WorldWideScience
1

High Voltage Power Supply for RPC detectors  

International Nuclear Information System (INIS)

A High Voltage Power Supply Unit (HVPSU) for biasing resistive plate chamber (RPC) detector has been developed for initial testing of the RPC prototypes. The unit, based on inexpensive encapsulated DC-DC converters, is capable of delivering positive and negative polarity independently adjustable high voltages to the detector. The HVPSU is overload protected and displays the output voltage and current loading in both channels. Test performance of the unit with a 300x300mm single gap RPC detector is reported.

2

Pulsed high voltage extraction power supply  

International Nuclear Information System (INIS)

The basic idea was to obtain a pulsed power supply up to 4 kV designated to extract the microwave from a usual magnetron. The magnetron used is a home appliance device from a microwave oven. The output power generally ranges from 200 to 800 watts, the power rate being controlled by a timer device. Practically the magnetron works at a constant filament voltage and a fixed extraction high voltage the last one being switched on/off on a pre-programmed scheme. The on/off time laps are ranging from tens seconds to few minutes. The magnetron used in our ECR ion source has a different way to furnish a lower microwave energy into the ionization chamber. The microwave energy required for the ECR ion source is much smaller ranging from 20 watts to a maximum of 100 watts. The volume of the chamber is very small and there are not possibilities for exhausting large amounts of heat. For this reason the high voltage is applied by means of a chopping device operating at 50 Hz frequency (the AC frequency). For a very few milliseconds the high voltage is turned on every period of the sinusoidal voltage. In this way the energy injected into the ion chamber is reduced to acceptable values. The only problem that occurs is the fact that this periodicity of microwave generation is found also into the extracted ion beam; the beam is obtained at a 50 Hz frequency in very intense thin pulses with a few milliseconds width. As we discussed in a previous paper we are mainly concerned with the timpaper we are mainly concerned with the time of flight RBS. From this point of view the obtained beam pulses are much to rare and wide. The electronic scheme proposed consists of a resonant circuitry working at 1.5 kHz frequency; a thyristor trigger device the pulses of which are less than 200 nsec wide. Three resonant cells are summed together to obtain 4000 V, enough to extract thin microwave pulses. The driving power supply for the three resonant cells is a DC 200 V. The next step was to inject the pulsed microwaves into the ECR ionization chamber. We have monitored the beam after 500 KV acceleration and detected it by means of a photomultiplier with a plastic detector on the top. The resulted ion beam pulses for protons and helium ions are very satisfactory showing a pulsed beam at 1.5 kHz with narrow particle bunches. The work is now in progress, and the goal is to narrow as much as possible the beam pulses. (authors)

3

BES III drift chamber high voltage power supply system  

International Nuclear Information System (INIS)

The high voltage power supply system of BES III drift chamber is reported. How to choose the exact high voltage of the sense wire, the HV power supply, the HV distribution, the HV board design and the program of HV control are described respectively. (authors)

4

Conceptual definition of a high voltage power supply test facility  

Science.gov (United States)

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

5

High-voltage power supply based on piezoelectric transformer  

OpenAIRE

High-voltage power supply based on piezoelectric transformer instead of traditional electromagnetic transformer is offered in the paper. The structure of the power supply is represented. The power supply operation principle is described, the diagrams that illustrate its operation are given.

Kryvoshei, Dmytro; Paerand, Yuriy

2012-01-01

6

High current and high voltage power supplies for accelerators  

International Nuclear Information System (INIS)

High voltage (HV) high current regulated DC power supplies are key components to accelerators using electrostatic or RF acceleration. HVDC power supplies used for biasing high power vacuum tubes in research demands continuous duty operation with good stability. In addition to regulation and ripple specifications these power supplies should have few mS order settling time and few ?S, order turn OFF time. Use of intelligent control methods along with efficient power semiconductors (like, Insulated Gate Bipolar Transistor: IGBT) has enabled development of these power converters. Various topologies of controlled HVDC power supplies are discussed and future prospects are examined here. (author)

7

Development of high voltage power supply for nuclear radiation detectors  

International Nuclear Information System (INIS)

The purpose of this thesis is to develop a versatile NIM compatible high voltage power supply for proper operation of nuclear radiation detectors especially for those high resolution detectors such as semiconductor detectors, and proportional counters which require high voltage power supply with very low output ripple and high output stability. A driven type dc-ac inverter and a voltage multiplier are applied to convert a low de voltage to high dc voltage. The filter circuit is used to reduce the output ripple when the power supply is loaded and a close-loop voltage control circuit is used to minimize the drift in the output voltage. Adjustment of the output level for desired value is done through a three turn high precision potentiometer. Besides, micro-circuits are used in order to reduce undesirable temperature effect and at the same time to minimize size and weight of the high voltage module

8

Development of an Economic High Voltage Power Supply  

International Nuclear Information System (INIS)

Full text: A 2000 V, 1 mA economical high voltage power supply for NaI(Tl) detector was developed. The purpose of this study was to design an electrical circuit upon local component availability for cost effective and ease maintenance. Besides, this circuit was designed to support computer interfacing for data manipulation and controls. The designed circuit showed capability of 2000 V, 1 mA high voltage power supply with ripple voltage less than 30 mVp-p and higher than 60 percent efficiency at maximum load. The linearity of high voltage adjustment in manual and automatic mode was found to be excellent with R2 = 0.9982 and 0.9997 respectively

9

Suppressing voltage transients in high voltage power supplies  

International Nuclear Information System (INIS)

A high voltage power supply for an X-ray tubes includes voltage adjusting means, a high voltage transformer, switch means connected to make and interrupt the primary current of the transformer, and over-voltage suppression means to suppress the voltage transient produced when the current is switched on. In order to reduce the power losses in the suppression means, an impedance is connected in the transformer primary circuit on operation of the switch means and is subsequently short-circuited by a switch controlled by a timer after a period which is automatically adjusted to the duration of the transient overvoltage. (U.K.)

10

High voltage power supplies for INDUS-2 RF system  

International Nuclear Information System (INIS)

The RF system of Indus-2 employs klystron amplifiers operating at 505.812 MHz. A precession controlled high voltage DC supply of appropriate rating is needed for each klystron amplifier, as its bias supply. Since internal flashover and arcing are common with the operation of these klystrons and stored energies beyond particular limit inside its bias power supply is detrimental to this device, a properly designed crowbar is incorporated between each klystron and its power supply. This crowbar bypass these stored energies and helps protecting klystron under any of these unfavorable conditions. In either case, power supply sees a near short circuit across its load. So, its power circuit is designed to reduce the fault current level and its various components are also designed to withstand these fault currents, as and when it appears. Finally, operation of these high voltage power supplies (HVPS) generates lot of harmonics on the source side, which distort the input waveform substantially and reduces the input power factor also. Source multiplication between two power supplies are planned to improve upon above parameters and suitable detuned line filters are incorporated to keep the input voltage total harmonics distortion (THD) below 5 % and input power factor (IFF) near unity. (author)

11

A battery powered high voltage bias supply for Ge detectors  

International Nuclear Information System (INIS)

A high voltage bias supply for Ge detectors has been built using low voltage batteries and a pulsed DC-DC converter. This design offers considerable reduction of size and weight and better operating specifications than supplies now in use based on high voltage batteries. (author)

12

Development of High Voltage Power Supply for a Photomultiplier  

OpenAIRE

Abstract The purpose of this thesis was to develop a 4-channel high voltage power supply for powering Hamamatsu SL10 photomultiplier tubes in the iTop detector. The iTop detector is part of the Belle 2 detector and it is made for detecting Kaons and Pions (K/?). The Belle 2 detector is made for detecting charged particle violations in the Super KEKB particle accelerator which is located in Tsukuba, Japan. The Super KEKB particle accelerator research project belongs to the KEK High Energy...

Virta, Vihtori

2013-01-01

13

DIII-D ICRF high voltage power supply regulator upgrade  

International Nuclear Information System (INIS)

For reliable operation and component protection, of the 2 MW 30--120 MHz ICRF Amplifier System on DIII-D, it is desirable for the amplifier to respond to high VSWR conditions as rapidly as possible. This requires a rapid change in power which also means a rapid change in the high voltage power supply current demands. An analysis of the power supply's regulator dynamics was needed to verify its expected operation during such conditions. Based on this information it was found that a new regulator with a larger dynamic range and some anticipation capability would be required. This paper will discuss the system requirements, the as-delivered regulator performance, and the improved performance after installation of the new regulator system. It will also be shown how this improvement has made the amplifier perform at higher power levels more reliably

14

E-beam high voltage switching power supply  

International Nuclear Information System (INIS)

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

15

E-beam high voltage switching power supply  

Science.gov (United States)

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

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

1997-01-01

16

Solid-state high voltage modulator and its application to rf source high voltage power supplies  

International Nuclear Information System (INIS)

A solid-state high voltage modulator is described in which series-connected insulated-gate bipolar transistors (IGBTs) are switched at a fixed frequency by a pulse width modulation (PWM) regulator, that adjusts the pulse width to control the voltage out of an inductor-capacitor filter network. General Atomics proposed the HV power supply (HVPS) topology of multiple IGBT modulators connected to a common HVdc source for the large number of 1 MW klystrons in the linear accelerator of the Accelerator Production of Tritium project. The switching of 24 IGBTs to obtain 20 kVdc at 20 A for short pulses was successfully demonstrated. This effort was incorporated into the design of a -70 kV, 80 A, IGBT modulator, and in a short-pulse test 12 IGBTs regulated -5 kV at 50 A under PWM control. These two tests confirm the practicality of solid-state IGBT modulators to regulate high voltage at reasonable currents. Tokamaks such as ITER require large rf heating and current drive systems with multiple rf sources. A HVPS topology is presented that readily adapts to the three rf heating systems on ITER. To take advantage of the known economy of scale for power conversion equipment, a single HVdc source feeds multiple rf sources. The large power conversion equipment, which is located outside, converts the incoming utility line voltage directly to the HVdc needed for the class of rf sources connected to it, to further reduce cost. The HVdc feeds a set of IGBT modulators, one for each rf soset of IGBT modulators, one for each rf source, to independently control the voltage applied to each source, maximizing operational flexibility. Only the modulators are indoors, close to the rf sources, minimizing the use of costly near-tokamak floor space.

17

A regulated high voltage power supply for accelerator driven system; A regulated high voltage power supply for accelerator driven system  

International Nuclear Information System (INIS)

This paper discusses a regulated high voltage power supply (RHVPS) developed for accelerator driven systems to drive a klystron. The RHVPS uses a large no. of small voltage choppers. These choppers are switched in tandem by a novel technique to regulate output voltage. Various parts of the system are novel. The front end is a pair of transformer with 40 secondaries each. Each secondary feeds a switched power module (SPM) which has a rectifier-filter unit followed by an IGBT switch to get 1.3 kV. All 80 SPMs are connected in series. The final output is taken from the two end SPMs. A central controller uses voltage sample from each SPM and generates switching pulses for each IGBT switch. IGBTs of all SPMs are switched with a fixed phase lag from each other, resulting in purely constant voltage with ripple limited to one SPM voltage. The frequency of ripple is high and can be filtered out with a simpler filter. The system can turn off for protection of the load in less than 2 ?s, the essential attribute for a power supply to be used with klystrons. The results of wire burn tests measure the low stored energy at fault turn off (less than 10 J). The power supply (rated for 100 kV at 2.5 MW) will be used for a continuous duty with the klystron for accelerator driven system at BARC (India). A power supply giving 80 kV. 75 A is being used with an accelerator system for extraction of beam along with a Neutral Beam Injector. This paper discusses the technology and experimentaldiscusses the technology and experimental results of the system. It also discusses various other options with similar power supply. (author)

18

High voltage power supply with modular series resonant inverters  

Science.gov (United States)

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

19

A tester for multi-channel high voltage power supply with load  

International Nuclear Information System (INIS)

The authors will introduce a test system used for multi-channel high voltage power supply, and also briefly introduce circuit construction and circuit design, operation principle and specifications. This instrument is mainly used to test single channel or multi-channel high voltage power supply in laboratory or in open field. Especially, it is very useful for the testing of detector's bias. The maximum high voltage value tested by this instrument is 6 kV. The range of output current of high voltage power supply under test is from 100 ?A to 10 mA. This instrument is portable, and of simple construction, high integration, small dimension. It can be operated with AC/DC power supply

20

A tester for multi-channel high voltage power supply with load  

International Nuclear Information System (INIS)

The authors will introduce a test system used for multi-channel high voltage power supply, and also briefly introduce circuit construction and circuit design, operation principle and specification. This instrument is mainly used to test single channel or multi-channel high voltage power supply in laboratory or in open field. Especially, it is very useful for the testing of detector's biases. The maximum high voltage value can be tested by this instrument is 6 kV. The range of output current of high voltage power supply under-test is from 100 ?A to 10 mA. This instrument is portable, and with simple construction, high integration, small dimension. It can be operated with AC/DC power supply

21

A high-voltage switching mode-power supply based on SCM  

International Nuclear Information System (INIS)

With the requirements of the efficiency, volume size and intelligent control of the power supply for the x-ray fluorescence analysis, a high-voltage power supply based on the technique of SUM and PWM has been developed. It was designed by single ended type promoted and PID control algorithm regulator, and controlled by STC89C52 SCM. The high-voltage power supply put out 0-50 kV continuous adjustable voltage by means of the transformer and voltage multiplying rectifier, and ran steadily for long time with the small size and high efficiency. (authors)

22

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

Science.gov (United States)

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

23

Design of Plasma Generator Driven by High-frequency High-voltage Power Supply  

Scientific Electronic Library Online (English)

Full Text Available In this research, a high-frequency high-voltage power supply designed for plasma generator is presented. The power supply mainly consists of a series resonant converter with a high-frequency high-voltage boost transformer. Due to the indispensable high-voltage inheritance in the operation of plasma [...] generator, the analysis of transformer need considering not only winding resistance, leakage inductance, magnetizing inductance, and core-loss resistance, but also parasitic capacitance resulted from the insulation wrappings on the high-voltage side. This research exhibits a simple approach to measuring equivalent circuit parameters of the high-frequency, high-voltage transformer with stray capacitance being introduced into the conventional modeling. The proposed modeling scheme provides not only a precise measurement procedure but also effective design information for series-load resonant converter. The plasma discharging plate is designed as part of the electric circuit in the series load-resonant converter and the circuit model of the plasma discharging plate is also conducted as well. Thus, the overall model of the high-voltage plasma generator is built and the designing procedures for appropriate selections of the corresponding resonant-circuit parameters can be established. Finally, a high-voltage plasma generator with 220V, 60Hz, and 1kW input, along with a 22 kHz and over 8kV output, is realized and implemented.

C., Yong-Nong; K., Chih-Ming.

2013-04-01

24

Development of compact high voltage switched mode power supply for microwave plasma sources supply for low pressure plasma  

Energy Technology Data Exchange (ETDEWEB)

Although microwave induced plasmas are well known as high efficiency plasma sources, their uses in laboratories are limited since the microwave power systems are complicated and expensive. The output power of commercially available low-cost microwave ovens is fixed and discontinuous resulting from the high voltage doubler topology of the magnetron tube power supply. In this paper, a high voltage switched mode power supply of forward topology has been developed for continuous microwave power radiation. The forward converter can generate a no-load high voltage output maximum of 7 kV. When driving the magnetron tube, the microwave output power could be varied from 0 to 35 W while the high voltage output level was constantly regulated at -3.4 kV. A microwave induced plasma system was setup to investigate the plasma produced. A low pressure argon plasma was produced with only 2 W over a wide range of pressures.

Kerdtongmee, P; Srinoum, D; Nisoa, M, E-mail: pansak20@hotmail.com [Plasma Technology for Agricultural Applications Research Laboratory, School of Science, Walailak University, Nakhon Si Thammarat (Thailand)

2011-08-15

25

Design of Plasma Generator Driven by High-frequency High-voltage Power Supply  

Directory of Open Access Journals (Sweden)

Full Text Available In this research, a high-frequency high-voltage power supply designed for plasma generator is presented. The powersupply mainly consists of a series resonant converter with a high-frequency high-voltage boost transformer. Due to theindispensable high-voltage inheritance in the operation of plasma generator, the analysis of transformer needconsidering not only winding resistance, leakage inductance, magnetizing inductance, and core-loss resistance, butalso parasitic capacitance resulted from the insulation wrappings on the high-voltage side. This research exhibits asimple approach to measuring equivalent circuit parameters of the high-frequency, high-voltage transformer with straycapacitance being introduced into the conventional modeling. The proposed modeling scheme provides not only aprecise measurement procedure but also effective design information for series-load resonant converter. The plasmadischarging plate is designed as part of the electric circuit in the series load-resonant converter and the circuit modelof the plasma discharging plate is also conducted as well. Thus, the overall model of the high-voltage plasmagenerator is built and the designing procedures for appropriate selections of the corresponding resonant-circuitparameters can be established. Finally, a high-voltage plasma generator with 220V, 60Hz, and 1kW input, along witha 22 kHz and over 8kV output, is realized and implemented.

C. Yong-Nong

2013-03-01

26

High-voltage power supply - 2.500 V - 4mA  

International Nuclear Information System (INIS)

A high-voltage power supply, in a NIM two-width module, was developed to be used in nuclear measurements systems. The design utilizes the principle of DC-DC conversion. A general description of the instrument and of its circuity is presented, as well as a report of the results obtained from the tests performed to establish its characteristics

27

Power supply, energy storage line, and grid pulsers for high voltage gridded klystrons  

International Nuclear Information System (INIS)

Designs for high power, gridded klystrons are being considered for driving accelerators. These designs have high voltage DC on the klystron cathodes, with the klystron current being turned on and off with a much lower voltage grid drive pulse. Such a klystron eliminates the need for a high power pulse modulator. The modulator is replaced by a high voltage energy storage line, an RF switching line charging supply, and a small electronics package consisting of a DC grid bias supply, a fast rise and fall time grid pulser, and a klystron cathode heater power supply. This paper outlines some of the design details of such a gridded klystron support system including specifications for the energy storage cable, and the fast grid pulse driver. Such a system can be very compact and reliable with low initial cost, and excellent operating efficiency

28

A new VME-based high voltage power supply for large photomultiplier systems  

International Nuclear Information System (INIS)

We describe a new high voltage power supply, developed for the leadglass calorimeter of the WA98 experiment at CERN. The high voltage is produced for each of the 10,080 photomultiplier tubes of the detector individually, by the same number of active bases with on-board Greinacher voltage multipliers. The full VME-based HV controller system, which addresses each base via bus cables once per second, is miniaturized and fits into a single VME crate. The main advantages of this approach are the low heat dissipation, the considerably reduced amount of cabling and cost, as well as the high stability and low noise of the system. (orig.)

29

Development of high voltage power supply for the KSTAR 170 GHz ECH and CD system  

Energy Technology Data Exchange (ETDEWEB)

Highlights: • A 3.6 MW (?66 kV/55 A) gyrotron power supply system was developed for the 170 GHz ECH system in KSTAR. • The main power supply includes a total of 32 PSM based HV power supply modules. • The voltage regulation of individual HV power module and LV power module is 3 kV and 0.5 kV, respectively. • The gyrotron is protected by means of a fast solid-state switch (MOS-FET). • The HV switching system can turn off the 60 kV to the cathode within 3 ?s in the event of gyrotron faults. -- Abstract: A 3.6 MW (66 kV/55 A) DC power supply system was developed for the 170 GHz EC H and CD system in KSTAR. The power supply system consists of a cathode power supply (CPS), an anode power supply (APS) and a body power supply (BPS). The cathode power supply is capable of supplying a maximum voltage of ?66 kV and a current of 55 A to the cathode with respect to the collector using pulse step modulation (PSM). The high voltage switching system for the cathode is made by a fast MOS-FET solid-state switch which can turn off the high voltage to the cathode within 3 ?s in the occurrence of gyrotron faults. The APS is a voltage divider system consisting of a fixed resistor and zener diode units with the capability of 60 kV stand-off voltage. The anode voltage with respect to the cathode is controlled in a range of 0–60 kV by turning the MOS-FET switches connected in parallel to each zener diode on and off. For high frequency current modulation of the gyrotron, the parallel discharge switch is introduced between the cathode and anode in order to clamp the charged voltage in the stray capacitance. The BPS is a DC power supply with the capability of 50 kV/160 mA. The nominal operation parameter of BPS was 23 kV and 10 mA, respectively, and the voltage output is regulated with a stability of 0.025% of the rated voltage. The series MOS-FET solid-state switch is used for on/off modulation in the body voltage sychronizing with anode voltage. The parallel discharge switch is also introduced between the body and collector for high frequency RF modulation. This paper describes the key features of the high voltage power supply system of the KSTAR 170 GHz gyrotron as well as the test results of the power supply.

Jeong, J.H., E-mail: jhjeong@nfri.re.kr [National Fusion Research Institute, Daejeon (Korea, Republic of); Bae, Y.S.; Joung, M.; Kim, H.J.; Park, S.I.; Han, W.S.; Kim, J.S.; Yang, H.L.; Kwak, J.G. [National Fusion Research Institute, Daejeon (Korea, Republic of); Sakamoto, K.; Kajiwara, K.; Oda, Y.; Hayashi, K. [Japan Atomic Energy Agency, Naka (Japan)

2013-06-15

30

A new VME based high voltage power supply for large experiments  

International Nuclear Information System (INIS)

A new VME based high voltage power supply has been developed for the D OE experiment at Fermilab. There are three types of supplies delivering up to ±5.6 kV at 1.0 mA or +2.0 kV at 3.0 mA with a set accuracy of 1.5 V and extremely low voltage ripples. Complete computer control has allowed many special features to be developed for the supply, including user-defined control land monitor groups, variable ramp rates, and advanced histogram and graphic functions. 3 refs

31

Optimization of a high voltage power supply for a nitrogen laser  

International Nuclear Information System (INIS)

In the present paper the optimization of a high voltage switching power supply for a compact TEA nitrogen laser is described. Taking as criterion the recovering of the charging voltage in a 95% of the maximal voltage, the relationships between the recovering rate coefficient, the recovering time and the maximal repetition frequency were obtained. Using an experimental set-up the power supply optimal values of turns in the primary transformer coil Np=35 and excitation pulse frequency fexc=25.5 kHz was determined

32

Low-Frequency High-Voltage Power Supply for Non-Thermal Plasma Generation  

International Nuclear Information System (INIS)

Full text: An economical 50-watts low-frequency high-voltage power supply with suitable performance for nonthermal atmospheric plasma generation has been developed. A neon transformer has been employed in conjunction with a sine-wave driving circuit whose frequency and output voltage can be varied. It is found from the performance test that the maximum voltage and current of 28 kV pp and 5 m A (rms), respectively, can be achieved. This power supply can be utilized for a dielectric barrier discharge plasma source, of both the coaxial and the parallel-plate types at frequency range between 100 Hz to 750 Hz

33

High voltage power supply for the inflector of K-500 superconducting cyclotron  

International Nuclear Information System (INIS)

A spiral inflector, consisting of two electrodes, is used in K-500 superconducting cyclotron at VECC for ion bending from axial to median plane. The front grid electrode allows the beam to enter the electric field and the back electrode bent the ion by applying the required voltage. High voltage inflector power supply system which consists of two power supplies (+10 KV/1mA and -10KV/1mA) has been designed and developed for providing these voltages across electrodes of inflector. This system also contain faraday cup unit for measuring current passing through inflector. (author)

34

Computer controlled multiple channel high voltage power supply [Paper No.: L8  

International Nuclear Information System (INIS)

This paper describes the design of a computer controlled high voltage multiple channel power supply for use in Gamma Ray Astrophysics Experiment (GRAPE). Each channel is rated for 2.5 kV, 1mA with over current protection and output voltage read back facility. A single HV supply on a single width NIM module has been tried successfully. At present 8 channels on a module is being tried to make a very compact HV system. (author). 2 refs., 2 figs

35

Measurement system for high voltage pulse power supply on HL-2A  

International Nuclear Information System (INIS)

A measurement system for the high voltage pulse power supply on HL-2A has been developed. It adopts the voltage divider based on high-frequency inductance-free glaze film resistor along with the fiber isolation technology based on voltage-frequency conversion. Moreover, a DSP chip is used in the fiber transmission, to realize A/D conversion, simplifying the circuit, enhancing the data transmission speed and anti-jamming ability of the system. The system has been applied to long-pulse (5 s) discharge experiments on HL-2A. The experimental results show that, the system realizes the potential isolation for power supply, and the measured voltage waveforms reflect the supply output faithfully, providing real-time voltage data for the feedback and protection system of the supply. (authors)

36

Control system of high voltage power supply of 3 MeV DC accelerator  

International Nuclear Information System (INIS)

A 3 MeV, 10 mA electron beam dc accelerator is being developed at EBC, Kharghar, Navi Mumbai. The 3 MV high voltage system of the accelerator consists of 10 kV/10 A DC power supply, 50 kW/120 kHz push- pull oscillator, 300 kV tuned air-core step-up transformer, 3 MV/10 mA multiplier column and cooling systems. The high voltage power supply requires a control system for its safe operation under stringent conditions of high electrical surges and electromagnetic interferences. A control system is developed for operation and protection of this high voltage system. Various functional safety and protection features are incorporated in this system. Salient features of this control system are; (i) Independent Alarm and trip setting for each signal as per desired levels, (ii) Analog displays for qualitative and digital display for precise measurements, (iii) Fault display on annunciation panel, (iv) Electrical isolations for each signal from one another and (v) better EMI compatibility. The control system is already commissioned and tested. This paper describes about the design philosophy and salient features of this control system

37

Study on the characters of high voltage charging power supply system for diagnostics neutral beam on HT-7 Tokamak  

International Nuclear Information System (INIS)

A high voltage power supply system has been developed for the diagnostic neutral beam on the HT-7 experimental Tokamak, and the over-voltage phenomenon of storage capacitor was founded in the experiment. In order to analyse and resolve this problem, the structure and principle of high voltage power supply is described and the primary high voltage charging power supply system is introduced in detail. The phenomenon of over-voltage on the capacitors is also studied with circuit model, and the conclusion is obtained that the leakage inductance is the mA in reason which causes the over-voltage on the capacitors. (authors)

38

An approach for high voltage power supply system for HCAL of LHCb experiment  

International Nuclear Information System (INIS)

The main aim of the calorimeter system of the LHCb (Large Hadron Collider Beauty) experiment dedicated to precision measurements of CP violation and rare phenomena is to provide identification of the electrons, hadrons and photons, for the level-0 trigger and offline analysis with measurements of position and energy. The system consists in a scintillator pad/preshower (SPD/PS) detector, an electromagnetic calorimeter (ECAL) and a hadron calorimeter (HCAL), all the sub-detectors having a similar technology with scintillating tiles as active material and being read out via wavelength-shifting fibers and with an identical readout electronics for ECAL and HCAL and similar electronics for the PS. During 1997-1999 a computer controlled High Voltage (HV) distribution scheme was developed by Horia Hulubei National Institute for Physics and Nuclear Engineering (IFIN-HH) group and used to supply the PMTs of half HCAL prototype during the beam tests (1998-2000). This scheme consisted of three parts: 1) a control box which includes low voltage power supply, the RS232 interface to a PC and three modules of high voltage power supply; 2) two types of multichannel HV distributors with an individual voltage setting; 3) a software package to control all settings and refresh them periodically. Based on the acquired experience, a new design for a High Voltage Power Supply (HVPS) which satisfies the LHCb requirements has been developed for PMTs of the hadron calorimeter. The demands of th the hadron calorimeter. The demands of this system are simplicity and low cost. This HVPS with multiple outputs (HV for photocathode and D1 - D4 dynodes) is destined to supply, with the same high voltage, groups of PMTs sorted by similar characteristics as gain and sensitivity. Because of the high rates (? 40 MHz) supported by PMTs, booster voltage sources are necessary to supply current for the last 4 dynodes. The box has 5 HV power supplies for photocathodes and the last 4 dynodes, each HV power supply being followed by a 4 channel distributor (10 mA/channel). The box can independently supply 4 groups of 40 PMTs each. The voltage setting can be made manually, through keyboard and LCD display located on the front panel using a ?C board which also contains a CAN interpreter, SJA 1000, that makes the serial CAN-bus link remotely. The connection is bidirectional allowing both the setting of output voltages and the reading of the output voltage and current values. The power supply has good output features, shortcut protection and special voltages. The output voltages for a group are given. The box dimensions are: 480 x 128 x 525 mm. The voltages are transmitted trough HV coaxial cables with SHV connectors. The PMTs of FEU-115m10 type were used. In the following HV system will be adapted to be used to supply PMTs of Hamamatsu type R7899 20 which have been largely investigated by LHCb collaboration. HV Power Supply is going to be integrated in CAN network. This HVPS with parallel power groups of fast PMTs has the following advantages: a) outside PMTs supply (power dissipation is not inside HCAL modules); b) very good stability for all HV supplies (photocathode and dynodes); c) low ripple because of distributor supplementary stabilization with series transistors; d) great reserve of current (it allows high counting rates); f) being operated remotely it needs not to be radiation-proof; g) easy service. The system can be used in any experiments with many fast PMTs. (authors)

39

High voltage power supply of low hybrid heating system for the HL-2A tokamak  

International Nuclear Information System (INIS)

The high voltage power supply of the low hybrid heating system for the HL-2A tokamak includes numerous energy storage elements and non-linear elements. Its output voltage will decline to a certain extent as the load of the klystrons is connected to it, and in the course of the HL-2A tokamak discharge, the output voltage will also change while the output voltage of the preceding power supply of the 125 MVA M-G set change. In order to resolve the problem, simulation using MATLAB is carried out. A strategy of PID feedback control and feed-forward compensation is used. Design and parameters choice of the PID controller are analyzed in detail. The experiment results show that this strategy designed according to the simulation can meet the requirements of the voltage stability of the power supply very well. (authors)

40

A high voltage pulse power supply for metal plasma immersion ion implantation and deposition  

International Nuclear Information System (INIS)

We describe the design and implementation of a high voltage pulse power supply (pulser) that supports the operation of a repetitively pulsed filtered vacuum arc plasma deposition facility in plasma immersion ion implantation and deposition (Mepiiid) mode. Negative pulses (micropulses) of up to 20 kV in magnitude and 20 A peak current are provided in gated pulse packets (macropulses) over a broad range of possible pulse width and duty cycle. Application of the system consisting of filtered vacuum arc and high voltage pulser is demonstrated by forming diamond-like carbon (DLC) thin films with and without substrate bias provided by the pulser. Significantly enhanced film/substrate adhesion is observed when the pulser is used to induce interface mixing between the DLC film and the underlying Si substrate.

41

Characterization of a pulsed mode high voltage power supply for nuclear detectors  

International Nuclear Information System (INIS)

This paper discusses the characterization of a pulsed mode high voltage power supply (HVPS) using LT1073 chip. The pulsed modulated signal generated from this chip is amplified using a step-up ferrite core transformer of 1:20 turn ratio and then further multiplied and converted into DC high voltage output using a diode-capacitor arrangement. The circuit is powered by a 9V alkaline battery but regulated at 5V supply. It was found that the output for this setup is 520V, 87 ?A with 10% load regulation. This output is suitable to operate a pancake-type GM detector, typically model LND 7317 where the plateau is from 475V to 675V. It was also found that when a ?-source with intensity of 120 cps is used, the power consumption of the circuit is 5 V, 10.1 mA only. When the battery was left 'on' for 40 hours continuously, the battery's voltage has dropped to 6.9V, meaning that the 5V supply as well as 520V output is still maintained. It is noted that the minimum output voltage of 475V has reached when the regulated supply has reduced to 4.6V and consequently the 9V battery dropped to 6.5V, and this had happened after approximately 3 days of continuous operation. The power efficiency for this circuitry was found to be 89.5%. This result has far better in performance since the commercial portable equipment of this type has normally specified that not less than 8 hours continuous operation only. On the circuit design for this power supply, it was found that the enveloped frequen it was found that the enveloped frequency is 133 Hz with approximately 50% duty cycle. The modulated frequency during 'on' state was found to be 256 KHz in which the majority of power consumption is required.

42

Characterization of a pulsed mode high voltage power supply for nuclear detectors  

Science.gov (United States)

This paper discusses the characterization of a pulsed mode high voltage power supply (HVPS) using LT1073 chip. The pulsed modulated signal generated from this chip is amplified using a step-up ferrite core transformer of 1:20 turn ratio and then further multiplied and converted into DC high voltage output using a diode-capacitor arrangement. The circuit is powered by a 9V alkaline battery but regulated at 5V supply. It was found that the output for this setup is 520V, 87 ?A with 10% load regulation. This output is suitable to operate a pancake-type GM detector, typically model LND 7317 where the plateau is from 475V to 675V. It was also found that when a ?-source with intensity of 120 cps is used, the power consumption of the circuit is 5 V, 10.1 mA only. When the battery was left 'on' for 40 hours continuously, the battery's voltage has dropped to 6.9V, meaning that the 5V supply as well as 520V output is still maintained. It is noted that the minimum output voltage of 475V has reached when the regulated supply has reduced to 4.6V and consequently the 9V battery dropped to 6.5V, and this had happened after approximately 3 days of continuous operation. The power efficiency for this circuitry was found to be 89.5%. This result has far better in performance since the commercial portable equipment of this type has normally specified that not less than 8 hours continuous operation only. On the circuit design for this power supply, it was found that the enveloped frequency is 133 Hz with approximately 50% duty cycle. The modulated frequency during 'on' state was found to be 256 KHz in which the majority of power consumption is required.

Ghazali, A. B.; Ahmad, T. S.; Abdullah, N. A.

2013-06-01

43

Adaptive control strategy for ECRH negative high-voltage power supply based on CMAC neural network  

International Nuclear Information System (INIS)

In order to solve the problem that the negative high-voltage power supply in an electron cyclotron resonance heating (ECRH) system can not satisfy the requirements because of the nonlinearity and sensitivity, the direct inverse model control strategy was proposed by using cerebellar model articulation controller(CMAC) for better control, and experiments were carried out to study the system performances with CMAC tracing dynamic signals. The results show that this strategy is strong in self-learning and self-adaptation and easy to be realized. (authors)

44

Leveraging the LEDA high voltage power supply systems for the LANSCE refurbishment project  

International Nuclear Information System (INIS)

The LANSCE Refurbishment Project (LANSCE-R) will revitalize the LANSCE accelerator infrastructure. Much of the equipment has been in use for over 39 years and is approaching the end of its design lifetime. As obsolescence issues make like-for-like replacements increasingly more expensive, modern systems with lower costs become a reasonable alternative. As part of the LANSCE-R project, four of the seven HV power supplies for the 805 MHz RF klystrons will be replaced. The present and future requirements for these power supplies influence the selection of replacement options. Details of the HV power supply replacement requirements and the different replacement options will be discussed. One option is to use four 95 kV, 21 A DC power supplies originally installed nearby as part of the Low Energy Demonstration Accelerator (LEDA) project. Significant material and labor cost savings can be achieved by leaving these supplies installed where they are and building a HV transport system to bring high voltage power from the existing LEDA facility to the LANSCE facility. The different replacement options will be compared based on material and labor costs as offset by long-term energy savings.

45

100 kV repetition-rate high-voltage pulsed power supply  

International Nuclear Information System (INIS)

To study the characteristics of gaseous discharge in spark gap, a high-voltage pulsed power supply has been designed, whose output voltage amplitude varies between 30?100 kV and repetition-rate varies from 1 Hz to 5 kHz. Adopting the principle of resonant charging, the power supply transfers energy from the primary source of 10 kV DC to the secondary energy storage capacitor that is charged at least to 18 kV. The hydrogen thyratron conducts under the action of optical trigger signal. Then the current flows through the pulse transformer, and voltage is raises from 18 kV to the peak of 100 kV. The output pulse is a negative voltage one with an pulse width of at least 200 ns. and fall time less than 90 ns. the device can continuously run for no less than 1 min without additional cooling system. (authors)

46

High voltage power supplies for ITER RF heating and current drive systems  

International Nuclear Information System (INIS)

The RF heating and current drive (H and CD) systems to be installed for the ITER fusion machine are the electron cyclotron (EC), ion cyclotron (IC) and, although not in the first phase of the project, lower hybrid (LH). These systems require high voltage, high current power supplies (HVPS) in CW operation. These HVPS should deliver around 50 MW electrical power to each of the RF H and CD systems with stringent requirements in terms of accuracy, voltage ripple, response time, turn off time and fault energy. The PSM (Pulse Step Modulation) technology has demonstrated over the past 20 years its ability to fulfill these requirements in many industrial facilities and other fusion reactors and has therefore been chosen as reference design for the IC and EC HVPS systems. This paper describes the technical specifications, including interfaces, the resulting constraints on the design, the conceptual design proposed for ITER EC and IC HVPS systems and the current status.

47

High voltage power supplies for ITER RF heating and current drive systems  

Energy Technology Data Exchange (ETDEWEB)

The RF heating and current drive (H and CD) systems to be installed for the ITER fusion machine are the electron cyclotron (EC), ion cyclotron (IC) and, although not in the first phase of the project, lower hybrid (LH). These systems require high voltage, high current power supplies (HVPS) in CW operation. These HVPS should deliver around 50 MW electrical power to each of the RF H and CD systems with stringent requirements in terms of accuracy, voltage ripple, response time, turn off time and fault energy. The PSM (Pulse Step Modulation) technology has demonstrated over the past 20 years its ability to fulfill these requirements in many industrial facilities and other fusion reactors and has therefore been chosen as reference design for the IC and EC HVPS systems. This paper describes the technical specifications, including interfaces, the resulting constraints on the design, the conceptual design proposed for ITER EC and IC HVPS systems and the current status.

Gassmann, T., E-mail: thibault.gassmann@iter.org [ITER Organization, CS 90 046, 13067 St. Paul Lez Durance Cedex (France); Arambhadiya, B.; Beaumont, B. [ITER Organization, CS 90 046, 13067 St. Paul Lez Durance Cedex (France); Baruah, U.K. [Institute for Plasma Research, Near Indira Bridge, Bhat, Gandhinagar 382428 (India); Bonicelli, T. [Fusion For Energy, C/3 Josep Pla 2, Torres Diagonal Litoral-B3, E-08019 Barcelona (Spain); Darbos, C.; Purohit, D.; Decamps, H. [ITER Organization, CS 90 046, 13067 St. Paul Lez Durance Cedex (France); Albajar, F. [Fusion For Energy, C/3 Josep Pla 2, Torres Diagonal Litoral-B3, E-08019 Barcelona (Spain); Gandini, F.; Henderson, M.; Kazarian, F.; Lamalle, P.U.; Omori, T. [ITER Organization, CS 90 046, 13067 St. Paul Lez Durance Cedex (France); Parmar, D.; Patel, A. [Institute for Plasma Research, Near Indira Bridge, Bhat, Gandhinagar 382428 (India); Rathi, D. [ITER Organization, CS 90 046, 13067 St. Paul Lez Durance Cedex (France); Singh, N.P. [Institute for Plasma Research, Near Indira Bridge, Bhat, Gandhinagar 382428 (India)

2011-10-15

48

A timing detector with pulsed high-voltage power supply for mass measurements at CSRe  

Energy Technology Data Exchange (ETDEWEB)

Accuracy of nuclear mass measurements in storage rings depends critically on the accuracy with which the revolution times of stored ions can be obtained. In such experiments, micro-channel plates (MCP) are used as timing detectors. Due to large phase space of injected secondary beams, a large number of ions cannot be stored in the ring and is lost within the first few revolutions. However, these ions interact with the detector and can saturate the MCP and thus deteriorate its performance. In order to eliminate such effects, a fast, pulsed high-voltage power supply (PHVPS) has been employed which keeps the detector switched-off during the first few revolutions. The new detector setup was taken into operation at the Experimental Cooler-Storage-Ring CSRe in Lanzhou and resulted in a significant improvement of the detector amplitude and efficiency characteristics.

Zhang, W. [Key Laboratory of High Precision Nuclear Spectroscopy and Center for Nuclear Matter Science, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Tu, X.L. [Key Laboratory of High Precision Nuclear Spectroscopy and Center for Nuclear Matter Science, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt (Germany); Max Planck Institute for Nuclear Physics, 69117 Heidelberg (Germany); Wang, M., E-mail: wangm@impcas.ac.cn [Key Laboratory of High Precision Nuclear Spectroscopy and Center for Nuclear Matter Science, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Zhang, Y.H. [Key Laboratory of High Precision Nuclear Spectroscopy and Center for Nuclear Matter Science, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Xu, H.S., E-mail: hushan@impcas.ac.cn [Key Laboratory of High Precision Nuclear Spectroscopy and Center for Nuclear Matter Science, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Litvinov, Yu. A. [Key Laboratory of High Precision Nuclear Spectroscopy and Center for Nuclear Matter Science, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt (Germany); Max Planck Institute for Nuclear Physics, 69117 Heidelberg (Germany); Blaum, K. [Max Planck Institute for Nuclear Physics, 69117 Heidelberg (Germany); and others

2014-08-01

49

A timing detector with pulsed high-voltage power supply for mass measurements at CSRe  

International Nuclear Information System (INIS)

Accuracy of nuclear mass measurements in storage rings depends critically on the accuracy with which the revolution times of stored ions can be obtained. In such experiments, micro-channel plates (MCP) are used as timing detectors. Due to large phase space of injected secondary beams, a large number of ions cannot be stored in the ring and is lost within the first few revolutions. However, these ions interact with the detector and can saturate the MCP and thus deteriorate its performance. In order to eliminate such effects, a fast, pulsed high-voltage power supply (PHVPS) has been employed which keeps the detector switched-off during the first few revolutions. The new detector setup was taken into operation at the Experimental Cooler-Storage-Ring CSRe in Lanzhou and resulted in a significant improvement of the detector amplitude and efficiency characteristics

50

PC-based control of high voltage power supply for HPGe detectors  

International Nuclear Information System (INIS)

NIM standard dual high voltage supply units being used in the laboratory for biasing high purity germanium detectors. The biasing of the detector is usually done slowly with constant monitoring of the output signal of the preamplifier for the health of FET, used in the first stage of the circuit. The units provide digital display of the applied voltage and current

51

The Application of MSVC Reactive Power Compensation Device to the High Voltage Power Supply of Coal Mine  

Directory of Open Access Journals (Sweden)

Full Text Available Through the introduction and technical comparative analysis of the SVC reactive power compensation device of the magnetic controlled reactor (MCR type (it is abbreviated as MSVC, this article measures the working condition of the electrical power distribution system for the Zhaizhen colliery, and confirm the application project of MSVC in the high voltage power supply of Zhaizhen colliery. This device has many obvious advantages such as small output harmonic, low power consumption, maintenance free, simple structure, high reliability, cheap price and small floor area, and it is an ideal dynamic reactive power compensation and voltage regulation device.

Zhenbao Zhu

2009-02-01

52

Atmospheric pressure plasma jet with high-voltage power supply based on piezoelectric transformer.  

Science.gov (United States)

The dielectric barrier discharge plasma jet, an example of the nonthermal atmospheric pressure plasma jet (APPJ), generates low-temperature plasmas that are suitable for the atomization of volatile species and can also be served as an ionization source for ambient mass and ion mobility spectrometry. A new design of APPJ for mass spectrometry has been built in our group. In these plasma sources magnetic transformers (MTs) and inductors are typically used in power supplies but they present several drawbacks that are even more evident when dealing with high-voltage normally used in APPJs. To overcome these disadvantages, high frequency generators with the absence of MT are proposed in the literature. However, in the case of miniaturized APPJs these conventional power converters, built of ferromagnetic cores and inductors or by means of LC resonant tank circuits, are not so useful as piezoelectric transformer (PT) based power converters due to bulky components and small efficiency. We made and examined a novel atmospheric pressure plasma jet with PT supplier served as ionization source for ambient mass spectrometry, and especially mobile spectrometry where miniaturization, integration of components, and clean plasma are required. The objective of this paper is to describe the concept, design, and implementation of this miniaturized piezoelectric transformer-based atmospheric pressure plasma jet. PMID:24880391

Babij, Micha?; Kowalski, Zbigniew W; Nitsch, Karol; Silberring, Jerzy; Gotszalk, Teodor

2014-05-01

53

Atmospheric pressure plasma jet with high-voltage power supply based on piezoelectric transformer  

International Nuclear Information System (INIS)

The dielectric barrier discharge plasma jet, an example of the nonthermal atmospheric pressure plasma jet (APPJ), generates low-temperature plasmas that are suitable for the atomization of volatile species and can also be served as an ionization source for ambient mass and ion mobility spectrometry. A new design of APPJ for mass spectrometry has been built in our group. In these plasma sources magnetic transformers (MTs) and inductors are typically used in power supplies but they present several drawbacks that are even more evident when dealing with high-voltage normally used in APPJs. To overcome these disadvantages, high frequency generators with the absence of MT are proposed in the literature. However, in the case of miniaturized APPJs these conventional power converters, built of ferromagnetic cores and inductors or by means of LC resonant tank circuits, are not so useful as piezoelectric transformer (PT) based power converters due to bulky components and small efficiency. We made and examined a novel atmospheric pressure plasma jet with PT supplier served as ionization source for ambient mass spectrometry, and especially mobile spectrometry where miniaturization, integration of components, and clean plasma are required. The objective of this paper is to describe the concept, design, and implementation of this miniaturized piezoelectric transformer-based atmospheric pressure plasma jet

54

Atmospheric pressure plasma jet with high-voltage power supply based on piezoelectric transformer  

Energy Technology Data Exchange (ETDEWEB)

The dielectric barrier discharge plasma jet, an example of the nonthermal atmospheric pressure plasma jet (APPJ), generates low-temperature plasmas that are suitable for the atomization of volatile species and can also be served as an ionization source for ambient mass and ion mobility spectrometry. A new design of APPJ for mass spectrometry has been built in our group. In these plasma sources magnetic transformers (MTs) and inductors are typically used in power supplies but they present several drawbacks that are even more evident when dealing with high-voltage normally used in APPJs. To overcome these disadvantages, high frequency generators with the absence of MT are proposed in the literature. However, in the case of miniaturized APPJs these conventional power converters, built of ferromagnetic cores and inductors or by means of LC resonant tank circuits, are not so useful as piezoelectric transformer (PT) based power converters due to bulky components and small efficiency. We made and examined a novel atmospheric pressure plasma jet with PT supplier served as ionization source for ambient mass spectrometry, and especially mobile spectrometry where miniaturization, integration of components, and clean plasma are required. The objective of this paper is to describe the concept, design, and implementation of this miniaturized piezoelectric transformer-based atmospheric pressure plasma jet.

Babij, Micha?; Kowalski, Zbigniew W., E-mail: zbigniew.w.kowalski@pwr.wroc.pl; Nitsch, Karol; Gotszalk, Teodor [Wroc?aw University of Technology, Wybrze?e Wyspia?skiego 27, 50-370 Wroc?aw (Poland); Silberring, Jerzy [AGH University of Science and Technology, Al. A. Mickiewicza 30, 30-059 Kraków (Poland)

2014-05-15

55

Design of power oscillator for 500 keV/20 mA Cockroft-Walton high voltage supply  

International Nuclear Information System (INIS)

A design of power oscillator for Cockroft-Walton high voltage supply was carried out. This high voltage supply would be used as the acceleration voltage supply of an electron beam machine designed to have 500 keV/20 mA capacity. The power oscillator design consisted of output specification, circuit diagram, power supply and oscillator main components determinations. The power oscillator output wave power, voltage and frequency designed according to voltage multiplier input requirements. The design results showed that the circuit was class-c tickler oscillator having an output specification of 12.1 kW, 15 kV and 40 kHz sinus wave. The main component was a ITK 15-2 triode tube. (author)

56

Proposed high voltage power supply for the ITER relevant lower hybrid current drive system  

International Nuclear Information System (INIS)

In the framework of the EFDA task HCD-08-03-01, the ITER lower hybrid current drive (LHCD) system design has been reviewed. The system aims to generate 24 MW of RF power at 5 GHz, of which 20 MW would be coupled to the plasmas. The present state of the art does not allow envisaging a unitary output of the klystrons exceeding 500 kW, so the project is based on 48 klystron units, leaving some margin when the transmission lines losses are taken into account. A high voltage power supply (HVPS), required to operate the klystrons, is proposed. A single HVPS would be used to feed and operate four klystrons in parallel configuration. Based on the above considerations, it is proposed to design and develop twelve HVPS, based on pulse step modulator (PSM) technology, each rated for 90 kV/90 A. This paper describes in details, the typical electrical requirements and the conceptual design of the proposed HVPS for the ITER LHCD system.

57

Simulation, Design and Construction of High Voltage DC Power Supply at 15 kV Output Using Voltage Multiplier Circuits  

Directory of Open Access Journals (Sweden)

Full Text Available This study describes the details of high voltage DC power supply whose output voltage is 15 kV. In this study, we review the major aspects of the design of voltage multiplier circuits and constructed a prototype power supply based on simulation, design and implementation of the hardware works in the laboratory. Its simulation works done by using EMTDC PSCAD and PSPICE software. Experimental results are presented to verify the simulation results.

N. Mariun

2006-01-01

58

Simulation, Design and Construction of High Voltage DC Power Supply at 15 kV Output Using Voltage Multiplier Circuits  

OpenAIRE

This study describes the details of high voltage DC power supply whose output voltage is 15 kV. In this study, we review the major aspects of the design of voltage multiplier circuits and constructed a prototype power supply based on simulation, design and implementation of the hardware works in the laboratory. Its simulation works done by using EMTDC PSCAD and PSPICE software. Experimental results are presented to verify the simulation results.

Mariun, N.; Ismail, D.; Anayet, K.; Khan, N.; Amran, M.

2006-01-01

59

Cable Insulation Breakdowns in the Modulator with a Switch Mode High Voltage Power Supply  

CERN Document Server

The Advanced Photon Source modulators are PFN-type pulsers with 40 kV switch mode charging power supplies (PSs). The PS and the PFN are connected to each other by 18 feet of high-voltage (HV) cable. Another HV cable connects two separate parts of the PFN. The cables are standard 75 kV x-ray cables. All four cable connectors were designed by the PS manufacturer. Both cables were operating at the same voltage level (about 35 kV). The PS?s output connector has never failed during five years of operation. One of the other three connectors failed approximately five times more often than the others. In order to resolve the failure problem, a transient analysis was performed for all connectors. It was found that transient voltage in the connector that failed most often was subjected to more high-frequency, high-amplitude AC components than the other three connectors. It was thought that these components caused partial discharge in the connector insulation and led to the insulation breakdown. Modification o...

Cours, A

2004-01-01

60

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

Science.gov (United States)

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

61

A high power water cooled resistor for the high voltage power supply in the TRIUMF RF system  

International Nuclear Information System (INIS)

The TRIUMF RF system high voltage power supply requires 0.5 ohm current limiting resistors to protect amplifier components during transients and crowbar operations. The crowbar typically causes a 16,000 amp transient pulse followed by a 4,000 amp current for 55 ms until the circuit breaker opens. The resulting stresses produced catastrophic failure of the original design within 100 crowbar cycles. A new resistor design has been developed to improve heat transfer characteristics and reduce current densities. Design changes were evaluated during extensive testing of a full scale model. The test results are reported with the resulting design described in detail

62

On-line control manipulator for regulation of high-voltage power supply of multi-channel detector counters  

International Nuclear Information System (INIS)

To regulate high-voltage power supply of total absorption 800-channel Cherenkov counters, a mechanical manipulator, operating on-line with HP-2100 A computer is developed. The manipulator comprises a two-coordinate carriage, resistor axis collet clamp, software and hardware systems. The manipulator clamps potentiometer axes and performs their rotation without slipping. The manipulator performs operations in sequence, it averagely spends 5 s per a counter. The accuracy of voltage adjustment using the manipulator makes up ± 5%

63

Fuzzy Control of High-Voltage Pulse Power Supply for Electron Cyclotron Resonance Heating Based on Integral-Separate Method  

International Nuclear Information System (INIS)

The negative high-voltage pulse power supply for the electron cyclotron resonance heating (ECRH) is a key support to the cyclotron's functioning and good performance is highly required. The principle of operation was analyzed and the model was given. According to the nonlinear characteristics of tetrode and the supply's control requirements, fuzzy control theory based on integral-separate was adopted, which combined intelligent control with power technology. Simulation results show that this system has good overshot-restrained, self-adaptive and auto-negotiating abilities using this method in comparison with PID method. This is a good new control and will be benefit to digital control intelligently. (authors)

64

The high voltage power supply for the acceleration grids of the TEXTOR neutral injectors  

International Nuclear Information System (INIS)

A description is given of the 55 kV, 100 A power supply for feeding the accel grid of the TEXTOR neutral beam injector. It introduces a new solution for such a power supply making use of 68 uncontrolled dc sources (choppers) connected in series. The output voltage of the system is given by the number of choppers which are switched on simultaneously. The first supply unit shall be commissioned in autumn 1985. (author)

65

Study on Power Supply System by Using CT in High-Voltage Transmission Lines  

OpenAIRE

In online monitoring of the transmission line, its power supply is one of the key issues. This study presents a device using special transformer which can induce power to supply the high side circuitry. The front-end of the protection device includes output-power-control circuitry, which can take output-power limited to a small range. At the back side it contains rechargeable lithium batteries. By using the reasonable control strategy, it can provide a stable output-power at the transmission ...

He Zhi-Min; Yue Tian-Chen; Liu Ya-Dong; Sheng Ge-Hao; Jiang Xiu-Chen; Zhang Ying-Bin; Li Shu-Qin; Wang Qiang

2013-01-01

66

Study on Power Supply System by Using CT in High-Voltage Transmission Lines  

Directory of Open Access Journals (Sweden)

Full Text Available In online monitoring of the transmission line, its power supply is one of the key issues. This study presents a device using special transformer which can induce power to supply the high side circuitry. The front-end of the protection device includes output-power-control circuitry, which can take output-power limited to a small range. At the back side it contains rechargeable lithium batteries. By using the reasonable control strategy, it can provide a stable output-power at the transmission line current ranging from 40 to 1500A. And in the larger current the fever of transformer is not serious. Experiments show that the power supply system has the high reliability and efficiency.

He Zhi-Min

2013-10-01

67

High frequency/high voltage solid state body power supplies for CPD gyrotrons  

International Nuclear Information System (INIS)

A conceptual design and feasibility study has been carried out for a fully solid state Body Power Supply providing the necessary performance required for the modulation of RF power from CW, high power gyrotrons. The selected solution, based on the Pulse Step Modulation concept, is expected to yield cost and operational advantages compared to systems based on vacuum tubes. A second phase for the manufacturing of a full size unit and its testing on a power gyrotron is now in progress

68

High frequency/high voltage solid state body power supplies for CPD gyrotrons  

Energy Technology Data Exchange (ETDEWEB)

A conceptual design and feasibility study has been carried out for a fully solid state Body Power Supply providing the necessary performance required for the modulation of RF power from CW, high power gyrotrons. The selected solution, based on the Pulse Step Modulation concept, is expected to yield cost and operational advantages compared to systems based on vacuum tubes. A second phase for the manufacturing of a full size unit and its testing on a power gyrotron is now in progress.

Bonicelli, T. E-mail: tullio.bonicelli@tech.efda.org; Claesen, R.; Coletti, A.; Mondino, P.L.; Pretelli, M.; Santinelli, M.; Sita, L.; Taddia, G

2003-09-01

69

MAGY: An innovative high voltage-low current power supply for gyrotron  

International Nuclear Information System (INIS)

From the electrical point of view, the body and the anode of high power gyrotrons behave as capacitive loads. A highly dynamic power supply is, therefore, hard to achieve. The MAGY concept (Modulator for the Anode of a triode type GYrotron) embodies an innovative solution to manage the capacitive current ensuring a very low ripple on the output voltage. It consists of a series of independent, bi-directional and regulated DC sources. Compared to existing topologies, this solution requires a smaller number of power modules. It avoids internal high frequency modulation and simultaneously offers high resolution of the output voltage and a wide range of operating scenarios.

70

130 kV 130 A High voltage switching mode power supply for neutral beam plasma heating: design issues  

International Nuclear Information System (INIS)

The company JEMA has designed and manufactured two High Voltage Switching Mode Power Supplies (HVSMPS), rated at 130 kV dc and 130 A, each of which will feed the accelerator grids of two Positive Ion Neutral Injector (PINI) loads, to be installed at the Joint European Torus (EFDA-JET facility located at Culham, UK). The solution designed by JEMA includes two matching transformers which adapt the 36 kV of the JET AC power distribution network to the required 670 V at the secondary side. Additionally, such transformers provide a 30 deg.phase shift which is required by a 30000 A 12 pulse thyristor rectifier. The obtained and stabilised 650 V feed 120 IGBT invertors, which operate at 2778 Hz with modulated square waveform. Each invertor feeds a High Insulation High Frequency Transformer. The 120 transformers corresponding to one power supply are arranged in three oil filled tanks and provide the main insulation from the low voltage to the high voltage side. The square waveform obtained at the secondary of each transformer is rectified by means of a diode bridge. The connection in series of the 120 diode bridges provides the required 130 kV d.c. at the output. In order to protect the load, a redundant solid state crowbar has been designed. Such short circuiting device is composed of 26 Light Triggered Thyristors (LTTs), connected in series. Electrical simulations have been carried out in order to ensure that the system complies with the requirements of high accuracy and adh the requirements of high accuracy and adequate protection of the load. The critical design of the High Voltage-High Frequency Transformers has also required electrostatic simulations of the electric field distribution

71

A novel high-frequency multiphase crowbarless high-voltage dc power supply  

International Nuclear Information System (INIS)

A novel topology based on high frequency switching resonant immittance converters (RICs) is proposed in this paper. The principle of operation, design, simulation and experimental results on a - 20 kV, 1 A dc prototype power supply, that uses a three-phase RIC operating with 120° phase shift involving switching at 25 kHz and a dc-dc step down converter with energy recovery snubber in the front-end, is presented. (author)

72

Multiple high voltage power supply controls solution using compact, distributed Ethernet based PC boards and Linux/Windows based GUIS  

International Nuclear Information System (INIS)

Compact Ethernet based High voltage PC boards have been developed, tested and produced to use as an integrated HV power supply unit to generate and control voltages varying from 0 to 2000 V dc from any OS independent PC platform. The Neutron gamma array (NAND) project at IUAC will need distributed control of at least 120 such units over a private Local Area Network to bias detectors. These Power supplies are being made as five independent boxes, each box consisting of 24 such HV PC boards and they will be interconnected using network switches. Presently, a compact two layer board with the PICO make DC-DC HV converter mounted on PCB, put together in a group of 24 of them, have been built and fully tested. The advantage of such a system is that, it is easily expandable to a large number of power supplies with low cost, globally accessible, multiple users in a network can set or read any power supply value through an OS independent PC. Control GUI applications are developed using C, IUAC PCLI, Qt C++ etc. and have been successfully tested. (author)

73

Design, Analysis &Implementation of Negative High Voltage DC Power Supply Using Voltage Multiplier Circuits.  

OpenAIRE

Voltage multipliers are widely used in many highvoltage and low-current applications where input voltage stability is not the major concern. Some application like microwave tubes requires negative high voltage for their safe operation. In this paper the design aspects of multiplier circuits are taken in account on the basis of analysis and simulation results. Simulation is done using PSIM Software and Implementation is done on basis of simulation results and theoretical calculation.

Dave, Priyen S. Patel D. B.

2013-01-01

74

Design, Analysis &Implementation of Negative High Voltage DC Power Supply Using Voltage Multiplier Circuits.  

Directory of Open Access Journals (Sweden)

Full Text Available Voltage multipliers are widely used in many highvoltage and low-current applications where input voltage stability is not the major concern. Some application like microwave tubes requires negative high voltage for their safe operation. In this paper the design aspects of multiplier circuits are taken in account on the basis of analysis and simulation results. Simulation is done using PSIM Software and Implementation is done on basis of simulation results and theoretical calculation.

Priyen S. Patel* & D.B. Dave

2013-04-01

75

Development of cast resin multisecondary 1600kVA transformer for Regulated High Voltage Power Supply- A prototype  

International Nuclear Information System (INIS)

Regulated High Voltage Power Supplies (RHVPS) are commonly used in high-energy particle accelerators. RHVPS is a modular power supply in which kV level modules (40 or 80) are cascaded to generate desired level of voltage/power. One of the most challenging tasks involved is to provide input power to number of rectifier modules with required isolation (inter-winding and winding to ground). This is accomplished by deploying multi-secondary (large numbers, say 40 secondaries) transformers. This RHVPS concept was realized for the first time in the country with development of oil filled multi-secondary transformer. A pair of 3.3MVA, 11kV/ (940Vx40) has been successfully demonstrated, isolation of 6kVDC (inter-winding) and 160kVDC (all secondary to ground) tested. The next generation power supplies are unitized with indoor installations. This has created the demand for dry type multi-secondary transformers in compliance with safety regulations. This paper presents manufacturing issues and testing of the prototype resin cast coil. On the manufactured prototype, inter-winding isolation is tested up to 6kVDC and 125kVDC with respect to ground.

76

Development of cast resin multisecondary 1600kVA transformer for Regulated High Voltage Power Supply- A prototype  

Science.gov (United States)

Regulated High Voltage Power Supplies (RHVPS) are commonly used in high-energy particle accelerators. RHVPS is a modular power supply in which kV level modules (40 or 80#) are cascaded to generate desired level of voltage/power [1]. One of the most challenging tasks involved is to provide input power to number of rectifier modules with required isolation (inter-winding and winding to ground). This is accomplished by deploying multi-secondary (large numbers, say 40 secondaries) transformers. This RHVPS concept was realized for the first time in the country with development of oil filled multi-secondary transformer. A pair of 3.3MVA, 11kV/ (940Vx40) has been successfully demonstrated, isolation of 6kVDC (inter-winding) and 160kVDC (all secondary to ground) tested. The next generation power supplies are unitized with indoor installations. This has created the demand for dry type multi-secondary transformers in compliance with safety regulations. This paper presents manufacturing issues and testing of the prototype resin cast coil. On the manufactured prototype, inter-winding isolation is tested up to 6kVDC and 125kVDC with respect to ground.

Tripathi, V.; Singh, N. P.; Gupta, L. N.; Oza, Kapil; Patel, Paresh; Baruah, U. K.

2010-02-01

77

Power-supply system for high-voltage electron guns with grid control  

International Nuclear Information System (INIS)

A power-supply system for electron guns with grid control is described which consists of a source of accelerating voltage between 20 and 180 kV with a current of 100 mA and a control circuit for an electron gun that contains a pulse generator having an output voltage of up to 5 kV for pulse durations of 2, 10, 50 and 90 microseconds. The output pulses of the generator are synchronized with a certain phase of the cathode heater current of the gun, and they can be repeated at a frequency between 100 and 0.4 Hz. The system is reliable and resistant to the overloads associated with breakdowns in the gun

78

Switching mode high voltage DC regulated power supply for inflector of cyclotron along with on-line beam current measurement  

International Nuclear Information System (INIS)

For the Inflector of K-130 cyclotron at V.E.C. Centre, Kolkata, a dc regulated power supply (15 kV, 10 ma, 0.1% regulation) with CV/CC mode of operation is designed and fabricated which is running round-the-clock for more then two years. Based on same technique, several other high voltage and high current type of dc regulated Switching- Mode-Power Supplies (SMPS), have been fabricated for VEC Centre and for other institutions also, such as SINP Calcutta, NPL New Delhi etc. This Power Supply uses Pulse-Width-Modulation (Pm) technique in which two similar square-wave pulses but opposite in phase are used for DC-to-Ac converter at very high frequency. By the process of switching, the power dissipation in the regulating elements is minimum which makes it highly efficient. The advantage of operating at higher switching frequency is to reduce the size of transformer and filter capacitors which makes it cheaper

79

Computer control of the high-voltage power supply for the DIII-D electron cyclotron heating system  

International Nuclear Information System (INIS)

This paper reports on the DIII-D Electron Cyclotron Heating (ECH) high voltage power supply which is controlled by a computer. Operational control is input via keyboard and mouse, and computer/power supply interfact is accomplished with a Computer Assisted Monitoring and Control (CAMAC) system. User-friendly tools allow the design and layout of simulated control panels on the computer screen. Panel controls and indicators can be changed, added or deleted, and simple editing of user-specific processes can quickly modify control and fault logic. Databases can be defined, and control panel functions are easily referred to various data channels. User-specific processes are written and linked using Fortran, to manage control and data acquisition through CAMAC. The resulting control system has significant advantages over the hardware it emulates: changes in logic, layout, and function are quickly and easily incorporated; data storage, retrieval, and processing are flexible and simply accomplished; physical components subject to wear and degradation are minimized. In addition, the system can be expanded to multiplex control of several power supplies, each with its own database, through a single computer console

80

Computer control of the high-voltage power supply for the DIII-D Electron Cyclotron Heating system  

International Nuclear Information System (INIS)

The D3-D Electron Cyclotron Heating (ECH) high voltage power supply is controlled by a computer. Operational control is input via keyboard and mouse, and computer/power supply interface is accomplished with a Computer Assisted Monitoring and Control (CAMAC) system. User-friendly tools allow the design and layout of simulated control panels on the computer screen. Panel controls and indicators can be changed, added or deleted, and simple editing of user-specific processes can quickly modify control and fault logic. Databases can be defined, and control panel functions are easily referred to various data channels. User-specific processes are written and linked using Fortran, to manage control and data acquisition through CAMAC. The resulting control system has significant advantages over the hardware it emulates: changes in logic, layout, and function are quickly and easily incorporated; data storage, retrieval, and processing are flexible and simply accomplished, physical components subject to wear and degradation are minimized. In addition, the system can be expanded to multiplex control of several power supplied, each with its own database, through a single computer and console. 5 refs., 4 figs., 1 tab

81

Computer control of the high-voltage power supply for the DIII-D Electron Cyclotron Heating system  

Energy Technology Data Exchange (ETDEWEB)

The D3-D Electron Cyclotron Heating (ECH) high voltage power supply is controlled by a computer. Operational control is input via keyboard and mouse, and computer/power supply interface is accomplished with a Computer Assisted Monitoring and Control (CAMAC) system. User-friendly tools allow the design and layout of simulated control panels on the computer screen. Panel controls and indicators can be changed, added or deleted, and simple editing of user-specific processes can quickly modify control and fault logic. Databases can be defined, and control panel functions are easily referred to various data channels. User-specific processes are written and linked using Fortran, to manage control and data acquisition through CAMAC. The resulting control system has significant advantages over the hardware it emulates: changes in logic, layout, and function are quickly and easily incorporated; data storage, retrieval, and processing are flexible and simply accomplished, physical components subject to wear and degradation are minimized. In addition, the system can be expanded to multiplex control of several power supplied, each with its own database, through a single computer and console. 5 refs., 4 figs., 1 tab.

Clow, D.D.; Kellman, D.H.

1991-10-01

82

Integrated high voltage power supply utilizing burst mode control and its performance impact on dielectric electro active polymer actuators  

DEFF Research Database (Denmark)

Through resent years new high performing Dielectric Electro Active Polymers (DEAP) have emerged. To fully utilize the potential of DEAPs a driver with high voltage output is needed. In this paper a piezoelectric transformer based power supply for driving DEAP actuators is developed, utilizing a burst mode control technique. Controlling and driving a DEAP actuator between 250V to 2.5kV is demonstrated, where discrete like voltage change and voltage ripple is observed, which is introduced by the burst mode control. Measurements of the actuator strain-force reveal that the voltage ripples translates to small strain-force ripples. Nevertheless the driver demonstrates good capabilities of following an input reference signal, as well as having the size to fit inside a 110 mm x 32 mm cylindrical InLastor Push actuator, forming a “low voltage” DEAP actuator.

Andersen, Thomas; RŘdgaard, Martin SchŘler

83

High voltage power supply systems for electron beam and plasma technologies. Its new element base  

International Nuclear Information System (INIS)

Transforming technique and high voltage technique supplementing each other more and more unite in indivisible constructions of modern apparatuses and systems and applicated in modern technologies providing its high efficiency. Specially worked out, ecologically clean, inertial, inflammable perfluororganic liquid is used in elements and electronic apparatuses simultaneously as insulating and cooling media. This liquid is highly fluid, fills tiny cavities in construction elements and in the places of high concentration of losses, where maximum local overheating of active parts or apparatus constructions takes place, it transforms to boiling state with highly intensive taking off of heat energy from cooled surface point. For instance, being cooled by mentioned perfluororganic liquid, copper wire can conduct current to 50 A/mm2 density, but in ordinary conditions of transformers, reactors and busses, current density can reach only few Amperes. Possibility of considerable increasing of current density, that is reached by means of intensive cooling, provided by worked out liquid, and taking into account its incredibly high insulating features (liquid has electric strength to 50 KV/mm) allows to provide optimum heat regime of active parts of transformers. reactors, condenser, semiconductor devices, resistors, construction elements and electrotechnical apparatus in general. Particularly high effect of decreasing of weight and dimensions characteristics of elements nd dimensions characteristics of elements and electrotechnical apparatus in general can be reached under working out of special constructions of each element and apparatus details, adapted to use of mentioned liquid as insulating and cooling media

84

Fault protection system in a 'regulated high voltage power supply (80 KV, 130A)' for neutral beam injector  

International Nuclear Information System (INIS)

Regulated High Voltage Power Supply (RHVPS) system has been developed at Institute for Plasma Research (IPR) for use with the Neutral Beam and RF applications. The highest ratings manufactured so far is 80 kV, 130 A. The system is developed in house and also being delivered at different research institutes for various applications. Since it is a multi megawatt output power system, and the loads have very low fault energy tolerant, fault protection system is mandatory. Protections are mandatory at each stage of conversion. Output fault protection is done in a variety of ways. Fast turn off at output is achieved and test results are discussed. Multi secondary transformers (5.6 MVA rating, with 40 outputs) are used in realising the power supply. These special transformers need protection even for over current at one secondary when the output fault current is not reflected to primaries to break the main circuit breaker. It becomes difficult to bifurcate fault in such situations. Special technique is applied to sense it. Electronic means are used for fast detection and tripping the system. This paper describes the basic RHVPS topology and test results along with presentation on the input and output fault protection systems. (author)

85

High-voltage power supplies for traveling wave tube WV-273A  

International Nuclear Information System (INIS)

Paper presents a description of two modifications of high-volt power sources described for preamplifier on UV-273A type travelling wave tube (TWT). Power source where anode power circuit contains semiconducting high-volt switch on thyristors was designed to average pulse mode of TWT operation. Time of switching-in this power circuit constitutes 20 mcs

86

Development of an amorphous surge blocker for a high voltage acceleration power supply of the neutral beam injectors  

International Nuclear Information System (INIS)

An amorphous surge blocker for a high voltage acceleration power supply for the neutral beam injectors has been developed. Since the saturation magnetic flux density of the amorphous core is higher than that of the ferrite core, the surge blocker made of amorphous cores can be reduced in size appreciably compared to the conventional ferrite surge blocker. A 350 kV, 0.05 volt-second amorphous surge blocker was designed, fabricated and tested. The amorphous core was made by winding an amorphous tape with a film for the layer insulation and was heat-treated to recover the magnetic characteristics. The core is molded by epoxy resin and installed in a FRP insulator tube filled with SF6 gas for the insulation. The volt-second measured was higher than the designed value and the electrical breakdown along the cores and between layers was not observed. This test result shows that the amorphous surge blocker is applicable for a dc acceleration power supply for high energy neutral beam injectors. (author)

87

A 600kV 15mA Cockcroft-Walton high-voltage power supply with high stability and low-ripple voltage  

International Nuclear Information System (INIS)

A Cockcroft-Walton high-voltage power supply with high stability and low-ripple voltage has been developed. This power supply has been operated in a ns pulse neutron generator. The maximum non-load voltage is 600kV while the working voltage and load current are 550kV and 15mA, respectively. The tested results indicate that when the power supply is operated at 300kV, 6.7mA and the input voltage varies +/-10%, the long-term stability of the output voltage is S=(0.300-1.006)x10-3. The ripple voltage is ?UP-P=6.2V at 300kV, 6.8-8.3mA and the ratio of ?UP-P to the output voltage VH is ?UP-P/VH=2.1x10-5

88

High-voltage-powered transistorized preamplifier  

International Nuclear Information System (INIS)

One of the problems that is frequently met in the field of nuclear electronics is that of coupling the signal from a high-impedance pulse-type radiation detector to a low-impedance transmission line. Radiation detectors and their associated counting equipment are often separated by a considerable distance and some efficient means of transmitting the signal from the detector to the counting system must be provided. In practice, a low-impedance coaxial cable is used for the transmission line and a cathode-follower or emitter-follower circuit is used to achieve the required impedance match. This paper describes a unique emitter-follower circuit that has been utilized very successfully at the University of Washington. The emitter-follower circuit is unique in that power for the transistor circuit is derived from the high voltage that is supplied to the radiation detector. The two pnp alloy-junction transistors employed in the preamplifier yield.a voltage gain of unity over a dynamic range of from 1 mV to 5 V. Stabilization of the operating voltage for the emitter-follower circuit is provided by a small zener diode. The current drain of a typical remote-scintillation detector employing the circuit ranges from 0.35 to 0.65 mA when the high voltage is supplied to the scintillation detector is varied from 800 to 1 500 V. The unit will drive 500 ft of 52-? coaxial line with a 25% loss in pulse amplitude and has been used with remotely operated scintillation-type detectors andoperated scintillation-type detectors and BF3-type neutron detectors with excellent results. (author)

89

Laser power supply  

International Nuclear Information System (INIS)

The laser power supply includes a regulator which has a high voltage control loop based on a linear approximation of a laser tube negative resistance characteristic. The regulator has independent control loops for laser current and power supply high voltage

90

Medium and high voltage power cables market in Europe  

International Nuclear Information System (INIS)

This note gives an overview of the European market for medium and high voltage power cables. In this text, emphasis is placed on suppliers and important European clients; there is also a brief review of the different techniques for cable laying and utilization in Europe. This not has mainly been drafted from informations supplied by EUROPACABLE

91

Computer controlled multichannel high voltage supply system for GRACE instrumentation  

International Nuclear Information System (INIS)

The high energy gamma ray telescopes being set up by NRL, BARC as part of the GRACE project, require a very large number of (? 1000 nos.) programmable high voltage power supplies for biasing photomultiplier tubes for the detection and characterization of the atmospheric Cerenkov events. These H.V. supplies need to be very compact and lightweight, as they will be mounted on moving telescopes. This paper describes the design aspects of the overall HV system and some preliminary results of the prototype HV modules being developed for such applications. In the new design, the switching frequency of the converters in the H.V. supplies has been increased by a factor of three times as compared to the earlier design, and surface mounted devices has been used to achieve size and weight reductions. The HV system that is designed for modular construction consists of multiple HV modules, each containing 16 independently adjustable HV supplies. All the HV modules in the system are interconnected via a serial I2C bus. Each HV supply has built in over voltage/current, thermal overload protections with output voltage read back and adjustable slew rate control facilities. (author)

92

High voltage surge protection system for gun power supplies of 3 MeV, 30 kW DC electron beam accelerator  

International Nuclear Information System (INIS)

A 3 MeV, 30 kW dc industrial electron beam Accelerator is being developed at EBC, Kharghar, Navi Mumbai. The electron gun located at 3 MV terminal requires remotely controlled floating power supplies for filament and anode. As the control electronics operate at low voltages of the order of 15 V, they are vulnerable for conducted and radiated noise from high voltage column discharges. The sensitive electronic components should be protected from common mode and differential mode HV surges. To minimize the surge voltages to safe operating limits of electronic components used, various methods were incorporated and tested in simulated and actual conditions. This surge protection scheme has been installed at 3 MV dome and gun supplies were operated at 1.2 MeV level. They have been withstanding several HV sparks and discharges in the Accelerator with nitrogen gas at 6 kg/cm2. The techniques such as spark gaps, electrostatic screen, surge limiting inductors, cascaded filters, isolation amplifiers, single point grounding and electromagnetic shielding have been described in this paper. (author)

93

Combined resonant tank capacitance and pulse frequency modulation control for ZCS-SR inverter-fed high voltage DC power supply  

Science.gov (United States)

Conventional pulse frequency modulated (PFM) zero current switching (ZCS) series resonant (SR) inverter fed high voltage dc power supplies have nearly zero switching loss. However, they have limitations of poor controllability at light loads and large output voltage ripple at low switching frequencies. To address these problems, this paper proposes a combined resonant tank capacitance and pulse frequency modulation based control approach. For the realization of the proposed control approach, the tank circuit of the resonant inverter is made up of several resonant capacitors that are switched into or out of the tank circuit by electromechanical switches. The output voltage of the converter is regulated by digitally modulating the resonant tank capacitance and narrowly varying the switching frequency. The proposed control scheme has several features, namely a wide range of controllability even at light loads, less output voltage ripple, and less current stress on the inverter's power switches at light loads. Therefore, the proposed control approach alleviates most of the problems associated with conventional PFM. Experimental results obtained from a scaled down laboratory prototype are presented to verify the effectiveness of the proposed system.

Lee, S. S.; Iqbal, S.; Kamarol, M.

2011-09-01

94

Performance of the TJ-II ECRH system with the new -80 kV 50 A high voltage power supply  

International Nuclear Information System (INIS)

The ECRH system of the TJ-II stellarator consists of two triode - 53.2 GHz - gyrotrons, which can deliver a maximum power of 300 kW each, during 1 s. Both gyrotrons are fed by a common high voltage power supply (HVPS). During the last experimental campaigns the performance of the gyrotrons were limited by the HVPS, whose maximum output current was limited to 30 A and the ripple level of the output voltage was around 7%. In order to guarantee the reliability of the ECRH system and to improve its performance, a new HVPS has been developed and manufactured by the company JEMA and was commissioned at CIEMAT during 2007. The design is based on solid-state technology and high frequency commutation techniques. The new unit reaches -80 kV and 50 A during a maximum pulse length of 1 s. The complete design, testing and commissioning of the HVPS are presented, as well as the routine operation of the ECRH system during the TJ-II experimental campaign.

95

Experiment and operation of a LHCD-35 kV/2.8 MW/1000 s high-voltage power supply on HT-7 tokamak  

International Nuclear Information System (INIS)

A-35 kV/2.8 MW/1000s high-voltage power supply (HVPS) for HT-7 superconducting tokamak has been built successfully. The HVPS is scheduled to run on a 2.45 GHz/1 MW lower hybrid current drive (LHCD) system of HT-7 superconducting tokamak before the set-up of HT-7 superconducting tokamak in 2003. The HVPS has a series of advantages such as good steady and dynamic response, logical computer program controlling the HVPS without any fault, operational panel and experimental board for data acquisition, which both are grounded distinctively in a normative way to protect the main body of HVPS along with its attached equipment from dangers. Electric power cables and other control cables are disposed reasonably, to prevent signals from magnetic interference and ensure the precision of signal transfer. The author introduced the experiment and operation of a 35 kV/2.8 MW/1000 s HVPS for 2.45 GHz/1 MW LHCD system. The reliability and feasibility of the HVPS has been demonstrated in comparison with experimental results of original design and simulation data

96

Combined resonant tank capacitance and pulse frequency modulation control for ZCS-SR inverter-fed high voltage DC power supply  

International Nuclear Information System (INIS)

Conventional pulse frequency modulated (PFM) zero current switching (ZCS) series resonant (SR) inverter fed high voltage dc power supplies have nearly zero switching loss. However, they have limitations of poor controllability at light loads and large output voltage ripple at low switching frequencies. To address these problems, this paper proposes a combined resonant tank capacitance and pulse frequency modulation based control approach. For the realization of the proposed control approach, the tank circuit of the resonant inverter is made up of several resonant capacitors that are switched into or out of the tank circuit by electromechanical switches. The output voltage of the converter is regulated by digitally modulating the resonant tank capacitance and narrowly varying the switching frequency. The proposed control scheme has several features, namely a wide range of controllability even at light loads, less output voltage ripple, and less current stress on the inverter's power switches at light loads. Therefore, the proposed control approach alleviates most of the problems associated with conventional PFM. Experimental results obtained from a scaled down laboratory prototype are presented to verify the effectiveness of the proposed system.

97

Advanced High Voltage Power Device Concepts  

CERN Document Server

Advanced High Voltage Power Device Concepts describes devices utilized in power transmission and distribution equipment, and for very high power motor control in electric trains and steel-mills. Since these devices must be capable of supporting more than 5000-volts in the blocking mode, this books covers operation of devices rated at 5,000-V, 10,000-V and 20,000-V. Advanced concepts (the MCT, the BRT, and the EST) that enable MOS-gated control of power thyristor structures are described and analyzed in detail. In addition, detailed analyses of the silicon IGBT, as well as the silicon carbide MOSFET and IGBT, are provided for comparison purposes. Throughout the book, analytical models are generated to give a better understanding of the physics of operation for all the structures. This book provides readers with: The first comprehensive treatment of high voltage (over 5000-volts) power devices suitable for the power distribution, traction, and motor-control markets;  Analytical formulations for all the device ...

Baliga, B Jayant

2012-01-01

98

High Voltage Power Transmission for Wind Energy  

Science.gov (United States)

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

99

High-voltage supply for backward-wave tube  

International Nuclear Information System (INIS)

A high-current high-voltage supply for a backward-wave tube is described that uses a generalppurpose semiconductor converter with pulse-width modulation and two-stage regulation. The load current is up to 250 mA for load voltages of from 0.5 to 4.5 kV. The voltage staiblity is less than or equal to 5 x 10-6. the root-mean-square output ripple is less than or equal to 2 x 10-6/ The supply is equipped with high-speed (5 usec) load-breakdown protection

100

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

Science.gov (United States)

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

101

Design and simulation for the pulse high-voltage DC power supply (HVPS) of 1.2 MW/2.45 GHz HT-7U lower hybrid current drive system  

International Nuclear Information System (INIS)

The superconducting tokamak HT-7U has been designed by the Institute of Plasma Physics since 1998 and will be set up before 2003. The 1.2 MW/2.45 GHz HT-7U LHCD (Lower hybrid current drive) system which being the most efficient non-induction device can heat the plasma and drive the plasma current has been efficiently in operation now, and a particular design of the 2.8 MW/-35 kV high-voltage DC power supply has been already completed and will apply to the klystron of LHCD on HT-7 and the future HT-7U, and the project of the power supply has been examined and approved professionally by an authorized group of high-level specialist in the Institute of Plasma Physics. The detailed design of the power supply and the simulation results are referred

102

Innovation of High Voltage Supply Adjustment Device on Diagnostic X-Ray Machine  

International Nuclear Information System (INIS)

Innovation of high voltage supply adjustment device on diagnostic x-ray machine has been carried out. The innovation is conducted by utilizing an electronic circuit as a high voltage adjustment device. Usually a diagnostic x-ray machine utilizes a transformer or an auto-transformer as a high voltage supply adjustment device. A high power diagnostic x-ray machine needs a high power transformer which has big physical dimension. Therefore a box control where the transformer is located has to have big physical dimension. Besides, the price of the transformer is expensive and hardly found in local markets. In this innovation, the transformer is replaced by an electronic circuit. The main component of the electronic circuit is Triac BTA-40. As adjustment device, the triac is controlled by a variable resistor which is coupled by a stepper motor. A step movement of stepper motor varies a value of resistor. The resistor value determines the triac gate voltage. Furthermore the triac will open according to the value of electrical current flowing to the gate. When the gate is open, electrical voltage and current will flow from cathode to anode of the triac. The value of these electrical voltage and current depend on gate open condition. Then this triac output voltage is feed to diagnostic x-ray machine high voltage supply. Therefore the high voltage value of diagnostic x-ray machine is adjusted by the output voltage of the electronic circuit. By using this electronic circuit, the physical dimension of diagnostic x-ray machine box control and the price of the equipment can be reduced. (author)

103

High voltage series resonant inverter ion engine screen supply. [SCR series resonant inverter for space applications  

Science.gov (United States)

A high-voltage, high-power LC series resonant inverter using SCRs has been developed for an Ion Engine Power Processor. The inverter operates within 200-400Vdc with a maximum output power of 2.5kW. The inverter control logic, the screen supply electrical and mechanical characteristics, the efficiency and losses in power components, regulation on the dual feedback principle, the SCR waveforms and the component weight are analyzed. Efficiency of 90.5% and weight density of 4.1kg/kW are obtained.

Biess, J. J.; Inouye, L. Y.; Shank, J. H.

1974-01-01

104

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

Science.gov (United States)

...high-voltage power centers and portable transformers; permit...High-Voltage Distribution § 75...high-voltage power centers and portable transformers; permit...Provisions] Power centers and portable transformers...

2010-07-01

105

High-voltage supply for neutral beam injection in the Tokamak experiment TEXTOR  

International Nuclear Information System (INIS)

In 1985, two identical high-voltage power supply systems were installed in the Juelich Nuclear Research Facility in the Federal Republic of Germany. The systems, which began operation in the following year, supply the energy required by both neutral beam injectors used in the TEXTOR fusion experiment. A new, major feature of the power supply systems is their 68 unregulated, series-connected d.c. sources, connected and disconnected by high-speed electronic switches. With this configuration it is possible to obtain a current of 100 A with a resistive load of 550 ? (corresponding to a load voltage of 55 kV) in 20 ?s, and to disconnect the same current in less than 10 ?s. A description of the design and operation of the power supplies is followed by a look at the tests performed by the manufacturer during commissioning of the individual modules. (Auth.)

106

Bipolar high voltage pulse power generator.  

Czech Academy of Sciences Publication Activity Database

Monterey, 2005, s. 44. [IEEE International Pulsed Power Conference/15th./. Portola Plaza Hotel, Monterey, CA, USA (US), 13.06.2005-17.06.2005] R&D Projects: GA AV ?R KSK2043105 Keywords : bipolar * pulse power generator * corona discharge Subject RIV: BL - Plasma and Gas Discharge Physics

Lukeš, Petr; ?lupek, Martin; Babický, Václav; Šunka, Pavel

107

Bipolar high voltage pulse power generator.  

Czech Academy of Sciences Publication Activity Database

Monterey : IEEE, 2007 - (Maenchen, J.; Schamiloglu, E.), s. 1061-1064 ISBN 0-7803-9190-X. [IEEE International Pulsed Power Conference/15th./. Portola Plaza Hotel, Monterey (US), 13.06.2005-17.06.2005] R&D Projects: GA AV ?R KSK2043105 Institutional research plan: CEZ:AV0Z20430508 Keywords : bipolar * pulse power generator * corona discharge Subject RIV: BL - Plasma and Gas Discharge Physics

Lukeš, Petr; ?lupek, Martin; Babický, Václav; Šunka, Pavel

108

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

Science.gov (United States)

...2010-07-01 false High-voltage power centers and transformers; record of examination. 75...MINES Underground High-Voltage Distribution § 75.812-2 High-voltage power centers and transformers; record of examination....

2010-07-01

109

High voltage, magnetically switched pulsed power systems  

International Nuclear Information System (INIS)

The principles of magnetic switching are briefly described. Then the results of experiments on the following substantive topics for magnetic switching are presented: material properties and how they relate to switch performance, risetime limitations, and core insulation. Magnetic switching is then evaluated from a system perspective. An idealized pulse power system with 200 kJ or stored energy and a 40 ns output pulse is examined. The multi-megavolt electrical insulation requirements impose limitations on the switches. The cost of the magnetically switched system exceeds the cost of the conventional superpower generator system by up to 75%. The potential for reliability, reproducibility, and repetitive pulse capability must be evaluated for each application to offset the increased cost

110

A method for encapsulating high voltage power transformers  

Science.gov (United States)

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 carboxyl terminated butadiene nitril (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, Robert O.

111

Advances in high voltage power switching with GTOs  

International Nuclear Information System (INIS)

The control of high voltage at high power, particularly opening switches, has been difficult in the past. Using gate turnoff thyristors (GTOs) arranged in series enables large currents to be switched at high voltage. The authors report a high voltage opening switch has been successfully demonstrated. This switch uses GTOs in series and successfully operates at voltages higher than the rated voltage of the individual devices. It is believed that this is the first time this has been successfully demonstrated, in that GTOs have been operated in series before, but always in a manner as to not exceed the voltage capability of the individual devices. In short, the devices have not worked together, sharing the voltage, but one device has been operated using several backup devices. Of particular interest is how well the individual devices share the voltage applied to them. Equal voltage sharing between devices is absolutely essential, in order to not exceed the voltage rating of any of the devices in the series chain. This is accomplished at high (microsecond) switching speeds. Thus, the system is useful for high frequency applications as well as high power, making for a flexible circuit system element. This demonstration system is rated at 5 KV and uses 1 KV devices. A larger 24 KV system is under design and will use 4.5 KV devices. In order to design the 24 KV switch, the safe operating area of the large devices must be known thoroughlyghly

112

Technological Aspects: High Voltage  

CERN Document Server

This paper covers the theory and technological aspects of high-voltage design for ion sources. Electric field strengths are critical to understanding high-voltage breakdown. The equations governing electric fields and the techniques to solve them are discussed. The fundamental physics of high-voltage breakdown and electrical discharges are outlined. Different types of electrical discharges are catalogued and their behaviour in environments ranging from air to vacuum are detailed. The importance of surfaces is discussed. The principles of designing electrodes and insulators are introduced. The use of high-voltage platforms and their relation to system design are discussed. The use of commercially available high-voltage technology such as connectors, feedthroughs and cables are considered. Different power supply technologies and their procurement are briefly outlined. High-voltage safety, electric shocks and system design rules are covered.

Faircloth, D C

2013-01-01

113

Design philosophy and use of high voltage power systems for multi-megawatt ion beam accelerators  

International Nuclear Information System (INIS)

The requirements for a neutral beam high voltage power system are derived from the characteristics of the ion source. High voltage system component characteristic requirements and choices are described

114

Design philosophy and use of high voltage power systems for multi-megawatt ion beam accelerators  

Energy Technology Data Exchange (ETDEWEB)

The requirements for a neutral beam high voltage power system are derived from the characteristics of the ion source. High voltage system component characteristic requirements and choices are described. (MHR)

Barber, G.C.; Broverman, A.Y.; Hill, R.E.; Loring, C.M.; Ponte, N.S.

1977-01-01

115

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

Science.gov (United States)

An earth-isolated optically-coupled wideband high voltage probe has been developed for pulsed power applications. The probe uses a capacitive voltage divider coupled to a fast light-emitting diode that converts high voltage into an amplitude-modulated optical signal, which is then conveyed to a receiver via an optical fiber. A solar cell array, powered by ambient laboratory lighting, charges a capacitor that, when triggered, acts as a short-duration power supply for an on-board amplifier in the probe. The entire system has a noise level ?0.03 kV, a DC-5 MHz bandwidth, and a measurement range from -6 to 2 kV; this range can be conveniently adjusted. PMID:23126786

Zhai, Xiang; Bellan, Paul M

2012-10-01

116

Specific features of high voltage supply of wire spark chambers in direct codinq regime  

International Nuclear Information System (INIS)

Direct coding of spark coordinate in a wire spark chamber is effected directly by a high-voltage pulse that feeds the chamber. The described high-voltaqe supply circuit makes it possible to control the coordinate recording mode in the coder independent of the spark chamber starting regime

117

Solid State High Voltage Supply for EB and X-Ray Generators.  

Czech Academy of Sciences Publication Activity Database

Ro?. 44, 5-6 (2009), s. 73-75. ISSN 0861-4717 R&D Projects: GA AV ?R KAN300100702 Institutional research plan: CEZ:AV0Z20650511 Keywords : high voltage supply * electron beam generator * x- ray generator Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

Zoba?, Martin; Vl?ek, Ivan

2009-01-01

118

Environmental impacts of high voltage power lines and stations  

International Nuclear Information System (INIS)

Environmental pollution due to high voltage power lines and stations (over 400 kV) shows up in several ways: high frequency (radio and TV range) radio waves; sound pollution (noises); various direct and indirect effects on living beings; aestethic pollution. The indirect effects of electromagnetic field may result in inducing high electric potential to earth insulated objects as cars, shelters and farming equipment, fencing, etc. which on human touch lead to discharge currents which only disappear by interrupting the contact. At high currents, due to muscle contraction, the man often cannot release the touched object, hence serious or even lethal accidents may happen. In depth analysis of such phenomena is possible by separating the electric and magnetic field effects. We shall concentrate on the electric field since the magnetic field effects are much less significant. 6 refs

119

Environmental impacts of high voltage power lines and stations  

Energy Technology Data Exchange (ETDEWEB)

Environmental pollution due to high voltage power lines and stations (over 400 kV) shows up in several ways: high frequency (radio and TV range) radio waves; sound pollution (noises); various direct and indirect effects on living beings; aestethic pollution. The indirect effects of electromagnetic field may result in inducing high electric potential to earth insulated objects as cars, shelters and farming equipment, fencing, etc. which on human touch lead to discharge currents which only disappear by interrupting the contact. At high currents, due to muscle contraction, the man often cannot release the touched object, hence serious or even lethal accidents may happen. In depth analysis of such phenomena is possible by separating the electric and magnetic field effects. We shall concentrate on the electric field since the magnetic field effects are much less significant. 6 refs.

Gillich, N.; Gillich, G.R. [' Eftimie Murgu' University, Resita (Romania)

2000-07-01

120

Fast Decoupled Power Flow for Power System with High Voltage Direct Current Transmission Line System  

OpenAIRE

Problem statement: High voltage direct current transmission line system has been widely applied for control power flow in power system. The power flow analysis was the one of powerful tools by which the power system equipped was analyzed both for planning and operation strategies. Approach: This study presented the method to analyze power flow of power system consisted of HVDC system. HVDC was modeled as the complex power injections. The presented complex power injected was incorporated into ...

Prechanon Kumkratug

2010-01-01

121

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

Energy Technology Data Exchange (ETDEWEB)

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.

1981-04-01

122

High Power, High Voltage FETs in Linear Applications: A User's Perspective  

International Nuclear Information System (INIS)

The specifications of the current crop of high-power, high-voltage field-effect transistors (FETs) can lure a designer into employing them in high-voltage DC equipment. Devices with extremely low on-resistance and very high power ratings are available from several manufacturers. However, our experience shows that high-voltage, linear operation of these devices at near-continuous duty can present difficult reliability challenges at stress levels well-below their published specifications. This paper chronicles the design evolution of a 600 volt, 8 ampere shunt regulator for use with megawatt-class radio transmitters, and presents a final design that has met its reliability criteria

123

Pulsed high voltages. High power switching. Application to new accelerators  

International Nuclear Information System (INIS)

This work deals with two aspects of the use of pulsed high voltages. The first one relies on the realisation of high energy generators (W>MJ) for magnetic striction plasma experiments (Z-pinch) in order to realize intense X sources (some few keV). The system retained is an inductive storage generator which includes a fast Marx generator (T/4<1 s) and a plasma opening switch (POS). The realization of a Marx generator with a minimized current rise time has led to study a low inductance switch (some few nH): the surface spark gap. The model built works in the ambient air at the nominal voltage of 40 kV and with a current of about 900 kA, and its inductance is lower than 5 nH. Its service life exceeds 1000 firings. The choice of materials, the triggering system, and most of the other influencing parameters of the surface spark gap have been studied. Some applications (system with two surface spark gaps, flat line Marx) of this spark gap are also indicated. The second aspect concerns the generation of microwaves using the electron beam - electromagnetic wave interaction (free electrons laser, Cherenkov plasma tube,..) using a generator developed in the laboratory: the Labutron, which particularity is its high impedance cables (about 1000) that can deliver a micro-second pulse with a stable voltage plateau during 700-800 ns. The work presented concerns the development of a cold cathode diode for the production of the electron beam. The diode built can work at about 400 kV aThe diode built can work at about 400 kV and under an impedance of about 950. Several options are proposed to improve the performances obtained. (J.S.)

124

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

Science.gov (United States)

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.

2014-12-01

125

Fast Decoupled Power Flow for Power System with High Voltage Direct Current Transmission Line System  

Directory of Open Access Journals (Sweden)

Full Text Available Problem statement: High voltage direct current transmission line system has been widely applied for control power flow in power system. The power flow analysis was the one of powerful tools by which the power system equipped was analyzed both for planning and operation strategies. Approach: This study presented the method to analyze power flow of power system consisted of HVDC system. HVDC was modeled as the complex power injections. The presented complex power injected was incorporated into the existing power flow program based on fast decoupled method. The presented method was tested on the multimachine power system. Results: The transmission line loss of the system with and without HVDC was compared. Conclusion: From the simulation results, the HVDC can reduce transmission line loss of power system.

Prechanon Kumkratug

2010-01-01

126

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

Science.gov (United States)

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.

1987-11-01

127

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

DEFF Research Database (Denmark)

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. However, new challenges appear for such topology, which have to be properly identified and successfully overcome. This paper presents possible concept for transformer-less wind turbine topology along with an overview of most promising candidates for optimal full-scale power converter design. Study is carried with proposed and justified high voltage wind turbine application along with selection of existing and most promising multilevel power converter topologies, which could be successfully proposed for transformer-less wind turbines.

Sztykiel, Michal

2011-01-01

128

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

Science.gov (United States)

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

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

2012-09-01

129

Digital measurement of pulsed high-voltage power  

International Nuclear Information System (INIS)

A method of measuring the passing power of the order of Mw on a frequency of approximately 3 Gcs, based on pulse signal conversion (with a duration of 3-10 ?sec) from an electron-tube detector head operating in the quadratic mode, in the sequence of pulses, recorded by a tridischarge decimal counter id described. Instrument linearity is not worse than 2% in the range of 18 db

130

Topics in high voltage pulsed power plasma devices and applications  

Science.gov (United States)

Pulsed power technology is one of the tools that is used by scientists and engineers nowadays to produce gas plasmas. The transient ultra high power is able to provide a huge pulse of energy which is sometimes greater than the ionization energy of the gas, and therefore separates the ions and electrons to form the plasma. Sometimes, the pulsed power components themselves are plasma devices. For example, the gas type switches can "turn on" the circuit by creating the plasma channel between the switch electrodes. Mini Back Lighted Thyratron, or as we call it, mini-BLT, is one of these gas type plasma switches. The development of the reduced size and weight "mini-BLT" is presented in this dissertation. Based on the operation characteristics testing of the mini-BLT, suggestions of optimizing the design of the switch are proposed. All the factors such as the geometry of the hollow electrodes and switch housing, the gas condition, the optical triggering source, etc. are necessary to consider when we design and operate the mini-BLT. By reducing the diameter of the cylindrical gas path between the electrodes in the BLT, a novel high density plasma source is developed, producing the plasma in the "squeezed" capillary. The pulsed power generator, of course, is inevitably used to provide the ionization energy for hydrogen gas sealed in the capillary. Plasma diagnostics are necessarily analyzed and presented in detail to properly complete and understand the capillary plasma. This high density plasma source (1019 cm-3) has the potential applications in the plasma wakefield accelerator. The resonant oscillation behavior of the particles in plasmas allows for dynamically generated accelerating electric fields that have orders of magnitude larger than those available in the conventional RF accelerators. Finally, the solid state switches are introduced as a comparison to the gas type switch. Pulsed power circuit topologies such as the Marx Bank, magnetic pulse compression and diode opening are used to accomplish the pulse generator design. Their applications for the transient plasma car engine combustion and bio-medical skin cancer cell treatments are also introduced.

Chen, Hao

131

High Voltage Power Converter for Large Wind Turbine  

DEFF Research Database (Denmark)

The increasing penetration of the wind energy has resulted in newly planned installations of offshore wind turbines. In order to minimize installation, material and transportation costs of the offshore wind power plants, large multi-MW wind turbine systems are being preferably employed and developed, which allow high power generation of each single unit. Nevertheless, further increase in the power ratings of the newly emerging turbines becomes a major concern related to the operating voltage level. In order to accommodate larger powers, presently employed low voltage (690 V) systems already require multi-parallel converter and filter modules, which increase the overall complexity. In this thesis, a concept for the medium voltage wind turbine is examined and evaluated, where voltage increase is dictated by the removal of the step-up transformer. As a result, an entire wind turbine electrical system operates at 20 kV level - identical as for the collector distribution network. Medium voltage operation allows the converter unit along with the filter to be installed on the base platform inside the tower. In this manner, more space in the nacelle can be flexibly accommodated by the mechanical parts. Due to limited voltage level of the generator insulation system (15 kV) along with the increasing grid integration requirements, special care has been made over the search for optimal full-scale power converter circuitry, which additionally has to compensate voltage differences between the generator-side and a grid-side. Three converter topologies with different conversion philosophies have been introduced (A, B and C), their performance examined and eventually compared with the conventional low voltage system. System A is a back-to-back MMC converter, which is commonly used in HVDC application. System B consists of the generator-side 2-level converter, DC/DC boost unit and a grid-side NPC-3L converter. System C is made of a seriesconnected full-bridge cells on the generator-side, and a grid-side NPC-5L converter. The performance of the proposed topologies is analyzed both under the normal and fault operation. In normal operation, medium and low voltage converter topologies are compared with regard to the efficiency and the required amount of silicon material in the semiconductor switches. In fault operation, maximum temporary ratings of the collector feeder components are compared also for different grounding schemes, which impact is the result of the removed step-up transformer. Finally, the ground fault detection scheme for feeder cable system is proposed - with the usage of current differential relay. Due to lack of the galvanic separation between the wind turbines and the feeder cable sections, careful investigation for the relay selective operation has been made, which distinguishes ground faults located at the wind turbine terminals from faults within the protected cables. The obtained results from the computer simulations in EMTDC/PSCAD software show, that the best performance has been achieved by the transformer-less turbine with a back-to-back modular multilevel converter (MMC) topology, which is single grounded only through its DC link common-mode point. It has also occurred that the results derived from losses and short circuit analyses have become advantageous over the equivalent conventional system consisting of low voltage wind turbines equipped with the step up transformer.

Sztykiel, Michal

2014-01-01

132

Hybrid voltage divider used for high voltage pulsed power measurement  

International Nuclear Information System (INIS)

The principle and structure of a hybrid voltage divider are proposed and the calibration and experimental testing are carried out. The ideal response conditions of the divider are analyzed by using the simplified divider model, the attenuation characteristic of two-stage voltage dividing is discussed, and then an error control method is presented. Through load calibration, the pulsed voltage frequency response of the divider can be greater than 2.9 MHz with the largest pulse width of 40 ?s, the attenuation ratio (or the attenuation coefficient) of 2. 60 kV/V and the measurement error of less than 5%. The divider has the merits of low cost, easy fabrication, and being capable of ns-to ?s-level pulsed voltage measurement, and it can be applied to laboratory- scale pulsed power measurement. (authors)

133

Transient Voltage Overshoots of High Voltage ESD Protections Based on Bipolar Transistors in Smart Power Technology  

OpenAIRE

Transient voltage overshoots of a high voltage (20 V) ESD clamp based on bipolar transistors in a smart power technology are studied using different TLP pulse conditions (rise time, voltage amplitude). The physical mechanisms involved during the ESD clamp turn-on are thoroughly analyzed by the mean of TCAD simulations, allowing the definition of a set of design guidelines for the overshoot reduction.

Delmas, Antoine; Gendron, Amaury; Bafleur, Marise; Nolhier, Nicolas; Gill, Chai

2010-01-01

134

Novel high-voltage, high-side and low-side power devices with a single control signal  

Science.gov (United States)

Novel high-voltage, high-side and low-side power devices, whose control circuits are referred to as the tub, are proposed and investigated to reduce chip area and improve the reliability of high-voltage integrated circuits. By using the tub circuit to control a branch circuit consisting of a PMOS and a resistor, a pulse signal is generated to control the low-side n-LDMOS after being processed by a low-voltage circuit. Thus, the high-voltage level-shifting circuit is not needed any more, and the parasitic effect of the conventional level-shifting circuit is eliminated. Moreover, the specific on-resistance of the proposed low-side device is reduced by more than 14.3% compared with the conventional one. In the meantime, integrated low-voltage power supplies for the low-voltage circuit and the tub circuit are also proposed. Simulations are performed with MEDICI and SPICE, and the results show that the expectant functions are achieved well.

Moufu, Kong; Xingbi, Chen

2013-09-01

135

Novel high-voltage, high-side and low-side power devices with a single control signal  

International Nuclear Information System (INIS)

Novel high-voltage, high-side and low-side power devices, whose control circuits are referred to as the tub, are proposed and investigated to reduce chip area and improve the reliability of high-voltage integrated circuits. By using the tub circuit to control a branch circuit consisting of a PMOS and a resistor, a pulse signal is generated to control the low-side n-LDMOS after being processed by a low-voltage circuit. Thus, the high-voltage level-shifting circuit is not needed any more, and the parasitic effect of the conventional level-shifting circuit is eliminated. Moreover, the specific on-resistance of the proposed low-side device is reduced by more than 14.3% compared with the conventional one. In the meantime, integrated low-voltage power supplies for the low-voltage circuit and the tub circuit are also proposed. Simulations are performed with MEDICI and SPICE, and the results show that the expectant functions are achieved well. (semiconductor devices)

136

A digital controlled negative high voltage power source for LINAC of HLS  

International Nuclear Information System (INIS)

This paper introduces the working principle of a 10-80 kV negative high voltage power source for the electronic gun of the 200 MeV LINAC of NSRL, especially how to realize the switch power, voltage/current sampling, feedback control and microcontroller module. The firmware design for the SOC microcontroller of ADuC8xx and the application software design for PC are also presented. (authors)

137

Dual use power supply development  

Science.gov (United States)

Size, weight, efficiency and reliability define space power systems. Then years ago NASA re-emphasized that missions such as Space Station needed cost effective critical technologies, one being power conversion. Thus, NASA began to emphasize ``dual-use'' technology through its center for Commercial Development of Space (mid 1980s). This CCDS program funded research and development efforts needed for future space missions as well as terrestrial applications for commercial markets. Maxwell and Auburn University (Space Power Institute) jointly developed reliable power systems for manned space projects as well as commercial applications of high power, high voltage switchmode power supplies. These serve the medical, scientific and industrial markets (lasers, accelerators and intense light sources). These applications required improvements in power density, efficiency, regulation, reliability and cost effectiveness to be successful. One of NASA's first programs at Auburn and Maxwell was a high frequency, series resonant power converter optimized for commercial applications. It also meets the needs of space missions (additional space flight qualification is needed). This power converter topology demonstrates dual-use technology for power density, power-to-weight, regulation, reliability and cost effectiveness. All goals were exceeded for both space and terrestrial applications. This was the first product of NASA's CCDS program producing a family of high voltage capacitor charging power supplies. Maxwell's CCDS capacitor power supplies are achieving greater acceptance demonstrating the value of the CCDS program.

Kolb, Alan C.; Strickland, Bryan E.

1995-01-01

138

Test Results from a Simulated High Voltage Lunar Power Transmission Line  

Science.gov (United States)

The Alternator Test Unit (ATU) in the Lunar Power System Facility (LPSF) located at the NASA Glenn Research Center (GRC) in Cleveland, OH was modified to simulate high voltage transmission capability. The testbed simulated a 1 km transmission cable length from the ATU to the LPSF using resistors and inductors installed between the distribution transformers. Power factor correction circuitry was used to compensate for the reactance of the distribution system to improve the overall power factor. This test demonstrated that a permanent magnet alternator can successfully provide high frequency AC power to a lunar facility located at a distance.

Birchenough, Arthur; Hervol, David

2008-01-01

139

Test Results From a Simulated High-Voltage Lunar Power Transmission Line  

Science.gov (United States)

The Alternator Test Unit (ATU) in the Lunar Power System Facility (LPSF) located at the NASA Glenn Research Center (GRC) in Cleveland, Ohio was modified to simulate high-voltage transmission capability. The testbed simulated a 1 km transmission cable length from the ATU to the LPSF using resistors and inductors installed between the distribution transformers. Power factor correction circuitry was used to compensate for the reactance of the distribution system to improve the overall power factor. This test demonstrated that a permanent magnet alternator can successfully provide high-frequency ac power to a lunar facility located at a distance.

Birchenough, Arthur; Hervol, David

2008-01-01

140

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

International Nuclear Information System (INIS)

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. Vexperimentally 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.

141

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

Science.gov (United States)

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

142

The DT-SJMOSFET : a new power MOSFET strucure for high-voltage applications  

OpenAIRE

New hybrid vehicles will probably use high voltage batteries (150 to 200 Volts). For these future automotive applications, the development of 600 Volts power MOSFET switches exhibiting low on-resistance is desired. The "Deep Trench SuperJunction" MOSFET (DT-SJMOSFET) is one of the new candidates. In this paper, a comparative theoretical study, using 2D simulations, shows that the DT-SJMOSFET should be a challenger to the conventional SJMOSFET in terms of "specific on-resistance / breakdown vo...

Theolier, Loic; Morancho, Fre?de?ric; Isoird, Karine; Mahfoz-kotb, Hicham; Tranduc, Henri

2007-01-01

143

Heavy-ion beams produced by high-voltage pulse-powered plasma focus  

International Nuclear Information System (INIS)

We report preliminary experimental studies of heavy-ion beams produced by a new type of plasma focus device which is powered by a fast high-voltage pulse of approx.500 kV, approx.20 kA, and approx.50 ns. A variety of ion species, either from solid materials or gases, were obtained and their beam characteristics, including charge states, energy spectrum, and emittance, were measured

144

Repetitive plasma opening switch for powerful high-voltage pulse generators  

International Nuclear Information System (INIS)

Results are presented of experimental studies of plasma opening switches that serve to sharpen the pulses of inductive microsecond high-voltage pulse generators. It is demonstrated that repetitive plasma opening switches can be used to create super-powerful generators operating in a quasi-continuous regime. An erosion switching mechanism and the problem of magnetic insulation in repetitive switches are considered. Achieving super-high peak power in plasma switches makes it possible to develop new types of high-power generators of electron beams and X radiation. Possible implementations and the efficiency of these generators are discussed

145

Pulsed power supply system  

International Nuclear Information System (INIS)

A circuit for supplying high voltage pulses at high repetition rate for energising an ion source in an accelerator tube comprises a drive transistor to which clock pulses (applied to the base of a transistor of a shaping network) are coupled, a transistor driving the primary of a transformer, the secondary of which supplies a voltage multiplier having end stages connected to the anode and cathode of the accelerator tube. A negative voltage is taken from capacitor and supplied to the tube grid

146

Fixed site monitoring of potential gradient fluctuations near to AC high voltage power lines  

International Nuclear Information System (INIS)

A fixed site monitoring station recorded the potential gradient disturbances near to two high voltage power lines during 2008. The full year's results show that the electrical environment downwind of power lines is modified compared to that upwind. Potential gradient disturbance was greater on days when there was rainfall. Humidity was inversely correlated with mean potential gradient when the station was both downwind and upwind of both power lines. Wind speed is weakly correlated with the standard deviation of a 10 minute sample of potential gradient downwind of both power lines, but not upwind. The distributions of mean and standard deviation of potential gradient in 10 minute samples showed that the field was more negative overnight and on days where there was rain, but less variable at night and on dry days. Upwind of the power lines, the average 24 hour trace exhibits the natural background Carnegie curve, with peaks corresponding to increased global thunderstorm activity, while local effects mask this trace when the FSMS is downwind of the power lines. The results show that corona ions can cause potential gradient disturbances downwind of high voltage power lines, most particularly during rain and high humidity, and overnight.

147

High voltage supply and low level discriminator for scintillation detector assemblies  

International Nuclear Information System (INIS)

The connection of a stabilized high voltage source and a low-level amplitude discriminator, suitable mainly for scintillation detector assemblies intended for the simple detection of nuclear radiation, is described. The connection is simple with low energy consumption, and the circuits can be fitted directly in the probe. The probe may be adjusted independently of the device with which it will be used. It is connected by a shielded single-core cable which transfers the shaped output pulses and simultaneously feeds the electronic circuits of the probe. The maximum total current drain for feeding the scintillation probe with the described circuits is 20 mA at a voltage of 5 V. (author)

148

High voltage-power frequency electrical heating in-situ conversion technology of oil shale  

Science.gov (United States)

With the depletion of conventional energy sources,oil shale has got much attention as a new type of energy resource,which is rich and widespread in the world.The conventional utilization of oil shale is mainly focused on resorting to produce shale oil and fuel gas with low extraction efficiency about one in a million due to many shortcomings and limitations.And the in-situ conversion of oil shale,more environmentally friendly,is still in the experimental stage.High voltage-power frequency electrical heating in-situ conversion of oil shale is a new type of in-situ pyrolysis technology.The main equipment includes a high voltage-power frequency generator and interior reactor. The high voltage-power frequency generator can provide a voltage between 220-8000 V which can be adjusted in real time according to the actual situation.Firstly,high voltage is used to breakdown the oil shale to form a dendritic crack between two electrodes providing a conductive channel inside the oil shale rock.And then the power frequency(220V) is used to generate the electric current for heating the internal surface of conductive channel,so that the energy can be transmitted to the surrounding oil shale.When the temperature reaches 350 degree,the oil shale begins to pyrolysis.In addition,the temperature in the conductive channel can be extremely high with high voltage,which makes the internal surface of conductive channel graphitization and improves its heat conduction performance.This technology can successfully make the oil shale pyrolysis, based on a lot of lab experiments,and also produce the combustible shale oil and fuel gas.Compared to other in-situ conversion technology,this method has the following advantages: high speed of heating oil shale,the equipment underground is simple,and easy to operate;it can proceed without the limitation of shale thickness, and can be used especially in the thin oil shale reservoir;the heating channel is parallel to the oil shale layers,which has more effective area for heating and heat transmitting;it has very good adaptability to the formation,the location and depth of the electrodes which can be adjusted according to the specific stratigraphic depth case;A positive(negative) electrode can be connected to multiple negative(positive) electrodes,and the arrangement of the positive and negative electrodes can be evaluated for improving the extraction efficiency.High voltage-power frequency electrical heating in-situ conversion technology is a very promising in-situ pyrolysis method,which could provide a new way of mining oil shale resources.

Sun, Youhong; Yang, Yang; Lopatin, Vladimir; Guo, Wei; Liu, Baochang; Yu, Ping; Gao, Ke; Ma, Yinlong

2014-05-01

149

Modeling of Eddy Current losses of the high voltage winding of power transformers for transient studies  

International Nuclear Information System (INIS)

One of the most suitable models for studying the electromagnetic transient behavior of the high voltage winding of the power transformers is the detailed model. This model consists of inductive and capacitive effects as well as the Eddy Current and dielectric losses in the form of lumped parameters. The losses have significant effects on the damping of transient over voltages. In this paper, the Eddy Current losses are expressed by a matrix which its elements satisfy the proximity effects and skin effects precisely. The matrix is calculated at low frequency by the finite element method and then generalized to the high frequencies. Simulations are presented for illustration and validation

150

High voltage power lines in Italy: Quantitation of exposure and health risk evaluation  

International Nuclear Information System (INIS)

In Italy, as in most developed countries, a lively debate has been raised in the last years on possible long-term health effects of exposure to power frequency magnetic fields. Though the exposure is quite ubiquitous, due to the large presence of electric sources in any domestic, work, and urban environment, most of the concern regards fields generated by overhead high-voltage lines. Several epidemiological studies have in fact indicated an increase of cancer, in particular childhood leukaemia, within the population residing near power lines. The quantitative evaluation of the health risk associated with power lines is obviously of crucial importance, in particular for decision makers, in view of the future development of the electric network. Reliable data on the dimension of the health impact of power lines may in fact help in finding some consensus between the Authorities and the general public, and hopefully to overcome the present controversies

151

High voltage fast switches for nuclear applications  

International Nuclear Information System (INIS)

SILVA process consists in a selective ionization of the 235 uranium isotope, using laser beams generated by dye lasers pumped by copper vapour laser (C.V.L.). SILVA involves power electronic for 3 power supplies: - copper vapour laser power supply, - extraction power supply to generate the electric field in the vapour, and - electron beam power supply for vapour generation. This article reviews the main switches that are proposed on the market or are on development and that could be used in SILVA power supplies. The SILVA technical requirements are: high power, high voltage and very short pulses (200 ns width). (A.C.)

152

High voltage fast switches for nuclear applications  

Energy Technology Data Exchange (ETDEWEB)

SILVA process consists in a selective ionization of the 235 uranium isotope, using laser beams generated by dye lasers pumped by copper vapour laser (C.V.L.). SILVA involves power electronic for 3 power supplies: - copper vapour laser power supply, - extraction power supply to generate the electric field in the vapour, and - electron beam power supply for vapour generation. This article reviews the main switches that are proposed on the market or are on development and that could be used in SILVA power supplies. The SILVA technical requirements are: high power, high voltage and very short pulses (200 ns width). (A.C.)

Chatroux, D.; Lausenaz, Y.; Villard, J.F. [CEA Centre de Pierrelatte, Dept. des Technologies de l' Enrichissement (DTE), 26 (France); Lafore, D. [CEGEMA-ESIM, 13 - Marseille (France)

1999-07-01

153

High voltage engineering  

CERN Document Server

Inspired by a new revival of worldwide interest in extra-high-voltage (EHV) and ultra-high-voltage (UHV) transmission, High Voltage Engineering merges the latest research with the extensive experience of the best in the field to deliver a comprehensive treatment of electrical insulation systems for the next generation of utility engineers and electric power professionals. The book offers extensive coverage of the physical basis of high-voltage engineering, from insulation stress and strength to lightning attachment and protection and beyond. Presenting information critical to the design, selec

Rizk, Farouk AM

2014-01-01

154

Material science and device physics in SiC technology for high-voltage power devices  

Science.gov (United States)

Power semiconductor devices are key components in power conversion systems. Silicon carbide (SiC) has received increasing attention as a wide-bandgap semiconductor suitable for high-voltage and low-loss power devices. Through recent progress in the crystal growth and process technology of SiC, the production of medium-voltage (600–1700 V) SiC Schottky barrier diodes (SBDs) and power metal–oxide–semiconductor field-effect transistors (MOSFETs) has started. However, basic understanding of the material properties, defect electronics, and the reliability of SiC devices is still poor. In this review paper, the features and present status of SiC power devices are briefly described. Then, several important aspects of the material science and device physics of SiC, such as impurity doping, extended and point defects, and the impact of such defects on device performance and reliability, are reviewed. Fundamental issues regarding SiC SBDs and power MOSFETs are also discussed.

Kimoto, Tsunenobu

2015-04-01

155

Low-power-loss and high voltage X-ray tube with graphite nanospines cold cathode  

International Nuclear Information System (INIS)

We report a low-power-loss and high voltage X-ray tubes with a graphite nanospines (GNS) cold cathode. The cathode is encapsulated in a glass tube having a Beryllium window with a Tantalum film to generate X-rays. The internal tube pressure was below 10-7 Pa and a tube current exceeding 1 mA at a tube voltage of 22.9 kV was observed in the fabricated X-ray tube. The tube current dispersion, defined as standard deviation/mean (?/mean), was relatively small at 2.4%. An X-ray radiation dose rate exceeding 5 Sv/h was obtained from the X-ray tube and the radiation dose rate dispersion was also small (?/mean=0.3%). As an application of the X-ray tube, we demonstrated radiography for the rapid inspection of organic products.

156

Interconnected High-Voltage Pulsed-Power Converters System Design for H? Ion Sources  

CERN Document Server

This paper presents the design and experimental validations of a system of three new high-voltage (HV) pulsedpower converters for the H? sources. The system requires three pulsed voltages (50, 40, and 25 kV to ground) at 2-Hz repetition rate, for 700 ?s of usable flat-top. The solution presents ripplefree output voltages and minimal stored energy to protect the ion source from the consequences of arc events. Experimental results on the final full-scale prototype are presented. In case of short-circuit events, the maximal energy delivered to the source is in the Joule range. HV flat-top stability of 1% is experimentally achieved with a simple Proportional-Integral- Derivative regulation and preliminary tuned H? source (e.g., radio frequency control, gas injection, and so forth). The system is running since more than a year with no power converter failures and damage to the source.

Aguglia, D

2014-01-01

157

Low Voltage Power Supply Incorporating Ceramic Transformer  

CERN Document Server

A low voltage power supply provides the regulated output voltage of 1 V from the supply voltage around 48 V. The low voltage power supply incorporates a ceramic transformer which utilizes piezoelectric effect to convert voltage. The ceramic transformer isolates the secondary from the primary, thus providing the ground isolation between the supply and the output voltages. The ceramic transformer takes the place of the conventional magnetic transformer. The ceramic transformer is constructed from a ceramic bar and does not include any magnetic material. So the low voltage power supply can operate under a magnetic field. The output voltage is stabilized by feedback. A feedback loop consists of an error amplifier, a voltage controlled oscillator and a driver circuit. The amplitude ratio of the transformer has dependence on the frequency, which is utilized to stabilize the output voltage. The low voltage power supply is investigated on the analogy of the high voltage power supply similarly incorporating the cerami...

Imori, M

2007-01-01

158

Radon Progeny Activities in the Vicinity of High Voltage Power Lines  

International Nuclear Information System (INIS)

The principal objective of the work reported here was to investigate the influence of electric fields from high voltage power lines on the behaviour of short-lived, alpha particle emitting radon progeny in outdoor air. Active and passive measurements of short-lived radon progeny were made at one metre above ground level, at various distances from a 400 kV power line, both when the line was energised and during a period when it was switched off for engineering modifications. Within the limitations of the measurement techniques used no effect at ground level on short-lived radon progeny behaviour due to the power line could be detected. Elevated levels of the long-lived radon decay product 210Po were measured on 36 year old glass insulators taken from a 110 kV power line indicating that electric fields from power lines may remove radon progeny from the air. Radon progeny detection techniques employed were based on the use of solid state nuclear track detectors. (author)

159

A vacuum tolerant high voltage system with a low noise and low power Cockcroft–Walton photomultiplier base  

International Nuclear Information System (INIS)

We developed a high voltage system for the electromagnetic calorimeter of the KOTO detector. The system is designed around a low noise, low power Cockcroft–Walton (CW) photomultiplier tube base with a high gain preamplifier. The low power makes it suitable for operations in vacuum. The low noise and high gain allow detecting signals in the 1 MeV range. We achieved a final noise level below 180?Vrms for a preamplifier gain of more than 40. A vacuum tolerant control system for the CW bases power distribution was also designed. This system is able to control and monitor the high voltage of each individual base

160

A vacuum tolerant high voltage system with a low noise and low power Cockcroft–Walton photomultiplier base  

Energy Technology Data Exchange (ETDEWEB)

We developed a high voltage system for the electromagnetic calorimeter of the KOTO detector. The system is designed around a low noise, low power Cockcroft–Walton (CW) photomultiplier tube base with a high gain preamplifier. The low power makes it suitable for operations in vacuum. The low noise and high gain allow detecting signals in the 1 MeV range. We achieved a final noise level below 180?V{sub rms} for a preamplifier gain of more than 40. A vacuum tolerant control system for the CW bases power distribution was also designed. This system is able to control and monitor the high voltage of each individual base.

Masuda, T., E-mail: taka@scphys.kyoto-u.ac.jp [Department of Physics, Kyoto University, Kyoto 606-8502 (Japan); Iwai, E. [Department of Physics, Osaka University, Osaka 560-0043 (Japan); Kawasaki, N. [Department of Physics, Kyoto University, Kyoto 606-8502 (Japan); Kim, E.J. [Division of Science Education, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Komatsubara, T.K. [High Energy Accelerator Research Organization (KEK), Ibaraki 305-0801 (Japan); Lee, J.W. [Department of Physics, Osaka University, Osaka 560-0043 (Japan); Lim, G.Y. [High Energy Accelerator Research Organization (KEK), Ibaraki 305-0801 (Japan); Maeda, Y.; Naito, D.; Nanjo, H. [Department of Physics, Kyoto University, Kyoto 606-8502 (Japan); Nomura, T. [High Energy Accelerator Research Organization (KEK), Ibaraki 305-0801 (Japan); Ri, Y.D. [Department of Physics, Osaka University, Osaka 560-0043 (Japan); Sasao, N. [Research Core for Extreme Quantum World, Okayama University, Tsushima-naka 3-1-1 Kita-ku, Okayama 700-8530 (Japan); Sato, K. [Department of Physics, Osaka University, Osaka 560-0043 (Japan); Seki, S. [Department of Physics, Kyoto University, Kyoto 606-8502 (Japan); Shiomi, K.; Sugiyama, Y.; Togawa, M. [Department of Physics, Osaka University, Osaka 560-0043 (Japan); Watanabe, H. [High Energy Accelerator Research Organization (KEK), Ibaraki 305-0801 (Japan); Yamanaka, T. [Department of Physics, Osaka University, Osaka 560-0043 (Japan)

2014-05-11

161

A vacuum tolerant high voltage system with a low noise and low power Cockcroft-Walton photomultiplier base  

Science.gov (United States)

We developed a high voltage system for the electromagnetic calorimeter of the KOTO detector. The system is designed around a low noise, low power Cockcroft-Walton (CW) photomultiplier tube base with a high gain preamplifier. The low power makes it suitable for operations in vacuum. The low noise and high gain allow detecting signals in the 1 MeV range. We achieved a final noise level below 180 ?Vrms for a preamplifier gain of more than 40. A vacuum tolerant control system for the CW bases power distribution was also designed. This system is able to control and monitor the high voltage of each individual base.

Masuda, T.; Iwai, E.; Kawasaki, N.; Kim, E. J.; Komatsubara, T. K.; Lee, J. W.; Lim, G. Y.; Maeda, Y.; Naito, D.; Nanjo, H.; Nomura, T.; Ri, Y. D.; Sasao, N.; Sato, K.; Seki, S.; Shiomi, K.; Sugiyama, Y.; Togawa, M.; Watanabe, H.; Yamanaka, T.

2014-05-01

162

Field testing, modelling and analysis of ferroresonance in a high-voltage power system  

Science.gov (United States)

Catastrophic equipment failures continue to occur today due to ferroresonance even though this phenomenon has been extensively studied over the past ninety years. This thesis is concerned with the tasks of defining where ferroresonance problems can exist in a high voltage power system, of determining methods for displaying safety margins between nonferroresonant and ferroresonant operating regions and improving upon existing ferroresonance simulation techniques. Several different ferroresonant circuits have been modelled and compared with field measurements taken on the Manitoba Hydro 230-kV power system or compared with laboratory measurements including: a de-energized transformer connected to the grading capacitance of an open circuit breaker, a transformer-terminated doublecircuit transmission line and a coupling capacitor voltage transformer. In a high voltage power system, the most prevalent ferroresonance circuit occurs between a de-energized transformer and the grading capacitor of an open circuit breaker. Experimental work has shown that losses in a practical transformer are much larger during ferroresonance oscillation modes than predicted by conventional modelling techniques. A simple switched eddy-current loss resistor is found able to model the losses during subharmonic and fundamental frequency ferroresonance in a laboratory transformer. A major contribution of this work is a new method of visualizing the margin between nonferroresonant and ferroresonant states in a transformer/grading capacitor circuit has been developed. A general set of averaged equations is derived that permit the analysis of an nth order polynomial approximation of the magnetization curve. The location of the saddle points and slope of the stable manifold through the saddle points can be determined for a particular transformer under study. The Limacon of Pascal is found to be a good approximation to the geometric shape of the basin of attraction of the period-1 ferroresonant attractor and can be calculated using the saddle point location and slope of the stable manifold. The critical parameters resulting in a crossing of the separatrix can then be found by iteratively solving the Limacon equations. The new method will assist utility engineers in quickly assessing the potential risk of ferroresonance in their power system.

Jacobson, David Allan Nils

2000-11-01

163

Design and development of power supplies at VECC for accelerators  

International Nuclear Information System (INIS)

Several power supplies have been designed and developed in-house incorporating various topologies to match the load requirements. Most of the power supplies have been being utilised in K-130 and K-500 cyclotrons operation successfully from last several years. Amongst other types, Switching Mode PS (SMPS), Phase Controlled Rectifier (PCR), Linear mode power supply are mostly in use, irrespective of their own merits and demerits. Switching mode power supply (SMPS) is most common topology for various applications ranging from high current to high voltage applications. Due to low stored energy and faster response, the SMPS incorporating Pulse Switch Modulation (PSM) configuration is most suitable for high voltage DC power supply at larger power compared to its counterparts, makes possible to operate the power system without crowbar. For an IOT cathode power supply, a 200kW at - 40kV High voltage power supply is under development incorporating SMPS and PSM technique. Earlier, High Voltage power supply was made by using Tetrode Tube in linear mode for RF amplifier for K-130 Cyclotron. Later, in K-500 Cyclotron, a High Voltage power supply was developed incorporating PCR topology rated at 20kV, 20 Amp for Anodes for 3 nos. of RF amplifiers. These HV power supply is equipped with ultra-fast acting Crowbar Protection System developed in VECC which is for the protection of costly RF Tubes against the internal arc. Design and development of SMPS based Bipolar Power Supply with 4-Quadrant operation rated at ± 27 V, ± 300 Amp with current stability around 100 ppm for Super-conducting Magnets along with quench protection and energy dumping scheme. (author)

164

Problems on unification of high-voltage electron accelerators  

International Nuclear Information System (INIS)

Problems of unification of high-voltage electron accelerators ''Electron-4'', ''Aurora'', and ''Aurora-2'' are considered. A description as well as principal specifications of unified accelerator systems are given: a high voltage source, radiator, cooling system, vacuum system, power supply system and accelerator control system. A level of electron accelerator standardization is shown. Methods of accelerator system elaboration are defined

165

Modern Risk Assessment for Nuclear Power Plants High-Voltage Substations  

International Nuclear Information System (INIS)

The paper describes a first Romanian attempt to set up the methodology for risk assessment and control within high-voltage substations, developed for the Nuclear power plant in Cernavoda (Romania). Considering the present risk assessment methods the MENER Project will develop a new methodology, in line with the European Community legislation and with the specific regional needs. In order to correctly shape the necessary resources required by a risk analysis a large size enterprise (a nuclear power plant) is selected and the following five indicators will be estimated: the economic profit, environmental risk, indirect (future) risk, technology improvement and physic and psychological risk. The results are expected to considerably facilitate risk assessment, by: evaluating project acceptability; evaluating equipment compliance to regulatory criteria; estimating excluding clearances; easing the design of emergency programmes; identifying the equipment use restrictions; identifying the risk sources; selecting the maintenance and risk reduction methods; testing the procedures leading to future regulatory norms; suitability of the risk management system modification. The immediate result of employing modern risk assessment methods could be the decrease by one third of the expenses required by environment protection, staff health and labor safety and quality management. (author)

166

High voltage bulk GaN-based photoconductive switches for pulsed power applications  

Science.gov (United States)

Switches are at the heart of all pulsed power and directed energy systems, which find utility in a number of applications. At present, those applications requiring the highest power levels tend to employ spark-gap switches, but these suffer from relatively high delay-times (~10-8 sec), significant jitter (variation in delay time), and large size. That said, optically-triggered GaN-based photoconductive semiconductor switches (PCSS) offer a suitably small form factor and are a cost-effective, versatile solution in which delay times and jitter can be extremely short. Furthermore, the optical control of the switch means that they are electrically isolated from the environment and from any other system circuitry, making them immune from electrical noise, eliminating the potential for inadvertent switch triggering. Our recent work shows great promise to extend high-voltage GaN-based extrinsic PCSS state-of-the-art performance in terms of subnanosecond response times, low on-resistance, high current carrying capacity and high blocking voltages. We discuss our recent results in this work.

Leach, J. H.; Metzger, R.; Preble, E. A.; Evans, K. R.

2013-03-01

167

High Power Amplifier and Power Supply  

Science.gov (United States)

A document discusses the creation of a high-voltage power supply (HVPS) that is able to contain voltages up to -20 kV, keep electrical field strengths to below 200 V/mil (approximately equal to 7.87 kV/mm), and can provide a 200-nanosecond rise/fall time focus modulator swinging between cathode potential of 16.3 kV and -19.3 kV. This HVPS can protect the 95-GHz, pulsed extended interaction klystron (EIK) from arcs/discharges from all sources, including those from within the EIK fs vacuum envelope. This innovation has a multi-winding pulse transformer design, which uses new winding techniques to provide the same delays and rise/fall times (less than 10 nanoseconds) at different potential levels ranging from -20 kV to -16 kV. Another feature involves a high-voltage printed-wiring board that was corona-free at -20 kV DC with a 3- kV AC swing. The corona-free multilayer high-voltage board is used to simulate fields of less than 200 V/mil (approximately equal to 7.87 kV/mm) at 20 kV DC. Drive techniques for the modulator FETs (field-effect transistors) (four to 10 in a series) were created to change states (3,000-V swing) without abrupt steps, while still maintaining required delays and transition times. The packing scheme includes a potting mold to house a ten-stage modulator in the space that, in the past, only housed a four-stage modulator. Problems keeping heat down were solved using aluminum oxide substrate in the high-voltage section to limit temperature rise to less than 10 while withstanding -20 kV DC voltage and remaining corona-free.

Duong, Johnny; Stride, Scot; Harvey, Wayne; Haque, Inam; Packard, Newton; Ng, Quintin; Ispirian, Julie Y.; Waian, Christopher; Janes, Drew

2008-01-01

168

High voltage systems (tube-type microwave)/low voltage system (solid-state microwave) power distribution  

Science.gov (United States)

SPS satellite power distribution systems are described. The reference Satellite Power System (SPS) concept utilizes high-voltage klystrons to convert the onboard satellite power from dc to RF for transmission to the ground receiving station. The solar array generates this required high voltage and the power is delivered to the klystrons through a power distribution subsystem. An array switching of solar cell submodules is used to maintain bus voltage regulation. Individual klystron dc voltage conversion is performed by centralized converters. The on-board data processing system performs the necessary switching of submodules to maintain voltage regulation. Electrical power output from the solar panels is fed via switch gears into feeder buses and then into main distribution buses to the antenna. Power also is distributed to batteries so that critical functions can be provided through solar eclipses.

Nussberger, A. A.; Woodcock, G. R.

1980-01-01

169

High Voltage Electrostatic Pendulum  

OpenAIRE

A pendulum powered by high voltage electricity is described. The pendulum consists of two conducting plates(thin foil) separated by copper rods and are insulated from each other. High voltage is applied to these plates through the connecting copper rods. Another stationary aluminum plate(thin foil) is placed in front of the pendulum such that it serves to attract the pendulum plates and makes electrical contact with them enabling charge transfer between the stationary plate ...

Baddi, Raju

2012-01-01

170

Novel high-voltage power lateral MOSFET with adaptive buried electrodes  

International Nuclear Information System (INIS)

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. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

171

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

Science.gov (United States)

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

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

2014-10-01

172

Trim coil power supplies  

International Nuclear Information System (INIS)

The 18 trim coil power supplies have been constructed and are now in place in the K500 pit and pit mezzanine. Final wiring of the primary power and control power is proceeding along with installation of cooling water supplies. The supplies are expected to be ready for final testing into resistive loads at the beginning of June, 1985

173

Peak voltage clamped power supply  

International Nuclear Information System (INIS)

The cost and energy efficiency of a power supply are optimized in a semi-regulated circuit wherein regulation occurs only under a high voltage, low current condition when peak output voltage would otherwise exceed a maximum specified voltage. The circuit includes a full wave rectifier driving a modified pi filter. A transistor in series with the filter is biased by a resistor to normally operate in a fully saturated, low power dissipating mode. When the output voltage approaches the specified maximum, the breakdown voltage of a zener diode is exceeded, and the output voltage is clamped to the specified maximum through the zener diode and the base-emitter junction of the transistor

174

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

Science.gov (United States)

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

175

Power supply for superconductor  

International Nuclear Information System (INIS)

A new power supply for superconductor is proposed. The conventional power supply consists of a transformer and thyristors. The present power supply does not consist of the large current transformer but only the switching devices to achieve the DC current amplification. The principle of new power supply is AC-DC-AC-DC conversion. The AC line is once rectified to small current of DC and next converted to large current of DC through switching device handling AC. On a test set, 800 A of superconducting current has been obtained with 50 A input DC current. The conceptual design of power supply for 20 kA has been done. The characteristic features of the new power supply have been compared with the conventional one. (author)

176

Stabilized power supply for the BKh-3 X-ray tube  

International Nuclear Information System (INIS)

A power supply is described which provides for stabilizing the high voltage and anodic current of the BKh-3 x-ray tube. Its basic parameters are: high voltage = 10 to 25 kV; output power = 2.5 W; integrated instability = 10-3; weight = 1 kg

177

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

Science.gov (United States)

Two general types of remote power controllers (RPC's), which combine the functions of a circuit breaker and a switch, were developed for use in dc aerospace systems. Power-switching devices used in the designs are the gate-turnoff thyristor (GTO) and MOSFET. The RPC's can switch dc voltages to 1200 V and currents to 1000 A. Seven different units were constructed and subjected to 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 which limit surge currents and voltage spiking from high di/dt. The GTO's have much faster transition times. All RPC's have programmable overload tripout proportional to I sq T and microsecond tripout for large overloads.

Sturman, J. C.

1985-05-01

178

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

Science.gov (United States)

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

179

Power supply arrangement for computerised tomographic apparatus  

International Nuclear Information System (INIS)

In a rotating tomographic scanner it is possible to transfer the X-ray tube supply via slip rings. It is difficult to transfer high voltage for the tube by slip rings, yet if the mains supply is transferred the transformers required to give 70KV are excessively heavy for the gantry. It is proposed to transfer the power at 300V, high frequency and then to convert to 70KV on the gantry. The equipment then mounted on the gantry is evenly distributed there-around so that no further counterweight is required. A closed circuit oil cooling system is also provided on the gantry. (author)

180

Proximity Effects of High Voltage Transmission Lines on Humans  

OpenAIRE

Recently new threats to humans are observed from electromagnetic radiation from various sources like mobile phones, transmission lines and many more. For providing continuous and uninterrupted supply of electric power to consumer's maintenance operation of high voltage power lines are often performed with systems energized or live. This is referred as Hot Line maintenance or live line maintenance in this paper authors are concentrating on effects due to high voltage transmission lines on pers...

Kulkarni, Girish; Gandhare, Dr W. Z.

2012-01-01

181

30 CFR 75.802 - Protection of high-voltage circuits extending underground.  

Science.gov (United States)

...Underground High-Voltage Distribution § 75.802 Protection...resistor at the source transformers, and a grounding circuit...extend along with the power conductors and serve...high-voltage equipment supplied power from that circuit...shields around each power conductor, and...

2010-07-01

182

30 CFR 77.802 - Protection of high-voltage circuits; neutral grounding resistors; disconnecting devices.  

Science.gov (United States)

...Surface High-Voltage Distribution § 77.802 Protection...resistor at the source transformers, and a grounding circuit...extend along with the power conductors and serve...high-voltage equipment supplied power from that circuit...observation that the power is...

2010-07-01

183

AC power supply systems  

International Nuclear Information System (INIS)

An ac power supply system includes a rectifier fed by a normal ac supply, and an inverter connected to the rectifier by a dc link, the inverter being effective to invert the dc output of the receiver at a required frequency to provide an ac output. A dc backup power supply of lower voltage than the normal dc output of the rectifier is connected across the dc link such that the ac output of the rectifier is derived from the backup supply if the voltage of the output of the inverter falls below that of the backup supply. The dc backup power may be derived from a backup ac supply. Use in pumping coolant in nuclear reactor is envisaged. (author)

184

New, rugged, high power Cockcroft-Walton power supply  

International Nuclear Information System (INIS)

A ten foot (3 m), ten-stage air-insulated Crockcroft-Walton power supply designed and built at LBL has been tested to 900 kV at the SuperHILAC. Operating at 80 kHz, the power supply features low ripple, moderate stored energy, 10 ma average current, and no bouncer requirement for pulsed loads. Other system features include: inexpensive generating voltmeters and a capacitive pick off for monitoring and regulation in lieu of costly resistance dividers, home-made semiconductor rectifier modules, excellent component protection against sparking, and easy maintenance. This report describes design, construction, and testing of the high voltage system

185

KEKB electromagnet power supply  

International Nuclear Information System (INIS)

Numbers of electromagnet power supply for KEKB are 2,243 except BT. To satisfy stability, DAC in the current control circuit, current detector, R and D of small thermostatic bath and a calibration method of current using CPU were introduced. They satisfied needs. With producing R and D apparatus of switching source, problems of ripple, stability and noise were solved, so that we began mass production. In this paper, many kinds of R and D and performance and troubles after operation of KEKB power source are described. A plan of design of power supply consisted of seven items such as high accuracy, serial communication of interface, small type, high affectivity, easy maintenance, independence of current setting and current detector for monitor and control of radiation and conduction noise of switching power supply. These items were satisfied by development of interface board of ARCNET communication, introduction of double buffer method for interface through CPU, power supply unit by air-cooled method using a switching method and small thermostatic oven for bending and quadrupole electromagnet. R and D of DCCT, burden and shunt resistance, DAC, thermostatic bath, power supply, offset and gain calibration by double buffer method, specification of power supply, various kinds of measurements of mass production apparatus at rising, after long operation and problems before and after operation are reported. The results of R and D made satisfy the specification of stability andsatisfy the specification of stability and ripple of power supply. Although many switching power supply were operated, there was no noise and troubles at the initial period decreased. However, in order to use many power supply, the performance measurement and maintenance are very important at long shut down. (S.Y.)

186

The impact of an increasing amount of wind power on the high voltage grid of Costa Rica  

Energy Technology Data Exchange (ETDEWEB)

The objective of the Costa Rica grid feed-in study is to determine the effect of an increasing amount of wind power on the stability of the high voltage grid of Costa Rica. Due to a favourable wind climate, the amount of wind power in Costa Rica is increasing steadily. There is some concern about the effect of fluctuating wind power on the frequency and voltage variations of the grid. Especially the loss of a large amount of wind power in a very short time, 30 second to a few minutes, is expected to result in a frequency control problem. This study intends to quantify this problem. The method used is twofold: dynamic simulations of the High Voltage grid of Costa Rica, including existing and future wind farms, are used to study the effect of wind power variations on the frequency stability; the probability of wind speeds exceeding 25 m/s at different locations at the same time is determined, in order to estimate the chance of cut-out of a complete wind farm in a short period of time.

Pierik, J.T.G.; Van Engelen, T.G.; Winkelaar, D. [ECN Wind Energy, Petten (Netherlands); Montero, J.C.; Sancho, R. [Instituto Constaricense de Electricidad ICE-LSSP, San Jose (Costa Rica)

2003-06-01

187

Design and power management of an offshore medium voltage DC microgrid realized through high voltage power electronics technologies and control  

Science.gov (United States)

The growth in the electric power industry's portfolio of Direct Current (DC) based generation and loads have captured the attention of many leading research institutions. Opportunities for using DC based systems have been explored in electric ship design and have been a proven, reliable solution for transmitting bulk power onshore and offshore. To integrate many of the renewable resources into our existing AC grid, a number of power conversions through power electronics are required to condition the equipment for direct connection. Within the power conversion stages, there is always a requirement to convert to or from DC. The AC microgrid is a conceptual solution proposed for integrating various types of renewable generation resources. The fundamental microgrid requirements include the capability of operating in islanding mode and/or grid connected modes. The technical challenges associated with microgrids include (1) operation modes and transitions that comply with IEEE1547 without extensive custom engineering and (2) control architecture and communication. The Medium Voltage DC (MVDC) architecture, explored by the University of Pittsburgh, can be visualized as a special type of DC microgrid. This dissertation is multi-faceted, focused on many design aspects of an offshore DC microgrid. The focal points of the discussion are focused on optimized high power, high frequency magnetic material performance in electric machines, transformers, and DC/DC power converters---all components found within offshore, power system architectures. A new controller design based upon model reference control is proposed and shown to stabilize the electric motor drives (modeled as constant power loads), which serve as the largest power consuming entities in the microgrid. The design and simulation of a state-of-the-art multilevel converter for High Voltage DC (HVDC) is discussed and a component sensitivity analysis on fault current peaks is explored. A power management routine is proposed and evaluated as the DC microgrid is disturbed through various mode transitions. Finally, two communication protocols are described for the microgrid---one to minimize communication overhead inside the microgrid and another to provide robust and scalable intra-grid communication. The work presented is supported by Asea Brown Boveri (ABB) Corporate Research Center within the Active Grid Infrastructure program, the Advanced Research Project Agency - Energy (ARPA-E) through the Solar ADEPT program, and Mitsubishi Electric Corporation (MELCO).

Grainger, Brandon Michael

188

Novel high-voltage power device based on self-adaptive interface charge  

International Nuclear Information System (INIS)

This paper presents a novel high-voltage lateral double diffused metal-oxide semiconductor (LDMOS) with self-adaptive interface charge (SAC) layer and its physical model of the vertical interface electric field. The SAC can be self-adaptive to collect high concentration dynamic inversion holes, which effectively enhance the electric field of dielectric buried layer (EI) and increase breakdown voltage (BV). The BV and EI of SAC LDMOS increase to 612 V and 600 V/?m from 204 V and 90.7 V/?m of the conventional silicon-on-insulator, respectively. Moreover, enhancement factors of ? which present the enhanced ability of interface charge on EI are defined and analysed. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

189

MOS power transistor and ceramic thyratron for fast high voltage pulser  

International Nuclear Information System (INIS)

A high reliability circuit has been developed in order to trigger a ceramic thyratron. The necessity of building a system highly protected from voltage and current glitches is due to the particular loads with are to be driven by the thyratron. In the circuit design, VMOS (both with 'p' or 'n' channel) and HEXFET transistors have been used. A delay time of about 60 ns between the NIM input signal and the thyratron grid voltage peak has been obtained. The delay between the NIM input signal and the thyratron trigger is about 80 ns. This apparatus has been developed in order to drive a high voltage pulse generator, used with a self-shunted streamer chamber. (orig.)

190

An optically coupled power stimulus isolation unit with high voltage and fast rise time output  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Recent technological developments have created new devices that could improve and simplify the construction of stimulus isolators. HEXFET transistors can switch large currents and hundreds of volts in nanoseconds. The newer opto-isolators can give a pulse rise time of a few nanoseconds, with output [...] compatible with MOSFET devices, in which delays are reduced to nanoseconds. Integrated DC/DC converters are now available. Using these new resources we developed a new electrical stimulus isolator circuit with selectable constant-current and constant-voltage modes, which are precise and easy to construct. The circuit works like a regulated power supply in both modes with output switched to zero or to free mode through an opto-isolator device. The isolator analyses showed good practical performance. The output to ground resistance was 1011 ohms and capacitance 35 picofarads. The rise time and fall time were identical (5 µs) and constant. The selectable voltage or current output mode made it very convenient to use. The current mode, with higher output resistance values in low current ranges, permits intracellular stimulation even with tip resistances close to 100 megaohms. The high compliance of 200 V guarantees the value of the current stimulus. The very low output resistance in the voltage mode made the device highly suitable for extracellular stimulation with low impedance electrodes. Most importantly, these characteristics were achieved with a circuit that was easy to build and modify and assembled with components available in Brazil.

R.O., Brasil; J.H., Leal-Cardoso.

1999-06-01

191

Optimized control strategy for crowbarless solid state modular power supply  

International Nuclear Information System (INIS)

Solid state modular power supply with series connected IGBT based power modules have been employed as high voltage bias power supply of klystron amplifier. Auxiliary compensation of full wave inverter bridge with ZVS/ZCS operations of all IGBTs over entire operating range is incorporated. An optimized control strategy has been adopted for this power supply needing no output filter, making this scheme crowbarless and is presented in this paper. DSP based fully digital control with same duty cycle for all power modules, have been incorporated for regulating this power supply along with adequate protection features. Input to this power supply is taken directly from 11 kV line and the input system is intentionally made 24 pulsed to reduce the input harmonics, improve the input power factor significantly, there by requiring no line filters. Various steps have been taken to increase the efficiency of major subsystems, so as to improve the overall efficiency of this power supply significantly. (author)

192

High Voltage Electrostatic Pendulum  

CERN Document Server

A pendulum powered by high voltage electricity is described. The pendulum consists of two conducting plates(thin foil) separated by copper rods and are insulated from each other. High voltage is applied to these plates through the connecting copper rods. Another stationary aluminum plate(thin foil) is placed in front of the pendulum such that it serves to attract the pendulum plates and makes electrical contact with them enabling charge transfer between the stationary plate and the pendulum plates. The pendulum is powered by the energy stored in the capacitance between the stationary aluminum plate and the pendulum plate. Attempt has been made to obtain the time period of oscillations as a function of applied voltage and other parameters. The derived formula for the time period has been verified experimentally. This apparatus can be used to demonstrate electrical phenomena in general and in particular electrical energy stored in conductors of small dimensions.

Baddi, Raju

2012-01-01

193

A High-Voltage Test Bed for the Evaluation of High-Voltage Dividers for Pulsed Applications  

CERN Document Server

The design, evaluation, and commissioning of a high-voltage reference test bed for pulsed applications to be used in the precision testing of high-voltage dividers is described. The test bed is composed of a pulsed power supply, a reference divider based on compressed-gas capacitor technology, and an acquisition system that makes use of the fast measurement capabilities of the HP3458 digital voltmeter. The results of the evaluation of the reference system are presented.

Bastos, M C; Hammarquist, M

2011-01-01

194

A High-voltage Reference Testbed for the Evaluation of High-voltage Dividers for Pulsed Applications  

CERN Document Server

The design, evaluation and commissioning of a high voltage reference testbed for pulsed applications to be used in the precision testing of high voltage dividers is described. The testbed is composed of a pulsed power supply, a reference divider based on compressed gas capacitor technology and an acquisition system which makes use of the fast measurement capabilities of the HP 3458 DVM. Results of the evaluation of the reference system are presented.

Bastos, M Cerqueira; Bergman, A

2010-01-01

195

Protection relay of phase-shifting device with thyristor switch for high voltage power transmission lines  

Science.gov (United States)

Problems of functioning of differential current protection systems of phase shifting devices (PSD) with mechanically changed coefficient of transformation of shunt transformer are analyzed. Requirements for devices of protection of PSD with thyristor switch are formulated. Based on use of nonlinear models of series-wound and shunt transformers of PSD modes of operation of major protection during PSD, switching to zero load operation and to operation under load and during short circuit operation were studied for testing PSD with failures. Use of the principle of duplicating by devices of differential current protection (with realization of functions of breaking) of failures of separate pares of PSD with thyristor switch was substantiated. To ensure protection sensitivity to the shunt transformer winding short circuit, in particular, to a short circuit that is not implemented in the current differential protection for PSD with mechanical switch, the differential current protection reacting to the amount of primary ampere-turns of high-voltage and low-voltage winding of this transformer was designed. Studies have shown that the use of differential current cutoff instead of overcurrent protection for the shunt transformer wndings allows one to provide the sensitivity during thyristor failure with the formation of a short circuit. The results of simulation mode for the PSD with switch thyristor designed to be installed as switching point of Voskhod-Tatarskaya-Barabinsk 220 kV transmission line point out the efficiency of the developed solutions that ensure reliable functioning of the PSD.

Lachugin, V. F.; Panfilov, D. I.; Akhmetov, I. M.; Astashev, M. G.; Shevelev, A. V.

2014-12-01

196

Experimental investigation of high temperature high voltage thermionic diode for the space power nuclear reactor  

International Nuclear Information System (INIS)

It is well known that the rise of arc from the dense glow discharge is connected with the thermion and secondary processes on the cathode surface (Granovsky, 1971; Leob, 1953; Engel, 1935). First model of breakdown of the cathode layer is connected with the increase of the cathode temperature in consequence of the ion bombardment that leads to the grows its thermo-emissive current. Other model shows the main role of the secondary effects on the cathode surface-the increase of the secondary ion emission coefficient--?i with the grows of glow discharge voltage. But the author of this investigation work of breakdown in Cs vapor (a transmission the glow discharge into self-maintaining arc discharge) discovered the next peculiarity: the value of breakdown voltage is constant when the values of vapor temperature (its pressure pcs) and cathode temperature Tk is constant too (Ub=constant with Tk=constant and pcs=constant) and it is not a statistical value (Onufryev, Grishin, 1996) (that was observed in gas glow discharges other authors (Granovsky, 1971; Leob, 1953; Engel, 1935)). The investigations of thermion high voltage high temperature diode (its breakdown characteristics in closed state and voltage-current characteristics in disclosed state) showed that the value of the breakdown voltage is depended on the vapor pressure in inter-electrode gap (IEG)-pcs and cathode temperature-Tk andand cathode temperature-Tk and is independent on IEG length--?ieg. On this base it was settled that the main role in transition of glow discharge to self-maintaining arc discharge plays an ion cathode layer but more exactly--the region of excited atoms--''Aston glow.''

197

High Voltage Generation for Physics Lab  

CERN Document Server

A power efficient way to generate low power high voltage is given. The article describes various aspects of functioning and derives quantitative relations between different parameters and high voltage generated. Use of voltage multiplier (Cockcroft-Walton multiplier) network can provide further boost in the high voltage(~1000V).

Baddi, Raju

2012-01-01

198

Gradient power supply  

International Nuclear Information System (INIS)

A power supply particularly suited for driving coils in a magnetic nuclear resonance device, or scanner, is described. Bipolar switches driven by field-effect devices are used to couple the coil to a high potential when a rapid current change is required, control devices also comprises bipolar transistors driven by field-effect transistors are used to to control the current through the coil in steady state conditions. The power supply provides a trapezoidal current waveform in the coils. The control devices and switches are operated via opto-coupling means. Various protection and sequencing operations are described. The Linear Control Loop provides active compensation against the demanded current waveform. (author)

199

On-chip High-Voltage Generator Design  

CERN Document Server

This book describes high-voltage generator design with switched-capacitor multiplier techniques.  The author provides various design techniques for switched-capacitor on-chip high-voltage generators, including charge pump circuits, regulators, level shifters, references, and oscillators.  Readers will see these techniques applied to system design in order to address the challenge of how the on-chip high-voltage generator is designed for Flash memories, LCD drivers, and other semiconductor devices to optimize the entire circuit area and power efficiency with a low voltage supply, while minimizing the cost.   ·         Shows readers how to design charge pump circuits with lower voltage operation, higher power efficiency, and smaller circuit area; ·         Describes comprehensive circuits and systems design of on-chip high-voltage generators; ·         Covers all the component circuit blocks, including charge pumps, pump regulators, level shifters, oscillators, and references.

Tanzawa, Toru

2013-01-01

200

Influence of the topology on the power flux of the Italian high-voltage electrical network  

CERN Document Server

A model of the Italian 380 kV electrical transmission network has been analyzed under the topological and the functional viewpoints. The DC power flow model used to evaluate the power flux has been solved on the basis of input conditions (injected power - extracted power, line's reactances and the maximum flux capacity of each line) taken from real data. The vulnerability of the network under load conditions has been estimated by evaluating the power flux redistribution along the lines subsequent to line's removal. When the perturbed network cannot sustain a given input--output demand, the maximum power sustainable by the network has been evaluated to optimize the \\texttt{Quality of Service}, defined as the difference between the expected and the effective dispatched power. The functional relevance of the different lines of the network has been classified according to the amount of power that the network must reduce, to keep alive, upon their removal. Results show that topological and functional relevances ar...

Rosato, V; Gianese, G; Bologna, S

2009-01-01

201

Lightweight Regulated Power Supply  

Science.gov (United States)

Power-supply circuit regulates output voltage by adjusting frequency of chopper circuit according to variations. Currently installed in battery charger for electric wheelchair, circuit is well suited to other uses in which light weight is important - for example, in portable computers, radios, and test instruments.

Mclyman, C. W.

1985-01-01

202

APS power supply controls  

International Nuclear Information System (INIS)

The purpose of this document is to provide comprehensive coverage of the APS power supply control design. This includes application software, embedded controller software, networks, and hardware. The basic components will be introduced first, followed by the requirements driving the overall design. Subsequent sections will address each component of the design one by one. Latter sections will address specific applications

203

Design of a system of high voltage pulsed power converters for CERN’s Linac4 H$^{?}$ ion source  

CERN Document Server

This paper presents the complete design and experimental validations of the full scale prototype of a system of three new high voltage pulsed power converters for the CERN Linac4 H$^{?}$ source. The system requires three pulsed voltages (50kV, 40kV and 25kV to ground) at 2Hz repetition rate, for a 700µs of usable flat-top. The solution presents switching frequency ripplefree voltages and a minimal stored energy to protect the ions source from arc events consequences. The main design aspects are presented. Experimental results on the final full-scale prototype are presented and show excellent behaviour in nominal and short circuit operations.

Aguglia, D

2014-01-01

204

Allowance for insulation aging in the new concept of accelerated life tests of high-voltage power transformers  

International Nuclear Information System (INIS)

This paper reports that the existing system of type and acceptance tests of high-voltage transformer insulation does not take into account insulation ageing, which is particularly objectionable with respect to equip-met with reduced insulation levels. Suggested in the paper is a new concept of accelerated life tests based on integrated simulation of basic operating loads, both periodic (surge) and long-term ones; by making a long-term accelerated test simulating the working conditions, with exposure of test object and/or its insulation to periodic operating surges (overvoltages and overcurrents). This test replaces a group of conventional individual acceptance tests and provides more ample and more precise information on performance and dependability of the equipment. The test procedure was checked in test of a small lot of 1600 kVA 35 kV power transformers

205

Additional heating power supplies: Design concept and first operation  

International Nuclear Information System (INIS)

Two additional heating methods are used in JET, e.g. the Neutral Injection (NI heating) and the Ion Cyclotron Resonance Heating (RF Heating). In the RF heating, 10 generators each deliver 3MW to their antenna; for the NI heating 16 ion sources each delivering 4.8MW ion beam are installed. In order to minimize the internal dissipation in the generator and hence to obtain the maximum output power of the RF generators under the varying load conditions given by the plasma, the high voltage on the anode of the tetrode is varied. This is one of the main features of the power supply. The requirements for the NI power supply are different to the ones for the RF power supply. The accelerating grid (G1) power supply has to be very stable and must be able to switch off in 10 microsec in case of a breakdown in the accelerating structure and re-apply within 50 ms. Both these functions, voltage regulation and switching on and off are performed by a high power tetrode (protection system). In addition to the accelerating grid power supply, other power supplies (Aux PS) are necessary. They are the arc power supply, the filament power supply, the suppression grid (G3) power supply, the gradient grid (G2) power supply and the bending magnet power supply

206

Engineering Design of the ITER AC/DC Power Supplies  

International Nuclear Information System (INIS)

To design high power pulse power supplies, especially in huge power supplies have not designed till now, it is necessary to analyze a system's characteristics and relations with another systems as well as to know high voltage, high current control technologies. Contents of this project are; - Study for the engineering designs changed recently by ITER Organization(IO) and writing specifications for the power supplies to reduce project risk. - Detailed analysis of the AC/DC Converters and writing subtask reports on the Task Agreement. - Study for thyristor numbers, DCR's specifications for Korea-China sharing meetings. - Study for the grounding systems of the ITER power supply system. The results may used as one of reference for practical designs of the high power coil power supplies and also may used in various field such as electroplating, plasma arc furnaces, electric furnaces

207

High voltage power lines with autonomous sensor nodes; Hochspannungsleitungen mit verteilten Sensornetzen. Erfolgreicher Feldtest. Dauertest geplant  

Energy Technology Data Exchange (ETDEWEB)

An autonomous sensor network for power line monitoring was developed. The sensor nodes detect the temperature and the inclination of the conductors. The measured data is transmitted by radio in the 2.4 GHz ISM frequency band from sensor node to each other and to a base station linking monitoring system and the control system. The energy required for the operation of the sensor nodes is harvested from the electric fringing field of the power lines.

Kurth, Steffen [Fraunhofer ENAS, Chemnitz (Germany); During, Hanjo; Lissek, Sebastian [Envia Verteilnetz GmbH, Halle/Saale (Germany); Grosser, Volker [Fraunhofer-Institut fuer Zuverlaessigkeit und Mikrointegration (IZM), Berlin (Germany)

2011-10-17

208

30 CFR 77.800 - High-voltage circuits; circuit breakers.  

Science.gov (United States)

...equipment shall be protected by suitable circuit breakers of adequate interrupting capacity...devices to provide protection against under voltage, grounded phase, short circuit and overcurrent. High-voltage circuits supplying power to...

2010-07-01

209

High voltage direct current (HVDC) link between the power networks of Italy and Greece  

International Nuclear Information System (INIS)

Interconnection between the power networks of Italy and Greece has long been declared of European interest. The link, which will directly connect Greece with the power network of UCPTE, is perfectly in line with the targets of the European Union in terms of trans-European power networks. The interconnection, which benefits of a financial contribution of the EU, will rely on a 400 kV d.c. transmission system with one submarine cable between the Italian and Greek coasts, overhead lines on land, d.c./a.c. conversion stations, return of current to sea via marine electrodes. The main technical features of the project are described, highlighting its most significant design concepts. (author)

210

Development of method for detecting signs deterioration in insulator of high-voltage motors. 2. Test Results of a new on-line partial discharge monitor for high-voltage motors in nuclear power stations  

International Nuclear Information System (INIS)

For the purpose of early detection of deterioration of insulators in high-voltage motors which are widely utilized in nuclear power stations, a new on-line partial discharge (PD) monitor was developed and was tested for sixteen motors which were practically running in nuclear power stations. From the test results, it is seen that (1) good signal to noise ratio is obtained by adopting a two frequency correlation method, (2) a resistance temperature detector (RTD) in a motor has sufficient sensitivity to detect PD, (3) when RTD is not installed or is unable to use for this purpose, a radio frequency current transformer (RFCT) can be utilized, although its sensitivity is about 1/10 of that of the RTD monitor. Finally we found a good correlation between the results of this on-line method and the conventional off-line method in which the insulator resistance of a concerned motor was measured during its shut-down, and thereby we demonstrated that this method could be applicable to the on-line test of high-voltage motors in nuclear power stations. (author)

211

Powerful electrostatic FEL: Regime of operation, recovery of the spent electron beam and high voltage generator  

Energy Technology Data Exchange (ETDEWEB)

FEL, driven by a Cockcroft-Walton electrostatic accelerator with the recovery of the spent electron beam, is proposed as powerful radiation source for plasma heating. The low gain and high gain regimes are compared in view of the recovery problem and the high gain regime is shown to be much more favourable. A new design of the onion Cockcroft-Walton is presented.

Boscolo, I. [Univ. and INFN, Milan (Italy); Gong, J. [Southwest Jiaotong Univ., Chengdu (China)

1995-02-01

212

Development of a high-voltage, high-power thermal battery  

Energy Technology Data Exchange (ETDEWEB)

The power requirements for an inverter application were specified to be 500 V at 360 A, or 180 kW per each of six 1-s pulses delivered over a period of 10 minutes. Conventional high-power sources (e.g., flywheels) could not meet these requirements and the use of a thermal battery was considered. The final design involved four, 125-cell, 50-kW modules connected in series. A module using the LiSi/CoS{sub 2} couple and all-Li (LiCI-LiBr-LiF minimum-melting) electrolyte was successfully developed and tested. A power level of over 40 kW was delivered during a 0.5-s pulse. This translates into a specific power level of over 9 kW/kg or 19.2 kW/L delivered from a module. The module was still able to deliver over 30 kW during a 1-s pulse after 10 minutes.

Guidotti, R.A.; Scharrer, G.L.; Binasiewicz, E.; Reinhardt, F.W.

1998-04-01

213

Light weight, high power, high voltage dc/dc converter technologies  

Science.gov (United States)

Power-conditioning weight reductions by orders of magnitude will be required to enable the megawatt-power-level space systems envisioned by the Strategic Defense Initiative, the Air Force, and NASA. An interagency program has been initiated to develop an 0.1-kg/kW dc/dc converter technology base for these future space applications. Three contractors are in the first phase of a competitive program to develop a megawatt dc/dc converter. Researchers at NASA Lewis Research Center are investigating innovative converter topology control. Three different converter subsystems based on square wave, resonant, and super-resonant topologies are being designed. The components required for the converter designs cover a wide array of technologies. Two different switches, one semiconductor and the other gas, are under development. Issues related to thermal management and material reliability for inductors, transformers, and capacitors are being investigated in order to maximize power density. A brief description of each of the concepts proposed to meet the goals of this program is presented.

Kraus, Robert; Myers, Ira; Baumann, Eric

1990-01-01

214

Minimization of Power Loss in Distribution Systems by Implementation of High Voltage Distribution System  

Directory of Open Access Journals (Sweden)

Full Text Available The loads in rustic area are preeminent pump sets used for various applications i.e. lift irrigation system. Minimal power factor and minimal load factor is found in loads. Further, being a factordissemination of loads, load density is found low. The present distribution system dwell of three-phase 11KV/433Volts distribution transformer with extended L.T Lines. In this system, voltage profile and reliability are poor. In this paper, HVDS is unveiled with smallcapacity distribution transformers. A simple load flow technique is used for solving distribution networks before and after implementation of HVDS. The advantages of implementing HVDS against LVDS system are discussed.

PARWAL Arvind

2013-05-01

215

Switched mode power supplies  

International Nuclear Information System (INIS)

The power supply comprises an oscillator arranged to drive the primary winding of a transformer. A nuclear impulse detector is arranged to discontinue drive to the primary winding in response to detection of a nuclear impulse. The detector comprises a monostable circuit which has its state changed for a predetermined time by photocurrents induced in response to gamma radiation. In this changed state the detector disables the oscillator. (author)

216

Rechargeable power supply:  

OpenAIRE

The invention relates to a rechargeable power supply suitable to be used in a battery-operated device comprising at least one supercapacitor and at least a first and a second DC-DC converter connected in series, wherein the supercapacitor is connectable to an entry of the first DC-DC converter and the device is connectable to an exit of the second DC-DC converter.

Den Uijl, S.; Bouman, C.; Smit, W.

2006-01-01

217

The current situation of diagnosis for insulation deterioration of high voltage induction motors in nuclear power plants  

International Nuclear Information System (INIS)

In order to evaluate aging effect on motor correctly, several data of high voltage induction motors in 17 nuclear power plants of Tokyo Electric Power Co. (TEPCO) have been collected since 1984. Collected data are non-destructive insulation diagnosis test data including insulation resistance, static capacitance and the results of insulation destructive test after replacement of motors. Evaluation based on the data shows that breakdown voltage (BDV) of motor coil has relationship with the motor parameters such as current increase ratio, maximum discharge magnitude, difference of dielectric dissipation factor, etc. From this viewpoint, BDV estimation formula for 6.6 kV motors is established by using multiple linear regression analysis method, considering parameter used in D-map evaluation. However the measured parameters may vary due to the factors besides insulation deterioration, not only the estimated BDV but also visual inspection data are took into account for overall diagnosis. Further collection of data and evaluation will be done continuously in order to enhance accuracy of the insulation diagnosis. The current situation of diagnosis for insulation deterioration of 6.6 kV class induction motors in nuclear power plants is described in this technical note. Also current situation of investigation on 3.3 kV class motors is described. (author)

218

High-voltage installations of the nuclear power station and their connections to Hungary's basic network  

International Nuclear Information System (INIS)

The 1760 MW power station will be realized in two stages, with 880 MW each. These will include two reactor sets each, together with four 220 MW electric generators. Every two of the 270 MVA main transformers, linked by isolators, are connected along 400 kV ''machine lines'' to the 400 kV switchgear of the 400/120 kV transformer station providing a link to the grid. The 400 kV switchgear of the transformer station is of a hybrid type, being made up partly of enclosed SF6-isolated, partly of traditional equipment. During the 1760 MW construction stage the transformer station will be completed with two 250 MVA, 400/132/18 kV transformers. (author)

219

Pneumatic Power Supply  

Science.gov (United States)

This brief interactive activity, by Electromechanical Digital Library and Wisconsin Technical College System faculty member Terry Bartelt, begins with a discussion of the three basic components of a pneumatic power system, the prime mover, compressor, and receiver tank. Visitors can learn about each one, its purpose in the system, and how it works through illustrations and animations. The next section discusses and demonstrates power supply operation, with all three parts working to complete the system. This is an excellent resource for electromechanical and pneumatics classes.

Bartelt, Terry L. M.

220

High voltage solar array experiments  

Science.gov (United States)

The interaction between the components of a high voltage solar array and a simulated space plasma is studied to obtain data for the design of a high voltage solar array capable of 15kW at 2 to 16kV. Testing was conducted in a vacuum chamber 1.5-m long by 1.5-m diameter having a plasma source which simulated the plasma conditions existing in earth orbit between 400 nautical miles and synchronous altitude. Test samples included solar array segments pinholes in insulation covering high voltage electrodes, and plain dielectric samples. Quantitative data are presented in the areas of plasma power losses, plasma and high voltage induced damage, and dielectric properties. Limitations of the investigation are described.

Kennerud, K. L.

1974-01-01

221

Study of static reactive power compensators for high-voltage power systems. Final report, May 12, 1981  

Energy Technology Data Exchange (ETDEWEB)

A general study of the application of static VAR compensators (SVC's) to high-voltage transmission systems has been performed. Considerable emphasis has been placed on improvements to synchronous stability, and it is shown that SVC's can provide significant benefits in terms of damping for unstable modes of oscillation and increases in transient stability limits. This report includes descriptions of static VAR compensators, technical and economic comparisons of different compensators, compensator models for system studies, comprehensive study procedures, study results for two small-scale systems, and guidelines for SVC application.

Byerly, R.T.; Bennon, R.J.; Taylor, E.R. Jr.; Poznaniak, D.T.

1981-05-12

222

The Upgraded CMS Preshower High Voltage System  

CERN Document Server

In March 2012 the high voltage system of the silicon-sensor-based CMS Preshower detector underwent a significant upgrade. In order to increase the granularity of the bias distribution lines, the number of power supplies was doubled and fully configurable distribution boards were developed and installed. These new boards provide much improved flexibility in the powering, necessary to cope with the expected evolution of the 4288 silicon sensors with radiation damage. They also provide measurement of the ~2200 bias-voltage lines that go to the detector, enabling fast identification/diagnosis of any anomalous currents and providing detailed knowledge of the sensor current evolution over time.

Vichoudis, Paschalis

2013-01-01

223

Radiatively heated high voltage pyroelectric crystal pulser  

Science.gov (United States)

Thin lithium tantalate pyroelectric crystals in a multi-stage pulser were heated by quartz lamps during their charging phase to generate high voltage pulses. The charging voltage was determined empirically based on the measured breakdown voltage in air and verified by the induced breakdown voltage of an external high voltage power supply. A four-stage pyroelectric crystal device generated pulse discharges of up to 86 kV using both quartz lamps (radiative) and thermoelectric (conductive) heating. Approximately 50 mJ of electrical energy was harvested from the crystals when radiatively heated in air, and up to 720 mJ was produced when the crystals were submerged in a dielectric fluid. It is anticipated that joule-level pulse discharges could be obtained by employing additional stages and optimizing the heating configuration.

Antolak, A. J.; Chen, A. X.; Leung, K.-N.; Morse, D. H.; Raber, T. N.

2014-01-01

224

Radiatively heated high voltage pyroelectric crystal pulser  

International Nuclear Information System (INIS)

Thin lithium tantalate pyroelectric crystals in a multi-stage pulser were heated by quartz lamps during their charging phase to generate high voltage pulses. The charging voltage was determined empirically based on the measured breakdown voltage in air and verified by the induced breakdown voltage of an external high voltage power supply. A four-stage pyroelectric crystal device generated pulse discharges of up to 86 kV using both quartz lamps (radiative) and thermoelectric (conductive) heating. Approximately 50 mJ of electrical energy was harvested from the crystals when radiatively heated in air, and up to 720 mJ was produced when the crystals were submerged in a dielectric fluid. It is anticipated that joule-level pulse discharges could be obtained by employing additional stages and optimizing the heating configuration

225

CMS HCAL Photodetector's Power Supply System  

CERN Document Server

In CMS HCAL subdetector proximity focused hybrid photo diodes (HPDs) are used, capable of operating in high magnetic field. For normal operation HPDs need two supply voltages - one high voltage (HV) about 10 kV and one bias voltage (BV) - about 100 V. The total number of HPDs in entire HCAL subdetector is around 500. The appropriate power supply system of about 500 HV and 500 BV channels is described in the article. The basic unit of the system is a 6U Eurocrate, containing 6 HPD power supply modules. There is in each module 4 HV and 4 BV channels. The whole system is controlled by a host computer, using standard RS485 interface between it and all crates, and custom protocol inside the crate. To provide the control and monitoring of the Power Supply System a program package has been developed. The package is built according to the Client/Server architecture. As interface the Distributed Information Manager (DIM) is used.

Dimitrov, Lubomir; Elias, John E; Ronzhin, Anatoly; Sergeev, Sergey

2005-01-01

226

The effect of high voltage power lines on radon concentrations in air using solid state nuclear track detector CR-39 in Baghdad city  

International Nuclear Information System (INIS)

This work involves the study of the effect of high Voltage power lines 400kV on radon concentration and its decay products using products using nuclear track detectors CR-39 in Baghdad city for one month inside and outside Bob Al-Sham station 400kV as well as in a number of the houses which are very close to the high voltage power during autumn. The concentrations of radon were determined through the comparison with the standard samples, and through the concluded results, we find that the value of weighted average of radon concentration inside the building which are under the effect of high voltage 400kV was (91.77 ± 0.12Bq/m3), As for the buildings which are far from the high voltage lines at distance 600m, it was equal to (23.27±0.773Bq/m3) and outside the buildings (13.63±0.99 Bq/m3). The results of the study show the increase of radon concentration in the ares which are close to high voltage power lines clear effect of high voltage power lines upon the concentration of radon, and this influence increases with increase of the force of electromagnetic field as well as the near distance with these lines. The increase of concentration was due to the fact that the walls of the buildings are considered to be the main source for generating radon inside the building as well as the building history and their height upon the level of earth surface. (Author)

227

Best use of high-voltage, high-powered electron beams: a new approach to contract irradiation services  

International Nuclear Information System (INIS)

Japan's first high-voltage, high-powered electron beam processing center is scheduled to come on-line during the first half of 1999. The center explores both challenges and opportunities of how best to use the 200 kW 10 MeV unit and its 5 MeV X-ray line. In particular, Nuclear Fuel Industries, Ltd. (NFI) has expanded the traditional model of a contract irradiation facility to include a much broader scope of services such as door-to-door transport, storage, and direct distribution to its customer's end-users. The new business scope not only finds new value-added components in a competitive marketplace, but serves to provide a viable mechanism to take advantage of the processing logistics of high throughput irradiation units. As such, the center features a high-capacity warehousing system, monitored by a newly developed PCMS (plant control management system), which has been comprehensively integrated into the irradiation unit's handling system, and will require only minimal human resources for its high rate of material handling. The identification and development of initial markets for this first unit will be discussed, concluding with how this same operational philosophy can help break open new irradiation segments in medical devices, consumer goods, animal feed, and food markets and NFI's other efforts in these same areas. (author)

228

Best use of high-voltage, high-powered electron beams: a new approach to contract irradiation services  

Science.gov (United States)

Japan's first high-voltage, high-powered electron beam processing center is scheduled to come on-line during the first half of 1999. The center explores both challenges and opportunities of how best to use the 200 kW 10 MeV unit and its 5 MeV X-ray line. In particular, Nuclear Fuel Industries, Ltd. (NFI) has expanded the traditional model of a contract irradiation facility to include a much broader scope of services such as door-to-door transport, storage, and direct distribution to its customer's end-users. The new business scope not only finds new value-added components in a competitive marketplace, but serves to provide a viable mechanism to take advantage of the processing logistics of high throughput irradiation units. As such, the center features a high-capacity warehousing system, monitored by a newly developed PCMS (plant control management system), which has been comprehensively integrated into the irradiation unit's handling system, and will require only minimal human resources for its high rate of material handling. The identification and development of initial markets for this first unit will be discussed, concluding with how this same operational philosophy can help break open new irradiation segments in medical devices, consumer goods, animal feed, and food markets and NFI's other efforts in these same areas.

Watanabe, T.

2000-03-01

229

Electromagnetic field model for the numerical computation of voltages induced on buried pipelines by high voltage overhead power lines  

Science.gov (United States)

This paper proposes an innovative, generally applicable numerical model for the calculation of the three-dimensional (3D) electromagnetic field generated by high voltage (HV) overhead power transmission lines (OHL) on the buried metallic structures (e.g., pipeline networks). The numerical analysis is based on a coupled finite element-boundary element model (FEM-BEM) designed to calculate the induced potential on buried pipelines for complex geometrical structures of HV OHL networks working on normal or fault conditions. The one-dimensional (1D) FEM technique based on pipe elements is used to discretize the mathematical model that describes the interior of the pipe and is coupled with the mathematical model that describes the exterior of the pipe using 3D-BEM integral equations. The full electromagnetic field model gives the flexibility to calculate the potential distribution in any point of the soil, providing useful information for the step and touching voltages. The computation accuracy of the numerical algorithm implemented is verified through two test problems by comparing the numerical results with those obtained using a software package based on the Transmission Line Method (TLM) and CIGRE formulae. Last part of the paper presents calculations of the induced potential on buried pipeline in the vicinity of a complex HV OHL working on normal and fault condition. The influence of the currents' direction and magnitude flowing on the HV OHL on the induced pipeline potential distribution is analyzed.

Munteanu, C.; Mates, G.; Purcar, M.; Topa, V.; Pop, I. T.; Grindei, L.; Racasan, A.

2012-07-01

230

High voltage InAlN/GaN HEMTs with nonalloyed Source/Drain for RF power applications  

Science.gov (United States)

In this work, we propose the nonalloyed Schottky Source/Drain (SSD) technology for high voltage InAlN/GaN HEMTs. The proposed device features excellent metal morphology both in lateral and vertical benefiting from the removal of metallic overflow associated with the conventional alloyed Ohmic contacts, which bodes well for device scaling and high breakdown voltage (BV) obtained in the proposed device. The nonalloyed Source/Drain (S/D) also paves the way for the SSD HEMTs using a gate-first fabrication process with the standard Ni/Au gate stack. Despite the Schottky Source/Drain, an SSD HEMT with LG = 1.25 ?m exhibits a decent maximum drain current of 575 mA/mm and peak transconductance of 216 mS/mm. The corresponding BV is 58 V which is the highest BV reported on GaN HEMTs for a short LGD of 250 nm. Without using any field-plate structure, the BV of 605 V is achieved in an SSD HEMT with LGD = 15 ?m, realizing 229% improvement compared with the conventional InAlN/GaN HEMTs. The proposed SSD technology featuring scaling capability and high breakdown voltage is suitable for RF power applications and can be further developed for self-aligned InAlN/GaN HEMTs.

Zhou, Qi; Yang, Shu; Chen, Wanjun; Zhang, Bo; Feng, Zhihong; Cai, Shujun; Chen, Kevin J.

2014-01-01

231

Power supplies for INDUS-1  

Energy Technology Data Exchange (ETDEWEB)

This paper describes the different schemes employed in the power supplies installed for microtron, transport line-1, Booster ring, Transport line-2 and 450 MeV Indus-1 Storage ring presently being commission at CAT, Indore. Approximately 130 Nos. of power supplies with ratings ranging from few VA to about 1.0 MVA are used to energise the electro-magnets for generation of magnetic field. The current stability requirement for the power supplies ranges from 1000 ppm to 100 ppm of current set. The schemes followed for power supplies are off line SMPS, linear series pass and SCR controlled power supplies. In booster the power supplies are of ramp type with repetition rate of 1 Hz and these are designed to take care of coupled voltages due to ramping field. All other power supplies are constant DC type. (author)

Tiwari, S.R.; Thakurta, A.C.; Thipsay, A.P.; Pagare, A.; Gandhi, M.L.; Singh, T.N.; Singh Shyam; Kotaiah, S. [Centre for Advanced Technology, Indore (India)

1998-11-01

232

Resonance power supplies for large accelerator  

International Nuclear Information System (INIS)

The resonance power supply has been proposed as an efficient power supply for a future 6 GB, keon producing accelerator. This report presents a detailed analysis of the circuit operation. Based on these analyses each component is designed, one line diagram is developed, component requirements are determined and a detailed cost estimate is prepared. The major components of the system are: the magnet power supply, high voltage by-pass thyristor switch, with l0kA repetitive interruption capability, capacitor banks, capacitor bank thyristor switch, and an energy make up device. The most important components are the bypass thyristor switch and the energy injection device. The bypass thyristor switch is designed to turn on and interrupt to 10 kA dc current with a recovery voltage of 20kV and repetition frequency of 3 Hz. The switch consists of a large array of series and parallel connected thyristors and gate turn off (GTO) devices. The make up energy device is designed to replace the circuit energy losses. A capacitor bank is charged with constant current and discharged during the acceleration period. One of the advantages of the developed circuit is that it can be supplied directly from the local power network. In order to prove the validity of the assumptions, a scaled down model circuit was thoroughly tested. These tests proved that the engineering design of critical components is correct and this resonant power supply can be properly controlled by an inventer/rectifier connected in series with the magnet and by the make up energy device. This finding reduces the system cost

233

Bipolar Pulsed-DC Power Supply for Magnetron Sputtering and Thin Films Synthesis  

OpenAIRE

A pulsed-dc power supply has been designed and constructed for use in a magnetron sputtering system and forthin film synthesis. The power supply consists of three major parts: (1) two high voltage direct current (dc) power suppliesutilizing a phase control circuit for power delivery, (2) pulse generator and two power switching circuits, and (3) feedbackcircuits for current and voltage controls, displays, and safety measures. For a high level of safety operation, opticalconnections were employ...

Vittaya Amornkitbamrung; Tosawat Seetawan; Ian Thomas; Weerasak Somkhunthot; Thanusit Burinprakhon

2007-01-01

234

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

Science.gov (United States)

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

235

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

International Nuclear Information System (INIS)

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

236

Energy discharge heater power supply  

International Nuclear Information System (INIS)

The heater power supply is intended to supply capacitively stored,energy to embedded heater strips in cryo magnets. The amount of energy can be controlled by setting different charge different capacitor values. Two chassis' can be operated in series or interlocks are provided. The charge voltage, number of capacitors pulse can be monitored. There and dual channel has two discharge supplies in one chassis. This report reviews the characteristics of this power supply further

237

High-voltage DC-feeder solution for electric railways  

OpenAIRE

For AC railway power supply systems with a different frequency than the public grid, high-voltage AC transmission lines are common, connected to the catenary by transformers. This study suggests an alternative design based on an high-voltage DC (HVDC)-feeder, which is connected to the catenary by converters. Such an HVDC line would also be appropriate for DC-fed railways and AC-fed railways working at a public-grid frequency. The converter stations between the public grid and the HVDCfeeder c...

Abrahamsson, Lars; Kjellqvist, Tommy; O?stlund, Stefan

2012-01-01

238

Nuclear reactor power supply  

International Nuclear Information System (INIS)

The neutron absorbing medium in a reactor is changed in dependence upon the loading of the reactor, or any other operating mode where the power distribution axially is to be maintained within acceptable limits, by varying the chemical shim in the coolant of the reactor. The error for effecting the change is derived by comparing the average temperature of the coolant and a reference temperature which is a programmed function of the power delivered by the turbine energized by the reactor. The reference temperature is derived by converting the turbine impulse chamber pressure into a temperature parameter. A compensated temperature error is derived from an electrical compensating network typically a pid controller. At the input of this network an electrical analog of the temperature error is impressed and its output, a compensated temperature error, is derived. The correcting command is derived from the output of a non-linear gain network. At the input of this gain network the compensated temperature error is impressed. The output is supplied to a facility for changing the neutron-absorbing medium which is connected to the reactor. The compensating network and the gain network may be part of an analog logic system or part of a digital computer system

239

Electron cyclotron heating power supplies on DIII-D  

Energy Technology Data Exchange (ETDEWEB)

The electron cyclotron heating system on DIII-D has been supporting experiments with six gyrotrons. The gyrotrons are connected to three power supplies: two have single modulators, each energizing two gyrotrons, while the third has three modulators that can energize three gyrotrons asynchronously. However, only two gyrotrons can be run synchronously due to the limitation of the high voltage dc power supply providing the input voltage to the modulators. These two configurations mimic proposed architectures of power systems for multiple gyrotron systems and demonstrate their advantages or disadvantages, which will be discussed in more detail. A fourth power system is being built as part of an upgrade to eight gyrotrons. The two future gyrotrons will have depressed collectors. A 1.2 MW gyrotron will be delivered in mid-2011 and the design of a 1.5 MW gyrotron has been initiated. This fourth power supply will have two modulators to independently energize the cathode of each gyrotron. Commercially available high voltage amplifiers will provide the body voltage. It will also have a solid-state crowbar instead of an ignitron crowbar. This power supply is described in more detail, as well as the testing performed on the solid-state crowbar to prove its performance.

Tooker, J.F., E-mail: tooker@gat.com [General Atomics, San Diego, CA (United States); Anastasi, D.D.; Guzman, T.J.; Huynh, P.; McDaniel, W.L.; Pawley, C.J. [General Atomics, San Diego, CA (United States)

2011-10-15

240

Nuclear fusion power supply device  

International Nuclear Information System (INIS)

Object: To use a hybrid power supply device, which comprises a thyristor power supply and a diode power supply, to decrease cost of a nuclear fusion power supply device. Structure: The device comprises a thyristor power supply connected through a closing unit and a diode power supply connected in parallel through a breaker, input of each power supply being applied with an output voltage of a flywheel AC generator. When a current transformer is excited, a disconnecting switch is turned on to close the diode power supply and a current of the current transformer is increased by an automatic voltage regulator to a set value within a predetermined period of time. Next, the current is cut off by a breaker, and when the breaker is in on position, the disconnecting switch is opened to turn on the closing unit. Thus, when a plasma electric current reaches a predetermined value, the breaker is turned on, and the current of the current transformer is controlled by the thyristor power supply. (Kamimura, M.)

241

High-voltage engineering and testing  

CERN Document Server

This 3rd edition of High Voltage Engineering Testing describes strategic developments in the field and reflects on how they can best be managed. All the key components of high voltage and distribution systems are covered including electric power networks, UHV and HV. Distribution systems including HVDC and power electronic systems are also considered.

Ryan, Hugh M

2013-01-01

242

Power supply system for negative ion source at IPR  

International Nuclear Information System (INIS)

The first step in the Indian program on negative ion beams is the setting up of Negative ion Experimental Assembly - RF based, where 100 kW of RF power shall be coupled to a plasma source producing plasma of density ?5 x 1012 cm-3, from which ? 10 A of negative ion beam shall be produced and accelerated to 35 kV, through an electrostatic ion accelerator. The experimental system is modelled similar to the RF based negative ion source, BATMAN presently operating at IPP, Garching, Germany. The mechanical system for Negative Ion Source Assembly is close to the IPP source, remaining systems are designed and procured principally from indigenous sources, keeping the IPP configuration as a base line. High voltage (HV) and low voltage (LV) power supplies are two key constituents of the experimental setup. The HV power supplies for extraction and acceleration are rated for high voltage (?15 to 35kV), and high current (? 15 to 35A). Other attributes are, fast rate of voltage rise (< 5ms), good regulation (< ±1%), low ripple (< ±2%), isolation (?50kV), low energy content (< 10J) and fast cut-off (< 100?s). The low voltage (LV) supplies required for biasing and providing heating power to the Cesium oven and the plasma grids; have attributes of low ripple, high stability, fast and precise regulation, programmability and remote operation. These power supplies are also equipped with over-voltage, over-current and current limit (CC Mode) protections. limit (CC Mode) protections. Fault diagnostics, to distinguish abnormal rise in currents (breakdown faults) with over-currents is enabled using fast response breakdown and over-current protection scheme. To restrict the fault energy deposited on the ion source, specially designed snubbers are implemented in each (extraction and acceleration) high voltage path to swap the surge energy. Moreover, the monitoring status and control signals from these power supplies are required to be electrically (? 50kV) isolated from the system. The paper shall present the design basis, topology selection, manufacturing, testing, commissioning, integration and control strategy of these HVPS. A complete power interconnection scheme, which includes all protective devices and measuring devices, low and high voltage power supplies, monitoring and control signals etc. shall also be discussed. The paper also discusses the protocols involved in grounding and shielding, particularly in operating the system in RF environment.

243

Power supply system for negative ion source at IPR  

Science.gov (United States)

The first step in the Indian program on negative ion beams is the setting up of Negative ion Experimental Assembly - RF based, where 100 kW of RF power shall be coupled to a plasma source producing plasma of density ~5 × 1012 cm-3, from which ~ 10 A of negative ion beam shall be produced and accelerated to 35 kV, through an electrostatic ion accelerator. The experimental system is modelled similar to the RF based negative ion source, BATMAN presently operating at IPP, Garching, Germany. The mechanical system for Negative Ion Source Assembly is close to the IPP source, remaining systems are designed and procured principally from indigenous sources, keeping the IPP configuration as a base line. High voltage (HV) and low voltage (LV) power supplies are two key constituents of the experimental setup. The HV power supplies for extraction and acceleration are rated for high voltage (~15 to 35kV), and high current (~ 15 to 35A). Other attributes are, fast rate of voltage rise (< 5ms), good regulation (< ±1%), low ripple (< ±2%), isolation (~50kV), low energy content (< 10J) and fast cut-off (< 100?s). The low voltage (LV) supplies required for biasing and providing heating power to the Cesium oven and the plasma grids; have attributes of low ripple, high stability, fast and precise regulation, programmability and remote operation. These power supplies are also equipped with over-voltage, over-current and current limit (CC Mode) protections. Fault diagnostics, to distinguish abnormal rise in currents (breakdown faults) with over-currents is enabled using fast response breakdown and over-current protection scheme. To restrict the fault energy deposited on the ion source, specially designed snubbers are implemented in each (extraction and acceleration) high voltage path to swap the surge energy. Moreover, the monitoring status and control signals from these power supplies are required to be electrically (~ 50kV) isolated from the system. The paper shall present the design basis, topology selection, manufacturing, testing, commissioning, integration and control strategy of these HVPS. A complete power interconnection scheme, which includes all protective devices and measuring devices, low & high voltage power supplies, monitoring and control signals etc. shall also be discussed. The paper also discusses the protocols involved in grounding and shielding, particularly in operating the system in RF environment.

Gahlaut, Agrajit; Sonara, Jashwant; Parmar, K. G.; Soni, Jignesh; Bandyopadhyay, M.; Singh, Mahendrajit; Bansal, Gourab; Pandya, Kaushal; Chakraborty, Arun

2010-02-01

244

Power supply system for negative ion source at IPR  

Energy Technology Data Exchange (ETDEWEB)

The first step in the Indian program on negative ion beams is the setting up of Negative ion Experimental Assembly - RF based, where 100 kW of RF power shall be coupled to a plasma source producing plasma of density {approx}5 x 10{sup 12} cm{sup -3}, from which {approx} 10 A of negative ion beam shall be produced and accelerated to 35 kV, through an electrostatic ion accelerator. The experimental system is modelled similar to the RF based negative ion source, BATMAN presently operating at IPP, Garching, Germany. The mechanical system for Negative Ion Source Assembly is close to the IPP source, remaining systems are designed and procured principally from indigenous sources, keeping the IPP configuration as a base line. High voltage (HV) and low voltage (LV) power supplies are two key constituents of the experimental setup. The HV power supplies for extraction and acceleration are rated for high voltage ({approx}15 to 35kV), and high current ({approx} 15 to 35A). Other attributes are, fast rate of voltage rise (< 5ms), good regulation (< {+-}1%), low ripple (< {+-}2%), isolation ({approx}50kV), low energy content (< 10J) and fast cut-off (< 100{mu}s). The low voltage (LV) supplies required for biasing and providing heating power to the Cesium oven and the plasma grids; have attributes of low ripple, high stability, fast and precise regulation, programmability and remote operation. These power supplies are also equipped with over-voltage, over-current and current limit (CC Mode) protections. Fault diagnostics, to distinguish abnormal rise in currents (breakdown faults) with over-currents is enabled using fast response breakdown and over-current protection scheme. To restrict the fault energy deposited on the ion source, specially designed snubbers are implemented in each (extraction and acceleration) high voltage path to swap the surge energy. Moreover, the monitoring status and control signals from these power supplies are required to be electrically ({approx} 50kV) isolated from the system. The paper shall present the design basis, topology selection, manufacturing, testing, commissioning, integration and control strategy of these HVPS. A complete power interconnection scheme, which includes all protective devices and measuring devices, low and high voltage power supplies, monitoring and control signals etc. shall also be discussed. The paper also discusses the protocols involved in grounding and shielding, particularly in operating the system in RF environment.

Gahlaut, Agrajit; Sonara, Jashwant; Parmar, K G; Soni, Jignesh; Bandyopadhyay, M; Singh, Mahendrajit; Bansal, Gourab; Pandya, Kaushal; Chakraborty, Arun, E-mail: agrajit@ipr.res.i [Institute for Plasma Research, Gandhinagar, Gujarat - 382428 (India)

2010-02-01

245

Practical switching power supply design  

CERN Document Server

Take the ""black magic"" out of switching power supplies with Practical Switching Power Supply Design! This is a comprehensive ""hands-on"" guide to the theory behind, and design of, PWM and resonant switching supplies. You'll find information on switching supply operation and selecting an appropriate topology for your application. There's extensive coverage of buck, boost, flyback, push-pull, half bridge, and full bridge regulator circuits. Special attention is given to semiconductors used in switching supplies. RFI/EMI reduction, grounding, testing, and safety standards are also deta

Brown, Martin C

1990-01-01

246

Tetrode bias power supply for Indus-1, synchrotron radiation source  

International Nuclear Information System (INIS)

An AC regulator based 7 kV, 3 A high voltage DC power supply is designed, fabricated and tested on dummy load for BEL make Tetrode type 15000CX, used in the high power RF amplifier at 31.613 MHz employed with INDUS-1, Synchrotron Radiation Source (SRS). Various protections features like over voltage, under voltage, over current, phase failure and phase reversal are incorporated in this power supply and presented in this paper. As Tetrode amplifier requires various other power supplies in addition to this bias power supply and they are operated in a particular sequence for its healthy operation, suitable interlock arrangements have been incorporated and also presented in this paper. The reliable operation of protection and interlock features incorporated in this power supply has been checked with dummy load under simulated conditions. Three numbers of series limiting inductors, one in each phase, have been incorporated in this power supply to limit fault currents under unfavourable conditions and there by increasing the overall life of this power supply. It will replace existing 7 kV, 3 A HVDC power supply, which is in operation for more than fifteen years with Indus-1 SRS and is likely to be helpful in reducing the down time of Indus-1 SRS. It has better performance features than the existing power supply. The long term voltage stability better than 0.3 % and output ripple less than 0.3 % have been achieved for this Tetrode bias power supply. This power supply is likely to be integrated with INDUS-1 SRS soon. (author)

247

A PC-PCL-based control system for the high-voltage pulsed-power operation of the Intense Diagnostic Neutral Beam (IDNB) Experiment  

International Nuclear Information System (INIS)

A stand-alone, semiautomated control system for the high-voltage pulsed-power energy sources on the Intense Diagnostic Neutral Beam Experiment at Los Alamos National Laboratory using personal computer (PC) and programmable logic controller (PLC) technology has been developed and implemented. The control system, consisting of a PC with the graphic operator interface, the network connecting the PC to the PLC, the PLC, the PLC I/O modules, fiber-optic interfaces and software, is described

248

Instrumentation architecture for ITER diagnostic neutral beam power supply system  

International Nuclear Information System (INIS)

A Neutral Beam (NB) Injection system is used for heating or diagnostics of the plasma in a Tokamak. The Diagnostics Neutral Beam (DNB) system for ITER (International Thermonuclear Experimental Reactor) based on acceleration of negative ions; injects a neutral (H0) beam at 100 KeV with specified modulation into the plasma for charge exchange recombination spectroscopy. DNB Power Supply (DNBPS) system consists of various high voltage power supplies, high current power supplies and RF Generators. The system operates in a given operating sequence; very high electromagnetic transients are intrinsically generated during frequent short circuit at the accelerator grid (breakdowns) and sudden loss of load (Beam off). Instrumentation is to be provided to operate the DNBPS system remotely with required control and protection in synchronisation with ITER operation as directed by CODAC (COntrol Data Access and Communication); the central control system for ITER. Instrumentation functionality includes 1. Operation and control of DNBPS subsystems and associated auxiliaries 2. Protection of DNB components and power supplies using interlock system, 3. To ensure safe operation of high voltage hazardous systems 4. Acquisition of injector performance parameters and 5. To facilitate test and maintenance of individual subsystem. This paper discusses about proposed DNBPS instrumentation architecture. The design generally follows the protocols from the ITER- Plant Control Design Handbook (PCDH). (author)

249

Electrical Structure of Future Off-shore Wind Power Plant with a High Voltage Direct Current Power Transmission  

DEFF Research Database (Denmark)

The increasing demand of electric power and the growing consciousness towards the changing climate has led to a rapid development of renewable energy in the recent years. Among all, wind energy has been the fastest growing energy source in the last decade. But the growing size of wind power plants, better wind conditions at off-shore and the general demand to put them out of sight have all contributed to the installation of large wind power plants in off-shore condition. However, moving wind power plants far out in the off-shore comes with many associated problems. One of the main challenges is the transmission of power over long distance. Historically, the power transmission from off-shore wind power plants has been done via HVAC submarine cables. This provides a simple solution, but AC cables cannot be arbitrarily long. It is shown in the report that major issues with HVAC cable transmission system are related to surplus reactive power and added losses. On the other hand, HVDC transmission system can be arbitrarily long and for long distance power transmission requirement it provides much better efficiency compared to a corresponding HVAC system. HVDC may provide a viable solution for high power transmission over long distances, but some issues related to fulfilling different grid code requirements still need further clarification. A transmission system should foremost provide a stable power transmission and participate in network stabilizing by providing efficient support for AC voltage control and frequency response requirements. These objectives are discussed and verification with simulation results is included in the report. A concept of negative sequence voltage compensation during small voltage unbalances and asymmetrical faults at the grid are also discussed. Secondly, a large WPP is not allowed to trip off during temporary grid side faults, commonly described as low voltage fault-ride-through requirement. There are four different fault-ride-through options discussed in the report. The first option includes controlling of collector network frequency. This provides a very good opportunity to use simple fixed speed wind turbines in the wind power plant. Induction generators attached to a large rotating mass show good response to frequency rise by allowing the rotor to speed up while reducing the active power output. However, it is observed that the post fault recovery process is very difficult to control and as such a high current capacity of the WPP side VSC might be required. Detailed simulation results are included in the report. The other option is to use a DC chopper, the results of which are also presented in detail in the report. It is observed that a DC chopper can provide a simple solution but the efforts required to remove the total heat during power dissipation is enormous. Alternatively, a telecommunication signal may be used, but the reliability and speed of such a system is in doubt. Finally, a controlled AC voltage drop at the collector network is derived and discussed in detail. It is illustrated in the report that such an option is advantageous in the sense that a fault at the grid side and at the wind power plant side can be dealt in the same way. More importantly, a similar wind turbine type can be used regardless of HVAC or HVDC connection strategy. A good co-ordination between the full-scale wind turbine and wind power plant side voltage sourced converter is also verified in the laboratory model based on real time digital simulation of wind turbine connected to an external voltage source converter via a power amplifier . The overall results show that the power transmission from long distance off-shore wind power plant is viable via HVDC system and at the same time the strict gird code requirements can also be fulfilled by selecting proper control methods.

Sharma, Ranjan

2012-01-01

250

Nuclear reactor power supply  

International Nuclear Information System (INIS)

The redundant signals from the sensor assemblies measuring the process parameters of a nuclear reactor power supply are transmitted each in its turn to a protection system which operates to actuate the protection apparatus for signals indicating off-process conditions. Each sensor assembly includes a number of like sensors measuring the same parameters. The protection system has a number of separate protection units, each unit receiving the process signals from the like sensors of each assembly in its turn. The sets of process signals derived from the sensor parameter assemblies are each in its turn transmitted from the protection system to the control system which impresses control signals on the reactor or its components to counteract the tendency for conditions to drift off-normal status requiring operation of the protection system. A parameter signal selector is interposed between the protection system and the control system. This selector prevents a parameter signal of a set of signals, which differs from the other parameter signals of the set by more than twice the allowable variation of the sensors which produce the set, from passing to the control system. The connection between the protection units and the selector is four separate fiber optic channels so that electrical interaction between the protection units and the selector or control system is precluded. The selectors include a pair of signal selection units, one unit sending selected process signals to punit sending selected process signals to primary control channels and the other sending selected process signals to back-up control channels. Test signals are periodically impressed on a selected pair of a selected unit and control channels. When test signals are so impressed the selected control channel is disabled from transmitting control signals to the reactor and/or its associated components

251

Nuclear reactor power supply  

International Nuclear Information System (INIS)

The redundant signals from the sensor assemblies measuring the process parameters of a nuclear reactor power supply are transmitted each in its turn to a protection system which operates to actuate the protection apparatus for signals indicating off-process conditions. Each sensor assembly includes a number of like sensors measuring the same parameters. The sets of process signals derived from the sensor assemblies are each in its turn transmitted from the protection system to the control system which impresses control signals on the reactor or its components to counteract the tendency for conditions to drift off-normal status requiring operation of the protection system. A parameter signal selector is interposed between the protection system and the control system. This selector prevents a parameter signal of a set of signals, which differs from the other parameters signals of the set by more than twice the allowable variation of the sensors which produce the set, from passing to the control system. The selectors include a pair of signal selection units, one unit sending selected process signals to primary control channels and the other sending selected process signals to back-up control channels. Test signals are periodically impressed by a test unit on a selected pair of a selected unit and control channels. When test signals are so impressed the selected control channel is disabled from transmitting control signals to the reactor and/or its associated components. reactor and/or its associated components. This arrangement eliminates the possibility that a single component failure which may be spurious will cause an inadvertent trip of the reactor during test

252

VEC power supplies - operating experience  

International Nuclear Information System (INIS)

The technology of fabricating precision d.c. magnet supplies has been developed and utilised in the Variable Energy Cyclotron. Stability of 0.01% at current levels upto 2500 A has been achieved. The reliability of the units was confirmed during the operation of the machine. Other power supplies such as the 20 kV, 20 A.d.c., oscillator supply, ion source supply and 120 kV Cockroft-Walton Deflector supply were also developed and their performance tested. Experience gained during operation of these units both under stable and erratic mains voltage conditions is discussed. (auth.)

253

Development of microcontroller based remote control system for HV power supply of ECR ion source for ADSS project  

International Nuclear Information System (INIS)

In this paper we will describe the design and development of the microcontroller based interface card used to control and monitor the operation of High Voltage Power supply 120kV/50mA (HVPS). This power supply is deployed for the extraction of proton beam from the microwave ion source in the ADSS project. (author)

254

High Voltage and High Reliability Silicon-on-Insulator Power IC Technologies and Their Application to 750 V 4.5 A Micro-Inverter IC  

Science.gov (United States)

We have successfully developed the record high blocking voltage of 750 V and the largest current capability of 4.5 A silicon-on-insulator (SOI) micro-inverter IC, which is made possible by the newly developed high voltage reliability technology and high-speed and low-dissipation extraction enhanced lateral insulated gate bipolar transistor (E2LIGBT). It has been found, for the first time, that the stable and reliable high blocking voltage of 760 V is assured by controlling the sheet-resistance of the polycrystalline silicon (poly-Si) layer of the scroll-shaped resistive field plate (SRFP). The high voltage and high reliability SOI power IC technology is expected as the key technology enabling 750 V 4.5 A micro-inverter IC for harsh applications such as automotive electronics.

Shiraki, Satoshi; Takahashi, Shigeki; Yamada, Akira; Yamamoto, Masahiro; Senda, Koji; Ashida, Youichi; Hiruma, Atsuyuki; Tokura, Norihito

2012-04-01

255

Pulsed power supplies for the synchrotron of INDUS-1  

International Nuclear Information System (INIS)

Pulsed power supplies for driving the injection septum, the injection kickers, the extraction septum and the fast extraction kicker of the synchrotron of INDUS-1 are discussed. All power supplies except that of the extraction kicker are of half sine wave type. The half sine wave is generated by discharging a capacitor into the inductance of the magnet through a thyristor switch. The magnet current is controlled by controlling the capacitor voltage. The power supply for the fast extraction kicker is required to generate a rectangular pulse of current with a rise time less than 55 nS. The pulse is generated by discharging a distributed type of pulse forming network (PFN) into a matched load, the inductance of the magnet being in series with the matched load. The single turn of extraction kicker magnet is split into two half turns to get the shortest rise time at the smallest possible high voltage. (author). 3 refs., 3 figs., 1 tab

256

Development of PMT high voltage control system for LASCAR detector array at RIBLL  

International Nuclear Information System (INIS)

It is described in this paper that the multi-channel PMT high voltage power supply control system, which matches with the PMT high voltage module CC123 of the LASCAR detector array at RIBLL experiment terminal. The MCU AT89C51 is selected as the central control part and other suitable accessories are also adopted in our design. The PMT control system of the detector array works steadily and effectively in out performance test of LASCAR detector array. (authors)

257

Reactive power compensation in ITER power supply system  

International Nuclear Information System (INIS)

ITER power supply system supplies the heating and current driving facilities and the magnetic coils which will typically produce the reactive power up to 930Mvar in full load operation of 500MW active power. The high voltage grid allows about 200Mvar and the reactive power compensator (RPC) of 795Mvar is planned. The control strategy of RPC is important because of the over voltages from abrupt changes of the load. Some or whole units of the load could be cut off in normal operations as well as in accidents. ITER RPC consists of TCR (thyristor controlled reactor) and capacitors with fixed values. The control, in strategy, calculates the susceptance of the load from the load current and drives TCR to keep the total susceptance at the given level. The control circuit is simulated using a commercial software, PSIM, and the over voltages are tested for typical cases of load loses. In order to respond as fast as possible and thereby reduce the peak values of transient over voltages, a scheme is suggested in which the signals of the susceptance change and the timing are provided by the load controllers. The improvements are also simulated by PSIM

258

Reactive power compensation in ITER power supply system  

Energy Technology Data Exchange (ETDEWEB)

ITER power supply system supplies the heating and current driving facilities and the magnetic coils which will typically produce the reactive power up to 930Mvar in full load operation of 500MW active power. The high voltage grid allows about 200Mvar and the reactive power compensator (RPC) of 795Mvar is planned. The control strategy of RPC is important because of the over voltages from abrupt changes of the load. Some or whole units of the load could be cut off in normal operations as well as in accidents. ITER RPC consists of TCR (thyristor controlled reactor) and capacitors with fixed values. The control, in strategy, calculates the susceptance of the load from the load current and drives TCR to keep the total susceptance at the given level. The control circuit is simulated using a commercial software, PSIM, and the over voltages are tested for typical cases of load loses. In order to respond as fast as possible and thereby reduce the peak values of transient over voltages, a scheme is suggested in which the signals of the susceptance change and the timing are provided by the load controllers. The improvements are also simulated by PSIM.

Jin, Jeong Tae; Hwang, Churl Kew; Oh, Byung Hoon; Lee, Kwang Won; Chang, Dae Sik [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Oh, Jong Seok; Choi, Jung Wan [National Fusion Research Institute, Daejeon (Korea, Republic of); Suh, Jae Hak [Pohang Accelerator Laboratory, Pohang (Korea, Republic of)

2009-05-15

259

Multiple resonant railgun power supply  

Science.gov (United States)

A multiple repetitive resonant railgun power supply provides energy for repetitively propelling projectiles from a pair of parallel rails. A plurality of serially connected paired parallel rails are powered by similar power supplies. Each supply comprises an energy storage capacitor, a storage inductor to form a resonant circuit with the energy storage capacitor and a magnetic switch to transfer energy between the resonant circuit and the pair of parallel rails for the propelling of projectiles. The multiple serial operation permits relatively small energy components to deliver overall relatively large amounts of energy to the projectiles being propelled.

Honig, Emanuel M. (Los Alamos, NM); Nunnally, William C. (Los Alamos, NM)

1988-01-01

260

Standby power supply for motor  

International Nuclear Information System (INIS)

A motor driving a pump of the cooling system of a plant, such as a sodium pump of a nuclear reactor, is located adjacent the plant and is electrically coupled to a synchronous condenser located remote from the plant, and a flywheel forms part of the rotor of the synchronous condenser. When the normal power supply is available the synchronous condenser provides reactive power to the motor, whereas if the normal supply fails, the flywheel drives the synchronous condenser which acts as a generator supplying electrical power to the motor. The system enables the flywheel to be removed from the restricted area around the reactor. (author)

261

High energy X-ray emission driven by high voltage circuit system  

Science.gov (United States)

The x-rays are produced by high voltage discharge applied inside plasma source interaction chamber; the control circuit system of high voltage is composed of a power supply and a LC-inverter. The goal of the project is based on the production of x-rays by a plasma to increase the efficiency of a classic x-ray tube with hot filament. Preliminary results of high energy x-rays emission, the layout and simulation with p-spice of the high voltage system are presented.

Emilio, M. Di Paolo; Palladino, L.

2014-04-01

262

Investigation of parameters of the three phase high-voltage alternating current plasma generator with power up to 100 kW working on steam  

International Nuclear Information System (INIS)

The paper presents the results of experimental investigation of parameters of the three-phase high voltage alternating current plasma generator with power up to 100 kW operating on steam with gas protection of the electrodes. Researches were carried out over a range of arc current from 25 to 50 A and range of steam consumption of 3-5 g/s. Current-voltage and volt consumable characteristics, operation oscillograms and dependence of power versus the flow rate of steam and protective gas are presented.

263

Investigation of parameters of the three phase high-voltage alternating current plasma generator with power up to 100 kW working on steam  

Energy Technology Data Exchange (ETDEWEB)

The paper presents the results of experimental investigation of parameters of the three-phase high voltage alternating current plasma generator with power up to 100 kW operating on steam with gas protection of the electrodes. Researches were carried out over a range of arc current from 25 to 50 A and range of steam consumption of 3-5 g/s. Current-voltage and volt consumable characteristics, operation oscillograms and dependence of power versus the flow rate of steam and protective gas are presented.

Rutberg, Ph G; Lukyanov, S A; Kiselev, A A; Kuschev, S A; Nakonechny, Gh V; Nikonov, A V; Popov, S D; Serba, E O; Spodobin, V A; Surov, A V, E-mail: sergey_popov1974@mail.ru [Institute for Electrophysics and Electric Power Russian Academy of Sciences, 18 Dvortsovaya emb., St.-Petersburg, 191186 (Russian Federation)

2011-01-01

264

Repetitive resonant railgun power supply  

Science.gov (United States)

A repetitive resonant railgun power supply provides energy for repetitively propelling projectiles from a pair of parallel rails. The supply comprises an energy storage capacitor, a storage inductor to form a resonant circuit with the energy storage capacitor and a magnetic switch to transfer energy between the resonant circuit and the pair of parallel rails for the propelling of projectiles.

Honig, Emanuel M. (Los Alamos, NM); Nunnally, William C. (Los Alamos, NM)

1988-01-01

265

Design of the HL-2M power supply control system  

International Nuclear Information System (INIS)

Highlights: • The control system is structured by using four kinds of control networks. • The controlling of converter is based on the real time network and FPGA. • With use of PROFINET, the status of all components can be monitored easily. • The SoE distinguishes input signals clearly to detect the fault rapidly. -- Abstract: The power supply control system is one of the most important local control systems of HL-2M tokamak. The power supply system of HL-2M is composed of four flywheel generator sets with total capacity of 600 MVA, all the magnetic field coil power supplies and high voltage power supplies of auxiliary heating system. The control system of power supply should make sure the large amount of on-site equipment and facilities to operate steadily and reliably. This paper presents the architecture of HL-2M control system and four kinds of established control networks. It describes how the power supply control system is built by using the established hardware structures and software agreements. Specially, it is focused on introducing an application of real-time technology based on the reflective shared memory and the fully digital compact solution for controlling the high power converters. Otherwise, a scheme which adopts PROFINET and Sequence of Events technology to carry out the intellect interlock control system is given

266

Design of the HL-2M power supply control system  

Energy Technology Data Exchange (ETDEWEB)

Highlights: • The control system is structured by using four kinds of control networks. • The controlling of converter is based on the real time network and FPGA. • With use of PROFINET, the status of all components can be monitored easily. • The SoE distinguishes input signals clearly to detect the fault rapidly. -- Abstract: The power supply control system is one of the most important local control systems of HL-2M tokamak. The power supply system of HL-2M is composed of four flywheel generator sets with total capacity of 600 MVA, all the magnetic field coil power supplies and high voltage power supplies of auxiliary heating system. The control system of power supply should make sure the large amount of on-site equipment and facilities to operate steadily and reliably. This paper presents the architecture of HL-2M control system and four kinds of established control networks. It describes how the power supply control system is built by using the established hardware structures and software agreements. Specially, it is focused on introducing an application of real-time technology based on the reflective shared memory and the fully digital compact solution for controlling the high power converters. Otherwise, a scheme which adopts PROFINET and Sequence of Events technology to carry out the intellect interlock control system is given.

Yao, Lieying, E-mail: yaoly@swip.ac.cn; Li, Weibin; Chen, Yuhong; Wang, Yingqiao; Bu, Mingnan; Wang, Yali; Hu, Haotian; Xuan, Weimin

2013-10-15

267

Design and implementation of the wireless high voltage control system  

International Nuclear Information System (INIS)

In this paper we will describe the implementation of the wireless link for controlling and monitoring the serial data between control PC and the interface card (general DAQ card), by replacing existing RS232 based remote control system for controlling and monitoring High Voltage Power Supply (120kV/50mA). The enhancement in the reliability is achieved by replacing old RS232 based control system with wireless system by isolating ground loop. (author)

268

1000 Amp filament power supply  

International Nuclear Information System (INIS)

A 15 V, 1000 A power supply was developed to supply filament power to the Oak Ridge multiple filament rectangular ion source. The power supply can operate steady state or in a pulsed mode to furnish filament heating for the ion source. The power supply is capable of maintaining an idling current to the filaments between extraction pulses to reduce the electron emission and heat dissipation to enhance the lifetime of the filaments. Prior to an ion beam extraction pulse, the filament current is increased from the idling current to full operating current; ion beam extraction commences when the filament emission reaches equilibrium. When the extraction terminates, the filament current is returned to the idling state

269

High-voltage engineering  

CERN Document Server

High-voltage engineering covers the application, the useful use and proper working of high voltages and high fields. Here we give some introductory examples, i.e., ‘septa’ and ‘kicker’ at the Large Hadron Collider (14 TeV), the Super Proton Synchrotron (450 GeV) and the Proton Synchrotron (26 GeV) accelerators as found at the European Orginization for Nuclear Research (CERN) today. We briefly cover the theoretical foundation (Maxwell equations) and aspects of numerical field simulation methods. Concepts relating to electrical fields, insulation geometry and medium and breakdown are introduced. We discuss ways of generating high voltages with examples of AC sources (50/60 Hz), DC sources, and pulse sources. Insulation and breakdown in gases, liquids, solids and vacuum are presented, including Paschen’s law (breakdown field and streamer breakdown). Applications of the above are discussed, in particular the general application of a transformer. We briefly discuss measurement techniques of partial disch...

Gaxiola, E

2006-01-01

270

Laser power supply  

International Nuclear Information System (INIS)

A method of energizing a laser source stimulating flash lamp directly from an ac power line is presented. Uncontrolled diodes couple the anode and cathode of the flash lamp directly to the ac line. The lamp is triggered by a separate triggering circuit which produces its trigger pulse at a predetermined phase of the ac power source. The use of high current carrying controlled rectifiers and large energy storage devices is thereby eliminated. (U.S.)

271

Analysis of a novel autonomous marine hybrid power generation/energy storage system with a high-voltage direct current link  

OpenAIRE

This paper presents both time-domain and frequency-domain simulated results of a novel marine hybrid renewable-energy power generation/energy storage system (PG/ESS) feeding isolated loads through an high-voltage direct current (HVDC) link. The studied marine PG subsystems comprise both offshore wind turbines andWells turbines to respectively capture wind energy and wave energy from marine wind and oceanwave. In addition to wind-turbine generators(WTGs) andwave-energy turbine generators (WETG...

Wang, L.; Lee, D. J.; Lee, W. J.; Chen, Zhe

2008-01-01

272

Photodetector power supply system for the CMS hadron calorimeter  

CERN Document Server

The power supply system developed for the hybrid photodiodes used as photodetectors in the hadron calorimeter of the Compact Muon Solenoid (CMS) experiment at LHC in CERN is described. The system includes about 500 channels, with two different voltage outputs on each channel, one high-voltage output up to 14000 V and one bias-voltage output up to 200 V. All output voltages are floating to facilitate single-point ground configuration. The system is computer controlled and ready to be interconnected with the CMS slow-control facility.

Dimitrov, L; Kunov, B; Sergueev, S; Ronzhin, A; Vankov, I

2005-01-01

273

Non-isolated DC-AC converter with high voltage gain for autonomous systems of electric power; Conversor CC-CA nao isolado com alto ganho de tensao para aplicacao em sistemas autonomos de energia eletrica  

Energy Technology Data Exchange (ETDEWEB)

A non-isolated DC-AC converter with high voltage gain with two output sinusoidal voltage - 110 V and 220 V - and frequency 60 Hz for application in autonomous systems of electric power is proposed in this work. This topology consists of a boost converter with high voltage gain, based on three-state switching cell combined with a double half bridge inverter. This configuration type the size and the cost are reduced and the efficiency is gotten better, due to the reduced number of switches. The converters that compose this topology operate with high frequency, reducing the volume of the magnetic materials. can be mention as important characteristics: the voltage stress across the switches of the boost converter are low, due they be naturally clamped by one output filter capacitor, which allows the utilization of switches with lower conduction resistances, and the waveforms of the output voltage of the double half bridge inverter supplies for the load it is sinusoidal and it possesses low harmonic content. (author)

Silveira, George Cajazeiras [Centro Federal de Educacao Tecnologica do Ceara (CEFET/CE), Fortaleza, CE (Brazil); Torrico-Bascope, Rene P. [Universidade Federal do Ceara (PPGEE/UFC), Fortaleza, CE (Brazil). Programa de Pos Graduacao em Engenharia Eletrica; Borges Neto, Manuel Rangel [Centro Federal de Educacao Tecnologica de Petrolina (CEFET-PET), PE (Brazil)

2008-07-01

274

RICH High Voltages & PDF Analysis @ LHCb  

CERN Multimedia

In the LHCb experiment an important issue is the identification of the hadrons of the final states of the B mesons decays. Two RICH subdetectors are devoted to this task, and the Hybrid Photon Detectors (HPDs) are the photodetectors used to detect Cherenkov light. In this poster there is a description of how the very high voltage (-18 KV) supply stability used to power the HPDs is monitored. It is also presented the basics of a study which can be done with the first collision data: the analysis of the dimuons from the Drell-Yan process. This process is well known and the acceptance of the LHCb detector in terms of pseudorapidity will be very useful to improve the knowledge of the proton structure functions or, alternatively, try to estimate the luminosity from it.

Fanchini, E

2009-01-01

275

Design and Development of High Voltage Direct Current (DC) Sources for the Solar Array Module Plasma Interaction Experiment  

Science.gov (United States)

Two programmable, high voltage DC power supplies were developed as part of the flight electronics for the Solar Array Module Plasma Interaction Experiment (SAMPIE). SAMPIE's primary objectives were to study and characterize the high voltage arcing and parasitic current losses of various solar cells and metal samples within the space plasma of low earth orbit (LEO). High voltage arcing can cause large discontinuous changes in spacecraft potential which lead to damage of the power system materials and significant Electromagnetic Interference (EMI). Parasitic currents cause a change in floating potential which lead to reduced power efficiency. These primary SAMPIE objectives were accomplished by applying artificial biases across test samples over a voltage range from -600 VDC to +300 VDC. This paper chronicles the design, final development, and test of the two programmable high voltage sources for SAMPIE. The technical challenges to the design for these power supplies included vacuum, space plasma effects, thermal protection, Shuttle vibrations and accelerations.

Bibyk, Irene K.; Wald, Lawrence W.

1995-01-01

276

Power supplies in Europe  

International Nuclear Information System (INIS)

The contribution takes a look at the current situation of the internal energy market, for which the EC-Commission demands more competition due to the differing price policies of the individual EC-countries and their effects on industrial policy, in addition due to the free merchandise traffic which is necessary for electricity as well and due to international investments. A first step toward perfecting the internal market for electricity consists in the two directives which the Council of Ministers passed regarding the transit of electricity and the transparency of prices, the first phase of which has been initiated. During the second phase there are plans for permitting liberalization for a limited number of new competitors while orienting oneself to the existing structures. This phase consists in carrying out the following three main tasks: First of all the rights for the production of energy and the construction of power lines should be extended. Second of all, in vertically consolidated enterprises, the concept of decartelization, i.e. the separation of management and accounting must be introduced in the production area and in the transference and distribution sectors. The third tasks consists in giving third parties access to the power-distribution network to a limited degree. The main points of criticism on the part of the power suppliers are the following: - Long-term investments can no longer be made to a sufficient extent. - The individual consumer is placed tent. - The individual consumer is placed at a disadvantage due to the competitive system. - The third-party-access system entails an unnecessary amount of bureaucratization. In closing, the contribution takes a brief look at energy taxes and CO2 stabilization as well as negotiations on the energy charter. (orig./HSCH)

277

A high-power high-voltage multi-pulse twin-output driver for radiation generators  

International Nuclear Information System (INIS)

This paper presents the second phase of a research programme aimed at producing twin series of high-voltage pulses from the single discharge of a capacitor into multiple arrays of exploding metallic wires. Details of the design and construction of a generator that is able to produce either three 200 kV pulses, two 250 kV pulses or a single 500 kV pulse, on resistive loads between 50 and 100 ? at each output, are given. In addition to describing the design of the exploding wire arrays, the paper also details other ancillary equipment that is needed for the generator. This includes the two compact air-cored transformers that provide the twin series of output pulses at the required voltage. The experimental performance of the generator is shown to be close to that predicted by numerical modelling. Results are presented with the resistive loads replaced by x-ray heads, and ways by which the system can be further developed to drive microwave sources are discussed. (author)

278

High voltage engineering fundamentals  

CERN Document Server

Provides a comprehensive treatment of high voltage engineering fundamentals at the introductory and intermediate levels. It covers: techniques used for generation and measurement of high direct, alternating and surge voltages for general application in industrial testing and selected special examples found in basic research; analytical and numerical calculation of electrostatic fields in simple practical insulation system; basic ionisation and decay processes in gases and breakdown mechanisms of gaseous, liquid and solid dielectrics; partial discharges and modern discharge detectors; and over

Kuffel, E; Hammond, P

1984-01-01

279

Magnetically switched power supply system for lasers  

Science.gov (United States)

A laser power supply system is described in which separate pulses are utilized to avalanche ionize the gas within the laser and then produce a sustained discharge to cause the gas to emit light energy. A pulsed voltage source is used to charge a storage device such as a distributed capacitance. A transmission line or other suitable electrical conductor connects the storage device to the laser. A saturable inductor switch is coupled in the transmission line for containing the energy within the storage device until the voltage level across the storage device reaches a predetermined level, which level is less than that required to avalanche ionize the gas. An avalanche ionization pulse generating circuit is coupled to the laser for generating a high voltage pulse of sufficient amplitude to avalanche ionize the laser gas. Once the laser gas is avalanche ionized, the energy within the storage device is discharged through the saturable inductor switch into the laser to provide the sustained discharge. The avalanche ionization generating circuit may include a separate voltage source which is connected across the laser or may be in the form of a voltage multiplier circuit connected between the storage device and the laser.

Pacala, Thomas J. (inventor)

1987-01-01

280

High voltage electrical injuries  

International Nuclear Information System (INIS)

Objective: To highlight the devastating nature and consequences of high voltage electrical injuries and to stress the need for its prevention. Design: It was a retrospective study. Place and duration of study: The study was conducted at Army Burn Centre, Combined Military Hospital Kharian Cantonment, between January 1,1998 to December 31, 2000. Subjects and Methods: All the patients reporting to Army Burn Centre with high voltage electrical injuries were included in the study. The epidemiology of these injuries were studied along with the pattern of their management and outcome in terms of mortality and morbidity. Results: Of all the patients admitted to the Army Burn Center, 5.94% were affected with electrical injuries. They were predominantly males in a ratio of 9.75:1 and mostly in the 3rd and 4th decades of their lives. Seventy percent of these injuries were injuries were work-related and 75% had associated surface burns. There was significant mortality rate of 18.6% and a limb amputation rate of 80% along with professional disability rate of 91% rendering it a highly morbid condition. Conclusion: This study stresses the necessity to educate the general public with regard to the devastating nature of high voltage electrical injury and highlight the importance of prevention. (author)

281

Design and Construction of a Test Bench to Characterize Efficiency and Reliability of High Voltage Battery Energy Storage Systems  

OpenAIRE

Stationary battery energy storage systems are widely used for uninterruptible power supply systems. Furthermore, they are able to provide grid services. This yields in rising installed power and capacity. One possibility uses high voltage batteries. This results in an improvement of the overall system efficiency. High voltage batteries may be advantageous for future medium voltage DC-grids as well. In all cases, high availability and reliability is indispensable. Investigations on the operati...

Blank, Tobias; Thomas, Stephan; Roggendorf, Christoph; Pollok, Thomas; Trintis, Ionut; Sauer, Dirk Uwe

2010-01-01

282

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

Science.gov (United States)

...equipment receiving power from ungrounded delta systems. 75.704 Section...equipment receiving power from ungrounded delta systems. [Statutory Provisions...equipment receiving power from ungrounded delta systems shall be grounded...

2010-07-01

283

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

Science.gov (United States)

...equipment receiving power from ungrounded delta systems. 77.703 Section...equipment receiving power from ungrounded delta systems. The frames of...equipment receiving power from ungrounded delta systems shall be grounded...

2010-07-01

284

Design & Fabrication of a High-Voltage Photovoltaic Cell  

Energy Technology Data Exchange (ETDEWEB)

Silicon photovoltaic (PV) cells are alternative energy sources that are important in sustainable power generation. Currently, applications of PV cells are limited by the low output voltage and somewhat low efficiency of such devices. In light of this fact, this project investigates the possibility of fabricating high-voltage PV cells on float-zone silicon wafers having output voltages ranging from 50 V to 2000 V. Three designs with different geometries of diffusion layers were simulated and compared in terms of metal coverage, recombination, built-in potential, and conduction current density. One design was then chosen and optimized to be implemented in the final device design. The results of the simulation serve as a feasibility test for the design concept and provide supportive evidence of the effectiveness of silicon PV cells as high-voltage power supplies.

Felder, Jennifer; /North Carolina State U. /SLAC

2012-09-05

285

Gyrotron and power supply development for upgrading the electron cyclotron heating system on DIII-D  

Energy Technology Data Exchange (ETDEWEB)

Highlights: ? Vendor completed design of 1.5 MW, 117.5 GHz gyrotron for DIII-D. ? Fabrication of gyrotron by vendor underway. ? Finalizing design of solid-state high voltage modulator for cathode power supply. ? Fabrication of solid-state high voltage modulator has begun. ? Finalizing design of high voltage linear amplifier for gyrotron body power supply. -- Abstract: An upgrade of the electron cyclotron heating system on DIII-D to almost 15 MW is being planned which will expand it from a system with six 1 MW 110 GHz gyrotrons to one with ten gyrotrons. A depressed collector 1.2 MW 110 GHz gyrotron is being commissioned as the seventh gyrotron. A new 117.5 GHz 1.5 MW depressed collector gyrotron has been designed, and the first article will be the eighth gyrotron. Two more are planned, increasing the system to ten total gyrotrons, and the existing 1 MW gyrotrons will subsequently be replaced with 1.5 MW gyrotrons. Communications and Power Industries completed the design of the 117.5 GHz gyrotron, and are now fabricating the first article. The design was optimized for a nominal 1.5 MW at a beam voltage of 105 kV, collector potential depression of 30 kV, and beam current of 50 A, but can achieve 1.8 MW at 60 A. The design of the collector permits modulation above 100 Hz by either the body or the cathode power supply, or both, while modulation below 100 Hz must use only the cathode power supply. General Atomics is developing solid-state power supplies for this upgrade: a solid-state modulator for the cathode power supply and a linear high voltage amplifier for the body power supply. The solid-state modulator has series-connected insulated-gate bipolar transistors that are switched at a fixed frequency by a pulse-width modulation regulator to control the output voltage. The design of the linear high voltage amplifier has series-connected transistors to control the output voltage, which was successfully demonstrated in a proof-of-principle test at 2 kV. The designs of complete power supplies are progressing. The design features of the 117.5 GHz 1.5 MW gyrotron and the solid-state cathode and body power supplies will be described and the current status and plans are presented.

Tooker, Joseph F., E-mail: tooker@fusion.gat.com [General Atomics, PO Box 85608, San Diego, CA 92186-5608 (United States); Huynh, Paul [General Atomics, PO Box 85608, San Diego, CA 92186-5608 (United States); Felch, Kevin; Blank, Monica; Borchardt, Philipp; Cauffman, Steve [Communications and Power Industries, 811 Hanson Way, Palo Alto, CA 94304 (United States)

2013-10-15

286

FFT Analysis of a Series Loaded Resonant Converter-Based Power Supply for Pulsed Power Applications  

International Nuclear Information System (INIS)

An impulse power supply has been designed, simulated, and tested in order to feed the primary of a high-frequency transformer. Pulse power system has been widely used for plasma applications. The operational principle of the pulse power system is that the energy from the input source is stored in the capacitor bank device through a dc-dc converter. Then, when a discharging signal is given, the stored energy is released to the load. The new family of ZCS converters is suitable for high-power applications using insulated gate bipolar transistors (IGBTs). The power converter can achieve zero switching with the aid of high-frequency transformer. The device is capable of charging a 0.1?F capacitor up to 5 kV which accounts for a charging power of 5 kJ/s. The novel control algorithm is achieved which eminently considers the nonlinear control characteristics of impulse power supply. The required charging voltage, together with the constraint on the charging time, translates into a required maximum power of 10 kW reduced in this initial version to 5 kW. The difficulty to reliably control such a power at the high-voltage side practically forbids any approach featuring a more or less stabilized DC high-voltage to be generated from a conventional 50 Hz transformer through rectification.

287

Specialized device of power supplies  

Directory of Open Access Journals (Sweden)

Full Text Available The specialized device of power supplies, capable to change parameters of output voltage depending on conditions of environment and parameters of the fed equipment is offered. Examples of its application for feed of the electroluminescent indicator are resulted.

Gunchenko Y. A.

2010-02-01

288

Design of auto-control high-voltage control system of pulsed neutron generator  

International Nuclear Information System (INIS)

It is difficult to produce multiple anode controlling time sequences under different logging mode for the high-voltage control system of the conventional pulsed neutron generator. It is also difficult realize sequential control among anode high-voltage, filament power supply and target voltage to make neutron yield stable. To these problems, an auto-control high-voltage system of neutron pulsed generator was designed. It not only can achieve anode high-voltage double blast time sequences, which can measure multiple neutron blast time sequences such as ?, activated spectrum, etc. under inelastic scattering mode, but also can realize neutron generator real-time measurement of multi-state parameters and auto-control such as target voltage pulse width modulation (PWM), filament current, anode current, etc., there by it can produce stable neutron yield and realize stable and accurate measurement of the pulsed neutron full spectral loging tool. (authors)

289

Cockcroft-Walton high voltage generator  

CERN Multimedia

Cockcroft-Walton generator (or voltage doubler)(600kV) built by Philips and used in the Linac experimental area of the proton synclotron south hall (1964).Served as high voltage supply for the pre-injector of the 3Mev experimental Linac.

1964-01-01

290

Operational experience with a klystron 50kV/30kW inverter power supply  

International Nuclear Information System (INIS)

We have developed an inverter type high-voltage power supply for an oil-filled klystron modulator. The power module produces 38-kJ/sec peak and 30 kJ/sec average power at a 50-kV output voltage. It drives a 1:16 step-up transformer to deliver -350 kV to a 50-MW C-band (5712-MHz) klystron. We obtained an output voltage regulation of around 0.34% (3?) at 50-kV. So far our experience with the inverter power supply has shown probable adequate long run reliability. (author)

291

Design and electrical charaterization of a low current-high voltage compact arc plasma torch  

International Nuclear Information System (INIS)

A new compact plasma torch associated with a resonance power supply allows the generation of low power discharges (typically 100 W-1 kW) under high voltage (>1 kV) low current (<1 A) conditions. The resonance power supply allows continuous control of the discharge current, which is a major improvement with respect to the traditional dc power source based on a high voltage transformer. In addition, this system is characterized by a high conversion efficiency that is crucial when it comes to industrial applications. It has been shown that different regimes ranging from streamer over gliding arc to continuous discharges were obtained depending on the operating conditions. The objective of this paper is a better understanding of the different observed behaviour through the determination of the main torch and power supply parameters

292

Fermilab D0 overpass power supply system  

International Nuclear Information System (INIS)

The overpass power supply system consists of two power supplies. A 1 kV, 3600A SCR supply drives eight Main Ring type magnets and must track twice the Main Ring current to within +/-0.1%. The second supply drives trim coils wound inside four of the main magnets. This dual-converter SCR supply, a modified Fermilab H.O.P.S. unit, supplies +/- 50A at +/-30V and it must generate +/-200V swings to buck-out the voltage inductively coupled from the main supply. Both power supply regulators use dead reckoned voltage drive programs to extend their effective bandwidths

293

Boeing's High Voltage Solar Tile Test Results  

Science.gov (United States)

Real concerns of spacecraft charging and experience with solar array augmented electrostatic discharge arcs on spacecraft have minimized the use of high voltages on large solar arrays despite numerous vehicle system mass and efficiency advantages. Boeing's solar tile (patent pending) allows high voltage to be generated at the array without the mass and efficiency losses of electronic conversion. Direct drive electric propulsion and higher power payloads (lower spacecraft weight) will benefit from this design. As future power demand grows, spacecraft designers must use higher voltage to minimize transmission loss and power cable mass for very large area arrays. This paper will describe the design and discuss the successful test of Boeing's 500-Volt Solar Tile in NASA Glenn's Tenney chamber in the Space Plasma Interaction Facility. The work was sponsored by NASA's Space Solar Power Exploratory Research and Technology (SERT) Program and will result in updated high voltage solar array design guidelines being published.

Reed, Brian J.; Harden, David E.; Ferguson, Dale C.; Snyder, David B.

2002-01-01

294

High voltage isolation transformer  

Science.gov (United States)

A high voltage isolation transformer is provided with primary and secondary coils separated by discrete electrostatic shields from the surfaces of insulating spools on which the coils are wound. The electrostatic shields are formed by coatings of a compound with a low electrical conductivity which completely encase the coils and adhere to the surfaces of the insulating spools adjacent to the coils. Coatings of the compound also line axial bores of the spools, thereby forming electrostatic shields separating the spools from legs of a ferromagnetic core extending through the bores. The transformer is able to isolate a high constant potential applied to one of its coils, without the occurrence of sparking or corona, by coupling the coatings, lining the axial bores to the ferromagnetic core and by coupling one terminal of each coil to the respective coating encasing the coil.

Clatterbuck, C. H.; Ruitberg, A. P. (inventors)

1985-01-01

295

Evaluation and measurement of magnetic field exposure at a typical high-voltage substation and its power lines  

International Nuclear Information System (INIS)

This study presents a survey of magnetic field measurements including those resulting from 380/154 kV power substations, which play a vital role in human body biological studies. The survey was carried out in the main power substation of Antalya (Turkey)), located at the suburban region of the city, under actual loads. The paper also presents the actual magnetic field strength measured near the 380/154 kV substation and power transmission lines (380 and 154 kV) connecting to the substation. Since most part of these lines pass through a residential area, they have been included in the study, and the actual magnetic field variation around them has been investigated by comparative analysis of measured data. For the occupants working at substations, occupational exposure has been analysed with actual magnetic fields at operating locations. Induced internal electric fields and current densities in the occupants' body due to exposure to external magnetic fields produced by a conventional 380/154 kV power substation have been investigated. (authors)

296

Circuit design and simulation of a HV-supply controlling the power of 140 GHz 1 MW gyrotrons for ECRH on W7-X  

International Nuclear Information System (INIS)

For plasma heating by ECR in the Stellarator W7-X under construction, 140 GHz gyrotrons with 1 MW cw output power are under development. These tubes have a voltage depressed collector for electron energy recovery. Each gyrotron is fed by two high-voltage sources: a high-power supply for driving the electron beam and a precision low-power supply for beam acceleration. In addition, a protection system with a thyratron crowbar for fast power removal in case of gyrotron arcing is installed. The low-power high-voltage source for beam acceleration is realized by a high-voltage servo-amplifier driving the depression voltage such that the influence of the voltage noise of the main high-power supply on the acceleration voltage is suppressed by feed-back control of the amplifier. Design and simulation of the servo-amplifier by PSpice is presented

297

Abort kicker power supply systems at Fermilab  

International Nuclear Information System (INIS)

Over the past several years, Fermilab has been operating with a single turn proton abort system in both the superconducting Tevatron and the conventional Main Ring. The abort kicker power supply for this system discharges a lumped capacitance into the inductive magnet load, causing the beam to enter the abort channel. The characteristics of this current waveform are defined by the requirements of the machine operation. The standard fixed target running mode calls for 12 booster batches of beam which leaves a rotating gap in the beams of approx.1.8 ?s. The current waveform is required to rise to 90% of I/sub max/ in this time to avoid beam loss from partially deflected beam. Aperture limitations in both the accelerator and the abort channel demand that the current in the magnets stays above this 90% I/sub max/ for the 21 ?s needed to ensure all the beam has left the machine. The 25 mm displacement needed to cleanly enter the abort channel at 1 TeV corresponds to a maximum current in each of the 4 modules of approx.20 kA. Similar constraints are needed for the Main Ring and Tevatron antiproton abort systems. A unique feature of this design is the high voltage, high current diode assembly used to clip the recharge of the capacitor bank. This allows the current to decay slowly with the L/R time constant of the magnet and diode series combination. Special attention is given to the diode characteristics needed for this passive switching element. Operational experience and proposed upgrades are given for the two operational systems. 2 refs., 4 figs., 1 tab

298

-1 MV DC UHV power supply for ITER NBI  

International Nuclear Information System (INIS)

A dc -1 MV ultra high voltage (UHV) power supply system is required for the ITER neutral beam injector (NBI) to accelerate negative ion beams up to the energy of 1 MeV with the beam current of 40 A for 3600 s. Domestic Agency of Japan (JADA) and Domestic Agency of EU (EUDA) have agreed the procurement sharing for the ITER NBI power supply system. JADA contributes procurement of dc -1 MV ultra-high voltage (UHV) components such as a -1 MV dc generator, a transmission line and a -1 MV insulating transformer. The dc UHV insulation is essential issue for the system, because dc long pulse insulation is different from conventional ac insulation. Voltage sharing is changed from capacitive distribution to resistive one by dc long pulse applying. Electric field distribution for multi-layer (oil/paper composites) insulation structure of the transformer has been studied by simulation for the long pulse operation up to 3600 s. The insulating structure has been designed and the overall dimensions of the dc UHV components have been finalized. In order to realize a stable NBI system, a surge energy suppression system is also essential to protect the accelerator from electric breakdowns. JADA contributes to provide an effective surge suppression system composed of a core snubber and resistors. Input energy from the power supply to the accelerator can be reduced to less than 20 joule which is smaller than design criteria of 50 joule at 1 MV breakdown. From these studies, JADA is readyeakdown. From these studies, JADA is ready for procurement arrangement for the UHV components. (author)

299

Fast quadrupole pulsed power supply in the AGS  

International Nuclear Information System (INIS)

As part of the Polarized Proton Project at the AGS, a pulsed power supply system has been developed to energize a set of twelve fast quadrupoles which are symmetrically distributed around the 1/2-mile circumference of the machine. During a typical acceleration cycle, which is normally repeated every 2.4 s, these magnets are energized with bursts of triangular current pulses. The rise-time of each pulse is less than 2 ?s and the width at the base varies from 1 to 3.5 ms depending on the pulse. Within a burst, pulses alternate in polarity and vary in amplitude from 160 A to 2700 A peak. Pulse separation is on the order of 40 ms. Due to the distributed nature of the load and high di/dt, each magnet is powered by a separate modulator. Magnets are driven via coaxial pulse transmission cables up to 200 ft long. In the modulators, the high power pulses are switched with thyratron/ignitron switch pairs. All modulators are charged in parallel with a common system of programmable high voltage power supplies. The overall system is controlled with a distributed network of microcomputers. This paper describes the development, construction and initial performance of the pulsed power supply system

300

Power supply for a plasma emitter  

International Nuclear Information System (INIS)

The basic circuit of a supply unit intended for pulse excitation of the arc discharge with a frequency of 5-50 Hz in electron accelerators with plasma emitters is described. The supply unit consists of a firing supply and a main supply. The firing supply is designed to fire the discharge and constitutes a generator of high-voltage pulses with an amplitude of 6 kV and low duration (1.5 ?s). The main supply made as a low-voltage artificial forming line shapes a required discharge current pulse with an amplitude of 10-40 A and duration of 100 ?s and is connected to discharge gap after firing the discharge. The circuit has been tested in a diode electron accelerator. At an accelerating voltage of 250 kV and a discharge current of 30 A the beam current constitutes 15 A. The pulsed supply of the discharge provides modulation of the electron beam current at a constant accelerating voltage. A conclusion has beeen drawn that employment of the described circuit makes it possible to increase the supply unit efficiency 10 times

301

High-Voltage, Asymmetric-Waveform Generator  

Science.gov (United States)

The shapes of waveforms generated by commercially available analytical separation devices, such as some types of mass spectrometers and differential mobility spectrometers are, in general, inadequate and result in resolution degradation in output spectra. A waveform generator was designed that would be able to circumvent these shortcomings. It is capable of generating an asymmetric waveform, having a peak amplitude as large as 2 kV and frequency of several megahertz, which can be applied to a capacitive load. In the original intended application, the capacitive load would consist of the drift plates in a differential-mobility spectrometer. The main advantage to be gained by developing the proposed generator is that the shape of the waveform is made nearly optimum for various analytical devices requiring asymmetric-waveform such as differential-mobility spectrometers. In addition, this waveform generator could easily be adjusted to modify the waveform in accordance with changed operational requirements for differential-mobility spectrometers. The capacitive nature of the load is an important consideration in the design of the proposed waveform generator. For example, the design provision for shaping the output waveform is based partly on the principle that (1) the potential (V) on a capacitor is given by V=q/C, where C is the capacitance and q is the charge stored in the capacitor; and, hence (2) the rate of increase or decrease of the potential is similarly proportional to the charging or discharging current. The proposed waveform generator would comprise four functional blocks: a sine-wave generator, a buffer, a voltage shifter, and a high-voltage switch (see Figure 1). The sine-wave generator would include a pair of operational amplifiers in a feedback configuration, the parameters of which would be chosen to obtain a sinusoidal timing signal of the desired frequency. The buffer would introduce a slight delay (approximately equal to 20 ns) but would otherwise leave the fundamental timing signal unchanged. The buffered timing signal would be fed as input to the level shifter. The output of the level shifter would serve as a timing and control signal for the high-voltage switch, causing the switch to alternately be (1) opened, allowing the capacitive load to be charged from a high-voltage DC power supply; then (2) closed to discharge the capacitive load to ground. Hence, the output waveform would closely approximate a series of exponential charging and discharging curves (see Figure 2).

Beegle, Luther W.; Duong, Tuan A.; Duong, Vu A.; Kanik, Isik

2008-01-01

302

Assessing the hazard from geomagnetically induced currents to the entire high-voltage power network in Spain  

Science.gov (United States)

After the good results obtained from an assessment of geomagnetically induced currents (GICs) in a relatively small subset of the Spanish power transmission network, we now present the first attempt to assess vulnerability across the entire Spanish system. At this stage, we have only included the power grid at the voltage level of 400 kV, which contains 173 substations along with their corresponding single or multiple transformers and almost 300 transmission lines; this type of analysis could be extended to include the 220-kV grid, and even the 110-kV lines, if more detailed information becomes available. The geoelectric field that drives the GICs can be derived with the assumption of plane wave geomagnetic variations and a homogeneous or layered conductivity structure. To assess the maximum expected GICs in each transformer as a consequence of extreme geomagnetic storms, a post-event analysis of data from the Ebre Geomagnetic Observatory (EBR) during the 2003 Halloween storm was performed, although other episodes coincident with very abrupt storm onsets, which have proven to be more hazardous at these mid-latitudes, were analyzed as well. Preferred geomagnetic/geoelectric field directions in which the maximum GICs occur are automatically given from the grid model. In addition, EBR digital geomagnetic data were used to infer statistical occurrence probability values and derive the GIC risk at 100-year or 200-year return period scenarios. Comparisons with GIC measurements at one of the transformers allowed us to evaluate the model uncertainties.

Miquel Torta, Joan; Marsal, Santiago; Quintana, Marta

2014-12-01

303

Power supply control protocol used at GANIL  

International Nuclear Information System (INIS)

This document intends to establish specifications for power supply control so that, if complied with by power supply manufacturers, power supplies from any manufacturer can be linked at once to the Ganil Control system. The only points to take care of are reduced to physical link and filling of the data base

304

The design of the auxiliary power supplies for the TEXTOR neutral injectors  

International Nuclear Information System (INIS)

The auxiliary power supplies deliver the power of 24*(10 VAC * 60 A) for heating the filaments and the arc power of 24*(150 VDC * 80 A) for the bucket type plasma source of the TEXTOR neutral injector. Both supplies influence the operating characteristic of the plasma source which should be operated in the emission limited regime of the arc current. It is essential for achieving a stable operating point to match the output values of both supplies and the heat up the filaments to the very same temperature i.e. to control the amplitude of heating voltages within a margin of +. 50 mV. The paper describes the filament supply meeting these requirements. It consists of 8 AC-AC-converter modules each connected to a single three phase filament transformer at the injector. The design features and the technical data are given. A further important issue is the joint operation of filament supply and arc supply, both located side to side on a high voltage Faraday's cage being insulated against a voltage of 70 kV. The cage is surrounded by a grounded shield. The capacitive and inductive coupling of these supplies with their housing, coaxial leads, and transformers can be treated by electrical network computations. Results of such computations are presented showing the transient voltage distribution of the high voltage deck and of the auxiliary supplies during a grid breakdown

305

Electrical safety for high voltage arrays  

Science.gov (United States)

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

306

Power supply with nuclear reactor  

International Nuclear Information System (INIS)

Each parameter of the processes of the nuclear reactor and of the components of a power supply which convert the thermal energy generated by the reactor into electrical power is monitored by a set of four like sensors. One each of the unlike sensors which monitor the different parameters is contained in a reactor-trip logic channel. Each such unlike sensor is referred to here as a ''local sensor''. Each channel is interlocked with the other three channels and receives the signals sensed by the other three sensors, herein called ''remote sensors''. Each channel also includes means for processing the signals from the local and remote sensors. The apparatus also includes means for tripping the reactor to deenergize or trip the control rod drive and insert the control rods fully into the core so that the reactor stops supplying power. The apparatus normally operates on a ''two out of four'' configuration. This assumes that all sensors are in normal operating condition. To achieve this purpose, eight circuit breakers are provided. Two breaker contactors are controlled by each channel. The control is through the undervoltage relays of the respective breakers. To trip the reactor, it is necessary that at least four breaker contactors be opened by operation of two channels

307

High voltage variable diameter insulator  

Science.gov (United States)

A high voltage feedthrough assembly (10) having a tubular insulator (15) extending between the ground plane ring (16) and the high voltage ring (30). The insulator (15) is made of Pyrex and decreases in diameter from the ground plane ring (16) to the high voltage ring (30), producing equipotential lines almost perpendicular to the wall (27) of the insulator (15) to optimize the voltage-holding capability of the feedthrough assembly (10).

Vanecek, David L. (Martinez, CA); Pike, Chester D. (Pinole, CA)

1984-01-01

308

A regulated power supply for accelerator driven system  

International Nuclear Information System (INIS)

This paper discusses a regulated high voltage power supply (RHVPS) developed for accelerator driven systems to drive a klystron. The RHVPS uses a large no. of small voltage choppers. These choppers are switched in tandem by a novel technique to regulate output voltage. Various parts of the system are novel. The front end is a pair of transformer with 40 secondaries each. Each secondary feeds a switched power module (SPM) which has a rectifier-filter unit followed by an IGBT switch to get 1.3 kV. All 80 SPMs are connected in series. The final output is taken from the two end SPMs. A central controller uses voltage sample from each SPM and generates switching pulses for each IGBT switch. IGBTs of all SPMs are switched with a fixed phase lag from each other, resulting in purely constant voltage with ripple limited to one SPM voltage. The frequency of ripple is high and can be filtered out with a simpler filter. The system can turn off for protection of the load in less than 2 microseconds, the essential attribute for a power supply to be used with klystrons. The results of wire burn tests measure the low stored energy at fault turn off (less than10 J). The power supply (rated for 100 kV at 2.5 MW) will be used for a continuous duty with the klystron for accelerator driven system at BARC (India). A power supply giving 80 kV, 75A is being used with an accelerator system for extraction of beam along with a Neutral Beam Injector. This paper discusses the technology and expers paper discusses the technology and experimental results of the system. It also discusses various other options with similar power supply. (author)

309

Meeting the power supply challenge  

International Nuclear Information System (INIS)

A review of activities at Ontario Power Generation since deregulation was presented. Since May 1, 2002, Ontario business and residential users have been able to choose to buy electricity from local utilities at the market price or from fixed-term, fixed-price contracts with retailers. A major heat wave in the summer of 2002 forced electricity prices to rise as supply was strained by record energy demands. On November 11, 2002, Bill 210 placed the retail market on temporary hold as the price of electricity was capped at 4.3 cents per kWh for low-volume consumers. On March 21, 2003, the fixed price was extended to users up to 250,000 kWh. It is expected that energy demand in Ontario will grow 1 per cent each year for the next 10 years. Electricity supply, transmission and distribution in the Greater Toronto area must be addressed to ensure safe, reliable and affordable power. Another issue that must be addressed is that 20 per cent of Ontario's aging generating facilities will have be overhauled or replaced by 2013. Environmental issues and the pending retirement of coal as a fuel source must also be addressed. Possible solutions include returning the Pickering 'A' nuclear facility to service, additional nuclear generation, hydroelectric upgrades, and new green generation initiatives such as wind or gas-fired combined cycle generation. Maintaining the fossil option is possible by reducing emissions. 8 figs

310

Resonant power supplies for a rapid-cycling accelerator  

International Nuclear Information System (INIS)

A resonant power supply has been proposed as an efficient power supply for a future 60 GeV, kaon-producing accelerator. This report presents a detailed analysis of the circuit operation. Based on these analyses each component is designed, one-line diagram is developed, component requirements are determined and a detailed cost estimate is prepared. The major components of the system are: the magnet power supply, high-voltage by-pass thyristor switch, with 10-kA repetitive interruption capability, capacitor banks, capacitor bank thyristor switch, and an energy make-up device. The most important components are the bypass thyristor switch and the energy injection device. The bypass thyristor switch is designed to turn on and interrupt 10-kA dc current with a recovery voltage of 20kV and repetition frequency of 3 Hz. The switch consists of a large array of series- and parallel-connected thyristors and gate turn-off (GTO) devices. The make-up energy device is designed to replace the circuit energy losses

311

Monitoring System for Uninterruptible Power Supply  

OpenAIRE

In industrial process today, reliability of equipment is very important. Power supply must be able to cater the need of industrial process. In case of power failure, backup power supply system must be able to support the main process plant. This is to ensure smooth operation and product quality. In order to do this, uninterruptible power supply (UPS) system can be used to ensure the reliability, stability and consistency of the entire system. This UPS system must be monitored in order to enab...

Murad, S. A. Z.; Isa, M. N. M.; Rahman, N. A.

2007-01-01

312

A fully digital power supply noise thermometer  

OpenAIRE

Power Supply Noise (PSN) is one of the main concerns in scaled technology circuits, both if performance reliability must be assured and if power supply is to be dynamically reduced for dissipation regulation. In this paper we propose a new system for digitally sensing Power Supply and Ground levels that can be both transferred to the output for verification purposes and used by a control block within the circuit under test (CUT) for the activation of power aware policies. The sensor system sh...

Graziano, Mariagrazia

2009-01-01

313

High voltage system for the CMS electromagnetic calorimeter  

International Nuclear Information System (INIS)

The CMS Electromagnetic Calorimeter (ECAL) is made of about 75 000 lead tungstate crystals. The 61 200 crystals of the barrel part are read by Avalanche Photodiodes (APD) with internal amplification of the signal. Since the gain strongly depends on the bias voltage, the APDs require a very stable power supply system. To preserve the high energy resolution of the calorimeter, a stability of the bias voltage of the order of 10-4 is required over several months, a typical interval between absolute calibrations of the full read-out chain with physics events. This paper describes the high voltage power supply system developed for CMS ECAL and its performances as measured in laboratory tests and during test-beam operations of several modules of the calorimeter

314

Alternating polarity power supply control apparatus  

International Nuclear Information System (INIS)

An electronic switching circuit is provided for controlling transfer of electrical power from an alternating polarity electrical power supply to a load means through use of a field effect transistor device as the primary power controlling element

315

Uninterruptible power supply (UPS) systems  

Energy Technology Data Exchange (ETDEWEB)

Use of this purchase specification is not mandatory. User should review the document and determine if it meets the user`s purpose. This document contains a fill-in-the-blanks guide specification for the procurement of uninterruptible power supply (UPS) systems greater than 10 kVA, organized as follows: Parts 1 through 7--technical requirements; Appendix A--technical requirements to be included in the proposal; Appendix B--UPS system data sheets to be completed by each bidder (Seller) and submitted with the proposal; Appendix C--general guidelines giving the specifier parameters for selecting a UPS system; it should be read before preparing an actual specification, and is not attached to the specification; Attachment 1--sketches prepared by the purchaser (Owner); Attachment 2--sample title page.

NONE

1997-04-01

316

Real-Time Feed-backed Anode Power Supply for 170GHz gyrotron in KSTAR  

Directory of Open Access Journals (Sweden)

Full Text Available 3.6 MW (66 kV/55 A high voltage power supply system was developed for the 170 GHz ECH&CD system in KSTAR. It consists of the cathode power supply (CPS, anode power supply (APS, and body power supply (BPS. Currently, modulation frequency of APS was limited to less than 1 kHz due to the parasitic capacitance of Zener diode circuit including gyrotron. In order to solve these lacks of controllability and high frequency modulation of APS, the existing APS is replaced by a new type of APS and it is tested for KSTAR 170 GHz gyrotron system. This paper presents the new APS design and characteristics and the test results for 170GHz gyrotron in KSTAR ECH system.

Seok Bong-Jun

2015-01-01

317

Real-Time Feed-backed Anode Power Supply for 170GHz gyrotron in KSTAR  

Science.gov (United States)

3.6 MW (66 kV/55 A) high voltage power supply system was developed for the 170 GHz ECH&CD system in KSTAR. It consists of the cathode power supply (CPS), anode power supply (APS), and body power supply (BPS). Currently, modulation frequency of APS was limited to less than 1 kHz due to the parasitic capacitance of Zener diode circuit including gyrotron. In order to solve these lacks of controllability and high frequency modulation of APS, the existing APS is replaced by a new type of APS and it is tested for KSTAR 170 GHz gyrotron system. This paper presents the new APS design and characteristics and the test results for 170GHz gyrotron in KSTAR ECH system.

Seok, Bong-Jun; Ahn, Il-kun; Lee, Seung-kyo; Shim, Eun-yong; Bae, Young-soon; Joung, Mi; Joung, Jin-Hyun

2015-03-01

318

RHIC BEAM ABORT KICKER POWER SUPPLY SYSTEM COMMISSIONING EXPERIENCE AND REMAINING ISSUES  

International Nuclear Information System (INIS)

The RHIC Beam Abort Kicker Power Supply Systems commissioning experience and the remaining issues will be reported in this paper. The RHIC Blue Ring Beam Abort Kicker Power Supply System initial commissioning took place in June 1999. Its identical system in Yellow Ring was brought on line during Spring 2000. Each of the RHIC Beam Abort Kicker Power Supply Systems consists of five high voltage modulators and subsystems. These systems are critical devices for RHIC machine protection and environmental protection. They are required to be effective, reliable and operating with sufficient redundancy to safely abort the beam to its beam dump at the end of accumulation or at any time when they are commanded. To deflect 66 GeV ion beam to the beam absorbers, the RHIC Beam Abort Kicker Power Supply Systems were operated at 22 kV level. The RHIC 2000 commissioning run was very successful

319

Engineering Design of the ITER AC/DC Power Supply System  

International Nuclear Information System (INIS)

To design high power pulse power supplies, especially in huge power supplies have not designed till now, it is necessary to analyze a system's characteristics and relations with another systems as well as to know high voltage, high current control technologies. Contents of this project are; - Analysis of the changed designs of the AC/DC converters. - Setup of the PSIM model for the calculation of the junction temperature of the converter thyristors. - Finalize the converter's simulation modules and estimate the parallel number of an arm for each converter. - Fix the protection sequence and make a simulation. - Stability check of the power distribution system against the reactive power effect. - Design of small size hardware AC/DC converter. The results of these studies may used as one of references for practical designs of the power supplies and also used for developing Tokamak type fusion reactors in the future

320

Engineering Design of the ITER AC/DC Power Supply System  

Energy Technology Data Exchange (ETDEWEB)

To design high power pulse power supplies, especially in huge power supplies have not designed till now, it is necessary to analyze a system's characteristics and relations with another systems as well as to know high voltage, high current control technologies. Contents of this project are; - Analysis of the changed designs of the AC/DC converters. - Setup of the PSIM model for the calculation of the junction temperature of the converter thyristors. - Finalize the converter's simulation modules and estimate the parallel number of an arm for each converter. - Fix the protection sequence and make a simulation. - Stability check of the power distribution system against the reactive power effect. - Design of small size hardware AC/DC converter. The results of these studies may used as one of references for practical designs of the power supplies and also used for developing Tokamak type fusion reactors in the future

Oh, B. H.; Lee, K. W.; Chang, D. S.; Jin, J. T.; Hwang, C. K.

2010-02-15

321

Bulk water distribution power supply failures  

Scientific Electronic Library Online (English)

Full Text Available SciELO South Africa | Language: English Abstract in english This paper considers the probability of power supply failures at bulk water distribution pump stations. Electrical power supply is important within the bulk water distribution environment, particularly when pumping is required. Reliability of power supply is commonly expressed by means of indices, s [...] uch as amongst others, the SAIDI and SAIFI indices as defined by the Institute of Electrical and Electronics Engineering (IEEE). These indices are used to calculate the probability of failure associated with power supply. Data was obtained from a number of sources and used to benchmark the reliability of South African power supply against that of other countries. The reliability of power supply from seven South African Water Board (Rand Water) pump stations is also analysed. Limited data seems to be available that allows one to quantify the reliability of pump systems, taking into account the reliability of the various system components.

D T, Nel; J, Haarhoff.

2011-04-01

322

Normal and emergent power supply in 'JT-60'  

International Nuclear Information System (INIS)

JT-60 successfully ignited the first plasma on April 8, 1985. Fuji Electric Co., Ltd. constructed the power distribution facilities for the operation and the emergency power source. These facilities receive power from the central substation through two independent circuits at 6.6 kV, and supply power to the various equipments of JT-60 as the high voltage or by lowering the voltage. These facilities are composed of the power distribution facilities for the operation, the emergency power source including no power failure source and the control system. On April 8, 1985, the plasma current of 150,000 A flowed in the JT-60 for 80 msec, which was the third plasma flame in the world, following the TFTR of USA and the JET of EC. On May 29, the plasma current of one million A flowed for 3 sec successfully. The outline of the ficilities is described. These facilities are not directly related to nuclear fusion, but are the important service system, therefore, utmost attention was paid to the clarification and confirmation of the requirement, the examination of the system constitution and the attainment of the requirement, the system design, and the design, manufacture, test and installation of the equipment, especially to the aseismatic design. (Kako, I.)

323

Simplified design of switching power supplies  

CERN Document Server

* Describes the operation of each circuit in detail * Examines a wide selection of external components that modify the IC package characteristics * Provides hands-on, essential information for designing a switching power supply Simplified Design of Switching Power Supplies is an all-inclusive, one-stop guide to switching power-supply design. Step-by-step instructions and diagrams render this book essential for the student and the experimenter, as well as the design professional. Simplified Design of Switching Power Supplies concentrates on the use of IC regulators. All popular forms of swit

Lenk, John

1995-01-01

324

Performance and modelling of 70kVdc power supply with solid-state crowbar  

International Nuclear Information System (INIS)

The experimental activities of tokamak research involve development of high power RF and microwave sources for fusion related heating and current drive applications. High power RF and microwave tubes like Klystron, Gyrotron and Tetrode are in general operated with high voltage DC power supplies. These HVDC power supplies of the order of 70 kVdc, must be equipped with necessary arc fault protection in addition to general over current and over voltage protection. The arc fault protection must act within few microseconds to prevent permanent damage to the RF tube, window, etc. When an arc fault is detected, output voltage of the DC power supply is short circuited using a crowbar device (generally Ignitron, Thyratron, thyristor, rail-gap, etc.) that operates in few microseconds. This diverts the fault current from the load to crowbar device, thereby protecting the load. This is necessary as conventional protection in the power supply input takes ?100 ms to switch-off. The crowbar device must be able to take the fault current till the circuit breaker placed at power supply input is switched off. The arc fault protection is tested for its effectiveness by “wire-burn” test. Full power short circuit of ?1.5 MW DC power supply puts enormous stress on the power supply, utility and the crowbar, therefore frequent wire-burn testing is to be avoided. This report presents simulation of wire-burn test using PSIM software. Optimization of the component values without conducting actual wire-burn test could be achieved

325

Novel piezoelectric transducers for high voltage measurements  

OpenAIRE

A prerequisite for safe and stable operation of an electric power system is the accurate and reliable measurement of the system parameters, in particular, current and voltage. Conventionally, this has been achieved on High Voltage (H.V.) systems by expensive, bulky iron-core transformers and also by capacitor transformers. Both of them are increasingly coming under review (chapter 1) in modern power system due to their cost, safety implications for personnel and surrounding plant if failure o...

Va?zquez Carazo, Alfredo

2000-01-01

326

Optically triggered high voltage switch network and method for switching a high voltage  

Science.gov (United States)

An optically triggered solid state switch and method for switching a high voltage electrical current. A plurality of solid state switches (350) are connected in series for controlling electrical current flow between a compensation capacitor (112) and ground in a reactive power compensator (50, 50') that monitors the voltage and current flowing through each of three distribution lines (52a, 52b and 52c), which are supplying three-phase power to one or more inductive loads. An optical transmitter (100) controlled by the reactive power compensation system produces light pulses that are conveyed over optical fibers (102) to a switch driver (110') that includes a plurality of series connected optical triger circuits (288). Each of the optical trigger circuits controls a pair of the solid state switches and includes a plurality of series connected resistors (294, 326, 330, and 334) that equalize or balance the potential across the plurality of trigger circuits. The trigger circuits are connected to one of the distribution lines through a trigger capacitor (340). In each switch driver, the light signals activate a phototransistor (300) so that an electrical current flows from one of the energy reservoir capacitors through a pulse transformer (306) in the trigger circuit, producing gate signals that turn on the pair of serially connected solid state switches (350).

El-Sharkawi, Mohamed A. (Renton, WA); Andexler, George (Everett, WA); Silberkleit, Lee I. (Mountlake Terrace, WA)

1993-01-19

327

Development of power supply for 'JT-60'  

International Nuclear Information System (INIS)

The power source for the tokamak type critical plasma test system (JT-60) was designed, and the characteristic feature was investigated. The power source is that for plasma generation with a DC thyristor breaker. The thyristors used are CF05V (2000V, 500A) and CA02 (4000V, 800A). The test of the thyristor breaker was performed. A result showed that the break was successful at the breaking current of 6.17 kA and the recovery voltage of 12.3 kV. Various circuits for current transformer power source were proposed and studied. Two circuits, which are a parallel type and a multiple repetition type, were accepted. Choice of the best one should be made according to the practical condition. Tests with the mini-models of the circuits were performed. High voltage was generated at every break of the breaker with both circuits. (Kato, T.)

328

Upgrading the TFTR Transrex Power Supplies  

International Nuclear Information System (INIS)

In order to provide improved and expanded experimental capabilities, the existing Transrex power supplies at PPPL are to be upgraded and modernized. Each of the 39 power supplies consists of two six pulse silicon controlled rectifier sections forming a twelve pulse power supply. The first modification is to split each supply into two independent six pulse supplies by replacing the existing obsolete twelve pulse firing generator with two commercially available six pulse firing generators. The second change replaces the existing control link with a faster system, with greater capacity, which will allow for independent control of all 78 power supply sections. The third change replaces the existing Computer Automated Measurement and Control (CAMAC) based fault detector with an Experimental Physics and Industrial Control System (EPICS) compatible unit, eliminating the obsolete CAMAC modules. Finally the remaining relay logic and interfaces to the 'Hardwired Control System' will be replaces with a Programmable Logic Controller (PLC)

329

Simplified design of switching power supplies  

CERN Document Server

Simplified Design of Switching Power Supplies is an all-inclusive, one-stop guide to switching power-supply design. Step-by-step instructions and diagrams render this book essential for the student and the experimenter, as well as the design professional.Simplified Design of Switching Power Supplies concentrates on the use of IC regulators. All popular forms of switching supplies, including DC-DC converters, inverters, buck, boost, buck-boost, pulse frequency modulation, pulse width modulation, current-mode control and pulse skipping, are described in detail. The design examples may

Lenk, John

1996-01-01

330

Controlled power supply for isotopes separator  

International Nuclear Information System (INIS)

This equipment is destined to equip the separator of isotopes who is the subject of the CEA report n 138. It includes: - a controlled power supply in voltage. - a controlled power supply in current. The spectra of fluctuations of these assembly is different in the two cases. (authors)

331

Neutrino horn power supply operational experience  

International Nuclear Information System (INIS)

The operational experiences required to run the 300 kA pulsed power supply at Brookhaven National Laboratory are given. Various interlocks and monitoring circuits are described and the impact on system reliability are discussed. The initial conditioning process of the power supply during startup is described

332

Design and development of HV power supply with crowbar protection for screen electrode of RF amplifier  

International Nuclear Information System (INIS)

K-130 room temperature Cyclotron is being renovated at VECC. Radio frequency system is most vital part of cyclotron which is also under modification. The screen biasing plays most critical role in tetrode power amplifiers. A high voltage power supply (1.5 kV and 1.0 A) with fast crowbar protection is required for screen electrode biasing of rf amplifier tube. This power supply is facilitated with primary variac control regulation loop. The EIMAC 4CW2000 tube is connected in shunt for closed loop ripple rejection of load. This active ripple rejecter reduces capacitor filter size as well as stored energy. Crowbar protection is incorporated by using thyristers. Crowbar protection scheme is designed in such a way, it divert the energy from screen electrode, in case any unfavourable condition occurring with tube. This paper presents detailed design, development and testing results of HV power supply for screen electrodes with fast crowbar protection. (author)

333

Transient phenomena analysis of a DC-1 MV power supply for the ITER NBI  

International Nuclear Information System (INIS)

A power supply for the ITER Neutral Beam Injector (NBI) is a DC ultra-high voltage (UHV) power supply to accelerate negative ion beams of 40 A up to an energy of 1 MeV. Japan Atomic Energy Agency as the Japan Domestic Agency for ITER contributes procurement of dc -1 MV main components such as step-up -1 MV transformers rectifiers, a high voltage deck 2, a -1 MV insulating transformer, a transmission line, a surge reduction system and equipments for site test. Design of the surge suppression in the NBI power supply is one of the key issues to obtain the stable injector performance. This report describes the design study using EMTDC code on the surge suppression by optimizing the core snubber and additional elements in the -1 MV power supply. The results show that the input energy from the stray capacitance to the accelerator at the breakdown can be reduced to about 25 J that is smaller than design criteria for ITER. (author)

334

Design of 500 kV/20 mA power supply for the electron beam machine accelerating voltage  

International Nuclear Information System (INIS)

The 500 kV/20 mA high voltage power supply for the electron beam machine accelerating voltage has been designed. The HV power supply is a Cocroft-Walton type and it's main components are voltage multiplier is designed using 20 stage of 0.22 ?F/50 kV capacitor and IN 4007 diodes. The power oscillator is designed using ITK 15-2 triode and the power supply for the oscillator is designed using 3-phase transformer. The design shows that the voltage multiplier has input voltage of 12.814 kV, power last of 503 want and input power of 12.6 kW. The power which must be supplied by power oscillator is 17.2 kW. (author)

335

Resonant converter topologies for constant-current power supplies and their applications  

International Nuclear Information System (INIS)

Power electronics, in general, and power supplies, in particular, is an important field of accelerator technology due to its widespread use, for instance in dc, ramp or pulse magnet power supplies, high voltage power supplies for electrostatic accelerators and RF amplifies, power supplies for vacuum pumps, vacuum gauges, beam diagnostic devices etc. It has been possible to meet stringent performance requirements with the continuing advancement in the field of power electronics. Resonant converters have been an active area of research in power electronics field due to variety of topologies, diverse, peculiar and useful characteristics. While the majority of the previous work on resonant converters has been directed towards developing methods of analysis and control techniques for the mentioned applications, very little has been done to explore their suitability for application as a constant-current power supply, which is either inherently required or can be advantageously applied in power supplies for various accelerator subsystems and other industrial applications such as electric arc welding, laser diode drivers, magnet illumination systems, battery charging, electrochemical processes etc.

336

Reliability analysis of emergency transfer logic for restoration of power supply to safety related loads  

International Nuclear Information System (INIS)

Nuclear Power Plants (NPPs) have normal as well as emergency power supply systems. Both the power supply systems are to be reliable for proper operation of the plant. Diesel Generators (DGs) are the main on site power sources in Class III Emergency power supply system in the Nuclear Power Plants. Normally station auxiliary loads are fed by Class IV power supply system and during Class IV failure, essential safety and safety related loads are fed by Class III power supply system. The transfer of these loads from Class IV to Class III power supply is done through Emergency Transfer (EMTR) logic. For effective restoration of loads, EMTR logic has to be reliable. The EMTR scheme covers the sensing of under voltage on the 6.6 kV emergency bus, starting of DG on auto mode, tripping of motor loads and closing of DG circuit breaker and then sequential load pick up at high voltage and medium voltage levels. Both hardwired logic and PLC based logic are adopted for EMTR in NPPs. This paper discusses the reliability analysis carried out for hardwired EMTR logic by constructing fault tree using ISOGRAPH software. The target unavailability of EMTR system for plant safety is 10-4. It is shown that hardwired logic developed meets the target unavailability. (author)

337

Design of a prototype of a van de Graaf high voltage generator  

International Nuclear Information System (INIS)

Prototype of a Generator van de Graaf which operates at atmospheric pressure is constructed. The electrode is made of copper with the diameter of 70 cm and with the height of 75 cm. Colomns are made of pralon and rubber belt and work with a rotary motor 1/3 HP, 1400 cycles per sec. A high voltage power supply of 6000 V is regulated with a transformator 110 V which is amplified by 4 stages Cockroft Walton system. (author)

338

Basic design concept, installation, commissioning and operation of the JET Integrated Power Supply System  

International Nuclear Information System (INIS)

A brief account of the main characteristics and performance of the JET Power Supply Subsystems is given in the paper. There are two Substations, the 132 kV/11 kV, 20 MVA one provides for the ''continuous'' AC loads, the other 400 kV/33 kV, 600 MVA supplies the pulsed loads, through the Controlled Rectifier Units for the JET Toroidal Coils, the Plasma Positioning Coils, the Neutral Injectors and the Radio Frequency Generators. The same Substation provides also power to the two Flywheel Motor Generator Sets, which complement the pulse power taken directly from the Grid, and supply the Toroidal Coils and the Ohmic Heating Coils. The concluding remarks deal with a brief technical and economic comparison between energy pulses taken from the Flywheel Generators and pulses taken directly from the High Voltage Grid

339

Adjustable high voltage pulse generator  

International Nuclear Information System (INIS)

The new high voltage pulse generator is mainly composed of condense capacitors, hydrogen thyratron, high voltage transformer and voltage adapter. The total capacitance and charged voltage of the condense capacitors can be changed and controlled. The output pulse of the generator has an exponential waveform, and its rising time is 0.4-0.6 ?s. By adjusting the capacitors and its charged voltage, the pulse width varies from 1.5 ?s to 4.0 ?s, and the pulse amplitude varies from 10 kV to 200 kV

340

Improvements to the power supply and control systems of Geiger-Mueller counter tubes  

International Nuclear Information System (INIS)

This invention aims to provide a power supply and control system for Geiger-Mueller counter tubes requiring only one high voltage output, corresponding to the 'active' phase voltage. With this in view, the invention proposes, inter alia, a system comprising a high voltage source connected to the anode of the GM tube whose cathode is connected to a determination and counting circuit, featuring a cathode connected to the source via an electronic switch and to earth by a component for holding the potential difference at a given level and by another electronic switch, placed in series. The switches are controlled in turn so as alternately to bring the cathode to a first voltage, enabling the tube to function, and to a second voltage, causing the blocking of the tube, this second voltage being set by the component creating the voltage difference

341

Power supply for a current ionization chamber  

International Nuclear Information System (INIS)

Power supply of compensation current ionization chamber in the dynamic range of 1 mA-1 pA of the chamber current measured is described. The power supply circuit is made using semiconductor elements and microschemes. Stabilitron is the basic element in the stabilization scheme. Infralow frequency background of output voltage of the power supply is comparable with the voltage background of dry battery. The power supply works out fixed voltage of positive polarity +50O V and smoothly regulated in the range of 0-500 V the voltage of negative polarity for ?-background compensation. The power supply load current is 0-1.5 mA. The voltage stabilization coefficient is >= 5x104. Several supply power blocks of compensation ionization chamber are made according to the scheme described which are used in critical test bed and energy reactors. The block described has been used for supply of chambers of reactivity analogous measurement in the experiments on the determination of reactivity of critical assembly with uranium-graphite fuel core

342

Nuclear power: energy security and supply assurances  

International Nuclear Information System (INIS)

Expectations are high for nuclear power. This paper first summarizes recent global and regional projections for the medium-term, including the 2007 updates of IAEA projections plus International Energy Agency and World Energy Technology Outlook projections to 2030 and 2050. One driving force for nuclear power is concern about energy supply security. Two potential obstacles are concerns about increased nuclear weapon proliferation risks, and concerns by some countries about potential politically motivated nuclear fuel supply interruptions. Concerning supply security, the paper reviews different definitions, strategies and costs. Supply security is not free; nor does nuclear power categorically increase energy supply security in all situations. Concerning proliferation and nuclear fuel cut-off risks, the IAEA and others are exploring possible 'assurance of supply' mechanisms with 2 motivations. First, the possibility of a political fuel supply interruption is a non-market disincentive discouraging investment in nuclear power. Fuel supply assurance mechanisms could reduce this disincentive. Second, the risk of interruption creates an incentive for a country to insure against that risk by developing a national enrichment capability. Assurance mechanisms could reduce this incentive, thereby reducing the possible spread of new national enrichment capabilities and any associated weapon proliferation risks. (orig.)

343

Design of ITER NBI power supply system  

International Nuclear Information System (INIS)

Power supply system for the ITER neutral beam injector (NBI) whose total injection power is 1 MeV, 50 MW from three modules, has been designed. The power supply system consists of a source power supply for negative ion production/extraction and a DC 1 MV, 45 A power supply for negative ion acceleration. An inverter controlled multi-transformer/rectifier system has been adopted to the acceleration power supply. An inverter frequency of 150 Hz was selected to satisfy required specifications which are rise time of <100 ms, voltage ripple of <10% peak to peak and cut off speed of <200?s. It was confirmed that the rise time, the ripple and the cut off speed is about 50 ms, 7% and <200?s respectively by computation. It was also confirmed that a surge current and an energy input to the ion source at the breakdown can be suppressed lower than 3 kA and 10 J, which are considered to be lower than allowable values. A 1 MV transmission line has been designed from a view point of electric field on the inner conductors and grounded conductor. The results from the design study indicate that all the required specification to the power supply system can be satisfied and that R and D on the transmission line is one of the most important subjects. (author)

344

Multi-Channel Adjustable DC Power Supply with Single Transformer Based on Spectral Separation  

Science.gov (United States)

To meet the need of multi-channel DC power supply to activate multiple macro fiber composite (MFC) material simultaneously, a novel multi-channel adjustable DC supply using single-input single-output transformer based on spectral separation is proposed. A hybrid signal containing multiple frequency bands is boosted to obtain a high-voltage signal without bands change. Several frequency selection circuits are then used to separate individual signals in different frequency band from the high-voltage signal. Finally, these signals are rectified and filtered respectively to obtain multiple channel DC voltages. The feasibility of the proposed scheme is analyzed theoretically and verified by simulation. The hybrid signal containing multiple frequency bands is constructed by MCU (Micro Control Unit) and boosted using push-pull boost circuit. Low-pass, band-pass and high-pass frequency selection circuits are used to obtain the individual high-voltage signal in different frequency bands, and the amplitude frequency response characteristics of these filters are simulated using PSpice. Experimental results prove that each part of the scheme runs reliable and the output is stable and adjustable.

Benfeng, Zhang; Huafeng, Li; Sunan, Li

2014-01-01

345

Control units for APS power supplies  

International Nuclear Information System (INIS)

The Advanced Photon Source (APS) accelerator facility is made up of five major subsystems in addition to the linac: the positron accumulator ring (PAR), low energy transport (LET), booster synchrotron (SYNCH), high energy transport (HET), the storage ring (SR). Each subsystem has multiple magnet power supply combinations, some requiring multiple of operation. These magnet and power supply combinations computer controlled and monitored. The power supply control unit (PSCU) is the first layer of hardware and software above the power supply itself and is described in this paper. The description includes the basic philosophy for each of operation and how it influences the topology and of implementing control. The design of the analog reference blocks (ARBs) influenced the design of other custom functions well as the feedback controls for vibration and other dynamic corrections. The command set supported by the PSCU is discussed

346

Correction magnet power supplies for APS machine  

International Nuclear Information System (INIS)

The Advanced Photon Source machine requires a number of correction magnets; five kinds for the storage ring, two for the injector synchrotron, and two for the positron accumulator ring. Three types of bipolar power supply will be used for all the correction magnets. This paper describes the design aspects and considerations for correction magnet power supplies for the APS machine. 3 refs., 3 figs., 1 tab

347

Optimization of Resonant Power Supply Circuit  

International Nuclear Information System (INIS)

A Resonant Power Supply has been proposed to power Rapid Cycling Accelerator magnets. The Resonant Power Supply circuits were studied extensively, but were not optimized. Most designs assume equal choke and magnet inductance, however, the variation of inductance affects both performance and cost of the system. This paper optimizes the Resonant Power Supply Circuit by selecting the most feasible choke inductance. For this optimization, a computer model and an approximate design method were developed. The effect of choke inductance on the components rating and cost was determined. It was found that the increase of choke inductance reduces the maximum and increases the minimum choke current, which leads to a significant increase of system losses. The maximum voltage is independent of the choke inductance. The described change of choke current reduces the current of the Bypass Thyristor Switch and the Capacitor Bank Switch, which results in cost reduction. The increase of choke inductance reduces the size of capacitor banks. The loss increase requires larger Make-up Power Supply and ac supply systems. It also increases the operation costs. The system cost function has a minimum, when the choke inductance is about 1.5--2 times larger than the magnet one. The application of the result will lead to a more economical and efficient Resonant Power Supply. 2 refs., 8 figs., 1 tab

348

Power supply strategy in Lithuania  

International Nuclear Information System (INIS)

Nuclear power plant produces about 80% of electricity in Lithuania. However, national energy strategy as a result of comprehensive assessment of technical, economic and political factors foresees closure of its first unit by 2005. Future fate of the second unit will be defined later in 2004 . Electricity demand requirements will be covered by other modernised power plants burning fossil fuel. This may create some environmental problems, especially if unit 2 would be closed. Earlier closure of the nuclear power plant is a great economical burden not only for the power sector but also to the whole national economy. This requires substantial technical and financial support from EU and other developed countries. (author)

349

New intelligent magnet power supplies for LAMPF  

International Nuclear Information System (INIS)

New magnet power supplies are scheduled to be installed in the proton linac at the Clinton P. Anderson Meson Physics Facility (LAMPF). The control and interface design of these power supplies represents a departure from all others onsite. A high-level ASCII control protocol has been designed. The supplies have sophisticated microprocessor control onboard and communicate with the accelerator control system via RS-422 (serial communications). The low-level software used by the accelerator control system is currently being rewritten to accommodate these new devices. They will communicate with the control system through a terminal server port connected to the site-wide ethernet backbone. This means that each supply will, for all intents and purposes, be a network object. Details of the design strategies for the analog and digital control for these supplies as well as the control protocol interface will be presented. 5 refs., 5 figs., 1 tab

350

The fast extraction kicker power supply for the main ring of J-PARC  

International Nuclear Information System (INIS)

An effect induced by parasitic inductance in a pulsed power supply for a fast extraction kicker was studied. The parasitic inductance in high voltage capacitors for a low impedance pulse forming network disturbs a sharp rise of an excitation current. A high voltage capacitor with a coaxial structure to minimize the parasitic inductance is proposed. The effectiveness was confirmed experimentally. An impedance mismatch by a leakage inductance of a pulse transformer in a transmission line was studied. The effect is serious at the flat-top period of the excitation current. By introducing a compensation circuit, which is composed by a capacitor and a resistor, impedance matching was established. The pulsed power supply for the fast extraction kicker was operated at a charging voltage of 30 kV. A required rise time of less than 1.1 ?s was achieved. The flatness was also confirmed to be in an acceptable value of less than 1%. -- Highlights: ?An effect by parasitic inductance of the energy storage capacitor of the PFN was studied. ?A faster rise time was achieved by introducing a coaxial structure for the PFN capacitor. ?An impedance mismatch by a leakage inductance of a pulse transformer was studied. ?Serious deterioration of the pulsed waveform was cured by a compensation circuit. ?The pulsed power supply for the fast extraction kicker was developed and operated successfully

351

ISABELLE magnet power supply system performance analysis  

International Nuclear Information System (INIS)

The power supply system that will energize the superconducting magnets in the ISABELLE 400 x 400 GeV accelerator must supply various voltages and currents. The voltages for the correction winding range from ten to one hundred twenty-five volts unipolar and bipolar with current rating of 50 to 300 amperes. The main field winding requires voltages from 90V (at flattop) to 600V during maximum ramp rate or acceleration cycle. The power supplies are programmable over their full range of output current with a reproducibility error varying from +- 10 ppM to +- 400 ppM of full scale. Included within the reproducibility error are the long and short term stability requirements of the power supplies. The purpose of this paper is to define some of the design goals and outline the approach taken in reaching these goals

352

General conditions for electric power supply  

International Nuclear Information System (INIS)

If it is uncertain whether future power bills will be paid fully, it is admissible to take an action claiming a declaration which states that the electricity rate payment boycotter has no right to non-payment nor a right to withhold payment towards the electricity supply utility, and that the electricity supply utility has the right to stop energy supply because of reduced electricity rate payments effected and/or announced, and to denounce the contract without observing any term of notice. If the electricity buyer reduces a power bill to be paid without any legal grounds, the electricity supply utility has the right to stop power supplies and to denounce the power supply contract without observing any term of notice. The freedom of thought and the freedom of opinion must not be expressed by reducing power bills to be paid. Basic rights discontinue to be effective as soon as a contract or law is broken. A weighing of protected interests is not effected if the exercise of a basic law is unlawful. (orig./HP)

353

Potential application of microporous structured poly(vinylidene fluoride-hexafluoropropylene)/poly(ethylene terephthalate) composite nonwoven separators to high-voltage and high-power lithium-ion batteries  

Energy Technology Data Exchange (ETDEWEB)

Highlights: > Microporous-structured PVdF-HFP/PET composite nonwoven separators for Li-batteries. > Well-developed microporous structure and liquid electrolyte wettability. > Provision of facile ion transport and suppressed growth of cell impedance. > Superior cell performance at high-voltages/high-current densities. - Abstract: We demonstrate potential application of a new composite non-woven separator, which is comprised of a phase inversion-controlled, microporous polyvinylidene fluoride-hexafluoropropylene (PVdF-HFP) gel polymer electrolyte and a polyethylene terephthalate (PET) non-woven support, to high-voltage and high-power lithium-ion batteries. In comparison to a commercialized polyethylene (PE) separator, the composite non-woven separator exhibits distinct improvements in microporous structure and liquid electrolyte wettability. Based on the understanding of the composite non-woven separator, cell performances of the separator at challenging charge/discharge conditions are investigated and discussed in terms of ion transport of the separator and AC impedance of the cell. The aforementioned advantageous features of the composite non-woven separator play a key role in providing facile ion transport and suppressing growth of cell impedance during cycling, which in turn contribute to superior cell performances at harsh charge/discharge conditions such as high voltages and high current densities.

Jeong, Hyun-Seok; Choi, Eun-Sun [Department of Chemical Engineering, Kangwon National University, Chuncheon, Kangwondo, 200-701 (Korea, Republic of); Kim, Jong Hun [Batteries R and D, LG Chem, Yusong-gu, Daejon, 305-380 (Korea, Republic of); Lee, Sang-Young, E-mail: syleek@kangwon.ac.kr [Department of Chemical Engineering, Kangwon National University, Chuncheon, Kangwondo, 200-701 (Korea, Republic of)

2011-05-30

354

Commissioning and early operation of the power supply and protection system for the extraction grid of the JET neutral injectors  

International Nuclear Information System (INIS)

After a brief description of the high voltage power supply and protection system, the various steps in the commissioning process are described. The major problem encountered during commissioning was that of spurious tetrode oscillations. The steps that were necessary to overcome this problem are described. Early operation with neutral injector on the test bed is also described and the status of the first eight units for the JET machine is given

355

Commissioning and early operation of the power supply and protection system for the extraction grid of the JET neutral injectors  

International Nuclear Information System (INIS)

After a brief description of the high voltage power supply and protection system, the various steps in the commissioning process are described. The major problem encountered during commissioning was that of spurious tetrode oscillations. The steps that were necessary to overcome this problem are described. Early operation with neutral injector on the test bed is also described and the status of the first eight units for the JET machine is given. (author)

356

A new type to quadrupole power supply  

International Nuclear Information System (INIS)

The maximum outputs of this new type of quadrupole power supply are 220 A and 530 A respectively at a repetition rate of 12.5 pulses per second with a current variation no greater than ± 0.1% during the beam time. The load current can be automatically adjusted by using power transistors which are in series with the magnet loads

357

Efficiency switching-mode power supply  

International Nuclear Information System (INIS)

A switching-mode, blocking oscillator based power supply employs proportional base drive and an improved design of rise-time suppression to improve effeciency and reliability. Current limiting elements cooperate with pass transistor control circuits to provide abrupt and power-efficient primary circuit switching

358

1000-kVA arc power supply  

International Nuclear Information System (INIS)

Because of ever-increasing power demands for the development of the Oak Ridge duoPIGatron ion source, a continuous-duty arc power supply was constructed for the Medium Energy Test Facility (METF) to furnish power for the plasma generator of experimental ion sources. The power supply utilizes 12-pulse rectification with half-wave switching in a delta and wye full-wave bridge that may be connected in series or parallel. It will deliver 340 V dc, 2500 A to an ion source when series connected and 170 V dc, 5000 A when paralleled connected. Silicon-controlled rectifiers (SCR) in each rectifier bridge can be switched for pulses as short as 10 ms through continuous duty. The filter section that reduces the ripple in the output consists of an inductor-to-capacitor (L-C) filter to smooth the 720-Hz pulses. The power transformer serves as an isolation transformer allowing the secondary to be elevated to the accelerating potential of the ion source. The dc output level is controlled with a 1000-kVA auto transformer connected to the primary of the power transformer. All elevated voltages and currents are monitored at ground potential with an optical telemetry system. This paper describes the power supply in detail, including block diagrams, component specifications, and waveforms when supplying power to an ion source

359

Basic technology of synchrotron power supply  

International Nuclear Information System (INIS)

The thyristor power supply for a synchrotron magnet system is described. An analysis of the magnet strings, power electronics and control system is carried out with a bird's-eye view, however the fundamental description is appeared. It assumes a student and an engineer in fields concepts, which can be the electronics designing in related fields, and a background in Laplas transforms. It presents an example of power supply, which is developed for the synchrotron- cooler ring TARN II at Institute for Nuclear Study, Univ. of Tokyo. (author)

360

Basic technology of synchrotron power supply  

Energy Technology Data Exchange (ETDEWEB)

The thyristor power supply for a synchrotron magnet system is described. An analysis of the magnet strings, power electronics and control system is carried out with a bird`s-eye view, however the fundamental description is appeared. It assumes a student and an engineer in fields concepts, which can be the electronics designing in related fields, and a background in Laplas transforms. It presents an example of power supply, which is developed for the synchrotron- cooler ring TARN II at Institute for Nuclear Study, Univ. of Tokyo. (author).

Watanabe, Shin-ichi

1995-01-01

361

DA?NE magnet power supply system  

International Nuclear Information System (INIS)

The e+-e-, 1020 MeV at center of mass, Particle Accelerator Complex DA?NE, consists of a linear accelerator (Linac), a damping ring (D.A.), nearly 180 m of transfer lines (T.L.) and two storage rings (S.R.), that intersect each other in two points (I.P.), for ? particle production. The D.A., T.L. and S.R. magnets are powered by means of 462 power supplies, rating from 100 W to 1 MW. The very different output currents, from 10 A to 2300 A, and output voltages, from 8 V to 1300 V, imposed many different technical solution realized by the world industry. This paper describes the Power Supply System giving also a description of the different typologies, their characteristics and control systems. The paper reports also the power supply performances and gives information on their installation and first year operation period

362

Implementation and design of monitoring and control system in the power supply system for EAST poloidal field  

International Nuclear Information System (INIS)

The monitoring interface is designed using configuration software. By means of this interface, the monitoring node can communicate with the high voltage monitoring node and field bus controllers, so the status of the poloidal field power supply system can be monitored in real time reliably. Meanwhile, the monitoring data will be sent to database node for backup through ODBC. The structure of the power supply monitoring and control system is briefly described. The procedure of real-time data transfer and processing is realized by different communication protocols. (authors)

363

A novel High-Voltage System for a triple GEM detector  

OpenAIRE

A novel High-Voltage System for a triple GEM detector has been designed and realized in Frascati within the LHCb muon detector framework. The system is built with seven floating power supply, with a maximum of 1200 V each, and controlled via CANbus, for voltage settings and monitoring. Several HV modules can be installed in a nano-ammeter mainframe already developed in Frascati, realizing a HV crate able to supply up to 24 triple GEM chambers with a 1 nA resolution monitoring system.

Corradi, Giovanni; Murtas, Fabrizio; Tagnani, Diego

2007-01-01

364

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

Science.gov (United States)

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

365

Analysis of three-phase power-supply systems using computer-aided design programs  

International Nuclear Information System (INIS)

A major concern of every designer of large, three-phase power-supply systems is the protection of system components from overvoltage transients. At present, three computer-aided circuit design programs are available in the Magnetic Fusion Energy (MFE) National Computer Center that can be used to analyze three-phase power systems: MINI SCEPTRE, SPICE I, and SPICE II. These programs have been used at Lawrence Livermore Laboratory (LLL) to analyze the operation of a 200-kV dc, 20-A acceleration power supply for the High Voltage Test Stand. Various overvoltage conditions are simulated and the effectiveness of system protective devices is observed. The simulated overvoltage conditions include such things as circuit breaker openings, pulsed loading, and commutation voltage surges in the rectifiers. These examples are used to illustrate the use of the computer-aided, circuit-design programs discussed in this paper

366

Power supply system for JAERI AVF cyclotron  

Energy Technology Data Exchange (ETDEWEB)

An AVF cyclotron (K number : 110) system, which is main accelerator to promote for advanced radiation application using various ion beams, has been introduced in Takasaki Establishment of JAERI. This cyclotron system consists of electro-static magnet, radio frequency, beam diagnostic, computer control vacuum, cooling systems and power supplies for these systems are equipped according to the function of their loads. This report describes the power supply system for the cyclotron. The primary electric-supply lines to TIARA (Takasaki Ion Accelerators for Advanced Radiation Application) facility and the secondary ones to the cyclotron system are explained briefly, then the construction of power supplies for the cyclotron system is illustrated. Measurement results of current stability and ripple are shown in regard to the power supplies for magnets which have occupied in the great part of them, especially. Temperature rise of assembled power cables into a bend sleeve which has penetrated across the shielding wall was estimated, and temperature measurement was also carried out practically. (author).

Nakamura, Yoshiteru; Yokota, Wataru; Okumura, Susumu [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment] [and others

1994-03-01

367

Design of multi-way composite switching power supply for intelligent sensor system  

International Nuclear Information System (INIS)

By the work principle of double grid air counter intelligent sensor system for detecting low energy electron emission, the design specifications of the power supply is put forward. The article goes on with particular design of each part of the multi-way output power supply circuit. The high-voltage-output circuit is a single-end reverse exciting switching power supply, the middle-voltage-output circuit is a push-pull switching power supply under close-loop control and low-voltage-output circuit is realized with integrated power circuit. To design different kinds of switching transformer, varied methods are analyzed in detail. In middle-voltage-output circuit, the following functions can be realized with KA7500B; (1) push-pull output mode, (2) PWM control, (3) soft start, (4) lack-voltage protection, (5) over-current protection. Experiments indicate that the multi-way output power supply, which adopts technology of PWM, satisfies the electrical requirements of sensor system, gets a high efficiency, realizes the miniaturization and has a rather long life duration. (authors)

368

High power fast ramping power supplies  

Energy Technology Data Exchange (ETDEWEB)

Hundred megawatt level fast ramping power converters to drive proton and heavy ion machines are under research and development at accelerator facilities in the world. This is a leading edge technology. There are several topologies to achieve this power level. Their advantages and related issues will be discussed.

Marneris,I.; Bajon, E.; Bonati, R.; Sandberg, J.; Roser, T.; Tsoupas, N.

2009-05-04

369

High voltage electrical amplifier having a short rise time  

Science.gov (United States)

A circuit, comprising an amplifier and a transformer is disclosed that produces a high power pulse having a fast response time, and that responds to a digital control signal applied through a digital-to-analog converter. The present invention is suitable for driving a component such as an electro-optic modulator with a voltage in the kilovolt range. The circuit is stable at high frequencies and during pulse transients, and its impedance matching circuit matches the load impedance with the output impedance. The preferred embodiment comprises an input stage compatible with high-speed semiconductor components for amplifying the voltage of the input control signal, a buffer for isolating the input stage from the output stage; and a plurality of current amplifiers connected to the buffer. Each current amplifier is connected to a field effect transistor (FET), which switches a high voltage power supply to a transformer which then provides an output terminal for driving a load. The transformer comprises a plurality of transmission lines connected to the FETs and the load. The transformer changes the impedance and voltage of the output. The preferred embodiment also comprises a low voltage power supply for biasing the FETs at or near an operational voltage.

Christie, David J. (Pleasanton, CA); Dallum, Gregory E. (Livermore, CA)

1991-01-01

370

Lunar surface fission power supplies: Radiation issues  

International Nuclear Information System (INIS)

A lunar space fission power supply shield that uses a combination of lunar regolith and materials brought from earth may be optimal for early lunar outposts and bases. This type of shield can be designed such that the fission power supply does not have to be moved from its landing configuration, minimizing handling and required equipment on the lunar surface. Mechanisms for removing heat from the lunar regolith are built into the shield, and can be tested on earth. Regolith activation is greatly reduced compared with a shield that uses only regolith, and it is possible to keep the thermal conditions of the fission power supply close to these seen in free space. For a well designed shield, the additional mass required to be brought fro earth should be less than 1000 kg. Detailed radiation transport calculations confirm the feasibility of such a shield

371

Lunar surface fission power supplies: Radiation issues  

International Nuclear Information System (INIS)

A lunar space fission power supply shield that uses a combination of lunar regolith and materials brought from earth may be optimal for early lunar outposts and bases. This type of shield can be designed such that the fission power supply does not have to be moved from its landing configuration, minimizing handling and required equipment on the lunar surface. Mechanisms for removing heat from the lunar regolith are built into the shield, and can be tested on earth. Regolith activation is greatly reduced compared with a shield that uses only regolith, and it is possible to keep the thermal conditions of the fission power supply close to those seen in free space. For a well designed shield, the additional mass required to be brought from earth should be less than 1,000 kg. Detailed radiation transport calculations confirm the feasibility of such a shield

372

Environmental impact of high voltage substations  

International Nuclear Information System (INIS)

The first Romanian methodology for simultaneous environmental and human risk evaluation in case of HV installations within substations pertaining to nuclear power stations, based on EU regulation is now applicable in Cernavoda substation. High voltage substations are zones where the environmental impact is focused on electromagnetic field that's causes particular effects in living tissues (human being included). That is the reason why is necessary to identify the potential risk sources, the asses including the way to correct them and to dissimulate the results to the staff and the operational personal.(author)

373

Smart Power Supply for Battery-Powered Systems  

Science.gov (United States)

A power supply for battery-powered systems has been designed with an embedded controller that is capable of monitoring and maintaining batteries, charging hardware, while maintaining output power. The power supply is primarily designed for rovers and other remote science and engineering vehicles, but it can be used in any battery alone, or battery and charging source applications. The supply can function autonomously, or can be connected to a host processor through a serial communications link. It can be programmed a priori or on the fly to return current and voltage readings to a host. It has two output power busses: a constant 24-V direct current nominal bus, and a programmable bus for output from approximately 24 up to approximately 50 V. The programmable bus voltage level, and its output power limit, can be changed on the fly as well. The power supply also offers options to reduce the programmable bus to 24 V when the set power limit is reached, limiting output power in the case of a system fault detected in the system. The smart power supply is based on an embedded 8051-type single-chip microcontroller. This choice was made in that a credible progression to flight (radiation hard, high reliability) can be assumed as many 8051 processors or gate arrays capable of accepting 8051-type core presently exist and will continue to do so for some time. To solve the problem of centralized control, this innovation moves an embedded microcontroller to the power supply and assigns it the task of overseeing the operation and charging of the power supply assets. This embedded processor is connected to the application central processor via a serial data link such that the central processor can request updates of various parameters within the supply, such as battery current, bus voltage, remaining power in battery estimations, etc. This supply has a direct connection to the battery bus for common (quiescent) power application. Because components from multiple vendors may have differing power needs, this supply also has a secondary power bus, which can be programmed a priori or on-the-fly to boost the primary battery voltage level from 24 to 50 V to accommodate various loads as they are brought on line. Through voltage and current monitoring, the device can also shield the charging source from overloads, keep it within safe operating modes, and can meter available power to the application and maintain safe operations.

Krasowski, Michael J.; Greer, Lawrence; Prokop, Norman F.; Flatico, Joseph M.

2010-01-01

374

Design and Construction of a Test Bench to Characterize Efficiency and Reliability of High Voltage Battery Energy Storage Systems  

DEFF Research Database (Denmark)

Stationary battery energy storage systems are widely used for uninterruptible power supply systems. Furthermore, they are able to provide grid services. This yields in rising installed power and capacity. One possibility uses high voltage batteries. This results in an improvement of the overall system efficiency. High voltage batteries may be advantageous for future medium voltage DC-grids as well. In all cases, high availability and reliability is indispensable. Investigations on the operating behavior of such systems are needed. For this purpose, a test bench for high voltage storage systems was built to analyze these processes for different battery technologies. A special safety infrastructure for the test bench was developed due to the high voltage and the storable energy of approximately 120 kWh. This paper presents the layout of the test bench for analyzing high voltage batteries with about 4,300 volts including all components, the safety requirements with the resultant safety circuit and the aim of theinvestigations to be performed with the test bench.

Blank, Tobias; Thomas, Stephan

2010-01-01

375

Power supply for thermonuclear devices  

International Nuclear Information System (INIS)

Purpose: To decrease the withstand voltage and the capacity of a capacitor and the power capacity of an AC - DC converter required for the change of current in air-core transformer coils, with respect to the plasma breakdown and plasma current rising. Method: Current changes in air-core transformer coils have been made so far by a capacitor system of discharging electrical energy at once stored in a capacitor or a variable voltage DC conversion system of suddenly interrupting the previous excitation by a variable voltage DC converter. The two systems are combined in this invention, in which a one-way flowing switch is used, to share the current change required for the previous excitation of the air-core transformer coils to the condenser system and share the low voltage and gradual current change required thereafter to the variable voltage DC converter system. (Nakamoto, H.)

376

Commissioning experiences on high voltage generator of 750 KeV DC accelerator at RRCAT, Indore  

International Nuclear Information System (INIS)

Design approach of high voltage generator for 750 keV DC accelerator, developed at RRCAT Indore, inculcates a unique feature of high frequency operation of symmetrical Cockcroft-Walton voltage generator. Apart from design simplicity and feasibility of modular construction, the high frequency use of symmetrical Cockcroft-Walton circuit gives added advantages of less ripple, better regulation, faster response and low stored energy in the system. Additionally the scheme allows us the use of low voltage, light weight components thus improving the overall economy of the system. The accelerator has been commissioned and made operational at its rated energy of 750 keV in the recent past. With brief introduction on design aspects of high voltage generator and filament power supply of this accelerator, the paper presented here describes the developmental steps of various components with focus on challenges encountered and solutions implemented. Development of high frequency inverter, high voltage ferrite core transformer, compensating inductors, interface bushings, voltage multiplier stack, and filament transformer along with floating power supply for electron emitter of the accelerator has been dealt in detail. The failures encountered during commissioning stages of the accelerator have been reported with measures taken for improvement of the specific components. Intricacies of the reflected capacitance of the multiplier stack and arc-current ground return are also described with their effects on system operation and reliability. (author)

377

A combined compensation method for the output voltage of an insulated core transformer power supply.  

Science.gov (United States)

An insulated core transformer (ICT) power supply is an ideal high-voltage generator for irradiation accelerators with energy lower than 3 MeV. However, there is a significant problem that the structure of the segmented cores leads to an increase in the leakage flux and voltage differences between rectifier disks. A high level of consistency in the output of the disks helps to achieve a compact structure by improving the utilization of both the rectifier components and the insulation distances, and consequently increase the output voltage of the power supply. The output voltages of the disks which are far away from the primary coils need to be improved to reduce their inhomogeneity. In this study, by investigating and comparing the existing compensation methods, a new combined compensation method is proposed, which increases the turns on the secondary coils and employs parallel capacitors to improve the consistency of the disks, while covering the entire operating range of the power supply. This method turns out to be both feasible and effective during the development of an ICT power supply. The non-uniformity of the output voltages of the disks is less than 3.5% from no-load to full-load, and the power supply reaches an output specification of 350 kV/60 mA. PMID:24985809

Yang, L; Yang, J; Liu, K F; Qin, B; Chen, D Z

2014-06-01

378

A combined compensation method for the output voltage of an insulated core transformer power supply  

Energy Technology Data Exchange (ETDEWEB)

An insulated core transformer (ICT) power supply is an ideal high-voltage generator for irradiation accelerators with energy lower than 3 MeV. However, there is a significant problem that the structure of the segmented cores leads to an increase in the leakage flux and voltage differences between rectifier disks. A high level of consistency in the output of the disks helps to achieve a compact structure by improving the utilization of both the rectifier components and the insulation distances, and consequently increase the output voltage of the power supply. The output voltages of the disks which are far away from the primary coils need to be improved to reduce their inhomogeneity. In this study, by investigating and comparing the existing compensation methods, a new combined compensation method is proposed, which increases the turns on the secondary coils and employs parallel capacitors to improve the consistency of the disks, while covering the entire operating range of the power supply. This method turns out to be both feasible and effective during the development of an ICT power supply. The non-uniformity of the output voltages of the disks is less than 3.5% from no-load to full-load, and the power supply reaches an output specification of 350 kV/60 mA.

Yang, L.; Yang, J., E-mail: jyang@mail.hust.edu.cn; Liu, K. F.; Qin, B.; Chen, D. Z. [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan 430074 (China)

2014-06-15

379

A combined compensation method for the output voltage of an insulated core transformer power supply  

Science.gov (United States)

An insulated core transformer (ICT) power supply is an ideal high-voltage generator for irradiation accelerators with energy lower than 3 MeV. However, there is a significant problem that the structure of the segmented cores leads to an increase in the leakage flux and voltage differences between rectifier disks. A high level of consistency in the output of the disks helps to achieve a compact structure by improving the utilization of both the rectifier components and the insulation distances, and consequently increase the output voltage of the power supply. The output voltages of the disks which are far away from the primary coils need to be improved to reduce their inhomogeneity. In this study, by investigating and comparing the existing compensation methods, a new combined compensation method is proposed, which increases the turns on the secondary coils and employs parallel capacitors to improve the consistency of the disks, while covering the entire operating range of the power supply. This method turns out to be both feasible and effective during the development of an ICT power supply. The non-uniformity of the output voltages of the disks is less than 3.5% from no-load to full-load, and the power supply reaches an output specification of 350 kV/60 mA.

Yang, L.; Yang, J.; Liu, K. F.; Qin, B.; Chen, D. Z.

2014-06-01

380

A combined compensation method for the output voltage of an insulated core transformer power supply  

International Nuclear Information System (INIS)

An insulated core transformer (ICT) power supply is an ideal high-voltage generator for irradiation accelerators with energy lower than 3 MeV. However, there is a significant problem that the structure of the segmented cores leads to an increase in the leakage flux and voltage differences between rectifier disks. A high level of consistency in the output of the disks helps to achieve a compact structure by improving the utilization of both the rectifier components and the insulation distances, and consequently increase the output voltage of the power supply. The output voltages of the disks which are far away from the primary coils need to be improved to reduce their inhomogeneity. In this study, by investigating and comparing the existing compensation methods, a new combined compensation method is proposed, which increases the turns on the secondary coils and employs parallel capacitors to improve the consistency of the disks, while covering the entire operating range of the power supply. This method turns out to be both feasible and effective during the development of an ICT power supply. The non-uniformity of the output voltages of the disks is less than 3.5% from no-load to full-load, and the power supply reaches an output specification of 350 kV/60 mA

381

Development of large high-voltage pressure insulators for the Princeton TFTR [Tokamak Fusion Test Reactor] flexible transmission lines  

International Nuclear Information System (INIS)

Specially formulated insulator materials with improved strength and high-voltage properties were developed and used for critical components of the flexible transmission lines to the TFTR neutral beam ion sources. These critical components are plates which support central conductors as they exit the high-voltage power supply and enter the ion source enclosure. Each plate acts both as a high-voltage insulator and as a pressure barrier to the SF6 insulating gas. The original plate was made of commercial glass-epoxy laminate which limited the plate voltage capacity. The newly developed insulator is made of specially-formulated cycloalphatic Di-epoxide whose isotropic properties exhibit increased arc resistance. It is cast in one piece with skirts which greatly increase the breakdown voltage. This paper discusses the design, fabrication and testing of the new insulator

382

Contribution to high voltage matrix switches reliability  

International Nuclear Information System (INIS)

Nowadays, power electronic equipment requirements are important, concerning performances, quality and reliability. On the other hand, costs have to be reduced in order to satisfy the market rules. To provide cheap, reliability and performances, many standard components with mass production are developed. But the construction of specific products must be considered following these two different points: in one band you can produce specific components, with delay, over-cost problems and eventuality quality and reliability problems, in the other and you can use standard components in a adapted topologies. The CEA of Pierrelatte has adopted this last technique of power electronic conception for the development of these high voltage pulsed power converters. The technique consists in using standard components and to associate them in series and in parallel. The matrix constitutes high voltage macro-switch where electrical parameters are distributed between the synchronized components. This study deals with the reliability of these structures. It brings up the high reliability aspect of MOSFETs matrix associations. Thanks to several homemade test facilities, we obtained lots of data concerning the components we use. The understanding of defects propagation mechanisms in matrix structures has allowed us to put forwards the necessity of robust drive system, adapted clamping voltage protection, and careful geometrical construction. All these reliability considerations in matrix associations have notably allowed the construction of a new matrix structure regrouping all solutions insuring reliability. Reliable and robust, this product has already reaches the industrial stage. (author)

383

Conductor warming in high-voltage grids  

International Nuclear Information System (INIS)

This illustrated article examines the heating-up of high-voltage power lines under load. As an example, the 105 km long Lukmanier power line that crosses the Alps in Switzerland is looked at. Varying loading caused by power transfers between Germany in the north and Italy in the south are discussed. Increasing instances of load variations resulting from the liberalisation of the electricity market in Switzerland are examined. The results of a pilot study carried out by Atel Netz AG and Etrans AG (today: Swissgrid AG) are presented and discussed. Various systems for the real-time measurement and analysis of various factors such as loading and temperature of the power lines are introduced and discussed. The geographical situation and the location of switch yards is looked at and the different climatic conditions encountered along the route over the Alps are discussed. Temporary and permanent measurement equipment installed for various electrical and meteorological data is described. The results obtained are discussed

384

Design of a low ripple high efficiency power supply for X ray detector  

International Nuclear Information System (INIS)

Combining with a voltage multiplier circuit and an electronic filter, the high efficiency DC-DC step up controller MAX668 is used to implement a high efficiency low noise positive 100 voltage power supply. Instead of the conventional linear constant current design mode, a step down switch power chip is used as the power regulator, and an instrumentation amplifier chip AD623 is selected to amplify the voltage signal drop on the current sense resistor and construct a negative feedback to the power regulator. Experimental results show that the power dissipation of high voltage supplier is 14.5 mW, while the ripple noise is less than 15 mV. When the output current is 350 mA, the efficiency of the constant current source is larger than 81.3%. (authors)

385

Wireless Power Transmission for Power Supply: State of Art  

Directory of Open Access Journals (Sweden)

Full Text Available The wireless power supply is motivated by simple and comfortable use of many small electric appliances with low power input. This paper reviews the concepts which are suitable for wireless power transmission with respect to power supply of such appliances in small areas. The categorization of the concepts is made. The efficiency of the concepts is discussed on general base. The reference levels for exposure to electric and magnetic fields are mentioned, and maximal power delivered to an appliance by fulfillment of these levels is considered.

M. Mazanek

2011-06-01

386

3.6MW Power Supply System of the 170GHz ECH&CD System in KSTAR  

Directory of Open Access Journals (Sweden)

Full Text Available A 3.6 MW (-66 kV/55 A Gyrotron power supply system was developed for the 170 GHz ECH&CD gyrotron system in KSTAR. This power supply system consists of Cathode Power Supply(CPS, Anode Power Supply(APS and Body Power Supply(BPS. The CPS is using the Pulse Step Modulation by the 32set of IGBT choppers. The respons time of Chopper is very fast. So the cathode voltaget is able to be controlled rapidly. The APS is a sort of voltage devider using zener and switch component. It was achieved 3kHz modulation operation. The BPS is combined the commercial power supply and special high voltage switches. It is very simple topology but 5kHz modulation was accomplished easily. Theses power supply system were installed and commissioned successfully in 2011. This paper presents the topology of the each power supply and test result for 170 GHz gyrotron in KSTAR.

Joung Jin-Hyun

2012-09-01

387

Stade nuclear power station supplies district heating  

International Nuclear Information System (INIS)

From the beginning of this year, the Stade nuclear power station supplies district heating to a nearby salt refinery company. This is the first time a commercial power station in the Federal Republic of Germany has employed electric power/heat cogeneration. To date, the station has generated 58 billion kWh in its 12 years of operation, at an availability rate of appr. 85% on average. These excellent operation results and the high availability make the Stade nuclear power station one of the leading companies of this kind on an international level. (orig.)

388

Power supply device for thermonuclear device  

International Nuclear Information System (INIS)

In a protection system against quenching of superconductive toroidal coils, an electromagnetic energy is rapidly converted into a heat energy consumed by a discharge resistor, but the volume of the discharge resistor is greatly increased because the energy is extremely great. Then, the quenching of the superconductive toroidal coils is detected to open a DC interrupter. A power supply for the toroidal coils is operated at the same time to partially transfer the electromagnetic energy generated from the superconductive toroidal coils to a power system through a power convertor. Other electromagnetic energy is transferred to energy storage coils. With such a constitution, even if a great amount of electromagnetic energy is generated from the superconductive toroidal coils, it can be distributed and absorbed rapidly. The efficiency of the entire device can be improved by utilizing the energy stored in the storage coils as the energy for other power supply devices. (N.H.)

389

Present status of klystron power supply systems for J-PARC linac 2012. Recovery from earthquake disaster, HVDCPS breakdown and energy upgrade  

International Nuclear Information System (INIS)

After the Great East Japan Earthquake, the klystron power supply systems for the J-PARC 181MeV linac had recovered in last October, and restarted the all-day operations in last November. In this March, the high-voltage DC power supply no.1 (HVDCPS no.1) broke down. The cause was the breakdown of the condensers, which were the parts of the stacks of the diode circuitries. For the linac energy upgrade to 400MeV, the new power supply systems were tested. (author)

390

LHCb Calorimeters High Voltage System  

CERN Document Server

The calorimeter system in LHCb aims to identify electrons, photons and hadrons. All calorimeters are equipped with Hamamatsu photo tubes as devices for light to signal conversion. Eight thousand R7899-20 tubes are used for electromagnetic and hadronic calorimeters and two hundred 64 channels multi-anode R7600-00-M64 for Scintillator-Pad/Preshower detectors. The calorimeter high voltage (HV) system is based on a Cockroft Walton (CW) voltage converter and a control board connected to the Experiment Control System (ECS) by serial bus. The base of each photomultiplier tube (PMT) is built with a high voltage converter and constructed on an individual printed circuit board, using compact surface mount components. The base is attached directly to the PMT. There are no HV cables in the system. A Field Programmable Gate Array (FPGA) is used on the control board as an interface between the ECS and the 200 control channels. The FPGA includes also additional functionalities allowing automated monitoring and ramp up of th...

Gilitsky, Y; Konoplyannikov, Anatoli; Lefrançois, J; Perret, P; Schopper, Andreas; Soldatov, M; Yakimchuk, V

2007-01-01

391

A controllable DC high voltage source  

International Nuclear Information System (INIS)

The paper introduces a controllable DC High voltage source. Because of adopting the oscillation circuit of signal amplitude regulated and the step of deep negative feedback, there is a good following quality between output high voltage and the control digit signal. The result of application shows that performance of DC High voltage source is steady and reliable. (authors)

392

Power supply method for quadrupolar mass spectrometers  

International Nuclear Information System (INIS)

A patent is claimed for the invention of a method for supplying power to quadrupolar mass spectrometers. The purpose of the invention is to minimize the imperfections of the signal relating to a chosen mass and to improve the resolution of the mass filter. The device contains an auxiliar alternative power generator. This voltage is superimposed to the main periodic voltages, applied to the pair of bars of the quadrupolar filter

393

Schedule Planning for Repairing Power Supply System  

OpenAIRE

Problem statement: Taiwan is located in the tropical ocean areas. The strong typhoon in summer often causes the collapse of electric transmission towers and results in power outages that seriously affect peoples lives and industrial production. Approach: In light of this situation, this study aims to employ project management techniques of Theory of Constraints (TOC) to develop a practical TOC model to quickly repair the towers and restore power supplied system. Results: The actual applicatio...

Kuo-Wei Lin; Chein-Jen Kang

2012-01-01

394

Daresbury SRS booster magnet power supply  

International Nuclear Information System (INIS)

Power supplies for energizing the combined function magnets of a 600 MeV electron synchrotron are described. The magnet current waveform is a fully-biased sinewave with a frequency of 10 Hz and a peak amplitude of 1350 A. The bias is produced by a high stability d.c. source, while the alternating component is generated by a power inverter operating at the 10 Hz fundamental. (author)

395

Pulsed power supply for Nova Upgrade  

International Nuclear Information System (INIS)

This report describes work carried out at the Center for Electromechanics at The University of Texas at Austin (CEM-UT). A baseline design of the Nova Upgrade has been completed by Lawrence Livermore National Laboratory. The Nova Upgrade is an 18 beamline Nd: glass laser design utilizing fully relayed 4x4 30 cm aperture segmented optical components. The laser thus consists of 288 independent beamlets nominally producing 1.5 to 2.0 MJ of 0.35 ?m light in a 3 to 5 ns pulse. The laser design is extremely flexible and will allow a wide range of pulses to irradiate ICF targets. This facility will demonstrate ignition/gain and the scientific feasibility of ICF for energy and defense applications. The pulsed power requirements for the Nova Upgrade are given. CEM-UT was contracted to study and develop a design for a homopolar generator/inductor (HPG/inductor) opening switch system which would satisfy the pulsed power supply requirements of the Nova Upgrade. The Nd:glass laser amplifiers used in the Nova Upgrade will be powered by light from xenon flashlamps. The pulsed power supply for the Nova Upgrade powers the xenon flashlamps. This design and study was for a power supply to drive flashlamps

396

Exploring the potential for new power supply  

International Nuclear Information System (INIS)

This presentation examined the possibility of independent power producers (IPPs) developing renewable energy sources such as run-of-river, biomass, small hydro and wind power in the province of British Columbia. The markets for these energy sources were reviewed along with the market restrictions, competition, and energy policies. The IPP potential in BC has been estimated at 7000 MWs, with the highest potential being with wind power. According to Helimax, a Montreal-based wind engineering firm, North Vancouver Island alone has more than 1500 MWs of wind potential. California represents a potential market for this energy source. California has instituted a renewable portfolio standard of over 15 per cent. The trend to buy green is also reflected in the decision by many utilities along the west coast to look for green energy sources to address the high costs and environmental risks associated with natural gas and other fossil fuels. Wind companies are also willing to write long term contracts, well past the limits of natural gas contracts. More utilities are seeking long range stable contracts to hedge rising fuel costs. A winning element of this dynamic is that wind power can stabilize long term electrical prices while gas destabilizes them due to different fuel risks. The long term outlook for renewables is good because they are a tool of choice for addressing global climate change. However, the aging transmission infrastructure poses a restriction to market access. ure poses a restriction to market access. Sea Breeze Pacific Regional Transmission System Inc. has presented some solutions to address this problem. Two power transmission projects are currently under study. These include a 1050 MW transmission capacity project for the Strait of Juan de Fuca; and the Greater West Coast projects which will increase power transfer capacity to and from Vancouver Island via a submarine high voltage DC system that would enable stranded provincial energy resources to be exported to high value markets, bypassing existing congested interfaces with minimal losses. Policy issues affecting the development of renewable energy sources were discussed along with the need for utilities to embrace the integration of independent power producers.figs

397

Time-varying system identification of high voltage switches of a power substation with slide-window least-squares parameter estimations  

International Nuclear Information System (INIS)

This paper is aimed at identifying the time-varying parameters and ultimate behavior of high voltage switch structures based on a series of full-scale shake table tests with harmonic excitations. Each structure involves a mechanical device for switch-on and switch-off, a friction-based switch, and three porcelain pillars. To identify the structural properties over time, a novel slide-window least-squares estimation method is developed. Each time-varying parameter is firstly approximately expressed by a simple polynomial or exponential function with time in a short slide-window. The time-invariant coefficients of the polynomial or exponential function are then estimated using a least-squares method. Finally, the time-varying parameters can be simply calculated from the estimated polynomial or exponential function. The proposed method is validated by simulated one- and two-story buildings with three kinds of time-varying parameters (stiffness varying abruptly, gradually, and periodically) under earthquake excitations. The application of the proposed method to the tested switch structures demonstrated that the time-varying fundamental frequency of the structures decreased from 7.5 to 6.5 Hz near resonance, which is consistent with the shake table test observations under an excitation of 1.27 and 2.54 mm in stroke. During the shake table tests, all switch structures failed at the bottom of the mechanical device under cyclic loading. (paper)g. (paper)

398

Development of three channel linear bipolar high voltage amplifier (±2 KV) for electrostatic steerer  

International Nuclear Information System (INIS)

Electrostatic steerers and scanners are planned for low energy ion beam facilities at IUAC to steer and scan the ion beam on target. The power supplies for electrostatic steerers are high voltage bipolar DC amplifiers and for scanners are bipolar AC amplifiers. To fulfil the requirements a common unit has been designed and assembled for AC and DC applications. It can be used with electrostatic devices in scanning, steering and sweeping of low energy ion beams at high frequencies to attain uniform implantation. The unit consist of three independent limited bandwidth high voltage, linear bipolar amplifiers (for X-axis, Y-axis and Y1-dog leg plates). The unit has been provided with both local and remote control. (author)

399

A high voltage gain quasi Z-source isolated DC/DC converter  

DEFF Research Database (Denmark)

A compact quasi-Z-source DC/DC converter is presented with high voltage gain, isolated output, and improved efficiency. The improvements in size and performance were achieved by using a square wave inverter with only two output switches driving an isolating transformer in push-pull mode, followed by a voltage doubling output rectifier. The converter is well-suited to applications requiring a high voltage gain, especially renewable energy sources such as photovoltaic and fuel-cell power supplies. To demonstrate the converter's performance a prototype designed to output 400 V at 500 W was constructed and tested. The efficiency at full load varied from 89.0% to 97.4% as the input voltage changed from 44 V to 82 V.

Siwakoti, Yam P.; Blaabjerg, Frede

2014-01-01

400

Broadband linear high-voltage amplifier for radio frequency ion traps.  

Science.gov (United States)

We developed a linear high-voltage amplifier for small capacitive loads consisting of a high-voltage power supply and a transistor amplifier. With this cost-effective circuit including only standard parts sinusoidal signals with a few volts can be amplified to 1.7 kVpp over a usable frequency range at large-signal response spanning four orders of magnitude from 20 Hz to 100 kHz under a load of 10 pF. For smaller output voltages the maximum frequency shifts up to megahertz. We test different capacitive loads to probe the influence on the performance. The presented amplifier is sustained short-circuit proof on the output side, which is a significant advantage over other amplifier concepts. The amplifier can be used to drive radio frequency ion traps for single charged nano- and microparticles, which will be presented in brief. PMID:25430133

Kuhlicke, Alexander; Palis, Klaus; Benson, Oliver

2014-11-01

401

78 FR 36278 - Fuel Oil Systems for Emergency Power Supplies  

Science.gov (United States)

...NRC-2012-0159] Fuel Oil Systems for Emergency Power Supplies AGENCY: Nuclear...RG) 1.137, ``Fuel Oil Systems for Emergency Power Supplies.'' Revision 2...Criteria (GDC) 17, Electric Power Systems'' in Appendix A to...

2013-06-17

402

Performance of a 2-megawatt high voltage test load  

International Nuclear Information System (INIS)

A high-power, water-cooled resistive load which simulates the electrical load characteristics of a high-power klystron, capable of 2 megawatts dissipation at 95 kV DC, was built and installed at the Advanced Photon Source for use in load-testing high voltage power supplies. During this testing, the test load has logged approximately 35 hours of operation at power levels in excess of one mezawatt. Slight variations in the resistance of the load during operation indicate that leakage currents in the cooling water may be a significant factor affecting the performance of the load. Sufficient performance data have been collected to indicate that leakage current through the deionized (DI) water coolant shunts roughly 15 percent of the full-load current around the load resistor elements. The leakage current could cause deterioration of internal components of the load. The load pressure vessel was disassembled and inspected internally for any signs of significant wear and distress. Results of this inspection and possible modifications for improved performance will be discussed

403

Magnet power supply as a network object  

International Nuclear Information System (INIS)

Magnet power supplies with embedded microprocessor controls are being installed in the beam-lines of the linear accelerator and proton storage ring at LAMPF. Using an RS422 link they communicate with the accelerator control system through a terminal server connected to the site-wide DECnet backbone. Each supply is, for all intents and purposes, a network object. The controller has a command set of over seventy-five three-character ASCII control and read-back instructions. Strategies for choosing the appropriate control protocol and the process of integrating these devices into a large accelerator control system will be presented. 7 refs., 2 figs., 1 tab

404

High-voltage MOS transistors compatible with CMOS VLSI technology  

Science.gov (United States)

In this paper high-voltage MOS transistors structures fabricated using a standard CMOS technology and a special design technique are presented. The design, characterization, and modeling of n-MOS, with the breakdown voltage of 50 V, and p-MOS, with the breakdown voltage of 130 V, fabricated using a standard 3 micrometers CMOS process are discussed. In addition, the possibility of high-voltage buffer circuit realization which is composed of n-MOS and p-MOS transistors, operating with the supply system USS equals 0, UDD equals 5 V, UE equals - 40 V, self-isolated from low-voltage components is demonstrated.

Podmiotko, Wlodzimierz

1992-08-01

405

Development of the 320 kA pulsed magnetic horn power supply with a novel energy recovery system for the T2K experiment  

International Nuclear Information System (INIS)

The 320 kA pulsed magnetic horn power supply with a novel magnetic energy recovery system for the T2K experiment has been developed. The magnetic energy once stored in the horn system during an excitation period by a pulsed current of 320 kA is recovered by a full-bridge circuit to the energy storage capacitors. Four switching arms by high-power thyristors in the full-bridge circuit are actively controlled for an efficient energy recovery process. Operational principle of the energy recovery system was proved by both the simulation study and the high-voltage test operation. Successful operations of the newly developed pulsed magnetic horn power supply were also confirmed by high-voltage test operations. -- Highlights: ?The 320 kA pulsed power supply for the T2K magnetic horn has been developed. ?A novel energy recovery method by a full-bridge circuit has been established. ?Successful operation of the pulsed power supply was confirmed by high-voltage operations

406

Development of connectors for high voltage motors  

International Nuclear Information System (INIS)

In the past the terminal cable connections of high-voltage motors of the 6.6 kV rate were made using self-bonding tape, by bolting the lead cable terminals in the motor terminal boxes. The terminal connection made by taping were not advantageous, because taping for termination and decoupling cables for motor inspection and maintenance were time-consuming. Furthermore, when curvature-forming of cables, processability of termination, and required performances were taken into consideration, the problems became more significant with increasing in size of termination boxes. In recent years it has been required that the time required for inspection and maintenance equipment in an environment exposed to the radiation like nuclear power plants be reduced to a minimum, and as a result the demand for cable connectors which would help to fulfil such purposes has been increasing. Under the circumstances Showa Electric Wire and Cable Co. has developed an ''inverted-T type plug-in connector'' which is quite easy to work with in making cable connections, is small in size, and is easy to remove and re-install in the inspection and maintenance of high-voltage motors, and it has been demonstrated in electrical, mechanical and other tests that this connector complies with the requirements. (author)

407

Nuclear power in German electricity supply  

International Nuclear Information System (INIS)

For many years, the power supply situation in Germany had been ruled by a fundamental consensus about the use of coal and nuclear power, which was given up in 1986 when the Social Democratic Party (SPD) decided to opt out of nuclear power. This robbed the electricity utilities of a reliable basis for longterm investment decisions. Not one new nuclear power plant has been built since Neckar-2 was commissioned in 1989. Even the consensus round was unable in 1993 to establish a new common base. Public acceptance needs to be built up again before this will be possible. The growing population of the world will require more and more energy. For this reason, nuclear power will maintain its role in the worldwide energy mix. This requires, however, that ecological and economic reason prevail also in Germany. (orig.)

408

International experiences with power supply crises  

International Nuclear Information System (INIS)

Many so-called deregulated power markets experience a hardened energy and power balance and some have had supply crises. This report discusses the crises, their impacts and their causes as well as the measures taken by the authorities to solve the crises. It also considers the similarities or dissimilarities with respect to the situation in Norway the winter 2002/2003. Like Norway, many of the countries have a considerable share of hydroelectric power. It is found, however, that the dependence on water of its own is not the reason for the crises, but that the inflow conditions give the market greater challenges. Furthermore, the Norwegian market has greater flexibility in the consumption, greater import capacity, better price security possibilities and less problems with market power than most of the countries here considered. Various factors influence a country's power consumption and production capacity. Economic growth and the availability of inexpensive power contribute to accelerate the consumption, while predictable external conditions and sufficient expected investment earnings are necessary to achieve an increase of the capacity - both through new investments and attendance to existing capacity. In a smooth power market there must be a certain correspondence between consumption and installed capacity, and the capacity must be such that it can cover the continuous demand for power and at the same time be flexible enough to deliver power at peak loads. This is a to deliver power at peak loads. This is also true of the transmission capacity. In addition, some extra capacity must be available for unexpected events. The basic problem is, in any power market, that the consumption may rise fast, while the investments in new capacity typically occurs in leaps, with long and costly construction phases. Many countries have lately experienced a hardening of the balance between consumption and capacity and so have been vulnerable to unexpected increases in consumption or resource failure. This was also the case with the Norwegian/Nordic market the winter 2002/2003, when the autumn rain failed to come and the winter came early and was unusually cold. The subject of this report is deregulated power markets outside of the Nordic countries, where the supply security is a serious problem or has been such. The report aims to: (1) Give an account of the course of events, the causes, the impacts and the measures taken to handle the crises, and (2) Analyze similarities and dissimilarities with respect to the situation in Norway. Information about the causes of supply crises and their impacts in other countries may help to create a better basis for the Norwegian authorities to make decisions about measures to secure a robust power market in Norway.

409

Power supply control module for magnet power supplies control system of Indus-1  

International Nuclear Information System (INIS)

Optics in a circular accelerator is mainly governed by magnetic field of the magnets in the path of the electron beam. Magnet Power Supplies Control System controls and monitors the power supplies feeding the magnets required to bend, steer, and focus etc the charged particle beam. New Control System for the Magnet Power Supplies of the Indus-1 is being implemented. Based on distributed control architecture in this system, each power supply is connected to an equipment interface unit, referred to as Power Supply Control Module (PSCM). The PSCMs communicate with the user interface layer through a custom protocol over an RS-485 serial bus. The PSCMs are developed using TMS320F28335 Digital Signal Controller (DSC). These are compact 19'' rack mountable systems. The PSCM provides digital control of eight parameters, status monitoring of eight parameters, current setting, and current monitoring with accuracy better than 0.01% and stability better than ±100 ppm. It features the generation of current reference of any programmed shape particularly required for cycling profile, ramping profile etc. Other than these functions, PSCMs also incorporate some features like synchronized data reading and fast data capturing which are useful for the analysis of transient phases of ramping and cycling. The set reference for current and current read-back are sampled at 1KHz and stored in the 512K Word memories in PSCM. The paper describes the PSCM of the new magnet power supplies control system for Indus-1. (author)

410

The Fermilab D0 overpass power supply system  

International Nuclear Information System (INIS)

The overpass power supply system consists of two power supplies. A 1 kV, 3600A SCR supply drives eight Main Ring type magnets and must track twice the Main Ring current to within + or -0.1%. The second supply drives trim coils wound inside four of the main magnets. This dual-converter SCR supply, a modified Fermilab H.O.P.S. unit, supplies + or -50A at + or -30V and it must generate + or -200V swings to buck-out the voltage inductively coupled from the main supply. Both power supply regulators use dead reckoned voltage drive programs to extend their effective bandwidths

411

Pulse electric power compensation for accelerator power supply  

International Nuclear Information System (INIS)

Some synchrotron accelerators are excited by pulse operation. Especially, power supply for the large-scale accelerator magnets, such as J-PARC, draws a large amount of power from the utility network. Such large pulse power will give un-allowed disturbances to the connected ac power system. Energy storage system, such as a SMES system, will be required for compensating the pulse electric power and reducing the disturbances. A SMES system is also expected to protect the instantaneous voltage drop and the load levelling so far. Load levelling is essential to reduce the running cost of medical use accelerators. Present status of R and D for SMES and other energy storage systems is presented. An application example for an accelerator power supply is also discussed. (author)

412

Microprocessor based power supply control system  

International Nuclear Information System (INIS)

A microprocessor based control system is being developed which would not only service many of the power supplies own internal functions, but also incorporates an intelligent computer communication port. This will often eliminate the need to use a separate interface. Certain configuration variables are stored on EEPROM (Electrically Erasable Programmable Read Only Memory), which can be programmed using simple ASCII commands via the computer port. 11 refs., 1 fig

413

Cost unit accounting for power supply companies  

International Nuclear Information System (INIS)

Cost unit accounting was introduced to the power supply company Energie-Versorgung Schwaben AG (EVS) in the Seventies. The initial method of peak load proportioning was later modified to the so-called VDEW method and further improved in consecutive steps through specific measurements. Here EVS focussed particularly on collecting data in the separate-contract sector. The authors describe the procedure adopted and results obtained. (orig.)

414

The SPS auxiliary magnet power supplies  

International Nuclear Information System (INIS)

A functional description is given of these thyristor power supplies - many of which are of the bipolar type without circulating current - with emphasis on the CERN-developed regulation circuits. A detailed analysis is given of a new thyristor gate control with low subharmonic content and fast response over a wide rectifier output range. A current regulation time constant of 14 msec is maintained even at near-zero output, where the thyristors conduct only during a small fraction of each cycle. (Auth.)

415

Thermal power in the Swedish energy supply  

International Nuclear Information System (INIS)

A survey is presented of the part played by thermal power plants including nuclear plants in the Swedish electric power supply system. The Swedish and Norwegian situations are compared. The background for the present structure is outlined and the optimisation of electricity production is briefly discussed. The Nordic grid is presented and the strategy and charges discussed. The prognosis for the development in Sweden is presented with a brief discussion of the influence of industrial development. Finally the responsibility of the politicians for the continued development is discussed. (JIW)

416

Precision, 32 channel power supply system  

International Nuclear Information System (INIS)

A modular, multichannel current regulator system has been developed to power the low current correction and focusing magnets used for beam transport. The basic module consists of a relay rack housing four card crates with eight regulators per crate. The rack also contains a utility chassis and common power supplies. Each regulator card includes a communications microprocessor and a temperature controlled analog circuit block containing precision reference, serial DAC, shunt resistor and error amplifier. The regulators are linear, bipolar units capable of furnishing up to 10 amps at 20 volts with less than 0.01% ripple and drift

417

SPEAR3 LARGE DC MAGNET POWER SUPPLIES  

International Nuclear Information System (INIS)

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

418

30 CFR 18.53 - High-voltage longwall mining systems.  

Science.gov (United States)

...high-voltage motor-starter enclosure...high-voltage primary windings that supply control...and secondary windings. The shielding... (f) Each motor-starter enclosure...for the maximum phase-to-phase voltage...must be of the single-window type...the following formulas on which...

2010-07-01

419

Development of a dc 1 MV power supply technology for NB injectors  

International Nuclear Information System (INIS)

Major issues of neutral beam (NB) injector power supplies are high-speed switching, regulation and transmission of dc ultra-high voltage (UHV) and suppression of surge energy input to the beam source at high voltage breakdown. A gate turn-off thyristor inverter type power supply where the control is performed on the low voltage ac side was designed for the ITER NB. Based on the remarkable progress of a high power IEGT (injection enhanced gate transistor), the design of the inverter has been modified to increase efficiency and compactness using such new elements. The power loss in the inverter is reduced to 0.5 MW from 1.6 MW by adopting the IEGT inverter system at the same frequency of 150 Hz. Further, power supply performance has been studied for higher frequency operation of the inverter at 300 Hz. It was confirmed that the voltage regulation was stable even when the filter capacitor was reduced to 1/5 of the original value by circuit simulation. For the transmission line of the dc UHV with intermediate voltages, a disc shape multi-conductor bushing with a transmission line test chamber has been developed. The dimensions of the bushing are 1.8 m (diameter) and 140 mm (thickness) at the edge. Electric fields at the conductor surface and insulator surface were designed to be lower than 5 kV mm-1 and 7 kV mm-1, respectively. An electric field at the bottom of the ground potential outer conductor was designed to be lower than 1.2 kV mm-1ed to be lower than 1.2 kV mm-1 to prevent particle levitation which triggers breakdown. The prototype transmission line has passed the lightning impulse test up to 1300 kV. A dc UHV up to 1175 kV was successfully sustained for 300 s. To prevent electric damage of the beam source at high voltage breakdown, core snubbers using Fe-based nanocrystalline soft magnetic materials have been adopted to dissipate the surge energy

420

Development of a dc 1 MV power supply technology for NB injectors  

Science.gov (United States)

Major issues of neutral beam (NB) injector power supplies are high-speed switching, regulation and transmission of dc ultra-high voltage (UHV) and suppression of surge energy input to the beam source at high voltage breakdown. A gate turn-off thyristor inverter type power supply where the control is performed on the low voltage ac side was designed for the ITER NB. Based on the remarkable progress of a high power IEGT (injection enhanced gate transistor), the design of the inverter has been modified to increase efficiency and compactness using such new elements. The power loss in the inverter is reduced to 0.5 MW from 1.6 MW by adopting the IEGT inverter system at the same frequency of 150 Hz. Further, power supply performance has been studied for higher frequency operation of the inverter at 300 Hz. It was confirmed that the voltage regulation was stable even when the filter capacitor was reduced to 1/5 of the original value by circuit simulation. For the transmission line of the dc UHV with intermediate voltages, a disc shape multi-conductor bushing with a transmission line test chamber has been developed. The dimensions of the bushing are 1.8 m (diameter) and 140 mm (thickness) at the edge. Electric fields at the conductor surface and insulator surface were designed to be lower than 5 kV mm-1 and 7 kV mm-1, respectively. An electric field at the bottom of the ground potential outer conductor was designed to be lower than 1.2 kV mm-1 to prevent particle levitation which triggers breakdown. The prototype transmission line has passed the lightning impulse test up to 1300 kV. A dc UHV up to 1175 kV was successfully sustained for 300 s. To prevent electric damage of the beam source at high voltage breakdown, core snubbers using Fe-based nanocrystalline soft magnetic materials have been adopted to dissipate the surge energy.

Watanabe, K.; Kashiwagi, M.; Kawashima, S.; Ono, Y.; Yamashita, Y.; Yamazaki, C.; Hanada, M.; Inoue, T.; Taniguchi, M.; Okumura, Y.; Sakamoto, K.

2006-06-01

421

ATF2 High Availability Power Supplies  

Energy Technology Data Exchange (ETDEWEB)

ATF2 is an accelerator test facility modeled after the final focus beamline envisioned for the ILC. By the end of 2008, KEK plans to commission the ATF2 [1]. SLAC and OCEM collaborated on the design of 38 power systems for beamline magnets. The systems range in output power from 1.5 kW to 6 kW. Since high availability is essential for the success of the ILC, Collaborators employed an N+1 modular approach, allowing for redundancy and the use of a single power module rating. This approach increases the availability of the power systems. Common power modules reduces inventory and eases maintenance. Current stability requirements are as tight as 10 ppm. A novel, SLAC designed 20-bit Ethernet Power Supply Controller provides the required precision current regulation. In this paper, Collaborators present the power system design, the expected reliability, fault immunity features, and the methods for satisfying the control and monitoring challenges. Presented are test results and the status of the power systems.

Bellomo, A; Lira, C.de; Lam, B.; MacNair, D.; White, G.; /SLAC

2008-06-27

422

Design of sampling circuit in negative high voltage unit in particle detector  

International Nuclear Information System (INIS)

A kind of Sampling Circuit in negative High Voltage Unit (HVU), which is used to provide the bias voltage to the solid detectors, is designed by using Auxiliary Winding. The Sampling Circuit is designed base on theoretical analysis and PSpice simulation analysis. In the design of HVU, the specifications are: input voltage +12 V, output voltage -160 V, pulse-space rate 6.45%, 0?18 (A load regulation 8.8, voltage regulation 3.9, ripple coefficient is 3.1. The theoretical analysis and PSpice simulation analysis are agreed to the experiments, so that this method can be a useful reference for such power supply design. (authors)

423

77 FR 48177 - Fuel Oil Systems for Emergency Power Supplies  

Science.gov (United States)

...Oil Systems for Emergency Power Supplies AGENCY: Nuclear...Oil Systems for Emergency Power Supplies,'' in the Federal...of a high quality from all stakeholders. Several factors have been...additional time will allow stakeholders to discuss the proposed...

2012-08-13

424

Correction magnet power supplies for APS machine  

International Nuclear Information System (INIS)

A number of correction magnets are required for the advanced photon source (APS) machine to correct the beam. There are five kinds of correction magnets for the storage ring, two for the injector synchrotron, and two for the positron accumulator ring (PAR). Table I shoes a summary of the correction magnet power supplies for the APS machine. For the storage ring, the displacement of the quadrupole magnets due to the low frequency vibration below 25 Hz has the most significant effect on the stability of the positron closed orbit. The primary external source of the low frequency vibration is the ground motion of approximately 20 ?m amplitude, with frequency components concentrated below 10 Hz. These low frequency vibrations can be corrected by using the correction magnets, whose field strengths are controlled individually through the feedback loop comprising the beam position monitoring system. The correction field require could be either positive or negative. Thus for all the correction magnets, bipolar power supplies (BPSs) are required to produce both polarities of correction fields. Three different types of BPS are used for all the correction magnets. Type I BPSs cover all the correction magnets for the storage ring, except for the trim dipoles. The maximum output current of the Type I BPS is 140 Adc. A Type II BPS powers a trim dipole, and its maximum output current is 60 Adc. The injector synchrotron and PAR correction magnets are powered form Type III BPSs, whose maximum output current is 25 Adc

425

Bipolar high-repetition-rate high-voltage nanosecond pulser  

International Nuclear Information System (INIS)

The pulser designed is mainly used for producing corona plasma in waste water treatment system. Also its application in study of dielectric electrical properties will be discussed. The pulser consists of a variable dc power source for high-voltage supply, two graded capacitors for energy storage, and the rotating spark gap switch. The key part is the multielectrode rotating spark gap switch (MER-SGS), which can ensure wider range modulation of pulse repetition rate, longer pulse width, shorter pulse rise time, remarkable electrical field distortion, and greatly favors recovery of the gap insulation strength, insulation design, the life of the switch, etc. The voltage of the output pulses switched by the MER-SGS is in the order of 3-50 kV with pulse rise time of less than 10 ns and pulse repetition rate of 1-3 kHz. An energy of 1.25-125 J per pulse and an average power of up to 10-50 kW are attainable. The highest pulse repetition rate is determined by the driver motor revolution and the electrode number of MER-SGS. Even higher voltage and energy can be switched by adjusting the gas pressure or employing N2 as the insulation gas or enlarging the size of MER-SGS to guarantee enough insulation level

426

Bipolar high-repetition-rate high-voltage nanosecond pulser  

Science.gov (United States)

The pulser designed is mainly used for producing corona plasma in waste water treatment system. Also its application in study of dielectric electrical properties will be discussed. The pulser consists of a variable dc power source for high-voltage supply, two graded capacitors for energy storage, and the rotating spark gap switch. The key part is the multielectrode rotating spark gap switch (MER-SGS), which can ensure wider range modulation of pulse repetition rate, longer pulse width, shorter pulse rise time, remarkable electrical field distortion, and greatly favors recovery of the gap insulation strength, insulation design, the life of the switch, etc. The voltage of the output pulses switched by the MER-SGS is in the order of 3-50kV with pulse rise time of less than 10ns and pulse repetition rate of 1-3kHz. An energy of 1.25-125J per pulse and an average power of up to 10-50kW are attainable. The highest pulse repetition rate is determined by the driver motor revolution and the electrode number of MER-SGS. Even higher voltage and energy can be switched by adjusting the gas pressure or employing N2 as the insulation gas or enlarging the size of MER-SGS to guarantee enough insulation level.

Tian, Fuqiang; Wang, Yi; Shi, Hongsheng; Lei, Qingquan

2008-06-01

427

Evolution of Very High Frequency Power Supplies  

DEFF Research Database (Denmark)

The ongoing demand for smaller and lighter power supplies is driving the motivation to increase the switching frequencies of power converters. Drastic increases however come along with new challenges, namely the increase of switching losses in all components. The application of power circuits used in radio frequency transmission equipment helps to overcome those. However those circuits were not designed to meet the same requirements as power converters. This paper summarizes the contributions in recent years in application of very high frequency (VHF) technologies in power electronics, shows results of the recent advances and describes the remaining challenges. The presented results include a self-oscillating gate-drive, air core inductor optimizations, an offline LED driver with a power density of 8.9 W/cm3 and a 120 MHz, 9 W DC powered LED driver with 89 % efficiency as well as a bidirectional VHF converter. The challenges to be solved before VHF converters can be used effectively in industrial products are within those three categories: components, circuit architectures and reliability testing.

Knott, Arnold; Andersen, Toke Meyer

2013-01-01

428

Compass poloidal field power supply system  

International Nuclear Information System (INIS)

The COMPASS experiment is designed to operate in both 'Pinch' and 'Tokamak' modes, the latter with both circular and shaped plasma cross-sections. In Tokamak mode, the primary windings are used as an inductive store with a two stage opening switch system to transfer the energy to the plasma loop. Three thyristor convertors (total power 17MW) are used to maintain the plasma current, to provide vertical (equilibrium) field and to produce the required plasma shapes. For Pinch operation, a conventional start bank/active crowbar circuit is used to feed a reconfigured winding arrangement. Three high power (250kW) transistor amplifiers are used to energize other machine windings to provide vertical and radial correction fields for fast control of plasma position. Most of the power supply system is now in manufacture and installation has begun; commissioning of the overall system is scheduled for the second half of 1987. (author)

429

Nuclear power as a regional energy supply  

International Nuclear Information System (INIS)

The author describes the Point Lepreau nuclear power plant and its impact on the electric power grid and the economy of the small province of New Brunswick. The 600 MW CANDU reactor is considered suitable for small operations and has an excellent world record. Although nuclear energy has high capital costs, its fuel costs are low, thus rendering it comparatively inflation free. Its fuel costs of 3 to 4 mills are contrasted with 40 mills for oil-fuelled units. The cost advantage of uranium over coal and oil permits New Brunswick to put aside funds for waste management and decommissioning. Regulatory streamlining is needed to reduce both expense and time of construction. The CANDU system is ideally suited to providing base load, with coal as an intermediate load supply and hydro for peaking. There is room for tidal power as a future part of the mix

430

Power supplies for heavy ion source test stand  

International Nuclear Information System (INIS)

Variable Energy Cyclotron at Calcutta uses a low power PIG-type of ion source at present for lighter ions like ?-particles, protons and deuterons. For accelerating heavier ions a new high power Penning ion gauge (PIG) type source, which will generate high charge state heavy ions, is needed. A programme has been taken up at VECC to develop this heavy ion source and a test stand (HISTS) for the purposes. The test stand which has to simulate the conditions of the cyclotron requires a numb