01

    This paper presents a pulse doubling technique in a 12-pulse ac-dc converter which supplies direct torque controlled motor drives (DTCIMDs) in order to have better power quality conditions at the point of common coupling. The proposed technique increases the number of rectification pulses without significant changes in the installations and yields in harmonic reduction in both ac and dc sides. The 12-pulse rectified output voltage is accomplished via two paralleled six-pulse acdc converters each of them consisting of three-phase diode bridge rectifiers. An autotransformer is designed to supply the rectifiers. The design procedure of magnetics is in a way such that makes it suitable for retrofit applications where a six-pulse diode bridge rectifier is being utilized. Independent operation of paralleled diode-bridge rectifiers, i.e. dc-ripple re-injection methodology, requires a Zero Sequence Blocking Transformer (ZSBT). Finally, a tapped interphase reactor is connected at the output of ZSBT to double the pulse numbers of output voltage up to 24 pulses. The aforementioned structure improves power quality criteria at ac mains and makes them consistent with the IEEE-519 standard requirements for varying loads. Furthermore, near unity power factor is obtained for a wide range of DTCIMD operation. A comparison is made between 6-pulse, 12-pulse, and proposed converters from view point of power quality indices. Results show that input current total harmonic distortion (THD) is less than 5% for the proposed topology at various loads.

  12. Automation of the Athens (Tennessee) electric power distribution system

    SciTech Connect

    Rizy, D.T.; Stovall, J.P.; Usry, G.H.

    1988-01-01

    A large scale distribution automation research and development project has been conducted at the Athens Utilities Board (AUB) in Athens, Tennessee. The project goal was to experiment with the integrated monitoring and control of an entire distribution system from a central distribution control center. The project was sponsored by the U.S. Department of Energy, Office of Energy Storage and Distribution, Electric Energy Systems Program and managed by the Oak Ridge National Laboratory. The experience with the distribution substation monitoring and control, feeder monitoring, voltage and reactive power (vary) control, system (or circuit) reconfiguration for emergency and maintenance situations, and load control are described. A distribution automation applications software package for assessing system configuration, and volt/var control on automated radial distribution feeders was developed and is also described. 8 refs.

  13. Distributed photovoltaic generation in residential distribution systems: Impacts on power quality and anti-islanding

    NASA Astrophysics Data System (ADS)

    Mitra, Parag

    The past few decades have seen a consistent growth of distributed PV sources. Distributed PV, like other DG sources, can be located at or near load centers and provide benefits which traditional generation may lack. However, distribution systems were not designed to accommodate such power generation sources as these sources might lead to operational as well as power quality issues. A high penetration of distributed PV resources may lead to bi-directional power flow resulting in voltage swells, increased losses and overloading of conductors. Voltage unbalance is a concern in distribution systems and the effect of single-phase residential PV systems on voltage unbalance needs to be explored. Furthermore, the islanding of DGs presents a technical hurdle towards the seamless integration of DG sources with the electricity grid. The work done in this thesis explores two important aspects of grid inte-gration of distributed PV generation, namely, the impact on power quality and anti-islanding. A test distribution system, representing a realistic distribution feeder in Arizona is modeled to study both the aforementioned aspects. The im-pact of distributed PV on voltage profile, voltage unbalance and distribution sys-tem primary losses are studied using CYMDIST. Furthermore, a PSCAD model of the inverter with anti-island controls is developed and the efficacy of the anti-islanding techniques is studied. Based on the simulations, generalized conclusions are drawn and the problems/benefits are elucidated.

  14. Biodeterioration of asbestos cement (AC) pipe in drinking water distribution systems

    Microsoft Academic Search

    Dunling Wang; Roy Cullimore; Yafei Hu; Rudaba Chowdhury

    2011-01-01

    Various types of microorganisms have been found to inhabit the inner surfaces of asbestos cement (AC) pipe and their activities can cause significant structural damage. They cause a patina to form on the inside surface of AC pipes as a distinctively continuous coating, commonly 2–5 mm in thickness and generally pigmented as yellow, orange, brown or black depending on the metallic

  15. Power laws, discontinuities and regional city size distributions

    USGS Publications Warehouse

    Garmestani, A.S.; Allen, C.R.; Gallagher, C.M.

    2008-01-01

    Urban systems are manifestations of human adaptation to the natural environment. City size distributions are the expression of hierarchical processes acting upon urban systems. In this paper, we test the entire city size distributions for the southeastern and southwestern United States (1990), as well as the size classes in these regions for power law behavior. We interpret the differences in the size of the regional city size distributions as the manifestation of variable growth dynamics dependent upon city size. Size classes in the city size distributions are snapshots of stable states within urban systems in flux. ?? 2008.

  16. A Control Method of a Small-Scale DC Power System Including Distributed Generators

    NASA Astrophysics Data System (ADS)

    Ito, Youichi; Yang, Zhongqing; Akagi, Hirofumi

    This paper describes a dc micro-grid system interconnecting distributed power generators. The system consists of five generation and control units; a solar-cell generation unit, a wind-turbine generation unit, a battery energy-storage unit, a flywheel power-leveling unit, and an ac grid-interconnecting power control unit. The control method is proposed for suppressing the circulating current by detecting only the dc grid voltage. This method brings high reliability, high-flexibility and maintenance-free operation to the system. The method pays attention to dc output voltage performance of each unit. Each of the power control unit and the energy-storage unit is controlled to act as a voltage source with imaginery impedance. On the other hand, each of the two generation units is controlled to act as a current source. The power-leveling unit is controlled to act as a current source having the function of frequency selectivity like a high-pass filter. A 10-kW prototype system verifies experimentally the validity and effectiveness of the proposed control method for the dc-grid system.

  17. Comparison of Wind Power and Load Forecasting Error Distributions: Preprint

    SciTech Connect

    Hodge, B. M.; Florita, A.; Orwig, K.; Lew, D.; Milligan, M.

    2012-07-01

    The introduction of large amounts of variable and uncertain power sources, such as wind power, into the electricity grid presents a number of challenges for system operations. One issue involves the uncertainty associated with scheduling power that wind will supply in future timeframes. However, this is not an entirely new challenge; load is also variable and uncertain, and is strongly influenced by weather patterns. In this work we make a comparison between the day-ahead forecasting errors encountered in wind power forecasting and load forecasting. The study examines the distribution of errors from operational forecasting systems in two different Independent System Operator (ISO) regions for both wind power and load forecasts at the day-ahead timeframe. The day-ahead timescale is critical in power system operations because it serves the unit commitment function for slow-starting conventional generators.

  18. Power management and distribution for the More Electric Aircraft

    SciTech Connect

    Weimer, J.A. [Wright Lab., Wright Patterson AFB, OH (United States)

    1995-12-31

    The Air Force More Electric Aircraft (MEA) initiative endorses the notion of driving aircraft subsystems electrically which have traditionally been powered by hydraulic, mechanical, and pneumatic means. Therefore subsystems like hydraulically driven flight control actuators, engine gearbox driven fuel pumps, and bleed air driven environmental control system compressors would be powered electrically via an electrical motor. Studies on two different military fighter aircraft have shown that the MEA concept will provide a significant payoff in aircraft performance and cost. This paper will address many of the technical issues and concerns in developing a fault tolerant, highly reliable electrical power system for the MEA. Additionally, the paper will review the selection of a predominantly 270 Volt DC power system for the MEA and the need to develop additional MEA electrical power system technologies and standards. Many of these issues, concerns and needs are being addressed under the Power Management and Distribution System for More Electric Aircraft (MADMEL) program.

  19. Proposal of an Innovative Electric Power Distribution System based on Packet Power Transactions

    NASA Astrophysics Data System (ADS)

    Inoue, Jun; Fujii, Yasumasa

    Recently, the introduction of decentralized generators, such as photovoltaic power generations, has been promoted rapidly. In the future, extensive use of PV is thought to give rise to the daytime surplus electricity, and a household will manage the surplus electricity rationally. The purpose of this research is to propose an innovative electric power distribution system based on packet power transactions. First, this paper explains distributed markets of which the price can easily reflect the geographical diversity of renewable energy availability and load curve characteristic within the local area. Second, this paper exemplifies the specific electronic circuit that makes pulse-shaped power transmission to develop the packet power distribution system. Finally, this paper shows the results of multi-agent simulations of electricity trading to evaluate the usefulness of the proposed system.

  20. Power-law correlated processes with asymmetric distributions

    NASA Astrophysics Data System (ADS)

    Podobnik, Boris; Ivanov, Plamen Ch.; Jazbinsek, Vojko; Trontelj, Zvonko; Stanley, H. Eugene; Grosse, Ivo

    2005-02-01

    Motivated by the fact that many physical systems display (i) power-law correlations together with (ii) an asymmetry in the probability distribution, we propose a stochastic process that can model both properties. The process depends on only two parameters, where one controls the scaling exponent of the power-law correlations, and the other controls the degree of asymmetry in the distributions leaving the correlations unaffected. We apply the process to air humidity data and find that the statistical properties of the process are in a good agreement with those observed in the data.

  1. Electrical Power Distribution and Control Modeling and Analysis

    NASA Technical Reports Server (NTRS)

    Fu, Johnny S.; Liffring, Mark; Mehdi, Ishaque S.

    2001-01-01

    This slide presentation reviews the use of Electrical Power Distribution and Control (EPD&C) Modeling and how modeling can support analysis. The presentation discusses using the EASY5 model to simulate and analyze the Space Shuttle Electric Auxiliary Power Unit. Diagrams of the model schematics are included, as well as graphs of the battery cell impedance, hydraulic load dynamics, and EPD&C response to hydraulic load variations.

  2. High-power distributed-feedback quantum cascade lasers

    Microsoft Academic Search

    W. W. Bewley; I. Vurgaftman; C. S. Kim; J. R. Meyer; J. Nguyen; A. J. Evans; J. S. Yu; S. R. Darvish; S. Slivken; M. Razeghi

    2006-01-01

    Whereas high-power operation (> 1 W of cw output power at 200 K) has been demonstrated for quantum cascade lasers emitting at lambda = 4.7-6.2 mum, those devices generally exhibited multiple longitudinal modes. Recently, a distributed-feedback quantum cascade laser operating in a single spectral mode at lambda = 4.8 mum and at temperatures up to 333 K has been reported.

  3. Fuzzy ARTMAP based forecast of renewable generation for a high frequency AC microgrid

    Microsoft Academic Search

    Sudipta Chakraborty; Marcelo G. Simões

    2005-01-01

    A single phase high frequency AC (HFAC) microgrid is a novel solution towards integration of renewable energy sources in a distributed generation system. Power flow and power quality issues in the HFAC microgrid are controlled by the active filtering solutions called universal active power line conditioner (UPLC) and unified power quality conditioner (UPQC) respectively. After power quality and power flow

  4. Photovoltaic powered 20-hp DC/AC irrigation system and a 3-kW nitrogen generator

    SciTech Connect

    Hopkinson, R.F.

    1980-01-01

    A 25-kWp photovoltaic power system has been providing power for irrigation and crop drying since July 1977 at an agricultural field station of the University of Nebraska, located at Mead, Nebraska. The system was designed and built by Massachusetts Institute of Technology's Lincoln Laboratory under US Department of Energy sponsorship and is being operated jointly by the university and MIT Lincoln Laboratory. The system consists of a 25-kWp PV array, a battery subsystem, a power dump, an inverter, a controller and a data acquisition system. This photovoltaic power system has been used as a test facility in order to test and evaluate a variety of PV-related agricultural applications, including irrigation, crop drying and fertilizer manufacturing. Two interesting applications presently under evaluation are a 20-hp DC/AC-powered irrigation system and an on-site nitrogen fertilizer production unit.

  5. Design of a Norm-Bounded LQG Controller for Power Distribution Networks with Distributed Generation

    E-print Network

    Pota, Himanshu Roy

    facilities. DG integration in these passive networks can affect the dynamic behaviour of the system. The performance of the controller is tested on a benchmark power distribution system. Simulation results show. Therefore, control of modern electric power systems becomes more and more challenging as the present trends

  6. Hall Probe Based System for Study of AC Transport Current Distribution in YBCO Coated Conductors at Frequencies Up to 700 Hz

    Microsoft Academic Search

    Eduard Demencik; Pavol Usak; Milan Polak; George A. Levin; Paul N. Barnes

    2007-01-01

    The distributions of dc transport current in a copper stabilized mono-core YBCO coated conductor sample were compared with that of sinusoidal ac transport current, i(t) = I0ldrsin(omegat), with frequencies up to 700 Hz. The current distribution was determined from the measurement of the magnetic field produced by the transport current using a small active area Hall probe. The ac magnetic

  7. Design of a power management and distribution system for a thermionic-diode powered spacecraft

    Microsoft Academic Search

    Greg L. Kimnach

    1996-01-01

    The Electrical Systems Development Branch of the Power Technology Division at the NASA Lewis Research Center in Cleveland, Ohio is designing a Power Management and Distribution (PMAD) System for the Air Force's Integrated Solar Upper Stage (ISUS) Engine Ground Test Demonstration (EGD). The ISUS program uses solar-thermal propulsion to perform orbit transfers from low Earth orbit (LEG) to geosynchronous orbit

  8. Latest Three-Phase CVCF Sinwave Power Conditioner with New Quasi-Resonant ZVS DC and High-Frequency AC Link for Telephone Power Supply Systems

    Microsoft Academic Search

    H. Yonemori; H. Nagura; M. Nakaoka

    1994-01-01

    This paper presents a newly-developed high-performance 3¿CVCF power conversion conditioner incorporating a new Quasi-Resonant DC Link (QRDCL) single-phase inverter with PWM function and high-frequency AC transformer linked cycloconverter topology. The operating characteristics of a proposed QRDCLI are discussed on the basis of computer-aided simulating results. In order to achieve a significant improvement in high performance and quick control response, the

  9. Impacts of electric vehicle loads on power distribution systems

    Microsoft Academic Search

    Jayakrishnan R. Pillai; Birgitte Bak-Jensen

    2010-01-01

    Electric vehicles (EVs) are the most promising alternative to replace a significant amount of gasoline vehicles to provide cleaner, CO2 free and climate friendly transportation. On integrating more electric vehicles, the electric utilities must analyse the related impacts on the electricity system operation. This paper investigates the effects on the key power distribution system parameters like voltages, line drops, system

  10. Pointers and linked lists in electric power distribution circuit analysis

    Microsoft Academic Search

    R. P. Broadwater; J. C. Thompson; T. E. McDermott

    1991-01-01

    Electric power distribution circuit analysis programs must efficiently manage a large quantity of system and equipment data. Utility engineers now wish to use integrated software packages with several functions that work efficiently and share data. The use of data structures stored in linked lists and processed through pointers is described. The pointers and linked lists compact the data storage and

  11. Rooftop Solar Potential Distributed Solar Power in NW

    E-print Network

    1 Rooftop Solar Potential Distributed Solar Power in NW Massoud Jourabchi June 2013 1 Renewables;3 Regional Growth In Solar Energy Consumption Solar consumption both Thermal and PV h b t d i i lhas been on steady increase since early 1990s. From 2000-2010 Solar PV grow at annual rate of 13% and solar thermal

  12. Rooftop Solar Potential Distributed Solar Power in NW

    E-print Network

    6/19/2013 1 Rooftop Solar Potential Distributed Solar Power in NW Massoud Jourabchi June 2013 1 in 2012 4 #12;6/19/2013 3 Regional Growth In Solar Energy Consumption Solar consumption both Thermal and PV h b t d i i lhas been on steady increase since early 1990s. From 2000-2010 Solar PV grow

  13. Distributed Detection and Isolation of Topology Attacks in Power Networks

    E-print Network

    Johansson, Karl Henrik

    Distributed Detection and Isolation of Topology Attacks in Power Networks James Weimer ACCESS Linnaeus Centre School of Electrical Engineering KTH Royal Institute of Technology Stockholm, Sweden 10044 Engineering KTH Royal Institute of Technology Stockholm, Sweden 10044 kallej@kth.se ABSTRACT This paper

  14. Simplified mantle architecture and distribution of radiogenic power

    E-print Network

    Mcdonough, William F.

    Simplified mantle architecture and distribution of radiogenic power Ricardo Arevalo Jr. Planetary of Maryland,, College Park, Maryland, USA [1] The mantle components that represent the source region of ocean a significant amount of recycled oceanic crust and constitutes 19þ3 À2 (2m)% of the mantle by mass. The mass

  15. Islanding detection in power electronic converter based distributed generation

    Microsoft Academic Search

    Daniel Persson

    2007-01-01

    Abstract During the last decades the global warming,and climate changes have been discussed in the media. Simultaneously the electricity consumers ,have experienced higher energy prices and the producers of electricity a rise in the energy consumption.,These factors have strong impacts in the community ,and stimulate further integration of sustainable energy generation in the power system. Significant for distributed energy resources

  16. An architecture for a power-aware distributed microsensor node

    Microsoft Academic Search

    Rex Min; Manish Bhardwaj; Seong-Hwan Cho; Amit Sinha; Eugene Shih; Alice Wang; Anantha Chandrakasan

    2000-01-01

    Networks of distributed microsensors are emerging as a compelling solution for a wide range of data gathering applications. Perhaps the most substantial challenge facing designers of small but long-lived microsensor nodes is the need for significant reductions in energy consumption. We propose a power-aware design methodology that emphasizes the graceful scalability of energy consumption with factors such as available resources,

  17. Distributional Information: A Powerful Cue for Acquiring Syntactic Categories

    Microsoft Academic Search

    Martin Redington; Nick Chater; Steven Finch

    1998-01-01

    Many theorists have dismissed a priori the idea that distributional information could play a significant role in syntactic category acquisition. We demonstrate empirically that such information provides a powerful cue to syntactic category membership, which can be exploited by a variety of simple, psychologically plausible mechanisms. We present a range of results using a large corpus of child-directed speech and

  18. System and Battery Charge Control for PV-Powered AC Lighting Systems

    SciTech Connect

    Kern, G.

    1999-04-01

    This report reviews a number of issues specific to stand-alone AC lighting systems. A review of AC lighting technology is presented, which discusses the advantages and disadvantages of various lamps. The best lamps for small lighting systems are compact fluorescent. The best lamps for intermediate-size systems are high- or low-pressure sodium. Specifications for battery charging and load control are provided with the goal of achieving lamp lifetimes on the order of 16,000 to 24,000 hours and battery lifetimes of 4 to 5 years. A rough estimate of the potential domestic and global markets for stand-alone AC lighting systems is presented. DC current injection tests were performed on high-pressure sodium lamps and the test results are presented. Finally, a prototype system was designed and a prototype system controller (with battery charger and DC/AC inverter) was developed and built.

  19. Electron beam machining using rotating and shaped beam power distribution

    DOEpatents

    Elmer, John W. (Pleasanton, CA); O'Brien, Dennis W. (Livermore, CA)

    1996-01-01

    An apparatus and method for electron beam (EB) machining (drilling, cutting and welding) that uses conventional EB guns, power supplies, and welding machine technology without the need for fast bias pulsing technology. The invention involves a magnetic lensing (EB optics) system and electronic controls to: 1) concurrently bend, focus, shape, scan, and rotate the beam to protect the EB gun and to create a desired effective power-density distribution, and 2) rotate or scan this shaped beam in a controlled way. The shaped beam power-density distribution can be measured using a tomographic imaging system. For example, the EB apparatus of this invention has the ability to drill holes in metal having a diameter up to 1000 .mu.m (1 mm or larger), compared to the 250 .mu.m diameter of laser drilling.

  20. Electron beam machining using rotating and shaped beam power distribution

    DOEpatents

    Elmer, J.W.; O`Brien, D.W.

    1996-07-09

    An apparatus and method are disclosed for electron beam (EB) machining (drilling, cutting and welding) that uses conventional EB guns, power supplies, and welding machine technology without the need for fast bias pulsing technology. The invention involves a magnetic lensing (EB optics) system and electronic controls to: (1) concurrently bend, focus, shape, scan, and rotate the beam to protect the EB gun and to create a desired effective power-density distribution, and (2) rotate or scan this shaped beam in a controlled way. The shaped beam power-density distribution can be measured using a tomographic imaging system. For example, the EB apparatus of this invention has the ability to drill holes in metal having a diameter up to 1,000 {micro}m (1 mm or larger), compared to the 250 {micro}m diameter of laser drilling. 5 figs.

  1. Multi-kw dc power distribution system study program

    NASA Technical Reports Server (NTRS)

    Berkery, E. A.; Krausz, A.

    1974-01-01

    The first phase of the Multi-kw dc Power Distribution Technology Program is reported and involves the test and evaluation of a technology breadboard in a specifically designed test facility according to design concepts developed in a previous study on space vehicle electrical power processing, distribution, and control. The static and dynamic performance, fault isolation, reliability, electromagnetic interference characterisitics, and operability factors of high distribution systems were studied in order to gain a technology base for the use of high voltage dc systems in future aerospace vehicles. Detailed technical descriptions are presented and include data for the following: (1) dynamic interactions due to operation of solid state and electromechanical switchgear; (2) multiplexed and computer controlled supervision and checkout methods; (3) pulse width modulator design; and (4) cable design factors.

  2. Methods to Mitigate Harmonics In Residential Power Distribution Systems

    NASA Astrophysics Data System (ADS)

    Bagheri, Pooya

    The excessive waveform distortions in the present power distribution systems are produced mainly by the large number of residential loads. Such distributed sources of harmonics cannot be easily treated by the traditional mitigation methods, which have been commonly applied for concentrated and easily detectable industrial distorting loads. This thesis presents new harmonic mitigation techniques necessary for managing this new situation. The proposed strategies are supported by several analytical and simulation studies. Different options for both active and passive centralized and distributed filters are investigated and compared to determine their different technical and economic aspects. Overall, the results of extensive studies confirm that the novel zero-sequence harmonic filter and the new scheme of the low-voltage distributed active filters introduced in this thesis are promising solutions for the increasing harmonic problems in residential feeders.

  3. Distributed Power Flow Control: Distributed Power Flow Control using Smart Wires for Energy Routing

    SciTech Connect

    None

    2012-04-24

    GENI Project: Smart Wire Grid is developing a solution for controlling power flow within the electric grid to better manage unused and overall transmission capacity. The 300,000 miles of high-voltage transmission line in the U.S. today are congested and inefficient, with only around 50% of all transmission capacity utilized at any given time. Increased consumer demand should be met in part with more efficient and an economical power flow. Smart Wire Grid’s devices clamp onto existing transmission lines and control the flow of power within—much like how internet routers help allocate bandwidth throughout the web. Smart wires could support greater use of renewable energy by providing more consistent control over how that energy is routed within the grid on a real-time basis. This would lessen the concerns surrounding the grid’s inability to effectively store intermittent energy from renewables for later use.

  4. Fiber-Optic Distribution Of Pulsed Power To Multiple Sensors

    NASA Technical Reports Server (NTRS)

    Kirkham, Harold

    1996-01-01

    Optoelectronic systems designed according to time-sharing scheme distribute optical power to multiple integrated-circuit-based sensors in fiber-optic networks. Networks combine flexibility of electronic sensing circuits with advantage of electrical isolation afforded by use of optical fibers instead of electrical conductors to transmit both signals and power. Fiber optics resist corrosion and immune to electromagnetic interference. Sensor networks of this type useful in variety of applications; for example, in monitoring strains in aircraft, buildings, and bridges, and in monitoring and controlling shapes of flexible structures.

  5. Power management and distribution considerations for a lunar base

    NASA Technical Reports Server (NTRS)

    Kenny, Barbara H.; Coleman, Anthony S.

    1991-01-01

    Design philosophies and technology needs for the power management and distribution (PMAD) portion of a lunar base power system are discussed. A process is described whereby mission planners may proceed from a knowledge of the PMAD functions and mission performance requirements to a definition of design options and technology needs. Current research efforts at the NASA LRC to meet the PMAD system needs for a Lunar base are described. Based on the requirements, the lunar base PMAD is seen as best being accomplished by a utility like system, although with some additional demands including autonomous operation and scheduling and accurate, predictive modeling during the design process.

  6. Electric power scheduling: A distributed problem-solving approach

    NASA Technical Reports Server (NTRS)

    Mellor, Pamela A.; Dolce, James L.; Krupp, Joseph C.

    1990-01-01

    Space Station Freedom's power system, along with the spacecraft's other subsystems, needs to carefully conserve its resources and yet strive to maximize overall Station productivity. Due to Freedom's distributed design, each subsystem must work cooperatively within the Station community. There is a need for a scheduling tool which will preserve this distributed structure, allow each subsystem the latitude to satisfy its own constraints, and preserve individual value systems while maintaining Station-wide integrity. The value-driven free-market economic model is such a tool.

  7. Dynamic voltage regulation and power export in a distribution system using distributed generation

    Microsoft Academic Search

    Aamir Hanif; Muhammad Ahmed Choudhry

    2009-01-01

    The major aim of power quality (PQ) enhancing techniques is to maintain a specified voltage magnitude at a desired frequency\\u000a for sensitive loads irrespective of faults on the power distribution network. The dynamic voltage restorer (DVR) is a device\\u000a used to mitigate voltage sags to regulate load voltage. This paper presents a mathematical model for leading series voltage\\u000a injection to

  8. Robust Distributed Power Control in Cognitive Radio Networks

    E-print Network

    fard, Saeideh Parsaei

    2011-01-01

    We propose a robust distributed uplink power allocation algorithm for underlay cognitive radio networks (CRNs) with a view to maximizing the total utility of secondary users (SUs) when channel gains from SUs to primary base stations, and interference caused by primary users (PUs) to the SUs' base station are uncertain. In doing so, we utilize the worst-case robust optimization to keep the interference caused by SUs to each primary base station below a given threshold, and satisfy the SUs' quality of service for all realizations of uncertainty. We model each uncertain parameter by a bounded distance between its estimated and exact values, and formulate the robust power allocation problem via protection values for constraints. We demonstrate that the convexity of our problem is preserved, and in some cases converts into a geometric programming problem, which we solve via a distributed algorithm by using Lagrange dual decomposition. To reduce the cost of robustness, defined as the reduction in the total utility ...

  9. Power and safety management of electrical appliances in a smart power distribution system

    Microsoft Academic Search

    Tsukasa Noma; Yasuhiko Ookuma

    2011-01-01

    This paper introduces a low-cost solution to the on\\/off control of home appliances using a new power distribution system, and discusses how the system contributes to the safe and convenient use of the appliances. In the proposed system, with an RFID tag in the plug and newly-designed sockets\\/power strips, the smart meter identifies appliances connected to individual (wall) sockets simply

  10. Parallel Computing Environments and Methods for Power Distribution System Simulation

    Microsoft Academic Search

    Ning Lu; Z. Todd Taylor; David P. Chassin; Ross T. Guttromson; R. Scott Studham

    2004-01-01

    The development of cost-effective high- performance parallel computing on multi-processor supercomputers makes it attractive to port excessively time consuming simulation software from personal computers (PC) to super computes. The power distribution system simulator (PDSS) takes a bottom-up approach and simulates load at the appliance level, where detailed thermal models for appliances are used. This approach works well for a small

  11. Distributed multiuser power control for digital subscriber lines

    Microsoft Academic Search

    Wei Yu; George Ginis; John M. Cioffi

    2002-01-01

    This paper considers the multiuser power control problem in a frequency-selective interference channel. The interference channel is modeled as a noncooperative game, and the existence and uniqueness of a Nash equilibrium are established for a two-player version of the game. An iterative water-filling algorithm is proposed to efficiently reach the Nash equilibrium. The iterative water-filling algorithm can be implemented distributively

  12. Dependence of complex permeabiity and harmonic power generation of a sintered YBa 2Cu 3O 7-? rod on applied AC and DC magnetic fields

    NASA Astrophysics Data System (ADS)

    Lam, Q. H.; Jeffries, C. D.

    1992-05-01

    Systematic experimental studies are reported for the AC permeability and harmonic generation power Pnf in a sintered rod of granular YBa 2Cu 3O 7-? at 77 K as a unction of simultaneously applied AC and DC magnetic field from 0.01 to several hundred Oe. The separate contributions of the inter- and intragranular supercurrents are quite resolved, enabling the development of a generalized critical state model, which with two components is found to well explain the AC permeability and harmonic generation power as functions of AC and DC field up to the n=9 harmonic. Intergranular currents dominate the behavior for fields less than about 50 Oe; intragranular currents dominate for fields greater than 100 Oe.

  13. Power Management and Distribution (PMAD) Model Development: Final Report

    NASA Technical Reports Server (NTRS)

    Metcalf, Kenneth J.

    2011-01-01

    Power management and distribution (PMAD) models were developed in the early 1990's to model candidate architectures for various Space Exploration Initiative (SEI) missions. They were used to generate "ballpark" component mass estimates to support conceptual PMAD system design studies. The initial set of models was provided to NASA Lewis Research Center (since renamed Glenn Research Center) in 1992. They were developed to estimate the characteristics of power conditioning components predicted to be available in the 2005 timeframe. Early 90's component and device designs and material technologies were projected forward to the 2005 timeframe, and algorithms reflecting those design and material improvements were incorporated into the models to generate mass, volume, and efficiency estimates for circa 2005 components. The models are about ten years old now and NASA GRC requested a review of them to determine if they should be updated to bring them into agreement with current performance projections or to incorporate unforeseen design or technology advances. This report documents the results of this review and the updated power conditioning models and new transmission line models generated to estimate post 2005 PMAD system masses and sizes. This effort continues the expansion and enhancement of a library of PMAD models developed to allow system designers to assess future power system architectures and distribution techniques quickly and consistently.

  14. Power-law distribution of pressure fluctuations in multiphase flow.

    PubMed

    Gheorghiu, S; van Ommen, J R; Coppens, M-O

    2003-04-01

    Bubbling fluidized beds are granular systems, in which a deep layer of particles is set in motion by a vertical gas stream, with the excess gas rising as bubbles through the bed. We show that pressure fluctuations in such a system have non-Gaussian statistics. The probability density function has a power-law drop-off and is very well represented by a Tsallis distribution. Its shape is explained through the folding of the Gaussian distribution of pressure fluctuations produced by a monodisperse set of bubbles, onto the actual distribution of bubble sizes in the bed, assuming that bubbles coalesce via a Smoluchowski-type aggregation process. Therefore, the Tsallis statistics arise as a result of bubble polydispersity, rather than system nonextensivity. PMID:12786360

  15. New 24-pulse diode rectifier systems for utility interface of high-power AC motor drives

    Microsoft Academic Search

    Sewan Choi; Bang Sup Lee; Prasad N. Enjeti

    1997-01-01

    This paper proposes two new passive 24-pulse diode rectifier systems for utility interface of pulsewidth modulated (PWM) AC motor drives. The first approach employs an extended delta transformer arrangement, which results in near equal leakage inductance in series with each diode rectifier bridge. This promotes equal current sharing and improved performance. A specially tapped interphase transformer is then introduced with

  16. Design of Instantaneous High Power Supply System with power distribution management for portable military devices

    NASA Astrophysics Data System (ADS)

    Kwak, Kiho; Kwak, Dongmin; Yoon, Joohong

    2015-08-01

    A design of an Instantaneous High Power Supply System (IHPSS) with a power distribution management (PDM) for portable military devices is newly addressed. The system includes a power board and a hybrid battery that can not only supply instantaneous high power but also maintain stable operation at critical low temperature (-30 °C). The power leakage and battery overcharge are effectively prevented by the optimal PDM. The performance of the proposed system under the required pulse loads and the operating conditions of a Korean Advanced Combat Rifle employed in the battlefield is modeled with simulations and verified experimentally. The system with the IHPSS charged the fuse setter with 1.7 times higher voltage (8.6 V) than the one without (5.4 V) under the pulse discharging rate (1 A at 0.5 duty, 1 ms) for 500 ms.

  17. Power Allocation and Admission Control in Multiuser Relay Networks via Convex Programming: Centralized and Distributed Schemes

    E-print Network

    Phan, Khoa T.

    The power allocation problem for multiuser wireless networks is considered under the assumption of amplify-and-forward cooperative diversity. Specifically, optimal centralized and distributed power allocation strategies ...

  18. A switched power filtter compensator scheme for ac motorized electrical loads

    Microsoft Academic Search

    Adel M. Sharaf; Moataz Ammar

    2008-01-01

    The paper presents a novel device for energy conservation, power quality enhancement using switched power filter and compensator device for three phase motorized electric loads. The modulated power filter and compensator (MPFC) was developed by the first author to vary the shunt power filter equivalent admittance, modify the reactive power flow to the motorized electric load, improve electrical utilization and

  19. A planning scheme for penetrating embedded generation in power distribution grids

    E-print Network

    Wang, Jiankang, Ph. D. Massachusetts Institute of Technology

    2013-01-01

    Penetrating Embedded Generation, or Distributed Generation (DG), in power distribution grids presents great benefits and substantial positive social impacts to utilities, system operators and electricity consumers. Existing ...

  20. Solid Oxide Fuel Cell Hybrid System for Distributed Power Generation

    SciTech Connect

    David Deangelis; Rich Depuy; Debashis Dey; Georgia Karvountzi; Nguyen Minh; Max Peter; Faress Rahman; Pavel Sokolov; Deliang Yang

    2004-09-30

    This report summarizes the work performed by Hybrid Power Generation Systems, LLC (HPGS) during the April to October 2004 reporting period in Task 2.3 (SOFC Scaleup for Hybrid and Fuel Cell Systems) under Cooperative Agreement DE-FC26-01NT40779 for the U. S. Department of Energy, National Energy Technology Laboratory (DOE/NETL), entitled ''Solid Oxide Fuel Cell Hybrid System for Distributed Power Generation''. This study analyzes the performance and economics of power generation systems for central power generation application based on Solid Oxide Fuel Cell (SOFC) technology and fueled by natural gas. The main objective of this task is to develop credible scale up strategies for large solid oxide fuel cell-gas turbine systems. System concepts that integrate a SOFC with a gas turbine were developed and analyzed for plant sizes in excess of 20 MW. A 25 MW plant configuration was selected with projected system efficiency of over 65% and a factory cost of under $400/kW. The plant design is modular and can be scaled to both higher and lower plant power ratings. Technology gaps and required engineering development efforts were identified and evaluated.

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

    SciTech Connect

    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

    2013-01-01

    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.

  2. Advanced building blocks of power converters for renewable energy based distributed generators

    Microsoft Academic Search

    Riming Shao; Mary Kaye; Liuchen Chang

    2011-01-01

    The power converter is a critical component of a distributed generation (DG) system, particularly for a renewable energy based distributed generator. With the rapid development and growing applications of DG systems, power converters have evolved from a traditional \\

  3. 7 CFR 1717.857 - Refinancing of existing secured debt-distribution and power supply borrowers.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...debt-distribution and power supply borrowers. ...distribution and power supply borrowers. ...in the present value analysis shall be equal to either...refinanced; (3) An analysis comparing the refinancing...revenues, margins, cash flows, TIER, and DSC,...

  4. The investigation of an electric arc in the long cylindrical channel of the powerful high-voltage AC plasma torch

    NASA Astrophysics Data System (ADS)

    Rutberg, Ph G.; Popov, S. D.; Surov, A. V.; Serba, E. O.; Nakonechny, Gh V.; Spodobin, V. A.; Pavlov, A. V.; Surov, A. V.

    2012-12-01

    The comparison of conductivity obtained in experiments with calculated values is made in this paper. Powerful stationary plasma torches with prolonged period of continuous work are popular for modern plasmachemical applications. The maximum electrode lifetime with the minimum erosion can be reached while working on rather low currents. Meanwhile it is required to provide voltage arc drop for the high power achievement. Electric field strength in the arc column of the high-voltage plasma torch, using air as a plasma-forming gas, does not exceed 15 V/cm. It is possible to obtain the high voltage drop in the long arc stabilized in the channel by the intensive gas flow under given conditions. Models of high voltage plasma torches with rod electrodes with power up to 50 kW have been developed and investigated. The plasma torch arcs are burning in cylindrical channels. Present investigations are directed at studying the possibility of developing long arc plasma torches with higher power. The advantage of AC power supplies usage is the possibility of the loss minimization due to the reactive power compensation. The theoretical maximum of voltage arc drop for power supplies with inductive current limitations is about 50 % of the no-load voltage for a single-phase circuit and about 30 % for the three-phase circuit. Burning of intensively blown arcs in the long cylindrical channel using the AC power supply with 10 kV no-load voltage is experimentally investigated in the work. Voltage drops close to the maximum possible had been reached in the examined arcs in single-phase and three-phase modes. Operating parameters for single-phase mode were: current -30 A, voltage drop -5 kV, air flow rate 35 g/s; for three-phase mode: current (40-85) A, voltage drop (2.5-3.2) kV, air flow rate (60-100) g/s. Arc length in the installations exceeded 2 m.

  5. Utility-Scale Power Router: Dynamic Control of Grid Assets Using Direct AC Converter Cells

    SciTech Connect

    None

    2010-09-01

    ADEPT Project: Georgia Tech is developing a cost-effective, utility-scale power router that uses an enhanced transformer to more efficiently direct power on the grid. Existing power routing technologies are too expensive for widespread use, but the ability to route grid power to match real-time demand and power outages would significantly reduce energy costs for utilities, municipalities, and consumers. Georgia Tech is adding a power converter to an existing grid transformer to better control power flows at about 1/10th the cost of existing power routing solutions. Transformers convert the high-voltage electricity that is transmitted through the grid into the low-voltage electricity that is used by homes and businesses. The added converter uses fewer steps to convert some types of power and eliminates unnecessary power storage, among other improvements. The enhanced transformer is more efficient, and it would still work even if the converter fails, ensuring grid reliability.

  6. Measurement of the temperature distribution inside the power cable using distributed temperature system

    NASA Astrophysics Data System (ADS)

    Jaros, Jakub; Liner, Andrej; Papes, Martin; Vasinek, Vladimir; Mach, Veleslav; Hruby, David; Kajnar, Tomas; Perecar, Frantisek

    2015-01-01

    Nowadays, the power cables are manufactured to fulfill the following condition - the highest allowable temperature of the cable during normal operation and the maximum allowable temperature at short circuit conditions cannot exceed the condition of the maximum allowable internal temperature. The distribution of the electric current through the conductor leads to the increase of the amplitude of electrons in the crystal lattice of the cables material. The consequence of this phenomenon is the increase of friction and the increase of collisions between particles inside the material, which causes the temperature increase of the carrying elements. The temperature increase is unwanted phenomena, because it is causing losses. In extreme cases, the long-term overload leads to the cable damaging or fire. This paper deals with the temperature distribution measurement inside the power cables using distributed temperature system. With cooperation with Kabex company, the tube containing optical fibers was installed into the center of power cables. These fibers, except telecommunications purposes, can be also used as sensors in measurements carrying out with distributed temperature system. These systems use the optical fiber as a sensor and allow the continual measurement of the temperature along the whole cable in real time with spatial resolution 1 m. DTS systems are successfully deployed in temperature measurement applications in industry areas yet. These areas include construction, drainage, hot water etc. Their advantages are low cost, resistance to electromagnetic radiation and the possibility of real time monitoring at the distance of 8 km. The location of the optical fiber in the center of the power cable allows the measurement of internal distribution of the temperature during overloading the cable. This measurement method can be also used for prediction of short-circuit and its exact location.

  7. Development of a low cost integrated 15 kW AC solar tracking subarray for grid connected PV power system applications

    Microsoft Academic Search

    M. J. Stern; R. T. West

    1996-01-01

    The Utility Power Group has reduced the installation cost of grid connected photovoltaic power systems through a two step approach of integrating and packaging all sub-array power conversion and control functions within a single factory produced enclosure and utilizing large area factory assembled photovoltaic panels. A modular 15 kW AC single axis solar tracking sub-array was designed to meet the

  8. Solid Oxide Fuel Cell Hybrid System for Distributed Power Generation

    SciTech Connect

    Nguyen Minh

    2004-07-04

    This report summarizes the work performed by Hybrid Power Generation Systems, LLC (HPGS) during the January to June 2004 reporting period under Cooperative Agreement DE-FC26-01NT40779 for the U. S. Department of Energy, National Energy Technology Laboratory (DOE/NETL) entitled ''Solid Oxide Fuel Cell Hybrid System for Distributed Power Generation''. The main objective of this project is to develop and demonstrate the feasibility of a highly efficient hybrid system integrating a planar Solid Oxide Fuel Cell (SOFC) and a micro-turbine. In addition, an activity included in this program focuses on the development of an integrated coal gasification fuel cell system concept based on planar SOFC technology. Also, another activity included in this program focuses on the development of SOFC scale up strategies.

  9. Tomographic determination of the power distribution in electron beams

    DOEpatents

    Teruya, Alan T. (Livermore, CA); Elmer, John W. (Pleasanton, CA)

    1996-01-01

    A tomographic technique for determining the power distribution of an electron beam using electron beam profile data acquired from a modified Faraday cup to create an image of the current density in high and low power beams. A refractory metal disk with a number of radially extending slits is placed above a Faraday cup. The beam is swept in a circular pattern so that its path crosses each slit in a perpendicular manner, thus acquiring all the data needed for a reconstruction in one circular sweep. Also, a single computer is used to generate the signals actuating the sweep, to acquire that data, and to do the reconstruction, thus reducing the time and equipment necessary to complete the process.

  10. Evidence of a Gamma Distribution for Prime Powers

    E-print Network

    J. LaChapelle

    2014-11-18

    If the prime numbers are pseudo-randomly distributed, then analogy with quantum systems suggests that counting primes might be modeled by a non-homogeneous Poisson process. Consequently, postulating underlying gamma statistics, more-or-less standard heuristic arguments borrowed from quantum mechanics in the context of functional integration allows to derive analytic expressions of several average counting functions associated with prime numbers. The expressions are certain sums of incomplete gamma functions that are closely related to logarithmic-type integral functions --- which in turn are well-known to give the asymptotic dependence of the various counting functions up to error terms. The relatively broad success of quantum heuristics applied to functional integrals in general along with the excellent numerical accuracy of the analytic expressions for the average counting functions provide strong evidence of a gamma distribution for prime powers.

  11. Estimating Hurricane Outage and Damage Risk in Power Distribution System 

    E-print Network

    Han, Seung Ryong

    2009-05-15

    of Department, David Rosowsky August 2008 Major Subject: Civil Engineering iii ABSTRACT Estimating Hurricane Outage and Damage Risk in Power Distribution Systems. (August 2008) Seung Ryong Han, B.S., KunKuk University at Seoul; M.S., Korea..., I used estimates of the maximum 3-second gust wind speed and the length of time that the winds were above 20 m/s (44.7 miles per hour) for each grid cell based on the hurricane wind field model developed by Huang et al. (2001), the same model...

  12. Automated fault location and diagnosis on electric power distribution feeders

    SciTech Connect

    Zhu, J. [Advanced Control Systems, Inc., Norcross, GA (United States); Lubkeman, D.L.; Girgis, A.A. [Clemson Univ., SC (United States). Dept. of Electrical and Computer Engineering

    1997-04-01

    This paper presents new techniques for locating and diagnosing faults on electric power distribution feeders. The proposed fault location and diagnosis scheme is capable of accurately identifying the location of a fault upon its occurrence, based on the integration of information available from disturbance recording devices with knowledge contained in a distribution feeder database. The developed fault location and diagnosis system can also be applied to the investigation of temporary faults that may not result in a blown fuse. The proposed fault location algorithm is based on the steady-state analysis of the faulted distribution network. To deal with the uncertainties inherent in the system modeling and the phasor estimation, the fault location algorithm has been adapted to estimate fault regions based on probabilistic modeling and analysis. Since the distribution feeder is a radial network, multiple possibilities of fault locations could be computed with measurements available only at the substation. To identify the actual fault location, a fault diagnosis algorithm has been developed to prune down and rank the possible fault locations by integrating the available pieces of evidence. Testing of the developed fault location and diagnosis system using field data has demonstrated its potential for practical use.

  13. Power superconducting power transmission cable

    DOEpatents

    Ashworth, Stephen P. (Cambridge, GB)

    2003-01-01

    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.

  14. Radiation Effects on Power Semiconductor Devices for Distributed Power Systems for Electromagnetic Calorimeters

    NASA Astrophysics Data System (ADS)

    Abbate, C.; Busatto, G.; Iannuzzo, F.; Porzio, A.; Sanseverino, A.; Velardi, F.; Baccaro, S.

    2010-04-01

    The present study faces the radiation tolerance aspect for two main device categories typically used for power supplies of electromagnetic calorimeters for high-energy physics, like ATLAS Liquid-Ar calorimeters: 200V-MOSFETs and 30V-MOSFETs, which are fundamental for manipulating the primary voltage and the secondary voltage, respectively, of the power distribution system. Results demonstrate that the gate driving policy can significantly affect the radiation tolerance of such devices, suggesting a promising method to reach the 1Mrad target.

  15. Single-phase power distribution system power flow and fault analysis

    NASA Technical Reports Server (NTRS)

    Halpin, S. M.; Grigsby, L. L.

    1992-01-01

    Alternative methods for power flow and fault analysis of single-phase distribution systems are presented. The algorithms for both power flow and fault analysis utilize a generalized approach to network modeling. The generalized admittance matrix, formed using elements of linear graph theory, is an accurate network model for all possible single-phase network configurations. Unlike the standard nodal admittance matrix formulation algorithms, the generalized approach uses generalized component models for the transmission line and transformer. The standard assumption of a common node voltage reference point is not required to construct the generalized admittance matrix. Therefore, truly accurate simulation results can be obtained for networks that cannot be modeled using traditional techniques.

  16. Space Station module Power Management And Distribution (PMAD) system

    NASA Technical Reports Server (NTRS)

    Walls, Bryan

    1990-01-01

    This project consists of several tasks which are unified toward experimentally demonstrating the operation of a highly autonomous, user-supportive power management and distribution system for Space Station Freedom (SSF) habitation/laboratory modules. This goal will be extended to a demonstration of autonomous, cooperative power system operation for the whole SSF power system through a joint effort with NASA's Lewis Research Center, using their Autonomous Power System. Short term goals for the space station module power management and distribution include having an operational breadboard reflecting current plans for SSF, improving performance of the system communications, and improving the organization and mutability of the artificial intelligence (AI) systems. In the middle term, intermediate levels of autonomy will be added, user interfaces will be modified, and enhanced modeling capabilities will be integrated in the system. Long term goals involve conversion of all software into Ada, vigorous verification and validation efforts and, finally, seeing an impact of this research on the operation of SSF. Conversion of the system to a DC Star configuration is now in progress, and should be completed by the end of October, 1989. This configuration reflects the latest SSF module architecture. Hardware is now being procured which will improve system communications significantly. The Knowledge-Based Management System (KBMS) is initially developed and the rules from FRAMES have been implemented in the KBMS. Rules in the other two AI systems are also being grouped modularly, making them more tractable, and easier to eventually move into the KBMS. Adding an intermediate level of autonomy will require development of a planning utility, which will also be built using the KBMS. These changes will require having the user interface for the whole system available from one interface. An Enhanced Model will be developed, which will allow exercise of the system through the interface without requiring all of the power hardware to be operational. The functionality of the AI systems will continue to be advanced, including incipient failure detection. Ada conversion will begin with the lowest level processor (LLP) code. Then selected pieces of the higher level functionality will be recorded in Ada and, where possible, moved to the LLP level. Validation and verification will be done on the Ada code, and will complete sometimes after completion of the Ada conversion.

  17. Impact of Increasing Distributed Wind Power and Wind Turbine Siting on Rural Distribution Feeder Voltage Profiles: Preprint

    SciTech Connect

    Allen, A.; Zhang, Y. C.; Hodge, B. M.

    2013-09-01

    Many favorable wind energy resources in North America are located in remote locations without direct access to the transmission grid. Building transmission lines to connect remotely-located wind power plants to large load centers has become a barrier to increasing wind power penetration in North America. By connecting utility-sized megawatt-scale wind turbines to the distribution system, wind power supplied to consumers could be increased greatly. However, the impact of including megawatt-scale wind turbines on distribution feeders needs to be studied. The work presented here examined the impact that siting and power output of megawatt-scale wind turbines have on distribution feeder voltage. This is the start of work to present a general guide to megawatt-scale wind turbine impact on the distribution feeder and finding the amount of wind power that can be added without adversely impacting the distribution feeder operation, reliability, and power quality.

  18. Distributed Optimal Power and Rate Control in Wireless Sensor Networks

    PubMed Central

    Tang, Meiqin; Bai, Jianyong; Li, Jing; Xin, Yalin

    2014-01-01

    With the rapid development of wireless sensor networks, reducing energy consumption is becoming one of the important factors to extend node lifetime, and it is necessary to adjust the launching power of each node because of the limited energy available to the sensor nodes in the networks. This paper proposes a power and rate control model based on the network utility maximization (NUM) framework, where a weighting factor is used to reflect the influence degree of the sending power and transmission rate to the utility function. In real networks, nodes interfere with each other in the procedure of transmitting signal, which may lead to signal transmission failure and may negatively have impacts on networks throughput. Using dual decomposition techniques, the NUM problem is decomposed into two distributed subproblems, and then the conjugate gradient method is applied to solve the optimization problem with the calculation of the Hessian matrix and its inverse in order to guarantee fast convergence of the algorithm. The convergence proof is also provided in this paper. Numerical examples show that the proposed solution achieves significant throughput compared with exiting approaches. PMID:24895654

  19. Distributed optimal power and rate control in wireless sensor networks.

    PubMed

    Tang, Meiqin; Bai, Jianyong; Li, Jing; Xin, Yalin

    2014-01-01

    With the rapid development of wireless sensor networks, reducing energy consumption is becoming one of the important factors to extend node lifetime, and it is necessary to adjust the launching power of each node because of the limited energy available to the sensor nodes in the networks. This paper proposes a power and rate control model based on the network utility maximization (NUM) framework, where a weighting factor is used to reflect the influence degree of the sending power and transmission rate to the utility function. In real networks, nodes interfere with each other in the procedure of transmitting signal, which may lead to signal transmission failure and may negatively have impacts on networks throughput. Using dual decomposition techniques, the NUM problem is decomposed into two distributed subproblems, and then the conjugate gradient method is applied to solve the optimization problem with the calculation of the Hessian matrix and its inverse in order to guarantee fast convergence of the algorithm. The convergence proof is also provided in this paper. Numerical examples show that the proposed solution achieves significant throughput compared with exiting approaches. PMID:24895654

  20. CO2 emission-incorporated ac optimal power flow and its primary impacts on power system dispatch and operations

    Microsoft Academic Search

    M. Shao; W. T. Jewell

    2010-01-01

    The electric power industry is and will continue to be a primary focus of existing and future greenhouse gas (GHG) emissions regulations. Different from other air pollutant regulations such as sulfur dioxide (SO2) and nitrous oxides (NOX), GHG regulations have the potential to significantly affect electric power system dispatch and operations soon, so the implications are significant enough to warrant

  1. Autonomous operation of hybrid AC-DC microgrids with progressive energy flow tuning

    Microsoft Academic Search

    Poh Chiang Loh; Ding Li; Yi Kang Chai; Frede Blaabjerg

    2012-01-01

    Modern distributed sources can either be ac or dc. It is thus possible to form hybrid microgrids with ac and dc sub-grids inter-tied by power converters. The resulting hybrid architecture allows loads to be flexibly placed so as to minimize the amount of energy conversion needed and hence its accompanied losses. Hybrid microgrids are therefore more efficient with a control

  2. RTDS-Based Design and Simulation of Distributed P-Q Power Resources in Smart Grid

    NASA Astrophysics Data System (ADS)

    Taylor, Zachariah David

    In this Thesis, we propose to utilize a battery system together with its power electronics interfaces and bidirectional charger as a distributed P-Q resource in power distribution networks. First, we present an optimization-based approach to operate such distributed P-Q resources based on the characteristics of the battery and charger system as well as the features and needs of the power distribution network. Then, we use the RTDS Simulator, which is an industry-standard simulation tool of power systems, to develop two RTDS-based design approaches. The first design is based on an ideal four-quadrant distributed P-Q power resource. The second design is based on a detailed four-quadrant distributed P-Q power resource that is developed using power electronics components. The hardware and power electronics circuitry as well as the control units are explained for the second design. After that, given the two-RTDS designs, we conducted extensive RTDS simulations to assess the performance of the designed distributed P-Q Power Resource in an IEEE 13 bus test system. We observed that the proposed design can noticeably improve the operational performance of the power distribution grid in at least four key aspects: reducing power loss, active power peak load shaving at substation, reactive power peak load shaving at substation, and voltage regulation. We examine these performance measures across three design cases: Case 1: There is no P-Q Power Resource available on the power distribution network. Case 2: The installed P-Q Power Resource only supports active power, i.e., it only utilizes its battery component. Case 3: The installed P-Q Power Resource supports both active and reactive power, i.e., it utilizes both its battery component and its power electronics charger component. In the end, we present insightful interpretations on the simulation results and suggest some future works.

  3. 2236 IEEE TRANSACTIONS ON POWER DELIVERY, VOL. 22, NO. 4, OCTOBER 2007 Direct Lightning Strikes to Test Power Distribution

    E-print Network

    Florida, University of

    and outages [1]. The design of lightning protection for distribution lines involves weighing the initial cost2236 IEEE TRANSACTIONS ON POWER DELIVERY, VOL. 22, NO. 4, OCTOBER 2007 Direct Lightning Strikes of rocket-triggered lightning with two unenergized power distribution lines of about 800 m length

  4. http://power.itp.ac.cn/~suncp/quantum.htm S. YangD.Z. Xu, C.P. Sun, J. Chem. Phys , June , 2010

    E-print Network

    Sun, Chang-Pu

    http://power.itp.ac.cn/~suncp/quantum.htm 20108 4 #12; : #12;4. S. YangD.Z. Xu, C.P. Sun, J solar cell (~15%) Germanium multijunction photovoltaic (~35%) VHESC Solar Cell (~42.1%) Science 8 June Lindblad #12; Energy transfer efficiency Average transfer time #12;· · · k #12;· k #12;14 k #12

  5. A STARTER\\/ALTERNATOR SYSTEM WITH PERMANENT MAGNET MACHINE AND AC POWER SUPPLY BASED ON A SPACE VECTOR CONTROLLED THREE AND SINGLE-PHASE CONVERTER FOR MOBILE APPLICATIONS

    Microsoft Academic Search

    Heinz Bausch; Harald Hofmann

    An electric power supply system for vehicles is described consisting of a permanent magnet ma- chine as starter\\/alternator, a DC bus bar and con- verters for the DC- and AC-supply. Due to the wide speed range the permanent magnet machine in gen- eral has to be operated in the field weakening range. The appropriate equations are given. In special purpose

  6. Design of a power management and distribution system for a thermionic-diode powered spacecraft

    NASA Technical Reports Server (NTRS)

    Kimnach, Greg L.

    1996-01-01

    The Electrical Systems Development Branch of the Power Technology Division at the NASA Lewis Research Center in Cleveland, Ohio is designing a Power Management and Distribution (PMAD) System for the Air Force's Integrated Solar Upper Stage (ISUS) Engine Ground Test Demonstration (EGD). The ISUS program uses solar-thermal propulsion to perform orbit transfers from Low Earth Orbit (LEO) to Geosynchronous Orbit (GEO) and from LEO to Molnya. The ISUS uses the same energy conversion receiver to perform the LEO to High Earth Orbit (HEO) transfer and to generate on-orbit electric power for the payloads. On-orbit power generation is accomplished via two solar concentrators heating a dual-cavity graphite-core which has Thermionic Diodes (TMD's) encircling each cavity. The graphite core and concentrators together are called the Receiver and Concentrator (RAC). The TDM-emitters reach peak temperatures of approximately 2200K, and the TID-collectors are run at approximately 1000K. Because of the high Specific Impulse (I(sup sp)) of solar thermal propulsion relative to chemical propulsion, and because a common bus is used for communications, GN&C, power, etc., a substantial increase in payload weight is possible. This potentially allows for a stepdown in the required launch vehicle size or class for similar payload weight using conventional chemical propulsion and a separate spacecraft bus. The ISUS power system is to provide 1000W(sub e) at 28+/-6V(sub dc) to the payload/spacecraft from a maximum TID generation capability of 1070W(sub e) at 2200K. Producing power with this quality, protecting the spacecraft from electrical faults and accommodating operational constraints of the TID's are the responsibilities of the PMAD system. The design strategy and system options examined along with the proposed designs for the Flight and EGD configurations are discussed herein.

  7. SOLID OXIDE FUEL CELL HYBRID SYSTEM FOR DISTRIBUTED POWER GENERATION

    SciTech Connect

    Kurt Montgomery; Nguyen Minh

    2003-08-01

    This report summarizes the work performed by Honeywell during the October 2001 to December 2001 reporting period under Cooperative Agreement DE-FC26-01NT40779 for the U. S. Department of Energy, National Energy Technology Laboratory (DOE/NETL) entitled ''Solid Oxide Fuel Cell Hybrid System for Distributed Power Generation''. The main objective of this project is to develop and demonstrate the feasibility of a highly efficient hybrid system integrating a planar Solid Oxide Fuel Cell (SOFC) and a turbogenerator. The conceptual and demonstration system designs were proposed and analyzed, and these systems have been modeled in Aspen Plus. Work has also started on the assembly of dynamic component models and the development of the top-level controls requirements for the system. SOFC stacks have been fabricated and performance mapping initiated.

  8. Solid Oxide Fuel Cell Hybrid System for Distributed Power Generation

    SciTech Connect

    Nguyen Minh

    2002-03-31

    This report summarizes the work performed by Honeywell during the January 2002 to March 2002 reporting period under Cooperative Agreement DE-FC26-01NT40779 for the U. S. Department of Energy, National Energy Technology Laboratory (DOE/NETL) entitled ''Solid Oxide Fuel Cell Hybrid System for Distributed Power Generation''. The main objective of this project is to develop and demonstrate the feasibility of a highly efficient hybrid system integrating a planar Solid Oxide Fuel Cell (SOFC) and a turbogenerator. For this reporting period the following activities have been carried out: {lg_bullet} Conceptual system design trade studies were performed {lg_bullet} System-level performance model was created {lg_bullet} Dynamic control models are being developed {lg_bullet} Mechanical properties of candidate heat exchanger materials were investigated {lg_bullet} SOFC performance mapping as a function of flow rate and pressure was completed

  9. A comparative study of AC\\/DC converters for high-power DC arc furnace

    Microsoft Academic Search

    Philippe Ladoux; Gianluca Postiglione; Henri Foch; Jacques Nuns

    2005-01-01

    Today, dc arc furnaces are supplied by thyristor rectifiers. Because of the phase control strategy on the rectifiers, the arc voltage swings induce large reactive power variations on the power network and a static VAr compensator (SVC) or a static synchronous compensator (STATCOM) is always added to avoid flicker effect. In this paper, the authors present a new control strategy

  10. Conditions for saddle-node bifurcations in AC\\/DC power systems

    Microsoft Academic Search

    C. A Cañizares

    1995-01-01

    Saddle-node bifurcations are dynamic instabilities of differential equation models that have been associated with voltage collapse problems in power systems. This paper presents the conditions needed for detecting these types of bifurcations using power flow equations for a dynamic model of ACIDC systems, represented by differential equations and algebraic constraints. Two methods typically used to detect saddle-node bifurcations, namely, direct

  11. 1620 IEEE TRANSACTIONS ON POWER DELIVERY, VOL. 27, NO. 3, JULY 2012 Hybrid AC/DC Transmission Expansion Planning

    E-print Network

    Fu, Yong

    matrix. ac bus-converter incidence matrix. ac bus-ac line incidence matrix. Variables: Load shedding operations. The proposed set of dc transmission system may use either current source converters or voltage source converters. Numerical examples illustrate the effectiveness of the proposed TEP model. Index Terms

  12. Development of a low cost integrated 15 kW A.C. solar tracking sub-array for grid connected PV power system applications

    Microsoft Academic Search

    M. Stern; G. Fourer; W. Whalen; M. van Loo; G. Duran

    1997-01-01

    Utility Power Group has achieved a significant reduction in the installed cost of grid-connected PV systems. The two part technical approach focused on 1) The utilization of a large area factory assembled PV panel, and 2) The integration and packaging of all sub-array power conversion and control functions within a single factory produced enclosure. Eight engineering prototype 15kW ac single

  13. C -parameter distribution at N3LL' including power corrections

    NASA Astrophysics Data System (ADS)

    Hoang, André H.; Kolodrubetz, Daniel W.; Mateu, Vicent; Stewart, Iain W.

    2015-05-01

    We compute the e+e- C -parameter distribution using the soft-collinear effective theory with a resummation to next-to-next-to-next-to-leading-log prime accuracy of the most singular partonic terms. This includes the known fixed-order QCD results up to O (?s3), a numerical determination of the two-loop nonlogarithmic term of the soft function, and all logarithmic terms in the jet and soft functions up to three loops. Our result holds for C in the peak, tail, and far tail regions. Additionally, we treat hadronization effects using a field theoretic nonperturbative soft function, with moments ?n. To eliminate an O (?QCD) renormalon ambiguity in the soft function, we switch from the MS ¯ to a short distance "Rgap" scheme to define the leading power correction parameter ?1. We show how to simultaneously account for running effects in ?1 due to renormalon subtractions and hadron-mass effects, enabling power correction universality between C -parameter and thrust to be tested in our setup. We discuss in detail the impact of resummation and renormalon subtractions on the convergence. In the relevant fit region for ?s(mZ) and ?1, the perturbative uncertainty in our cross section is ? 2.5 % at Q =mZ.

  14. MHD-EMP interaction with power transmission and distribution systems

    SciTech Connect

    Tesche, F.M. [Tesche (F.M.), Dallas, TX (United States); Barnes, P.R. [Oak Ridge National Lab., TN (United States)

    1991-12-01

    A nuclear detonation at altitudes of several hundred kilometers above the earth will distort the earth`s magnetic field and results in a time-variation of the geomagnetic field on the earth`s surface. This magnetic field interacts with the finitely conducting earth to produce a time varying electric field, also on the earth`s surface. Known at the magnetohydrodynamic electromagnetic pulse (MHD-EMP), this resulting E-field can induce a net voltage in long electrical conductors, such as power transmission lines. If these conductors are electrically connected to the earth at both ends, a current can be induced to flow in the conductors, and this can cause damage or upset to certain electrical systems. This paper presents the results of a study on the interaction of the MHD-EMP with power transmission and distribution (T&D) systems. A brief overview of the MHD-EMP environment used in the study is presented, and the analytical models used for estimating the coupling of this environment to T&D lines are discussed. Because of the quasi-static nature of MHD-EMP, the models are essentially simple DC circuit models. However, complications arise in attempting to treat realistic line configurations having a large number of support towers and an overhead shield or neutral wires. There models are discussed in detail. 3 refs., 5 figs., 1 tab.

  15. MHD-EMP interaction with power transmission and distribution systems

    SciTech Connect

    Tesche, F.M. (Tesche (F.M.), Dallas, TX (United States)); Barnes, P.R. (Oak Ridge National Lab., TN (United States))

    1991-01-01

    A nuclear detonation at altitudes of several hundred kilometers above the earth will distort the earth's magnetic field and results in a time-variation of the geomagnetic field on the earth's surface. This magnetic field interacts with the finitely conducting earth to produce a time varying electric field, also on the earth's surface. Known at the magnetohydrodynamic electromagnetic pulse (MHD-EMP), this resulting E-field can induce a net voltage in long electrical conductors, such as power transmission lines. If these conductors are electrically connected to the earth at both ends, a current can be induced to flow in the conductors, and this can cause damage or upset to certain electrical systems. This paper presents the results of a study on the interaction of the MHD-EMP with power transmission and distribution (T D) systems. A brief overview of the MHD-EMP environment used in the study is presented, and the analytical models used for estimating the coupling of this environment to T D lines are discussed. Because of the quasi-static nature of MHD-EMP, the models are essentially simple DC circuit models. However, complications arise in attempting to treat realistic line configurations having a large number of support towers and an overhead shield or neutral wires. There models are discussed in detail. 3 refs., 5 figs., 1 tab.

  16. Power Law Distributions of Patents as Indicators of Innovation

    E-print Network

    O'Neale, D R J

    2012-01-01

    The total number of patents produced by a country (or the number of patents produced per capita) is often used as an indicator for innovation. Here we present evidence that the distribution of patents amongst applicants within many OECD countries is well-described by power laws with exponents that vary between 1.66 (Japan) and 2.37 (Poland). Using simulations based on simple preferential attachment-type rules that generate power laws, we find we can explain some of the variation in exponents between countries, with countries that have larger numbers of patents per applicant generally exhibiting smaller exponents in both the simulated and actual data. Similarly we find that the exponents for most countries are inversely correlated with other indicators of innovation, such as R&D intensity or the ubiquity of export baskets. This suggests that in more advanced economies, which tend to have smaller values of the exponent, a greater proportion of the total number of patents are filed by large companies than in...

  17. C -parameter distribution at N 3 LL ' including power corrections

    DOE PAGESBeta

    Hoang, André H.; Kolodrubetz, Daniel W.; Mateu, Vicent; Stewart, Iain W.

    2015-05-01

    We compute the e?e? C-parameter distribution using the soft-collinear effective theory with a resummation to next-to-next-to-next-to-leading-log prime accuracy of the most singular partonic terms. This includes the known fixed-order QCD results up to O(?3s), a numerical determination of the two-loop nonlogarithmic term of the soft function, and all logarithmic terms in the jet and soft functions up to three loops. Our result holds for C in the peak, tail, and far tail regions. Additionally, we treat hadronization effects using a field theoretic nonperturbative soft function, with moments ?n. To eliminate an O(?QCD) renormalon ambiguity in the soft function, we switchmore »from the MS¯ to a short distance “Rgap” scheme to define the leading power correction parameter ?1. We show how to simultaneously account for running effects in ?1 due to renormalon subtractions and hadron-mass effects, enabling power correction universality between C-parameter and thrust to be tested in our setup. We discuss in detail the impact of resummation and renormalon subtractions on the convergence. In the relevant fit region for ?s(mZ) and ?1, the perturbative uncertainty in our cross section is ? 2.5% at Q=mZ.« less

  18. Distributed Genetic Algorithms with New Sharing Approach Multiobjective Optimization Problems

    E-print Network

    Coello, Carlos A. Coello

    Distributed Genetic Algorithms with New Sharing Approach Multiobjective Optimization Problems@mail.doshisha.ac.jp sin@mikilab.doshisha.ac.jp 1 Abstract­ this paper, a new distributed genetic algorithm multiobjective and those in the relationship of trade­off. genetic algorithm powerful timization methods based mechanics

  19. Small Inverter-Interfaced Distributed Energy Resources for Reactive Power Support

    E-print Network

    Liberzon, Daniel

    rectifier inputs, and wind turbine power converters. How- ever, most devices today seek to operate at unitySmall Inverter-Interfaced Distributed Energy Resources for Reactive Power Support Alejandro D. Dom}@ILLINOIS.EDU Abstract--The use of small inverter-interfaced distributed energy resources for reactive power

  20. Power Allocation Policy for Distributed Estimation in Wireless Networks Ion Matei and John S. Baras

    E-print Network

    Baras, John S.

    and therefore communicating with the relevant sensors is of outmost importance. Therefore, the power allocationPower Allocation Policy for Distributed Estimation in Wireless Networks Ion Matei and John S. Baras introduce a distributed algorithm which computes a power allocation scheme aimed at ensuring accurate state

  1. Reverse-Link Power Control in CDMA Distributed Antenna Systems Arif Obaid Halim Yanikomeroglu

    E-print Network

    Yanikomeroglu, Halim

    = = L j iji 1 ( )1 ( )2 Reverse-Link Power Control in CDMA Distributed Antenna Systems Arif Obaid power control is an essential component of any CDMA system. In conventional cellular systems requirements in a CDMA system that employs power control with a distributed antenna architecture. Computer

  2. Subsystem Interaction Analysis in Power Distribution Systems of Next Generation Airlifters

    E-print Network

    Lindner, Douglas K.

    1 Subsystem Interaction Analysis in Power Distribution Systems of Next Generation Airlifters Sriram of the electromechanical actuators used in the analysis. Keywords «Airplanes», «Power quality», «Control», «High frequency power distribution system of a next generation transport aircraft is addressed. Detailed analysis

  3. Simultaneous Co-Design of Distributed On-Chip Power Supplies and Decoupling Capacitors

    E-print Network

    Friedman, Eby G.

    Simultaneous Co-Design of Distributed On-Chip Power Supplies and Decoupling Capacitors Selc¸uk K-chip power supplies and intentional decoupling capacitors inserted throughout an integrated circuit further and decoupling capacitors, a new design methodology is required to simultaneously design the power distribution

  4. A Better Steam Engine: Designing a Distributed Concentrating Solar Combined Heat and Power System

    E-print Network

    California at Berkeley, University of

    A Better Steam Engine: Designing a Distributed Concentrating Solar Combined Heat and Power System of analysis of Distributed Concentrating Solar Combined Heat and Power (DCS-CHP) systems is a design of a theoretical solar CHP system. Then, we explore the economic and technological impetus for a solar powered

  5. Impact of Renewable Distributed Generation on Power Systems M. Begovi, A. Pregelj, A. Rohatgi D. Novosel

    E-print Network

    Impact of Renewable Distributed Generation on Power Systems M. Begovi, A. Pregelj, A. Rohatgi D the electric power distribution system. The prevailing utility strategy, so far, is to treat the DG devices generation is to have centralized plants distributing electricity through an extensive transmission

  6. Abstract--Distributed generation (DG) has brought great attention from the power community, especially

    E-print Network

    Catholic University of Chile (Universidad Católica de Chile)

    1 Abstract-- Distributed generation (DG) has brought great attention from the power community applications, especially on high penetration levels, may have adverse impact on the transmission/distribution and penetration of DG is affecting power flow of the networks and Distributed FACTS (DFACTS) devices

  7. A multi-agent approach for a self-reconfigurable electric power distribution system

    Microsoft Academic Search

    Janeth G. Gómez--Gualdrón; Miguel Vélez-Reyes

    2006-01-01

    Electric power distribution systems can be found almost everywhere, from ship power systems to data centers. In many critical applications, there is needed to maintain minimal operating capability under fault conditions. To carry out this goal it is necessary to develop energy distribution control techniques, which let implement a self-reconfigurable energy distribution system. This research project is looking at the

  8. Simulating a Multi-Agent based Self-Reconfigurable Electric Power Distribution System

    Microsoft Academic Search

    Janeth G. Gómez-Gualdrón; Miguel Vélez-Reyes

    2006-01-01

    Electric power distribution systems can be found almost everywhere, from ship power systems to data centers. In many critical applications, there is need to maintain minimal operating capability under fault conditions. To carry out this goal it is necessary to develop energy distribution control techniques, which let implement a self-reconfigurable energy distribution system. This research project is looking at the

  9. Distribution of MdACS3 null alleles in apple (Malus × domestica Borkh.) and its relevance to the fruit ripening characters

    PubMed Central

    Bai, Songling; Wang, Aide; Igarashi, Megumi; Kon, Tomoyuki; Fukasawa-Akada, Tomoko; Li, Tianzhong; Harada, Takeo; Hatsuyama, Yoshimichi

    2012-01-01

    Expression of MdACS3a, one of the ripening-related ACC synthase genes, plays a pivotal role in initiating the burst of ethylene production by MdACS1 in apple fruit. Although previous studies have demonstrated the presence of MdACS3a-null alleles through deficiency of transcription activity or loss of enzyme activity due to amino acid substitution, which may affect the storage properties of certain fruit cultivars, an overall picture of these null alleles in cultivars is still lacking. The present study investigated the distribution of null allelic genes in 103 cultivars and 172 breeding selections by using a simple sequence repeat (SSR) marker linked to them. The results indicated that both allelic genes were widely distributed throughout the examined cultivars and selections, some occurring as the null genotype, either homozygously or heterozygously, with each null allele. The implications of MdACS3a distribution results and the influence of its null allelotypes in fruit characters are discussed. PMID:23136513

  10. Aging Management Guideline for commercial nuclear power plants: Power and distribution transformers

    SciTech Connect

    Toman, G.; Gazdzinski, R. [Sandia National Labs., Albuquerque, NM (United States)

    1994-05-01

    This Aging Management Guideline (AMG) provides recommended methods for effective detection and mitigation of age-related degradation mechanisms in power and distribution transformers important to license renewal in commercial nuclear power plants. The intent of this AMG to assist plant maintenance and operations personnel in maximizing the safe, useful life of these components. It also supports the documentation of effective aging management programs required under the License Renewal Rule 10 CFR Part 54. This AMG is presented in a manner which allows personnel responsible for performance analysis and maintenance to compare their plant-specific aging mechanisms (expected or already experienced) and aging management program activities to the more generic results and recommendations presented herein.

  11. Comprehensive Diagnosis of Complex Electrical Power Distribution Systems

    E-print Network

    Daigle, Matthew

    accurate models, and generating fast and accurate diagnoses while ensuring robustness to measurement noise and data to estimate and validate our model parameters, and the installed sensors providing data sample-state analysis of ac measurements, which exhibit fault transients that occur faster than the sensor sampling

  12. The p-sphere and the geometric substratum of power-law probability distributions [rapid communication

    NASA Astrophysics Data System (ADS)

    Vignat, C.; Plastino, A.

    2005-08-01

    Links between power law probability distributions and marginal distributions of uniform laws on p-spheres in R show that a mathematical derivation of the Boltzmann Gibbs distribution necessarily passes through power law ones. Results are also given that link parameters p and n to the value of the non-extensivity parameter q that characterizes these power laws in the context of non-extensive statistics.

  13. Distributed Relay Selection and Power Control for Multiuser Cooperative Communication Networks Using Buyer/Seller Game

    E-print Network

    Liu, K. J. Ray

    in cooperative communications depend on careful resource allocation such as relay selection and power controlDistributed Relay Selection and Power Control for Multiuser Cooperative Communication Networks framework over multiuser cooperative communication networks to stimulate cooperation and improve the system

  14. Submodule Integrated Distributed Maximum Power Point Tracking for Solar Photovoltaic Applications

    E-print Network

    Pilawa-Podgurski, Robert C. N.

    This paper explores the benefits of distributed power electronics in solar photovoltaic applications through the use of submodule integrated maximum power point trackers (MPPT). We propose a system architecture that provides ...

  15. Proceedings of Power Systems 03: Distributed Generation and Advanced Metering 2002 Wichita State University

    E-print Network

    Proceedings of Power Systems 03: Distributed Generation and Advanced Metering © 2002 Wichita State. The combustion products at high temperature (about 1700o F) and high pressure are #12;Proceedings of Power

  16. Wind energy converters with FACTS Capabilities for optimized integration of wind power into transmission and distribution systems

    Microsoft Academic Search

    A. Beekmann; J. Marques; E. Quitmann; S. Wachtel

    2009-01-01

    In a lot of power systems renewable energies and especially wind power are main drivers for the actual restructuring of transmission and distribution systems. Enhanced power exchange capabilities over long distances will be one of the necessary transmission system characteristics in order to achieve a higher penetration level of wind power. Distribution systems change from pure load distribution to distributed

  17. Low-power digital filtering using multiple voltage distribution and adaptive voltage scaling (poster session)

    Microsoft Academic Search

    Sandeep Dhar; Dragan Maksimovi?

    2000-01-01

    This paper describes an adaptive power management architecture to reduce power consumption in digital filters. The proposed approach combines two low-power techniques which utilize supply voltage reduction. The first technique, multiple voltage distribution (MVD), attempts to reduce power consumption by assigning reduced supply voltages to circuit modules while satisfying timing constraints. The second technique, adaptive voltage scaling (AVS), dynamically adjusts

  18. Bound of the distribution of instantaneous power in single carrier modulation

    Microsoft Academic Search

    Dov Wulich; Lev Goldfeld

    2005-01-01

    This paper deals with the distribution of the instantaneous power (IP) in single carrier (SC) modulation. An upper bound for the complementary distribution of the IP is found using the Chernoff bound. It is also shown, as a \\

  19. Measurement of the spatiotemporal surface charge distribution in an ac plasma display cell using Pockels effect

    NASA Astrophysics Data System (ADS)

    Jeong, D. C.; Bae, H. S.; Whang, K. W.

    2005-01-01

    We measured the surface charge distribution in a coplanar type alternating current plasma display panel cell by the longitudinal electro-optic amplitude modulation method with BSO (Bi12SiO20) single crystal. The effects of the initialization condition were investigated to take care of the errors coming from the charge relaxation phenomena of the BSO crystal. Using BSO single crystal as the dielectric layer, the two-dimensional spatiotemporal surface charge distribution was successfully measured in a discharge cell with a discharge gas of neon and xenon 4% at the pressure of 100torr driven by square-type sustaining pulses. The temporal behavior of the surface charge is compared with the simulated result and the measurement of the infrared light emission from the discharge. The positive and negative surface charges show somewhat different spatiotemporal characteristics.

  20. MODELING OF A DSTATCOM WITH ULTRA-CAPACITOR ENERGY STORAGE FOR POWER DISTRIBUTION SYSTEM APPLICATIONS

    Microsoft Academic Search

    M. G. MOLINA; Puerto Iguazú Argentina

    Summary - This paper describes the dynamic modeling of a distribution static synchronous compensator (DSTATCOM) coupled with ultra-capacitor energy storage (UCES) for improving the power quality of power distribution systems. Two modes of operation are assessed, i.e. voltage control for voltage fluctuations ride-through and dynamic active power control for power flow compensation. New detailed models and dynamic control schemes are

  1. Improved dynamic security assessment for AC\\/DC power systems using transient energy functions

    Microsoft Academic Search

    Nilkamal Fernandopulle

    2006-01-01

    Due to rapid changes in electricity demand and disturbances caused by faults and equipment switching, power systems are often in a state of change. A method to predict transient stability that can accurately process a range of conditions frequently and faster than time simulation is highly advantageous. The Transient Energy Function (TEF) method is such a tool for this purpose.

  2. High speed AC generator (7200 RPM, 60 Hz) for autonomous power systems

    Microsoft Academic Search

    O. Honorati; F. Caricchi; E. Santini

    1989-01-01

    The authors analyze the features of an electric generator whose angular speed is twice that of the rotating field. Two versions are studied: series- and parallel-connected windings. A technical analysis is presented in order to determine which type of machine to choose for specific applications. The relevant mathematical models are deduced. Self-excitation of the machine feeding an autonomous power system

  3. Numerical Electric Field Analysis of Power Status Sensor Observing Power Distribution System Taking into Account Voltage Divider Measurement Circuit

    NASA Astrophysics Data System (ADS)

    Kubo, Takuro; Furukawa, Tatsuya; Itoh, Hideaki; Fukumoto, Hisao; Wakuya, Hiroshi; Ohchi, Masashi

    We have proposed and preproducted the voltage-current waveform sensor of resin molded type for measuring the power factor and harmonics in power distribution systems. We have executed numerical electromagnetic analyses using the finite element method to estimate the characteristics and behaviours of the sensor. Although the magnetic field analyses for the current sensor have involved the measurement circuit, the electric field analyses have not included the measurement circuit for measuring voltage waveforms of power lines. In this paper, we describe the electric field analyses with the measurement circuit and prove the insulating strength of the proposed sensor permissible to the use in 22kV power distribution systems.

  4. Soft-switched high-frequency, high power DC\\/AC converter with IGBT

    Microsoft Academic Search

    Knut Vangen; Terje Melaa; Alf Khe Adnanes

    1992-01-01

    A 20 kVA direct DC\\/LFAC dual active bridge (DAB) power converter projected for operation at 100 kHz with insulated gate bipolar transistor (IGBT) switches is presented. It has dual-angle, constant-frequency phase shift control, and is soft switched in a large part of the output V-I plane. It also has a high performance digital control system. The topology and its properties

  5. A new power distribution strategy for area array bonded ICs and packages of future deep sub-micron ULSI

    Microsoft Academic Search

    L. Cao; J. P. Krusius

    1997-01-01

    Signal and power distribution of deep sub-micron ULSI ICs compete for on-chip wiring resources because of increasing chip power dissipation, reduced supply voltage, increased signal wiring demand, higher operating frequency and interconnect delay limitations. We propose a novel cascaded power\\/ground ring approach for on-chip power distribution, which simultaneously addresses power and signal distribution. Three power distribution approaches have been analyzed

  6. Analysis and design of matrix converters for adjustable speed drives and distributed power sources

    E-print Network

    Cha, Han Ju

    2004-11-15

    Recently, matrix converter has received considerable interest as a viable alternative to the conventional back-to-back PWM (Pulse Width Modulation) converter in the ac/ac conversion. This direct ac/ac converter provides some attractive...

  7. Analysis and design of matrix converters for adjustable speed drives and distributed power sources 

    E-print Network

    Cha, Han Ju

    2004-11-15

    Recently, matrix converter has received considerable interest as a viable alternative to the conventional back-to-back PWM (Pulse Width Modulation) converter in the ac/ac conversion. This direct ac/ac converter provides ...

  8. Future electronic power distribution systems a contemplative view

    Microsoft Academic Search

    Dushan Boroyevich; I. Cvetkovic; Dong Dong; R. Burgos; Fei Wang; F. Lee

    2010-01-01

    Although it has long been argued that electronic power converters can help improve system controllability, reliability, size, and efficiency, their penetration in power systems is still quite low. The often-cited barriers of higher cost and lower reliability of the power converters are quite high if power electronics is used as direct, one-to-one, replacement for the existing electromechanical equipment. However, if

  9. Optimal distributed power generation under network load constraints

    E-print Network

    Utrecht, Universiteit

    , mainly because of the development of novel components for decentral power generation (solar panels, small wind turbines and heat pumps). This gives rise to the question how many units of each type (solar panel Abstract. In electrical power networks nowadays more and more customers are becoming power- producers

  10. Assisting tools for a new maintenance planning in a power distribution system

    Microsoft Academic Search

    Miguel A. Sanz-Bobi; Rafael Palacios; R. J. A. Vieira; G. Nicolau; P. Ferrarons

    2010-01-01

    This paper describes a framework in which several tools have been integrated in order to help the maintenance planning in a power distribution network. This framework will help to improve the process of decision making in an asset management context of a power distribution company. Two kinds of tools have been developed, one has been oriented to the identification of

  11. Performance Monitoring of Energy Flow in the Power Transmission and Distribution System Using Grid Computing

    Microsoft Academic Search

    C. Senthamarai; A. Krishnan; R. Hemalatha

    2007-01-01

    Grid Computing is a promising infrastructure and technology that involves the integrated and collaborative use of Computers, networks, databases and scientific instruments owned and managed by multiple organizations. In this context our research primarily aims at developing an application framework for monitoring the Performance of Power Transmission and Distribution System using Grid Computing. Power Transmission and Distribution System of Electrical

  12. Multi-agent system based intelligent distributed control system for power plants

    Microsoft Academic Search

    Kwang Y. Lee; Jason D. Head; Jason R. Gomes; Craig S. Williams

    2011-01-01

    This paper presents an approach for intelligent distributed control of power plants using the concept of multi- agent systems (MAS). Solving the problem of optimally controlling a power plant based on multiple objectives, such as minimizing pollution, maximizing equipment life, etc., and coordinating each of the involved tasks that must be performed in distributed environments is a challenge, which involves

  13. Orthogonalized correlation–distribution method for acquiring power offer and demand in energy informatics

    Microsoft Academic Search

    J. Sachau

    2003-01-01

    Groups of decentral power systems are usually managed in an integrated way to keep efforts reasonable. For fluctuating power offer and demand, i.e., their time series of monitoring data, a generic description is proposed based on decoupled modelling of correlation and distribution functions. Distributed monitoring databases together with standardized evaluation tools give a broad representation of operation experience for the

  14. Industrial Fieldbus Improvements in Power Distribution and Conducted Noise Immunity With No Extra Costs

    Microsoft Academic Search

    Alberto Menendez; Antonio Barbancho; Diego Fco. Larios

    2011-01-01

    Industrial distributed control continues the move toward networks at all levels. At lower levels, control networks provide flexibility, reliability, and low cost, although perhaps the simplest but most important advantage is the reduced volume of wiring. Powered fieldbuses offer particular notable benefits in system wiring simplification. Nevertheless, very few papers are dealing with the potentials and limitations in power distribution

  15. Impact of PV generation to voltage variation and power losses of distribution systems

    Microsoft Academic Search

    Wei-Lin Hsieh; Chia-Hung Lin; Chao-Shun Chen; C. T. Hsu; Te-Tien Ku; Cheng-Ta Tsai; Chin-Ying Ho

    2011-01-01

    To promote the PV installation in Taiwan, a large scale photovoltaic (PV) system with total capacity of 1000kWp has been installed in a sporting complex in Kaohsiung, which is connected to the Taiwan Power Company (Taipower) distribution feeder. This paper is to investigate the impact of large PV system to the operation of distribution feeders. The PV power generation is

  16. Injection-Locked Clocking: A Low-Power Clock Distribution Scheme for High-End Microprocessors

    E-print Network

    Wu, Hui

    Injection-Locked Clocking: A Low-Power Clock Distribution Scheme for High-End Microprocessors Hui-performance microprocessors. Clocking circuitry accounts for an overwhelming amount of total power consumption in multi is a crucial aspect of modern multi- GHz microprocessor design. Conventional distribution schemes are more

  17. A low-power geographically distributed data acquisition system with WWVB synchronization

    Microsoft Academic Search

    Jay Allison; Rick Hormigo; Emil Jovanov

    2003-01-01

    Geographically distributed data acquisition systems provide a challenge when synchronization of the data acquisition is required. Current products and research do not provide a low-cost, low-power solution suitable for use in the field. GPS receivers are commonly used for their precision, but their power consumption is excessive. In this paper we present a method for synchronizing geographically distributed systems via

  18. A Multi-core High Performance Computing Framework for Distribution Power Flow

    E-print Network

    Franchetti, Franz

    A Multi-core High Performance Computing Framework for Distribution Power Flow Tao Cui and Franz developed a high performance parallel distribution power flow solver for Monte Carlo styled application. From computer architecture and programming point of view, we show that by applying various performance

  19. Measurements of Film Flow Rate in Heated Tubes with Various Axial Power Distributions

    E-print Network

    Haviland, David

    Adamsson February 2006 Technical Reports from Royal Institute of Technology KTH Nuclear Reactor Technology, Measurements of Film Flow Rate in Heated Tubes with Various Axial Power Distributions KTH Nuclear ReactorMeasurements of Film Flow Rate in Heated Tubes with Various Axial Power Distributions by Carl

  20. Self-Reconfigurable Electric Power Distribution System using Multi-Agent Systems

    Microsoft Academic Search

    Janeth G. Gómez-Gualdrón; Miguel Vélez-Reyes; Luis J. Collazo

    2007-01-01

    Electric power distribution systems (EPDS) can be found almost everywhere, from ship power systems to data centers. In many critical applications, there is needed to maintain minimal operating capability under fault conditions. Therefore, it is necessary to develop energy distribution control techniques, which allow the implementation of a self-reconfigurable EPDS. This research project focuses on the application of multi agent

  1. PC\\/104 and FPGA based automatic test research for airborne power distribution equipment

    Microsoft Academic Search

    Bo Yang; Yunlu Wang; Guang Yang

    2009-01-01

    The power distribution equipment, the key equipment in certain unmanned aerial vehicle (UAV), is in charge of the power distribution management and the signal conversion of airborne sensors, and must be comprehensively tested before the trial flight of UAV to ensure the flight safety. The automatic test method for the equipment is researched and an automatic test system is developed

  2. Phase and power density distributions on plane apertures of reflector antennas

    Microsoft Academic Search

    F. Brickell; B. S. Westcott

    1978-01-01

    Complex coordinates are used under the assumptions of geometrical optics to study the relations between phase and power density distributions on plane apertures of reflector antenna systems. No symmetry assumptions are made and the results form a generalisation of existing work in the field. The synthesis of a dual reflector system to produce given aperture phase and power distributions when

  3. A new generic family of saturable reactor-assisted soft-switching PWM DC-DC converters for high-power density distributed power systems

    Microsoft Academic Search

    M. Nakaoka; M. Michihira; S. Hamada; Y. Murakami

    1992-01-01

    A generic family of high power density DC-DC power converter topologies with high-frequency AC link and without transformer isolation link is described. A saturable reactor assisted (SRA) soft switching mode constant frequency pulse width modulation (PWM) technique efficiently operates at a zero voltage switching transition scheme. This kind of quasi-trapezoidal wave mode PWM DC-DC power converter incorporates a small saturable

  4. Power distribution in complex environmental negotiations: Does balance matter?

    USGS Publications Warehouse

    Burkardt, N.; Lamb, B.L.; Taylor, J.G.

    1997-01-01

    We studied six interagency negotiations covering Federal Energy Regulatory Commission (FERC) hydroelectric power licenses. Negotiations occurred between state and federal resource agencies and developers over project operations and natural resource mitigation. We postulated that a balance of power among parties was necessary for successful negotiations. We found a complex relationship between balanced power and success and conclude that a balance of power was associated with success in these negotiations. Power played a dynamic role in the bargaining and illuminates important considerations for regulatory design.

  5. Power components for the Space Station 20-kHz power distribution system

    NASA Technical Reports Server (NTRS)

    Renz, David D.

    1988-01-01

    Since 1984, NASA Lewis Research Center was developing high power, high frequency space power components as part of The Space Station Advanced Development program. The purpose of the Advanced Development program was to accelerate existing component programs to ensure their availability for use on the Space Station. These components include a rotary power transfer device, remote power controllers, remote bus isolators, high power semiconductor, a high power semiconductor package, high frequency-high power cable, high frequency-high power connectors, and high frequency-high power transformers. All the components were developed to the prototype level and will be installed in the Lewis Research Center Space Station power system test bed.

  6. Power components for the space station 20-kHz power distribution system

    NASA Technical Reports Server (NTRS)

    Renz, David D.

    1988-01-01

    Since 1984, NASA Lewis Research Center was developing high power, high frequency space power components as part of The Space Station Advanced Development program. The purpose of The Advanced Development program was to accelerate existing component programs to ensure their availability for use on the Space Station. These components include a rotary power transfer device, remote power controllers, remote bus isolators, high power semiconductor, a high power semiconductor package, high frequency-high power cable, high frequency-high power connectors, and high frequency-high power transformers. All the components were developed to the prototype level and will be installed in the Lewis Research Center Space Station power system test bed.

  7. HA 2 TSD: hierarchical time slack distribution for ultra-low power CMOS VLSI

    Microsoft Academic Search

    Kyu-won Choi; Abhijit Chatterjee

    2002-01-01

    This paper describes an efficient hierarchical design and optimization approach for ultra-low power CMOS logic circuits. We introduce the Hierarchical Activity-Aware Time Slack Distribution (HA2TSD) algorithm, which distributes the surplus time slack into the most power-hungry modules hierarchically. HA2TSD ensures that the total slack budget is maximal and the total power is near-minimal. Based on these time slacks, we have

  8. Integrated Network Security Protocol Layer for Open-Access Power Distribution Systems

    Microsoft Academic Search

    Todd Mander; Farhad Nabhani; Lin Wang; Richard Cheung

    2007-01-01

    Power distribution system cyber-security concerns are increasing rapidly with growing demands for open accesses to the distribution systems for electricity generation and trading imposed by new government deregulations. This paper proposes a new integrated network security protocol layer, located below the data-link layer of DNP3 - a popular utility protocol, to enhance the data transmission cyber-security for power distribution systems.

  9. Soft Power and Desirable Relationship Outcomes: The Case of Zimbabwean Distribution Channels

    Microsoft Academic Search

    Richard Chinomona; Julia Ying-Chao Lin; Michael Chih-Hung Wang; Julian Ming-Sung Cheng

    2010-01-01

    The current research attempts to investigate the use of the two sources of dealers' soft channel power (i.e., expert power and referent power) as a means of achieving three desirable channel relationship outcomes in Zimbabwe's channel of distribution system. The field study is conducted in Harare and Chitungwiza, and research data are collected from 447 small and medium-size enterprise (SME)

  10. Self-adaptive distributed power control for opportunistic QOS provision in wireless communication networks

    Microsoft Academic Search

    F. de S. Chaves; J. M. T. Romano; M. Abbas-Turki; H. Abou-Kandil

    2009-01-01

    Emerging wireless communication networks are required to provide data services which tolerate large variations of link quality. Such applications allow flexible power control procedures. In this paper, we approach the distributed power control problem from an automatic control point of view. A new framework for opportunistic power control is proposed, where the target quality of service at each link is

  11. Z-Source-Inverter-Based Flexible Distributed Generation System Solution for Grid Power Quality Improvement

    Microsoft Academic Search

    Chandana Jayampathi Gajanayake; D. Mahinda Vilathgamuwa; Poh Chiang Loh; Remus Teodorescu; Frede Blaabjerg

    2009-01-01

    Distributed generation (DG) systems are usually connected to the grid using power electronic converters. Power delivered from such DG sources depends on factors like energy availability and load demand. The converters used in power conversion do not operate with their full capacity all the time. The unused or remaining capacity of the converters could be used to provide some ancillary

  12. Upper capacity bound and power allocation in polarized distributed MIMO system

    Microsoft Academic Search

    Wei Lu; Desheng Wang; Yingzhuang Liu

    2011-01-01

    By deriving the upper capacity bound of the polarized distributed MIMO system on Rician channel, the suboptimal power allocation scheme is presented by applying Lagrangian optimization. The suboptimal power allocation is based on the path loss fading information, and it needs less feedback information than other power allocation schemes which are based on channel mean or covariance matrix. The suboptimal

  13. Practical power allocation for clustered distributed antenna systems in the low SNR regime

    Microsoft Academic Search

    Wei Feng; Yanmin Wang; Ming Zhao; Shidong Zhou; Jing Wang

    2011-01-01

    In this letter, we address the problem of downlink power allocation for the generalized clustered distributed antenna systems in the low SNR regime. With the practical assumption that only the large-scale channel state information is known at the transmitter, a sub-optimal power allocation scheme is proposed, subject to a total transmit power constraint for each cooperative clusters. It is observed

  14. Distributed topology control for power efficient operation in multihop wireless ad hoc networks

    Microsoft Academic Search

    Roger Wattenhofer; L. Li; P. Bahl; Y.-M. Wang

    2001-01-01

    The topology of wireless multihop ad hoc networks can be controlled by varying the transmission power of each node. We propose a simple distributed algorithm where each node makes local decisions about its transmission power and these local decisions collectively guarantee global connectivity. Specifically, based on the directional information, a node grows it transmission power until it finds a neighbor

  15. Effect of Void Distribution Parameter and Axial Power Profile on Boiling Water Reactor Bifurcation Characteristics

    Microsoft Academic Search

    D. D. B. van Bragt; Rizwan-uddin; T. H. J. J. van der Hagen

    2000-01-01

    Bifurcation analyses of the impact of the void distribution parameter Câ and the axial power profile on the stability of boiling water reactors (BWRs) are reported. Bifurcation characteristics of heated channels (without nuclear feedback) appear to be very sensitive to the axial power profile. A turning point bifurcation was detected for a (symmetrically) peaked axial power profile. This kind of

  16. Sensor Selection and Power Allocation for Distributed Estimation in Sensor Networks: Beyond the Star Topology

    Microsoft Academic Search

    Gautam Thatte; Urbashi Mitra

    2008-01-01

    Optimal power allocation for distributed parameter estimation in a wireless sensor network with a fusion center under a total network power constraint is considered. For the simple star topology, an analysis of the effect of the measurement noise variance on the optimal power allocation policy is presented. The optimal solution evolves from sensor selection, to water- filling, to channel inversion

  17. The MLP Distribution: A Modified Lognormal Power-Law Model for the Stellar Initial Mass Function

    E-print Network

    Basu, Shantanu; Auddy, Sayantan

    2015-01-01

    This work explores the mathematical properties of a distribution introduced by Basu & Jones (2004), and applies it to model the stellar initial mass function (IMF). The distribution arises simply from an initial lognormal distribution, requiring that each object in it subsequently undergoes exponential growth but with an exponential distribution of growth lifetimes. This leads to a modified lognormal with a power-law tail (MLP) distribution, which can in fact be applied to a wide range of fields where distributions are observed to have a lognormal-like body and a power-law tail. We derive important properties of the MLP distribution, like the cumulative distribution, the mean, variance, arbitrary raw moments, and a random number generator. These analytic properties of the distribution can be used to facilitate application to modeling the IMF. We demonstrate how the MLP function provides an excellent fit to the IMF compiled by Chabrier (2005) and how this fit can be used to quickly identify quantities like...

  18. Proposal of Novel Power Converter Suitable for Wireless Power Distribution System with Capacitive Coupling using One-Pulse Switching Active Capacitor

    NASA Astrophysics Data System (ADS)

    Funato, Hirohito; Chiku, Yuki

    Wireless electric power distribution is very attractive to provide for mobile equipments. Wireless power distribution with capacitive coupling was proposed to overcome disadvantages of wireless power distribution with magnetic-field coupling which is the most popular way. It is however difficult to transfer large power due to small capacitance of capacitive coupling. In this paper, a new power converter suitable for wireless power distribution using capacitive coupling is proposed. In the proposed circuit, a novel one-pulse switching active negative capacitor is used to increase transfer power.

  19. Distributed PI-Control with Applications to Power Systems Frequency Control

    E-print Network

    Dimarogonas, Dimos

    Distributed PI-Control with Applications to Power Systems Frequency Control Martin Andreasson12 Distributed control is the only feasible control strategy for many large-scale systems, when sensing strategy, as it will in general eliminate static control errors [2]. For many distributed systems however

  20. Voltage Stability and Frequency Synchronization of Weak Power Distribution Networks with Inverter-Based

    E-print Network

    Lemmon, Michael

    Voltage Stability and Frequency Synchronization of Weak Power Distribution Networks with Inverter not apply to truly weak networks. Key words: Weak networks, inverter-based distributed generator, voltage and frequency stability. 1 INTRODUCTION Inverter-based distributed generation (DG) sources are usually a part

  1. Distributed Energy Resources and Control: A power system point of view

    E-print Network

    Distributed Energy Resources and Control: A power system point of view Oliver Gehrke, Stephanie of buzz words. The terms for three general types of control - centralized, distributed and decentralized-R-1608(EN) 248 #12;A distributed control system refers to a collection of independent devices

  2. Distributed PI-Control with Applications to Power Systems Frequency Control

    E-print Network

    Johansson, Karl Henrik

    Distributed PI-Control with Applications to Power Systems Frequency Control Martin Andreasson12 Institute of Technology, Stockholm, Sweden. Abstract--This paper considers a distributed PI Distributed control is the only feasible control strategy for many large-scale systems, when sensing

  3. Low Insertion HVDC Circuit Breaker: Magnetically Pulsed Hybrid Breaker for HVDC Power Distribution Protection

    SciTech Connect

    None

    2012-01-09

    GENI Project: General Atomics is developing a direct current (DC) circuit breaker that could protect the grid from faults 100 times faster than its alternating current (AC) counterparts. Circuit breakers are critical elements in any electrical system. At the grid level, their main function is to isolate parts of the grid where a fault has occurred—such as a downed power line or a transformer explosion—from the rest of the system. DC circuit breakers must interrupt the system during a fault much faster than AC circuit breakers to prevent possible damage to cables, converters and other grid-level components. General Atomics’ high-voltage DC circuit breaker would react in less than 1/1,000th of a second to interrupt current during a fault, preventing potential hazards to people and equipment.

  4. OPTIMAL DISTRIBUTED POWER GENERATION UNDER NETWORK LOAD CONSTRAINTS,

    E-print Network

    Frank, Jason

    of novel components for decentral power generation (solar panels, small wind turbines and heat pumps). This gives rise to the question how many units of each type (solar panel, small wind turbine or central networks nowadays more and more customers are becoming power- producers, mainly because of the development

  5. Ac/Ds-transposon activation tagging in poplar: a powerful tool for gene discovery

    PubMed Central

    2012-01-01

    Background Rapid improvements in the development of new sequencing technologies have led to the availability of genome sequences of more than 300 organisms today. Thanks to bioinformatic analyses, prediction of gene models and protein-coding transcripts has become feasible. Various reverse and forward genetics strategies have been followed to determine the functions of these gene models and regulatory sequences. Using T-DNA or transposons as tags, significant progress has been made by using "Knock-in" approaches ("gain-of-function" or "activation tagging") in different plant species but not in perennial plants species, e.g. long-lived trees. Here, large scale gene tagging resources are still lacking. Results We describe the first application of an inducible transposon-based activation tagging system for a perennial plant species, as example a poplar hybrid (P. tremula L. × P. tremuloides Michx.). Four activation-tagged populations comprising a total of 12,083 individuals derived from 23 independent "Activation Tagging Ds" (ATDs) transgenic lines were produced and phenotyped. To date, 29 putative variants have been isolated and new ATDs genomic positions were successfully determined for 24 of those. Sequences obtained were blasted against the publicly available genome sequence of P. trichocarpa v2.0 (Phytozome v7.0; http://www.phytozome.net/poplar) revealing possible transcripts for 17 variants. In a second approach, 300 randomly selected individuals without any obvious phenotypic alterations were screened for ATDs excision. For one third of those transposition of ATDs was confirmed and in about 5% of these cases genes were tagged. Conclusions The novel strategy of first genotyping and then phenotyping a tagging population as proposed here is, in particular, applicable for long-lived, difficult to transform plant species. We could demonstrate the power of the ATDs transposon approach and the simplicity to induce ATDs transposition in vitro. Since a transposon is able to pass chromosomal boundaries, only very few primary transposon-carrying transgenic lines are required for the establishment of large transposon tagging populations. In contrast to T-DNA-based activation tagging, which is plagued by a lack of transformation efficiency and its time consuming nature, this for the first time, makes it feasible one day to tag (similarly to Arabidopsis) every gene within a perennial plant genome. PMID:22309468

  6. Load flow and state estimation algorithms for three-phase unbalanced power distribution systems

    NASA Astrophysics Data System (ADS)

    Madvesh, Chiranjeevi

    Distribution load flow and state estimation are two important functions in distribution energy management systems (DEMS) and advanced distribution automation (ADA) systems. Distribution load flow analysis is a tool which helps to analyze the status of a power distribution system under steady-state operating conditions. In this research, an effective and comprehensive load flow algorithm is developed to extensively incorporate the distribution system components. Distribution system state estimation is a mathematical procedure which aims to estimate the operating states of a power distribution system by utilizing the information collected from available measurement devices in real-time. An efficient and computationally effective state estimation algorithm adapting the weighted-least-squares (WLS) method has been developed in this research. Both the developed algorithms are tested on different IEEE test-feeders and the results obtained are justified.

  7. A power electronic transformer for PWM AC drive with lossless commutation and common-mode voltage suppression

    Microsoft Academic Search

    Kaushik Basu; N. Mohan

    2010-01-01

    This paper presents a novel dc\\/ac converter topology with a high frequency transformer-link for three-phase adjustable magnitude and frequency PWM ac drives. Such drives find wide range of applications including UPS systems and drives involving renewable energy sources like solar and fuel cells. One recent potential area of application is renewable energy sources like wind or wave connected with HVDC

  8. Development of transient power quality indices based on time-frequency distribution

    NASA Astrophysics Data System (ADS)

    Shin, Yong-June; Crapse, Philip

    2005-08-01

    For an assessment of the power quality in power distribution systems, classical Fourier series-based power quality indices are normally employed. The classical Fourier series-based power quality indices assume the periodicity of the disturbance so that the applications are limited to the harmonics. Hence, it is necessary for us to redefine power quality indices for the "transient" disturbances. In this paper, development of time-frequency based power quality indices are discussed for an assessment of transient power quality. The time and frequency localized information of the transient disturbance signals will be utilized for a new definition of the transient power quality indices. As an example of time-frequency based power quality indices, new definition of transient telephone interference factor has been carefully derived and verified in comparison with traditional telephone interference factor. Time-frequency based power quality indices allow one to quantify the effects of transient disturbances by time and frequency localized information.

  9. Estimation of initiating event distribution at nuclear power plants by Bayesian procedure

    SciTech Connect

    Chen Guangming [Morgan State Univ., Baltimore, MD (United States). Dept. of Industrial Engineering; Chu, T.L. [Brookhaven National Lab., Upton, NY (United States)

    1995-12-31

    Initiating events at nuclear power plants such as human errors or components failures may lead to a nuclear accident. The study of the frequency of these events or the distribution of the failure rate is necessary in probabilistic risk assessment for nuclear power plants. This paper presents Bayesian modelling methods for the analysis of the distribution of the failure rate. The method can also be utilized in other related fields especially where the data is sparse. An application of the Bayesian modelling in the analysis of distribution of the time to recover Loss of Off-Site Power ( LOSP) is discussed in the paper.

  10. Distributed Adaptive Power Allocation for Wireless Relay Networks

    Microsoft Academic Search

    Yonghui Li; Branka Vucetic; Zhendong Zhou; Mischa Dohler

    2007-01-01

    In this paper, we consider a 2-hop wireless diversity relay network. We explore transmit power allocation among the source and relays to maximize the received signal to noise ratio (SNR) at the destination. We consider two relay protocols, \\

  11. Distributed Throughput Maximization in Wireless Networks via Random Power Allocation

    E-print Network

    Modiano, Eytan H.

    We consider throughput-optimal power allocation in multi-hop wireless networks. The study of this problem has been limited due to the non-convexity of the underlying optimization problems, that prohibits an efficient ...

  12. Space power distribution system technology. Volume 3: Test facility design

    NASA Technical Reports Server (NTRS)

    Decker, D. K.; Cannady, M. D.; Cassinelli, J. E.; Farber, B. F.; Lurie, C.; Fleck, G. W.; Lepisto, J. W.; Messner, A.; Ritterman, P. F.

    1983-01-01

    The AMPS test facility is a major tool in the attainment of more economical space power. The ultimate goals of the test facility, its primary functional requirements and conceptual design, and the major equipment it contains are discussed.

  13. ACS Failure: ACS Side-1 failed on June 19, 2006

    E-print Network

    Sirianni, Marco

    ACS Failure: ACS Side-1 failed on June 19, 2006 · The loss of the +15V CEB power rail, which for the failure: 1. Interpoint Converter on LVPS3 board in MEB1 2. Short to ground in the transformer T6 on LVPS3 supplied power to both the WFC and HRC CEBs, precluded all CCD imaging. · Probable candidates

  14. Fuzzy logic based operated device identification in power distribution systems 

    E-print Network

    Manivannan, Karthick Muthu

    2002-01-01

    Fault location in distribution systems is a challenging task because of the lack of homogeneity in the system and due to uncertainity in the data used for estimating the faulted sections. Fuzzy logic has widely been applied for handling...

  15. Power-Demand Routing in massive geo-distributed systems

    E-print Network

    Qureshi, Asfandyar

    2010-01-01

    There is an increasing trend toward massive, geographically distributed systems. The largest Internet companies operate hundreds of thousands of servers in multiple geographic locations, and are growing at a fast clip. A ...

  16. Anode-cathode power distribution systems and methods of using the same for electrochemical reduction

    DOEpatents

    Koehl, Eugene R; Barnes, Laurel A; Wiedmeyer, Stanley G; Williamson, Mark A; Willit, James L

    2014-01-28

    Power distribution systems are useable in electrolytic reduction systems and include several cathode and anode assembly electrical contacts that permit flexible modular assembly numbers and placement in standardized connection configurations. Electrical contacts may be arranged at any position where assembly contact is desired. Electrical power may be provided via power cables attached to seating assemblies of the electrical contacts. Cathode and anode assembly electrical contacts may provide electrical power at any desired levels. Pairs of anode and cathode assembly electrical contacts may provide equal and opposite electrical power; different cathode assembly electrical contacts may provide different levels of electrical power to a same or different modular cathode assembly. Electrical systems may be used with an electrolyte container into which the modular cathode and anode assemblies extend and are supported above, with the modular cathode and anode assemblies mechanically and electrically connecting to the respective contacts in power distribution systems.

  17. Design Concepts for Power Distribution Equipment Serving Non-Linear Loads 

    E-print Network

    Massey, G. W.

    1995-01-01

    This paper explores the effects of power system harmonics induced by non-sinusoidal loads on electrical distribution equipment. The first portion examines the harmonic phenomenon to more fully understand harmonic current behavior from an intuitive...

  18. Investigation of anti-islanding schemes for utility interconnection of distributed fuel cell powered generations 

    E-print Network

    Jeraputra, Chuttchaval

    2006-04-12

    The rapid emergence of distributed fuel cell powered generations (DFPGs) operating in parallel with utility has brought a number of technical concerns as more DFPGs are connected to utility grid. One of the most challenging problems is known...

  19. GENERIC VERIFICATION PROTOCOL: DISTRIBUTED GENERATION AND COMBINED HEAT AND POWER FIELD TESTING PROTOCOL

    EPA Science Inventory

    This report is a generic verification protocol by which EPA?s Environmental Technology Verification program tests newly developed equipment for distributed generation of electric power, usually micro-turbine generators and internal combustion engine generators. The protocol will ...

  20. A Review of Power Electronics Based Microgrids 181 JPE 12-1-23 http://dx.doi.org/10.6113/JPE.2012.12.1.181

    E-print Network

    Chen, Zhe

    The increased penetration of Distributed Energy Resources (DER) is challenging the entire architecture is followed by the descriptions of system controls and power management strategies for AC microgrids. Finally, Power converters I. INTRODUCTION Liberalized electricity market, environmental concerns with greenhouse

  1. Power efficient distributed low-noise amplifier in 90 nm CMOS

    Microsoft Academic Search

    Brecht Machiels; Patrick Reynaert; Michiel Steyaert

    2010-01-01

    A low-power wideband distributed low-noise amplifier (DLNA) in 90 nm CMOS is presented. Various techniques have been combined in the design to increase the distributed amplifier's power efficiency. These techniques range from moderate inversion biasing to transmission line tapering. The measured gain of the 12.5 mW DLNA is larger than 15 dB from DC to 21 GHz. The average noise

  2. An algorithm for adaptive phase overcurrent protection of power distribution feeders

    E-print Network

    Flournoy, Caroll Lynn

    1989-01-01

    AN ALGORITHM FOR ADAPTIVE PHASE OVERCURRENT PROTECTION OF POWER DISTRIBUTION FEEDERS A Thesis by CAROLL LYNN FLOURNOY Submitted to the Office of Graduate Studies of Texas ARM University in partial fulfillment of the requirements... for the degree oi' MASTER OF SCIENCE December 1989 a~or Subject: Electrical Engineering AN ALGORITHM FOR ADAPTIVE PHASE OVERCURRENT PROTECTION OF POWER DISTRIBUTION FEEDERS A Thesis by CAROLL LYNN FLOL RNOY Approved as to style and content by: B. Don...

  3. Method of detecting the direction of arcing faults on power distribution feeders

    E-print Network

    Fernando, W. Anand Krisantha

    1992-01-01

    METHOD OF DETECTING THE DIRECTION OF ARCING FAULTS ON POWER DISTRIBUTION FEEDERS A Thesis by W. ANAND KRISANTHA FERNANDO Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements... for the degree of MASTER OF SCIENCE May 1992 Major Subject: Electrical Engineering METHOD OF DETECTING THE DIRECTION OF ARCING FAULTS ON POWER DISTRIBUTION FEEDERS A Thesis by W. ANAND KRISANTHA FERNANDO Approved as to style and content by: B. Don...

  4. Method of detecting the direction of arcing faults on power distribution feeders 

    E-print Network

    Fernando, W. Anand Krisantha

    1992-01-01

    METHOD OF DETECTING THE DIRECTION OF ARCING FAULTS ON POWER DISTRIBUTION FEEDERS A Thesis by W. ANAND KRISANTHA FERNANDO Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements... for the degree of MASTER OF SCIENCE May 1992 Major Subject: Electrical Engineering METHOD OF DETECTING THE DIRECTION OF ARCING FAULTS ON POWER DISTRIBUTION FEEDERS A Thesis by W. ANAND KRISANTHA FERNANDO Approved as to style and content by: B. Don...

  5. The characteristics of arcing faults in 480-volt power distribution systems 

    E-print Network

    Shih, Yu?

    1994-01-01

    THE CHARACTERISTICS OF ARCING FAULTS IN 480-VOLT POWER DISTRIBUTION SYSTEMS A Thesis by YU SHI Submitted to the Office of Graduate Studies of Texas ASM University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE... December 1994 Major Subject: Electrical Engineering THE CHARACTERISTICS OF ARCING FAULTS IN 480-VOLT POWER DISTRIBUTION SYSTEMS A Thesis by YU SHI Submitted to Texas ARM University in partial fulfillment of the requirements for the degree...

  6. Power-profile Driven Variable Voltage Sealing for Heterogeneous Distributed Real-time Embedded Systems

    Microsoft Academic Search

    Jiong Luo; Niraj K. Jha

    2003-01-01

    Presents a power-aware real-time distributed embedded system scheduling algorithm. It tries to satisfy the hard real-time constraints and precedence relationships of the tasks in the distributed embedded system specification. At the same time, it performs variable voltage scaling by addressing variations in power consumption of different tasks and characteristics of different voltage-scalable processing elements (PEs) in an effective and efficient

  7. Power-Efficient Scheduling for Heterogeneous Distributed Real-Time Embedded Systems

    Microsoft Academic Search

    Jiong Luo; Niraj K. Jha

    2007-01-01

    This paper addresses the problem of variable-voltage scheduling of multirate periodic task graphs (i.e., tasks with precedence relationships) in heterogeneous distributed real-time embedded systems. Such an embedded system may contain general-purpose processors, field-programmable gate arrays, and application-specific integrated circuits. First, we discuss the implications of the distribution of power consumption, i.e., power profile, of tasks and characteristics of voltage-scalable processing

  8. Power-law and exponential rank distributions: A panoramic Gibbsian perspective

    NASA Astrophysics Data System (ADS)

    Eliazar, Iddo

    2015-04-01

    Rank distributions are collections of positive sizes ordered either increasingly or decreasingly. Many decreasing rank distributions, formed by the collective collaboration of human actions, follow an inverse power-law relation between ranks and sizes. This remarkable empirical fact is termed Zipf's law, and one of its quintessential manifestations is the demography of human settlements - which exhibits a harmonic relation between ranks and sizes. In this paper we present a comprehensive statistical-physics analysis of rank distributions, establish that power-law and exponential rank distributions stand out as optimal in various entropy-based senses, and unveil the special role of the harmonic relation between ranks and sizes. Our results extend the contemporary entropy-maximization view of Zipf's law to a broader, panoramic, Gibbsian perspective of increasing and decreasing power-law and exponential rank distributions - of which Zipf's law is one out of four pillars.

  9. Application of the mobility power flow approach to structural response from distributed loading

    NASA Technical Reports Server (NTRS)

    Cuschieri, J. M.

    1988-01-01

    The problem of the vibration power flow through coupled substructures when one of the substructures is subjected to a distributed load is addressed. In all the work performed thus far, point force excitation was considered. However, in the case of the excitation of an aircraft fuselage, distributed loading on the whole surface of a panel can be as important as the excitation from directly applied forces at defined locations on the structures. Thus using a mobility power flow approach, expressions are developed for the transmission of vibrational power between two coupled plate substructures in an L configuration, with one of the surfaces of one of the plate substructures being subjected to a distributed load. The types of distributed loads that are considered are a force load with an arbitrary function in space and a distributed load similar to that from acoustic excitation.

  10. Explaining the Power-law Distribution of Human Mobility Through Transportation Modality Decomposition

    E-print Network

    Zhao, Kai; Hui, Pan; Rao, Weixiong; Tarkoma, Sasu

    2014-01-01

    Human mobility has been empirically observed to exhibit Levy flight characteristics and behaviour with power-law distributed jump size. The fundamental mechanisms behind this behaviour has not yet been fully explained. In this paper, we analyze urban human mobility and we propose to explain the Levy walk behaviour observed in human mobility patterns by decomposing them into different classes according to the different transportation modes, such as Walk/Run, Bicycle, Train/Subway or Car/Taxi/Bus. Our analysis is based on two real-life GPS datasets containing approximately 10 and 20 million GPS samples with transportation mode information. We show that human mobility can be modelled as a mixture of different transportation modes, and that these single movement patterns can be approximated by a lognormal distribution rather than a power-law distribution. Then, we demonstrate that the mixture of the decomposed lognormal flight distributions associated with each modality is a power-law distribution, providing an e...

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

    SciTech Connect

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

    2010-04-15

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

  12. Multiple voltage electrical power distribution system for automotive applications

    Microsoft Academic Search

    John M. Miller

    1996-01-01

    Over the course of the 20th Century, the automobile electrical system has experienced one architectural change, one significant electrical power plant change and one notable change in the electrical storage component. There is now growing disparity in voltage level requirements between electronic and electrical loads to the point that a single voltage system may no longer be the most efficient

  13. Protecting Intelligent Distributed Power Grids against Cyber Attacks

    SciTech Connect

    Dong Wei; Yan Lu; Mohsen Jafari; Paul Skare; Kenneth Rohde

    2010-12-31

    Like other industrial sectors, the electrical power industry is facing challenges involved with the increasing demand for interconnected operations and control. The electrical industry has largely been restructured due to deregulation of the electrical market and the trend of the Smart Grid. This moves new automation systems from being proprietary and closed to the current state of Information Technology (IT) being highly interconnected and open. However, while gaining all of the scale and performance benefits of IT, existing IT security challenges are acquired as well. The power grid automation network has inherent security risks due to the fact that the systems and applications for the power grid were not originally designed for the general IT environment. In this paper, we propose a conceptual layered framework for protecting power grid automation systems against cyber attacks. The following factors are taken into account: (1) integration with existing, legacy systems in a non-intrusive fashion; (2) desirable performance in terms of modularity, scalability, extendibility, and manageability; (3) alignment to the 'Roadmap to Secure Control Systems in the Energy Sector' and the future smart grid. The on-site system test of the developed prototype security system is briefly presented as well.

  14. Centralised and distributed power allocation algorithms in cooperative networks

    Microsoft Academic Search

    J. Adeane; M. R. D. Rodrigues; I. J. Wassell

    2005-01-01

    Cooperation among network nodes provides transmit diversity in cases where wireless transmitters, due to size and power limitation, cannot support multiple antennas. We consider cooperation among M nodes, where each node achieves space diversity by using other nodes' antennas as relays. Cooperation among nodes has been shown to achieve impressive bit error rate (BER) gains as compared to a non-cooperative

  15. Delay time distribution of high power microwave surface flashover

    Microsoft Academic Search

    J. Foster; H. Krompholz; A. Neuber

    2011-01-01

    Breakdown phenomena in a high power microwave (HPM) system present unique obstacles for the further development of HPM technology. The non-uniformity of a high frequency electric field and the statistics associated with breakdown in general along with the stochastic nature of naturally occurring electron generating mechanisms introduce significant challenges for predicting and preventing breakdown occurrences within a HPM system. An

  16. Transient temperature distribution of a power reactor fuel element

    Microsoft Academic Search

    R. Forghieri; G. Orru; G. Papa

    1973-01-01

    From 1st international conference on structural mechanics in reactor ; technology; Berlin, Federal Republic of Germany (20 Sep A mathematical model for ; the dynamic heat transfer of a power reactor with a cylindrical type fuel element ; is presented. The cylindrical fuel element is composed of a hollow fuel core and ; its cladding separated by a vacuum gap:

  17. Allocation of power in medium voltage DC distribution circuits

    Microsoft Academic Search

    George L. Kusic

    2011-01-01

    in this paper, dynamic programming is applied to forthcoming medium voltage direct current (MVDC) substations which have a mixture of power sources, renewable energy, and storage. Technical changes in the substation due to the dc equipment, efficiency of the substation, and protective measures are major aspects to consider in the MVDC development. The paper demonstrates how dynamic programming can minimize

  18. Effects of assembly local power distribution on storage rack criticality

    Microsoft Academic Search

    M. Todosow; J. F. Carew

    1985-01-01

    Fuel storage rack criticality calculations have been performed for a set of 8 x 8 BWR k infinity-equivalent fuel bundles. The results of these calculations indicate that the storage rack multiplication factor is not determined solely by the k infinity's of the individual fuel assemblies, but is also sensitive to the local power, and underlying enrichment, burnable poison, water hole,

  19. Distributed Generation Interconnection Planning: A Wind Power Case Study

    Microsoft Academic Search

    Sheng-Yi Su; Chan-Nan Lu; Rung-Fang Chang; Guillermo Gutierrez-Alcaraz

    2011-01-01

    There is increasing requests for noncontrollable distribution generation (DG) interconnections in the medium and low voltage networks. Many studies have suggested that with proper system planning, DG could provide benefits such as reliability enhancement, investment deferment, and reduced losses. However, without network reinforcements, the allowable interconnection capacity in a network is often restricted due to fault current level, voltage variation,

  20. Distributed generation islanding-implications on power system dynamic performance

    Microsoft Academic Search

    R. A. Walling; N. W. Miller

    2002-01-01

    Distributed generation can potentially support unintentional system islands, isolated from the remainder of the system. These islands pose a significant risk to safety and equipment, and need to be quickly detected and eliminated. Islands are detected by sensitive under- and over-voltage and frequency functions, sometimes aided by active island destabilization techniques. Both the passive voltage and frequency trip point and

  1. Implementation of distributed generation technologies in isolated power systems

    Microsoft Academic Search

    Andreas Poullikkas

    2007-01-01

    In this work a parametric cost–benefit analysis concerning the use of distributed generation (DG) technologies for isolated systems, such as in the case of Cyprus is carried out. In particular, the potential market and the different technologies of various DG options are presented and a parametric study is carried out with variations in capital cost of the various candidate DG

  2. Distributed Leadership: The Uses and Abuses of Power

    ERIC Educational Resources Information Center

    Lumby, Jacky

    2013-01-01

    In about a decade the theory of distributed leadership has moved from a tool to better understand the ecology of leadership to a widely prescribed practice. This article considers how to account for its spread and dominance and what purpose it serves. The concept offers an enticing suggestion of including more in leadership, and even sometimes…

  3. Distributed Power Generation: Requirements and Recommendations for an ICT Architecture

    E-print Network

    Appelrath, Hans-Jürgen

    , and communication and security challenges are ad- dressed. Keywords: Information and Communication Technologies (ICT conversion of resources that will eventually expire like burning oil and coal or fission. There are two main to distribute the energy to the consumers. Besides, both the process of converting raw material as well

  4. Distributed OFDMA Resource and Power Allocation Using Gibbs Sampling Methods

    E-print Network

    Paris-Sud XI, Université de

    sampling based algorithms to perform a distributed optimization that would lead to the global optimum number of BSs. Various stochastic optimization methods have been intro- ducedsuch as particle swarm optimization, genetic algorithm, ant colony or tabu search [4]. These approaches generally require a knowledge

  5. Recognizing animal-caused faults in power distribution systems using artificial neural networks

    Microsoft Academic Search

    Mo Yuen Chow; S. O. Yee; L. S. Taylor

    1993-01-01

    Faults are likely to occur in most power distribution systems. If the causes of the faults are known, specific action can be taken to eliminate the fault sources as soon as possible to avoid unnecessary costs, such as power system down-time cost, that are caused by failing to identify the fault sources. However, experts that can accurately recognize the causes

  6. Maximum Effective Distance of On-Chip Decoupling Capacitors in Power Distribution Grids

    E-print Network

    Friedman, Eby G.

    Maximum Effective Distance of On-Chip Decoupling Capacitors in Power Distribution Grids Mikhail@freescale.com ABSTRACT Decoupling capacitors are widely used to reduce power sup- ply noise. On-chip decoupling capacitors have traditionally been allocated into the available white space on a die. The efficacy

  7. Geographical distribution of agricultural residues and optimum sites of biomass based power plant in Bathinda, Punjab

    Microsoft Academic Search

    Jagtar Singh; B. S. Panesar; S. K. Sharma

    2011-01-01

    Agricultural residues are spatially scattered in Punjab. The spatial distribution and associated costs on collection and transportation of this resource are the critical factor in planning the biomass based power plants. This paper presents a case study of Bathinda district of Punjab, using geographical information system to evaluate the feasibility of setting up biomass based power plants and optimizing their

  8. Co-design of signal, power, and thermal distribution networks for 3D ICs

    Microsoft Academic Search

    Young-joon Lee; Yoon Jo Kim; Gang Huang; Muhannad Bakir; Yogendra Joshi; Andrei Fedorov; Sung Kyu Lim

    2009-01-01

    Heat removal and power delivery are two major reliability concerns in the 3D stacked IC technology. Liquid cooling based on micro-fluidic channels is proposed as a viable solution to dramatically reduce the operating temperature of 3D ICs. In addition, designers use a highly complex hierarchical power distribution network in conjunction with decoupling capacitors to deliver currents to all parts of

  9. Co-Optimization of Signal, Power, and Thermal Distribution Networks for 3D ICs

    Microsoft Academic Search

    Young-Joon Lee; Sung Kyu Lim

    2009-01-01

    Heat removal and power delivery are two major reliability concerns in the 3D stacked IC technology. Liquid cooling based on micro- fluidic channels is proposed as a viable solution to dramatically reduce the operating temperature of 3D ICs. In addition, designers use a highly complex hierarchical power distribution network in conjunction with decoupling capacitors to deliver currents. However, these thermal

  10. Co-Optimization of signal, power, and thermal distribution networks for 3D ICs

    Microsoft Academic Search

    Young-Joon Lee; Sung Kyu Lim

    2008-01-01

    Heat removal and power delivery are two major reliability concerns in the 3D stacked IC technology. Liquid cooling based on micro-fluidic channels is proposed as a viable solution to dramatically reduce the operating temperature of 3D ICs. In addition, designers use a highly complex hierarchical power distribution network in conjunction with decoupling capacitors to deliver currents. However, these thermal and

  11. Power harvesting for smart sensor networks in monitoring water distribution system

    Microsoft Academic Search

    M. I. Mohamed; W. Y. Wu; M. Moniri

    2011-01-01

    Recently, there has been a growing interest in using wireless sensor networks for monitoring water distribution infrastructure to help drinking water utilities to have better understanding of hydraulic and water quality statement of their underground assets. One of the challenges is limited power resources for operating the smart sensors and sensor networks. Current common used power supplies for sensor node

  12. Predicting the Power Output of Distributed Renewable Energy Resources within a Broad Geographical Region

    E-print Network

    Chalkiadakis, Georgios

    Predicting the Power Output of Distributed Renewable Energy Resources within a Broad Geographical- mental concerns regarding their use growing, the generation of power from renewable energy sources has been hailed as the way forward to an energy-sufficient future. Renewable energy sources, however

  13. Power, bureaucracy, influence, and performance: Their relationships in industrial distribution channels

    Microsoft Academic Search

    F. Robert Dwyer

    1995-01-01

    Set in an industrial product distribution channel, the authors investigate the relationship between: (1) a supplier's power and its use of influence tactics with a distributor, (2) the level of bureaucracy (operationalized as centralization and formalization) with use of influence, (3) influence use and relationship performance, and (4) bureaucracy and performance. A series of structural equation models revealed that high-power

  14. High power singlemode GaInAs lasers with distributed Bragg reflectors

    NASA Technical Reports Server (NTRS)

    O'Brien, S.; Parke, R.; Welch, D. F.; Mehuys, D.; Scifres, D.

    1992-01-01

    High power singlemode strained GaInAs lasers have been fabricated which use buried second order gratings as distributed Bragg reflectors. The lasers operate in an edge emitting fashion with CW powers in excess of 110 mW with single longitudinal and transverse mode operation at 971.9 nm up to 42 mW.

  15. Effect of substrate resistivity on switching noise in on-chip power distribution networks

    Microsoft Academic Search

    Jifeng Mao; M. Swaminathan; J. Libous; D. O'Connor

    2003-01-01

    This paper describes the effect of substrate loss on simultaneous switching noise (SSN) in on-chip power distribution networks (PDN). Conformal mapping and first-order Debye approximation based Finite Difference Time Domain (FDTD) have been used for model extraction and time domain simulation with frequency dependent parameters, respectively. The importance of substrate loss on power supply noise has been quantified in this

  16. Distributing Power to Electric Vehicles on a Smart Grid Yingjie Zhou*,

    E-print Network

    Maxemchuk, Nicholas F.

    Distributing Power to Electric Vehicles on a Smart Grid Yingjie Zhou*, , Student Member, IEEE.edu Abstract--Electric vehicles create a demand for additional electrical power. As the popularity of electric. However, in the interim the rate at which electric vehicles can be deployed will depend on our ability

  17. Power Control and Number of Antenna Elements in CDMA Distributed Antenna Systems \\Lambda

    E-print Network

    Yanikomeroglu, Halim

    Power Control and Number of Antenna Elements in CDMA Distributed Antenna Systems \\Lambda Halim, the dynamic range of the power control decreases. It is demonstrated that by using a DA system with as small of antenna elements in a CDMA dis­ tributed antenna (DA) system and the yielding reverse link SIR

  18. Electrical Power Transmission and Distribution Safety. Module SH-40. Safety and Health.

    ERIC Educational Resources Information Center

    Center for Occupational Research and Development, Inc., Waco, TX.

    This student module on electrical power transmission and distribution safety is one of 50 modules concerned with job safety and health. This module focuses on some of the general safety rules, techniques, and procedures that are essential in establishing a safe environment for the electrical power transmission worker. Following the introduction,…

  19. Power distribution networks for system-on-package: status and challenges

    Microsoft Academic Search

    Madhavan Swaminathan; Joungho Kim; Istvan Novak; James P. Libous

    2004-01-01

    The power consumption of microprocessors is increasing at an alarming rate leading to 2X reduction in the power distribution impedance for every product generation. In the last decade, high I\\/O ball grid array (BGA) packages have replaced quad flat pack (QFP) packages for lowering the inductance. Similarly, multilayered printed circuit boards loaded with decoupling capacitors are being used to meet

  20. Solar-thermal electric power generation using a system of distributed parabolic trough collectors

    Microsoft Academic Search

    J. W. Ramsey; E. M. Sparrow; E. R. G. Eckert

    1975-01-01

    The paper describes a solar-thermal collection and transport system for electric power generation. The system employs water as the working fluid; steam at 60 bars pressure and 276 C is generated locally by distributed parabolic solar collectors. A transfer loop conveys the steam to a central site at which the power plant is situated. The design of the collector and

  1. Using Batteries to Reduce the Power Costs of Internet-scale Distributed

    E-print Network

    Berger, Emery

    Demand(KWs) Energy (KWHs) #12;Key Idea: Use batteries to reduce the power supply from Psupply to Pbatt (+ safetyUsing Batteries to Reduce the Power Costs of Internet-scale Distributed Networks Darshan S), cb = cost of battery ($/KWH), B= battery size, L = battery lifetime. #12;Alternate view: Use

  2. Distributed Algorithm for Power Aware Minimum Connected Dominating Set for Routing in Wireless Ad Hoc Network

    Microsoft Academic Search

    Tamaghna Acharya; Rajarshi Roy

    2005-01-01

    In this paper we have proposed a distributed algorithm for finding power aware connected dominating set in a graph representing an ad hoc network. Our simulation indicates that we always formulate power aware dominating sets using our method. The dominating sets we obtain are in general smaller in size compared to the same obtained by Wu et al. (2001). We

  3. Positive Feed-Forward Control Scheme for Distributed Power Conversion System With Multiple Voltage Sources

    Microsoft Academic Search

    Ray-Lee Lin; Po-Yao Yeh; Ching-Hsiung Liu

    2012-01-01

    This paper presents the positive feed-forward control (PFFC) scheme associated with the average current-mode control (ACMC) scheme for the distributed power conversion system with the multiple voltage sources of different power ratings to protect individual voltage sources from the chain reaction of the undervoltage lockout in order not to cause system voltage collapse. The ACMC scheme has the inherent function

  4. Distributed Battery Control to Improve Peak Power Shaving Efficiency in Data Centers

    E-print Network

    Simunic, Tajana

    Distributed Battery Control to Improve Peak Power Shaving Efficiency in Data Centers Baris Aksanli, Eddie Pettis and Tajana S. Rosing UCSD, Google Stored energy in batteries can be used to cap peak power.8% 99% 91.5% 84% Battery Configuration StudyBattery Configuration Study Goal: Improve the overall

  5. Distributed multi-agent microgrids: a decentralized approach to resilient power system self-healing

    Microsoft Academic Search

    C. M. Colson; M. H. Nehrir; R. W. Gunderson

    2011-01-01

    The predominance of recent self-healing power system research has been directed towards centralized command and control functions. In this paper, a decentralized multi-agent control method for distributed microgrids is introduced. Given the complexity of a large power system spanning hundreds of miles and comprised of numerous microgrids, it is potentially unrealistic to expect that centralizing total system control functions is

  6. A laboratory based microgrid and distributed generation infrastructure for studying connectivity issues to operational power systems

    Microsoft Academic Search

    O. A. Mohammed; M. A. Nayeem; A. K. Kaviani

    2010-01-01

    This paper presents an infrastructure and laboratory implementation of a hardware test-bed system emulating alternate sources and conventional power plant emulators connected as a complete power system. The distributed generation components were connected to the test-bed to study the issues of connecting alternates and various types of loads during operations. The various sources and loads can be connected in varying

  7. Algorithms for distributed decision-making for multi-agent microgrid power management

    Microsoft Academic Search

    C. M. Colson; M. H. Nehrir

    2011-01-01

    A key component to future smart grids may be microgrid systems capable of integrating generation, load, and storage assets into an autonomous power system entity. As a potential building block for expanding power networks, microgrids can enable the broad integration of distributed energy resources (DER), as well as providing customers a means to optimize local assets based on multiple objectives.

  8. Power distribution synthesis for analog and mixed-signal ASICs in RAIL

    Microsoft Academic Search

    Balsha R. Stanisic; Rob A. Rutenbar; L. Richard Carley

    1993-01-01

    The authors present new power distribution synthesis techniques that can handle realistic analog and mixed-signal performance concerns. The key ideas are to employ asymptotic waveform evaluation techniques to reduce complex macro, substrate, and package electrical models to accurate, low-order analytical expressions that can be quickly evaluated by a simulated annealing optimizer that selects and sizes the power bus topology while

  9. Independent Orbiter Assessment (IOA): Analysis of the electrical power distribution and control/electrical power generation subsystem

    NASA Technical Reports Server (NTRS)

    Patton, Jeff A.

    1986-01-01

    The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA approach features a top-down analysis of the hardware to determine failure modes, criticality, and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. This report documents the independent analysis results corresponding to the Orbiter Electrical Power Distribution and Control (EPD and C)/Electrical Power Generation (EPG) hardware. The EPD and C/EPG hardware is required for performing critical functions of cryogenic reactant storage, electrical power generation and product water distribution in the Orbiter. Specifically, the EPD and C/EPG hardware consists of the following components: Power Section Assembly (PSA); Reactant Control Subsystem (RCS); Thermal Control Subsystem (TCS); Water Removal Subsystem (WRS); and Power Reactant Storage and Distribution System (PRSDS). The IOA analysis process utilized available EPD and C/EPG hardware drawings and schematics for defining hardware assemblies, components, and hardware items. Each level of hardware was evaluated and analyzed for possible failure modes and effects. Criticality was assigned based upon the severity of the effect for each failure mode.

  10. Optimal Power Allocation for Distributed Detection over MIMO Channels in Wireless Sensor Networks

    Microsoft Academic Search

    Xin Zhang; H. Vincent Poor; Mung Chiang

    2007-01-01

    In distributed detection systems with wireless sensor networks, the communication between sensors and a fusion center is not perfect due to interference and limited transmitter power at the sensors to combat noise at the fusion center's receive r. The problem of optimizing detection performance with such imperfect communication brings a new challenge to distributed detection. In this paper, sensors are

  11. New Certification Program Available for Distributed Generation and Combined Heat and Power Professionals

    Microsoft Academic Search

    Barney L. Capehart; Wayne C. Turner; Carl E. Salas; Steven A. Parker

    2003-01-01

    The Association of Energy Engineers recently created a new certification program for distributed generation and combined heat and power professionals. The purpose of this article is to discuss this new program, describe a new distributed generation course that will soon be offered, and explain the topics that will be covered by the certification examination. The article then outlines the certification

  12. INTELLIGENT MONITORING SYSTEM WITH HIGH TEMPERATURE DISTRIBUTED FIBEROPTIC SENSOR FOR POWER PLANT COMBUSTION PROCESSES

    Microsoft Academic Search

    Kwang Y. Lee; Stuart S. Yin; Andre Boheman

    2003-01-01

    The objective of the proposed work is to develop an intelligent distributed fiber optical sensor system for real-time monitoring of high temperature in a boiler furnace in power plants. Of particular interest is the estimation of spatial and temporal distributions of high temperatures within a boiler furnace, which will be essential in assessing and controlling the mechanisms that form and

  13. Intelligent Monitoring System With High Temperature Distributed Fiberoptic Sensor For Power Plant Combustion Processes

    Microsoft Academic Search

    Kwang Y. Lee; Stuart S. Yin; Andre Boheman

    2005-01-01

    The objective of the proposed work is to develop an intelligent distributed fiber optical sensor system for real-time monitoring of high temperature in a boiler furnace in power plants. Of particular interest is the estimation of spatial and temporal distributions of high temperatures within a boiler furnace, which will be essential in assessing and controlling the mechanisms that form and

  14. INTELLIGENT MONITORING SYSTEM WITH HIGH TEMPERATURE DISTRIBUTED FIBEROPTIC SENSOR FOR POWER PLANT COMBUSTION PROCESSES

    Microsoft Academic Search

    Kwang Y. Lee; Stuart S. Yin; Andre Boheman

    2004-01-01

    The objective of the proposed work is to develop an intelligent distributed fiber optical sensor system for real-time monitoring of high temperature in a boiler furnace in power plants. Of particular interest is the estimation of spatial and temporal distributions of high temperatures within a boiler furnace, which will be essential in assessing and controlling the mechanisms that form and

  15. On-line Power Savings in a Distributed Multi-stage Router Architecture

    E-print Network

    On-line Power Savings in a Distributed Multi-stage Router Architecture Andrea Bianco, Fikru on a distributed multi-stage software router (MSSR) architecture internally composed by several per- sonal computers (PCs) to overcome scalability and performance issues of software routers (SRs) based on a single

  16. A Distributed State Estimator for Electric Power Systems in Avionic and Naval Applications

    Microsoft Academic Search

    G. D'Antona; A. Monti; F. Ponci; L. Rocca

    2006-01-01

    This paper shows the performance of a state estimator based on a distributed Kalman filter applied to an electric power system for avionic and naval applications. The main characteristics of this type of approach are firstly the increased computational efficiency, due to the parallel distribution of the computational burden among the local estimators, and secondly an increased reliability of the

  17. Independent power producer parallel operation modeling in transient network simulations for interconnected distributed generation studies

    Microsoft Academic Search

    Fabrício A. M. Moura; José R. Camacho; Marcelo L. R. Chaves; Geraldo C. Guimarães

    2010-01-01

    The main task in this paper is to present a performance analysis of a distribution network in the presence of an independent power producer (IP) synchronous generator with its speed governor and voltage regulator modeled using TACS –Transient Analysis of Control Systems, for distributed generation studies. Regulators were implemented through their transfer functions in the S domain. However, since ATP-EMTP

  18. Application of RF Circuit Design Principles to Distributed Power Converters

    Microsoft Academic Search

    Ronald J. Gutmann

    1980-01-01

    The application of RF circuit design principles to high-frequency power converters is described. Compared to conventional converter design, emphasis is placed on obtaining sinusoidal-type waveforms (instead of rectangular-type waveforms) to minimize device switching time requirements and alleviate transforming requirements. A 25-W 48-V to 5-V dc-to-dc converter design using a 5-MHz switching frequency is presented illustrating these principles, using a Class

  19. Effects of assembly local power distribution on storage rack criticality

    Microsoft Academic Search

    M. Todosow; J. F. Carew

    1985-01-01

    Fuel storage rack criticality calculations have been performed for a set of 8 x 8 BWR k\\/sub infinity\\/-equivalent fuel bundles. The results of these calculations indicate that the storage rack multiplication factor is not determined solely by the k\\/sub infinity\\/'s of the individual fuel assemblies, but is also sensitive to the local power, and underlying enrichment, burnable poison, water hole

  20. Steady-State Model and Power Flow Analysis of Electronically-Coupled Distributed Resource Units

    Microsoft Academic Search

    Hassan Nikkhajoei; Reza Iravani

    2007-01-01

    This paper presents closed-form steady-state, fundamental-frequency models of power electronic converter systems for coupling distributed resource (DR) units to the utility power grid. Based on the developed models, the paper introduces a two-step power flow analysis approach that accurately and efficiently represents electronically-coupled DR units. A feature of the proposed approach is that it solves for the internal variables of

  1. The harmonic impact of variable speed air conditioners on residential power distribution

    Microsoft Academic Search

    Richard S. Wallace; A. Variable-Speed Air Conditioners

    1992-01-01

    Power electronic circuits fed directly from electric utility power systems are often the source of significant harmonic currents. The susceptibility of residential power distribution systems to harmonics generated by inverter-driven variable-speed air conditioners, which are expected to see wider application in the future, is examined. In general, variable-speed air conditioners are 15-40% more energy efficient than comparable single-speed air conditioners.

  2. Progress in Development of a Low Energy Reaction Cell for Distributed Power Applications

    Microsoft Academic Search

    G. H. Miley; C. Castano; A. Lipson; S. O. Kim; N. Luo

    2002-01-01

    Power units using Low Energy Nuclear Reactions (LENRs) potentially offer a radical new approach to power units that could provide distributed power units in the 1-50 kW range. As described in prior ICONE papers [9, 23] these cells employ thin metallic film cathodes (order of 500 Angstrom, using variously Ni, Pd and Ti) with electrolytes such as 0.5-1 molar lithium

  3. Impact of Distributed Wind on Bulk Power System Operations in ISO-NE (Presentation)

    SciTech Connect

    Brancucci Martinez-Anido, C.; Hodge, B. M.; Palchak, D.; Miettinen, J.

    2014-11-01

    The work presented in the paper corresponding to this presentation aims to study the impact of a range of penetration levels of distributed wind on the operation of the electric power system at the transmission level. This presentation is an overview of a case study on the power system in Independent System Operator New England. It is analyzed using PLEXOS, a commercial power system simulation tool

  4. Two-level network architecture for open-access power systems with distributed generations

    Microsoft Academic Search

    Helen Cheung; Lin Wang; Alexander Hamlyn; Frank Chen; Cungang Yang; Richard Cheung

    2008-01-01

    Recently increased use of network-enabled devices in power systems, rapid development of distributed generations from renewable energy resources, and government-imposed open access competition have resulted utilities in greater reliance on computer networks for proper power grid operations. This paper proposes a new two-level architecture for power-grid computer networks and to strength the networks' security. A new network access control strategy

  5. A floorplan-based planning methodology for power and clock distribution in ASICs

    Microsoft Academic Search

    Joon-Seo Yim; Seong-Ok Bae; Chong-Min Kyung

    1999-01-01

    In deep submicron technology, IR-drop and clock skew issues become more crucial to the functionality of chip. This paper presents a floorplan-based power and clock distribution methodology for ASIC design. From the floorplan and the estimated power consumption, the power network size is determined at an early design stage. Next, without detailed gate-level netlist, clock interconnect sizing, the number and

  6. Proposal of a hybrid rectifier structure with HPF and low THD suitable for front-end trolleybuses systems supplied by AC distribution networks

    Microsoft Academic Search

    Luiz C. G. Freitas; Gustavo B. Lima; Flávio A. S. Gonçalves; Guilherme A. Melo; Carlos A. Canesin

    2009-01-01

    This paper presents the development and the experimental analysis of a new single-phase hybrid rectifier structure with high power factor (PF) and low harmonic distortion of current (THDI), suitable for application in traction systems of electrical vehicles pulled by electrical motors (trolleybus), which are powered by urban distribution network. This front-end rectifier structure is capable of providing significant improvements in

  7. Power-law relationship and self-similarity in the itemset support distribution: analysis and applications

    Microsoft Academic Search

    Kun-ta Chuang; Jiun-long Huang; Ming-syan Chen

    2008-01-01

    In this paper, we identify and explore that the power-law relationship and the self-similar phenomenon appear in the itemset\\u000a support distribution. The itemset support distribution refers to the distribution of the count of itemsets versus their supports.\\u000a Exploring the characteristics of these natural phenomena is useful to many applications such as providing the direction of\\u000a tuning the performance of the

  8. A Power Distribution System for the AMS experiment on the International Space Station

    NASA Astrophysics Data System (ADS)

    Kim, K. S.; Capell, M.; Lebedev, A.; Viertel, G. M.; Yang, J.

    2006-12-01

    The Alpha Magnetic Spectrometer (AMS) experiment on the International Space Station (ISS) requires a fully redundant, highly efficient, space qualified power distribution system. The device receives up to 2.8 kW of electrical power from the ISS and distributes it to the various subsystems of the experiment. The majority of these subsystems require the power to be converted from the ISS delivered nominal voltage level of 120 VDC to 28 VDC. The entire system and the individual output channels will be monitored and controlled from the Control Centers on the ground.

  9. Low-power clock distribution circuits for the Macro Pixel ASIC

    NASA Astrophysics Data System (ADS)

    Gaioni, L.; De Canio, F.; Manghisoni, M.; Ratti, L.; Re, V.; Traversi, G.; Marchioro, A.; Kloukinas, K.

    2015-01-01

    Clock distribution circuits account for a significant fraction of the power dissipation of the Macro Pixel ASIC (MPA), designed for the pixel layer readout of the so-called Pixel-Strip module in the innermost part of the CMS tracker at the HL-LHC. This work reviews different CMOS circuit architectures envisioned for low power clock distribution in the MPA. Two main topologies will be discussed, based on standard supply voltage and on auxiliary, reduced supply. Circuit performance, in terms of power consumption and speed, is evaluated for each of the proposed solutions and compared with that relevant to standard CMOS drivers.

  10. The equivalence of isothermal and non-isothermal power law distributions with temperature duality

    NASA Astrophysics Data System (ADS)

    Zheng, Yahui; Du, Jiulin

    2015-06-01

    The concept of temperature duality states that the physical temperature and Lagrange temperature both have physical sense in the nonextensive system. By use of this concept, the isothermal power law distribution and the non-isothermal power law distribution are equivalent to each other when the detailed balance is satisfied. Also, the polytropic equation in stellar system and self-gravitating gaseous system can be deduced from both of these two distributions. This indicates that the polytropic system exhibits some 'equilibrium' configuration which, in the stellar system, is probably the result of so called 'violent relaxation'.

  11. The integration of renewable energy sources into electric power distribution systems. Volume 1: National assessment

    SciTech Connect

    Barnes, P.R.; Van Dyke, J.W. [Oak Ridge National Lab., TN (United States); Tesche, F.M. [6714 Norway Road, Dallas, TX (United States); Zaininger, H.W. [Zaininger Engineering Co., San Jose, CA (United States)

    1994-06-01

    Renewable energy technologies such as photovoltaic, solar thermal electricity, and wind turbine power are environmentally beneficial sources of electric power generation. The integration of renewable energy sources into electric power distribution systems can provide additional economic benefits because of a reduction in the losses associated with transmission and distribution lines. Benefits associated with the deferment of transmission and distribution investment may also be possible for cases where there is a high correlation between peak circuit load and renewable energy electric generation, such as photovoltaic systems in the Southwest. Case studies were conducted with actual power distribution system data for seven electric utilities with the participation of those utilities. Integrating renewable energy systems into electric power distribution systems increased the value of the benefits by about 20 to 55% above central station benefits in the national regional assessment. In the case studies presented in Vol. II, the range was larger: from a few percent to near 80% for a case where costly investments were deferred. In general, additional savings of at least 10 to 20% can be expected by integrating at the distribution level. Wind energy systems were found to be economical in good wind resource regions, whereas photovoltaic systems costs are presently a factor of 2.5 too expensive under the most favorable conditions.

  12. Loss Reduction of Power Distribution Network Using Optimum Size and Location of Distributed

    E-print Network

    Pota, Himanshu Roy

    directly to utility distribution system. The insulation level of the machines may not synchronize flow based method have been compared for three IEEE distribution test systems. This analysis shows, Sensitivity analysis. I. INTRODUCTION The growth of electricity demand is increasing rapidly. DG is one

  13. Fuzzy logic based operated device identification in power distribution systems

    E-print Network

    Manivannan, Karthick Muthu

    2002-01-01

    of Pass I - Evaluation of Fuzzy Rules . . . . . . . . . . . . . . . . . . . . . . . . 38 47 43 4. 9 Flow Chart of Pass 2 44 4. 10 Operating Curves of a Device with Nmax op =3 . . . 49 4. 11 Example Event with NS-E =3 . . 49 4. 12 Pi-I Membership... ACKNOWLEDGMENTS. TABLE OF CONTENTS . . . . . Vt . . vu LIST OF FIGURES . xl LIST OF TABLES. CHAPTER x tv I INTRODUCTION 1. 1 Need for Automated Fault Location. 1. 2 A New Distribution Fault Location Approach . . . 1. 3 Expected Benefits of the New...

  14. Evaluation of 400V DC distribution in telco and data centers to improve energy efficiency

    Microsoft Academic Search

    Annabelle Pratt; Pavan Kumar; Tomm V. Aldridge

    2007-01-01

    In a typical data center, less than half the energy consumed is delivered to the compute load, with the rest lost in power conversion, distribution and cooling. Traditionally power distribution is at 400\\/480 V AC in data centers and at -48 V DC in telco facilities. Higher voltage DC has been proposed as an energy efficient distribution option for both

  15. Distributed Power Control Network and Green Building Test-Bed for Demand Response in Smart Grid

    NASA Astrophysics Data System (ADS)

    Sakaguchi, Kei; Nguyen, Van Ky; Tao, Yu; Tran, Gia Khanh; Araki, Kiyomichi

    It is known that demand and supply power balancing is an essential method to operate power delivery system and prevent blackouts caused by power shortage. In this paper, we focus on the implementation of demand response strategy to save power during peak hours by using Smart Grid. It is obviously impractical with centralized power control network to realize the real-time control performance, where a single central controller measures the huge metering data and sends control command back to all customers. For that purpose, we propose a new architecture of hierarchical distributed power control network which is scalable regardless of the network size. The sub-controllers are introduced to partition the large system into smaller distributed clusters where low-latency local feedback power control loops are conducted to guarantee control stability. Furthermore, sub-controllers are stacked up in an hierarchical manner such that data are fed back layer-by-layer in the inbound while in the outbound control responses are decentralized in each local sub-controller for realizing the global objectives. Numerical simulations in a realistic scenario of up to 5000 consumers show the effectiveness of the proposed scheme to achieve a desired 10% peak power saving by using off-the-shelf wireless devices with IEEE802.15.4g standard. In addition, a small scale power control system for green building test-bed is implemented to demonstrate the potential use of the proposed scheme for power saving in real life.

  16. Power law distribution in high frequency financial data? An econometric analysis

    NASA Astrophysics Data System (ADS)

    Todorova, Lora; Vogt, Bodo

    2011-11-01

    Power law distributions are very common in natural sciences. We analyze high frequency financial data from XETRA and the NYSE using maximum likelihood estimation and the Kolmogorov-Smirnov statistic to test whether the power law hypothesis holds also for these data. We find that the universality and scale invariance properties of the power law are violated. Furthermore, the returns of Daimler Chrysler and SAP traded simultaneously on both exchanges follow a power law at one exchange, but not at the other. These results raise some questions about the no-arbitrage condition. Finally, we find that an exponential function provides a better fit for the tails of the sample distributions than a power law function.

  17. Non-uniform spatial distributions of both the magnitude and phase of AC electric fields determine dielectrophoretic forces

    Microsoft Academic Search

    X.-B Wang; M. P Hughes; Y Huang; F. F Becker; P. R. C Gascoyne

    1995-01-01

    It is well known that the conventional dielectrophoretic force acting on a polarised particle in a non-uniform AC electric field is proportional to the in-phase component of the induced dipole moment and the non-uniformity of the field strength. In contrast, the travelling-wave-dielectrophoretic force that acts on a particle subjected to a travelling electric field is proportional to the out-of-phase component

  18. Instantaneous Active and Nonactive Power Control of Distributed Energy Resources with Current Limiter

    SciTech Connect

    Xu, Yan [ORNL; Li, Huijuan [ORNL; Rizy, D Tom [ORNL; Li, Fangxing [ORNL; Kueck, John D [ORNL

    2010-01-01

    Abstract -- Distributed energy resources (DER) with a power electronics inverter interface can provide both active power and nonactive power simultaneously and independently. A decoupled control algorithm of active power and nonactive power is developed based on the instantaneous active power and nonactive power theory. A current limiter is combined to the control algorithm, and it ensures that the inverter is not overloaded. During the normal system operation, the active power has higher priority over the nonactive power so that the energy from a DER can be fully transferred to the grid. Within the inverter s capability, nonactive power is provided to the grid as required. With this control algorithm, the inverter s capabilities are taken full advantage at all times, both in terms of functionality as well as making use of its full KVA rating. Through the algorithm, the inverter s active power and nonactive power are controlled directly, simultaneously, and independently. Several experimental results fully demonstrate the validity and effectiveness of this new control algorithm. As evidenced by the fast dynamic response that results, a DER system with the control algorithm can provide full services to the grid in both steady state and during transient events.

  19. THE REAL POWERS OF THE CONVOLUTION OF A NEGATIVE BINOMIAL DISTRIBUTION AND A BERNOULLI DISTRIBUTION

    Microsoft Academic Search

    G ERARD LETAC; DHAFER MALOUCHE; STEFAN MAURER

    For c> 0; this note computes essentially the set of (x;y )i n (0; +1)2 such that the entire series in z dened by (1 +z=c)x(1 z) y has all its coecients non-negative. If X and Y are independent random variables which have respectively Bernoulli and negative binomial distributions, denote by the distribution of X +Y. The above problem is

  20. Flywheel energy storage system design for distribution network

    Microsoft Academic Search

    Jiancheng Zhang; Zhiye Chen; Lijun Cai; Yuhua Zhao

    2000-01-01

    It is necessary to install flywheel energy storage (FES) systems in distribution networks, which can improve the quality and supplying reliability of electric power. In this paper, a 10 MJ FES system is designed, the power of which can reach 10 kW. The FES system is composed of four parts: (1) flywheel; (2) bearing; (3) motor\\/generator; and (4) AC power

  1. Intelligent Monitoring System With High Temperature Distributed Fiberoptic Sensor For Power Plant Combustion Processes

    SciTech Connect

    Kwang Y. Lee; Stuart S. Yin; Andre Boheman

    2005-12-26

    The objective of the proposed work is to develop an intelligent distributed fiber optical sensor system for real-time monitoring of high temperature in a boiler furnace in power plants. Of particular interest is the estimation of spatial and temporal distributions of high temperatures within a boiler furnace, which will be essential in assessing and controlling the mechanisms that form and remove pollutants at the source, such as NOx. The basic approach in developing the proposed sensor system is three fold: (1) development of high temperature distributed fiber optical sensor capable of measuring temperatures greater than 2000 C degree with spatial resolution of less than 1 cm; (2) development of distributed parameter system (DPS) models to map the three-dimensional (3D) temperature distribution for the furnace; and (3) development of an intelligent monitoring system for real-time monitoring of the 3D boiler temperature distribution. Under Task 1, we set up a dedicated high power, ultrafast laser system for fabricating in-fiber gratings in harsh environment optical fibers, successfully fabricated gratings in single crystal sapphire fibers by the high power laser system, and developed highly sensitive long period gratings (lpg) by electric arc. Under Task 2, relevant mathematical modeling studies of NOx formation in practical combustors. Studies show that in boiler systems with no swirl, the distributed temperature sensor may provide information sufficient to predict trends of NOx at the boiler exit. Under Task 3, we investigate a mathematical approach to extrapolation of the temperature distribution within a power plant boiler facility, using a combination of a modified neural network architecture and semigroup theory. The 3D temperature data is furnished by the Penn State Energy Institute using FLUENT. Given a set of empirical data with no analytic expression, we first develop an analytic description and then extend that model along a single axis. Extrapolation capability was demonstrated for estimating enthalpy in a power plant.

  2. High-performance programmable AC power source with low harmonic distortion using DSP-based repetitive control technique

    Microsoft Academic Search

    Ying-Yu Tzou; Rong-Shyang Ou; Shih-Liang Jung; Meng-Yueh Chang

    1997-01-01

    This paper proposes a new control scheme based on a two-layer control structure to improve both the transient and steady-state responses of a closed-loop regulated pulse-width-modulated (PWM) inverter for high-quality sinusoidal AC voltage regulation. The proposed two-layer controller consists of a tracking controller and a repetitive controller. Pole assignment with state feedback has been employed in designing the tracking controller

  3. Low-cost distributed solar-thermal-electric power generation

    NASA Astrophysics Data System (ADS)

    Der Minassians, Artin; Aschenbach, Konrad H.; Sanders, Seth R.

    2004-01-01

    Due to their high relative cost, solar electric energy systems have yet to be exploited on a widespread basis. It is believed in the energy community that a technology similar to photovoltaic (PV), but offered at about $1/W would lead to widespread deployment at residential and commercial sites. This paper addresses the investigation and feasibility study of a low-cost solar thermal electricity generation technology, suitable for distributed deployment. Specifically, we discuss a system based on nonimaging solar concentrators, integrated with free-piston Stirling engine devices incorporating integrated electric generation. We target concentrator-collector operation at moderate temperatures, in the range of 125°C to 150°C. This temperature is consistent with use of optical concentrators with concentration ratios on the order of 1-2. These low ratio concentrators admit wide angles of radiation acceptance and are thus compatible with no diurnal tracking, and no or only a few seasonal adjustments. Thus, costs and reliability hazards associated with tracking hardware systems are avoided. Further, we note that in the intended application, there is no shortage of incident solar energy, but rather it is the capital cost of the solar-electric system that is most precious. Thus, we outline a strategy for exploiting solar resources in a cost constrained manner. The paper outlines design issues, and a specific design for an appropriately dimensioned free-piston Stirling engine. Only standard low-cost materials and manufacturing methods are required to realize such a machine.

  4. Integrated Computing, Communication, and Distributed Control of Deregulated Electric Power Systems

    SciTech Connect

    Bajura, Richard; Feliachi, Ali

    2008-09-24

    Restructuring of the electricity market has affected all aspects of the power industry from generation to transmission, distribution, and consumption. Transmission circuits, in particular, are stressed often exceeding their stability limits because of the difficulty in building new transmission lines due to environmental concerns and financial risk. Deregulation has resulted in the need for tighter control strategies to maintain reliability even in the event of considerable structural changes, such as loss of a large generating unit or a transmission line, and changes in loading conditions due to the continuously varying power consumption. Our research efforts under the DOE EPSCoR Grant focused on Integrated Computing, Communication and Distributed Control of Deregulated Electric Power Systems. This research is applicable to operating and controlling modern electric energy systems. The controls developed by APERC provide for a more efficient, economical, reliable, and secure operation of these systems. Under this program, we developed distributed control algorithms suitable for large-scale geographically dispersed power systems and also economic tools to evaluate their effectiveness and impact on power markets. Progress was made in the development of distributed intelligent control agents for reliable and automated operation of integrated electric power systems. The methodologies employed combine information technology, control and communication, agent technology, and power systems engineering in the development of intelligent control agents for reliable and automated operation of integrated electric power systems. In the event of scheduled load changes or unforeseen disturbances, the power system is expected to minimize the effects and costs of disturbances and to maintain critical infrastructure operational.

  5. The MLP distribution: a modified lognormal power-law model for the stellar initial mass function

    NASA Astrophysics Data System (ADS)

    Basu, Shantanu; Gil, M.; Auddy, Sayantan

    2015-05-01

    This work explores the mathematical properties of a distribution introduced by Basu & Jones (2004), and applies it to model the stellar initial mass function (IMF). The distribution arises simply from an initial lognormal distribution, requiring that each object in it subsequently undergoes exponential growth but with an exponential distribution of growth lifetimes. This leads to a modified lognormal with a power-law (MLP) distribution, which can in fact be applied to a wide range of fields where distributions are observed to have a lognormal-like body and a power-law tail. We derive important properties of the MLP distribution, like the cumulative distribution, the mean, variance, arbitrary raw moments, and a random number generator. These analytic properties of the distribution can be used to facilitate application to modelling the IMF. We demonstrate how the MLP function provides an excellent fit to the IMF compiled by Chabrier and how this fit can be used to quickly identify quantities like the mean, median, and mode, as well as number and mass fractions in different mass intervals.

  6. Distributed power-supply systems in the built environment Co-evolution of institutes and technology for different transition paths

    Microsoft Academic Search

    Albert Faber

    Distributed power generation in the built environment Sustainable local power generation technologies and technologies with a high domestic electricity demand are generally expected to develop in the future. Sustainable distributed power-supply systems are a realistic option to ensure a sustainable, affordable and secure energy supply, but systemic, technical and institutional adaptations are required for their further development and incorporation in

  7. Electrical energy management of virtual power plants in distribution networks with renewable energy resources and energy storage systems

    Microsoft Academic Search

    Parastoo Nezamabadi; G. B. Gharehpetian

    2011-01-01

    r Abstract: Production of energy in centralized power plants and transmitted via transmission lines to the customers is always with high power losses. Distributed generation (DG) especially renewable energy resources (RES) and energy storage systems (ESS) through distributed system are very cost saving and sometimes inevitable. If these small DGs want to connect to power system and participate in energy

  8. An Encoding Technique for Multiobjective Evolutionary Algorithms Applied to Power Distribution System Reconfiguration

    PubMed Central

    Guardado, J. L.; Rivas-Davalos, F.; Torres, J.; Maximov, S.; Melgoza, E.

    2014-01-01

    Network reconfiguration is an alternative to reduce power losses and optimize the operation of power distribution systems. In this paper, an encoding scheme for evolutionary algorithms is proposed in order to search efficiently for the Pareto-optimal solutions during the reconfiguration of power distribution systems considering multiobjective optimization. The encoding scheme is based on the edge window decoder (EWD) technique, which was embedded in the Strength Pareto Evolutionary Algorithm 2 (SPEA2) and the Nondominated Sorting Genetic Algorithm II (NSGA-II). The effectiveness of the encoding scheme was proved by solving a test problem for which the true Pareto-optimal solutions are known in advance. In order to prove the practicability of the encoding scheme, a real distribution system was used to find the near Pareto-optimal solutions for different objective functions to optimize. PMID:25401144

  9. Finite-Element Model Predicts Current Density Distribution for Clinical Applications of tDCS and tACS

    PubMed Central

    Neuling, Toralf; Wagner, Sven; Wolters, Carsten H.; Zaehle, Tino; Herrmann, Christoph S.

    2012-01-01

    Transcranial direct current stimulation (tDCS) has been applied in numerous scientific studies over the past decade. However, the possibility to apply tDCS in therapy of neuropsychiatric disorders is still debated. While transcranial magnetic stimulation (TMS) has been approved for treatment of major depression in the United States by the Food and Drug Administration (FDA), tDCS is not as widely accepted. One of the criticisms against tDCS is the lack of spatial specificity. Focality is limited by the electrode size (35?cm2 are commonly used) and the bipolar arrangement. However, a current flow through the head directly from anode to cathode is an outdated view. Finite-element (FE) models have recently been used to predict the exact current flow during tDCS. These simulations have demonstrated that the current flow depends on tissue shape and conductivity. To face the challenge to predict the location, magnitude, and direction of the current flow induced by tDCS and transcranial alternating current stimulation (tACS), we used a refined realistic FE modeling approach. With respect to the literature on clinical tDCS and tACS, we analyzed two common setups for the location of the stimulation electrodes which target the frontal lobe and the occipital lobe, respectively. We compared lateral and medial electrode configuration with regard to their usability. We were able to demonstrate that the lateral configurations yielded more focused stimulation areas as well as higher current intensities in the target areas. The high resolution of our simulation allows one to combine the modeled current flow with the knowledge of neuronal orientation to predict the consequences of tDCS and tACS. Our results not only offer a basis for a deeper understanding of the stimulation sites currently in use for clinical applications but also offer a better interpretation of observed effects. PMID:23015792

  10. AC Metering Circuits

    NSDL National Science Digital Library

    Kuphaldt, Tony R.

    All About Circuits is a website that â??provides a series of online textbooks covering electricity and electronics.â? Written by Tony R. Kuphaldt, the textbooks available here are wonderful resources for students, teachers, and anyone who is interested in learning more about electronics. This specific section, AC Metering Circuits, is the twelfth chapter in Volume II â??Alternating Current. A few of the topics covered in this chapter include: AC voltmeters and ammeters; Power measurement; AC bridge circuits; and AC instrumentation transducers. Diagrams and detailed descriptions of concepts are included throughout the chapter to provide users with a comprehensive lesson. Visitors to the site are also encouraged to discuss concepts and topics using the All About Circuits discussion forums (registration with the site is required to post materials).

  11. Next generation of AC coupled Hybrid systems - 3 phase parallel operation of grid forming battery inverters

    Microsoft Academic Search

    A. Engler; C. Hardt; N. Bechtel; M. Rothert

    Summary: The AC-coupling of components for stand-alone PV-battery-diesel hybrid power systems and the distributed generation in renewable energy micro grids is a challenging task for the control technology. Today's systems mostly run in master\\/slave operation with one battery inverter or one genset as the grid master. Extendable distributed power supplies can be considerably improved by introducing multi-master control concepts for

  12. HIGH POWER RF DISTRIBUTION AND CONTROL FOR MULTI-CAVITY CRYOMODULE TESTING

    SciTech Connect

    Kang, Yoon W [ORNL; Broyles, Michael R [ORNL; Crofford, Mark T [ORNL; Geng, Xiaosong [ORNL; Kim, Sang-Ho [ORNL; Lee, Sung-Woo [ORNL; Phibbs, Curtis L [ORNL; Shin, Ki [ORNL; Strong, William Herb [ORNL

    2011-01-01

    Qualification of the superconducting radio-frequency (SRF) cavities in the cryomodules for the accelerating performance needs to be done through high power processing. A four-way waveguide power distribution system with independent control of power outputs has been being developed for testing the multi-cavity cryomodules for the SNS linac. SNS is employing two types of cryomodules: one type with three medium beta six-cell cavities and the other with four high beta six-cell cavities. The cryomodule that is being manufactured as a spare and the new crymodules for the future power upgrade project (PUP) of SNS will be high beta types. The four-way power distribution with independently controlled power outputs was considered useful for powering all cavities at the same time with a klystron amplifier since the SNS test facility was configured for a single klystron operation. Since certain interaction between the cavities under severe field emission was suspected in existing cryomodules, this type of high power test can be valuable for characterization of SRF cavities. By implementing a vector modulator at each arm of the splitting system, the amplitudes and the phases of RF outputs can be controlled independently. This paper discusses the present status of the development.

  13. Distributing Power Grid State Estimation on HPC Clusters A System Architecture Prototype

    SciTech Connect

    Liu, Yan; Jiang, Wei; Jin, Shuangshuang; Rice, Mark J.; Chen, Yousu

    2012-08-20

    The future power grid is expected to further expand with highly distributed energy sources and smart loads. The increased size and complexity lead to increased burden on existing computational resources in energy control centers. Thus the need to perform real-time assessment on such systems entails efficient means to distribute centralized functions such as state estimation in the power system. In this paper, we present our early prototype of a system architecture that connects distributed state estimators individually running parallel programs to solve non-linear estimation procedure. The prototype consists of a middleware and data processing toolkits that allows data exchange in the distributed state estimation. We build a test case based on the IEEE 118 bus system and partition the state estimation of the whole system model to available HPC clusters. The measurement from the testbed demonstrates the low overhead of our solution.

  14. Apollo experience report: Command and service module electrical power distribution on subsystem

    NASA Technical Reports Server (NTRS)

    Munford, R. E.; Hendrix, B.

    1974-01-01

    A review of the design philosophy and development of the Apollo command and service modules electrical power distribution subsystem, a brief history of the evolution of the total system, and some of the more significant components within the system are discussed. The electrical power distribution primarily consisted of individual control units, interconnecting units, and associated protective devices. Because each unit within the system operated more or less independently of other units, the discussion of the subsystem proceeds generally in descending order of complexity; the discussion begins with the total system, progresses to the individual units of the system, and concludes with the components within the units.

  15. Power-like corrections and the determination of the gluon distribution

    E-print Network

    F. Hautmann

    2006-10-06

    Power-suppressed corrections to parton evolution may affect the theoretical accuracy of current determinations of parton distributions. We study the role of multigluon-exchange terms in the extraction of the gluon distribution for the Large Hadron Collider (LHC). Working in the high-energy approximation, we analyze multi-gluon contributions in powers of 1/Q^2. We find a moderate, negative correction to the structure function's derivative d F_2 / d \\ln Q^2, characterized by a slow fall-off in the region of low to medium Q^2 relevant for determinations of the gluon at small momentum fractions.

  16. Time-Series-Based Maximization of Distributed Wind Power Generation Integration

    Microsoft Academic Search

    Luis F. Ochoa; Antonio Padilha-Feltrin; Gareth P. Harrison

    2008-01-01

    Energy policies and technological progress in the development of wind turbines have made wind power the fastest growing renewable power source worldwide. The inherent variability of this resource requires special attention when analyzing the impacts of high penetration on the distribution network. A time-series steady-state analysis is proposed that assesses technical issues such as energy export, losses, and short-circuit levels.

  17. Intensity and absorbed-power distribution in a cylindrical solar-pumped dye laser

    NASA Technical Reports Server (NTRS)

    Williams, M. D.

    1984-01-01

    The internal intensity and absorbed-power distribution of a simplified hypothetical dye laser of cylindrical geometry is calculated. Total absorbed power is also calculated and compared with laboratory measurements of lasing-threshold energy deposition in a dye cell to determine the suitability of solar radiation as a pump source or, alternatively, what modifications, if any, are necessary to the hypothetical system for solar pumping.

  18. Advanced electrical power, distribution and control for the Space Transportation System

    NASA Technical Reports Server (NTRS)

    Hansen, Irving G.; Brandhorst, Henry W., Jr.

    1990-01-01

    High frequency power distribution and management is a technology ready state of development. As such, a system employs the fewest power conversion steps, and employs zero current switching for those steps. It results in the most efficiency, and lowest total parts system count when equivalent systems are compared. The operating voltage and frequency are application specific trade off parameters. However, a 20 kHz Hertz system is suitable for wide range systems.

  19. Joint power allocation and receiver design for Distributed Space-Time Coded cooperative MIMO systems

    Microsoft Academic Search

    Tong Peng; Rodrigo C. de Lamare; Anke Schmeink

    2011-01-01

    In this paper, a joint power allocation algorithm with minimum mean-squared error (MMSE) receiver for a cooperative Multiple-Input and Multiple-Output (MIMO) network which employs multiple relays and a Decode-and-Forward (DF) strategy is proposed. A Distributed Space-Time Coding (DSTC) scheme is applied in each relay node. We present a joint constrained optimization algorithm to determine the power allocation parameters and the

  20. Predicting incident energy to better manage the electric arc hazard on 600 V power distribution systems

    Microsoft Academic Search

    R. L. Doughty; T. E. Neal

    1998-01-01

    A test program has been completed to measure incident energy from 6-cycle arcs on 600 V 3-phase electric power distribution systems. Testing was performed using an arc electrode gap of 1.25 inches that had previously produced maximum incident energy for a 600 V power system with a 36.25 kA prospective fault current. The effect on incident energy of enclosing the