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1

Voltage, energy and power in electric circuits  

E-print Network

Voltage, energy and power in electric circuits Science teaching unit #12;Disclaimer The Department-2008DVD-EN Voltage, energy and power in electric circuits #12;#12;© Crown copyright 2008 1The National Strategies | Secondary Voltage, energy and power in electric circuits 00094-2008DVD-EN Contents Voltage

Berzins, M.

2

Electric current flow through human skin at power frequency voltages  

PubMed Central

Carter, A.O., and Morley R. (1969).Brit. J. industr. Med.,26, 217-223. Electric current flow through human skin at power frequency voltages. Alternating power voltages were applied to small pieces of living skin. Current and voltage were recorded continuously using voltages from 25 V to 250 V. At the lower voltages the skin appeared unaffected, but rapid destruction occurred at the higher voltages. It is concluded that skin impedance, whilst being extremely variable on account of many physical factors, is dependent on voltage and time of application in the range where dangerous electric shock occurs to human beings at power frequencies. PMID:5794946

Carter, A. O.; Morley, R.

1969-01-01

3

High Power, High Voltage Electric Power System for Electric Propulsion  

NASA Technical Reports Server (NTRS)

This paper provides an overview of the 30 KW, 600 V MRHE power subsystem. Descriptions of the power subsystem elements, the mode of power transfer, and power and mass estimates are presented. A direct-drive architecture for electric propulsion is considered which reduces mass and complexity. Solar arrays with concentrators are used for increased efficiency. Finally, the challenges due to the environment of a hypothetical lunar mission as well as due to the advanced technologies considered are outlined.

Aintablian, Harry; Kirkham, Harold; Timmerman, Paul

2006-01-01

4

Investigations of voltage flicker in electric arc furnace power systems  

Microsoft Academic Search

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

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

1996-01-01

5

Online Monitoring of the Electrical Power Transfer Stability and Voltage Profile Stability Margins in Electric Power Transmission Systems Using Phasor Measurement Units Data Sets  

Microsoft Academic Search

An innovative method to monitor the electric power transfer stability on power transmission paths and the voltage profile stability at the power systems nodes in real time modus is proposed. Based on the laws of electric circuit theory, the transfer operating mode of each relevant transmission line is formulated in an active power-voltage PV characteristic. The relevant transmission line parameters

Yves Nguegan; Albert Claudi; Carsten Strunge

2009-01-01

6

Characteristic Analysis of Temperature Sensor in Dynamic Capacity Increase of High Voltage Electric Power Transmission Lines  

Microsoft Academic Search

Dynamic capacity increase in high voltage electric power transmission line is currently the most economical method for solving electric power transmission bottleneck nowadays. Temperature measurement error of the transmission line will affect the calculated current capacity of the transmission line. In this paper, conductor temperature model was applied to analyze the influence of the measurement error on the maximum current

Yuan Dai; Anqi Song; Wei Wang; Yangchun Cheng; Yongchun Liang; Jianliang Kong; Kai Xiao; Yuning Zhang

2012-01-01

7

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

Microsoft Academic Search

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

F. Kajiyama; Y. Nakamura

1999-01-01

8

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

Microsoft Academic Search

\\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

S. Leirens; R. R. Negenborn

9

Effect of induced alternating current voltage on cathodically protected pipelines paralleling electric power transmission lines  

SciTech Connect

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 of CP was obtained after field testing for 1 year, when probes were removed to ascertain corrosion rates.

Kajiyama, F.; Nakamura, Y. [Tokyo Gas Co., Ltd. (Japan). Fundamental Technology Research Lab.

1999-02-01

10

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

NASA Technical Reports Server (NTRS)

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.

Kerslake, Thomas W.

2003-01-01

11

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

SciTech Connect

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.

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

1994-11-01

12

Generating Electrical Voltage  

NSDL National Science Digital Library

This interactive resource adapted from the Wisconsin Online Resource Center illustrates how electrical voltage is generated through a process called magnetic induction and describes some of the factors that affect the magnitude of the voltage produced.

2009-12-08

13

Characterization of vertical electric fields and associated voltages induced on a overhead power line from close artificially initiated lightning  

NASA Technical Reports Server (NTRS)

Measurements were characterized of simultaneous vertical electric fields and voltages induced at both ends of a 448 m overhead power line by artificially initiated lightning return strokes. The lightning discharges struck ground about 20 m from one end of the line. The measured line voltages could be grouped into two categories: those in which multiple, similarly shaped, evenly spaced pulses were observed, which are called oscillatory; and those dominated by a principal pulse with subsidiary oscillations of much smaller amplitude, which are called impulsive. Voltage amplitudes range from tens of kilovolts for oscillatory voltages to hundreds of kilovolts for impulsive voltages.

Rubinstein, Marcos; Uman, Martin A.; Thomson, Ewen M.; Medelius, Pedro J.

1991-01-01

14

Load insensitive electrical device. [power converters for supplying direct current at one voltage from a source at another voltage  

NASA Technical Reports Server (NTRS)

A class of power converters is described for supplying direct current at one voltage from a source at another voltage. It includes a simple passive circuit arrangement of solid-state switches, inductors, and capacitors by which the output voltage of the converter tends to remain constant in spite of changes in load. The switches are sensitive to the current flowing in the circuit and are employed to permit the charging of capacitance devices in accordance with the load requirements. Because solid-state switches (such as SCR's) may be used with relatively high voltage and because of the inherent efficiency of the invention that permits relatively high switching frequencies, power supplies built in accordance with the invention, together with their associated cabling, can be substantially lighter in weight for a given output power level and efficiency of operation than systems of the prior art.

Schwarz, F. C. (inventor)

1974-01-01

15

Feasibility of power electronic converters for low-voltage (42 V) SRM drives in mildly hybrid electric traction systems  

Microsoft Academic Search

The more electric car (MEC) concept emphasizes utilizing electrical power to drive more automotive conventional systems and to facilitate new introduced luxury loads. Improving fuel economy, emissions, reliability, and comfort are the main motivations towards the MEC concept, which necessitates going to a higher system voltage such as the proposed 42 V. This paper presents that the 42 V system

Ali Emadi

2001-01-01

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

High-Voltage Closing Switches Using Vacuum Electric Breakdown for Pulsed-Power Applications  

Microsoft Academic Search

In our previous research, a high-voltage vacuum closing switch has been proposed to synchronize the output pulses delivered from multiple parallel plasma opening switch modules to the load in a scheme of power conditioning of a generator of high-power nanosecond pulses. However, the breakdown voltage for each stage of the closing switch has to be increased to 150-300 kV to

Georgy I. Dolgachev; Andrey G. Ushakov

2007-01-01

18

Voltage profile program for the Kennedy Space Center electric power distribution system  

NASA Technical Reports Server (NTRS)

The Kennedy Space Center voltage profile program computes voltages at all busses greater than 1 Kv in the network under various conditions of load. The computation is based upon power flow principles and utilizes a Newton-Raphson iterative load flow algorithm. Power flow conditions throughout the network are also provided. The computer program is designed for both steady state and transient operation. In the steady state mode, automatic tap changing of primary distribution transformers is incorporated. Under transient conditions, such as motor starts etc., it is assumed that tap changing is not accomplished so that transformer secondary voltage is allowed to sag.

1976-01-01

19

Environmental justice: a contrary finding for the case of high-voltage electric power transmission lines.  

PubMed

Environmental justice is the consideration of whether minority and/or lower-income residents in a geographic area are likely to have disproportionately higher exposures to environmental toxins than those living elsewhere. Such situations have been identified for a variety of factors, such as air pollution, hazardous waste, water quality, noise, residential crowding, and housing quality. This study investigates the application of this concept to high-voltage electric power transmission lines (HVTL), which some perceive as a health risk because of the magnetic fields they generate, and also as esthetically unpleasing. We mapped all 345 kV and higher voltage HVTL in New York State and extracted and summarized proximate US Census sociodemographic and housing characteristic data into four categories on the basis of distances from HVTL. Contrary to our expectation, people living within 2000 ft from HVTL were more likely to be exposed to magnetic fields, white, of higher income, more educated and home owners, than those living farther away, particularly in urban areas. Possible explanations for these patterns include the desire for the open space created by the rights-of-way, the preference for new homes/subdivisions that are often located near HVTL, and moving closer to HVTL before EMFs were considered a risk. This study suggests that environmental justice may not apply to all environmental risk factors and that one must be cautious in generalizing. In addition, it shows the utility of geographical information system methodology for summarizing information from extremely large populations, often a challenge in epidemiology. PMID:19352413

Wartenberg, Daniel; Greenberg, Michael R; Harris, Gerald

2010-05-01

20

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

NASA Astrophysics Data System (ADS)

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.

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

21

Electrical aging markers for EPR-based low-voltage cable insulation wiring of nuclear power plants  

NASA Astrophysics Data System (ADS)

This paper presents results of electrical property measurements on EPR-based insulations of low-voltage power cables used in nuclear power plants. The specimens underwent accelerated aging through the simultaneous application of high temperature and gamma-radiation. Mechanical properties and the dielectric response at different frequencies were investigated. Results showed significant variation of the electrical and mechanical properties of aged cables at low frequencies, i.e. lower than 10-2 Hz. In particular, the real and imaginary parts of permittivity increase with aging time, accumulated dose and stress levels applied showing good correlation with elongation at break, which decreases as a function of extent of insulation aging.

Verardi, L.; Fabiani, D.; Montanari, G. C.

2014-01-01

22

The irrelevance of electric power system dynamics for the loading margin to voltage collapse and its sensitivities  

NASA Astrophysics Data System (ADS)

The loading margin to a saddle-node or fold bifurcation measures the proximity to voltage collapse blackouts of electric power transmission systems. Sensitivities of the loading margin can be used to select controls to avoid voltage collapse. We analytically justify the use of static models to compute loading margins and their sensitivities and explain how the results apply to underlying dynamic models. The relation between fold bifurcations of the static models and saddle-node bifurcations of the underlying dynamic models is clarified.

Dobson, Ian

23

How to reduce radio interference from high-voltage electric power transmission lines  

Microsoft Academic Search

Data from measurements of the radio frequency interference from overhead electric power transmission lines are presented. The quality of radio broadcast and television reception and expansion of reliable reception zones are emphasized.

V. V. Kapitonov; Y. M. Abramson

1978-01-01

24

Voltage correction power flow  

SciTech Connect

A method for power flow solution of weakly meshed distribution and transmission networks is presented. It is based on oriented ordering of network elements. That allows an efficient construction of the loop impedance matrix and rational organization of the processes such as: power summation (backward sweep), current summation (backward sweep) and node voltage calculation (forward sweep). The first step of the algorithm is calculation of node voltages on the radial part of the network. The second step is calculation of the breakpoint currents. Then, the procedure continues with the first step, which is preceded by voltage correction. It is illustrated that using voltage correction approach, the iterative process of weakly meshed network voltage calculation is faster and more reliable.

Rajicic, D.; Ackovski, R.; Taleski, R. (Univ. Sv. Kiril i Metodij'', Skopje, Macedonia (Greece). Dept. of Electrical Engineering)

1994-04-01

25

High voltage power supply  

NASA Technical Reports Server (NTRS)

A high voltage power supply is formed by three discrete circuits energized by a battery to provide a plurality of concurrent output signals floating at a high output voltage on the order of several tens of kilovolts. In the first two circuits, the regulator stages are pulse width modulated and include adjustable ressistances for varying the duty cycles of pulse trains provided to corresponding oscillator stages while the third regulator stage includes an adjustable resistance for varying the amplitude of a steady signal provided to a third oscillator stage. In the first circuit, the oscillator, formed by a constant current drive network and a tuned resonant network included a step up transformer, is coupled to a second step up transformer which, in turn, supplies an amplified sinusoidal signal to a parallel pair of complementary poled rectifying, voltage multiplier stages to generate the high output voltage.

Ruitberg, A. P.; Young, K. M. (inventors)

1985-01-01

26

Electrical system architecture having high voltage bus  

DOEpatents

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.

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

2011-03-22

27

Aircraft Electric Secondary Power  

NASA Technical Reports Server (NTRS)

Technologies resulted to aircraft power systems and aircraft in which all secondary power is supplied electrically are discussed. A high-voltage dc power generating system for fighter aircraft, permanent magnet motors and generators for aircraft, lightweight transformers, and the installation of electric generators on turbine engines are among the topics discussed.

1983-01-01

28

High voltage DC power supply  

DOEpatents

A high voltage DC power supply having a first series resistor at the output for limiting current in the event of a short-circuited output, a second series resistor for sensing the magnitude of output current, and a voltage divider circuit for providing a source of feedback voltage for use in voltage regulation is disclosed. The voltage divider circuit is coupled to the second series resistor so as to compensate the feedback voltage for a voltage drop across the first series resistor. The power supply also includes a pulse-width modulated control circuit, having dual clock signals, which is responsive to both the feedback voltage and a command voltage, and also includes voltage and current measuring circuits responsive to the feedback voltage and the voltage developed across the second series resistor respectively. 7 figs.

Droege, T.F.

1989-12-19

29

High voltage DC power supply  

DOEpatents

A high voltage DC power supply having a first series resistor at the output for limiting current in the event of a short-circuited output, a second series resistor for sensing the magnitude of output current, and a voltage divider circuit for providing a source of feedback voltage for use in voltage regulation is disclosed. The voltage divider circuit is coupled to the second series resistor so as to compensate the feedback voltage for a voltage drop across the first series resistor. The power supply also includes a pulse-width modulated control circuit, having dual clock signals, which is responsive to both the feedback voltage and a command voltage, and also includes voltage and current measuring circuits responsive to the feedback voltage and the voltage developed across the second series resistor respectively.

Droege, Thomas F. (Batavia, IL)

1989-01-01

30

An intelligent on line voltage regulation in power distribution system  

Microsoft Academic Search

In a reliable power system one of the most important requirements is to maintain the voltage at consumer premises within permissible ranges to ensure high quality of customer service. Since the voltage profile is consistently varied by load fluctuations hence it should be controlled by voltage regulators. Voltage stability and power quality of electrical systems depend on the proper voltage

Shrabani Pal; Sudipta Nath

2010-01-01

31

Electrical safety for high voltage arrays  

NASA Technical Reports Server (NTRS)

A number of key electrical safety requirements for the high voltage arrays of central station photovoltaic power systems are explored. The suitability of representative industrial DC power switchgear for control and fault protection was evaluated. Included were AC/DC circuit breakers, electromechanical contactors and relays, load interruptors, cold disconnect devices, sectionalizing switches, and high voltage DC fuses. As appropriate, steady state and transient characteristics were analyzed. Failure modes impacting upon operation and maintenance safety were also identified, as were the voltage withstand and current interruption levels.

Marshall, N. A.

1983-01-01

32

Spacecraft high-voltage power supply construction  

NASA Technical Reports Server (NTRS)

The design techniques, circuit components, fabrication techniques, and past experience used in successful high-voltage power supplies for spacecraft flight systems are described. A discussion of the basic physics of electrical discharges in gases is included and a design rationale for the prevention of electrical discharges is provided. Also included are typical examples of proven spacecraft high-voltage power supplies with typical specifications for design, fabrication, and testing.

Sutton, J. F.; Stern, J. E.

1975-01-01

33

Output voltage regulation in matrix converter fed power electronic transformer for power systems application in electric ship  

Microsoft Academic Search

The system described in this paper uses three matrix converters and a high frequency transformer to achieve isolation and voltage transformation from primary to secondary side. Two matrix converters produce high frequency voltage across a transformer, with open ended primary. A third matrix converter converts the high frequency chopped voltage to line frequency. The non-idealities such as leakage inductance of

Shabari Nath; K. K. Mohapatra; Ned Mohan

2009-01-01

34

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)

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.

Sulaeman, M. Y.; Widita, R.

2014-09-01

35

Packaging of high voltage power semiconductor modules  

NASA Astrophysics Data System (ADS)

As the breakdown voltage capability of power semiconductor devices increases, new methods have become necessary to facilitate these devices in the packaging of high voltage power semiconductor modules. Silicon carbide has been hailed as one of the successors to silicon power semiconductor devices due to its wide bandgap, low on-state resistance, and high operating temperature, among others. As the breakdown voltage of the next generation of silicon carbide devices pass the 10kV threshold, new packaging schemes must be utilized to take full advantage of these devices. This thesis investigates a direct attachment packaging scheme and the use of benzocyclobutene (BCB) as a substrate passivation layer for the high-voltage silicon carbide power module. A discussion on the physics of breakdown through gasses and solids is presented as well as simulations for determining electric field strength in a high voltage module. The processing steps required to coat a direct bond copper substrate with BCB are detailed in addition to materials selection and fabrication procedures necessary to construct the final high voltage module. Final testing resulted in a module capable of blocking up to 6.3 kV without failure.

Evans, Tristan

36

Electric Double-Layer Capacitors Applying to Voltage Sag Compensator  

NASA Astrophysics Data System (ADS)

Recently the electric double-layer capacitor (EDLC) which is rapidly charged and discharged and offers long life, maintenance-free, has been developed as a new energy storage element. Therefore, we developed the uninterruptible power supply as voltage sag compensator utilizing EDLC. This paper describes an abstract of EDLC and applying to voltage sag compensation.

Nara, Hidetaka

37

High voltage photovoltaic power converter  

DOEpatents

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.

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

2001-01-01

38

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)

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.

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

2014-01-01

39

Electric power trends  

SciTech Connect

This book provides information about the forces shaping the electric power industry. It provides data on trends in the electric power industry, such as: electric utility ownership; sources of energy; industrial electricity demand; manufacturing energy for heat and power; fossil fuels consumed in electric power generation; electric power transmission; nuclear power plant generators; and residential energy consumption.

Not Available

1989-01-01

40

High Voltage Power Transmission for Wind Energy  

NASA Astrophysics Data System (ADS)

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.

Kim, Young il

41

Wind Power Plant Voltage Stability Evaluation: Preprint  

SciTech Connect

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.

Muljadi, E.; Zhang, Y. C.

2014-09-01

42

Living and Working Safely Around High-Voltage Power Lines.  

SciTech Connect

High-voltage transmission lines can be just as safe as the electrical wiring in the homes--or just as dangerous. The crucial factor is ourselves: they must learn to behave safely around them. This booklet is a basic safety guide for those who live and work around power lines. It deals primarily with nuisance shocks due to induced voltages, and with potential electric shock hazards from contact with high-voltage lines. References on possible long-term biological effects of transmission lines are shown. In preparing this booklet, the Bonneville Power Administration has drawn on more than 50 years of experience with high-voltage transmission. BPA operates one of the world`s largest networks of long-distance, high-voltage lines. This system has more than 400 substations and about 15,000 miles of transmission lines, almost 4,400 miles of which are operated at 500,000 volts.

United States. Bonneville Power Administration.

2001-06-01

43

Developments in Electric Power Transmission  

Microsoft Academic Search

A brief account of some significant events in the history of electric power transmission related by a past-president of the Institute whose name is closely linked with many of those events and who for many years has been actively engaged in the study of high voltage phenomena.

Harris J. Ryan

1934-01-01

44

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

E-print Network

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

Lehman, Brad

45

TOPEX electrical power system  

NASA Technical Reports Server (NTRS)

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.

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

1991-01-01

46

Electric fingerprint of voltage sensor domains.  

PubMed

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

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

2014-12-01

47

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

NASA Technical Reports Server (NTRS)

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.

Vazquez Carazo, Alfredo (Inventor)

2006-01-01

48

An improved voltage control on large-scale power system  

SciTech Connect

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

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

1996-08-01

49

Strong and Weak Electric Field Interfering: Capacitive Icing Detection and Capacitive Energy Harvesting on a 220kV High-Voltage Overhead Power Line  

Microsoft Academic Search

This paper focuses on problems which arise when both a power-harvesting system based on a capacitive princi- ple and a capacitive measurement device (i.e., a capacitance-to- digital converter (CDC)) are used in one electronic system to build up an autonomous measurement device for icing detection on a high-voltage overhead power line. The overall capacitance of the measurement circuitry between the

Michael J. Moser; Thomas Bretterklieber; Hubert Zangl; Georg Brasseur

2011-01-01

50

Low power, scalable multichannel high voltage controller  

DOEpatents

A low voltage control circuit is provided for individually controlling high voltage power provided over bus lines to a multitude of interconnected loads. An example of a load is a drive for capillary channels in a microfluidic system. Control is distributed from a central high voltage circuit, rather than using a number of large expensive central high voltage circuits to enable reducing circuit size and cost. Voltage is distributed to each individual load and controlled using a number of high voltage controller channel switches connected to high voltage bus lines. The channel switches each include complementary pull up and pull down photo isolator relays with photo isolator switching controlled from the central high voltage circuit to provide a desired bus line voltage. Switching of the photo isolator relays is further controlled in each channel switch using feedback from a resistor divider circuit to maintain the bus voltage swing within desired limits. Current sensing is provided using a switched resistive load in each channel switch, with switching of the resistive loads controlled from the central high voltage circuit.

Stamps, James Frederick (Livermore, CA); Crocker, Robert Ward (Fremont, CA); Yee, Daniel Dadwa (Dublin, CA); Dils, David Wright (Fort Worth, TX)

2006-03-14

51

Low power, scalable multichannel high voltage controller  

DOEpatents

A low voltage control circuit is provided for individually controlling high voltage power provided over bus lines to a multitude of interconnected loads. An example of a load is a drive for capillary channels in a microfluidic system. Control is distributed from a central high voltage circuit, rather than using a number of large expensive central high voltage circuits to enable reducing circuit size and cost. Voltage is distributed to each individual load and controlled using a number of high voltage controller channel switches connected to high voltage bus lines. The channel switches each include complementary pull up and pull down photo isolator relays with photo isolator switching controlled from the central high voltage circuit to provide a desired bus line voltage. Switching of the photo isolator relays is further controlled in each channel switch using feedback from a resistor divider circuit to maintain the bus voltage swing within desired limits. Current sensing is provided using a switched resistive load in each channel switch, with switching of the resistive loads controlled from the central high voltage circuit.

Stamps, James Frederick (Livermore, CA); Crocker, Robert Ward (Fremont, CA); Yee, Daniel Dadwa (Dublin, CA); Dils, David Wright (Fort Worth, TX)

2008-03-25

52

Development of Voltage Reactive Power Control Considering Load Change  

NASA Astrophysics Data System (ADS)

Modern power system has become large and complex networks, which require more flexible system operation. Voltage and reactive power control (VQC) that transports more electric powers especially maintaining voltages within range of constraints is expected to become more important for a high-performance system operation. In this paper, we propose a new technique of VQC considering load change with a short-term load forecasting and an optimal control by a new Meta-heuristics technique with combination of Particle Swarm Optimization (PSO) and Tabu Search (TS).

Shimone, Takaaki; Yatsubo, Osamu; Ishigame, Atsushi; Hasegawa, Tsuguto

53

Evaluation of electromagnetic disturbances injected in high voltage networks by large electrical installations  

Microsoft Academic Search

In the actual technological context, continuous improvement of the evaluation of the electromagnetic disturbances injected by the large electrical end users and the distribution system topology into high voltage networks is highly necessary. In this case, the power quality really means the voltage quality. The disturbances phenomena occurring in the high voltage network due to some important 110 kV and

MARILENA UNGUREANU; RALUCA ROSCA

54

Voltage regulator modeling for the three-phase power flow in distribution networks  

Microsoft Academic Search

In this paper a three-phase power flow for electrical distribution systems considering different models of voltage regulators is presented. A voltage regulator (VR) is an equipment that maintains the voltage level in a predefined value in a distribution line in spite of the load variations within its nominal power. Three different types of connections are analyzed: 1) wye- connected regulators,

L. A. Gallego; A. Padilha-Feltrin

2008-01-01

55

Visualization of an electric power transmission system  

Microsoft Academic Search

Visualization techniques are applied to an electric power system transmission network to create a graphical picture of network power flows and voltages. A geographic data map is used. Apparent power flow is encoded as the width of an arrow, with direction from real power flow. Flows are superposed on flow limits. Contour plots and color coding failed for representing bus

P. M. Mahadev; R. D. Christie

1994-01-01

56

Calculation of geomagnetically induced currents (GIC) in a high-voltage electric power transmission system and estimation of effects of overhead shield wires on GIC modelling  

Microsoft Academic Search

Geomagnetically induced currents (GIC) flowing in ground-based technological networks, such as electric power transmission grids, are the ground end of the space weather chain originating from the Sun. GIC constitute a possible source of problems to the system. Matrix formulas enabling the calculation of GIC in a power grid have been presented before. In this paper, we summarise the formulas

Risto Pirjola

2007-01-01

57

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

...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...

2014-10-01

58

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

Code of Federal Regulations, 2012 CFR

...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...

2012-10-01

59

FBG based intelligent sensors and structure for electrical power system  

Microsoft Academic Search

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

Yuan Yao; Benshun Yi; Jinsheng Xiao; Zhaohui Li

2007-01-01

60

Electric Power Demand and Emerging Technology in Highly-sophisticated Electric Power Systems  

NASA Astrophysics Data System (ADS)

In the last few years, the increase of the electric power demand has been remarkable, especially in Asia district. In such trend, the electric power system of Japan has been supplied with high quality, high reliability and highly-stabilized electric power. This is supported by highly-sophisticated electric power system which prides oneself on high voltage and large capacity. In this paper, outlines of these technologies are described. And, newest technology trends such as electric power liberalization, innovation of dispersed power source, effective utilization of natural energy are also explained. In addition, the global standards are important to make the technological level of Japan to be the world one in future.

Matsumoto, Satoshi; Hikita, Masayuki

61

Research and Design of High-Voltage Electronic Power Equipment Monitor System Based on Wireless Communication Technology  

Microsoft Academic Search

Temperature improvement of electronic power switchgear and handcart contact, as well as circuit breaker contact electrical arc erosion are easy to cause control action failure, trip, and power off, even more serious accident. So, it is a key to realize electric power system running through monitoring high-voltage equipment in real time. This paper design a kind of new high-voltage electric

Yu Chen; Haijun Zhang

2009-01-01

62

Local Dynamic Reactive Power for Correction of System Voltage Problems  

SciTech Connect

Distribution systems are experiencing outages due to a phenomenon known as local voltage collapse. Local voltage collapse is occurring in part because modern air conditioner compressor motors are much more susceptible to stalling during a voltage dip than older motors. These motors can stall in less than 3 cycles (.05s) when a fault, such as on the sub-transmission system, causes voltage to sag to 70 to 60%. The reasons for this susceptibility are discussed in the report. During the local voltage collapse, voltages are depressed for a period of perhaps one or two minutes. There is a concern that these local events are interacting together over larger areas and may present a challenge to system reliability. An effective method of preventing local voltage collapse is the use of voltage regulation from Distributed Energy Resources (DER) that can supply or absorb reactive power. DER, when properly controlled, can provide a rapid correction to voltage dips and prevent motor stall. This report discusses the phenomenon and causes of local voltage collapse as well as the control methodology we have developed to counter voltage sag. The problem is growing because of the use of low inertia, high efficiency air conditioner (A/C) compressor motors and because the use of electric A/C is growing in use and becoming a larger percentage of system load. A method for local dynamic voltage regulation is discussed which uses reactive power injection or absorption from local DER. This method is independent, rapid, and will not interfere with conventional utility system voltage control. The results of simulations of this method are provided. The method has also been tested at the ORNL s Distributed Energy Communications and Control (DECC) Laboratory using our research inverter and synchronous condenser. These systems at the DECC Lab are interconnected to an actual distribution system, the ORNL distribution system, which is fed from TVA s 161kV sub-transmission backbone. The test results are also provided and discussed. The simulations and testing show that local voltage control from DER can prevent local voltage collapse. The results also show that the control can be provided so quickly, within 0.5 seconds, that is does not interfere with conventional utility methods.

Kueck, John D [ORNL; Rizy, D Tom [ORNL; Li, Fangxing [ORNL; Xu, Yan [ORNL; Li, Huijuan [University of Tennessee, Knoxville (UTK); Adhikari, Sarina [ORNL; Irminger, Philip [ORNL

2008-12-01

63

Voltage Regulator Chip: Power Supplies on a Chip  

SciTech Connect

ADEPT Project: CPES at Virginia Tech is finding ways to save real estate on a computer's motherboard that could be used for other critical functions. Every computer processor today contains a voltage regulator that automatically maintains a constant level of electricity entering the device. These regulators contain bulky components and take up about 30% of a computer's motherboard. CPES at Virginia Tech is developing a voltage regulator that uses semiconductors made of gallium nitride on silicon (GaN-on-Si) and high-frequency soft magnetic material. These materials are integrated on a small, 3D chip that can handle the same amount of power as traditional voltage regulators at 1/10 the size and with improved efficiency. The small size also frees up to 90% of the motherboard space occupied by current voltage regulators.

None

2010-09-01

64

Electric power annual 1993  

SciTech Connect

This report presents a summary of electric power industry statistics at national, regional, and state levels: generating capability and additions, net generation, fossil-fuel statistics, retail sales and revenue, finanical statistics, environmental statistics, power transactions, demand side management, nonutility power producers. Purpose is to provide industry decisionmakers, government policymakers, analysts, and the public with historical data that may be used in understanding US electricity markets.

Not Available

1994-12-08

65

Contract networks for electric power transmission  

Microsoft Academic Search

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

William W. Hogan

1992-01-01

66

Evaluation of high-voltage, high-power, solid-state remote power controllers for amps  

NASA Technical Reports Server (NTRS)

The Electrical Power Branch at Marshall Space Flight Center has a Power System Development Facility where various power circuit breadboards are tested and evaluated. This project relates to the evaluation of a particular remote power controller (RPC) energizing high power loads. The Facility equipment permits the thorough testing and evaluation of high-voltage, high-power solid-state remote power controllers. The purpose is to evaluate a Type E, 30 Ampere, 200 V dc remote power controller. Three phases of the RPC evaluation are presented. The RPC is evaluated within a low-voltage, low-power circuit to check its operational capability. The RPC is then evaluated while performing switch/circuit breaker functions within a 200 V dc, 30 Ampere power circuit. The final effort of the project relates to the recommended procedures for installing these RPC's into the existing Autonomously Managed Power System (AMPS) breadboard/test facility at MSFC.

Callis, Charles P.

1987-01-01

67

Modular high voltage power supply for chemical analysis  

DOEpatents

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.

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

2008-07-15

68

Modular high voltage power supply for chemical analysis  

DOEpatents

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.

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

2010-05-04

69

Modular high voltage power supply for chemical analysis  

DOEpatents

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.

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

2007-01-09

70

Voltage collapse precipitated by the immediate change in stability when generator reactive power limits are encountered  

Microsoft Academic Search

When a generator of a heavily loaded electric power system reaches a reactive power limit, the system can become immediately unstable and a dynamic voltage collapse leading to blackout may follow. The statics and dynamics of this mechanism for voltage collapse are studied by example and by the generic theory of saddle node and transcritical bifurcations. It is shown that

I. Dobson; L. Lu

1992-01-01

71

Generator voltage stabilisation for series-hybrid electric vehicles.  

PubMed

This paper presents a controller for use in speed control of an internal combustion engine for series-hybrid electric vehicle applications. Particular reference is made to the stability of the rectified DC link voltage under load disturbance. In the system under consideration, the primary power source is a four-cylinder normally aspirated gasoline internal combustion engine, which is mechanically coupled to a three-phase permanent magnet AC generator. The generated AC voltage is subsequently rectified to supply a lead-acid battery, and permanent magnet traction motors via three-phase full bridge power electronic inverters. Two complementary performance objectives exist. Firstly to maintain the internal combustion engine at its optimal operating point, and secondly to supply a stable 42 V supply to the traction drive inverters. Achievement of these goals minimises the transient energy storage requirements at the DC link, with a consequent reduction in both weight and cost. These objectives imply constant velocity operation of the internal combustion engine under external load disturbances and changes in both operating conditions and vehicle speed set-points. An electronically operated throttle allows closed loop engine velocity control. System time delays and nonlinearities render closed loop control design extremely problematic. A model-based controller is designed and shown to be effective in controlling the DC link voltage, resulting in the well-conditioned operation of the hybrid vehicle. PMID:18262528

Stewart, P; Gladwin, D; Stewart, J; Cowley, R

2008-04-01

72

High voltage solar cell power generating system  

NASA Technical Reports Server (NTRS)

A laboratory solar power system regulated by on-panel switches has been delivered for operating high power (3 kW), high voltage (15,000 volt) loads (communication tubes, ion thrusters). The modular system consists of 26 solar arrays, each with an integral light source and cooling system. A typical array contains 2,560 series-connected cells. Each light source consists of twenty 500-watt tungsten iodide lamps providing plus or minus 5 percent uniformity at one solar constant. An array temperature of less than 40 C is achieved using an infrared filter, a water-cooled plate, a vacuum hold-down system, and air flushing.

Levy, E., Jr.; Opjorden, R. W.; Hoffman, A. C.

1974-01-01

73

High Voltage Power Supply Design Guide for Space  

NASA Technical Reports Server (NTRS)

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.

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

2006-01-01

74

Index-based reactive power compensation scheme for voltage regulation  

NASA Astrophysics Data System (ADS)

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.

Dike, Damian Obioma

2008-10-01

75

Electric power monthly  

SciTech Connect

The Energy Information Administration (EIA) prepares the Electric Power Monthly (EPM) for a wide audience including Congress, Federal and State agencies, the electric utility industry, and the general public. This publication provides monthly statistics 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. The EIA publishes statistics in the EPM on net generation by energy source, consumption, stocks, quantity, quality, and cost of fossil fuels; and capability of new generating units by company and plant. 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.

NONE

1995-08-01

76

Electrical degradation mechanisms of RF power GaAs PHEMTs  

E-print Network

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 ...

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

2007-01-01

77

Radio-frequency powered glow discharge device and method with high voltage interface  

DOEpatents

A high voltage accelerating potential, which is supplied by a high voltage direct current power supply, is applied to the electrically conducting interior wall of an RF powered glow discharge cell. The RF power supply desirably is electrically grounded, and the conductor carrying the RF power to the sample held by the probe is desirably shielded completely excepting only the conductor's terminal point of contact with the sample. The high voltage DC accelerating potential is not supplied to the sample. A high voltage capacitance is electrically connected in series between the sample on the one hand and the RF power supply and an impedance matching network on the other hand. The high voltage capacitance isolates the high DC voltage from the RF electronics, while the RF potential is passed across the high voltage capacitance to the plasma. An inductor protects at least the RF power supply, and desirably the impedance matching network as well, from a short that might occur across the high voltage capacitance. The discharge cell and the probe which holds the sample are configured and disposed to prevent the probe's components, which are maintained at ground potential, from bridging between the relatively low vacuum region in communication with the glow discharge maintained within the cell on the one hand, and the relatively high vacuum region surrounding the probe and cell on the other hand. The probe and cell also are configured and disposed to prevent the probe's components from electrically shorting the cell's components.

Duckworth, Douglas C. (Knoxville, TN); Marcus, R. Kenneth (Clemson, SC); Donohue, David L. (Vienna, AT); Lewis, Trousdale A. (Oak Ridge, TN)

1994-01-01

78

Radio-frequency powered glow discharge device and method with high voltage interface  

DOEpatents

A high voltage accelerating potential, which is supplied by a high voltage direct current power supply, is applied to the electrically conducting interior wall of an RF powered glow discharge cell. The RF power supply desirably is electrically grounded, and the conductor carrying the RF power to the sample held by the probe is desirably shielded completely excepting only the conductor's terminal point of contact with the sample. The high voltage DC accelerating potential is not supplied to the sample. A high voltage capacitance is electrically connected in series between the sample on the one hand and the RF power supply and an impedance matching network on the other hand. The high voltage capacitance isolates the high DC voltage from the RF electronics, while the RF potential is passed across the high voltage capacitance to the plasma. An inductor protects at least the RF power supply, and desirably the impedance matching network as well, from a short that might occur across the high voltage capacitance. The discharge cell and the probe which holds the sample are configured and disposed to prevent the probe's components, which are maintained at ground potential, from bridging between the relatively low vacuum region in communication with the glow discharge maintained within the cell on the one hand, and the relatively high vacuum region surrounding the probe and cell on the other hand. The probe and cell also are configured and disposed to prevent the probe's components from electrically shorting the cell's components. 11 figures.

Duckworth, D.C.; Marcus, R.K.; Donohue, D.L.; Lewis, T.A.

1994-06-28

79

Electric Power Annual  

EIA Publications

Presents 12 years (2001 - 2012) 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.)

2013-01-01

80

Advanced electric propulsion system concept for electric vehicles. Addendum 1: Voltage considerations  

NASA Technical Reports Server (NTRS)

The two electric vehicle propulsion systems that best met cost and performance goals were examined to assess the effect of battery pack voltage on system performance and cost. A voltage range of 54 to 540 V was considered for a typical battery pack capacity of 24 k W-hr. The highest battery specific energy (W-hr/kg) and the lowest cost ($/kW-hr) were obtained at the minimum voltage level. The flywheel system traction motor is a dc, mechanically commutated with shunt field control, and due to the flywheel the traction motor and the battery are not subject to extreme peaks of power demand. The basic system uses a permanent-magnet motor with electronic commutation supplied by an ac power control unit. In both systems battery cost were the major factor in system voltage selection, and a battery pack with the minimum voltage of 54 V produced the lowest life-cycle cost. The minimum life-cycle cost for the basic system with lead-acid batteries was $0.057/km and for the flywheel system was $0.037/km.

Raynard, A. E.; Forbes, F. E.

1980-01-01

81

Electric power monthly  

SciTech Connect

The Electric Power Monthly is prepared by the Survey Management Division; Office of Coal, Nuclear, Electric and Alternate Fuels, Energy Information Administration (EIA), Department of Energy. This publication provides monthly statistics at the national, Census division, and State levels for net generation, fuel consumption, fuel stocks, quantity and quality of fuel, cost of fuel, electricity sales, revenue, and average revenue per kilowatthour of electricity sold. Data on net generation, fuel consumption, fuel stocks, quantity and cost of fuel are also displayed for the North American Electric Reliability Council (NERC) regions. Additionally, statistics by company and plant are published in the EPM on capability of new plants, new generation, fuel consumption, fuel stocks, quantity and quality of fuel, and cost of fuel.

Not Available

1992-05-01

82

Federal electric power  

SciTech Connect

Western Area Power Administration in the Department of Energy markets electric power generated by federal hydroelectric dams in 15 central and western states. Western is planning to construct the Craig/Bonanza transmission line and the controversy involves the questioning of Western's role in the project by an investor-owned utility. GAO found no legal basis to question Western's general authority to construct this project.

Not Available

1989-01-01

83

Power plant and method of production of synchronous commercial electric power using diesel electric locomotives  

SciTech Connect

This patent describes a method of producing synchronous electric power at utility transmission or subtransmission voltages to an electric utility grid during periods of peak electrical demand. It comprises providing at least two conventional diesel electric railroad locomotives, each having a diesel engine with a speed governor for such engine, an electrical generator driven by the engine, electrical drive motors driven from electricity provided by the generator, railroad wheels on axles driven by the drive motors, positioning the locomotives stationary at a location on railroad tracks, disconnecting the electric drive motors of the locomotives from the locomotive generator, connecting the output of the locomotive generators in parallel to generate synchronous electric power, controlling the speed of the diesel engines within the tolerances required for synchronous alternating current generation, and connecting the electrical output of the locomotive generators to step up transformer means and to an electric utility distribution grid.

Jenkins, C.P.

1991-11-19

84

The interaction of spacecraft high voltage power systems with the space plasma environment  

NASA Technical Reports Server (NTRS)

The development of spacecraft with electrical loads that require high voltage power is discussed. The high voltage solar array has been considered for supplying d.c. power directly to high voltage loads such as ion thrusters and communication tubes without intermediate power processing. Space power stations for transferring solar power to earth are being studied in the 40 kilovolt, multikilowatt regime. Analytical and experimental studies have determined that with the advent of high voltage power, new problems will arise through the interaction of the high voltage surfaces with the charged particle environment of space. The interactive environment has been identified and duplicated to some extent in simulation facilities at NASA-Lewis Research Center and at several contractor locations.

Domitz, S.; Grier, N. T.

1974-01-01

85

Aircraft Electric Power-Supply System  

Microsoft Academic Search

An ever increasing demand for electric power in aircraft has been felt for some time. The necessity of using an electric storage battery started the practice of accompanying it with a d-c generator, first of low current and voltage capacity, later of 50-ampere 12-volt rating, and for the past few years of 200-ampere 24-volt output. In the largest four-engine aircraft,

J. E. Yarmack

1943-01-01

86

A high voltage power supply for the AE-C and D low energy electron experiment  

NASA Technical Reports Server (NTRS)

A description is given of the electrical and mechanical design and operation of high voltage power supplies for space flight use. The supply was used to generate the spiraltron high voltage for low energy electron experiment on AE-C and D. Two versions of the supply were designed and built; one design is referred to as the low power version (AE-C) and the other as the high power version (AE-D). Performance is discussed under all operating conditions.

Gillis, J. A.

1974-01-01

87

Reducing electric power transmission losses  

Microsoft Academic Search

The reduction of transmission-related power losses in electric grids has become increasingly important in every phase of power systems concerned with conservation of fuel and power resources. The most effective approaches to the matter of electric power loss reduction in power transmission lines are discussed. These methods include reactive power compensation, both on loads and system substations, optimization of grid

A. I. Kulchitskii; S. P. Elagina

1982-01-01

88

Direct fault location in electrical power systems  

SciTech Connect

This thesis presents an alternative to existing fault locating procedures in electrical power systems. The theoretical approach is based on the adjoint network concept, utilizing Tellegen's theorem. This theorem may be applied in the frequency or time domain. Also the current and voltage measurements taken from different networks, with the same topology and branch numbering, may be taken at different times. The aim is to apply the theorem in locating balanced or unbalanced faults in electric power transmission and distribution systems, using terminal voltage and current measurements combined with a minimum knowledge of the internal voltages and currents of the network. A detailed description of the theoretical basis for the proposed approach is presented along with numerical examples illustrating the potential application of the proposed technique.

Thomas, B.J.

1985-01-01

89

A Novel Series Connected Batteries State of High Voltage Safety Monitor System for Electric Vehicle Application  

PubMed Central

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

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

2013-01-01

90

Constant frequency aircraft electric power systems with harmonic reduction  

Microsoft Academic Search

The ever-increasing number of power electronic converters connected to the aircraft electric power system significantly increases harmonic levels and voltage transients in that system. Stringent limits on harmonic current distortion and perturbation of the aircraft electric power supply demands accurate simulation and development of high performance filters for the mitigation of harmonics and minimization of system transients. This paper presents

A. Eid; H. El-Kishky; M. Abdel-Salam; T. El-Mohandes

2008-01-01

91

Capturing power at higher voltages from arrays of microbial fuel cells without voltage reversal  

E-print Network

Capturing power at higher voltages from arrays of microbial fuel cells without voltage reversal 31st August 2011 DOI: 10.1039/c1ee02451e Voltages produced by microbial fuel cells (MFCs) cannot an electronic circuit containing two sets of multiple capacitors that were alternately charged and discharged

92

Electric power emergency handbook  

SciTech Connect

The Emergency Electric Power Administration's Emergency Operations Handbook is designed to provide guidance to the EEPA organization. It defines responsibilities and describes actions performed by the government and electric utilities in planning for, and in operations during, national emergencies. The EEPA Handbook is reissued periodically to describe organizational changes, to assign new duties and responsibilities, and to clarify the responsibilities of the government to direct and coordinate the operations of the electric utility industry under emergencies declared by the President. This Handbook is consistent with the assumptions, policies, and procedures contained in the National Plan for Emergency Preparedness. Claimancy and restoration, communications and warning, and effects of nuclear weapons are subjects covered in the appendices.

Labadie, J.R.

1980-09-01

93

Electric power transmission systems  

Microsoft Academic Search

An updated edition (from 1972) of technical aspects exhibited by electric systems which transmit power from the generator to the loads. A new area covered is the calculation of short-circuit currents due to symetrical faults and their impact on the ratings of circuit-interrupting devices. Not only have problems been added, but the use of a computer (over a wide-range of

J. R. Eaton; E. Cohen

1983-01-01

94

Wind power. [electricity generation  

NASA Technical Reports Server (NTRS)

A historical background on windmill use, the nature of wind, wind conversion system technology and requirements, the economics of wind power and comparisons with alternative systems, data needs, technology development needs, and an implementation plan for wind energy are presented. Considerable progress took place during the 1950's. Most of the modern windmills feature a wind turbine electricity generator located directly at the top of their rotor towers.

Savino, J. M.

1975-01-01

95

High frequency AC power converter for low voltage circuits  

E-print Network

This thesis presents a novel AC power delivery architecture that is suitable for VHF frequency (50-100MHz) polyphase AC/DC power conversion in low voltage integrated circuits. A complete AC power delivery architecture was ...

Salazar, Nathaniel Jay Tobias

2012-01-01

96

Monitoring and control of voltage stability in power systems  

SciTech Connect

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.

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

1995-12-31

97

Programmable high voltage power supply with regulation confined to the high voltage section  

NASA Technical Reports Server (NTRS)

A high voltage power supply in a dc-dc converter configuration includes a pre-regulator which filters and regulates the dc input and drives an oscillator which applies, in turn, a low voltage ac signal to the low side of a step-up high voltage transformer. The high voltage side of the transformer drives a voltage multiplier which provides a stepped up dc voltage to an output filter. The output voltage is sensed by a feedback network which then controls a regulator. Both the input and output of the regulator are on the high voltage side, avoiding isolation problems. The regulator furnishes a portion of the drive to the voltage multiplier, avoiding having a regulator in series with the load with its attendant, relatively high power losses. This power supply is highly regulated, has low power consumption, a low parts count and may be manufactured at low cost. The power supply has a programmability feature that allows for the selection of a large range of output voltages.

Castell, Karen D. (inventor); Ruitberg, Arthur P. (inventor)

1994-01-01

98

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

PubMed Central

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

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

2013-01-01

99

Measuring Helical FCG Voltage with an Electric Field Antenna  

SciTech Connect

A method of measuring the voltage produced by a helical explosive flux compression generator using a remote electric field antenna is described in detail. The diagnostic has been successfully implemented on several experiments. Measured data from the diagnostic compare favorably with voltages predicted using the code CAGEN, validating our predictive modeling tools. The measured data is important to understanding generator performance, and is measured with a low-risk, minimally intrusive approach.

White, A D; Anderson, R A; Javedani, J B; Reisman, D B; Goerz, D A; Ferriera, A J; Speer, R D

2011-08-01

100

E-beam high voltage switching power supply  

DOEpatents

A high-power power supply produces a controllable, constant high voltage put under varying and arcing loads. The power supply includes 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, an output rectifier for producing a dc voltage at the output of each module, and a current sensor for sensing output current. The power supply also provides dynamic response to varying loads by controlling the voltage regulator duty cycle and circuitry is provided for sensing incipient arc currents at the output of the power supply to simultaneously decouple the power supply circuitry from the arcing load. The power supply includes a plurality of discrete switching type dc--dc converter modules.

Shimer, Daniel W. (Danville, CA); Lange, Arnold C. (Livermore, CA)

1996-01-01

101

E-beam high voltage switching power supply  

DOEpatents

A high-power power supply produces a controllable, constant high voltage output under varying and arcing loads. The power supply includes 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, an output rectifier for producing a dc voltage at the output of each module, and a current sensor for sensing output current. The power supply also provides dynamic response to varying loads by controlling the voltage regulator duty cycle and circuitry is provided for sensing incipient arc currents at the output of the power supply to simultaneously decouple the power supply circuitry from the arcing load. The power supply includes a plurality of discrete switching type dc--dc converter modules. 5 figs.

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

1996-10-15

102

The Fifth Northwest Electric Power  

E-print Network

demand for electricity, hydro conditions, and forced outages of major power plants. Other uncer- taintiesThe Fifth Northwest Electric Power and Conservation Plan #12;#12;1 Background The Northwest is unique in how it plans its energy future. Through the Northwest Power and Conservation Council's power

103

Analysis of system wide distortion in an integrated power system utilizing a high voltage DC bus and silicon carbide power devices  

E-print Network

This research investigates the distortion on the electrical distribution system for a high voltage DC Integrated Power System (IPS). The analysis was concentrated on the power supplied to a propulsion motor driven by an ...

Fallier, William F. (William Frederick)

2007-01-01

104

Case study: visualization of an electric power transmission system  

Microsoft Academic Search

Visualization techniques are applied to an electric power system transmission network to create a graphical picture of network power flows and voltages. A geographic data map is used. Apparent power flow is encoded as the width of an arrow, with direction from real power flow. Flows are superposed on flow limits. Contour plots and color coding failed for representing bus

Pramod M. Mahadev; Richard D. Christie

1994-01-01

105

Copper wire theft and high voltage electrical burns  

PubMed Central

High voltage electrical burns are uncommon. However in the midst of our economic recession we are noticing an increasing number of these injuries. Copper wire is a valuable commodity with physical properties as an excellent conductor of electricity making it both ubiquitous in society and prized on the black market. We present two consecutive cases referred to the National Burns Unit who sustained life threatening injuries from the alleged theft of high voltage copper wire and its omnipresence on an international scale. PMID:25356371

Francis, Eamon C; Shelley, Odhran P

2014-01-01

106

Arc lamp power supply using a voltage multiplier  

NASA Technical Reports Server (NTRS)

A power supply is provided for an arc discharge lamp which includes a relatively low voltage high current power supply section and a high voltage starter circuit. The low voltage section includes a transformer, rectifier, variable resistor and a bank of capacitors, while the starter circuit comprises several diodes and capacitors connected as a Cockcroft-Walton multiplier. The starting circuit is effectively bypassed when the lamp arc is established and serves to automatically provide a high starting voltage to re-strike the lamp arc if the arc is extinguished by a power interruption.

Leighty, Bradley D.

1988-01-01

107

Medium power voltage multipliers with a large number of stages  

NASA Technical Reports Server (NTRS)

Voltage multiplier techniques are extended at medium power levels to larger multiplication ratios. A series of dc-dc converters were built, with from 20 to 45 stages and with power levels up to 100 watts. Maximum output voltages were about 10,000 volts.

Harrigill, W. T.; Myers, I. T.

1978-01-01

108

Analysis and design of Power R Gyrators for Voltage Regulation  

Microsoft Academic Search

This paper presents a new type of voltage regulators based on the power R-gyrators concept. Also, the semigyrator notion is introduced. Power R-semigyrators based in boost and boost-shunt converter are presented. Finally, voltage regulation is achieved with both types of semigyrators

A. Cid-Pastor; L. Martinez-Salamero; C. Alonso; B. Estibals; L. Seguier; G. Schweitz

2006-01-01

109

Insulation Requirements of High-Voltage Power Systems in Future Spacecraft  

NASA Technical Reports Server (NTRS)

The scope, size, and capability of the nation's space-based activities are limited by the level of electrical power available. Long-term projections show that there will be an increasing demand for electrical power in future spacecraft programs. The level of power that can be generated, conditioned, transmitted, and used will have to be considerably increased to satisfy these needs, and increased power levels will require that transmission voltages also be increased to minimize weight and resistive losses. At these projected voltages, power systems will not operate satisfactorily without the proper electrical insulation. Open or encapsulated power supplies are currently used to keep the volume and weight of space power systems low and to protect them from natural and induced environmental hazards. Circuits with open packaging are free to attain the pressure of the outer environment, whereas encapsulated circuits are imbedded in insulating materials, which are usually solids, but could be liquids or gases. Up to now, solid insulation has usually been chosen for space power systems. If the use of solid insulation is continued, when voltages increase, the amount of insulation for encapsulation also will have to increase. This increased insulation will increase weight and reduce system reliability. Therefore, non-solid insulation media must be examined to satisfy future spacecraft power and voltage demands. In this report, we assess the suitability of liquid, space vacuum, and gas insulation for space power systems.

Qureshi, A. Haq; Dayton, James A., Jr.

1995-01-01

110

Conceptual definition of a high voltage power supply test facility  

NASA Technical Reports Server (NTRS)

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.

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

1989-01-01

111

High voltage power supply with modular series resonant inverters  

DOEpatents

A relatively small and compact high voltage, high current power supply for a laser utilizes a plurality of modules containing series resonant half bridge inverters. A pair of reverse conducting thyristors are incorporated in each series resonant inverter module such that the series resonant inverter modules are sequentially activated in phases 360.degree./n apart, where n=number of modules for n>2. Selective activation of the modules allows precise output control reducing ripple and improving efficiency. Each series resonant half bridge inverter module includes a transformer which has a cooling manifold for actively circulating a coolant such as water, to cool the transformer core as well as selected circuit elements. Conductors connecting and forming various circuit components comprise hollow, electrically conductive tubes such as copper. Coolant circulates through the tubes to remove heat. The conductive tubes act as electrically conductive lines for connecting various components of the power supply. Where it is desired to make electrical isolation breaks, tubes comprised of insulating material such as nylon are used to provide insulation and continue the fluid circuit.

Dreifuerst, Gary R. (Livermore, CA); Merritt, Bernard T. (Livermore, CA)

1995-01-01

112

High voltage power supply with modular series resonant inverters  

DOEpatents

A relatively small and compact high voltage, high current power supply for a laser utilizes a plurality of modules containing series resonant half bridge inverters. A pair of reverse conducting thyristors are incorporated in each series resonant inverter module such that the series resonant inverter modules are sequentially activated in phases 360{degree}/n apart, where n=number of modules for n>2. Selective activation of the modules allows precise output control reducing ripple and improving efficiency. Each series resonant half bridge inverter module includes a transformer which has a cooling manifold for actively circulating a coolant such as water, to cool the transformer core as well as selected circuit elements. Conductors connecting and forming various circuit components comprise hollow, electrically conductive tubes such as copper. Coolant circulates through the tubes to remove heat. The conductive tubes act as electrically conductive lines for connecting various components of the power supply. Where it is desired to make electrical isolation breaks, tubes comprised of insulating material such as nylon are used to provide insulation and continue the fluid circuit. 11 figs.

Dreifuerst, G.R.; Merritt, B.T.

1995-07-18

113

Power processing units for high power solar electric propulsion  

NASA Technical Reports Server (NTRS)

An evaluation of high-power processing units (PPUs) for multimegawatt solar electric propulsion (SEP) vehicles using advanced ion thrusters is presented. Significant savings of scale are possible for PPUs used to supply power to ion thrusters operating at 0.1 to 1.5 MWe per thruster. The PPU specific mass is found to be strongly sensitive to variations in the ion thruster's power per thruster and moderately sensitive to variations in the thruster's screen voltage due to varying the I(sp) of the thruster. Each PPU consists of a dc-to-dc converter to increase the voltage from the 500 V dc of the photovoltaic power system to the 5 to 13 kV dc required by the ion thrusters.

Frisbee, Robert H.; Das, Radhe S.; Krauthamer, Stanley

1992-01-01

114

Power processing units for high power solar electric propulsion  

NASA Astrophysics Data System (ADS)

An evaluation of high-power processing units (PPUs) for multimegawatt solar electric propulsion (SEP) vehicles using advanced ion thrusters is presented. Significant savings of scale are possible for PPUs used to supply power to ion thrusters operating at 0.1 to 1.5 MWe per thruster. The PPU specific mass is found to be strongly sensitive to variations in the ion thruster's power per thruster and moderately sensitive to variations in the thruster's screen voltage due to varying the I(sp) of the thruster. Each PPU consists of a dc-to-dc converter to increase the voltage from the 500 V dc of the photovoltaic power system to the 5 to 13 kV dc required by the ion thrusters.

Frisbee, Robert H.; Das, Radhe S.; Krauthamer, Stanley

115

Power converter design for a fuel cell electric vehicle  

Microsoft Academic Search

This research is developed the electric vehicle by the fuel cell. Between fuel cell source and motor controller, we add new power converter, offer steady output voltage to motor controller and drive the direct current hub motor. Converter not only offers steady output voltage but it also combines with coupling inductance technology to battery charger. Besides offers energy to drive

Van-Tsai Liu; Jia-Wei Hong; Kuo-Ching Tseng

2010-01-01

116

Teaching Electrical Energy, Voltage and Current: An Alternative Approach.  

ERIC Educational Resources Information Center

A program for teaching the concepts of electric energy, voltage, and current is proposed. The ideas and concepts are introduced in a sequence that places more emphasis on some aspects that are normally treated very briefly. A phenomenological orientation, qualitative and quantitative micro- and macroscopic treatments, and the inclusion of the…

Licht, Pieter

1991-01-01

117

59. View of high voltage (4160 volts alternating current) electric ...  

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

59. View of high voltage (4160 volts alternating current) electric load center and motor control center at mezzanine level in transmitter building no. 102. - Clear Air Force Station, Ballistic Missile Early Warning System Site II, One mile west of mile marker 293.5 on Parks Highway, 5 miles southwest of Anderson, Anderson, Denali Borough, AK

118

Students' understanding of voltage in simple parallel electric circuits  

Microsoft Academic Search

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

Robin Millar; Kian Lim Beh

1993-01-01

119

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 utility, with restructuring they are increasingly inadequate. This paper presents results of human factors

120

Low Power, High Voltage Power Supply with Fast Rise/Fall Time  

NASA Technical Reports Server (NTRS)

A low power, high voltage power supply system includes a high voltage power supply stage and a preregulator for programming the power supply stage so as to produce an output voltage which is a predetermined fraction of a desired voltage level. The power supply stage includes a high voltage, voltage doubler stage connected to receive the output voltage from the preregulator and for, when activated, providing amplification of the output voltage to the desired voltage level. A first feedback loop is connected between the output of the preregulator and an input of the preregulator while a second feedback loop is connected between the output of the power supply stage and the input of the preregulator.

Bearden, Douglas B. (Inventor)

2007-01-01

121

Low power, high voltage power supply with fast rise/fall time  

NASA Technical Reports Server (NTRS)

A low power, high voltage power supply system includes a high voltage power supply stage and a preregulator for programming the power supply stage so as to produce an output voltage which is a predetermined fraction of a desired voltage level. The power supply stage includes a high voltage, voltage doubler stage connected to receive the output voltage from the preregulator and for, when activated, providing amplification of the output voltage to the desired voltage level. A first feedback loop is connected between the output of the preregulator and an input of the preregulator while a second feedback loop is connected between the output of the power supply stage and the input of the preregulator.

Bearden, Douglas B. (Inventor)

2007-01-01

122

Structure Design and Analysis of High-Voltage Power Supply for ECRH  

NASA Astrophysics Data System (ADS)

In order to develop a high-voltage power supply (HVPS) with high quality parameters, not only its electrical circuit but also its structure should be studied in detail. In this paper, the structure design of the collector power supply for gyrotron is discussed first. Then the electrical field and potential simulations of its main devices are analyzed. Finally, relevant calculations and conclusions are given.

Wang, Lei; Huang, Yiyun; Zhao, Yanping; Zhang, Jian; Yang, Lei; Guo, Wenjun

2014-11-01

123

Effects of neutral point reactors and series capacitors on geomagnetically induced currents in a high-voltage electric power transmission system  

NASA Astrophysics Data System (ADS)

Geomagnetically induced currents (GIC) are DC-like currents compared to power transmission frequencies. Consequently, it may be possible to reduce the magnitudes of GIC by installing resistive components or series capacitors into a power grid. We simulate the effects of neutral point reactors and series capacitors on GIC in the Finnish 400 kV network. Reactors add an additional resistance to earthing leads of transformers, and series capacitors block the flow of GIC in transmission lines. The geoelectric field impacting the system is considered to be uniform. The use of reactors does not necessarily reduce the GIC risk. Although the installation of reactors tends to decrease GIC on the average, maximum GIC may even increase. Assuming a reactor at all stations results in a 50% reduction of the maximum GIC compared to the situation with no reactors. With up to four series capacitors, the maximum GIC is reduced by 40% when they are optimally located. However, even small changes in the topology of the grid can cause large changes in GIC. A combination of reactors and series capacitors could in principle provide a way to diminish the GIC risk. This study also emphasizes the difficulty of preventing GIC problems by these means.

ArajäRvi, Esko; Pirjola, Risto; Viljanen, Ari

2011-11-01

124

Bidirectional power electronic transformer based compact dynamic voltage restorer  

Microsoft Academic Search

In this paper a dynamic voltage restorer (DVR) circuit with a bi-directional power electronic transformer (PET) structure is proposed to correct input utility voltage distortions on a sensitive load. This DVR-PET contains full-bridge DC-link inverter (FBDCI), high frequency isolating transformer (HFIT), cyclo-converter and output filter. A phase shift modulation (PSM) control scheme is used to regulate compensation voltage. The proper

S. H. Hosseini; M. B. B. Sharifian; M. Sabahi; A. Y. Goharrizi; G. B. Gharehpetian

2009-01-01

125

A Field Study of Lightning Surges Propagating through Low-voltage Electric Appliances  

NASA Astrophysics Data System (ADS)

In today's highly information-based society, lightning damage has a significant impact on an increasing number of electric appliances such as personal computers and facsimile machines. Lightning surge protection devices for electric appliances are on the market and concern for lightning protection has been increasing, but there are still many unknown aspects of lightning surges that propagate into residences. To provide effective lightning protection measures, clarification of surge propagation patterns is needed. The Tokyo Electric Power Company has observed the patterns of lightning surge propagation into houses using lightning surge waveform detectors installed at ordinary residences and obtained data on 30 lightning surge current waveforms between 2008 and 2009. This paper discusses various aspects of lightning surge currents propagating into low-voltage appliances, including home electric appliances, based on the lightning surge current waveform data obtained from lightning observations. The result revealed the patterns of lightning surge currents propagating into the ground and lines of low-voltage appliances.

Ishii, Tsunayoshi; Sakamoto, Yoshiki; Oguchi, Shuichi; Okabe, Shigemitsu

126

Electric power 2007  

SciTech Connect

Subjects covered include: power industry trends - near term fuel strategies - price/quality/delivery/opportunity; generating fleet optimization and plant optimization; power plant safety and security; coal power plants - upgrades and new capacity; IGCC, advanced combustion and CO{sub 2} capture technologies; gas turbine and combined cycle power plants; nuclear power; renewable power; plant operations and maintenance; power plant components - design and operation; environmental; regulatory issues, strategies and technologies; and advanced energy strategies and technologies. The presentations are in pdf format.

NONE

2007-07-01

127

Sinusoidal voltage controller for uninterruptible power supply by robust control  

Microsoft Academic Search

The output voltage of an uninterruptible power supply (UPS) is distorted by nonlinear loads. To obtain sinusoidal output voltage of a UPS, a new control method of a pulse width modulated (PWM) inverter is proposed applying sliding mode control. The feedback gains of conventional sliding mode control are determined by offline calculation; however this proposed control method calculates the feedback

Tomonobu Senjyu; Katsumi Uezato

1993-01-01

128

Dynamic voltage scaling on a low-power microprocessor  

Microsoft Academic Search

Power consumption is the limiting factor for the functionality of future wearable devices. Since interactive applications like wireless information access generate bursts of activities, it is important to match the performance of the wearable device accordingly. This paper describes a system with a microprocessor whose speed can be varied (frequency scaling) as well as its supply voltage. Voltage scaling is

Johan A. Pouwelse; Koen Langendoen; Henk J. Sips

2001-01-01

129

Very-high-frequency low-voltage power delivery  

E-print Network

Power conversion for the myriad low-voltage electronic circuits in use today, including portable electronic devices, digital electronics, sensors and communication circuits, is becoming increasingly challenging due to the ...

Li, Wei, Ph. D. Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science

2013-01-01

130

Reliability improvement methodology for cockpit high-voltage power supplies  

Microsoft Academic Search

High voltage power supplies (HVPS) have traditionally been among the least reliable components in airborne display electronics. NAVMAT P- 4855-1A, a power supply design manual adopted by the U.S. Navy in 1989, highlighted the source of these problems in industry's failure to apply appropriate methods for high voltage design, development and materials selection. Also, the nature of airborne HVPS is

Dominic D. Chow; John Ardussi

1995-01-01

131

Broadband Access over Medium and Low Voltage Power-lines and use of White Light Emitting Diodes for Indoor Communications  

E-print Network

Broadband Access over Medium and Low Voltage Power-lines and use of White Light Emitting Diodes. Broadband power-line communication has advanced through last decade and it is going to be a mature access promising technology, Broadband over Power-lines (BPL), uses electric power-lines as a high-speed digital

Kavehrad, Mohsen

132

Optimal control of shunt active power filters in multibus industrial power systems for harmonic voltage mitigation  

Microsoft Academic Search

The bus voltage and branch current detection control strategies of the active power filters used in industrial multibus power systems for harmonic voltage mitigation are analyzed and compared in the paper. The effectiveness of both the methods with real control gains is assessed in terms of the harmonic bus voltage mitigation and of the demanded current spectrum injected by the

Josef Tlustý; Pavel Santarius; Viktor Valouch; Jirí Skramlík

2006-01-01

133

Voltage regulator dissipates minimal power and functions as a voltage divider  

NASA Technical Reports Server (NTRS)

Regulator requires minimum amount of power for voltage division and it is not required continuously. The only power loss, except for regulating purposes, is that needed to provide for imbalances in load current requirements. For balanced loads, only leakage current flows through regulating transistors.

Hester, H. B.

1971-01-01

134

Electric Power Monthly  

EIA Publications

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.

2015-01-01

135

Power conditioning system with cascaded H-bridge multilevel converter — DC-link voltage balancing method  

Microsoft Academic Search

Multilevel converters have become an attractive choice for high voltage and high power applications. One of the most popular multilevel converter topologies is the cascaded H-bridge converter. Besides its simplicity this topology requires separate DC sources. In electric drive applications these DC sources are normally performed by multi-winding transformers with diode rectifiers. In STATCOM or PWM rectifiers there is no

Marcin Zygmanowski; Boguslaw Grzesik; Jaroslaw Michalak

2011-01-01

136

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

Code of Federal Regulations, 2013 CFR

...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...

2013-07-01

137

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

...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...

2014-07-01

138

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

Code of Federal Regulations, 2010 CFR

...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...

2010-07-01

139

NASCAP modelling of high-voltage power system interactions with space charged-particle environments  

NASA Technical Reports Server (NTRS)

A simple space power system operating in geosynchronous orbit was analyzed. This system consisted of two solar array wings and a central body. Each solar array wing was considered to be divided into three regions operating at 2000 volts. The center body was considered to be an electrical ground with the array voltages both positive and negative relative to ground. The system was analyzed for both a normal environment and a moderate geomagnetic substorm environment. Initial results indicate a high probability of arcing at the interconnects on the negative operating voltage wing. The dielectric strength of the substrate may be exceeded giving rise to breakdown in the bulk of the material. The geomagnetic substorm did not seem to increase the electrical gradients at the interconnects on the negative operating voltage wing but did increase the gradients on the positive operating voltage wing which could result in increased coupling current losses.

Stevens, N. J.; Roche, J. C.; Mandell, M. J.

1979-01-01

140

Current and voltage monitors on a pulsed-power accelerator “Gamma-1”  

NASA Astrophysics Data System (ADS)

There is presented a system of registering electric parameters of high-current pulsed electron accelerator “Gamma-1” its output electric power being 1.5 TW. The accelerator system of registration makes it possible to register in a single time scale the voltage pulses with the amplitude up to 3 MV, current pulses with the amplitude up to 1 MA and duration from several nanoseconds to a microsecond. Into the system of registration there are included two-step resistive voltage dividers, capacitive voltage divider, Rogowski coils, sectionalized Rogowski coils, B-dots, shunts, transmission line, attenuators, oscilloscopes, program system. The program system is aimed at reading, transmitting and processing information from oscilloscopes on the archival computer and provides interaction with database of current and voltage sensors, cables and filters. For each registration session the system also forms a map of experiment where system configuration and experiment parameters are presented.

Zavyalov, N. V.; Gordeev, V. S.; Grishin, A. V.; Puchagin, S. Yu.; Strabykin, K. V.; Kalashnikov, D. A.; Mansurov, D. O.; Moiseevskikh, M. A.; Majornikova, V. L.; Kozachek, A. V.; Mikhailov, E. S.; Kalashnikov, D. A.; Kozachek, A. V.

2014-08-01

141

Voltage Stability Impact of Grid-Tied Photovoltaic Systems Utilizing Dynamic Reactive Power Control  

NASA Astrophysics Data System (ADS)

Photovoltaic (PV) DGs can be optimized to provide reactive power support to the grid, although this feature is currently rarely utilized as most DG systems are designed to operate with unity power factor and supply real power only to the grid. In this work, the voltage stability of a power system embedded with PV DG is examined in the context of the high reactive power requirement after a voltage sag or fault. A real-time dynamic multi-function power controller that enables renewable source PV DGs to provide the reactive power support necessary to maintain the voltage stability of the microgrid, and consequently, the wider power system is proposed. The loadability limit necessary to maintain the voltage stability of an interconnected microgrid is determined by using bifurcation analysis to test for the singularity of the network Jacobian and load differential equations with and without the contribution of the DG. The maximum and minimum real and reactive power support permissible from the DG is obtained from the loadability limit and used as the limiting factors in controlling the real and reactive power contribution from the PV source. The designed controller regulates the voltage output based on instantaneous power theory at the point-of-common coupling (PCC) while the reactive power supply is controlled by means of the power factor and reactive current droop method. The control method is implemented in a modified IEEE 13-bus test feeder system using PSCADRTM power system analysis software and is applied to the model of a Tampa ElectricRTM PV installation at Lowry Park Zoo in Tampa, FL. This dissertation accomplishes the systematic analysis of the voltage impact of a PV DG-embedded power distribution system. The method employed in this work bases the contribution of the PV resource on the voltage stability margins of the microgrid rather than the commonly used loss-of-load probability (LOLP) and effective load-carrying capability (ELCC) measures. The results of the proposed method show good improvement in the before-, during-, and post-start voltage levels at the motor terminals. The voltage stability margin approach provides the utility a more useful measure in sizing and locating PV resources to support the overall power system stability in an emerging smart grid.

Omole, Adedamola

142

Electrical power systems for Mars  

NASA Technical Reports Server (NTRS)

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.

Giudici, Robert J.

1986-01-01

143

Electrical power systems for Mars  

NASA Astrophysics Data System (ADS)

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.

Giudici, Robert J.

1986-05-01

144

Power line carrier interference caused by DC electric arc furnaces  

Microsoft Academic Search

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

Gregory A. Franklin; Shih-Min Hsu

2003-01-01

145

Electric power monthly, April 1993  

SciTech Connect

The Electric Power Monthly is prepared by the Survey Management Division; Office of Coal, Nuclear, Electric and Alternate Fuels, Energy Information Administration (EIA), Department of Energy. This publication provides monthly statistics at the US, 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.

Not Available

1993-05-07

146

Electric power monthly, May 1993  

SciTech Connect

The Electric Power Monthly (EPM) is prepared by the Survey Management Division; Office of Coal, Nuclear, Electric and Alternate Fuels, Energy Information Administration (EIA), Department of Energy. This publication provides monthly statistics at the US, 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.

Not Available

1993-05-25

147

Review on partial discharge detection techniques related to high voltage power equipment using different sensors  

NASA Astrophysics Data System (ADS)

When operating an equipment or a power system at the high voltage, problems associated with partial discharge (PD) can be tracked down to electromagnetic emission, acoustic emission or chemical reactions such as the formation of ozone and nitrous oxide gases. The high voltage equipment and high voltage installation owners have come to terms with the need for conditions monitoring the process of PD in the equipments such as power transformers, gas insulated substations (GIS), and cable installations. This paper reviews the available PD detection methods (involving high voltage equipment) such as electrical detection, chemical detection, acoustic detection, and optical detection. Advantages and disadvantages of each method have been explored and compared. The review suggests that optical detection techniques provide many advantages in the consideration of accuracy and suitability for the applications when compared to other techniques.

Yaacob, M. M.; Alsaedi, M. A.; Rashed, J. R.; Dakhil, A. M.; Atyah, S. F.

2014-09-01

148

On Power Quality of Variable-Speed Constant-Frequency Aircraft Electric Power Systems  

Microsoft Academic Search

In this paper, a comprehensive model of the variable-speed constant-frequency aircraft electric power system is developed to study the performance characteristics of the system and, in particular, the system power quality over a frequency range of operation of 400 Hz to 800 Hz. A fully controlled active power filter is designed to regulate the load terminal voltage, eliminate harmonics, correct

Ahmad Eid; Hassan El-Kishky; Mazen Abdel-Salam; Mohamed T. El-Mohandes

2010-01-01

149

Electrical power generation systems - Combat aircraft perspective  

NASA Astrophysics Data System (ADS)

The electrical power generation system requirements of combat aircraft are briefly examined. In particular, attention is given to customer requirements, development of the installed electrical power in aircraft, electrical load analysis for designing the power generation system, and definition of aircraft electrical power supply characteristics and consumer qualities. The discussion also covers reliability requirements for power generation systems, design of a power generation system, control and protection equipment in power generation systems, and helicopter electrical power systems.

Moeller, R.

150

A zero-voltage-switching controlled high-power-factor converter for DC uninterruptible power supply  

Microsoft Academic Search

A new zero-voltage-switching controlled high-power-factor power converter suitable for a DC uninterruptible power supply is proposed. A control method for achieving zero voltage switching (ZVS) without auxiliary switches is examined. ZVS operations and power-factor characteristics in the power converter are analyzed and verified experimentally. A power-factor of 0.99 and conversion efficiency of 88% were measured using a bread-board circuit

Akira TAKEUCHI; Satoshi OHTSU; S. Muroyama

1996-01-01

151

Multiple high voltage output DC-to-DC power converter  

NASA Technical Reports Server (NTRS)

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.

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

1977-01-01

152

Voltage controllable power factor corrector based inductive coupling power transfer system  

Microsoft Academic Search

This paper proposed a novel inductive coupling power transfer (ICPT) topology to improve the power factor, output voltage regulation and efficiency. The proposed ICPT is mainly constructed by a voltage controllable power factor corrector (VC-PFC) and a LLC resonant circuit. Additionally, the series compensation and series-parallel compensation are used in the primary and the secondary sides of the coupling transformer

Liang-Rui Chen; Hai-Wen Chang; Chia-Hsuan Wu; Chung-Ming Young; Neng-Yi Chu

2012-01-01

153

Electric power monthly, August 1993  

SciTech Connect

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. The EPM is prepared by the Survey Management Division; Office of Coal, Nuclear, Electric and Alternate Fuels, Energy Information Administration (EIA), Department of Energy. This publication provides monthly statistics at the US, 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.

Not Available

1993-08-13

154

Electric power monthly, September 1993  

SciTech Connect

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. The EPM is prepared by the Survey Management Division; Office of Coal, Nuclear, Electric and Alternate Fuels, Energy Information Administration (EIA), Department of Energy. This publication provides monthly statistics at the US, 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.

Not Available

1993-09-17

155

Emission Characteristics and Interference Constraint of Overhead Medium-Voltage Broadband Power Line (BPL) Systems  

Microsoft Academic Search

We investigate the measurement, interference and capacity issues of the overhead medium-voltage (MV) broadband over power line (BPL) systems operating between 1.7 and 80 MHz. The MV power lines are modeled as a 3-phase set of parallel wires with infinite length and above a lossy earth. Electric field strength is calculated. Two important parameter settings are addressed for the measurement

Song Liu; Larry J. Greenstein

2008-01-01

156

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

SciTech Connect

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.)

Not Available

1993-08-01

157

30 CFR 75.812-2 - High-voltage power centers and transformers; record of examination.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false High-voltage power centers and transformers; record...STANDARDS-UNDERGROUND COAL MINES Underground High-Voltage Distribution § 75.812-2 High-voltage power centers and transformers;...

2010-07-01

158

30 CFR 75.812 - Movement of high-voltage power centers and portable transformers; permit.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Movement of high-voltage power centers and portable transformers...STANDARDS-UNDERGROUND COAL MINES Underground High-Voltage Distribution § 75.812 Movement of high-voltage power centers and portable...

2010-07-01

159

Electrical Analysis of Wind Power  

NSDL National Science Digital Library

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.

Peterson, Lina J.

160

LENR Powered Electric Vehicles  

E-print Network

Abstract – Current electric vehicles (EV) and fuel cell vehicles (FCEV) suffer from several limitations that prevent them from becoming a true commercial success. When available, kilowatt class LENR generators combined with modern thermoelectric conversion technology could enable designing new type of automobiles, being low cost, maintenance free and zero emission at the same time. In the present talk, we will discuss what are to current limitations of electric vehicles and battery technology, how LENR technology can propose an alternative to large battery storage on EV, what are the available compact solutions for energy harvesting and thermoelectric conversion from LENR thermal energy, what are the longer term design alternatives and finally what is the expected timeline to develop prototypes and commercial products.

Nicolas Chauvin

161

Decoupling Capacitors for Power Distribution Systems with Multiple Power Supply Voltages  

E-print Network

target timing constraints) while permitting modules along the non-critical paths to use a lower voltage by the Semiconductor Research Corporation under Contract No. 2003-TJ-1068, the DARPA/ITO under AFRL Contract F29601 a small fraction of the power supply voltage (about 5%) is permitted as ripple voltage (noise), a target

Friedman, Eby G.

162

Applying power quality characteristics of wind turbines for assessing impact on voltage quality  

NASA Astrophysics Data System (ADS)

Injection of wind power into an electric grid affects the voltage quality. As the voltage quality must be within certain limits to comply with utility requirements, the effect should be assessed prior to installation. To assess the effect, knowledge about the electrical characteristics of the wind turbines is needed or else the result could easily be an inappropriate design of the grid connection. The electrical characteristics of wind turbines are manufacturer-specific but not site-specific. This means that, having the actual parameter values for a specific wind turbine, the expected impact of the wind turbine type on voltage quality when deployed at a specific site, possibly as a group of wind turbines, can be calculated. The methodology for this is explained and illustrated by case studies considering a 5 × 750 kW wind farm on a 22 kV distribution feeder. The detailed analysis suggests that the wind farm capacity can be operated at the grid without causing unacceptable voltage quality. For comparison, a simplified design criterion is considered assuming that the wind farm is only allowed to cause a voltage increment of 1%. According to this criterion, only a very limited wind power capacity would be allowed. Measurements confirm, however, the suggestion of the detailed analysis, and it is concluded that a simplified design criterion such as the 1% rule should not be used for dimensioning the grid connection of wind farms. Rather, this article suggests a systematic approach including assessment of slow voltage variations, flicker, voltage dips and harmonics, possibly supported by more detailed analyses, e.g. system stability if the wind farm is large or the grid is very weak, and impact on grid frequency in systems where wind power covers a high fraction of the load, i.e. most relevant for isolated systems.

Giæver Tande, John Olav

2002-01-01

163

Electric power monthly, July 1993  

SciTech Connect

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.

Not Available

1993-07-29

164

Electric power monthly, August 1994  

SciTech Connect

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.

Not Available

1994-08-24

165

Electric power monthly, June 1994  

SciTech Connect

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.

Not Available

1994-06-01

166

Improvement of Electric Power Conversion Efficiency of Magnetic Oscillation-Type DC–AC Converter  

Microsoft Academic Search

This paper describes fundamental characteristics of a direct current\\/alternating current (dc-ac) converter utilizing magnetic oscillation. An ac-voltage source such as the line electric power source is connected to an excitation winding of the magnetic oscillation circuit in series. The dc-ac converter can supply electric power to the ac-voltage source, and can control electric power with small signal current, which flows

Shinichi Okanuma; Yoshitomo Ogata

2009-01-01

167

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

Microsoft Academic Search

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

Hitoshi Okubo; Naoki Hayakawa; Gian Carlo Montanari

2007-01-01

168

Electrical Properties and Power Considerations of a Piezoelectric Actuator  

NASA Technical Reports Server (NTRS)

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.

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

1999-01-01

169

Electric power monthly, May 1994  

SciTech Connect

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. This publication provides monthly statistics 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. Statistics by company and plant are published on the capability of new generating units, net generation, fuel consumption, fuel stocks, quantity and quality of fuel, and cost of fossil fuels.

Not Available

1994-05-01

170

Electric power monthly, April 1994  

SciTech Connect

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.

Not Available

1994-04-01

171

Voltage biasing, cyclic voltammetry, & electrical impedance spectroscopy for neural interfaces.  

PubMed

Electrical impedance spectroscopy (EIS) and cyclic voltammetry (CV) measure properties of the electrode-tissue interface without additional invasive procedures, and can be used to monitor electrode performance over the long term. EIS measures electrical impedance at multiple frequencies, and increases in impedance indicate increased glial scar formation around the device, while cyclic voltammetry measures the charge carrying capacity of the electrode, and indicates how charge is transferred at different voltage levels. As implanted electrodes age, EIS and CV data change, and electrode sites that previously recorded spiking neurons often exhibit significantly lower efficacy for neural recording. The application of a brief voltage pulse to implanted electrode arrays, known as rejuvenation, can bring back spiking activity on otherwise silent electrode sites for a period of time. Rejuvenation alters EIS and CV, and can be monitored by these complementary methods. Typically, EIS is measured daily as an indication of the tissue response at the electrode site. If spikes are absent in a channel that previously had spikes, then CV is used to determine the charge carrying capacity of the electrode site, and rejuvenation can be applied to improve the interface efficacy. CV and EIS are then repeated to check the changes at the electrode-tissue interface, and neural recordings are collected. The overall goal of rejuvenation is to extend the functional lifetime of implanted arrays. PMID:22395095

Wilks, Seth J; Richner, Tom J; Brodnick, Sarah K; Kipke, Daryl R; Williams, Justin C; Otto, Kevin J

2012-01-01

172

Voltages induced on a power distribution line by overhead cloud lightning  

NASA Technical Reports Server (NTRS)

Voltages induced by overhead cloud lightning on a 448 m open circuited power distribution line and the corresponding north-south component of the lightning magnetic field were simultaneously measured at the NASA Kennedy Space Center during the summer of 1986. The incident electric field was calculated from the measured magnetic field. The electric field was then used as an input to the computer program, EMPLIN, that calculated the voltages at the two ends of the power line. EMPLIN models the frequency domain field/power coupling theory found, for example, in Ianoz et al. The direction of the source, which is also one of the inputs to EMPLIN, was crudely determined from a three station time delay technique. The authors found reasonably good agreement between calculated and measured waveforms.

Yacoub, Ziad; Rubinstein, Marcos; Uman, Martin A.; Thomson, Ewen M.; Medelius, Pedro J.

1991-01-01

173

Characteristics of pulsed power generator by versatile inductive voltage adder  

NASA Astrophysics Data System (ADS)

A pulsed power generator by inductive voltage adder, versatile inductive voltage adder (VIVA-I), which features a high average potential gradient (2.5 MV/m), was designed and is currently in operation,. It was designed to produce an output pulse of 4 MV/60 ns by adding 2 MV pulses in two-stages of induction cells, where amorphous cores are installed. As a pulse forming line, we used a Blumlein line with the switching reversed, where cores are automatically biased due to the presence of prepulse. Good reproducibility was obtained even in the absence of the reset pulse. Within [similar]40% of full charge voltage, pulsed power characteristics of Marx generator, pulse forming line (PFL), transmission line (TL), and induction cells were tested for three types of loads; open-circuit, dummy load of liquid (CuSO4) resistor, and electron beam diode. In the open-circuit test, [similar]2.0 MV of output voltage was obtained with good reproducibility. Dependences of output voltage on diode impedances were evaluated by using various dummy loads, and the results were found as expected. An electron-beam diode was operated successfully, and [similar]18 kA of beam current was obtained at the diode voltage of [similar]1 MV.

Yatsui, Kiyoshi; Shimiya, Kouichi; Masugata, Katsumi; Shigeta, Masao; Shibata, Kazuhiko

2005-10-01

174

Oceans and electrical power  

Microsoft Academic Search

The first part of this paper focused on the potential energy that could be extracted from salinity an'd thermal differences in the oceans; possibilities of converting marine biomass into an energy source were likewise examined. Closest to implementation are apparently schemes to harness thermal differences and wave energy. Tidal power is already producing energy in France, U.S.S.R. and China. Of

Roger H. Charlier

1982-01-01

175

Study of a High Voltage Ion Engine Power Supply  

NASA Technical Reports Server (NTRS)

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.

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

1996-01-01

176

Nuclear electric power sources  

NASA Technical Reports Server (NTRS)

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.

Singh, J. J.

1978-01-01

177

New approach to the design of digital algorithms for electric power measurements  

E-print Network

Voltage and Current Signal Pair W5 Voltage and Current Signal Pair W6 Voltage and Current Signal Pair W7 Voltage and Current Signal Pair W8 32 33 35 47 48 49 50 51 52 54 CHAPTER I INTRODUCTION Power components in electric power systems... component besides the fundamental component. The fiow of the harmonic currents through the systeni pro- duces corresponding voltage drops that, in turn produce harmonic current in linear loa. ds. Leiel of harmonics in electrical delivery systems has been...

Soljanin, Emina

2012-06-07

178

Skylab technology electrical power system  

NASA Technical Reports Server (NTRS)

The solar array/battery power systems for the Skylab vehicle were designed to operate in a solar inertial pointing mode to provide power continuously to the Skylab. Questions of power management are considered, taking into account difficulties caused by the reduction in power system performance due to the effects of structural failure occurring during the launching process. The performance of the solar array of the Apollo Telescope Mount Power System is discussed along with the Orbital Workshop solar array performance and the Airlock Module power conditioning group performance. A list is presented of a number of items which have been identified during mission monitoring and are recommended for electrical power system concepts, designs, and operation for future spacecraft.

Woosley, A. P.; Smith, O. B.; Nassen, H. S.

1974-01-01

179

Incorporating voltage security into the planning, operation and monitoring of restructured electric energy markets  

E-print Network

marketplace. This dissertation investigates issues associated with incorporating voltage security into the unbundled operating environment of electricity markets. It includes addressing voltage security in the monitoring, operational and planning horizons...

Nair, Nirmal-Kumar

2006-04-12

180

Electric Power annual 1996: Volume II  

SciTech Connect

This document presents a summary of electric power industry statistics. Data are included on electric utility retail sales of electricity, revenues, environmental information, power transactions, emissions, and demand-side management.

NONE

1997-12-01

181

an electric power transmission system  

E-print Network

“Geomagnetically induced currents ” (GIC) in ground-based technological networks are a manifestation of space weather. GIC are a potential source of problems to the systems and therefore important in practice. GIC in a power system (or in principle in any other discretely-earthed system) can be calculated conveniently by using matrix equations presented earlier. Since temporal variations associated with GIC are slow compared to the 50/60 Hz frequency used in power transmission, a dc treatment is acceptable. An essential quantity in calculations of GIC in a power grid is the earthing impedance matrix, which is the transfer function coupling GIC flowing to (from) the Earth with the voltages between the earthing points, called nodes or (sub)stations, and a remote earth. The diagonal elements of the matrix equal the earthing resistances of the nodes whereas an off-diagonal element expresses how much GIC at one earthing point affects the voltage at another node. In GIC calculations, except for some special treatments of individual sites, the off-diagonal elements are usually neglected by saying simply that the earthing points (are assumed to) lie distantly enough. In this paper, we examine the effects of off-diagonal elements of the earthing impedance matrix, i.e. the effects of interactions between different stations, on GIC calculations in greater detail and more quantitatively than before. We consider a fictitious system that represents a high-voltage power grid and a simple “network ” consisting of two stations with a line connecting them. For both systems, the conclusion can be drawn that the off-diagonal elements do not play a major role

Risto Pirjola

2007-01-01

182

Test results of high-voltage, high-power, solid-state remote power controllers  

NASA Technical Reports Server (NTRS)

This report discusses the results of testing high-voltage, high-power, solid-state remote power controllers (RPC) using RPCs designed and built by John C. Sturman at the Lewis Research Center, Cleveland, Ohio, and utilizing the Autonomously Managed Power Systems (AMPS) breadboard/test facility. These test results are used to determine usefulness of the RPCs for future applications in high-voltage direct-current space power.

Johnson, Yvette Binford; Kapustka, Robert E.

1988-01-01

183

Low-Power Low-Voltage Current Readout Circuit for Inductively Powered Implant System  

Microsoft Academic Search

Low voltage and low power are two key requirements for on-chip realization of wireless power and data telemetry for applications in biomedical sensor instrumentation. Batteryless operation and wireless telemetry facilitate robust, reliable, and longer lifetime of the implant unit. As an ongoing research work, this paper demonstrates a low-power low-voltage sensor readout circuit which could be easily powered up with

Mohammad R. Haider; Syed K. Islam; Salwa Mostafa; Mo Zhang; Taeho Oh

2010-01-01

184

Electric Power Monthly, July 1990  

SciTech Connect

The Electric Power Monthly (EPM) is prepared by the Electric Power Division; Office of Coal, Nuclear, Electric and Alternate Fuels, Energy Information Administration (EIA), Department of Energy. This publication provides monthly statistics at the national, Census division, and State levels for net generation, fuel consumption, fuel stocks, quantity and quality of fuel, cost of fuel, electricity sales, and average revenue per kilowatthour of electricity sold. Data on net generation are also displayed at the North American Electric Reliability Council (NERC) region level. Additionally, company and plant level information are published in the EPM on capability of new plants, net generation, fuel consumption, fuel stocks, quantity and quality of fuel, and cost in fuel. Quantity, quality, and cost of fuel data lag the net generation, fuel consumption, fuel stocks, electricity sales, and average revenue per kilowatthour data by 1 month. This difference in reporting appears in the national, Census division, and State level tables. However, at the plant level, all statistics presented are for the earlier month for the purpose of comparison. 12 refs., 4 figs., 48 tabs.

Not Available

1990-10-12

185

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

E-print Network

1 Intelligent Voltage and Reactive Power Control of Mini-Hydro Power Stations for Maximisation Control (APFC) modes. The ability to export active and reactive power from mini-hydro power generators that are connected to the Distribution Network (DN) in many countries. Mini-hydro power generation plants based

Harrison, Gareth

186

Fast Probabilistic Assessment of Voltage Dips in Power Systems  

Microsoft Academic Search

The stochastic prediction of voltage dips due to faults in transmission and distribution systems can be effected applying the fault position method. Also assuming deterministic operating condition before the faults and pre-assigned failure rates of the faulted components, this method may require severe computational efforts in case of high dimension power systems. In the paper a Monte Carlo simulation procedure

P. Caramia; G. Carpinelli; C. di Perna; P. Varilone; P. Verde

2006-01-01

187

Power optimization of variable-voltage core-based systems  

Microsoft Academic Search

The growing class of portable systems, such as personal computing and communication devices, has resulted in a new set of system design requirements, mainly characterized by dominant importance of power minimization and design reuse. The energy efficiency of systems-on-a-chip (SOC) could be much improved if one were to vary the supply voltage dynamically at run time. We develop the design

Inki Hong; Darko Kirovski; Gang Qu; Miodrag Potkonjak; Mani B. Srivastava

1999-01-01

188

Evaluation of high temperature dielectric films for high voltage power electronic applications  

NASA Technical Reports Server (NTRS)

Three high temperature films, polyimide, Teflon perfluoroalkoxy and poly-P-xylene, were evaluated for possible use in high voltage power electronic applications, such as in high energy density capacitors, cables and microelectronic circuits. The dielectric properties, including permittivity and dielectric loss, were obtained in the frequency range of 50 Hz to 100 kHz at temperatures up to 200 C. The dielectric strengths at 60 Hz were determined as a function of temperature to 250 C. Confocal laser microscopy was performed to diagnose for voids and microimperfections within the film structure. The results obtained indicate that all films evaluated are capable of maintaining their high voltage properties, with minimal degradation, at temperatures up to 200 C. However, above 200 C, they lose some of their electrical properties. These films may therefore become viable candidates for high voltage power electronic applications at high temperatures.

Suthar, J. L.; Laghari, J. R.

1992-01-01

189

Power optimization of variable voltage core-based systems  

Microsoft Academic Search

The growing class of portable systems, such as personal computing and communication devices, has resulted in a new set of system design requirements, mainly characterized by dominant importance of power minimization and design reuse. We develop the design methodology for the low power core-based real-time system-on-chip based on dynamically variable voltage hardware. The key challenge is to develop effective scheduling

Inki Hong; Darko Kirovski; Gang Qu; Miodrag Potkonjak; Mani B. Srivastava

1998-01-01

190

Power Usage and Electrical Circuit Analysis for Electric Arc Furnaces  

Microsoft Academic Search

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

J. J. Trageser

1980-01-01

191

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

Microsoft Academic Search

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

Dake Liu; Christer Svensson

1993-01-01

192

Electrical stress and inception voltage of discharges in gaseous cavities in an anisotropic dielectric material  

Microsoft Academic Search

The electric field stress and the inception voltage of discharges in a gaseous void present in an anisotropic dielectric material is developed from the solution of the Laplace equation. The relevant equations for the determination of the electric field and the inception voltage of discharges in voids are presented in a format that can be readily used. The electric field

M. M. A. Salama; M. S. Rizk; R. Hackam

1986-01-01

193

Application of high voltage electric field (HVEF) drying technology in potato chips  

NASA Astrophysics Data System (ADS)

In order to improve the drying efficiency and qualities of vegetable by high voltage electric field (HVEF), potato chips as a representative of vegetable was dried using a high voltage electric drying systems at 20°C. The shrinkage rate, water absorption and rehydration ratio of dried potato chips were measured. The results indicated that the drying rate of potato chips was significantly improved in the high voltage electric drying systems. The shrinkage rate of potato chips dried by high voltage electric field was 1.1% lower than that by oven drying method. And the rehydration rate of high voltage electric field was 24.6% higher than that by oven drying method. High voltage electric field drying is very advantageous and can be used as a substitute for traditional drying method.

Bai, Yaxiang; Shi, Hua; Yang, Yaxin

2013-03-01

194

Converting a Motorcycle to Electric Power  

E-print Network

Research was conducted to determine how simple and practical it would be to convert a standard gasoline powered motorcycle to electric power. The research involved background investigation of useful concepts in electric powered motorcycles...

Simcoe, Christopher M.

2009-12-18

195

30 CFR 75.812 - Movement of high-voltage power centers and portable transformers; permit.  

Code of Federal Regulations, 2012 CFR

...high-voltage power centers and portable transformers; permit. 75.812 Section...high-voltage power centers and portable transformers; permit. [Statutory Provisions... Power centers and portable transformers shall be deenergized...

2012-07-01

196

30 CFR 75.812 - Movement of high-voltage power centers and portable transformers; permit.  

Code of Federal Regulations, 2013 CFR

...high-voltage power centers and portable transformers; permit. 75.812 Section...high-voltage power centers and portable transformers; permit. [Statutory Provisions... Power centers and portable transformers shall be deenergized...

2013-07-01

197

30 CFR 75.812 - Movement of high-voltage power centers and portable transformers; permit.  

Code of Federal Regulations, 2011 CFR

...high-voltage power centers and portable transformers; permit. 75.812 Section...high-voltage power centers and portable transformers; permit. [Statutory Provisions... Power centers and portable transformers shall be deenergized...

2011-07-01

198

30 CFR 75.812 - Movement of high-voltage power centers and portable transformers; permit.  

...high-voltage power centers and portable transformers; permit. 75.812 Section...high-voltage power centers and portable transformers; permit. [Statutory Provisions... Power centers and portable transformers shall be deenergized...

2014-07-01

199

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

NASA Astrophysics Data System (ADS)

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.

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

2007-07-01

200

Electric generating water power device  

Microsoft Academic Search

The invention discloses a submerged water power machine in which a plurality of vertical blades are connected to two endless chains, one located at the top ends and the other located at the bottom ends of the blades. The blades drive the chains about two endless horizontal tracks, and the chains are drivingly coupled to electric generators. Each blade is

Davison

1979-01-01

201

Pulsed power for electric guns  

Microsoft Academic Search

Pulsed power requirements for electric guns are described and preferred technologies for energy storage and pulse compression are discussed. Primary approaches are rotating machines and capacitor based, pulse-forming networks, but alternative technologies that may offer some operational benefits are also discussed. These include linear magnetic flux compressors, cryogenically cooled, high-temperature superconducting inductors, novel dielectrics for energy storage, and pulsed magnetohydrodynamic

Ian R. McNab

1997-01-01

202

High voltage characteristics of the electrodynamic tether and the generation of power and propulsion  

NASA Technical Reports Server (NTRS)

The Tethered Satellite System (TSS) will deploy and retrieve a satellite from the Space Shuttle orbiter with a tether of up to 100 km in length attached between the satellite and the orbiter. The characteristics of the TSS which are related to high voltages, electrical currents, energy storage, power, and the generation of plasma waves are described. A number of specific features of the tether system of importance in assessing the operational characteristics of the electrodynamic TSS are identified.

Williamson, P. R.

1986-01-01

203

Software control program for 25 kW breadboard testing. [spacecraft power supplies; high voltage batteries  

NASA Technical Reports Server (NTRS)

A data acquisition software program developed to operate in conjunction with the automated control system of the 25 kW PM Electric Power System Breadboard Test facility is described. The proram provides limited interactive control of the breadboard test while acquiring data and monitoring parameters, allowing unattended continuous operation. The breadboard test facility has two positions for operating separate configurations. The main variable in each test setup is the high voltage Ni-Cd battery.

Pajak, J. A.

1981-01-01

204

Electric power monthly, January 1994  

SciTech Connect

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. This publication provides monthly statistics at the US 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. Statistics by company and plant are published in the EPM on the capability of new generating units, net generation, fuel consumption, fuel stocks, quantity and quality of fuel, and cost of fossil fuels.

Not Available

1994-01-26

205

Electric power monthly, February 1994  

SciTech Connect

The Electric Power Monthly (EMP) 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. This publication provides monthly statistics at the US, Census division, and State levels for net generation, fossil fuel consumption and stocks, quantity and quality of fossil fuels, cost of 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. Statistics by company and plant are published in the EPM on the capability of new generating units, net generation, fuel consumption, fuel stocks, quantity and quality of fuel, and cost of fossil fuels.

Not Available

1994-02-16

206

Electric power monthly, October 1993  

SciTech Connect

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. This publication provides monthly statistics at the US, 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. Statistics by company and plant are published in the EPM on the capability of new generating units, net generation, fuel consumption, fuel stocks, quantity and quality of fuel, and cost of fossil fuels.

Not Available

1993-10-20

207

Electric power annual 1995. Volume II  

SciTech Connect

This document summarizes pertinent statistics on various aspects of the U.S. electric power industry for the year and includes a graphic presentation. Data is included on electric utility retail sales and revenues, financial statistics, environmental statistics of electric utilities, demand-side management, electric power transactions, and non-utility power producers.

NONE

1996-12-01

208

A method for encapsulating high voltage power transformers  

SciTech Connect

Voltage breakdowns become a major concern in reducing the size of high-voltage power converter transformers. Even the smallest of voids can provide a path for corona discharge which can cause a dielectric breakdown leading to a transformer failure. A method of encapsulating small high voltage transformers has been developed. The method virtually eliminates voids in the impregnation material, provides an exceptional dielectric between windings and provides a mechanically rugged package. The encapsulation material is a CTBN modified mica filled epoxy. The method requires heat/vacuum to impregnate the coil and heat/pressure to cure the encapsulant. The transformer package utilizes a Diallyl Phthalate (DAP) contact assembly in which a coated core/coil assembly is mounted and soldered. This assembly is then loaded into an RTV mold and the encapsulation process begins.

Sanchez, R.O.

1990-01-01

209

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

Microsoft Academic Search

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.

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

1995-01-01

210

Electric power monthly, July 1994  

SciTech Connect

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. The EPM is prepared by the Survey Management Division; Office of Coal, Nuclear, Electric and Alternate Fuels, Energy Information Administration (EIA), Department of Energy. This publication provides monthly statistics at the US, 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. Statistics by company and plant are published in the EPM on the capability of new generating units, net generation, fuel consumption, fuel stocks, quantity and quality of fuel, and cost of fossil fuels. Data on quantity, quality, and cost of fossil fuels lag data on net generation, fuel consumption, fuel stocks, electricity sales, and average revenue per kilowatthour by 1 month. This difference in reporting appears in the US, Census division, and State level tables. However, for purposes of comparison, plant-level data are presented for the earlier month.

Not Available

1994-07-01

211

Manned spacecraft electrical power systems  

NASA Technical Reports Server (NTRS)

A brief history of the development of electrical power systems from the earliest manned space flights illustrates a natural trend toward a growth of electrical power requirements and operational lifetimes with each succeeding space program. A review of the design philosophy and development experience associated with the Space Shuttle Orbiter electrical power system is presented, beginning with the state of technology at the conclusion of the Apollo Program. A discussion of prototype, verification, and qualification hardware is included, and several design improvements following the first Orbiter flight are described. The problems encountered, the scientific and engineering approaches used to meet the technological challenges, and the results obtained are stressed. Major technology barriers and their solutions are discussed, and a brief Orbiter flight experience summary of early Space Shuttle missions is included. A description of projected Space Station power requirements and candidate system concepts which could satisfy these anticipated needs is presented. Significant challenges different from Space Shuttle, innovative concepts and ideas, and station growth considerations are discussed. The Phase B Advanced Development hardware program is summarized and a status of Phase B preliminary tradeoff studies is presented.

Simon, William E.; Nored, Donald L.

1987-01-01

212

75 FR 23823 - Sixth Northwest Electric Power and Conservation Plan  

Federal Register 2010, 2011, 2012, 2013

...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...

2010-05-04

213

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.

214

Electric Power Monthly, June 1990  

SciTech Connect

The EPM is prepared by the Electric Power Division; Office of Coal, Nuclear, Electric and Alternate Fuels, Energy Information Administration (EIA), Department of Energy. This publication provides monthly statistics at the national, Census division, and State levels for net generation, fuel consumption, fuel stocks, quantity and quality of fuel, electricity sales, and average revenue per kilowatthour of electricity sold. Data on net generation are also displayed at the North American Electric Reliability Council (NERC) region level. Additionally, company and plant level information are published in the EPM on capability of new plants, net generation, fuel consumption, fuel stocks, quantity and quality of fuel, and cost of fuel. Quantity, quality, and cost of fuel data lag the net generation, fuel consumption, fuel stocks, electricity sales, and average revenue per kilowatthour data by 1 month. This difference in reporting appears in the national, Census division, and State level tables. However, at the plant level, all statistics presented are for the earlier month for the purpose of comparison. 40 tabs.

Not Available

1990-09-13

215

High Input Voltage Discharge Supply for High Power Hall Thrusters Using Silicon Carbide Devices  

NASA Technical Reports Server (NTRS)

A power processing unit for a 15 kW Hall thruster is under development at NASA Glenn Research Center. The unit produces up to 400 VDC with two parallel 7.5 kW discharge modules that operate from a 300 VDC nominal input voltage. Silicon carbide MOSFETs and diodes were used in this design because they were the best choice to handle the high voltage stress while delivering high efficiency and low specific mass. Efficiencies in excess of 97 percent were demonstrated during integration testing with the NASA-300M 20 kW Hall thruster. Electromagnet, cathode keeper, and heater supplies were also developed and will be integrated with the discharge supply into a vacuum-rated brassboard power processing unit with full flight functionality. This design could be evolved into a flight unit for future missions that requires high power electric propulsion.

Pinero, Luis R.; Scheidegger, Robert J.; Aulsio, Michael V.; Birchenough, Arthur G.

2014-01-01

216

Power processing for electric propulsion  

NASA Technical Reports Server (NTRS)

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).

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

1975-01-01

217

Advanced voltage regulation method of power distribution systems interconnected with dispersed storage and generation systems  

Microsoft Academic Search

This paper deals with an issue of voltage regulation for power distribution systems interconnected with dispersed storage and generation (DSG) systems. Since DSGs within power distribution systems impact on the conventional voltage regulation method, there is a possibility that customers' voltages violate the permissible limits. A multiple line drop compensation (MLDC) voltage regulation method that determines tap positions of under-load

Joon-Ho Choi; Jae-Chul Kim

2001-01-01

218

High-efficiency power amplifier using dynamic power-supply voltage for CDMA applications  

Microsoft Academic Search

Efficiency and linearity of the microwave power amplifier are critical elements for mobile communication systems. This paper discusses improvements in system efficiency that are obtainable when a DC-DC converter is used to convert available battery voltage to an optimal supply voltage for the output RF amplifier. A boost DC-DC converter with an operating frequency of 10 MHz is demonstrated using

Gary Hanington; Pin-Fan Chen; Peter M. Asbeck; Lawrence E. Larson

1999-01-01

219

Novel high-voltage power lateral MOSFET with adaptive buried electrodes  

NASA Astrophysics Data System (ADS)

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.

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

2012-07-01

220

Capacity of Overhead Medium Voltage Power Line Communication Channels  

Microsoft Academic Search

This paper considers broadband transmission via the overhead medium voltage (MV) grid. The MV broadband over power lines (MV\\/BPL) channels considered are three-phase overhead MV lines above lossy plane ground. To determine the end-to-end transfer function of any MV\\/BPL configuration the scattering matrix method is adopted. Various topologies of MV\\/BPL transmission channels have been studied with regard to their end-to-end

Athanasios G. Lazaropoulos; Panayiotis G. Cottis

2010-01-01

221

Power Sales to Electric Utilities  

SciTech Connect

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

None

1989-02-01

222

Module Two: Voltage; Basic Electricity and Electronics Individualized Learning System.  

ERIC Educational Resources Information Center

In this module the student will study and learn what voltage is, how it is generated, what AC (alternating current) and DC (direct current) are and why both kinds are needed, and how to measure voltages. The module is divided into six lessons: EMF (electromotive force) from chemical action, magnetism, electromagnetic induction, AC voltage, the…

Bureau of Naval Personnel, Washington, DC.

223

Seismic reliability of electrical power transmission systems  

Microsoft Academic Search

The reliability of electric power transmission systems is important for the probabilistic safety assessment of nuclear power plants under a given earthquake loading as it relates to the loss of off site power to the nuclear power plants. Here, a comprehensive model to evaluate the seismic reliability of electric power transmission systems is presented. The model provides probabilistic assessments of

J. A. Pires; A. H.-S. Ang; R. Villaverde

1996-01-01

224

Electric Power Reliability in Chemical Plants  

E-print Network

The quality and reliability of utility-generated electric power is presently receiving a great deal of attention from the chemical and refining industry. What changes have taken place to make electric power reliability a major topic of discussion...

Cross, M. B.

225

Interline photovoltaic (I-PV) power plants for voltage unbalance compensation  

E-print Network

This paper proposes a stationary-frame control method for voltage unbalance compensation using Interline Photovoltaic (I-PV) power system. I-PV power systems are controlled to compensate voltage unbalance autonomously. The ...

Moawwad, Ahmed

226

Electric vehicles as a new power source for electric utilities  

Microsoft Academic Search

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

Steven E. Letendre

1997-01-01

227

Electric power distribution and load transfer system  

NASA Technical Reports Server (NTRS)

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.

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

1987-01-01

228

Electric power distribution and load transfer system  

NASA Technical Reports Server (NTRS)

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.

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

1989-01-01

229

FBG based intelligent sensors and structure for electrical power system  

NASA Astrophysics Data System (ADS)

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 the FBG, while the magnetic field or current sensor is based on the giant magnetostriction material (GMM). The characteristics of FBG strain, the relationship between the electrostriction displacement of piezoelectric ceramic (PZT) material and the excitation voltage, relationship of the magnetostriction displacement with excitation current, are analyzed respectively. The designed intelligent electrostrictive and magnetostrictive sensors are both with temperature compensation. In each sensor, two FBG's are bonded in perpendicular to each other that the electrostictive or magnetostrictive effects on the two gratings are added together, while the temperature effects are cancelled out. These electrical parameter sensors can be widely used for fault diagnosis in electrical substation. The development trend and applications of FBG sensors for power system are discussed.

Yao, Yuan; Yi, Benshun; Xiao, Jinsheng; Li, Zhaohui

2007-07-01

230

A wide input voltage range ZVS isolated bidirectional DC-DC converter for ultra-capacitor application in hybrid and electric vehicles  

Microsoft Academic Search

This paper presents a new wide input voltage range ZVS isolated bidirectional DC\\/DC converter for an ultra-capacitor module used as an auxiliary power supply in electric vehicles. Compared to the conventional bidirectional converters, this modified circuit minimizes device current stress over a wide input voltage range. A natural zero-voltage switching for the transformer-connected switches is achieved without additional device. Moreover,

Shenghui Cui; Dawei He; Zhuoyu Chen; Thomas G. Habetler

2012-01-01

231

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

SciTech Connect

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.

Not Available

1981-04-01

232

VSCF aircraft electric power system performance with active power filters  

Microsoft Academic Search

A three-phase three-wire shunt active power filter (APF) is presented to regulate the load terminal voltage, eliminate harmonics, correct supply power-factor and balance the nonlinear unbalanced loads. A three-phase based current controlled voltage source inverter is used as an active power filter. The control algorithm for the APF is based on the perfect harmonic cancellation method which provides a three-phase

A. Eid; H. El-Kishky; M. Abdel-Salam; T. El-Mohandes

2010-01-01

233

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

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.

None

2012-01-25

234

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

NASA Astrophysics Data System (ADS)

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.

Haubert, T.; Mindl, P.

235

High voltage electrical burn injuries in teenage children: case studies with similarities (an indian perspective)  

PubMed Central

Summary From 1992 to 2012, a total of 911 paediatric burns were admitted and treated at Kanchi Kamakoti Childs Trust Hospital Intensive Burn Care Unit, of these 28 children had suffered electrical injuries and burns. 7 teenagers suffered high voltage electrical burn injuries: 2 were involved in train accidents which caused fatal electrical injuries, and 5 had electrical burn injuries caused by similar types of accidents, requiring Paediatric Intensive Care Unit (PICU) care, repeated surgeries and extensive rehabilitation. A common factor among these latter 5 patients was that they were injured by overhead high electrical voltage cables. Their management was labour intensive and highly costly. In this report, the type of accident, the electrical voltage that produced burns and the treatment details are elaborated. Findings included similarities in age and type of accident, and failure to implement safety procedures and apply standard norms of high voltage transmission feeder lines. PMID:24563637

Mathangi Ramakrishnan, K.; Babu, M.; Mathivanan; Ramachandran, B.; Balasubramanian, S.; Raghuram, K.

2013-01-01

236

Limiting electric fields of HVDC overhead power lines.  

PubMed

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

Leitgeb, N

2014-05-01

237

30 CFR 77.703 - Grounding frames of stationary high-voltage equipment receiving power from ungrounded delta systems.  

Code of Federal Regulations, 2010 CFR

...Grounding frames of stationary high-voltage equipment receiving power from...Grounding frames of stationary high-voltage equipment receiving power from... The frames of all stationary high-voltage equipment receiving power...

2010-07-01

238

30 CFR 75.704 - Grounding frames of stationary high-voltage equipment receiving power from ungrounded delta systems.  

Code of Federal Regulations, 2010 CFR

...Grounding frames of stationary high-voltage equipment receiving power from...Grounding frames of stationary high-voltage equipment receiving power from... The frames of all stationary high-voltage equipment receiving power...

2010-07-01

239

Application of Newton's optimal power flow in voltage/reactive power control  

SciTech Connect

This paper considers an application of Newton's optimal power flow to the solution of the secondary voltage/reactive power control in transmission networks. An efficient computer program based on the latest achievements in the sparse matrix/vector techniques has been developed for this purpose. It is characterized by good robustness, accuracy and speed. A combined objective function appropriate for various system load levels with suitable constraints, for treatment of the power system security and economy is also proposed. For the real-time voltage/reactive power control, a suboptimal power flow procedure has been derived by using the reduced set of control variables. This procedure is based on the sensitivity theory applied to the determination of zones for the secondary voltage/reactive power control and corresponding reduced set of regulating sources, whose reactive outputs represent control variables in the optimal power flow program. As a result, the optimal power flow program output becomes a schedule to be used by operators in the process of the real-time voltage/reactive power control in both normal and emergency operating states.

Bjelogrlic, M.; Babic, B.S. (Electric Power Board of Serbia, Belgrade (YU)); Calovic, M.S. (Dept. of Electrical Engineering, University of Belgrade, Belgrade (YU)); Ristanovic, P. (Institute Nikola Tesla, Belgrade (YU))

1990-11-01

240

Ferroelectric Emission Cathodes for Low-Power Electric Propulsion  

NASA Technical Reports Server (NTRS)

Low- or no-flow electron emitters are required for low-power electric thrusters, spacecraft plasma contactors, and electrodynamic tether systems to reduce or eliminate the need for propellant/expellant. Expellant-less neutralizers can improve the viability of very low-power colloid thrusters, field emission electric propulsion devices, ion engines, Hall thrusters, and gridded vacuum arc thrusters. The NASA Glenn Research Center (GRC) is evaluating ferroelectric emission (FEE) cathodes as zero expellant flow rate cathode sources for the applications listed above. At GRC, low voltage (100s to approx. 1500 V) operation of FEE cathodes is examined. Initial experiments, with unipolar, bipolar, and RF burst applied voltage, have produced current pulses 250 to 1000 ns in duration with peak currents of up to 2 A at voltages at or below 1500 V. In particular, FEE cathodes driven by RF burst voltages from 1400 to 2000 V peak to peak, at burst frequencies from 70 to 400 kHz, emitted average current densities from 0.1 to 0.7 A/sq cm. Pulse repeatability as a function of input voltage has been initially established. Reliable emission has been achieved in air background at pressures as high as 10(exp -6) Torr.

Kovaleski, Scott D.; Burke, Tom (Technical Monitor)

2002-01-01

241

Power Management Unit A digitalized Embedded Linear Voltage Regulator for  

E-print Network

, DVD player, car, electric motors, display devices, trains, ... #12;Page 4Copyright © Infineon Hybrid Battery Management Mirror IntroductionIntroduction Modern high-end cars contain up to one hundred Control Chassis Active Suspension, Power Steering Powertrain Engine Control Transmission Control Battery

Wichmann, Felix

242

Wildlife and electric power transmission  

USGS Publications Warehouse

Hundreds of thousands of miles of transmission lines have been introduced into our natural environment. These lines and their corridors can be damaging or beneficial to wildlife communities depending on how they are designed, where they are placed, and when they are constructed and maintained. With the current trend toward UHV systems, new problems (associated with additional increments in audible noise, electric and magnetic force fields, etc.) must be addressed. We recommend the following areas for careful study: (1) the response of wilderness species to transmission lines and line construction and maintenance activities (2) the magnitude of bird collision and electrocution mortality, (3) the response of power corridor and power tower in habiting wildlife to laboratory and field doses of electro-chemical oxidants, corona noise, electric and magnetic fields, etc., (4) the productivity of tower inhabiting birds compared with nearby non-tower nesters, and (5) the influence of powerline corridors on mammalian and avian migration patterns. It is our hope that the questions identified in this study will help stimulate further research so that we can maximize wildlife benefits and minimize wildlife detriments.

Ellis, D.H.; Goodwin, J.G., Jr.; Hunt, J.R.

1978-01-01

243

Voltage measurements at the vacuum post-hole convolute of the Z pulsed-power accelerator  

NASA Astrophysics Data System (ADS)

Presented are voltage measurements taken near the load region on the Z pulsed-power accelerator using an inductive voltage monitor (IVM). Specifically, the IVM was connected to, and thus monitored the voltage at, the bottom level of the accelerator's vacuum double post-hole convolute. Additional voltage and current measurements were taken at the accelerator's vacuum-insulator stack (at a radius of 1.6 m) by using standard D -dot and B -dot probes, respectively. During postprocessing, the measurements taken at the stack were translated to the location of the IVM measurements by using a lossless propagation model of the Z accelerator's magnetically insulated transmission lines (MITLs) and a lumped inductor model of the vacuum post-hole convolute. Across a wide variety of experiments conducted on the Z accelerator, the voltage histories obtained from the IVM and the lossless propagation technique agree well in overall shape and magnitude. However, large-amplitude, high-frequency oscillations are more pronounced in the IVM records. It is unclear whether these larger oscillations represent true voltage oscillations at the convolute or if they are due to noise pickup and/or transit-time effects and other resonant modes in the IVM. Results using a transit-time-correction technique and Fourier analysis support the latter. Regardless of which interpretation is correct, both true voltage oscillations and the excitement of resonant modes could be the result of transient electrical breakdowns in the post-hole convolute, though more information is required to determine definitively if such breakdowns occurred. Despite the larger oscillations in the IVM records, the general agreement found between the lossless propagation results and the results of the IVM shows that large voltages are transmitted efficiently through the MITLs on Z . These results are complementary to previous studies [R. D. McBride et al., Phys. Rev. ST Accel. Beams 13, 120401 (2010)] that showed efficient transmission of large currents through the MITLs on Z . Taken together, the two studies demonstrate the overall efficient delivery of very large electrical powers through the MITLs on Z .

Waisman, E. M.; McBride, R. D.; Cuneo, M. E.; Wenger, D. F.; Fowler, W. E.; Johnson, W. A.; Basilio, L. I.; Coats, R. S.; Jennings, C. A.; Sinars, D. B.; Vesey, R. A.; Jones, B.; Ampleford, D. J.; Lemke, R. W.; Martin, M. R.; Schrafel, P. C.; Lewis, S. A.; Moore, J. K.; Savage, M. E.; Stygar, W. A.

2014-12-01

244

Nonlinear behavior of electric power transmission through an elastic wall by acoustic waves and piezoelectric transducers  

Microsoft Academic Search

Weakly nonlinear behavior of electric power transmission through an elastic wall by piezoelectric transducers and acoustic waves near resonance is studied based on the cubic theory of nonlinear electroelasticity. An approximate analytical solution is obtained. Output voltage is calculated and plotted. Basic nonlinear behaviors of the power transmission structure are examined. It is found that near nonlinear resonance the electrical

Zengtao Yang; Jiashi Yang; Yuantai Hu

2008-01-01

245

Precise time and time interval applications to electric power systems  

NASA Technical Reports Server (NTRS)

There are many applications of precise time and time interval (frequency) in operating modern electric power systems. Many generators and customer loads are operated in parallel. The reliable transfer of electrical power to the consumer partly depends on measuring power system frequency consistently in many locations. The internal oscillators in the widely dispersed frequency measuring units must be syntonized. Elaborate protection and control systems guard the high voltage equipment from short and open circuits. For the highest reliability of electric service, engineers need to study all control system operations. Precise timekeeping networks aid in the analysis of power system operations by synchronizing the clocks on recording instruments. Utility engineers want to reproduce events that caused loss of service to customers. Precise timekeeping networks can synchronize protective relay test-sets. For dependable electrical service, all generators and large motors must remain close to speed synchronism. The stable response of a power system to perturbations is critical to continuity of electrical service. Research shows that measurement of the power system state vector can aid in the monitoring and control of system stability. If power system operators know that a lightning storm is approaching a critical transmission line or transformer, they can modify operating strategies. Knowledge of the location of a short circuit fault can speed the re-energizing of a transmission line. One fault location technique requires clocks synchronized to one microsecond. Current research seeks to find out if one microsecond timekeeping can aid and improve power system control and operation.

Wilson, Robert E.

1992-01-01

246

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

247

A market mechanism for electric power transmission  

Microsoft Academic Search

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

Hung-Po Chao; Stephen Peck

1996-01-01

248

Investigation of Voltage and Current Variations in a Multiphase AC Electric Arc System  

E-print Network

Investigation of Voltage and Current Variations in a Multiphase AC Electric Arc System Ph. G-6]. High-current electric arcs or electric arc plasma torches are used practically in all plasma into the arc is transformed by means of heat exchange to the internal energy of the working gas. Use of plasma

Boyer, Edmond

249

Reactive power control for variable speed wind turbines to low voltage ride through grid code compliance  

Microsoft Academic Search

This paper is dealing with the reactive power management of two kinds of variable speed wind turbine (WT) technologies in order to respect the grid code requirements during voltage dips. Nowadays, the WT systems are asked to fulfil with many grid connection requirements, especially to provide reactive power during dip voltage with the aim of better voltage recovering. Specific controls

A. Teninge; D. Roye; S. Bacha

2010-01-01

250

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

E-print Network

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

Bellan, Paul M.

251

COMPOSITE LOAD SENSITIVITY IN VOLTAGE STABILITY PROBLEM SOLVED BY UNIFIED POWER FLOW CONTROLLER  

Microsoft Academic Search

Alleviation of voltage stability problem by using Unified Power Flow Controller (UPFC) represents main concern of this paper. The UPFC is analysed as the device capable of giving voltage support and\\/or co- ordinating power flow control action. Voltage stability problem is viewed from longer-term time domain response of a composite load model. Sensitivity analysis is applied with respect to parameters

Nijaz Dizdarevi? S; Göran Andersson

2002-01-01

252

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

NASA Technical Reports Server (NTRS)

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.)

Vorpenian, Vatche

2008-01-01

253

Reducing the Vulnerability of Electric Power Grids to Terrorist Attacks  

SciTech Connect

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.

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

2009-01-31

254

Renewable and Efficient Electric Power Systems  

E-print Network

­2004 #12;#12;CONTENTS Preface xvii 1 Basic Electric and Magnetic Circuits 1 1.1 Introduction to Electric Circuits 1 1.2 Definitions of Key Electrical Quantities 2 1.2.1 Charge 2 1.2.2 Current 3 1.2.3 KirchhoffRenewable and Efficient Electric Power Systems Gilbert M. Masters Stanford University A JOHN WILEY

Kammen, Daniel M.

255

Design and installation of extra high voltage cryogenic dielectric test facilities for the superconducting electric equipment  

NASA Astrophysics Data System (ADS)

Superconducting electric equipments have a lot of advantages over the conventional devices such as improvements in overall efficiency, size reduction, high current carrying capability, and also environment-friendly products. Owing to these advantages, many research institutes have been tried to develop commercial superconducting devices, which could be applicable to the high voltage and high current electric networks. But up to now, most of the research works to develop commercial products were delayed because it was not easy to acquire reliable high voltage insulation properties and optimum insulation design skills considering extremely low temperature environments. Furthermore, it was difficult to determine optimum high voltage insulation level due to the lack of high voltage cryogenic dielectric test facilities. Thus, in order to establish the cryogenic dielectric technology regarding insulating design, cryogenic dielectric test skills, and to implement more reliable high voltage superconducting devices, high voltage cryogenic dielectric test facilities should be prepared for extra high voltage superconducting electric equipments. Recently, cryogenic dielectric test facilities were installed including 3 m long 2 m wide cryostat system with bushing, and 1.6 MVA lightening impulse generators, 400 kVA AC overvoltage test system in Korea. In this paper, design and installation of high voltage cryogenic dielectric test system including very big size FRP cryostat and high voltage bushing were minutely introduced. And some test results to develop high voltage bushings for liquid nitrogen cryostat in order to implement extra high voltage level bushings were illustrated. These test facilities will be fully utilized for the optimization of insulation design for extra high voltage superconducting electric equipments.

Lee, S. H.; Shin, W. J.; Khan, Umer A.; Oh, S. H.; Seong, J. K.; Lee, B. W.

2011-11-01

256

Review of electric power engineering education worldwide  

Microsoft Academic Search

The Power Engineering Education Committee sponsored panel session gives an outline of the status of electric power system education in different countries of the world. Graduate and undergraduate electrical power engineering programs typical to a particular country are described. The descriptions include the concepts of graduate and undergraduate education, typical courses and laboratory schedules, tutorials, credits or number of courses

G. G. Karady; G. T. Heydt; M. Michel; P. Crossley; H. Rudnick; S. Iwamoto

1999-01-01

257

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

258

Wind wheel electric power generator  

NASA Technical Reports Server (NTRS)

Wind wheel electric power generator apparatus includes a housing rotatably mounted upon a vertical support column. Primary and auxiliary funnel-type, venturi ducts are fixed onto the housing for capturing wind currents and conducting to a bladed wheel adapted to be operatively connected with the generator apparatus. Additional air flows are also conducted onto the bladed wheel; all of the air flows positively effecting rotation of the wheel in a cumulative manner. The auxiliary ducts are disposed at an acute angle with respect to the longitudinal axis of the housing, and this feature, together with the rotatability of the housing and the ducts, permits capture of wind currents within a variable directional range.

Kaufman, J. W. (inventor)

1980-01-01

259

Voltage-Sensitive Dyes And Imaging Techniques Reveal New Patterns Of Electrical Activity In Heart Cortex  

NASA Astrophysics Data System (ADS)

Voltage-sensitive dyes bind to the plasms membrane of excitable cells (ie., muscle or nerve cells) and exhibit fluorescence and/or absorption changes that vary linearly with changes in transmembrane electrical potential. These potentiometric optical probes can be used to measure local changes in transmembrane potential by monitoring optical signals from dye molecules bound to the surface membrane. Consequently, when excitable cells are stained with such a dye and are stimulated to fire an electrical impulse (ie., an action potential (AP)), the changes in dye fluorescence have the characteristic shape and time course of APs recorded with an intracellular micro-electrode. Potentiometric dyes in conjuction with imaging techniques can now be used to visualize complex patterns and propagation of electrical activity. With photodiode arrays on video imaging techniques, patterns of biological electrical activity can be obtained with high temporal and spatial resolution which could not be obtained by conventional micro-electrodes. These methods reveal new details and offer powerful approaches to study fundamental problem in cardiac electrophysiology, communication in nerve networks, and the organization of cortical neurons.

Salama, Guy

1988-04-01

260

High voltage space plasma interactions. [charging the solar power satellites  

NASA Technical Reports Server (NTRS)

Two primary problems resulted from plasma interactions; one of concern to operations in geosynchronous orbit (GEO), the other in low orbits (LEO). The two problems are not the same. Spacecraft charging has become widely recognized as a problem, particularly for communications satellites operating in GEO. The very thin thermal plasmas at GEO are insufficient to bleed off voltage buildups due to higher energy charged particle radiation collected on outer surfaces. Resulting differential charging/discharging causes electrical transients, spurious command signals and possible direct overload damage. An extensive NASA/Air Force program has been underway for several years to address this problem. At lower altitudes, the denser plasmas of the plasmasphere/ionosphere provide sufficient thermal current to limit such charging to a few volts or less. Unfortunately, these thermal plasma currents which solve the GEO spacecraft charging problem can become large enough to cause just the opposite problem in LEO.

Mccoy, J. E.

1980-01-01

261

Reduction in overvoltages and dynamic power losses in power switches of multilevel voltage inverters  

NASA Astrophysics Data System (ADS)

A number of the circuit and design decisions that provide a reduction in overvoltage and dynamic power losses in power switches of multilevel voltage inverters with clamping diodes is considered. It is shown that the integral or unpackaged version is the most effective method for a reduction in the stray inductance in the multilevel circuit, which is the general cause for occurrence of dynamic overvoltage. To reduce dynamic losses of power, a method for resonant commutation on fronts, which provides commutation of switches in the multilevel circuit at zero voltage (SZV) and zero current (SZC), is proposed. The resonant switching method as applied to the multilevel circuit simultaneously solves a problem of dynamic overvoltage by means of limitation for the rate of voltage rise in the SZV mode or the mode of preliminary fault of energy stored in the inductance of the switching circuit in the SZC mode.

Voronin, P. A.; Voronin, I. P.; Panfilov, D. I.; Rozhkov, D. V.

2014-12-01

262

Multi-Objective Differential Evolution for Voltage Security Constrained Optimal Power Flow in Deregulated Power Systems  

NASA Astrophysics Data System (ADS)

Voltage stability is an important issue in the planning and operation of deregulated power systems. The voltage stability problems is a most challenging one for the system operators in deregulated power systems because of the intense use of transmission line capabilities and poor regulation in market environment. This article addresses the congestion management problem avoiding offline transmission capacity limits related to voltage stability by considering Voltage Security Constrained Optimal Power Flow (VSCOPF) problem in deregulated environment. This article presents the application of Multi Objective Differential Evolution (MODE) algorithm to solve the VSCOPF problem in new competitive power systems. The maximum of L-index of the load buses is taken as the indicator of voltage stability and is incorporated in the Optimal Power Flow (OPF) problem. The proposed method in hybrid power market which also gives solutions to voltage stability problems by considering the generation rescheduling cost and load shedding cost which relieves the congestion problem in deregulated environment. The buses for load shedding are selected based on the minimum eigen value of Jacobian with respect to the load shed. In the proposed approach, real power settings of generators in base case and contingency cases, generator bus voltage magnitudes, real and reactive power demands of selected load buses using sensitivity analysis are taken as the control variables and are represented as the combination of floating point numbers and integers. DE/randSF/1/bin strategy scheme of differential evolution with self-tuned parameter which employs binomial crossover and difference vector based mutation is used for the VSCOPF problem. A fuzzy based mechanism is employed to get the best compromise solution from the pareto front to aid the decision maker. The proposed VSCOPF planning model is implemented on IEEE 30-bus system, IEEE 57 bus practical system and IEEE 118 bus system. The pareto optimal front obtained from MODE is compared with reference pareto front and the best compromise solution for all the cases are obtained from fuzzy decision making strategy. The performance measures of proposed MODE in two test systems are calculated using suitable performance metrices. The simulation results show that the proposed approach provides considerable improvement in the congestion management by generation rescheduling and load shedding while enhancing the voltage stability in deregulated power system.

Roselyn, J. Preetha; Devaraj, D.; Dash, Subhransu Sekhar

2013-11-01

263

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

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

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

2002-01-01

264

Consumption of the electric power inside silent discharge reactors  

NASA Astrophysics Data System (ADS)

An experimental study was made in this paper to investigate the relation between the places of the dielectric barriers, which cover the surfaces of the electrodes in the coaxial cylindrical reactors, and the rate of change of the electric power that is consumed in forming silent discharges. Therefore, silent discharges have been formed inside three coaxial cylindrical reactors. The dielectric barriers in these reactors were pasted on both the internal surface of the outer electrode in the first reactor and the external surface of the inner electrode in the second reactor as well as the surfaces of the two electrodes in the third reactor. The reactor under study has been fed by atmospheric air that flowed inside it with a constant rate at normal temperature and pressure, in parallel with the application of a sinusoidal ac voltage between the electrodes of the reactor. The electric power consumed in forming the silent discharges inside the three reactors was measured as a function of the ac peak voltage. The validity of the experimental results was investigated by applying Manley's equation on the same discharge conditions. The results have shown that the rate of consumption of the electric power relative to the ac peak voltage per unit width of the discharge gap improves by a ratio of either 26.8% or 80% or 128% depending on the places of the dielectric barriers that cover the surfaces of the electrodes inside the three reactors.

Yehia, Ashraf

2015-01-01

265

Electrical power requirements analysis. Single failure tolerant entry  

NASA Technical Reports Server (NTRS)

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.

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

1977-01-01

266

Electric power substation capital costs  

SciTech Connect

The displacement or deferral of substation equipment is a key benefit associated with several technologies that are being developed with the support of the US Department of Energy`s Office of Utility Technologies. This could occur, for example, as a result of installing a distributed generating resource within an electricity distribution system. The objective of this study was to develop a model for preparing preliminary estimates of substation capital costs based on rudimentary conceptual design information. The model is intended to be used by energy systems analysts who need ``ballpark`` substation cost estimates to help establish the value of advanced utility technologies that result in the deferral or displacement of substation equipment. This cost-estimating model requires only minimal inputs. More detailed cost-estimating approaches are recommended when more detailed design information is available. The model was developed by collecting and evaluating approximately 20 sets of substation design and cost data from about 10 US sources, including federal power marketing agencies and private and public electric utilities. The model is principally based on data provided by one of these sources. Estimates prepared with the model were compared with estimated and actual costs for the data sets received from the other utilities. In general, good agreement (for conceptual level estimating) was found between estimates prepared with the cost-estimating model and those prepared by the individual utilities. Thus, the model was judged to be adequate for making preliminary estimates of typical substation costs for US utilities.

Dagle, J.E.; Brown, D.R.

1997-12-01

267

Electric power annual 1997. Volume 2  

SciTech Connect

The Electric Power Annual 1997, Volume 2 contains annual summary statistics at national, regional, and state levels for the electric power industry, including information on both electric utilities and nonutility power producers. Included are data for electric utility retail sales of electricity, associated revenue, and average revenue per kilowatthour of electricity sold; financial statistics; environmental statistics; power transactions; and demand-side management. Also included are data for US nonutility power producers on installed capacity; gross generation; emissions; and supply and disposition of energy. 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. 15 figs., 62 tabs.

NONE

1998-10-01

268

Solar energy thermally powered electrical generating system  

NASA Technical Reports Server (NTRS)

A thermally powered electrical generating system for use in a space vehicle is disclosed. The rate of storage in a thermal energy storage medium is controlled by varying the rate of generation and dissipation of electrical energy in a thermally powered electrical generating system which is powered from heat stored in the thermal energy storage medium without exceeding a maximum quantity of heat. A control system (10) varies the rate at which electrical energy is generated by the electrical generating system and the rate at which electrical energy is consumed by a variable parasitic electrical load to cause storage of an amount of thermal energy in the thermal energy storage system at the end of a period of insolation which is sufficient to satisfy the scheduled demand for electrical power to be generated during the next period of eclipse. The control system is based upon Kalman filter theory.

Owens, William R. (Inventor)

1989-01-01

269

Effects of nano-sized MgO-filler on electrical phenomena under DC voltage application in LDPE  

Microsoft Academic Search

A nanocomposite material, composed of nano-sized MgO-filler added to a low-density polyethylene (LDPE), was subjected to electrical property investigations under DC voltage application. The volume resistivity of LDPE, under 40-80 kV\\/mm DC field at 90 °C, increases by the power of 10 due to the addition of only a few percent of nano-filler. The amount of space charge in LDPE

Y. Murata; Y. Murakarni; M. Nemoto; Y. Sekiguchil; Y. Inoue; M. Kanaokal; N. Hozumi; M. Nagao

2005-01-01

270

Power supply quality improvement with a dynamic voltage restorer (DVR)  

Microsoft Academic Search

This paper presents the technical aspects of designing a dynamic voltage restorer to meet the stringent requirements of voltage dips mitigation with respect to the magnitude of voltage dip, fault duration, permissible line voltage deviations and response time. An introduction to IGCT technology based on latest transparent anode GTO (T-GTO) and gate technology is given. The performance of the DVR

A. Kara; P. Dahler; D. Amhof; H. Gruning

1998-01-01

271

Electrical power generation by mechanically modulating electrical double layers.  

PubMed

Since Michael Faraday and Joseph Henry made their great discovery of electromagnetic induction, there have been continuous developments in electrical power generation. Most people today get electricity from thermal, hydroelectric, or nuclear power generation systems, which use this electromagnetic induction phenomenon. Here we propose a new method for electrical power generation, without using electromagnetic induction, by mechanically modulating the electrical double layers at the interfacial areas of a water bridge between two conducting plates. We find that when the height of the water bridge is mechanically modulated, the electrical double layer capacitors formed on the two interfacial areas are continuously charged and discharged at different phases from each other, thus generating an AC electric current across the plates. We use a resistor-capacitor circuit model to explain the results of this experiment. This observation could be useful for constructing a micro-fluidic power generation system in the near future. PMID:23403587

Moon, Jong Kyun; Jeong, Jaeki; Lee, Dongyun; Pak, Hyuk Kyu

2013-01-01

272

The New Rules for Purchasing Electric Power  

E-print Network

utility business: - deregulation has created a competitive business - demand side management has grown in stature to rival supply side challenges - power rates have become marketing tools These developments affect the industrial sector more than...THE NEW RULES FOR PURCHASING ELECTRIC POWER KENNETH M. STERN CHEM SYSTEMS, INC. TARRYTOWN, NEW YORK SUMMARY The creation of new rules for purchasing electric power is largely an outgrowth of several recent developments affecting the electric...

Stern, K.

273

Predicting market power in wholesale electricity markets  

E-print Network

Predicting market power in wholesale electricity markets#3; David M Newbery Faculty of Economics, University of Cambridge August 26, 2008 Abstract The traditional measure of market power is the HHI, which gives implausible results given the low... elasticity of demand in electricity spot markets, unless it is adapted to take account of contracting. In its place the Residual Supply Index has been proposed as a more suitable index to measure potential market power in electricity markets, notably...

Newbery, David

274

Power Si-MOSFET operating with high efficiency under low supply voltage  

Microsoft Academic Search

A design method for RF power Si-MOSFETs suitable for low-voltage operation with high power-added efficiency is presented. In our experiments, supply voltages from 1 V to 3 V are examined. As the supply voltage is decreased, degradation of transconductance also takes place. However, this problem is overcome, even at extremely low supply voltages, by adopting a short gate length and

Tatsuya Ohguro; Masanobu Saito; Eiji Morifuji; Koji Murakami; Kazuhiro Matsuzaki; Takashi Yoshitomi; Toyota Morimoto; Hisayo Sasaki Momose; Yasuhiro Katsumata; Hiroshi Iwai

2000-01-01

275

Electric power annual 1995. Volume I  

SciTech Connect

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.

NONE

1996-07-01

276

Computer Power. Part 2: Electrical Power Problems and Their Amelioration.  

ERIC Educational Resources Information Center

Describes electrical power problems that affect computer users, including spikes, sags, outages, noise, frequency variations, and static electricity. Ways in which these problems may be diagnosed and cured are discussed. Sidebars consider transformers; power distribution units; surge currents/linear and non-linear loads; and sizing the power

Price, Bennett J.

1989-01-01

277

Casablanca Carlos American Electric Power Transmission Owner  

E-print Network

(Facilitator) Chantal PJM Interconnection Not Applicable Horstmann John Dayton Power & Light Company (The) Transmission Owner Issermoyer John PPL Electric Utilities Corp. dba PPL Utilities Transmission Owner

Pjm Interconnection Llc; Teleconference Webex Participants; Firstenergy Solutions; Corp Transmission Owner; Boltz Jeff; Firstenergy Solutions; Corp Transmission Owner; Fecho Thomas; Indiana Michigan; Power Company; Transmission Owner; Patten Kevin; Company Transmission Owner

2012-01-01

278

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

Code of Federal Regulations, 2011 CFR

...2011-07-01 false Electric power circuit and electric equipment; deenergization...Equipment-General § 75.509 Electric power circuit and electric equipment; deenergization. [Statutory Provisions] All power circuits and electric equipment shall be...

2011-07-01

279

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

...2014-07-01 false Electric power circuit and electric equipment; deenergization...Equipment-General § 75.509 Electric power circuit and electric equipment; deenergization. [Statutory Provisions] All power circuits and electric equipment shall be...

2014-07-01

280

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; deenergization...Equipment-General § 75.509 Electric power circuit and electric equipment; deenergization. [Statutory Provisions] All power circuits and electric equipment shall be...

2013-07-01

281

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

...2014-07-01 false Electric power circuits and electric equipment; deenergization...Equipment-General § 77.500 Electric power circuits and electric equipment; deenergization. Power circuits and electric equipment shall be...

2014-07-01

282

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

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Electric power circuits and electric equipment; deenergization...Equipment-General § 77.500 Electric power circuits and electric equipment; deenergization. Power circuits and electric equipment shall be...

2010-07-01

283

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

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Electric power circuits and electric equipment; deenergization...Equipment-General § 77.500 Electric power circuits and electric equipment; deenergization. Power circuits and electric equipment shall be...

2013-07-01

284

Methods for Estimation of Market Power in Electric Power Industry  

NASA Astrophysics Data System (ADS)

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.

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

2012-01-01

285

Processing of thermionic power on an electrically propelled spacecraft  

NASA Technical Reports Server (NTRS)

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.

Macie, T. W.

1973-01-01

286

Energy Management Fuzzy Logic Supervisory for Electric Vehicle Power Supplies System  

Microsoft Academic Search

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

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

2008-01-01

287

Compact high-power MHD electric station on natural gas  

SciTech Connect

The results of preliminary study of the compact combined electric power station (CPS) of high-power, composed from 4 autonomous identical power units, are presented. Each power unit includes the closed cycle disk MHD generator on non-equilibrium plasma with gas turbine and gas turbine power plant (GTPP) of open cycle. The power station is intended for conversion of the chemical energy of natural gas into electric power immediately on a field with the subsequent transmission of it to the existing power system. The proposed electric power of CPS amounts to {approx}16 GWe ({approx}28 GWt) at consumption of a natural gas mass flow rate 590 kg/s. The power of one unit is {approx}4 GWe. A binary combined Brayton cycle on a ground of GTPP with firing of natural gas and MHD generator on inert gas (Ar) of high-pressure (2.5 MPa) is reviewed. It provides CPS efficiency {approx}58%. Conceptual system of power unit include the 3 identical open loops with GTPP and closed loop with high power disk MHD generator. The transformation and transmission systems of electric power from ac generator and dc MHD generator, a direct current with 500 kV voltage by cable to distances up to 600 km, are calculated and designed. The CPS structural block-scheme, multiple-unit scheme of cycles, main components, both parameters and features of power unit, layout and general view of CPS are presented. The minimization of mass and volume of units and CPS as a whole at reasonable meaning of efficiency is fulfilled. The executed designs have shown that the proposed CPS can be accommodated in bulk 140 x 140 x 50 m{sup 3}, thus its complete mass will make {approx}60,000 tons.

Velikhov, E.P.; Bykov, V.P.; Kuznetsov, V.P.; Lavkovsky, S.A.; Topelberg, V.V.; Osipov, M.I.; Panchenko, V.P.

1998-07-01

288

Superconductivity for electric power systems: Program overview  

SciTech Connect

Largely due to government and private industry partnerships, electric power applications based upon high-temperature superconductivity are now being designed and tested only seven years after the discovery of the high-temperature superconductors. These applications offer many benefits to the national electric system including: increased energy efficiency, reduced equipment size, reduced emissions, increased stability/reliability, deferred expansion, and flexible electricity dispatch/load management. All of these benefits have a common outcome: lower electricity costs and improved environmental quality. The U.S. Department of Energy (DOE) sponsors research and development through its Superconductivity Program for Electric Power Systems. This program will help develop the technology needed for U.S. industries to commercialize high-temperature superconductive electric power applications. DOE envisions that by 2010 the U.S. electric power systems equipment industry will regain a major share of the global market by offering superconducting products that outperform the competition.

Not Available

1995-02-01

289

Modular Solar Electric Power (MSEP) Systems (Presentation)  

SciTech Connect

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.

Hassani, V.

2000-06-18

290

Conic optimization of electric power systems  

E-print Network

The electric power grid is recognized as an essential modern infrastructure that poses numerous canonical design and operational problems. Perhaps most critically, the inherently large scale of the power grid and similar ...

Taylor, Joshua Adam

2011-01-01

291

Integration of large electrical space power systems  

NASA Astrophysics Data System (ADS)

Methods for combining solar/battery space power plants with space nuclear reactor power plants are discussed, noting the eventual application for a manned space station. The load will have both dc and ac components, and it is expected that solar/battery power will be used in the initial growth stages of the station. The battery power is regarded as a dc source only, and all power is inverted by equipment located near the end use. Shunt regulation can be implemented to handle excess power, especially with regard to a concept of an expanding power supply. A direct energy transfer system (DETS) is described, and involves channeling power directly to loads, with excess power radiated away by the shunt regulator. Power processing controls would respond to voltage deviations. A block diagram is furnished for a reliable high voltage battery modular array which would be capable of furnishing 28 kW demand. If the energy source is a constant speed alternator, then constant speed operation, load leveling, and adaptation of the alternator to different voltages would be necessary.

Hayden, J. H.; Kirpich, A.

292

FPGA Based Voltage & Current Dual Drive System for High Frame Rate Electrical Impedance Tomography.  

PubMed

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 frequencydifference 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 signalaveraging factor of 8, the DAQ frame rate at 100 kHz exceeded 110 frames s-1, and SNR exceeded 90 dB across the spectrum. Reciprocity error was found to be <1% for frequencies up to 1 MHz. Static imaging experiments were performed on a highconductivity 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

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

2014-11-01

293

Students' understanding of voltage in simple series electric circuits  

Microsoft Academic Search

This paper reports an investigation of the performance of students at age 15 on written diagnostic questions involving the prediction of voltmeter readings in circuits consisting of two resistors in series. The results show that these students have particular difficulty with qualitative questions. Few perceive the two?resistor series circuit as a voltage divider and many display local, as opposed to

Robin Millar; Tom King

1993-01-01

294

Cathode plasma in electrical breakdown of high voltage vacuum devices  

Microsoft Academic Search

The production and subsequent motion of cathode plasma determine the characteristics of many high voltage vacuum devices. These devices include electron beam generators, ion beam generators, high speed switches, and a type of plasma recombination laser. A thorough understanding of the cathode plasma phenomenon is essential in designing these devices. In this thesis a detailed study is reported of the

Yen

1984-01-01

295

Sulfur hexafluoride and the electric power industry  

Microsoft Academic Search

The use of gas-insulated electrical equipment has a demonstrated value for society. The problems relating to SF 6 are not without solution and can lead to new opportunities. To this end, besides the current efforts to curtail the releases of SF 6 into the environment, a comprehensive and focused program is needed to develop alternative gaseous insulators and alternative high-voltage

L. G. Christophorou; J. K. Olthoff; R. J. Van Brunt

1997-01-01

296

High-voltage, high-power, solid-state remote power controllers for aerospace applications  

NASA Technical Reports Server (NTRS)

Two general types of remote power controller (RPC) that combine the functions of a circuit breaker and a switch were developed for use in direct-current (dc) aerospace systems. Power-switching devices used in these designs are the relatively new gate-turnoff thyristor (GTO) and poweer metal-oxide-semiconductor field-effect transistors (MOSFET). The various RPC's can switch dc voltages to 1200 V and currents to 100 A. Seven different units were constructed and subjected to comprehensive laboratory and thermal vacuum testing. Two of these were dual units that switch both positive and negative voltages simultaneously. The RPC's using MOSFET's have slow turnon and turnoff times to limit voltage spiking from high di/dt. The GTO's have much faster transition times. All RPC's have programmable overload tripout and microsecond tripout for large overloads. The basic circuits developed can be used to build switchgear limited only by the ratings of the switching device used.

Sturman, J. C.

1985-01-01

297

Electric power monthly, September 1990. [Glossary included  

SciTech Connect

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)

Not Available

1990-12-17

298

Fault-tolerant electrical power system  

NASA Astrophysics Data System (ADS)

An electrical system that will meet the requirements of a 1990s two-engine fighter is being developed in the Fault-Tolerant Electrical Power System (FTEPS) program, sponsored by the AFWAL Aero Propulsion Laboratory. FTEPS will demonstrate the generation and distribution of fault-tolerant, reliable, electrical power required for future aircraft. The system incorporates MIL-STD-1750A digital processors and MIL-STD-1553B data buses for control and communications. Electrical power is distributed through electrical load management centers by means of solid-state power controllers for fault protection and individual load control. The system will provide uninterruptible power to flight-critical loads such as the flight control and mission computers with sealed lead-acid batteries. Primary power is provided by four 60 kVA variable speed constant frequency generators. Buildup and testing of the FTEPS demonstrator is expected to be complete by May 1988.

Mehdi, Ishaque S.; Weimer, Joseph A.

1987-10-01

299

A Multiphase, Modular, Bidirectional, Triple-Voltage DC-DC Converter Power Systems  

SciTech Connect

Electrical power systems in future hybrid and fuel cell vehicles may employ three voltage [14 V, 42 V, and high voltage (HV)] nets. These will be necessary to accommodate existing 14-V loads as well as efficiently handle new heavy loads at the 42-V net and a traction drive on the HV bus. A low-cost DC-DC converter was proposed for connecting the three voltage nets. It minimizes the number of switches and their associated gate driver components by using two half-bridges and a high-frequency transformer. Another salient feature is that the half bridge on the 42-V bus is also utilized to provide the 14-V bus by operating at duty ratios around an atypical value of 1/3. Moreover, it makes use of the parasitic capacitance of the switches and the transformer leakage inductance for soft switching. The use of half bridges makes the topology well suited for interleaved multiphase modular configurations as a means to increase the power level because the capacitor legs can be shared. This paper presents simulation and experimental results on an interleaved two-phase arrangement rated at 4.5 kW. Also discussed are the benefits of operating with an atypical duty ratio on the transformer and a preferred multiphase configuration to minimize capacitor ripple currents.

Su, Gui-Jia [ORNL; Tang, Lixin [ORNL

2008-01-01

300

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

PubMed

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

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

2012-09-01

301

Voltage Control of Distribution Networks with Distributed Generation using Reactive Power  

E-print Network

Voltage Control of Distribution Networks with Distributed Generation using Reactive Power levels. However, with significant penetration of distributed generation, the power flows may become with power flows and voltages determined by the generation as well as load. Hence, there are dramatic changes

Pota, Himanshu Roy

302

A New Bifurcation Analysis for Power System Dynamic Voltage Stability Studies  

E-print Network

A New Bifurcation Analysis for Power System Dynamic Voltage Stability Studies Garng M. Huang, Senior Member, IEEE, Liang Zhao, Xuefeng Song Abstract: The dynamic of a large class of power systems can bifurcation, saddle-node and Hopf bifurcation. In this paper the dynamic voltage stability of power system

303

Microarchitectural Simulation and Control of di\\/dt-induced Power Supply Voltage Variation  

Microsoft Academic Search

As the power consumption of modern high-performance microprocessors increases beyond 100 W, power becomes an increasingly important design consideration. This paper presents a novel technique to simulate power supply voltage variation as a result of varying activity levels within the microprocessor when executing typical software. The voltage simulation capability may be added to existing microarchitecture simulators that determine the activities

Ed Grochowski; David Ayers; Vivek Tiwari

2002-01-01

304

Voltage regulator for battery power source. [using a bipolar transistor  

NASA Technical Reports Server (NTRS)

A bipolar transistor in series with the battery as the control element also in series with a zener diode and a resistor is used to maintain a predetermined voltage until the battery voltage decays to very nearly the predetermined voltage. A field effect transistor between the base of the bipolar transistor and a junction between the zener diode and resistor regulates base current of the bipolar transistor, thereby regulating the conductivity of the bipolar transistor for control of the output voltage.

Black, J. M. (inventor)

1979-01-01

305

Advanced electrical power system technology for the all electric aircraft  

NASA Technical Reports Server (NTRS)

The application of advanced electric power system technology to an all electric airplane results in an estimated reduction of the total takeoff gross weight of over 23,000 pounds for a large airplane. This will result in a 5 to 10 percent reduction in direct operating costs (DOC). Critical to this savings is the basic electrical power system component technology. These advanced electrical power components will provide a solid foundation for the materials, devices, circuits, and subsystems needed to satisfy the unique requirements of advanced all electric aircraft power systems. The program for the development of advanced electrical power component technology is described. The program is divided into five generic areas: semiconductor devices (transistors, thyristors, and diodes); conductors (materials and transmission lines); dielectrics; magnetic devices; and load management devices. Examples of progress in each of the five areas are discussed. Bipolar power transistors up to 1000 V at 100 A with a gain of 10 and a 0.5 microsec rise and fall time are presented. A class of semiconductor devices with a possibility of switching up to 100 kV is described. Solid state power controllers for load management at 120 to 1000 V and power levels to 25 kW were developed along with a 25 kW, 20 kHz transformer weighing only 3.2 kg.

Finke, R. C.; Sundberg, G. R.

1983-01-01

306

Advanced electrical power system technology for the all electric aircraft  

NASA Technical Reports Server (NTRS)

The application of advanced electric power system technology to an all electric airplane results in an estimated reduction of the total takeoff gross weight of over 23,000 pounds for a large airplane. This will result in a 5 to 10 percent reduction in direct operating costs (DOC). Critical to this savings is the basic electrical power system component technology. These advanced electrical power components will provide a solid foundation for the materials, devices, circuits, and subsystems needed to satisfy the unique requirements of advanced all electric aircraft power systems. The program for the development of advanced electrical power component technology is described. The program is divided into five generic areas: semiconductor devices (transistors, thyristors, and diodes); conductors (materials and transmission lines); dielectrics; magnetic devices; and load management devices. Examples of progress in each of the five areas are discussed. Bipolar power transistors up to 1000 V at 100 A with a gain of 10 and a 0.5 microsec rise and fall time are presented. A class of semiconductor devices with a possibility of switching up to 100 kV is described. Solid state power controllers for load management at 120 to 1000 V and power levels to 25 kW were developed along with a 25 kW, 20 kHz transformer weighing only 3.2 kg. Previously announced in STAR as N83-24764

Finke, R. C.; Sundberg, G. R.

1983-01-01

307

Power Sharing Control between Load-Side Inverters in DC Microgrid for Super High Quality Electric Power Distribution System  

NASA Astrophysics Data System (ADS)

DC microgrid is a novel power system using dc distribution in order to provide a super high quality electric power. The dc distribution system is suitable for dc output type distributed generations such as photovoltaic and fuel cells, and energy storages such as batteries and electric double layer capacitors. Power is distributed through dc distribution line and converted to required ac or dc voltage by converters placed near loads. Load-side single phase inverters are connected through transformers in order to share active and reactive power. In this paper, a power sharing control scheme was proposed, and the power sharing characteristics were demonstrated by experimental results.

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

308

The CIS Common Electric Power Market  

Microsoft Academic Search

Trade in electric power and mutual investments are at a low level and do not correspond with the sector’s potential. The CIS is a net exporter of electric power, but the actual volumes of import and export are small. CIS countries are capable of more, having large coal and gas reserves with huge potential for energy production, vast hydropower potential,

Evgeny Vinokurov

2009-01-01

309

Well completion for electrical power transmission  

Microsoft Academic Search

There is provided a well completion for electrical alternating current power transmission that minimizes power losses and related corrosion problems. Casing is used both as the electrode and conductor. Most of the conductor portion is made of nonmagnetic metal, for example aluminum, and is electrically insulated both exteriorly and interiorly. The insulation extends below the point where the nonmagnetic metal

Perkins

1984-01-01

310

Isolation of an electrical power transmission well  

Microsoft Academic Search

In processes using electrical power to apply heat to a subsurface formation through a transmission well, power losses are reduced by installing in flowlines leading to the well one or more devices that electrically disrupts the flowline and that creates a tortuous flow path for liquids flowing through the device. The parts of the device contacting liquids are either fabricated

Perkins

1985-01-01

311

Electric power monthly, March 1995  

SciTech Connect

This report for March 1995, presents monthly electricity statistics for a wide audience including Congress, Federal and State agencies, the electric utility industry, and the general public. 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.

NONE

1995-03-20

312

Electric Power Monthly, August 1990. [Glossary included  

SciTech Connect

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.

Not Available

1990-11-29

313

Students' understanding of voltage in simple series electric circuits  

NSDL National Science Digital Library

This paper reports an investigation of the performance of students at age 15 on written diagnostic questions involving the prediction of voltmeter readings in circuits consisting of two resistors in series. The results show that these students have particular difficulty with qualitative questions. Few perceive the two-resistor series circuit as a voltage divider and many display local, as opposed to global, reasoning in predicting circuit behaviour. These are identified as instructional goals which need to be more strongly and explicitly emphasized.

Millar, Robin; King, T.

2006-06-19

314

Electric Power Delivery Testing Feasibility Study Task 6 Final Report  

SciTech Connect

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.

Thomas Tobin

2009-07-01

315

Application of Electric Double Layer Capacitor to Single-Phase Composite PWM Voltage Source Inverter  

NASA Astrophysics Data System (ADS)

This paper proposes an application of electric double layer capacitor (EDLC) to single-phase composite PWM voltage source inverter (VSI). The VSI consist of the normal single-phase bridge circuit and an additional arm. The two auxiliary self-turn-off devices of the arm avail to adopt a composite PWM control, which contributes to reduce the ripple in the ac output current. In the dc side, the dc current contains the ac component, which has twice the system frequency. Until now, LC series resonance circuit tuned to twice the utility frequency is necessary to connect to the smoothing capacitor in parallel. Hence, the smoothing capacitor is drastically reduced. The VSI is disadvantageous in maintenance to use storage battery in order to stabilize the dc voltage. This paper describes an application of EDLC to smoothing capacitor in the dc side of the PWM VSI. The EDLC absorbs the ac component with twice the utility frequency and the ripple caused by PWM switching included the dc pulsating current. The smooth dc current is obtained by using the EDLC. The experiment shows that the single-phase composite PWM VSI used for the utility connected residential photovoltaic power generation system (PV system).

Harada, Katsuhiko; Nonaka, Sakutaro

316

Evaluation of Voltage Instability Countermeasures in Constrained Sub-transmission Power Networks.  

E-print Network

?? This paper investigates the various parameters that effect voltage stability in sub-transmission power networks. The paper first looks at contributions from equipment: generators, transmission… (more)

Jones, Peter Gibson

2012-01-01

317

Numerical determination of electric field induced currents on human body standing under a high voltage transmission line  

Microsoft Academic Search

In this paper, biological effects of high voltage transmission line electric field on biological systems especially on a grounded human body standing under a high voltage transmission line have been studied. The electric field distribution on a human body standing underneath extra high voltage overhead transmission lines has been calculated by using Boundary element method (BEM). Induced currents and current

S. M. El-Makkawy

2007-01-01

318

Voltage Stability Evaluation of The Khouzestan Power System in Iran Using CPF Method and Modal Analysis  

Microsoft Academic Search

Voltage stability is an important factor that needs to be taken into consideration during the planning and operation of power systems in order to avoid voltage collapse and subsequently partial or full system blackout. The study of the voltage collapse phenomenon can provide a way to prevent this event from happening. There have been many methods developed to study the

Farbod Larki; Mahmood Joorabian; H. M. Kelk; M. Pishvaei

2010-01-01

319

On-Chip Point-of-Load Voltage Regulator for Distributed Power Supplies  

E-print Network

, switching, switched capacitor, and linear DC-DC convert- ers [3, 4]. Buck converters, which are step down of the stepped down voltage. Due to the large area requirement of a passive LC filter, buck con- verters Terms Design Keywords On-chip voltage regulator, power delivery, DC-DC voltage regulation, active filter

Friedman, Eby G.

320

Advanced voltage regulation method at the power distribution systems interconnected with dispersed storage and generation systems  

Microsoft Academic Search

DSGs (dispersed storage and generation systems) in power distribution systems impact on the conventional voltage regulation method. Therefore, there is a possibility that the customers' voltage will violate the permissible limits. In this paper, we propose the MLDC (multiple line drop compensation) voltage regulation method considering the unbalanced load diversity among feeders, the operations of DSGs, and the hysterical tap

Joon-Ho Choi; Jae-Chul Kim

2000-01-01

321

Method for combined cycle electrical power generation  

SciTech Connect

A method for combined cycle electrical power generation is disclosed wherein electrical power is generated by an electrical generator driven by a gas turbine, which is in turn driven by two gaseous products of a coal gasification process. The first gaseous product is produced with hot char by the reduction of a coal/water slurry by stream in a gasifier. The second gaseous product is produced by oxidation of the hot char in a combustor.

Mitchell, D.S.; Sageman, D.R.

1984-04-24

322

The effect of high voltage, high frequency pulsed electric field on slain ovine cortical bone.  

PubMed

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

Asgarifar, Hajarossadat; Oloyede, Adekunle; Zare, Firuz

2014-04-01

323

Trees and Power Lines: Minimizing Conflicts between Electric Power  

E-print Network

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

Kammen, Daniel M.

324

Observation of pressure stimulated voltages in rocks using an electric potential sensor  

SciTech Connect

Recent interest in the electrical activity in rock and the use of electric field transients as candidates for earthquake precursors has led to studies of pressure stimulated currents in laboratory samples. In this paper, an electric field sensor is used to measure directly the voltages associated with these currents. Stress was applied as uniaxial compression to marble and granite at an approximately constant rate. In contrast with the small pressure stimulated currents previously measured, large voltage signals are reported. Polarity reversal of the signal was observed immediately before fracture for the marble, in agreement with previous pressure stimulated current studies.

Aydin, A.; Prance, R. J.; Prance, H.; Harland, C. J. [Centre for Physical Electronics and Quantum Technology, School of Engineering and Design, University of Sussex, Brighton BN1 9QT (United Kingdom)

2009-09-21

325

35. SITE BUILDING 004 ELECTRIC POWER STATION CONTROL ...  

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

35. SITE BUILDING 004 - ELECTRIC POWER STATION - CONTROL ROOM OF ELECTRIC POWER STATION WITH DIESEL ENGINE POWERED ELECTRIC GENERATION EQUIPMENT IN BACKGROUND. - Cape Cod Air Station, Technical Facility-Scanner Building & Power Plant, Massachusetts Military Reservation, Sandwich, Barnstable County, MA

326

SITE ELECTRICAL POWER SYSTEM DESCRIPTION DOCUMENT  

SciTech Connect

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.

E.P. McCann

1999-04-16

327

National Maglev initiative: California line electric utility power system requirements  

NASA Technical Reports Server (NTRS)

The electrical utility power system requirements were determined for a Maglev line from San Diego to San Francisco and Sacramento with a maximum capacity of 12,000 passengers an hour in each direction at a speed of 300 miles per hour, or one train every 30 seconds in each direction. Basically the Maglev line requires one 50-MVA substation every 12.5 miles. The need for new power lines to serve these substations and their voltage levels are based not only on equipment loading criteria but also on limitations due to voltage flicker and harmonics created by the Maglev system. The resulting power system requirements and their costs depend mostly on the geographical area, urban or suburban with 'strong' power systems, or mountains and rural areas with 'weak' power systems. A reliability evaluation indicated that emergency power sources, such as a 10-MW battery at each substation, were not justified if sufficient redundancy is provided in the design of the substations and the power lines serving them. With a cost of $5.6 M per mile, the power system requirements, including the 12-kV DC cables and the inverters along the Maglev line, were found to be the second largest cost component of the Maglev system, after the cost of the guideway system ($9.1 M per mile), out of a total cost of $23 M per mile.

Save, Phil

1994-01-01

328

DC power system having battery voltage equalizer circuit  

SciTech Connect

An equalizer circuit is disclosed for permitting two series 12 volt batteries to supply both 24 volts and 12 volts and which maintains the batteries charged to equal voltages. The equalizer circuit is a regulated DC to DC converter with its output connected across the 12 volt battery which is connected to 12 volt loads and its input connected across either the other battery or the 24 volts of the input series pair of batteries. The reference voltage for the regulator is derived from a voltage dividing circuit which is connected across the 24 volt terminals of the two batteries. The voltage dividing circuit provides a reference voltage which is equal to half the voltage across the sum of the voltages of the two batteries.

Sullivan, J.D.

1984-10-23

329

Analyzing Techniques for Increasing Power Transfer in the Electric Grid  

NASA Astrophysics Data System (ADS)

The worldwide demand for electric energy is slated to increase by 80% between the years 1990 and 2040. In order to satisfy this increase in load, many new generators and transmission lines are planned. Implementations of various plans that can augment existing infrastructure have been hindered due to environmental constraints, public opposition and difficulties in obtaining right-of-way. As a result, stress on the present electrical infrastructure has increased, resulting in congestion within the system. The aim of this research is to analyze three techniques that could improve the power transfer capability of the present electric grid. These include line compaction, use of high temperature low sag conductors and high phase order systems. The above methods were selected as they could be readily employed without the need for additional right-of-way. Results from the line compaction tests indicate that line compaction up to 30% is possible and this increases the power transfer capability up to 53%. Additional advantages of employing line compaction are the reduction in electric and magnetic fields, increase in system stability and better voltage regulation. High temperature low sag conductors that were applied on thermally limited lines were seen to increase the power transfer capability. However, a disadvantage of this technique was that the second most congested line, limits the power transfer capability of the system. High phase (six phase) order system was noted to have several advantages over three phase system such as lower voltage requirement to transfer equal amount of power and lower electric and magnetic field across the right of way. An IEEE 9 and 118 bus test system were used to evaluate the above mentioned techniques.

Dave, Kushal

330

Automatic voltage imbalance detector  

DOEpatents

A device for indicating and preventing damage to voltage cells such as galvanic cells and fuel cells connected in series by detecting sequential voltages and comparing these voltages to adjacent voltage cells. The device is implemented by using operational amplifiers and switching circuitry is provided by transistors. The device can be utilized in battery powered electric vehicles to prevent galvanic cell damage and also in series connected fuel cells to prevent fuel cell damage.

Bobbett, Ronald E. (Los Alamos, NM); McCormick, J. Byron (Los Alamos, NM); Kerwin, William J. (Tucson, AZ)

1984-01-01

331

Compact, high voltage power supply for the lab-on-a-chip.  

PubMed

The design, construction and operation of a simple, inexpensive and compact high voltage power supply (HVPS) for use in conjunction with a simple cross capillary electrophoresis microchip is presented. The microchip HVPS utilizes a single high voltage power supply (15 kV), a voltage-divider network, to give the voltages necessary to operate a gated injection valve, and two high voltage relays for switching between the open and closed gate sequences of the injection. In order to accommodate the application of different simple cross microchip dimensions, a set of equations for defining the resistor network and ensuring proper gate performance are presented. PMID:15269813

Collins, Greg E; Wu, Peter; Lu, Qin; Ramsey, Jeremy D; Bromund, Richard H

2004-08-01

332

Electric power annual 1996. Volume 1  

SciTech Connect

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.

NONE

1997-08-01

333

IEEE International Conference on Power and Energy (PECon 08), December 1-3, 2008, Johor Baharu, Malaysia Variable High Frequency Voltage Source for an  

E-print Network

. The rate of ohmic heating critically depends on the Electrical Conductivity of the food during the process; Electrical Conductivity; Power Electronics; High Frequency; Electrolyze; Oxidation I. INTRODUCTION Heating, Malaysia Variable High Frequency Voltage Source for an Ohmic Heating Process A. Toudeshki, N. Mariun SMIEEE

Hammerton, James

334

Electric power monthly, May 1996  

SciTech Connect

This publication presents monthly electricity statistics for a wide audience including Congress, Federal and Stage 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 to fulfill its data collection and dissemination responsibilities in Federal Energy Administration Act of 1974 (Public Law 93-275) as amended.

NONE

1996-05-01

335

Electric Power monthly, November 1996  

SciTech Connect

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.

NONE

1996-11-01

336

Power transmission cable development for the Space Station Freedom electrical power system  

NASA Technical Reports Server (NTRS)

Power transmission cable is presently being evaluated under a NASA Lewis Research Center advanced development contract for application in the Space Station Freedom (SSF) electrical power system (EPS). Evaluation testing has been performed by TRW and NASA Lewis Research Center. The results of this development contract are presented. The primary cable design goals are to provide (1) a low characteristic inductance to minimize line voltage drop at 20 kHz, (2) electromagnetic compatibility control of the 20-kHz ac power current, (3) a physical configuration that minimizes ac resistance and (4) release of trapped air for corona-free operation.

Schmitz, Gregory V.; Biess, John J.

1989-01-01

337

Electrical Model of Balanced AC HTS Power Cable  

NASA Astrophysics Data System (ADS)

The future electricity grid will be more sustainable and it will have more power transmission and distribution capability with more electrical power added from decentralized sources on distribution level and from wind parks and other large sources on transmission level. More interconnections and more underground transmission and distribution will be put up. Use of high temperature superconducting (HTS) power cables provides solutions to many of the future grid problems caused by these trends. In this paper we present an electrical model of a balanced 6 km-long three phase triaxial HTS power cable for the Dutch project being developed by a consortium of Alliander, Ultera™ and TUD. The cable currents in all three phases are balanced by selecting proper twist pitches and insulation thickness. The paper focuses on determining inductances, capacitances and AC losses of the balanced cable. Using the developed model, we also determine the voltage drop as function of the cable length, the neutral current and the effect of the imbalanced capacitances on the current distribution of the Dutch distribution cable. The model is validated and it can be used for accurate simulation of the electrical behaviour of triaxial HTS cables in electrical grids.

Zuijderduin, R.; Chevtchenko, O.; Smit, J. J.; Willén, D.; Melnik, I.; Geschiere, A.

338

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

E-print Network

) 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...

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

339

Roadway powered electric vehicle: An alternate to the electric car  

Microsoft Academic Search

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.

Siuru

1991-01-01

340

The All-digital Electrical Energy Metering System Based on Optical Current and Voltage Transducer  

Microsoft Academic Search

The communication protocol structure of digital substation in smart grid has changed greatly, and the electrical energy metering system is changed greatly too. In this paper, an all-digital electrical energy metering system based on pure optical voltage transducer (OVT) and optical current transducer (OCT) is introduced. The advanced communication protocol IEC618509-2 is adopted in the all-digital electrical metering system firstly.

Yang Huayun; Jiang Bo; Jiang Wei; Zhang Jiamin; Jiang Yinxia; Liu Kun

2010-01-01

341

Characteristic Analysis of DC Electric Railway Systems with Superconducting Power Cables Connecting Power Substations  

NASA Astrophysics Data System (ADS)

The application of superconducting power cables to DC electric railway systems has been studied. It could leads to an effective use of regenerative brake, improved energy efficiency, effective load sharing among the substations, etc. In this study, an electric circuit model of a DC feeding system is built and numerical simulation is carried out using MATLAB-Simulink software. A modified electric circuit model with an AC power grid connection taken into account is also created to simulate the influence of the grid connection. The analyses have proved that a certain amount of energy can be conserved by introducing superconducting cables, and that electric load distribution and concentration among the substations depend on the substation output voltage distribution.

Ohsaki, H.; Matsushita, N.; Koseki, T.; Tomita, M.

2014-05-01

342

Manager's guide to electrical power quality  

SciTech Connect

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.

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

1993-05-01

343

Educational Electrical Appliance Power Meter and Logger  

ERIC Educational Resources Information Center

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

Nunn, John

2013-01-01

344

Tidal energy in electric power systems  

Microsoft Academic Search

This paper discusses the uses and advantages of tidal energy in restructured power systems. The paper defines the resources as well as the ways in which tidal energy is converted into electricity. The paper also reviews a few tidal power projects around the world. It also shows the working of hydro tidal power plant. A comparative review of renewable energy

S. Sheth; M. Shahidehpour

2005-01-01

345

The unitary theory of the electrical powers  

E-print Network

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.

Gheorghe Mihai

2009-04-07

346

Electric discharge coaxial laser power measurement  

Microsoft Academic Search

This report presents a theoretical and empirical treatment of the power-measuring techniques used in determining the output power of the Electric Discharge Coaxial Laser (EDCL). Errors in power measurement associated with the diagnostic beam splitter were investigated. These areas included errors associated with the removal of the beam splitter for storage overnight and the repositioning of the beam splitter the

Arnold L. Augustoni

1986-01-01

347

Electric currents and voltage drops along auroral field lines  

NASA Technical Reports Server (NTRS)

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.

Stern, D. P.

1983-01-01

348

Electric currents and voltage drops along auroral field lines  

NASA Astrophysics Data System (ADS)

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.

Stern, D. P.

1983-03-01

349

Bulk power system voltage phenomena -III: Voltage stability, security & control, Davos, Switzerland, August 1994 THE IRRELEVANCE OF LOAD DYNAMICS FOR THE LOADING MARGIN  

E-print Network

and their sensitivities depend only on the static parts of dynamic power system models. For example, a dynamic power dynamic power system models to be properly understood, the computation of loading mar- gin and itsBulk power system voltage phenomena - III: Voltage stability, security & control, Davos

Dobson, Ian

350

Hybrid fiber optic voltage sensor for remote monitoring of electrical submersible pump motors  

NASA Astrophysics Data System (ADS)

We report on the design and experimental evaluation of the hybrid fiber Bragg grating (FBG) piezoelectric voltage sensor developed specifically for remote monitoring of electrical submersible pump (ESP) motors. Unlike a previously reported transducer based on a single piezoelectric element, the voltage rating of the presented device could be as low as 500 V due to the use of a multilayer piezoelectric stack as the primary voltage-to-strain transducer. This enables the use of such sensors across a wider range of ESP applications, which often have subkilovolt voltage ratings. In addition to the design details, we present details of the full characterization of the device, including the hysteresis and temperature-dependence characteristics and discuss ways of eliminating or reducing these effects. We also demonstrate that the sensor can be used to simultaneously measure voltage and temperature.

Dziuda, L.; Niewczas, Pawel; Fusiek, G.; McDonald, James R.

2005-06-01

351

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

Microsoft Academic Search

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

Ali Emadi; Young Joo Lee; Kaushik Rajashekara

2008-01-01

352

Flexible Low-Voltage Electric-Double-Layer TFTs Self-Assembled on Paper Substrates  

Microsoft Academic Search

Flexible low-voltage electric-double-layer (EDL) thin-film transistors (TFTs) with a patterned indium-tin-oxide (ITO) channel are self-assembled on paper substrates by only one shadow mask at room temperature. The operation voltage is 1.5 V when a microporous SiO2 solid electrolyte with large EDL capaci- tance is used as the gate dielectric. Such flexible TFTs operate in a full-depletion mode with a high

Aixia Lu; Mingzhi Dai; Jia Sun; Jie Jiang; Qing Wan

2011-01-01

353

Design of a low-voltage low-power dc-dc HF converter  

E-print Network

Many portable electronic applications could benefit from a power converter able to achieve high efficiency across wide input and output voltage ranges at a small size. However, it is difficult for many conventional power ...

Hu, Jingying, Ph. D. Massachusetts Institute of Technology.

2008-01-01

354

30 CFR 75.812-2 - High-voltage power centers and transformers; record of examination.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 false High-voltage power centers and transformers; record of examination. 75.812-2 Section 75.812-2...Distribution § 75.812-2 High-voltage power centers and transformers; record of examination. The operator shall...

2011-07-01

355

30 CFR 75.812-2 - High-voltage power centers and transformers; record of examination.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false High-voltage power centers and transformers; record of examination. 75.812-2 Section 75.812-2...Distribution § 75.812-2 High-voltage power centers and transformers; record of examination. The operator shall...

2013-07-01

356

30 CFR 75.812-2 - High-voltage power centers and transformers; record of examination.  

...2014-07-01 false High-voltage power centers and transformers; record of examination. 75.812-2 Section 75.812-2...Distribution § 75.812-2 High-voltage power centers and transformers; record of examination. The operator shall...

2014-07-01

357

30 CFR 75.812-2 - High-voltage power centers and transformers; record of examination.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false High-voltage power centers and transformers; record of examination. 75.812-2 Section 75.812-2...Distribution § 75.812-2 High-voltage power centers and transformers; record of examination. The operator shall...

2012-07-01

358

Medium voltage overhead power-line broadband communications; transmission capacity and electromagnetic interference  

Microsoft Academic Search

A channel model suitable for multi-wire overhead medium-voltage lines is proposed. This model is then employed in order to evaluate the multipath channel impulse response and the associated transmission capacity limit in actual overhead medium-voltage power distribution networks for broadband power-line communications applications. Electromagnetic interference limitations of such systems are discussed.

P. Amirshahi; M. Kavehrad

2005-01-01

359

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

NASA Technical Reports Server (NTRS)

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.

Plumer, J. A.

1974-01-01

360

Mini-Scale Power Distribution Network Feeding Trapezoidal-Wave Voltages to Power Electronic Loads with Diode Rectifiers  

NASA Astrophysics Data System (ADS)

This paper proposes a novel three-phase power distribution system feeding trapezoidal voltages to various power electronic loads with diode rectifier front-ends. The network distributes trapezoidal voltages generated by synchronous superposition of wave-shaping voltages onto sinusoidal voltages available from a utility power grid. The power distribution by the trapezoidal voltages allows reducing harmonics of the line currents without electronic switching devices because of a spontaneously widened conduction period of the current waveforms. The reduction of the harmonic currents also contributes to improve total power factor at the load input terminals and efficiency of the power transmission cables. Since the diodes of the rectifiers successively commutate the trapezoidal waves during periods of their flat parts, not only total harmonic distortion of the currents is improved, but also voltage ripple across the dc-buses of the rectifiers can effectively be reduced with less filter capacitors. In addition, the system offers an uninterruptible power supply function by immediately changing its outputs from the wave-shaping voltages to the trapezoidal voltages when interruption occurs in the power grid. In this paper, a prototype of the system is experimentally examined from various angles of operating characteristics and test results are presented to prove feasibility of the proposed system.

Noguchi, Toshihiko; Imoto, Masaru; Sato, Yoshikazu

361

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

Microsoft Academic Search

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

D. Stade; H. Schau; St. Prinz

2000-01-01

362

Re-Dispatching Generation to Increase Power System Security Margin and Support Low Voltage Bus  

E-print Network

Re-Dispatching Generation to Increase Power System Security Margin and Support Low Voltage Bus as generation directions (patterns). Keywords: power generation dispatch, power system control, power system cause many stability problems. Between the power system generation pattern and the load pattern

363

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-term accuracy of the forecast will be lower, while short-term will be higher. Problems: (1) Combine the economy

364

Artificial Neural Network Maximum Power Point Tracker for Solar Electric Vehicle  

Microsoft Academic Search

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

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

2005-01-01

365

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

Microsoft Academic Search

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

Phatiphat Thounthong; Stéphane Raël; Bernard Davat

2006-01-01

366

Analysis and design of electronic transformers for electric power distribution system  

Microsoft Academic Search

A power transformer performs many functions such as voltage transformation, isolation, noise decoupling and is an indispensable component in electricity distribution systems. However, at low frequencies (60\\/50 Hz) it is a bulky and expensive component. In this paper, the concept of electronic transformers is further discussed. Several possible topologies employing static power converters connected on the primary and secondary side

Moonshik Kang; Prasad N. Enjeti; Ira J. Pitel

1997-01-01

367

Analysis and design of electronic transformers for electric power distribution system  

Microsoft Academic Search

A transformer performs many functions such as voltage transformation, isolation and noise decoupling, and it is an indispensable component in electric power distribution systems. However, at low frequencies (60\\/50 Hz), it is a bulky and expensive component. In this paper, the concept of electronic transformers is further extended and explored for its suitability in power distribution systems. It should be

Moonshik Kang; Prasad N. Enjeti; Ira J. Pitel

1999-01-01

368

Electric utility of the year for 1984: Potomac Electric Power  

SciTech Connect

High performance, efficiency improvements, a modest construction program, a clear balance sheet, and an effort to expend power plant life were among the qualities that earned Potomac Electric Power (PEPCO) the title of 1984 Utility of the Year. Other key elements in the utility's selection were its strategy for purchasing power, a load management plan, diversified investments into subsidiary businesses, community concern that considers the aesthetics of transmission facilities, and its interest in personnel development, especially among minorities. 3 figures.

Not Available

1984-11-01

369

Electric power annual 1989. [Contains glossary  

SciTech Connect

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.

Not Available

1991-01-17

370

18 CFR 801.12 - Electric power generation.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 false Electric power generation. 801.12 Section 801...POLICIES § 801.12 Electric power generation. (a) Significant uses...waters of the basin for the generation of electric power at hydro, pumped...

2011-04-01

371

18 CFR 801.12 - Electric power generation.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 false Electric power generation. 801.12 Section 801...POLICIES § 801.12 Electric power generation. (a) Significant uses...waters of the basin for the generation of electric power at hydro, pumped...

2012-04-01

372

18 CFR 801.12 - Electric power generation.  

...2014-04-01 false Electric power generation. 801.12 Section 801...POLICIES § 801.12 Electric power generation. (a) Significant uses...waters of the basin for the generation of electric power at hydro, pumped...

2014-04-01

373

18 CFR 801.12 - Electric power generation.  

Code of Federal Regulations, 2013 CFR

...2012-04-01 true Electric power generation. 801.12 Section 801...POLICIES § 801.12 Electric power generation. (a) Significant uses...waters of the basin for the generation of electric power at hydro, pumped...

2013-04-01

374

18 CFR 801.12 - Electric power generation.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 false Electric power generation. 801.12 Section 801...POLICIES § 801.12 Electric power generation. (a) Significant uses...waters of the basin for the generation of electric power at hydro, pumped...

2010-04-01

375

46 CFR 28.375 - Emergency source of electrical power.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 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...

2013-10-01

376

46 CFR 28.375 - Emergency source of electrical power.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 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...

2011-10-01

377

46 CFR 28.375 - Emergency source of electrical power.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 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...

2010-10-01

378

46 CFR 28.375 - Emergency source of electrical power.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 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...

2012-10-01

379

Planning available capacity in electrical power generation  

Microsoft Academic Search

In planning for the utilisation of available capacity, an electrical company needs to know the power requirements of the system. The load versus duration curve provides information on past demand patterns and thus forms a basis for planning future supply needs. Since electrical supply is discrete by nature, the load versus duration curve only approximates to the true supply requirements.

John S. Maybee; Paul H. Randolph; Noel D. Uri

1981-01-01

380

Concepts for central solar electric power generation  

NASA Technical Reports Server (NTRS)

The investigation reported was conducted to select the best conceptual design of a power plant for the dynamic conversion of solar heat to electricity. Conversion of thermal energy to electricity was to be an accomplished with conventional turbomachinery. Questions of site selection are discussed along with solar energy collection systems, aspects of candidate system definition, and reference systems.

Kintigh, J. K.

1974-01-01

381

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

DOEpatents

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.

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

2000-01-01

382

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

DOEpatents

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.

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

2001-01-01

383

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

NASA Astrophysics Data System (ADS)

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.

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

384

Novel High-Voltage, High-Power Piezoelectric Transformer Developed and Demonstrated for Space Communications Applications  

NASA Technical Reports Server (NTRS)

Improvements in individual piezoelectric transformer (PT) performance and the combination of these PTs in a unique modular topology under a Phase I contract with the NASA Glenn Research Center have enabled for the first time the simultaneous achievement of both high voltage and high power at much higher levels than previously obtained with any PT. Feasibility was demonstrated by a prototype transformer (called a Tap-Soner), which is shown in the preceding photograph as part of a direct-current to direct-current (dc-dc) converter having two outputs rated at 1.5 kV/5 W and 4.5 kV/20 W. The power density of 3.5 W/cm3 is significantly lower than for magnetic transformers with the same voltage and power output. This development, which is being done under a Small Business Innovation Research (SBIR) contract by Face Electronics, LC (Norfolk, VA), is based on improvements in the materials and design of Face's basic patented Transoner-T3 PT, shown in the left in the following figure. The T3 PT is most simply described as a resonant multilayer transducer where electrical energy at the input section is efficiently mechanically coupled to the output section, which then vibrates in a fundamental longitudinal mode to generate a high gain in voltage. The piezoelectric material used is a modified lead-zirconium-titanate-based ceramic. One of the significant improvements in PT design was the incorporation of a symmetrical double input layer, shown on the right in the following figure, which eliminated the lossy bending vibration modes characteristic of a single input layer. The performance of the improved PT was optimized to 1.5 kV/5 W. The next step was devising a way to combine the individual PTs in a modular circuit topology needed to achieve the desired high voltage and power output. Since the optimum performance of the individual PT occurs at resonance, the most efficient operation of the modular transformer was achieved by using a separate drive circuit for each PT. The output section consists of a separate output rectifier for each PT connected in series.

Carazo, Alfredo V.; Wintucky, Edwin G.

2004-01-01

385

Transmission Channel Model and Capacity of Overhead Multi-conductor Medium-Voltage Power-lines for Broadband Communications  

E-print Network

-voltage power distribution networks for broadband power-line communications applications. Keywords - channelTransmission Channel Model and Capacity of Overhead Multi-conductor Medium-Voltage Power-lines model, impulse response, power-line communications, ground admittance, medium voltage, capacity. I

Kavehrad, Mohsen

386

Electric power substation capital costs  

Microsoft Academic Search

The displacement or deferral of substation equipment is a key benefit associated with several technologies that are being developed with the support of the US Department of Energy`s Office of Utility Technologies. This could occur, for example, as a result of installing a distributed generating resource within an electricity distribution system. The objective of this study was to develop a

J. E. Dagle; D. R. Brown

1997-01-01

387

Neurological Complication After Low-Voltage Electric Injury: A Case Report  

PubMed Central

Electrical shock can result in neurological complications, involving both peripheral and central nervous systems, which may present immediately or later on. However, delayed neurological complications caused by low-voltage electric shock are rarely reported. Here, a case of a man suffering from weakness and aphasia due to the delayed-onset of the peripheral nerve injury and ischemic stroke following an electrical shock is presented. Possible mechanisms underlying the neurological complications include thermal injury to perineural tissue, overactivity of the sympathetic nervous system, vascular injury, and histological or electrophysiological changes. Moreover, vasospasms caused by low-voltage alternating current may predispose individuals to ischemic stroke. Therefore, clinicians should consider the possibility of neurological complications, even if the onset of the symptoms is delayed, and should perform diagnostic tests, such as electrophysiology or imaging, when patients present with weakness following an electric injury. PMID:24855625

Kim, Ha Min; Ko, Yeong-A; Kim, Joon Sung; Lim, Seong Hoon

2014-01-01

388

Development of a linear piston-type pulse power electric generator for powering electric guns  

Microsoft Academic Search

There is a vigorous program within the US Army to produce fieldable electric gun systems for both tactical and strategic defense missions. Princeton Combustion Research Laboratories proposes to develop its concept for a linear piston-type electric pulse-power generator capable of powering electric guns, both electromagnetic (EM rail and EM coil) guns and electrothermal (ET) guns, now under development. The pulse-power

Martin Summerfield

1993-01-01

389

Scheduling Planned Maintenance of Electrical Power Transmission Networks Using  

E-print Network

Scheduling Planned Maintenance of Electrical Power Transmission Networks Using Genetic Algorithms Technical Report: CSRP­97­26 10 November 1997 Abstract The maintenance of the electrical power transmission

Fernandez, Thomas

390

Power Processing for a Conceptual Project Prometheus Electric Propulsion System  

NASA Technical Reports Server (NTRS)

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.

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

2005-01-01

391

Brayton Power Conversion Unit Tested: Provides a Path to Future High-Power Electric Propulsion Missions  

NASA Technical Reports Server (NTRS)

Closed-Brayton-cycle conversion technology has been identified as an excellent candidate for nuclear electric propulsion (NEP) power conversion systems. Advantages include high efficiency, long life, and high power density for power levels from about 10 kWe to 1 MWe, and beyond. An additional benefit for Brayton is the potential for the alternator to deliver very high voltage as required by the electric thrusters, minimizing the mass and power losses associated with the power management and distribution (PMAD). To accelerate Brayton technology development for NEP, the NASA Glenn Research Center is developing a low-power NEP power systems testbed that utilizes an existing 2- kWe Brayton power conversion unit (PCU) from previous solar dynamic technology efforts. The PCU includes a turboalternator, a recuperator, and a gas cooler connected by gas ducts. The rotating assembly is supported by gas foil bearings and consists of a turbine, a compressor, a thrust rotor, and an alternator on a single shaft. The alternator produces alternating-current power that is rectified to 120-V direct-current power by the PMAD unit. The NEP power systems testbed will be utilized to conduct future investigations of operational control methods, high-voltage PMAD, electric thruster interactions, and advanced heat rejection techniques. The PCU was tested in Glenn s Vacuum Facility 6. The Brayton PCU was modified from its original solar dynamic configuration by the removal of the heat receiver and retrofitting of the electrical resistance gas heater to simulate the thermal input of a steady-state nuclear source. Then, the Brayton PCU was installed in the 3-m test port of Vacuum Facility 6, as shown. A series of tests were performed between June and August of 2002 that resulted in a total PCU operational time of about 24 hr. An initial test sequence on June 17 determined that the reconfigured unit was fully operational. Ensuing tests provided the operational data needed to characterize PCU performance over its full operating range. The primary test variables used in operating the Brayton PCU were heater input power and rotor speed. Testing demonstrated a maximum steady-state alternating-current power output of 1835 W at a gas heater power of 9000 W and a rotor speed of 52000 rpm. The corresponding measured turbine inlet gas temperature was 1076 K, and the compressor inlet gas temperature was 282 K. When insulation losses from the gas heater were neglected, the Brayton cycle efficiency for the maximum power point was calculated to be 24 percent. The net direct-current power output was 1750 W, indicating a PMAD efficiency of about 95 percent.

Mason, Lee S.

2003-01-01

392

Power Conditioning System Modelling for Nuclear Electric Propulsion  

NASA Technical Reports Server (NTRS)

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.

Metcalf, Kenneth J.

1993-01-01

393

Power conditioning system modelling for nuclear electric propulsion  

NASA Astrophysics Data System (ADS)

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.

Metcalf, Kenneth J.

1993-11-01

394

Management of the geomagnetically induced current risks on the national grid company's electric power transmission system  

Microsoft Academic Search

The National Grid Company plc (NGC) is the owner and operator of one of the world's largest privatised high-voltage electric power transmission systems in England and Wales at 400 and 275kV. As owner operator it is responsible for the secure and reliable delivery of electrical energy to all the 25 million electricity supply customers in England and Wales. The transmission

I. Arslan Erinmez; John G Kappenman; William A Radasky

2002-01-01

395

Blackouts in electric power transmission systems  

Microsoft Academic Search

In this paper an analysis of blackouts in electric power transmission systems is implemented and studied in simple networks with a regular structure. The proposed model describes load demand and network improvements evolving on a slow timescale as well as the fast dynamics of cascading overloads and outages. The model dynamics are demonstrated on the simple power system networks.

KARAMITSOS IOANNIS; ORFANIDIS KONSTANTINOS

2006-01-01

396

Power Processing, Part 1. Electric Machinery Analysis.  

ERIC Educational Resources Information Center

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

Hamilton, Howard B.

397

Voltage stability limits for weak power systems with high wind penetration  

NASA Astrophysics Data System (ADS)

Analysis of power system voltage stability has practical value in increasing wind penetration levels. As wind penetration levels increase in power systems, voltage stability challenges arise due to locating wind resources far away from load centers. This dissertation presents several different voltage stability methods for sizing new wind farms. Power system wind penetration levels depend on the available voltage stability margins (VSMs) of the existing power system and system load characteristics. Three new iterative methods have been developed to maximize wind penetration level in weak power systems based on systems' VSMs. The first two methods use an iterative approach for increasing the size of each wind farm until reaching the collapse point. Wind farms with less negative impact on system VSMs are sized larger than others. A third wind farm sizing method has been developed using modal analysis in conjunction with the traditional voltage stability method (Q-V method). Wind farms are placed at buses in the power system which have the lowest negative impact on voltage instability modes (strong wind injection buses). By placing the wind farms at the strongest wind injection buses, higher amounts of wind power can be injected into the power system. To further increase wind penetration in weak power systems, two additional techniques are introduced and applied to the western Kansas power system. The first technique uses modes of voltage instability to place voltage support equipment like static var compensators at locations in the power system where they provide the needed reactive power support for increasing levels of wind penetration. The second technique uses the fact that wind patterns at a wind farm site may rarely allow the wind farm to produce its maximum capacity during the peak loading hours. Wind farm maximum sizes can be increased above their maximum voltage stable size limit without driving the power system into becoming voltage unstable. Preventing voltage collapse for the additional increases in wind farm sizes is accomplished by disconnecting some wind turbines inside the wind farm during critical times to reduce its power output to a voltage stable level.

Tamimi, Ala

398

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

SciTech Connect

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.

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

399

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

NASA Astrophysics Data System (ADS)

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.

Hur, Jin-Suk; Roh, Myung-Sub

2014-02-01

400

Measurements of power loss distribution in a typical stator core under PWM voltage excitation  

NASA Astrophysics Data System (ADS)

The pulse width modulated (PWM) inverter is widely used to feed small induction motors for variable speed and torque control. When a laminated stator core is energised in this way additional iron losses occur due to localised distorted flux. Flux density and power loss distribution under PWM and sinusoidal voltage excitations were measured in a typical induction motor stator core lamination at 1.3 T, 50 Hz by using a computer-aided magnetising system to set up flux distribution as would occur in a practical three-phase stator core. The iron loss increased 15-20% under PWM excitation. The loss increase under PWM excitation in the stator core laminations was 3% lower than in Epstein strips of the same electrical steel under the same conditions showing an effect of the magnetic circuit geometry.

Tutkun, N.; Moses, A. J.

2003-06-01

401

Low-voltage transparent electric-double-layer ZnO-based thin-film transistors for portable transparent electronics  

NASA Astrophysics Data System (ADS)

Room-temperature deposited 8.0 ?m-thick mesoporous SiO2 dielectric shows a huge electric double layer (EDL) gate specific capacitance (4.16 ?F/cm2). Battery drivable low-voltage (1.5 V) transparent EDL thin-film transistors (TFTs) with Al-doped ZnO nanocrystal channel layer gated by such dielectric are fabricated at room-temperature. The TFTs exhibit high-performance n-type transistor characteristics with a high field-effect mobility of 14.9 cm2/V s. The current on/off ratio and subthreshold gate voltage swing are estimated to be 2×106 and 82 mV/decade, respectively. Our results demonstrate that mesoporous SiO2 dielectrics with EDL effect are very promising for battery-powered portable transparent macroelectronics on temperature-sensitive substrates.

Lu, Aixia; Sun, Jia; Jiang, Jie; Wan, Qing

2010-01-01

402

Combined dynamic voltage scaling and adaptive body biasing for lower power microprocessors under dynamic workloads  

Microsoft Academic Search

Dynamic voltage scaling (DVS) reduces the power consumption of processors when peak performance is unnecessary. However, the achievable power savings by DVS alone is becoming limited as leakage power increases. In this paper, we show how the simultaneous use of adaptive body biasing (ABB) and DVS can be used to reduce power in high-performance processors. Analytical models of the leakage

Steven M. Martin; Krisztian Flautner; Trevor N. Mudge; David Blaauw

2002-01-01

403

Electrical Experiments. VT-214-12-4. Part IV. A-C Reduced Voltage Controls.  

ERIC Educational Resources Information Center

Designed for high school electronics students, this fourth document in a series of six electrical learning activity packages focuses on alternating current-reduced voltage controls. An introductory section gives the objective for the activities, an introduction, and an outline of the content. The remainder of the guidebook is comprised of…

Connecticut State Dept. of Education, Hartford. Div. of Vocational Education.

404

Solving electric energy supply to rural areas; The capacitive voltage divider  

Microsoft Academic Search

This paper describes the design, construction, testing, and installation of a system intended so supply electricity to rural communities directly from transmission lines. The system is comprised of a capacitive voltage divider, a split air-core reactor, and associated protective devices. A series of laboratory tests were performed on the whole system and the main results, as well as the results

H. G. Sarmiento; R. DeLaRosa; V. Carrillo; J. Vilar

1990-01-01

405

High speed electric field and voltage measurements with field coupled sensors  

SciTech Connect

In this paper, we introduce the concept of displacement vector (D) measurements with floating electrodes, discuss measurements with resistively grounded electrodes, and explore how measurements of voltage and electric field are related. Finally, we discuss errors in measurements with floating electrodes.

Di Capua, M.S.

1984-12-12

406

Power console development for NASA's electric propulsion outreach program  

NASA Technical Reports Server (NTRS)

NASA LeRC is developing a 30 cm diameter xenon ion thruster for auxiliary and primary propulsion applications. To maximize expectations for user-acceptance of ion propulsion technology, NASA LeRC, through their Electric Propulsion Outreach Program, is providing sectors of industry with portable power consoles for operation of 5 KW-class xenon ion thrusters. This power console provides all necessary functions to permit thruster operations over a 0.5-5 KW envelope under both manual and automated control. These functions include the following: discharge, cathode heater, neutralizer keeper, and neutralizer heater currents, screen and accelerator voltages, and a gas feed system to regulate and control propellant flow to the thruster. An electronic circuit monitors screen and accelerator currents and controls arcing events. The power console was successfully integrated with the NASA 30 cm thruster.

Pinero, Luis R.; Patterson, Michael J.; Satterwhite, Vincent E.

1993-01-01

407

Parallel Power Flow AC\\/DC Converter with High Input Power Factor and Tight Output Voltage Regulation for Universal Voltage Application  

Microsoft Academic Search

In this paper, a new parallel-connected single phase power factor correction (PFC) topology using flyback converter in parallel with forward converter is proposed to improve the input power factor with simultaneously output voltage regulation taking consideration of current harmonic norms. Paralleling of converter modules is a well-known technique that is often used in medium-power applications to achieve the desired output

A. K. Jha; K. H. Babu; B. M. Karan

2006-01-01

408

Switched-capacitor power supplies: DC voltage ratio, efficiency, ripple, regulation  

Microsoft Academic Search

A comprehensive and accurate steady-state analysis of a step-up DC-DC switched-capacitor power converter is performed. No approximations, such as average techniques, are invoked. Parasitic elements such as diode forward voltages, on-resistances of transistors and equivalent-series resistances of capacitors are included into the model. The converter performance functions, i.e. DC voltage ratio, efficiency, output voltage ripple, are expressed in terms of

Guangyong Zhu; Adrian Ioinovici

1996-01-01

409

78 FR 4873 - Electrical Protective Equipment Standard and the Electric Power Generation, Transmission, and...  

Federal Register 2010, 2011, 2012, 2013

...Equipment Standard and the Electric Power Generation, Transmission, and Distribution...CFR 1910.137) and Electric Power Generation, Transmission, and Distribution...1910.137) and the Electric Power Generation, Transmission, and...

2013-01-23

410

Fundamentals of electric power conversion  

SciTech Connect

Its rugged nature and straightforward design make the induction motor the most commonly used type of electric motor. This motor ranges in size fro the fractional-horsepower, single-phase motors found in household appliances to polyphase motors rated at thousands of horsepower for industrial applications. Volume 1 of this report describes the function of induction motors, their characteristics, and induction motor testing. Volume 2 describes the characteristics of high-efficiency induction motors, with emphasis on the techniques used to obtain high efficiency. This two-volume report is written in nontechnical language and is intended for readers who require background from applications, marketing, motor planning, or managerial perspective.

Umans, S.D. (Umans (Stephen D.), Belmont, MA (United States))

1992-12-01

411

Fundamentals of electric power conversion  

SciTech Connect

Its rugged nature and straightforward design make the induction motor the most commonly used type of electric motor. This motor ranges in size from the fractional-horsepower, single-phase motors found in household appliances to polyphase motors rated at thousands of horsepower for industrial applications. Volume 1 of this report describes the function of induction motors, their characteristics, and induction motor testing. Volume 2 describes the characteristics of high-efficiency induction motors, with emphasis on the techniques used to obtain high efficiency. This two-volume report is written in nontechnical language and is intended for readers who require background from an applications, marketing, motor planning, or managerial perspective.

Umans, S.D. (Umans (Stephen D.), Belmont, MA (United States))

1992-12-01

412

Assessing the impact of space weather on the electric power grid based on insurance claims for industrial electrical equipment  

NASA Astrophysics Data System (ADS)

Geomagnetically induced currents are known to induce disturbances in the electric power grid. Here we perform a statistical analysis of 11,242 insurance claims from 2000 through 2010 for equipment losses and related business interruptions in North American commercial organizations that are associated with damage to, or malfunction of, electrical and electronic equipment. We find that claim rates are elevated on days with elevated geomagnetic activity by approximately 20% for the top 5% and by about 10% for the top third of most active days ranked by daily maximum variability of the geomagnetic field. When focusing on the claims explicitly attributed to electrical surges (amounting to more than half the total sample), we find that the dependence of claim rates on geomagnetic activity mirrors that of major disturbances in the U.S. high-voltage electric power grid. The claim statistics thus reveal that large-scale geomagnetic variability couples into the low-voltage power distribution network and that related power-quality variations can cause malfunctions and failures in electrical and electronic devices that, in turn, lead to an estimated 500 claims per average year within North America. We discuss the possible magnitude of the full economic impact associated with quality variations in electrical power associated with space weather.

Schrijver, C. J.; Dobbins, R.; Murtagh, W.; Petrinec, S. M.

2014-07-01

413

dc side active power filters for aircraft electric power systems  

Microsoft Academic Search

A dc side active filter for a 400 Hz aircraft electric power system is proposed. The filter provides continuous adjustable reactive power, has fast response and high efficiency, and does not necessitate excess capacitive kVA required to supply highly unbalanced or nonlinear loads.

P. Enjeti; S. Kim

1992-01-01

414

Fuel cell power conditioning for electric power applications: a summary  

E-print Network

Fuel cell power conditioning for electric power applications: a summary X. Yu, M.R. Starke, L.M. Tolbert and B. Ozpineci Abstract: Fuel cells are considered to be one of the most promising sources, multiple complications exist in fuel cell operation. Fuel cells cannot accept current in the reverse

Tolbert, Leon M.

415

Structural Vulnerability Assessment of Electric Power Grids  

E-print Network

Cascading failures are the typical reasons of black- outs in power grids. The grid topology plays an important role in determining the dynamics of cascading failures in power grids. Measures for vulnerability analysis are crucial to assure a higher level of robustness of power grids. Metrics from Complex Networks are widely used to investigate the grid vulnerability. Yet, these purely topological metrics fail to capture the real behaviour of power grids. This paper proposes a metric, the effective graph resistance, as a vulnerability measure to de- termine the critical components in a power grid. Differently than the existing purely topological measures, the effective graph resistance accounts for the electrical properties of power grids such as power flow allocation according to Kirchoff laws. To demonstrate the applicability of the effective graph resistance, a quantitative vulnerability assessment of the IEEE 118 buses power system is performed. The simulation results verify the effectiveness of the effect...

Koç, Yakup; Kooij, Robert E; Brazier, Frances M T

2013-01-01

416

Real Power and Reactive Power Control of a Three-Phase Single-Stage-PV System and PV voltage Stability  

SciTech Connect

Grid-connected photovoltaic (PV) systems with power electronic interfaces can provide both real and reactive power to meet power system needs with appropriate control algorithms. This paper presents the control algorithm design for a three-phase single-stage grid-connected PV inverter to achieve either maximum power point tracking (MPPT) or a certain amount of real power injection, as well as the voltage/var control. The switching between MPPT control mode and a certain amount of real power control mode is automatic and seamless. Without the DC-to-DC booster stage, PV DC voltage stability is an important issue in the control design especially when the PV inverter is operating at maximum power point (MPP) with voltage/var control. The PV DC voltage collapse phenomenon and its reason are discussed. The method based on dynamic correction of the PV inverter output is proposed to ensure PV DC voltage stability. Simulation results of the single-stage PV system during system disturbances and fast solar irradiation changes confirm that the proposed control algorithm for single-stage PV inverters can provide appropriate real and reactive power services and ensure PV DC voltage stability during dynamic system operation and atmospheric conditions.

Li, Huijuan [ORNL] [ORNL; Xu, Yan [ORNL] [ORNL; Adhikari, Sarina [ORNL] [ORNL; Rizy, D Tom [ORNL] [ORNL; Li, Fangxing [ORNL] [ORNL; Irminger, Philip [ORNL] [ORNL

2012-01-01

417

United States Space Nuclear Electric Power Program.  

NASA Technical Reports Server (NTRS)

The principal characteristics and design features of major systems and technological developments in U.S. space nuclear power activities are reviewed, covering radioisotope thermoelectric generators, reactor space electric power technology, and the advanced liquid metal cooled power reactor program. The topics also include heat source design and development, thermoelectric efficiency, high performance thermoelectric materials, and alloy developments. The U.S. Space Electric Power Program is described as one aimed at the development of a minimum number of standard components and power modules for both radioisotopes and reactor systems that will meet the widest possible range of future requirements. The need to reduce the high cost of the isotopic generators already used in space missions is stressed.

Newby, G. A.

1972-01-01

418

Uninterruptible power supply multiloop control employing digital predictive voltage and current regulators  

Microsoft Academic Search

A digital control technique for the inverter stage of uninterruptible power supplies (UPSs) is described, which is based on voltage and current predictive regulators. Its aim is to achieve a deadbeat dynamic response for the controlled variables (output voltage and inverter current). The controller maintains the advantageous conventional multiloop structure and is capable of guaranteeing a high-quality dynamic performance. Moreover,

Simone Buso; Sandro Fasolo; Paolo Mattavelli

2001-01-01

419

Uninterruptible power supply multi-loop control employing digital predictive voltage and current regulators  

Microsoft Academic Search

A digital control technique for the inverter stage of uninterruptible power supplies (UPSs) is described, which is based on voltage and current predictive regulators. Its aim is to achieve a dead-beat dynamic response for the controlled variables (output voltage and inverter current). The controller maintains the advantageous conventional multi-loop structure and is capable of guaranteeing a high quality dynamic performance.

S. Buso; S. Fasolo; P. Mattavelli

2001-01-01

420

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

E-print Network

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

421

LLC Resonant Converter With Adaptive Link-Voltage Variation for a High-Power-Density Adapter  

Microsoft Academic Search

The output voltage of an adapter for a laptop computer should vary according to the load current in order to supply power to the computer. To satisfy this requirement, an LLC resonant converter with an adaptive link-voltage-variation (ALVV) scheme is proposed in this letter. The proposed ALVV scheme helps the LLC resonant converter to operate at a nearly constant resonant

Bong-Chul Kim; Ki-Bum Park; Chong-Eun Kim; Byoung-Hee Lee; Gun-Woo Moon

2010-01-01

422

Effects of applied voltages and dissolved oxygen on sustained power generation by microbial fuel cells  

E-print Network

Effects of applied voltages and dissolved oxygen on sustained power generation by microbial fuel chamber MFCs at the end of a cycle when the substrate is depleted. A slight increase in dissolved oxygen chamber for sustained performance of MFCs. Key words | anode, applied voltage, dissolved oxygen, microbial

423

Speed and voltage regulation of d.c. shunt machines using power transistor in field circuit  

Microsoft Academic Search

A simple method for speed and voltage regulation of d.c. shunt machines is presented. The method is based on the use of a power transistor circuit which automatically adjusts the field current Such that the Speed or output voltage, as the case may be, is maintained constant with increasing load on the machine. An added advantage of this inothod is

VIMAL SINGH; S. K. KAK

1974-01-01

424

Fuel cell electric power production  

DOEpatents

A process for generating electricity from a fuel cell includes generating a hydrogen-rich gas as the fuel for the fuel cell by treating a hydrocarbon feed, which may be a normally liquid feed, in an autothermal reformer utilizing a first monolithic catalyst zone having palladium and platinum catalytic components therein and a second, platinum group metal steam reforming catalyst. Air is used as the oxidant in the hydrocarbon reforming zone and a low oxygen to carbon ratio is maintained to control the amount of dilution of the hydrogen-rich gas with nitrogen of the air without sustaining an insupportable amount of carbon deposition on the catalyst. Anode vent gas may be utilized as the fuel to preheat the inlet stream to the reformer. The fuel cell and the reformer are preferably operated at elevated pressures, up to about a pressure of 150 psia for the fuel cell.

Hwang, Herng-Shinn (Livingston, NJ); Heck, Ronald M. (Frenchtown, NJ); Yarrington, Robert M. (Westfield, NJ)

1985-01-01

425

Galena Electric Power A Situational Analysis  

SciTech Connect

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.

Robert E. Chaney; Stephen G. Colt; Ronald A. Johnson; Richard W. Wiles; Gregory J. White

2008-12-31

426

Analysis of induced voltage in metal shield of power cable and research on its restraining technology based on asymmetric state  

Microsoft Academic Search

Three segments transposition is often used to decrease the induced voltage in metal shield of high voltage power cable, But since the power cable is rebuilt more and more frequently caused by city construction, the length of the three segments will be unequal while the power cable rebuilt, which will make the induced voltage in metal shield unbalanced, and produce

Hongzhong Ma; Jingang Song; Xinrong Ni; Limin Zhang

2008-01-01

427

A 230 KV power factor correction installation taking into account the low voltage filters  

SciTech Connect

Power factor is an important component for utilities in maintaining the overall efficiency of the power delivery. Utilities encourage industrial customers to provide their own power factor correction for low power factor loads. At the end of large capacity transmission lines utilities tend to provide power factor correction through shunt capacitor banks. With increased number of filter banks in low voltage distribution systems for power factor correction and harmonic filtering, installation of high voltage capacitor banks require careful considerations. In this paper, the study results of a practical 105 MVAR, 230 kV capacitor bank is discussed. The effect of the existing 13.8 kV filter on the installation of the high voltage power factor correction capacitors is examined. The frequency domain analysis to evaluate various resonant frequencies are also discussed.

Natarajan, R. [ABB Power T and D Co., Raleigh, NC (United States); Hale, E. [Black and Veatch Construction, Inc., Lake Oswego, OR (United States); Ashmore, S. [ABB HV Capacitors, Saint-Laurent (Canada); Larsson, K. [ABB, Quebec (Canada)

1999-11-01

428

Primary electric power generation systems for advanced-technology engines  

NASA Technical Reports Server (NTRS)

The advantages of the all electric airplane are discussed. In the all electric airplane the generator is the sole source of electric power; it powers the primary and secondary flight controls, the environmentals, and the landing gear. Five candidates for all electric power systems are discussed and compared. Cost benefits of the all electric airplane are discussed.

Cronin, M. J.

1983-01-01

429

The design and development of a high voltage power supply  

NASA Technical Reports Server (NTRS)

A high voltage circuit system was redesigned, breadboarded, and tested to meet revised specification requirements. Circuit component subassemblies are described and include the firing unit, regulator, dc to dc converter, and output and trigger circuits. Design changes, tests, and equipment fabrication are outlined chronologically by month. A list of design specifications is included.

Ting, R.

1974-01-01

430

Formulating electric-power policy with perspective  

SciTech Connect

The electric power policymaking process is under stress. Criteria that served it well for twenty-five years prior to the mid-1970's no longer seem adequate. A sense of change, but not of direction, is widely acknowledged. Under these circumstances, the policymaker is hard pressed to judge whether disparate policy actions are relevant and mutually supportive. This article is based on the findings of an electric power study, a technology assessment, funded by the National Science Foundation. It is offered to the end that policymakers may practice their craft with heightened awareness of issues of long-term importance and clearer perspectives on the turmoil that today pervades the electric power policy arena. 27 references, 6 figures, 3 tables.

Frederick, D.O. (Scientific Foresight, Inc., Austin, TX); Vanston, J.H., Jr.

1983-12-01

431

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

NASA Technical Reports Server (NTRS)

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.

Walko, L. C.

1974-01-01

432

Energy and power needs of electric vehicles  

Microsoft Academic Search

Both energy and energy rate (power) requirements are described based on the mechanical output requirements of typical electric automobiles, the electrical input requirements at the inverter, and the requirements from a utility into a charger. The impact of lithium-ion battery input-output efficiency is considered. A fully loaded full-size car with a mass of 2000 kg, for example, requires only about

Philip T. Krein

2012-01-01

433

Power Requirements Determined for High-Power-Density Electric Motors for Electric Aircraft Propulsion  

NASA Technical Reports Server (NTRS)

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.

Johnson, Dexter; Brown, Gerald V.

2005-01-01

434

A new generation of high voltage pulsed power converters  

Microsoft Academic Search

Improving efficiency and flexibility in pulsed power supply technologies are the most substantial concerns of pulsed power systems specifically for plasma generation. Recently, the improvement of pulsed power supply becomes of greater concern due to extension of pulsed power applications to environmental and industrial areas. A current source based topology is proposed in this paper which gives the possibility of

Sasan Zabihi; Firuz Zare; Gerard Ledwich; A. Ghosh; H. Akiyama

2010-01-01

435

Modified filter prevents conduction of microwave signals along high-voltage power supply leads  

NASA Technical Reports Server (NTRS)

Very lossy powdered iron material, in the lining of a polyester resin, replaces the dielectric material in the short coaxial transmission line of a simple filter. The lossy material absorbs microwave signals along high voltage power supply leads.

Mathison, R. P.

1964-01-01

436

46 CFR 28.870 - Emergency source of electrical power.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 false Emergency source of electrical power. 28.870 Section 28.870 Shipping...Vessels § 28.870 Emergency source of electrical power. (a) The following electrical loads must be connected to an...

2012-10-01

437

46 CFR 28.355 - Main source of electrical power.  

Code of Federal Regulations, 2011 CFR

...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...

2011-10-01

438

46 CFR 28.870 - Emergency source of electrical power.  

...2014-10-01 false Emergency source of electrical power. 28.870 Section 28.870 Shipping...Vessels § 28.870 Emergency source of electrical power. (a) The following electrical loads must be connected to an...

2014-10-01

439

46 CFR 28.355 - Main source of electrical power.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 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...

2010-10-01

440

46 CFR 28.355 - Main source of electrical power.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 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...

2013-10-01

441

Trends in electric power technologies  

SciTech Connect

Research and development (R and D) on power plants is now aimed at increasing plant efficiency and reliability to avoid the high capital costs of new plant construction. The trend toward larger generating plants makes efficiency and reliability even more important. Studies include ways to improve operator judgment and minimize error by feeding continuous in-plant information into models of plant subsystems, efforts to improve fuel conversion efficiency by studying higher-temperature thermodynamics, ways to replace existing generators with superconducting generators, and to meet environmental needs with atmospheric fluidized-bed combustion. As fuel costs rise, the US will shift more toward coal and nuclear plants, with research aimed at optimizing performance. (DCK)

Starr, C.; Lihach, N.

1982-06-01

442

Application of optical fibre sensor for partial discharge detection in high-voltage power equipment  

Microsoft Academic Search

The insulation system of HV power equipment deteriorates due to partial discharges. It is thus desirable to monitor the insulation of power apparatus whilst in service. Ultrasonic signals generated by the partial discharges in high-voltage power equipment can be detected with suitable pressure transducers and related to the PD (Partial Discharge) source. Acoustooptic sensors have shown high sensitivity and good

Abbas Zargari; Trevor R. Blackburn

1996-01-01

443

Efficiency-Improved High-Voltage Analog Power Amplifier for Driving Piezoelectric Actuators  

Microsoft Academic Search

A novel high-voltage analog power amplifier derived from a well-known complementary class B amplifier is presented in this paper. The amplifier offers improved efficiency when driving capacitive loads such as piezoelectric multilayer actuators, while maintaining a high level of signal quality, peak power and low electromagnetic radiation. The main drawback of a class B amplifier in comparison to other power

Carsten Wallenhauer; Bernhard Gottlieb; Roland Zeichfusl; Andreas Kappel

2010-01-01

444

Kysat-2 electrical power system design and analysis  

NASA Astrophysics Data System (ADS)

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.

Molton, Brandon L.

445

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

PubMed

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

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

2015-02-01

446

Inductor-free low power step-down dc-dc switching voltage converter  

Microsoft Academic Search

In low power IC systems, low-dropout, buck and switched-capacitor voltage converters are the three alternative power sources. This paper presents an inductor-free switching voltage converter which possesses the merits of aforementioned converters. It features inductor-less structure like SC based switching converter, adjustable output by PWM mechanism like buck converter, and OPA based structure like LDO. Circuit modeling shows that the

Chun-Hsun Wu; Le-Ren Chang-Chien

2008-01-01

447

Overview of power converter designs feasible for high voltage transformer-less wind turbine  

Microsoft Academic Search

Many leading wind turbine manufacturers are pushing forward in variable-speed wind turbines, often exceeding 5 MW. Therefore, novel designs and concepts for optimal high power wind turbines appeared. One of the most promising concepts is the high voltage (10-35 kV) transformer-less topology. High voltage design enables low power losses and elimination of bulky step-up transformer from the wind turbine system.

Michal Sztykiel

2011-01-01

448

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

PubMed

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

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

2010-10-01

449

A test and measurement technique for determining possible lightning-induced voltages in aircraft electrical circuits  

NASA Technical Reports Server (NTRS)

Transient analyzer consists of four 0.5 microfarads capacitors chargeable by self-contained solid state 50 KV dc power supply operating from standard 110 Vac line voltage. Unit can circulate unidirectional current impulses of up to 500 amperes through aircraft at waveshapes similar to those of natural lightning strokes.

Plumer, J. A.; Walko, L. C.

1975-01-01

450

Coal gasification for electric power generation.  

PubMed

The electric utility industry is being severely affected by rapidly escalating gas and oil prices, restrictive environmental and licensing regulations, and an extremely tight money market. Integrated coal gasification combined cycle (IGCC) power plants have the potential to be economically competitive with present commercial coal-fired power plants while satisfying stringent emission control requirements. The current status of gasification technology is discussed and the critical importance of the 100-megawatt Cool Water IGCC demonstration program is emphasized. PMID:17788466

Spencer, D F; Gluckman, M J; Alpert, S B

1982-03-26

451

HEMP-induced transients in electric power substations  

SciTech Connect

A nuclear detonation in or above the earth's atmosphere produces an intense electromagnetic pulse (EMP). A large portion of the EMP electromagnetic energy is within the RF spectrum. A detonation at high altitudes above 40 km produces an EMP called high-altitude EMP (HEMP). HEMP is a steep-front short duration transient with a rise time on the order of a few nanoseconds which decays to near zero in less than a microsecond. A single high-altitude burst can subject much of the continental United States to intense HEMP electric fields on the order of tens of kilovolts per meter. The intense transient HEMP will induce fast transients in high-voltage transmission lines and bus structures, instrumentation cables, and control wires in power transmission and distribution (T D) substations. A system of traveling wave coupling models for a 500 kV substation, including models for the high voltage primary bus, components (circuit breakers, disconnect switches, power transformers, and current and voltage instrument transformers), low voltage control wiring circuits, and a number of conducted and radiated interference coupling modes, had been developed earlier by EPRI. These EPRI served as the baseline for the present HEMP coupling investigations. The HEMP effects on protective relays were assessed for a nominal HEMP environment using several new field coupling models merged with the switching transient data. It is found that a representative solid state relay is unlikely to be damaged or to misoperate by the nominal HEMP threat with a peak field strength of 50 kV/m. However, it is possible for both DC control wires to flash over to ground simultaneously, causing fuses to blow and placing the relay in an inoperative state.

Wiggins, C.M.; Thomas, D.E.; Salas, T.M. (BDM International, Inc., Albuquerque, NM (United States))

1992-02-01

452

HEMP-induced transients in electric power substations. Final report  

SciTech Connect

A nuclear detonation in or above the earth`s atmosphere produces an intense electromagnetic pulse (EMP). A large portion of the EMP electromagnetic energy is within the RF spectrum. A detonation at high altitudes above 40 km produces an EMP called high-altitude EMP (HEMP). HEMP is a steep-front short duration transient with a rise time on the order of a few nanoseconds which decays to near zero in less than a microsecond. A single high-altitude burst can subject much of the continental United States to intense HEMP electric fields on the order of tens of kilovolts per meter. The intense transient HEMP will induce fast transients in high-voltage transmission lines and bus structures, instrumentation cables, and control wires in power transmission and distribution (T & D) substations. A system of traveling wave coupling models for a 500 kV substation, including models for the high voltage primary bus, components (circuit breakers, disconnect switches, power transformers, and current and voltage instrument transformers), low voltage control wiring circuits, and a number of conducted and radiated interference coupling modes, had been developed earlier by EPRI. These EPRI served as the baseline for the present HEMP coupling investigations. The HEMP effects on protective relays were assessed for a nominal HEMP environment using several new field coupling models merged with the switching transient data. It is found that a representative solid state relay is unlikely to be damaged or to misoperate by the nominal HEMP threat with a peak field strength of 50 kV/m. However, it is possible for both DC control wires to flash over to ground simultaneously, causing fuses to blow and placing the relay in an inoperative state.

Wiggins, C.M.; Thomas, D.E.; Salas, T.M. [BDM International, Inc., Albuquerque, NM (United States)

1992-02-01

453

49 CFR 571.305 - Standard No. 305; Electric-powered vehicles: electrolyte spillage and electrical shock protection.  

Code of Federal Regulations, 2010 CFR

...component that has a working voltage greater than 30 VAC or...components or electric circuit to propel the vehicle...is supplied by a high voltage source. These include...measurements for calculating voltage(s) and electrical isolation are made after a minimum of 5 seconds after...

2010-10-01

454

New live line tester for porcelain suspension insulators on high-voltage power lines  

SciTech Connect

Suspension insulator assemblies known as insulator strings are used in overhead power transmission lines to mechanically support high-voltage conductors while providing adequate insulation to withstand switching and lightning overvoltages. Since the useful life in service of the individual insulator elements making up these strings is hard to predict, they must be verified periodically to insure that adequate line reliability is maintained at all times. Over the years many testing methods have been used for this purpose, each one with its own advantages and disadvantages. Until now at Hydro-Quebec, porcelain insulators had been tested by the buzz method which simply consists of applying a short-circuit to each insulator in a string and listening for a buzz-like sound indicating a good insulator. However, safety considerations that preclude short-circuiting insulators and other disadvantages of that method have led Hydro-Quebec to undertake and complete the development of a new insulator tester. The working principle of this new device is based on the automatic measurement and recording of the electric field along the insulator string which decreases considerably in front of an internally-shorted insulator. The tester is slid along the string while the insulators are counted automatically. The information from tests on up to 200 strings can be stored in the device to be later transferred in a host computer for interpretation and/or permanent storage. The new tester also gives information on voltage distribution along the insulator strings which can be useful for the design of future power transmission lines.

Vaillancourt, G.H.; St-Jean, M. (Hydro-Quebec, Varennes, Quebec (Canada)); Bellerive, J.P. (Hydro-Quebec, Montreal, Quebec (Canada)); Jean, C. (Positron Inc., Montreal, Quebec (Canada))

1994-01-01

455

Gyrotron Output Power Stabilization by PID Feedback Control of Heater Current and Anode Voltage  

NASA Astrophysics Data System (ADS)

To provide stable output power of a gyrotron during long operation time the power stabilization was achieved by two schemes with PID feedback control of heater current and anode voltage. It was based on the dependence of the output power on both the anode voltage and the beam current and also on the dependence of the beam current on the gun heater current. Both schemes provided decrease of the power standard deviation to 0.3-0.5%. The comparison between parameters of both schemes is discussed in the paper.

Khutoryan, E. M.; Idehara, T.; Kuleshov, A. N.; Ueda, K.

2014-12-01

456

Solar Electric Propulsion (SEP) Tug Power System Considerations  

NASA Technical Reports Server (NTRS)

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.

Kerslake, Thomas W.; Bury, Kristen M.; Hojinicki, Jeffrey S.; Sajdak, Adam M.; Scheiddegger, Robert J.

2011-01-01

457

Miniaturized Power Processing Unit Study: A Cubesat Electric Propulsion Technology Enabler Project  

NASA Technical Reports Server (NTRS)

This study evaluates High Voltage Power Processing Unit (PPU) technology and driving requirements necessary to enable the Microfluidic Electric Propulsion technology research and development by NASA and university partners. This study provides an overview of the state of the art PPU technology with recommendations for technology demonstration projects and missions for NASA to pursue.

Ghassemieh, Shakib M.

2014-01-01

458

A Wireless Sensor Network Communication Model for Automation of Electric Power Distribution  

Microsoft Academic Search

Automation of electric power distribution in a cost-efficient and reliable manner can be accomplished by complete automation of the load dispatch centers and substations on a large scale. For efficient load balancing among the feed lines, a continuous monitoring of parameters, such as voltage, current in the line, temperature, pressure, and oil level of the transformers is required. Currently, automation

M. Muthukumar; N. Sureshkumar

459

Applications of high temperature superconductors to direct current electric power transmission and distribution  

Microsoft Academic Search

For several reasons, the application of superconductors to both the transmission and distribution of electric power is a desire that is best accomplished by using direct current. The inherent low loss, high current capability of dc superconducting cables allows the replacement of ultra-high voltage apparatus and the associated high cost and inversion-rectification difficulties with a compact potentially lower cost, low

Benjamin Wade McConnell

2005-01-01

460

[The characteristics of the electromagnetic situation close to overhead electric power transmission lines in St. Petersburg].  

PubMed

According to task by Environmental Protection Department of St. Petersburg Municipal Administration, levels of electromagnetic fields induced by high-voltage electric power lines were measured in development lands of St. Petersburg. The authors present hygienic evaluation of electromagnetic fields intensity, match calculated and actual values of magnetic induction of occupational magnetic fields. PMID:9885493

Nikitina, V N; Marchenko, E A; Kolesnikov, G A; Naumova, T M; Shubnikova, N N; Cherniavski?, A A

1998-01-01

461

Unraveling Geographic Interdependencies in Electric Power Infrastructure  

Microsoft Academic Search

Interdependencies among infrastructure systems are now becoming commonplace, and present both opportunities and vulnerabilities. Initial attention was paid to functional interdependencies among infrastructure systems regardless of locational characteristics. Using electric power as a focal point, geographic interdependencies are evaluated, that is, outages that spread across several states rather than being confined to single states. The analysis evaluates the extent to

Carlos E. Restrepo; Jeffrey S. Simonoff; Rae Zimmerman

2006-01-01

462

Emerging Electric Power Systems and Future Grid  

NSDL National Science Digital Library

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.

Sen, P.K.

463

ECONOMIC MODELING OF ELECTRIC POWER SECTOR  

EPA Science Inventory

CAMD performs a variety of economic modeling analyses to evaluate the impact of air emissions control policies on the electric power sector. A range of tools are used for this purpose including linear programming models, general equilibrium models, and spreadsheet models. Examp...

464

Statistical Design of Electric Power Transmission Networks  

Microsoft Academic Search

This thesis presents a statistical planning method for expanding electric power transmission networks in the presence of load\\/generation and network uncertainties. The objective of the proposed algorithm is to obtain a set of alternative network expansion plans which have optimum reliability and expansion cost. Present methods optimize the existing network based on a deterministic performance index. Therefore, they are limited

Albert Guvenis

1983-01-01

465

Structural Analysis for Electric Power Transmission Structures  

Microsoft Academic Search

The electric power transmission industry is facing numerous changes in the ways in which traditional structures are being designed. De-regulation, and subsequent re- regulation, has resulted in increased oversight of the design process. Concurrently, budget reductions have led to staff reductions, often achieved through retirements and promotions. Thus, there is now increased reliance upon computer software for the performance-based design

William F. Cofer

466

Bidder cost revelation in electric power auctions  

Microsoft Academic Search

Competitive auctions for electric power sources whose operation will be based upon economic dispatch raise new challenges for auction designers. The efficient selection and operation of such generation sources requires revelation of bidder types over two-dimensions, fixed and variable costs. The way in which fixed and variable prices are combined into a net score, which determines the winning bids, plays

James B. Bushnell; Shmuel S. Oren

1994-01-01

467

High voltage equipment parts evaluation tests  

Microsoft Academic Search

Airborne power supplies and equipment which supply megawatts of power at multi-kilovolts require designs of minimum weight and volume which imply compact systems with high density packaging. This is a design concern of high voltage electrical components. This paper describes high voltage tests, test parameters, and the test results of several high voltage components. In addition, the value of dielectric

W. G. Dunbar; D. L. Schweickart

1982-01-01

468

Electromechanical phase transition in dielectric elastomers under uniaxial tension and electrical voltage  

NASA Astrophysics Data System (ADS)

Subject to forces and voltage, a dielectric elastomer may undergo electromechanical phase transition. A phase diagram is constructed for an ideal dielectric elastomer membrane under uniaxial force and voltage, reminiscent of the phase diagram for liquid-vapor transition of a pure substance. We identify a critical point for the electromechanical phase transition. Two states of deformation (thick and thin) may coexist during the phase transition, with the mismatch in lateral stretch accommodated by wrinkling of the membrane in the thin state. The processes of electromechanical phase transition under various conditions are discussed. A reversible cycle is suggested for electromechanical energy conversion using the dielectric elastomer membrane, analogous to the classical Carnot cycle for a heat engine. The amount of energy conversion, however, is limited by failure of the dielectric elastomer due to electrical breakdown. With a particular combination of material properties, the electromechanical energy conversion can be significantly extended by taking advantage of the phase transition without electrical breakdown.

Huang, Rui; Suo, Zhigang

2012-02-01

469

PWM Inverter with Voltage Boosters with Regenerating Capability Augmented by Electric Double-Layer Capacitor  

NASA Astrophysics Data System (ADS)

An interior permanent magnet (IPM) motor drive system which has regenerating capability augmented by electric double-layer capacitors (EDLCs) is proposed. In the proposed system, EDLCs are arranged in series with batteries so that a lesser number of the EDLCs and batteries will be required. The proposed system has two bi-directional voltage boosters: one is for both the batteries and EDLCs to control the dc-link voltage of a PWM inverter and the other is for only the EDLCs and is used to control the energy flow from and to the EDLCs. In this paper, a strategy to control the energy flow to and from the EDLCs is explained and its effectiveness is confirmed by simulation and experimental results. Furthermore, the efficiencies of the voltage booster, inverter, PM motor, and whole system are measured for the system with the basic configuration, i.e., which consists of only one bi-directional voltage booster and PWM inverter. Then, the steady-state characteristics are determined. Finally, the efficiency of the voltage boosters in the proposed system is determined, and the advantage of the proposed PM motor drive system is discussed.

Yamamoto, Kichiro; Imakiire, Akihiro; Iimori, Kenichi

470

Electric Power Research Institute: Journal Online  

NSDL National Science Digital Library

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.

Dietrich, David

2007-07-08

471

The Tucson Electric Power Solar Test Yard  

NASA Astrophysics Data System (ADS)

In collaboration with Tucson Electric Power we studied the performance of twenty different grid-tied photovoltaic systems, consisting of over 600 PV modules in all. We added data acquisition hardware to monitor DC power from the modules, AC power from the inverters, PV module temperatures, and meteorological data such as the irradiance incident on the PV systems. We report measurements of PV system yields and efficiencies over periods of minutes, days, and years. We also report temperature and irradiance coefficients of efficiency and measurements of long-term degradation. We also use our data to validate models that predict the output from PV systems.

Lonij, Vincent; Orsburn, Sean; Salhab, Anas; Kopp, Emily; Brooks, Adria; Jayadevan, Vijai; Greenberg, James; St. Germaine, Michael; Allen, Nate; Jones, Sarah; Hardesty, Garrett; Cronin, Alex

2011-10-01

472

Mutism and Amnesia following High-Voltage Electrical Injury: Psychogenic Symptomatology Triggered by Organic Dysfunction?  

Microsoft Academic Search

Background: Mutism and dense retrograde amnesia are found both in organic and dissociative contexts. Moreover, dissociative symptoms may be modulated by right prefrontal activity. A single case, M.R., developed left hemiparesis, mutism and retrograde amnesia after a high-voltage electric shock without evidence of lasting brain lesions. M.R. suddenly recovered from his mutism following a mild brain trauma 2 years later.

Fribourg County Hospital

473

Mutism and Amnesia following High-Voltage Electrical Injury: Psychogenic Symptomatology Triggered by Organic Dysfunction?  

Microsoft Academic Search

Background: Mutism and dense retrograde amnesia are found both in organic and dissociative contexts. Moreover, dissociative symptoms may be modulated by right prefrontal activity. A single case, M.R., developed left hemiparesis, mutism and retrograde amnesia after a high-voltage electric shock without evidence of lasting brain lesions. M.R. suddenly recovered from his mutism following a mild brain trauma 2 years later.

Nishant K. Mishra; Heike Russmann; Cristina Granziera; Philippe Maeder; Jean-Marie Annoni

2011-01-01

474

Solving electric energy supply to rural areas; The capacitive voltage divider  

SciTech Connect

This paper describes the design, construction, testing, and installation of a system intended so supply electricity to rural communities directly from transmission lines. The system is comprised of a capacitive voltage divider, a split air-core reactor, and associated protective devices. A series of laboratory tests were performed on the whole system and the main results, as well as the results from a special test set-up, are presented. Preliminary operating results are discussed.

Sarmiento, H.G.; DeLaRosa, R.; Carrillo, V.; Vilar, J. (Instituto de Investigaciones Electricas, Cuernavaca, Morelos (MX))

1990-01-01

475

A Fluorometric Approach to Local Electric Field Measurements in a Voltage-Gated Ion Channel  

Microsoft Academic Search

Site-specific electrostatic measurements have been limited to soluble proteins purified for in vitro spectroscopic characterization or proteins of known structure; however, comparable measurements have not been made for functional membrane bound proteins. Here, using an electrochromic fluorophore, we describe a method to monitor localized electric field changes in a voltage-gated potassium channel. By coupling the novel probe Di-1-ANEPIA to cysteines

Osei Kwame Asamoah; Joseph P. Wuskell; Leslie M. Loew; Francisco Bezanilla

2003-01-01

476

Electrical Conductivity of Frozen Shrimp and Flounder at Different Temperatures and Voltage Levels  

Microsoft Academic Search

Electrical conductivity (EC) is an important property during ohmic thawing of seafood. EC of frozen flounder, tiger and white shrimp, and shrimp shells at different voltages and temperatures (T) was measured. The materials were homogenized in a blender. PVC tubes (lengths: 4.1 to 5.6 cm, diameter: 1.5 cm) were filled with the material and fitted with circular stainless steel electrodes

Diego A. Luzuriaga; Murat O. Balaban

1996-01-01

477

The effect of solar array voltage patterns on plasma power losses  

NASA Technical Reports Server (NTRS)

The use of high-voltage solar arrays in space is discussed in connection with the draining of array power by currents flowing between exposed surfaces through the surrounding plasma. The possibility of reducing the power loss by arranging solar cell strings in repeated small-area modules to eliminate any large areas at high potentials is investigated. It is found that the difference in power loss between modular and linear patterned high-voltage arrays is fairly small. Although the use of modular patterns can reduce the effective mean potential by about 10%, for the type of configuration being considered there is also a 10% increase in sheath area, leading to only a few percent change in total power loss. It is concluded that plasma power loss should not be a primary consideration in designing the physical arrangement of high-voltage arrays.

Mandell, M. J.; Katz, I.; Steen, P. G.; Schnuelle, G. W.

1980-01-01

478

Voltage Sag Mitigation Strategies for an Indian Power Systems: A Case Study  

NASA Astrophysics Data System (ADS)

Under modern deregulated environment, both utilities and customers are concerned with the power quality improvement but with different objectives/interests. The utility reconfigure its power network and install mitigation devices, if needed, to improve power quality. The paper presents a strategy for selecting cost-effective solutions to mitigate voltage sags, the most frequent power quality disturbance. In this paper, mitigation device(s) is/are inducted in the optimal network topology at suitable places for their better effectiveness for further improvement in power quality. The optimal placement is looked from utility perspectives for overall benefit. Finally, their performance is evaluated on the basis of reduction in total number of voltage sags, reduction in total number of process trips and reduction in total financial losses due to voltage sags.

Goswami, A. K.; Gupta, C. P.; Singh, G. K.

2014-08-01

479

A zero-voltage switching technique for minimizing the current-source power of implanted stimulators.  

PubMed

The current-source power of an implanted stimulator is reduced almost to the theoretical minimum by driving the electrodes directly from the secondary port of the inductive link with a dedicated zero-voltage switching power supply. A feedback loop confined to the secondary of the inductive link adjusts the timing and conduction angle of switching to provide just the right amount of supply voltage needed for keeping the current-source voltage constant at or slightly above the compliance limit. Since drive is based on current rather than voltage, and supply-voltage update is near real-time, the quality of the current pulses is high regardless of how the electrode impedance evolves during stimulation. By scaling the switching frequency according to power demand, the technique further improves overall power consumption of the stimulator. The technique is implemented with a very simple control circuitry comprising a comparator, a Schmitt trigger and a logic gate of seven devices in addition to an on-chip switch and an off-chip capacitor. The power consumed by the proposed supply circuit itself is no larger than what the linear regulator of a conventional supply typically consumes for the same stimulation current. Still, the sum of supply and current-source power is typically between 20% and 75% of the conventional source power alone. Functionality of the proposed driver is verified experimentally on a proof-of-concept prototype built with 3.3 V devices in a 0.18 ?m CMOS technology. PMID:23893206

Çilingiro?lu, U?ur; ?pek, Sercan

2013-08-01

480

Multiloop Rapid-Rise/Rapid Fall High-Voltage Power Supply  

NASA Technical Reports Server (NTRS)

A proposed multiloop power supply would generate a potential as high as 1.25 kV with rise and fall times <100 s. This power supply would, moreover, be programmable to generate output potentials from 20 to 1,250 V and would be capable of supplying a current of at least 300 A at 1,250 V. This power supply is intended to be a means of electronic shuttering of a microchannel plate that would be used to intensify the output of a charge-coupled-device imager to obtain exposure times as short as 1 ms. The basic design of this power supply could also be adapted to other applications in which high voltages and high slew rates are needed. At the time of reporting the information for this article, there was no commercially available power supply capable of satisfying the stated combination of voltage, rise-time, and fall-time requirements. The power supply would include a preregulator that would be used to program a voltage 1/30 of the desired output voltage. By means of a circuit that would include a pulse-width modulator (PWM), two voltage doublers, and a transformer having two primary and two secondary windings, the preregulator output voltage would be amplified by a factor of 30. A resistor would limit the current by controlling a drive voltage applied to field-effect transistors (FETs) during turn-on of the PWM. Two feedback loops would be used to regulate the high output voltage. A pulse transformer would be used to turn on four FETs to short-circuit output capacitors when the outputs of the PWM were disabled. Application of a 0-to-5-V square to a PWM shut-down pin would cause a 20-to-1,250-V square wave to appear at the output.

Bearden, Douglas

2007-01-01

481

Carbon Constraints and the Electric Power Industry  

SciTech Connect

The report is designed to provide a thorough understanding of the type of carbon constraints that are likely to be imposed, when they are likely to take effect, and how they will impact the electric power industry. The main objective of the report is to provide industry participants with the knowledge they need to plan for and react to a future in which carbon emissions are restricted. The main goal of the report is to ensure an understanding of the likely restrictions that will be placed on carbon emissions, the methods available for reducing their carbon emissions, and the impact that carbon reductions will have on the electric power industry. A secondary goal of the report is to provide information on key carbon programs and market participants to enable companies to begin participating in the international carbon marketplace. Topics covered in the report include: overview of what climate change and the Kyoto Protocol are; analysis of the impacts of climate change on the U.S. and domestic efforts to mandate carbon reductions; description of carbon reduction mechanisms and the types of carbon credits that can be created; evaluation of the benefits of carbon trading and the rules for participation under Kyoto; Description of the methods for reducing carbon emissions available to the U.S. electric power industry; analysis of the impact of carbon restrictions on the U.S. electric power industry in terms of both prices and revenues; evaluation of the impact of carbon restrictions on renewable energy; overview of the current state of the global carbon market including descriptions of the three major marketplaces; descriptions of the industry and government programs already underway to reduce carbon emissions in the U.S. electric power industry; and, profiles of the major international carbon exchanges and brokers.

NONE

2007-11-15

482

Flex-gear electrical power transmission  

NASA Technical Reports Server (NTRS)

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.

Vranish, John; Peritt, Jonathan

1993-01-01

483

Automatic voltage-imbalance detector  

SciTech Connect

A device is described for indicating and preventing damage to voltage cells such as galvanic cells and fuel cells connected in series by detecting sequential voltages and comparing these voltages to adjacent voltage cells. The device is implemented by using operational amplifiers and switching circuitry is provided by transistors. The device can be utilized in battery powered electric vehicles to prevent galvanic cell damage and also in series connected fuel cells to prevent fuel cell damage.

Bobbett, R.E.; McCormick, J.B.; Kerwin, W.J.

1981-05-20