Sample records for voltage electric power

  1. 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

  2. Voltage Collapse Risk Associated to UnderVoltage Capacitive Compensation in Electric Power System Operation

    Microsoft Academic Search

    Heraldo Silveira Barbuy; Alexandre Rocco

    2009-01-01

    Problem statement: In the operation of an Electric Power System (EPS), it has been usual to provide reactive power injection to avoid an under-voltage bus condition. In some situations an adequate voltage profile will not be a guarantee against Voltage Collapses (VCs) that may cause blackouts as seen in many occurrences around the world. The repeatedly injection of reactive power

  3. Integrated voltage and reactive power control for all electric ship power systems

    Microsoft Academic Search

    V. Arcidiacono; S. Castellan; R. Menis; G. Sulligoi

    2006-01-01

    All electric ship alternators are connected to a main busbar which feeds all shipboard electric loads. To fulfill power quality requirements of the resulting electrical system, high-performance control of busbar voltage and frequency is needed. Such a task is not of easy accomplishment, due to the complexity of shipboard power station (generators are many and differ by sizes, prime movers,

  4. Electric Power System UnderVoltage Load Shedding Protection Can Become a Trap

    Microsoft Academic Search

    Luiz Augusto Pereira Fe; Alexandre Rocco; Heraldo Silveira B; Geraldo Caixeta Gu

    2009-01-01

    Problem statement: Under-Voltage Load Shedding (UVLS) protection of Electric Power Systems (EPS) is frequently used against Voltage Co llapse (VC), however when there is automatic bus voltage regulation with excessive capacitive compen sation, the UVLS scheme may not trip. In this case, load shedding must be based in a Voltage Coll apse Proximity Indicator (VCPI). Many UVLS procedures may not

  5. Electric Power System UnderVoltage Load Shedding Protection Can Become a Trap

    Microsoft Academic Search

    Luiz Augusto Pereira Fernandes; Alexandre Rocco; Heraldo Silveira Barbuy; Geraldo Caixeta Guimarães

    Problem statement: Under-Voltage Load Shedding (UVLS) protection of Electric Power Systems (EPS) is frequently used against Voltage Co llapse (VC), however when there is automatic bus voltage regulation with excessive capacitive compen sation, the UVLS scheme may not trip. In this case, load shedding must be based in a Voltage Coll apse Proximity Indicator (VCPI). Many UVLS procedures may not

  6. Investigations of voltage flicker in electric arc furnace power systems

    Microsoft Academic Search

    S. R. Mendis; M. T. Bishop; J. F. Witte

    1996-01-01

    Operation of rapidly varying loads such as AC and DC arc furnaces in large industrial power systems will cause voltage flicker on the utility system. System planning will help in determining the available short-circuit duty at the point-of-common-coupling to keep the voltage flicker within acceptable limits. Perceptible flicker limit curves are useful in determining the amount of flicker in a

  7. Electricity meters for coordinated voltage control in medium voltage networks with wind power

    Microsoft Academic Search

    Ingmar Leisse; Olof Samuelsson; Jörgen Svensson

    2010-01-01

    During the last years the amount of electricity generated by Distributed Energy Resources (DER), especially wind turbines, has been increasing a lot. These Distributed Generation (DG) units are often connected to rural distribution networks, where they have a large impact on the voltage and the network losses. The network voltage at the customers point of connection is an important quality

  8. Power electronics and control of two-voltage-level flywheel based all-electric driveline

    Microsoft Academic Search

    Janaina G. Oliveira; Hans Bernhoff

    2011-01-01

    A novel all-electric driveline comprising a flywheel with a permanent magnet doubly wound synchronous motor\\/generator is presented. The flywheel machine with a double set of windings divides the system in two voltage levels: a low voltage\\/power level, which is connected to the main energy storage source (e.g. battery) and a high voltage\\/power level, which is connected to the traction machine.

  9. Research on UnderVoltage Load-Shedding to Prevent Voltage Collapse of Electric Power System

    Microsoft Academic Search

    Jingjing Zhang; Ming Ding; Shenghu Li

    2009-01-01

    A voltage collapse is defined as the process by which voltage instability leads to a very low voltage profile in a significant part of the system. Under-voltage load-shedding is an efficient scheme to prevent voltage collapse. The paper analyses the mechanism of under-voltage load-shedding preventing voltage collapse, compares distributed load-shedding scheme with centralized scheme, introduces under-voltage load-shedding scheme employment at

  10. 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.

  11. Electrical safety analysis in low voltage systems with electronic power converters

    Microsoft Academic Search

    M. Brenna; F. Iannone; D. Zaninelli

    2005-01-01

    The widespread use of the power electronic place the problem of the correct operation of the protection system, in order to guarantee the electrical safety for the person in case of indirect contact downstream a converter. The aim of this paper is to estimate the various shapes of voltage and current waves in case of fault in order to give

  12. Effect of Induced Alternating Current Voltage on Cathodically Protected Pipelines Paralleling Electric Power Transmission Lines

    Microsoft Academic Search

    F. Kajiyama; Y. Nakamura

    1999-01-01

    A field study was conducted to evaluate the effect of induced alternating current (AC) voltage on a cathodically protected pipeline paralleling an electric power transmission line. The study used the instant-off method, with steel probes simulating coating defects. Data regarding probe potentials and currents were compared with the proposed tentative criterion for cathodic protection (CP). Positive proof of the adequacy

  13. Prevention of Emergency Voltage Collapses in Electric Power Networks using Hybrid Predictive Control

    Microsoft Academic Search

    S. Leirens; R. R. Negenborn

    \\u000a The reliable operation of electricity transport and distribution networks plays a crucial role in modern societies. However,\\u000a too often, when a fault occurs in electricity networks, such as a transmission line drop, loss of generation, or any other\\u000a important failure, voltages start to decay, potentially leading to complete blackouts with dramatic consequences. Thus, techniques\\u000a are required that improve the power

  14. Effect of Voltage Level on Power System Design for Solar Electric Propulsion Missions

    NASA Technical Reports Server (NTRS)

    Kerslake, Thomas W.

    2003-01-01

    This paper presents study results quantifying the benefits of higher voltage, electric power system designs for a typical solar electric propulsion spacecraft Earth orbiting mission. A conceptual power system architecture was defined and design points were generated for system voltages of 28-V, 50-V, 120-V, and 300-V using state-of-the-art or advanced technologies. A 300-V 'direct-drive' architecture was also analyzed to assess the benefits of directly powering the electric thruster from the photovoltaic array without up-conversion. Fortran and spreadsheet computational models were exercised to predict the performance and size power system components to meet spacecraft mission requirements. Pertinent space environments, such as electron and proton radiation, were calculated along the spiral trajectory. In addition, a simplified electron current collection model was developed to estimate photovoltaic array losses for the orbital plasma environment and that created by the thruster plume. The secondary benefits of power system mass savings for spacecraft propulsion and attitude control systems were also quantified. Results indicate that considerable spacecraft wet mass savings were achieved by the 300-V and 300-V direct-drive architectures.

  15. Electric power high-voltage transmission lines: Design options, cost, and electric and magnetic field levels

    SciTech Connect

    Stoffel, J.B.; Pentecost, E.D.; Roman, R.D.; Traczyk, P.A.

    1994-11-01

    This report provides background information about (1) the electric and magnetic fields (EMFs) of high-voltage transmission lines at typical voltages and line configurations and (2) typical transmission line costs to assist on alternatives in environmental documents. EMF strengths at 0 {+-} 200 ft from centerline were calculated for ac overhead lines, and for 345 and 230-kV ac underground line and for a {+-}450-kV dc overhead line. Compacting and height sensitivity factors were computed for the variation in EMFs when line conductors are moved closer or raised. Estimated costs for the lines are presented and discussed so that the impact of using alternative strategies for reducing EMF strengths and the implications of implementing the strategies can be better appreciated.

  16. Generating Electrical Voltage

    NSDL National Science Digital Library

    Teachers' Domain presents this interactive lesson designed to help students "learn how a generator converts mechanical energy into electrical energy. Investigate the principle of magnetic induction by moving a conductor through a magnetic field to see how voltage is generated." The lesson is divided into three major sections: How Do Generators Work?, What Factors Influence Voltage Strength?, and What Determines Voltage Polarity? There are plenty of animations to help students visualize the processes at work in electricity generation. On the site, visitors will also find a supplemental background essay, discussion questions, and standards alignment from Teachers' Domain.

  17. Influence of the under load tap changers on the dynamic voltage collapse of an electric power system

    Microsoft Academic Search

    R. M. Monteiro Pereira; C. M. Machado Ferreira; J. A. Dias Pinto; F. P. Maciel Barbosa

    2004-01-01

    Most power systems are nowadays operated very near to their operating limits due to increase in consumption, while economic and environmental constraints have limited construction of new generation facilities and lines. This paper is devoted to the analysis of the ULTC effect in the dynamic voltage stability of an electric power network. Usually substations are provided with transformers with tap-changers

  18. 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.

  19. High voltage power transistor development

    NASA Technical Reports Server (NTRS)

    Hower, P. L.

    1981-01-01

    Design considerations, fabrication procedures, and methods of evaluation for high-voltage power-transistor development are discussed. Technique improvements such as controlling the electric field at the surface and perserving lifetimes in the collector region which have advanced the state of the art in high-voltage transistors are discussed. These improvements can be applied directly to the development of 1200 volt, 200 ampere transistors.

  20. Design of 154 kV Extra-High-Voltage Prototype SF6 Bushing for Superconducting Electric Power Applications

    NASA Astrophysics Data System (ADS)

    Koo, Ja-yoon; Seong, Jae-gyu; Hwang, Jae-sang; Lee, Bang-wook; Lee, Sang-hwa

    2012-09-01

    One of the critical components to be developed for high-voltage superconducting devices, such as superconducting transformers, cables, and fault current limiters, is a high-voltage bushing to supply a high current to devices without insulation difficulties in cryogenic environments. Unfortunately, suitable bushings for high-temperature-superconductivity (HTS) equipment have not been fully developed to address cryogenic insulation issues. As a fundamental step towards developing the optimum design of the 154 kV prototype SF6 bushing of HTS devices, the puncture and creepage breakdown voltages of glass-fiber-reinforced-plastic (GFRP) were analyzed with a variety of configurations of electrodes and gap distances in the insulation material. And design factors of high-voltage cryogenic bushings were obtained from the result of tests. Finally, the withstand voltage tests of manufacturing a 154 kV extra-high-voltage (EHV) prototype bushing has been performed. Consequently, we verified the insulation level of the newly designed 154 kV EHV cryogenic prototype bushings for superconducting electric power applications.

  1. Electrical system architecture having high voltage bus

    DOEpatents

    Hoff, Brian Douglas (East Peoria, IL); Akasam, Sivaprasad (Peoria, IL)

    2011-03-22

    An electrical system architecture is disclosed. The architecture has a power source configured to generate a first power, and a first bus configured to receive the first power from the power source. The architecture also has a converter configured to receive the first power from the first bus and convert the first power to a second power, wherein a voltage of the second power is greater than a voltage of the first power, and a second bus configured to receive the second power from the converter. The architecture further has a power storage device configured to receive the second power from the second bus and deliver the second power to the second bus, a propulsion motor configured to receive the second power from the second bus, and an accessory motor configured to receive the second power from the second bus.

  2. Analysis and detection of arcing faults in low-voltage electrical power systems

    Microsoft Academic Search

    D. G. Ece; F. M. Wells

    1994-01-01

    This work focuses on developing a more complete understanding of the properties of arcing fault waveforms in a 230 volt, three-phase electrical system and to detect them in a cost efficient way. Analysis of waveform properties of experimental arcing fault current waveforms revealed significant variations from an unfaulted system current. Using the results of the analysis of the data gathered

  3. Technical evaluation report on the adequacy of station electric distribution system voltages for the Peach Bottom Atomic Power Station. Units 2 and 3

    SciTech Connect

    White, R.L.

    1982-06-21

    This report documents the technical evaluation of the adequacy of the station electric distribution system voltages for the Peach Bottom Atomic Power Station, Units 2 and 3. The evaluation is to determine if the onsite distribution system, in conjunction with the offsite power sources, has sufficient capacity to automatically start and operate all Class 1E loads within the equipment voltage ratings under certain conditions established by the Nuclear Regulatory Commission. The analysis submitted indicates that the capacity is sufficient to meet the NRC requirements provided specific plant procedures are followed for shutting down the second unit after an accident in the first unit and with a loss of one offsite source.

  4. Nanosecond pulsed electric fields (nsPEFs) low cost generator design using power MOSFET and Cockcroft-Walton multiplier circuit as high voltage DC source

    NASA Astrophysics Data System (ADS)

    Sulaeman, M. Y.; Widita, R.

    2014-09-01

    Purpose: Non-ionizing radiation therapy for cancer using pulsed electric field with high intensity field has become an interesting field new research topic. A new method using nanosecond pulsed electric fields (nsPEFs) offers a novel means to treat cancer. Not like the conventional electroporation, nsPEFs able to create nanopores in all membranes of the cell, including membrane in cell organelles, like mitochondria and nucleus. NsPEFs will promote cell death in several cell types, including cancer cell by apoptosis mechanism. NsPEFs will use pulse with intensity of electric field higher than conventional electroporation, between 20-100 kV/cm and with shorter duration of pulse than conventional electroporation. NsPEFs requires a generator to produce high voltage pulse and to achieve high intensity electric field with proper pulse width. However, manufacturing cost for creating generator that generates a high voltage with short duration for nsPEFs purposes is highly expensive. Hence, the aim of this research is to obtain the low cost generator design that is able to produce a high voltage pulse with nanosecond width and will be used for nsPEFs purposes. Method: Cockcroft-Walton multiplier circuit will boost the input of 220 volt AC into high voltage DC around 1500 volt and it will be combined by a series of power MOSFET as a fast switch to obtain a high voltage with nanosecond pulse width. The motivation using Cockcroft-Walton multiplier is to acquire a low-cost high voltage DC generator; it will use capacitors and diodes arranged like a step. Power MOSFET connected in series is used as voltage divider to share the high voltage in order not to damage them. Results: This design is expected to acquire a low-cost generator that can achieve the high voltage pulse in amount of -1.5 kV with falltime 3 ns and risetime 15 ns into a 50? load that will be used for nsPEFs purposes. Further detailed on the circuit design will be explained at presentation.

  5. Nanosecond pulsed electric fields (nsPEFs) low cost generator design using power MOSFET and Cockcroft-Walton multiplier circuit as high voltage DC source

    SciTech Connect

    Sulaeman, M. Y.; Widita, R. [Department of Physics, Nuclear Physics and Biophysics Research Division, Faculty of Mathematics and Natural Science, Institut Teknologi Bandung, Bandung (Indonesia)

    2014-09-30

    Purpose: Non-ionizing radiation therapy for cancer using pulsed electric field with high intensity field has become an interesting field new research topic. A new method using nanosecond pulsed electric fields (nsPEFs) offers a novel means to treat cancer. Not like the conventional electroporation, nsPEFs able to create nanopores in all membranes of the cell, including membrane in cell organelles, like mitochondria and nucleus. NsPEFs will promote cell death in several cell types, including cancer cell by apoptosis mechanism. NsPEFs will use pulse with intensity of electric field higher than conventional electroporation, between 20–100 kV/cm and with shorter duration of pulse than conventional electroporation. NsPEFs requires a generator to produce high voltage pulse and to achieve high intensity electric field with proper pulse width. However, manufacturing cost for creating generator that generates a high voltage with short duration for nsPEFs purposes is highly expensive. Hence, the aim of this research is to obtain the low cost generator design that is able to produce a high voltage pulse with nanosecond width and will be used for nsPEFs purposes. Method: Cockcroft-Walton multiplier circuit will boost the input of 220 volt AC into high voltage DC around 1500 volt and it will be combined by a series of power MOSFET as a fast switch to obtain a high voltage with nanosecond pulse width. The motivation using Cockcroft-Walton multiplier is to acquire a low-cost high voltage DC generator; it will use capacitors and diodes arranged like a step. Power MOSFET connected in series is used as voltage divider to share the high voltage in order not to damage them. Results: This design is expected to acquire a low-cost generator that can achieve the high voltage pulse in amount of ?1.5 kV with falltime 3 ns and risetime 15 ns into a 50? load that will be used for nsPEFs purposes. Further detailed on the circuit design will be explained at presentation.

  6. Power-MOSFET Voltage Regulator

    NASA Technical Reports Server (NTRS)

    Miller, W. N.; Gray, O. E.

    1982-01-01

    Ninety-six parallel MOSFET devices with two-stage feedback circuit form a high-current dc voltage regulator that also acts as fully-on solid-state switch when fuel-cell out-put falls below regulated voltage. Ripple voltage is less than 20 mV, transient recovery time is less than 50 ms. Parallel MOSFET's act as high-current dc regulator and switch. Regulator can be used wherever large direct currents must be controlled. Can be applied to inverters, industrial furnaces photovoltaic solar generators, dc motors, and electric autos.

  7. A combined current voltage sensor for metering and protection in high voltage power systems

    Microsoft Academic Search

    W. Z. Fam

    1994-01-01

    This paper describes a patented Poynting-vector transducer for the simultaneous measurement of both current and voltage in a high voltage power system. It also describes its application for protective relaying, high voltage metering, and measurement of losses in large transformers and shunt reactors. The principle of operation is based on the measurement of the Poynting vector from its constituent electric

  8. High voltage photovoltaic power converter

    DOEpatents

    Haigh, Ronald E. (Arvada, CO); Wojtczuk, Steve (Cambridge, MA); Jacobson, Gerard F. (Livermore, CA); Hagans, Karla G. (Livermore, CA)

    2001-01-01

    An array of independently connected photovoltaic cells on a semi-insulating substrate contains reflective coatings between the cells to enhance efficiency. A uniform, flat top laser beam profile is illuminated upon the array to produce electrical current having high voltage. An essentially wireless system includes a laser energy source being fed through optic fiber and cast upon the photovoltaic cell array to prevent stray electrical signals prior to use of the current from the array. Direct bandgap, single crystal semiconductor materials, such as GaAs, are commonly used in the array. Useful applications of the system include locations where high voltages are provided to confined spaces such as in explosive detonation, accelerators, photo cathodes and medical appliances.

  9. Costs of voltage security in electricity markets

    Microsoft Academic Search

    W. Rosehart; C. Canizares; V. Quintana

    2000-01-01

    As open access market principles are applied to power systems, an increased emphasis is being placed on determining ways to price different auxiliary services. The present paper studies the incorporation of voltage security into an optimal power flow formulation to analyze the aggregated costs associated with guaranteeing adequate voltage security levels in the system. Thus, several hybrid optimal power flow

  10. Three-dimensional electric field calculation and measurements inside high voltage substations

    Microsoft Academic Search

    Sayed A. Word; Samy M. Ghania; Essam M. Shaalan

    2011-01-01

    The exposure to electric field now-a-days is an integral part in the design area of electrical power apparatus and systems. Moreover the electric field produced by power lines, busbars and all high voltage equipments inside high voltage (HV) substations is receiving more and more concerns to guarantee the safety of workers inside these substations. Therefore monitoring the electric field inside

  11. Low electrical potential anode modified with Fe/ferric oxide and its application in marine benthic microbial fuel cell with higher voltage and power output

    NASA Astrophysics Data System (ADS)

    Fu, Yubin; Xu, Qian; Zai, Xuerong; Liu, Yuanyuan; Lu, Zhikai

    2014-01-01

    Low voltage and power output limit the widespread application of marine benthic microbial fuel cell (BMFCs). To increase the cell power, a Fe/Ferric oxide modified anode fabricating by electrolytic deposition is reported here. The novel anode has a lower surface contact angle and higher wettability, which favors the adhesion of bacteria. It is firstly demonstrated that the electrical potential of the modified anode is about -775 mV, much lower than that of the plain graphite (about -450 mV). Open circuit potential of BMFC with the modified anode is about 1050 ± 50 mV, while the potential for the plain cells is only 700 ± 50 mV. In comparison with the plain graphite, the modified anode presents a 393-fold exchange current density and a higher kinetic activity. The output power reaches 7.4 × 10-2 mW cm-2, 17.4-fold higher than that of the plain graphite. A composite mechanism of both chemical and microbial enhancement of the modified anode is proposed to explain its excellent electrochemical performance. The modified anode has potential for high-power output cell and novel voltage-booster design to make the BMFC utilization feasibility.

  12. Scalable High Insulation Power Supply for Medium Voltage Power Converters

    Microsoft Academic Search

    Iosu Aizpuru; Jose Maria Canales; Jesus Fernandez

    2012-01-01

    Medium Voltage (MV) Power devices are used in High Power applications. To use MV devices in High Power applications is necessary to use series connection configurations, multilevel topologies, or cascade connections due to semiconductors voltage limitations. These devices are connected to Medium Voltage so we need High Insulation between Low Voltage Power Supplies and the semiconductor drivers. In this paper

  13. High Voltage Power Transmission for Wind Energy

    NASA Astrophysics Data System (ADS)

    Kim, Young il

    The high wind speeds and wide available area at sea have recently increased the interests on offshore wind farms in the U.S.A. As offshore wind farms become larger and are placed further from the shore, the power transmission to the onshore grid becomes a key feature. Power transmission of the offshore wind farm, in which good wind conditions and a larger installation area than an onshore site are available, requires the use of submarine cable systems. Therefore, an underground power cable system requires unique design and installation challenges not found in the overhead power cable environment. This paper presents analysis about the benefit and drawbacks of three different transmission solutions: HVAC, LCC/VSC HVDC in the grid connecting offshore wind farms and also analyzed the electrical characteristics of underground cables. In particular, loss of HV (High Voltage) subsea power of the transmission cables was evaluated by the Brakelmann's theory, taking into account the distributions of current and temperature.

  14. Voltage surge suppression power circuits

    NASA Astrophysics Data System (ADS)

    Stahl, George J.

    1995-02-01

    The utilization of clusters of two or more metal oxide varistors (MOV's) connected in parallel for suppressing surges and transients. Particular embodiments are disclosed for both grounded and ungrounded power systems. Also disclosed are two-stage and multi-stage uni-directional and bi-directional suppressors. Uni-directional means that the suppressor is intended to be placed between a source and a load for the purpose-of preventing voltage surges and transients from being propagated from the source into the load.

  15. Optimal power flow incorporating voltage collapse constraints

    Microsoft Academic Search

    William Rosehart; C. Canizares; Victor Quintana

    1999-01-01

    The paper presents applications of optimization techniques to voltage collapse studies. First a “maximum distance to voltage collapse” algorithm that incorporates constraints on the current operating conditions is presented. Second, an optimal power flow formulation that incorporates voltage-stability criteria is proposed. The algorithms are tested on a 30-bus system using a standard power flow model, where the effect of limits

  16. Technical evaluation of the adequacy of station electric distribution system voltages for the R. E. Ginna Nuclear Power Station, Unit 1: selected issues program (Docket No. 50-244)

    SciTech Connect

    Selan, J. C.

    1981-11-05

    This report documents the technical evaluation of the adequacy of the station electric distribution system voltages for the R.E. Ginna Nuclear Power Station, Unit 1. The evaluation is to determine if the onsite distribution system, in conjunction with the offsite power sources, has sufficient capacity to automatically start and operate all Class 1E loads within the equipment voltage ratings under certain conditions established by the Nuclear Regulatory Commission. The analysis submitted demonstrates that acceptable voltages will be supplied to the Class 1E equipment under worst case conditions.

  17. Technical evaluation of the adequacy of station electric distribution systems voltages for the Calvert Cliffs Nuclear Power Plant, Units 1 and 2. Docket Nos. 50-317, 50-318

    SciTech Connect

    Selan, J. C.

    1982-04-09

    This report documents the technical evaluation of the adequacy of the station electric distribution system voltages for the Calvert Cliffs Nuclear Power Plant, Units 1 and 2. The evaluation is to determine if the onsite distribution system in conjunction with the offsite power sources has sufficient capacity to automatically start and operate all Class 1E loads within the equipment voltage ratings under certain conditions established by the Nuclear Regulatory Commission. The analyses submitted demonstrate that adequate voltage will be supplied to the Class 1E equipment under worst case conditions.

  18. Insulating materials and large high voltage electric systems

    NASA Astrophysics Data System (ADS)

    Dale, Steinar J.

    1990-09-01

    The traveler attended the 33rd Session of CIGRE (The International Conference on Large High Voltage Electric Systems) as a U.S. technical expert advisor. Over 200 papers were discussed, contributed from over 45 countries at the conference on all aspects of electric power generation and transmission. Of special interest was a panel session on superconducting technology for electric power systems and the participation on a new task force on the electrical insulation at cryogenic temperatures. Significant insight was gained into the development of superconducting power technologies in Europe and Japan. CIGRE has set up a committee to follow the development in research on the biological effects of electric and magnetic fields. The traveler also visited the Centre for Electric Power Engineering at the University of Strathclyde, Glasgow, Scotland and discussed research on degradation of polymeric cable insulation and gas insulated equipment.

  19. Wind Power Plant Voltage Stability Evaluation: Preprint

    SciTech Connect

    Muljadi, E.; Zhang, Y. C.

    2014-09-01

    Voltage stability refers to the ability of a power system to maintain steady voltages at all buses in the system after being subjected to a disturbance from a given initial operating condition. Voltage stability depends on a power system's ability to maintain and/or restore equilibrium between load demand and supply. Instability that may result occurs in the form of a progressive fall or rise of voltages of some buses. Possible outcomes of voltage instability are the loss of load in an area or tripped transmission lines and other elements by their protective systems, which may lead to cascading outages. The loss of synchronism of some generators may result from these outages or from operating conditions that violate a synchronous generator's field current limit, or in the case of variable speed wind turbine generator, the current limits of power switches. This paper investigates the impact of wind power plants on power system voltage stability by using synchrophasor measurements.

  20. Adaptive Phase Adjustment Synchronization Method for Source Voltage Distortion in Electric Ship

    E-print Network

    Lehman, Brad

    Adaptive Phase Adjustment Synchronization Method for Source Voltage Distortion in Electric Ship, the source voltage typically contains some distortion. Specifically, US Navy ship power generators experience such as aeroplanes, vehicles and electric ships. Due to the extensive use of devices with power electronics

  1. Intense neutron source: high-voltage power supply specifications

    SciTech Connect

    Riedel, A.A.

    1980-08-01

    This report explains the need for and sets forth the electrical, mechanical and safety specifications for a high-voltage power supply to be used with the intense neutron source. It contains sufficient information for a supplier to bid on such a power supply.

  2. Electrical Safety In The High Voltage Laboratory

    Microsoft Academic Search

    L. B. Gordon; D. L. Counts; W. W. Hofer; C. W. Jordan; A. E. Kirkewoog; B. R. Schleicher

    1989-01-01

    In the process of reevaluating the thoroughness and long-term retention of existing electrical safety training programs at Lawrence Livermore National Lab, a new, intensive training program has been developed. Although it encompasses the electrical safety of utility power it is primarily designed to include the specialized safety issues present in the high energy or pulsed power laboratory. The unique approach

  3. Electrical safety in the high voltage laboratory

    Microsoft Academic Search

    L. B. Gordon; D. L. Counts; W. W. Hofer; C. W. Jordan; A. E. Kirkewoog; B. R. Schleicher

    1989-01-01

    In the process of reevaluating the thoroughness and long term retention of existing electrical safety training programs at Lawrence Livermore National Lab, a new, intensive training program was developed. Although it encompasses the electrical safety of utility power it is primarily designed to include the specialized safety issues present in the high energy or pulsed power laboratory. The unique approach

  4. Electric fingerprint of voltage sensor domains.

    PubMed

    Souza, Caio S; Amaral, Cristiano; Treptow, Werner

    2014-12-01

    A dynamic transmembrane voltage field has been suggested as an intrinsic element in voltage sensor (VS) domains. Here, the dynamic field contribution to the VS energetics was analyzed via electrostatic calculations applied to a number of atomistic structures made available recently. We find that the field is largely static along with the molecular motions of the domain, and more importantly, it is minimally modified across VS variants. This finding implies that sensor domains transfer approximately the same amount of gating charges when moving the electrically charged S4 helix between fixed microscopic configurations. Remarkably, the result means that the observed operational diversity of the domain, including the extension, rate, and voltage dependence of the S4 motion, as dictated by the free energy landscape theory, must be rationalized in terms of dominant variations of its chemical free energy. PMID:25422443

  5. Piezoelectric transformer and modular connections for high power and high voltage power supplies

    NASA Technical Reports Server (NTRS)

    Vazquez Carazo, Alfredo (Inventor)

    2006-01-01

    A modular design for combining piezoelectric transformers is provided for high voltage and high power conversion applications. The input portions of individual piezoelectric transformers are driven for a single power supply. This created the vibration and the conversion of electrical to electrical energy from the input to the output of the transformers. The output portions of the single piezoelectric transformers are combining in series and/or parallel to provide multiple outputs having different rating of voltage and current.

  6. Electric motor alternating power supply for vehicles

    Microsoft Academic Search

    1982-01-01

    An electric motor alternating power supply for vehicles to replace gas-fueled engines, wherein the power supply includes an electric motor having a transmission mounted thereto, the motor being operated by two alternating power circuits, each having a battery that is alternately charged and discharged in a regulated sequential order by a sensing voltage relay which activates a secondary relay between

  7. TOPEX electrical power system

    NASA Technical Reports Server (NTRS)

    Chetty, P. R. K.; Roufberg, Lew; Costogue, Ernest

    1991-01-01

    The TOPEX mission requirements which impact the power requirements and analyses are presented. A description of the electrical power system (EPS), including energy management and battery charging methods that were conceived and developed to meet the identified satellite requirements, is included. Analysis of the TOPEX EPS confirms that all of its electrical performance and reliability requirements have been met. The TOPEX EPS employs the flight-proven modular power system (MPS) which is part of the Multimission Modular Spacecraft and provides high reliability, abbreviated development effort and schedule, and low cost. An energy balance equation, unique to TOPEX, has been derived to confirm that the batteries will be completely recharged following each eclipse, under worst-case conditions. TOPEX uses three NASA Standard 50AH Ni-Cd batteries, each with 22 cells in series. The MPS contains battery charge control and protection based on measurements of battery currents, voltages, temperatures, and computed depth-of-discharge. In case of impending battery depletion, the MPS automatically implements load shedding.

  8. Planning Reconfigurable Reactive Control for Voltage Stability Limited Power Systems

    Microsoft Academic Search

    Haifeng Liu; Licheng Jin; James D. McCalley; Ratnesh Kumar; Venkataramana Ajjarapu; Nicola Elia

    2009-01-01

    This paper proposes an optimization-based method of planning reactive power control for electric transmission systems to endow them with the capability of being reconfigured to a secure configuration under a list of contingencies. The overall objective function is to minimize the installation cost of new controls such as mechanically switched capacitors, while satisfying the requirements of voltage stability margin and

  9. 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

  10. 46 CFR 111.79-13 - Different voltages and power types.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...79-13 Section 111.79-13 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Receptacles § 111.79-13 Different voltages and power...

  11. 46 CFR 111.79-13 - Different voltages and power types.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...79-13 Section 111.79-13 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Receptacles § 111.79-13 Different voltages and power...

  12. Intelligent Voltage and Reactive Power Control of Mini-Hydro Power Stations for Maximisation of Real

    E-print Network

    Harrison, Gareth

    that are connected to the Distribution Network (DN) in many countries. Mini-hydro power generation plants based and electrically remote from load centres [1,2]. Unlike large-hydro plants that are connected to dedicated1 Intelligent Voltage and Reactive Power Control of Mini-Hydro Power Stations for Maximisation

  13. CPFLOW for Power Tracer and Voltage Monitoring

    E-print Network

    contact: Professor Hsiao-Dong Chiang School of Electrical and Computer Engineering Cornell University 328 a restructuring electric power industry and educating the next generation of power engineers. More information the `nose' point without the numerical difficulties of repeated power flow solvers. It can generate P-V, Q

  14. FBG based intelligent sensors and structure for electrical power system

    Microsoft Academic Search

    Yuan Yao; Benshun Yi; Jinsheng Xiao; Zhaohui Li

    2007-01-01

    Fiber Bragg grating (FBG) sensors are of particular interest for applications in the high voltage environments of electric power industry. The study on the parameter examination and health monitor of the electric power apparatus has great social significance and economic benefits. In this paper, the electric field or voltage sensor is constructed by using the electrostriction material PZT combined with

  15. Monitoring of high voltage power transformer using direct optical partial discharge detection technique

    Microsoft Academic Search

    S. Karmakar; N. K. Roy; P. Kumbhakar

    2009-01-01

    In electrical power systems, high voltage power transformers are used to transfer the power from one substation to another.\\u000a The insulation of the high voltage power transformers are gradually deteriorated due to electrical, chemical and mechanical\\u000a stresses caused by the partial discharges (PDs). It is well established from several studies that PDs are the major source\\u000a of insulation failure in

  16. Powering the electric car

    Microsoft Academic Search

    G. O. Murray; G. J. Ostrowski

    1981-01-01

    The electric car may represent major new opportunities for America and its electric utilities. Widespread use of electric cars can reduce consumption of both imported and domestic oil, substituting abundant American fuels such as coal and nuclear power. Air and noise pollution can be reduced since emissions from a single power plant are easier to control than those from thousands

  17. High voltage high frequency power transformer for pulsed power application

    Microsoft Academic Search

    Todor Filchev; Fabio Carastro; Pat Wheeler; Jon Clare

    2010-01-01

    This paper presents a new topology for a high voltage 50kV, high frequency (HF) 20kHz, multi-cored transformer. The transformer is suitable for use in pulsed power application systems. The main requirements are: high voltage capability, small size and weight. The HV, HF transformer is the main critical block of a high frequency power converter system. The transformer must have high

  18. Modular high voltage power supply for chemical analysis

    DOEpatents

    Stamps, James F. (Livermore, CA); Yee, Daniel D. (Dublin, CA)

    2008-07-15

    A high voltage power supply for use in a system such as a microfluidics system, uses a DC-DC converter in parallel with a voltage-controlled resistor. A feedback circuit provides a control signal for the DC-DC converter and voltage-controlled resistor so as to regulate the output voltage of the high voltage power supply, as well as, to sink or source current from the high voltage supply.

  19. Modular high voltage power supply for chemical analysis

    DOEpatents

    Stamps, James F. (Livermore, CA); Yee, Daniel D. (Dublin, CA)

    2007-01-09

    A high voltage power supply for use in a system such as a microfluidics system, uses a DC--DC converter in parallel with a voltage-controlled resistor. A feedback circuit provides a control signal for the DC--DC converter and voltage-controlled resistor so as to regulate the output voltage of the high voltage power supply, as well as, to sink or source current from the high voltage supply.

  20. Modular high voltage power supply for chemical analysis

    DOEpatents

    Stamps, James F. (Livermore, CA); Yee, Daniel D. (Dublin, CA)

    2010-05-04

    A high voltage power supply for use in a system such as a microfluidics system, uses a DC-DC converter in parallel with a voltage-controlled resistor. A feedback circuit provides a control signal for the DC-DC converter and voltage-controlled resistor so as to regulate the output voltage of the high voltage power supply, as well as, to sink or source current from the high voltage supply.

  1. Nanosecond High Voltage Pulse Generator using Water Gap Switch for Compact High Power Pulsed Microwave Generator

    Microsoft Academic Search

    Y. Minamitani; Y. Ohe; Y. Higashiyama

    2006-01-01

    Nanosecond and subnanosecond high voltage pulses can provide new applications. A cancer treatment by ultra-short pulse high electric field is one of them. High power pulsed microwave has been proposed to apply the high electric field for that treatment. This work focuses on the design of a compact high power pulsed microwave generator using nanosecond pulse power generator for the

  2. Nanosecond High Voltage Pulse Generator Using Water Gap Switch for Compact High Power Pulsed Microwave Generator

    Microsoft Academic Search

    Yasushi Minamitani; Yoshinori Ohe; Yoshio Higashiyama

    2007-01-01

    Nanosecond and sub-nanosecond high voltage pulses can provide new applications. A cancer treatment by an ultra-short pulse high electric field is one of them. High power pulsed microwave has been proposed to apply the high electric field for that treatment. This work focuses on the design of a compact high power pulsed microwave generator using a nanosecond pulse power generator

  3. Contract networks for electric power transmission

    Microsoft Academic Search

    William W. Hogan

    1992-01-01

    A contract network extends the concept of a contract path to address the problem of loop flow and congestion in electric power transmission systems. A contract network option provides an internally consistent framework for assigning long-term capacity rights to a complicated electric transmission network. The contract network respects the special conditions induced by Kirchoff's Laws; accommodates thermal, voltage, and contingency

  4. Electric power annual 1992

    SciTech Connect

    Not Available

    1994-01-06

    The Electric Power Annual presents a summary of electric utility statistics at national, regional and State levels. The objective of the publication is to provide industry decisionmakers, government policymakers, analysts and the general public with historical data that may be used in understanding US electricity markets. The Electric Power Annual is prepared by the Survey Management Division; Office of Coal, Nuclear, Electric and Alternate Fuels; Energy Information Administration (EIA); US Department of Energy. ``The US Electric Power Industry at a Glance`` section presents a profile of the electric power industry ownership and performance, and a review of key statistics for the year. Subsequent sections present data on generating capability, including proposed capability additions; net generation; fossil-fuel statistics; retail sales; revenue; financial statistics; environmental statistics; electric power transactions; demand-side management; and nonutility power producers. In addition, the appendices provide supplemental data on major disturbances and unusual occurrences in US electricity power systems. Each section contains related text and tables and refers the reader to the appropriate publication that contains more detailed data on the subject matter. Monetary values in this publication are expressed in nominal terms.

  5. Peak power bi-directional transfer from high speed flywheel to electrical regulated bus voltage system: A practical proposal for vehicular technology

    SciTech Connect

    Szabados, B.; Schaible, U.

    1998-03-01

    This paper provides a design outline and implementation procedure for a Secondary Energy Storage Unit (SESU) that can be used to meet the peak energy requirements of an electric vehicle during both acceleration and regenerative braking. The life cycle of the electric vehicle`s batteries can be extended considerably by supplying peak energy requirements from a secondary source. A simulation study was conducted to determine the peak power and energy requirements over the SAE recommended electric vehicle test procedure. A scaled prototype SESU was built using flywheel energy storage, and tests were performed to determine the energy transfer capabilities of a flywheel coupled high speed permanent magnet synchronous machine through the proposed system`s energy storage tank. Results are presented that indicate the necessity of the energy storage tank. An evaluation of the proposed system is also included which indicates the practicality of the system when compared to conventional regenerative control techniques.

  6. TOPEX electrical power system

    Microsoft Academic Search

    P. R. K. Chetty; Lew Roufberg; Ernest Costogue

    1991-01-01

    The TOPEX mission requirements which impact the power requirements and analyses are presented. A description of the electrical power system (EPS), including energy management and battery charging methods that were conceived and developed to meet the identified satellite requirements, is included. Analysis of the TOPEX EPS confirms that all of its electrical performance and reliability requirements have been met. The

  7. Electric Power Monitor

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Control center for SAMAC (System Automatic Monitor and Control) is a sophisticated dispatch computer system, developed by Rockwell International and operated by Philadelphia Electric Co. SAMAC monitors and controls the generation and distribution of electric power throughout the Philadelphia electric network. With the assistance of NASA's Apollo computer system technology, it enables human operators to isolate and correct power distribution problems more rapidly than was possible with earlier dispatch systems without centralized computer control.

  8. Voltage quality and reliability from electrical energy-storage systems

    Microsoft Academic Search

    B. Ratering-Schnitzler; R. Harke; M. Schroeder; T. Stephanblome; U. Kriegler

    1997-01-01

    Due to the increasing use of sensitive equipment for process control, the requirements for the voltage shape are growing. Voltage irregularities often cause the process control to fail, while the process at high performance is insensitive. Thus, the use of uninterruptible power systems (UPS) is indispensable. To improve voltage quality a new system is presented using the energy storage of

  9. High voltage power supplies - An engineering overview

    Microsoft Academic Search

    James W. Williams

    1987-01-01

    This overview paper presents an engineering-oriented status and progress report on several high voltage power supply applications. Although high-reliability aerospace uses are the main topic, industrial and commercial applications are also described. Traveling-wave-tube (TWT) supplies for ECM and radar systems are described, as are cathode-ray tube (CRT) and laser supplies. An update to the author's 1980 'report card' on aerospace

  10. High Voltage Power Supply Design Guide for Space

    NASA Technical Reports Server (NTRS)

    Bever, Renate S.; Ruitberg, Arthur P.; Kellenbenz, Carl W.; Irish, Sandra M.

    2006-01-01

    This book is written for newcomers to the topic of high voltage (HV) in space and is intended to replace an earlier (1970s) out-of-print document. It discusses the designs, problems, and their solutions for HV, mostly direct current, electric power, or bias supplies that are needed for space scientific instruments and devices, including stepping supplies. Output voltages up to 30kV are considered, but only very low output currents, on the order of microamperes. The book gives a brief review of the basic physics of electrical insulation and breakdown problems, especially in gases. It recites details about embedment and coating of the supplies with polymeric resins. Suggestions on HV circuit parts follow. Corona or partial discharge testing on the HV parts and assemblies is discussed both under AC and DC impressed test voltages. Electric field analysis by computer on an HV device is included in considerable detail. Finally, there are many examples given of HV power supplies, complete with some of the circuit diagrams and color photographs of the layouts.

  11. Index-based reactive power compensation scheme for voltage regulation

    NASA Astrophysics Data System (ADS)

    Dike, Damian Obioma

    2008-10-01

    Increasing demand for electrical power arising from deregulation and the restrictions posed to the construction of new transmission lines by environment, socioeconomic, and political issues had led to higher grid loading. Consequently, voltage instability has become a major concern, and reactive power support is vital to enhance transmission grid performance. Improved reactive power support to distressed grid is possible through the application of relatively unfamiliar emerging technologies of "Flexible AC Transmission Systems (FACTS)" devices and "Distributed Energy Resources (DERS)." In addition to these infrastructure issues, a lack of situational awareness by system operators can cause major power outages as evidenced by the August 14, 2003 widespread North American blackout. This and many other recent major outages have highlighted the inadequacies of existing power system indexes. In this work, a novel "Index-based reactive compensation scheme" appropriate for both on-line and off-line computation of grid status has been developed. A new voltage stability index (Ls-index) suitable for long transmission lines was developed, simulated, and compared to the existing two-machine modeled L-index. This showed the effect of long distance power wheeling amongst regional transmission organizations. The dissertation further provided models for index modulated voltage source converters (VSC) and index-based load flow analysis of both FACTS and microgrid interconnected power systems using the Newton-Raphson's load flow model incorporated with multi-FACTS devices. The developed package has been made user-friendly through the embodiment of interactive graphical user interface and implemented on the IEEE 14, 30, and 300 bus systems. The results showed reactive compensation has system wide-effect, provided readily accessible system status indicators, ensured seamless DERs interconnection through new islanding modes and enhanced VSC utilization. These outcomes may contribute to optimal utilization of compensation devices and available transfer capability as well as reduce system outages through better regulation of power operating voltages.

  12. Electrical degradation mechanisms of RF power GaAs PHEMTs

    E-print Network

    Villanueva, Anita A. (Anita Ariel), 1978-

    2007-01-01

    GaAs Pseudomorphic High-Electron Mobility Transistors (PHEMTs) are widely used in RF power applications. Since these devices typically operate at high power levels and under high voltage biasing, their electrical reliability ...

  13. Fuzzy based coordinated controller for power system stability and voltage regulation

    Microsoft Academic Search

    N. Yadaiah; A. Ganga Dinesh Kumar; J. L. Bhattacharya

    2004-01-01

    This paper deals with the design of a fuzzy based coordinated controller to prevent an electric power system losing synchronism after a large sudden fault and to achieve good post-fault voltage level. The developed controller has a fuzzy logic unit (FLU) which, accepts change in terminal voltage and speed deviation as its inputs and generates the required weightage for the

  14. A novel series connected batteries state of high voltage safety monitor system for electric vehicle application.

    PubMed

    Jiaxi, Qiang; Lin, Yang; Jianhui, He; Qisheng, Zhou

    2013-01-01

    Batteries, as the main or assistant power source of EV (Electric Vehicle), are usually connected in series with high voltage to improve the drivability and energy efficiency. Today, more and more batteries are connected in series with high voltage, if there is any fault in high voltage system (HVS), the consequence is serious and dangerous. Therefore, it is necessary to monitor the electric parameters of HVS to ensure the high voltage safety and protect personal safety. In this study, a high voltage safety monitor system is developed to solve this critical issue. Four key electric parameters including precharge, contact resistance, insulation resistance, and remaining capacity are monitored and analyzed based on the equivalent models presented in this study. The high voltage safety controller which integrates the equivalent models and control strategy is developed. By the help of hardware-in-loop system, the equivalent models integrated in the high voltage safety controller are validated, and the online electric parameters monitor strategy is analyzed and discussed. The test results indicate that the high voltage safety monitor system designed in this paper is suitable for EV application. PMID:24194677

  15. Recent Advances in High-Voltage Direct-Current Power Transmission Systems

    Microsoft Academic Search

    Vassilios G. Agelidis; Georgios D. Demetriades; Nikolas Flourentzou

    2006-01-01

    The ever increasing progress of high-voltage high-power fully-controlled semiconductor technology continues to have a significant impact on the development of advanced power electronic apparatus used to support optimised operations and efficient management of electrical grids, which in many cases, are fully or partially deregulated networks. Developments advance both the high-voltage direct-current (HVDC) power transmission and the flexible alternating current transmission

  16. Voltage dips at the terminals of wind power installations

    Microsoft Academic Search

    Math H. J. Bollen; Gabriel Olguin; Marcia Martins

    2005-01-01

    This article gives an overview of the kind of voltage dips that can be expected at the terminals of a wind power installation. The overview is based on the study of those dips at the terminals of industrial installations and provides a guideline for the testing of wind power installations against voltage dips. For voltage dips due to faults, a

  17. Electric power monthly, June 1988

    SciTech Connect

    Not Available

    1988-09-15

    Total net generation by electric utilities in the United States for the month of June 1988 was 232,183 gigawatthours, 3 percent higher than the amount reported a year ago. Although temperatures (measured by cooling degree days) for June 1988 were 9 percent warmer than normal, they were 3 percent cooler than for June 1987. A large portion of that higher demand for electricity was met by nuclear-powered generation. Net generation from nuclear power during June 1988 (44,079 gigawatthours) was only 1 percent below the record set in January of this year, and 21 percent above that reported in June 1987 (36,560 gigawatthours). The only energy source other than nuclear that reported higher levels of net generation during June 1988 was coal, up 2 percent over the same period last year. Warmer-than-normal temperatures did, however, have an affect on various parts of the country. For example, on Wednesday, June 22, 1988, unseasonably high temperatures forced the Pennsylvania, New Jersey, and Maryland Interconnection (PJM) into a system-wide 5-percent voltage reduction for 2 hours. Contributing to that reduction in voltage was the shutdown of the Three Mile Island, Unit 1, for refueling and the closing of the Peach Bottom Units 2 and 3 by the Nuclear Regulatory Commission. Three Mile Island, Unit 1, normally provides the PJM system with about 800 megawatts while the two Peach Bottom units, combined, provide approximately 2100 megawatts. 10 refs., 1 fig., 27 tabs.

  18. Low-voltage and High-current DC Power Supply Using Direct Power Control Based Three-phase to Single-phase Direct Converter

    E-print Network

    Fujimoto, Hiroshi

    PE 07 9 PSE 07 24 SPC 07 49 1 6 Low-voltage and High-current DC Power Supply Using Direct Power University of Technology) This paper describes a low-voltage and high-current DC power supply with a direct-power-controlled (DPC) AC-AC converter, which is applied to electric furnaces. The AC-AC converter operates

  19. Preventive strategy method for voltage and reactive power dispatch

    SciTech Connect

    Sun, D.T.W.

    1981-01-01

    The cause of 1977 New York blackout and several other power system collapses could be traced back to the reactive power problem. The fact that these recent power disruptions were caused by the voltage and reactive power problem has strongly indicated that voltage and reactive power dispatching plays a major role in the security of modern electric power system. The conventional VAR dispatching scheme just considers the security constraints of the intact system. The operating condition obtained from this scheme can not sustain contingency cases. A preventive strategy method of the voltage and reactive power dispatching, referred to as the global VAR dispatching method, as been developed in this research. A short-term forecasted operating condition is used as the base case. Basing upon this condition, some severe contingency cases are selected. The base case and selected contingency cases are considered together in the global VAR dispatching calculation to achieve an optimal operating condition which can cope with the contingency. The global VAR dispatching method is divided into two stages. Stage One, the rough action calculation, provides system operators a quick but rough guideline to eliminate violations. Stage Two, the fine tune calculation, can obtain an optimal point and improve the system security. A computer program has been developed on an IBM 4341 computer. This program, which needs 232 kilo-bytes of core memory, can solve the actual Con. Edison system (420 buses, 930 lines) with ten pre-selected severe contingencies in 152 seconds. To the author's knowledge, there are not any published articles discussing the global VAR dispatch. The global VAR dispatching method and the program developed in this research is a contribution.

  20. High-Power Controllable Voltage Quality Disturbance Generator

    Microsoft Academic Search

    Gu Ren; Xiao Xiangning

    \\u000a This paper proposes a high-power controllable voltage quality disturbance generator, which is composed of multiplex cascade\\u000a H bridge modules, and simulates many types of voltage quality problems, such as voltage swell and sag, fluctuation and flicker\\u000a and so on. One side of the device connects the power system with cascade H bridge to improve voltage level. The other side\\u000a connects

  1. Electric Power Annual

    EIA Publications

    2015-01-01

    Presents 11 years (2003 - 2013) of national-level data on electricity generating capacity, electricity generation and useful thermal output, fuel receipts, consumption, and emissions. This year's Electric Power Annual has expanded to include several new table series. These include several new annual breakouts of renewable biomass energy sources including wood/wood waste, landfill gas, and biogenic municipal solid waste in Chapter 5 (Consumption of Fossil Fuels); state details of emissions from energy consumption at conventional power plants and combined-heat-and-power plants (Table 9.5); and monthly capacity factors for the past three years and annual capacity factors back to 2008 (Tables 4.8.A. and 4.8.B.)

  2. 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

  3. Monitoring and control of voltage stability in power systems

    SciTech Connect

    Sallam, A.A.; Aboul-Ela, M.E.; Elaraby, E.E. [Suez Canal Univ., Port-Said (Egypt)

    1995-12-31

    This paper proposes a new technique in controlling voltage instability in power systems. This technique coordinates between the reactive power of excitation systems and that of static var compensators (SVCs). The method starts with the decomposition of system into several voltage control areas (VCAs). When a reactive power deficiency occurs in certain area, excitation systems respond first to supply the required reactive power by increasing reactive generation of synchronous generators to its upper limit. If more reactive power is needed within the specific area to recover voltage instability, a SVC will be inserted by a switching controller in order to achieve the reactive balance. This controller receives an actuating signal when the terminal voltage is still unsatisfactory. By this technique, it is possible to fully utilize the excitation systems reactive power, and to design economic size SVCs to recover voltage instability. The application of the proposed technique on the New-England 39 bus system proves its efficiency in controlling voltage instability.

  4. Improved detection of electrical activity with a voltage probe based on a voltage-sensing phosphatase

    PubMed Central

    Tsutsui, Hidekazu; Jinno, Yuka; Tomita, Akiko; Niino, Yusuke; Yamada, Yoshiyuki; Mikoshiba, Katsuhiko; Miyawaki, Atsushi; Okamura, Yasushi

    2013-01-01

    One of the most awaited techniques in modern physiology is the sensitive detection of spatiotemporal electrical activity in a complex network of excitable cells. The use of genetically encoded voltage probes has been expected to enable such analysis. However, in spite of recent progress, existing probes still suffer from low signal amplitude and/or kinetics too slow to detect fast electrical activity. Here, we have developed an improved voltage probe named Mermaid2, which is based on the voltage-sensor domain of the voltage-sensing phosphatase from Ciona intestinalis and Förster energy transfer between a pair of fluorescent proteins. In mammalian cells, Mermaid2 permits ratiometric readouts of fractional changes of more than 50% over a physiologically relevant voltage range with fast kinetics, and it was used to follow a train of action potentials at frequencies of up to 150 Hz. Mermaid2 was also able to detect single action potentials and subthreshold voltage responses in hippocampal neurons in vitro, in addition to cortical electrical activity evoked by sound stimuli in single trials in living mice. PMID:23836686

  5. The design, construction, and operation of long-distance high-voltage electricity transmission technologies.

    SciTech Connect

    Molburg, J. C.; Kavicky, J. A.; Picel, K. C.

    2008-03-03

    This report focuses on transmission lines, which operate at voltages of 115 kV and higher. Currently, the highest voltage lines comprising the North American power grid are at 765 kV. The grid is the network of transmission lines that interconnect most large power plants on the North American continent. One transmission line at this high voltage was built near Chicago as part of the interconnection for three large nuclear power plants southwest of the city. Lines at this voltage also serve markets in New York and New England, also very high demand regions. The large power transfers along the West Coast are generally at 230 or 500 kV. Just as there are practical limits to centralization of power production, there are practical limits to increasing line voltage. As voltage increases, the height of the supporting towers, the size of the insulators, the distance between conductors on a tower, and even the width of the right-of-way (ROW) required increase. These design features safely isolate the electric power, which has an increasing tendency to arc to ground as the voltage (or electrical potential) increases. In addition, very high voltages (345 kV and above) are subject to corona losses. These losses are a result of ionization of the atmosphere, and can amount to several megawatts of wasted power. Furthermore, they are a local nuisance to radio transmission and can produce a noticeable hum. Centralized power production has advantages of economies of scale and special resource availability (for instance, hydro resources), but centralized power requires long-distance transfers of power both to reach customers and to provide interconnections for reliability. Long distances are most economically served at high voltages, which require large-scale equipment and impose a substantial footprint on the corridors through which power passes. The most visible components of the transmission system are the conductors that provide paths for the power and the towers that keep these conductors at a safe distance from each other and from the ground and the natural and built environment. Common elements that are generally less visible (or at least more easily overlooked) include the maintained ROW along the path of the towers, access roads needed for maintenance, and staging areas used for initial construction that may be restored after construction is complete. Also visible but less common elements along the corridor may include switching stations or substations, where lines of similar or different voltages meet to transfer power.

  6. Electricity: From Tabletop to Power Plant

    NASA Astrophysics Data System (ADS)

    Moran, Timothy

    2009-01-01

    While electricity is central to our daily lives, it remains "black box" technology to most students. They know that electricity is produced somewhere and that it costs money, but they do not have personal experience with the operation and scale of the machines that provide it. Fortunately, electricity generation can be added to the more basic circuit topics (series, parallel, current, voltage, etc.) with only a small investment in equipment. Providing students with hands-on experience with small power sources will help them make wise decisions about electricity.

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

    E-print Network

    Gou, Jian

    1992-01-01

    A DSP BASED REAL TIME POWER QUALITY MEASUREMENT SYSTEM WITH VOLTAGE DISTORTION IMPROVEMENT CAPABILITY A Thesis by JIAN GOU Submitted to the Office of Graduate Studies oi' Texas ARM University m partial fulfillment of the requirements... for the degree of MASTER OF SCIENCE August 1992 Major Subject: Electrical Engineering A DSP BASED REAL TIME POWER QUALITY MEASUREMENT SYSTEM WITH VOLTAGE DISTORTION IMPROVEMENT CAPABILITY A Thesis by JIAN GOU Approved as to style and content by: P...

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

    E-print Network

    Gou, Jian

    1992-01-01

    A DSP BASED REAL TIME POWER QUALITY MEASUREMENT SYSTEM WITH VOLTAGE DISTORTION IMPROVEMENT CAPABILITY A Thesis by JIAN GOU Submitted to the Office of Graduate Studies oi' Texas ARM University m partial fulfillment of the requirements... for the degree of MASTER OF SCIENCE August 1992 Major Subject: Electrical Engineering A DSP BASED REAL TIME POWER QUALITY MEASUREMENT SYSTEM WITH VOLTAGE DISTORTION IMPROVEMENT CAPABILITY A Thesis by JIAN GOU Approved as to style and content by: P...

  9. Voltage versus VAr\\/power factor regulation on synchronous generators

    Microsoft Academic Search

    Thomas W. Eberly; Richard C. Schaefer

    2002-01-01

    When paralleled to the utility bus, synchronous generators can be controlled using either terminal voltage or VAr\\/power factor control. Selection is dependent upon the size of the generator and the stiffness of the connecting utility bus. For large generators where the kVA is significant, these machines are usually terminal voltage regulated and dictate the system's bus voltage. When smaller terminal

  10. Electric powered wheelchairs

    Microsoft Academic Search

    D. Ding; R. A. Cooper

    2005-01-01

    The purpose of this review is to convey the depth and breadth of the research conducted on electric-powered wheelchair (EPW) control technology as well as provide insights into future directions. We review the concepts and previous work on velocity control, traction control, suspension control, stability control, stair-climbing wheelchairs, and wheelchair navigation. The information gathered in this study is intended to

  11. Motor vehicle electrical system providing multiple DC voltages

    Microsoft Academic Search

    1987-01-01

    This patent describes a multiple DC voltage electrical system for an automotive vehicle, comprising: a three-phase AC generator driven by the engine of the vehicle for producing a three-phase AC voltage across three-phase output windings connected in a wye configuration having a neutral node; means for connecting the neutral node of the wye configured three-phase output windings of the generator

  12. Multi-objective Optimal Power Flows to Evaluate Voltage Security Costs in Power Networks

    E-print Network

    Cañizares, Claudio A.

    1 Multi-objective Optimal Power Flows to Evaluate Voltage Security Costs in Power Networks William-objective methodologies to op- timize active and reactive power dispatch while maximizing volt- age security in power to suggest possible ways of costing voltage security in power systems. Index Terms-- Voltage collapse

  13. Plasma Membrane Voltage Changes during Nanosecond Pulsed Electric Field Exposure

    PubMed Central

    Frey, W.; White, J. A.; Price, R. O.; Blackmore, P. F.; Joshi, R. P.; Nuccitelli, R.; Beebe, S. J.; Schoenbach, K. H.; Kolb, J. F.

    2006-01-01

    The change in the membrane potential of Jurkat cells in response to nanosecond pulsed electric fields was studied for pulses with a duration of 60 ns and maximum field strengths of ?100 kV/cm (100 V/cell diameter). Membranes of Jurkat cells were stained with a fast voltage-sensitive dye, ANNINE-6, which has a subnanosecond voltage response time. A temporal resolution of 5 ns was achieved by the excitation of this dye with a tunable laser pulse. The laser pulse was synchronized with the applied electric field to record images at times before, during, and after exposure. When exposing the Jurkat cells to a pulse, the voltage across the membrane at the anodic pole of the cell reached values of 1.6 V after 15 ns, almost twice the voltage level generally required for electroporation. Voltages across the membrane on the side facing the cathode reached values of only 0.6 V in the same time period, indicating a strong asymmetry in conduction mechanisms in the membranes of the two opposite cell hemispheres. This small voltage drop of 0.6–1.6 V across the plasma membrane demonstrates that nearly the entire imposed electric field of 10 V/?m penetrates into the interior of the cell and every organelle. PMID:16513782

  14. Plasma membrane voltage changes during nanosecond pulsed electric field exposure.

    PubMed

    Frey, W; White, J A; Price, R O; Blackmore, P F; Joshi, R P; Nuccitelli, R; Beebe, S J; Schoenbach, K H; Kolb, J F

    2006-05-15

    The change in the membrane potential of Jurkat cells in response to nanosecond pulsed electric fields was studied for pulses with a duration of 60 ns and maximum field strengths of approximately 100 kV/cm (100 V/cell diameter). Membranes of Jurkat cells were stained with a fast voltage-sensitive dye, ANNINE-6, which has a subnanosecond voltage response time. A temporal resolution of 5 ns was achieved by the excitation of this dye with a tunable laser pulse. The laser pulse was synchronized with the applied electric field to record images at times before, during, and after exposure. When exposing the Jurkat cells to a pulse, the voltage across the membrane at the anodic pole of the cell reached values of 1.6 V after 15 ns, almost twice the voltage level generally required for electroporation. Voltages across the membrane on the side facing the cathode reached values of only 0.6 V in the same time period, indicating a strong asymmetry in conduction mechanisms in the membranes of the two opposite cell hemispheres. This small voltage drop of 0.6-1.6 V across the plasma membrane demonstrates that nearly the entire imposed electric field of 10 V/mum penetrates into the interior of the cell and every organelle. PMID:16513782

  15. US electric power system reliability

    NASA Astrophysics Data System (ADS)

    Electric energy supply, transmission and distribution systems are investigated in order to determine priorities for legislation. The status and the outlook for electric power reliability are discussed.

  16. Study on Location of All-Dielectric Self-Supporting Fiber-Optic Cable on High-Voltage Power Tower

    Microsoft Academic Search

    Lu Tiebing; Zhao Zhibin; Cui Xiang

    2006-01-01

    ADSS (all-dielectric self-supporting) fiber-optic cable will be seriously damaged when it is located at the position of intensive electric field. Therefore, it is necessary to analyze the distribution of the electric field near the high-voltage power towers. By using method of moment (MoM), the electric field near some high-voltage power towers is calculated, and the location of ADSS fiber-optic cable

  17. Peak power bi-directional transfer from high speed flywheel to electrical regulated bus voltage system: a practical proposal for vehicular technology

    Microsoft Academic Search

    B. Szabodos; Uwe Schaible

    1998-01-01

    This paper provides a design outline and implementation procedure for a secondary energy storage unit (SESU) that can be used to meet the peak energy requirements of an electric vehicle during both acceleration and regenerative braking. The life cycle of the electric vehicle's batteries can be extended considerably by supplying peak energy requirements from a secondary source. A simulation study

  18. Interesting Case Series High-Voltage Electrical Shock Without Injury

    E-print Network

    Illinois at Urbana-Champaign, University of

    has a hand-to-foot current path with no electrical contact to the head. Name 3 mechanisms of injury that commonly lead to severe cognitive deficits with such electrical contacts. 3. The effects of electricity or electrical burn injuries between 1992 and 1998. In those cases, contact with overhead power lines caused 41

  19. Milligram-scale high-voltage power electronics for piezoelectric microrobots

    Microsoft Academic Search

    Michael Karpelson; Gu-yeon Wei; Robert J. Wood

    2009-01-01

    Piezoelectric actuators can achieve high efficiency and power density in very small geometries, which shows promise for microrobotic applications, such as flapping-wing robotic insects. From the perspective of power electronics, such actuators present two challenges: high operating voltages, ranging from tens to thousands of volts, and a low electromechanical coupling factor, which necessitates the recovery of unused electrical energy. This

  20. Phasor measurement placement for voltage stability analysis of power systems

    Microsoft Academic Search

    L. Mili; T. Baldwin; R. Adapa

    1990-01-01

    The use of real-time phasor measurements for voltage stability analysis of power systems is considered. Two schemes of phasor measurement unit (PMU) placement have been investigated. In the first scheme, PMUs are used as pilot points for the secondary voltage control of a power system. Several criteria for pilot point selections are reviewed and assessed. In the second scheme, the

  1. Conceptual definition of a high voltage power supply test facility

    NASA Technical Reports Server (NTRS)

    Biess, John J.; Chu, Teh-Ming; Stevens, N. John

    1989-01-01

    NASA Lewis Research Center is presently developing a 60 GHz traveling wave tube for satellite cross-link communications. The operating voltage for this new tube is - 20 kV. There is concern about the high voltage insulation system and NASA is planning a space station high voltage experiment that will demonstrate both the 60 GHz communications and high voltage electronics technology. The experiment interfaces, requirements, conceptual design, technology issues and safety issues are determined. A block diagram of the high voltage power supply test facility was generated. It includes the high voltage power supply, the 60 GHz traveling wave tube, the communications package, the antenna package, a high voltage diagnostics package and a command and data processor system. The interfaces with the space station and the attached payload accommodations equipment were determined. A brief description of the different subsystems and a discussion of the technology development needs are presented.

  2. Voltage saturation in electrical contacts via viscoplastic creep

    SciTech Connect

    Streator, Jeffrey L [ORNL; Bansal, Dinesh G [ORNL

    2011-01-01

    Electrical contact resistance affects the performance of electrical switches and other current-carrying interfaces. This study investigates the behavior of electrical contact resistance for copper copper and aluminum aluminum sphere-on-flat contact as a function of current through the interface. It is observed that the contact resistance may either increase or decrease with increasing current, depending on the current level as well as the current history. At low current levels the voltage drop across the interface increases initially with increasing current until it saturates. The voltage level remains nearly constant even if the current is increased beyond the value corresponding to saturation. Hereafter any subsequent decrease in current yields a corresponding decrease in voltage, so that the associated current cycle shows substantial hysteresis. However, subsequent cycles of current are reversible so long as the voltage remains below the saturation point. Analyses of the results suggest that the mechanism of viscoplastic creep is responsible for the voltage saturation phenomenon. 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  3. Electric power for space satellites

    NASA Technical Reports Server (NTRS)

    Mackenzie, C. M.

    1974-01-01

    The development of electric power systems for satellites is discussed as an evolutionary process requiring the integration of power generation, power storage, and power control and distribution. The growth of space electric power systems is traced. The capabilities and limitations of the various elements (i.e. silicon solar cells) are discussed together with their impact on future technological growth.

  4. Human Factors Aspects of Power System Voltage Visualizations Douglas A. Wiegmann Aaron M. Rich Thomas J. Overbye Yan Sun

    E-print Network

    Human Factors Aspects of Power System Voltage Visualizations Douglas A. Wiegmann Aaron M. Rich with the human factors aspects of using color contours to visualize electric power system bus voltage magnitude, the second only one-line contour data, while the third saw both. The purpose of the experiment

  5. E-beam high voltage switching power supply

    Microsoft Academic Search

    Daniel W. Shimer; Arnold C. Lange

    1997-01-01

    A high power, solid state power supply is described for producing a controllable, constant high voltage output under varying and arcing loads suitable for powering an electron beam gun or other ion source. The present power supply is most useful for outputs in a range of about 100-400 kW or more. The power supply is comprised of a plurality of

  6. Tc-99m PYP scanning following low voltage electrical injury.

    PubMed

    Spencer, R R; Williams, A G; Mettler, F A; Christie, J H; Rosenberg, R D; Weaver, W D

    1983-12-01

    An adolescent boy sustained low voltage electrical injury to his extremities when he inadvertently touched a low tension (440 volts) wire with a metal tube. Early in his hospital course, he was evaluated with Tc-99m pyrophosphate whole body scanning for the extent of his injuries. The scintigraphic findings correlated well with his subsequent clinical course. PMID:6317262

  7. Electrical aging and electroluminescence in epoxy under repetitive voltage surges

    Microsoft Academic Search

    G. C. Stone; R. G. Van Heeswijk; R. Bartnikas

    1992-01-01

    An extensive statistical accelerated aging experiment, involving a total of 180 unfilled type epoxy specimens, has been conducted to determine the number of voltage surges required to initiate electrical trees under various magnitudes, surge repetition rates, and polarity conditions. The specimens were tested one at a time according to a full factorial experimental design. During many of the aging tests,

  8. Students' understanding of voltage in simple parallel electric circuits

    Microsoft Academic Search

    Robin Millar; Kian Lim Beh

    1993-01-01

    This paper reports an investigation of the performance of school students at age 15 on written diagnostic questions involving the prediction of meter readings in simple electric circuits with parallel branches. Results show that these students tend to perceive such questions in resistance?current terms, with a primary focus on resistor addition, rather than in voltage terms, with two loads being

  9. High voltage electrical insulation coating for refractory materials

    NASA Technical Reports Server (NTRS)

    Lent, W. E.

    1972-01-01

    Formula and process have been developed for coating refractory metal surfaces with high voltage electrical insulation for use at temperatures to 600 C. Coatings were specifically developed as an insulation for the surface of a perforated, molybdenum, ion-accelerator grid, but are not limited to this application.

  10. 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.

  11. Electricity Today30 American Electric Power, working

    E-print Network

    Laughlin, Robert B.

    Electricity Today30 American Electric Power, working at the request of, and in partnership with by building transmis- sion infrastructure that will enable wind power to become a larger part of the nation, the American Wind Energy Association (AWEA), presents a high-level, concep- tual interstate transmission plan

  12. Method of assessment of the state of charge and voltage level in the electric power distribution network. Implementation in the improvement of supply quality

    Microsoft Academic Search

    J. I. García-Román; E. Gonzalez-Romera; F. Barrero-González; D. Carmona-Fernández; J. A. Álvarez-Moreno

    2006-01-01

    Nowadays in order to know in real time the level of charge existing in a distribution network, the installation of a remote infrastructure of operation and supervision is necessary, allowing an immediate view of its electrical state, both normal operation as well as in case of incident. The analysis of the state of the network provides useful data for the

  13. High-Voltage Power Source on the Basis of Magnetocumulative Generator of the Type EMG-80

    NASA Astrophysics Data System (ADS)

    Boriskin, A. S.; Dimant, Ye. M.; Selemir, V. D.; Solov'yev, A. A.

    2004-11-01

    Some mathematical models and results of mathematical simulations of voltage source operation (high-voltage generator) consisting of a magneto-cumulative generator (MCG) and voltage multiplier are presented in this paper. A voltage multiplier is a device in which all voltages resulting from electric explosions of the conductors in separate inductive storage capacitors, connected in parallel to the MCG, are summed with the help of special switching. For numerical studies we chose the MCG with the EMG-80-type transfomer. It is in serial production, has a significant power capacity of 200 kJ and has a small volume of ~0.25 m3. Adaptability of this model for the analysis was confirmed with the experimental results. Calculations showed the possibility of obtaining megavolt voltage levels.

  14. Optimal reactive power dispatch algorithm for voltage stability improvement

    Microsoft Academic Search

    Bansilal D. Thukaram; K. Parthasarathy

    1996-01-01

    This paper presents an algorithm for monitoring and improving voltage stability in power systems for a base case and credible contingency conditions. The monitoring methodology proposed here is based on the L-index of load buses. This index uses information on a normal load flow and is in the range of 0 (no load of system) to 1 (voltage collapse). The

  15. Breaking the power delivery wall using voltage stacking

    Microsoft Academic Search

    Kaushik Mazumdar; Mircea Stan

    2012-01-01

    We propose the use of voltage stacking for addressing some of the power delivery issues for many-core processors. To demonstrate the effectiveness of our method we first design a proxy for a many-core stacked processor in the form of a regular structure using multiple ring oscillators where we can control the voltage, frequency and switching activity for individual rings. For

  16. Electric and magnetic field measurements in a high voltage center

    Microsoft Academic Search

    A. S. Safigianni; A. I. Spyridopoulos; V. L. Kanas

    2011-01-01

    This paper investigates the electric and magnetic fields inside a high voltage center in Philippi, Greece, constituted both of 400\\/150 kV and 150\\/20 kV substation areas. Results of previous field measurements and calculations in substations are presented first. The basic data distinguishing the examined center from previously examined substations follow. The main results of the field measurements in the areas

  17. Improving Electrical Efficiency of Edm Power Supply

    NASA Astrophysics Data System (ADS)

    Toma, Emanoil; Simion, Carmen Mihaela

    2014-11-01

    This paper briefly presents the principal types of Pulse Generators for Electrical Discharge Machining and ways to improve electrical efficiency. A resonant converter with series-parallel LCC circuit, for EDM applications, was analyzed by PSpice simulation. The performances of EDM Power Supply were improved by adding an energy recovering - voltage limiter circuit. The shape of current pulse was changed by adding a supplementary MOSFET Switch in parallel with the gap. Two or more converters can be parallelized, in this way output current can be changed. A bloc-schema was conceived for EDM experimental set up

  18. Secondary and Tertiary Voltage Regulation based on optimal power flows

    Microsoft Academic Search

    Bo Hu; Claudio A. Cañizares; Mingbo Liu

    2010-01-01

    This paper proposes a combined Secondary and Tertiary Voltage Regulation (SVR+TVR) methodology based on real-time optimal power flows (OPFs) to periodically update the generators' voltage regulator set points. Minimum active power losses (MAPL) and maximum loadability (ML) OPF approaches are used for the proposed SVR+TVR control. The presented technique is compared against a “classical” SVR control, where the pilot-bus set

  19. Power voltage current convertor using quasi complementary MOSFET current mirrors

    PubMed Central

    MacLachlan, R. A.; Riviere, C. N.

    2011-01-01

    A voltage current convertor is described having a quasi complementary class AB architecture that is particularly suited to implementation using discrete power MOSFETs. High-voltage mirror designs are presented, enabling the construction of sources with kilovolt compliance range, tens of watts of output power and greater than 100 kHz bandwidth. G? output impedance and distortion below 1% can be obtained with no trimming or transistor matching. PMID:22312182

  20. Design of Low Voltage Low Power Operational Amplifier

    Microsoft Academic Search

    Manju Sandhu; Manju Bala

    2012-01-01

    With the demand of low power applications, running circuits with reduced supply voltage can be of great advantage. Integrated circuit designers start to face a power wall as the most difficult constraints in new technology and circuit development are not triggered by process scaling factors, but by barriers imposed by packaging and cooling. The demand of circuits with reduced power

  1. Contribution Allocation for Voltage Stability In Deregulated Power Systems

    E-print Network

    that the power factor of the load is constant as the load changes. We also assumed that the voltage dynamic, stability margin I. INTRODUCTION The deregulated power system is based on transactions; each part and one load bus system is used to demonstrate our approach. The system has three basic parts of the power

  2. A practical voltage-stability-constrained optimal power flow

    Microsoft Academic Search

    Rafael J. Avalos; Claudio A. Canizares; Miguel F. Anjos

    2008-01-01

    This paper proposes a novel and practical method to enforce a voltage stability constraint (VSC) in an optimal power flow (OPF) auction model, based on the minimum singular value and minimum singular vectors of the power flow Jacobian. The proposed technique is based on a singular value decomposition of the power flow Jacobian at a given solution point, plus an

  3. 30 CFR 56.12071 - Movement or operation of equipment near high-voltage power lines.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Electricity § 56.12071 Movement or operation of equipment near high-voltage power lines. When equipment must be moved or...

  4. 30 CFR 56.12071 - Movement or operation of equipment near high-voltage power lines.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Electricity § 56.12071 Movement or operation of equipment near high-voltage power lines. When equipment must be moved or...

  5. 30 CFR 56.12071 - Movement or operation of equipment near high-voltage power lines.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Electricity § 56.12071 Movement or operation of equipment near high-voltage power lines. When equipment must be moved or...

  6. Transdisciplinary electric power grid science

    E-print Network

    Brummitt, Charles D; Dobson, Ian; Moore, Cristopher; D'Souza, Raissa M

    2013-01-01

    The 20th-century engineering feat that most improved the quality of human life, the electric power system, now faces discipline-spanning challenges that threaten that distinction. So multilayered and complex that they resemble ecosystems, power grids face risks from their interdependent cyber, physical, social and economic layers. Only with a holistic understanding of the dynamics of electricity infrastructure and human operators, automatic controls, electricity markets, weather, climate and policy can we fortify worldwide access to electricity.

  7. Power quality improvement at medium-voltage grids using Hexagram Active Power Filter

    Microsoft Academic Search

    Jun Wen; Liang Zhou; Keyue Smedley

    2010-01-01

    A new Hexagram Active Power Filter (APF) is proposed for harmonics elimination at medium-voltage grids. The new converter is composed of six interconnected three-phase standard two-level voltage source converter modules with advantages including modular structure with easy construction and maintenance, no voltage unbalance problem, reduced voltage stress, symmetrical structure with automatic and equal voltage and current sharing, and easy control

  8. E-beam high voltage switching power supply

    DOEpatents

    Shimer, D.W.; Lange, A.C.

    1997-03-11

    A high power, solid state power supply is described for producing a controllable, constant high voltage output under varying and arcing loads suitable for powering an electron beam gun or other ion source. The present power supply is most useful for outputs in a range of about 100-400 kW or more. The power supply is comprised of a plurality of discrete switching type dc-dc converter modules, each comprising a voltage regulator, an inductor, an inverter for producing a high frequency square wave current of alternating polarity, an improved inverter voltage clamping circuit, a step up transformer, and an output rectifier for producing a dc voltage at the output of each module. The inputs to the converter modules are fed from a common dc rectifier/filter and are linked together in parallel through decoupling networks to suppress high frequency input interactions. The outputs of the converter modules are linked together in series and connected to the input of the transmission line to the load through a decoupling and line matching network. The dc-dc converter modules are phase activated such that for n modules, each module is activated equally 360{degree}/n out of phase with respect to a successive module. The phased activation of the converter modules, combined with the square current waveforms out of the step up transformers, allows the power supply to operate with greatly reduced output capacitance values which minimizes the stored energy available for discharge into an electron beam gun or the like during arcing. The present power supply also provides dynamic response to varying loads by controlling the voltage regulator duty cycle using simulated voltage feedback signals and voltage feedback loops. Circuitry is also provided for sensing incipient arc currents reflected at the output of the power supply and for simultaneously decoupling the power supply circuitry from the arcing load. 7 figs.

  9. IEEE TRANSACTIONS ON POWER ELECTRONICS, VOL. 21, NO. 3, MAY 2006 613 Model Requirements for Simulation of Low-Voltage

    E-print Network

    Paris-Sud XI, Université de

    focuses on the modeling of low-voltage automotive power electronic circuits to obtain accurate system. This work was supported by Valeo Electrical Systems. Recommended by Associate Editor J. Shen. C. Buttay for Simulation of Low-Voltage MOSFET in Automotive Applications Cyril Buttay, Member, IEEE, Hervé Morel, Member

  10. Continuous electricity generation at high voltages and currents using stacked microbial fuel cells

    Microsoft Academic Search

    Peter Aelterman; Korneel Rabaey; Hai The Pham; Nico Boon; Willy Verstraete

    2006-01-01

    Connecting several microbial fuel cell (MFC) units in series or parallel\\u000a can increase voltage and current; the effect on the microbial\\u000a electricity generation was as yet unknown. Six individual continuous MFC\\u000a units in a stacked configuration produced a maximum hourly averaged\\u000a power output of 258 W m(-3) using a hexacyanoferrate cathode. The\\u000a connection of the 6 MFC units in series

  11. The integrated 2W high voltage\\/high power 0. 12-?m RF CMOS power amplifier

    Microsoft Academic Search

    L. Wu; R. Tao; U. Basaran; J. Luger; I. Dettmann; M. Berroth

    2004-01-01

    A 2W HiVP power amplifier for GSM mobile communication system is designed using 0.12-µm CMOS process. To solve the problem of low breakdown voltage in deep-submicron CMOS technology, the new High Voltage\\/High Power (HiVP) device configuration is used. With HiVP configuration, a large voltage can be divided by several devices, so that the voltage drop on each device is reduced.

  12. Programmable timed electrical power management device

    SciTech Connect

    Nyenya, S.S.

    1994-01-11

    A programmable timed electrical power management device protects and controls electrical equipment and peripherals which are plugged into it. The front of the housing containing the electrical circuitry is provided with a LCD display, a series of pressure sensitive switches for inputting function and control commands to control the operation of the device. A series of LED's mounted on the front of the housing indicate the operational status of the device. The back of the housing is provided with an AC power input receptacle, an on/off reset switch, a series of AC outlets which are divided into pairs of filtered banks, and two or more modular jacks for receiving the modular plug of a telephone, fax, and/or modem. The device circuitry includes a CPU, timer/calendar, a sound generator, voltage sensors, and a back-up battery power supply. The outlets and modular plugs are protected from electrical surges. Each bank of outlets can be selectively programmed to turn on and off at a different time of the day and different days of the week. When more than one bank is set to start at the same time, power is sequentially supplied to each electrical outlet bank allowing the voltage to stabilize before turning on the next bank. A warning tone will sound fifteen, ten, and five minutes prior to shutting off any of the banks, to alert the user that the system is approaching the preset time for the power to the outlets to be turned off, to prevent accidental loss of information. 9 figs.

  13. Voltage, energy and power in electric circuits

    E-print Network

    Berzins, M.

    for Children, Schools and Families wishes to make it clear that the Department and its agents accept approaches, particularly in that the `rope loop' analogy is used throughout. We are convinced that the consistent use of a carefully selected analogy provides a sound basis for effective teaching and meaningful

  14. Statistical Evaluation of Voltage Variation of Power Distribution System with Clustered Home-Cogeneration Systems

    NASA Astrophysics Data System (ADS)

    Kato, Takeyoshi; Minagata, Atsushi; Suzuoki, Yasuo

    This paper discusses the influence of mass installation of a home co-generation system (H-CGS) using a polymer electrolyte fuel cell (PEFC) on the voltage profile of power distribution system in residential area. The influence of H-CGS is compared with that of photovoltaic power generation systems (PV systems). The operation pattern of H-CGS is assumed based on the electricity and hot-water demand observed in 10 households for a year. The main results are as follows. With the clustered H-CGS, the voltage of each bus is higher by about 1-3% compared with the conventional system without any distributed generators. Because H-CGS tends to increase the output during the early evening, H-CGS contributes to recover the voltage drop during the early evening, resulting in smaller voltage variation of distribution system throughout a day. Because of small rated power output about 1kW, the influence on voltage profile by the clustered H-CGS is smaller than that by the clustered PV systems. The highest voltage during the day time is not so high as compared with the distribution system with the clustered PV systems, even if the reverse power flow from H-CGS is allowed.

  15. Extra high voltage power transmission. (Latest citations from the NTIS bibliographic database). Published Search

    SciTech Connect

    Not Available

    1993-08-01

    The bibliography contains citations concerning the design, construction, and use of extra high voltage power transmission lines. Both underground and overhead lines are discussed, as well as superconducting and resistive cryogenic lines. Health, safety, and psychological aspects of the electrical field, corona, ozone, and acoustic effects of these lines are discussed. New conductors, insulators, mounting, monitoring, control, and lightning protection of EHV power transmission lines are presented. (Contains a minimum of 82 citations and includes a subject term index and title list.)

  16. Voltage stability analysis of an Urban Distribution Network (UDN) with high penetration of combined heat & Power (CHP) generation

    Microsoft Academic Search

    Sreto Boljevic; Michael F. Conlon

    2010-01-01

    The capacity of Combined Heat and Power (CHP) generation connected to Urban Distribution Network (UDN) will increase significantly as a result of EU government targets and initiatives. CHP generators can have a significant impact on the power flow, voltage profile and the power quality for customers and electricity suppliers. The connection of CHP plant at UDN creates a number of

  17. Multiple high voltage output DC-to-DC power converter

    NASA Technical Reports Server (NTRS)

    Cronin, Donald L. (Inventor); Farber, Bertrand F. (Inventor); Gehm, Hartmut K. (Inventor); Goldin, Daniel S. (Inventor)

    1977-01-01

    Disclosed is a multiple output DC-to-DC converter. The DC input power is filtered and passed through a chopper preregulator. The chopper output is then passed through a current source inverter controlled by a squarewave generator. The resultant AC is passed through the primary winding of a transformer, with high voltages induced in a plurality of secondary windings. The high voltage secondary outputs are each solid-state rectified for passage to individual output loads. Multiple feedback loops control the operation of the chopper preregulator, one being responsive to the current through the primary winding and another responsive to the DC voltage level at a selected output.

  18. Effects of load voltage on voltage breakdown modes of electrical exploding aluminum wires in air

    NASA Astrophysics Data System (ADS)

    Wu, Jian; Li, Xingwen; Yang, Zefeng; Wang, Kun; Chao, Youchuang; Shi, Zongqian; Jia, Shenli; Qiu, Aici

    2015-06-01

    The effects of the load voltage on the breakdown modes are investigated in exploding aluminum wires driven by a 1 kA, 0.1 kA/ns pulsed current in air. From laser probing images taken by laser shadowgraphy, schlieren imaging, and interferometry, the position of the shockwave front, the plasma channel, and the wire core edge of the exploding product can be determined. The breakdown mode makes a transition from the internal mode, which involves breakdown inside the wire core, to the shunting mode, which involves breakdown in the compressed air, with decreasing charging voltage. The breakdown electrical field for a gaseous aluminum wire core of nearly solid density is estimated to be more than 20 kV/cm, while the value for gaseous aluminum of approximately 0.2% solid density decreases to 15-20 kV/cm. The breakdown field in shunting mode is less than 20 kV/cm and is strongly affected by the vaporized aluminum, the desorbed gas, and the electrons emitted from the wire core during the current pause. Ohmic heating during voltage collapses will induce further energy deposition in the current channel and thus will result in different expansion speeds for both the wire core and the shockwave front in the different modes.

  19. Technical Development on Partial Discharge Measurement and Electrical Insulation Techniques for Low Voltage Motors Driven by Voltage Inverters

    Microsoft Academic Search

    Hitoshi Okubo; Naoki Hayakawa; Gian Carlo Montanari

    2007-01-01

    This paper reviews the up-to-date research activities on electrical insulation techniques under repetitive surge voltages with steep wavefront for low voltage inverter-fed motors. Partial discharge (PD) inception, propagation, ageing and breakdown characteristics of magnet wires, including recently developed PD-resistant wires such as nanocomposite enameled wires, are described. PD measurement techniques under the steep-front voltages and IEC activity toward their standardization

  20. High voltage spiral generators for electric propulsion applications

    NASA Astrophysics Data System (ADS)

    Rose, M. Franklin

    2002-01-01

    The principles of Spiral Line Vector Inversion Generators is introduced and described in terms of frequency, efficiency and pulsed power levels for space applications. Spiral generators are a variant of the familiar Blumlein voltage doubler. They allow the production of high voltage-high power radio frequency energy from electrostatically stored energy in a one-step one component process. They are extremely simple devices to build and demonstrate. Spiral line vector inversion generators can operate as a pulser or in an oscillator mode. In the oscillator mode, devices have been built by the author that can operate at frequencies as high as 200 Mhz at peak power levels in excess of 50 megawatts. At lower frequencies, devices have been built which operate at the megavolt level at about 10 Mhz. Energy storage and conversion efficiency are on the order of 2-3 kilojoules/pulse for large generators and greater than 50% respectively in optimum geometry. Average power is determined by the repetition rate. This paper will describe the state of the art for these generators, present the performance of several small laboratory units and show how they can be used to power small thrusters such as rf arcjets. Problems and limitations will be discussed within the context of space applications. .

  1. Power line carrier interference caused by DC electric arc furnaces

    Microsoft Academic Search

    Gregory A. Franklin; Shih-Min Hsu

    2003-01-01

    Alabama Power Company has experienced problems with power line carrier equipment used on high voltage transmission systems resulting from the operation of DC electric arc furnaces. Problems experienced include tuning equipment and communication equipment failures, as well as false signal reception and signal interference. This paper describes the nature and causes of the problems, and discusses results from field measurements

  2. Power supply and impedance matching to drive technological radio-frequency plasmas with customized voltage waveforms

    NASA Astrophysics Data System (ADS)

    Franek, James; Brandt, Steven; Berger, Birk; Liese, Martin; Barthel, Matthias; Schüngel, Edmund; Schulze, Julian

    2015-05-01

    We present a novel radio-frequency (RF) power supply and impedance matching to drive technological plasmas with customized voltage waveforms. It is based on a system of phase-locked RF generators that output single frequency voltage waveforms corresponding to multiple consecutive harmonics of a fundamental frequency. These signals are matched individually and combined to drive a RF plasma. Electrical filters are used to prevent parasitic interactions between the matching branches. By adjusting the harmonics' phases and voltage amplitudes individually, any voltage waveform can be approximated as a customized finite Fourier series. This RF supply system is easily adaptable to any technological plasma for industrial applications and allows the commercial utilization of process optimization based on voltage waveform tailoring for the first time. Here, this system is tested on a capacitive discharge based on three consecutive harmonics of 13.56 MHz. According to the Electrical Asymmetry Effect, tuning the phases between the applied harmonics results in an electrical control of the DC self-bias and the mean ion energy at almost constant ion flux. A comparison with the reference case of an electrically asymmetric dual-frequency discharge reveals that the control range of the mean ion energy can be significantly enlarged by using more than two consecutive harmonics.

  3. Direct power control of PWM converter without power-source voltage sensors

    Microsoft Academic Search

    Toshihiko Noguchi; Hiroaki Tomiki; Seiji Kondo; Isao Takahashi

    1998-01-01

    This paper proposes a novel control strategy of a pulsewidth modulation (PWM) converter with no power-source voltage sensors. The strategy has two main features to improve a total power factor and efficiency, taking harmonic components into account without detecting the voltage waveforms. One feature is a direct instantaneous power control technique for the converter, which has been developed to control

  4. Nuclear electromagnetic pulse (EMP) and electric power systems

    SciTech Connect

    Barnes, P.R.; Vance, E.F.; Askins, H.W. Jr.

    1984-04-01

    A nuclear detonation at high altitudes produces a transient electromagnetic pulse (EMP) of high-intensity electromagnetic fields. A single high-altitude burst can subject most of the continental United States to a strong EMP. These intense fields induce voltage and current transients in electrical conductors. Surges would be induced by EMP in transmission and distribution circuits and in control and communication elements in electric power systems throughout the national grid. Such widespread disturbances could upset the stability of electrical energy systems and result in massive power failures. The extent and nature of EMP-caused damages are not well known for utility electric power systems. Failures are likely to be associated with insulation damage and failures of low-voltage and solid-state components. It is concluded from a review of past studies that EMP may pose a serious threat to the nation's electrical energy supply.

  5. XI SIMPÓSIO DE ESPECIALISTAS EM PLANEJAMENTO DA OPERAÇÃO E EXPANSÃO ELÉTRICA XI SYMPOSIUM OF SPECIALISTS IN ELECTRIC OPERATIONAL AND EXPANSION PLANNING Synchronized Phasor Data Estimation of Dynamic Parameters for Radial Power System Transfer Path with and without Voltage Reinforcement

    Microsoft Academic Search

    ARANYA CHAKRABORTTY; JOE H. CHOW

    SUMMARY In this paper, we develop a measurement based method for constructing a reduced physical model to represent the transfer path of a radial, multi-machine, two-area power system with and without intermediate voltage support. The method is made practical by the availability of networks of GPS- synchronized, high sampling-rate phasor measurement units (PMU). Starting from a small-signal model for the

  6. Electric Power Monthly

    EIA Publications

    2015-01-01

    Provides monthly statistics at the state, Census division, and U.S. levels for net generation, fossil fuel consumption and stocks, quantity and quality of fossil fuels, cost of fossil fuels, electricity sales, revenue, and average revenue per kilowatthour of electricity sold.

  7. Autonomously managed electrical power systems

    NASA Technical Reports Server (NTRS)

    Callis, Charles P.

    1986-01-01

    The electric power systems for future spacecraft such as the Space Station will necessarily be more sophisticated and will exhibit more nearly autonomous operation than earlier spacecraft. These new power systems will be more reliable and flexible than their predecessors offering greater utility to the users. Automation approaches implemented on various power system breadboards are investigated. These breadboards include the Hubble Space Telescope power system test bed, the Common Module Power Management and Distribution system breadboard, the Autonomusly Managed Power System (AMPS) breadboard, and the 20 kilohertz power system breadboard. Particular attention is given to the AMPS breadboard. Future plans for these breadboards including the employment of artificial intelligence techniques are addressed.

  8. Electrical power systems for Mars

    NASA Astrophysics Data System (ADS)

    Giudici, Robert J.

    1986-05-01

    Electrical power system options for Mars Manned Modules and Mars Surface Bases were evaluated for both near-term and advanced performance potential. The power system options investigated for the Mission Modules include photovoltaics, solar thermal, nuclear reactor, and isotope power systems. Options discussed for Mars Bases include the above options with the addition of a brief discussion of open loop energy conversion of Mars resources, including utilization of wind, subsurface thermal gradients, and super oxides. Electrical power requirements for Mission Modules were estimated for three basic approaches: as a function of crew size; as a function of electric propulsion; and as a function of transmission of power from an orbiter to the surface of Mars via laser or radio frequency. Mars Base power requirements were assumed to be determined by production facilities that make resources available for follow-on missions leading to the establishment of a permanently manned Base. Requirements include the production of buffer gas and propellant production plants.

  9. Study of a High Voltage Ion Engine Power Supply

    NASA Technical Reports Server (NTRS)

    Stuart, Thomas A.; King, Roger J.; Mayer, Eric

    1996-01-01

    A complete laboratory breadboard version of a ion engine power converter was built and tested. This prototype operated on a line voltage of 80-120 Vdc, and provided output ratings of 1100 V at 1.8 kW, and 250 V at 20 mA. The high-voltage (HV) output voltage rating was revised from the original value of 1350 V at the beginning of the project. The LV output was designed to hold up during a 1-A surge current lasting up to 1 second. The prototype power converter included a internal housekeeping power supply which also operated from the line input. The power consumed in housekeeping was included in the overall energy budget presented for the ion engine converter. HV and LV output voltage setpoints were commanded through potentiometers. The HV converter itself reached its highest power efficiency of slightly over 93% at low line and maximum output. This would dip below 90% at high line. The no-load (rated output voltages, zero load current) power consumption of the entire system was less than 13 W. A careful loss breakdown shows that converter losses are predominately Metal-Oxide-Semiconductor Field Effect Transistor (MOSFET) conduction losses and HV rectifier snubbing losses, with the rectifier snubbing losses becoming predominant at high line. This suggests that further improvements in power efficiency could best be obtained by either developing a rectifier that was adequately protected against voltage overshoot with less snubbing, or by developing a pre-regulator to reduced the range of line voltage on the converter. The transient testing showed the converter to be fully protected against load faults, including a direct short-circuit from the HV output to the LV output terminals. Two currents sensors were used: one to directly detect any core ratcheting on the output transformer and re-initiate a soft start, and the other to directly detect a load fault and quickly shut down the converter for load protection. The finished converter has been extensively fault tested without failure. The finished converter has been packaged suitable for use as a laboratory prototype for further testing. The finished converter is readily transportable. An article on design issues for high voltage converters for ion engines is included as an attachement.

  10. Optimal load shedding with the support of dynamic generation control in electric power systems

    Microsoft Academic Search

    Bo Gong; Arthur Pinheiro; Ian Hiskens

    2010-01-01

    Load recovery dynamics and generator reactive power limitation are two major contributing factors for voltage collapse in electric power systems. Even though impending voltage collapse can often be avoided by appropriate control of loads, the traditional form of load control (shedding) is unpopular due to the resulting consumer disruption. On the other hand, the enforced generators' reactive power limits in

  11. Wireless transfer of electric power

    E-print Network

    Moffatt, Robert Alexander

    2009-01-01

    In this dissertation, I describe the design and construction of a system which can transfer electric power wirelessly. This is accomplished using inductive, near-field, non-radiative coupling between self-resonant copper ...

  12. Space station electrical power system

    NASA Technical Reports Server (NTRS)

    Labus, Thomas L.; Cochran, Thomas H.

    1987-01-01

    The purpose of this paper is to describe the design of the Space Station Electrical Power System. This includes the Photovoltaic and Solar Dynamic Power Modules as well as the Power Management and Distribution System (PMAD). In addition, two programmatic options for developing the Electrical Power System will be presented. One approach is defined as the Enhanced Configuration and represents the results of the Phase B studies conducted by the NASA Lewis Research Center over the last two years. Another option, the Phased Program, represents a more measured approach to reaching about the same capability as the Enhanced Configuration.

  13. High-Voltage Pulsed Current Electrical Stimulation in Wound Treatment.

    PubMed

    Polak, Anna; Franek, Andrzej; Taradaj, Jakub

    2014-02-01

    Significance: A range of studies point to the efficacy of electrical stimulation (ES) in wound treatment, but the methodology of its application has not been determined to date. This article provides a critical review of the results of clinical trials published by researchers using high-voltage pulsed current (HVPC) to treat chronic wounds. In describing the methodology of the trials, the article gives special attention to electric stimulus parameters, the frequency of procedures and total treatment duration. Recent Advances: HVPC is a monophasic pulsed electric current that consists of double-peaked impulses (5-200??s), at very high peak-current amplitude (2-2.5?A), and high voltage (up to 500?V), at a frequency of 1-125?pulses per second. HVPC can activate "skin battery" and cellular galvanotaxis, and improves blood flow and capillary density. Critical Issues: HVPC efficacy was evaluated in conservatively treated patients with diabetic foot, venous leg and pressure ulcers (PUs), and in some patients with surgically treated venous insufficiency. Future Directions: The efficacy of HVPC as one of several biophysical energies promoting venous leg ulcer (VLU) and PU healing has been confirmed. Additional studies are needed to investigate its effect on the healing of other types of soft tissue defects. Other areas that require more research include the identification of the therapeutic effect of HVPC on infected wounds, the determination of the efficacy of cathodal versus anodal stimulation, and the minimal daily/weekly duration of HVPC required to ensure optimal promotion of wound healing. PMID:24761351

  14. Electrical Properties and Power Considerations of a Piezoelectric Actuator

    NASA Technical Reports Server (NTRS)

    Jordan, T.; Ounaies, Z.; Tripp, J.; Tcheng, P.

    1999-01-01

    This paper assesses the electrical characteristics of piezoelectric wafers for use in aeronautical applications such as active noise control in aircraft. Determination of capacitive behavior and power consumption is necessary to optimize the system configuration and to design efficient driving electronics. Empirical relations are developed from experimental data to predict the capacitance and loss tangent of a PZT5A ceramic as nonlinear functions of both applied peak voltage and driving frequency. Power consumed by the PZT is the rate of energy required to excite the piezoelectric system along with power dissipated due to dielectric loss and mechanical and structural damping. Overall power consumption is thus quantified as a function of peak applied voltage and driving frequency. It was demonstrated that by incorporating the variation of capacitance and power loss with voltage and frequency, satisfactory estimates of power requirements can be obtained. These relations allow general guidelines in selection and application of piezoelectric actuators and driving electronics for active control applications.

  15. The propagation of voltage sag through transformer connections in a power system network

    Microsoft Academic Search

    R. F. Mustapa; M. S. Serwan; N. Hamzah; Z. Zakaria

    2010-01-01

    Due to the increasing of power system fault and failure, voltage sag (dip) will occur instantaneously with respect to the fault and failure itself. The power system network consists of high voltage (HV), medium voltage (MV) and low voltage busbar (LV). Monitoring equipment in the power systems network are installed at strategic and appropriate 33\\/11 kV feeder. The propagation and

  16. Trading speed for low power by choice of supply and threshold voltages

    Microsoft Academic Search

    Dake Liu; Christer Svensson

    1993-01-01

    The trading of speed for low power consumption in CMOS VLSI by using the supply voltage and the threshold voltage as variables was investigated. It is shown that it is desirable to minimize the supply voltage for minimizing the power consumption. The lower bound of the supply voltage and the possible decrease in power consumption without speed loss were investigated

  17. Single Event Transients in Voltage Regulators for FPGA Power Supply Applications

    NASA Technical Reports Server (NTRS)

    Poivey, Christian; Sanders, Anthony; Kim, Hak; Phan, Anthony; Forney, Jim; LaBel, Kenneth A.; Karsh, Jeremy; Pursley, Scott; Kleyner, Igor; Katz, Richard

    2006-01-01

    As with other bipolar analog devices, voltage regulators are known to be sensitive to single event transients (SET). In typical applications, large output capacitors are used to provide noise immunity. Therefore, since SET amplitude and duration are generally small, they are often of secondary importance due to this capacitance filtering. In low voltage applications, however, even small SET are a concern. Over-voltages may cause destructive conditions. Under-voltages may cause functional interrupts and may also trigger electrical latchup conditions. In addition, internal protection circuits which are affected by load as well as internal thermal effects can also be triggered from heavy ions, causing dropouts or shutdown ranging from milliseconds to seconds. In the case of FPGA power supplies applications, SETS are critical. For example, in the case of Actel FPGA RTAX family, core power supply voltage is 1.5V. Manufacturer specifies an absolute maximum rating of 1.6V and recommended operating conditions between 1.425V and 1.575V. Therefore, according to the manufacturer, any transient of amplitude greater than 75 mV can disrupt normal circuit functions, and overvoltages greater than 100 mV may damage the FPGA. We tested five low dropout voltage regulators for SET sensitivity under a large range of circuit application conditions.

  18. Voltage Drop

    NSDL National Science Digital Library

    The first site with information on voltage drop is provided by Power and System Innovations on their Frequently Asked Questions: Voltage Drop (1) page. Visitors can read what voltage drop is, what causes it, what happens as a result of it, and what the maximum recommended voltage drop is. The second site, Basics of Electricity (2), is part of General Electric's Lighting for Business Web site. Through descriptions and illustrations, the site explains what voltage drop is and gives examples of how it is calculated using Ohm's law. The next site is a lab worksheet that is part of a class from the Electrical and Computer Engineering Department of Montana State University called Voltage Drop in Cables (3). The objective of the lesson is to determine the internal resistance of an extension cord and choose the proper wire size for a particular application. Students are given an explanation of the procedure and a number of questions to answer related to the exercise. The Oregon Building Congress offers the Lesson Plans (4) Web site and the downloadable Voltage Drop educational activity. The lesson, which is suggested to be contained within a unit on formulas and solving literal equations, explores the concept of voltage drop that is encountered in basic wiring. The fifth site entitled Explanation of Voltage Drop in a Series Circuit (5) is offered by the Horizons Electronic Lesson Plan Resource. The page describes voltage drop as an electronic concept, gives a formula determining voltage drop, provides a schematic that helps illustrate the concept, and offers a quiz and answer sheet. Next, from electrician.com, is the online Voltage Drop Calculator (6). Users input the type and size of wire being used, the voltage and phase, circuit length, and amp load to calculate voltage drop and several other parameters. The seventh site, entitled The Hazards of Voltage Drop (7), is provided within the Electrical Construction Maintenance Web site. The page describes how electrical equipment can overheat or even power down if it operates below its voltage rating. It also provides a thorough explanation of how to determine the load's operating voltage. The last site, maintained by Williamson Labs (8), is a comprehensive learning site called Elementary Electricity. Visitors will find a wealth of information here, including fun descriptions, graphics, and animations on all aspects of electricity including voltage drop.

  19. Impact of wind turbine systems on power system voltage stability

    Microsoft Academic Search

    D. Devaraj; R. Jeevajyothi

    2011-01-01

    This paper investigates the effect of fixed speed and variable speed grid-connected wind generators on the voltage stability of a power system network. The wind generators considered are the squirrel cage induction generator (SCIG), which is a fixed speed, the doubly-fed induction generator (DFIG) and the direct driven synchronous generator (DDSG) which are variable speed. Studies were conducted on a

  20. 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

  1. A programmable high voltage electrical switching analyzer for I-V characterization of phase change materials

    NASA Astrophysics Data System (ADS)

    Bhanu Prashanth, S. B.; Asokan, S.

    2007-07-01

    Ovonic Phase-Change Materials have found a renewed interest in the recent times owing to their applications in Non-Volatile Random Access Memories. In the present work, a cost-effective high voltage electrical switching analyzer has been developed to enable investigations on the I-V characteristics and electrical switching of bulk solids, which are necessary for identifying suitable materials for memory and other applications such as power control. The developed set up mainly consists of a PC based programmable High Voltage DC Power Supply which acts as an excitation source and a high speed Digital Storage Oscilloscope. For flexible control options, a Graphical User Interface has also been developed using LabVIEW-6i to control the excitation source through the analog outputs of a data acquisition card. Options are made in the system to sweep the output voltage from 45 to 1750 V or the output current in the range 0-45 mA with resolutions of 1.5 V & 5 or 50 ?A at variable rates. I-V characteristics and switching behavior of the sample material are instantaneously acquired on the storage oscilloscope and transferred to PC for post processing. The system can be used to investigate a broad range of materials and some typical results are presented to illustrate the capability of the system developed. The closed-loop stability of the system has also been confirmed by frequency response plots.

  2. Power electronics in automotive electrical systems

    Microsoft Academic Search

    Iftikhar A. Khan

    1996-01-01

    The role of power electronics as an enabling technology for various automotive applications is illustrated with examples. Automotive electrical power systems that address the demands of increased electrical power, improved fuel economy and reduced emissions are discussed. Considerations related to high-efficiency automotive electrical power systems such as the selection of the types of electrical machines and power converters, selection of

  3. Power quality measurements performed on a low-voltage grid equipped with two wind turbines

    Microsoft Academic Search

    T. Thiringer

    1996-01-01

    The power quality of a low-voltage grid with two wind turbines is investigated. Slow voltage variations as well as transients and harmonics are measured and analysed. Furthermore, the spectrum of the power is determined so that the presence of periodic power components can be investigated. Although periodic power fluctuations reaching 10% of the rated power are registered, voltage variations are

  4. High-Voltage, Low-Power BNC Feedthrough Terminator

    NASA Technical Reports Server (NTRS)

    Bearden, Douglas

    2012-01-01

    This innovation is a high-voltage, lowpower BNC (Bayonet Neill-Concelman) feedthrough that enables the user to terminate an instrumentation cable properly while connected to a high voltage, without the use of a voltage divider. This feedthrough is low power, which will not load the source, and will properly terminate the instrumentation cable to the instrumentation, even if the cable impedance is not constant. The Space Shuttle Program had a requirement to measure voltage transients on the orbiter bus through the Ground Lightning Measurement System (GLMS). This measurement has a bandwidth requirement of 1 MHz. The GLMS voltage measurement is connected to the orbiter through a DC panel. The DC panel is connected to the bus through a nonuniform cable that is approximately 75 ft (approximately equal to 23 m) long. A 15-ft (approximately equal to 5-m), 50-ohm triaxial cable is connected between the DC panel and the digitizer. Based on calculations and simulations, cable resonances and reflections due to mismatched impedances of the cable connecting the orbiter bus and the digitizer causes the output not to reflect accurately what is on the bus. A voltage divider at the DC panel, and terminating the 50-ohm cable properly, would eliminate this issue. Due to implementation issues, an alternative design was needed to terminate the cable properly without the use of a voltage divider. Analysis shows how the cable resonances and reflections due to the mismatched impedances of the cable connecting the orbiter bus and the digitizer causes the output not to reflect accurately what is on the bus. After simulating a dampening circuit located at the digitizer, simulations were performed to show how the cable resonances were dampened and the accuracy was improved significantly. Test cables built to verify simulations were accurate. Since the dampening circuit is low power, it can be packaged in a BNC feedthrough.

  5. Electric power monthly, June 1994

    SciTech Connect

    Not Available

    1994-06-01

    The Electric Power Monthly (EPM) presents monthly electricity statistics. The purpose of this publication is to provide energy decisionmakers with accurate and timely information that may be used in forming various perspectives on electric issues that lie ahead. Data in this report are presented for a wide audience including Congress, Federal and State agencies, the electric utility industry, and the general public. The EIA collected the information in this report to fulfill its data collection and dissemination responsibilities as specified in the Federal Energy Administration Act of 1974 (Public Law 93-275) as amended.

  6. Electrical Analysis of Wind Power

    NSDL National Science Digital Library

    Lina Jiang and Philip Peterson

    For this experiment, students use a DC motor as a generator and various shaped turbine designs to test which design produces the most electrical power. Using a fan to generate the "wind", students attach different blades made of folded paper or card stock to the motor to see how much power is generated.

  7. Power unit for electric cars

    SciTech Connect

    Ishikawa, Masami; Minezawa, Yukihiro.

    1993-07-06

    A power unit for mounting on the body of an electric car is described, comprising: a sensor for detecting a running condition of the car; a first power supply mounted on the electric car body; a second power supply module; means for detachably mounting different, interchangeable types of the second power supply module on the electric car body; a motor control circuit, including a computer, connected to the first power supply and the second power supply module for feeding a current to a motor as commanded by the computer; the computer including control means for determining (1) whether the second power supply module is mounted or not and (2) for determining the type of second power supply module mounted; setting means for connecting the first power supply and the second power supply module with the motor control circuit, in parallel or in series, responsive to the detected running condition; and the computer controlling the motor control circuit according to determinations of the control means.

  8. Efficient power conversion for ultra low voltage micro scale energy transducers

    Microsoft Academic Search

    Chao Lu; Sang Phill Park; Vijay Raghunathan; Kaushik Roy

    2010-01-01

    Energy harvesting has emerged as a feasible and attractive option to improve battery lifetime in micro-scale electronic systems such as biomedical implants and wireless sensor nodes. A key challenge in designing micro-scale energy harvesting systems is that miniature energy transducers (e.g., photovoltaic cells, thermo-electric generators, and fuel cells) output very low voltages (0--0.4V). Therefore, a fully on-chip power converter (usually

  9. 1-V power supply high-speed digital circuit technology with multithreshold-voltage CMOS

    Microsoft Academic Search

    S. Mutoh; T. Douseki; Y. Matsuya; T. Aoki; S. Shigematsu; J. Yamada

    1995-01-01

    1-V power supply high-speed low-power digital circuit technology with 0.5-?m multithreshold-voltage CMOS (MTCMOS) is proposed. This technology features both low-threshold voltage and high-threshold voltage MOSFET's in a single LSI. The low-threshold voltage MOSFET's enhance speed performance at a low supply voltage of 1 V or less, while the high-threshold voltage MOSFET's suppress the stand-by leakage current during the sleep period.

  10. A high-power MEMS electric induction motor

    Microsoft Academic Search

    Carol Livermore; Anthony R. Forte; Theodore Lyszczarz; Stephen D. Umans; Arturo A. Ayon; Jeffrey H. Lang

    2004-01-01

    An electric induction micromotor with a 4-mm-diameter rotor was designed and built for high-power operation. Operated at partial actuating voltage, the motor has demonstrated an air gap power in excess of 20 mW and torque of 3.5 ?Nm at speeds in excess of 55 000 rpm. Operation at higher power and speed was limited by bearing stability at higher rotational

  11. Electric power monthly, April 1994

    SciTech Connect

    Not Available

    1994-04-01

    The Electric Power Monthly (EPM) presents monthly electricity statistics. The purpose of this publication is to provide energy decisionmakers with accurate and timely information that may be used in forming various perspectives on electric issues that lie ahead. This publication provides monthly statistics at the U.S., Census division, and State levels for net generation, fossil fuel consumption and stocks, quantity and quality of fossil fuels, cost of fossil fuels, electricity sales, revenue, and average revenue per kilowatthour of electricity sold. Data on net generation, fuel consumption, fuel stocks, quantity and cost of fossil fuels are also displayed for the North American Electric Reliability Council (NERC) regions. This April 1994 issue contains 1993 year-end data and data through January 1994.

  12. Inspira™ — an enabling battery technology for high voltage automotive electrical systems

    Microsoft Academic Search

    Robert G Gruenstern; John R Pierson

    2000-01-01

    Vehicle manufacturers worldwide are recognizing the need to elevate the electrical system voltage on their product from the present standard of 12 V to a significantly higher, yet safe, voltage. One of the major challenges emerging from the move to higher voltages is the size, weight, volume, cost and complexity of the battery required to support such a system. Inspira™,

  13. Electric Vehicles participation in distribution network voltage regulation

    Microsoft Academic Search

    Loredana Carradore; Roberto Turri

    2010-01-01

    A widespread diffusion of Electric Vehicles plugged into distribution networks is strongly dependent on the establishment of a suitable co-ordinated management of all active resources in the grid. Vehicle-to-grid technology, allowing bidirectional power flows of on-board batteries, would enable a responsive behaviour of vehicles. EVs aggregators, such as swapping stations and car parking, could provide strategic ancillary services for the

  14. Unilateral sensorineural hearing loss and facial nerve paralysis associated with low-voltage electrical shock.

    PubMed

    Ozkiris, Mahmut

    2014-02-01

    Electrical injuries can occur as a result of contact with low- or high-voltage electricity. Low-voltage injuries are more common, as they usually occur in the home, but reports in the literature are few. After exposure to electric current, almost every organ system in the body is affected. The severity of an injury depends on many factors, including the type of current, the duration of exposure, and the resistance of the tissue involved. Reported cases of hearing loss and facial nerve paralysis associated with low-voltage electrical shock are rare, and minimal information is available about this circumstance. In this article, the author describes a case of low-voltage electrical shock in a 20-year-old man. To the best of the author's knowledge, this is the first report in the literature of a resolution of unilateral sensorineural hearing loss and facial nerve paralysis caused by a low-voltage electrical shock. PMID:24526477

  15. Voltage-drop aware analytical placement by global power spreading for mixed-size circuit designs

    Microsoft Academic Search

    Yi-Lin Chuang; Po-Wei Lee; Yao-Wen Chang

    2009-01-01

    Excessive supply voltage drops in a circuit may lead to significant circuit performance degradation and even malfunction. To handle this problem, existing power delivery aware placement algorithms model voltage drops as an optimization objective. We observe that directly minimizing voltage drops in an objective function might not resolve voltage-drop violations and might even cause problems in power-integrity convergence. To remedy

  16. Novel high-voltage power lateral MOSFET with adaptive buried electrodes

    NASA Astrophysics Data System (ADS)

    Zhang, Wen-Tong; Wu, Li-Juan; Qiao, Ming; Luo, Xiao-Rong; Zhang, Bo; Li, Zhao-Ji

    2012-07-01

    A new high-voltage and low-specific on-resistance (Ron,sp) adaptive buried electrode (ABE) silicon-on-insulator (SOI) power lateral MOSFET and its analytical model of the electric fields are proposed. The MOSFET features are that the electrodes are in the buried oxide (BOX) layer, the negative drain voltage Vd is divided into many partial voltages and the output to the electrodes is in the buried oxide layer and the potentials on the electrodes change linearly from the drain to the source. Because the interface silicon layer potentials are lower than the neighboring electrode potentials, the electronic potential wells are formed above the electrode regions, and the hole potential wells are formed in the spacing of two neighbouring electrode regions. The interface hole concentration is much higher than the electron concentration through designing the buried layer electrode potentials. Based on the interface charge enhanced dielectric layer field theory, the electric field strength in the buried layer is enhanced. The vertical electric field EI and the breakdown voltage (BV) of ABE SOI are 545 V/?m and -587 V in the 50 ?m long drift region and the 1 ?m thick dielectric layer, and a low Ron,sp is obtained. Furthermore, the structure also alleviates the self-heating effect (SHE). The analytical model matches the simulation results.

  17. A preventive strategy method for voltage and reactive power dispatch

    SciTech Connect

    Sun, D.T.W.; Shoults, R.R.

    1985-07-01

    A preventive control program for voltage and reactive power dispatch is developed to enhance a system's capability to cope with outages. In this program, not only the base case but also associated contingency cases have been considered. Therefore, it is referred to as the Global VAR Dispatch Method. The global VAR dispatch method is developed by extending the reactive-power part of the decoupled optimal load flow program by incorporating outagecontingency constraints into the scheme to give an optimal steady-state secure operating point. The reactive power control variables (i.e., generator terminal voltage magnitudes, transformer taps, shunt capacitors/reactors) of the base case are optimized within their limits according to a defined objective, so that violations on state variables (i.e., generator var outputs, load-bus voltage magnitudes, reactive power flows in transmission lines) are minimized in both the base case and under selected contingency system operating conditions. The global VAR dispatch method is formulated, in the principle of the (P-/theta/) and (Q-V) decomposition, with the reduced gradient method. The reciprocity theorem, linearized network models, and the compensation technique are employed to achieve a very efficient computational feature.

  18. Power Usage and Electrical Circuit Analysis for Electric Arc Furnaces

    Microsoft Academic Search

    J. J. Trageser

    1980-01-01

    Power usage in ultrahigh-powered electric arc furnaces requires considerably more investigation into system parameters, furnace secondary circuit analysis, and operating characteristics than previously given to normal powered electric arc furnaces. The power input must be analyzed from the infinite electric utility bus to the arc at the electrode. All interested parties must participate in the analysis to assure a mutual

  19. Electrical aging tests on different nanostructured enamels subjected to severe voltage waveforms

    Microsoft Academic Search

    Francesco Guastavino; Alessandro Ratto; Eugenia Torello; Giovanna Biondi; Giovanni Loggi; Andrea Ceci

    2011-01-01

    ) Abstract - Nowadays electrical motors used in industry applications are usually coupled with inverter drives so that the stator motor windings are subjected to severe voltage waveforms such as PWM. When electrical motors having stator windings realized by means of type I random wire wound are subjected to these kinds of voltage waveforms, reliability problems due to degradation phenomena

  20. Water tree characteristics in low-density polyethylene under power-frequency voltages with high-frequency components

    Microsoft Academic Search

    Hidenori Suzuki; Yoshimichi Ohki; Yoshinobu Nakamichi; Kohji Ajiki

    1996-01-01

    For magnetic levitation railway systems using linear synchronous motors, pulse-width-modulation inverters and polymer insulated cables are used for driving cars and feeding electricity, respectively. This means that ac voltages with many harmonics induced by inverters are applied to cables. Water-tree characteristics have been investigated for low-density polyethylene using power-frequency ac voltages with high-frequency components. It was found that water trees

  1. Nuclear electric power sources

    NASA Technical Reports Server (NTRS)

    Singh, J. J.

    1978-01-01

    Measurements on radioactive commercial p-n junction silicon cells show that these units are capable of delivering several hundred microwatts per curie of Am-241 alpha source, indicating their usefulness in such electronic devices as hearing aids, heart pacemakers, electronic watches, delay timers and nuclear dosimeter chargers. It is concluded that the Am-241 sources are superior to the beta sources used previously, because of higher alpha specific ionization and simultaneous production of low energy photons which are easily converted into photoelectrons for additional power.

  2. Transient stability enhancement and voltage regulation of power systems

    Microsoft Academic Search

    Youyi Wang; David J. Hill; Richard H. Middleton; Long Gao

    1993-01-01

    Improvement of the transient stability and voltage regulation of a single-machine-infinite-bus power system under the effects of a symmetrical three-phase short-circuit fault is detailed. The dynamical model of the system is described. A design strategy for nonlinear controllers is considered, and the design of a nonlinear variable-structure excitation controller is described. Simulation results obtained using the nonlinear excitation controller are

  3. A model for the critical voltage for electrical degradation of GaN high electron mobility transistors

    E-print Network

    Joh, Jungwoo

    We have found that there is a critical drain-to-gate voltage beyond which GaN high-electron mobility transistors start to degrade in electrical-stress experiments. The critical voltage depends on the detailed voltage biasing ...

  4. Design of a high voltage input - output ratio dc-dc converter dedicated to small power fuel cell systems

    NASA Astrophysics Data System (ADS)

    Béthoux, O.; Cathelin, J.

    2010-12-01

    Consuming chemical energy, fuel cells produce simultaneously heat, water and useful electrical power [J.M. Andújar, F. Segura, Renew. Sust. Energy Rev. 13, 2309 (2009)], [J. Larminie, A. Dicks, Fuel Cell Systems Explained, 2nd edn. (John Wiley & Sons, 2003)]. As a matter of fact, the voltage generated by a fuel cell strongly depends on both the load power demand and the operating conditions. Besides, as a result of many design aspects, fuel cells are low voltage and high current electric generators. On the contrary, electric loads are commonly designed for small voltage swing and a high V/I ratio in order to minimize Joule losses. Therefore, electric loads supplied by fuel cells are typically fed by means of an intermediate power voltage regulator. The specifications of such a power converter are to be able to step up the input voltage with a high ratio (a ratio of 10 is a classic situation) and also to work with an excellent efficiency (in order to minimize its size, its weight and its losses) [A. Shahin, B. Huang, J.P. Martin, S. Pierfederici, B. Davat, Energy Conv. Manag. 51, 56 (2010)]. This paper deals with the design of this essential ancillary device. It intends to bring out the best structure for fulfilling this function. Several dc-dc converters with large voltage step-up ratios are introduced. A topology based on a coupled inductor or tapped inductor is closely studied. A detailed modelling is performed with the purpose of providing designing rules. This model is validated with both simulation and implementation. The experimental prototype is based on the following specifications: the fuel cell output voltage ranges from a 50 V open-voltage to a 25 V rated voltage while the load requires a constant 250 V voltage. The studied coupled inductor converter is compared with a classic boost converter commonly used in this voltage elevating application. Even though the voltage regulator faces severe FC specifications, the measured efficiency reaches 96% at the rated power whereas conventional boost efficiency barely achieves 91.5% in the same operating conditions.

  5. Utility-Scale Solar Power Converter: Agile Direct Grid Connect Medium Voltage 4.7-13.8 kV Power Converter for PV Applications Utilizing Wide Band Gap Devices

    SciTech Connect

    None

    2012-01-25

    Solar ADEPT Project: Satcon is developing a compact, lightweight power conversion device that is capable of taking utility-scale solar power and outputting it directly into the electric utility grid at distribution voltage levels—eliminating the need for large transformers. Transformers “step up” the voltage of the power that is generated by a solar power system so it can be efficiently transported through transmission lines and eventually “stepped down” to usable voltages before it enters homes and businesses. Power companies step up the voltage because less electricity is lost along transmission lines when the voltage is high and current is low. Satcon’s new power conversion devices will eliminate these heavy transformers and connect a utility-scale solar power system directly to the grid. Satcon’s modular devices are designed to ensure reliability—if one device fails it can be bypassed and the system can continue to run.

  6. 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

  7. Multiobjective optimal power flows to evaluate voltage security costs in power networks

    Microsoft Academic Search

    William D. Rosehart; Claudio A. Cañizares; Victor H. Quintana

    2003-01-01

    In this paper, new optimal power flow (OPF) techniques are proposed based on multiobjective methodologies to optimize active and reactive power dispatch while maximizing voltage security in power systems. The use of interior point methods together with goal programming and linearly combined objective functions as the basic optimization techniques are explained in detail. The effects of minimizing operating costs, minimizing

  8. 75 FR 23823 - Sixth Northwest Electric Power and Conservation Plan

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-04

    ...PACIFIC NORTHWEST ELECTRIC POWER AND CONSERVATION PLANNING COUNCIL Sixth Northwest Electric Power and Conservation Plan AGENCY: Pacific Northwest Electric Power and Conservation Planning Council (Northwest Power and...

  9. Static reactive power compensators for high-voltage power systems. Final report

    SciTech Connect

    Not Available

    1981-04-01

    A study conducted to summarize the role of static reactive power compensators for high voltage power system applications is described. This information should be useful to the utility system planning engineer in applying static var systems (SVS) to high voltage as (HVAC) systems. The static var system is defined as a form of reactive power compensator. The general need for reactive power compensation in HVAC systems is discussed, and the static var system is compared to other devices utilized to provide reactive power compensation. Examples are presented of applying SVS for specific functions, such as the prevention of voltage collapse. The operating principles of commercially available SVS's are discussed in detail. The perormance and active power loss characteristics of SVS types are compared.

  10. 1993 Power in Europe world electricity conference

    SciTech Connect

    Hammons, T.J. (Univ. of Glasgow (United Kingdom))

    1994-03-01

    This article reports on the 1993 Power in Europe World Electricity Conference held in London, England, November, 1993. The topics of the article include gas and electricity deregulation, internationalization of the electric power industry, the changing structure of the electric power industry, privatization, competition, supply-side technology developments, Poland's experience in restructuring the electricity sector, US experience in developments in independent power generation, and the need for energy efficient utilities in developing countries.

  11. Buried Oxide Densification for Low Power, Low Voltage CMOS Applications

    NASA Technical Reports Server (NTRS)

    Allen, L. P.; Anc, M. J.; Dolan, B.; Jiao, J.; Guss, B.; Seraphin, S.; Liu, S. T.; Jenkins, W.

    1998-01-01

    Special technology and circuit architecture are of growing interest for implementation of circuits which operate at low supply voltages and consume low power levels without sacrificing performance[1]. Use of thin buried oxide SOI substrates is a primary approach to simultaneously achieve these goals. A significant aspect regarding SIMOX SOI for low voltage, low power applications is the reliability and performance of the thin buried oxide. In addition, when subjected to high total dose irradiation, the silicon islands within the BOX layer of SIMOX can store charges and significantly effect the back channel threshold voltages of devices. Thus, elimination of the islands within the buried oxide (BOX) layer is preferred in order to prevent leakage through these conductive islands and charge build-up within the buried oxide layer. A differential (2-step) ramp rate as applied to full and 100 nm BOX SIMOX was previously reported to play a significant role in the stoichiometry and island formation within the buried layer[2]. This paper focus is on the properties of a thin (120nm) buried oxide as a function of the anneal ramp rate and the temperature of anneal. In this research, we have found an improvement in the buried oxide stoichiometry with the use of a slower, singular ramp rate for specified thin buried oxides, with slower ramp rates and higher temperatures of anneal suggested for reducing the presence of Si islands within the BOX layer.

  12. Advanced silicon rich automotive electrical power systems

    Microsoft Academic Search

    Ali Emadi; Mehrdad Ehsani; John M. Miller

    1999-01-01

    In order to optimize automotive fuel economy, emissions, performance, and reliability, the More Electric Vehicles (MEV) concept emphasizes the utilization of electrical power systems instead of mechanical and hydraulic power systems. The proposed More Electric Systems facilitate high power loads and enable the introduction of power electronics in a silicon rich environment. On the other hand, there is a growing

  13. Comparing secondary voltage regulation and shunt compensation for improving voltage stability and transfer capability in the Italian power system

    Microsoft Academic Search

    Claudio A. Cañizares; Claudio Cavallo; Massimo Pozzi; Sandro Corsi

    2005-01-01

    This paper concentrates on comparing the advantages and disadvantages, including costs, of using secondary voltage regulation (SVR) versus using shunt-connected controllers, in particular mechanical switched capacitors (MSC), static var compensators (SVC) and static synchronous compensators (STATCOM), to improve voltage stability (VS) and the external transfer capability (TC) of the Italian power network. Basic VS and TC concepts and tools, as

  14. Electrical power technology for the more electric aircraft

    Microsoft Academic Search

    J. A. Weimer

    1993-01-01

    The Air Force's More Electric Aircraft (MEA) initiative embraces the concept of utilizing electrical power for driving aircraft subsystems currently powered by hydraulic, pneumatic or mechanical means including utility and flight control actuation, environmental control system, lubrication and fuel pumps, and numerous other utility functions. An important part of this initiative is the development and demonstration of electrical power and

  15. 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.

  16. Application of Superconducting Power Cables to DC Electric Railway Systems

    NASA Astrophysics Data System (ADS)

    Ohsaki, Hiroyuki; Lv, Zhen; Sekino, Masaki; Tomita, Masaru

    For novel design and efficient operation of next-generation DC electric railway systems, especially for their substantial energy saving, we have studied the feasibility of applying superconducting power cables to them. In this paper it is assumed that a superconducting power cable is applied to connect substations supplying electric power to trains. An analysis model line was described by an electric circuit, which was analyzed with MATLAB-Simulink. From the calculated voltages and currents of the circuit, the regenerative brake and the energy losses were estimated. In addition, assuming the heat loads of superconducting power cables and the cryogenic efficiency, the energy saving of the total system was evaluated. The results show that the introduction of superconducting power cables could achieve the improved use of regenerative brake, the loss reduction, the decreased number of substations, the reduced maintenance, etc.

  17. Features and challenges for Auxiliary Power Module (APM) design for hybrid\\/electric vehicle applications

    Microsoft Academic Search

    S. M. Nayeem Hasan; Mohammad N. Anwar; Mehrdad Teimorzadeh; Teimorzadeh David

    2011-01-01

    Electric and hybrid electric vehicle (EV\\/HEV) architectures require a small DC\\/DC converter to replace a conventional vehicle's alternator. The small DC\\/DC converter, also described as the vehicle Auxiliary Power Module (APM), provides power flow between the vehicle high voltage (HV) and low voltage (LV) DC bus. The APM HV interface is connected to the HV DC bus that contains energy

  18. Energy efficient ECS powered by a variable voltage/variable frequency power system

    SciTech Connect

    Cronin, M. J.

    1985-10-15

    The invention is an ECS system designed to utilize an induction motor and a cabin compressor for providing pressurized air that serves as a source of energy for heating, cooling, pressurizing and other air needs of modern aircraft. An aircraft engine driven generator, preferably a permanent-magnet generator (of the samarium-cobalt, SmCo, type), furnishes variable-voltage/variable frequency, VV/VF, power to the motor. The electric motor itself in the preferred embodiment is a highly reliable squirrel-cage induction motor powered directly from the VV/VF supply, with the result that its speed is proportional to the generator frequency, which in turn is dependent on the aircraft engine speed. The main cabin compressor and a secondary (auxiliary) supercharging compressor are both mounted on the motor shaft. The motor-compressor configuration is further characterized in that the ac motor has pole-changing winding (typically two), which permits two speed operation, while the cabin compressor is provided with inlet guide vanes. The interactive combination of these two features makes it possible to furnish the requisite air mass flow and pressurization levels over the conditions of variable air density and variable atmospheric pressure, as the airplane operates throughout its flight envelope.

  19. Energy efficient ECS powered by a variable voltage/variable frequency power system

    SciTech Connect

    Cronin, M.J.

    1984-07-31

    The invention is an ECS system designed to utilize an induction motor and a cabin compressor for providing pressurized air that serves as a source of energy for heating, cooling, pressurizing and other air needs of modern aircraft. An aircraft engine driven generator, preferably a permanent-magnet generator (of the samarium-cobalt, SmCo, type), furnishes variable-voltage/variable frequency, VV/VF, power to the motor. The electric motor itself in the preferred embodiment is a highly reliable squirrel-cage induction motor powered directly from the VV/VF supply, with the result that its speed is proportional to the generator frequency, which in turn is dependent on the aircraft engine speed. The main cabin compressor and a secondary (auxiliary) supercharging compressor are both mounted on the motor shaft. The motor-compressor configuration is further characterized in that the ac motor has pole-changing winding (typically two), which permits two speed operation, while the cabin compressor is provided with inlet guide vanes. The interactive combination of these two features makes it possible to furnish the requisite air mass flow and pressurization levels over the conditions of variable air density and variable atmospheric pressure, as the airplane operates throughout its flight envelope.

  20. Power processing for electric propulsion

    NASA Technical Reports Server (NTRS)

    Finke, R. C.; Herron, B. G.; Gant, G. D.

    1975-01-01

    The inclusion of electric thruster systems in spacecraft design is considered. The propulsion requirements of such spacecraft dictate a wide range of thruster power levels and operational lifetimes, which must be matched by lightweight, efficient, and reliable thruster power processing systems. Electron bombardment ion thruster requirements are presented, and the performance characteristics of present power processing systems are reviewed. Design philosophies and alternatives in areas such as inverter type, arc protection, and control methods are discussed along with future performance potentials for meeting goals in the areas of power process or weight (10 kg/kW), efficiency (approaching 92 percent), reliability (0.96 for 15,000 hr), and thermal control capability (0.3 to 5 AU).

  1. Reliability evaluation of the power supply of an electrical power net for safety-relevant applications

    E-print Network

    Liberzon, Daniel

    automotive safety-relevant systems. With the introduction of safety-relevant electronic systems in cars of occurrence. A new power net architecture with application to new safety-relevant automotive systems voltage will collapse and no actuation of any electrical systems will be possible. Although

  2. 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.

  3. 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.

  4. Power system voltage stability and agent based distribution automation in smart grid

    NASA Astrophysics Data System (ADS)

    Nguyen, Cuong Phuc

    2011-12-01

    Our interconnected electric power system is presently facing many challenges that it was not originally designed and engineered to handle. The increased inter-area power transfers, aging infrastructure, and old technologies, have caused many problems including voltage instability, widespread blackouts, slow control response, among others. These problems have created an urgent need to transform the present electric power system to a highly stable, reliable, efficient, and self-healing electric power system of the future, which has been termed "smart grid". This dissertation begins with an investigation of voltage stability in bulk transmission networks. A new continuation power flow tool for studying the impacts of generator merit order based dispatch on inter-area transfer capability and static voltage stability is presented. The load demands are represented by lumped load models on the transmission system. While this representation is acceptable in traditional power system analysis, it may not be valid in the future smart grid where the distribution system will be integrated with intelligent and quick control capabilities to mitigate voltage problems before they propagate into the entire system. Therefore, before analyzing the operation of the whole smart grid, it is important to understand the distribution system first. The second part of this dissertation presents a new platform for studying and testing emerging technologies in advanced Distribution Automation (DA) within smart grids. Due to the key benefits over the traditional centralized approach, namely flexible deployment, scalability, and avoidance of single-point-of-failure, a new distributed approach is employed to design and develop all elements of the platform. A multi-agent system (MAS), which has the three key characteristics of autonomy, local view, and decentralization, is selected to implement the advanced DA functions. The intelligent agents utilize a communication network for cooperation and negotiation. Communication latency is modeled using a user-defined probability density function. Failure-tolerant communication strategies are developed for agent communications. Major elements of advanced DA are developed in a completely distributed way and successfully tested for several IEEE standard systems, including: Fault Detection, Location, Isolation, and Service Restoration (FLISR); Coordination of Distributed Energy Storage Systems (DES); Distributed Power Flow (DPF); Volt-VAR Control (VVC); and Loss Reduction (LR).

  5. Power Sales to Electric Utilities

    SciTech Connect

    None

    1989-02-01

    The Public Utilities Regulatory Policies Act (PURPA) of 1979 requires that electrical utilities interconnect with qualifying facilities and purchase electricity at a rate based upon their full avoided costs (i.e., costs of providing both capacity and energy). Qualifying facilities (QF) include solar or geothermal electric units, hydropower, municipal solid waste or biomass-fired power plants, and cogeneration projects that satisfy maximum size, fuel use, ownership, location, and/or efficiency criteria. In Washington State, neither standard power purchase prices based upon a proxy ''avoided plant'', standard contracts, or a standard offer process have been used. Instead, a variety of power purchase contracts have been negotiated by developers of qualifying facilities with investor-owned utilities, public utility districts, and municipally-owned and operated utilities. With a hydro-based system, benefits associated with resource acquisition are determined in large part by how compatible the resource is with a utility's existing generation mix. Power purchase rates are negotiated and vary according to firm energy production, guarantees, ability to schedule maintenance or downtime, rights of refusal, power plant purchase options, project start date and length of contract; front-loading or levelization provisions; and the ability of the project to provide ''demonstrated'' capacity. Legislation was also enacted which allows PURPA to work effectively. Initial laws established ownership rights and provided irrigation districts, PUDs, and municipalities with expanded enabling powers. Financial processes were streamlined and, in some cases, simplified. Finally, laws were passed which are designed to ensure that development proceeds in an environmentally acceptable manner. In retrospect, PURPA has worked well within Washington. In the state of Washington, 20 small-scale hydroelectric projects with a combined generating capacity of 77 MW, 3 solid waste-to-energy facilities with 55 MW of electrical output, 4 cogeneration projects with 34.5 MW of generating capability, and 4 wastewater treatment facility digester gas-to-energy projects with 5 MW of electrical production have come on-line (or are in the final stages of construction) since the passage of PURPA. These numbers represent only a small portion of Washington's untapped and underutilized cogeneration and renewable resource generating potentials. [DJE-2005

  6. DC/DC Power Converter for Super-Capacitor Supplied by Electric Power Splitter

    NASA Astrophysics Data System (ADS)

    Haubert, T.; Mindl, P.

    The aim of the article is design of DC/DC converter and discussing of problematic supply using electric power splitter. The electric power splitter with AC/DC converter is source for the DC/DC converter, which is dedicated for charging and discharging of hybrid car drive super-capacitor energy storage. The electric power splitter is synchronous machine with two rotating parts. First rotor contains permanent magnet and the second rotor contains three-phase windings. The amplitude of output voltage depends on difference between first and second rotor speed. The main role of the DC/DC converter is to optimize energy content in super-capacitor storage used to acceleration and deceleration driving period of the passenger car with hybrid electric vehicle (HEV) drive system using electric power splitter.

  7. Electric vehicles as a new power source for electric utilities

    Microsoft Academic Search

    Steven E. Letendre

    1997-01-01

    Electric-drive vehicles, whether fueled by batteries or by liquid or gaseous fuels generating electricity on-board, will have value to electric utilities as power resources. The power capacity of the current internal combustion passenger vehicle fleet is enormous and under-utilized. In the United States, for example, the vehicle fleet has over 10 times the mechanical power of all current U.S. electrical

  8. Threshold voltage of luminescence and electrical tree inception in low-density polyethylene

    SciTech Connect

    Bamji, S.S.; Bulinski, A.T.; Densley, R.J.

    1988-06-15

    The characteristics of luminescence observed during the initiation of an electrical tree have been studied for polyethylene subjected to high electrical stresses. Use of a light detection system which is at least three orders-of-magnitude more sensitive than conventional partial discharge detectors shows that luminescence occurs during tree initiation and this luminescence is not due to partial discharges. Applying a constant high voltage to the polymer or interrupting the voltage several times does not change the behavior of luminescence. The light starts at about the same voltage and its intensity returns to the same value as before the interruption. This behavior is contrary to that observed for partial discharges. The luminescence inception voltage is the threshold voltage at which the polymer starts to degrade. Thus, it is important that the insulation of electrical equipment be protected from transient overvoltages which exceed the threshold level.

  9. Electric Power System Analysis and Design of an Expanding Steel Cogeneration Plant

    Microsoft Academic Search

    Cheng-Ting Hsu; Chao-Shun Chen; Chia-Hung Lin

    2010-01-01

    This paper presents the electric power system analysis and design of an expanding steel cogeneration plant. The power system configuration and the equipment parameters of the cogeneration plant are well designed according to the power flow, short circuit, voltage fluctuation, harmonic flow and transient stability analyses. According to the power flow analysis, the site and capacity of shunt capacitor banks

  10. Optical sensors for electrical elements of a medium voltage distribution network

    NASA Astrophysics Data System (ADS)

    De Maria, Letizia; Bartalesi, Daniele; Serragli, Paolo; Paladino, Domenico

    2012-04-01

    The aging of most of the components of the National transmission and distribution system can potentially influence the reliability of power supply in a Medium Voltage (MV) network. In order to prevent possible dangerous situations, selected diagnostic indicators on electrical parts exploiting reliable and potentially low-cost sensors are required. This paper presents results concerning two main research activities regarding the development and application of innovative optical sensors for the diagnostic of MV electrical components. The first concerns a multi-sensor prototype for the detection of pre-discharges in MV switchboards: it is the combination of three different types of sensors operating simultaneously to detect incipient failure and to reduce the occurrence of false alarms. The system is real-time controlled by an embedded computer through a LabView interface. The second activity refers to a diagnostic tool to provide significant real-time information about early aging of MV/Low Voltage (LV) transformers by means of its vibration fingerprint. A miniaturized Optical Micro-Electro-Mechanical System (MEMS) based unit has been assembled for vibration measurements, wireless connected to a remote computer and controlled via LabView interface. Preliminary comparative tests were carried out with standard piezoelectric accelerometers on a conventional MV/LV test transformer under open circuit and in short-circuited configuration.

  11. An earth-isolated optically coupled wideband high voltage probe powered by ambient light

    E-print Network

    Bellan, Paul M.

    An earth-isolated optically coupled wideband high voltage probe powered by ambient light Xiang Zhai) An earth-isolated optically coupled wideband high voltage probe powered by ambient light Xiang Zhaia online 9 October 2012) An earth-isolated optically-coupled wideband high voltage probe has been developed

  12. Voltage-Clock-Scaling Adaptive Scheduling Techniques for Low Power in Hard Real-Time Systems

    Microsoft Academic Search

    C. Mani Krishna; Yann-hang Lee

    2000-01-01

    Many embedded systems operate under severe power and energy constraints. Voltage clock scaling is one mechanism by which energy consumption may be reduced; it is based on the fact that power consumption is a quadratic function of the voltage, while the speed is a linear function. The authors show how voltage scaling can be scheduled to reduce energy usage while

  13. Stochastic Power/Ground Supply Voltage Prediction and Optimization via Analytical Placement

    E-print Network

    Liu, Bao

    1 Stochastic Power/Ground Supply Voltage Prediction and Optimization via Analytical Placement-- Increasingly significant power/ground (P/G) supply voltage degradation in nanometer VLSI designs leads techniques. We represent the supply voltage degradation at a P/G node as a function of the supply currents

  14. 46 CFR 111.79-13 - Different voltages and power types.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 2010-10-01 false Different voltages and power types. 111.79-13 ...Receptacles § 111.79-13 Different voltages and power types. If receptacle outlets on a vessel are supplied by different voltages (e.g., 110 volts and 220...

  15. 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

  16. Limiting electric fields of HVDC overhead power lines.

    PubMed

    Leitgeb, N

    2014-05-01

    As a consequence of the increased use of renewable energy and the now long distances between energy generation and consumption, in Europe, electric power transfer by high-voltage (HV) direct current (DC) overhead power lines gains increasing importance. Thousands of kilometers of them are going to be built within the next years. However, existing guidelines and regulations do not yet contain recommendations to limit static electric fields, which are one of the most important criteria for HVDC overhead power lines in terms of tower design, span width and ground clearance. Based on theoretical and experimental data, in this article, static electric fields associated with adverse health effects are analysed and various criteria are derived for limiting static electric field strengths. PMID:24573710

  17. TEP Power Partners Project [Tucson Electric Power

    SciTech Connect

    None

    2013-11-19

    The Arizona Governor’s Office of Energy Policy, in partnership with Tucson Electric Power (TEP), Tendril, and Next Phase Energy (NPE), formed the TEP Power Partners pilot project to demonstrate how residential customers could access their energy usage data and third party applications using data obtained from an Automatic Meter Reading (AMR) network. The project applied for and was awarded a Smart Grid Data Access grant through the U.S. Department of Energy. The project participants’ goal for Phase I is to actively engage 1,700 residential customers to demonstrate sustained participation, reduction in energy usage (kWh) and cost ($), and measure related aspects of customer satisfaction. This Demonstration report presents a summary of the findings, effectiveness, and customer satisfaction with the 15-month TEP Power Partners pilot project. The objective of the program is to provide residential customers with energy consumption data from AMR metering and empower these participants to better manage their electricity use. The pilot recruitment goals included migrating 700 existing customers from the completed Power Partners Demand Response Load Control Project (DRLC), and enrolling 1,000 new participants. Upon conclusion of the project on November 19, 2013: ? 1,390 Home Area Networks (HANs) were registered. ? 797 new participants installed a HAN. ? Survey respondents’ are satisfied with the program and found value with a variety of specific program components. ? Survey respondents report feeling greater control over their energy usage and report taking energy savings actions in their homes after participating in the program. ? On average, 43 % of the participants returned to the web portal monthly and 15% returned weekly. ? An impact evaluation was completed by Opinion Dynamics and found average participant savings for the treatment period1 to be 2.3% of their household use during this period.2 In total, the program saved 163 MWh in the treatment period of 2013.

  18. A constant current high voltage capacitor charging power supply for pulsed power applications

    Microsoft Academic Search

    G.-H. Rim; I.-W. Jeong; Y.-W. Choi; H.-J. Ryoo; J.-S. Kim; K.-H. Kim; S.-P. Lee; H.-K. Chang

    2001-01-01

    Summary form only given. Various industry applications such as lasers, accelerators, plasma source ion implantations and non-thermal pollution gas treatment need high voltage high repetition rate pulsed power supplies. This paper presents a compact capacitor charging power supply for gas treatment. It consists of a three-phase rectifier with soft starting, a three phase IGBT inverter, three high frequency transformers and

  19. Wireless power transfer and fault diagnosis of high-voltage power line via robotic bird

    NASA Astrophysics Data System (ADS)

    Liu, Chunhua; Chau, K. T.; Zhang, Zhen; Qiu, Chun; Li, Wenlong; Ching, T. W.

    2015-05-01

    This paper presents a new idea of wireless power transfer (WPT) and fault diagnosis (FD) of high-voltage power line via robotic bird. The key is to present the conceptual robotic bird with WPT coupling coil for detecting and capturing the energy from the high-voltage power line. If the power line works in normal condition, the robotic bird is able to stand on the power line and extract energy from it. If fault occurs on the power line, the corresponding magnetic field distribution will become different from that in the normal situation. By analyzing the magnetic field distribution of the power line, the WPT to the robotic bird and the FD by the robotic bird are performed and verified.

  20. EMC in dual voltage vehicle electrical system: experimental investigation of transient disturbance problems and comparison with conventional 14 V electrical systems behaviour

    Microsoft Academic Search

    M. C. Di Piazza; A. Ragusa; G. Tine; G. Vitale

    2002-01-01

    This paper is focused on some electromagnetic compatibility problems concerning automotive electrical loads in dual-voltage vehicle architecture. Transient disturbances produced by a new prototypical vehicle electrical load have been analysed. In particular the considered electrical load is a DC cooling fan drive intended for a 42 V rated voltage. Both current and voltage transient disturbances produced by the 42 V

  1. Cyber security of the electric power grid

    Microsoft Academic Search

    J. E. Dagle

    2009-01-01

    Economic security and quality of life in modern society depend on the reliable supply and delivery of electric power. New cyber security vulnerabilities are emerging that introduce new risks to the Nation's electric power grid. This presentation will describe issues, trends, and research opportunities for enhancing the cyber security of control systems associated with electric power system operations.

  2. Distributed low voltage power supply system for front end electronics of the TRT detector in ATLAS experiment

    E-print Network

    Hajduk, Zbigniew; Farthouat, P; Kisielewski, B; Lichard, P; Olszowska, J; Ryzhov, V; Cardiel-Sas, L

    2007-01-01

    We present a low voltage power supply system which has to deliver to the front end electronics of the ATLAS TRT detector [1] ca. 23 kW of electrical power over the distance of 55 -106 m (which adds another 24 kW). The system has to operate in magnetic field and under radiation environment of the LHC experimental cavern. The system has ~ 3000 individual channels which are all monitored and controlled (voltage and current measurement). The hardware solutions are described as well as the system control software.

  3. Electrical treeing caused by rapid DC-voltage grounding of XLPE cable insulation

    Microsoft Academic Search

    Mildrid Selsjord; Erling Ildstad

    2006-01-01

    This report presents results from an experimental investigation using Rogowski shaped test objects with needle implants, either fully insulated or in contact with one of the electrodes. In both cases abrupt grounding caused electric breakdown to be initiated at a voltage much lower than the short term breakdown voltage. Reduced breakdown strength occurred due to increased DC pre-stress level, number

  4. Probe for measurements of the DC electric field in air around high voltage apparatus

    Microsoft Academic Search

    K. Johansson; L. Walfridsson; U. Ga?fvert; B. Ka?llstrand; S. Ho?rnfeldt

    2010-01-01

    Knowledge of the external field distribution around high voltage apparatus is of vital importance. As a part of the effort to improve the physical understanding of the DC field distribution outside high voltage apparatus, a small probe that can measure DC electric fields has been developed and a first version of this probe has been tested. The probe is 26

  5. Design and Construction of a High Voltage Pulsed Source for Electric Excitation of the Gas Laser

    NASA Astrophysics Data System (ADS)

    Díaz, Xavier Daza; Neira, Oscar León B.; Díaz-Pérez, H. Abraham

    2008-04-01

    In this paper, the design, construction and implementation of High Voltage Pulsed Source for Electrical Excitation of the Gas Lasers, as a first phase of the research project "Design and Construction of an economically and reliable Laser System constituted by a molecular pulsed laser and a single optical head for dyes" is presented. We proposed and considered the design and the construction of a source of pulsed high voltage that adjusts to the requirements of the pumping system that requires a low pressure nitrogen laser. The design and construction of the source high voltage prototype is presented like part of the electrical pumping system for a Pulsed Nitrogen Laser. The electrical pumping System is conformed by three subsystems: the high pulsed regulated voltage Source, the storage and unloading system of electrical energy of active medium, and the frequency control system of discharge repetition (spark gap) constituted by a circuit RLC and the electrodes of the laser discharge tube. In the present work the aspects related to the pulsed high regulated voltage Source is presented, Our Source of high pulsed voltage is constituted by four fundamental stages: the Stage of Conversion AC-DC (voltage reducer), the Stage of Commutation by means of a Insulated Gate Bipolar Transistor (IGBT), the stage of Generation of signal modulated by the pulses width "PWM" (with base to Circuit TL 494) and the Stage of Elevation of Voltage (using a FlyBack Transformer).

  6. Risks of leukaemia among residents close to high voltage transmission electric lines

    Microsoft Academic Search

    G Thériault; C Y Li

    1997-01-01

    OBJECTIVES: To reassess the risk of leukaemia associated with residential exposure near high voltage transmission electric lines of 49 kV and above in view of the recent publications. METHODS: Through a review of papers considering the risk of leukaemia among people living near high voltage transmission lines, the combined risks of leukaemia were calculated for distances < or = 50

  7. Design and Fabrication of a PD Measurement System for Dielectric Test of Low-voltage Electrical and Electronic Devices

    Microsoft Academic Search

    GYUNG-SUK KIL; JAE-YONG SONG; IL-KWON KIM; SEUNG-BO MOON

    2006-01-01

    Partial discharge (PD) analysis as a non-destructive dielectric test is getting spread. For the application of PD test to low-voltage electrical and electronic devices, PD test measurement system detects apparent charge below 1 pC is essential. In this paper, we described a PD measurement system which is composed of noise free power source and coupling network, a low-noise amplifier. A

  8. Importance of the Equlibrium Node in Preventing the Voltage Collapse Occurs in the Wind Power System

    E-print Network

    Lavaei, Javad

    Importance of the Equlibrium Node in Preventing the Voltage Collapse Occurs in the Wind Power collapse will occurs in a wind power system is discussed next. The method of power flow calculation is the specific analysis of a given simplified wind power system. Keywords--voltage collapse; Newton

  9. Architecture for a High-to-Medium-Voltage Power Converter

    NASA Technical Reports Server (NTRS)

    Vorpenian, Vatche

    2008-01-01

    A power converter now undergoing development is required to operate at a DC input potential ranging between 5.5 and 10 kV and a DC output potential of 400 V at a current up to 25 A. This power converter is also required to be sufficiently compact and reliable to fit and operate within the confines of a high-pressure case to be lowered to several miles (approx.5 km) below the surface of the ocean. The architecture chosen to satisfy these requirements calls for a series/ parallel arrangement of 48 high-frequency, pulse-width-modulation (PWM), transformer-isolation DC-to-DC power converter blocks. The input sides of the converter blocks would be connected in series so that the input potential would be divided among them, each of them being exposed to an input potential of no more than 10 kV/48 . 210 V. The series connection of inputs would also enforce a requirement that all the converter blocks operate at the same input current. The outputs of the converter blocks would be connected in a matrix comprising 6 parallel legs, each leg being a cascade of eight outputs wired in series (see figure). All the converter blocks would be identical within the tolerances of the values of their components. A single voltage feedback loop would regulate the output potential. All the converter blocks would be driven by the same PWM waveform generated by this feedback loop. The power transformer of each converter block would have a unity turns ratio and would be capable of withstanding as much as 10 kVDC between its primary and secondary windings. (Although, in general, the turns ratio could be different from unity, the simplest construction for minimizing leakage and maximizing breakdown voltage is attained at a turns ratio of unity.)

  10. 30 CFR 75.509 - Electric power circuit and electric equipment; deenergization.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... false Electric power circuit and electric equipment...STANDARDS-UNDERGROUND COAL MINES Electrical Equipment-General § 75.509 Electric power circuit and electric equipment...Provisions] All power circuits and electric...

  11. 30 CFR 75.509 - Electric power circuit and electric equipment; deenergization.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... false Electric power circuit and electric equipment...STANDARDS-UNDERGROUND COAL MINES Electrical Equipment-General § 75.509 Electric power circuit and electric equipment...Provisions] All power circuits and electric...

  12. 30 CFR 75.509 - Electric power circuit and electric equipment; deenergization.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... false Electric power circuit and electric equipment...STANDARDS-UNDERGROUND COAL MINES Electrical Equipment-General § 75.509 Electric power circuit and electric equipment...Provisions] All power circuits and electric...

  13. 30 CFR 77.500 - Electric power circuits and electric equipment; deenergization.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... false Electric power circuits and electric equipment...UNDERGROUND COAL MINES Electrical Equipment-General § 77.500 Electric power circuits and electric equipment; deenergization. Power circuits and electric...

  14. Ultra Low-Voltage\\/Low-Power Digital Floating-Gate Circuits

    Microsoft Academic Search

    Y. Berg; D. t. Wisland; T. s. Lande

    1999-01-01

    This paper describes a novel technique for implementing ultra low-voltage\\/low-power digital circuits. The effective threshold voltage seen from a control gate is adjusted during a UV-light activated tuning procedure. The optimal effective threshold voltage matching the supply voltage and speed may be programmed by UV-light through an activated conductance between the power-rails and the floating gates. Measured results are provided

  15. ACEEE Int. J. on Electrical and Power Engineering, Vol. 01, No. 03, Dec 2010 2010 ACEEE

    E-print Network

    Paris-Sud XI, Université de

    controlled drives employ mostly a Voltage Source Inverter (VSI) to control the motor armature, despite@tce.edu Abstract In today s high-power electrical drives using vector controlled induction machines, voltage source inverters (VSI) based on PWM technology and current source inverters (CSI) based on based on PWM technology

  16. Development of a method of measuring relative phase difference between sending and receiving voltage on a power line

    E-print Network

    Rackley, Benton Tiburce

    1950-01-01

    of Measuri np, Relative Phase Difference Between Sending ~nd Receiving Voltage on ~ Power Line. Conclusions. 4. Bibliography 29 FIGURFS 1. Two Machine System 2. Magnetic Cylinder Shunt for Current Transformer 4. Phase Shift Meter Network 5. Standard... of Phase Angle vs. Load Reading . . . . . 26 INTNODUGTION During World War II the electrical power system of the United States was operated at full cap~city--indeed, m~ny units carr1ed overloads for extended periods of time. genera tins stations...

  17. Electric power systems, 3rd ed. , Revised

    SciTech Connect

    Weedy, B.M.

    1987-01-01

    The contents of this book are: Introduction. Basic Concepts. Components of a Power System. Control of Power and Frequency. Control of Voltage and Reactive Power. Load Flows. Fault Analysis. Stability Limits. Direct Current Transmission. Overvoltages and Insulation Requirements. Overhead Lines and Underground Cables. Protection.

  18. Application of modelling and computer simulation for the development of a test setup for calibration of power quality measurement transducers for high voltage networks

    Microsoft Academic Search

    HÉDIO TATIZAWA; ERASMO SILVEIRA NETO; GERALDO F. BURANI; ANTÔNIO A. C. A RRUDA; KLEIBER T. SOLETTO; NELSON M. MATSUO

    2008-01-01

    T he term power quality is, in general, closely related to the quality of the voltage. Considering the widespread presence of sensitive loads in the electric grid, and the increasing awareness of the consumers concerning the quality of the power supply, the control and measurement of power quality parameters, for instance, harmonics, interharmonics, sags, swells, etc., are increasingly becoming much

  19. Electric power annual 1997. Volume 1

    SciTech Connect

    NONE

    1998-07-01

    The Electric Power Annual presents a summary of electric power industry statistics at national, regional, and State levels. The objective of the publication is to provide industry decisionmakers, government policy-makers, analysts, and the general public with data that may be used in understanding US electricity markets. The Electric Power Annual is prepared by the Electric Power Division; Office of Coal, Nuclear, Electric and Alternate Fuels; Energy Information Administration (EIA); US Department of Energy. Volume 1 -- with a focus on US electric utilities -- contains final 1997 data on net generation and fossil fuel consumption, stocks, receipts, and cost; preliminary 1997 data on generating unit capability, and retail sales of electricity, associated revenue, and the average revenue per kilowatthour of electricity sold (based on a monthly sample: Form EIA-826, ``Monthly Electric Utility Sales and Revenue Report with State Distributions``). Additionally, information on net generation from renewable energy sources and on the associated generating capability is included in Volume 1 of the EPA.

  20. A Complex Permittivity Based Sensor for the Electrical Characterization of High-Voltage Transformer Oils

    PubMed Central

    Dervos, Constantine T.; Paraskevas, Christos D.; Skafidas, Panayotis D.; Vassiliou, Panayota

    2005-01-01

    This work investigates the use of a specially designed cylindrical metal cell, in order to obtain complex permittivity and tan? data of highly insulating High Voltage (HV) transformer oil samples. The data are obtained at a wide range of frequencies and operation temperatures to demonstrate the polarization phenomena and the thermally stimulated effects. Such complex permittivity measurements may be utilized as a criterion for the service life prediction of oil field electrical equipment (OFEE). Therefore, by one set of measurements on a small oil volume, data may be provided on the impending termination, or continuation of the transformer oil service life. The oil incorporating cell, attached to the appropriate measuring units, could be described as a complex permittivity sensor. In this work, the acquired dielectric data from a great number of operating distribution network power transformers were correlated to corresponding physicochemical ones to demonstrate the future potential employment of the proposed measuring technique.

  1. Reducing the Vulnerability of Electric Power Grids to Terrorist Attacks

    SciTech Connect

    Ross Baldick; Thekla Boutsika; Jin Hur; Manho Joung; Yin Wu; Minqi Zhong

    2009-01-31

    This report describes the development of a cascading outage analyzer that, given an initial disturbance on an electric power system, checks for thermal overloads, under-frequency and over-frequency conditions, and under-voltage conditions that would result in removal of elements from the system. The analyzer simulates the successive tripping of elements due to protective actions until a post-event steady state or a system blackout is reached.

  2. FPGA-based voltage and current dual drive system for high frame rate electrical impedance tomography.

    PubMed

    Khan, Shadab; Manwaring, Preston; Borsic, Andrea; Halter, Ryan

    2015-04-01

    Electrical impedance tomography (EIT) is used to image the electrical property distribution of a tissue under test. An EIT system comprises complex hardware and software modules, which are typically designed for a specific application. Upgrading these modules is a time-consuming process, and requires rigorous testing to ensure proper functioning of new modules with the existing ones. To this end, we developed a modular and reconfigurable data acquisition (DAQ) system using National Instruments' (NI) hardware and software modules, which offer inherent compatibility over generations of hardware and software revisions. The system can be configured to use up to 32-channels. This EIT system can be used to interchangeably apply current or voltage signal, and measure the tissue response in a semi-parallel fashion. A novel signal averaging algorithm, and 512-point fast Fourier transform (FFT) computation block was implemented on the FPGA. FFT output bins were classified as signal or noise. Signal bins constitute a tissue's response to a pure or mixed tone signal. Signal bins' data can be used for traditional applications, as well as synchronous frequency-difference imaging. Noise bins were used to compute noise power on the FPGA. Noise power represents a metric of signal quality, and can be used to ensure proper tissue-electrode contact. Allocation of these computationally expensive tasks to the FPGA reduced the required bandwidth between PC, and the FPGA for high frame rate EIT. In 16-channel configuration, with a signal-averaging factor of 8, the DAQ frame rate at 100 kHz exceeded 110 frames s (-1), and signal-to-noise ratio exceeded 90 dB across the spectrum. Reciprocity error was found to be for frequencies up to 1 MHz. Static imaging experiments were performed on a high-conductivity inclusion placed in a saline filled tank; the inclusion was clearly localized in the reconstructions obtained for both absolute current and voltage mode data. PMID:25376037

  3. Design considerations for high-voltage high-power full-bridge zero-voltage-switched PWM converter

    Microsoft Academic Search

    J. A. Sabate; V. Vlatkovic; R. B. Ridley; F. C. Lee; B. H. Cho

    1990-01-01

    A steady-state analysis is presented with complete characterization of the converter operation. A small-signal model of the converter is established. The design procedures based on the analysis are presented and the various losses in the circuit assessed. Critical design considerations for a high-power, high-voltage application are analyzed. The results of the analysis are verified using a high-voltage. 2 kW prototype

  4. High voltage ignition of high pressure microwave powered UV light sources

    SciTech Connect

    Frank, J.D.; Cekic, M.; Wood, C.H. [Fusion U.V. Curing Systems Corp., Gaithersburg, MD (United States)

    1997-12-31

    Industrial microwave powered (electrodeless) light sources have been limited to quiescent pressures of {approximately}300 Torr of buffer gas and metal-halide fills. The predominant reason for such restrictions has been the inability to microwave ignite the plasma due to the collisionality of higher pressure fills and/or the electronegativity of halide bulb chemistries. Commercially interesting bulb fills require electric fields for ionization that are often large multiples of the breakdown voltage for air. Many auxiliary ignition methods are evaluated for efficiency and practicality before the choice of a high-voltage system with a retractable external electrode. The scheme utilizes a high voltage pulse power supply and a novel field emission source. Acting together they create localized condition of pressure reduction and high free electron density. This allows the normal microwave fields to drive this small region into avalanche, ignite the bulb, and heat the plasma to its operating point (T{sub e} {approx} 0.5 eV). This process is currently being used in a new generation of lamps, which are using multi-atmospheric excimer laser chemistries and pressure and constituent enhanced metal-halide systems. At the present time, production prototypes produce over 900 W of radiation in a 30 nm band, centered at 308 nm. Similarly, these prototypes when loaded with metal-halide bulb fills produce over 1 kW of radiation in 30 nm wide bands, centered about the wavelength of interest.

  5. Modeling market power in electricity markets: Is the devil only in the details?

    SciTech Connect

    Bautista, Guillermo; Anjos, Miguel F.; Vannelli, Anthony

    2007-01-15

    Basic approximations of the transmission system are ubiquitous in the literature on modeling competition in electricity markets. Because the main concern of market power is with active power, reactive power and voltage-related issues are commonly neglected, even though they are inherent features of an electrical power system. However, the usefulness of stylized formulations that do not comprise these system elements may be severely limited. (author)

  6. Single action potentials and subthreshold electrical events imaged in neurons with a fluorescent protein voltage probe.

    PubMed

    Jin, Lei; Han, Zhou; Platisa, Jelena; Wooltorton, Julian R A; Cohen, Lawrence B; Pieribone, Vincent A

    2012-09-01

    Monitoring neuronal electrical activity using fluorescent protein-based voltage sensors has been limited by small response magnitudes and slow kinetics of existing probes. Here we report the development of a fluorescent protein voltage sensor, named ArcLight, and derivative probes that exhibit large changes in fluorescence intensity in response to voltage changes. ArcLight consists of the voltage-sensing domain of Ciona intestinalis voltage-sensitive phosphatase and super ecliptic pHluorin that carries the point mutation A227D. The fluorescence intensity of ArcLight A242 decreases by 35% in response to a 100 mV depolarization when measured in HEK293 cells, which is more than five times larger than the signals from previously reported fluorescent protein voltage sensors. We show that the combination of signal size and response speed of these new probes allows the reliable detection of single action potentials and excitatory potentials in individual neurons and dendrites. PMID:22958819

  7. The Constant Voltage Transformer (CVT) for Mitigating Effects of Voltage Sags on Industrial Equipment 

    E-print Network

    Ferraro, R. J.; Osborne, R.; Stephens, R.

    2000-01-01

    ) an increase in loads that use power electronics in some type of power conversion configuration [1][2]. This paper presents applications of the constant-voltage transformer (CVT) for mitigating the effects of electric service voltage sags on industrial...

  8. Electrical power requirements analysis. Single failure tolerant entry

    NASA Technical Reports Server (NTRS)

    Pipher, M. D.; Green, P. A.; Wolfgram, D. F.

    1977-01-01

    The results of an analysis of the orbiter electrical power system for the case of a single failure tolerant (SFT) entry are presented. The analysis was performed using the shuttle electrical power system analysis computer program. It was performed to permit assessment of the capability of the orbiter systems to support the proposed entry configuration and to provide the data necessary to identify potential constraints and limitations. Three contingency modes have been identified which would require an SFT entry. This analysis addresses an SFT entry resulting from the loss of two fuel cell powerplants, while on orbit. The results of the analysis indicate that, even under near optimum conditions, the fuel cell power demand will exceed the tested operating capacity of 16 kw, and that various electrical components may experience voltages below 24 VDC.

  9. A market mechanism for electric power transmission

    Microsoft Academic Search

    Hung-Po Chao; Stephen Peck

    1996-01-01

    As competition is introduced into the electric power industry, access and pricing policy for transmission will play a pivotal role in shaping future market structure and performance. The externalities associated with the loop flow phenomenon in an electric power network constitute a significant barrier to the formation of efficient markets for electricity and transmission services. In this paper, we present

  10. Reactive Power Support Services in Electricity Markets

    E-print Network

    this Project For information about this project contact: Peter W. Sauer, Project Leader Professor ElectricalReactive Power Support Services in Electricity Markets Costing and Pricing of Ancillary Services Reactive Power Support Services in Electricity Markets Costing and Pricing of Ancillary Services Project

  11. Power Attack Resistant Cryptosystem Design: A Dynamic Voltage and Frequency Switching Approach

    E-print Network

    Boyer, Edmond

    Power Attack Resistant Cryptosystem Design: A Dynamic Voltage and Frequency Switching Approach|wolf}@princeton.edu {vijay|yuanxie}@cse.psu.edu {serpanos}@ee.upatras.gr Abstract-- A novel power attack resistant the power attacks, i.e., Dynamic Voltage and Frequency Switching (DVFS). Three designs, naive, improved

  12. A new approach to enhance power quality for medium voltage drives

    Microsoft Academic Search

    P. W. Hammond

    1995-01-01

    A new approach to medium voltage, variable frequency, static AC motor drives offers improvements in power quality. Harmonic current injection into power lines is below the most severe requirements of IEEE 519-1992. The power factor of this new type of drive exceeds 94% at full load and is above 90% at 10% load. Motor voltage and current waveforms are improved

  13. Energy Management Fuzzy Logic Supervisory for Electric Vehicle Power Supplies System

    Microsoft Academic Search

    AndrÉ Augusto Ferreira; JosÉ Antenor Pomilio; Giorgio Spiazzi; Leonardo de Araujo Silva

    2008-01-01

    This paper introduces an energy management strategy based on fuzzy logic supervisory for road electric vehicle, combining a fuel cell power source and two energy storage devices, i.e., batteries and ultracapacitors. The control strategy is designed to achieve the high-efficiency operation region of the individual power source and to regulate current and voltage at peak and average power demand, without

  14. Parallel flow to analyze the impact of the voltage regulator model in nanoscale power distribution network

    Microsoft Academic Search

    Amirali Shayan Arani; Xiang Hu; He Peng; Wenjian Yu; Wanping Zhang; Chung-kuan Cheng; Mikhail Popovich; Xiaoming Chen; Lew Chua-eoan; Xiaohua Kong

    2009-01-01

    In this paper, an efficient parallel flow for the design of the full power distribution network (PDN) is proposed. The analysis demonstrates the impact of the voltage regulator model in both frequency and time domain response. Based on the experimental results, it is observed that including the voltage regulator model in the PDN model increases the transient voltage drop and

  15. Fault Coverage Analysis for Physically-Based CMOS Bridging Faults at Different Power Supply Voltages

    Microsoft Academic Search

    Yuyun Liao; D. M. H. Walker

    1996-01-01

    Bridging faults in CMOS circuits sometimes degrade the output voltage and time performance without altering the logic function. The traditional voltage testing models based on the normal power supply voltage do not accurately model this behavior. In this paper we develop a model of bridging faults that accounts for both the bridging resistance distribution and gate sensitization and propagation choices.

  16. Power quality analysis based on fuzzy estimation algorithm: Voltage flicker measurements

    Microsoft Academic Search

    A. M. Al-Kandari; S. A. Soliman; R. A. Alammari

    2006-01-01

    This paper presents a method based on fuzzy linear estimation for voltage flicker measurements. The proposed algorithm uses the digitized samples of the voltage signal at the location where the power quality standards are implemented. The voltage signal is modeled as a fuzzy linear parameter estimation problem, where the coefficients are assumed to be fuzzy having certain middle and spread.

  17. FUSE satellite electrical power subsystem

    SciTech Connect

    Roufberg, L.; Noah, K.

    1998-07-01

    The Far Ultraviolet Spectroscopic Explorer (FUSE) satellite will be placed into a low earth orbit to investigate astrophysical processes related to the formation and development of the early universe. The FUSE satellite is considered a pathfinder for NASA's Mid-Class Explorers (MIDEX). To reduce mission cost and development time while delivering quality science, NASA has enforced strict cost caps with a clear definition of high-level science objectives. As a result, a significant design driver for the electrical power subsystem (EPS) was to minimize cost. The FUSE EPS is a direct energy transfer, unregulated bus architecture, with batteries directly on the bus and solar array power limted by pulse-width-modulated shunt regulators. The power subsystem electronics (PSE) contains circuitry to control battery charging, provide power to the loads, and provide fault protection. The electronics is based on the PSE which Orbital (formerly, Fairchild Space) designed and built for NASA/GSFC's XTE spacecraft. However, the FUSE PSE design incorporates a number of unique features to meet the mission requirements. To minimize size of the solar panels due to stowed attachment constraints, GaAs/Ge solar cells were selected. This is the first time this type of large area, thinned solar cell with integral bypass diodes are being used for a NASA LEO mission. The solar panels support a satellite load power of 520W. Nickel Cadmium (NiCd) batteries are used which are identical to the RADARSAT-I design, except for different temperature sensors. This is the first mission for which Orbital is using SAFT NiCd batteries. The spacecraft bus, including the EPS, has successfully completed environmental testing and has been delivered for instrument integration. Tradeoffs involved in designing the EPS and selecting components based on the requirements are discussed. Analyses including solar array and battery sizing and energy balance are presented in addition to results from testing the flight hardware.

  18. Electric Power Transfer Capability: Concepts, Applications,

    E-print Network

    Electric Power Transfer Capability: Concepts, Applications, Sensitivity, Uncertainty Power Systems since 1996 PSERC #12;ELECTRIC POWER TRANSFER CAPABILITY: CONCEPTS, APPLICATIONS, SENSITIVITY this Project Project information can be obtained at http://www.pserc.cornell.edu/tcc/info.html or by contacting

  19. Electrical power technology for robotic planetary rovers

    NASA Technical Reports Server (NTRS)

    Bankston, C. P.; Shirbacheh, M.; Bents, D. J.; Bozek, J. M.

    1993-01-01

    Power technologies which will enable a range of robotic rover vehicle missions by the end of the 1990s and beyond are discussed. The electrical power system is the most critical system for reliability and life, since all other on board functions (mobility, navigation, command and data, communications, and the scientific payload instruments) require electrical power. The following are discussed: power generation, energy storage, power management and distribution, and thermal management.

  20. Electric Power: Decisions for the Future.

    ERIC Educational Resources Information Center

    Cardon, Phillip L.; Preston, John

    2003-01-01

    Reviews the past 25 years of electricity consumption in the United States and considers the implications for the near future. Discusses strategies for energy conservation and provides a student activity for measuring and conserving electric power. (Author/JOW)

  1. Processing of thermionic power on an electrically propelled spacecraft

    NASA Technical Reports Server (NTRS)

    Macie, T. W.

    1973-01-01

    A study to define the power processing equipment required between a thermionic reactor and an array of mercury-ion thrusters for a nuclear electric propulsion system is reported. Observations and recommendations that resulted from this study were: (1) the preferred thermionic-fuel-element source voltages are 23 V or higher; (2) transistor characteristics exert a strong effect on power processor mass; (3) the power processor mass could be considerably reduced should the magnetic materials that exhibit low losses at high frequencies, that have a high Curie point, and that can operate at 15 to 20 kG become avaliable; (4) electrical component packaging on the radiator could reduce the area that is sensitive to meteoroid penetration, thereby reducing the meteoroid shielding mass requirement; (5) an experimental model of the power processor design should be built and tested to verify the efficiencies, masses, and all the automatic operational aspects of the design.

  2. The Effect of High Voltage, High Frequency Pulsed Electric Field on Slain Ovine Cortical Bone

    PubMed Central

    Asgarifar, Hajarossadat; Oloyede, Adekunle; Zare, Firuz

    2014-01-01

    High power, high frequency pulsed electric fields known as pulsed power (PP) has been applied recently in biology and medicine. However, little attention has been paid to investigate the application of pulse power in musculoskeletal system and its possible effect on functional behavior and biomechanical properties of bone tissue. This paper presents the first research investigating whether or not PP can be applied safely on bone tissue as a stimuli and what will be the possible effect of these signals on the characteristics of cortical bone by comparing the mechanical properties of this type of bone pre and post expose to PP and in comparison with the control samples. A positive buck-boost converter was applied to generate adjustable high voltage, high frequency pulses (up to 500 V and 10 kHz). The functional behavior of bone in response to pulse power excitation was elucidated by applying compressive loading until failure. The stiffness, failure stress (strength) and the total fracture energy (bone toughness) were determined as a measure of the main bone characteristics. Furthermore, an ultrasonic technique was applied to determine and comprise bone elasticity before and after pulse power stimulation. The elastic property of cortical bone samples appeared to remain unchanged following exposure to pulse power excitation for all three orthogonal directions obtained from ultrasonic technique and similarly from the compression test. Nevertheless, the compressive strength and toughness of bone samples were increased when they were exposed to 66 h of high power pulsed electromagnetic field compared to the control samples. As the toughness and the strength of the cortical bone tissue are directly associated with the quality and integrity of the collagen matrix whereas its stiffness is primarily related to bone mineral content these overall results may address that although, the pulse power stimulation can influence the arrangement or the quality of the collagen network causing the bone strength and toughness augmentation, it apparently did not affect the mineral phase of the cortical bone material. The results also confirmed that the indirect application of high power pulsed electric field at 500 V and 10 kHz through capacitive coupling method was safe and did not destroy the bone tissue construction. PMID:24761375

  3. Full bridge ZCS PWM converter for high-voltage high-power applications

    Microsoft Academic Search

    CHRIS IANNELLO; SHIGUO LUO; ISSA BATARSEH

    2002-01-01

    This paper presents a comprehensive study of a full bridge (FB) zero-current switched (ZCS) PWM converter which is suitable for high-voltage and high-power DC application that achieves ZCS for all active switches, and zero-voltage-switched (ZVS) operation for all diodes on the high voltage side. The given converter utilizes component parasitic parameters, particularly for the high-voltage transformer, and employs fixed-frequency phase-shift

  4. Electric Power Controller for Steering Wheel Management in Electric Cars

    E-print Network

    Paris-Sud XI, Université de

    Electric Power Controller for Steering Wheel Management in Electric Cars Vicente Milanés, Joshué. An electric car has been equipped with the system designed and tests to prove the behavior of the system transportation systems. Among these topics, the automation of the actuators involved in the management of a car

  5. Compact portable electric power sources

    SciTech Connect

    Fry, D.N.; Holcomb, D.E.; Munro, J.K.; Oakes, L.C.; Matson, M.J.

    1997-02-01

    This report provides an overview of recent advances in portable electric power source (PEPS) technology and an assessment of emerging PEPS technologies that may meet US Special Operations Command`s (SOCOM) needs in the next 1--2- and 3--5-year time frames. The assessment was performed through a literature search and interviews with experts in various laboratories and companies. Nineteen PEPS technologies were reviewed and characterized as (1) PEPSs that meet SOCOM requirements; (2) PEPSs that could fulfill requirements for special field conditions and locations; (3) potentially high-payoff sources that require additional R and D; and (4) sources unlikely to meet present SOCOM requirements. 6 figs., 10 tabs.

  6. Electric power annual 1995. Volume I

    SciTech Connect

    NONE

    1996-07-01

    The Electric Power Annual presents a summary of electric power industry statistics at national, regional, and State levels. The objective of the publication is to provide industry decisionmakers, government policymakers, analysts, and the general public with data that may be used in understanding U.S. electricity markets. The Electric Power Annual is prepared by the Coal and Electric Data and Renewables Division; Office of Coal, Nuclear, Electric and Alternate Fuels; Energy Information Administration (EIA); U.S. Department of Energy. In the private sector, the majority of the users of the Electric Power Annual are researchers and analysts and, ultimately, individuals with policy- and decisionmaking responsibilities in electric utility companies. Financial and investment institutions, economic development organizations interested in new power plant construction, special interest groups, lobbyists, electric power associations, and the news media will find data in the Electric Power Annual useful. In the public sector, users include analysts, researchers, statisticians, and other professionals with regulatory, policy, and program responsibilities for Federal, State, and local governments. The Congress and other legislative bodies may also be interested in general trends related to electricity at State and national levels. Much of the data in these reports can be used in analytic studies to evaluate new legislation. Public service commissions and other special government groups share an interest in State-level statistics. These groups can also compare the statistics for their States with those of other jurisdictions.

  7. Generalized charge simulation method for the calculation of the electric field in high voltage substations

    Microsoft Academic Search

    Aleksandar Rankovi?; Milan S. Savi?

    2010-01-01

    This paper deals with the calculation of the electric field strength in high voltage (HV) substations comprising complex geometrical\\u000a structures. Generalized charge simulation method is proposed for improving the precision of the calculation of the electric\\u000a field strength. The objective of this analysis is to examine the influence of towers, HV apparatus and fences on the spatial\\u000a electric field distribution.

  8. Power system characteristics for more electric aircraft

    NASA Technical Reports Server (NTRS)

    Hansen, Irving G.

    1993-01-01

    It should not be suprising that more electric aircraft must meet significantly more difficult electrical power system requirements than were considereed when today's power distribution systems were being developed. Electric power, no longer a secondary system, will become a critical element of the primary control system. Functional reliability requiirements will be extremely stringent and can only be met by controlling element redundancy within a distributed power system. Existing electrical systems were not developed to have both the power system and the control/sensing elements distributed and yet meet the requirements of lighting tolerance and high intensity radio frequency (HIRF). In addition, the operation of electric actuators involves high transient loading and reverse energy flows. Such phenomena were also not anticipated when power quality was specified for either 270 vdc or 400 Hertz ac power systems. This paper will expand upon the issues and discuss some of the technologies involved in their resolution.

  9. Power load forecasting Organization: Huizhou Electric Power, P. R. China

    E-print Network

    Power load forecasting Organization: Huizhou Electric Power, P. R. China Presenter: Zhifeng Hao (South China University of Technology, P. R. China) E-mail: mazfhao@scut.edu.cn Power load forecasting can be divided into load forecasting and electrical consumption predicting according to forecasting

  10. Determination of the cathode and anode voltage drops in high power low-pressure amalgam lamps

    SciTech Connect

    Vasilyak, L. M., E-mail: vasilyak@ihed.ras.ru [Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation); Vasiliev, A. I., E-mail: vasiliev@npo.lit.ru; Kostyuchenko, S. V.; Sokolov, D. V.; Startsev, A. Yu. [Joint Stock Company NPO LIT (Russian Federation); Kudryavtsev, N. N. [Moscow Institute of Physics and Technology (State University) (Russian Federation)

    2011-12-15

    For the first time, cathode and anode drops of powerful low-pressure amalgam lamps were measured. The lamp discharge current is 3.2 A, discharge current frequency is 43 kHz, linear electric power is 2.4 W/cm. The method of determination of a cathode drop is based on the change of a lamp operating voltage at variation of the electrode filament current at constant discharge current. The total (cathode plus anode) drop of voltage was measured by other, independent ways. The maximum cathode fall is 10.8 V; the anode fall corresponding to the maximal cathode fall is 2.4 V. It is shown that in powerful low pressure amalgam lamps the anode fall makes a considerable contribution (in certain cases, the basic one) to heating of electrodes. Therefore, the anode fall cannot be neglected, at design an electrode and ballast of amalgam lamps with operating discharge current frequency of tens of kHz.

  11. Electric auxiliary power unit for Shuttle evolution

    NASA Technical Reports Server (NTRS)

    Meyer, Doug; Weber, Kent; Scott, Walter

    1989-01-01

    The Space Shuttle Orbiter currently uses three hydrazine fueled auxiliary power units (APUs) to provide hydraulic power for the vehicle aerodynamic surface controls, main engine thrust vector control, landing gear, steering, and brakes. Electric auxiliary power units have been proposed as possible replacements to the hydrazine auxiliary power units. Along with the potential advantages, this paper describes an Electric APU configuration and addresses the technical issues and risks associated with the subsystem components. Additionally, characteristics of an Electric APU compared to the existing APU and the direction of future study with respect to the Electric APU is suggested.

  12. Developments in voltage regulation of variable-speed PM synchronous alternators in automotive electric systems

    Microsoft Academic Search

    Levent Ovacik; Berker Bilgin

    2011-01-01

    ó This paper evaluates the performance of a voltage regulator for a high-efciency , high-energy density alternator system that comprises of a PM syn- chronous generator and a swithced-mode rectier . A closed-loop control system is designed to regulate the out- put dc voltage of the alternator system operated under varying engine speeds, electrical loads, and battery state- of-charge conditions.

  13. Power quality load management for large spacecraft electrical power systems

    NASA Technical Reports Server (NTRS)

    Lollar, Louis F.

    1988-01-01

    In December, 1986, a Center Director's Discretionary Fund (CDDF) proposal was granted to study power system control techniques in large space electrical power systems. Presented are the accomplishments in the area of power system control by power quality load management. In addition, information concerning the distortion problems in a 20 kHz ac power system is presented.

  14. Methods for Estimation of Market Power in Electric Power Industry

    NASA Astrophysics Data System (ADS)

    Turcik, M.; Oleinikova, I.; Junghans, G.; Kolcun, M.

    2012-01-01

    The article is related to a topical issue of the newly-arisen market power phenomenon in the electric power industry. The authors point out to the importance of effective instruments and methods for credible estimation of the market power on liberalized electricity market as well as the forms and consequences of market power abuse. The fundamental principles and methods of the market power estimation are given along with the most common relevant indicators. Furthermore, in the work a proposal for determination of the relevant market place taking into account the specific features of power system and a theoretical example of estimating the residual supply index (RSI) in the electricity market are given.

  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 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

  16. 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

  17. Modular Solar Electric Power (MSEP) Systems (Presentation)

    SciTech Connect

    Hassani, V.

    2000-06-18

    This presentation discusses the development and deployment of Modular Solar Electric Power (MSEP) systems, the feasibility of application of existing binary power cycles to solar trough technology, and identification of next action items.

  18. AC electrical transport properties and current-voltage hysteresis behavior of PVA-CNT nanocomposite film

    NASA Astrophysics Data System (ADS)

    Das, Amit Kumar; Sinha, Subhojyoti; Meikap, Ajit Kumar

    2015-06-01

    Polyvinyl alcohol (PVA) - Carbon nanotube (CNT) composite has been prepared and its electric modulus, ac conductivity, impedance spectroscopy and current-voltage characteristics have been studied, at and above room temperature, to understand the prevailing charge transport mechanism. Non-Debye type relaxation behavior was observed with activation energy of 1.27 eV whereas correlated barrier hopping was found to be the dominant charge transport mechanism with maximum barrier height of 48.7 meV above room temperature. The sample, under ±80 V applied voltage, exhibits hysteresis behavior in its current - voltage characteristics.

  19. A full bridge ZCS PWM converter for high voltage and high power applications

    Microsoft Academic Search

    Chris Iannello; Shiguo Luo; Issa Batarseh

    2000-01-01

    This paper presents the detailed analysis of a full bridge zero current switched (FB-ZCS) PWM converter that is suitable for high-voltage and high-power DC applications. It exhibits excellent ability to incorporate parasitic parameters, zero current turn-off characteristics for all active switches and ZVS operation for all diodes on the high voltage side. Based on the features of high-voltage power supplies,

  20. Reactive power compensation and harmonics elimination at Medium-Voltage using Hexagram converter

    Microsoft Academic Search

    Jun Wen; Liang Zhou; Keyue Smedley

    2010-01-01

    This paper introduced Hexagram converter - a new type of multilevel converter for reactive power compensation and harmonics elimination at Medium-Voltage (MV) grids to improve the power quality. The Hexagram converter is composed of six three-phase two-level Voltage Source Converters (VSCs) interconnected through the inductors, and has the advantages of modular structure with easy construction, even and much reduced voltage

  1. Architecture of a low-power FPGA based on self-adaptive voltage control

    Microsoft Academic Search

    Shota Ishihara; Zhengfan Xia; Masanori Hariyama; Michitaka Kameyama

    2009-01-01

    This paper presents a low-power FPGA with multiple supply voltages. In the proposed FPGA, the supply voltage of each logic block is self-adaptive to the workload, data path and temperature to minimize the power consumption without system performance degradation. In the self-adaptive voltage control scheme, features of the asynchronous architecture are exploited. The data arrival of the asynchronous architecture can

  2. Electric power plant capital costs

    SciTech Connect

    Dodero, G.; Castellie, D.; Coffetti, M.

    1998-07-01

    Due to the increase of technology options, it is becoming day by day more important to have an overview of electric power plants capital costs so to take the right decisions in the preliminary stages of the project choices. From 1970 through the 1980's and 1990's, the capital costs of traditional steam power plants increased steadily, due in part to the addition of more advanced, and more costly, pollution control equipment. On the other hand the availability of ample natural gas, the scaling up of gas turbine machinery and the appearance on the market of new technologies (PFB, IGCC, fuel cells, etc.) are offering new opportunities to the traditional utilities and to the new players including the independent power producers, developers and private operators. The costs indicated will be referred to the two main world markets, that is, the Western countries and Asian area. These costs are obviously for preliminary studies and project assessment. To minimize the cost/benefit ratio, the design activities of the architect-engineer consultant have a very important role. Impact of manufacturing area on main component costs and on erection works: The three main factors, which influence machinery price are: local labor cost, license or research cost and raw material cost. An additional impact on plant cost on local basis are the raw material cost for erection, erection manpower, their skill and components available/manufactured in the erection area. Local taxation and custom duties must also be considered. Labor costs in Eastern Germany are still much lower than in the West Germany, but they are not indicated in the survey. Portuguese and Greek workers have the lowest labor costs.

  3. Influence of the current control loops of DC arc furnaces on voltage fluctuations and harmonics in the HV power supply system

    Microsoft Academic Search

    D. Stade; H. Schau; St. Prinz

    2000-01-01

    It is necessary, to an increasing extent, to take controllers and control loops into consideration in mathematical modelling and simulations for power quality studies. DC arc furnaces belong to those electric loads which network behaviour is essentially influenced by control processes. Rated at more than 100 MVA, these furnaces cause voltage fluctuations and harmonics in the HV power system. Based

  4. Analysis and calculation of lightning-induced voltages in aircraft electrical circuits

    NASA Technical Reports Server (NTRS)

    Plumer, J. A.

    1974-01-01

    Techniques to calculate the transfer functions relating lightning-induced voltages in aircraft electrical circuits to aircraft physical characteristics and lightning current parameters are discussed. The analytical work was carried out concurrently with an experimental program of measurements of lightning-induced voltages in the electrical circuits of an F89-J aircraft. A computer program, ETCAL, developed earlier to calculate resistive and inductive transfer functions is refined to account for skin effect, providing results more valid over a wider range of lightning waveshapes than formerly possible. A computer program, WING, is derived to calculate the resistive and inductive transfer functions between a basic aircraft wing and a circuit conductor inside it. Good agreement is obtained between transfer inductances calculated by WING and those reduced from measured data by ETCAL. This computer program shows promise of expansion to permit eventual calculation of potential lightning-induced voltages in electrical circuits of complete aircraft in the design stage.

  5. Electric power monthly, September 1990. [Glossary included

    SciTech Connect

    Not Available

    1990-12-17

    The purpose of this report is to provide energy decision makers with accurate and timely information that may be used in forming various perspectives on electric issues. The power plants considered include coal, petroleum, natural gas, hydroelectric, and nuclear power plants. Data are presented for power generation, fuel consumption, fuel receipts and cost, sales of electricity, and unusual occurrences at power plants. Data are compared at the national, Census division, and state levels. 4 figs., 52 tabs. (CK)

  6. Electric Power Delivery Testing Feasibility Study Task 6 Final Report

    SciTech Connect

    Thomas Tobin

    2009-07-01

    This Final Report is covers the completion of the Electric Power Delivery Testing Feasibility Study. The objective of this project was to research, engineer, and demonstrate high-power laboratory testing protocols to accurately reproduce the conditions on the electric power grid representing both normal load switching and abnormalities such as short-circuit fault protection. Test circuits, equipment, and techniques were developed and proven at reduced power levels to determine the feasibility of building a large-scale high-power testing laboratory capable of testing equipment and systems at simulated high-power conditions of the U.S. power grid at distribution levels up through 38 kiloVolts (kV) and transmission levels up through 230 kV. The project delivered demonstrated testing techniques, high-voltage test equipment for load testing and synthetic short-circuit testing, and recommended designs for future implementation of a high-power testing laboratory to test equipment and systems, enabling increased reliability of the electric transmission and distribution grid.

  7. Three-Dimensional Animations of Power-Electronics Circuits Visualize Voltage and

    E-print Network

    Three-Dimensional Animations of Power-Electronics Circuits Visualize Voltage and Current C. R the IEEE. #12;Three-Dimensional Animations of Power-Electronics Circuits Visualize Voltage and Current about circuits in the classroom and in paper or electronic documents. In addition, without a way

  8. Measurement based Voltage Stability Monitoring of Power system Garng M. Huang

    E-print Network

    factors for the voltage stability problem, etc. II. FUNDAMENTALS: SIGLE GENERATOR AND LOAD SYSTEM #12;A to find the most vulnerable area in a system, to find the impacts of other loads, areas and power, Transient Analysis I. INTRODUCTION Voltage stability is a major concern in planning and operations of power

  9. ASSESSING THE ACCURACY AND INTEGRITY OF RTK GPS BENEATH HIGH VOLTAGE POWER LINES

    Microsoft Academic Search

    Brent MANUEL; Rafe PENINGTON

    This paper reports the results of several tests conducted at the University of Southern Queensland (USQ) to determine the frequency with which initialisation failures occur in the Trimble 4700 RTK receivers when operating beneath high voltage power lines. Anecdotal evidence from some practitioners suggested that problems were experienced when measuring beneath high voltage power lines. Some surveyors had reported quite

  10. A New Optimal Routing Algorithm for Loss Minimization and Voltage Stability Improvement in Radial Power Systems

    Microsoft Academic Search

    Joong-Rin Shin; Byung-Seop Kim; Jong-Bae Park; Kwang Y. Lee

    2007-01-01

    This paper presents an optimal routing algorithm (ORA) for minimizing power loss and at the same time maximizing the voltage stability in radial power systems. In the proposed ORA, a voltage stability index (VSI) for real-time assessment is introduced based on the conventional critical transmission path framework. In addition, the algorithm can automatically detect the critical transmission paths that will

  11. A new current control strategy for active power filters using three PWM voltage source inverters

    Microsoft Academic Search

    Luis Moran; Pedro Godoy; Rogel Wallace; Juan Dixon

    1993-01-01

    A new current control strategy for active power filters using multiple PWM voltage-source inverters is presented and analyzed. The proposed current control strategy operates each PWM voltage-source inverter with a different switching frequency generating specific current harmonic components of the load. Reactive power is compensated without sensing and computing the reactive component of the load current, thus simplifying the control

  12. Three essays on "making" electric power markets

    NASA Astrophysics Data System (ADS)

    Kench, Brian Thomas

    2000-10-01

    Technological change over the past three decades has altered most of the basic conditions in the electric power industry. Because of technical progress, the dominant paradigm has shifted from the provision of electric power by regulated and vertically integrated local natural monopolies to competition and vertical separation. In the first essay I provide a historical context of the electric industry's power current deregulation debate. Then a dynamic model of induced institutional change is used to investigate how endogenous technological advancements have induced radical institutional change in the generation and transmission segments of the electric power industry. Because the Federal Energy Regulatory Commission (FERC) ordered regulated utilities to provide open access to their transmission networks and to separate their generation and transmission functions, transmission networks have been used more intensively and in much different ways then in the past. The second essay tests experimentally the predictions of neoclassical theory for a radial electric power market under two alternative deregulated transmission institutions: financial transmission rights and physical transmission rights. Experimental evidence presented there demonstrates that an electric power market with physical transmission rights governing its transmission network generates more "right" market signals relative to a transmission network governed by financial transmission rights. The move to a greater reliance on markets for electric power is an idea that has animated sweeping and dramatic changes in the traditional business of electric power. The third essay examines two of the most innovative and complex initiatives of making electric power markets in the United States: California and PJM. As those markets mature and others are made, they must revise their governance mechanisms to eliminate rules that create inefficiency and adopt rules that work efficiently elsewhere. I argue that restructured electric power markets in the United States we should consider adopting an integrated procurement approach for electric power and ancillary services, binding forward markets for those commodities, and a market for physical transmission rights.

  13. Voltage dips due to direct connection of induction generators in low head hydro electric schemes

    SciTech Connect

    Hammons, T.J.; Lai, S.C. (Glasgow Univ. (United Kingdom))

    1994-09-01

    This paper analyzes phenomena which affect voltage dip due to direct connection of induction generators running close to synchronous speed to electrical distribution systems in low head hydro electric schemes. The paper examines transient phenomena on connection of induction generators at close to synchronous speed in determining whether costly system reinforcement may be avoided thus making many uneconomic developments viable while satisfying constraints of permissible voltage dip if the transient phenomena is taken duly into account. More use of renewable energy in electricity supply thus receding greenhouse gas emissions from fossil plant will therefore result. Parameters of significance in evaluating voltage dip due to direct connection of induction generators running at close to synchronous speed which are studied include (1) effective resistance of stator together with system resistance and reactance of effective infinite supply, (2) rotor circuit parameters, (3) speed of generator on connection, and (4) equivalent inertia of rotor and turbine. Results depicted in Tables an din Time Response demonstrate relative importance of the parameters on voltage dip. It is concluded that costly system reinforcement may be avoided if detailed simulations are performed where dynamics and transients are fully modeled in assessing magnitude and duration of voltage dip. The analysis is based on a detailed induction generator model with single and double rotor bar simulation using Park's equations with simulation of rotor dynamics on connection of the generator to the electrical supply.

  14. Power supply

    DOEpatents

    Yakymyshyn, Christopher Paul (Seminole, FL); Hamilton, Pamela Jane (Seminole, FL); Brubaker, Michael Allen (Loveland, CO)

    2007-12-04

    A modular, low weight impedance dropping power supply with battery backup is disclosed that can be connected to a high voltage AC source and provide electrical power at a lower voltage. The design can be scaled over a wide range of input voltages and over a wide range of output voltages and delivered power.

  15. Electric currents and voltage drops along auroral field lines

    NASA Technical Reports Server (NTRS)

    Stern, D. P.

    1983-01-01

    An assessment is presented of the current state of knowledge concerning Birkeland currents and the parallel electric field, with discussions focusing on the Birkeland primary region 1 sheets, the region 2 sheets which parallel them and appear to close in the partial ring current, the cusp currents (which may be correlated with the interplanetary B(y) component), and the Harang filament. The energy required by the parallel electric field and the associated particle acceleration processes appears to be derived from the Birkeland currents, for which evidence is adduced from particles, inverted V spectra, rising ion beams and expanded loss cones. Conics may on the other hand signify acceleration by electrostatic ion cyclotron waves associated with beams accelerated by the parallel electric field.

  16. Performance analysis of automotive power systems: effects of power electronic intensive loads and electrically-assisted propulsion systems

    Microsoft Academic Search

    S. M. Lukic; A. Emadi

    2002-01-01

    Demands for higher fuel economy, performance, and reliability as well as reduced emissions push the automotive industry to seek electrification of ancillaries and engine augmentations. In the future cars, throttle actuation, power steering, anti-lock braking, rear-wheel steering, air-conditioning, ride-height adjustment, active suspension, and electrically heated catalyst will all benefit from the electrical power system. Therefore, a higher system voltage, such

  17. Design and optimization of dual-threshold circuits for low-voltage low-power applications

    Microsoft Academic Search

    Liqiong Wei; Zhanping Chen; Kaushik Roy; Mark C. Johnson; Yibin Ye; Vivek De

    1999-01-01

    Reduction in leakage power has become an important concern in low-voltage, low-power, and high-performance applications. In this paper, we use the dual-threshold technique to reduce leakage power by assigning a high-threshold voltage to some transistors in noncritical paths, and using low-threshold transistors in critical path(s). In order to achieve the best leakage power saving under target performance constraints, an algorithm

  18. An active power filter implemented with a three-level NPC voltage-source inverter

    Microsoft Academic Search

    Victor Aburto; M. Schneider; L. Moran; Juan Dixon

    1997-01-01

    This paper presents an active power filter implemented using a three-level neutral point-clamped voltage-source inverter. The active power filter can compensate current harmonics and reactive power in medium voltage distribution systems. The paper presents the principles of operation and design criteria for both the power and control circuits. Finally, the viability of the proposed scheme is shown with computer simulation

  19. Low-power design technique for ASICs by partially reducing supply voltage

    Microsoft Academic Search

    Kimiyoshi Usami; Takashi Ishikawa; Masahiro Kanazawa; Hiroko Kotani

    1996-01-01

    In this paper, we discuss power reduction by comparing two different design techniques targeting low-power ASICs: clustered voltage scaling (CVS) and gate resizing. The CVS is a technique to reduce supply voltage partially, allowing one to reduce power without performance degradation. As a result of application to real gate-array circuits, the CVS reduced power by 30-60% even at dominant wire

  20. Exposure assessment for power frequency electric and magnetic fields.

    PubMed

    Bracken, T D

    1993-04-01

    Over the past decade considerable data have been collected on electric and magnetic fields in occupational environments. These data have taken the form of area measurements, source characterizations, and personal exposure measurements. Occupational EMF levels are highly variable in space and time. Exposures associated with these fields exhibit similar large variations during a day, between days, and between individuals within a group. The distribution of exposure measures is skewed over several decades with only a few values occurring at the maximum field levels. The skewness of exposure measures implies that large sample sizes may be required for assessments and that multiple statistical descriptors are preferred to describe individual and group exposures. Except for the relatively few occupational settings where high voltage sources are prevalent, electric fields encountered in the workplace are probably similar to residential exposures. Consequently, high electric field exposures are essentially limited to utility environments and occupations. Within the electric utility industry, it is definitely possible to identify occupations with high electric field exposures relative to those of office workers or other groups. The highly exposed utility occupations are linemen, substation operators, and utility electricians. The distribution of electric field exposures in the utility worker population is very skewed even within a given occupation. As with electric fields, magnetic fields in the workplace appear to be comparable with residential levels, unless a clearly defined high-current source is present. Since high-current sources are more prevalent than high-voltage sources, environments with relatively high magnetic field exposures encompass a more diverse set of occupations than do those with high electric fields. Within the electric utility industry, it is possible to identify occupational environments with high magnetic field exposure relative to the office environment. Utility job categories with the highest exposures are generation facility workers, substation operators, utility linemen, and utility electricians. There are also higher exposures among traditional "electrical worker" job categories. Outside the electrical utility industry, potential sources of high occupational magnetic field exposures at ELF are induction furnaces, welding machines, electrical transportation systems, and electrical distribution vaults. However, the use of low power electrical equipment such as small motors in close proximity to workers and possibly for long periods of time could also lead to high exposure situations. Handheld survey instruments are available to perform area measurements of electric and magnetic fields at power frequencies but not aat all frequencies within the ELF range. Sophisticated personal computer-based instruments are available to characterize areas and sources across the entire frequency range.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:8480632

  1. Effects of a low-voltage static electric field on energy metabolism in astrocytes

    SciTech Connect

    Huang, R.; Peng, L.; Hertz, L. [Univ. of Saskatchewan, Saskatoon, Saskatchewan (Canada). Dept. of Pharmacology] [Univ. of Saskatchewan, Saskatoon, Saskatchewan (Canada). Dept. of Pharmacology

    1997-03-01

    Mouse astrocytes (glial cells) in primary cultures were exposed to a low-voltage static DC electric field with no current flow and thus with no generation of magnetic fields. The electric field altered the rate of glycolysis, measured by 2-deoxyglucose accumulation. The magnitude and direction of this effect depended on the polarization of the field and the applied voltage. The maximum effect was an increase of {approximately}30%, which occurred with field across the cells at an intensity that can be calculated to be 0.3 mV/cm or less. Reversal of the polarization converted the stimulation to a small but statistically significant inhibition.

  2. V-edge: Fast Self-constructive Power Modeling of Smartphones Based on Battery Voltage Dynamics

    E-print Network

    Li, Qun

    - powered mobile devices, including smartphones. Power modeling is a key technology and an effective wayV-edge: Fast Self-constructive Power Modeling of Smartphones Based on Battery Voltage Dynamics System power models are important for power manage- ment and optimization on smartphones. However

  3. Easily disassembled electrical connector for high voltage, high frequency connections

    DOEpatents

    Milner, Joseph R. (Livermore, CA)

    1994-01-01

    An easily accessible electrical connector capable of rapid assembly and disassembly wherein a wide metal conductor sheet may be evenly contacted over the entire width of the conductor sheet by opposing surfaces on the connector which provide an even clamping pressure against opposite surfaces of the metal conductor sheet using a single threaded actuating screw.

  4. Load management on the electric power system

    Microsoft Academic Search

    H. M. Long; J. C. Smith

    1979-01-01

    Load management is the systems concept of altering the real or apparent pattern of electricity use in order to conserve resources, both fuel and capital, in the production and distribution of electrical energy. Load management is achieved through controlling the power flow in the electric system at the generating end (supply management) or the customer end (use management). Traditionally, the

  5. Programmable timed electrical power management device

    Microsoft Academic Search

    Nyenya

    1994-01-01

    A programmable timed electrical power management device protects and controls electrical equipment and peripherals which are plugged into it. The front of the housing containing the electrical circuitry is provided with a LCD display, a series of pressure sensitive switches for inputting function and control commands to control the operation of the device. A series of LED's mounted on the

  6. Electric Power Equipment for Steel Plants

    Microsoft Academic Search

    Ralph H. Wright

    1935-01-01

    The rapid increase in the use of electric power equipment in steel plants in the United States during the last 3 decades is outlined briefly in this paper, and the principal types of apparatus now in use are discussed. Power generation and distribution equipment is considered briefly and the types of electric motors used in different kinds of main mill

  7. Electric Power Monthly, August 1990. [Glossary included

    SciTech Connect

    Not Available

    1990-11-29

    The Electric Power Monthly (EPM) presents monthly summaries of electric utility statistics at the national, Census division, and State level. The purpose of this publication is to provide energy decisionmakers with accurate and timely information that may be used in forming various perspectives on electric issues that lie ahead. Data includes generation by energy source (coal, oil, gas, hydroelectric, and nuclear); generation by region; consumption of fossil fuels for power generation; sales of electric power, cost data; and unusual occurrences. A glossary is included.

  8. Shrinking stability regions and voltage collapse in power systems

    Microsoft Academic Search

    Khoi T. Vu; Chen-Ching Liu

    1992-01-01

    The dynamic process of voltage collapse is analyzed based on three mechanisms: on-load tap-changing, load dynamics, and generator excitation limiting. The interaction among these mechanisms and how the voltage collapse takes place are thoroughly investigated in a general interconnected network model under the assumption that system frequency remains unchanged. It is found that, so long as an equilibrium exists, there

  9. Supply and threshold voltage scaling for low power CMOS

    Microsoft Academic Search

    Ricardo Gonzalez; Benjamin M. Gordon; Mark A. Horowitz

    1997-01-01

    This paper investigates the effect of lowering the supply and threshold voltages on the energy efficiency of CMOS circuits. Using a first-order model of the energy and delay of a CMOS circuit, we show that lowering the supply and threshold voltage is generally advantageous, especially when the transistors are velocity saturated and the nodes have a high activity factor, In

  10. Electrical voltages and resistances measured to inspect metallic cased wells and pipelines

    DOEpatents

    Vail III, William Banning; Momii, Steven Thomas

    2003-06-10

    A cased well in the earth is electrically energized with A.C. current. Voltages are measured from three voltage measurement electrodes in electrical contact with the interior of the casing while the casing is electrically energized. In a measurement mode, A.C. current is conducted from a first current carrying electrode within the cased well to a remote second current carrying electrode located on the surface of the earth. In a calibration mode, current is passed from the first current carrying electrode to a third current carrying electrode located vertically at a different position within the cased well, where the three voltage measurement electrodes are located vertically in between the first and third current carrying electrodes. Voltages along the casing and resistances along the casing are measured to determine wall thickness and the location of any casing collars present so as to electrically inspect the casing. Similar methods are employed to energize a pipeline to measure the wall thickness of the pipeline and the location of pipe joints to electrically inspect the pipeline.

  11. Electrical voltages and resistances measured to inspect metallic cased wells and pipelines

    DOEpatents

    Vail, III, William Banning (Bothell, WA); Momii, Steven Thomas (Seattle, WA)

    2001-01-01

    A cased well in the earth is electrically energized with A.C. current. Voltages are measured from three voltage measurement electrodes in electrical contact with the interior of the casing while the casing is electrically energized. In a measurement mode, A.C. current is conducted from a first current carrying electrode within the cased well to a remote second current carrying electrode located on the surface of the earth. In a calibration mode, current is passed from the first current carrying electrode to a third current carrying electrode located vertically at a different position within the cased well, where the three voltage measurement electrodes are located vertically in between the first and third current carrying electrodes. Voltages along the casing and resistances along the casing are measured to determine wall thickness and the location of any casing collars present so as to electrically inspect the casing. Similar methods are employed to energize a pipeline to measure the wall thickness of the pipeline and the location of pipe joints to electrically inspect the pipeline.

  12. Trees and Power Lines: Minimizing Conflicts between Electric Power

    E-print Network

    Kammen, Daniel M.

    Trees and Power Lines: Minimizing Conflicts between Electric Power Infrastructure and the Urban Forest By William Brock Most 1 and Steven Weissman 2 March 10, 2012 #12;iiTrees and Power Lines Trees and Power Lines 5 5. Benefits of the Urban Forest 6 a. Carbon Sequestration 6 b. Property Value 6

  13. SITE ELECTRICAL POWER SYSTEM DESCRIPTION DOCUMENT

    SciTech Connect

    E.P. McCann

    1999-04-16

    The Site Electrical Power System receives and distributes utility power to all North Portal site users. The major North Portal users are the Protected Area including the subsurface facility and Balance of Plant areas. The system is remotely monitored and controlled from the Surface Operations Monitoring and Control System. The system monitors power quality and provides the capability to transfer between Off-Site Utility and standby power (including dedicated safeguards and security power). Standby power is only distributed to selected loads for personnel safety and essential operations. Security power is only distributed to essential security operations. The standby safeguards and security power is independent from all other site power. The system also provides surface lighting, grounding grid, and lightning protection for the North Portal. The system distributes power during construction, operation, caretaker, and closure phases of the repository. The system consists of substation equipment (disconnect switches, breakers, transformers and grounding equipment) and power distribution cabling from substation to the north portal switch gear building. Additionally, the system includes subsurface facility substation (located on surface), switch-gear, standby diesel generators, underground duct banks, power cables and conduits, switch-gear building and associated distribution equipment for power distribution. Each area substation distributes power to the electrical loads and includes the site grounding, site lighting and lightning protection equipment. The site electrical power system distributes power of sufficient quantity and quality to meet users demands. The Site Electrical Power System interfaces with the North Portal surface systems requiring electrical power. The system interfaces with the Subsurface Electrical Distribution System which will supply power to the underground facilities from the North Portal. Power required for the South Portal and development side activities of the subsurface facility will be provided at the South Portal by the Subsurface Electrical Distribution System. The Site Electrical Power System interfaces with the Off-Site Utility System for the receipt of power. The System interfaces with the Surface Operations Monitoring and Control System for monitoring and control. The System interfaces with MGR Site Layout System for the physical location of equipment and power distribution.

  14. Electric power annual 1996. Volume 1

    SciTech Connect

    NONE

    1997-08-01

    The Electric Power Annual presents a summary of electric power industry statistics at national, regional, and State levels. The objective of the publication is to provide industry decisionmakers, government policy-makers, analysts, and the general public with data that may be used in understanding US electricity markets. The Electric Power Annual is prepared by the Coal and Electric Data and Renewables Division; Office of Coal, Nuclear, Electric and Alternate Fuels; Energy Information Administration (EIA); US Department of Energy. Volume 1--with a focus on US electric utilities--contains final 1996 data on net generation and fossil fuel consumption, stocks, receipts, and cost; preliminary 1996 data on generating unit capability, and retail sales of electricity, associated revenue, and the average revenue per kilowatthour of electricity sold. Additionally, information on net generation from renewable energy sources and on the associated generating capability is included in Volume 1 of the EPA. Data published in the Electric Power Annual Volume 1 are compiled from three statistical forms filed monthly and two forms filed annually by electric utilities. These forms are described in detail in the Technical Notes. 5 figs., 30 tabs.

  15. Simulation of an energy storage system to compensate pulsed loads on shipboard electric power system

    Microsoft Academic Search

    Franck Scuiller

    2011-01-01

    For warship electric power system, the pulsed loads (as radar or sonar) can be particularly embarrassing: when the pulsed load is running, the generators can be always in transients which can stress prime-mover and exciter actuators. Regarding the power quality, frequency and voltage modulation troubles can appear which can lead to sensitive load mis-operations and grid instability. In this paper,

  16. Artificial Neural Network Maximum Power Point Tracker for Solar Electric Vehicle

    Microsoft Academic Search

    Theodore Amissah Ocran; Junyi Cao; Binggang Cao; Xinghua Sun

    2005-01-01

    This paper proposes an artificial neural network maximum power point tracker (MPPT) for solar electric vehicles. The MPPT is based on a highly efficient boost converter with insulated gate bipolar transistor (IGBT) power switch. The reference voltage for MPPT is obtained by artificial neural network (ANN) with gradient descent momentum algorithm. The tracking algorithm changes the duty-cycle of the converter

  17. High frequency alternating current power supply for automobile auxiliary electrical systems

    Microsoft Academic Search

    C. Antaloae; J. Marco; N. D. Vaughan

    2010-01-01

    This paper presents an HFAC power source concept for vehicle auxiliary electrical systems. The proposed power supply is based on a resonant DC to HFAC inverter, which constructs the output sinusoidal voltage and current. Mathematical modelling is employed to design the control strategy and Matlab Simulink is used to model and simulate the circuit operation under various load conditions. Simulation

  18. Control strategy of fuel cell\\/supercapacitors hybrid power sources for electric vehicle

    Microsoft Academic Search

    Phatiphat Thounthong; Stéphane Raël; Bernard Davat

    2006-01-01

    This paper presents a control principle for utilizing PEM fuel cell as main power source and supercapacitors as auxiliary power source for electric vehicle applications. The strategy is based on dc link voltage regulation, and fuel cell is simply operating in almost steady state conditions in order to minimize the mechanical stresses of fuel cell and to ensure a good

  19. Electric Power System Analysis and Design of an Expanding Steel Cogeneration Plant

    Microsoft Academic Search

    Cheng-Ting Hsu; Chao-Shun Chen; Chia-Hung Lin

    2011-01-01

    This paper presents the electric power system analy- sis and design of an expanding steel cogeneration plant. The site and capacity of shunt capacitor banks as well as the tap position of transformers are determined according to the power flow analysis. Also, to comply with the restriction of circuit breaker capacity, the high-impedance transformers are designed. In addition, the voltage

  20. Boosting the voltage of a salinity-gradient-power electrochemical cell by means of complex-forming solutions

    NASA Astrophysics Data System (ADS)

    Marino, M.; Misuri, L.; Carati, A.; Brogioli, D.

    2014-07-01

    We report experiments on a concentration cell with zinc electrodes and ZnCl2 solutions at different concentrations, separated by a porous diaphragm. The cell is aimed at the conversion of the free energy associated to the concentration difference into electrical energy, for renewable and clean energy applications. Usually, the diffusion of the solute across the diaphragm constitutes a waste of free energy, which impairs the voltage generation of the concentration cell with respect to other well-known techniques that work quasi-reversibly, such as reverse electrodialysis or the "mixing entropy battery." Quite surprisingly, we find that the voltage produced by our concentration cell is significantly higher than the voltage obtained with the other quasi-reversible techniques. We show that the surplus voltage comes from the active transformation of the mixing free energy into electrical energy performed by the liquid junction, and we show the connection with the negative apparent transference number of the zinc ion. This fortunate consequence of using ZnCl2 solution is ultimately related to the formation of complexes. We present the results of a cell for power production, which has excellent performances with respect to known salinity-difference-power methods.

  1. Computational modelling of electrical field intensity for high voltage semiconductor package design

    Microsoft Academic Search

    N. S. Nobeen; D. C. Whalley; D. A. Hutt; B. Haworth

    2010-01-01

    Although plastic packaging has successfully replaced ceramic and metal packages for many high reliability electronic packaging applications (e.g. military and aerospace), hermetically sealed ceramic packages are still the dominant technology for large power devices, such as the thyristors and diodes used in high voltage DC (HVDC) power transmission. With increasing energy requirements of growing economies, the demand for higher operating

  2. Basic Characteristics of New Developed Higher-Voltage Direct-Current Power-Feeding Prototype System

    NASA Astrophysics Data System (ADS)

    Babasaki, Tadatoshi; Tanaka, Toshimitsu; Tanaka, Toru; Nozaki, Yousuke; Aoki, Tadahito; Kurokawa, Fujio

    High efficiency power feeding systems are effective solutions for reducing the ICT power consumption with reducing power consumption of the ICT equipment and cooling systems. A higher voltage direct current (HVDC) power feeding system prototype was produced. This system is composed of a rectifier equipment, power distribution unit, batteries, and the ICT equipment. The configuration is similar to a -48V DC power supply system. The output of the rectifier equipment is 100kW, and the output voltage is 401.4V. This paper present the configuration of the HVDC power feeding system and discuss its basic characteristics in the prototype system.

  3. Verification of voltage/frequency requirement for emergency diesel generator in nuclear power plant using dynamic modeling

    SciTech Connect

    Hur, Jin-Suk; Roh, Myung- Sub [KEPCO International Nuclear Graduate School, 1456-1 Shinam-ri, Seosaeng-myeon, Ulju-gun, Ulsan, 689-882 (Korea, Republic of)

    2014-02-12

    One major cause of the plant shutdown is the loss of electrical power. The study is to comprehend the coping action against station blackout including emergency diesel generator, sequential loading of safety system and to ensure that the emergency diesel generator should meet requirements, especially voltage and frequency criteria using modeling tool. This paper also considered the change of the sequencing time and load capacity only for finding electrical design margin. However, the revision of load list must be verified with safety analysis. From this study, it is discovered that new load calculation is a key factor in EDG localization and in-house capability increase.

  4. Verification of voltage/frequency requirement for emergency diesel generator in nuclear power plant using dynamic modeling

    NASA Astrophysics Data System (ADS)

    Hur, Jin-Suk; Roh, Myung-Sub

    2014-02-01

    One major cause of the plant shutdown is the loss of electrical power. The study is to comprehend the coping action against station blackout including emergency diesel generator, sequential loading of safety system and to ensure that the emergency diesel generator should meet requirements, especially voltage and frequency criteria using modeling tool. This paper also considered the change of the sequencing time and load capacity only for finding electrical design margin. However, the revision of load list must be verified with safety analysis. From this study, it is discovered that new load calculation is a key factor in EDG localization and in-house capability increase.

  5. Threshold voltage for electrical tree inception in underground HV transmission cables

    Microsoft Academic Search

    S. S. Bamji; A. T. Bulinski; Y. Chen; R. J. Densley

    1992-01-01

    Experimental evidence is provided to show that irreversible aging which leads to electrical treeing in polymeric insulation such as low-density and crosslinked polyethylene used in HV transmission cables, does not start at local fields between 5 and 20 kV\\/mm. It is shown that a much higher stress is required for electrical tree inception and that the electroluminescence inception voltage is

  6. A ZCS Lossless Snubber Cells-Applied Half-Bridge Bidirectional DC—DC Converter for Automotive Electric Power Systems

    Microsoft Academic Search

    Tomokazu Mishima; Eiji Hiraki; Toshihiko Tanaka

    2006-01-01

    A new type of bidirectional DC—DC converter for electric power systems in advanced electric vehicles is proposed in this paper. This converter consists of half-bridge circuits with a high frequency transformer, which is well applicable as an interface between a high-voltage DC bus line and a low-voltage power source. In order to reduce the switching loss, newly developed ZCS loss-less

  7. Roadway powered electric vehicle: An alternate to the electric car

    SciTech Connect

    Siuru, B.

    1991-07-01

    This article examines an alternative to the battery operated electric vehicle in the form of an electric vehicle which receives its motive power from conductors buried in the pavement of a highway. Topics discussed are current research and demonstration activities, conductor burial, the vehicles involved, and research and demonstration schedule and costs.

  8. Measurements of induced voltages and currents in a distribution power line and associated atmospheric parameters

    NASA Technical Reports Server (NTRS)

    Santiago-Perez, Julio

    1988-01-01

    The frequency and intensity of thunderstorms around the Kennedy Space Center (KSC) has affected scheduled launch, landing, and other ground operations for many years. In order to protect against and provide safe working facilities, KSC has performed and hosted several studies on lightning phenomena. For the reasons mentioned above, KSC has established the Atmospheric Science Field Laboratory (ASFL). At these facilities KSC launches wire-towing rockets into thunderstorms to trigger natural lightning to the launch site. A program named Rocket Triggered Lightning Program (RTLP) is being conducted at the ASFL. This report calls for two of the experiments conducted in the summer 1988 Rocket Triggered Lightning Program. One experiment suspended an electric field mill over the launching areas from a balloon about 500 meters high to measure the space charges over the launching area. The other was to connect a waveform recorder to a nearby distribution power line to record currents and voltages wave forms induced by natural and triggered lightning.

  9. Power Electronics and Motor Drives in Electric, Hybrid Electric, and Plug-In Hybrid Electric Vehicles

    Microsoft Academic Search

    Ali Emadi; Young Joo Lee; Kaushik Rajashekara

    2008-01-01

    With the requirements for reducing emissions and improving fuel economy, automotive companies are developing electric, hybrid electric, and plug-in hybrid electric vehicles. Power electronics is an enabling technology for the development of these environmentally friendlier vehicles and implementing the advanced electrical architectures to meet the demands for increased electric loads. In this paper, a brief review of the current trends

  10. A model of electromagnetic radiated emissions for dual voltage automotive electrical systems

    Microsoft Academic Search

    M. C. Di Piazza; Antonella Ragusa; Giovanni Tine; Gianpaolo Vitale

    2004-01-01

    In the automotive electromagnetic environment the impact of electromagnetic compatibility (EMC) has to be considered since the design step, together with performance and cost aspects, for obtaining reliable systems. Especially for the new dual voltage vehicle electrical architectures where EMC oriented design is in a very early stage and no suitable technical standard currently exists. In this paper a method

  11. A soft start technique to minimize EMI implications in dual voltage vehicle electrical system

    Microsoft Academic Search

    M. C. Di Piazza; A. Ragusa; G. Tine; G. Vitale

    2002-01-01

    In this paper the electromagnetic compatibility of the new automotive 14\\/42 V dual voltage electrical systems has been examined. From this point of view EMI (electromagnetic interference) must be minimized since the design stage. The attention has been particularly focused on the 42 V engine cooling fan drive. In order to reduce its inrush current a soft start circuit has

  12. Conducted and radiated emissions in distributed automotive dual voltage vehicle electrical systems

    Microsoft Academic Search

    M. C. Di Piazza; A. Ragusa; G. Tine; G. Vitale

    2003-01-01

    In this paper a study on conducted and radiated emissions in new dual voltage (14 V\\/42 V) automotive electrical systems is presented. The experimental investigations reported in this paper have the objective of finding out the main characteristics of the involved electromagnetic phenomena taking into account the final application of the drive in the automotive environment. The investigation is particularly

  13. Blast chilling and low voltage electrical stimulation influences on bison ( Bison bison bison) meat quality

    Microsoft Academic Search

    J. A. M. Janz; J. L. Aalhus; M. A. Price

    2001-01-01

    Conventional carcass chilling is a lengthy and energy expensive process. Blast chilling (BL) can reduce cooling time and associated shrink loss, although its application may compromise meat quality, particularly in lean carcasses or those with localized finish such as bison. Low voltage electrical stimulation (LVES) can reduce the risk of decreased meat quality by inducing rapid rigor onset prior to

  14. Electrically silent divalent cation entries in resting and active voltage-controlled muscle fibers

    E-print Network

    Paris-Sud XI, Université de

    1 Electrically silent divalent cation entries in resting and active voltage-controlled muscle 1, CNRS UMR 5123, Villeurbanne, France Running title: Mn2+ entry and current in muscle cells to enter skeletal muscle at rest and during activity. Except for the well characterized Ca2+ entry through

  15. Inverter type high voltage DC power supply for negative-ion-based neutral beam injectors

    Microsoft Academic Search

    M. Mizuno; M. Dairaku; Y. Ohara; A. Ozaki; S. Tanaka; T. Uede; K. Watanabe; Y. Yamashita; K. Yokoyama

    1989-01-01

    A design of a high-voltage DC power supply for future neutral beam injectors (NBI) is presented together with the latest R&D results for a 100-kV, 5-A, 5-kHz inverter-type power supply. A negative-ion based NBI is used for heating and current drive in the JT-60U (JAERI Tokamak-60 upgrade) and the FER (Fusion Experimental Reactor). For a high-voltage DC power supply of

  16. Wind generator output power smoothing and terminal voltage regulation by using STATCOM\\/SMES

    Microsoft Academic Search

    M. R. I. Sheikh; F. Eva; M. A. Motin; M. A. Hossain

    2012-01-01

    Due to random variations of wind speed, the output power and terminal voltage of a fixed speed wind generator fluctuates continuously. These irregularities in power output affect the power quality and thus an energy storage system is needed. In this work, the STATCOM\\/SMES system with a voltage-source IGBT converter is proposed as a controllable energy storage system. The proposed STATCOM\\/SMES

  17. Design and testing under actual condition of performance of an optical voltage measurement transformer for transmission lines electrical of high voltage

    NASA Astrophysics Data System (ADS)

    Gomez, Nicolas; Salazar, Hernan; Ciro, Alberto

    2013-11-01

    In this research paper briefly describes the design and construction of an optical voltage transducer measurement based on the effect electro - optical Pockels. The equipment is designed to operate in electric transmission lines 110 kV AC. It then describes the electrical tests performed on transformer to actual operating conditions. In the design and construction of the optical transformer used a photorefractive crystal Bi4Ge3O20 (BGO), which was used because of its high sensitivity to changes in the electric field as a light source is used a laser diode with a wavelength of 670 nm. Presents the results of performance tests on potential levels appropriate to the optical laboratory. In the second part of this work was subjected to optical transformer operating voltage levels of 110 kV ac in this test the voltage was applied gradually until the operating voltage. Team performance was satisfactory.

  18. Electric Power monthly, November 1996

    SciTech Connect

    NONE

    1996-11-01

    This publication presents monthly electricity statistics for a wide audience including Congress, Federal and state agencies, the electric utility industry, and the general public. Purpose is to provide energy decisionmakers with accurate and timely information that may be used in forming various perspectives on electric issues that lie ahead. EIA collected the information in this report to fulfill its data collection and dissemination responsibilities as specified in the Federal Energy Administration Act of 1974 (Public Law 93-275) as amended.

  19. Manager's guide to electrical power quality

    SciTech Connect

    Ludbrook, A. (Ludbrook and Associates, Dundas, Ontario (Canada))

    1993-05-01

    Electronic equipment has become exceedingly sensitive to the electrical environment. Industry standards to cope with this sensitivity have not been available when needed. Therefore, the term power quality has emerged as a catch-all to explain almost any malfunction of electronic equipment. When a malfunction occurs, for whatever reason, power quality can be invoked to make the power system the scapegoat and the equipment, or its installation, blameless. The power quality syndrome includes such issues as grounding, radio interference, transients, outages, harmonics, etc. Power compatibility or electrical environment compatibility (EEC) would be a more objective term to substitute for power quality. The sensitivity of today's electronic equipment arises from the equipment designers' lack of understanding and concern for the realities of the electrical environment and, to some extent, the utilities' lack of concern of the users' application problems. Consequently, to avoid process interruptions, the user's manager must mediate between the equipment and the power system. The manager must insure that specifications exist for both the equipment and all facets of the plant electrical environment, along with test procedures to insure that these specifications are met. The objective of this article is to show how a manager can handle EEC and, thus, avoid costly redesigns and down time of electrical equipment. Common fallacies, tools for defining the electrical equipment. Common fallacies, tools for defining the electrical environment and some applicable standards (existing and emerging) will also be discussed.

  20. Optically powered sensor system using conventional electrical sensors

    NASA Astrophysics Data System (ADS)

    Nieuwkoop, E.; Kapsenberg, Theo; Steenvoorden, Gijs K.; Bruinsma, Anastasius J.

    1991-08-01

    Large-scale installation of optical fiber sensors in an industrial or military environment is handicapped for several reasons. However, optical fibers are widely accepted to be applied for data transmission. An optically powered sensor system is proposed in which conventional well-proven transducers and data transmission along optical fibers are combined. The fiber is also used to transmit 10 mW of optical power from a remote control unit to the sensor head. In the sensor head the optical power is converted into electrical power to supply the sensor and datatransmission electronics. When a minimum supply voltage level of 4 V is detected, the pressure or temperature is sampled and a pulse position modulated (PPM) signal is transmitted along the fiber to the control unit, where it is demodulated. Feasibility of the system was demonstrated in the laboratory, and field experiments are planned. Alternative system configurations are discussed, in which intelligence is incorporated in the sensor head.

  1. PMU Configuration Scheme of Regional Power System and Dynamic Voltage Stability Online Evaluation of Substation

    Microsoft Academic Search

    Dongxiao Niu; Zhuangzhi Liu; Honglei Yang

    2010-01-01

    By use of power system analysis software BPA, the power flow of a certain regional power network was simulated; From this the nodes and zones with weak voltage stability were found out , and an optimal configuration scheme of pharos measurement units(PMUs) in this regional power network was proposed. By means of indentifying equivalent impedances with recursive least square method,

  2. An improved direct feedback linearization technique for transient stability enhancement and voltage regulation of power generators

    Microsoft Academic Search

    Godpromesse Kenné; Raphaël Goma; Homère Nkwawo; Françoise Lamnabhi-Lagarrigue; Amir Arzandé; Jean Claude Vannier

    2010-01-01

    In this paper, a simple improved direct feedback linearization design method for transient stability and voltage regulation of power systems is discussed. Starting with the classical direct feedback linearization technique currently applied to power systems, an adaptive nonlinear excitation control of synchronous generators is proposed, which is new and effective for engineering. The power angle and mechanical power input are

  3. Control Strategy of Active Power Filters Using Multiple Voltage-Source PWM Converters

    Microsoft Academic Search

    Hirofumi Akagi; Akira Nabae; Satoshi Atoh

    1986-01-01

    The control strategy of active power filters using switching devices is proposed on the basis of the instantaneous reactive power theory. This aims at excellent compensation characteristics in transient states as well as steady states. The active power filter is developed, of which the power circuit consists of quadruple voltage-source PWM converters. As the result, interesting compensation characteristics were verified

  4. Series resonant high-voltage ZCS-PFM DC-DC converter for medical power electronics

    Microsoft Academic Search

    Junmine Sun; Hitoshi Konishi; Yoshio Ogino; Mutsuo Nakaoka

    2000-01-01

    In general, high-voltage DC power supplies employing a variety of high-frequency inverters are implemented for constant value control schemes. In particular, their good transient and steady-state performances cannot be achieved under wide load variations involved in a medical-use X ray tube drive high voltage generator ranging from 20 kV to 150 kV in the output voltage and from 0.5 mA

  5. Scalable High Voltage CMOS technology for Smart Power and sensor applications

    Microsoft Academic Search

    M. Schrems; M. Knaipp; Hubert Enichlmair; V. Vescoli; Rainer Minixhofer; E. Seebacher; F. Leisenberger; E. Wachmann; G. Schatzberger; H. Gensinger

    2008-01-01

    Summary  Integration of low voltage analog and logic circuits as well as high-voltage (HV) devices for operation at greater than 5\\u000a V enables Smart Power ICs used in almost any system that contains electronics. HVCMOS (High-Voltage CMOS) technologies offer\\u000a much lower process cost, if compared to BCD technologies, they enable multiple HV levels on a single chip, and need less effort

  6. Design of low power current\\/voltage refrence source in CMOS 0.35?m technology

    Microsoft Academic Search

    M. Kachel; P. Kmon; P. Grybos

    2008-01-01

    This paper describes the design and simulations of reference low power current\\/voltage source in CMOS 0.35?m technology. Idea of the circuit is based on bandgap reference. Two voltages with different temperature coefficients are added resulting with near zero coefficient of output voltage. With use of Howlland current source the reference current is produced. In range of temperatures from ?20° C

  7. The unitary theory of the electrical powers

    E-print Network

    Gheorghe Mihai

    2009-04-07

    General physics approach is applied to analysis of power components in electrical systems under sinusoidal and non-sinusoidal conditions. Physical essence of active, reactive and distorting powers are determinate. It is shown that the all three powers are the different aspects of the same physical phenomenon: mechanical action per time of Coulomb forces or inertial forces.

  8. Power coupling and electrical characterization of a radio-frequency micro atmospheric pressure plasma jet

    NASA Astrophysics Data System (ADS)

    Marinov, D.; Braithwaite, N. St. J.

    2014-12-01

    We propose an efficient RF power coupling scheme for a micro atmospheric pressure plasma jet operating in helium. The discharge gap is used as a resonant element in a series LC circuit. In resonance, the voltage across the discharge gap is amplified and the ignition of the plasma is enabled with the input RF power as low as 0.5 W. High power coupling efficiency and simplicity of the circuit allow accurate electrical characterization of the discharge. Systematic measurements of the dissipated power as a function of the applied voltage are reported for the discharge operating in helium with molecular admixtures of N2 and O2.

  9. Electric power supply for use downhole

    SciTech Connect

    Schultz, R.L.; Manke, K.R.; Skinner, N.G.; Bohan, W.L.; Young, A.R.

    1992-09-22

    This patent describes a downhole electrical power supply apparatus, it comprises: a high fluid pressure source zone defined at least partially in the apparatus; a low fluid pressure discharge zone defined at least partially in the apparatus; a fluid powered engine means, a fluid supply valve means between the source zone and the discharge zone for controlling flow of fluid from the source zone through the engine means; and electrical power generating means for converting the rotational mechanical output of the engine means into electrical output.

  10. Primary Side Power Flow Control of Wireless Power Transfer for Electric Vehicle Charging

    SciTech Connect

    Miller, John M [ORNL; Onar, Omer C [ORNL; Chinthavali, Madhu Sudhan [ORNL

    2015-01-01

    Various noncontacting methods of plug-in electric vehicle charging are either under development or now deployed as aftermarket options in the light-duty automotive market. Wireless power transfer (WPT) is now the accepted term for wireless charging and is used synonymously for inductive power transfer and magnetic resonance coupling. WPT technology is in its infancy; standardization is lacking, especially on interoperability, center frequency selection, magnetic fringe field suppression, and the methods employed for power flow regulation. This paper proposes a new analysis concept for power flow in WPT in which the primary provides frequency selection and the tuned secondary, with its resemblance to a power transmission network having a reactive power voltage control, is analyzed as a transmission network. Analysis is supported with experimental data taken from Oak Ridge National Laboratory s WPT apparatus. This paper also provides an experimental evidence for frequency selection, fringe field assessment, and the need for low-latency communications in the feedback path.

  11. Technical evaluation report on the monitoring of electric power to the reactor-protection system for the Pilgrim Nuclear Power Station

    SciTech Connect

    Selan, J.C.

    1982-04-29

    This report documents the technical evaluation of the monitoring of electric power to the reactor protection system (RPS) at the Pilgrim Nuclear Power Station. The evaluation is to determine if the proposed design modification will protect the RPS from abnormal voltage and frequency conditions which could be supplied from the power supplies and will meet certain requirements set forth by the Nuclear Regulatory Commission. The proposed design modifications will protect the RPS from sustained abnormal voltage and frequency conditions from the supplying sources.

  12. Journal of Power Sources 167 (2007) 1117 Voltage reversal during microbial fuel cell stack operation

    E-print Network

    2007-01-01

    Journal of Power Sources 167 (2007) 11­17 Voltage reversal during microbial fuel cell stack February 2007; accepted 9 February 2007 Available online 20 February 2007 Abstract Microbial fuel cells Elsevier B.V. All rights reserved. Keywords: Microbial fuel cell; Voltage reversal; Stack; Direct electron

  13. On-site diagnostic tests on medium voltage, XLPE-insulated power cables

    Microsoft Academic Search

    Mahmoud Abou Dakka; Alexander Bulinski; Soli Bamji

    2008-01-01

    The dc depolarization current measurement technique was used to test 20 medium voltage, underground XLPE-insulated cables in the local utility power distribution network between January and March 2006 and then in March 2007. The cables varied in length (30 m to ~1600 m), voltage rating (9 to 28 kV), and age (4 to 36 years). Unlike a typical depolarization current

  14. A harmonic filter installation to reduce voltage distortion from static power converters

    Microsoft Academic Search

    P. W. Hammond

    1988-01-01

    Voltage distortion on plant distribution systems is becoming an increasingly serious problem as sources of harmonic currents (primarily static power converters) proliferate. The use of interference-prone control and instrumentation equipment is also rapidly expanding. The problem is well defined by IEEE Standard 519, which proposes a 5% limit to voltage distortion for general applications. IEEE 519 is frequently cited in

  15. Two-Stage Power Conversion Architecture Suitable for Wide Range Input Voltage

    E-print Network

    Lim, Seungbum

    This paper presents a merged-two-stage circuit topology suitable for either wide-range dc input voltage or ac line voltage at low-to-moderate power levels (e.g., up to 30 W). This two-stage topology is based on a soft-charged ...

  16. 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

  17. 30 CFR 56.12071 - Movement or operation of equipment near high-voltage power lines.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...high-voltage power lines. When equipment must be moved or operated near energized high-voltage powerlines (other than trolley lines) and the clearance is less than 10 feet, the lines shall be deenergized or other precautionary measures shall be...

  18. 46 CFR 28.375 - Emergency source of electrical power.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 false Emergency source of electrical power. 28.375 Section 28... § 28.375 Emergency source of electrical power. (a) Each vessel must have an emergency source of electrical power which is independent of...

  19. Fault-induced delayed voltage recovery in a long inhomogeneous power-distribution feeder

    NASA Astrophysics Data System (ADS)

    Stolbova, Irina; Backhaus, Scott; Chertkov, Michael

    2015-02-01

    We analyze the dynamics of a distribution circuit loaded with many induction motors and subjected to sudden changes in voltage at the beginning of the circuit. As opposed to earlier work by Duclut et al. [Phys. Rev. E 87, 062802 (2013), 10.1103/PhysRevE.87.062802], the motors are disordered, i.e., the mechanical torque applied to the motors varies in a random manner along the circuit. In spite of the disorder, many of the qualitative features of a homogeneous circuit persist, e.g., long-range motor-motor interactions mediated by circuit voltage and electrical power flows result in coexistence of the spatially extended and propagating normal and stalled phases. We also observed a new phenomenon absent in the case without inhomogeneity or disorder. Specifically, the transition front between the normal and stalled phases becomes somewhat random, even when the front is moving very slowly or is even stationary. Motors within the blurred domain appear in a normal or stalled state depending on the local configuration of the disorder. We quantify the effects of the disorder and discuss the statistics of distribution dynamics, e.g., the front position and width, total active and reactive consumption of the feeder, and maximum clearing time.

  20. Automating a spacecraft electrical power system using expert systems

    NASA Technical Reports Server (NTRS)

    Lollar, L. F.

    1991-01-01

    Since Skylab, Marshall Space Flight Center (MSFC) has recognized the need for large electrical power systems (EPS's) in upcoming Spacecraft. The operation of the spacecraft depends on the EPS. Therefore, it must be efficient, safe, and reliable. In 1978, as a consequence of having to supply a large number of EPS personnel to monitor and control Skylab, the Electrical power Branch of MSFC began the autonomously managed power system (AMPS) project. This project resulted in the assembly of a 25-kW high-voltage dc test facility and provided the means of getting man out of the loop as much as possible. AMPS includes several embedded controllers which allow a significant level of autonomous operation. More recently, the Electrical Division at MSFC has developed the space station module power management and distribution (SSM/PMAD) breadboard to investigate managing and distributing power in the Space Station Freedom habitation and laboratory modules. Again, the requirement for a high level of autonomy for the efficient operation over the lifetime of the station and for the benefits of enhanced safety has been demonstrated. This paper describes the two breadboards and the hierarchical approach to automation which was developed through these projects.

  1. Electric power annual 1989. [Contains glossary

    SciTech Connect

    Not Available

    1991-01-17

    This publication presents a summary of electric utility statistics at the national, regional and state levels. The Industry At A Glance'' section presents a profile of the electric power industry ownership and performance; a review of key statistics for the year; and projections for various aspects of the electric power industry through 2010. Subsequent sections present data on generating capability, including proposed capability additions; net generation; fossil-fuel statistics; electricity sales, revenue and average revenue per kilowatthour sold; financial statistics; environmental statistics; and electric power transactions. In addition, the appendices provide supplemental data on major disturbances and unusual occurrences. Each section contains related text and tables and refers the reader to the appropriate publication that contains more detailed data on the subject matter. 24 figs., 57 tabs.

  2. Electrical conduction mechanism in bulk ceramic insulators at high voltages until dielectric breakdown

    NASA Astrophysics Data System (ADS)

    Neusel, C.; Jelitto, H.; Schneider, G. A.

    2015-04-01

    In order to develop and verify a dielectric breakdown model for bulk insulators thicker than 100 ?m, the knowledge of the dominating conduction mechanism at high electric fields, or respectively voltages, is necessary. The dielectric breakdown is the electrical failure of an insulator. In some existing breakdown models, ohmic conduction is assumed as dominating conduction mechanism. For verification, the dominating dc conduction mechanism of bulk insulators at room temperature was investigated by applying high voltages up to 70 kV to the insulator until dielectric breakdown occurs. Four conduction models, namely, ohmic, space charge limited, Schottky, and Poole-Frenkel conduction, were employed to identify the dominating conduction mechanism. Comparing the calculated permittivities from the Schottky and Poole-Frenkel coefficients with experimentally measured permittivity, Schottky and Poole-Frenkel conduction can be excluded as dominating conduction mechanism. Based on the current density voltage characteristics (J-V-curve) and the thickness-dependence of the current density, space charge limited conduction (SCLC) was identified to be the dominating conduction mechanism at high voltages leading to dielectric breakdown. As a consequence, breakdown models based on ohmic conduction are not appropriate to explain the breakdown of the investigated bulk insulators. Furthermore, the electrical failure of the examined bulk insulators can only be described correctly by a breakdown model which includes SCLC as conduction mechanism.

  3. Mechanical and electrical properties of GeSb2Te4 film with external voltage applied

    NASA Astrophysics Data System (ADS)

    Cheng, Guang-Gui; Zhang, Zhong-Qiang; Ding, Jian-Ning; Ling, Zhiyong; Chen, Yu-Bing

    2013-11-01

    A GeSb2Te4 (GST) film was deposited by RF magnetron sputtering with microwave electron cyclotron resonance plasma chemical vapor deposition equipment. Mechanical and electrical properties together with the morphologies of the film were studied by a nanoindenter which was equipped with nano-electrical contact resistance (nano-ECR) tool and atomic force microscope (AFM). Results show that when no voltage applied between sample and indent tip during indenting, the pile-up phenomenon was observed, the hardness and elastic modulus increases with the load mainly due to the underestimate of the contact area; when external voltages of -7 V, -8 V, -9 V, -10 V were applied, the resistance of the film decreased with applied voltages in about four orders of magnitude, while the elastic modulus increased from 159 GPa to 233 GPa, this changing in mechanical and electrical properties demonstrated that phase change happen during intending, a shrinking region with radius of about 2.5 ?m was observed around the indentation when -8 V applied. Furthermore, indent load can also promote the phase change at given negative voltage.

  4. Power Processing for a Conceptual Project Prometheus Electric Propulsion System

    NASA Technical Reports Server (NTRS)

    Scina, Joseph E., Jr.; Aulisio, Michael; Gerber, Scott S.; Hewitt, Frank; Miller, Leonard; Elbuluk, Malik; Pinero, Luis R. (Technical Monitor)

    2005-01-01

    NASA has proposed a bold mission to orbit and explore the moons of Jupiter. This mission, known as the Jupiter Icy Moons Orbiter (JIMO), would significantly increase NASA s capability to explore deep space by making use of high power electric propulsion. One electric propulsion option under study for JIMO is an ion propulsion system. An early version of an ion propulsion system was successfully used on NASA's Deep Space 1 mission. One concept for an ion thruster system capable of meeting the current JIMO mission requirement would have individual thrusters that are 16 to 25 kW each and require voltages as high as 8.0 kV. The purpose of this work is to develop power processing schemes for delivering the high voltage power to the spacecraft ion thrusters based upon a three-phase AC distribution system. In addition, a proposed DC-DC converter topology is presented for an ion thruster ancillary supply based upon a DC distribution system. All specifications discussed in this paper are for design convenience and are speculative in nature.

  5. QUALITY CONTROL OF HVDC EXTRUDED CABLES: ELECTRICAL TREEING IN XLPE UNDER DIFFERENT VOLTAGE STRESSES

    Microsoft Academic Search

    F. Mauseth; E. Ildstad; M. Ytterstad; R. Hegerberg; B. Sanden; M. Jeroense; J. E. Skog

    The main purpose of this work has been to study initiation and growth of electrical trees in XLPE insulation subjected to different types of electrical stress. The insight gained can be used to evaluate proposed test methods for quality assurance of long lengths of polymer insulated power cables. Experiments were performed examining electrical treeing from the tip of needles embedded

  6. Parabolic Trough Solar Thermal Electric Power Plants

    SciTech Connect

    Not Available

    2003-06-01

    Although many solar technologies have been demonstrated, parabolic trough solar thermal electric power plant technology represents one of the major renewable energy success stories of the last two decades.

  7. A test technique for measuring lightning-induced voltages on aircraft electrical circuits

    NASA Technical Reports Server (NTRS)

    Walko, L. C.

    1974-01-01

    The development of a test technique used for the measurement of lightning-induced voltages in the electrical circuits of a complete aircraft is described. The resultant technique utilizes a portable device known as a transient analyzer capable of generating unidirectional current impulses similar to lightning current surges, but at a lower current level. A linear relationship between the magnitude of lightning current and the magnitude of induced voltage permitted the scaling up of measured induced values to full threat levels. The test technique was found to be practical when used on a complete aircraft.

  8. Power conditioning system modelling for nuclear electric propulsion

    NASA Astrophysics Data System (ADS)

    Metcalf, Kenneth J.

    1993-11-01

    NASA LeRC is currently developing a Fortran based model of a complete nuclear electric propulsion (NEP) vehicle that would be used for piloted and cargo missions to the Moon or Mars. The proposed vehicle design will use either a Brayton or K-Rankine power conversion cycle to drive a turbine coupled with a rotary alternator. Two thruster types are also being studied, ion and magnetoplasmadynamic (MPD). In support of this NEP model, Rocketdyne developed a power management and distribution (PMAD) subroutine that provides parametric outputs for selected alternator operating voltages and frequencies, thruster types, system power levels, and electronics coldplate temperatures. The end-to-end PMAD model described is based on the direct use of the alternator voltage and frequency for transmitting power to either ion or MPD thrusters. This low frequency transmission approach was compared with dc and high frequency ac designs, and determined to have the lowest mass, highest efficiency, highest reliability and lowest development costs. While its power quality is not as good as that provided by a high frequency system, it was considered adequate for both ion and MPD engine applications. The low frequency architecture will be used as the reference in future NEP PMAD studies.

  9. Power Conditioning System Modelling for Nuclear Electric Propulsion

    NASA Technical Reports Server (NTRS)

    Metcalf, Kenneth J.

    1993-01-01

    NASA LeRC is currently developing a Fortran based model of a complete nuclear electric propulsion (NEP) vehicle that would be used for piloted and cargo missions to the Moon or Mars. The proposed vehicle design will use either a Brayton or K-Rankine power conversion cycle to drive a turbine coupled with a rotary alternator. Two thruster types are also being studied, ion and magnetoplasmadynamic (MPD). In support of this NEP model, Rocketdyne developed a power management and distribution (PMAD) subroutine that provides parametric outputs for selected alternator operating voltages and frequencies, thruster types, system power levels, and electronics coldplate temperatures. The end-to-end PMAD model described is based on the direct use of the alternator voltage and frequency for transmitting power to either ion or MPD thrusters. This low frequency transmission approach was compared with dc and high frequency ac designs, and determined to have the lowest mass, highest efficiency, highest reliability and lowest development costs. While its power quality is not as good as that provided by a high frequency system, it was considered adequate for both ion and MPD engine applications. The low frequency architecture will be used as the reference in future NEP PMAD studies.

  10. Electrical safety for an offshore power system

    Microsoft Academic Search

    L. M. Lavie

    2004-01-01

    This paper describes the electrical safety for a power system analysis. For an efficient and reliable electrical system, routine and detailed maintenance must be performed. One method of preventive maintenance uses infrared thermography. This technology visually depicts heat differentials in a circuit breakers and transformers that are housed in metal-glad switchgear. Predictive maintenance involves testing equipment for proper operation. This

  11. Electric propulsion power system-overview

    Microsoft Academic Search

    D. B. Hamilton

    1996-01-01

    Electric automobile power system technology has not improved substantially beyond what it was in the 1930s. The 1976 Electric and Hybrid Vehicle Act's research and development efforts have focused on technologies to reduce costs and to improve system performance through programs like the US Automotive Battery Consortium (USABC). Despite renewed interest and increased research and development efforts, the problems of

  12. High power density, high frequency, and high voltage pulse transformer

    Microsoft Academic Search

    S. C. Kim; S. H. Nam; D. T. Kim

    2001-01-01

    Summary form only given, as follows. In designing a compact and high efficiency TWT microwave amplifier, the role of a high power density DC power supply is very important. In order to reduce volume of the power supply, it is necessary to increase switching frequency of the power supply. The high operation frequency mainly reduces transformer volume in the power

  13. High power density, high frequency, and high voltage pulse transformer

    Microsoft Academic Search

    S. C. Kim; S. H. Nam; S. H. Kim; D. T. Kim; S. H. Jeong

    2001-01-01

    In designing a compact and high efficiency TWT microwave amplifier, the role of a high power density DC power supply is very important. In order to reduce volume of the power supply, it is necessary to increase switching frequency of the power supply. The high operation frequency mainly reduces transformer volume in the power supply. However, a step-up ratio of

  14. A low-power, high-bandwidth LDO voltage regulator with no external capacitor

    E-print Network

    Ha, Miranda J. (Miranda Joy)

    2008-01-01

    A low-dropout (LDO) voltage regulator for low-power applications is designed without an external capacitor for compensation. The regulator has two stages, the first a folded cascode amplifier and the second a large pass ...

  15. Introduction Literature Review Integrated Electric Power Supply Chains Empirical Examples Conclusions An Integrated Electric Power Supply Chain and Fuel

    E-print Network

    Nagurney, Anna

    Introduction Literature Review Integrated Electric Power Supply Chains Empirical Examples - 28, 2009, Chicago, IL #12;Introduction Literature Review Integrated Electric Power Supply Chains://www.nasa.gov #12;Introduction Literature Review Integrated Electric Power Supply Chains Empirical Examples

  16. Introduction Literature Review Integrated Electric Power Supply Chains Empirical Examples Conclusions An Integrated Electric Power Supply Chain and Fuel

    E-print Network

    Nagurney, Anna

    Introduction Literature Review Integrated Electric Power Supply Chains Empirical Examples, June 26-28, 2008 #12;Introduction Literature Review Integrated Electric Power Supply Chains Empirical://www.nasa.gov #12;Introduction Literature Review Integrated Electric Power Supply Chains Empirical Examples

  17. Outline Introduction Literature Review Electric Power Supply Chains Empirical Examples Conclusions An Integrated Electric Power Supply Chain and Fuel Market

    E-print Network

    Nagurney, Anna

    Outline Introduction Literature Review Electric Power Supply Chains Empirical Examples Conclusions An Integrated Electric Power Supply Chain and Fuel Market Network Framework: Theoretical Modeling with Empirical Literature Review Electric Power Supply Chains Empirical Examples Conclusions Support Support

  18. Fault location algorithms for super high voltage power transmission lines

    Microsoft Academic Search

    A. Sauhats; M. Danilova

    2003-01-01

    This paper presents a new approach for calculation of fault location on high voltage transmission lines. The proposed fault location algorithm utilizes statistical information about the equivalent impedances of the system at the unmonitored end of the transmission line. Knowledge about the distribution laws of these values or their numerical characteristics, which are more accessible for practical use, results in

  19. Automotive electrical systems: architecture and components

    Microsoft Academic Search

    I. A. Khan

    1999-01-01

    Automotive electrical power systems that address the demands of increased electrical power, improved fuel economy and reduced emissions are discussed. Considerations related to high-efficiency automotive electrical power systems such as the selection of the types of electrical machines and power converters, selection of system voltages, battery voltage equalization, load management, energy management, regenerative braking, centralized and distributed power system architectures,

  20. Novel BiCMOS compatible, short channel LDMOS technology for medium voltage RF & power applications

    Microsoft Academic Search

    Andrej Litwin; Olof Bengtsson; Jorgen Olsson

    2002-01-01

    We describe a very short channel, 0.15 ?m, LDMOS transistor, with a breakdown voltage of up to 45 V, manufactured in a standard 0.35 ?m BiCMOS process. At 1900 MHz and a 12 V supply voltage the 0.4 mm gate width device gives 100 mW output power P1 dB at a drain efficiency of 43%. It has a transducer power

  1. Novel BiCMOS compatible, short channel LDMOS technology for medium voltage RF and power applications

    Microsoft Academic Search

    Andrej Litwin; O. Bengtsson; J. Olsson

    2002-01-01

    We describe a very short channel, 0.15 ?m, LDMOS transistor, with a breakdown voltage of up to 45 V, manufactured in a standard 0.35 ?m BiCMOS process. At 1900 MHz and a 12 V supply voltage the 0.4 mm gate width device gives 100 mW output power P1 dB at a drain efficiency of 43%. It has a transducer power

  2. Run-time voltage hopping for low-power real-time systems

    Microsoft Academic Search

    Seongsoo Lee; Takayasu Sakurai

    2000-01-01

    This paper presents a novel run-time dynamic voltage scaling scheme for low-power real-time systems. It employs software feedback control of supply voltage, which is applicable to off-the-shelf processors. It avoids interface problems from variable clock frequency. It provides efficient power reduction by fully exploiting slack time arising from workload variation. Using software analysis environment, the proposed scheme is shown to

  3. A new application area for fullerenes: voltage stabilizers for power cable insulation.

    PubMed

    Jarvid, Markus; Johansson, Anette; Kroon, Renee; Bjuggren, Jonas M; Wutzel, Harald; Englund, Villgot; Gubanski, Stanislaw; Andersson, Mats R; Müller, Christian

    2015-02-01

    Fullerenes are shown to be efficient voltage-stabilizers for polyethylene, i.e., additives that increase the dielectric strength of the insulation material. Such compounds are highly sought-after because their use in power-cable insulation may considerably enhance the transmission efficiency of tomorrow's power grids. On a molal basis, fullerenes are the most efficient voltage stabilizers reported to date. PMID:25504254

  4. 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

  5. Power balance control and voltage conditioning for fuel cell converter with multiple sources

    Microsoft Academic Search

    C. Liu; T. Nergaard; L. Leslie; J. Ferrell; X. Huang; T. Shearer; J. Reichl; J. Lai; John Bates

    2002-01-01

    Due to the long time-constant of the fuel cell, the generated power and load become unbalanced under dynamic conditions, resulting in control difficulty for a front-end DC-DC converter. To maximize the fuel cell output power, a current control is employed; however, the DC bus voltage becomes unregulated. Thus, a voltage conditioner utilizing a battery source is proposed to balance the

  6. Primary measurement of total ultrasonic power with improved accuracy in rf voltage measurement.

    PubMed

    Dubey, P K; Kumar, Ashok; Kumar, Yudhisther; Gupta, Reeta; Joshi, Deepa

    2010-10-01

    Out of the various existing ultrasonic power measurement techniques, the radiation force balance method using microbalance is most widely used in low power (below 1 W) regime. The major source of uncertainty associated with this technique is the error in ac voltage measurement applied to the transducer for the generation of ultrasonic waves. The sources that deteriorate the ac voltage measurement accuracy include cable length and impedance mismatch. We introduce a new differential peak to peak measurement approach to reduce the ac voltage measurement error. The method holds the average peak amplitude of each polarity. Ultralow offset difference amplifier is used to measure peak to peak voltage. The method is insensitive to the variations in the dc offset of the source. The functionality of this method has been tested and compared with the conventional rf voltage measurement method. The output of this proposed technique is dc, which can be measured with an error of less than 0.1%. PMID:21034111

  7. Design and analysis of new protection structures for smart power technology with controlled trigger and holding voltage

    Microsoft Academic Search

    V. De Heyn; G. Groeseneken; B. Keppens; M. Natarajan; L. Vacaresse; G. Gallopyn

    2001-01-01

    The physical mechanisms that influence the triggering and holding voltage in a DMOS transistor in CMOS smart power technology are investigated. We demonstrate that a high and a low holding voltage device can be designed by changing the lateral bipolar base distance and that also the trigger voltage can be easily tuned. The layout variation that controls the holding voltage

  8. All solid state high voltage power supply for neutral beam sources

    SciTech Connect

    Praeg, W.F.

    1984-09-14

    The conceptual design of a high frequency solid state, high power, high voltage, power system that reacts fast enough to be compatible with the requirements of a neutral beam source is presented. The system offers the potential of significant advantages over conventional power line frequency systems; such as high reliability, long life, relatively little maintenance requirements, compact size and modular design.

  9. Power Supply Rejection Improvement Techniques In Low Drop-Out Voltage Regulators 

    E-print Network

    Ganta, Saikrishna

    2011-10-21

    of battery charging control unit whose main job is to monitor the battery voltage and take action in case of over voltage. Generally lithium ion batteries are used which provides a voltage in between 3.1 to 4.6V depending on its charging condition. 5... INTRODUCTION Extended battery life has become one of the most important design aspects for System on Chip (SoC) designs in portable, battery-powered applications, while power consumption is a concern in high-performance desktop and server applications...

  10. Automatic Detection of Electric Power Troubles (ADEPT)

    Microsoft Academic Search

    Caroline Wang; Hugh Zeanah; Audie Anderson; Clint Patrick; Mike Brady; Donnie Ford

    1988-01-01

    Automatic Detection of Electric Power Troubles (A DEPT) is an expert system that integrates knowledge from three different suppliers to offer an advanced fault-detection system. It is designed for two modes of operation: real time fault isolation and simulated modeling. Real time fault isolation of components is accomplished on a power system breadboard through the Fault Isolation Expert System (FIES

  11. Power Processing, Part 1. Electric Machinery Analysis.

    ERIC Educational Resources Information Center

    Hamilton, Howard B.

    This publication was developed as a portion of a two-semester sequence commencing at either the sixth or seventh term of the undergraduate program in electrical engineering at the University of Pittsburgh. The materials of the two courses, produced by a National Science Foundation grant, are concerned with power conversion systems comprising power

  12. Introduction The electric power grid and electric power

    E-print Network

    with a brain"--the power grid of the 20th century is evolving into the 21st century's smart grid. Consumers, manufacturers, and utilities are already seeing new benefits from the emerging "smart grid version 1.0." As work many of the critical elements that make up the smart grid. Since its establishment in 1901, NIST

  13. The electrical breakdown characteristics of oil-paper insulation under steep front impulse voltages

    SciTech Connect

    Vandermaar, A.J.; Wang, M.; Neilson, J.B. (Powertech Labs Inc., Surrey, British Columbia (Canada)); Srivastava, K.D. (Univ. of British Columbia, Vancouver (Canada))

    1994-10-01

    Disconnecting switch operations in gas insulated equipment cause transient voltages with rise times as steep as 5 to 20 nanoseconds and magnitudes as high as 2.5 pu. There is very little information on the effect of these transients on oil-paper insulated equipment. There have been reports, however of transformer and bushing failures caused by these transients. The electrical breakdown characteristics of oil-paper insulation under steep front impulse were studied in this project, which was co-sponsored by the Canadian Electrical Association and B.C. Hydro. V[sub 50] (50% breakdown probability voltage) breakdown data was obtained with steep front (10 ns/2500 [mu]s), lightning and switching impulse waveforms. Insulation breakdown voltage vs breakdown time (V-t) data and multiple impulse breakdown data were obtained with the steep front impulse waveform. The V[sub 50] results showed that the breakdown strengths were lower for steep front impulses than for lightning impulses. The multiple impulse breakdown results showed that oil-paper insulation breakdown strength can be lower than 100 kV/mm. These results are alarming, since they suggest that oil-paper insulated equipment subjected to steep front transients will fail at voltages below the lightning impulse design level (BIL). The Volt-time data had a discontinuity. The breakdown process at risetime below about 50 ns was different from the breakdown process at rise times above 50 ns.

  14. Development of a 55 kw diesel powered auxiliary power unit for hybrid electric vehicles. Interim report

    SciTech Connect

    Likos, W.E.; Podnar, D.J.; Smith, J.A.; Steiber, J.

    1998-03-01

    Three auxillary power units (APU) were developed for military hybrid vehicle applications with funding from DARPA. One APU was for the electric M113 troop carrier originally converted to electric power in the 1960`s. The other two APU`s developed during this project were for hybrid electric High Mobility Multipurpose Wheeled Vehicle (HMMWV) projects. For this APU design a Volkswagen 1.5-1 diesel engine drives a permanent magnet generator, that with associated inverter produces 55kW of DC power at 380 volts. Overall thermal efficiencies of 33% were observed. The controller for the APU`s was based on the personal computer (PC) CPU. Basing the controller on the PC allowed flexibility in meeting the individual requirements of the different vehicles. Given a power level request from the vehicle controller, the APU controller set the engine speed for optimum thermal efficiency. The generator electronics adjusts the voltage and thus the current output from the inverter to deliver the requested power to the vehicle`s electrical bus.

  15. Novel high voltage capacitor charger for pulsed power modulator

    Microsoft Academic Search

    S. R. Jang; S. H. Ahn; H. J. Ryoo; G. H. Rim

    2010-01-01

    This paper describes a novel 10kW (10kV, 1A) high voltage capacitor charger which has the combined advantage both series loaded resonant inverter and ZVS full-bridge PWM inverter. Series loaded resonant inverter has a wide ZV or ZC switching range regardless of load condition. However it can generate audible noise at light load condition and requires careful filter design because it

  16. Wind systems for electrical power production

    SciTech Connect

    Thresher, R.W.; Hock, S.M. (National Renewable Energy Lab., Golden, CO (United States))

    1994-08-01

    This article examines the status of wind power plants as a choice for future new electric generation expansion. The topics of the article include wind power plant architecture and control systems, designs of currently available power plants, designs that are in development, and a look at next-generation turbines that will offer changes in blade design, variable-speed operation, advanced generators, advanced control systems, and aerodynamic controls.

  17. 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.

  18. Experimental cutaneous wound healing in rabbits: using continuous microamperage low-voltage electrical stimulation

    Microsoft Academic Search

    Aboutorab Tabatabaei Naeini; Ahmad Oryan; Seifollah Dehghani; Behrooz Nikahval

    2008-01-01

    This study was designed to determine the effects of continuous microamperage low-voltage electrical stimulation on cutaneous\\u000a wound healing. Sixty mature rabbits were randomly divided into three equal groups (experimental, open control, and closed\\u000a or sutured control groups). After routine surgical preparations, two 3?×?1 cm pieces of lumbosacral skin were excised on both\\u000a sides in each animal. An incision was made over

  19. 78 FR 1252 - Schneider Electric, U.S.A., Subsidiary of Schneider Electric, Power Business Unit, Power...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-08

    ...Electric, Power Business Unit, Power Solutions Division, Including On-Site Leased Workers From Volt Workforces Solutions and Resource Tek, Lavergne, TN...Electric, Power Business Unit, Power Solutions Division, including on-site...

  20. Application of Particle Swarm Optimization for Optimal Placement of Unified Power Flow Controllers in Electrical Systems with Line Outages

    Microsoft Academic Search

    S. T. Jaya Christa; P. Venkatesh

    2007-01-01

    This paper proposes particle swarm optimization (PSO) for the optimal location and parameters of unified power flow controllers (UPFCs) in electrical power systems with line outages. The goal of the optimization technique is to maximize the loadability of transmission system using unified power flow controllers subject to the transmission line capacity limits and acceptable bus voltage levels, even during a

  1. Multimegawatt potassium rankine power for nuclear electric power

    Microsoft Academic Search

    Richard D. Rovang; Joseph C. Mills; Ernie B. Baumeister

    1991-01-01

    Nuclear electric propulsion (NEP) has been identified as a potentially attractive option for future space exploratory missions. Under sponsorship of the U.S. Department of Energy and the NASA Lewis Research Center, a cermet fueled potassium rankine power system concept has been developed for various power ranges and operating lifetimes. This concept utilizes a single primary lithium loop to transport thermal

  2. Nuclear reactor power for an electrically powered orbital transfer vehicle

    Microsoft Academic Search

    L. Jaffe; R. Beatty; P. Bhandari; E. Chow; W. Deininger; R. Ewell; T. Fujita; M. Grossman; T. Kia; B. Nesmith

    1987-01-01

    To help determine the systems requirements for a 300-kWe space nuclear reactor power system, a mission and spacecraft have been examined which utilize electric propulsion and this nuclear reactor power for multiple transfers of cargo between low earth orbit (LEO) and geosynchronous earth orbit (GEO). A propulsion system employing ion thrusters and xenon propellant was selected. Propellant and thrusters are

  3. Nuclear reactor power for an electrically powered orbital transfer vehicle

    Microsoft Academic Search

    L. Jaffe; R. Beatty; P. Bhandari; E. Chow; W. Deininger; R. Ewell; T. Fujita; M. Grossman; T. Kia; B. Nesmith

    1987-01-01

    To help determine the systems requirements for a 300-kWe space nuclear reactor power system, a mission and spacecraft have been examined which utilize electric propulsion and this nuclear reactor power for multiple transfers of cargo between low Earth orbit (LEO) and geosynchronous Earth orbit (GEO). A propulsion system employing ion thrusters and xenon propellant was selected. Propellant and thrusters are

  4. Utility-Scale Silicon Carbide Semiconductor: Monolithic Silicon Carbide Anode Switched Thyristor for Medium Voltage Power Conversion

    SciTech Connect

    None

    2010-09-01

    ADEPT Project: GeneSiC is developing an advanced silicon-carbide (SiC)-based semiconductor called an anode-switched thyristor. This low-cost, compact SiC semiconductor conducts higher levels of electrical energy with better precision than traditional silicon semiconductors. This efficiency will enable a dramatic reduction in the size, weight, and volume of the power converters and electronic devices it's used in.GeneSiC is developing its SiC-based semiconductor for utility-scale power converters. Traditional silicon semiconductors can't process the high voltages that utility-scale power distribution requires, and they must be stacked in complicated circuits that require bulky insulation and cooling hardware. GeneSiC's semiconductors are well suited for high-power applications like large-scale renewable wind and solar energy installations.

  5. Performance of International Space Station Alpha electric power systems

    SciTech Connect

    Hill, R.; Lu, C.Y.; Padhye, V.; Hajela, G.; Hague, L. [Rockwell International, Canoga Park, CA (United States). Rocketdyne Division

    1995-12-31

    The International Space Station Alpha (ISSA) will be an Earth-orbiting laboratory in space. It will house experimental payloads, distribute resource utilities, and support human habitation for conducting research and science experiments in a microgravity environment. Electrical power is a major utility to support successful achievement of the mission goal. The ISSA United States On-Orbit Segment (USOS) Electric Power System (EPS) power generation capability will vary with orbital parameters, natural and induced environment, and hardware aging/replacement throughout the ISSA life. Power capability will be further restricted by various assembly configurations during ISSA buildup, by various flight attitudes, by shadowing on the solar arrays, by EPS operational constraints, such as pointing accuracy, battery charging, as well as operating voltage setpoints, and by ISSA operational constraints either to avoid long-term solar array shadowing from the adjacent solar array or to accommodate ISSA maneuver during proximity operations with other space vehicles, mating, and departing. Design of the ISSA USOS EPS takes into consideration the various equipment degradation modes, operation constraints, and orbital conditions to make it compatible with the environments and to meet power, lifetime, and performance requirements.

  6. Geomagnetically Induced Currents in European High-Voltage Power Systems

    Microsoft Academic Search

    Risto J. Pirjola; David H. Boteler

    2006-01-01

    Geomagnetically induced currents (GIC) in power systems are a ground manifestation of space weather arising from solar activity. Most of the research on GIC done in Europe so far refers to Scandinavian power grids. A power outage due to GIC occurred in southern Sweden in October 2003. The principal reason that similar GIC problems as in Sweden have not occurred

  7. Topics in high voltage pulsed power plasma devices and applications

    Microsoft Academic Search

    Hao Chen

    2010-01-01

    Pulsed power technology is one of the tools that is used by scientists and engineers nowadays to produce gas plasmas. The transient ultra high power is able to provide a huge pulse of energy which is sometimes greater than the ionization energy of the gas, and therefore separates the ions and electrons to form the plasma. Sometimes, the pulsed power

  8. Electrical Power Working Group report

    NASA Technical Reports Server (NTRS)

    Vanommering, Gerrit; Myers, Ira T.

    1986-01-01

    The status of and need for power technologies for Spacecraft 2000 were assessed and development programs required to establish an achievable and competitive technology base for spacecraft of the 21st century were identified. The results are summarized, including the recommendations and the underlying rationale.

  9. Electrical safety problems in MV-power networks of a surface mining

    Microsoft Academic Search

    B. Miedzitiski; Z. Okraszewski; S. Szkolka; A. Szymanski

    1999-01-01

    Problems of an electric shock hazard in middle voltage (6 kV-30 kV) power networks of brown coal surface minings in Poland are discussed. They are found based on two years of investigations carried out for real ground fault conditions

  10. Educational electrical appliance power meter and logger

    NASA Astrophysics Data System (ADS)

    Nunn, John

    2013-09-01

    The principles behind two different designs of inductive power meter are presented. They both make use of the microphone input of a computer which, together with a custom-written program, can record the instantaneous power of a domestic electrical appliance. The device can be built quickly and can be calibrated with reference to a known power device such as an electric kettle. Typical power-versus-time profiles are shown for a kettle, a dishwasher and a fridge-freezer. The components are cheap and the cost may be recouped many times over from the resultant energy saving. Custom software will be made available free of charge to anyone who requests it. It is hoped that students attending poorly resourced schools will be able to make power loggers for educational use.

  11. Integrated high-voltage inductive power and data-recovery front end dedicated to implantable devices.

    PubMed

    Mounaim, F; Sawan, M

    2011-06-01

    In near-field electromagnetic links, the inductive voltage is usually much larger than the compliance of low-voltage integrated-circuit (IC) technologies used for the implementation of implantable devices. Thus most integrated power-recovery approaches limit the induced signal to low voltages with inefficient shunt regulation or voltage clipping. In this paper, we propose using high-voltage (HV) complementary metal-oxide semiconductor technology to fully integrate the inductive power and data-recovery front end while adopting a step-down approach where the inductive voltage is left free up to 20 or 50 V. The advantage is that excessive inductive power will translate to an additional charge that can be stored in a capacitor, instead of shunting to ground excessive current with voltage limiters. We report the design of two consecutive HV custom ICs-IC1 and IC2-fabricated in DALSA semiconductor C08G and C08E technologies, respectively, with a total silicon area (including pads) of 4 and 9 mm(2), respectively. Both ICs include HV rectification and regulation; however, IC2 includes two enhanced rectifier designs, a voltage-doubler, and a bridge rectifier, as well as data recovery. Postlayout simulations show that both IC2 rectifiers achieve more than 90% power efficiency at a 1-mA load and provide enough room for 12-V regulation at a 3-mA load and a maximum-available inductive power of 50 mW only. Successful measurement results show that HV regulators provide a stable 3.3- to 12-V supply from an unregulated input up to 50 or 20 V for IC1 and IC2, respectively, with performance that matches simulation results. PMID:23851479

  12. 46 CFR 28.355 - Main source of electrical power.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...2011-10-01 false Main source of electrical power. 28.355 Section 28.355...Board § 28.355 Main source of electrical power. (a) Applicability. ...essential loads must have at least two electrical generators to supply these...

  13. 46 CFR 28.355 - Main source of electrical power.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 false Main source of electrical power. 28.355 Section 28.355...Board § 28.355 Main source of electrical power. (a) Applicability. ...essential loads must have at least two electrical generators to supply these...

  14. Sixth Northwest Conservation and Electric Power Plan Chapter 1: Introduction

    E-print Network

    electricity can provide, such as heat for homes, lights for commercial buildings, or motors for industrialSixth Northwest Conservation and Electric Power Plan Chapter 1: Introduction Purpose of the Power............................................................................................................................ 7 Electricity Demand

  15. Kysat-2 electrical power system design and analysis

    NASA Astrophysics Data System (ADS)

    Molton, Brandon L.

    In 2012, Kentucky Space, LLC was offered the opportunity to design KYSat-2, a CubeSat mission which utilizes an experimental stellar-tracking camera system to test its effectiveness of determining the spacecraft's attitude while on orbit. Kentucky Space contracted Morehead State University to design the electrical power system (EPS) which will handle all power generation and power management and distribution to each of the KYSat-2 subsystems, including the flight computer, communications systems, and the experimental payload itself. This decision came as a result of the success of Morehead State's previous CubeSat mission, CXBN, which utilized a custom built power system and successfully launched in 2011. For the KYSat-2 EPS to be successful, it was important to design a system which was efficient enough to handle the power limitations of the space environment and robust enough to handle the challenges of powering a spacecraft on orbit. The system must be developed with a positive power budget, generating and storing more power than will be stored by KYSat-2 over mission lifetime. To accomplish this goal, the use of deployable solar panels has been utilized to double the usable surface area of the satellite for power generation, effectively doubling the usable power of the satellite system on orbit. The KYSat-2 EPS includes of set of gold plated deployable solar panels utilizing solar cells with a 26% efficiency. Power generated by this system is fed into a shunt regulator circuit which regulates the voltage generated to be stored in a 3-cell series battery pack. Stored powered is maintained using a balancing circuit which increases the efficiency and lifetime of the cells on-orbit. Power distribution includes raw battery voltage, four high-power outputs (two 5V and two 3.3 V) and a low-noise, low power 3.3V output for use with noise sensitive devices, such as microcontrollers. The solar panel deployment system utilizes the nichrome wire which draws current directly from the battery pack which a solid state relay receives logic-high signal. This nichrome wire, while under current, cuts a nylon wire which holds the solar panels in a stowed state prior to deployment on orbit. All logic control, current/voltage measurement, and commanding/communications is handled through the use of a Texas Instruments MSP430 microcontroller over UART serial communications. Results of the completed EPS demonstrated high-power output efficiencies approaching 90% under the highest anticipated loads while on orbit. They showed maximum noise levels of approximately +/- 41.30 mV at 83.10 MHz under maximum load. The low-noise 3.3V outputs displayed very little noise, however, this came at the cost of efficiency showing only 26% efficiency at the outputs when under maximum load. The EPS has been successfully integrated with other KYSat-2 subsystems including the spacecraft flight computer, in which the flight computer was able to communicate with the EPS and carry out its functions while functioning solely off the power distributed by the power system. Finally, testing on the solar panels show that a positive voltage margin was achieved when under light and the deployment system was able to cut the nylon wire completely under control by the EPS.

  16. Galena Electric Power A Situational Analysis

    SciTech Connect

    Robert E. Chaney; Stephen G. Colt; Ronald A. Johnson; Richard W. Wiles; Gregory J. White

    2008-12-31

    The purpose of the investigation is to compare the economics of various electrical power generation options for the City of Galena. Options were assessed over a 30-year project period, beginning in 2010, and the final results were compared on the basis of residential customer electric rates ($/kWh). Galena's electric utility currently generates power using internal combustion diesel engines and generator sets. Nearby, there is an exposed coal seam, which might provide fuel for a power plant. Contributions to the energy mix might come from solar, municipal solid waste, or wood. The City has also been approached by Toshiba, Inc., as a demonstration site for a small (Model 4S) nuclear reactor power plant. The Yukon River is possibly a site for in-river turbines for hydroelectric power. This report summarizes the comparative economics of various energy supply options. This report covers: (1) thermal and electric load profiles for Galena; (2) technologies and resources available to meet or exceed those loads; (3) uses for any extra power produced by these options; (4) environmental and permitting issues and then; and (5) the overall economics of each of the primary energy options.

  17. Growing the Space Station's electrical power plant

    NASA Technical Reports Server (NTRS)

    Sundberg, Gale R.

    1990-01-01

    For over a decade NASA LeRC has been defining, demonstrating, and evaluating power electronic components and multi-kilowatt, multiply redundant, electrical power systems as part of OAST charter. Whether one considers aircraft (commercial transport/military), Space Station Freedom, growth station, launch vehicles, or the new Human Exploration Initiative, the conclusions remain the same: high frequency AC power distribution and control is superior to all other approaches for achieving a fast, smart, safe, versatile, and growable electrical power system that will meet a wide range of mission options. To meet the cost and operability goals of future aerospace missions that require significantly higher electrical power and longer durations, we must learn to integrate multiple technologies in ways that enhance overall system synergisms. The way NASA is doing business in space electric power is challenged and some approaches for evolving large space vehicles and platforms in well constructed steps to provide safe, ground testable, growable, smart systems that provide simple, replicative logic structures, which enable hardware and software verification, validation, and implementation are proposed. Viewgraphs are included.

  18. A combined uninterruptible power supply and dynamic voltage compensator using a flywheel energy storage system

    NASA Astrophysics Data System (ADS)

    Weissbach, Robert Stephen

    Due to recent technological advances in materials, power electronics, magnetic bearings and controls, the flywheel energy storage system has become a viable alternative to electrochemical batteries. The advantages of the flywheel system are its higher power density, insensitivity to environmental conditions, lack of hazardous materials and ease of checking the charge. One potential use is in a power distribution system. The flywheel energy storage system may be used as both an uninterruptible power supply as well as a means of dynamic voltage compensation to protect critical loads on radial distribution feeders. To perform dynamic voltage compensation, a comparison was performed which shows that the series injection of power is preferable to the shunt injection of power in utilizing the available kVA of the flywheel system motor/generator. The system was designed and modeled using the Electromagnetic Transients Program to ensure a proper dynamic response of the flywheel energy storage system in either mode of operation. The design incorporates a boost converter on the dc link to enable the load voltage to be maintained as the flywheel spins down. The same boost converter also allows for extended operation in the series compensation mode, by implementing a novel control scheme where sinusoidal pulse width modulation control is used for to compensate for smaller supply voltage dips, while the boost converter is used to control the compensation for larger supply voltage dips.

  19. Control design of three-level voltage source inverter for SMES power conditioning system

    Microsoft Academic Search

    Nikola Celanovic; Dong-Ho Lee; Dengming Peng; Dusan Borojevic; Fred C. Lee

    1999-01-01

    This paper describes the control design of the power processing system for superconductive magnetic energy storage (SMES). The proposed SMES power-processing system consists of series connection of a three-level voltage source inverter and a three-level chopper. The control design enables stable high-bandwidth control of power transfer to and from the SMES coil. The issues of series connection of power converters

  20. Control of voltage resonance type power supplies by an auxiliary switch

    Microsoft Academic Search

    Toshihiro Onodera; Toshiba Corp

    1991-01-01

    In variable-period output control of a voltage resonance-type converter, the minimum output power is obtained in the subclass-E mode and the maximum output power is obtained at such a duty ratio that the off-time is half the resonance period. In an example, the ration of the maximum output power to the minimum output power was 16:1. When the period was

  1. Characterization of voltage-gated sodium-channel blockers by electrical stimulation and fluorescence detection of membrane potential

    Microsoft Academic Search

    Chien-Jung Huang; Alec Harootunian; Michael P Maher; Catherine Quan; Christopher D Raj; Ken McCormack; Randal Numann; Paul A Negulescu; Jesús E González

    2006-01-01

    Voltage-gated ion channels regulate many physiological functions and are targets for a number of drugs. Patch-clamp electrophysiology is the standard method for measuring channel activity because it fulfils the requirements for voltage control, repetitive stimulation and high temporal resolution, but it is laborious and costly. Here we report an electro-optical technology and automated instrument, called the electrical stimulation voltage ion

  2. Electrical Power Generation by Mechanically Modulating Electrical Double Layers

    NASA Astrophysics Data System (ADS)

    Lee, Dongyun; Moon, Jong Kyun; Jeong, Jaeki; Pak, Hyuk Kyu

    2012-11-01

    Many objects in contact with a liquid acquire some electronic charges on their surfaces. These charges on the surface attract counter ions from the liquid phase. This complex system is called electrical double layer (EDL). Since its geometry and structure is similar to an electric capacitor, it is also called an electrical double layer capacitor (EDLC). In this work we studied two EDLCs formed in a liquid droplet bridge between two parallel solid conducting plates. We found that when the bridge height was mechanically modulated, each EDLC was continuously charged and discharged generating an AC electric current across the plates. The results of this experiment can be useful for constructing a micro-fluidic power generation.

  3. Power Requirements Determined for High-Power-Density Electric Motors for Electric Aircraft Propulsion

    NASA Technical Reports Server (NTRS)

    Johnson, Dexter; Brown, Gerald V.

    2005-01-01

    Future advanced aircraft fueled by hydrogen are being developed to use electric drive systems instead of gas turbine engines for propulsion. Current conventional electric motor power densities cannot match those of today s gas turbine aircraft engines. However, if significant technological advances could be made in high-power-density motor development, the benefits of an electric propulsion system, such as the reduction of harmful emissions, could be realized.

  4. Cogeneration of chemicals and electrical power

    SciTech Connect

    Vayenas, C.G.; Yentekakis, I.Y.; Neophytides, S. (Patras Univ. (Greece))

    1988-01-01

    This paper describes solid electrolyte fuel cell reactors with appropriate catalytic electrodes used for chemical cogeneration, i.e., for the simultaneous production of electrical power and useful chemicals. In this mode of operation the solid electrolyte cell serves both as a fuel cell and as a chemical reactor. The ratio of electrical power to heat generated and the total reactant conversion can be conveniently controlled by varying the external resistive load of the cell. Using silver and platinum based porous catalyst-electrodes, respectively, it was found that methanol can be converted to formaldehyde and H/sub 2/S can be quantitatively oxidized to SO/sub 2/ with simultaneous production of electrical energy. Experimental kinetic and power output results are compared with mathematical model predictions.

  5. Electric field and space charge of spherical electrode at high voltage concentric with a spherical grounded conductive target

    Microsoft Academic Search

    Ghaffar Kazkaz

    1996-01-01

    Point electrodes at high voltage are used in many diverse electrostatic particle charging and deposition applications, such as electrostatic liquid and powder coating, aerosol and ash filtrations, and pesticide spraying of agricultural crops. The electric field and the space charge generated by the high voltage electrode are important parameters for particle charging and particle deposition. To improve system design and

  6. Biological effects from electric fields associated with high voltage transmission lines

    SciTech Connect

    Not Available

    1983-11-01

    Efforts during the past year by the US Department of Energy and the Electric Power Research Institute-funded laboratories to investigate the biological effects from electric fields are described in resume form. Investigations generally have been summarized with objectives, accomplishments of the past year, and some indication of projected studies.

  7. Generation of voltage fluctuations in power systems with DC arc furnaces

    Microsoft Academic Search

    D. Stade; H. Schau; M. Malsch; J. Hunermund; S. Prinz

    1998-01-01

    There is an increasing use of high-power DC arc furnaces for scrap melting all over the world. Onsite measurements in several steel plants with these furnaces have shown that flicker relevant voltage fluctuations cannot be prevented. The first reason is the time-varying need of reactive power. Also dynamic compensators like TCRs are often not able to avoid considerable flicker, particularly

  8. Low-power technology mapping for FPGA architectures with dual supply voltages

    Microsoft Academic Search

    Deming Chen; Jason Cong; Fei Li; Lei He

    2004-01-01

    In this paper we study the technology mapping problem of FPGA architectures with dual supply voltages (Vdds) for power optimization. This is done with the guarantee that the mapping depth of the circuit will not increase compared to the circuit with a single Vdd. We first design a single-Vdd mapping algorithm that achieves better power results than the latest published

  9. Tolerable Limits of Voltage Fluctuations Produced by Magnets Pulsed Directly from Alternating Current Power Lines

    Microsoft Academic Search

    W. F. Praeg

    1969-01-01

    Switching magnets, for time sharing of beam lines, can be pulsed directly from the ac power line if it does not cause objectionable line voltage fluctuations (flicker). Switching circuits, which are less expensive and more reliable than conventional magnet power supplies are often all that are needed. Of particular interest for beam lines of the Zero Gradient Synchrotron (ZGS) was

  10. Power flow and transient stability models of FACTS controllers for voltage and angle stability studies

    Microsoft Academic Search

    C. A. Canizares

    2000-01-01

    This paper presents transient stability and power flow models of thyristor controlled reactor (TCR) and voltage sourced inverter (VSI) based flexible AC transmission system (FACTS) controllers. Models of the static VAr compensator (SVC), the thyristor controlled series compensator (TCSC), the static VAr compensator (STATCOM), the static synchronous source series compensator (SSSC), and the unified power flow controller (UPFC) appropriate for

  11. A low-power circuit for piezoelectric vibration control by synchronized switching on voltage sources

    E-print Network

    Paris-Sud XI, Université de

    A low-power circuit for piezoelectric vibration control by synchronized switching on voltage Accepted 18 April 2010 Available online 6 May 2010 Keywords: Piezoelectric Control Structural damping Semi-passive damping Energy harvesting a b s t r a c t In the paper, a vibration damping system powered by harvested

  12. Broadband Power Line Communications: The factors Influencing Wave Propagations in the Medium Voltage Lines

    Microsoft Academic Search

    Justinian Anatory; Nelson Theethayi; Mussa Kissaka; Nerey Mvungi

    2007-01-01

    This paper presents the influencing of load impedance, line length and branches on the performance of medium voltage power line communication (PLC) network. The power line network topology adopted here is similar to that of the system in Tanzania. Different investigation with regard to network load impedances, direct line length (from transmitter to receiver), branched line length and number of

  13. Statistical Study of Voltage Fluctuations in Power Connectors During Fretting Vibration

    Microsoft Academic Search

    Erwann Carvou; Noureddine Ben Jemaa

    2009-01-01

    It is well known that vibration of contact interfaces is the main cause of contact degradation by the so called fretting corrosion phenomenon. In fact the process of generating particles by mechanical wear produces an increase of contact voltage, frequently manifested by a high contact resistance in low power and signal connectors. In high power connectors, this degradation is expected

  14. Time evolution of electrical degradation under high-voltage stress in GaN high electron mobility transistors

    E-print Network

    Joh, Jungwoo

    In this work, we investigate the time evolution of electrical degradation of GaN high electron mobility transistors under high voltage stress in the OFF state. We found that the gate current starts to degrade first, followed ...

  15. ICT in distribution networks with wind power generation to improve voltage profiles

    Microsoft Academic Search

    V. Calderaro; V. Galdi; S. Raiti; A. Vaccaro

    2004-01-01

    Dispersed generation (DG) is today considered one of the most important openings for electric power systems in a liberalized energy market, able to join the increasing power demands and more and more pressing social and environmental constraints. In most cases, renewable power generation, such as wind power, solar power, or low head hydropower production, guarantees a low environmental impact and

  16. A Dual Voltage Power System by Battery\\/Supercapacitors Hybrid Configuration

    Microsoft Academic Search

    T. Mishima; Eiji Hiraki

    2005-01-01

    This paper explores a bidirectional DC-DC converter applied for a dual voltage power system using a battery and supercapacitors. The presented converter consists of a MOSFET full bridge topology on the primary side of the high frequency transformer and a current-fed push-pull topology on the secondary side. To reduce the device-conduction losses in the low voltage side of the converter,

  17. Wavelet analysis in transient based protection for power system high voltage transmission line

    Microsoft Academic Search

    Ming-Chao Xia; Yi-Zhuang Huang

    2010-01-01

    Transient Based Protection using the transient information of fault generated current signals of high voltage transmission line is a new direction of power system protection. According to the attenuation effects of high voltage transmission line and busbar capacitance to high-frequency current transients, differences of current transients at each end of the transmission line when in-zone faulted and out-zone faulted are

  18. Low-voltage infrared free-electron lasers based on gyrotron-powered RF wigglers

    Microsoft Academic Search

    Arne W. Fliflet; Wallace M. Manheimer; Phillip A. Sprangle

    1997-01-01

    Designs are presented for infrared free-electron lasers (FEL's) with gyrotron-powered electromagnetic wigglers and relatively low voltage electron beams. The use of an electromagnetic wiggler formed by a quasi-optical gyrotron, where the radiation is coupled into a corrugated waveguide, has the potential for substantial increases of FEL gain compared to an open mirror system. Designs for proof-of-principle low-voltage infrared FEL experiments

  19. Compensating the island network voltage unsymmetricity with DTC-modulation-based power conditioning system

    Microsoft Academic Search

    Antti Tarkiainen; Riku Pöllänen; Markku Niemelä; Juha Pyrhönen; Mikko Vertanen

    2004-01-01

    An algorithm for compensating island network voltage unsymmetricity with a direct torque control modulation-based scalar-controlled power conditioning system is introduced and experimentally verified. The proposed method consists of two separate stages where at first the unsymmetricity is detected and then a compensating negative-sequence system is calculated. Experimental results show that the proposed method fully compensates the voltage unsymmetricity resulting from

  20. Solid-state laser-pumped high-power electric-discharge HF laser

    SciTech Connect

    Velikanov, S D; Garanin, Sergey G; Kodola, B E; Komarov, Yu N; Shchurov, V V [Russian Federal Nuclear Center - The All-Russian Research Institute of Experimental Physics, Sarov, Nizhnii Novgorod region (Russian Federation); Efanov, V M; Efanov, M V; Yarin, P M ['FID Technology' Research and Production Association, St.Petersburg (Russian Federation); Kazantsev, S Yu; Kononov, I G; Firsov, K N [A M Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation); Domazhirov, A P; Podlesnykh, S V; Sivachev, A A

    2010-08-03

    We report the possibility of creating high-power nonchain electric-discharge HF lasers with an all-solid-state pump source. The maximum energy stored in the pump source capacitors based on solid-state FID-switches is 990 J for the open-circuit voltage of 240 kV. The pulse energy of 30 J is obtained in the hydrogen-containing SF{sub 6} mixture at the electric efficiency of the order of 3%. (lasers)

  1. Outline Introduction Literature Review Electric Power Supply Chains Empirical Examples Conclusions An Integrated Electric Power Supply Chain and Fuel

    E-print Network

    Nagurney, Anna

    Outline Introduction Literature Review Electric Power Supply Chains Empirical Examples Conclusions Introduction Literature Review Electric Power Supply Chains Empirical Examples Conclusions Support NSF to John F. Smith Memorial Professor Anna Nagurney) #12;Outline Introduction Literature Review Electric

  2. Solar Electric Propulsion (SEP) Tug Power System Considerations

    NASA Technical Reports Server (NTRS)

    Kerslake, Thomas W.; Bury, Kristen M.; Hojinicki, Jeffrey S.; Sajdak, Adam M.; Scheiddegger, Robert J.

    2011-01-01

    Solar electric propulsion (SEP) technology is truly at the "intersection of commercial and military space" as well as the intersection of NASA robotic and human space missions. Building on the use of SEP for geosynchronous spacecraft station keeping, there are numerous potential commercial and military mission applications for SEP stages operating in Earth orbit. At NASA, there is a resurgence of interest in robotic SEP missions for Earth orbit raising applications, 1-AU class heliocentric missions to near Earth objects (NEOs) and SEP spacecraft technology demonstrations. Beyond these nearer term robotic missions, potential future human space flight missions to NEOs with high-power SEP stages are being considered. To enhance or enable this broad class of commercial, military and NASA missions, advancements in the power level and performance of SEP technologies are needed. This presentation will focus on design considerations for the solar photovoltaic array (PVA) and electric power system (EPS) vital to the design and operation of an SEP stage. The engineering and programmatic pros and cons of various PVA and EPS technologies and architectures will be discussed in the context of operating voltage and power levels. The impacts of PVA and EPS design options on the remaining SEP stage subsystem designs, as well as spacecraft operations, will also be discussed.

  3. Engineering manual and electric powered wheelchairs.

    PubMed

    Cooper, R A

    1999-01-01

    The sophistication required to develop and properly configure a wheelchair is illustrated by the amount and complexity of the research being conducted. At this time there appears to be between 1.5 and 2.0 million full-time wheelchair users within the United States. The reliance of the user on the wheelchair and the amount of time in the wheelchair provide significant challenges for the wheelchair design engineer. Currently there are a wide variety of wheelchair designs that are commercially available. These wheelchairs accommodate a variety of people's needs, and represent significant progress. The current trend among manufacturers of manual wheelchairs seems to be cost-reduction engineering. The ergonomics of long-term wheelchair use are critical to the advancement of wheelchair design and to the clinical selection of wheelchairs. Electric powered wheelchairs appear to be progressing faster than nearly all other types of wheelchairs. This is due to the availability of computing power with low cost microcontrollers and associated peripherals. The greater range and availability of sensors are also making changes into the design of electric powered wheelchairs. The interaction between an electric powered wheelchair and the user can be extremely complex. In many cases, individual solutions are necessary. One of the more challenging questions is determining the abilities of the user required to drive an electric powered wheelchair effectively. There have been substantial improvements in the engineering of all wheelchairs. However, there remain significant issues to be addressed. PMID:10638849

  4. A combined compensation method for the output voltage of an insulated core transformer power supply

    SciTech Connect

    Yang, L.; Yang, J., E-mail: jyang@mail.hust.edu.cn; Liu, K. F.; Qin, B.; Chen, D. Z. [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2014-06-15

    An insulated core transformer (ICT) power supply is an ideal high-voltage generator for irradiation accelerators with energy lower than 3 MeV. However, there is a significant problem that the structure of the segmented cores leads to an increase in the leakage flux and voltage differences between rectifier disks. A high level of consistency in the output of the disks helps to achieve a compact structure by improving the utilization of both the rectifier components and the insulation distances, and consequently increase the output voltage of the power supply. The output voltages of the disks which are far away from the primary coils need to be improved to reduce their inhomogeneity. In this study, by investigating and comparing the existing compensation methods, a new combined compensation method is proposed, which increases the turns on the secondary coils and employs parallel capacitors to improve the consistency of the disks, while covering the entire operating range of the power supply. This method turns out to be both feasible and effective during the development of an ICT power supply. The non-uniformity of the output voltages of the disks is less than 3.5% from no-load to full-load, and the power supply reaches an output specification of 350 kV/60 mA.

  5. EEE 463 Electrical Power Plants (3) [F] Course (Catalog) Description

    E-print Network

    Zhang, Junshan

    EEE 463 Electrical Power Plants (3) [F] Course (Catalog) Description: Generation of electric power, energy sources. Power plant thermal cycle analysis. Cogeneration and combined cycles. Economics using fossil, nuclear and renewable, including solar, geothermal, wind, hydroelectric, biomass and ocean

  6. Time and Level Analysis of Contact Voltage Intermittences Induced by Fretting in Power Connector

    Microsoft Academic Search

    E. Carvou; N. Ben Jemaa

    2007-01-01

    It is well known that vibrations of contact interfaces are the main cause of contact degradation by the so called fretting corrosion phenomena. In fact the process of generated particles by mechanical wear produce either the increase of contact voltage accompanied with rapid fluctuations. The main objective of this work is to examine the electrical behaviour of contact interface under

  7. Cryogenic voltage withstand and heat transfer tests for the General Electric large coil turn heaters

    Microsoft Academic Search

    S. W. Schwenterly; C. M. Fitzpatrick; W. R. Court

    1981-01-01

    In order to assess the stability of the various Large Coil Program concepts, each of the three U.S.-made coils incorporates heaters to create a normal zone in the conductor. Based on results of finite-element heat transfer calculations, voltages in the neighborhood of 1 kV are needed to supply the required power over a half-turn. By comparing the results with room-temperature

  8. Miniaturized, low-voltage power converters with fast dynamic response

    E-print Network

    Giuliano, David (David Michael)

    2013-01-01

    This thesis introduces a two-stage architecture that combines the strengths of switched capacitor (SC) techniques (small size, light-load performance) with the high efficiency and regulation capability of switch-mode power ...

  9. Spin control by application of electric current and voltage in FeCo-MgO junctions.

    PubMed

    Suzuki, Yoshishige; Kubota, Hitoshi; Tulapurkar, Ashwin; Nozaki, Takayuki

    2011-09-28

    Efficient control and detection of spins are the most important tasks in spintronics. The current and voltage applied to a magnetic tunnel junction may exert a torque on the magnetic thin layer in the junction and cause its reversal or continuous precession. The discovery of the giant tunnelling magnetoresistance effect in ferromagnetic tunnelling junctions using an MgO barrier enabled us to obtain a large signal output from the magnetization reversal and precession. Also, the interplay of large spin configuration-electric conduction coupling provides highly nonlinear effects like the spin-torque diode effect. The negative resistance effect and amplification using it are predicted. A new discovery about a voltage-induced magnetic anisotropy change in Fe ultrathin films is also discussed. PMID:21859728

  10. High-fidelity optical reporting of neuronal electrical activity with an ultrafast fluorescent voltage sensor

    PubMed Central

    St-Pierre, François; Marshall, Jesse D; Yang, Ying; Gong, Yiyang; Schnitzer, Mark J; Lin, Michael Z

    2015-01-01

    Accurate optical reporting of electrical activity in genetically defined neuronal populations is a long-standing goal in neuroscience. Here we describe Accelerated Sensor of Action Potentials 1 (ASAP1), a novel voltage sensor design in which a circularly permuted green fluorescent protein is inserted within an extracellular loop of a voltage-sensing domain, rendering fluorescence responsive to membrane potential. ASAP1 demonstrates on- and off- kinetics of 2.1 and 2.0 ms, reliably detects single action potentials and subthreshold potential changes, and tracks trains of action potential waveforms up to 200 Hz in single trials. With a favorable combination of brightness, dynamic range, and speed, ASAP1 enables continuous monitoring of membrane potential in neurons at KHz frame rates using standard epifluorescence microscopy. PMID:24755780

  11. EMTP based stability analysis of Space Station Electric Power System in a test bed environment

    NASA Technical Reports Server (NTRS)

    Dravid, Narayan V.; Kacpura, Thomas J.; O'Connor, Andrew M.

    1992-01-01

    The Space Station Freedom Electric Power System (EPS) will convert solar energy into electric energy and distribute the same using an 'all dc', Power Management and Distribution (PMAD) System. Power conditioning devices (dc to dc converters) are needed to interconnect parts of this system operating at different nominal voltage levels. Operation of such devices could generate under damped oscillations (instability) under certain conditions. Criteria for instability are examined and verified for a single device. Suggested extension of the criteria to a system operation is examined by using the EMTP model of the PMAD dc test bed. Wherever possible, data from the test bed is compared with the modeling results.

  12. EMTP based stability analysis of space station electric power system in a test bed environment

    NASA Technical Reports Server (NTRS)

    Dravid, Narayan V.; Kacpura, Thomas J.; Oconnor, Andrew M.

    1992-01-01

    The Space Station Freedom Electric Power System (EPS) will convert solar energy into electric energy and distribute the same using an 'all dc', Power Management and Distribution (PMAD) System. Power conditioning devices (dc to dc converters) are needed to interconnect parts of this system operating at different nominal voltage levels. Operation of such devices could generate under damped oscillations (instability) under certain conditions. Criteria for instability are examined and verified for a single device. Suggested extension of the criteria to a system operation is examined by using the EMTP model of the PMAD DC test bed. Wherever possible, data from the test bed is compared with the modeling results.

  13. An earth-isolated optically coupled wideband high voltage probe powered by ambient light.

    PubMed

    Zhai, Xiang; Bellan, Paul M

    2012-10-01

    An earth-isolated optically-coupled wideband high voltage probe has been developed for pulsed power applications. The probe uses a capacitive voltage divider coupled to a fast light-emitting diode that converts high voltage into an amplitude-modulated optical signal, which is then conveyed to a receiver via an optical fiber. A solar cell array, powered by ambient laboratory lighting, charges a capacitor that, when triggered, acts as a short-duration power supply for an on-board amplifier in the probe. The entire system has a noise level ?0.03 kV, a DC-5 MHz bandwidth, and a measurement range from -6 to 2 kV; this range can be conveniently adjusted. PMID:23126786

  14. High voltage pulse power supply of piezoelectric transformer based on adaptive frequency tracking control

    NASA Astrophysics Data System (ADS)

    Guo, Ze-rong; Bai, Chun-yu; Li, Hua-bo

    2010-07-01

    The damage capacity of weapon systems is enhanced when all-electronic safety and arming device (ESAD) is applied, so that ESAD has been favored by the military power. ESAD must ensure the normal work in the stipulation of -40 °C ~ +60°C temperature. When high voltage pulse power supply of piezoelectric transformer (PT) is used in ESAD the charging time has the large dispersion and affects the striking capability of weapon systems. In order to control the inconsistency charging time due to environment temperature change the adaptive frequency tracking control system for high-voltage pulse power supply of PT is designed. Theoretical calculation of current lag angle under zero voltage switching condition for resonant current is derived. Sampling circuit and control circuit are designed by applying the phase-locked loop (PLL) control technology. Experiment results have proved that this control can ensure the consistency of converter output under different environment.

  15. A Consideration of Stable Operating Power Limits of HVDC System Composed of Voltage Source Converters

    NASA Astrophysics Data System (ADS)

    Konishi, Hiroo; Takahashi, Choei; Kishibe, Hideto; Sato, Hiromichi

    The stable operating power limits of a small scale HVDC system composed of voltage source converters (VSC-HVDC system) are analyzed with a simple model. The VSC-HVDC system could operate where the AC system must be somewhat larger in capacity than the VSC-HVDC system capacity. The stable operating power limits were between one and two times the SCR (short circuit ratio). When the inverter of the VSC-HVDC system was operated with lead reactive (capacitive) power control conditions, the stable operating limits were increased through AC voltage stabilization. When the inverter was a STATCOM operation, it could operate regardless of the SCR but regions within allowable AC voltage variations.

  16. Emerging Electric Power Systems and Future Grid

    NSDL National Science Digital Library

    Sen, P.K.

    This page provides a 2011 presentation on electric power systems and future grid by P.K. Sen, Colorado School of Mines, for ATEEC/CSM's Sustainable Energy Education and Training (SEET) Technology Workshop. This resource is free to download. Users must first create a login with ATEEC's website to access the file.

  17. Earthquake Triggering by High Power Electric Pulses

    Microsoft Academic Search

    Victor Novikov; Yuri Konev; Vladimir Zeigarnik

    2010-01-01

    The study carried out by the Joint Institute for High Temperatures in cooperation with the Institute of Physics of the Earth and the Research Station in Bishkek of Russian Academy of Sciences in 1999-2008 showed a response of weak seismicity at field experiments with electric pulsed power systems, as well as acoustic emission of rock specimens under laboratory conditions on

  18. Laser energy converted into electric power

    NASA Technical Reports Server (NTRS)

    Shimada, K.

    1973-01-01

    Apparatus verifies concepts of converting laser energy directly into electric energy. Mirror, placed in beam and inclined at angle to it, directs small amount of incident radiation to monitor which establishes precise power levels and other beam characteristics. Second mirror and condensing lens direct bulk of laser energy into laser plasmadynamic converter.

  19. Survey of aircraft electrical power systems

    NASA Technical Reports Server (NTRS)

    Lee, C. H.; Brandner, J. J.

    1972-01-01

    Areas investigated include: (1) load analysis; (2) power distribution, conversion techniques and generation; (3) design criteria and performance capabilities of hydraulic and pneumatic systems; (4) system control and protection methods; (5) component and heat transfer systems cooling; and (6) electrical system reliability.

  20. Force sensing control for electric powered wheelchairs

    Microsoft Academic Search

    Rory A. Cooper; Lana M. Widman; Daniel K. Jones; Rick N. Robertson

    2000-01-01

    People with many types of disabilities use electric powered wheelchairs (EPWs) for mobility. Excessive intention tremor, limited range of motion, athetoid motions, and spastic rigidity can reduce or prohibit the control over an EPW. This study focused on the design and testing of a newly developed isometric joystick (IJ) for EPW control. The IJ was tested against existing performance standards

  1. Radiant energy to electrical power conversion system

    Microsoft Academic Search

    Brunson

    1980-01-01

    A radiant energy to electrical power thermionic conversion system is disclosed that uses a transducer structure with very closely spaced cathode and anode elements in a vacuum to minimize space charge buildup and to optimize cross transfer of electrons from cathode to anode. The materials chosen are for a high work function high melt temperature cathode, tungsten for example with

  2. Technical evaluation report on the monitoring of electric power to the reactor-protection system for the Brunswick Steam Electric Plant, Units 1 and 2

    SciTech Connect

    Selan, J.C.

    1982-04-26

    This report documents the technical evaluation of the monitoring of electric power to the reactor protection system (RPS) at the Brunswick Steam Electric Plant, Units 1 and 2. The evaluation is to determine if the proposed design modification will protect the RPS from abnormal voltage and frequency conditions which could be supplied from the power supplies and will meet certain requirements set forth by the Nuclear Regulatory Commission. The proposed design modifications with time delays verified by GE, will protect the RPS from sustained abnormal voltage and frequency conditions from the supplying sources.

  3. Electric power divider of hybrid car propulsion systems

    Microsoft Academic Search

    Z. Cerovsky; P. Mindl

    2007-01-01

    The paper deals with the power splitting synchronous permanent magnet generator used in hybrid electric cars. The synchronous permanent magnet generator is special electric double rotor generator which acts as power divider. This special electric machine concentrates planetary gear and electric generator, known from other solutions, into one special electric double rotor machine. The paper deals with this new machine

  4. Generalized Bohm’s criterion and negative anode voltage fall in electric discharges

    SciTech Connect

    Londer, Ya. I.; Ul’yanov, K. N., E-mail: kulyanov@vei.ru [Lenin All-Russian Electrotechnical Institute (Russian Federation)

    2013-10-15

    The value of the voltage fall across the anode sheath is found as a function of the current density. Analytic solutions are obtained in a wide range of the ratio of the directed velocity of plasma electrons v{sub 0} to their thermal velocity v{sub T}. It is shown that the voltage fall in a one-dimensional collisionless anode sheath is always negative. At the small values of v{sub 0}/v{sub T}, the obtained expression asymptotically transforms into the Langmuir formula. Generalized Bohm’s criterion for an electric discharge with allowance for the space charge density ?(0), electric field E(0), ion velocity v{sub i}(0), and ratio v{sub 0}/v{sub T} at the plasma-sheath interface is formulated. It is shown that the minimum value of the ion velocity v{sub i}{sup *}(0) corresponds to the vanishing of the electric field at one point inside the sheath. The dependence of v{sub i}{sup *} (0) on ?(0), E(0), and v{sub 0}/v{sub T} determines the boundary of the existence domain of stationary solutions in the sheath. Using this criterion, the maximum possible degree of contraction of the electron current at the anode is determined for a short high-current vacuum arc discharge.

  5. Electric Power Research Institute: Journal Online

    NSDL National Science Digital Library

    Dietrich, David

    The Electric Power Research Institute (EPRI) produces an online journal that covers many important developments in power generation and distribution. Most of the articles deal with technological breakthroughs in this field; this can include, for example, environmental issues, energy efficiency, energy storage, and power plant operation. The EPRI journal is divided into six departments on the Web site. In the Field is a section that describes the latest applications and innovations at EPRI. The Discovery section looks more closely at the research conducted at the institute. Some of the articles may note a particular product available for purchase; however, all of them can be viewed without cost.

  6. Flex-gear electrical power transmission

    NASA Astrophysics Data System (ADS)

    Vranish, John; Peritt, Jonathan

    1993-09-01

    This study was conducted to develop an alternative way of transferring electricity across a continuously rotating joint, with little wear and the potential for low electrical noise. The problems with wires, slip rings, electromagnetic couplings, and recently invented roll-rings are discussed. Flex-gears, an improvement of roll-rings, are described. An entire class of flexgear devices is developed. Finally, the preferred flex-gear device is optimized for maximum electrical contact and analyzed for average mechanical power loss and maximum stress. For a device diameter of six inches, the preferred device is predicted to have a total electrical contact area of 0.066 square inches. In the preferred device, a small amount of internal sliding produces a 0.003 inch-pound torque that resists the motion of the device.

  7. Electric power steering system for vehicles

    SciTech Connect

    Shimizu, Y.; Kawai, T.

    1988-03-01

    An electric power steering system for vehicles is described comprising: an input shaft operatively connected to a steering wheel; an output shaft operatively connected to a steered wheel; an electric motor for operatively supplying auxiliary torque to the output shaft; steering torque detection means for detecting steering torque acting on the input shaft; driving control means for feeding the electric motor with a motor drive signal based on an output signal from the steering torque detecting means; steering angle detection means for detecting a steering angle of the steering wheel; and correction means for gradually decreasing the motor drive signal to reduce the auxiliary torque to be developed at the electric motor, when the steering angle of the steering wheel is detected to be exceeding a predetermined angle by the steering angle detection means, the predetermined angle being slightly less than a maximum steering angle of the steering wheel.

  8. Field emission electric propulsion power conditioning unit design concept, volume 1

    NASA Astrophysics Data System (ADS)

    Gasparini, A.; Devambez, F.; Valentian, D.

    The requirements for auxiliary and primary propulsion systems were investigated in order to define the requirements for the field emission electric propulsion power conditioning unit (PCU). Emphasis was placed on simplifying the PCU design and improving weight. The PCU consists of a central power and control module (CPCM) connected to several thruster dedicated power supply modules (TDPDM). The connections between the CPCM and the TDPDM the command and control philosophy, and the power components and power circuits are considered. The use of high inverter frequencies and optical fiber data transmission to aleviate high voltage insulation problems are addressed.

  9. Application of TCR-Type SVC in power substation and electric arc furnaces

    Microsoft Academic Search

    ZhongYuan Zhao; ChiHan Chen; ShunXian Bao; TaiXun Fang; XiaoHong Wang

    2010-01-01

    The situation at electric arc furnace factory is always severe containing voltage fluctuation and flicker, three-phase imbalance and low power factor. The dynamic var compensator is a good solution to this condition. The svc, with its continuously variable compensation, also safeguards the plant against overcompensation during furnace outages. The svc equipment, offered by NARI-RELAYS, presents a phase-wise open-loop reactive power

  10. Reduction of voltage violations at remote location by intelligent active and reactive power control of a DFIG based wind turbine

    Microsoft Academic Search

    Jean Patric da Costa; Peter Zacharias; Francisco Gafaro

    2011-01-01

    This paper presents a Doubly Fed Induction Generator (DFIG) with an intelligent active and reactive power control to support the operation in weak networks. The impact of a 850 kW DFIG based Wind Turbine on the voltage profile of a sample distribution feeder is analyzed. Then, the DFIG power capability is designed to support the grid voltage with reactive power

  11. Marine High Voltage Power Conditioning and Transmission System with Integrated Storage DE-EE0003640 Final Report

    SciTech Connect

    Frank Hoffmann, PhD; Aspinall, Rik

    2012-12-10

    Design, Development, and test of the three-port power converter for marine hydrokinetic power transmission. Converter provides ports for AC/DC conversion of hydrokinetic power, battery storage, and a low voltage to high voltage DC port for HVDC transmission to shore. The report covers the design, development, implementation, and testing of a prototype built by PPS.

  12. 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.

  13. A high-power high-voltage DC-DC converter for space applications

    SciTech Connect

    Weinberg, A.H.; Schreuders, J.

    1986-07-01

    The design details of a modular dc-dc converter used to power the main anode supply of a mercury-iron motor are presented. This motor, the RIT-35 built by Messerschmitt-Bolkow-Blohm (MBB), Germany, is used as the propulsion unit of a future Asteroid Gravity Optical and Radar Analysis (AGORA) mission. The design selected to cope with the high-voltage high-power conversion for space applications is shown, as well as the requirement to operate from an unregulated solar array with a voltage excursion of from 150 V at beginning-of-mission (BOM) to 240 V at end-of-mission (EOM).

  14. A high power high voltage dc/dc converter for space applications

    NASA Astrophysics Data System (ADS)

    Weinberg, A.; Schreuders, J.

    The design details of a modular dc/dc converter used to power the main anode supply of a mercury ion motor are presented. This motor, the RIT-35 built by M.B.B. Germany, is used as the propulsion unit of a future Asteroid Gravity Optical and Radar Analysis (AGORA) mission. This paper shows the design selected to cope with the high voltage, high power conversion for space applications and the requirement to operate from an unregulated solar array with a voltage excursion of from 150 volts beginning-of-mission (BOM) to 240 volts end-of-mission (EOM).

  15. Electromagnetic field model for the numerical computation of voltages induced on buried pipelines by high voltage overhead power lines

    NASA Astrophysics Data System (ADS)

    Munteanu, C.; Mates, G.; Purcar, M.; Topa, V.; Pop, I. T.; Grindei, L.; Racasan, A.

    2012-07-01

    This paper proposes an innovative, generally applicable numerical model for the calculation of the three-dimensional (3D) electromagnetic field generated by high voltage (HV) overhead power transmission lines (OHL) on the buried metallic structures (e.g., pipeline networks). The numerical analysis is based on a coupled finite element-boundary element model (FEM-BEM) designed to calculate the induced potential on buried pipelines for complex geometrical structures of HV OHL networks working on normal or fault conditions. The one-dimensional (1D) FEM technique based on pipe elements is used to discretize the mathematical model that describes the interior of the pipe and is coupled with the mathematical model that describes the exterior of the pipe using 3D-BEM integral equations. The full electromagnetic field model gives the flexibility to calculate the potential distribution in any point of the soil, providing useful information for the step and touching voltages. The computation accuracy of the numerical algorithm implemented is verified through two test problems by comparing the numerical results with those obtained using a software package based on the Transmission Line Method (TLM) and CIGRE formulae. Last part of the paper presents calculations of the induced potential on buried pipeline in the vicinity of a complex HV OHL working on normal and fault condition. The influence of the currents' direction and magnitude flowing on the HV OHL on the induced pipeline potential distribution is analyzed.

  16. Korea Electric Power flue gas desulfurization program

    SciTech Connect

    Choi, B.N. [Korea Electric Power Corp., Taejon (Korea, Republic of); Kim, B.H. [Korea Power Engineering Co. (Korea, Republic of); Altin, C.A. [Raytheon Engineers and Constructors, Inc., Norcross, GA (United States)

    1997-09-01

    Over the past 40 years, the Republic of Korea has developed a modern industrial economy, based on blending traditional manufacturing processes with high technology. As thy move into the next millennium, planning for sustained economic growth is essential to the national interest, requiring abundant, low-cost, environmentally safe and reliable electric power supplies. Accordingly, between 1995 and 2005, the Korea Electric Power Corporation (KEPCO), working through its subsidiary, the Korea Power engineering Company (KOPEC), will install over 35,000 MWs of new generating capacity to meet growing industrial and residential demands. Approximately 45% of this new generating capacity will rely on burning coal. Mindful that the burning of coal can have dramatic effects on the environment, the Republic of Korea has developed long-range governmental policies which support economic growth while protecting the environment.

  17. Power electronic interface circuits for batteries and ultracapacitors in electric vehicles and battery storage systems

    DOEpatents

    King, R.D.; DeDoncker, R.W.A.A.

    1998-01-20

    A method and apparatus for load leveling of a battery in an electrical power system includes a power regulator coupled to transfer power between a load and a DC link, a battery coupled to the DC link through a first DC-to-DC converter and an auxiliary passive energy storage device coupled to the DC link through a second DC-to-DC converter. The battery is coupled to the passive energy storage device through a unidirectional conducting device whereby the battery can supply power to the DC link through each of the first and second converters when battery voltage exceeds voltage on the passive storage device. When the load comprises a motor capable of operating in a regenerative mode, the converters are adapted for transferring power to the battery and passive storage device. In this form, resistance can be coupled in circuit with the second DC-to-DC converter to dissipate excess regenerative power. 8 figs.

  18. Power Flow Analysis and DC-Capacitor Voltage Regulation for the MMCC-DSCC

    NASA Astrophysics Data System (ADS)

    Fujita, Hideaki; Hagiwara, Makoto; Akagi, Hirofumi

    This paper discusses the power flow analysis and dc-capacitor voltage regulation for the modular multilevel cascaded converter (MMCC) based on double-star chopper cells (DSCC). This analysis reveals the relationship between the circulating current through the dc link and the mean power flowing out of or into each chopper cell. The dc component on the circulating current supplies a half of the active output power to the upper and lower strings of chopper cells, whereas the fundamental-frequency component transfers an amount of power between the upper and lower strings. Thus, the MMCC-DSCC can balance the capacitor voltages among the cells by controlling the amplitude of the fundamental-frequency component on the circulating current. A new control method based on the power flow analysis is employed, and its effectiveness is verified by circuit simulation.

  19. Modification of atmospheric DC fields by space charge from high-voltage power lines

    Microsoft Academic Search

    A. P. Fews; R. J. Wilding; P. A. Keitch; N. K. Holden; D. L. Henshaw

    2002-01-01

    Corona ion discharge is responsible for a flux of small ions emanating from an overhead power line capable of modifying the ambient electrical environment. The ensuing space charge can be detected as a change in magnitude of the earth's natural DC electric field at ground level. DC field mill meters were used to measure the vertical component of electric fields

  20. Auxiliary quasi-resonant dc tank electrical power converter

    DOEpatents

    Peng, Fang Z.

    2006-10-24

    An auxiliary quasi-resonant dc tank (AQRDCT) power converter with fast current charging, voltage balancing (or charging), and voltage clamping circuits is provided for achieving soft-switched power conversion. The present invention is an improvement of the invention taught in U.S. Pat. No. 6,111,770, herein incorporated by reference. The present invention provides faster current charging to the resonant inductor, thus minimizing delay time of the pulse width modulation (PWM) due to the soft-switching process. The new AQRDCT converter includes three tank capacitors or power supplies to achieve the faster current charging and minimize the soft-switching time delay. The new AQRDCT converter further includes a voltage balancing circuit to charge and discharge the three tank capacitors so that additional isolated power supplies from the utility line are not needed. A voltage clamping circuit is also included for clamping voltage surge due to the reverse recovery of diodes.

  1. Voltage regulated hybrid DC power source using supercapacitors as energy storage device

    Microsoft Academic Search

    Mohamed-Yacine Ayad; Serge Pierfederici; Stéphane Raël; Bernard Davat

    2007-01-01

    The management of embedded electrical energy needs a storage system with high dynamic performances in order to shave transient power peaks and to compensate for the intrinsic limitations of the main source. The use of supercapacitors for this storage system is quite suitable because of appropriate electrical characteristics (huge capacitance, weak series resistance, high specific energy, high specific power), direct

  2. Multifunctional Voltage Source Inverter for Renewable Energy Integration and Power Quality Conditioning

    PubMed Central

    Dai, NingYi; Lam, Chi-Seng; Zhang, WenChen

    2014-01-01

    In order to utilize the energy from the renewable energy sources, power conversion system is necessary, in which the voltage source inverter (VSI) is usually the last stage for injecting power to the grid. It is an economical solution to add the function of power quality conditioning to the grid-connected VSI in the low-voltage distribution system. Two multifunctional VSIs are studied in this paper, that is, inductive-coupling VSI and capacitive-coupling VSI, which are named after the fundamental frequency impedance of their coupling branch. The operation voltages of the two VSIs are compared when they are used for renewable energy integration and power quality conditioning simultaneously. The operation voltage of the capacitive-coupling VSI can be set much lower than that of the inductive-coupling VSI when reactive power is for compensating inductive loads. Since a large portion of the loads in the distribution system are inductive, the capacitive-coupling VSI is further studied. The design and control method of the multifunctional capacitive-coupling VSI are proposed in this paper. Simulation and experimental results are provided to show its validity. PMID:25177725

  3. Multifunctional voltage source inverter for renewable energy integration and power quality conditioning.

    PubMed

    Dai, NingYi; Lam, Chi-Seng; Zhang, WenChen

    2014-01-01

    In order to utilize the energy from the renewable energy sources, power conversion system is necessary, in which the voltage source inverter (VSI) is usually the last stage for injecting power to the grid. It is an economical solution to add the function of power quality conditioning to the grid-connected VSI in the low-voltage distribution system. Two multifunctional VSIs are studied in this paper, that is, inductive-coupling VSI and capacitive-coupling VSI, which are named after the fundamental frequency impedance of their coupling branch. The operation voltages of the two VSIs are compared when they are used for renewable energy integration and power quality conditioning simultaneously. The operation voltage of the capacitive-coupling VSI can be set much lower than that of the inductive-coupling VSI when reactive power is for compensating inductive loads. Since a large portion of the loads in the distribution system are inductive, the capacitive-coupling VSI is further studied. The design and control method of the multifunctional capacitive-coupling VSI are proposed in this paper. Simulation and experimental results are provided to show its validity. PMID:25177725

  4. MSFC Skylab electrical power systems mission evaluation

    NASA Technical Reports Server (NTRS)

    Woosley, A. P.

    1974-01-01

    The design, development, and operation of the Skylab electrical power system are discussed. The electrical systems for the airlock module of the orbital workshop and the Apollo telescope mount are described. Skylab is considered an integral laboratory, however, both cluster and module hardware distinct sections are included. Significant concept and requirement evolution, testing, and modifications resulting from tests are briefly summarized to aid in understanding the launch configuration description and the procedures and performance discussed for in-orbit operation. Specific problems encountered during Skylab orbital missions are analyzed.

  5. An ammeter that indicates electric current by the movement of a light spot, and voltage by the colour

    Microsoft Academic Search

    Masahiro Kamata; Chiho Hara

    2005-01-01

    A new type of ammeter (PikoPikoII) has been developed which indicates the measured current by the movement of a spot of light and the voltage by the colour of the spot. Since this tool can make students feel as if they are observing a visual image of electricity, it is easy to prepare schematic explanations on electric circuits that match

  6. Recent advances in the mitigation of AC voltages occurring in pipelines located close to electric transmission lines

    Microsoft Academic Search

    R. D. Southey; F. P. Dawalibi; W. Vukonich

    1994-01-01

    In joint-use corridors where both pipelines and AC electric transmission lines are present, a portion of the energy contained in the electromagnetic field surrounding the electric transmission lines is captured by each pipeline, resulting in induced AC voltages which vary in magnitude throughout the length of each pipeline. During a fault on any of the transmission lines, energization of the

  7. ACEEE Int. J. on Electrical and Power Engineering, Vol. 02, No. 01, Feb 2011 2011 ACEEE

    E-print Network

    Paris-Sud XI, Université de

    . The voltage provided by a voltage-source PWM inverter is always in quadrature to the STATCOM current-pulse Gate Turn-Off (GTO) thyristor voltage source converter for combined reactive power compensation employing 4 × 12-pulse voltage source converter [4] is realized and employed to regulate voltage in high-voltage

  8. High-voltage electrical apparatus utilizing an insulating gas of sulfur hexafluoride and helium

    DOEpatents

    Wootton, Roy E. (Murrysville, PA)

    1980-01-01

    High-voltage electrical apparatus includes an outer housing at low potential, an inner electrode disposed within the outer housing at high potential with respect thereto, and support means for insulatably supporting the inner electrode within the outer housing. Conducting particles contaminate the interior of the outer housing, and an insulating gas electrically insulates the inner electrode from the outer housing even in the presence of the conducting particles. The insulating gas is comprised of sulfur hexafluoride at a partial pressure of from about 2.9 to about 3.4 atmospheres absolute, and helium at a partial pressure from about 1.1 to about 11.4 atmospheres absolute. The sulfur hexafluoride comprises between 20 and 65 volume percent of the insulating gas.

  9. 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.

  10. Electrical properties of SnO2 ceramics for low voltage varistors

    NASA Astrophysics Data System (ADS)

    Glot, A. B.; Bulpett, R.; Ivon, A. I.; Gallegos-Acevedo, P. M.

    2015-01-01

    It is shown that an addition of bismuth oxide Bi2O3 (0.5 mol%) to the system SnO2-CoO-Nb2O5-Cr2O3 with small amounts of Nb2O5 and Cr2O3 (0.05 mol%) leads to a significant decrease in the electric field where a strong nonlinearity of the current-voltage characteristic takes place. This effect facilitates manufacture of ceramic materials for low voltage varistors with a relatively high nonlinearity coefficient of 15-20 and an electric field of 430 - 580 Vcm-1 (at a sintering temperature of 1300 °C) and, respectively, 11 and 287 Vcm-1 (at 1400 °C). The obtained experimental data indicate that ceramic materials in the system SnO2-CoO-Nb2O5-Cr2O3-Bi2O3 exhibit the typical structure of varistor ceramics with conductive grains of tin dioxide (SnO2) and highly resistive grain boundaries. In particular, the capacitance at 10 Hz and high dc bias becomes negative as in other SnO2 and ZnO varistors.

  11. Structural modification of proteins by direct electric current from low voltage.

    PubMed

    Calzia, Daniela; Panfoli, Isabella; Ravera, Silvia; Dazzi, Elisa; Gandolfo, Simona; Pepe, Isidoro Mario; Vergani, Laura; Morelli, Alessandro M

    2009-01-01

    The interaction of direct electric current (dc) and proteins is a little explored topic. We had reported that exposure of Crotalus atrox venom to dc caused irreversible inactivation of phospholipase A(2) and metalloprotease and that the eukaryote adenylate kinases (AK) precipitate in nondenaturing gel electrophoresis. AK1 displays an elevated percent difference of CHarged versus POlar amino acid content (CH-PO 14). Commercial AK1 and other 17 enzymes with various CH-PO values were exposed in solution to dc (0-0.7 mA) from low voltage (0-10 V), then enzymatic activity was assayed. The enzymes with CH-PO higher than 10.0 were irreversibly inactivated by current exposure; those with CH-PO between +3 and -5 were not. Inactivation was dependent on the ionic strength of the medium and not on the net charge of the protein. Circular dichroic spectroscopy showed a structural modification in some of the inactivated enzymes. CH-PO could be a crucial, although rough, parameter for predicting protein inactivation by low-voltage exposure. The observed effect seems due to the current density. Enzymatic activity maybe a more accurate sensor of conformational changes than circular dichroism spectroscopy. A better understanding of efficacy of many electrical devices utilized in medical practice may follow. PMID:19827034

  12. Cool-Water Immersion and High-Voltage Electric Stimulation Curb Edema Formation in Rats

    PubMed Central

    Mychaskiw, Anna M.; Mendel, Frank C.

    2003-01-01

    Objective: Although cryotherapy and high-voltage electric stimulation, both alone and in combination, are commonly applied to curb acute edema, little evidence from randomized controlled studies supports these procedures. Our purpose was to examine the effects of cool-water immersion (CWI) at 12.8°C (55°F), cathodal high-voltage pulsed current (CHVPC) at 120 pulses per second and 90% of visible motor threshold, and the combination of CWI and CHVPC (CWI + CHVPC) on edema formation after impact injury to the hind limbs of rats. Design and Setting: Both feet of 34 rats were traumatized after hind-limb volumes were determined. Animals were randomly assigned to 1 of 3 groups: CWI (n = 10), CHVPC (n = 10), or CWI + CHVPC (n = 14). One randomly selected hind limb of each rat was exposed to four 30-minute treatments, interspersed with four 30-minute rest periods beginning immediately after posttraumatic limb volumes were determined. Contralateral limbs served as controls. Limbs remained dependent during all treatments, rest periods, and volumetric measurements. Subjects: We used 34 anesthetized Zucker Lean rats in this study. Measurements: We measured limb volumes immediately before and after trauma and after each of 4 treatment and rest periods. Results: Volumes of treated limbs of all 3 experimental groups were smaller (P < .05) than those of untreated limbs. No treatment was more effective than another. Conclusions: Cool-water immersion, cathodal high-voltage electric stimulation, and simultaneous application of these treatments were effective in curbing edema after blunt injury. Combining CWI and CHVPC was not more effective than either CWI or CHVPC alone. PMID:14608432

  13. Advanced Power Electronics and Electric Motors Annual Report -- 2013

    SciTech Connect

    Narumanchi, S.; Bennion, K.; DeVoto, D.; Moreno, G.; Rugh, J.; Waye, S.

    2015-01-01

    This report describes the research into advanced liquid cooling, integrated power module cooling, high temperature air cooled power electronics, two-phase cooling for power electronics, and electric motor thermal management by NREL's Power Electronics group in FY13.

  14. Fuzzy logic in voltage and reactive power control in regulated and deregulated environments

    Microsoft Academic Search

    P. Ya. Ekel; L. D. B. Terra; M. F. D. Junges; F. J. A. de Oliveira; A. Melek; T. Y. Taguti

    2001-01-01

    This paper presents results of research aimed at improving the efficiency of coordinated on-line control of voltage and reactive power on the basis of developing models, methods, and a control system integrating traditional numerical methods with fuzzy logic technology. An approach based on experimental design is applied to construct diverse types of sensitivity indices, which serve for evaluating efficiency of

  15. Transient Stability using Energy Function Method in Power Systems Close to Voltage Collapse

    Microsoft Academic Search

    Manfred F. Bedriñana; V. Leonardo Paucar; Carlos A. Castro

    2007-01-01

    In this paper, the direct methods performance, based in energy functions, are analyzed for transient stability of power systems close to voltage collapse. These cases were simulated, increasing the loading close to maximum loading point (MLP) values. According the obtained results, in potential energy boundary surface (PEBS) method, unstable equilibrium point (UEP) were computed and the interaction resultant was shown

  16. Design and Fabrication of Ultralight High-Voltage Power Circuits for Flapping-Wing Robotic Insects

    E-print Network

    Wood, Robert

    Design and Fabrication of Ultralight High-Voltage Power Circuits for Flapping-Wing Robotic Insects@seas.harvard.edu Abstract-- Flapping-wing robotic insects are small, highly ma- neuverable flying robots inspired by biological insects and useful for a wide range of tasks, including exploration, environmen- tal monitoring

  17. Voltage and power limitations of generation systems with uncontrolled PMSMs and DC\\/DC converters

    Microsoft Academic Search

    Zhu Lei; Wen Xuhui; Zhao Feng; Yao Yi

    2011-01-01

    Uncontrolled Generation (UCG) systems can be used in vehicles for their low cost and high reliability. This paper analyzes the output characteristics of UCG taking parameters and speed into consideration. New normalization method is used to simplify the analysis and the calculation. The voltage and power limitations are calculated in the normalized frame which is independent to the machine parameters.

  18. Real-Time Dynamic Voltage Scaling for Low-Power Embedded Operating Systems

    Microsoft Academic Search

    Padmanabhan Pillai; Kang G. Shin

    2001-01-01

    In recent years, there has been a rapid and wide spread of non-traditional computing platforms, especially mobile and portable computing devices. As applications become increasingly sophisticated and processing power increases, the most serious limitation on these devices is the available battery life. Dynamic Voltage Scaling (DVS) has been a key technique in exploiting the hardware characteristics of processors to reduce

  19. Fast estimation of voltage and current phasors in power networks using an adaptive neural network

    Microsoft Academic Search

    P. K. Dash; S. K. Panda; B. Mishra; D. P. Swain

    1997-01-01

    A new algorithm for the estimation of parameters of voltage or current waveform of power networks contaminated by noise is proposed. The problem of estimation is formulated by using an adaptive neural network consisting of linear adaptive neurons called adaline. The learning parameters of the adaline are adjusted to force the error between the actual and desired outputs to satisfy

  20. Method for reducing fuel cell output voltage to permit low power operation

    DOEpatents

    Reiser, Carl A. (Glastonbury, CT); Landau, Michael B. (West Hartford, CT)

    1980-01-01

    Fuel cell performance is degraded by recycling a portion of the cathode exhaust through the cells and, if necessary, also reducing the total air flow to the cells for the purpose of permitting operation below a power level which would otherwise result in excessive voltage.