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Sample records for high voltage divider

  1. APPLICATION OF HIGH VOLTAGE DIVIDERS FOR POWER QUALITY INDICES MEASUREMENT

    Directory of Open Access Journals (Sweden)

    Y. L. Anokhin

    2017-12-01

    Full Text Available Introduction. Determination of power quality indices in high-voltage power grids allows to find the reasons for the deterioration of the power quality. The relevant national and International Standards for power quality contain relevant norms of quality indices and requirements for their accuracy measurement. Problem. The most complicated part in the process of measuring the power quality indices at high voltage is the selection of the corresponding high-voltage scale voltage converters. Therefore, comparing the requirements of IEC 61000-4-30 to high voltage scale voltage converters is an important task. Goal. Analysis of the International Standard IEC 61000-4-30 requirements feasibility for measuring the indices of power quality in high-voltage electrical networks using different types of high-voltage scale voltage converters. Methodology. Comparison of the requirements of IEC 61000-4-30 Standard to high-voltage scale voltage converters, when measuring power quality indices, with the characteristics of high voltage electromagnetic transformers used in Ukraine, and with promising developments of high-voltage converters of other types. Results. It is shown in the study that in order to fulfill some of the requirements for class A of IEC 61000-4-30, the characteristics of electromagnetic voltage transformers should be determined in the substation conditions using mobile calibration high-voltage laboratories. To meet all the requirements for Class A IEC 61000-4-30, it is recommended to use broadband high-voltage dividers of resistive-capacitive type. Originality. In study it is shown firstly that all the requirements of the IEC 61000-4-30 Standard for high-voltage scale voltage converters can be performed on the basis of the use of broadband resistive-capacitive damped voltage dividers. Practical value. Expositions of specific types of resistive-capacitive high-voltage dividers are presented, their parameters are confirmed by the results of state

  2. Enhancement of AC high voltage measurements’ uncertainty using a high voltage divider calibration method

    Directory of Open Access Journals (Sweden)

    El-Rifaie Ali M.

    2015-01-01

    Full Text Available This paper discusses enhancing of the measurements’ uncertainty for AC high voltage up to 100 kV. This is achieved by using a high voltage divider calibration method. Voltage measurements have been carried out at the Egyptian national institute for standards (NIS, using a high voltage measuring system (Phenix-KVM100, that consists of a high voltage divider and a voltage display. The voltage divider and display have been calibrated in low and high voltage ranges. Reference standard digital voltmeter and a multifunction calibrator have been used to calibrate the KVM100 for achieving accurate and traceable results. All calibrations have been performed automatically using Laboratory Virtual Instrument Engineering Workbench (LabVIEW programs specially designed for this task. Uncertainty budget has been evaluated to get the measurements’ expanded uncertainties.

  3. Enhanced Model of Nonlinear Spiral High Voltage Divider

    Directory of Open Access Journals (Sweden)

    V. Panko

    2015-04-01

    Full Text Available This paper deals with the enhanced accurate DC and RF model of nonlinear spiral polysilicon voltage divider. The high resistance polysilicon divider is a sensing part of the high voltage start-up MOSFET transistor that can operate up to 700 V. This paper presents the structure of a proposed model, implemented voltage, frequency and temperature dependency, and scalability. A special attention is paid to the ability of the created model to cover the mismatch and influence of a variation of process parameters on the device characteristics. Finally, the comparison of measured data vs. simulation is presented in order to confirm the model validity and a typical application is demonstrated.

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

    CERN Document Server

    Bastos, M C; Hammarquist, M

    2011-01-01

    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.

  5. Calibration of the ISOLDE acceleration voltage using a high-precision voltage divider and applying collinear fast beam laser spectroscopy

    CERN Document Server

    Krieger, A.; Catherall, R.; Hochschulz, F.; Kramer, J.; Neugart, R.; Rosendahl, S.; Schipper, J.; Siesling, E.; Weinheimer, Ch.; Yordanov, D.T.; Nortershauser, W.

    2011-01-01

    A high-voltage divider with accuracy at the ppm level and collinear laser spectroscopy were used to calibrate the highvoltage installation at the radioactive ion beam facility ISOLDE at CERN. The accurate knowledge of this voltage is particularly important for collinear laser spectroscopy measurements. Beam velocity measurements using frequencycomb based collinear laser spectroscopy agree with the new calibration. Applying this, one obtains consistent results for isotope shifts of stable magnesium isotopes measured using collinear spectroscopy and laser spectroscopy on laser-cooled ions in a trap. The long-term stability and the transient behavior during recovery from a voltage dropout were investigated for the different power supplies currently applied at ISOLDE.

  6. High Voltage Resistive Divider Based on Cast Microwire in Glass Insulation on 6–24 kV Alternating Current of Commercial Frequency.

    Directory of Open Access Journals (Sweden)

    Juravleov A.

    2008-12-01

    Full Text Available It is presented the analysis and description of the construction of the high voltage resistive divider on the base of cast microwire in glass insulation on 6–24 kV alternating current of commercial frequency. It is presented the procedure of compensation of frequency error during the process of fabrication of divides and results of tests of the sample model of the divider as well.

  7. The Design and Characterization of a Prototype Wideband Voltage Sensor Based on a Resistive Divider.

    Science.gov (United States)

    Garnacho, Fernando; Khamlichi, Abderrahim; Rovira, Jorge

    2017-11-17

    The most important advantage of voltage dividers over traditional voltage transformers is that voltage dividers do not have an iron core with non-linear hysteresis characteristics. The voltage dividers have a linear behavior with respect to over-voltages and a flat frequency response larger frequency range. The weak point of a voltage divider is the influence of external high-voltage (HV) and earth parts in its vicinity. Electrical fields arising from high voltages in neighboring phases and from ground conductors and structures are one of their main sources for systematic measurement errors. This paper describes a shielding voltage divider for a 24 kV medium voltage network insulated in SF6 composed of two resistive-capacitive dividers, one integrated within the other, achieving a flat frequency response up to 10 kHz for ratio error and up to 5 kHz for phase displacement error. The metal shielding improves its immunity against electric and magnetic fields. The characterization performed on the built-in voltage sensor shows an accuracy class of 0.2 for a frequency range from 20 Hz to 5 kHz and a class of 0.5 for 1 Hz up to 20 Hz. A low temperature effect is also achieved for operation conditions of MV power grids.

  8. The Design and Characterization of a Prototype Wideband Voltage Sensor Based on a Resistive Divider

    Directory of Open Access Journals (Sweden)

    Fernando Garnacho

    2017-11-01

    Full Text Available The most important advantage of voltage dividers over traditional voltage transformers is that voltage dividers do not have an iron core with non-linear hysteresis characteristics. The voltage dividers have a linear behavior with respect to over-voltages and a flat frequency response larger frequency range. The weak point of a voltage divider is the influence of external high-voltage (HV and earth parts in its vicinity. Electrical fields arising from high voltages in neighboring phases and from ground conductors and structures are one of their main sources for systematic measurement errors. This paper describes a shielding voltage divider for a 24 kV medium voltage network insulated in SF6 composed of two resistive-capacitive dividers, one integrated within the other, achieving a flat frequency response up to 10 kHz for ratio error and up to 5 kHz for phase displacement error. The metal shielding improves its immunity against electric and magnetic fields. The characterization performed on the built-in voltage sensor shows an accuracy class of 0.2 for a frequency range from 20 Hz to 5 kHz and a class of 0.5 for 1 Hz up to 20 Hz. A low temperature effect is also achieved for operation conditions of MV power grids.

  9. 110-KV optical fiber voltage transformer using a porcelain capacitor divider

    Science.gov (United States)

    Ye, Miaoyuan; Ou, Chaolong; Cui, Ying; Zhou, Jianying; Li, Kaicheng; Chen, Zhiping; Xu, Yan; Luo, Sunan

    1998-08-01

    In this paper, a new type of optical fiber voltage transformer is introduced, which utilizes new porcelain capacitor divider. The optical; fiber voltage sensor is based on the BGO crystal Pockels effect modulated horizontally, sealed in a glass box with low expansion rate. Both the divider and the sensor are sealed in the compound silicon rubber insulator filled with SF6 gas. It has many advantages such as small volume, light weight, low price and high precision.

  10. Technological Aspects: High Voltage

    CERN Document Server

    Faircloth, D.C.

    2013-12-16

    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.

  11. High voltage engineering

    CERN Document Server

    Rizk, Farouk AM

    2014-01-01

    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

  12. High voltage test techniques

    CERN Document Server

    Kind, Dieter

    2001-01-01

    The second edition of High Voltage Test Techniques has been completely revised. The present revision takes into account the latest international developments in High Voltage and Measurement technology, making it an essential reference for engineers in the testing field.High Voltage Technology belongs to the traditional area of Electrical Engineering. However, this is not to say that the area has stood still. New insulating materials, computing methods and voltage levels repeatedly pose new problems or open up methods of solution; electromagnetic compatibility (EMC) or components and systems al

  13. High voltage engineering fundamentals

    CERN Document Server

    Kuffel, E; Hammond, P

    1984-01-01

    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

  14. KCNE1 divides the voltage sensor movement in KCNQ1/KCNE1 channels into two steps

    Science.gov (United States)

    Barro-Soria, Rene; Rebolledo, Santiago; Liin, Sara I.; Perez, Marta E.; Sampson, Kevin J.; Kass, Robert S.; Larsson, H. Peter

    2014-04-01

    The functional properties of KCNQ1 channels are highly dependent on associated KCNE-β subunits. Mutations in KCNQ1 or KCNE subunits can cause congenital channelopathies, such as deafness, cardiac arrhythmias and epilepsy. The mechanism by which KCNE1-β subunits slow the kinetics of KCNQ1 channels is a matter of current controversy. Here we show that KCNQ1/KCNE1 channel activation occurs in two steps: first, mutually independent voltage sensor movements in the four KCNQ1 subunits generate the main gating charge movement and underlie the initial delay in the activation time course of KCNQ1/KCNE1 currents. Second, a slower and concerted conformational change of all four voltage sensors and the gate, which opens the KCNQ1/KCNE1 channel. Our data show that KCNE1 divides the voltage sensor movement into two steps with widely different voltage dependences and kinetics. The two voltage sensor steps in KCNQ1/KCNE1 channels can be pharmacologically isolated and further separated by a disease-causing mutation.

  15. High Voltage Seismic Generator

    Science.gov (United States)

    Bogacz, Adrian; Pala, Damian; Knafel, Marcin

    2015-04-01

    This contribution describes the preliminary result of annual cooperation of three student research groups from AGH UST in Krakow, Poland. The aim of this cooperation was to develop and construct a high voltage seismic wave generator. Constructed device uses a high-energy electrical discharge to generate seismic wave in ground. This type of device can be applied in several different methods of seismic measurement, but because of its limited power it is mainly dedicated for engineering geophysics. The source operates on a basic physical principles. The energy is stored in capacitor bank, which is charged by two stage low to high voltage converter. Stored energy is then released in very short time through high voltage thyristor in spark gap. The whole appliance is powered from li-ion battery and controlled by ATmega microcontroller. It is possible to construct larger and more powerful device. In this contribution the structure of device with technical specifications is resented. As a part of the investigation the prototype was built and series of experiments conducted. System parameter was measured, on this basis specification of elements for the final device were chosen. First stage of the project was successful. It was possible to efficiently generate seismic waves with constructed device. Then the field test was conducted. Spark gap wasplaced in shallowborehole(0.5 m) filled with salt water. Geophones were placed on the ground in straight line. The comparison of signal registered with hammer source and sparker source was made. The results of the test measurements are presented and discussed. Analysis of the collected data shows that characteristic of generated seismic signal is very promising, thus confirms possibility of practical application of the new high voltage generator. The biggest advantage of presented device after signal characteristics is its size which is 0.5 x 0.25 x 0.2 m and weight approximately 7 kg. This features with small li-ion battery makes

  16. Low power, scalable multichannel high voltage controller

    Science.gov (United States)

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

    2008-03-25

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

  17. High Voltage Charge Pump

    KAUST Repository

    Emira, Ahmed A.

    2014-10-09

    Various embodiments of a high voltage charge pump are described. One embodiment is a charge pump circuit that comprises a plurality of switching stages each including a clock input, a clock input inverse, a clock output, and a clock output inverse. The circuit further comprises a plurality of pumping capacitors, wherein one or more pumping capacitors are coupled to a corresponding switching stage. The circuit also comprises a maximum selection circuit coupled to a last switching stage among the plurality of switching stages, the maximum selection circuit configured to filter noise on the output clock and the output clock inverse of the last switching stage, the maximum selection circuit further configured to generate a DC output voltage based on the output clock and the output clock inverse of the last switching stage.

  18. High voltage variable diameter insulator

    Science.gov (United States)

    Vanecek, David L.; Pike, Chester D.

    1984-01-01

    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).

  19. Spectroscopic measurements with a silicon drift detector having a continuous implanted drift cathode-voltage divider

    CERN Document Server

    Bonvicini, V; D'Acunto, L; Franck, D; Gregorio, A; Pihet, P; Rashevsky, A; Vacchi, A; Vinogradov, L I; Zampa, N

    2000-01-01

    A silicon drift detector (SDD) prototype where the drift electrode also plays the role of a high-voltage divider has been realised and characterised for spectroscopic applications at near-room temperatures. Among the advantages of this design, is the absence of metal on the sensitive surface which makes this detector interesting for soft X-rays. The detector prototype has a large sensitive area (2x130 mm sup 2) and the charge is collected by two anodes (butterfly-like detector). The energy resolution of a such a detector has been investigated at near-room temperatures using a commercial, hybrid, low-noise charge-sensitive preamplifier. The results obtained for the X-ray lines from sup 5 sup 5 Fe and sup 2 sup 4 sup 1 Am are presented.

  20. Investigation about decoupling capacitors of PMT voltage divider effects on neutron-gamma discrimination

    Energy Technology Data Exchange (ETDEWEB)

    Divani, Nazila, E-mail: n-divani@birjand.ac.ir; Firoozabadi, Mohammad M. [Dep. Of Physics, Faculty of Science, University of Birjand, Birjand (Iran, Islamic Republic of); Bayat, Esmail [Nuclear Science and Technology Research Institute, Atomic Energy Organization of Iran (Iran, Islamic Republic of)

    2014-11-24

    Scintillators are almost used in any nuclear laboratory. These detectors combine of scintillation materials, PMT and a voltage divider. Voltage dividers are different in resistive ladder design. But the effect of decoupling capacitors and damping resistors haven’t discussed yet. In this paper at first a good equilibrium circuit designed for PMT, and it was used for investigating about capacitors and resistors in much manner. Results show that decoupling capacitors have great effect on PMT output pulses. In this research, it was tried to investigate the effect of Capacitor’s value and places on PMT voltage divider in Neutron-Gamma discrimination capability. Therefore, the voltage divider circuit for R329-02 Hamamatsu PMT was made and Zero Cross method used for neutron-gamma discrimination. The neutron source was a 20Ci Am-Be. Anode and Dynode pulses and discrimination spectrum were saved. The results showed that the pulse height and discrimination quality change with the value and setting of capacitors.

  1. Calibration of Voltage Transformers and High- Voltage Capacitors at NIST

    Science.gov (United States)

    Anderson, William E.

    1989-01-01

    The National Institute of Standards and Technology (NIST) calibration service for voltage transformers and high-voltage capacitors is described. The service for voltage transformers provides measurements of ratio correction factors and phase angles at primary voltages up to 170 kV and secondary voltages as low as 10 V at 60 Hz. Calibrations at frequencies from 50–400 Hz are available over a more limited voltage range. The service for high-voltage capacitors provides measurements of capacitance and dissipation factor at applied voltages ranging from 100 V to 170 kV at 60 Hz depending on the nominal capacitance. Calibrations over a reduced voltage range at other frequencies are also available. As in the case with voltage transformers, these voltage constraints are determined by the facilities at NIST. PMID:28053409

  2. Modular High Voltage Power Supply

    Energy Technology Data Exchange (ETDEWEB)

    Newell, Matthew R. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-05-18

    The goal of this project is to develop a modular high voltage power supply that will meet the needs of safeguards applications and provide a modular plug and play supply for use with standard electronic racks.

  3. Portable High Voltage Impulse Generator

    Directory of Open Access Journals (Sweden)

    S. Gómez

    2011-06-01

    Full Text Available This paper presents a portable high voltage impulse generator which was designed and built with insulation up to 20 kV. This design was based on previous work in which simulation software for standard waves was developed. Commercial components and low-cost components were used in this work; however, these particular elements are not generally used for high voltage applications. The impulse generators used in industry and laboratories are usually expensive; they are built to withstand extra high voltage and they are big, making them impossible to transport. The proposed generator is portable, thereby allowing tests to be made on devices that cannot be moved from their location. The results obtained with the proposed impulse generator were satisfactory in terms of time and waveforms compared to other commercial impulse generators and the standard impulse wave simulator.

  4. Analysis of the match problem of a capacitive voltage divider with a long measurement cable

    Science.gov (United States)

    Yu, Bin-Xiong; Li, Rui; Su, Jian-Cang; Zhao, Liang; Zhang, Yu; Zheng, Lei; Zeng, Bo; Cheng, Jie; Gao, Peng-Cheng; Qiu, Xu-Dong; Xu, Xu-dong

    2017-09-01

    Research is carried out on the basis of the traditional two-end matched circuit of a capacitive voltage divider with a long measurement cable. Transmission progress in the circuit is analyzed theoretically. A match condition of the circuit is acquired, which requires that the circuit satisfies two conditions: (1) the measurement error should be small for a pulse with a duration of less than twice the delay time of the measurement cable; (2) the initial division ratio and the stable division ratio of the circuit are the same. Two matched methods of the circuit are acquired, including the first-order matched method and the second-order matched method. Numerical simulations are carried out. According to the simulation results, the relative errors of the circuits with a cable of 20 m are less than 1.5%, obtained by using both match methods for measurement of rectangular pulses with rise and fall times of 5 ns. An improved circuit is presented, which is suitable for any situation where the low-voltage capacitance of the capacitive divider is even smaller than the capaictance of the measurement cable. A verification experment is carried out, and the test result confirms the simulation result.

  5. Transient voltage sharing in series-coupled high voltage switches

    Directory of Open Access Journals (Sweden)

    Editorial Office

    1992-07-01

    Full Text Available For switching voltages in excess of the maximum blocking voltage of a switching element (for example, thyristor, MOSFET or bipolar transistor such elements are often coupled in series - and additional circuitry has to be provided to ensure equal voltage sharing. Between each such series element and system ground there is a certain parasitic capacitance that may draw a significant current during high-speed voltage transients. The "open" switch is modelled as a ladder network. Analy­sis reveals an exponential progression in the distribution of the applied voltage across the elements. Overstressing thus oc­curs in some of the elements at levels of the total voltage that are significantly below the design value. This difficulty is overcome by grading the voltage sharing circuitry, coupled in parallel with each element, in a prescribed manner, as set out here.

  6. High-Voltage Droplet Dispenser

    Science.gov (United States)

    Eichenberg, Dennis J.

    2003-01-01

    An apparatus that is extremely effective in dispensing a wide range of droplets has been developed. This droplet dispenser is unique in that it utilizes a droplet bias voltage, as well as an ionization pulse, to release a droplet. Apparatuses that deploy individual droplets have been used in many applications, including, notably, study of combustion of liquid fuels. Experiments on isolated droplets are useful in that they enable the study of droplet phenomena under well-controlled and simplified conditions. In this apparatus, a syringe dispenses a known value of liquid, which emerges from, and hangs onto, the outer end of a flat-tipped, stainless steel needle. Somewhat below the needle tip and droplet is a ring electrode. A bias high voltage, followed by a high-voltage pulse, is applied so as to attract the droplet sufficiently to pull it off the needle. The voltages are such that the droplet and needle are negatively charged and the ring electrode is positively charged.

  7. TRANSISTOR HIGH VOLTAGE POWER SUPPLY

    Science.gov (United States)

    Driver, G.E.

    1958-07-15

    High voltage, direct current power supplies are described for use with battery powered nuclear detection equipment. The particular advantages of the power supply described, are increased efficiency and reduced size and welght brought about by the use of transistors in the circuit. An important feature resides tn the employment of a pair of transistors in an alternatefiring oscillator circuit having a coupling transformer and other circuit components which are used for interconnecting the various electrodes of the transistors.

  8. Advances in high voltage engineering

    CERN Document Server

    Haddad, A

    2005-01-01

    This book addresses the very latest research and development issues in high voltage technology and is intended as a reference source for researchers and students in the field, specifically covering developments throughout the past decade. This unique blend of expert authors and comprehensive subject coverage means that this book is ideally suited as a reference source for engineers and academics in the field for years to come.

  9. First high-voltage measurements using Ca+ ions at the ALIVE experiment

    Science.gov (United States)

    König, K.; Geppert, Ch.; Krämer, J.; Maaß, B.; Otten, E. W.; Ratajczyk, T.; Nörtershäuser, W.

    2017-11-01

    Many physics experiments depend on accurate high-voltage measurements to determine for example the exact retardation potential of an electron spectrometer as in the KATRIN experiment or the acceleration voltage of the ions at ISOL facilities. Until now only precision high-voltage dividers can be used to measure voltages up to 65 kV with an accuracy of 1 ppm. However, these dividers need frequent calibration and cross-checking and the direct traceability is not given. In this article we will describe the status of an experiment which aims to measure high voltages using collinear laser spectroscopy and which has the potential to provide a high-voltage standard and hence, a calibration source for precision high-voltage dividers on the 1 ppm level.

  10. First high-voltage measurements using Ca{sup +} ions at the ALIVE experiment

    Energy Technology Data Exchange (ETDEWEB)

    König, K., E-mail: kkoenig@ikp.tu-darmstadt.de [Technische Universität Darmstadt, Institut für Kernphysik (Germany); Geppert, Ch. [Universität Mainz, Institut für Kernchemie (Germany); Krämer, J.; Maaß, B. [Technische Universität Darmstadt, Institut für Kernphysik (Germany); Otten, E. W. [Universität Mainz, Institut für Physik (Germany); Ratajczyk, T.; Nörtershäuser, W. [Technische Universität Darmstadt, Institut für Kernphysik (Germany)

    2017-11-15

    Many physics experiments depend on accurate high-voltage measurements to determine for example the exact retardation potential of an electron spectrometer as in the KATRIN experiment or the acceleration voltage of the ions at ISOL facilities. Until now only precision high-voltage dividers can be used to measure voltages up to 65 kV with an accuracy of 1 ppm. However, these dividers need frequent calibration and cross-checking and the direct traceability is not given. In this article we will describe the status of an experiment which aims to measure high voltages using collinear laser spectroscopy and which has the potential to provide a high-voltage standard and hence, a calibration source for precision high-voltage dividers on the 1 ppm level.

  11. High voltage MOSFET switching circuit

    Science.gov (United States)

    McEwan, Thomas E.

    1994-01-01

    The problem of source lead inductance in a MOSFET switching circuit is compensated for by adding an inductor to the gate circuit. The gate circuit inductor produces an inductive spike which counters the source lead inductive drop to produce a rectangular drive voltage waveform at the internal gate-source terminals of the MOSFET.

  12. High-voltage engineering and testing

    CERN Document Server

    Ryan, Hugh M

    2013-01-01

    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.

  13. High-voltage power supply unit

    CERN Document Server

    Garipov, G K; Silaev, A A; Shirokov, A V

    2002-01-01

    A unit comprising four high-voltage power sources (HPS) is designed for power supply of four independent photomultipliers. Each HPS comprises a pulse-width modulator, digital-to-analog converter, base voltage source and digital interface. HPS unit supplies up to 2000 V output voltage, up to 2.5 mA current and long-term stability equal to +- 0.03%

  14. Compact, Lightweight, High Voltage Propellant Isolators Project

    Data.gov (United States)

    National Aeronautics and Space Administration — TA&T, Inc. proposes an enabling fabrication process for high voltage isolators required in high power solar electric and nuclear electric propulsion (SEP and...

  15. High voltage electricity installations a planning perspective

    CERN Document Server

    Jay, Stephen Andrew

    2006-01-01

    The presence of high voltage power lines has provoked widespread concern for many years. High Voltage Electricity Installations presents an in-depth study of policy surrounding the planning of high voltage installations, discussing the manner in which they are percieved by the public, and the associated environmental issues. An analysis of these concerns, along with the geographical, environmental and political influences that shape their expression, is presented. Investigates local planning policy in an area of the energy sector that is of highly topical environmental and public concern Cover

  16. High voltage and electrical insulation engineering

    CERN Document Server

    Arora, Ravindra

    2011-01-01

    "The book is written for students as well as for teachers and researchers in the field of High Voltage and Insulation Engineering. It is based on the advance level courses conducted at TU Dresden, Germany and Indian Institute of Technology Kanpur, India. The book has a novel approach describing the fundamental concept of field dependent behavior of dielectrics subjected to high voltage. There is no other book in the field of high voltage engineering following this new approach in describing the behavior of dielectrics. The contents begin with the description of fundamental terminology in the subject of high voltage engineering. It is followed by the classification of electric fields and the techniques of field estimation. Performance of gaseous, liquid and solid dielectrics under different field conditions is described in the subsequent chapters. Separate chapters on vacuum as insulation and the lightning phenomenon are included"--

  17. High Voltage Power Supply With High Output Current and Low Power Consumption for Photomultiplier Tubes

    Science.gov (United States)

    Cunha, José Paulo V. S.; Begalli, Marcia; Bellar, Maria Dias

    2012-04-01

    In some applications, photomultiplier tubes (PMTs) are powered by battery based circuits, where the available energy is severely limited. The most simple approach to design high voltage power supplies (HVPS) for PMTs has considered resistive voltage dividers in order to bias the dynodes. However, this approach usually results in high power losses and, consequently, this undermines the PMT performance. In this work, the proposed solution is the use of a power circuit based on the forward converter connected to a transformer built with several secondary windings. Each secondary voltage is rectified and filtered to eliminate voltage ripple. Each dynode voltage is supplied by a rectified secondary voltage. The proposed topology provides low power consumption as well as low sensitivity of the PMT gain with respect to the dynode currents. Taking into account the Waste Electrical and Electronic Equipment Directive (WEEE), this HVPS has been designed to allow the recycling of old PMTs.

  18. High voltage testing for the Majorana Demonstrator

    Energy Technology Data Exchange (ETDEWEB)

    Abgrall, N.; Arnquist, Isaac J.; Avignone, F. T.; Barabash, A.; Bertrand, F.; Bradley, A. W.; Brudanin, V.; Busch, Matthew; Buuck, M.; Byram, D.; Caldwell, A. S.; Chan, Yuen-Dat; Christofferson, C. D.; Chu, Pamela M.; Cuesta, C.; Detwiler, Jason A.; Doe, P. J.; Dunagan, C.; Efremenko, Yuri; Ejiri, H.; Elliott, S. R.; Fu, Z.; Galindo-Uribarri, A.; Giovanetti, G. K.; Goett, J.; Green, M. P.; Gruszko, J.; Guinn, I.; Guiseppe, V. E.; Henning, R.; Hoppe, Eric W.; Howard, S.; Howe, M. A.; Jasinski, B. R.; Keeter, K.; Kidd, M. F.; Konovalov, S.; Kouzes, Richard T.; Laferriere, Brian D.; Leon, Jonathan D.; Li, Alexander D.; MacMullin, J.; Martin, R. D.; Massarcyk, R.; Meijer, S. J.; Mertens, S.; Orrell, John L.; O' Shaughnessy, C.; Poon, Alan W.; Radford, D. C.; Rager, J.; Rielage, Keith; Robertson, R. G. H.; Romero Romo, M.; Shanks, B.; Shirchenko, M.; Snyder, N.; Suriano, Anne-Marie E.; Tedeschi, D.; Thompson, Andrew; Ton, K. T.; Trimble, J. E.; Varner, R. L.; Vasilyev, Sergey; Vetter, Kai; Vorren, Kris R.; White, Brandon R.; Wilkerson, J. F.; Wiseman, C.; Xu, W.; Yakushev, E.; Yu, Chang-Hong; Yumatov, V.

    2016-07-01

    The Majorana Collaboration is constructing theMajorana Demonstrator, an ultra-low background, 44-kg modular high-purity Ge (HPGe) detector array to search for neutrinoless double-beta decay in 76Ge. The phenomenon of surface micro-discharge induced by high-voltage has been studied in the context of theMajorana Demonstrator. This effect can damage the front-end electronics or mimic detector signals. To ensure the correct performance, every high-voltage cable and feedthrough must be capable of supplying HPGe detector operating voltages as high as 5 kV without exhibiting discharge. R&D measurements were carried out to understand the testing system and determine the optimum design configuration of the high-voltage path, including different improvements of the cable layout and feedthrough flange model selection. Every cable and feedthrough to be used at the Majorana Demonstrator was characterized and the micro-discharge effects during theMajorana Demonstrator commissioning phase were studied. A stable configuration has been achieved, and the cables and connectors can supply HPGe detector operating voltages without exhibiting discharge.

  19. 76 FR 70721 - Voltage Coordination on High Voltage Grids; Notice of Staff Workshop

    Science.gov (United States)

    2011-11-15

    ... Energy Regulatory Commission Voltage Coordination on High Voltage Grids; Notice of Staff Workshop Take notice that the Federal Energy Regulatory Commission will hold a Workshop on Voltage Coordination on High Voltage Grids on Thursday, December 1, 2011 from 9 a.m. to 4:30 p.m. This staff-led workshop will be held...

  20. High Efficiency Power Converter for Low Voltage High Power Applications

    DEFF Research Database (Denmark)

    Nymand, Morten

    . A detailed analysis of dominant loss factors in high power converters for low voltage applications is presented. The analysis concludes that: • Power transformers for low voltage high power, if properly designed, will have extremely low leakage inductance. • If optimally designed, boost converters......The topic of this thesis is the design of high efficiency power electronic dc-to-dc converters for high-power, low-input-voltage to high-output-voltage applications. These converters are increasingly required for emerging sustainable energy systems such as fuel cell, battery or photo voltaic based......, if a converter is properly designed, primary side voltage clamp circuits will not even work in low voltage high power converters. • Very high conversion efficiency can be achieved. Peak efficiency of 98% and worst case minimum efficiency of 96.8% are demonstrated on a 1.5 kW converter. The ability...

  1. High Efficiency Power Converter for Low Voltage High Power Applications

    DEFF Research Database (Denmark)

    Nymand, Morten

    and maximum output power. In chapter 3, a detailed analysis of dominant loss factors in high power converters for low voltage applications is presented. The analysis concludes that: • Power transformers for low voltage high power, if properly designed, will have extremely low leakage inductance......The topic of this thesis is the design of high efficiency power electronic dc-to-dc converters for high-power, low-input-voltage to high-output-voltage applications. These converters are increasingly required for emerging sustainable energy systems such as fuel cell, battery or photo voltaic based....... • If optimally designed, boost converters will be much more efficient than comparable buck type converters for high power low voltage applications. • The use of voltage clamp circuits to protect primary switches in boost converters is no longer needed for device protection. On the other hand...

  2. Pulsed high voltage discharge induce hematologic changes

    African Journals Online (AJOL)

    STORAGESEVER

    2009-10-19

    Oct 19, 2009 ... The aim of this work to examine the effect of the gas-liquid hybrid discharge treatment system on some hematological ... liquid phase. The high energy plasma arc produces a pressure shock wave, electromagnetic radiations, .... through a 50 kilo-ohm resistor by a negative dc high-voltage power supply and ...

  3. High-voltage test and measuring techniques

    CERN Document Server

    Hauschild, Wolfgang

    2014-01-01

    It is the intent of this book to combine high-voltage (HV) engineering with HV testing technique and HV measuring technique. Based on long-term experience gained by the authors as lecturer and researcher as well as member in international organizations, such as IEC and CIGRE, the book will reflect the state of the art as well as the future trends in testing and diagnostics of HV equipment to ensure a reliable generation, transmission and distribution of electrical energy. The book is intended not only for experts but also for students in electrical engineering and high-voltage engineering.

  4. 76 FR 72203 - Voltage Coordination on High Voltage Grids; Notice of Reliability Workshop Agenda

    Science.gov (United States)

    2011-11-22

    ... Energy Regulatory Commission Voltage Coordination on High Voltage Grids; Notice of Reliability Workshop... between voltage control, reliability, and economic dispatch. In addition, the Commission will consider how improvements to dispatch and voltage control software could improve reliability and market efficiency. This...

  5. Modular high voltage power supply for chemical analysis

    Science.gov (United States)

    Stamps, James F [Livermore, CA; Yee, Daniel D [Dublin, CA

    2008-07-15

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

  6. An Inexpensive Source of High Voltage

    Science.gov (United States)

    Saraiva, Carlos

    2012-01-01

    As a physics teacher I like recycling old apparatus and using them for demonstrations in my classes. In physics laboratories in schools, sources of high voltage include induction coils or electronic systems that can be bought from companies that sell lab equipment. But these sources can be very expensive. In this article, I will explain how you…

  7. 30 CFR 75.804 - Underground high-voltage cables.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Underground high-voltage cables. 75.804 Section... AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Underground High-Voltage Distribution § 75.804 Underground high-voltage cables. (a) Underground high-voltage cables used in resistance...

  8. 30 CFR 77.810 - High-voltage equipment; grounding.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false High-voltage equipment; grounding. 77.810... COAL MINES Surface High-Voltage Distribution § 77.810 High-voltage equipment; grounding. Frames, supporting structures, and enclosures of stationary, portable, or mobile high-voltage equipment shall be...

  9. High-voltage multijunction photovoltaic solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Doroshenko, V.G.; Zaks, M.B.; Kalash' yan, V.A.; Lozovskiy, V.N.; Skokov, Yu.V.; Solodukha, O.I.

    1979-01-01

    The possibility of developing a high-voltage multijunction photovoltaic cell (HMPC) based on a single crystal with multiple vertical p-n junctions formed by heavily doped zones at right angles to the illuminated surface of the instrument is demonstrated. A laboratory technology for producing HMPC based on the zone recrystallization method with a temperature gradient and linear zones is presented. The investigated variant of HMPC was made of n-type silicon with resistivity of 1 ohm.cm in which are formed vertical p/sup +/ type zones doped with aluminum or an aluminum-boron alloy. The performance HMPC (with 11 and 5 vertical p-n junctions) was experimentally investigated in the presence of 400 to 500 ms light pulses from a xenon lamp with a near-solar spectrum and the current-voltage characteristic of the HMPC was found to be then virtually unaffected.

  10. Energy harvesting in high voltage measuring techniques

    Science.gov (United States)

    Żyłka, Pawel; Doliński, Marcin

    2016-02-01

    The paper discusses selected problems related to application of energy harvesting (that is, generating electricity from surplus energy present in the environment) to supply autonomous ultra-low-power measurement systems applicable in high voltage engineering. As a practical example of such implementation a laboratory model of a remote temperature sensor is presented, which is self-powered by heat generated in a current-carrying busbar in HV- switchgear. Presented system exploits a thermoelectric harvester based on a passively cooled Peltier module supplying micro-power low-voltage dc-dc converter driving energy-efficient temperature sensor, microcontroller and a fibre-optic transmitter. Performance of the model in laboratory simulated conditions are presented and discussed.

  11. High Voltage in Noble Liquids for High Energy Physics

    Energy Technology Data Exchange (ETDEWEB)

    Rebel, B. [Fermilab; Bernard, E. [Yale U.; Faham, C. H. [LBL, Berkeley; Ito, T. M. [Los Alamos; Lundberg, B. [Maryland U.; Messina, M. [Columbia U.; Monrabal, F. [Valencia U., IFIC; Pereverzev, S. P. [LLNL, Livermore; Resnati, F. [Zurich, ETH; Rowson, P. C. [SLAC; Soderberg, M. [Fermilab; Strauss, T. [Bern U.; Tomas, A. [Imperial Coll., London; Va' vra, J. [SLAC; Wang, H. [UCLA

    2014-08-22

    A workshop was held at Fermilab November 8-9, 2013 to discuss the challenges of using high voltage in noble liquids. The participants spanned the fields of neutrino, dark matter, and electric dipole moment physics. All presentations at the workshop were made in plenary sessions. This document summarizes the experiences and lessons learned from experiments in these fields at developing high voltage systems in noble liquids.

  12. Maintenance Optimization of High Voltage Substation Model

    Directory of Open Access Journals (Sweden)

    Radim Bris

    2008-01-01

    Full Text Available The real system from practice is selected for optimization purpose in this paper. We describe the real scheme of a high voltage (HV substation in different work states. Model scheme of the HV substation 22 kV is demonstrated within the paper. The scheme serves as input model scheme for the maintenance optimization. The input reliability and cost parameters of all components are given: the preventive and corrective maintenance costs, the actual maintenance period (being optimized, the failure rate and mean time to repair - MTTR.

  13. Advanced High Voltage Power Device Concepts

    CERN Document Server

    Baliga, B Jayant

    2012-01-01

    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 ...

  14. High Voltage GaN Schottky Rectifiers

    Energy Technology Data Exchange (ETDEWEB)

    CAO,X.A.; CHO,H.; CHU,S.N.G.; CHUO,C.-C.; CHYI,J.-I.; DANG,G.T.; HAN,JUNG; LEE,C.-M.; PEARTON,S.J.; REN,F.; WILSON,R.G.; ZHANG,A.P.

    1999-10-25

    Mesa and planar GaN Schottky diode rectifiers with reverse breakdown voltages (V{sub RB}) up to 550V and >2000V, respectively, have been fabricated. The on-state resistance, R{sub ON}, was 6m{Omega}{center_dot} cm{sup 2} and 0.8{Omega}cm{sup 2}, respectively, producing figure-of-merit values for (V{sub RB}){sup 2}/R{sub ON} in the range 5-48 MW{center_dot}cm{sup -2}. At low biases the reverse leakage current was proportional to the size of the rectifying contact perimeter, while at high biases the current was proportional to the area of this contact. These results suggest that at low reverse biases, the leakage is dominated by the surface component, while at higher biases the bulk component dominates. On-state voltages were 3.5V for the 550V diodes and {ge}15 for the 2kV diodes. Reverse recovery times were <0.2{micro}sec for devices switched from a forward current density of {approx}500A{center_dot}cm{sup -2} to a reverse bias of 100V.

  15. A High-Voltage Level Tolerant Transistor Circuit

    NARCIS (Netherlands)

    Annema, Anne J.; Geelen, Godefridus Johannes Gertrudis Maria

    2001-01-01

    A high-voltage level tolerant transistor circuit, comprising a plurality of cascoded transistors, including a first transistor (T1) operatively connected to a high-voltage level node (3) and a second transistor (T2) operatively connected to a low-voltage level node (2). The first transistor (T1)

  16. Prediction of breakdown voltages in novel gases for high voltage insulation

    Energy Technology Data Exchange (ETDEWEB)

    Koch, M.

    2015-07-01

    This thesis submitted to the Swiss Federal Institute of Technology ETH in Zurich examines the use of sulphur hexafluoride (SF{sub 6}) and similar gases as important insulation media for high voltage equipment. Due to its superior insulation properties, SF{sub 6} is widely used in gas-insulated switchgear. However, the gas also has a very high global warming potential and the content of SF{sub 6} in the atmosphere is constantly increasing. The search for new insulation gases using classical breakdown experiments is discussed. A model for SF{sub 6} based on the stepped leader model is described. This calculates the breakdown voltages in arbitrary electrode configurations and under standard voltage waveforms. Thus, the thesis provides a method for the prediction of breakdown voltages of arbitrary field configurations under standard voltage waveforms for gases with electron-attaching properties. With this, further gases can be characterized for usage as high voltage insulation media.

  17. RICH High Voltages & PDF Analysis @ LHCb

    CERN Multimedia

    Fanchini, E

    2009-01-01

    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.

  18. External loading of High Voltage Pylons

    Directory of Open Access Journals (Sweden)

    Peter Polák

    2013-12-01

    Full Text Available This contribution is devoted to issues of long term safe service of high-voltage pylons, which are loaded during service by variable loading with simultaneous acting of external environment. There were proved the procedures ensuring that the limit state will not occur during the period of technical life and the service will be safe for a long time. A draft of diagnostic procedures was elaborated, applied in suitable inspection intervals, following from the analysis of failure risks. The maintenance and repair procedures, assuring the safety of service until next inspection are planned on the basis of application of analytic methods of dynamic fracture mechanics. This procedure of controlled ageing is designed for the new and serviced pylons as well. The controlled ageing at the same time prolongs the technical life of structure with a high measure of safety. Residual life can be determined in each phase of pylon life. Controlled ageing allows saving high economic values at spending considerable lower costs for inspection and maintenance.

  19. Energy Storage Options for Voltage Support in Low-Voltage Grids with High Penetration of Photovoltaic

    DEFF Research Database (Denmark)

    Marra, Francesco; Tarek Fawzy, Y.; Bülo, Thorsten

    2012-01-01

    The generation of power by photovoltaic (PV) systems is constantly increasing in low-voltage (LV) distribution grids, in line with the European environmental targets. To cope with the effects on grid voltage profiles during high generation and low demand periods, new solutions need to be establis......The generation of power by photovoltaic (PV) systems is constantly increasing in low-voltage (LV) distribution grids, in line with the European environmental targets. To cope with the effects on grid voltage profiles during high generation and low demand periods, new solutions need...... to be established. In the long term, these solutions should also aim to allow further more PV installed capacity, while meeting the power quality requirements. In this paper, different concepts of energy storage are proposed to ensure the voltage quality requirements in a LV grid with high PV penetration...

  20. Design and development of high voltage high power operational ...

    Indian Academy of Sciences (India)

    systems and the electron deflection systems. Power operational amplifiers have ... approach is cost and availability of high voltage devices in chip form. 2.2 Amplifier with opamp input stage .... power opamp, using chip passive components, semiconductor bare dice minimizes the size while increasing the reliability.

  1. Low-voltage and high-voltage TEM observations on MWCNTs of rat in vivo.

    Science.gov (United States)

    Sakaguchi, Norihito; Watari, Fumio; Yokoyama, Atsuro; Nodasaka, Yoshinobu; Ichinose, Hideki

    2009-01-01

    In the present study, we focused on the optimal conditions for observation of morphology and atomic structure of carbon nanotube (CNT) in vivo by transmission electron microscopy (TEM). Either low-voltage or high-voltage TEMs was chosen for the high-contrast or high-resolution imaging of subcutaneous tissue and the multi-wall CNT (MWCNT). The morphology and structure of each cell organelle were well recognized using the low-voltage TEM at 75 kV. Individual MWCNTs forming the cluster were also visible by the low-voltage TEM. On the contrary, the high-voltage TEM image at 1250 kV shows poor contrast on both the cell organelles and MWCNTs. However, graphene layers of MWCNT were clearly visible in the HRTEM image using the high-voltage TEM. The influence of the surrounding biological tissue can be disregarded by the high-energy electrons due to their weak scattering/absorption effect in the tissue. It was indicated that the usage of the high-voltage TEM is quite effective to the atomic structure analysis of nano-crystalline materials in vivo.

  2. As "Accelerated Learning" Booms, High School-College Divide Blurs

    Science.gov (United States)

    Olson, Lynn

    2006-01-01

    One indication that the lines between high schools and colleges are blurring is the growth in programs that permit students to earn college credit while still in high school. More than 250 educators and policymakers representing both the K-12 and higher education communities gathered on June 8-9, 2006 to discuss such "accelerated-learning…

  3. LED-Based High-Voltage Lines Warning System

    Directory of Open Access Journals (Sweden)

    Eldar MUSA

    2013-04-01

    Full Text Available LED-based system, running with the current of high-voltage lines and converting the current flowing through the line into the light by using a toroid transformer, has been developed. The transformer’s primary winding is constituted by the high voltage power line. Toroidal core consists of two equal parts and the secondary windings are evenly placed on these two parts. The system is mounted on the high-voltage lines as a clamp. The secondary winding ends are connected in series by the connector on the clamp. LEDs are supplied by the voltage at the ends of secondary. Current flowing through highvoltage transmission lines is converted to voltage by the toroidal transformer and the light emitting LEDs are supplied with this voltage. The theory of the conversion of the current flowing through the line into the light is given. The system, running with the current of the line and converting the current into the light, has been developed. System has many application areas such as warning high voltage lines (warning winches to not hinder the high-voltage lines when working under the lines, warning planes to not touch the high-voltage lines, remote measurement of high-voltage line currents, and local illumination of the line area

  4. High Voltage Application of Explosively Formed Fuses

    Energy Technology Data Exchange (ETDEWEB)

    Tasker, D.G.; Goforth, J.H.; Fowler, C.M.; Lopez, E.M.; Oona, H.; Marsh, S.P.; King, J.C.; Herrera, D.H.; Torres, D.T.; Sena, F.C.; Martinez, E.C.; Reinovsky, R.E.; Stokes, J.L.; Tabaka, L.J.; Kiuttu, G.; Degnan, J.

    1998-10-18

    At Los Alamos, the authors have primarily applied Explosively Formed Fuse (EFF) techniques to high current systems. In these systems, the EFF has interrupted currents from 19 to 25 MA, thus diverting the current to low inductance loads. The magnitude of transferred current is determined by the ratio of storage inductance to load inductance, and with dynamic loads, the current has ranged from 12 to 20 MA. In a system with 18 MJ stored energy, the switch operates at a power up to 6 TW. The authors are now investigating the use of the EFF technique to apply high voltages to high impedance loads in systems that are more compact. In these systems, they are exploring circuits with EFF lengths from 43 to 100 cm, which have storage inductances large enough to apply 300 to 500 kV across high impedance loads. Experimental results and design considerations are presented. Using cylindrical EFF switches of 10 cm diameter and 43 cm length, currents of approximately 3 MA were interrupted producing {approximately}200 kV. This indicate s the switch had an effective resistance of {approximately}100 m{Omega} where 150--200 m{Omega} was expected. To understand the lower performance, several parameters were studied, including: electrical conduction through the explosive products; current density; explosive initiation; insulator type; conductor thickness; and so on. The results show a number of interesting features, most notably that the primary mechanism of switch operation is mechanical and not electrical fusing of the conductor. Switches opening on a 10 to 10 {micro}s time scale with resistances starting at 50 {micro}{Omega} and increasing to perhaps 1 {Omega} now seem possible to construct, using explosive charges as small as a few pounds.

  5. Artificial neural networks in high voltage transmission line problems

    Science.gov (United States)

    Ekonomou, L.; Kontargyri, V. T.; Kourtesi, St.; Maris, T. I.; Stathopulos, I. A.

    2007-07-01

    According to the literature high voltage transmission line problems are faced using conventional analytical methods, which include in most cases empirical and/or approximating equations. Artificial intelligence and more specifically artificial neural networks (ANN) are addressed in this work, in order to give accurate solutions to high voltage transmission line problems using in the calculations only actual field data. Two different case studies are studied, i.e., the estimation of critical flashover voltage on polluted insulators and the estimation of lightning performance of high voltage transmission lines. ANN models are developed and are tested on operating high voltage transmission lines and polluted insulators, producing very satisfactory results. These two ANN models can be used in electrical engineers' studies aiming at the more effective protection of high voltage equipment.

  6. Demonstration of the two-chamber approach for high-voltage measurements using collinear laser spectroscopy

    Science.gov (United States)

    Will, Elisa; Ullmann, Johannes; Frömmgen, Nadja; Geppert, Christopher; Gorges, Christian; Hammen, Michael; Kaufmann, Simon; Krieger, Andreas; Nörtershäuser, Wilfried

    2014-06-01

    An electronic measurement of high-voltages of several ten kV with accuracy as required for precision experiments is currently only feasible using highly sophisticated voltage dividers. Collinear laser spectroscopy can provide a direct and precise measurement of high-voltages using the Doppler shift of accelerated ions. Although proposed already in 1982, a measurement with relative accuracy better than 10-4 was not reported so far. To improve this accuracy, a dedicated new setup for high-voltage measurements will be installed at the Technische Universität Darmstadt. A two-chamber approach will be used to remove uncertainties due to the insufficiently known starting potential inside the ion source. Here we present a demonstration of the pump-and-probe technique performed in preparatory studies at the TRIGA-LASER experiment in Mainz.

  7. High-Voltage Digital-To-Analog Converter

    Science.gov (United States)

    Huston, Steven W.

    1990-01-01

    High-voltage 10-bit digital-to-analog converter operates under computer control to put out voltages up to 500 V at currents up to 35 mA. Circuit includes high-voltage power supply used to generate high-voltage square wave at frequency set by computer at value between 0.2 Hz and 10 Hz. Used to drive 0.02-microfarad, 1-kV capacitor at slewing rate of 1 V/microsecond to provide signal for robotic imaging system.

  8. ON SELECTION OF CIRCUIT-BREAKERS SWITCHING ELECTRICAL INSTALLATIONS OF HIGH AND EXTRA-HIGH VOLTAGE

    Directory of Open Access Journals (Sweden)

    T. M. Lazimov

    2005-01-01

    Full Text Available The paper proposes some additional conditions for high-voltage circuit-breaker selection keeping in mind coordination of the switched over-voltages and voltages induced in secondary circuits with their permissible values.

  9. High voltage switches having one or more floating conductor layers

    Science.gov (United States)

    Werne, Roger W.; Sampayan, Stephen; Harris, John Richardson

    2015-11-24

    This patent document discloses high voltage switches that include one or more electrically floating conductor layers that are isolated from one another in the dielectric medium between the top and bottom switch electrodes. The presence of the one or more electrically floating conductor layers between the top and bottom switch electrodes allow the dielectric medium between the top and bottom switch electrodes to exhibit a higher breakdown voltage than the breakdown voltage when the one or more electrically floating conductor layers are not present between the top and bottom switch electrodes. This increased breakdown voltage in the presence of one or more electrically floating conductor layers in a dielectric medium enables the switch to supply a higher voltage for various high voltage circuits and electric systems.

  10. Integrated reconfigurable high-voltage transmitting circuit for CMUTs

    DEFF Research Database (Denmark)

    Llimos Muntal, Pere; Larsen, Dennis Øland; Jørgensen, Ivan Harald Holger

    2015-01-01

    In this paper a high-voltage transmitting circuit aimed for capacitive micromachined ultrasonic transducers (CMUTs) used in scanners for medical applications is designed and implemented in a 0.35 μm high-voltage CMOS process. The transmitting circuit is reconfigurable externally making it able...

  11. PV source based high voltage gain current fed converter

    Science.gov (United States)

    Saha, Soumya; Poddar, Sahityika; Chimonyo, Kudzai B.; Arunkumar, G.; Elangovan, D.

    2017-11-01

    This work involves designing and simulation of a PV source based high voltage gain, current fed converter. It deals with an isolated DC-DC converter which utilizes boost converter topology. The proposed converter is capable of high voltage gain and above all have very high efficiency levels as proved by the simulation results. The project intends to produce an output of 800 V dc from a 48 V dc input. The simulation results obtained from PSIM application interface were used to analyze the performance of the proposed converter. Transformer used in the circuit steps up the voltage as well as to provide electrical isolation between the low voltage and high voltage side. Since the converter involves high switching frequency of 100 kHz, ultrafast recovery diodes are employed in the circuitry. The major application of the project is for future modeling of solar powered electric hybrid cars.

  12. Multiple High Voltage Pulse Stressing of Polymer Thick Film Resistors

    Directory of Open Access Journals (Sweden)

    Busi Rambabu

    2014-01-01

    Full Text Available The purpose of this paper is to study high voltage interactions in polymer thick film resistors, namely, polyvinyl chloride- (PVC- graphite thick film resistors, and their applications in universal trimming of these resistors. High voltages in the form of impulses for various pulse durations and with different amplitudes have been applied to polymer thick film resistors and we observed the variation of resistance of these resistors with high voltages. It has been found that the resistance of polymer thick film resistors decreases in the case of higher resistivity materials and the resistance of polymer thick film resistor increases in the case of lower resistivity materials when high voltage impulses are applied to them. It has been also found that multiple high voltage pulse (MHVP stressing can be used to trim the polymer thick film resistors either upwards or downwards.

  13. Electrical system architecture having high voltage bus

    Science.gov (United States)

    Hoff, Brian Douglas [East Peoria, IL; Akasam, Sivaprasad [Peoria, IL

    2011-03-22

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

  14. Planar LTCC transformers for high voltage flyback converters.

    Energy Technology Data Exchange (ETDEWEB)

    Schofield, Daryl (NASCENT Technology Inc. , Watertown, SD); Schare, Joshua M.; Glass, Sarah Jill; Roesler, Alexander William; Ewsuk, Kevin Gregory; Slama, George (NASCENT Technology Inc. , Watertown, SD); Abel, Dave (NASCENT Technology Inc. , Watertown, SD)

    2007-06-01

    This paper discusses the design and use of low-temperature (850 C to 950 C) co-fired ceramic (LTCC) planar magnetic flyback transformers for applications that require conversion of a low voltage to high voltage (> 100V) with significant volumetric constraints. Measured performance and modeling results for multiple designs showed that the LTCC flyback transformer design and construction imposes serious limitations on the achievable coupling and significantly impacts the transformer performance and output voltage. This paper discusses the impact of various design factors that can provide improved performance by increasing transformer coupling and output voltage. The experiments performed on prototype units demonstrated LTCC transformer designs capable of greater than 2 kV output. Finally, the work investigated the effect of the LTCC microstructure on transformer insulation. Although this paper focuses on generating voltages in the kV range, the experimental characterization and discussion presented in this work applies to designs requiring lower voltage.

  15. High Voltage Piezoelectric System for Generating Neutrons

    Science.gov (United States)

    2013-06-01

    10 mm × 1.5 mm -45-degree rotated y-cut lithium niobate slabs. Input electrodes, shown as gray regions on the top and bottom (not visible) surfaces on...the left portion of the bar in Fig. ??, were used to deliver electrical power to the crystal and applied using silver paint with a measured layer ...voltage, stress, and displacement. The crystals for the PTPS were disks of lithium niobate with 5 mm radius and 2 mm thickness, shown in Fig

  16. Recycling potential for low voltage and high voltage high rupturing capacity fuse links.

    Science.gov (United States)

    Psomopoulos, Constantinos S; Barkas, Dimitrios A; Kaminaris, Stavros D; Ioannidis, George C; Karagiannopoulos, Panagiotis

    2017-12-01

    Low voltage and high voltage high-rupturing-capacity fuse links are used in LV and HV installations respectively, protecting mainly the LV and HV electricity distribution and transportation networks. The Waste Electrical and Electronic Equipment Directive (2002/96/EC) for "Waste of electrical and electronic equipment" is the main related legislation and as it concerns electrical and electronic equipment, it includes electric fuses. Although, the fuse links consist of recyclable materials, only small scale actions have been implemented for their recycling around Europe. This work presents the possibilities for material recovery from this specialized industrial waste for which there are only limited volume data. Furthermore, in order to present the huge possibilities and environmental benefits, it presents the potential for recycling of HRC fuses used by the Public Power Corporation of Greece, which is the major consumer for the country, but one of the smallest ones in Europe and globally, emphasizing in this way in the issue. According to the obtained results, fuse recycling could contribute to the effort for minimize the impacts on the environment through materials recovery and reduction of the wastes' volume disposed of in landfills. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

    Vorpenian, Vatche

    2008-01-01

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

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

    Science.gov (United States)

    El-Sharkawi, Mohamed A.; Andexler, George; Silberkleit, Lee I.

    1993-01-19

    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).

  19. High voltage high repetition rate pulse using Marx topology

    Science.gov (United States)

    Hakki, A.; Kashapov, N.

    2015-06-01

    The paper describes Marx topology using MOSFET transistors. Marx circuit with 10 stages has been done, to obtain pulses about 5.5KV amplitude, and the width of the pulses was about 30μsec with a high repetition rate (PPS > 100), Vdc = 535VDC is the input voltage for supplying the Marx circuit. Two Ferrite ring core transformers were used to control the MOSFET transistors of the Marx circuit (the first transformer to control the charging MOSFET transistors, the second transformer to control the discharging MOSFET transistors).

  20. Mechanical Properties of Composites Used in High-Voltage Applications

    Directory of Open Access Journals (Sweden)

    Andreas Moser

    2016-07-01

    Full Text Available Materials used in high voltage applications have to meet a lot of regulations for their safety and functional usage during their lifetime. For high voltage applications the electrical properties are the most relevant designing criteria. However, the mechanical properties of such materials have rarely been considered for application dimensioning over the last decades. This article gives an overview of composite materials used in high voltage applications and some basic mechanical and thermo-mechanical characterization methods of such materials, including a discussion of influences on practically used epoxy based thermosets.

  1. Integrated differential high-voltage transmitting circuit for CMUTs

    DEFF Research Database (Denmark)

    Llimos Muntal, Pere; Larsen, Dennis Øland; Farch, Kjartan

    2015-01-01

    In this paper an integrated differential high-voltage transmitting circuit for capacitive micromachined ultrasonic transducers (CMUTs) used in portable ultrasound scanners is designed and implemented in a 0.35 μm high-voltage process. Measurements are performed on the integrated circuit in order...... to assess its performance. The circuit generates pulses at differential voltage levels of 60V, 80V and 100 V, a frequency up to 5MHz and a measured driving strength of 1.75 V/ns with the CMUT connected. The total on-chip area occupied by the transmitting circuit is 0.18 mm2 and the power consumption...

  2. Highly-Efficient and Modular Medium-Voltage Converters

    Science.gov (United States)

    2015-09-28

    of the modular multilevel converter based on si and sic switching devices for medium/high-voltage applications," IEEE Trans. Electron Devices, vol...4. TITLE AND SUBTITLE Highly-Efficient and Modula Medium-Voltage Converters 6. AUTHOR(S) Maryam Saeedifard 7. PERFORMING ORGANIZATIC i NAME(S...improving the converter’s efficiency and power density. 15. SUBJECT TERMS Modular Multilevel Converters , DC-DC Conversion, DC-AC Conversion 16

  3. High Voltage Bi-directional Flyback Converter for Capacitive Actuator

    DEFF Research Database (Denmark)

    Thummala, Prasanth; Zhang, Zhe; Andersen, Michael A. E.

    2013-01-01

    This paper presents a high voltage DC-DC converter topology for bi-directional energy transfer between a low voltage DC source and a high voltage capacitive load. The topology is a bi-directional flyback converter with variable switching frequency control during the charge mode, and constant...... switching frequency control during the discharge mode. The converter is capable of charging the capacitive load from 24 V DC source to 2.5 kV, and discharges it to 0 V. The flyback converter has been analyzed in detail during both charge and discharge modes, by considering all the parasitic elements...... in the converter, including the most dominating parameters of the high voltage transformer viz., self-capacitance and leakage inductance. The specific capacitive load for this converter is a dielectric electro active polymer (DEAP) actuator, which can be used as an effective replacement for conventional actuators...

  4. High Input Voltage, Silicon Carbide Power Processing Unit Performance Demonstration

    Science.gov (United States)

    Bozak, Karin E.; Pinero, Luis R.; Scheidegger, Robert J.; Aulisio, Michael V.; Gonzalez, Marcelo C.; Birchenough, Arthur G.

    2015-01-01

    A silicon carbide brassboard power processing unit has been developed by the NASA Glenn Research Center in Cleveland, Ohio. The power processing unit operates from two sources: a nominal 300 Volt high voltage input bus and a nominal 28 Volt low voltage input bus. The design of the power processing unit includes four low voltage, low power auxiliary supplies, and two parallel 7.5 kilowatt (kW) discharge power supplies that are capable of providing up to 15 kilowatts of total power at 300 to 500 Volts (V) to the thruster. Additionally, the unit contains a housekeeping supply, high voltage input filter, low voltage input filter, and master control board, such that the complete brassboard unit is capable of operating a 12.5 kilowatt Hall effect thruster. The performance of the unit was characterized under both ambient and thermal vacuum test conditions, and the results demonstrate exceptional performance with full power efficiencies exceeding 97%. The unit was also tested with a 12.5kW Hall effect thruster to verify compatibility and output filter specifications. With space-qualified silicon carbide or similar high voltage, high efficiency power devices, this would provide a design solution to address the need for high power electric propulsion systems.

  5. High Input Voltage, Silicon Carbide Power Processing Unit Performance Demonstration

    Science.gov (United States)

    Bozak, Karin E.; Pinero, Luis R.; Scheidegger, Robert J.; Aulisio, Michael V.; Gonzalez, Marcelo C.; Birchenough, Arthur G.

    2015-01-01

    A silicon carbide brassboard power processing unit has been developed by the NASA Glenn Research Center in Cleveland, Ohio. The power processing unit operates from two sources - a nominal 300-Volt high voltage input bus and a nominal 28-Volt low voltage input bus. The design of the power processing unit includes four low voltage, low power supplies that provide power to the thruster auxiliary supplies, and two parallel 7.5 kilowatt power supplies that are capable of providing up to 15 kilowatts of total power at 300-Volts to 500-Volts to the thruster discharge supply. Additionally, the unit contains a housekeeping supply, high voltage input filter, low voltage input filter, and master control board, such that the complete brassboard unit is capable of operating a 12.5 kilowatt Hall Effect Thruster. The performance of unit was characterized under both ambient and thermal vacuum test conditions, and the results demonstrate the exceptional performance with full power efficiencies exceeding 97. With a space-qualified silicon carbide or similar high voltage, high efficiency power device, this design could evolve into a flight design for future missions that require high power electric propulsion systems.

  6. Planar LTCC transformers for high voltage flyback converters: Part II.

    Energy Technology Data Exchange (ETDEWEB)

    Schofield, Daryl (NASCENTechnology, Inc., Watertown, SD); Schare, Joshua M., Ph.D.; Slama, George (NASCENTechnology, Inc., Watertown, SD); Abel, David (NASCENTechnology, Inc., Watertown, SD)

    2009-02-01

    This paper is a continuation of the work presented in SAND2007-2591 'Planar LTCC Transformers for High Voltage Flyback Converters'. The designs in that SAND report were all based on a ferrite tape/dielectric paste system originally developed by NASCENTechnoloy, Inc, who collaborated in the design and manufacturing of the planar LTCC flyback converters. The output/volume requirements were targeted to DoD application for hard target/mini fuzing at around 1500 V for reasonable primary peak currents. High voltages could be obtained but with considerable higher current. Work had begun on higher voltage systems and is where this report begins. Limits in material properties and processing capabilities show that the state-of-the-art has limited our practical output voltage from such a small part volume. In other words, the technology is currently limited within the allowable funding and interest.

  7. On-chip High-Voltage Generator Design

    CERN Document Server

    Tanzawa, Toru

    2013-01-01

    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.

  8. Reliability and Characterization of High Voltage Power Capacitors

    Science.gov (United States)

    2014-03-01

    permittivity EVCS electric vehicle charging system GPIB general-purpose interface bus GW giga-watt HVST high voltage stress test IV current voltage...traditional fossil fuel . The typical solar power system requires multiple subsystems as well as the physical infrastructure to support the solar panels. The...that will last, reducing the militaries overall dependence on traditional fossil fuel . B. CONVERTER OVERVIEW The typical solar power system

  9. Experimental investigation of SDBD plasma actuator driven by AC high voltage with a superimposed positive pulse bias voltage

    Science.gov (United States)

    Qi, Xiao-Hua; Yan, Hui-Jie; Yang, Liang; Hua, Yue; Ren, Chun-Sheng

    2017-08-01

    In this work, a driven voltage consisting of AC high voltage with a superimposed positive pulse bias voltage ("AC+ Positive pulse bias" voltage) is adopted to study the performance of a surface dielectric barrier discharge plasma actuator under atmospheric conditions. To compare the performance of the actuator driven by single-AC voltage and "AC+ Positive pulse bias" voltage, the actuator-induced thrust force and power consumption are measured as a function of the applied AC voltage, and the measured results indicate that the thrust force can be promoted significantly after superimposing the positive pulse bias voltage. The physical mechanism behind the thrust force changes is analyzed by measuring the optical properties, electrical characteristics, and surface potential distribution. Experimental results indicate that the glow-like discharge in the AC voltage half-cycle, next to the cycle where a bias voltage pulse has been applied, is enhanced after applying the positive pulse bias voltage, and this perhaps is the main reason for the thrust force increase. Moreover, surface potential measurement results reveal that the spatial electric field formed by the surface charge accumulation after positive pulse discharge can significantly affect the applied external electric field, and this perhaps can be responsible for the experimental phenomenon that the decrease of thrust force is delayed by pulse bias voltage action after the filament discharge occurs in the glow-like discharge region. The schlieren images further verify that the actuator-induced airflow velocity increases with the positive pulse voltage.

  10. Statistical characteristics of transient enclosure voltage in ultra-high-voltage gas-insulated switchgear

    Science.gov (United States)

    Cai, Yuanji; Guan, Yonggang; Liu, Weidong

    2017-06-01

    Transient enclosure voltage (TEV), which is a phenomenon induced by the inner dielectric breakdown of SF6 during disconnector operations in a gas-insulated switchgear (GIS), may cause issues relating to shock hazard and electromagnetic interference to secondary equipment. This is a critical factor regarding the electromagnetic compatibility of ultra-high-voltage (UHV) substations. In this paper, the statistical characteristics of TEV at UHV level are collected from field experiments, and are analyzed and compared to those from a repeated strike process. The TEV waveforms during disconnector operations are recorded by a self-developed measurement system first. Then, statistical characteristics, such as the pulse number, duration of pulses, frequency components, magnitude and single pulse duration, are extracted. The transmission line theory is introduced to analyze the TEV and is validated by the experimental results. Finally, the relationship between the TEV and the repeated strike process is analyzed. This proves that the pulse voltage of the TEV is proportional to the corresponding breakdown voltage. The results contribute to the definition of the standard testing waveform of the TEV, and can aid the protection of electronic devices in substations by minimizing the threat of this phenomenon.

  11. Temperature Stabilized Characterization of High Voltage Power Supplies

    CERN Document Server

    Krarup, Ole

    2017-01-01

    High precision measurements of the masses of nuclear ions in the ISOLTRAP experiment relies on an MR-ToF. A major source of noise and drift is the instability of the high voltage power supplies employed. Electrical noise and temperature changes can broaden peaks in time-of-flight spectra and shift the position of peaks between runs. In this report we investigate how the noise and drift of high-voltage power supplies can be characterized. Results indicate that analog power supplies generally have better relative stability than digitally controlled ones, and that the high temperature coefficients of all power supplies merit efforts to stabilize them.

  12. High voltage switch triggered by a laser-photocathode subsystem

    Science.gov (United States)

    Chen, Ping; Lundquist, Martin L.; Yu, David U. L.

    2013-01-08

    A spark gap switch for controlling the output of a high voltage pulse from a high voltage source, for example, a capacitor bank or a pulse forming network, to an external load such as a high gradient electron gun, laser, pulsed power accelerator or wide band radar. The combination of a UV laser and a high vacuum quartz cell, in which a photocathode and an anode are installed, is utilized as triggering devices to switch the spark gap from a non-conducting state to a conducting state with low delay and low jitter.

  13. High-Voltage Converter for the Traction Application

    Directory of Open Access Journals (Sweden)

    Sergey Volskiy

    2016-01-01

    Full Text Available High-voltage converter employing IGCT switches (VDC=2800 V for traction application is presented. Such a power traction drive operates with an unstable input voltage over 2000⋯4000 V DC and with an output power up to 1200 kW. The original power circuit of the high-voltage converter is demonstrated. Development of the attractive approach to designing the low-loss snubber circuits of the high-frequency IGCT switches is proposed. It is established on the complex multilevel analysis of the transient phenomena and power losses. The essential characteristics of the critical parameters under transient modes and the relation between the snubber circuit parameters and the losses are discussed. Experimental results for the prototype demonstrate the properties of new power circuit. The test results confirm the proposed high-voltage converter performance capability as well as verifying the suitability of the conception for its use in the Russian suburban train power system and other high-voltage applications.

  14. High-Capacity, High-Voltage Composite Oxide Cathode Materials

    Science.gov (United States)

    Hagh, Nader M.

    2015-01-01

    This SBIR project integrates theoretical and experimental work to enable a new generation of high-capacity, high-voltage cathode materials that will lead to high-performance, robust energy storage systems. At low operating temperatures, commercially available electrode materials for lithium-ion (Li-ion) batteries do not meet energy and power requirements for NASA's planned exploration activities. NEI Corporation, in partnership with the University of California, San Diego, has developed layered composite cathode materials that increase power and energy densities at temperatures as low as 0 degC and considerably reduce the overall volume and weight of battery packs. In Phase I of the project, through innovations in the structure and morphology of composite electrode particles, the partners successfully demonstrated an energy density exceeding 1,000 Wh/kg at 4 V at room temperature. In Phase II, the team enhanced the kinetics of Li-ion transport and electronic conductivity at 0 degC. An important feature of the composite cathode is that it has at least two components that are structurally integrated. The layered material is electrochemically inactive; however, upon structural integration with a spinel material, the layered material can be electrochemically activated and deliver a large amount of energy with stable cycling.

  15. E-beam high voltage switching power supply

    Science.gov (United States)

    Shimer, Daniel W.; Lange, Arnold C.

    1997-01-01

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

  16. Gaseous insulators for high voltage electrical equipment

    Science.gov (United States)

    Christophorou, Loucas G.; James, David R.; Pace, Marshall O.; Pai, Robert Y.

    1979-01-01

    Gaseous insulators comprise compounds having high attachment cross sections for electrons having energies in the 0-1.3 electron volt range. Multi-component gaseous insulators comprise compounds and mixtures having overall high electron attachment cross sections in the 0-1.3 electron volt range and moderating gases having high cross sections for inelastic interactions with electrons of energies 1-4 electron volts. Suitable electron attachment components include hexafluorobutyne, perfluorobutene-2, perfluorocyclobutane, perfluorodimethylcyclobutane, perfluorocyclohexene, perfluoromethylcyclohexane, hexafluorobutadiene, perfluoroheptene-1 and hexafluoroazomethane. Suitable moderating gases include N.sub.2, CO, CO.sub.2 and H.sub.2. The gaseous insulating mixture can also contain SF.sub.6, perfluoropropane and perfluorobenzene.

  17. Modeling of long High Voltage AC Underground

    DEFF Research Database (Denmark)

    Gudmundsdottir, Unnur Stella; Bak, Claus Leth; Wiechowski, W. T.

    2010-01-01

    cable models, perform highly accurate field measurements for validating the model and identifying possible disadvantages of the cable model. Furthermore the project suggests and implements improvements and validates them against several field measurements. It is shown in this paper how a new method...

  18. High-Voltage Multiplexing for ATLAS ITk

    CERN Document Server

    Hommels, Bart; The ATLAS collaboration

    2017-01-01

    The High Luminosity upgrade to the Large Hadron Collider (HL-LHC) requires a replacement of the present ATLAS inner tracker with an all-silicon inner tracker (ITk). The outer radii of the ITk will consist of groups of silicon strip sensors mounted on common support structures. Lack of space for additional cabling will require groups of sensors to share a common HV bus (-500 V). This creates a need to remotely disable a failing sensor from the common HV bus to permit continued operation of the other sensors. We have developed circuitry consisting of a Gallium Nitride Field-Effect transistor (GaNFET) and a HV Multiplier circuit to disable a failed sensor. The devices have been shown to survive radiation doses as high as 1 x 1016 neutrons/cm2 and ionizing doses over 200 Mrad. We will present the HV Mux circuitry and show irradiation results on individual components with an emphasis on the GaNFET results with neutrons, protons, pions, and gammas. We will present a dual-stage variation of the HV Mux that will perm...

  19. High voltage pulsed cable design: a practical example

    Energy Technology Data Exchange (ETDEWEB)

    Kewish, R.W. Jr.; Boicourt, G.P.

    1979-01-01

    The design of optimum high voltage pulse cable is difficult because very little emperical data are available on performance in pulsed applications. This paper follows the design and testing of one high voltage pulse cable, 40/100 trigger cable. The design was based on an unproven theory and the impressive outcome lends support to the theory. The theory is outlined and it is shown that there exists an inductance which gives a cable of minimum size for a given maximum stress. Test results on cable manufactured according to the design are presented and compared with the test results on the cable that 40/100 replaces.

  20. Ultra High Voltage Surge Waveforms Measurement Using an Optical Transducer

    Directory of Open Access Journals (Sweden)

    Francisco G. PEÑA-LECONA

    2010-05-01

    Full Text Available Ultra high voltage surge waveforms measurement by means of a portable optical transducer is presented. The sensor system uses a transducer element based on the longitudinal electro-optic effect with a double pass configuration to obtain a better sensitivity. The transducer head is allocated to one meter of distance from the generating element of electric field and it is able to measure waveform surges from 515 kV up to 1090 kV with fast response. It is demonstrated that the telemetry of ultra high voltage surge waveforms can be successfully done by means of this proposed optical transducer.

  1. Digitally gain controlled linear high voltage amplifier for laboratory applications

    Science.gov (United States)

    Koçum, C.

    2011-08-01

    The design of a digitally gain controlled high-voltage non-inverting bipolar linear amplifier is presented. This cost efficient and relatively simple circuit has stable operation range from dc to 90 kHz under the load of 10 kΩ and 39 pF. The amplifier can swing up to 360 Vpp under these conditions and it has 2.5 μs rise time. The gain can be changed by the aid of JFETs. The amplifiers have been realized using a combination of operational amplifiers and high-voltage discrete bipolar junction transistors. The circuit details and performance characteristics are discussed.

  2. The research of high voltage switchgear detecting unit

    Science.gov (United States)

    Ji, Tong; Xie, Wei; Wang, Xiaoqing; Zhang, Jinbo

    2017-07-01

    In order to understand the status of the high voltage switch in the whole life circle, you must monitor the mechanical and electrical parameters that affect device health. So this paper gives a new high voltage switchgear detecting unit based on ARM technology. It can measure closing-opening mechanical wave, storage motor current wave and contactor temperature to judge the device’s health status. When something goes wrong, it can be on alert and give some advice. The practice showed that it can meet the requirements of circuit breaker mechanical properties temperature online detection.

  3. High-voltage, high-current, solid-state closing switch

    Energy Technology Data Exchange (ETDEWEB)

    Focia, Ronald Jeffrey

    2017-08-22

    A high-voltage, high-current, solid-state closing switch uses a field-effect transistor (e.g., a MOSFET) to trigger a high-voltage stack of thyristors. The switch can have a high hold-off voltage, high current carrying capacity, and high time-rate-of-change of current, di/dt. The fast closing switch can be used in pulsed power applications.

  4. Diagnosis of High Voltage Insulators Made of Ceramic Using Spectrophotometry

    Directory of Open Access Journals (Sweden)

    Paweł Frącz

    2016-01-01

    Full Text Available The paper presents results of comparative analysis of optical signals emitted by partial discharges occurring on three types of high voltage insulators made of porcelain. The research work consisted of diagnosis of the following devices: a long rod insulator, a cap insulator, and an insulating cylinder. For optical signal registration a spectrophotometer was applied. All measurements were performed under laboratory conditions by changing the value of partial discharges generation voltage. For the cylindrical insulator also the distance between high voltage and ground electrodes was subjected for investigation as a factor having influence on partial discharges. The main contribution which resulted from the studies is statement that application of spectrophotometer enables faster recognition of partial discharges, as compared to standard methods.

  5. Digitally Programmable High-Q Voltage Mode Universal Filter

    Directory of Open Access Journals (Sweden)

    D. Singh

    2013-12-01

    Full Text Available A new low-voltage low-power CMOS current feedback amplifier (CFA is presented in this paper. This is used to realize a novel digitally programmable CFA (DPCFA using transistor arrays and MOS switches. The proposed realizations nearly allow rail-to-rail swing capability at all the ports. Class-AB output stage ensures low power dissipation and high current drive capability. The proposed CFA/ DPCFA operates at supply voltage of ±0.75 V and exhibits bandwidth better than 95 MHz. An application of the DPCFA to realize a novel voltage mode high-Q digitally programmable universal filter (UF is given. Performances of all the proposed circuits are verified by PSPICE simulation using TSMC 0.25μm technology parameters.

  6. High-voltage discharge in supersonic jet of plumbum vapor

    Science.gov (United States)

    Amirov, R. Kh; Antonov, N. N.; Liziakin, G. D.; Polistchook, V. P.; Samoylov, I. S.; Usmanov, R. A.; Yartsev, I. M.

    2015-11-01

    During study of vacuum discharge in plumbum evaporating from molybdenum crucible in identical geometry of discharge gap and the same crucible temperature existence of two different discharge forms were observed. These two forms are vacuum arc with current above 10 A and voltage about 15 V and high-voltage discharge with current about 10 mA and voltage of 340 V. Plumbum was placed in heat-isolated crucible (cathode). Electron-beam heater was situated under the crucible. At the temperature of 1.25 kK that corresponds to plumbum saturated vapor pressure about 0.1 kPa voltage from power source (380 V, 200 A) was applied to anode and high-voltage discharge initiated with characteristics mentioned above. After a few seconds this discharge could turn into arc or could exist hundreds of seconds until total plumbum evaporation. Glow of discharge could take the form of a cone, harness or plasma bunch that hanged at the appreciable distance from the electrodes. The estimations of plasma parameters are presented.

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

    OpenAIRE

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

    2013-01-01

    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 fr...

  8. Ultra-compact Marx-type high-voltage generator

    Science.gov (United States)

    Goerz, David A.; Wilson, Michael J.

    2000-01-01

    An ultra-compact Marx-type high-voltage generator includes individual high-performance components that are closely coupled and integrated into an extremely compact assembly. In one embodiment, a repetitively-switched, ultra-compact Marx generator includes low-profile, annular-shaped, high-voltage, ceramic capacitors with contoured edges and coplanar extended electrodes used for primary energy storage; low-profile, low-inductance, high-voltage, pressurized gas switches with compact gas envelopes suitably designed to be integrated with the annular capacitors; feed-forward, high-voltage, ceramic capacitors attached across successive switch-capacitor-switch stages to couple the necessary energy forward to sufficiently overvoltage the spark gap of the next in-line switch; optimally shaped electrodes and insulator surfaces to reduce electric field stresses in the weakest regions where dissimilar materials meet, and to spread the fields more evenly throughout the dielectric materials, allowing them to operate closer to their intrinsic breakdown levels; and uses manufacturing and assembly methods to integrate the capacitors and switches into stages that can be arranged into a low-profile Marx generator.

  9. Study of a High Voltage Ion Engine Power Supply

    Science.gov (United States)

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

    1996-01-01

    A complete laboratory breadboard version of a ion engine power converter was built and tested. This prototype operated on a line voltage of 80-120 Vdc, and provided output ratings of 1100 V at 1.8 kW, and 250 V at 20 mA. The high-voltage (HV) output voltage rating was revised from the original value of 1350 V at the beginning of the project. The LV output was designed to hold up during a 1-A surge current lasting up to 1 second. The prototype power converter included a internal housekeeping power supply which also operated from the line input. The power consumed in housekeeping was included in the overall energy budget presented for the ion engine converter. HV and LV output voltage setpoints were commanded through potentiometers. The HV converter itself reached its highest power efficiency of slightly over 93% at low line and maximum output. This would dip below 90% at high line. The no-load (rated output voltages, zero load current) power consumption of the entire system was less than 13 W. A careful loss breakdown shows that converter losses are predominately Metal-Oxide-Semiconductor Field Effect Transistor (MOSFET) conduction losses and HV rectifier snubbing losses, with the rectifier snubbing losses becoming predominant at high line. This suggests that further improvements in power efficiency could best be obtained by either developing a rectifier that was adequately protected against voltage overshoot with less snubbing, or by developing a pre-regulator to reduced the range of line voltage on the converter. The transient testing showed the converter to be fully protected against load faults, including a direct short-circuit from the HV output to the LV output terminals. Two currents sensors were used: one to directly detect any core ratcheting on the output transformer and re-initiate a soft start, and the other to directly detect a load fault and quickly shut down the converter for load protection. The finished converter has been extensively fault tested

  10. Digital measurement system for the LHC klystron high voltage modulator.

    CERN Document Server

    Mikkelsen, Anders

    Accelerating voltage in the Large Hadron Collider (LHC) is created by a means of 16 superconducting standing wave RF cavities, each fed by a 400MHz/300kW continuous wave klystron amplifier. Part of the upgrade program for the LHC long shutdown one is to replace the obsolete analogue current and voltage measurement circuitry located in the high voltage bunkers by a new, digital system, using ADCs and optical fibres. A digital measurement card is implemented and integrated into the current HV modulator oil tank (floating at -58kV) and interfaced to the existing digital VME boards collecting the data for several klystrons at the ground potential. Measured signals are stored for the logging, diagnostics and post-mortem analysis purposes.

  11. A novel ZVS high voltage power supply for micro-channel plate photomultiplier tubes

    Science.gov (United States)

    Pei, Chengquan; Tian, Jinshou; Liu, Zhen; Qin, Hong; Wu, Shengli

    2017-04-01

    A novel resonant high voltage power supply (HVPS) with zero voltage switching (ZVS), to reduce the voltage stress on switching devices and improve conversion efficiency, is proposed. The proposed HVPS includes a drive circuit, a transformer, several voltage multiplying circuits, and a regulator circuit. The HVPS contains several secondary windings that can be precisely regulated. The proposed HVPS performed better than the traditional resistor voltage divider, which requires replacing matching resistors resulting in resistor dispersibility in the Micro-Channel Plate (MCP). The equivalent circuit of the proposed HVPS was established and the operational principle analyzed. The entire switching element can achieve ZVS, which was validated by a simulation and experiments. The properties of this HVPS were tested including minimum power loss (240 mW), maximum power loss (1 W) and conversion efficiency (85%). The results of this research are that the proposed HVPS was suitable for driving the micro-channel plate photomultiplier tube (MCP-PMT). It was therefore adopted to test the MCP-PMT, which will be used in Daya Bay reactor neutrino experiment II in China.

  12. A novel ZVS high voltage power supply for micro-channel plate photomultiplier tubes

    Energy Technology Data Exchange (ETDEWEB)

    Pei, Chengquan [Key Laboratory for Physical Electronics and Devices of the Ministry of Education, Xi' an Jiaotong University, Xi’an 710049 (China); Tian, Jinshou [Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi' an 710119 (China); Liu, Zhen [Key Laboratory for Physical Electronics and Devices of the Ministry of Education, Xi' an Jiaotong University, Xi’an 710049 (China); Qin, Hong [School of Computer Science and Technology, Xi' an University of Science and Technology, Xi' an 710054 (China); Wu, Shengli, E-mail: slwu@mail.xjtu.edu.cn [Key Laboratory for Physical Electronics and Devices of the Ministry of Education, Xi' an Jiaotong University, Xi’an 710049 (China)

    2017-04-11

    A novel resonant high voltage power supply (HVPS) with zero voltage switching (ZVS), to reduce the voltage stress on switching devices and improve conversion efficiency, is proposed. The proposed HVPS includes a drive circuit, a transformer, several voltage multiplying circuits, and a regulator circuit. The HVPS contains several secondary windings that can be precisely regulated. The proposed HVPS performed better than the traditional resistor voltage divider, which requires replacing matching resistors resulting in resistor dispersibility in the Micro-Channel Plate (MCP). The equivalent circuit of the proposed HVPS was established and the operational principle analyzed. The entire switching element can achieve ZVS, which was validated by a simulation and experiments. The properties of this HVPS were tested including minimum power loss (240 mW), maximum power loss (1 W) and conversion efficiency (85%). The results of this research are that the proposed HVPS was suitable for driving the micro-channel plate photomultiplier tube (MCP-PMT). It was therefore adopted to test the MCP-PMT, which will be used in Daya Bay reactor neutrino experiment II in China.

  13. Proximity effects of high voltage electric power transmission lines on ...

    African Journals Online (AJOL)

    Yomi

    Zeki Demir. Department of Landscape Architecture, Faculty of Forestry, Düzce University. Konuralp, 81620 Düzce, Turkey. E-mail: zekidemir@duzce.edu.tr. Tel: +90-380-5421136. Fax: +90-380-5421136. Accepted 18 August, 2010. The proximity effects of high voltage electric power transmission lines on Leyland Cypress.

  14. A Review of High Voltage Drive Amplifiers for Capacitive Actuators

    DEFF Research Database (Denmark)

    Huang, Lina; Zhang, Zhe; Andersen, Michael A. E.

    2012-01-01

    This paper gives an overview of the high voltage amplifiers, which are used to drive capacitive actuators. The amplifiers for both piezoelectric and DEAP (dielectric electroactive polymer) actuator are discussed. The suitable topologies for driving capacitive actuators are illustrated in detail...

  15. High Voltage Electrical Injuries In The University Of Calabar ...

    African Journals Online (AJOL)

    Background: Burn injuries are a common presentation in Nigerian hospitals and result from a variety of causes. Recently, many have resulted from Petroleum related fire incidents. High voltage electrical injuries are relatively rare; lightning strikes even rarer. In traditional societies where Traditional medicine practitioners are ...

  16. Proximity effects of high voltage electric power transmission lines on ...

    African Journals Online (AJOL)

    The proximity effects of high voltage electric power transmission lines on Leyland Cypress (xCupressocyparis leylandii (Dallim. and A.B. Jacks.) Dallim) and Japanese Privet (Ligustrum japonicum Thunb.) growth were examined in a private nursery located in Sakarya, Turkey. Five transect were randomly chosen in both ...

  17. Pulsed high voltage discharge induce hematologic changes | El ...

    African Journals Online (AJOL)

    The aim of this work to examine the effect of the gas-liquid hybrid discharge treatment system on some hematological parameters. The gas-liquid hybrid discharge (HD) reactor consists of high voltage point discharge electrode above blood surface and cylinderical ground copper electrode containing the blood (in the same ...

  18. 30 CFR 75.810 - High-voltage trailing cables; splices.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false High-voltage trailing cables; splices. 75.810... SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Underground High-Voltage Distribution § 75.810 High-voltage trailing cables; splices. In the case of high-voltage cables used as trailing...

  19. 30 CFR 77.807-1 - High-voltage powerlines; clearances above ground.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false High-voltage powerlines; clearances above... OF UNDERGROUND COAL MINES Surface High-Voltage Distribution § 77.807-1 High-voltage powerlines; clearances above ground. High-voltage powerlines located above driveways, haulageways, and railroad tracks...

  20. 30 CFR 18.53 - High-voltage longwall mining systems.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false High-voltage longwall mining systems. 18.53... and Design Requirements § 18.53 High-voltage longwall mining systems. (a) In each high-voltage motor-starter enclosure, with the exception of a controller on a high-voltage shearer, the disconnect device...

  1. 30 CFR 75.800 - High-voltage circuits; circuit breakers.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false High-voltage circuits; circuit breakers. 75.800... SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Underground High-Voltage Distribution § 75.800 High-voltage circuits; circuit breakers. High-voltage circuits entering the underground area...

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

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false High-voltage power centers and transformers... High-Voltage Distribution § 75.812-2 High-voltage power centers and transformers; record of examination... record shall be kept in a book approved by the Secretary. High-Voltage Longwalls Source: 67 FR 11001, Mar...

  3. 30 CFR 77.800 - High-voltage circuits; circuit breakers.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false High-voltage circuits; circuit breakers. 77.800... COAL MINES Surface High-Voltage Distribution § 77.800 High-voltage circuits; circuit breakers. High-voltage circuits supplying power to portable or mobile equipment shall be protected by suitable circuit...

  4. 30 CFR 77.804 - High-voltage trailing cables; minimum design requirements.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false High-voltage trailing cables; minimum design... OF UNDERGROUND COAL MINES Surface High-Voltage Distribution § 77.804 High-voltage trailing cables; minimum design requirements. (a) High-voltage trailing cables used in resistance grounded systems shall be...

  5. Design and development of high voltage high power operational ...

    Indian Academy of Sciences (India)

    Normally power opamps can deliver current more than 50 mA and can operate on the supply voltage more than ±25 V. This paper gives the details of one of the power opamps developed to drive the Piezo Actuators for Active Vibration Control (AVC) of aircraft/aerospace structures. The designed power opamp will work on ...

  6. Operational characteristics of a high voltage dense plasma focus

    Science.gov (United States)

    Woodall, D. M.

    1985-11-01

    A high voltage dense plasma focus powered by a single stage Marx bank was designed, built and operated. The maximum bank parameters are: voltage--120 kV, energy--20 kJ, short circuit current--600kA. The bank impedance is about 200 millohms. The plasma focus center electrode diameter is 1.27 cm. The outer electrode diameter is 10.16 cm. Rundown length is about 10 cm, corresponding to a bank quarter period of about 900 millohms ns. Rundown L is about 50 milliohms. The context of this work is established with a review of previous plasma focus theoretical, experimental and computational work and related topics. Theoretical motivation for high voltage operation is presented. The design, construction and operation of this device are discussed in detail. Results and analysis of measurements obtained are presented. Device operation was investigated primarily at 80 kV (9 kJ), with a gas fill of about 1 torr H2, plus 3-5 percent A. The following diagnostics were used: gun voltage and current measurements; filtered, time resolved x ray PIN measurements of the pinch region; time integrated x ray pinhole photographs of the pinch region; fast frame visible light photographs of the sheath during rundown; and B probe measurements of the current sheath shortly before collapse.

  7. Electronic Current Transducer (ECT) for high voltage dc lines

    Science.gov (United States)

    Houston, J. M.; Peters, P. H., Jr.; Summerayes, H. R., Jr.; Carlson, G. J.; Itani, A. M.

    1980-02-01

    The development of a bipolar electronic current transducer (ECT) for measuring the current in a high voltage dc (HVDC) power line at line potential is discussed. The design and construction of a free standing ECT for use on a 400 kV line having a nominal line current of 2000 A is described. Line current is measured by a 0.0001 ohm shunt whose voltage output is sampled by a 14 bit digital data link. The high voltage interface between line and ground is traversed by optical fibers which carry digital light signals as far as 300 m to a control room where the digital signal is converted back to an analog representation of the shunt voltage. Two redundant electronic and optical data links are used in the prototype. Power to operate digital and optical electronics and temperature controlling heaters at the line is supplied by a resistively and capacitively graded 10 stage cascade of ferrite core transformers located inside the hollow, SF6 filled, porcelain support insulator. The cascade is driven by a silicon controlled rectifier inverter which supplies about 100 W of power at 30 kHz.

  8. High transmembrane voltage raised by close contact initiates fusion pore

    Directory of Open Access Journals (Sweden)

    Bing Bu

    2016-12-01

    Full Text Available Membrane fusion lies at the heart of neuronal communication but the detailed mechanism of a critical step, fusion pore initiation, remains poorly understood. Here, through atomistic molecular dynamics simulations, a transient pore formation induced by a close contact of two apposed bilayers is firstly reported. Such a close contact gives rise to a high local transmembrane voltage that induces the transient pore formation. Through simulations on two apposed bilayers fixed at a series of given distances, the process in which two bilayers approaching to each other under the pulling force from fusion proteins for membrane fusion was mimicked. Of note, this close contact induced fusion pore formation is contrasted with previous reported electroporation under ad hoc applied external electric field or ionic charge in-balance. We show that the transmembrane voltage increases with the decrease of the distance between the bilayers. Below a critical distance, depending on the lipid composition, the local transmembrane voltage can be sufficiently high to induce the transient pores. The size of these pores is approximately 1~2 nm in diameter, which is large enough to allow passing of neurotransmitters. A resealing of the membrane pores resulting from the neutralization of the transmembrane voltage by ions through the pores was then observed. We also found that the membrane tension can either prolong the lifetime of transient pores or cause them to dilate for full collapse. This result provides a possible mechanism for fusion pore formation and regulation of pathway of fusion process.

  9. 30 CFR 18.54 - High-voltage continuous mining machines.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false High-voltage continuous mining machines. 18.54... and Design Requirements § 18.54 High-voltage continuous mining machines. (a) Separation of high-voltage components from lower voltage components. In each motor-starter enclosure, barriers, partitions...

  10. 30 CFR 75.705-2 - Repairs to energized surface high-voltage lines.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Repairs to energized surface high-voltage lines... Repairs to energized surface high-voltage lines. An energized high-voltage surface line may be repaired... on power circuits with a phase-to-phase nominal voltage no greater than 15,000 volts; (3) Such...

  11. Square-Wave Voltage Injection Algorithm for PMSM Position Sensorless Control With High Robustness to Voltage Errors

    DEFF Research Database (Denmark)

    Ni, Ronggang; Xu, Dianguo; Blaabjerg, Frede

    2017-01-01

    relationship with the magnetic field distortion. Position estimation errors caused by higher order harmonic inductances and voltage harmonics generated by the SVPWM are also discussed. Both simulations and experiments are carried out based on a commercial PMSM to verify the superiority of the proposed method......Rotor position estimated with high-frequency (HF) voltage injection methods can be distorted by voltage errors due to inverter nonlinearities, motor resistance, and rotational voltage drops, etc. This paper proposes an improved HF square-wave voltage injection algorithm, which is robust to voltage...... errors without any compensations meanwhile has less fluctuation in the position estimation error. The average position estimation error is investigated based on the analysis of phase harmonic inductances, and deduced in the form of the phase shift of the second-order harmonic inductances to derive its...

  12. High-voltage plasma interactions calculations using NASCAP/LEO

    Science.gov (United States)

    Mandell, M. J.; Katz, I.

    1990-01-01

    This paper reviews four previous simulations (two laboratory and two space-flight) of interactions of a high-voltage spacecraft with a plasma under low-earth orbit conditions, performed using a three-dimensional computer code NASCAP/LEO. Results show that NASCAP/LEO can perform meaningful simulations of high-voltage plasma interactions taking into account three-dimensional effects of geometry, spacecraft motion, and magnetic field. Two new calculations are presented: (1) for current collection by 1-mm pinholes in wires (showing that a pinhole in a wire can collect far more current than a similar pinhole in a flat plate); and (2) current collection by Charge-2 mother vehicle launched in December 1985. It is shown that the Charge-2 calculations predicted successfully ion collection at negative bias, the floating potential of a probe outside or inside the sheath under negative bias conditions, and magnetically limited electron collection under electron beam operation at high altitude.

  13. Highly Reliable NPP Instrumentation Using Constant Voltage Feedback Circuits

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Seung J.; Choi, Bo H.; Kim, Ji H.; Rim, Chun T. [KAIST, Daejeon (Korea, Republic of)

    2014-08-15

    A highly reliable nuclear power plant (NPP) instrumentation using constant voltage feedback circuits is proposed. Contrary to conventional NPP instrumentation, two operational amplifiers are used at auxiliary building to supply constant DC voltage across the potentiometer or wheatstone bridge type sensors, such as resistance temperature detectors (RTD) and strain gauges. The proposed constant voltage feedback circuits maintain its output voltage as constant regardless of the length of lead wire from the auxiliary building to the sensors. A detail analysis of the proposed feedback circuits and design procedures including the internal resistance and parasitic LC components of lead wire are presented. A prototype with lumped RLC values for modeling lead wires is fabricated and experimentally verified to supply constant 10V up to 200m distance under 0.8% error. Due to its versatile characteristics with cost effective structure, the proposed scheme can be generally extended to pressure meters and water-level recorders to guarantee robust measurements without conventional current transducers under severe accidents.

  14. A high voltage method for measuring low capacitance for tomography.

    Science.gov (United States)

    Lu, Decai; Shao, Fuqun; Guo, Zhiheng

    2009-05-01

    Low capacitance measurement is involved in many industrial applications, especially in the applications of electrical capacitance tomography (ECT). Most of the low capacitance measurement circuits employ an ac-based method or a charge/discharge method because of high sensitivity, high resolution, and immunity to stray capacitance; and its excitation or charge voltage are not more than 20 V. When ECT techniques for large industrial equipment such as blast furnaces or grain barns are explored, the existing methods for measuring low capacitance have some limitations. This paper proposes a high excitation voltage ac-based method for measuring low capacitance to improve the resolution of measurement. The method uses a high excitation voltage of several hundred volts and a transformer ratio arms as the C/V transducer. Experimental results indicate that the new method has a resolution of 0.005 fF, a good stability (about 0.003 fF over 4 h) and linearity (0.9992).

  15. Bottlenecks reduction using superconductors in high voltage transmission lines

    Directory of Open Access Journals (Sweden)

    Daloub Labib

    2016-01-01

    Full Text Available Energy flow bottlenecks in high voltage transmission lines known as congestions are one of the challenges facing power utilities in fast developing countries. Bottlenecks occur in selected power lines when transmission systems are operated at or beyond their transfer limits. In these cases, congestions result in preventing new power supply contracts, infeasibility in existing contracts, price spike and market power abuse. The “Superconductor Technology” in electric power transmission cables has been used as a solution to solve the problem of bottlenecks in energy transmission at high voltage underground cables and overhead lines. The increase in demand on power generation and transmission happening due to fast development and linked to the intensive usage of transmission network in certain points, which in turn, lead to often frequent congestion in getting the required power across to where it is needed. In this paper, a bottleneck in high voltage double overhead transmission line with Aluminum Conductor Steel Reinforced was modeled using conductor parameters and replaced by Gap-Type Superconductor to assess the benefit of upgrading to higher temperature superconductor and obtain higher current carrying capacity. This proved to reduce the high loading of traditional aluminum conductors and allow more power transfer over the line using superconductor within the same existing right-of-way, steel towers, insulators and fittings, thus reducing the upgrade cost of building new lines.

  16. DISTRIBUTION OF HIGH-FREQUENCY VOLTAGE IN DISTRIBUTION NETWORK

    Directory of Open Access Journals (Sweden)

    M. I. Polujanov

    2005-01-01

    Full Text Available The paper reveals a method for remote determination of a location of single-phase short circuit on the ground in distribution networks with isolated neutral point. The method is based on measurement of high-frequency (a tone  range inter-phase voltage at all transformer substations and it creates preconditions for automation of searching process.  

  17. Pollution Maintenance Techniques in Coastal High Voltage Installations

    OpenAIRE

    Pyrgioti, E.; I. Vitellas; Thalassinakis, E.; D. Pylarinos; K. Siderakis

    2011-01-01

    Pollution of outdoor high voltage insulators is a common problem for utilities, with a considerable impact to power system reliability. In an effort to prevent possible flashovers due to pollution, many methods have been applied, aiming to improve the insulation performance, either by suppressing the formation of surface conductivity or by increasing the possible insulation level. In the case of substations, the selection of the appropriate technique is complex due to certain issues correlate...

  18. THE EFFECT OF LIGHTNING ON HIGH VOLTAGE ELECTRICAL SUBSTATIONS’ LOW VOLTAGE SYSTEMS

    Directory of Open Access Journals (Sweden)

    M. I. Fursanov

    2016-01-01

    Full Text Available The article presents the results of studies of the effects of lightning on low voltage systems of high voltage electrical substations with outdoor switchgears of 110 kV. The topicality of research is associated with a wide spreading of such substations as well as with a high reliability requirements of their work and, also, with their widespread distribution and high probability of lightning strikes to the substation or around it. The highest probable and the most dangerous effects of lightning on low voltage systems of a substation are determined on the basis of critical review and special literature analysis and, also, of systematization of practical information that had been collected during the survey of operating substations. Adequate physical models were developed for the list of hazardous effects based on physical processes of lightning. A model of each effect was studied on the basis of the sensitivity theory. The accuracy and adequacy of the models were verified by means of comparison of calculation results for the models under investigation with the results of calculations fulfilled in accordance with specialized programs, as well as from practical or theoretical data obtained by other authors. The factors that had been included in the models were studied and were defined in accordance with their nature (natural or artificial, the range of possible values in a substation was determined; the coefficients of elasticity were calculated. The obtained results enable to ascertain the contribution of the factor in the effect of lightning and the ability to control the factor. The relationship between the factors and the effects of lightning are shown as graphs. For practical application the information, obtained as the result of the research, was organized in the form of checklists that can be applied when collecting baseline information to develop the lightning protection of the substation, to examine the existing lightning protection, to

  19. Prototype high voltage bushing: Configuration to its operational demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Shah, Sejal, E-mail: sshah@iter-india.org [ITER-India, Institute for Plasma Research, Bhat, Gandhinagar 382428 (India); Sharma, D. [Institute for Plasma Research, Bhat, Gandhinagar 382428 (India); Parmar, D.; Tyagi, H.; Joshi, K.; Shishangiya, H.; Bandyopadhyay, M.; Rotti, C.; Chakraborty, A. [ITER-India, Institute for Plasma Research, Bhat, Gandhinagar 382428 (India)

    2016-12-15

    High Voltage Bushing (HVB) is the key component of Diagnostic Neutral Beam (DNB) system of ITER as it provides access to high voltage electrical, hydraulic, gas and diagnostic feedlines to the beam source with isolation from grounded vessel. HVB also provides primary vacuum confinement for the DNB system. Being Safety Important Class (SIC) component of ITER, it involves several configurational, technological and operational challenges. To ensure its operational performance & reliability, particularly electrostatic behavior, half scale down Prototype High Voltage Bushing (PHVB) is designed considering same design criteria of DNB HVB. Design optimization has been carried out followed by finite element (FE) analysis to obtain DNB HVB equivalent electric stress on different parts of PHVB, taking into account all design, manufacturing & space constraints. PHVB was tested up to 60 kV without breakdown, which validates its design for the envisaged operation of 50 kV DC. This paper presents the design of PHVB, FEA validation, manufacturing constraints, experimental layout with interfacing auxiliary systems and operational results related to functional performance.

  20. Health problems from radiation of high-voltage facilities

    Directory of Open Access Journals (Sweden)

    Hossein Ali Yousefi Rizi

    2013-01-01

    Full Text Available Aims: The aim of this study was to survey the health problems caused by exposure to high-voltage facility radiation. Materials and Methods: Sampling included workers exposed to electromagnetic fields at high-voltage facilities. The strength of the electric and magnetic fields was determined by a field meter. A questionnaire was used to evaluate the prevalence of subjective and psychological symptoms. Statistical descriptive used and data analyzed by a Student′s t-tests. Results: This study indicates that increased symptoms among the exposed workers including depression, anxiety, hostility, paranoia, inter-sensitivity, and obsession-compulsion. Some of the self-reported symptoms were, headache (53.5%, fatigue (35.6%, difficulties in concentration (32.5%, vertigo/dizziness (30.4%, attention disorders (28.8%, nervousness (28.1%, and palpitations (14.7%. A significant relationship was observed between the exposure to the electromagnetic field and psychological symptoms (P < 0.05. Conclusion: Radiation of high-voltage facilities probably increased the risk of mental disorders and intensified them in susceptible workers, especially depression. This finding confirmed the results obtained in provocative studies that indicated an increase in the risk of psychological symptoms, which was put forth by several investigators Observation of occupational health and other control measures play an important role in decreasing the symptoms.

  1. Design and Implementation of a High-Voltage Generator with Output Voltage Control for Vehicle ER Shock-Absorber Applications

    Directory of Open Access Journals (Sweden)

    Chih-Lung Shen

    2013-01-01

    Full Text Available A self-oscillating high-voltage generator is proposed to supply voltage for a suspension system in order to control the damping force of an electrorheological (ER fluid shock absorber. By controlling the output voltage level of the generator, the damping force in the ER fluid shock absorber can be adjusted immediately. The shock absorber is part of the suspension system. The high-voltage generator drives a power transistor based on self-excited oscillation, which converts dc to ac. A high-frequency transformer with high turns ratio is used to increase the voltage. In addition, the system uses the car battery as dc power supply. By regulating the duty cycle of the main switch in the buck converter, the output voltage of the buck converter can be linearly adjusted so as to obtain a specific high voltage for ER. The driving system is self-excited; that is, no additional external driving circuit is required. Thus, it reduces cost and simplifies system structure. A prototype version of the actual product is studied to measure and evaluate the key waveforms. The feasibility of the proposed system is verified based on experimental results.

  2. The Relativity of Sociodemographic Determinism on the Digital Divide in High School Students in Ecuador

    OpenAIRE

    Tirado Morueta, Ramón; Mendoza Zambrano, Damian Marilú; Marín Gutiérrez, Isidro; Mendoza Zambrano, Mariuxi

    2017-01-01

    Although the digital divide on physical access to the Internet in developing countries is closing with respect to developed countries, a new gap on the social usage of the Internet is opening. This study focuses on Ecuador for the purpose of (a) determining the level of access to Internet use of the younger sector of the population (high school students) and (b) understanding to what extent sociodemographic factors determine Internet access and its use. This study uses a random sample (3,754 ...

  3. PHENIX Resistive Plate Chambers High Voltage Performance Analysis

    Science.gov (United States)

    Towell, Marshall; Phenix Collaboration

    2013-10-01

    The PHENIX experiment at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory studies polarized proton-proton collisions to better understand the spin structure of the proton. While RHIC is operating there are millions of collisions each second, but the PHENIX data acquisition system can only record a few thousand each second. To help select the rare events of interest, a new forward trigger has been commissioned that includes four stations of Resistive Plate Chambers (RPCs). During the most recent RHIC run, significant polarized proton-proton data were recorded with the new trigger for the first time. The RPC high voltage was recorded and studied for each module and each run. Every physics run was classified into one of four categories depending on its high voltage conditions, including the number of trips and the number and magnitude of mismatches between the HV set point and readback voltage. Each condition that was required to consider a run to have good HV was investigated systematically to determine the appropriate set points. The methods and results of this systematic study will be presented. This research was supported in part by the DOE under grant number DE-FG03-94ER40860.

  4. Experimental validation of a high voltage pulse measurement method.

    Energy Technology Data Exchange (ETDEWEB)

    Cular, Stefan; Patel, Nishant Bhupendra; Branch, Darren W.

    2013-09-01

    This report describes X-cut lithium niobates (LiNbO3) utilization for voltage sensing by monitoring the acoustic wave propagation changes through LiNbO3 resulting from applied voltage. Direct current (DC), alternating current (AC) and pulsed voltage signals were applied to the crystal. Voltage induced shift in acoustic wave propagation time scaled quadratically for DC and AC voltages and linearly for pulsed voltages. The measured values ranged from 10 - 273 ps and 189 ps 2 ns for DC and non-DC voltages, respectively. Data suggests LiNbO3 has a frequency sensitive response to voltage. If voltage source error is eliminated through physical modeling from the uncertainty budget, the sensors U95 estimated combined uncertainty could decrease to ~0.025% for DC, AC, and pulsed voltage measurements.

  5. A High Voltage Swing 1.9 GHz PA in Standard CMOS

    NARCIS (Netherlands)

    Aartsen, W.A.J.; Annema, Anne J.; Nauta, Bram

    A circuit technique for RF power amplifiers that reliably handle voltage peaks well above the nominal supply voltage is presented. To achieve this high-voltage tolerance the circuit implements switched-cascode transistors that yield reliable operation for voltages up to 7V at RF frequencies in a

  6. Impact of Solar Array Designs on High Voltage Operations

    Science.gov (United States)

    Brandhorst, Henry W., Jr.; Ferguson, Dale; Piszczor, Mike; ONeill, Mark

    2006-01-01

    As power levels of advanced spacecraft climb above 25 kW, higher solar array operating voltages become attractive. Even in today s satellites, operating spacecraft buses at 100 V and above has led to arcing in GEO communications satellites, so the issue of spacecraft charging and solar array arcing remains a design problem. In addition, micrometeoroid impacts on all of these arrays can also lead to arcing if the spacecraft is at an elevated potential. For example, tests on space station hardware disclosed arcing at 75V on anodized A1 structures that were struck with hypervelocity particles in Low Earth Orbit (LEO) plasmas. Thus an understanding of these effects is necessary to design reliable high voltage solar arrays of the future, especially in light of the Vision for Space Exploration of NASA. In the future, large GEO communication satellites, lunar bases, solar electric propulsion missions, high power communication systems around Mars can lead to power levels well above 100 kW. As noted above, it will be essential to increase operating voltages of the solar arrays well above 80 V to keep the mass of cabling needed to carry the high currents to an acceptable level. Thus, the purpose of this paper is to discuss various solar array approaches, to discuss the results of testing them at high voltages, in the presence of simulated space plasma and under hypervelocity impact. Three different types of arrays will be considered. One will be a planar array using thin film cells, the second will use planar single or multijunction cells and the last will use the Stretched Lens Array (SLA - 8-fold concentration). Each of these has different approaches for protection from the space environment. The thin film cell based arrays have minimal covering due to their inherent radiation tolerance, conventional GaAs and multijunction cells have the traditional cerium-doped microsheet glasses (of appropriate thickness) that are usually attached with Dow Corning DC 93-500 silicone

  7. Study on cathode high voltage pulse control in image intensifier

    Science.gov (United States)

    Yang, Ye; Yan, Bo; Ni, Xiao-bing; Zhi, Qiang; Li, Jun-guo; Yao, Ze; Deng, Guang-xu

    2016-03-01

    This paper briefly introduces the basic working principle of auto-gating power source. Due to the presence of noise in the circuit, the cathode pulse signal generated by the AD converter is unstable. In this paper, the circuit of the AD converter is adjusted to improve the instability of the cathode high voltage pulse signal, especially in the case of low light and high illumination to avoid the jitter of the pulse. The experiment was carried out. And it could guide the implementation of this part of the circuit.

  8. Spacecraft-generated plasma interaction with high voltage solar array

    Science.gov (United States)

    Parks, D. E.; Katz, I.

    1978-01-01

    Calculations are made of the effect of interactions of spacecraft-generated plasmas and high voltage solar array components on an advanced Solar Electric Propulsion system. The plasma consists of mercury ions and electrons resulting from the operation of ion thrusters and associated hollow cathode neutralizers. Because large areas of the solar array are at high potential and not completely insulated from the surrounding plasma, the array can, under some conditions, collect excessive electron currents. Results are given for the parasitic currents collected by the solar arrays and means for reducing these currents are considered.

  9. Temperature and Voltage Offsets in High-ZT Thermoelectrics

    Science.gov (United States)

    Levy, George S.

    2017-10-01

    Thermodynamic temperature can take on different meanings. Kinetic temperature is an expectation value and a function of the kinetic energy distribution. Statistical temperature is a parameter of the distribution. Kinetic temperature and statistical temperature, identical in Maxwell-Boltzmann statistics, can differ in other statistics such as those of Fermi-Dirac or Bose-Einstein when a field is present. Thermal equilibrium corresponds to zero statistical temperature gradient, not zero kinetic temperature gradient. Since heat carriers in thermoelectrics are fermions, the difference between these two temperatures may explain voltage and temperature offsets observed during meticulous Seebeck measurements in which the temperature-voltage curve does not go through the origin. In conventional semiconductors, temperature offsets produced by fermionic electrical carriers are not observable because they are shorted by heat phonons in the lattice. In high-ZT materials, however, these offsets have been detected but attributed to faulty laboratory procedures. Additional supporting evidence for spontaneous voltages and temperature gradients includes data collected in epistatic experiments and in the plasma Q-machine. Device fabrication guidelines for testing the hypothesis are suggested including using unipolar junctions stacked in a superlattice, alternating n/n + and p/p + junctions, selecting appropriate dimensions, doping, and loading.

  10. New perspectives in vacuum high voltage insulation. II. Gas desorption

    CERN Document Server

    Diamond, W T

    1998-01-01

    An examination has been made of gas desorption from unbaked electrodes of copper, niobium, aluminum, and titanium subjected to high voltage in vacuum. It has been shown that the gas is composed of water vapor, carbon monoxide, and carbon dioxide, the usual components of vacuum outgassing, plus an increased yield of hydrogen and light hydrocarbons. The gas desorption was driven by anode conditioning as the voltage was increased between the electrodes. The gas is often desorbed as microdischarges-pulses of a few to hundreds of microseconds-and less frequently in a more continuous manner without the obvious pulsed structure characteristic of microdischarge activity. The quantity of gas released was equivalent to many monolayers and consisted mostly of neutral molecules with an ionic component of a few percent. A very significant observation was that the gas desorption was more dependent on the total voltage between the electrodes than on the electric field. It was not triggered by field-emitted electrons but oft...

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

    Directory of Open Access Journals (Sweden)

    C. Yong-Nong

    2013-04-01

    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.

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

    Directory of Open Access Journals (Sweden)

    C. Yong-Nong

    2013-03-01

    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.

  13. SEMICONDUCTOR DEVICES: A novel high voltage start up circuit for an integrated switched mode power supply

    Science.gov (United States)

    Hao, Hu; Xingbi, Chen

    2010-09-01

    A novel high voltage start up circuit for providing an initial bias voltage to an integrated switched mode power supply (SMPS) is presented. An enhanced mode VDMOS transistor, the gate of which is biased by a floating p-island, is used to provide start up current and sustain high voltage. An NMOS transistor having a high source to ground breakdown voltage is included to extend the bias voltage range to the SMPS. Simulation results indicate that the high voltage start up circuit can start and restart as designed. The proposed structure is believed to be more energy saving and cost-effective compared with other solutions.

  14. Properties of Polymer Composites Used in High-Voltage Applications

    Directory of Open Access Journals (Sweden)

    Ilona Pleşa

    2016-04-01

    Full Text Available The present review article represents a comprehensive study on polymer micro/nanocomposites that are used in high-voltage applications. Particular focus is on the structure-property relationship of composite materials used in power engineering, by exploiting fundamental theory as well as numerical/analytical models and the influence of material design on electrical, mechanical and thermal properties. In addition to describing the scientific development of micro/nanocomposites electrical features desired in power engineering, the study is mainly focused on the electrical properties of insulating materials, particularly cross-linked polyethylene (XLPE and epoxy resins, unfilled and filled with different types of filler. Polymer micro/nanocomposites based on XLPE and epoxy resins are usually used as insulating systems for high-voltage applications, such as: cables, generators, motors, cast resin dry-type transformers, etc. Furthermore, this paper includes ample discussions regarding the advantages and disadvantages resulting in the electrical, mechanical and thermal properties by the addition of micro- and nanofillers into the base polymer. The study goals are to determine the impact of filler size, type and distribution of the particles into the polymer matrix on the electrical, mechanical and thermal properties of the polymer micro/nanocomposites compared to the neat polymer and traditionally materials used as insulation systems in high-voltage engineering. Properties such as electrical conductivity, relative permittivity, dielectric losses, partial discharges, erosion resistance, space charge behavior, electric breakdown, tracking and electrical tree resistance, thermal conductivity, tensile strength and modulus, elongation at break of micro- and nanocomposites based on epoxy resin and XLPE are analyzed. Finally, it was concluded that the use of polymer micro/nanocomposites in electrical engineering is very promising and further research work

  15. High impedance fault detection in low voltage networks

    Energy Technology Data Exchange (ETDEWEB)

    Christie, R.D. (Univ. of Washington, Seattle, WA (United States). Dept. of Electrical Engineering); Zadehgol, H.; Habib, M.M. (Seattle City Light, WA (United States))

    1993-10-01

    High impedance faults are those with fault current magnitude similar to load currents. Experimental results were obtained that conform operating experience that such faults can occur in the low voltage (600V and below) underground distribution networks typically found in urban power systems. These faults produce current waveforms qualitatively similar to those found on overhead feeders, but quantitatively smaller. Loose connectors can produce similar, but cleaner current characteristics. Noisy loads remain a major impediment to reliable detection. Design and installation of an inexpensive prototype fault detector on the Seattle City Light street network is described.

  16. Self-monitoring high voltage transmission line suspension insulator

    Science.gov (United States)

    Stemler, Gary E.; Scott, Donald N.

    1981-01-01

    A high voltage transmission line suspension insulator (18 or 22) which monitors its own dielectric integrity. A dielectric rod (10) has one larger diameter end fitting attachable to a transmission line and another larger diameter end fitting attachable to a support tower. The rod is enclosed in a dielectric tube (14) which is hermetically sealed to the rod's end fittings such that a liquidtight space (20) is formed between the rod and the tube. A pressurized dielectric liquid is placed within that space. A discoloring dye placed within this space is used to detect the loss of the pressurized liquid.

  17. Semiclassical "Divide-and-Conquer" Method for Spectroscopic Calculations of High Dimensional Molecular Systems

    Science.gov (United States)

    Ceotto, Michele; Di Liberto, Giovanni; Conte, Riccardo

    2017-07-01

    A new semiclassical "divide-and-conquer" method is presented with the aim of demonstrating that quantum dynamics simulations of high dimensional molecular systems are doable. The method is first tested by calculating the quantum vibrational power spectra of water, methane, and benzene—three molecules of increasing dimensionality for which benchmark quantum results are available—and then applied to C60 , a system characterized by 174 vibrational degrees of freedom. Results show that the approach can accurately account for quantum anharmonicities, purely quantum features like overtones, and the removal of degeneracy when the molecular symmetry is broken.

  18. 30 CFR 77.704-1 - Work on high-voltage lines.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Work on high-voltage lines. 77.704-1 Section 77... MINES Grounding § 77.704-1 Work on high-voltage lines. (a) No high-voltage line shall be regarded as... provided in § 77.103) that such high-voltage line has been deenergized and grounded. Such qualified person...

  19. An accurate continuous calibration system for high voltage current transformer.

    Science.gov (United States)

    Tong, Yue; Li, Bin Hong

    2011-02-01

    A continuous calibration system for high voltage current transformers is presented in this paper. The sensor of this system is based on a kind of electronic instrument current transformer, which is a clamp-shape air core coil. This system uses an optical fiber transmission system for its signal transmission and power supply. Finally the digital integrator and fourth-order convolution window algorithm as error calculation methods are realized by the virtual instrument with a personal computer. It is found that this system can calibrate a high voltage current transformer while energized, which means avoiding a long calibrating period in the power system and the loss of power metering expense. At the same time, it has a wide dynamic range and frequency band, and it can achieve a high accuracy measurement in a complex electromagnetic field environment. The experimental results and the on-site operation results presented in the last part of the paper, prove that it can reach the 0.05 accuracy class and is easy to operate on site.

  20. Survey of high voltage electron microscopy worldwide in 1998.

    Energy Technology Data Exchange (ETDEWEB)

    Allen, C. W.

    1998-03-05

    High voltage TEMs were introduced commercially thirty years ago, with the installations of 500 kV Hitachi instruments at the Universities of Nagoya and Tokyo. Since that time 53 commercial instruments, having maximum accelerating potentials of 0.5-3.5 MV, will have been delivered by the end of 1998. Table 1 summarizes the sites and some information regarding those HVEMS which are available in 1998. This corrects, updates and expands an earlier report of this sort [2]. There have been three commercial HVEM manufacturers: AEI (UK), Hitachi and JEOL (Japan). The proportion of the total number of HVEMS produced by each manufacturer is similar to that reflected in Table 1: AEI and Kratos/AEI (12), Hitachi (20) and JEOL (21). The term Kratos/AEI refers to instruments delivered after the takeover of AEI by Grates in the late 1970's. In Table 1 only maximum accelerating potentials are listed, which is generally also the design value for which the resolution for imaging was optimized. It is important to realize that in many applications, especially those studying irradiation effects, much lower voltages may be employed somewhat routinely to minimize atom displacements by the incident electron beam during analysis. These minimum values range from 100 kV for the AEI and Kratos/AEI instruments to typically 400 kV for the current generation of atomic resolution instruments, the latter being well above the thresholds for displacement in light elements such as Al and Si and for displacement of anions in many ceramic materials such as the high Tc superconductors, for example. An additional potential problem is electron-induced sputtering and differential sputtering (unequal sputtering rates in multicomponent materials), especially when accurate elemental microanalysis is being attempted. These same issues may arise for intermediate voltage TEMs as well, of course.

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

    Science.gov (United States)

    Bearden, Douglas B. (Inventor)

    2007-01-01

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

  2. Novel Interleaved Converter with Extra-High Voltage Gain to Process Low-Voltage Renewable-Energy Generation

    Directory of Open Access Journals (Sweden)

    Chih-Lung Shen

    2016-10-01

    Full Text Available This paper presents a novel interleaved converter (NIC with extra-high voltage gain to process the power of low-voltage renewable-energy generators such as photovoltaic (PV panel, wind turbine, and fuel cells. The NIC can boost a low input voltage to a much higher voltage level to inject renewable energy to DC bus for grid applications. Since the NIC has two circuit branches in parallel at frond end to share input current, it is suitable for high power applications. In addition, the NIC is controlled in an interleaving pattern, which has the advantages that the NIC has lower input current ripple, and the frequency of the ripple is twice the switching frequency. Two coupled inductors and two switched capacitors are incorporated to achieve a much higher voltage gain than conventional high step-up converters. The proposed NIC has intrinsic features such as leakage energy totally recycling and low voltage stress on power semiconductor. Thorough theoretical analysis and key parameter design are presented in this paper. A prototype is built for practical measurements to validate the proposed NIC.

  3. A New High Frequency Injection Method Based on Duty Cycle Shifting without Maximum Voltage Magnitude Loss

    DEFF Research Database (Denmark)

    Wang, Dong; Lu, Kaiyuan; Rasmussen, Peter Omand

    2015-01-01

    The conventional high frequency signal injection method is to superimpose a high frequency voltage signal to the commanded stator voltage before space vector modulation. Therefore, the magnitude of the voltage used for machine torque production is limited. In this paper, a new high frequency...

  4. 76 FR 19698 - Safety Zone; Repair of High Voltage Transmission Lines to Logan International Airport, Saugus...

    Science.gov (United States)

    2011-04-08

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Repair of High Voltage Transmission Lines..., within the Captain of the Port (COTP) Boston Zone to allow for repair of high voltage transmission lines... during the repair of high voltage transmission lines. Entering into, transiting through, mooring or...

  5. 76 FR 4575 - Safety Zone; Repair of High Voltage Transmission Lines to Logan International Airport, Saugus...

    Science.gov (United States)

    2011-01-26

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AAOO Safety Zone; Repair of High Voltage Transmission Lines... of high voltage transmission lines to Logan Airport. This safety zone is required to provide for the safety of life on navigable waters during the repair of high voltage transmission lines. Entering into...

  6. 30 CFR 75.705-10 - Tying into energized high-voltage surface circuits.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Tying into energized high-voltage surface....705-10 Tying into energized high-voltage surface circuits. If the work of forming an additional circuit by tying into an energized high-voltage surface line is performed from the ground, any person...

  7. 30 CFR 75.811 - High-voltage underground equipment; grounding.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false High-voltage underground equipment; grounding... COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Underground High-Voltage Distribution § 75.811 High-voltage underground equipment; grounding. Frames, supporting structures and...

  8. 30 CFR 77.807-3 - Movement of equipment; minimum distance from high-voltage lines.

    Science.gov (United States)

    2010-07-01

    ... high-voltage lines. 77.807-3 Section 77.807-3 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... WORK AREAS OF UNDERGROUND COAL MINES Surface High-Voltage Distribution § 77.807-3 Movement of equipment; minimum distance from high-voltage lines. When any part of any equipment operated on the surface of any...

  9. 21 CFR 892.1700 - Diagnostic x-ray high voltage generator.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Diagnostic x-ray high voltage generator. 892.1700... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1700 Diagnostic x-ray high voltage generator. (a) Identification. A diagnostic x-ray high voltage generator is a device that is intended to...

  10. 30 CFR 77.704-10 - Tying into energized high-voltage surface circuits.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Tying into energized high-voltage surface... AREAS OF UNDERGROUND COAL MINES Grounding § 77.704-10 Tying into energized high-voltage surface circuits. If the work of forming an additional circuit by tying into an energized high-voltage surface line is...

  11. 30 CFR 75.705-1 - Work on high-voltage lines.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Work on high-voltage lines. 75.705-1 Section 75... AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Grounding § 75.705-1 Work on high-voltage lines. (a) Section 75.705 specifically prohibits work on energized high-voltage lines underground; (b...

  12. A high-voltage rechargeable magnesium-sodium hybrid battery

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yifei; An, Qinyou; Cheng, Yingwen; Liang, Yanliang; Ren, Yang; Sun, Cheng-Jun; Dong, Hui; Tang, Zhongjia; Li, Guosheng; Yao, Yan

    2017-04-01

    Growing global demand of safe and low-cost energy storage technology triggers strong interests in novel battery concepts beyond state-of-art Li-ion batteries. Here we report a high-voltage rechargeable Mg–Na hybrid battery featuring dendrite-free deposition of Mg anode and Na-intercalation cathode as a low-cost and safe alternative to Li-ion batteries for large-scale energy storage. A prototype device using a Na3V2(PO4)3 cathode, a Mg anode, and a Mg–Na dual salt electrolyte exhibits the highest voltage (2.60 V vs. Mg) and best rate performance (86% capacity retention at 10C rate) among reported hybrid batteries. Synchrotron radiation-based X-ray absorption near edge structure (XANES), atomic-pair distribution function (PDF), and high-resolution X-ray diffraction (HRXRD) studies reveal the chemical environment and structural change of Na3V2(PO4)3 cathode during the Na ion insertion/deinsertion process. XANES study shows a clear reversible shift of vanadium K-edge and HRXRD and PDF studies reveal a reversible two-phase transformation and V–O bond length change during cycling. The energy density of the hybrid cell could be further improved by developing electrolytes with a higher salt concentration and wider electrochemical window. This work represents a significant step forward for practical safe and low-cost hybrid batteries.

  13. Pollution Maintenance Techniques in Coastal High Voltage Installations

    Directory of Open Access Journals (Sweden)

    E. Pyrgioti

    2011-02-01

    Full Text Available Pollution of outdoor high voltage insulators is a common problem for utilities, with a considerable impact to power system reliability. In an effort to prevent possible flashovers due to pollution, many methods have been applied, aiming to improve the insulation performance, either by suppressing the formation of surface conductivity or by increasing the possible insulation level. In the case of substations, the selection of the appropriate technique is complex due to certain issues correlated to the nature of the installation. In this paper, several techniques usually implemented by utilities, are investigated based on the experienced gained in the case of Crete, a Greek island in southern Europe, where due to the coastal development of the power system, the majority of high voltage installations are exposed to intense marine pollution. The technique of coating insulators with Room Temperature Vulcanized Silicone Rubber (RTV SIR has proved rather efficient and therefore is presented extendedly. Correlation of the material behaviour with environmental conditions is discussed and results from long term monitoring, including environmental parameters and leakage current measurements, in a 150 kV Substation are presented. It is shown that RTV SIR coatings have remarkably suppressed surface activity and that porcelain insulators exhibit different activity period when coated.

  14. High-Speed Fuses in IGBT based Voltage Source Converters

    DEFF Research Database (Denmark)

    Iov, Florin; Blaabjerg, Frede; Rasmussen, Henrik

    2005-01-01

    The demand for protection of power electronic applications has during the last couple of years increased regarding the high-power IGBT modules. Even with an active protection, a high power IGBT still has a risk of exhibiting a violent rupture in the case of a fault if IGBT fuses do not protect it....... By introducing fuses into voltage source converters a better protection of IGBTs can be achieved. This paper is a complete overview of a research project carried out in cooperation by Aalborg University, Denmark and Cooper Bussmann International. This paper discusses three main issues regarding the IGBT fuse...... protection. First, the problem of adding inductance in the DC-link circuit is treated, second a short discussion of the protection of the IGBT module is done, and finally, the impact of the high frequency loading on the current carrying capability of the fuses is presented....

  15. 30 CFR 77.704-2 - Repairs to energized high-voltage lines.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Repairs to energized high-voltage lines. 77.704... UNDERGROUND COAL MINES Grounding § 77.704-2 Repairs to energized high-voltage lines. An energized high-voltage... repairs will be performed on power circuits with a phase-to-phase nominal voltage no greater than 15,000...

  16. High precision, low disturbance calibration of the High Voltage system of the CMS Barrel Electromagnetic Calorimeter

    CERN Document Server

    Marzocchi, Badder

    2017-01-01

    The CMS Electromagnetic Calorimeter is made of scintillating lead tungstate crystals, using avalanche photodiodes (APD) as photo-detectors in the barrel part. The high voltage system, consisting of 1224 channels, biases groups of 50 APD pairs, each at a voltage of about 380 V. The APD gain dependence on the voltage is 3pct/V. A stability of better than 60 mV is needed to have negligible impact on the calorimeter energy resolution. Until 2015 manual calibrations were performed yearly. A new calibration system was deployed recently, which satisfies the requirement of low disturbance and high precision. The system is discussed in detail and first operational experience is presented.

  17. A high voltage asymmetric waveform generator for FAIMS.

    Science.gov (United States)

    Canterbury, Jesse D; Gladden, James; Buck, Lon; Olund, Roy; MacCoss, Michael J

    2010-07-01

    High field asymmetric waveform ion mobility spectrometry (FAIMS) has been used increasingly in recent years as an additional method of ion separation and selection before mass spectrometry. The FAIMS electrodes are relatively simple to design and fabricate for laboratories wishing to implement their own FAIMS designs. However, construction of the electronics apparatus needed to produce the required high magnitude asymmetric electric field oscillating at a frequency of several hundred kilohertz is not trivial. Here we present an entirely custom-built electronics setup capable of supplying the required waveforms and voltages. The apparatus is relatively simple and inexpensive to implement. We also present data acquired on this system demonstrating the use of FAIMS as a gas-phase ion filter interface to an ion trap mass spectrometer. Copyright 2010 American Society for Mass Spectrometry. Published by Elsevier Inc. All rights reserved.

  18. High-voltage atmospheric breakdown across intervening rutile dielectrics.

    Energy Technology Data Exchange (ETDEWEB)

    Williamson, Kenneth Martin; Simpson, Sean; Coats, Rebecca Sue; Jorgenson, Roy Eberhardt; Hjalmarson, Harold Paul; Pasik, Michael Francis

    2013-09-01

    This report documents work conducted in FY13 on electrical discharge experiments performed to develop predictive computational models of the fundamental processes of surface breakdown in the vicinity of high-permittivity material interfaces. Further, experiments were conducted to determine if free carrier electrons could be excited into the conduction band thus lowering the effective breakdown voltage when UV photons (4.66 eV) from a high energy pulsed laser were incident on the rutile sample. This report documents the numerical approach, the experimental setup, and summarizes the data and simulations. Lastly, it describes the path forward and challenges that must be overcome in order to improve future experiments for characterizing the breakdown behavior for rutile.

  19. Unique Power Dense, Configurable, Robust, High-Voltage Power Supplies Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Princeton Power will develop and deliver three small, lightweight 50 W high-voltage power supplies that have a configurable output voltage range from 500 to 50 kVDC....

  20. 75 FR 17529 - High-Voltage Continuous Mining Machine Standard for Underground Coal Mines

    Science.gov (United States)

    2010-04-06

    ... condition occurs. Ungrounded circuits include high-voltage transformers that power low- and medium-voltage... transformers in the power center. This will provide a safe means of de-energizing high-voltage circuits in the... machines in underground coal mines. It also revises MSHA's design requirements for approval of these mining...

  1. Battery powered high output voltage bidirectional flyback converter for cylindrical DEAP actuator

    DEFF Research Database (Denmark)

    Huang, Lina; Thummala, Prasanth; Zhang, Zhe

    2012-01-01

    DEAP (Dielectric Electro Active Polymer) actuator is essentially a capacitive load and can be applied in various actuation occasions. However, high voltage is needed to actuate it. In this paper, a high voltage bidirectional flyback converter with low input voltage is presented. The fundamental...

  2. On-load Tap Changer Diagnosis on High-Voltage Power Transformers using Dynamic Resistance Measurements

    NARCIS (Netherlands)

    Erbrink, J.J.

    2011-01-01

    High-voltage transformers have tap changers to regulate the voltage in the high-voltage network when the load changes. Those tap changers are subject to different degradation mechanisms and need regular maintenance. Various defects, like contact degradation, often remain undetected and the

  3. 30 CFR 57.12071 - Movement or operation of equipment near high-voltage powerlines.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Movement or operation of equipment near high-voltage powerlines. 57.12071 Section 57.12071 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION...-voltage powerlines. When equipment must be moved or operated near energized high-voltage powerlines (other...

  4. 30 CFR 77.807-2 - Booms and masts; minimum distance from high-voltage lines.

    Science.gov (United States)

    2010-07-01

    ...-voltage lines. 77.807-2 Section 77.807-2 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... WORK AREAS OF UNDERGROUND COAL MINES Surface High-Voltage Distribution § 77.807-2 Booms and masts; minimum distance from high-voltage lines. The booms and masts of equipment operated on the surface of any...

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

    Science.gov (United States)

    2010-07-01

    ...-voltage power lines. 56.12071 Section 56.12071 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... NONMETAL MINES Electricity § 56.12071 Movement or operation of equipment near high-voltage power lines. When equipment must be moved or operated near energized high-voltage powerlines (other than trolley...

  6. Simulation Model solves exact the Enigma named Generating high Voltages and high Frequencies by Tesla Coil

    Directory of Open Access Journals (Sweden)

    Simo Janjanin

    2016-11-01

    Full Text Available Simulation model of Tesla coil has been successfully completed, and has been verified the procedure and functioning. The literature and documentation for the model were taken from the rich sources, especially the copies of Tesla patents. The oscillating system‟s electrical scheme consists of the voltage supply 220/50 Hz, Fe transformer, capacitor and belonging chosen electrical components, the air gap in the primary Tesla coil (air transformer and spark gap in the exit of the coil. The investigation of the oscillating process Tesla coil‟s system using the simulation model in MATLAB & SIMULINK have given the exact solution the enigma named the generating high voltage and high frequency the Tesla‟s coil. The inductance voltage from the spark current in the primary (coil with its high voltage impulse excites the oscillating series circuit Ce-L3-R3 on the secondary of the air transformer to its own damped oscillations

  7. Understanding and Improving High Voltage Vacuum Insulators for Microsecond Pulses

    Energy Technology Data Exchange (ETDEWEB)

    Javedani, J B; Goerz, D A; Houck, T L; Lauer, E J; Speer, R D; Tully, L K; Vogtlin, G E; White, A D

    2007-03-05

    High voltage insulation is one of the main areas of pulsed power research and development, and dielectric breakdown is usually the limiting factor in attaining the highest possible performance in pulsed power devices. For many applications the delivery of pulsed power into a vacuum region is the most critical aspect of operation. The surface of an insulator exposed to vacuum can fail electrically at an applied field more than an order or magnitude below the bulk dielectric strength of the insulator. This mode of breakdown, called surface flashover, imposes serious limitations on the power flow into a vacuum region. This is especially troublesome for applications where high voltage conditioning of the insulator and electrodes is not practical and for applications where relatively long pulses, on the order of several microseconds, are required. The goal of this project is to establish a sound fundamental understanding of the mechanisms that lead to surface flashover, and then evaluate the most promising techniques to improve vacuum insulators and enable high voltage operation at stress levels near the intrinsic bulk breakdown limits of the material. The approach we proposed and followed was to develop this understanding through a combination of theoretical and computation methods coupled with experiments to validate and quantify expected behaviors. In this report we summarize our modeling and simulation efforts, theoretical studies, and experimental investigations. The computational work began by exploring the limits of commercially available codes and demonstrating methods to examine field enhancements and defect mechanisms at microscopic levels. Plasma simulations with particle codes used in conjunction with circuit models of the experimental apparatus enabled comparisons with experimental measurements. The large scale plasma (LSP) particle-in-cell (PIC) code was run on multiprocessor platforms and used to simulate expanding plasma conditions in vacuum gap regions

  8. Hybrid-PIC Modeling of a High-Voltage, High-Specific-Impulse Hall Thruster

    Science.gov (United States)

    Smith, Brandon D.; Boyd, Iain D.; Kamhawi, Hani; Huang, Wensheng

    2013-01-01

    The primary life-limiting mechanism of Hall thrusters is the sputter erosion of the discharge channel walls by high-energy propellant ions. Because of the difficulty involved in characterizing this erosion experimentally, many past efforts have focused on numerical modeling to predict erosion rates and thruster lifespan, but those analyses were limited to Hall thrusters operating in the 200-400V discharge voltage range. Thrusters operating at higher discharge voltages (V(sub d) >= 500 V) present an erosion environment that may differ greatly from that of the lower-voltage thrusters modeled in the past. In this work, HPHall, a well-established hybrid-PIC code, is used to simulate NASA's High-Voltage Hall Accelerator (HiVHAc) at discharge voltages of 300, 400, and 500V as a first step towards modeling the discharge channel erosion. It is found that the model accurately predicts the thruster performance at all operating conditions to within 6%. The model predicts a normalized plasma potential profile that is consistent between all three operating points, with the acceleration zone appearing in the same approximate location. The expected trend of increasing electron temperature with increasing discharge voltage is observed. An analysis of the discharge current oscillations shows that the model predicts oscillations that are much greater in amplitude than those measured experimentally at all operating points, suggesting that the differences in oscillation amplitude are not strongly associated with discharge voltage.

  9. Investigating Enhancement Mode Gallium Nitride Power FETs in High Voltage, High Frequency Soft Switching Converters

    DEFF Research Database (Denmark)

    Nour, Yasser; Knott, Arnold; Jørgensen, Ivan Harald Holger

    2016-01-01

    of using enhancement mode gallium nitride switches to form a 50V quasi-square-wave zero-voltage-switching buck converter running at 2-6 MHz under full load. The designed converter achieved 83% efficiency converting 50V input voltage to 12.2V at 9W load.......An increased attention has been detected to develop smaller and lighter high voltage power converters in the range of 50V to 400V domain. The main applications for these converters are mainly focused for Power over Ethernet (PoE), LED lighting and AC adapters. This work will discuss a study...

  10. Investigating Enhancement Mode Gallium Nitride Power FETs in High Voltage, High Frequency Soft Switching Converters

    DEFF Research Database (Denmark)

    Nour, Yasser; Knott, Arnold; Jørgensen, Ivan Harald Holger

    2016-01-01

    An increased attention has been detected to develop smaller and lighter high voltage power converters in the range of 50V to 400V domain. The main applications for these converters are mainly focused for Power over Ethernet (PoE), LED lighting and AC adapters. This work will discuss a study of us...... of using enhancement mode gallium nitride switches to form a 50V quasi-square-wave zero-voltage-switching buck converter running at 2-6 MHz under full load. The designed converter achieved 83% efficiency converting 50V input voltage to 12.2V at 9W load....

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

    Science.gov (United States)

    Safigianni, Anastasia S; Spyridopoulos, Anastasios I; Kanas, Vasilis L

    2012-01-01

    This paper investigates the electric and magnetic fields inside a large high voltage center constituted both of 400/150 and 150/20 kV substation areas. Results of previous field measurements and calculations in substations, made by the authors of this paper or other researchers, are presented first. The basic data distinguishing the examined center from previously examined substations follow. The main results of the field measurements in the areas of the above-mentioned center are presented in relevant diagrams. General conclusions arising from the comparison of the measured field values with relevant reference levels in force for safe public and occupational exposure as well as with the results of previous research are finally given.

  12. High Voltage Installation of PS Linac 1 Preinjector

    CERN Multimedia

    CERN PhotoLab

    1974-01-01

    The high-voltage installation of the linac 1 preinjector in its house-sized Faraday cage. Originally driven by a 520 kV Cockcroft-Walton generator, at the time of this picture the HV came from a 520 kV SAMES generator. The column in the front carries a capacitor. The cubicle in the right background is the electronics platform (see 7403120). The round structure at left houses the ion source, from where the protons (and sometimes other ions), electrostatically accelerated to 520 keV, enter the Alvarez structure of linac 1, to be accelerated to 50 MeV. Jean-Luc Vallet is busy with servicing the installation. See also 7403064X, 7403066X.

  13. Growing of semiinsulating Si for high-voltage devices

    Directory of Open Access Journals (Sweden)

    Turtsevich A. S.

    2008-02-01

    Full Text Available The effect of the N2O/SiH4 flow ratio ( on the peculiarities of initial stages, structural, morphological and electrophysical properties of the SiPOS film has been investigates. The average roughness of thin SiPOS films (Ra is 0.09 nm (for polysilicon films - 1.52 nm. The films having 2.5-22.0 at.% oxygen have quasi-crystal structure. Explanation of the obtained results on the base of multi-route layer deposition process in SiH4-N2O gas system has been presented. The obtained results have been used for the optimization of SiPOS film deposition process under high-voltage device.

  14. High voltage and high specific capacity dual intercalating electrode Li-ion batteries

    Science.gov (United States)

    West, William C. (Inventor); Blanco, Mario (Inventor)

    2010-01-01

    The present invention provides high capacity and high voltage Li-ion batteries that have a carbonaceous cathode and a nonaqueous electrolyte solution comprising LiF salt and an anion receptor that binds the fluoride ion. The batteries can comprise dual intercalating electrode Li ion batteries. Methods of the present invention use a cathode and electrode pair, wherein each of the electrodes reversibly intercalate ions provided by a LiF salt to make a high voltage and high specific capacity dual intercalating electrode Li-ion battery. The present methods and systems provide high-capacity batteries particularly useful in powering devices where minimizing battery mass is important.

  15. High-Voltage-Input Level Translator Using Standard CMOS

    Science.gov (United States)

    Yager, Jeremy A.; Mojarradi, Mohammad M.; Vo, Tuan A.; Blalock, Benjamin J.

    2011-01-01

    proposed integrated circuit would translate (1) a pair of input signals having a low differential potential and a possibly high common-mode potential into (2) a pair of output signals having the same low differential potential and a low common-mode potential. As used here, "low" and "high" refer to potentials that are, respectively, below or above the nominal supply potential (3.3 V) at which standard complementary metal oxide/semiconductor (CMOS) integrated circuits are designed to operate. The input common-mode potential could lie between 0 and 10 V; the output common-mode potential would be 2 V. This translation would make it possible to process the pair of signals by use of standard 3.3-V CMOS analog and/or mixed-signal (analog and digital) circuitry on the same integrated-circuit chip. A schematic of the circuit is shown in the figure. Standard 3.3-V CMOS circuitry cannot withstand input potentials greater than about 4 V. However, there are many applications that involve low-differential-potential, high-common-mode-potential input signal pairs and in which standard 3.3-V CMOS circuitry, which is relatively inexpensive, would be the most appropriate circuitry for performing other functions on the integrated-circuit chip that handles the high-potential input signals. Thus, there is a need to combine high-voltage input circuitry with standard low-voltage CMOS circuitry on the same integrated-circuit chip. The proposed circuit would satisfy this need. In the proposed circuit, the input signals would be coupled into both a level-shifting pair and a common-mode-sensing pair of CMOS transistors. The output of the level-shifting pair would be fed as input to a differential pair of transistors. The resulting differential current output would pass through six standoff transistors to be mirrored into an output branch by four heterojunction bipolar transistors. The mirrored differential current would be converted back to potential by a pair of diode-connected transistors

  16. Advances in high voltage insulation and arc interruption in SF6 and vacuum

    CERN Document Server

    Maller, V N

    1982-01-01

    Advances in High Voltage Insulation and Arc Interruption in SF6 and Vacuum deals with high voltage breakdown and arc extinction in sulfur hexafluoride (SF6) and high vacuum, with special emphasis on the application of these insulating media in high voltage power apparatus and devices. The design and developmental aspects of various high voltage power apparatus using SF6 and high vacuum are highlighted. This book is comprised of eight chapters and opens with a discussion on electrical discharges in SF6 and high vacuum, along with the properties and handling of SF6 gas. The following chapters fo

  17. Method and system for a gas tube switch-based voltage source high voltage direct current transmission system

    Energy Technology Data Exchange (ETDEWEB)

    She, Xu; Chokhawala, Rahul Shantilal; Zhou, Rui; Zhang, Di; Sommerer, Timothy John; Bray, James William

    2016-12-13

    A voltage source converter based high-voltage direct-current (HVDC) transmission system includes a voltage source converter (VSC)-based power converter channel. The VSC-based power converter channel includes an AC-DC converter and a DC-AC inverter electrically coupled to the AC-DC converter. The AC-DC converter and a DC-AC inverter include at least one gas tube switching device coupled in electrical anti-parallel with a respective gas tube diode. The VSC-based power converter channel includes a commutating circuit communicatively coupled to one or more of the at least one gas tube switching devices. The commutating circuit is configured to "switch on" a respective one of the one or more gas tube switching devices during a first portion of an operational cycle and "switch off" the respective one of the one or more gas tube switching devices during a second portion of the operational cycle.

  18. Megahertz high voltage pulse generator suitable for capacitive load

    Science.gov (United States)

    Xu, Yu; Chen, Wei; Liang, Hao; Li, Yu-Huai; Liang, Fu-Tian; Shen, Qi; Liao, Sheng-Kai; Peng, Cheng-Zhi

    2017-11-01

    A high voltage pulse generator is presented to drive Pockels cell. The Pockels cell behaves like a capacitor which slows the rise/fall time of the pulse and restrains the repetition rate of the generator. To drive the Pockels cell applied in quantum communication system, it requires about 1 MHz repetition rate with the rise/fall time of the pulse less than 50 ns, adjustable amplitude up to 800 V and an adjustable duration. With the assistance of self-designed transformers, the circuits is simplified that a pair of high current radio frequency (RF) MOSFET drivers are employed to switch the power MOSFETs at a high speed, and the power MOSFETs shape the final output pulse with the requirements. From the tests, the generator can produce 800 V square pulses continously at 1 MHz rate with 46 ns in risetime and 31 ns in falltime when driving a 51 pF capacitive load. And the generator is now used to drive Pockels cell for encoding the polarization of photons.

  19. Megahertz high voltage pulse generator suitable for capacitive load

    Directory of Open Access Journals (Sweden)

    Yu Xu

    2017-11-01

    Full Text Available A high voltage pulse generator is presented to drive Pockels cell. The Pockels cell behaves like a capacitor which slows the rise/fall time of the pulse and restrains the repetition rate of the generator. To drive the Pockels cell applied in quantum communication system, it requires about 1 MHz repetition rate with the rise/fall time of the pulse less than 50 ns, adjustable amplitude up to 800 V and an adjustable duration. With the assistance of self-designed transformers, the circuits is simplified that a pair of high current radio frequency (RF MOSFET drivers are employed to switch the power MOSFETs at a high speed, and the power MOSFETs shape the final output pulse with the requirements. From the tests, the generator can produce 800 V square pulses continously at 1 MHz rate with 46 ns in risetime and 31 ns in falltime when driving a 51 pF capacitive load. And the generator is now used to drive Pockels cell for encoding the polarization of photons.

  20. The Investigation of Field Plate Design in 500 V High Voltage NLDMOS

    Directory of Open Access Journals (Sweden)

    Donghua Liu

    2015-01-01

    Full Text Available This paper presents a 500 V high voltage NLDMOS with breakdown voltage (VBD improved by field plate technology. Effect of metal field plate (MFP and polysilicon field plate (PFP on breakdown voltage improvement of high voltage NLDMOS is studied. The coeffect of MFP and PFP on drain side has also been investigated. A 500 V NLDMOS is demonstrated with a 37 μm drift length and optimized MFP and PFP design. Finally the breakdown voltage 590 V and excellent on-resistance performance (Rsp = 7.88 ohm * mm2 are achieved.

  1. Effect of high-voltage impulse current on the structure and function of rabbit heart

    Directory of Open Access Journals (Sweden)

    Xin-ping XU

    2011-06-01

    Full Text Available Objective To explore the effect of high-voltage impulse current(HVIC on the structure and function of rabbit heart.Methods Sixty healthy male rabbits were involved in present study and divided into 6 groups randomly(n=10.The rabbits were then shocked using a high-voltage pulse generator with current intensity of 0,50,100,150,250 and 500mA(pulse width 100μs,duration 5s respectively.The heart rate and electrocardiogram(ECG of rabbits were detected before and 0,1,3,7,14 and 28 days after the electric shock.Moreover,the myocardial tissue of rabbits was obtained immediately and 28 days after shock to observe the pathological changes.Results Immediately after electric shock of 50 to 500mA,the heart rate of rabbit increased by different degree,and the ECG showed arrhythmia,myocardial ischemia,atrial fibrillation and atrioventricular block,and the changes recovered gradually one day later.The pathological observation showed cell swelling,separation of myofibril and sarcoplasmic condensation of Purkinje fibers immediately after electric shock of 50 to 500mA,and the changes recovered 28 days after shock.The cardiac injuries aggravated with the increasing of current intensity,especially when it exceeded 150mA,and the recovery time prolonged.Conclusion High-voltage impulse current may induce recoverable injuries on heart structure and function,and the damage effect shows a correlation with the current intensity.

  2. High-Voltage LED Light Engine with Integrated Driver

    Energy Technology Data Exchange (ETDEWEB)

    Soer, Wouter [Lumileds LLC, San Jose, CA (United States)

    2016-02-29

    LED luminaires have seen dramatic changes in cost breakdown over the past few years. The LED component cost, which until recently was the dominant portion of luminaire cost, has fallen to a level of the same order as the other luminaire components, such as the driver, housing, optics etc. With the current state of the technology, further luminaire performance improvement and cost reduction is realized most effectively by optimization of the whole system, rather than a single component. This project focuses on improving the integration between LEDs and drivers. Lumileds has developed a light engine platform based on low-cost high-power LEDs and driver topologies optimized for integration with these LEDs on a single substrate. The integration of driver and LEDs enables an estimated luminaire cost reduction of about 25% for targeted applications, mostly due to significant reductions in driver and housing cost. The high-power LEDs are based on Lumileds’ patterned sapphire substrate flip-chip (PSS-FC) technology, affording reduced die fabrication and packaging cost compared to existing technology. Two general versions of PSS-FC die were developed in order to create the desired voltage and flux increments for driver integration: (i) small single-junction die (0.5 mm2), optimal for distributed lighting applications, and (ii) larger multi-junction die (2 mm2 and 4 mm2) for high-power directional applications. Two driver topologies were developed: a tapped linear driver topology and a single-stage switch-mode topology, taking advantage of the flexible voltage configurations of the new PSS-FC die and the simplification opportunities enabled by integration of LEDs and driver on the same board. A prototype light engine was developed for an outdoor “core module” application based on the multi-junction PSS-FC die and the single-stage switch-mode driver. The light engine meets the project efficacy target of 128 lm/W at a luminous flux

  3. Improvement of high-voltage staircase drive circuit waveform for high-intensity therapeutic ultrasound

    Science.gov (United States)

    Tamano, Satoshi; Jimbo, Hayato; Azuma, Takashi; Yoshizawa, Shin; Fujiwara, Keisuke; Itani, Kazunori; Umemura, Shin-Ichiro

    2016-07-01

    Recently, in the treatment of diseases such as cancer, noninvasive or low-invasive modality, such as high-intensity focused ultrasound (HIFU), has been put into practice as an alternative to open surgery. HIFU induces thermal ablation of the target tissue to be treated. To improve the efficiency of HIFU, we have proposed a “triggered-HIFU” technique, which uses the combination of a short-duration, high-voltage transmission and a long-duration, medium-voltage transmission. In this method, the transmission device must endure high peak voltage for the former and the high time-average power for the latter. The triggered-HIFU sequence requires electronic scanning of the HIFU focus to maximize its thermal efficiency. Therefore, the transmission device must drive an array transducer with the number of elements on the order of a hundred or more, which requires that each part of the device that drives each element must be compact. The purpose of this work is to propose and construct such a transmission device by improving the staircase drive circuit, which we previously proposed. The main point of improvement is that both N and P MOSFETs are provided for each staircase voltage level instead of only one of them. Compared with the previous ultrasonic transmission circuit, high-voltage spikes were significantly reduced, the power consumption was decreased by 26.7%, and the transmission circuit temperature rise was decreased by 14.5 °C in the triggered-HIFU heating mode.

  4. Characteristics and Breakdown Behaviors of Polysilicon Resistors for High Voltage Applications

    Directory of Open Access Journals (Sweden)

    Xiao-Yu Tang

    2015-01-01

    Full Text Available With the rapid development of the power integrated circuit technology, polysilicon resistors have been widely used not only in traditional CMOS circuits, but also in the high voltage applications. However, there have been few detailed reports about the polysilicon resistors’ characteristics, like voltage and temperature coefficients and breakdown behaviors which are critical parameters of high voltage applications. In this study, we experimentally find that the resistance of the polysilicon resistor with a relatively low doping concentration shows negative voltage and temperature coefficients, while that of the polysilicon resistor with a high doping concentration has positive voltage and temperature coefficients. Moreover, from the experimental results of breakdown voltages of the polysilicon resistors, it could be deduced that the breakdown of polysilicon resistors is thermally rather than electrically induced. We also proposed to add an N-type well underneath the oxide to increase the breakdown voltage in the vertical direction when the substrate is P-type doped.

  5. Development of high voltage lead wires using electron beam irradiation

    Science.gov (United States)

    Hun-Jai, Bae; Ho-Soung, Sohn; Dong-Jung, Choi

    1995-09-01

    It is known to those skilled to the art that the electric wires used in high voltage operating electric equipments such as TV sets, microwave ovens, duplicators and etc., have such a structure that a conductor is coated with an insulating layer which is encapsulated with a protecting jacket layer. The electric wire specification such as UL and CSA requires superior cut-through property and flame-retardant property of the wire for utilization safety. The cut-through property of insulation material, for example, high density polyethylene, can be increased by crosslinking of the polymer. Also the flame-retardant property of jacket material which protects the flammable inner insulation can be raised by flame-retardant formulating of the material. In the wire and cable industry, crosslinking by electron beam processing is more effective than that by chemical processing in the viewpoint of through-put rate of the products. The jacket layer of the wire plays the role of protecting the insulation material from burning. The protecting ability of the jacket is related to its inherent flammability and formability of swollen carbonated layer when burned. Crosslinking of the material gives a good formability of swollen carbonated layer, and it protects the insulation material from direct flame. In formulating the flame-retardant jacket material, a crosslinking system must be considered with base polymers and other flame-retardant additives.

  6. Photoconductivity of high-voltage space insulating materials

    Science.gov (United States)

    Coffey, H. T.; Nanevicz, J. E.; Adamo, R. C.

    1975-01-01

    The dark and photoconductivities of four high voltage spacecraft insulators, Kapton-H, FEP Teflon, Parylene, and fused quartz, were studied under a variety of conditions intended to simulate a space environment. All measurements were made in a vacuum of less than .00001 torr while the temperature was varied from 22 C to 100 C. Some of the samples used employed conventional deposited metal electrodes--others employed electrodes composed either of an electron beam or a plasma formed by ionization of the residual gas in the test chamber. Test results show: (1) Kapton had unusual conduction properties; it conductivity decreased by more than an order of magnitude when heated at 100 C in a vacuum, but ultimately attained a stable and reproducible value. (2) Both Teflon and fused quartz had high dark resistivities but low photoresistivities when exposed to UV. Optical-density measurements revealed that both materials transmitted UV with little attenuation. (3) Parylene was found to have a low but relatively stable resistivity--comparatively minor changes occurred upon heating or illuminating the sample. Optical-density measurements showed that Parylene was absorbent in the UV and would prevent photoemission from the metal electrode on the back surface.

  7. BEHAVIOUR OF BACKFILL MATERIALS FOR ELECTRICAL GROUNDING SYSTEMS UNDER HIGH VOLTAGE CONDITIONS

    Directory of Open Access Journals (Sweden)

    S. C. LIM

    2015-06-01

    Full Text Available Backfill materials like Bentonite and cement are effective in lowering grounding resistance of electrodes for a considerable period. During lightning, switching impulses and earth fault occurrences in medium and high voltage networks, the grounding system needs to handle extremely high currents either for a short duration or prolonged period respectively. This paper investigates the behaviour of bentonite, cement and sand under impulse and alternating high voltage (50Hz conditions. Fulguritic-formation was observed in all materials under alternating high voltage. The findings reveal that performance of grounding systems under high voltage conditions may significantly change from the outcomes anticipated at design stage.

  8. An Underappreciated Radiation Hazard from High Voltage Electrodes in Vacuum.

    Science.gov (United States)

    West, Adam D; Lasner, Zack; DeMille, David; West, Elizabeth P; Panda, Cristian D; Doyle, John M; Gabrielse, Gerald; Kryskow, Adam; Mitchell, Corinne

    2017-01-01

    The use of high voltage (HV) electrodes in vacuum is commonplace in physics laboratories. In such systems, it has long been known that electron emission from an HV cathode can lead to bremsstrahlung x rays; indeed, this is the basic principle behind the operation of standard x-ray sources. However, in laboratory setups where x-ray production is not the goal and no electron source is deliberately introduced, field-emitted electrons accelerated by HV can produce x rays as an unintended hazardous byproduct. Both the level of hazard and the safe operating regimes for HV vacuum electrode systems are not widely appreciated, at least in university laboratories. A reinforced awareness of the radiation hazards associated with vacuum HV setups would be beneficial. The authors present a case study of a HV vacuum electrode device operated in a university atomic physics laboratory. They describe the characterization of the observed x-ray radiation, its relation to the observed leakage current in the device, the steps taken to contain and mitigate the radiation hazard, and suggested safety guidelines.

  9. An Underappreciated Radiation Hazard from High Voltage Electrodes in Vacuum

    CERN Document Server

    West, Adam; DeMille, David; West, Elizabeth; Panda, Cristian; Doyle, John; Gabrielse, Gerald; Kryskow, Adam; Mitchell, Corinne

    2016-01-01

    The use of high voltage (HV) electrodes in vacuum is commonplace in physics laboratories. In such systems, it has long been known that electron emission from an HV cathode can lead to bremsstrahlung X-rays; indeed, this is the basic principle behind the operation of standard X-ray sources. However, in laboratory setups where X-ray production is not the goal and no electron source is deliberately introduced, field-emitted electrons accelerated by HV can produce X-rays as an unintended hazardous byproduct. Both the level of hazard and the safe operating regimes for HV vacuum electrode systems are not widely appreciated, at least in university laboratories. A reinforced awareness of the radiation hazards associated with vacuum HV setups would be beneficial. We present a case study of a HV vacuum electrode device operated in a university atomic physics laboratory. We describe the characterisation of the observed X-ray radiation, its relation to the observed leakage current in the device, the steps taken to contai...

  10. Increase the threshold voltage of high voltage GaN transistors by low temperature atomic hydrogen treatment

    Energy Technology Data Exchange (ETDEWEB)

    Erofeev, E. V., E-mail: erofeev@micran.ru [Tomsk State University of Control Systems and Radioelectronics, Research Institute of Electrical-Communication Systems (Russian Federation); Fedin, I. V.; Kutkov, I. V. [Research and Production Company “Micran” (Russian Federation); Yuryev, Yu. N. [National Research Tomsk Polytechnic University, Institute of Physics and Technology (Russian Federation)

    2017-02-15

    High-electron-mobility transistors (HEMTs) based on AlGaN/GaN epitaxial heterostructures are a promising element base for the fabrication of high voltage electronic devices of the next generation. This is caused by both the high mobility of charge carriers in the transistor channel and the high electric strength of the material, which makes it possible to attain high breakdown voltages. For use in high-power switches, normally off-mode GaN transistors operating under enhancement conditions are required. To fabricate normally off GaN transistors, one most frequently uses a subgate region based on magnesium-doped p-GaN. However, optimization of the p-GaN epitaxial-layer thickness and the doping level makes it possible to attain a threshold voltage of GaN transistors close to V{sub th} = +2 V. In this study, it is shown that the use of low temperature treatment in an atomic hydrogen flow for the p-GaN-based subgate region before the deposition of gate-metallization layers makes it possible to increase the transistor threshold voltage to V{sub th} = +3.5 V. The effects under observation can be caused by the formation of a dipole layer on the p-GaN surface induced by the effect of atomic hydrogen. The heat treatment of hydrogen-treated GaN transistors in a nitrogen environment at a temperature of T = 250°C for 12 h reveals no degradation of the transistor’s electrical parameters, which can be caused by the formation of a thermally stable dipole layer at the metal/p-GaN interface as a result of hydrogenation.

  11. High-Mixed-Voltage Analog and RF Circuit Techniques for Nanoscale CMOS

    CERN Document Server

    Mak, Pui-In

    2012-01-01

    This book presents high-/mixed-voltage analog and radio frequency (RF) circuit techniques for developing low-cost multistandard wireless receivers in nm-length CMOS processes.  Key benefits of high-/mixed-voltage RF and analog CMOS circuits are explained, state-of-the-art examples are studied, and circuit solutions before and after voltage-conscious design are compared. Three real design examples are included, which demonstrate the feasibility of high-/mixed-voltage circuit techniques.    Provides a valuable summary and real case studies of the state-of-the-art in high-/mixed-voltage circuits and systems; Includes novel high-/mixed-voltage analog and RF circuit techniques – from concept to practice; Describes the first high-voltage-enabled mobile-TVRF front-end in 90nm CMOS and the first mixed-voltage full-band mobile-TV Receiver in 65nm CMOS; Demonstrates the feasibility of high-/mixed-voltage circuit techniques with real design examples.  

  12. Electric Power High-Voltage Transmission Lines: Design Options, Cost, and Electric and Magnetic Field Levels

    Energy Technology Data Exchange (ETDEWEB)

    Stoffel, J. B. [Argonne National Lab. (ANL), Argonne, IL (United States). Environmental Assessment Division. Electronics and Computing Technologies Division; Pentecost, E. D. [Argonne National Lab. (ANL), Argonne, IL (United States). Environmental Assessment Division; Roman, R. D. [Argonne National Lab. (ANL), Argonne, IL (United States). Environmental Assessment Division; Traczyk, P. A. [Argonne National Lab. (ANL), Argonne, IL (United States). Environmental Assessment Division

    1994-11-01

    The aim of this report is to provide background information about (1) the electric and magnetic fields (EMFs) of high-voltage transmission lines at typical voltages and line configurations and (2) typical transmission line costs to assist preparers and reviewers of the section on alternatives in environmental documents. This report will give the reviewing individual a better appreciation of the factors affecting EMF strengths near high-voltage transmission lines and the approaches that might be used to reduce EMF impacts on humans and other biological species in the vicinity of high-voltage overhead or underground alternating-current (ac) or direct-current (dc) transmission lines.

  13. CFD Simulation of Transonic Flow in High-Voltage Circuit Breaker

    Directory of Open Access Journals (Sweden)

    Xiangyang Ye

    2012-01-01

    Full Text Available A high-voltage circuit breaker is an indispensable piece of equipment in the electric transmission and distribution systems. Transonic flow typically occurs inside breaking chamber during the current interruption, which determines the insulating characteristics of gas. Therefore, accurate compressible flow simulations are required to improve the prediction of the breakdown voltages in various test duties of high-voltage circuit breakers. In this work, investigation of the impact of the solvers on the prediction capability of the breakdown voltages in capacitive switching is presented. For this purpose, a number of compressible nozzle flow validation cases have been presented. The investigation is then further extended for a real high-voltage circuit breaker geometry. The correlation between the flow prediction accuracy and the breakdown voltage prediction capability is identified.

  14. High precision, low disturbance calibration of the High Voltage system of the CMS Barrel Electromagnetic Calorimeter

    CERN Document Server

    Fasanella, Giuseppe

    2016-01-01

    The CMS Electromagnetic Calorimeter utilizes scintillating lead tungstate crystals, with avalanche photodiodes (APD) as photo-detectors in the barrel part. 1224 HV channels bias groups of 50 APD pairs, each at a voltage of about 380 V. The APD gain dependence on the voltage is 3pct/V. A stability of better than 60 mV is needed to have negligible impact on the calorimeter energy resolution. Until 2015 manual calibrations were performed yearly. A new calibration system was deployed recently, which satisfies the requirement of low disturbance and high precision. The system is discussed in detail and first operational experience is presented.

  15. High Bandwidth Zero Voltage Injection Method for Sensorless Control of PMSM

    DEFF Research Database (Denmark)

    Ge, Xie; Lu, Kaiyuan; Kumar, Dwivedi Sanjeet

    2014-01-01

    High frequency signal injection is widely used in PMSM sensorless control system for low speed operations. The conventional voltage injection method often needs filters to obtain particular harmonic component in order to estimate the rotor position; or it requires several voltage pulses to be inj......High frequency signal injection is widely used in PMSM sensorless control system for low speed operations. The conventional voltage injection method often needs filters to obtain particular harmonic component in order to estimate the rotor position; or it requires several voltage pulses...

  16. Integrated Reconfigurable High-Voltage Transmitting Circuit for CMUTs

    DEFF Research Database (Denmark)

    Llimos Muntal, Pere; Larsen, Dennis Øland; Jørgensen, Ivan Harald Holger

    2014-01-01

    -out and measurements are performed on the integrated circuit. The transmitting circuit is reconfigurable externally making it able to drive a wide variety of CMUTs. The transmitting circuit can generate several pulse shapes, pulse voltages up to 100 V, maximum pulse range of 50 V and frequencies up to 5 MHz. The area...

  17. High Power Combiner/Divider with Coupled Lines for Broadband Applications

    Science.gov (United States)

    2017-03-20

    are required for emerging applications in Electronic Warfare (EW), multi-band radar, and multi- function RF. The Wilkinson divider is one of the most...introduce signal filtering or dual band operation [8]. The use of coupled lines gives flexibility. However, the added complexity may lead to greater...of the original Gysel structure (with its low loss, due to low impedance, lines) while introducing the minimum number of coupled lines. This

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

    Science.gov (United States)

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

    2013-01-01

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

  19. 30 CFR 77.704 - Work on high-voltage lines; deenergizing and grounding.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Work on high-voltage lines; deenergizing and grounding. 77.704 Section 77.704 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF... OF UNDERGROUND COAL MINES Grounding § 77.704 Work on high-voltage lines; deenergizing and grounding...

  20. 30 CFR 75.705 - Work on high-voltage lines; deenergizing and grounding.

    Science.gov (United States)

    2010-07-01

    ... grounding. 75.705 Section 75.705 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Grounding § 75.705 Work on high-voltage lines; deenergizing and grounding. High-voltage lines, both on the surface and...

  1. 30 CFR 77.802 - Protection of high-voltage circuits; neutral grounding resistors; disconnecting devices.

    Science.gov (United States)

    2010-07-01

    ... grounding resistors; disconnecting devices. 77.802 Section 77.802 Mineral Resources MINE SAFETY AND HEALTH... of high-voltage circuits; neutral grounding resistors; disconnecting devices. High-voltage circuits... grounded through a suitable resistor at the source transformers, and a grounding circuit, originating at...

  2. 76 FR 26183 - Safety Zone; Repair of High Voltage Transmission Lines to Logan International Airport, Saugus...

    Science.gov (United States)

    2011-05-06

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Repair of High Voltage Transmission Lines... transmission lines to Logan Airport. This safety zone is required to provide for the safety of life on navigable waters during the repair of high voltage transmission lines. Entering into, transiting through...

  3. 75 FR 20918 - High-Voltage Continuous Mining Machine Standard for Underground Coal Mines

    Science.gov (United States)

    2010-04-22

    ... From the Federal Register Online via the Government Publishing Office ] DEPARTMENT OF LABOR Mine Safety and Health Administration 30 CFR Parts 18 and 75 RIN 1219-AB34 High-Voltage Continuous Mining... the table titled Table 10--HIGH VOLTAGE TRAILING CABLE AMPACITIES AND OUTSIDE DIAMETERS, the first...

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

    Directory of Open Access Journals (Sweden)

    Qiang Jiaxi

    2013-01-01

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

  5. High voltage bus and auxiliary heater control system for an electric or hybrid vehicle

    Science.gov (United States)

    Murty, Balarama Vempaty

    2000-01-01

    A control system for an electric or hybrid electric vehicle includes a vehicle system controller and a control circuit having an electric immersion heater. The heater is electrically connected to the vehicle's high voltage bus and is thermally coupled to a coolant loop containing a heater core for the vehicle's climate control system. The system controller responds to cabin heat requests from the climate control system by generating a pulse width modulated signal that is used by the control circuit to operate the heater at a duty cycle appropriate for the amount of cabin heating requested. The control system also uses the heater to dissipate excess energy produced by an auxiliary power unit and to provide electric braking when regenerative braking is not desirable and manual braking is not necessary. The control system further utilizes the heater to provide a safe discharge of a bank of energy storage capacitors following disconnection of the battery or one of the high voltage connectors used to transmit high voltage operating power to the various vehicle systems. The control circuit includes a high voltage clamping circuit that monitors the voltage on the bus and operates the heater to clamp down the bus voltage when it exceeds a pre-selected maximum voltage. The control system can also be used to phase in operation of the heater when the bus voltage exceeds a lower threshold voltage and can be used to phase out the auxiliary power unit charging and regenerative braking when the battery becomes fully charged.

  6. Particle flows to shape and voltage surface discontinuities in the electron sheath surrounding a high voltage solar array in LEO

    Science.gov (United States)

    Metz, Roger N.

    1991-01-01

    This paper discusses the numerical modeling of electron flows from the sheath surrounding high positively biased objects in LEO (Low Earth Orbit) to regions of voltage or shape discontinuity on the biased surfaces. The sheath equations are derived from the Two-fluid, Warm Plasma Model. An equipotential corner and a plane containing strips of alternating voltage bias are treated in two dimensions. A self-consistent field solution of the sheath equations is outlined and is pursued through one cycle. The electron density field is determined by numerical solution of Poisson's equation for the electrostatic potential in the sheath using the NASCAP-LEO relation between electrostatic potential and charge density. Electron flows are calculated numerically from the electron continuity equation. Magnetic field effects are not treated.

  7. High-Capacity Cathode Material with High Voltage for Li-Ion Batteries.

    Science.gov (United States)

    Shi, Ji-Lei; Xiao, Dong-Dong; Ge, Mingyuan; Yu, Xiqian; Chu, Yong; Huang, Xiaojing; Zhang, Xu-Dong; Yin, Ya-Xia; Yang, Xiao-Qing; Guo, Yu-Guo; Gu, Lin; Wan, Li-Jun

    2018-01-15

    Electrochemical energy storage devices with a high energy density are an important technology in modern society, especially for electric vehicles. The most effective approach to improve the energy density of batteries is to search for high-capacity electrode materials. According to the concept of energy quality, a high-voltage battery delivers a highly useful energy, thus providing a new insight to improve energy density. Based on this concept, a novel and successful strategy to increase the energy density and energy quality by increasing the discharge voltage of cathode materials and preserving high capacity is proposed. The proposal is realized in high-capacity Li-rich cathode materials. The average discharge voltage is increased from 3.5 to 3.8 V by increasing the nickel content and applying a simple after-treatment, and the specific energy is improved from 912 to 1033 Wh kg-1 . The current work provides an insightful universal principle for developing, designing, and screening electrode materials for high energy density and energy quality. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Tesla’s high voltage and high frequency generators with oscillatory circuits

    OpenAIRE

    Cvetić Jovan M.

    2016-01-01

    The principles that represent the basics of the work of the high voltage and high frequency generator with oscillating circuits will be discussed. Until 1891, Tesla made and used mechanical generators with a large number of extruded poles for the frequencies up to about 20 kHz. The first electric generators based on a new principle of a weakly coupled oscillatory circuits he used for the wireless signal transmission, for the study of the discharges in vacuu...

  9. A high-voltage test for the ATLAS RPC qualification

    CERN Document Server

    Aielli, G; Cardarelli, R; Di Ciaccio, A; Di Simone, A; Liberti, B; Santonico, R

    2004-01-01

    The RPC production sequence for the ATLAS experiment includes a specific test of current absorption at the operating point, which concerns the RPC "gas volumes", namely the bare detectors not yet assembled with the read-out panels and the mechanical support structures. The test, which is carried out at the production site, consists of two phases. The gas volumes are initially conditioned with pure argon, keeping the voltage constant just above the breakdown value of about 2 kV. The final test, performed after the volumes have undergone inner surface varnishing with linseed oil, is based on the measurement of the current-voltage characteristics with the binary operating gas, C//2H//2F//4/i-C//4H//1//0 = 95/5. The results presented here concern 45% of the total foreseen production.

  10. Fast Coordinated Control of DFIG Wind Turbine Generators for Low and High Voltage Ride-Through

    DEFF Research Database (Denmark)

    Wang, Yun; Wu, Qiuwei; Xu, Honghua

    2014-01-01

    (HVRT) capability of the DFIG WTGs. The characteristics of DFIG WTGs under voltage sags and swells were studied focusing on the DFIG WTG stator flux and rotor voltages during the transient periods of grid voltage changes. The protection schemes of the rotor crowbar circuit and the dc chopper circuit......This paper presents a fast coordinated control scheme of the rotor side converter (RSC), the DC chopper and the grid side converter (GSC) of doubly fed induction generator (DFIG) wind turbine generators (WTGs) which is to improve the low voltage ride through (LVRT) and high voltage ride through...... were proposed considering the characteristics of the DFIG WTGs during voltage changes. The fast coordinated control of RSC and GSC were developed based on the characteristic analysis in order to realize efficient LVRT and HVRT of the DFIG WTGs. The proposed fast coordinated control schemes were...

  11. Enhanced Local Grid Voltage Support Method for High Penetration of Distributed Generators

    DEFF Research Database (Denmark)

    Demirok, Erhan; Sera, Dezso; Rodriguez, Pedro

    2011-01-01

    Grid voltage rise and thermal loading of network components are the most remarkable barriers to allow high number of distributed generator (DG) connections on the medium voltage (MV) and low voltage (LV) electricity networks. The other barriers such as grid power quality (harmonics, voltage...... unbalance, flicker etc.) and network protection mechanisms can be figured out once the maximum DG connection capacity of the network is reached. In this paper, additional reactive power reserve of inverter interfaced DGs is exploited to lower the grid voltage level by means of location-adaptive Q(U) droop...... function. The proposed method aims to achieve less grid voltage violations thus more DG connection on the electricity distribution networks can be allowed....

  12. Fast Coordinated Control of DFIG Wind Turbine Generators for Low and High Voltage Ride-Through

    Directory of Open Access Journals (Sweden)

    Yun Wang

    2014-06-01

    Full Text Available This paper presents a fast coordinated control scheme of the rotor side converter (RSC, the Direct Current (DC chopper and the grid side converter (GSC of doubly fed induction generator (DFIG wind turbine generators (WTGs to improve the low voltage ride through (LVRT and high voltage ride through (HVRT capability of the DFIG WTGs. The characteristics of DFIG WTGs under voltage sags and swells were studied focusing on the DFIG WTG stator flux and rotor voltages during the transient periods of grid voltage changes. The protection schemes of the rotor crowbar circuit and the DC chopper circuit were proposed considering the characteristics of the DFIG WTGs during voltage changes. The fast coordinated control of RSC and GSC were developed based on the characteristic analysis in order to realize efficient LVRT and HVRT of the DFIG WTGs. The proposed fast coordinated control schemes were verified by time domain simulations using Matlab-Simulink.

  13. Design of a pulsewidth-modulated resonant converter for a high-output-voltage power supply

    Science.gov (United States)

    Turnbull, Fred G.; Tompkins, Russell E.

    1987-12-01

    The design and fabrication of a parallel resonant converter circuit and a high-frequency step-up transformer used to supply an adjustable dc voltage to a load is described. The 500-W system is operated from 115/230 V single-phase 60Hz power, which is rectified and filtered to form a 310-V dc link. A two-transistor half-bridge circuit operating at a fixed frequency above the ciruits resonant frequency converts the dc voltage to an ac voltage at approximately 20 kHx. This high-frequency voltage is transformed with a low-capacitance oil-impregnated ferrite transformer. The output voltage is rectified to form a dc voltage with a maximum value of 90-kV peak. The output voltage is adjustable using pulsewidth modulation of the conduction time of the two transistors in the power circuit. The energy stored in the resonant circuit provides a sinusoidal transformer voltage at fixed frequency over a wide range of control. The system is provided with a closed-loop peak-voltage regulator and an on-off capability from the control electronics. The transformer is designed for a specific value of inductance and capacitance to operate at the desired resonant frequency and characteristic impedance.

  14. Design and dSpace interfacing of current fed high gain dc to dc boost converter for low voltage applications

    Science.gov (United States)

    Mukhopadhyay, Debraj; Das, Subhrajit; Arunkumar, G.; Elangovan, D.; Ragunath, G.

    2017-11-01

    In this paper a current fed interleaved DC - DC boost converter which has an isolated topology and used for high voltage step up is proposed. A basic DC to DC boost converter converts uncontrolled DC voltage into controlled DC voltage of higher magnitude. Whereas this topology has the advantages of lower input current ripple, lesser output voltage, lesser stress on switches, faster transient response, improved reliability and much lesser electromagnetic emission over the conventional DC to DC boost converter. Most important benefit of this interleaved DC to DC boost converter is much higher efficiency. The input current is divided into two paths, substantially ohmic loss (I2R) and inductor ac loss gets reduced and finally the system achieves much higher efficiency. With recent mandates on energy saving interleaved DC to DC boost converter may be used as a very powerful tool to maintain good power density keeping the input current manageable. Higher efficiency also allows higher switching frequency and as a result the topology becomes more compact and cost friendly. The proposed topology boosts 48v DC to 200 V DC. Switching frequency is 100 kHz and PSIM 9.1 Platform has been used for the simulation.

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

    Science.gov (United States)

    Callis, Charles P.

    1987-01-01

    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.

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

    Science.gov (United States)

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

    2014-01-01

    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.

  17. DEVELOPMENT OF HIGH-VOLTAGE HIGH-FREQUENCY POWER SUPPLY FOR OZONE GENERATION

    Directory of Open Access Journals (Sweden)

    NACERA HAMMADI

    2016-05-01

    Full Text Available A high-voltage high-frequency power supply for ozone generation is presented in this paper. Ozone generation is intended to be used in air and in water disinfection. A power stage consisting of a single-phase full bridge inverter for regulating the output power, a current push-pull inverter (driver and a control circuit are described and analyzed. This laboratory build power supply using a high voltage ferrite transformer and a PIC microcontroller was employed to energize a dielectric barrier discharge (DBD ozone generator. The inverter working on the basis of control strategy is of simple structure and has a variation range of the working frequency in order to obtain the optimal frequency value. The experimental results concerning electrical characterization and water treatment using a cylindrical DBD ozone generator supplied by this power supply are given in the end.

  18. An Integrated Chip High-Voltage Power Receiver for Wireless Biomedical Implants

    Directory of Open Access Journals (Sweden)

    Vijith Vijayakumaran Nair

    2015-06-01

    Full Text Available In near-field wireless-powered biomedical implants, the receiver voltage largely overrides the compliance of low-voltage power receiver systems. To limit the induced voltage, generally, low-voltage topologies utilize limiter circuits, voltage clippers or shunt regulators, which are power-inefficient methods. In order to overcome the voltage limitation and improve power efficiency, we propose an integrated chip high-voltage power receiver based on the step down approach. The topology accommodates voltages as high as 30 V and comprises a high-voltage semi-active rectifier, a voltage reference generator and a series regulator. Further, a battery management circuit that enables safe and reliable implant battery charging based on analog control is proposed and realized. The power receiver is fabricated in 0.35-μm high-voltage Bipolar-CMOS-DMOStechnology based on the LOCOS0.35-μm CMOS process. Measurement results indicate 83.5% power conversion efficiency for a rectifier at 2.1 mA load current. The low drop-out regulator based on the current buffer compensation and buffer impedance attenuation scheme operates with low quiescent current, reduces the power consumption and provides good stability. The topology also provides good power supply rejection, which is adequate for the design application. Measurement results indicate regulator output of 4 ± 0.03 V for input from 5 to 30 V and 10 ± 0.05 V output for input from 11 to 30 V with load current 0.01–100 mA. The charger circuit manages the charging of the Li-ion battery through all if the typical stages of the Li-ion battery charging profile.

  19. Spatial and temporal instabilities in high voltage power devices

    Energy Technology Data Exchange (ETDEWEB)

    Milady, Saeed

    2010-01-29

    Dynamic avalanche can occur during the turn-off process of high voltage bipolar devices, e.g. IGBTs and p{sup +}n{sup -}n{sup +} power diodes, that may result in spatial instabilities of the homogeneous current density distribution across the device and the formation of current filaments. Filaments may cause the destruction of the device, mainly because of the high local temperatures. The first part of this work is dedicated to the current filament behavior. The positive feedback mechanisms caused by the transient current flow through the gate capacitance of an IGBT operating under short circuit conditions may result in oscillations and temporal instabilities of the IGBT current. The oscillations may cause electromagnetic interference (EMI). Furthermore, the positive feedback mechanism may accelerate the over-heating of the device and result in a thermal run-away. This is the subject of the second part of this work. In the first part of this work using the device simulation results of power diodes the underlying physical mechanisms of the filament dynamic is investigated. Simulation results of diode structures with evenly distributed doping inhomogeneities show that, the filament motion gets smoother as the distance between the inhomogeneities decreases. Hopping to faraway inhomogeneities turns into the hopping to neighboring ones and finally a smooth motion. In homogeneous structures the slow inhibitory effect of the electron-hole plasma extraction and the fast activation, due to hole current flowing along the filament, result in a smooth filament motion. An analytical model for the filament velocity under isothermal conditions is presented that can reproduce the simulation data satisfactorily. The influence of the boundary conditions on the filament behavior is discussed. The positive beveled edge termination prohibits a long stay of the filament at the edge reducing the risk of filament pinning. Self-heating effects may turn the initially electrically triggered

  20. Dividing Discipline

    DEFF Research Database (Denmark)

    Kristensen, Peter Marcus

    2012-01-01

    the periphery of the network—security studies and international political economy in particular—but communication is also divided along the lines of geography and policy/theory. The article concludes that divisions notwithstanding, IR communication remains centered around American, general, and theoretical IR...... than 20,000 articles published in 59 IR journals to construct a network among IR journals and finds a discipline with a center consisting of pedigreed IR journals, albeit closely related to political science. Divisions are identifiable as specialty areas that form clusters of specialized journals along...

  1. Response of low voltage networks with high penetration of photovoltaic systems to transmission network faults

    NARCIS (Netherlands)

    Skaloumpakas, K.; Boemer, J.C.; Van Ruitenbeek, E.; Gibescu, M.

    2014-01-01

    The installed capacity of photovoltaic (PV) systems connected to low voltage (LV) networks in Germany has increased to more than 25 GW. Current grid codes still mandate these PV systems to disconnect in case of voltage dips below 0.8 p.u. The resulting response of LV distribution systems with high

  2. High performance AC–DC control power supply for low voltage ride ...

    Indian Academy of Sciences (India)

    Home; Journals; Sadhana; Volume 41; Issue 2 ... The CPS design presented here maintains a constant 24Vdc output even over a wide (90Vrms to 270Vrms ) ac voltage variation at its input for a High Power Converter (HPC). ... The CPS was tested for wide input voltage range (vin) and the performance validates the design.

  3. High voltage conversion ratio, switched C & L cells, step-down DC-DC converter

    DEFF Research Database (Denmark)

    Pelan, Ovidiu; Muntean, Nicolae; Cornea, Octavian

    2013-01-01

    The paper presents a high voltage conversion ratio DC-DC step-down topology obtained from a classical buck converter associated with an input switched-capacitor cell and an output switched-inductor cell. Analytical descriptions, the voltage and current limits of the main components are synthesize...

  4. Nonlinear Parasitic Capacitance Modelling of High Voltage Power MOSFETs in Partial SOI Process

    DEFF Research Database (Denmark)

    Fan, Lin; Knott, Arnold; Jørgensen, Ivan Harald Holger

    2016-01-01

    : off-state, sub-threshold region, and on-state in the linear region. A high voltage power MOSFET is designed in a partial Silicon on Insulator (SOI) process, with the bulk as a separate terminal. 3D plots and contour plots of the capacitances versus bias voltages for the transistor summarize...

  5. Toward a High Performance Tile Divide and Conquer Algorithm for the Dense Symmetric Eigenvalue Problem

    KAUST Repository

    Haidar, Azzam

    2012-01-01

    Classical solvers for the dense symmetric eigenvalue problem suffer from the first step, which involves a reduction to tridiagonal form that is dominated by the cost of accessing memory during the panel factorization. The solution is to reduce the matrix to a banded form, which then requires the eigenvalues of the banded matrix to be computed. The standard divide and conquer algorithm can be modified for this purpose. The paper combines this insight with tile algorithms that can be scheduled via a dynamic runtime system to multicore architectures. A detailed analysis of performance and accuracy is included. Performance improvements of 14-fold and 4-fold speedups are reported relative to LAPACK and Intel\\'s Math Kernel Library.

  6. Efficient Parametric Identification Method for High Voltage Pulse Transformers

    CERN Document Server

    Aguglia, D; Viarouge, P; Cros, J

    2014-01-01

    This paper presents a new identification method for a pulse transformer equivalent circuit. It is based on an analytical approximation of the frequency-domain impedance data derived from a no-load test with open-circuited secondary winding and only requires measurements of primary current and voltage without phase data. Compared with time consuming and complex methods based on off-line non-linear identification procedures, this simple method also gives an estimation of the error on the identified parameters. The method is validated on an existing pulse transformer.

  7. High Voltage Power Converter for Large Wind Turbine

    DEFF Research Database (Denmark)

    Sztykiel, Michal

    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...... 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...

  8. Light-weight DC to very high voltage DC converter

    Science.gov (United States)

    Druce, R.L.; Kirbie, H.C.; Newton, M.A.

    1998-06-30

    A DC-DC converter capable of generating outputs of 100 KV without a transformer comprises a silicon opening switch (SOS) diode connected to allow a charging current from a capacitor to flow into an inductor. When a specified amount of charge has flowed through the SOS diode, it opens up abruptly; and the consequential collapsing field of the inductor causes a voltage and current reversal that is steered into a load capacitor by an output diode. A switch across the series combination of the capacitor, inductor, and SOS diode closes to periodically reset the SOS diode by inducing a forward-biased current. 1 fig.

  9. On-chip high-voltage generator design design methodology for charge pumps

    CERN Document Server

    Tanzawa, Toru

    2016-01-01

    This book 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.  This new edition includes a variety of useful updates, including coverage of power efficiency and comprehensive optimization methodologies for DC-DC voltage multipliers, modeling of extremely low voltage Dickson charge pumps, and modeling and optimum design of AC-DC switched-capacitor multipliers for energy harvesting and power transfer for RFID.

  10. Understanding and Prevention of Transient Voltages and Dielectric Breakdown in High Voltage Battery Systems

    Science.gov (United States)

    2017-07-31

    other provision of law , no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a...in high current battery systems and how vented Li-ion electrolyte gas impacts the dielectric breakdown strength of ambient air. 1S. SUBJECTTERMS...electrical grid, either in homes or in the distribution network, but the loads being sourced in those applications are vastly different than those being

  11. Process engineering of high voltage alginate encapsulation of mesenchymal stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Gryshkov, Oleksandr, E-mail: gryshkov@imp.uni-hannover.de [Institute for Multiphase Processes, Leibniz University Hannover, D-30167 Hannover (Germany); Pogozhykh, Denys, E-mail: pogozhykh@imp.uni-hannover.de [Institute for Multiphase Processes, Leibniz University Hannover, D-30167 Hannover (Germany); Zernetsch, Holger, E-mail: zernetsch@imp.uni-hannover.de [Institute for Multiphase Processes, Leibniz University Hannover, D-30167 Hannover (Germany); Hofmann, Nicola, E-mail: hofmann@imp.uni-hannover.de [Institute for Multiphase Processes, Leibniz University Hannover, D-30167 Hannover (Germany); Mueller, Thomas, E-mail: mueller.thomas@mh-hannover.de [Institute for Transfusion Medicine, Medical School Hannover, D-30625 Hannover (Germany); Glasmacher, Birgit, E-mail: glasmacher@imp.uni-hannover.de [Institute for Multiphase Processes, Leibniz University Hannover, D-30167 Hannover (Germany)

    2014-03-01

    Encapsulation of stem cells in alginate beads is promising as a sophisticated drug delivery system in treatment of a wide range of acute and chronic diseases. However, common use of air flow encapsulation of cells in alginate beads fails to produce beads with narrow size distribution, intact spherical structure and controllable sizes that can be scaled up. Here we show that high voltage encapsulation (≥ 15 kV) can be used to reproducibly generate spherical alginate beads (200–400 μm) with narrow size distribution (± 5–7%) in a controlled manner under optimized process parameters. Flow rate of alginate solution ranged from 0.5 to 10 ml/h allowed producing alginate beads with a size of 320 and 350 μm respectively, suggesting that this approach can be scaled up. Moreover, we found that applied voltages (15–25 kV) did not alter the viability and proliferation of encapsulated mesenchymal stem cells post-encapsulation and cryopreservation as compared to air flow. We are the first who employed a comparative analysis of electro-spraying and air flow encapsulation to study the effect of high voltage on alginate encapsulated cells. This report provides background in application of high voltage to encapsulate living cells for further medical purposes. Long-term comparison and work on alginate–cell interaction within these structures will be forthcoming. - Highlights: • High voltage alginate encapsulation of mesenchymal stem cells (MSCs) was designed. • Reproducible and spherical alginate beads were generated via high voltage. • Air flow encapsulation was utilized as a comparative approach to high voltage. • High voltage did not alter the viability and proliferation of encapsulated MSCs. • High voltage encapsulation can be scaled up and applied in cell-based therapy.

  12. A 3.1-4.8 GHz transmitter with a high frequency divider in 0.18 {mu}m CMOS for OFDM-UWB

    Energy Technology Data Exchange (ETDEWEB)

    Zheng Renliang; Ren Junyan; Li Wei; Li Ning, E-mail: jyren@fudan.edu.c [Micro/Nano Science and Innovation Platform, State Key Laboratory of ASIC and System, Fudan University, Shanghai 201203 (China)

    2009-12-15

    A fully integrated low power RF transmitter for a WiMedia 3.1-4.8 GHz multiband orthogonal frequency division multiplexing ultra-wideband system is presented. With a separate transconductance stage, the quadrature up-conversion modulator achieves high linearity with low supply voltage. The co-design of different resonant frequencies of the modulator and the differential to single (D2S) converter ensures in-band gain flatness. By means of a series inductor peaking technique, the D2S converter obtains 9 dB more gain without extra power consumption. A divided-by-2 divider is used for carrier signal generation. The measurement results show an output power between -10.7 and -3.1 dBm with 7.6 dB control range, an OIP3 up to 12 dBm, a sideband rejection of 35 dBc and a carrier rejection of 30 dBc. The ESD protected chip is fabricated in the Jazz 0.18 {mu}m RF CMOS process with an area of 1.74 mm{sup 2} and only consumes 32 mA current (at 1.8 V) including the test associated parts. (semiconductor integrated circuits)

  13. Results of the 2015 testbeam of a 180 nm AMS High-Voltage CMOS sensor prototype

    CERN Document Server

    Benoit, M.

    2016-07-21

    Active pixel sensors based on the High-Voltage CMOS technology are being investigated as a viable option for the future pixel tracker of the ATLAS experiment at the High-Luminosity LHC. This paper reports on the testbeam measurements performed at the H8 beamline of the CERN Super Proton Synchrotron on a High-Voltage CMOS sensor prototype produced in 180 nm AMS technology. Results in terms of tracking efficiency and timing performance, for different threshold and bias conditions, are shown.

  14. Preparation methodology and possible treatments for improved ceramics for high voltage vacuum applications

    CERN Document Server

    Tan, J

    1998-01-01

    The flashover characteristics of an insulator bridged high voltage vacuum gap can play an important role in the overall performance of a high voltage device, for example in the extreme environments of high energy particle accelerators. The detailed preparation of the insulators is, at present, governed by the commercial production methods and by standard bulk cleaning processes, which for a particular application may be far from optimum. The influence of the mechanical preparation, thermal history and particular cleaning technique have been investigated for commercially available alumina samples, with measurement of surface characteristics by scanning electron microscopy and laser diffraction, measurement of the secondary electron emission curve and analysis of the high voltage performance with the possibility of applied fields up to 200kV/cm. The results of the different measurements are discussed in the overall context of the problems encountered in the full sized high voltage devices, and suggestions are m...

  15. An Annotated Bibliography of High-Voltage Direct-Current Transmission and Flexible AC Transmission (FACTS) Devices, 1991-1993.

    Energy Technology Data Exchange (ETDEWEB)

    Litzenberger, Wayne; Lava, Val

    1994-08-01

    References are contained for HVDC systems, converter stations and components, overhead transmission lines, cable transmission, system design and operations, simulation of high voltage direct current systems, high-voltage direct current installations, and flexible AC transmission system (FACTS).

  16. Insulation co-ordination in high-voltage electric power systems

    CERN Document Server

    Diesendorf, W

    2015-01-01

    Insulation Co-ordination in High-Voltage Electric Power Systems deals with the methods of insulation needed in different circumstances. The book covers topics such as overvoltages and lightning surges; disruptive discharge and withstand voltages; self-restoring and non-self-restoring insulation; lightning overvoltages on transmission lines; and the attenuation and distortion of lightning surges. Also covered in the book are topics such as the switching surge designs of transmission lines, as well as the insulation coordination of high-voltage stations. The text is recommended for electrical en

  17. Bidirectional Flyback Converter with Multiple Series Connected Outputs for High Voltage Capacitive Charge and Discharge Applications

    DEFF Research Database (Denmark)

    Thummala, Prasanth; Schneider, Henrik; Zhang, Zhe

    2015-01-01

    V) in series with a high voltage blocking diode is added, in parallel with a high voltage freewheeling diode of a conventional flyback topology, to enable bidirectional operation. Experimental result from a digitally controlled bidirectional flyback converter shows that the discharge energy efficiency...... by lower voltage rating MOSFETs driven by a gate drive transformer. Simulation results to compare the operation of conventional and proposed converters are provided. The advantages of proposed implementation are improved energy efficiency and lower cost. Experimental results with two series connected...

  18. A Sepic-Type Single-Stage Electronic Ballast for High Line Voltage Applications

    Science.gov (United States)

    Shen, Chih-Lung; Chen, Kuo-Kuang

    In this paper, a sepic-type single-stage electronic ballast (STSSEB) is proposed, which is derived from the combination of a sepic converter and a half-bridge inverter. The ballast can not only step down input voltage directly but achieve high power factor, reduce voltage stress, improve efficiency and lower cost. Since component stress is reduced significantly, the presented ballast can be applied to high voltage mains. Derivation of the STSSEB is first presented. Then, analysis, design and practical consideration for the STSSEB are discussed. A 347Vac 60W prototype has been simulated and implemented. Simulations and experimental results have verified the feasibility of the proposed STSSEB.

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

    DEFF Research Database (Denmark)

    Siwakoti, Yam P.; Blaabjerg, Frede; Loh, Poh Chiang

    2014-01-01

    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......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...

  20. A low knee voltage and high breakdown voltage of 4H-SiC TSBS employing poly-Si/Ni Schottky scheme

    Science.gov (United States)

    Kim, Dong Young; Seok, Ogyun; Park, Himchan; Bahng, Wook; Kim, Hyoung Woo; Park, Ki Cheol

    2018-02-01

    We report a low knee voltage and high breakdown voltage 4H-SiC TSBS employing poly-Si/Ni dual Schottky contacts. A knee voltage was significantly improved from 0.75 to 0.48 V by utilizing an alternative low work-function material of poly-Si as an anode electrode. Also, reverse breakdown voltage was successfully improved from 901 to 1154 V due to a shrunk low-work-function Schottky region by a proposed self-align etching process between poly-Si and SiC. SiC TSBS with poly-Si/Ni dual Schottky scheme is a suitable structure for high-efficiency rectification and high-voltage blocking operation.

  1. Coordination of voltage and reactive power control in the extra high voltage substations based on the example of solutions applied in the national power system

    Directory of Open Access Journals (Sweden)

    Dariusz Kołodziej

    2012-06-01

    Full Text Available This paper presents examples of coordination between automatic voltage and reactive power control systems (ARST covering adjacent and strongly related extra high voltage substations. Included are conclusions resulting from the use of these solutions. The Institute of Power Engineering, Gdańsk Division has developed and deployed ARST systems in the national power system for a dozen or so years.

  2. A high voltage, constant current stimulator for electrocutaneous stimulation through small electrodes.

    Science.gov (United States)

    Poletto, C J; Van Doren, C L

    1999-08-01

    A high-voltage stimulator has been designed to allow transcutaneous stimulation of tactile fibers of the fingertip. The stimulator's output stage was based upon an improved Howland current pump topology, modified to allow high load impedances and small currents. The compliance voltage of approximately 800 V is achieved using commercially available high-voltage operational amplifiers. The output current accuracy is better than +/- 5% over the range of 1 to 25 mA for 30 microseconds or longer pulses. The rise time for square pulses is less than 1 microsecond. High-voltage, common-mode, latch-up power supply problems and solutions are discussed. The stimulator's input stage is optically coupled to the controlling computer and complies with applicable safety standards for use in a hospital environment. The design presented here is for monophasic stimulation only, but could be modified for biphasic stimulation.

  3. Project resumes: biological effects from electric fields associated with high-voltage transmission lines

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-01-01

    Abstracts of research projects are presented in the following areas: measurements and special facilities; cellular and subcellular studies; physiology; behavior; environmental effects; modeling, scaling and dosimetry; and high voltage direct current. (ACR)

  4. Lithium-Ion Electrolytes with Improved Safety Tolerance to High Voltage Systems

    Science.gov (United States)

    Smart, Marshall C. (Inventor); Bugga, Ratnakumar V. (Inventor); Prakash, Surya G. (Inventor); Krause, Frederick C. (Inventor)

    2015-01-01

    The invention discloses various embodiments of electrolytes for use in lithium-ion batteries, the electrolytes having improved safety and the ability to operate with high capacity anodes and high voltage cathodes. In one embodiment there is provided an electrolyte for use in a lithium-ion battery comprising an anode and a high voltage cathode. The electrolyte has a mixture of a cyclic carbonate of ethylene carbonate (EC) or mono-fluoroethylene carbonate (FEC) co-solvent, ethyl methyl carbonate (EMC), a flame retardant additive, a lithium salt, and an electrolyte additive that improves compatibility and performance of the lithium-ion battery with a high voltage cathode. The lithium-ion battery is charged to a voltage in a range of from about 2.0 V (Volts) to about 5.0 V (Volts).

  5. Spontaneous aggregation of lithium ion coordination polymers in fluorinated electrolytes for high-voltage batteries.

    Science.gov (United States)

    Malliakas, Christos D; Leung, Kevin; Pupek, Krzysztof Z; Shkrob, Ilya A; Abraham, Daniel P

    2016-04-28

    Fluorinated carbonates are pursued as liquid electrolyte solvents for high-voltage Li-ion batteries. Here we report aggregation of [Li(+)(FEC)3]n polymer species in fluoroethylene carbonate containing electrolytes and scrutinize the causes for this behavior.

  6. AC Voltage Control of DC/DC Converters Based on Modular Multilevel Converters in Multi-Terminal High-Voltage Direct Current Transmission Systems

    Directory of Open Access Journals (Sweden)

    Rui Li

    2016-12-01

    Full Text Available The AC voltage control of a DC/DC converter based on the modular multilevel converter (MMC is considered under normal operation and during a local DC fault. By actively setting the AC voltage according to the two DC voltages of the DC/DC converter, the modulation index can be near unity, and the DC voltage is effectively utilized to output higher AC voltage. This significantly decreases submodule (SM capacitance and conduction losses of the DC/DC converter, yielding reduced capital cost, volume, and higher efficiency. Additionally, the AC voltage is limited in the controllable range of both the MMCs in the DC/DC converter; thus, over-modulation and uncontrolled currents are actively avoided. The AC voltage control of the DC/DC converter during local DC faults, i.e., standby operation, is also proposed, where only the MMC connected on the faulty cable is blocked, while the other MMC remains operational with zero AC voltage output. Thus, the capacitor voltages can be regulated at the rated value and the decrease of the SM capacitor voltages after the blocking of the DC/DC converter is avoided. Moreover, the fault can still be isolated as quickly as the conventional approach, where both MMCs are blocked and the DC/DC converter is not exposed to the risk of overcurrent. The proposed AC voltage control strategy is assessed in a three-terminal high-voltage direct current (HVDC system incorporating a DC/DC converter, and the simulation results confirm its feasibility.

  7. Effect of cathodal high-voltage electrical stimulation on pain in women with TMD.

    Science.gov (United States)

    Gomes, Natalia C M C; Berni-Schwarzenbeck, Kelly C S; Packer, Amanda C; Rdrigues-Bigaton, Delaine

    2012-01-01

    Pain is the main symptom of patients with temporomandibular disorder (TMD). To evaluate the effect of cathodal high-voltage electrical stimulation (HVES) on pain intensity in women with TMD. Twenty women with TMD (24.25 ± 8.90 years old) participated in the study. They were divided into experimental group (EG, n=10), which received 10 applications of HVES, and placebo group (PG, n=10), which received sham treatment with disconnected HVES equipment. For the sample selection, we used the Research Diagnostic Criteria for Temporomandibular Disorder (RDC/TMD). Pain level was evaluated using a visual analog scale (VAS) applied prior to and after the tenth application of HVES. Data were analyzed using the Wilcoxon signed-rank test and the Mann-Whitney test. Ten applications of HVES reduced pain intensity in the EG (p=0.01). In the PG, there was no significant difference (p=0.20). After the application of HVES, no difference was found (p=0.65) between the groups. The cathodal HVES was effective in reducing pain in women with TMD. Trial Registration RBR-4bk94x.

  8. The high voltage system of the RICH and the multiplicity study with LHCb data

    CERN Document Server

    Fanchini, E; Pessina, G; Gys, T

    2011-01-01

    This thesis is about the work done during my PhD at the Univerità degli studi di Milano–Bicocca. During these three years I was involved in the RICH group of the LHCb experiment. LHCb is one of the four main experiments at CERN. It uses proton–proton collisions to study CP violation and to search for new physics beyond the Standard Model in the $b$ decays. One of the main feature of the experiment is the particle identification, performed with the Ring Imaging Cherenkov (RICH) technology. The RICH detects Cherenkov rings via photons emitted by charged particles traversing radiator materials. The photon detection system used consists of pixel Hybrid Photon Detectors (HPDs). They convert photons into photoelectrons which are then accelerated by means of a field generated by three electrodes, biased with high voltages (-18 kV, -17.7 kV and -14.8 kV), onto the silicon pixel anode. The energy released in the pixel is converted into a binary output. My work can be divided in two main parts: the hardware and th...

  9. Detailed Behavior Analysis for High Voltage Bidirectional Flyback Converter Driving DEAP Actuator

    DEFF Research Database (Denmark)

    Huang, Lina; Zhang, Zhe; Andersen, Michael A. E.

    2013-01-01

    flyback based converter has been implemented. The parasitic elements have serious influence for the operation of the converter, especially in the high output voltage condition. The detailed behavior analysis has been performed considering the impact of the critical parasitic parameters. The converter has...... been analyzed for both charging and discharging processes in low and high output voltage operating occasions. The experimental waveforms can validate the analysis....

  10. Preparation and characterization of EPDM-silica nano/micro composites for high voltage insulation applications

    OpenAIRE

    Ali Muhammad; Choudhry Muhammad Ahmad

    2015-01-01

    The rising market for substitute materials in high voltage insulation components is stimulated largely by the need to reduce overall costs. In this respect, polymer insulators offer significant advantages over old traditional materials. In the present research, efforts have been made to quantify the effect of silica (having different particle size nano, micro and hybrid) loading on the mechanical and thermal behaviors of Ethylene-Propylene-Diene Monomer (EPDM) based high voltage electrical in...

  11. Static Electricity as Part of Electromagnetic Environment on High-Voltage Electrical Substation

    Directory of Open Access Journals (Sweden)

    M. I. Fursanov

    2012-01-01

    Full Text Available Causes of occurrences electrostatic discharges (ESD on high-voltage electric substation were investigated and dependences values ESD’s on parameters interaction structures, humidity of air were found. Experimental research values ESD’s on high-voltage electric substation and in man-made conditions was fulfilled. Uncertainty measurement’s was taken into consideration by research results analyze. Matching with research of other authors was made. Danger ESD’s for electric devises was established.

  12. A STUDY ON LOSS & COST MINIMIZATION BY USING HIGH VOLTAGE DISTRIBUTION SYSTEM

    OpenAIRE

    P. Hussain Khan*, Ch. Punya Sekhar

    2016-01-01

    This paper presents a converter free system to improve the loss minimization and to reduce the cost of power distribution. The high voltage distribution system is implemented to reduce the loss in the present distribution system. The detailed cost estimation and loss minimization in high voltage distribution system is calculated through simulation results. These performance analysis are presented in this paper.      

  13. High-voltage electroporation of bacteria: genetic transformation of Campylobacter jejuni with plasmid DNA.

    OpenAIRE

    Miller, J F; Dower, W J; Tompkins, L S

    1988-01-01

    Electroporation permits the uptake of DNA by mammalian cells and plant protoplasts because it induces transient permeability of the cell membrane. We investigated the utility of high-voltage electroporation as a method for genetic transformation of intact bacterial cells by using the enteric pathogen Campylobacter jejuni as a model system. This report demonstrates that the application of high-voltage discharges to bacterial cells permits genetic transformation. Our method involves exposure of...

  14. Study of the plasma interference with high voltage electrode array for space power application

    OpenAIRE

    Iwasa, Minoru; Tanaka, Koji; Sasaki, Susumu; Odawara, Osamu; 岩佐 稔; 田中 孝治; 佐々木 進; 小田原 修

    2005-01-01

    We are studying the problems associated with high voltage power systems in space. Especially we are interested in the potential distribution of the solar array that is resistant to the electrical discharge. We have carried out experiments on the interaction between the high voltage solar array and the ambient plasma. In the experiment, an array of electrodes distributed on the insulation panel was used to simulate the inter-connectors of the solar array. An electrode array without the insulat...

  15. Analysis and mitigation of external factors induced failures in high voltage equipment

    OpenAIRE

    AKALP, Onur; Kaya, İbrahim; Efe, Serhat Berat

    2016-01-01

    In this study, insulators and switchyard equipment with porcelain outer surface with the most experienced equipment failures in high voltage power systems have been investigated. The effects of the external environment cause malfunctions in these equipments are determined. Due to the external environment effects failures occurring in equipment were examined. Firstly, high-voltage switchgear equipments which are the subject of study are explained. These include circuit breakers, disconnectors,...

  16. A New Approach to High Efficincy in Isolated Boost Converters for High-Power Low-Voltage Fuel Cell Apllications

    DEFF Research Database (Denmark)

    Nymand, Morten; Andersen, Michael A. E.

    2008-01-01

    A new low-leakage-inductance low-resistance design approach to low-voltage high-power isolated boost converters is presented. Very low levels of parasitic circuit inductances are achieved by optimizing transformer design and circuit lay-out. Primary side voltage clamp circuits can be eliminated b...

  17. Design and Development of Autonomous High Voltage Driving System for DEAP Actuator in Radiator Thermostat

    DEFF Research Database (Denmark)

    Huang, Lina; Zhang, Zhe; Andersen, Michael A. E.

    2014-01-01

    make a high voltage capacitive load driving system to be necessary. The only energy source battery determines it needs to be an autonomous system. The detailed system specifications have been introduced and the corresponding system level design has been proposed. In addition, the detailed design......In radiator thermostat applications, DEAP (Dielectric Electro Active Polymer) actuator tends to be a good candidate to replace the conventional self-actuating or step motor based actuator due to its intrinsic advantages. The capacitive property and high voltage (HV) driving demand of DEAP actuator...... and implementation information has been provided as well, including the power and control stage inside the high voltage converter, the output voltage measurement circuit, the feedback control, etc. Finally, the experimental results have been provided to validate the capability and performance of the driving system....

  18. Environmental and biotechnological applications of high-voltage pulsed discharges in water

    Science.gov (United States)

    Sato, Masayuki

    2008-05-01

    A high-voltage pulse has wide application in fields such as chemistry, physics and biology and their combinations. The high-voltage pulse forms two kinds of physical processes in water, namely (a) a pulsed electric field (PEF) in the parallel electrode configuration and (b) plasma generation by a pulsed discharge in the water phase with a concentrated electric field. The PEF can be used for inactivation of bacteria in liquid foods as a non-thermal process, and the underwater plasma is applicable not only for the decomposition of organic materials in water but also for biological treatment of wastewater. These discharge states are controlled mainly by the applied pulse voltage and the electrode shape. Some examples of environmental and biotechnological applications of a high-voltage pulse are reviewed.

  19. Emerging Consumerism and the Accelerated "Education Divide": The Case of Specialized High Schools in South Korea

    Science.gov (United States)

    Park, Hyu-Yong

    2007-01-01

    This paper criticizes the neoliberal shift in Korean education toward educational consumerism by analyzing the boom in Specialized High schools (SHs). For its theoretical background, this paper discusses the issues of freedom, equal opportunity, and choice in education, and investigates how neoliberal consumerism has been encouraging the boom in…

  20. Self-Healable Electrical Insulation for High Voltage Applications

    Science.gov (United States)

    Williams, Tiffany S.

    2017-01-01

    Polymeric aircraft electrical insulation normally degrades by partial discharge with increasing voltage, which causes excessive localized Joule heating in the material and ultimately leads to dielectric failure of the insulator through thermal breakdown. Developing self-healing insulation could be a viable option to mitigate permanent mechanical degradation, thus increasing the longevity of the insulation. Instead of relying on catalyst and monomer-filled microcapsules to crack, flow, and cure at the damaged sites described in well-published mechanisms, establishment of ionic crosslinks could allow for multiple healing events to occur with the added benefit of achieving full recovery strength under certain thermal environments. This could be possible if the operating temperature of the insulator is the same as or close to the temperature where ionic crosslinks are formed. Surlyn, a commercial material with ionic crosslinks, was investigated as a candidate self-healing insulator based off prior demonstrations of self-healing behavior. Thin films of varying thicknesses were investigated and the effects of thickness on the dielectric strength were evaluated and compared to representative polymer insulators. The effects of thermal conditioning on the recovery strength and healing were observed as a function of time following dielectric breakdown. Moisture absorption was also studied to determine if moisture absorption rates in Surlyn were lower than that of common polyimides.

  1. Modulation of High-Voltage Activated Ca2+ Channels by Membrane Phosphatidylinositol 4,5-Bisphosphate

    Science.gov (United States)

    Suh, Byung-Chang; Leal, Karina; Hille, Bertil

    2010-01-01

    SUMMARY Modulation of voltage-gated Ca2+ channels controls activities of excitable cells. We show that high-voltage activated Ca2+ channels are regulated by membrane phosphatidylinositol 4,5-bisphosphate (PIP2) with different sensitivities. Plasma membrane PIP2 depletion by rapamycin-induced translocation of an inositol lipid 5-phosphatase or by a voltage-sensitive 5-phosphatase (VSP) suppresses CaV1.2 and CaV1.3 channel currents by ~35%, and CaV2.1 and CaV2.2 currents by 29 and 55%, respectively. Other CaV channels are less sensitive. Inhibition is not relieved by strong depolarizing prepulses. It changes the voltage dependence of channel gating little. Recovery of currents from inhibition needs intracellular hydrolysable ATP, presumably for PIP2 resynthesis. When PIP2 is increased by overexpressing PIP 5-kinase, activation and inactivation of CaV2.2 current slow and voltage-dependent gating shifts to slightly higher voltages. Thus, endogenous membrane PIP2 supports high-voltage activated L-, N-, and P/Q- type Ca2+ channels, and stimuli that activate phospholipase C deplete PIP2 and reduce those Ca2+ channel currents. PMID:20670831

  2. Voltage magnitude and margin controller for remote industrial microgrid with high wind penetration

    DEFF Research Database (Denmark)

    Cai, Yu; Lin, Jin; Song, Yonghua

    2013-01-01

    It is well known that the remote industrial microgrid is located at the periphery of the grid, which is weakly connected to the main grid. In order to enhance the voltage stability and ensure a good power quality for industries, a voltage magnitude and margin controller based on wind turbines...... is proposed in this paper. This controller includes two parts to improve voltage stability in different time scales by using local measurements. Case studies conducted for a remote microgrid with high wind penetration have proved the effectiveness of the proposed control scheme....

  3. A Novel Quasi-SEPIC High-Voltage Boost DC-DC Converter

    DEFF Research Database (Denmark)

    Siwakoti, Yam Prasad; N. Soltani, Mohsen; Blaabjerg, Frede

    2017-01-01

    This paper proposes a modified coupled-inductor SEPIC dc-dc converter for low power and high voltage gain applications such as for piezoelectric drive systems. The converter uses the same components as of SEPIC converter with an additional diode. Compared to conventional topologies with similar...... voltage gain expression, the proposed topology uses less components to achieve same or even higher voltage gain. This helps to design a very compact and light weight converter with higher power density at lower cost. Due to brevity, the principle of operation, theoretical analysis and comparison supported...

  4. Behavior of AC High Voltage Polyamide Insulators: Evolution of Leakage Current in Different Surface Conditions

    OpenAIRE

    Mohammed El Amine Slama; Abderrahmane Beroual

    2015-01-01

    This paper is aimed at a systematic study of the leakage current of high voltage polyamide insulator string under different conditions of pollution for possible application in the electric locomotive systems. It is shown that in the case of clean/dry and clean/wetted insulators, the leakage current and applied voltage are linear. While in the case of pollution with saline spray, the leakage current and the applied voltage are not linear; the leakage current changes from a linear regime to a n...

  5. Behavior of AC High Voltage Polyamide Insulators: Evolution of Leakage Current in Different Surface Conditions

    Directory of Open Access Journals (Sweden)

    Mohammed El Amine Slama

    2015-01-01

    Full Text Available This paper is aimed at a systematic study of the leakage current of high voltage polyamide insulator string under different conditions of pollution for possible application in the electric locomotive systems. It is shown that in the case of clean/dry and clean/wetted insulators, the leakage current and applied voltage are linear. While in the case of pollution with saline spray, the leakage current and the applied voltage are not linear; the leakage current changes from a linear regime to a nonlinear regime up to total flashover of the insulators sting. Traces of erosion and tracking of insulators resulting of partial discharges are observed.

  6. Electric Field Simulations and Analysis for High Voltage High Power Medium Frequency Transformer

    Directory of Open Access Journals (Sweden)

    Pei Huang

    2017-03-01

    Full Text Available The electronic power transformer (EPT raises concerns for its notable size and volume reduction compared with traditional line frequency transformers. Medium frequency transformers (MFTs are important components in high voltage and high power energy conversion systems such as EPTs. High voltage and high power make the reliable insulation design of MFT more difficult. In this paper, the influence of wire type and interleaved winding structure on the electric field distribution of MFT is discussed in detail. The electric field distributions for six kinds of typical non-interleaved windings with different wire types are researched using a 2-D finite element method (FEM. The electric field distributions for one non-interleaved winding and two interleaved windings are also studied using 2-D FEM. Furthermore, the maximum electric field intensities are obtained and compared. The results show that, in this case study, compared with foil conductor, smaller maximum electric field intensity can be achieved using litz wire in secondary winding. Besides, interleaving can increase the maximum electric field intensity when insulation distance is constant. The proposed method of studying the electric field distribution and analysis results are expected to make a contribution to the improvement of electric field distribution in transformers.

  7. High-Voltage, High-Power Gaseous Electronics Switch For Electric Grid Power Conversion

    Science.gov (United States)

    Sommerer, Timothy J.

    2014-05-01

    We are developing a high-voltage, high-power gas switch for use in low-cost power conversion terminals on the electric power grid. Direct-current (dc) power transmission has many advantages over alternating current (ac) transmission, but at present the high cost of ac-dc power interconversion limits the use of dc. The gas switch we are developing conducts current through a magnetized cold cathode plasma in hydrogen or helium to reach practical current densities > 1 A/cm2. Thermal and sputter damage of the cathode by the incident ion flux is a major technical risk, and is being addressed through use of a ``self-healing'' liquid metal cathode (eg, gallium). Plasma conditions and cathode sputtering loss are estimated by analyzing plasma spectral emission. A particle-in-cell plasma model is used to understand various aspects of switch operation, including the conduction phase (where plasma densities can exceed 1013 cm-3), the switch-open phase (where the high-voltage must be held against gas breakdown on the left side of Paschen's curve), and the switching transitions (especially the opening process, which is initiated by forming an ion-matrix sheath adjacent to a control grid). The information, data, or work presented herein was funded in part by the Advanced Research Projects Agency-Energy (ARPA-E), U.S. Department of Energy, under Award Number DE-AR0000298.

  8. High-performance cryogenic fractal 180° hybrid power divider with integrated directional coupler

    Science.gov (United States)

    Ladu, Adelaide; Montisci, Giorgio; Valente, Giuseppe; Navarrini, Alessandro; Marongiu, Pasqualino; Pisanu, Tonino; Mazzarella, Giuseppe

    2017-06-01

    A 180° hybrid and a directional coupler to be employed in the P-band cryogenic receiver of the Sardinia Radio Telescope are proposed in this work. An in-depth study of the issues related to the use of microwave components for cryogenic radio astronomy receivers is carried out to select the best suited technology and configuration. As a result, a planar fractal 180° hybrid configuration available in the literature has been optimized aiming to increase the operating bandwidth in order to comply with the design specifications of the application at hand. A coupled line directional coupler with weak coupling and high isolation, used to calibrate the receiver chain, is cascaded to the 180° hybrid and realized in the same layout. The final device, consisting of the 180° hybrid and the directional coupler, has been manufactured and tested at the cryogenic temperature of 20 K, showing a good agreement between experimental results and predicted performance.

  9. A Novel Transformerless DC–DC Converters With High Step-Up Voltage Gain And Low Voltage Stress On The Switch

    Directory of Open Access Journals (Sweden)

    hossein ajdarfaeghi

    2016-10-01

    Full Text Available In this paper, a single switch transformerless high step up dc-dc converter with low voltage stress on the switch is proposed. In the proposed converter only one switch is used which makes the control scheme simple as well as reducing the switching power loss. The voltage gain of the proposed converter is higher than the conventional boost converter and buck boost converter and Proposed converter works in wide rang than conventional converters. The proposed converter has low voltage stress on the switch which makes reducing the switching power loss. The proposed converter can be operated in the continuous conduction mode (CCM and the discontinuous conduction mode (DCM. In this paper, different operation modes of the proposed converter, calculation of the voltage gain, the currents that flow through the components, efficiency and capacitors voltage ripple are presented. To verify the operation of the proposed converter, simulation results via PSCAD software and experimental results are provided.

  10. Derivation of Parabolic Current Control with High Precision, Fast Convergence and Extended Voltage Control Application

    OpenAIRE

    Zhang, Lanhua

    2016-01-01

    Current control is an important topic in modern power electronics system. For voltage source inverters, current control loop ensures the waveform quality at steady state and the fast response at transient state. To improve the current control performance, quite a few nonlinear control strategies have been presented and one well-known strategy is the hysteresis current control. It achieves fast response without stability issue and it has high control precision. However, for voltage source inve...

  11. High Voltage Pulsed Radiofrequency for the Treatment of Refractory Neuralgia of the Infraorbital Nerve: A Prospective Double-Blinded Randomized Controlled Study.

    Science.gov (United States)

    Luo, Fang; Wang, Tao; Shen, Ying; Meng, Lan; Lu, Jingjing; Ji, Nan

    2017-05-01

    A recent study showed that 50% of patients who suffered from refractory neuralgia of the infraorbital nerve obtained satisfactory efficacy after pulsed radiofrequency (PRF) treatment. A pilot study showed that increasing the output voltage of PRF significantly improved the efficacy for trigeminal neuralgia; however, whether increasing the output voltage of PRF can improve the treatment outcomes for neuralgia of the infraorbital nerve is unknown. To evaluate the efficacy and safety of high voltage PRF treatment in comparison with standard voltage PRF for neuralgia of the infraorbital nerve. Prospective, single-center, double-blinded, randomized, controlled trial. Beijing Tiantan Hospital, Capital Medical University. A total of 60 patients with refractory neuralgia of the infraorbital nerve were randomly divided into the high voltage PRF group and the standard voltage PRF group to treat their infraorbital nerves. Neither the patients, pain physicians, nor the follow-up evaluators knew the patient group assignments. The primary outcome measure was the one-year response rate. The secondary outcome measures included the time to take effect after PRF, the one-month, 3-month, and 6-month response rates, the relapse rate, and adverse reactions. The intent-to-treat analysis showed that the one-month, 3-month, 6-month, and one-year response rates were all 90% in the high voltage group, which were significantly higher than the rates in the standard voltage group (67% [P voltage group and 13% of the patients in the standard voltage group experienced minor transient (10 - 30 days) numbness in the innervation area after PRF; no other serious adverse reactions were observed in the 2 groups (P > 0.05). We did not investigate the dose-effect relationship between the output voltage and efficacy or the effect of a higher pulse dose on efficacy. This study was a single-center study, and multi-center, randomized, controlled studies are needed to obtain the highest level of empirical

  12. Fast response double series resonant high-voltage DC-DC converter

    Science.gov (United States)

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

    2012-10-01

    In this paper, a novel double series resonant high-voltage dc-dc converter with dual-mode pulse frequency modulation (PFM) control scheme is proposed. The proposed topology consists of two series resonant tanks and hence two resonant currents flow in each switching period. Moreover, it consists of two high-voltage transformer with the leakage inductances are absorbed as resonant inductor in the series resonant tanks. The secondary output of both transformers are rectified and mixed before supplying to load. In the resonant mode operation, the series resonant tanks are energized alternately by controlling two Insulated Gate Bipolar Transistor (IGBT) switches with pulse frequency modulation (PFM). This topology operates in discontinuous conduction mode (DCM) with all IGBT switches operating in zero current switching (ZCS) condition and hence no switching loss occurs. To achieve fast rise in output voltage, a dual-mode PFM control during start-up of the converter is proposed. In this operation, the inverter is started at a high switching frequency and as the output voltage reaches 90% of the target value, the switching frequency is reduced to a value which corresponds to the target output voltage. This can effectively reduce the rise time of the output voltage and prevent overshoot. Experimental results collected from a 100-W laboratory prototype are presented to verify the effectiveness of the proposed system.

  13. Response characteristic of high-speed on/off valve with double voltage driving circuit

    Science.gov (United States)

    Li, P. X.; Su, M.; Zhang, D. B.

    2017-07-01

    High-speed on/off valve, an important part of turbocharging system, its quick response has a direct impact on the turbocharger pressure cycle. The methods of improving the response characteristic of high speed on/off valve include increasing the magnetic force of armature and the voltage, decreasing the mass and current of coil. The less coil number of turns, the solenoid force is smaller. The special armature structure and the magnetic material will raise cost. In this paper a new scheme of double voltage driving circuit is investigated, in which the original driving circuit of high-speed on/off valve is replaced by double voltage driving circuit. The detailed theoretical analysis and simulations were carried out on the double voltage driving circuit, it showed that the switching time and delay time of the valve respectively are 3.3ms, 5.3ms, 1.9ms and 1.8ms. When it is driven by the double voltage driving circuit, the switching time and delay time of this valve are reduced, optimizing its response characteristic. By the comparison related factors (such as duty cycle or working frequency) about influences on response characteristic, the superior of double voltage driving circuit has been further confirmed.

  14. A new high-voltage interconnection shielding method for SOI monolithic ICs

    Science.gov (United States)

    Zhang, Long; Zhu, Jing; Sun, Weifeng; Huang, Xuequan; Zhao, Minna; Chen, Jiajun; Shi, Longxing; Chen, Jian; Ding, Desheng

    2017-07-01

    The high-voltage interconnection (HVI) issue becomes severe in the high-voltage monolithic ICs when single-layer metal is used for lowering the cost. This paper proposes a dual deep-oxide trenches (DDOT) structure for 500 V Silicon-on-Insulator Lateral Insulated Gate Bipolar Transistor (SOI-LIGBT) to shield the influence of HVI on the breakdown voltage. Compared with the conventional DDOT structure, HVI region of the proposed DDOT structure is shrunk by employing a shallow trench (T1) and a deep trench (T2). Besides the breakdown mechanism in the off-state, the current density and impact ionization rate distributions in the on-state of the proposed structure are also investigated. The experiments demonstrate that the proposed DDOT structure can fully shield the influence of HVI with significant reduction in the area of silicon region beneath the HVI. With almost the same off-state breakdown voltage (BVoff) of 550 V as the conventional DDOT structure, the length of the silicon region under the HVI in the proposed structure is shortened from 45 μm to 15 μm. Meanwhile, no on-state breakdown voltage (BVon) degradation is observed according to the measured results. The new method proposed in this work can also be used for other types of high-voltage devices such as LDMOS and free-wheeling diode in SOI Monolithic ICs.

  15. Generic inertia emulation controller for multi-terminal voltage-source-converter high voltage direct current systems

    DEFF Research Database (Denmark)

    Zhu, Jiebei; Guerrero, Josep M.; Hung, William

    2014-01-01

    A generic Inertia Emulation Controller (INEC) scheme for Multi-Terminal Voltage-Source-Converter based HVDC (VSC-MTDC) systems is proposed and presented in this paper. The proposed INEC can be incorporated in any Grid-side Voltage-Source-Converter (GVSC) station, allowing the MTDC terminal to con...

  16. "Divide and conquer" semiclassical molecular dynamics: A practical method for spectroscopic calculations of high dimensional molecular systems.

    Science.gov (United States)

    Di Liberto, Giovanni; Conte, Riccardo; Ceotto, Michele

    2018-01-07

    We extensively describe our recently established "divide-and-conquer" semiclassical method [M. Ceotto, G. Di Liberto, and R. Conte, Phys. Rev. Lett. 119, 010401 (2017)] and propose a new implementation of it to increase the accuracy of results. The technique permits us to perform spectroscopic calculations of high-dimensional systems by dividing the full-dimensional problem into a set of smaller dimensional ones. The partition procedure, originally based on a dynamical analysis of the Hessian matrix, is here more rigorously achieved through a hierarchical subspace-separation criterion based on Liouville's theorem. Comparisons of calculated vibrational frequencies to exact quantum ones for a set of molecules including benzene show that the new implementation performs better than the original one and that, on average, the loss in accuracy with respect to full-dimensional semiclassical calculations is reduced to only 10 wavenumbers. Furthermore, by investigating the challenging Zundel cation, we also demonstrate that the "divide-and-conquer" approach allows us to deal with complex strongly anharmonic molecular systems. Overall the method very much helps the assignment and physical interpretation of experimental IR spectra by providing accurate vibrational fundamentals and overtones decomposed into reduced dimensionality spectra.

  17. High-voltage pulse generator with inductive energy storage and thyratron

    CERN Document Server

    Vereshchagin, N M

    2002-01-01

    The high-voltage pulse generator with the energy storage on the basis of the single layer solenoid with inductivity of 10-35 mu H is described. The TGI2-500/20 thyratron able of breaking reliably the current with the amplitude of 800-850 A was used as the current breaker. The voltage on the load is formed in two stages. The first stage is characterized by the voltage of 20-25 kV and the growth time of 150-200 m. At the second stage there takes place fast (approx 60 ns) formation of the voltage up 90 kV. The scheme of the charge quenching decreases the instability of the current breaker time

  18. High impulse voltage and current measurement techniques fundamentals, measuring instruments, measuring methods

    CERN Document Server

    Schon, Klaus

    2013-01-01

    Equipment to be installed in electric power-transmission and distribution systems must pass acceptance tests with standardized high-voltage or high-current test impulses which simulate the stress on the insulation caused by external lightning discharges and switching operations in the grid. High impulse voltages and currents are also used in many other fields of science and engineering for various applications. Therefore, precise impulse-measurement techniques are necessary, either to prevent an over- or understressing of the insulation or to guarantee the effectiveness and quality of the application. The book deals with: principal generator circuits for generating high-voltage and high-current impulses measuring systems and their calibration according to IEC 60060 and IEC 62475 methods of estimating uncertainties of measurement mathematical and experimental basis for characterizing the transfer behavior of spatially extended systems used for measuring fast transients. This book is intended for engineers and ...

  19. Low Voltage, High-Q SOI MEMS Varactors for RF Applications

    DEFF Research Database (Denmark)

    Yalcinkaya, Arda Deniz; Jensen, Søren; Hansen, Ole

    2003-01-01

    A micro electromechanical tunable capacitor with a low control voltage, a wide tuning range and high electrical quality factor is presented with detailed characterizations. A 50μm thick single-crystalline silicon layer was etched using deep reactive ion etching (DRIE) for obtaining high-aspect ra......A micro electromechanical tunable capacitor with a low control voltage, a wide tuning range and high electrical quality factor is presented with detailed characterizations. A 50μm thick single-crystalline silicon layer was etched using deep reactive ion etching (DRIE) for obtaining high...

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

    DEFF Research Database (Denmark)

    Sztykiel, Michal

    2011-01-01

    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...... 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...

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

    Science.gov (United States)

    Bearden, Douglas

    2007-01-01

    A proposed multiloop power supply would generate a potential as high as 1.25 kV with rise and fall times rise-time, and fall-time requirements. The power supply would include a preregulator that would be used to program a voltage 1/30 of the desired output voltage. By means of a circuit that would include a pulse-width modulator (PWM), two voltage doublers, and a transformer having two primary and two secondary windings, the preregulator output voltage would be amplified by a factor of 30. A resistor would limit the current by controlling a drive voltage applied to field-effect transistors (FETs) during turn-on of the PWM. Two feedback loops would be used to regulate the high output voltage. A pulse transformer would be used to turn on four FETs to short-circuit output capacitors when the outputs of the PWM were disabled. Application of a 0-to-5-V square to a PWM shut-down pin would cause a 20-to-1,250-V square wave to appear at the output.

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

    Science.gov (United States)

    Grainger, Brandon Michael

    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

  3. Analytical Model of Rain-Wind Induced Vibration of High-Voltage Transmission Line

    Directory of Open Access Journals (Sweden)

    Chao Zhou

    2014-10-01

    Full Text Available Under rainfall conditions, rain-wind induced vibration occurs on high-voltage transmission line occasionally. This phenomenon is caused by raindrops hitting the high-voltage conductor with a certain velocity and suspends to the bottom surface of the high-voltage conductor. By action of wind velocity and high-voltage conductor's motion, some suspended raindrops will be blown away or shaken off. The remaining water may be reformed as upper rivulet and lower rivulet. Like the effect of icing galloping, this type of vibration can cause metal fatigue on fittings and towers, while its mechanism remains unknown. The objective of this paper is to validate an analytical model of rain-wind induced vibration of the high-voltage transmission line and to investigate the effect of wind velocity, rivulet motion, raindrop velocity, and time varying mass on the vibration amplitude. Taking Tuo-chang transmission line as an example, the analytical model is solved by Galerkin weighted residual method and central difference method. The numerical results are in agreement with the experimental data available in the literature. The analytical model enables more comprehensive understanding of the rain-wind induced vibration mechanism.

  4. High Input Voltage Hall Thruster Discharge Converter Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The overall scope of this Phase I/II effort is the development of a high efficiency 15kW (nominal) Hall thruster discharge converter. In Phase I, Busek Co. Inc. will...

  5. Power MOSFET Linearizer of a High-Voltage Power Amplifier for High-Frequency Pulse-Echo Instrumentation

    OpenAIRE

    Hojong Choi; Park Chul Woo; Jung-Yeol Yeom; Changhan Yoon

    2017-01-01

    A power MOSFET linearizer is proposed for a high-voltage power amplifier (HVPA) used in high-frequency pulse-echo instrumentation. The power MOSFET linearizer is composed of a DC bias-controlled series power MOSFET shunt with parallel inductors and capacitors. The proposed scheme is designed to improve the gain deviation characteristics of the HVPA at higher input powers. By controlling the MOSFET bias voltage in the linearizer, the gain reduction into the HVPA was compensated, thereby reduci...

  6. Serially Connected Micro Amorphous Silicon Solar Cells for Compact High-Voltage Sources

    Directory of Open Access Journals (Sweden)

    Jiyoon Nam

    2016-01-01

    Full Text Available We demonstrate a compact amorphous silicon (a-Si solar module to be used as high-voltage power supply. In comparison with the organic solar module, the main advantages of the a-Si solar module are its compatibility with photolithography techniques and relatively high power conversion efficiency. The open circuit voltage of a-Si solar cells can be easily controlled by serially interconnecting a-Si solar cells. Moreover, the a-Si solar module can be easily patterned by photolithography in any desired shapes with high areal densities. Using the photolithographic technique, we fabricate a compact a-Si solar module with noticeable photovoltaic characteristics as compared with the reported values for high-voltage power supplies.

  7. Solid-Body Fuse Developed for High- Voltage Space Power Missions

    Science.gov (United States)

    Dolce, James L.; Baez, Anastacio N.

    2001-01-01

    AEM Incorporated has completed the development, under a NASA Glenn Research Center contract, of a solid-body fuse for high-voltage power systems of satellites and spacecraft systems. High-reliability fuses presently defined by MIL-PRF-23419 do not meet the increased voltage and amperage requirements for the next generation of spacecraft. Solid-body fuses exhibit electrical and mechanical attributes that enable these fuses to perform reliably in the vacuum and high-vibration and -shock environments typically present in spacecraft applications. The construction and screening techniques for solid-body fuses described by MIL-PRF-23419/12 offer an excellent roadmap for the development of high-voltage solid-body fuses.

  8. High power, medium voltage, series resonant converter for DC wind turbines

    DEFF Research Database (Denmark)

    Dincan, Catalin Gabriel; Kjær, Philip Carne; Chen, Yu-Hsing

    2017-01-01

    A new modulation scheme is introduced for a single-phase series-resonant converter, which permits continuous regulation of power from nominal level to zero, in presence of variable input and output dc voltage levels. Rearranging the circuit to locate the resonant LC tank on the rectifier side...... of the high turns-ratio transformer combined with frequency control and phase-shifted inverter modulation keep transformer flux constant from nominal frequency down to DC, always in sub-resonant continuous or discontinuous conduction mode. This overcomes the principal deficit of series-resonant converters......, and the resulting compact and efficient transformer, and soft-commutated inverter, present particular advantages in high-power, high-voltage applications, like DC offshore wind turbines. With transformer excitation frequency in hundreds of Hz range, line-frequency diodes can be employed in the high-voltage...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-03-03

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

  10. Tunable microwave bandpass filter integrated power divider based on the high anisotropy electro-optic nematic liquid crystal.

    Science.gov (United States)

    Liu, Yupeng; Liu, Yang; Li, Haiyan; Jiang, Di; Cao, Weiping; Chen, Hui; Xia, Lei; Xu, Ruimin

    2016-07-01

    A novel, compact microwave tunable bandpass filter integrated power divider, based on the high anisotropy electro-optic nematic liquid crystal, is proposed in this letter. Liquid crystal, as the electro-optic material, is placed between top inverted microstrip line and the metal plate. The proposed structure can realize continuous tunable bandpass response and miniaturization. The proposed design concept is validated by the good performance of simulation results and experimental results. The electro-optic material has shown great potential for microwave application.

  11. Overhead high-voltage lines - a electromagnetic environment restrictions on use areas

    Directory of Open Access Journals (Sweden)

    Jacek Paś

    2014-09-01

    Full Text Available The paper presents the influence of exploitation of high voltage overhead lines in the vicinity of the lands that are intended for built-up areas. Near distribution stations and high voltage overhead lines can be present some physical and chemical factors which under certain conditions and at their high levels will be inconvenient to the environment. The environmental impacts of these factors are complex problems which are analysed both in technical and biological-medical aspects. [b]Keywords[/b]: overhead lines, electric field and magnetic, lines of force

  12. An interleaved structure for a high-voltage planar transformer for a Travelling-wave Tube

    DEFF Research Database (Denmark)

    Zhao, Bin; Wang, Gang; Hurley, William G.

    2016-01-01

    is proposed to reduce leakage inductance and the insulation’s thickness is adjusted to optimize the electric isolation. In addition, the resistance and parasitic capacitance are investigated. With this method, a planar transformer used for a Travelling-Wave Tube Amplifier (TWTA) is designed. Calculations......Fully interleaved structure can significantly reduce leakage inductance in transformers, However, it is hard to apply them into high-voltage applications due to the electric insulation. In this paper, a partially interleaved structure that is suitable for high-voltage high frequency applications...

  13. Design of high voltage DC power supply based on LCC resonant converter

    Science.gov (United States)

    Wang, Z. Q.; Liu, Z. G.; Wang, J. J.; Li, G. F.

    2013-03-01

    The aim of this paper is to design a small size, light weight high frequency high voltage (HFHV) power supply. It presents a comprehensive procedure for designing a high output voltage power supply based on series-parallel (LCC) resonant converter, aiming to realize the soft-switching. Through mathematical calculation based on an extensive of the first harmonic analysis, the paper derives the approach of determining the resonant parameters of the LCC converter. Then, a 35 kV power supply featuring a series-parallel resonant converter topology to compensate the distributed parameter is built to verify the correctness of the theory.

  14. Non-aqueous electrolyte for high voltage rechargeable magnesium batteries

    Science.gov (United States)

    Doe, Robert Ellis; Lane, George Hamilton; Jilek, Robert E; Hwang, Jaehee

    2015-02-10

    An electrolyte for use in electrochemical cells is provided. The properties of the electrolyte include high conductivity, high Coulombic efficiency, and an electrochemical window that can exceed 3.5 V vs. Mg/Mg.sup.+2. The use of the electrolyte promotes the electrochemical deposition and dissolution of Mg without the use of any Grignard reagents, other organometallic materials, tetraphenyl borate, or tetrachloroaluminate derived anions. Other Mg-containing electrolyte systems that are expected to be suitable for use in secondary batteries are also described.

  15. Improvement in the Design of Metal-Ceramic High Voltage Feedthroughs for use in High Energy Particle Accelerators

    CERN Document Server

    Weterings, W

    1999-01-01

    Large high-voltage devices operate in particle accelerators to steer charged particles in the desired direction. Solid and hollow rods of sintered alumina are used as insulating supports and high-voltage feedthroughs to power the electrodes of these electrostatic systems. The performance of the systems is often limited by voltage breakdown along the surface of the ceramic insulator (so-called surface flashover) or discharge between feedthrough and vacuum tank, which can lead to significant disruptions in terms of overall machine efficiency. Available results on the influence of the mechanical preparation, thermal history and particular cleaning techniques on commercially obtainable alumina samples have been studied in order to investigate possibilities for better preparation methodology of the insulating supports. Also the influence of the relative position of the feedthrough inside the vacuum tank on the high-voltage breakdown behaviour has been studied. This paper describes the theoretical and practical bac...

  16. Protein transport through a narrow solid-state nanopore at high voltage: experiments and theory.

    Science.gov (United States)

    Cressiot, Benjamin; Oukhaled, Abdelghani; Patriarche, Gilles; Pastoriza-Gallego, Manuela; Betton, Jean-Michel; Auvray, Loïc; Muthukumar, Murugappan; Bacri, Laurent; Pelta, Juan

    2012-07-24

    We report experimentally the transport of an unfolded protein through a narrow solid-state nanopore of 3 nm diameter as a function of applied voltage. The random coil polypeptide chain is larger than the nanopore. The event frequency dependency of current blockades from 200 to 750 mV follows a van't Hoff-Arrhenius law due to the confinement of the unfolded chain. The protein is an extended conformation inside the pore at high voltage. We observe that the protein dwell time decreases exponentially at medium voltage and is inversely proportional to voltage for higher values. This is consistent with the translocation mechanism where the protein is confined in the pore, creating an entropic barrier, followed by electrophoretic transport. We compare these results to our previous work with a larger pore of 20 nm diameter. Our data suggest that electro-osmotic flow and protein adsorption on the narrowest nanopore wall are minimized. We discuss the experimental data obtained as compared with recent theory for the polyelectrolyte translocation process. This theory reproduces clearly the experimental crossover between the entropic barrier regime with medium voltage and the electrophoretic regime with higher voltage.

  17. Comprehensive behavioral model of dual-gate high voltage JFET and pinch resistor

    Science.gov (United States)

    Banáš, Stanislav; Paňko, Václav; Dobeš, Josef; Hanyš, Petr; Divín, Jan

    2016-09-01

    Many analog technologies operate in large voltage range and therefore include at least one or more high voltage devices built from low doped layers. Such devices exhibit effects not covered by standard compact models, namely pinching (depletion) effects, in high voltage FETs often called quasisaturation. For example, the conventional compact JFET model is insufficient and oversimplified. Its scalability is controlled by the area factor, which only multiplies currents and capacitances but does not take into account existing 3-D effects. Also the optional second independent gate is missing. Therefore, the customized four terminal (4T) model written in Verilog-A (FitzPatrick and Miller, 2007; Sagdeo, 2007) was developed. It converges very well, its simulation speed is comparable with conventional compact models, and contains all required phenomena, including parasitic effects as, for example, impact ionization. This model has universal usage for many types of devices in various high voltage technologies such as stand-alone voltage dependent resistor, pinch resistor, drift area of power FET, part of special high side or start-up devices, and dual-gate JFET.

  18. High voltage performance of a dc photoemission electron gun with centrifugal barrel-polished electrodes

    Science.gov (United States)

    Hernandez-Garcia, C.; Bullard, D.; Hannon, F.; Wang, Y.; Poelker, M.

    2017-09-01

    The design and fabrication of electrodes for direct current (dc) high voltage photoemission electron guns can significantly influence their performance, most notably in terms of maximum achievable bias voltage. Proper electrostatic design of the triple-point junction shield electrode minimizes the risk of electrical breakdown (arcing) along the insulator-cable plug interface, while the electrode shape is designed to maintain interior surface of superconducting radio frequency cavities but implemented here for the first time to polish electrodes for dc high voltage photoguns. The technique reduced polishing time from weeks to hours while providing surface roughness comparable to that obtained with diamond-paste polishing and with unprecedented consistency between different electrode samples. We present electrode design considerations and high voltage conditioning results to 360 kV (˜11 MV/m), comparing barrel-polished electrode performance to that of diamond-paste polished electrodes. Tests were performed using a dc high voltage photogun with an inverted-geometry ceramic insulator design.

  19. Special features of large-size resistors for high-voltage pulsed installations

    Science.gov (United States)

    Minakova, N. N.; Ushakov, V. Ya.

    2017-12-01

    Many structural materials in pulsed power engineering operate under extreme conditions. For example, in high-voltage electrophysical installations among which there are multistage high-voltage pulse generators (HVPG), rigid requirements are imposed on characteristics of solid-state resistors that are more promising in comparison with widely used liquid resistors. Materials of such resistors shall be able to withstand strong electric fields, operate at elevated temperatures, in transformer oil, etc. Effective charge of high-voltage capacitors distributed over the HVPG steps (levels) requires uniform voltage distribution along the steps of the installation that can be obtained using large-size resistors. For such applications, polymer composite materials are considered rather promising. They can work in transformer oil and have small mass in comparison with bulky resistors on inorganic basis. This allows technical solutions already developed and implemented in HVPG with liquid resistors to be employed. This paper is devoted to the solution of some tasks related to the application of filled polymers in high-voltage engineering.

  20. Class D audio amplifiers for high voltage capacitive transducers

    DEFF Research Database (Denmark)

    Nielsen, Dennis

    Audio reproduction systems contains two key components, the amplifier and the loudspeaker. In the last 20 – 30 years the technology of audio amplifiers have performed a fundamental shift of paradigm. Class D audio amplifiers have replaced the linear amplifiers, suffering from the well-known issues...... of high volume, weight, and cost. High efficient class D amplifiers are now widely available offering power densities, that their linear counterparts can not match. Unlike the technology of audio amplifiers, the loudspeaker is still based on the traditional electrodynamic transducer invented by C.W. Rice......-of-the-art for class D audio amplifiers driving the electrodynamic transducer is presented. Chapter 3 gives an introduction to the DEAP transducer as a load in loudspeaker systems. The main purpose being to established the frequency response of the DEAP input impedance, but also investigate the large signal...

  1. Review of the Dynamics of Coalescence and Demulsification by High-Voltage Pulsed Electric Fields

    Directory of Open Access Journals (Sweden)

    Ye Peng

    2016-01-01

    Full Text Available The coalescence of droplets in oil can be implemented rapidly by high-voltage pulse electric field, which is an effective demulsification dehydration technological method. At present, it is widely believed that the main reason of pulse electric field promoting droplets coalescence is the dipole coalescence and oscillation coalescence in pulse electric field, and the optimal coalescence pulse electric field parameters exist. Around the above content, the dynamics of high-voltage pulse electric field promoting the coalescence of emulsified droplets is studied by researchers domestically and abroad. By review, the progress of high-voltage pulse electric field demulsification technology can get a better understanding, which has an effect of throwing a sprat to catch a whale on promoting the industrial application.

  2. Development of High Voltage Power Supply Controls for the STAR Experiment at RHIC

    Science.gov (United States)

    Ruiz, Samuel; Fujita, Jiro

    2017-09-01

    The STAR (Solenoidal Tracker at RHIC) experiment at RHIC (Relativistic Heavy Ion Collider) at Brookhaven National Laboratory studies the collisions of various ion species. The large number of channels to be controlled and monitored require an experiment-wide control system for efficient operation. Additionally, the radiation levels require that the user interfaces of the system are located outside the experimental hall. Each sub-detector system at STAR is controlled by software input/output controllers (IOCs). Aging high voltages systems at STAR are being replaced or are having their software updated to run on new processors. The outdated high voltage controls systems occasionally malfunction or require frequent rebooting of the remote hardware. This project aims to design and implement more effective controls software for the Beam-Beam Counter and the Zero Degree Calorimeter high voltage systems in order to mitigate this problem. This work will also be applicable to other subsystems with similar hardware issues.

  3. A strategy for protection of high voltage systems using resistive superconducting fault current limiters

    Science.gov (United States)

    Schettino, H. J.; Andrade, R. de, Jr.; Polasek, A.; Kottonau, D.; de Sousa, W. T. B.

    2018-01-01

    This work describes an use of a resistive superconducting fault current limiter (R-SFCL) device based on second generation high temperature superconductors tapes (2G tapes), using a thermal-electrical analogy method to represent heat exchanges. The considered SFCL is supposed to be inserted into the coupling point of a new generation unit to a 12 bar CIGRE benchmark transmission system. The strategy is the investigation of the limitation performance in the high voltage grid by connecting the SFCL at medium voltage grid. We evaluated the performance of the SFCL through the analysis of two cases of faults in different points of the system. Results show that a correct design of the SFCL may effectively limit the contribution of fault currents in the high voltage side. Additionally, it was possible to investigate the behavior of the device internal variables such as the temperature of the superconducting layers for the different cases studied.

  4. 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)

    Sulaeman, M. Y.; Widita, R.

    2014-09-01

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

  5. High-Voltage Solid Polymer Batteries for Electric Drive Vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Eitouni, Hany; Yang, Jin; Pratt, Russell; Wang, Xiao; Grape, Ulrik

    2014-09-29

    The purpose of this project was for Seeo to develop a high energy lithium based technology with targets of over 500 Wh/l and 325 Wh/kg. Seeo would leverage the work already achieved with its unique proprietary solid polymer DryLyteTM technology in cells which had a specific energy density of 220 Wh/kg. The development work was focused on establishing a dual electrolyte system, coated cathode particle techniques, various types of additives, and different conductive salts. The program had a duration of three years, with Seeo delivering the final cells at the end of 2014 for evaluation by a DOE laboratory.

  6. Dual design resistor for high voltage conditioning and transmission lines

    Science.gov (United States)

    Siggins, Timothy Lynn [Newport News, VA; Murray, Charles W [Hayes, VA; Walker, Richard L [Norfolk, VA

    2007-01-23

    A dual resistor for eliminating the requirement for two different value resistors. The dual resistor includes a conditioning resistor at a high resistance value and a run resistor at a low resistance value. The run resistor can travel inside the conditioning resistor. The run resistor is capable of being advanced by a drive assembly until an electrical path is completed through the run resistor thereby shorting out the conditioning resistor and allowing the lower resistance run resistor to take over as the current carrier.

  7. System high voltage stress degradation test in various photovoltaic modules and encapsulant sheets

    Science.gov (United States)

    Liu, Han-Chang; Lee, Wen-Kuei; Lin, Mei-Hsiu; Huang, Chung-Teng; Lin, Fu-Ming; Huang, Jen-Loong

    2013-09-01

    The more and more solar power requirements and balance of system (BOS) cost saving issues, photovoltaic power plants have increasing system voltage, in Europe, for example, the system voltage requirements up to 1000 volts to 1500 volts. Solar module reliability expose to the high voltage stress (HVS) need reassessment. It is well-known that HVS can lower the PV power significantly that means potential induced degradation (PID) effect. However, the effects of the PID and other environmental conditions on module performance have not been included in the IEC qualification standards yet. In this paper we review various PV module type, example MG-Si, poly-Si, CIGS module and encapsulant sheets performance suffer high voltage stress effect. To evaluate module durability in the presence of continuous high voltage we used four accelerated tests to qualify the HVS effect. The first one is under room temperature, 100% relative humidity (RH), second method is room temperature and aluminum foil covered the front sheet, the third method is climatic chamber test at 85℃and 85% RH and the last one is the 60°C and 85%RH with -1000V bias applied to active layer, respectively. The I-V characteristics and Electroluminescence (EL) images have been measured after several time steps to quantify the degradation process of each module. Besides the recovery characterization was also investigation.

  8. Design of interleaved multilayer rosen type piezoelectric transformer for high voltage dc/dc applications

    DEFF Research Database (Denmark)

    Rødgaard, Martin Schøler; Andersen, Thomas; Meyer, Kaspar Sinding

    2012-01-01

    Research and development within piezoelectric transformer (PT) based converters are rapidly increasing as the technology is maturing and starts to prove its capabilities. Especially for high voltage and high step-up applications, PT based converters have demonstrated good performance and DC/AC...

  9. Current-voltage curve of a bipolar membrane at high current density

    NARCIS (Netherlands)

    Aritomi, T.; van den Boomgaard, Anthonie; Strathmann, H.

    1996-01-01

    The potential drop across a bipolar membrane was measured as a function of the applied current density. As a result, an inflection point was observed in the obtained current-voltage curve at high current density. This inflection point indicates that at high current densities water supply from

  10. Topics in high voltage pulsed power plasma devices and applications

    Science.gov (United States)

    Chen, Hao

    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

  11. High-voltage integrated linear regulator with current sinking capabilities for portable ultrasound scanners

    DEFF Research Database (Denmark)

    Pausas, Guifre Vendrell; Llimos Muntal, Pere; Jørgensen, Ivan Harald Holger

    2017-01-01

    This paper presents a high-voltage integrated regulator capable of sinking current for driving pulse-triggered level shifters in drivers for ultrasound applications. The regulator utilizes a new topology with a feedback loop and a current sinking circuit to satisfy the requirements of the portable....... The proposed design has been implemented in high-voltage 0.18 μm process whithin an area of 0.11 mm2 and it is suitable for system-on-chip integration due to its low component count and the fully integrated design....

  12. The Applications of Current Comparators in the Measurements on High Voltage Insulation

    Directory of Open Access Journals (Sweden)

    Fei Yi-jun

    2016-01-01

    Full Text Available This paper describes the basic structure of the current comparator used for high voltage insulation measurements. Further applications for the current comparator in high voltage insulation are investigated and developed. A measuring system for the measurement of harmonics in the loss current of water tree aged insulation is described, as well as the principles to measure partial discharges with the current comparator bridge. A new system for the measurement of the DC component in the leakage current of insulation is de1veloped and presented. The results of experiments on XLPE cable insulation are also given.

  13. Comparative Study of Si and SiC MOSFETs for High Voltage Class D Audio Amplifiers

    DEFF Research Database (Denmark)

    Nielsen, Dennis; Knott, Arnold; Andersen, Michael A. E.

    2014-01-01

    Silicon (Si) Metal-Oxide-Semiconductor Field-Effect Transistors (MOSFETs) are traditional utilised in class D audio amplifiers. It has been proposed to replace the traditional inefficient electrodynamic transducer with the electrostatic transducer. This imposes new high voltage requirements...... on the MOSFETs of class D amplifiers, and significantly reduces the selection of suitable MOSFETs. As a consequence it is investigated, if Silicon-Carbide (SiC) MOSFETs could represent a valid alternative. The theory of pulse timing errors are revisited for the application of high voltage and capactive loaded...

  14. Enhancement of Surface Flashover Performance of High Voltage Ceramic Disc Insulators

    Science.gov (United States)

    Subba Reddy, B.; Kumar, Udaya

    2011-02-01

    In this paper, an effort is made to study accurately the field distribution for various types of ceramic insulators used for high-voltage transmission. The surface charge simulation method (SCSM) is employed for the field computation. With the help of SCSM program, a Novel field reduction electrode is designed and developed to reduce the maximum field around the pin region. In order to experimentally analyze the performance of discs with field reduction electrode, special artificial pollution test facility was built and utilized. The experimental results show better surface flashover performance of ceramic insulators used in high-voltage transmission and distribution systems.

  15. Experimental observation of high-voltage, low-current vacuum arcs

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, R.Y.; Puzanov, S.V.; Yashnov, Y.M. [Scientific-Research Inst. Titan, Moscow (Russian Federation)

    1995-12-01

    A poorly explored type of discharge has been investigated in high vacuum (10{sup {minus}7} to 10{sup {minus}6} torr), with a DC high voltage across 0.2- to 0.8-mm gaps. The discharge has been found to be quite different from other widely known types of vacuum and gas discharges by the combination of its voltage-current characteristics (hyperbola-type), source and carriers of current (mostly electrons), and spatial potential distribution (a considerable electric field across the gap and a steep potential fall near the cathode).

  16. Solar array experiments on the SPHINX satellite. [Space Plasma High voltage INteraction eXperiment satellite

    Science.gov (United States)

    Stevens, N. J.

    1974-01-01

    The Space Plasma, High Voltage Interaction Experiment (SPHINX) is the name given to an auxiliary payload satellite scheduled to be launched in January 1974. The principal experiments carried on this satellite are specifically designed to obtain the engineering data on the interaction of high voltage systems with the space plasma. The classes of experiments are solar array segments, insulators, insulators with pin holes and conductors. The satellite is also carrying experiments to obtain flight data on three new solar array configurations: the edge illuminated-multijunction cells, the teflon encased cells, and the violet cells.

  17. Connection for transfer of Liquid Nitrogen from High Voltage to ground potential

    DEFF Research Database (Denmark)

    Rasmussen, Claus Nygaard; Hansen, Finn; Willén, Dag

    2001-01-01

    In order to operate a superconducting cable conductor it must be kept at a cryogenic temperature (e.g. using liquid nitrogen). The superconducting cable conductor is at high voltage and the cooling equipment is kept at ground potential. This requires a thermally insulating connection that is also...... properties and withstand towards high-pressure liquid nitrogen. The length per joint is approximately 900 mm, including a Johnstoncoupling. The joints are tested in a closed liquid nitrogen circuit, with a pressure of up to 10 bars. The rated voltage of the cable system is 36 kV (phase-phase)....

  18. Supplementary High-Input Impedance Voltage-Mode Universal Biquadratic Filter Using DVCCs

    Directory of Open Access Journals (Sweden)

    Jitendra Mohan

    2012-01-01

    Full Text Available To further extend the existing knowledge on voltage-mode universal biquadratic filter, in this paper, a new biquadratic filter circuit with single input and multiple outputs is proposed, employing three differential voltage current conveyors (DVCCs, three resistors, and two grounded capacitors. The proposed circuit realizes all the standard filter functions, that is, high-pass, band-pass, low-pass, notch, and all-pass filters simultaneously. The circuit enjoys the feature of high-input impedance, orthogonal control of resonance angular frequency (o, and quality factor (Q via grounded resistor and the use of grounded capacitors which is ideal for IC implementation.

  19. High-voltage integrated transmitting circuit with differential driving for CMUTs

    DEFF Research Database (Denmark)

    Llimos Muntal, Pere; Larsen, Dennis Øland; Færch, Kjartan Ullitz

    2016-01-01

    In this paper, a high-voltage integrated differential transmitting circuit for capacitive micromachined ultrasonic transducers (CMUTs) used in portable ultrasound scanners is presented. Due to its application, area and power consumption are critical and need to be minimized. The circuitry...... is designed and implemented in AMS 0.35 μ m high-voltage process. Measurements are performed on the fabricated integrated circuit in order to assess its performance. The transmitting circuit consists of a low-voltage control logic, pulse-triggered level shifters and a differential output stage that generates...... conditions is 0.936 mW including the load. The integrated circuits measured prove to be consistent and robust to local process variations by measurements....

  20. High Voltage Coil Current Sensor for DC-DC Converters Employing DDCC

    Directory of Open Access Journals (Sweden)

    M. Drinovsky

    2015-12-01

    Full Text Available Current sensor is an integral part of every switching converter. It is used for over-current protection, regulation and in case of multiphase converters for balancing. A new high voltage current sensor for coil-based current sensing in DC-DC converters is presented. The sensor employs DDCC with high voltage input stage and gain trimming. The circuit has been simulated and implemented in 0.35 um BCD technology as part of a multiphase DC-DC converter where its function has been verified. The circuit is able to sustain common mode voltage on the input up to 40 V, it occupies 0.387*0.345 mm2 and consumes 3.2 mW typically.

  1. Design and validation of a high-voltage levitation circuit for electrostatic accelerometers

    Energy Technology Data Exchange (ETDEWEB)

    Li, G.; Wu, S. C.; Zhou, Z. B.; Bai, Y. Z.; Hu, M.; Luo, J. [MOE Key Laboratory of Fundamental Physical Quantities Measurements, School of Physics, Huazhong University of Science and Technology, Wuhan, Hubei 430074 (China)

    2013-12-15

    A simple high-voltage circuit with a voltage range of 0 to 900 V and an open-loop bandwidth of 11 kHz is realized by using an operational amplifier and a MOSFET combination. The circuit is used for the levitation of a test mass of 71 g, suspended below the top-electrodes with a gap distance of 57 μm, so that the performance of an electrostatic accelerometer can be tested on the ground. The translation noise of the accelerometer, limited by seismic noise, is about 4 × 10{sup −8} m/s{sup 2}/Hz{sup 1/2} at 0.1 Hz, while the high-voltage coupling noise is one-order of magnitude lower.

  2. A Low Voltage High Gain Transformer Noise-Canceling Current Mode Ultrawideband CMOS Low Noise Amplifier

    Science.gov (United States)

    Sun, Jingru; Cao, Xiaodong; Wang, Chunhua; Liu, Jinjiang; Zhao, Manfeng

    2012-03-01

    This paper presents a novel current mode differential UWB LNA. A common-gate stage with transformer realizes a low noise input matching and produces a current gain. The output of the LNA is differential current, which can avoid the current-to-voltage conversion. The LNA is simulated with TSMC 0.18 μm RF CMOS process. Simulation results show that the max noise figure is only 2.65 dB, transconductance gain is larger than 18.7 dB, input reflection coefficient is lower than -9.9 dB, and third order input intercept point is about 2.8 dBm over 3-5 GHz. With a voltage of 0.8 V, the power consumption is 11 mW. A comparison with conventional UWB LNA shows that this LNA has advantages of low voltage, low noise, high gain, and high linearity.

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

    Energy Technology Data Exchange (ETDEWEB)

    1981-04-01

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

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

    Science.gov (United States)

    Domitz, S.; Grier, N. T.

    1974-01-01

    Research work has shown that the interaction of a spacecraft and its high voltage power systems with the space plasma environment can result in harmful power loss and damage to insulators and metal surfaces. Insulator and solar panel tests were performed and flight tests are planned. High voltage power processing equipment was shown to be affected by power loss, and by transients due to plasma interactions. Power loss was determined to be roughly proportional to the square of the voltage and increases approximately as the square root of the area. Kapton, Teflon, and glass were found to be satisfactory insulating materials and it is concluded that for large space power stations should consider the effect of large pinhole currents.

  5. Design and validation of a high-voltage levitation circuit for electrostatic accelerometers

    Science.gov (United States)

    Li, G.; Wu, S. C.; Zhou, Z. B.; Bai, Y. Z.; Hu, M.; Luo, J.

    2013-12-01

    A simple high-voltage circuit with a voltage range of 0 to 900 V and an open-loop bandwidth of 11 kHz is realized by using an operational amplifier and a MOSFET combination. The circuit is used for the levitation of a test mass of 71 g, suspended below the top-electrodes with a gap distance of 57 μm, so that the performance of an electrostatic accelerometer can be tested on the ground. The translation noise of the accelerometer, limited by seismic noise, is about 4 × 10-8 m/s2/Hz1/2 at 0.1 Hz, while the high-voltage coupling noise is one-order of magnitude lower.

  6. Risk assessment of desert pollution on composite high voltage insulators.

    Science.gov (United States)

    El-Shahat, Mohammed; Anis, Hussein

    2014-09-01

    Transmission lines located in the desert are subjected to desert climate, one of whose features is sandstorms. With long accumulation of sand and with the advent of moisture from rain, ambient humidity and dew, a conductive layer forms and the subsequent leakage current may lead to surface discharge, which may shorten the insulator life or lead to flashover thus interrupting the power supply. Strategically erected power lines in the Egyptian Sinai desert are typically subject to such a risk, where sandstorms are known to be common especially in the spring. In view of the very high cost of insulator cleaning operation, composite (silicon rubber) insulators are nominated to replace ceramic insulators on transmission lines in Sinai. This paper examines the flow of leakage current on sand-polluted composite insulators, which in turn enables a risk assessment of insulator failure. The study uses realistic data compiled and reported in an earlier research project about Sinai, which primarily included grain sizes of polluting sand as well as their salinity content. The paper also uses as a case study an ABB-designed composite insulator. A three-dimensional finite element technique is used to simulate the insulator and seek the potential and electric field distribution as well as the resulting leakage current flow on its polluted surface. A novel method is used to derive the probabilistic features of the insulator's leakage current, which in turn enables a risk assessment of insulator failure. This study is expected to help in critically assessing - and thus justifying - the use of this type of insulators in Sinai and similar critical areas.

  7. Risk assessment of desert pollution on composite high voltage insulators

    Directory of Open Access Journals (Sweden)

    Mohammed El-Shahat

    2014-09-01

    Full Text Available Transmission lines located in the desert are subjected to desert climate, one of whose features is sandstorms. With long accumulation of sand and with the advent of moisture from rain, ambient humidity and dew, a conductive layer forms and the subsequent leakage current may lead to surface discharge, which may shorten the insulator life or lead to flashover thus interrupting the power supply. Strategically erected power lines in the Egyptian Sinai desert are typically subject to such a risk, where sandstorms are known to be common especially in the spring. In view of the very high cost of insulator cleaning operation, composite (silicon rubber insulators are nominated to replace ceramic insulators on transmission lines in Sinai. This paper examines the flow of leakage current on sand-polluted composite insulators, which in turn enables a risk assessment of insulator failure. The study uses realistic data compiled and reported in an earlier research project about Sinai, which primarily included grain sizes of polluting sand as well as their salinity content. The paper also uses as a case study an ABB-designed composite insulator. A three-dimensional finite element technique is used to simulate the insulator and seek the potential and electric field distribution as well as the resulting leakage current flow on its polluted surface. A novel method is used to derive the probabilistic features of the insulator’s leakage current, which in turn enables a risk assessment of insulator failure. This study is expected to help in critically assessing – and thus justifying – the use of this type of insulators in Sinai and similar critical areas.

  8. Design of the all solid high-voltage power supply for a gyrotron body

    Energy Technology Data Exchange (ETDEWEB)

    Rao, Yihua [School of Mathematics and Physics, University of South China, Hengyang, 421001 (China); Chen, Wenguang, E-mail: 430000485393@usc.edu.cn [School of Electrical Engineering, University of South China, Hengyang, 421001 (China); Hu, Bo [School of Electrical Engineering, University of South China, Hengyang, 421001 (China); Rao, Jun; Huang, Mei; Kang, Zihua; Feng, Kun [Southwestern Institute of Physics, Chengdu, 610041 (China); Huang, Jiaqi [School of Electrical Engineering, University of South China, Hengyang, 421001 (China)

    2017-04-15

    Highlights: • Completed design of all solid-state high-voltage power supply for gyrotron body on HL-2M ECRH. • Consist of 58 PSM modules and one BUCK module, controlled by DSP system. • Fabricated full voltage 35 kV, 200 mA BPS and tested in dummy load. • The BPS can operate in three modes: single pulse mode, multi-pulse modulation mode and the six-level preset mode. - Abstract: Gyrotron plays an important role in the research of electron cyclotron resonance heating (ECRH) on Tokomak. The high-frequency switched power supply technology and pulse step modulation (PSM) technology are used in the development of the all solid high-voltage body power supply (BPS) for 1 MW/105 GHz Gyrotron on ECRH system. Firstly, the basic structure of the BPS and its control system are introduced. Secondly, the software control algorithm of voltage stabilization and modulate method are developed. Finally, the design is verified by the experiments. The experimental results of the single pulse mode, the multi-pulse modulation mode and the six-level preset mode, are shown. The output voltage of the power supply can reach 35 kV and the current at about 200 mA, which are adjustable in the full range. The maximum modulation frequency can reach 1 kHz and the front edge of the pulse can be adjust from 0 to 3 ms and the accuracy of the output voltage is less than 100 V. The results show that the control method is feasible and can be applied to other high power microwave sources.

  9. Subnanosecond breakdown development in high-voltage pulse discharge: Effect of secondary electron emission

    Science.gov (United States)

    Alexandrov, A. L.; Schweigert, I. V.; Zakrevskiy, Dm. E.; Bokhan, P. A.; Gugin, P.; Lavrukhin, M.

    2017-10-01

    A subnanosecond breakdown in high-voltage pulse discharge may be a key tool for superfast commutation of high power devices. The breakdown in high-voltage open discharge at mid-high pressure in helium was studied in experiment and in kinetic simulations. The kinetic model of electron avalanche development was constructed, based on PIC-MCC simulations, including dynamics of electrons, ions and fast helium atoms, produced by ions scattering. Special attention was paid to electron emission processes from cathode, such as: photoemission by Doppler-shifted resonant photons, produced in excitation processes involving fast atoms; electron emission by ions and fast atoms bombardment of cathode; the secondary electron emission (SEE) by hot electrons from bulk plasma. The simulations show that the fast atoms accumulation is the main reason of emission growth at the early stage of breakdown, but at the final stage, when the voltage on plasma gap diminishes, namely the SEE is responsible for subnanosecond rate of current growth. It was shown that the characteristic time of the current growth can be controlled by the SEE yield. The influence of SEE yield for three types of cathode material (titanium, SiC, and CuAlMg-alloy) was tested. By changing the pulse voltage amplitude and gas pressure, the area of existence of subnanosecond breakdown is identified. It is shown that in discharge with SiC and CuAlMg-alloy cathodes (which have enhanced SEE) the current can increase with a subnanosecond characteristic time value as small as τs = 0.4 ns, for the pulse voltage amplitude of 5÷12 kV. An increase of gas pressure from 15 Torr to 30 Torr essentially decreases the time of of current front growth, whereas the pulse voltage variation weakly affects the results.

  10. Preparation of Power Distribution System for High Penetration of Renewable Energy Part I. Dynamic Voltage Restorer for Voltage Regulation Pat II. Distribution Circuit Modeling and Validation

    Science.gov (United States)

    Khoshkbar Sadigh, Arash

    Part I: Dynamic Voltage Restorer In the present power grids, voltage sags are recognized as a serious threat and a frequently occurring power-quality problem and have costly consequence such as sensitive loads tripping and production loss. Consequently, the demand for high power quality and voltage stability becomes a pressing issue. Dynamic voltage restorer (DVR), as a custom power device, is more effective and direct solutions for "restoring" the quality of voltage at its load-side terminals when the quality of voltage at its source-side terminals is disturbed. In the first part of this thesis, a DVR configuration with no need of bulky dc link capacitor or energy storage is proposed. This fact causes to reduce the size of the DVR and increase the reliability of the circuit. In addition, the proposed DVR topology is based on high-frequency isolation transformer resulting in the size reduction of transformer. The proposed DVR circuit, which is suitable for both low- and medium-voltage applications, is based on dc-ac converters connected in series to split the main dc link between the inputs of dc-ac converters. This feature makes it possible to use modular dc-ac converters and utilize low-voltage components in these converters whenever it is required to use DVR in medium-voltage application. The proposed configuration is tested under different conditions of load power factor and grid voltage harmonic. It has been shown that proposed DVR can compensate the voltage sag effectively and protect the sensitive loads. Following the proposition of the DVR topology, a fundamental voltage amplitude detection method which is applicable in both single/three-phase systems for DVR applications is proposed. The advantages of proposed method include application in distorted power grid with no need of any low-pass filter, precise and reliable detection, simple computation and implementation without using a phased locked loop and lookup table. The proposed method has been verified

  11. ELABORATION OF HIGH-VOLTAGE PULSE INSTALLATIONS AND PROVIDING THEIR OPERATION PROTECTIVE MEASURES

    Directory of Open Access Journals (Sweden)

    А. М. Hashimov

    2016-01-01

    Full Text Available The article presents design engineering methods for the high-voltage pulse installations of technological purpose for disinfection of drinking water, sewage, and edible liquids by high field micro- and nanosecond pulsing exposure. Designing potentialities are considered of the principal elements of the high-voltage part and the discharge circuit of the installations towards assuring the best efficient on-load utilization of the source energy and safe operation of the high-voltage equipment. The study shows that for disinfection of drinking water and sewage it is expedient to apply microsecond pulse actions causing the electrohydraulic effect in aqueous media with associated complex of physical processes (ultraviolet emission, generation of ozone and atomic oxygen, mechanical compression waves, etc. having detrimental effect on life activity of the microorganisms. In case of disinfecting edible liquids it is recommended to use the nanosecond pulses capable of straight permeating the biological cell nucleus, inactivating it. Meanwhile, the nutritive and biological values of the foodstuffs are saved and their organoleptic properties are improved. It is noted that in elaboration process of high-frequency pulse installations special consideration should be given to issues of the operating personnel safety discipline and securing conditions for the entire installation uninterrupted performance. With this objective in view the necessary requirements should be fulfilled on shielding the high- and low-voltage installation parts against high-frequency electromagnetic emissions registered by special differential sensors. Simultaneously, the abatement measures should be applied on the high-voltage equipment operational noise level. The authors offer a technique for noise abatement to admissible levels (lower than 80 dB A by means of coating the inside surface with shielded enclosure of densely-packed abutting sheets of porous electro-acoustic insulating

  12. Efficient kesterite solar cells with high open-circuit voltage for applications in powering distributed devices

    Science.gov (United States)

    Antunez, Priscilla D.; Bishop, Douglas M.; Luo, Yu; Haight, Richard

    2017-11-01

    Simultaneously achieving high voltage and high efficiency in thin-film solar cells is of paramount importance for real-world applications. While solar cells fabricated from the Earth-abundant kesterite absorber Cu2ZnSn(SxSe1-x)4 provide an attractive, non-toxic, energy harvesting solution, their utilization has been constrained by relatively low open-circuit voltages that limit efficiency. Increasing the sulfur content to widen the bandgap boosts the voltage, but usually at the expense of efficiency. Here, we report important progress on this fundamental problem by fabricating solar cells with high sulfur content that exhibit efficiencies up to 11.89% with open-circuit voltages as high as 670 mV. In a multistep process, fully functional solar cells are separated from their growth substrate, and a high-work-function back contact is subsequently deposited. With this approach, we fabricated a series-connected device that produces 5.7 V under 1 Sun illumination and 2 V under low lighting conditions, below 10-3 Suns.

  13. Li-Ion Electrolytes with Improved Safety and Tolerance to High-Voltage Systems

    Science.gov (United States)

    Smart, Marshall C.; Bugga, Ratnakumar V.; Prakash, Surya; Krause, Frederick C.

    2013-01-01

    Given that lithium-ion (Li-ion) technology is the most viable rechargeable energy storage device for near-term applications, effort has been devoted to improving the safety characteristics of this system. Therefore, extensive effort has been devoted to developing nonflammable electrolytes to reduce the flammability of the cells/battery. A number of promising electrolytes have been developed incorporating flame-retardant additives, and have been shown to have good performance in a number of systems. However, these electrolyte formulations did not perform well when utilizing carbonaceous anodes with the high-voltage materials. Thus, further development was required to improve the compatibility. A number of Li-ion battery electrolyte formulations containing a flame-retardant additive [i.e., triphenyl phosphate (TPP)] were developed and demonstrated in high-voltage systems. These electrolytes include: (1) formulations that incorporate varying concentrations of the flame-retardant additive (from 5 to 15%), (2) the use of mono-fluoroethylene carbonate (FEC) as a co-solvent, and (3) the use of LiBOB as an electrolyte additive intended to improve the compatibility with high-voltage systems. Thus, improved safety has been provided without loss of performance in the high-voltage, high-energy system.

  14. Fast switching thyristor applied in nanosecond-pulse high-voltage generator with closed transformer core.

    Science.gov (United States)

    Li, Lee; Bao, Chaobing; Feng, Xibo; Liu, Yunlong; Fochan, Lin

    2013-02-01

    For a compact and reliable nanosecond-pulse high-voltage generator (NPHVG), the specification parameter selection and potential usage of fast controllable state-solid switches have an important bearing on the optimal design. The NPHVG with closed transformer core and fast switching thyristor (FST) was studied in this paper. According to the analysis of T-type circuit, the expressions for the voltages and currents of the primary and secondary windings on the transformer core of NPHVG were deduced, and the theoretical maximum analysis was performed. For NPHVG, the rise-rate of turn-on current (di/dt) across a FST may exceed its transient rating. Both mean and maximum values of di/dt were determined by the leakage inductances of the transformer, and the difference is 1.57 times. The optimum winding ratio is helpful to getting higher voltage output with lower specification FST, especially when the primary and secondary capacitances have been established. The oscillation period analysis can be effectively used to estimate the equivalent leakage inductance. When the core saturation effect was considered, the maximum di/dt estimated from the oscillating period of the primary current is more accurate than one from the oscillating period of the secondary voltage. Although increasing the leakage inductance of NPHVG can decrease di/dt across FST, it may reduce the output peak voltage of the NPHVG.

  15. Development of a Marx-coupled trigger generator with high voltages and low time delay

    Science.gov (United States)

    Hu, Yixiang; Zeng, Jiangtao; Sun, Fengju; Cong, Peitian; Su, Zhaofeng; Yang, Shi; Zhang, Xinjun; Qiu, Ai'ci

    2016-10-01

    Coupled by the Marx of the "JianGuang-I" facility, a high voltage, low time-delay trigger generator was developed. Working principles of this trigger generator and its key issues were described in detail. Structures of this generator were also carefully designed and optimized. Based on the "JianGuang-I" Marx generator, a test stand was established. And a series of experiment tests were carried out to the study performance of this trigger generator. Experiment results show that the output voltage of this trigger generator can be continuously adjusted from 58 kV to 384 kV. The time delay (from the beginning of the Marx-discharging pulse to the time that the output pulse of the trigger generator arises) of this trigger pulse is about 200 ns and its peak time (0%˜100%) is less than 50 ns. Experiment results also indicate that the time-delay jitter of trigger voltages decreases rapidly with the increase in the peak voltage of trigger pulses. When the trigger voltage is higher than 250 kV, the time-delay jitters (the standard deviation) are less than 7.7 ns.

  16. Mechanism of formation of subnanosecond current front in high-voltage pulse open discharge

    Science.gov (United States)

    Schweigert, I. V.; Alexandrov, A. L.; Zakrevsky, Dm. E.; Bokhan, P. A.

    2014-11-01

    The mechanism of subnanosecond current front rise observed previously in the experiment in high-voltage pulse open discharge in helium is studied in kinetic particle-in-cell simulations. The Boltzmann equations for electrons, ions, and fast atoms are solved self-consistently with the Poisson equations for the electrical potential. The partial contributions to the secondary electron emission from the ions, fast atoms, photons, and electrons, bombarding the electrode, are calculated. In simulations, as in the experiment, the discharge glows between two symmetrical cathodes and the anode grid in the midplane at P =6 Torr and the applied voltage of 20 kV. The electron avalanche development is considered for two experimental situations during the last stage of breakdown: (i) with constant voltage and (ii) with decreasing voltage. For case (i), the subnanosecond current front rise is set by photons from the collisional excitation transfer reactions. For the case (ii), the energetic electrons swamp the cathode during voltage drop and provide the secondary electron emission for the subnanosecond current rise, observed in the experiment.

  17. A novel High-Voltage System for a triple GEM detector

    CERN Document Server

    Corradi, Giovanni; Tagnani, Diego; 10.1016/j.nima.2006.10.166

    2007-01-01

    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.

  18. THREE-DIMENSIONAL OBSERVATIONS ON THICK BIOLOGICAL SPECIMENS BY HIGH VOLTAGE ELECTRON MICROSCOPY

    Directory of Open Access Journals (Sweden)

    Tetsuji Nagata

    2011-05-01

    Full Text Available Thick biological specimens prepared as whole mount cultured cells or thick sections from embedded tissues were stained with histochemical reactions, such as thiamine pyrophosphatase, glucose-6-phosphatase, cytochrome oxidase, acid phosphatase, DAB reactions and radioautography, to observe 3-D ultrastructures of cell organelles producing stereo-pairs by high voltage electron microscopy at accerelating voltages of 400-1000 kV. The organelles demonstrated were Golgi apparatus, endoplasmic reticulum, mitochondria, lysosomes, peroxisomes, pinocytotic vesicles and incorporations of radioactive compounds. As the results, those cell organelles were observed 3- dimensionally and the relative relationships between these organelles were demonstrated.

  19. Measurements of gas pressure in voids in epoxy castings for high voltage equipment

    DEFF Research Database (Denmark)

    Larsen, Esben; Henriksen, Mogens; Nielsen, E

    1988-01-01

    An investigation of samples of epoxy each containing one void, which were produced at different pressures, is reported. The samples were of the disk type with the void located in the center. The gas in the voids has a pressure somewhat related to the curing pressure, thereby directly influencing...... the partial-discharge inception voltage. Data show that gas pressure in voids in epoxy castings can be determined by use of an ultrasound test method. A relationship between the void gas pressure and the epoxy curing pressure is also found. This investigation is part of an effort to predict the inception...... voltage of partial discharges in high-voltage epoxy castings from the processing parameters...

  20. Interconnected High-Voltage Pulsed-Power Converters System Design for H− Ion Sources

    CERN Document Server

    Aguglia, D

    2014-01-01

    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 μs 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.

  1. High-voltage boost quasi-Z-source isolated DC/DC converter

    DEFF Research Database (Denmark)

    Siwakoti, Yam P.; Blaabjerg, Frede; Loh, Poh Chiang

    2014-01-01

    A high-voltage gain two-switch quasi-Z-source isolated DC/DC converter has been presented in this study. It consists of a quasi-Z-source network at its input, a push-pull square-wave inverter at its middle, and a voltage-doubler rectifier at its output. When coordinated appropriately, the new...... converter uses less switches, a smaller common duty cycle and less turns for the transformer when compared with existing topologies. Its size and weight are therefore smaller, whereas its efficiency is higher. It is therefore well-suited for applications, where a wide range of voltage gain is required like...... renewable energy systems, DC power supplies found in telecom, aerospace and electric vehicles. To demonstrate the performance of the proposed converter, a 400 V, 500 W prototype has been implemented in the laboratory. Efficiency of the prototype measured is found to vary from 89.0 to 97.4% when its input...

  2. High voltage characteristics of junctionless poly-silicon thin film transistors

    Science.gov (United States)

    Cheng, Ya-Chi; Wu, Yung-Chun; Chen, Hung-Bin; Han, Ming-Hung; Lu, Nan-Heng; Su, Jun-Ji; Chang, Chun-Yen

    2013-09-01

    The breakdown voltage (VBD) and breakdown mechanism of junctionless (JL) poly-Si thin film transistor (TFT) were compared to the conventional inversion-mode (IM) TFT using fabricated devices and 3D quantum-corrected hydrodynamic transport device simulation. The simulated results are correspondent with experimental ones. The analyses of electric field distributions in on-state show that the channel of JL devices can equally share the voltage like a resistor, because there are no junctions formed between channel and source/drain. The JL TFT shows excellent breakdown characteristics; the off-state VBD of 53.4 V is several times larger than VBD of 9.5 V in IM TFT with same device size. JL devices have large potential for high voltage power metal-oxide-semiconductor devices and circuit applications.

  3. High voltage threshold for stable operation in a dc electron gun

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Masahiro, E-mail: masahiro@post.kek.jp [High Energy Accelerator Research Organization (KEK), Oho, Tsukuba, Ibaraki 305-0801 (Japan); Nishimori, Nobuyuki, E-mail: n-nishim@tagen.tohoku.ac.jp [National Institutes for Quantum and Radiological Science and Technology (QST), Tokai, Naka, Ibaraki 319-1195 (Japan)

    2016-07-04

    We report clear observation of a high voltage (HV) threshold for stable operation in a dc electron gun. The HV hold-off time without any discharge is longer than many hours for operation below the threshold, while it is roughly 10 min above the threshold. The HV threshold corresponds to the minimum voltage where discharge ceases. The threshold increases with the number of discharges during HV conditioning of the gun. Above the threshold, the amount of gas desorption per discharge increases linearly with the voltage difference from the threshold. The present experimental observations can be explained by an avalanche discharge model based on the interplay between electron stimulated desorption (ESD) from the anode surface and subsequent secondary electron emission from the cathode by the impact of ionic components of the ESD molecules or atoms.

  4. Measurements and interpretations concerning leakage currents on polluted high voltage insulators

    Science.gov (United States)

    Thalassinakis, E.; Karagiannopoulos, C. G.

    2003-04-01

    This paper presents data that may aid physical interpretation of leakage currents on insulators suffering pollution under real physical conditions. The measurements were performed on the power distribution system on the island of Crete. An on-line recording system has been installed on the insulators of the 150 kV network, in order to monitor the leakage currents on the polluted insulators and investigate the various parameters of the phenomena. It is convincingly shown that in the timeframe of one period of 50 Hz, above a threshold voltage value (smaller than the peak voltage) a non-linear i-v relationship may develop, leading to bistability and non-linear conductance phenomena. The well-established theory regarding leakage currents on high voltage insulators, as well as that concerning dielectrics in strong electric fields, provide the required theoretical basis for the interpretation of the experimental results obtained.

  5. Research of magnetic self-balance used in a repetitive high voltage rectangular waveform pulse adder

    Science.gov (United States)

    Qianyu, ZHOU; Liqing, TONG; Kefu, LIU

    2018-01-01

    Compared with a sinusoidal operation, pulsed operation has more homogeneity and more efficiency in dielectric barrier discharge. In this paper, an improved pulse adder is designed and assembled to create repetitive high voltage rectangular pulses when resistive loads or capacitive loads exist. Beyond the normal pulse adder based on solid-state switches, additional metal–oxide–semiconductor field effect transistors are used in each stage for a faster falling edge. Further, the voltage difference between stages is eliminated by balancing windings. In this paper, we represent our theoretical derivation, software simulations and hardware experiments on magnetic self-balance. The experiments show that the voltage difference between stages is eliminated by balancing windings, which matches the result of simulations with almost identical circuits and parameters.

  6. Experimental study and mathematical modelling of flashover on extra-high voltage insulators covered with ice

    Science.gov (United States)

    Farzaneh-Dehkordi, J.; Zhang, J.; Farzaneh, M.

    2004-12-01

    Using a test method developed at the high-voltage laboratory of the NSERC/Hydro-Quebec/UQAC Industrial Chair on Atmospheric Icing of Power Network Equipment (CIGELE), the relation between the minimum flashover voltage VMF and the insulator dry arcing distance for standard porcelain station post insulators, as typically used in Hydro-Quebec substations, was investigated under icing conditions. The experimental results show that, under wet-grown ice, known as the most dangerous type of ice for power transmission systems, the VMF increases nonlinearly with an increase in insulator length. Based on these results, an improved mathematical model for predicting the critical flashover voltage versus length of ice-covered insulators is presented. This model is helpful for understanding the flashover phenomenon on ice-covered insulators and presents a powerful tool for choosing the proper length of outdoor insulators in cold climate regions. Copyright

  7. High-Voltage Clock Driver for Photon-Counting CCD Characterization

    Science.gov (United States)

    Baker, Robert

    2013-01-01

    A document discusses the CCD97 from e2v technologies as it is being evaluated at Goddard Space Flight Center's Detector Characterization Laboratory (DCL) for possible use in ultra-low background noise space astronomy applications, such as Terrestrial Planet Finder Coronagraph (TPF-C). The CCD97 includes a photoncounting mode where the equivalent output noise is less than one electron. Use of this mode requires a clock signal at a voltage level greater than the level achievable by the existing CCD (charge-coupled-device) electronics. A high-voltage waveform generator has been developed in code 660/601 to support the CCD97 evaluation. The unit generates required clock waveforms at voltage levels from -20 to +50 V. It deals with standard and arbitrary waveforms and supports pixel rates from 50 to 500 kHz. The system is designed to interface with existing Leach CCD electronics.

  8. Design of RF MEMS Switch with High Stability Effect at the Low Actuation Voltage

    Directory of Open Access Journals (Sweden)

    Bandana MISHRA

    2009-12-01

    Full Text Available MEMS switches are one of the most promising future micro-machined products that have attracted numerous research efforts in recent years. This paper presents an innovative design of RF MEMS switch, with low actuation voltage (VT, improved mechanical stability and reduced stiction. The proposed switch is fabricated on a coplanar waveguide (CPW & actuated by electrostatic force. The mechanical and electrical performance of the switch has been tested. The simulation results show that the actuation voltage can be reduced by using serpentine folded spring, and improved mechanical stability and reduced stiction can be achieved by using a hydrophobic material with high Young’s modulus as insulator in between top and bottom electrode. The measured pull-in voltage is 4 V.

  9. Study on using high injection voltage and spiral inflector in the ...

    Indian Academy of Sciences (India)

    Abstract. A feasibility study of using high injection voltage and spiral inflector in the present heavy ion central region of VEC is described. Conditions necessary for waist-to-waist transfer of the ion beam in the hole lens of main magnet have been obtained. The results of orbit studies of a variety of heavy ions indicate that a ...

  10. Page 1 34 C N R Rao meters, high speed samplers and Voltage ...

    Indian Academy of Sciences (India)

    meters, high speed samplers and Voltage standards based on Josephson effects as well as non-Josephson devices such as Superconducting bolometers and SIS mixers are areas where success is likely. Transistor-like devices compatible with oxide superconductors need to be explored vigorously. The new bismuth ...

  11. Using Expert Systems in Evaluation of the State of High Voltage Machine Insulation Systems

    Directory of Open Access Journals (Sweden)

    K. Záliš

    2000-01-01

    Full Text Available Expert systems are used for evaluating the actual state and future behavior of insulating systems of high voltage electrical machines and equipment. Several rule-based expert systems have been developed in cooperation with top diagnostic workplaces in the Czech Republic for this purpose. The IZOLEX expert system evaluates diagnostic measurement data from commonly used offline diagnostic methods for the diagnostic of high voltage insulation of rotating machines, non-rotating machines and insulating oils. The CVEX expert system evaluates the discharge activity on high voltage electrical machines and equipment by means of an off-line measurement. The CVEXON expert system is for evaluating the discharge activity by on-line measurement, and the ALTONEX expert system is the expert system for on-line monitoring of rotating machines. These developed expert systems are also used for educating students (in bachelor, master and post-graduate studies and in courses which are organized for practicing engineers and technicians and for specialists in the electrical power engineering branch. A complex project has recently been set up to evaluate the measurement of partial discharges. Two parallel expert systems for evaluating partial dischatge activity on high voltage electrical machines will work at the same time in this complex evaluating system.

  12. High Order Voltage and Current Harmonic Mitigation Using the Modular Multilevel Converter STATCOM

    NARCIS (Netherlands)

    Kontos, E.; Tsolaridis, Georgios; Teodorescu, Remus; Bauer, P.

    2017-01-01

    Due to the increase of power electronic-based loads, the maintenance of high power quality poses a challenge in modern power systems. To limit the total harmonic distortion in the line voltage and currents at the point of the common coupling (PCC), active power filters are commonly employed. This

  13. High-Voltage DC-DC Converter Topology for PV Energy Utilization - Investigation and Implementation

    DEFF Research Database (Denmark)

    Sanjeevikumar, Padmanaban; Blaabjerg, Frede; Wheeler, Patrick

    2017-01-01

    This paper exploited the utilization of photovoltaic (PV) energy system with high-voltage (HV) output DC-DC converter. Classical boost converters are used for both renewable energy integration and HV applications, but limited by reducing output/efficiency in performance. Moreover, as parasitic el...

  14. Design Comparison of Autonomous High Voltage Driving System for DEAP Actuator

    DEFF Research Database (Denmark)

    Huang, Lina; Pittini, Riccardo; Zhang, Zhe

    2014-01-01

    As a new type of smart material, the Dielectric Electro Active Polymer (DEAP) is introduced in terms of configuration, working principle and potential applications. The design of an autonomous high voltage driving system for DEAP actuator is investigated. The system configuration and the design...

  15. High-Voltage class-D power amplifiers: design and optimization

    NARCIS (Netherlands)

    Ma, H.

    2015-01-01

    ABSTRACT Nowadays transducers are ubiquitous as interfaces between the increasingly digital world and the real physical world. The same holds for the power amplifiers driving them. This thesis focuses on the design and optimization of high-voltage class-D amplifiers, which are used for driving

  16. A miniature high voltage plasma interaction flight experiment - Project MINX. [for measuring solar cell array parasitic current drain

    Science.gov (United States)

    Riley, T. J.; Triner, J. E.; Sater, B. L.; Cohen, D.; Somberg, H.

    1974-01-01

    A miniature high-voltage array was fabricated, incorporating the multi-junction edge illuminated (MJC) cell technique. The array consists of 32 2x2.2 cm MJCs, series connected, capable of 1600 V open circuit at 1 AMO and 1.2 mA short circuit. A solid state, high-voltage relay is connected across each 4-cell subgroup of the array. It was built to test plasma current drain on space systems using high voltage as might occur when a high-voltage solar array is operated from low to synchronous orbit.

  17. Development of a Novel Bidirectional DC/DC Converter Topology with High Voltage Conversion Ratio for Electric Vehicles and DC-Microgrids

    Directory of Open Access Journals (Sweden)

    Ching-Ming Lai

    2016-05-01

    Full Text Available The main objective of this paper was to study a bidirectional direct current to direct current converter (BDC topology with a high voltage conversion ratio for electric vehicle (EV batteries connected to a dc-microgrid system. In this study, an unregulated level converter (ULC cascaded with a two-phase interleaved buck-boost charge-pump converter (IBCPC is introduced to achieve a high conversion ratio with a simpler control circuit. In discharge state, the topology acts as a two-stage voltage-doubler boost converter to achieve high step-up conversion ratio (48 V to 385 V. In charge state, the converter acts as two cascaded voltage-divider buck converters to achieve high voltage step-down conversion ratio (385 V to 48 V. The features, operation principles, steady-state analysis, simulation and experimental results are made to verify the performance of the studied novel BDC. Finally, a 500 W rating prototype system is constructed for verifying the validity of the operation principle. Experimental results show that highest efficiencies of 96% and 95% can be achieved, respectively, in charge and discharge states.

  18. The High Voltage Line Becomes a Power Distributor: A Successful Test in Congo Brazzaville

    Directory of Open Access Journals (Sweden)

    A. Omboua

    2006-03-01

    Full Text Available The high line voltage passes over the head but we don’t have electricity to have our mill functioned, we continue to live without the power! In many developing countries, we have a lot of high lines voltage which cross many regions to supply electricity to the main towns or connect to networks the distanced electric stations.These booked lines for supplying electricity to big towns cross a lot of villages whose people broadly poor hope to be supplied with electricity without a suitable solution. However it seems very deplorable that the power conducted by these lines doesn’t profit to surrounding population. Unfortunately, for these villages, the use of classical stations is too expensive to the power distributors because of high cost of investment and production for these potential scattered consumers with the feeble demand of electricity.This paper presents the original solution, settled in 2002 in one of the village located in Congo Brazzaville, and continues to function correctly. It is a new power transformer with one phase called PLX which is connected on one phase of the high line voltage 220kV and which produces extraordinary the low voltage 230 V directly useful by the rural population. This conceived sample for the rural electrification has been dimensioned for the power of 50kVA. A cheap and resistant advice! It requires a large popularization and mainly in sub saharian Africa that has got many opportunities. Outside the role of conduction of the power, the high line voltage distributes it

  19. Process engineering of high voltage alginate encapsulation of mesenchymal stem cells.

    Science.gov (United States)

    Gryshkov, Oleksandr; Pogozhykh, Denys; Zernetsch, Holger; Hofmann, Nicola; Mueller, Thomas; Glasmacher, Birgit

    2014-03-01

    Encapsulation of stem cells in alginate beads is promising as a sophisticated drug delivery system in treatment of a wide range of acute and chronic diseases. However, common use of air flow encapsulation of cells in alginate beads fails to produce beads with narrow size distribution, intact spherical structure and controllable sizes that can be scaled up. Here we show that high voltage encapsulation (≥ 15 kV) can be used to reproducibly generate spherical alginate beads (200-400 μm) with narrow size distribution (± 5-7%) in a controlled manner under optimized process parameters. Flow rate of alginate solution ranged from 0.5 to 10 ml/h allowed producing alginate beads with a size of 320 and 350 μm respectively, suggesting that this approach can be scaled up. Moreover, we found that applied voltages (15-25 kV) did not alter the viability and proliferation of encapsulated mesenchymal stem cells post-encapsulation and cryopreservation as compared to air flow. We are the first who employed a comparative analysis of electro-spraying and air flow encapsulation to study the effect of high voltage on alginate encapsulated cells. This report provides background in application of high voltage to encapsulate living cells for further medical purposes. Long-term comparison and work on alginate-cell interaction within these structures will be forthcoming. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. INVESTIGATION OF LOSSES IN INSULATION OF HIGH-VOLTAGE CABLES WITH XLPE INSULATION

    Directory of Open Access Journals (Sweden)

    L.A. Shchebeniuk

    2016-09-01

    Full Text Available In this paper the authors calculate the losses in insulation system cable with XLPE-polyethylene as a solid dielectric insulation and with semiconductor polyethylene used as a conductor screen and a insulation screen. The paper is devoted to the investigation of losses in the insulation system of high- voltage XLPE-cables. The line of XLPE-cables in group running horizontally, provided that the cables are of equal diameter and emit equal losses. It is limited to the following: the air flow around the cables may be necessary restricted by proximity to next cables. The dielectric losses are voltage depended and related to the insulation system materials being used. All current in this insulation system are complex quantities containing both real (Re(I and imaginary (Im(I parts. Values of the loss factor of the insulation system at power frequency tgd are given astgd = Re(I/Im(I. It was proposed the quantities criterion of the loss factor of the insulation system to high voltage XLPE-cables. The work is devoted to creation of a method for calculation of the current rating of high-voltage cables in conditions function.

  1. Evaluation of Niobium as Candidate Electrode Material for DC High Voltage Photoelectron Guns

    Science.gov (United States)

    BastaniNejad, M.; Mohamed, Abdullah; Elmustafa, A. A.; Adderley, P.; Clark, J.; Covert, S.; Hansknecht, J.; Hernandez-Garcia, C.; Poelker, M.; Mammei, R.; hide

    2012-01-01

    The field emission characteristics of niobium electrodes were compared to those of stainless steel electrodes using a DC high voltage field emission test apparatus. A total of eight electrodes were evaluated: two 304 stainless steel electrodes polished to mirror-like finish with diamond grit and six niobium electrodes (two single-crystal, two large-grain, and two fine-grain) that were chemically polished using a buffered-chemical acid solution. Upon the first application of high voltage, the best large-grain and single-crystal niobium electrodes performed better than the best stainless steel electrodes, exhibiting less field emission at comparable voltage and field strength. In all cases, field emission from electrodes (stainless steel and/or niobium) could be significantly reduced and sometimes completely eliminated, by introducing krypton gas into the vacuum chamber while the electrode was biased at high voltage. Of all the electrodes tested, a large-grain niobium electrode performed the best, exhibiting no measurable field emission (< 10 pA) at 225 kV with 20 mm cathode/anode gap, corresponding to a field strength of 18:7 MV/m.

  2. Evaluation of niobium as candidate electrode material for dc high voltage photoelectron guns

    Directory of Open Access Journals (Sweden)

    M. BastaniNejad

    2012-08-01

    Full Text Available The field emission characteristics of niobium electrodes were compared to those of stainless steel electrodes using a DC high voltage field emission test apparatus. A total of eight electrodes were evaluated: two 304 stainless steel electrodes polished to mirrorlike finish with diamond grit and six niobium electrodes (two single-crystal, two large-grain, and two fine-grain that were chemically polished using a buffered-chemical acid solution. Upon the first application of high voltage, the best large-grain and single-crystal niobium electrodes performed better than the best stainless steel electrodes, exhibiting less field emission at comparable voltage and field strength. In all cases, field emission from electrodes (stainless steel and/or niobium could be significantly reduced and sometimes completely eliminated, by introducing krypton gas into the vacuum chamber while the electrode was biased at high voltage. Of all the electrodes tested, a large-grain niobium electrode performed the best, exhibiting no measurable field emission (<10  pA at 225 kV with 20 mm cathode/anode gap, corresponding to a field strength of 18.7  MV/m.

  3. Effect of high solenoidal magnetic fields on breakdown voltages of high vacuum 805 MHz cavities

    Energy Technology Data Exchange (ETDEWEB)

    Moretti, A.; Bross, A.; Geer, S.; Qian, Z.; /Fermilab; Norem, J.; /Argonne; Li, D.; Zisman, M.; /LBL, Berkeley; Torun, Y.; /IIT, Chicago; Rimmer, R.; /Jefferson Lab; Errede,; /Illinois U., Urbana

    2005-10-01

    There is an on going international collaboration studying the feasibility and cost of building a muon collider or neutrino factory [1,2]. An important aspect of this study is the full understanding of ionization cooling of muons by many orders of magnitude for the collider case. An important muon ionization cooling experiment, MICE [3], has been proposed to demonstrate and validate the technology that could be used for cooling. Ionization cooling is accomplished by passing a high-emittance muon beam alternately through regions of low Z material, such as liquid hydrogen, and very high accelerating RF Cavities within a multi-Tesla solenoidal field. To determine the effect of very large solenoidal magnetic fields on the generation of dark current, x-rays and on the breakdown voltage gradients of vacuum RF cavities, a test facility has been established at Fermilab in Lab G. This facility consists of a 12 MW 805 MHz RF station and a large warm bore 5 T solenoidal superconducting magnet containing a pill box type cavity with thin removable window apertures. This system allows dark current and breakdown studies of different window configurations and materials. The results of this study will be presented. The study has shown that the peak achievable accelerating gradient is reduced by a factor greater than 2 when solenoidal field of greater than 2 T are applied to the cavity.

  4. High-Efficiency Isolated Boost DCDC Converter for High-Power Low-Voltage Fuel-Cell Applications

    DEFF Research Database (Denmark)

    Nymand, Morten; Andersen, Michael A. E.

    2010-01-01

    of the primary-switch voltage rating can thus be avoided, significantly reducing switch-conduction losses. Finally, silicon carbide rectifying diodes allow fast diode turn-off, further reducing losses. Detailed test results from a 1.5-kW full-bridge boost dc-dc converter verify the theoretical analysis......A new design approach achieving very high conversion efficiency in low-voltage high-power isolated boost dc-dc converters is presented. The transformer eddy-current and proximity effects are analyzed, demonstrating that an extensive interleaving of primary and secondary windings is needed to avoid...... and demonstrate very high conversion efficiency. The efficiency at minimum input voltage and maximum power is 96.8%. The maximum efficiency of the proposed converter is 98%....

  5. Breakdown in helium in high-voltage open discharge with subnanosecond current front rise

    Energy Technology Data Exchange (ETDEWEB)

    Schweigert, I. V., E-mail: ischweig@itam.nsc.ru; Alexandrov, A. L. [Russian Academy of Sciences, Khristianovich Institute of Theoretical and Applied Mechanics, Siberian Branch (Russian Federation); Bokhan, P. A.; Zakrevskiy, Dm. E. [Russian Academy of Sciences, Rzhanov Institute of Semiconductors Physics, Siberian Branch (Russian Federation)

    2016-07-15

    Investigations of high-voltage open discharge in helium have shown a possibility of generation of current pulses with subnanosecond front rise, due to ultra-fast breakdown development. The open discharge is ignited between two planar cathodes with mesh anode in the middle between them. For gas pressure 6 Torr and 20 kV applied voltage, the rate of current rise reaches 500 A/(cm{sup 2} ns) for current density 200 A/cm{sup 2} and more. The time of breakdown development was measured for different helium pressures and a kinetic model of breakdown in open discharge is presented, based on elementary reactions for electrons, ions and fast atoms. The model also includes various cathode emission processes due to cathode bombardment by ions, fast atoms, electrons and photons of resonant radiation with Doppler shift of frequency. It is shown, that the dominating emission processes depend on the evolution of the discharge voltage during the breakdown. In the simulations, two cases of voltage behavior were considered: (i) the voltage is kept constant during the breakdown; (ii) the voltage is reduced with the growth of current. For the first case, the exponentially growing current is maintained due to photoemission by the resonant photons with Doppler-shifted frequency. For the second case, the dominating factor of current growth is the secondary electron emission. In both cases, the subnanosecond rise of discharge current was obtained. Also the effect of gas pressure on breakdown development was considered. It was found that for 20 Torr gas pressure the time of current rise decreases to 0.1 ns, which is in agreement with experimental data.

  6. Synthesis of crystalline CoFe{sub x} nanowire arrays through high voltage pulsed electrochemical deposition

    Energy Technology Data Exchange (ETDEWEB)

    Ji, Renlong; Cao, Chuanbao, E-mail: cbcao@bit.edu.cn; Chen, Zhuo; Yao, Ruimin

    2014-08-01

    A high voltage pulsed electrochemical deposition (50 Hz, −50 V) technique was used to synthesize CoFe{sub x} (x=1.57, 2.02) nanowire arrays in anodic aluminum oxide templates. The nanowire arrays (NA) are different in diameter (NA A, 40 nm; NA B, 50 nm), center-to-center distance (NA A, 60 nm; NA B, 100 nm) and length (NA A, 4 μm; NA B, 8 μm). Microstructural characterization shows high crystallinity of the formed nanowires. The magnetic measurements indicate that the nanowire arrays possess uniaxial anisotropy with the easy magnetization axis along the nanowire. When magnetic field is applied in this direction, the coercivities of both nanowire arrays are larger than 1600 Oe. The shape difference between two magnetization hysteresis loops is due to dipolar magnetostatic interaction, and analytical calculation is performed to interpret the magnetic properties as a function of the wire geometry. The results suggest that during high voltage electrodeposition, reduced atoms are highly energetic and the crystallographic growth planes can be (110), (111) and (211). - Highlights: • High voltage pulsed electrochemical deposition technique (−50 V) is employed. • Nanowire arrays exhibit high coercivities (>1600 Oe). • Crystallites with high crystallinity and different growth orientations are discovered in the nanowires. • The high-energetic reduced atoms can stack on the usually reported (110) plane together with (111) or (211) plane. • The shape difference between two magnetization hysteresis loops is due to dipolar magnetostatic interaction.

  7. A Novel High-Frequency Voltage Standing-Wave Ratio-Based Grounding Electrode Line Fault Supervision in Ultra-High Voltage DC Transmission Systems

    Directory of Open Access Journals (Sweden)

    Yufei Teng

    2017-03-01

    Full Text Available In order to improve the fault monitoring performance of grounding electrode lines in ultra-high voltage DC (UHVDC transmission systems, a novel fault monitoring approach based on the high-frequency voltage standing-wave ratio (VSWR is proposed in this paper. The VSWR is defined considering a lossless transmission line, and the characteristics of the VSWR under different conditions are analyzed. It is shown that the VSWR equals 1 when the terminal resistance completely matches the characteristic impedance of the line, and when a short circuit fault occurs on the grounding electrode line, the VSWR will be greater than 1. The VSWR will approach positive infinity under metallic earth fault conditions, whereas the VSWR in non-metallic earth faults will be smaller. Based on these analytical results, a fault supervision criterion is formulated. The effectiveness of the proposed VSWR-based fault supervision technique is verified with a typical UHVDC project established in Power Systems Computer Aided Design/Electromagnetic Transients including DC(PSCAD/EMTDC. Simulation results indicate that the proposed strategy can reliably identify the grounding electrode line fault and has strong anti-fault resistance capability.

  8. An improved partially interleaved transformer structure for high-voltage high-frequency multiple-output applications

    DEFF Research Database (Denmark)

    Zhao, Bin; Ouyang, Ziwei; Andersen, Michael A. E.

    2017-01-01

    . The proposed structure features lower leakage inductance, smaller AC capacitance and lower rate of AC-DC resistance, which is suitable for high-frequency high-efficiency applications. A planar transformer with the proposed structure was built and tested in an LCLC resonant converter, where the input voltage...

  9. Study on the lightning impulse breakdown characteristics of gaseous insulation media for the design of a high voltage superconducting apparatus

    Science.gov (United States)

    Kang, H.; Na, J. B.; Ahn, M. C.; Bae, D. K.; Kim, Y. H.; Ko, T. K.

    2010-11-01

    In general, the current leads of high voltage superconducting apparatuses cooled by liquid nitrogen are exposed to gaseous insulation media. Therefore, the investigation on the electrical breakdown characteristics of gaseous insulation media should be performed to develop electrically reliable high voltage superconducting power apparatuses. In this study, the lightning impulse breakdown tests on gaseous insulation media are conducted by using sphere-to-plane electrode systems made of stainless steel. Also, the lightning impulse breakdown voltage tests on gaseous insulation media according to various pressures are performed. The experimental results show that the electrical breakdown characteristics under lightning impulse voltage are affected by the gap length between electrode systems, the size of electrodes, and the field utilization factors. From these results, the electrical insulation design criteria to estimate the electrical breakdown voltage are established. The results are expected to be applicable to the design of current leads for high voltage superconducting apparatuses.

  10. A Fiber-Optic Sensor for Acoustic Emission Detection in a High Voltage Cable System

    Directory of Open Access Journals (Sweden)

    Tongzhi Zhang

    2016-11-01

    Full Text Available We have proposed and demonstrated a Michelson interferometer-based fiber sensor for detecting acoustic emission generated from the partial discharge (PD of the accessories of a high-voltage cable system. The developed sensor head is integrated with a compact and relatively high sensitivity cylindrical elastomer. Such a sensor has a broadband frequency response and a relatively high sensitivity in a harsh environment under a high-voltage electric field. The design and fabrication of the sensor head integrated with the cylindrical elastomer is described, and a series of experiments was conducted to evaluate the sensing performance. The experimental results demonstrate that the sensitivity of our developed sensor for acoustic detection of partial discharges is 1.7 rad / ( m ⋅ Pa . A high frequency response up to 150 kHz is achieved. Moreover, the relatively high sensitivity for the detection of PD is verified in both the laboratory environment and gas insulated switchgear. The obtained results show the great potential application of a Michelson interferometer-based fiber sensor integrated with a cylindrical elastomer for in-situ monitoring high-voltage cable accessories for safety work.

  11. A Fiber-Optic Sensor for Acoustic Emission Detection in a High Voltage Cable System

    Science.gov (United States)

    Zhang, Tongzhi; Pang, Fufei; Liu, Huanhuan; Cheng, Jiajing; Lv, Longbao; Zhang, Xiaobei; Chen, Na; Wang, Tingyun

    2016-01-01

    We have proposed and demonstrated a Michelson interferometer-based fiber sensor for detecting acoustic emission generated from the partial discharge (PD) of the accessories of a high-voltage cable system. The developed sensor head is integrated with a compact and relatively high sensitivity cylindrical elastomer. Such a sensor has a broadband frequency response and a relatively high sensitivity in a harsh environment under a high-voltage electric field. The design and fabrication of the sensor head integrated with the cylindrical elastomer is described, and a series of experiments was conducted to evaluate the sensing performance. The experimental results demonstrate that the sensitivity of our developed sensor for acoustic detection of partial discharges is 1.7 rad/(m⋅Pa). A high frequency response up to 150 kHz is achieved. Moreover, the relatively high sensitivity for the detection of PD is verified in both the laboratory environment and gas insulated switchgear. The obtained results show the great potential application of a Michelson interferometer-based fiber sensor integrated with a cylindrical elastomer for in-situ monitoring high-voltage cable accessories for safety work. PMID:27916900

  12. Solar powered high voltage energization for vehicular exhaust cleaning: A step towards possible retrofitting in vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Rajanikanth, B.S.; Mohapatro, Sankarsan [High Voltage Lab, Indian Institute of Science, Bangalore-560012 (India); Umanand, L. [CEDT, Indian Institute of Science, Bangalore-560012 (India)

    2009-03-15

    This paper proposes a novel way of generating high voltage for electric discharge plasma in controlling NO{sub x} emission in diesel engine exhaust. A solar powered high frequency electric discharge topology has been suggested that will improve the size and specific energy density required when compared to the traditional repetitive pulse or 50 Hz AC energization. This methodology has been designed, fabricated and experimentally verified by conducting studies on real diesel engine exhaust. (author)

  13. Rad-Hard, Miniaturized, Scalable, High-Voltage Switching Module for Power Applications Rad-Hard, Miniaturized

    Science.gov (United States)

    Adell, Philippe C.; Mojarradi, Mohammad; DelCastillo, Linda Y.; Vo, Tuan A.

    2011-01-01

    A paper discusses the successful development of a miniaturized radiation hardened high-voltage switching module operating at 2.5 kV suitable for space application. The high-voltage architecture was designed, fabricated, and tested using a commercial process that uses a unique combination of 0.25 micrometer CMOS (complementary metal oxide semiconductor) transistors and high-voltage lateral DMOS (diffusion metal oxide semiconductor) device with high breakdown voltage (greater than 650 V). The high-voltage requirements are achieved by stacking a number of DMOS devices within one module, while two modules can be placed in series to achieve higher voltages. Besides the high-voltage requirements, a second generation prototype is currently being developed to provide improved switching capabilities (rise time and fall time for full range of target voltages and currents), the ability to scale the output voltage to a desired value with good accuracy (few percent) up to 10 kV, to cover a wide range of high-voltage applications. In addition, to ensure miniaturization, long life, and high reliability, the assemblies will require intensive high-voltage electrostatic modeling (optimized E-field distribution throughout the module) to complete the proposed packaging approach and test the applicability of using advanced materials in a space-like environment (temperature and pressure) to help prevent potential arcing and corona due to high field regions. Finally, a single-event effect evaluation would have to be performed and single-event mitigation methods implemented at the design and system level or developed to ensure complete radiation hardness of the module.

  14. Promise and Challenges of High-Voltage SiC Bipolar Power Devices

    Directory of Open Access Journals (Sweden)

    Tsunenobu Kimoto

    2016-11-01

    Full Text Available Although various silicon carbide (SiC power devices with very high blocking voltages over 10 kV have been demonstrated, basic issues associated with the device operation are still not well understood. In this paper, the promise and limitations of high-voltage SiC bipolar devices are presented, taking account of the injection-level dependence of carrier lifetimes. It is shown that the major limitation of SiC bipolar devices originates from band-to-band recombination, which becomes significant at a high-injection level. A trial of unipolar/bipolar hybrid operation to reduce power loss is introduced, and an 11 kV SiC hybrid (merged pin-Schottky diodes is experimentally demonstrated. The fabricated diodes with an epitaxial anode exhibit much better forward characteristics than diodes with an implanted anode. The temperature dependence of forward characteristics is discussed.

  15. Carbon nanotubes as an efficient hole collector for high voltage methylammonium lead bromide perovskite solar cells.

    Science.gov (United States)

    Li, Zhen; Boix, Pablo P; Xing, Guichuan; Fu, Kunwu; Kulkarni, Sneha A; Batabyal, Sudip K; Xu, Wenjing; Cao, Anyuan; Sum, Tze Chien; Mathews, Nripan; Wong, Lydia Helena

    2016-03-28

    A high open circuit voltage (V(OC)) close to 1.4 V under AM 1.5, 100 mW cm(-2) conditions is achieved when carbon nanotubes (CNTs) are used as a hole conductor in methyl ammonium lead bromide (MAPbBr3) perovskite solar cells. Time-resolved photoluminescence and impedance spectroscopy investigations suggest that the observed high V(OC) is a result of the better charge extraction and lower recombination of the CNT hole conductor. Tandem solar cells with all perovskite absorbers are demonstrated with a MAPbBr3/CNT top cell and a MAPbI3 bottom cell, achieving a V(OC) of 2.24 V in series connection. The semitransparent and high voltage MAPbBr3/CNT solar cells show great potential for applications in solar cell windows, tandem solar cells and solar driven water splitting.

  16. High-Voltage Power Supply With Fast Rise and Fall Times

    Science.gov (United States)

    Bearden, Douglas B.; Acker, Richard M.; Kapuslka, Robert E.

    2007-01-01

    A special-purpose high-voltage power supply can be electronically switched on and off with fast rise and fall times, respectively. The output potential is programmable from 20 to 1,250 V. An output current of 50 A can be sustained at 1,250 V. The power supply was designed specifically for electronically shuttering a microchannel plate in an x-ray detector that must operate with exposure times as short as 1 ms. The basic design of the power supply is also adaptable to other applications in which there are requirements for rapid slewing of high voltages. The power-supply circuitry (see figure) includes a preregulator, which is used to program the output at 1/30 of the desired output potential. After the desired voltage has been set, the outputs of a pulse width modulator (PWM) are enabled and used to amplify the preregulator output potential by 30. The amplification is achieved by use of two voltage doublers with a transformer that has two primary and two secondary windings. A resistor is used to limit the current by controlling the drive voltage of two field-effect transistors (FETs) during turn-on of the PWM. A pulse transformer is used to turn on four FETs to short-circuit four output capacitors when the outputs of the PWM have been disabled. The most notable aspects of the performance of the power supply are a rise time of only 80 s and a fall time of only 60 s at a load current of 50 A or less. Another notable aspect is that the application of a 0-to-5-V square wave to a shutdown pin of the PWM causes the production of a 0-to-1,250-V square wave at the output terminals.

  17. Porous and mesh alumina formed by anodization of high purity aluminum films at low anodizing voltage

    Energy Technology Data Exchange (ETDEWEB)

    Abd-Elnaiem, Alaa M., E-mail: alaa.abd-elnaiem@science.au.edu.eg [KACST-Intel Consortium Center of Excellence in Nano-manufacturing Applications (CENA), Riyadh (Saudi Arabia); Physics Department, Faculty of Science, Assiut University, Assiut 71516 (Egypt); Mebed, A.M. [Physics Department, Faculty of Science, Assiut University, Assiut 71516 (Egypt); Department of Physics, Faculty of Science, Al-Jouf University, Sakaka 2014 (Saudi Arabia); El-Said, Waleed Ahmed [Department of Chemistry, Faculty of Science, Assiut University, Assiut 71516 (Egypt); Abdel-Rahim, M.A. [Physics Department, Faculty of Science, Assiut University, Assiut 71516 (Egypt)

    2014-11-03

    Electrochemical oxidation of high-purity aluminum (Al) films under low anodizing voltages (1–10) V has been conducted to obtain anodic aluminum oxide (AAO) with ultra-small pore size and inter-pore distance. Different structures of AAO have been obtained e.g. nanoporous and mesh structures. Highly regular pore arrays with small pore size and inter-pore distance have been formed in oxalic or sulfuric acids at different temperatures (22–50 °C). It is found that the pore diameter, inter-pore distance and the barrier layer thickness are independent of the anodizing parameters, which is very different from the rules of general AAO fabrication. The brand formation mechanism has been revealed by the scanning electron microscope study. Regular nanopores are formed under 10 V at the beginning of the anodization and then serve as a template layer dominating the formation of ultra-small nanopores. Anodization that is performed at voltages less than 5 V leads to mesh structured alumina. In addition, we have introduced a simple one-pot synthesis method to develop thin walls of oxide containing lithium (Li) ions that could be used for battery application based on anodization of Al films in a supersaturated mixture of lithium phosphate and phosphoric acid as matrix for Li-composite electrolyte. - Highlights: • We develop anodic aluminum oxide (AAO) with small pore size and inter-pore distance. • Applying low anodizing voltages onto aluminum film leads to form mesh structures. • The value of anodizing voltage (1–10 V) has no effect on pore size or inter-pore distance. • Applying anodizing voltage less than 5 V leads to mesh structured AAO. • AAO can be used as a matrix for Li-composite electrolytes.

  18. Impact-Based Electromagnetic Energy Harvester with High Output Voltage under Low-Level Excitations

    Directory of Open Access Journals (Sweden)

    Qian Luo

    2017-11-01

    Full Text Available To expand the applications of vibrational energy harvesters (VEHs as power sources of wireless sensor nodes, it is of significance to improve the scavenging efficiency for the broadband, low-frequency, and low-level vibrational energy. The output voltages of electromagnetic vibrational energy harvesters (EMVEHs are usually low, which complicates the power management circuit by an indispensable voltage boosting element. To this end, an impact-based non-resonant EMVEH mainly composed of an outer frame and an inner frame on rollers is proposed. Numerical simulations based on a mathematical model of the harvester are conducted to analyze the effects of structural parameters on the output performance. Under base excitation of 0.1 and 0.3 (where g is the gravitational acceleration, 1 g = 9.8 m · s − 2 , the experimental maximum root mean square voltages of a harvester prototype across a resistor of 11 kΩ are as high as 7.6 and 16.5 V at 6.0 and 8.5 Hz, respectively, with the maximum output powers of 5.3 and 24.8 mW, or the power densities of 54.6 and 256 μW cm−3. By using a management circuit without a voltage boosting element, a wireless sensor node driven by the prototype can measure and transmit the temperature and humidity every 20 s under base excitation of 0.1 g at 5.4 Hz.

  19. Locational Pricing to Mitigate Voltage Problems Caused by High PV Penetration

    Directory of Open Access Journals (Sweden)

    Sam Weckx

    2015-05-01

    Full Text Available In this paper, a locational marginal pricing algorithm is proposed to control the voltage in unbalanced distribution grids. The increasing amount of photovoltaic (PV generation installed in the grid may cause the voltage to rise to unacceptable levels during periods of low consumption. With locational prices, the distribution system operator can steer the reactive power consumption and active power curtailment of PV panels to guarantee a safe network operation. Flexible loads also respond to these prices. A distributed gradient algorithm automatically defines the locational prices that avoid voltage problems. Using these locational prices results in a minimum cost for the distribution operator to control the voltage. Locational prices can differ between the three phases in unbalanced grids. This is caused by a higher consumption or production in one of the phases compared to the other phases and provides the opportunity for arbitrage, where power is transferred from a phase with a low price to a phase with a high price. The effect of arbitrage is analyzed. The proposed algorithm is applied to an existing three-phase four-wire radial grid. Several simulations with realistic data are performed.

  20. Push-pull with recovery stage high-voltage DC converter for PV solar generator

    Science.gov (United States)

    Nguyen, The Vinh; Aillerie, Michel; Petit, Pierre; Pham, Hong Thang; Vo, Thành Vinh

    2017-02-01

    A lot of systems are basically developed on DC-DC or DC-AC converters including electronic switches such as MOS or bipolar transistors. The limits of efficiency are quickly reached when high output voltages and high input currents are needed. This work presents a new high-efficiency-high-step-up based on push-pull DC-DC converter integrating recovery stages dedicated to smart HVDC distributed architecture in PV solar energy production systems. Appropriate duty cycle ratio assumes that the recovery stage work with parallel charge and discharge to achieve high step-up voltage gain. Besides, the voltage stress on the main switch is reduced with a passive clamp circuit and thus, low on-state resistance Rdson of the main switch can be adopted to reduce conduction losses. Thus, the efficiency of a basic DC-HVDC converter dedicated to renewable energy production can be further improved with such topology. A prototype converter is developed, and experimentally tested for validation.

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

    Science.gov (United States)

    Asgarifar, Hajarossadat; Oloyede, Adekunle; Zare, Firuz

    2014-04-01

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

  2. 30 CFR 75.704 - Grounding frames of stationary high-voltage equipment receiving power from ungrounded delta systems.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Grounding frames of stationary high-voltage equipment receiving power from ungrounded delta systems. 75.704 Section 75.704 Mineral Resources MINE SAFETY...-UNDERGROUND COAL MINES Grounding § 75.704 Grounding frames of stationary high-voltage equipment receiving...

  3. Procedures and results of the high voltage tests performed in March 2009 on the PS Booster main ring magnets.

    CERN Document Server

    Newborough, A

    2009-01-01

    The last high voltage test (Fig 1) for the PSB was conducted in 1997. In view of the LHC operation starting later in the year a repeat of this high voltage test has been conducted during the hardware test period (March 2009) to verify the ground insulation of the PSB main magnet circuits

  4. 16 CFR Figures 1 and 2 to Part 1204 - Suggested Instrumentation for Current Monitoring Device and High Voltage Facility

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Suggested Instrumentation for Current Monitoring Device and High Voltage Facility 1 Figures 1 and 2 to Part 1204 Commercial Practices CONSUMER... Instrumentation for Current Monitoring Device and High Voltage Facility EC03OC91.008 ...

  5. Nuclear microprobe investigation of the effects of ionization and displacement damage in vertical, high voltage GaN diodes

    Science.gov (United States)

    Vizkelethy, G.; King, M. P.; Aktas, O.; Kizilyalli, I. C.; Kaplar, R. J.

    2017-08-01

    Radiation responses of high-voltage, vertical gallium-nitride (GaN) diodes were investigated using Sandia National Laboratories' nuclear microprobe. Effects of the ionization and the displacement damage were studied using various ion beams. We found that the devices show avalanche effect for heavy ions operated under bias well below the breakdown voltage. The displacement damage experiments showed a surprising effect for moderate damage: the charge collection efficiency demonstrated an increase instead of a decrease for higher bias voltages.

  6. High-Voltage Electroporation of Bacteria: Genetic Transformation of Campylobacter jejuni with Plasmid DNA

    Science.gov (United States)

    Miller, Jeff F.; Dower, William J.; Tompkins, Lucy S.

    1988-02-01

    Electroporation permits the uptake of DNA by mammalian cells and plant protoplasts because it induces transient permeability of the cell membrane. We investigated the utility of high-voltage electroporation as a method for genetic transformation of intact bacterial cells by using the enteric pathogen Campylobacter jejuni as a model system. This report demonstrates that the application of high-voltage discharges to bacterial cells permits genetic transformation. Our method involves exposure of a Campylobacter cell suspension to a high-voltage exponential decay discharge (5-13 kV/cm) for a brief period of time (resistance-capacitance time constant = 2.4-26 msec) in the presence of plasmid DNA. Electrical transformation of C. jejuni results in frequencies as high as 1.2 × 106 transformants per μ g of DNA. We have investigated the effects of pulse amplitude and duration, cell growth conditions, divalent cations, and DNA concentration on the efficiency of transformation. Transformants of C. jejuni obtained by electroporation contained structurally intact plasmid molecules. In addition, evidence is presented that indicates that C. jejuni possesses DNA restriction and modification systems. The use of electroporation as a method for transforming other bacterial species and guidelines for its implementation are also discussed.

  7. Test setups for the development of high voltage circuit breakers for high short circuit capacities

    Science.gov (United States)

    Patzelt, R.; Ruhnau, W.; Zemann, E.

    1981-10-01

    A number of test setups and procedures are described for measuring and simulating the current and voltage conditions prevailing in short circuit breakers designed to interrupt short circuit currents from 80 to 100 kA. A synthetic test circuit was successfully developed, using the principles of both voltage and current injection. A capacitance current injection procedure allows for the establishment of the influence of iron in the magnetic circuit on the prospective transient recovery voltage of the breaker. Methods for measuring the post-arc current are indicated, and developed meshed grid and tube shunts are described. Synthetic test circuits are presented which are suitable for testing the capacitive switching capabilities of breakers.

  8. Preparation and characterization of EPDM-silica nano/micro composites for high voltage insulation applications

    Directory of Open Access Journals (Sweden)

    Ali Muhammad

    2015-03-01

    Full Text Available The rising market for substitute materials in high voltage insulation components is stimulated largely by the need to reduce overall costs. In this respect, polymer insulators offer significant advantages over old traditional materials. In the present research, efforts have been made to quantify the effect of silica (having different particle size nano, micro and hybrid loading on the mechanical and thermal behaviors of Ethylene-Propylene-Diene Monomer (EPDM based high voltage electrical insulations. The fabricated composites were subjected to mechanical, thermal and electrical properties measurements. The results of dielectric strength, surface and volume resistivities showed that all composites had insulator properties, while their mechanical and thermal properties improved considerably. EPDM was compounded with different types of silica in a two roll mill using sulphur cure system. The outcome achieved from the comparative study revealed that the EPDM nanocomposites had enhanced mechanical, thermal and electrical properties even at 5 % loadings.

  9. The ATLAS liquid argon calorimeter high-voltage system: commissioning, optimisation, and LHC relative luminosity measurement.

    CERN Document Server

    Arfaoui, Samir; Monnier, E

    2011-01-01

    The main goals of the ATLAS scientific programme are the observation or exclusion of physics beyond the Standard Model (SM), as well as the measurement of production cross-sections of SM processes. In oder to do so,it is important to measure the luminosity at the interaction point with great precision. The ATLAS luminosity is extracted using several detectors with varying efficiencies and acceptances. Different methods, such as inclusive - or coincidence - event counting and calorimeter integrated current measurements, are calibrated and cross-compared to provide the most accurate luminosity determination. In order to provide more cross-checks and a better control on the systematic uncertainties, an independent measurement using the liquid argon (LAr) forward calorimeter (FCal), based on the readout current of its high-voltage system, has been developed. This document describes how the LAr calorimeter high-voltage system has been installed and commissioned, as well as its application to a relative luminosity ...

  10. A Study on Gas Insulation Characteristics for Design Optimization of High Voltage Power Apparatus

    Energy Technology Data Exchange (ETDEWEB)

    Kim, I. S.; Kim, M. K.; Seo, K. S.; Moon, I. W.; Choi, C. K. [Korea Electrotechnology Research Institute (Korea, Republic of)

    1996-12-01

    This study aim of obtaining the basic data for gas insulation in the high voltage apparatus and for investigating the breakdown characteristics in uniform field and non-uniform which the geometric construction in the practical power apparatus. In this study, the research results on the insulation technology published earlier are reviewed and the basic data for an optimum design of a high voltage apparatus are obtained thorough the experiment and computer simulation by using a uniform field. The main result are summarized as follows: (A) Investigation on the insulation technology in a large-capacity power apparatus. (B) Investigation on the breakdown characteristics in particle contaminated condition. (C) Investigation on the design in computer simulation. (D) Investigation on the simulation technology of breakdown characteristics. (E) Investigation on breakdown characteristics in the nonuniform field and experiment. (author). refs., figs., tabs.

  11. Voltage Based Detection Method for High Impedance Fault in a Distribution System

    Science.gov (United States)

    Thomas, Mini Shaji; Bhaskar, Namrata; Prakash, Anupama

    2016-09-01

    High-impedance faults (HIFs) on distribution feeders cannot be detected by conventional protection schemes, as HIFs are characterized by their low fault current level and waveform distortion due to the nonlinearity of the ground return path. This paper proposes a method to identify the HIFs in distribution system and isolate the faulty section, to reduce downtime. This method is based on voltage measurements along the distribution feeder and utilizes the sequence components of the voltages. Three models of high impedance faults have been considered and source side and load side breaking of the conductor have been studied in this work to capture a wide range of scenarios. The effect of neutral grounding of the source side transformer is also accounted in this study. The results show that the algorithm detects the HIFs accurately and rapidly. Thus, the faulty section can be isolated and service can be restored to the rest of the consumers.

  12. Simulation on Temperature and Ampacity of Mining Flame-proof High Voltage Cable Connector

    Directory of Open Access Journals (Sweden)

    Li Haiying

    2017-01-01

    Full Text Available To investigate the accident causes of mining flame-proof high voltage (F-HV cable connector, the temperature and ampacity of LBG1-200/6 high voltage cable connector are analyzed. At first, the material properties and structure of connector are introduced from the aspects of electrical, insulation and thermal. Then the electromagnetic field and thermal field coupling model of cable connector are established by the finite element method. Finally, in the numerical examples, temperature distribution and ampacity change caused by power harmonics, dielectric loss and slight structure change are quantitatively plotted and analyzed. The paper provides great insight into the security operation of F-HV cable connector.

  13. Daikin Advanced Lithium Ion Battery Technology – High Voltage Electrolyte - REVISED

    Energy Technology Data Exchange (ETDEWEB)

    Sunstrom, Joseph [Daikin America, Inc., Orangeburg, NY (United States); Hendershot, Ron E. [Daikin America, Inc., Orangeburg, NY (United States)

    2017-03-06

    An evaluation of high voltage electrolytes which contain fluorochemicals as solvents/additive has been completed with the objective of formulating a safe, stable electrolyte capable of operation to 4.6 V. Stable cycle performance has been demonstrated in LiNi1/3Mn1/3Co1/3O2 (NMC111)/graphite cells to 4.5 V. The ability to operate at high voltage results in significant energy density gain (>30%) which would manifest as longer battery life resulting in higher range for electric vehicles. Alternatively, a higher energy density battery can be made smaller without sacrificing existing energy. In addition, the fluorinated electrolytes examined showed better safety performance when tested in abuse conditions. The results are promising for future advanced battery development for vehicles as well as other applications.

  14. Electric field analysis of extra high voltage (EHV) underground cables using finite element method

    DEFF Research Database (Denmark)

    Kumar, Mantosh; Bhaskar, Mahajan Sagar; Padmanaban, Sanjeevikumar

    2017-01-01

    Transmission and Distribution of electric power through underground cables is a viable alternative to overhead lines, particularly in residential or highly populated areas. The electrical stresses are consequences of regular voltages and over voltages and the thermal stresses are related to heat...... produced inside the conductor due to flow of high rated current which is the main factors that affect its reliability. The performance of these underground power cables is important for proper operation of the power system. Long-term problems with them are related to the degradation of polymer materials...... used for the insulator due electrical, thermal or environmental stress. Most of these problems are related to the electric field stress on the insulation of the underground cables. The objective of the electric field analysis by using different numerical techniques is to find electric field stress...

  15. DC high voltage to drive helium plasma jet comprised of repetitive streamer breakdowns

    CERN Document Server

    Wang, Xingxing

    2016-01-01

    This paper demonstrates and studies helium atmospheric pressure plasma jet comprised of series of repetitive streamer breakdowns, which is driven by a pure DC high voltage (auto-oscillations). Repetition frequency of the breakdowns is governed by the geometry of discharge electrodes/surroundings and gas flow rate. Each next streamer is initiated when the electric field on the anode tip recovers after the previous breakdown and reaches the breakdown threshold value of about 2.5 kV/cm. Repetition frequency of the streamer breakdowns excited using this principle can be simply tuned by reconfiguring the discharge electrode geometry. This custom-designed type of the helium plasma jet, which operates on the DC high voltage and is comprised of the series of the repetitive streamer breakdowns at frequency about 13 kHz, is demonstrated.

  16. A capacitive level shifter for high voltage (2.5kV)

    DEFF Research Database (Denmark)

    Andersen, Thomas; Andersen, Michael A. E.; Thomsen, Ole Cornelius

    2012-01-01

    A capacitive level-shifter as a part of a high voltage halfbridge gate driver is resented in this work. The levelshifter utilizes a differential capacitor pair to transfer the information from low side to high side. A thorough evaluation of the critical parts of the level-shifter is presented...... with focus on low power consumption as well as low capacitive load between the floating half-bridge node and ground (output capacitance). The operation of the level-shifter is tested and verified by measurements on a prototype half-bridge gate driver. Results conclude stabile operation at 2.44kV, 50k......Hz with a current consumption of 0.5mA. Operation voltage was limited by test equipment. The output capacitance is 4pF@1.5kV....

  17. Study on Earthquake Response of High Voltage Electrical Equipment Coupling System with Flexible Busbar

    Science.gov (United States)

    Liu, Chuncheng; Qu, Da; Wang, Chongyang; Lv, Chunlei; Li, Guoqiang

    2017-12-01

    With the rapid development of technology and society, all walks of life in China are becoming more and more dependent on power systems. When earthquake occurs, the electrical equipment of substation is prone to damage because of its own structural features, top-heavy, and brittleness of main body. At the same time, due to the complex coupling of the soft electrical connection of substation electrical equipment, the negative impact can not be estimated. In this paper, the finite element model of the coupling system of the single unit of high voltage electrical equipment with the connecting soft bus is established and the seismic response is analysed. The results showed that there is a significant difference between the simple analysis for the seismic response of electrical equipment monomer and the analytical results of electrical equipment systems, and the impact on different electrical equipment is different. It lays a foundation for the future development of seismic performance analysis of extra high voltage electrical equipment.

  18. A study on stimulation of DC high voltage power of LCC series parallel resonant in projectile velocity measurement system

    Science.gov (United States)

    Lu, Dong-dong; Gu, Jin-liang; Luo, Hong-e.; Xia, Yan

    2017-10-01

    According to specific requirements of the X-ray machine system for measuring velocity of outfield projectile, a DC high voltage power supply system is designed for the high voltage or the smaller current. The system comprises: a series resonant circuit is selected as a full-bridge inverter circuit; a high-frequency zero-current soft switching of a high-voltage power supply is realized by PWM output by STM32; a nanocrystalline alloy transformer is chosen as a high-frequency booster transformer; and the related parameters of an LCC series-parallel resonant are determined according to the preset parameters of the transformer. The concrete method includes: a LCC series parallel resonant circuit and a voltage doubling circuit are stimulated by using MULTISM and MATLAB; selecting an optimal solution and an optimal parameter of all parts after stimulation analysis; and finally verifying the correctness of the parameter by stimulation of the whole system. Through stimulation analysis, the output voltage of the series-parallel resonant circuit gets to 10KV in 28s: then passing through the voltage doubling circuit, the output voltage gets to 120KV in one hour. According to the system, the wave range of the output voltage is so small as to provide the stable X-ray supply for the X-ray machine for measuring velocity of outfield projectile. It is fast in charging and high in efficiency.

  19. High-voltage electrical burns due to copper theft - Case series.

    Science.gov (United States)

    Braga, M J; Oliveira, I; Egipto, P; Silva, A

    2016-03-31

    Electrical burns are among the most devastating trauma inflicted on the human body. These burns have a higher morbidity, length of stay and a much higher risk of amputation than any other type of burn. Electrical burns affect mostly young, working males because they are more frequently the result of a work accident. However, possibly due to the worldwide economic crisis, we are experiencing a new phenomenon: the theft of high-voltage copper wiring.

  20. High-voltage electrical burns due to copper theft – Case series

    Science.gov (United States)

    Braga, M.J.; Oliveira, I.; Egipto, P.; Silva, A.

    2016-01-01

    Summary Electrical burns are among the most devastating trauma inflicted on the human body. These burns have a higher morbidity, length of stay and a much higher risk of amputation than any other type of burn. Electrical burns affect mostly young, working males because they are more frequently the result of a work accident. However, possibly due to the worldwide economic crisis, we are experiencing a new phenomenon: the theft of high-voltage copper wiring. PMID:27857650

  1. Tests of industrial ethylene-propylene rubber high voltage cable for cryogenic use

    CERN Document Server

    Balhan, B; Goddard, B; Muratori, G; Otwinowski, S; Rieubland, Jean Michel; Wang, H; CERN. Geneva. SPS and LEP Division

    1999-01-01

    At the beginning of 1999 UCLA has received a prototype High Voltage Cryogenic Cable supplied fee of charge by Pirelli. The cable is intended for more than ten years of service at 100 kV D.C. and liquid argon temperature. Thecable uses an all welded construction, whichi is axially tight and free of ionizable voids. The cable was submitted to a number of mechanical and electrical tests as described below.

  2. Research of Measurement Circuits for High Voltage Current Transformer Based on Rogowski Coils

    OpenAIRE

    Yan Bing; Wang Yutian; Li Hui; Wang Huixin; Chen Yiqiang

    2014-01-01

    The electronic current transformer plays an irreplaceable position in the field of relay protection and current measurement of the power system. Rogowski coils are used as sensor parts, and in order to improve the measurement accuracy and reliability, the circuits at the high voltage system are introduced and improved in this paper, including the analog integral element, the filtering circuit and the phase shift circuit. Simulations results proved the reliability and accuracy of the improved ...

  3. Research of Measurement Circuits for High Voltage Current Transformer Based on Rogowski Coils

    Directory of Open Access Journals (Sweden)

    Yan Bing

    2014-02-01

    Full Text Available The electronic current transformer plays an irreplaceable position in the field of relay protection and current measurement of the power system. Rogowski coils are used as sensor parts, and in order to improve the measurement accuracy and reliability, the circuits at the high voltage system are introduced and improved in this paper, including the analog integral element, the filtering circuit and the phase shift circuit. Simulations results proved the reliability and accuracy of the improved circuits.

  4. Calculation of surface leakage currents on high voltage insulators by ant colony algorithm-supported FEM

    OpenAIRE

    ÖZTÜRK, DURSUN; CEBECİ, MEHMET

    2015-01-01

    The weakness of the outer insulation at high voltages is the reduction of the surface resistance as a result of the environmental pollution yielding formation of flashover due to the surface leakage currents. In this study, it was shown how to calculate the surface leakage currents resulting in flashover in polluted insulators and therefore power cuts by means of the ant colony algorithm (ACA). For this purpose, first, field distribution on the sample insulator surface in question was defined...

  5. System for Relay Protection Command Transmission by High-Voltage Lines

    Directory of Open Access Journals (Sweden)

    D. A. Yenkov

    2009-01-01

    Full Text Available Development of a system for relay protection command transmission by high-voltage lines is shown in the paper. The paper describes an architecture of the system, main principles of its operation, engineering aspects of the development that is accomplishment of technical requirements, solution of trades-off. Justification of the selected design and an algorithm of the reliable detection of relay protection signals are given in the paper.

  6. Analysis of Dielectric Electro Active Polymer Actuator and its High Voltage Driving Circuits

    DEFF Research Database (Denmark)

    Thummala, Prasanth; Huang, Lina; Zhang, Zhe

    2012-01-01

    Actuators based on dielectric elastomers have promising applications in artificial muscles, space robotics, mechatronics, micro-air vehicles, pneumatic and electric automation technology, heating valves, loud speakers, tissue engineering, surgical tools, wind turbine flaps, toys, rotary motors...... actuator is analyzed in detail and the actuator structures, for the wind turbine flap and the heating valve applications are shown. Different high voltage switch mode power supply topologies for driving the DEAP actuator are discussed. The simulation and experimental results are discussed....

  7. Distributed Control of Battery Energy Storage Systems for Voltage Regulation in Distribution Networks with High PV Penetration

    DEFF Research Database (Denmark)

    Zeraati, Mehdi; Golshan, Mohamad Esmaeil Hamedani; Guerrero, Josep M.

    2017-01-01

    issues of distribution networks. In this paper, the battery energy storage (BES) systems are used in order to solve the voltage rise during the peak PV generation as well as the voltage drop while meeting the peak load. A coordinated control strategy is proposed to regulate the charge/discharge of BESs......The voltage rise problem in low voltage (LV) distribution networks with high penetration of photovoltaic (PV) resources is one of the most important challenges in the development of these renewable resources since it may prevent the maximum PV penetration considering the reliability and security...... using a combination of the local droop based control method and a distributed control scheme which ensures the voltages of feeder remain within allowed limits. Therefore, two different consensus algorithms are used: The first algorithm determines the BESs participation in voltage regulation in terms...

  8. Dynamic voltage stability of a distribution system with high penetration of grid-connected photovoltaic type solar generators

    Directory of Open Access Journals (Sweden)

    Zetty Adibah Kamaruzzaman

    2016-06-01

    Full Text Available This paper presents the impact of grid-connected photovoltaic (PV generator on dynamic voltage stability of a power distribution system by considering solar intermittency, PV penetration level, and contingencies such as line outage and load increase. The IEEE 13 node test feeder is used as a test system, and a solar PV of 0.48 kV/0.5 MVA is integrated into the test system. Test results show that system voltage is stable at high PV penetration levels. Increase in load causes voltage instability, in which voltage drops below its allowable operating limit. Thus, increase in PV penetration level does not improve system voltage stability because the system experiences voltage collapse during line outage.

  9. Evaluation of the Fretting Resistance of the High Voltage Insulation on the ITER Magnet Feeder Busbars

    Science.gov (United States)

    Clayton, N.; Crouchen, M.; Evans, D.; Gung, C.-Y.; Su, M.; Devred, A.; Piccin, R.

    2017-12-01

    The high voltage (HV) insulation on the ITER magnet feeder superconducting busbars and current leads will be prepared from S-glass fabric, pre-impregnated with an epoxy resin, which is interleaved with polyimide film and wrapped onto the components and cured during feeder manufacture. The insulation architecture consists of nine half-lapped layers of glass/Kapton, which is then enveloped in a ground-screen, and two further half-lapped layers of glass pre-preg for mechanical protection. The integrity of the HV insulation is critical in order to inhibit electrical arcs within the feeders. The insulation over the entire length of the HV components (bus bar, current leads and joints) must provide a level of voltage isolation of 30 kV. In operation, the insulation on ITER busbars will be subjected to high mechanical loads, arising from Lorentz forces, and in addition will be subjected to fretting erosion against stainless steel clamps, as the pulsed nature of some magnets results in longitudinal movement of the busbar. This work was aimed at assessing the wear on, and the changes in, the electrical properties of the insulation when subjected to typical ITER operating conditions. High voltage tests demonstrated that the electrical isolation of the insulation was intact after the fretting test.

  10. Characterization of low temperature high voltage axial insulator breaks for the ITER cryogenic supply line

    Science.gov (United States)

    Fernandez Pison, P.; Sgobba, S.; Aviles Santillana, I.; Langeslag, S. A. E.; Su, M.; Piccin, R.; Journeaux, J. Y.; Laurenti, A.; Pan, W.

    2017-12-01

    Cable-in-conduit conductors of the ITER magnet system are directly cooled by supercritical helium. Insulation breaks are required in the liquid helium feed pipes to isolate the high voltage system of the magnet windings from the electrically grounded helium coolant supply line. They are submitted to high voltages and significant internal helium pressure and will experience mechanical forces resulting from differential thermal contraction and electro-mechanical loads. Insulation breaks consist essentially of stainless steel tubes overwrapped by an outer glass – fiber reinforced composite and bonded to an inner composite tube at each end of the stainless steel fittings. For some types of insulator breaks Glass – Kapton – Glass insulation layers are interleaved in the outer composite. Following an extensive mechanical testing campaign at cryogenic temperature combined with leak tightness tests, the present paper investigates through non-destructive and destructive techniques the physical and microstructural characteristics of the low temperature high voltage insulation breaks and of their individual components, thus allowing to correlate the structure and properties of the constituents to their overall performance. For all the tests performed, consistent and reproducible results were obtained within the range of the strict acceptance criteria defined for safe operation of the insulation breaks.

  11. Effects of high voltage pulse trimming on structural properties of thick-film resistors

    Directory of Open Access Journals (Sweden)

    Stanimirović Zdravko

    2017-01-01

    Full Text Available Nowadays, compact and reliable electronic devices including up-to-date ceramic micro-electro-mechanical systems require thick-film resistors with significantly reduced dimensions and stable and precise resistance values. For that reason, instead of standard laser trimming method, high voltage pulse trimming of thick-film resistors is being introduced. This method allows controlled and reliable resistance adjustment regardless of resistor position or dimensions and without the presence of cuts. However, it causes irreversible structural changes in the pseudorandom network formed during sintering causing the changes in conducting mechanisms. In this paper results of the experimental investigation of high voltage pulse trimming of thick-film resistors are presented. Obtained results are analyzed and correlations between resistance and low-frequency noise changes and changes in conducting mechanisms in resistors due to high voltage pulse trimming are observed. Sources of measured fluctuations are identified and it is shown that this type of trimming is a valid alternative trimming method to the dominant laser trimming. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. III44003 and III45007

  12. Integration Testing of a Modular Discharge Supply for NASA's High Voltage Hall Accelerator Thruster

    Science.gov (United States)

    Pinero, Luis R.; Kamhawi, hani; Drummond, Geoff

    2010-01-01

    NASA s In-Space Propulsion Technology Program is developing a high performance Hall thruster that can fulfill the needs of future Discovery-class missions. The result of this effort is the High Voltage Hall Accelerator thruster that can operate over a power range from 0.3 to 3.5 kW and a specific impulse from 1,000 to 2,800 sec, and process 300 kg of xenon propellant. Simultaneously, a 4.0 kW discharge power supply comprised of two parallel modules was developed. These power modules use an innovative three-phase resonant topology that can efficiently supply full power to the thruster at an output voltage range of 200 to 700 V at an input voltage range of 80 to 160 V. Efficiencies as high as 95.9 percent were measured during an integration test with the NASA103M.XL thruster. The accuracy of the master/slave current sharing circuit and various thruster ignition techniques were evaluated.

  13. Communication Characteristics of Faulted Overhead High Voltage Power Lines at Low Radio Frequencies

    Directory of Open Access Journals (Sweden)

    Nermin Suljanović

    2017-11-01

    Full Text Available This paper derives a model of high-voltage overhead power line under fault conditions at low radio frequencies. The derived model is essential for design of communication systems to reliably transfer information over high voltage power lines. In addition, the model can also benefit advanced systems for power-line fault detection and classification exploiting the phenomenon of changed conditions on faulted power line, resulting in change of low radio frequency signal propagation. The methodology used in the paper is based on the multiconductor system analysis and propagation of electromagnetic waves over the power lines. The model for the high voltage power line under normal operation is validated using actual measurements obtained on 400 kV power line. The proposed model of faulted power lines extends the validated power-line model under normal operation. Simulation results are provided for typical power line faults and typical fault locations. Results clearly indicate sensitivity of power-line frequency response on different fault types.

  14. Determination of threshold and maximum operating electric stresses for selected high voltage insulations. Task III. Investigation of high voltage capacitor insulation. Progress report No. 4

    Energy Technology Data Exchange (ETDEWEB)

    Sosnowski, M.; Eager, G.S. Jr.

    1984-03-01

    This report covers the investigation of threshold voltage of capacitor insulation. The experimental work was performed on samples prepared from commercial polypropylene insulated, liquid-filled capacitors. The samples were vacuum-impregnated with the original capacitor insulating liquid obtained from the manufacturer. A limited number of full-size capacitor elements also were tested. Impulse voltage breakdown tests with dc voltage prestressing were performed at room temperature and 75/sup 0/C. From the results of these tests, the threshold voltage of the samples of the capacitor insulation was determined at both temperatures and that of the whole capacitor elements at room temperature. The threshold voltage of the capacitor insulation was found to be approximately equal to the impulse breakdown voltage. No difference was found between the threshold voltage at room temperature and at 75/sup 0/C. The threshold voltage of the whole capacitor elements at room temperature was found to be equal to approximately 80% of the threshold voltage of the capacitor insulation samples.

  15. Tesla’s high voltage and high frequency generators with oscillatory circuits

    Directory of Open Access Journals (Sweden)

    Cvetić Jovan M.

    2016-01-01

    Full Text Available The principles that represent the basics of the work of the high voltage and high frequency generator with oscillating circuits will be discussed. Until 1891, Tesla made and used mechanical generators with a large number of extruded poles for the frequencies up to about 20 kHz. The first electric generators based on a new principle of a weakly coupled oscillatory circuits he used for the wireless signal transmission, for the study of the discharges in vacuum tubes, the wireless energy transmission, for the production of the cathode rays, that is x-rays and other experiments. Aiming to transfer the signals and the energy to any point of the surface of the Earth, in the late of 19th century, he had discovered and later patented a new type of high frequency generator called a magnifying transmitter. He used it to examine the propagation of electromagnetic waves over the surface of the Earth in experiments in Colorado Springs in the period 1899-1900. Tesla observed the formation of standing electromagnetic waves on the surface of the Earth by measuring radiated electric field from distant lightning thunderstorm. He got the idea to generate the similar radiation to produce the standing waves. On the one hand, signal transmission, i.e. communication at great distances would be possible and on the other hand, with more powerful and with at least three magnifying transmitters the wireless transmission of energy without conductors at any point of the Earth surface could also be achieved. The discovery of the standing waves on the surface of the Earth and the invention of the magnifying transmitter he claimed his greatest inventions. Less than two years later, at the end of 1901, he designed and started to build a much stronger magnifying transmitter on Long Island near New York City (the Wardenclyffe tower wishing to become a world telecommunication center. During the tower construction, he elaborated the plans for an even stronger transmitter based on

  16. A high-sensitivity magnetocardiography system with a divided gradiometer array inside a low boil-off Dewar

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Y H; Yu, K K; Kim, J M; Kwon, H; Kim, K, E-mail: yhlee@kriss.re.k [Korea Research Institute of Standards and Science, 1 Doryong, Yuseong, Daejeon 305-600 (Korea, Republic of)

    2009-11-15

    We fabricated a low-noise 64-channel first-order axial gradiometer system for measuring magnetocardiography (MCG) signals. The key technical features of the system are the compact structure of the gradiometer, division of the sensor array plate, direct mounting of the sensor plates into the Dewar bottom, reduced neck diameter of the liquid He Dewar, and compact readout electronics. To make the refill interval of liquid He longer, the distance between the compensation coil of the gradiometer and the input coil pads of the superconducting quantum interference device (SQUID) was reduced to 20 mm. By using direct ultrasonic bonding of Nb wires between the pickup coil wires and input coil pads, the superconductive connection structure became simple. The baseline of the first-order gradiometer is 70 mm, a little longer than for typical conventional axial gradiometers, to provide a larger signal amplitude for deep sources. The 64-channel gradiometer array consists of four blocks, and each block is fixed separately onto the bottom of the Dewar. The neck diameter of the He Dewar (192 mm) is smaller than the bottom diameter (280 mm) in which the gradiometers are distributed. The average boil-off rate of the Dewar is 3 l per day when the 64-channel system is in operation every day. Double relaxation oscillation SQUIDs (DROSs) having large flux-to-voltage transfer coefficients were used to operate SQUIDs via compact electronics. The magnetically shielded room (MSR) has a wall thickness of 80 mm, and consists of two layers of permalloy and one layer of aluminum. When the 64-channel system was installed inside the MSR, the field noise level of the system was about 3.5 fT{sub rms} Hz{sup -1/2} at 100 Hz. MCG measurements with high signal quality were done successfully using the developed system. In addition to the parameter analysis method, we developed software for the three-dimensional imaging of the myocardial current on a realistic image of the heart based on the anatomical

  17. Series operation of power MOSFETs for high-speed, high-voltage switching applications

    Science.gov (United States)

    Baker, R. J.; Johnson, B. P.

    1993-06-01

    Series operation of power metal-oxide semiconductor field-effect transistors (MOSFETs) to increase their effective hold off voltage is described. The design procedure presented is a modification of a recently reported [Baker and Johnson, Rev. Sci. Instrum. 63, 5799 (1992)] method. Comments are made on implementing MOSFET stacks in various types of instrumentation.

  18. Development of ultra-short high voltage pulse technology using magnetic pulse compression

    Energy Technology Data Exchange (ETDEWEB)

    Cha, Byung Heon; Kim, S. G.; Nam, S. M.; Lee, B. C.; Lee, S. M.; Jeong, Y. U.; Cho, S. O.; Jin, J. T.; Choi, H. L

    1998-01-01

    The control circuit for high voltage switches, the saturable inductor for magnetic assist, and the magnetic pulse compression circuit were designed, constructed, and tested. The core materials of saturable inductors in magnetic pulse compression circuit were amorphous metal and ferrite and total compression stages were 3. By the test, in high repetition rate, high pulse compression were certified. As a result of this test, it became possible to increase life-time of thyratrons and to replace thyratrons by solid-state semiconductor switches. (author). 16 refs., 16 tabs.

  19. Precision monitoring and calibration of the high-voltage for the KATRIN experiment; Praezisionsueberwachung und Kalibration der Hochspannung fuer das KATRIN-Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Thuemmler, T.

    2007-11-12

    The goal of the KATRIN(KArlsruhe TRIritium Neutrino) Experiment is to directly determine the neutrino rest mass from the kinematics of the tritium-{beta}-decay. KATRIN uses the high resolution and luminosity of a spectrometer following the MAC-E filter principle. Based on the experience of the successful predecessor experiments in Mainz and Troisk and the improved experimental technology, KATRIN aims to reach a sensitivity on the neutrino mass of 0.2 eV/c{sup 2} (90% C.L.). One of the few systematic uncertainties that have to be reduced to meet this goal is the uncertainty of measuring and monitoring the potential of the electrostatic filter of the spectrometer. In tritium measurement mode voltages of about U{sub 0} =-18.6 kV have to be permanently monitored with a maximum uncertainty of 3.3 ppm ({approx} 61mV at U{sub 0}), in order not to add more than {delta}m{sup 2}{sub {nu}{sub ec}}{sup 4} {<=} 0.0075 eV{sup 2} to the total systematic uncertainty. The goal of this work is to build a new precision high voltage divider in cooperation with PTB Braunschweig that reaches an uncertainty of about 1 ppm at voltages up to 35 kV. The divider is based on a new type of precision resistors, which have been screened with respect to their warm up drift and their temperature coefficient at the ppm level. By combining 100 of the best matching samples, the mutual warm up effect could be reduced to a computed value of <0.02 ppm. The precision resistors are mounted in a shielded and temperature stabilized vessel under N{sub 2} gas. The properties of both installed low voltage outputs with the ratios 1972:1 and 3944:1 have been repeatedly calibrated with about one year time difference at the DC high voltage laboratory (division 2.31) of PTB. The performance of the new divider in real measurements has been tested with the prototype of the new condensed {sup 83m}Kr calibration source (CKrS) [Ost08] at the Mainz spectrometer. Detailed stability investigations of the energy of the {sup

  20. Monolithic blue LED series arrays for high-voltage AC operation

    Energy Technology Data Exchange (ETDEWEB)

    Ao, Jin-Ping [Satellite Venture Business Laboratory, University of Tokushima, Tokushima 770-8506 (Japan); Sato, Hisao; Mizobuchi, Takashi; Morioka, Kenji; Kawano, Shunsuke; Muramoto, Yoshihiko; Sato, Daisuke; Sakai, Shiro [Nitride Semiconductor Co. Ltd., Naruto, Tokushima 771-0360 (Japan); Lee, Young-Bae; Ohno, Yasuo [Department of Electrical and Electronic Engineering, University of Tokushima, Tokushima 770-8506 (Japan)

    2002-12-16

    Design and fabrication of monolithic blue LED series arrays that can be operated under high ac voltage are described. Several LEDs, such as 3, 7, and 20, are connected in series and in parallel to meet ac operation. The chip size of a single device is 150 {mu}m x 120 {mu}m and the total size is 1.1 mm x 1 mm for a 40(20+20) LED array. Deep dry etching was performed as device isolation. Two-layer interconnection and air bridge are utilized to connect the devices in an array. The monolithic series array exhibit the expected operation function under dc and ac bias. The output power and forward voltage are almost proportional to LED numbers connected in series. On-wafer measurement shows that the output power is 40 mW for 40(20+20) LED array under ac 72 V. (Abstract Copyright [2002], Wiley Periodicals, Inc.)

  1. Physiological effects of high- and low-voltage pulse combinations for gene electrotransfer in muscle

    DEFF Research Database (Denmark)

    Hojman, Pernille; Gissel, Hanne; Andre, Franck M

    2008-01-01

    electrotransfer, comparing it with 8 HV pulses designed to ensure extensive permeabilization of the muscle membrane. Using both mouse and rat skeletal muscle tissue, we investigated cell permeabilization by the 51Cr-labeled EDTA assay, lactate dehydrogenase release, Na+ and Ca2+ influx, K+ efflux, ATP release......, and water content, as well as muscle function both in vivo and ex vivo, Hsp70 induction, and histology. In all these assays, the HVLV pulse combination gave rise to minimal disturbance of cell function, in all cases significantly different from results when using 8 HV pulses. The evaluated parameters were...... a comprehensive evaluation of the physiological and molecular effects on host tissue after DNA electrotransfer. We have tested several pulse regimens with special emphasis on the pulse combination of a short (100 microsec) high-voltage (HV) pulse followed by a long low-voltage (LV) pulse used for DNA...

  2. Reliability of High-Voltage Tantalum Capacitors. Parts 3 and 4)

    Science.gov (United States)

    Teverovsky, Alexander

    2010-01-01

    Weibull grading test is a powerful technique that allows selection and reliability rating of solid tantalum capacitors for military and space applications. However, inaccuracies in the existing method and non-adequate acceleration factors can result in significant, up to three orders of magnitude, errors in the calculated failure rate of capacitors. This paper analyzes deficiencies of the existing technique and recommends more accurate method of calculations. A physical model presenting failures of tantalum capacitors as time-dependent-dielectric-breakdown is used to determine voltage and temperature acceleration factors and select adequate Weibull grading test conditions. This model is verified by highly accelerated life testing (HALT) at different temperature and voltage conditions for three types of solid chip tantalum capacitors. It is shown that parameters of the model and acceleration factors can be calculated using a general log-linear relationship for the characteristic life with two stress levels.

  3. A high voltage pulsed power supply for capillary discharge waveguide applications

    Science.gov (United States)

    Abuazoum, S.; Wiggins, S. M.; Issac, R. C.; Welsh, G. H.; Vieux, G.; Ganciu, M.; Jaroszynski, D. A.

    2011-06-01

    We present an all solid-state, high voltage pulsed power supply for inducing stable plasma formation (density ˜1018 cm-3) in gas-filled capillary discharge waveguides. The pulser (pulse duration of 1 μs) is based on transistor switching and wound transmission line transformer technology. For a capillary of length 40 mm and diameter 265 μm and gas backing pressure of 100 mbar, a fast voltage pulse risetime of 95 ns initiates breakdown at 13 kV along the capillary. A peak current of ˜280 A indicates near complete ionization, and the r.m.s. temporal jitter in the current pulse is only 4 ns. Temporally stable plasma formation is crucial for deploying capillary waveguides as plasma channels in laser-plasma interaction experiments, such as the laser wakefield accelerator.

  4. Design of a high DC voltage generator and D-T fuser based on particle accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Wagner L.; Campos, Tarcisio P.R., E-mail: wagnerleite@ufmg.b, E-mail: campos@nuclear.ufmg.b [Universidade Federal de Minas Gerais (DEN/ UFMG), Belo Horizonte, MG (Brazil). Dept. de Engenharia Nuclear

    2011-07-01

    This paper approaches a design and simulation of a high voltage Cockcroft Walton multiplier and a compact size deuteron accelerator addressed in neutron generation by d-t fusion. We proposed a circuit arrangement, which was led to simulations. The particle accelerator was computer-generated providing particle transport and electric potential analysis. As results, the simulated voltage multiplier achieved 119 kV, and the accelerator presented a deuteron beam current up to 15 mA, achieving energies in order to 100 keV. In conclusion, the simulation motivates experimental essays in order to investigate the viability of a deuteron accelerator powered by a Cockcroft-Walton source. Such d-t fusor shall produce an interesting ion beam profile, reaching energy values near the d-t fusion cross section peak. (author)

  5. Control of Grid Interactive PV Inverters for High Penetration in Low Voltage Distribution Networks

    DEFF Research Database (Denmark)

    Demirok, Erhan

    distorted conditions. Chapter 2, therefore; overviews the latest ancillary services such as real power reduction during over frequency/over voltage events and reactive power control for static grid voltage support function of PV inverters. In case of high density of PV integration, grid connection rules...... of these inverters may depend on grid connection rules which are forced by DSOs. Minimum requirement expected from PV inverters is to transfer maximum power by taking direct current (DC) form from PV modules and release it into AC grid and also continuously keep the inverters synchronized to the grid even under...... widespread usage in residential areas and are usually single-phase connected to 230/400-V grid. Since realistic assessment of PV integration should include both single- and three-phase PV connections, a three-phase load flow script which is able to allow more precise estimation of PV hosting capacity...

  6. Effect of Doppler-shifted photons on subnanosecond breakdown in high-voltage pulse discharge

    Energy Technology Data Exchange (ETDEWEB)

    Schweigert, I. V. [Institute of Theoretical and Applied Mechanics, Novosibirsk 630090 (Russian Federation); George Washington University, Washington D.C. 20052 (United States); Alexandrov, A. L. [Institute of Theoretical and Applied Mechanics, Novosibirsk 630090 (Russian Federation); Zakrevsky, Dm. E.; Bokhan, P. A. [A.V. Rzhanov Institute of Semiconductor Physics, Novosibirsk 630090 (Russian Federation)

    2016-06-08

    The experiments in high-voltage open discharge in helium [1, 2] showed a controlled current growth rate of 500 A/(cm{sup 2}ns) for an applied voltage of 20 kV and gas pressure of 6 Torr. A kinetic model of the subnanosecond breakdown is developed to analyze the mechanism of current growth, which takes into account the kinetics of electrons, ions, fast atoms and photons with a Doppler shift (DS). DS photons appear in discharge due to collisions of heavy particles. Using particle in cell simulations, we show a critical role of DS photons in the electron emission from the cathode during the breakdown. Our experimental and calculation results show a decrease of the breakdown time with increasing gas pressure from 3 Torr to 16 Torr.

  7. Forward voltage short-pulse technique for measuring high power laser array junction temperature

    Science.gov (United States)

    Meadows, Byron L. (Inventor); Amzajerdian, Frazin (Inventor); Barnes, Bruce W. (Inventor); Baker, Nathaniel R. (Inventor)

    2012-01-01

    The present invention relates to a method of measuring the temperature of the P-N junction within the light-emitting region of a quasi-continuous-wave or pulsed semiconductor laser diode device. A series of relatively short and low current monitor pulses are applied to the laser diode in the period between the main drive current pulses necessary to cause the semiconductor to lase. At the sufficiently low current level of the monitor pulses, the laser diode device does not lase and behaves similar to an electronic diode. The voltage across the laser diode resulting from each of these low current monitor pulses is measured with a high degree of precision. The junction temperature is then determined from the measured junction voltage using their known linear relationship.

  8. Soft switching (ZVZCS) high current, low voltage modular power converter (13 kA, 16 V)

    CERN Document Server

    Bordry, Frederick; Thiesen, H

    2001-01-01

    The Large Hadron Collider (LHC) is the next accelerator being constructed at the European Laboratory for Particle Physics (CERN). The superconducting LHC particle accelerator requires high currents (13 kA) and relatively low voltages (16 V) for its magnets. This paper describes the development and the production of a (13 kA, 16 V) power converter. The converter is made with a modular concept with five current sources (3.25 kA, 16 V) in parallel. The 3.25 kA sources are built as plug-in modules: a diode rectifier on the AC mains, a zero voltage zero current switching (ZVZCS) inverter working at 25 k Hz and an output stage. The obtained performance is presented and discussed. (6 refs).

  9. Fabrication of 4H-SiC Schottky barrier diodes with high breakdown voltages

    CERN Document Server

    Kum, B H; Shin, M W; Park, J D

    1999-01-01

    This paper discusses the fabrication and the breakdown characteristics of 4H-SiC Schottky barrier diodes (SBDs). Optimal processing conditions for the ohmic contacts were extracted using the transmission-line method (TLM) and were applied to the device fabrication. The Ti/4H-SiC SBDs with Si sub x B sub y passivation showed a maximum reverse breakdown voltage of 268 V with a forward current density as high as 70 mA/cm sup 2 at a forward voltage of 2 V. The breakdown of the Pt. 4H-SiC SBDs without any passivation occurred at near 110 V. It is concluded that the breakdown enhancement in the Ti/4H-SiC SBDs can be attributed to the passivation; otherwise, excess surface charge near the edge of the Schottky contact would lead to electric fields of sufficient magnitude to cause field emission.

  10. The use of commercial thyristors in repetitive high voltage switching devices for plasma sources

    Science.gov (United States)

    Bac, J.; Reess, T.; Pecastaing, L.; Paillol, J.; Domens, P.

    2007-02-01

    This paper presents a commercial high voltage thyristor used as a switch allowing a tank capacitor to discharge in a load. In classical high power pulse technology applications the output voltage pulse has to be characterized mainly by its crest value, its rise-time, the period the thyristor is held in the on-state and the fall-time. These parameters are studied as a function of the power circuit and of the trigger circuit. The thyristor presents two behaviours: the main current is either higher or lower than the latching current. The “low current” behaviour is extensively investigated as it allows repetitive operation of the device. Two pulse power applications triggering electrical discharges are presented. Each one necessitates a specific pulsed power supply using series thyristor stacks or Marx structures. The first pulsed source delivers negative pulses with a crest voltage VoM=-35 kV, a turn on capability of Tr=90 ns and a repetition rate F=900 Hz. The second is built using Marx structure and is characterized by VoM=60 kV, Tr=250 ns, F=900 Hz.

  11. Substrate effects in high gain, low operating voltage SnSe2 photoconductor

    Science.gov (United States)

    Krishna, Murali; Kallatt, Sangeeth; Majumdar, Kausik

    2018-01-01

    High gain photoconductive devices find wide spread applications in low intensity light detection. Ultra-thin layered materials have recently drawn a lot of attention from researchers in this regard. However, in general, a large operating voltage is required to obtain large responsivity in these devices. In addition, the characteristics are often confounded by substrate induced trap effects. Here we report multi-layer SnSe2 based photoconductive devices using two different structures: (1) SiO2 substrate supported inter-digitated electrode (IDE), and (2) suspended channel. The IDE device exhibits a responsivity of ≈ {10}3 A W‑1 and ≈ 8.66× {10}4 A W‑1 at operating voltages of 1 mV and 100 mV, respectively—a superior low voltage performance over existing literature on planar 2D structures. However, the responsivity reduces by more than two orders of magnitude, while the transient response improves for the suspended device—providing insights into the critical role played by the channel-substrate interface in the gain mechanism. The results, on one hand, are promising for highly sensitive photoconductive applications consuming ultra-low power, and on the other hand, show a generic methodology that could be applied to other layered material based photoconductive devices as well for extracting the intrinsic behavior.

  12. Kinetics of charged particles in a high-voltage gas discharge in a nonuniform electrostatic field

    Energy Technology Data Exchange (ETDEWEB)

    Kolpakov, V. A., E-mail: kolpakov683@gmail.com; Krichevskii, S. V.; Markushin, M. A. [Korolev Samara National Research University (Russian Federation)

    2017-01-15

    A high-voltage gas discharge is of interest as a possible means of generating directed flows of low-temperature plasma in the off-electrode space distinguished by its original features [1–4]. We propose a model for calculating the trajectories of charges particles in a high-voltage gas discharge in nitrogen at a pressure of 0.15 Torr existing in a nonuniform electrostatic field and the strength of this field. Based on the results of our calculations, we supplement and refine the extensive experimental data concerning the investigation of such a discharge published in [1, 2, 5–8]; good agreement between the theory and experiment has been achieved. The discharge burning is initiated and maintained through bulk electron-impact ionization and ion–electron emission. We have determined the sizes of the cathode surface regions responsible for these processes, including the sizes of the axial zone involved in the discharge generation. The main effect determining the kinetics of charged particles consists in a sharp decrease in the strength of the field under consideration outside the interelectrode space, which allows a free motion of charges with specific energies and trajectories to be generated in it. The simulation results confirm that complex electrode systems that allow directed plasma flows to be generated at a discharge current of hundreds or thousands of milliamperes and a voltage on the electrodes of 0.3–1 kV can be implemented in practice [3, 9, 10].

  13. A compact high-voltage pulse generator based on pulse transformer with closed magnetic core.

    Science.gov (United States)

    Zhang, Yu; Liu, Jinliang; Cheng, Xinbing; Bai, Guoqiang; Zhang, Hongbo; Feng, Jiahuai; Liang, Bo

    2010-03-01

    A compact high-voltage nanosecond pulse generator, based on a pulse transformer with a closed magnetic core, is presented in this paper. The pulse generator consists of a miniaturized pulse transformer, a curled parallel strip pulse forming line (PFL), a spark gap, and a matched load. The innovative design is characterized by the compact structure of the transformer and the curled strip PFL. A new structure of transformer windings was designed to keep good insulation and decrease distributed capacitance between turns of windings. A three-copper-strip structure was adopted to avoid asymmetric coupling of the curled strip PFL. When the 31 microF primary capacitor is charged to 2 kV, the pulse transformer can charge the PFL to 165 kV, and the 3.5 ohm matched load can deliver a high-voltage pulse with a duration of 9 ns, amplitude of 84 kV, and rise time of 5.1 ns. When the load is changed to 50 ohms, the output peak voltage of the generator can be 165 kV, the full width at half maximum is 68 ns, and the rise time is 6.5 ns.

  14. Effect of secondary electron emission on subnanosecond breakdown in high-voltage pulse discharge

    Science.gov (United States)

    Schweigert, I. V.; Alexandrov, A. L.; Gugin, P.; Lavrukhin, M.; Bokhan, P. A.; Zakrevsky, Dm E.

    2017-11-01

    The subnanosecond breakdown in open discharge may be applied for producing superfast high power switches. Such fast breakdown in high-voltage pulse discharge in helium was explored both in experiment and in kinetic simulations. The kinetic model of electron avalanche development was developed using PIC-MCC technique. The model simulates motion of electrons, ions and fast helium atoms, appearing due to ions scattering. It was shown that the mechanism responsible for ultra-fast breakdown development is the electron emission from cathode. The photoemission and emission by ions or fast atoms impact is the main reason of current growth at the early stage of breakdown, but at the final stage, when the voltage on discharge gap drops, the secondary electron emission (SEE) is responsible for subnanosecond time scale of current growth. It was also found that the characteristic time of the current growth τS depends on the SEE yield of the cathode material. Three types of cathode material (titanium, SiC, and CuAlMg-alloy) were tested. It is shown that in discharge with SiC and CuAlMg-alloy cathodes (which have enhanced SEE) the current can increase with a subnanosecond characteristic time as small as τS = 0.4 ns, for the pulse voltage amplitude of 5- 12 kV..

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

    Directory of Open Access Journals (Sweden)

    R.O. Brasil

    1999-06-01

    Full Text Available 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.

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

    Science.gov (United States)

    Brasil, R O; Leal-Cardoso, J H

    1999-06-01

    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 10(11) ohms and capacitance 35 picofarads. The rise time and fall time were identical (5 microseconds) 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.

  17. Ultra-Low-Voltage CMOS-Based Current Bleeding Mixer with High LO-RF Isolation

    Directory of Open Access Journals (Sweden)

    Gim Heng Tan

    2014-01-01

    Full Text Available This journal presents an ultra-low-voltage current bleeding mixer with high LO-RF port-to-port isolation, implemented on 0.13 μm standard CMOS technology for ZigBee application. The architecture compliments a modified current bleeding topology, consisting of NMOS-based current bleeding transistor, PMOS-based switching stage, and integrated inductors achieving low-voltage operation and high LO-RF isolation. The mixer exhibits a conversion gain of 7.5 dB at the radio frequency (RF of 2.4 GHz, an input third-order intercept point (IIP3 of 1 dBm, and a LO-RF isolation measured to 60 dB. The DC power consumption is 572 µW at supply voltage of 0.45 V, while consuming a chip area of 0.97 × 0.88 mm2.

  18. Marine High Voltage Power Conditioning and Transmission System with Integrated Storage DE-EE0003640 Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Frank Hoffmann, PhD; Aspinall, Rik

    2012-12-10

    Design, Development, and test of the three-port power converter for marine hydrokinetic power transmission. Converter provides ports for AC/DC conversion of hydrokinetic power, battery storage, and a low voltage to high voltage DC port for HVDC transmission to shore. The report covers the design, development, implementation, and testing of a prototype built by PPS.

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

    Science.gov (United States)

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

    2014-05-01

    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

  20. Design of High-Voltage Switch-Mode Power Amplifier Based on Digital-Controlled Hybrid Multilevel Converter

    National Research Council Canada - National Science Library

    Hou, Yanbin; Sun, Wanrong; Ren, Aifeng; Liu, Shuming

    2016-01-01

    ...) and hybrid multilevel converter. Under the control of input signal, cascaded power converters with separate DC sources operate in PSM switch mode to directly generate high-voltage and high-power output...

  1. Novel Nonflammable Electrolytes for Secondary Magnesium Batteries and High Voltage Electrolytes for Electrochemcial Supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Dixon, Brian

    2008-12-30

    Magnesium has been used successfully in primary batteries, but its use in rechargeable cells has been stymied by the lack of suitable non-aqueous electrolyte that can conduct Mg+2 species, combined with poor stripping and plating properties. The development of a suitable cathode material for rechargeable magnesium batteries has also been a roadblock, but a nonflammable electrolyte is key. Likewise, the development of safe high voltage electrochemical supercapaitors has been stymied by the use of flammable solvents in the liquid electrolyte; to wit, acetonitrile. The purpose of the research conducted in this effort was to identify useful compositions of magnesium salts and polyphosphate solvents that would enable magnesium ions to be cycled within a secondary battery design. The polyphosphate solvents would provide the solvent for the magnesium salts while preventing the electrolyte from being flammable. This would enable these novel electrolytes to be considered as an alternative to THF-based electrolytes. In addition, we explored several of these solvents together with lithium slats for use as high voltage electrolytes for carbon-based electrochemical supercapacitors. The research was successful in that: 1) Magnesium imide dissolved in a phosphate ester solvent that contains a halogented phosphate ester appears to be the preferred electrolyte for a rechargeable Mg cell. 2) A combination of B-doped CNTs and vanadium phosphate appear to be the cathode of choice for a rechargeable Mg cell by virtue of higher voltage and better reversibility. 3) Magnesium alloys appear to perform better than pure magnesium when used in combination with the novel polyphosphate electrolytes. Also, this effort has established that Phoenix Innovation's family of phosphonate/phosphate electrolytes together with specific lithium slats can be used in supercapacitor systems at voltages of greater than 10V.

  2. Loading effect of a barium titanate artificial interface on high voltage capabilities at high charge and discharge rates

    Science.gov (United States)

    Yoshikawa, Yumi; Teranishi, Takashi; Hayashi, Hidetaka; Kishimoto, Akira

    2017-10-01

    Cyclic characteristics of BaTiO3 (BT)-decorated LiCoO2 (LC), for use as an artificial solid electrolyte interface (SEI) were evaluated at high voltages. Within the standard voltage window (i.e., 3.3-4.2 V), the BT-decorated LC exhibited greater capacities for up to 80 cycles compared with both the Al2O3 (paraelectric)-decorated and bare LC SEIs. The discharge capacity retention after 80 cycles (compared with the initial value) was 86.0% for the BT-LC cathode. This is a significant improvement over both the bare LC that showed 19.9% retention and the Al2O3-LC that displayed 71.5% retention. Thereafter, the cyclic stabilities of the BT-LC and bare LC were compared within potential windows at cutoff voltages as high as 4.9 V. In this region, BT decoration yielded marked improvements in capacity retention after 50 cycles, up to a potential of 4.7 V. The post-situ XRD analysis of the cathode sheets showed that BT decoration effectively stabilized the hexagonal crystal structure of the LC, H1, resulting in the said cyclic stability increase. These observations demonstrate that the use of BT in SEI allows a significant increase in working voltage while maintaining the chemical stability of the underlying LC matrix, a key advancement in the perpetual pursuit of ever higher cell energy densities.

  3. Modeling of high composition AlGaN channel high electron mobility transistors with large threshold voltage

    Energy Technology Data Exchange (ETDEWEB)

    Bajaj, Sanyam, E-mail: bajaj.10@osu.edu; Hung, Ting-Hsiang; Akyol, Fatih; Nath, Digbijoy; Rajan, Siddharth [Department of Electrical and Computer Engineering, The Ohio State University, Columbus, Ohio 43210 (United States)

    2014-12-29

    We report on the potential of high electron mobility transistors (HEMTs) consisting of high composition AlGaN channel and barrier layers for power switching applications. Detailed two-dimensional (2D) simulations show that threshold voltages in excess of 3 V can be achieved through the use of AlGaN channel layers. We also calculate the 2D electron gas mobility in AlGaN channel HEMTs and evaluate their power figures of merit as a function of device operating temperature and Al mole fraction in the channel. Our models show that power switching transistors with AlGaN channels would have comparable on-resistance to GaN-channel based transistors for the same operation voltage. The modeling in this paper shows the potential of high composition AlGaN as a channel material for future high threshold enhancement mode transistors.

  4. High voltage spinel oxides for Li-ion batteries: From the material research to the application

    Science.gov (United States)

    Patoux, Sébastien; Daniel, Lise; Bourbon, Carole; Lignier, Hélène; Pagano, Carole; Le Cras, Frédéric; Jouanneau, Séverine; Martinet, Sébastien

    Li-ion batteries are already used in many nomad applications, but improvement of this technology is still necessary to be durably introduced on new markets such as electric vehicles (EVs), hybrid electric vehicles (HEVs) or eventually photovoltaic solar cells. Modification of the nature of the active materials of electrodes is the most challenging and innovative aspect. High voltage spinel oxides for Li-ion batteries, with general composition LiMn 2- xM xO 4 (M a transition metal element), may be used to face increasing power source demand. It should be possible to obtain up to 240 Wh kg -1 at cell level when combining a nickel manganese spinel oxide with graphite (even more with silicon/carbon nanocomposites at the anode). Specific composition and material processing have to be selected with care, as discussed in this paper. It is demonstrated that 'LiNi 0.5Mn 1.5O 4' and LiNi 0.4Mn 1.6O 4 have remarkable properties such as high potential, high energy density, good cycle life and high rate capability. Choice of the electrolyte is also of primary importance in order to prevent its degradation at high voltage in contact with active surfaces. We showed that a few percents of additive in the electrolyte were suitable for protecting the positive electrode/electrolyte interface, and reducing the self-discharge. High voltage materials are also possibly interesting to be used in safe and high power Li-ion cells. In this case, the negative electrode may be made of Li 4Ti 5O 12 or TiO 2 to give a '3 V' system.

  5. Highly Stable Anion Exchange Membranes for High-Voltage Redox-Flow Batteries

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Yushan

    2018-02-26

    In this work, multiple polymer backbones were screened for oxidation resistance and multiple chemistries were explored for tethering tris(2,4,6-trimethylphenyl)phosphonium (9MeTTP+) to the selected polymer backbones. A new tethering strategy through brominated 9MeTTP+ cation was developed and used to obtain the desired 9MeTTP+−functionalized polysulfone (PSf) and hexafluoro polybenzimidazole (F6PBI) polymer. The crosslinked 9MeTTP+−functionalized hexafluoro polybenzimidazole (9MeTTP−F6PBI) polymer demonstrated excellent oxidation stability that met the go-no-go milestone of the first year. However, large-scale bromination inevitably involved multi-bromination products, which led to polymer crosslinking in the next tethering. A new synthesis strategy with diiodobutane as linker was developed to overcome the crosslinking problem. The prepared 9MeTTP+-F6PBI membrane without crosslinking showed only 3.58% water uptake and less than 1 mS/cm OH- conductivity in water at 20°C, possibly due to the hydrophobic 9MeTTP+ cation. In order to improve the conductivity, hydrophilic tris(2,4,6-trimethoxylphenyl)phosphonium (9MeOTTP+) cation was tethered to an F6PBI backbone, and a 9MeOTTP+-F6PBI PTFE reinforced membrane was prepared with 17.4% water uptake to increase the mechanical strength and durability in cerium (IV) solution. A 9MeOTTP+-F6PBI PTFE reinforced membrane had less than 20% conductivity loss during an accelerated stability test in 0.5 M cerium (IV) and 1.3 M HClO4 at 55°C for 100 hours. Moreover, a 9MeOTTP+-F6PBI PTFE reinforced membrane had more than double the lifetime of commercial FAS-30 and FAB-PK-130 AEMs during an accelerated stability test in 0.5 M cerium (IV) and 1.3 M HClO4 at 55°C. Low area specific resistance (ASR) of a 9MeOTTP+-F6PBI PTFE reinforced membrane in the sulfuric acid system was also achieved due to the high acid doping ability of the polymer structure. The cationic 9MeOTTP+-F6PBI PTFE reinforced membrane shows a cerium (IV

  6. High Voltage EEE Parts for EMA/EHA Applications on Manned Launch Vehicles

    Science.gov (United States)

    Griffin, Trent; Young, David

    2011-01-01

    The objective of this paper is an assessment of high voltage electronic components required for high horsepower electric thrust vector control (TVC) systems for human spaceflight launch critical application. The scope consists of creating of a database of available Grade 1 electrical, electronic and electromechanical (EEE) parts suited to this application, a qualification path for potential non-Grade 1 EEE parts that could be used in these designs, and pathfinder testing to validate aspects of the proposed qualification plan. Advances in the state of the art in high power electric power systems enable high horsepower electric actuators, such as the electromechnical actuator (EMA) and the electro-hydrostatic actuator (EHA), to be used in launch vehicle TVC systems, dramaticly reducing weight, complexity and operating costs. Designs typically use high voltage insulated gate bipolar transistors (HV-IGBT). However, no Grade 1 HV-IGBT exists and it is unlikely that market factors alone will produce such high quality parts. Furthermore, the perception of risk, the lack of qualification methodoloy, the absence of manned space flight heritage and other barriers impede the adoption of commercial grade parts onto the critical path. The method of approach is to identify high voltage electronic component types and key parameters for parts currently used in high horsepower EMA/EHA applications, to search for higher quality substitutes and custom manufacturers, to create a database for these parts, and then to explore ways to qualify these parts for use in human spaceflight launch critical application, including grossly derating and possibly treating hybrid parts as modules. This effort is ongoing, but results thus far include identification of over 60 HV-IGBT from four manufacturers, including some with a high reliability process flow. Voltage ranges for HV-IGBT have been identified, as has screening tests used to characterize HV-IGBT. BSI BS ISO 21350 Space systems Off

  7. Test Results from a Simulated High Voltage Lunar Power Transmission Line

    Science.gov (United States)

    Birchenough, Arthur; Hervol, David

    2008-01-01

    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.

  8. The progress of funnelling gun high voltage condition and beam test

    Energy Technology Data Exchange (ETDEWEB)

    Wang, E. [Brookhaven National Lab. (BNL), Upton, NY (United States); Ben-Zvi, I. [Brookhaven National Lab. (BNL), Upton, NY (United States); Gassner, D. M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Lambiase, R. [Brookhaven National Lab. (BNL), Upton, NY (United States); Meng, W. [Brookhaven National Lab. (BNL), Upton, NY (United States); Rahman, O. [Brookhaven National Lab. (BNL), Upton, NY (United States); Pikin, A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Rao, T. [Brookhaven National Lab. (BNL), Upton, NY (United States); Sheehy, B. [Brookhaven National Lab. (BNL), Upton, NY (United States); Skaritka, J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Pietz, J. [Transfer Engineering and Manufacturing, Inc., Fremont, CA (United States); Ackeret, M. [Transfer Engineering and Manufacturing, Inc., Fremont, CA (United States); Yeckel, C. [Thompson, Stangenes Industries, Palo Alto, CA (United States); Miller, R. [Thompson, Stangenes Industries, Palo Alto, CA (United States); Dobrin, E. [Thompson, Stangenes Industries, Palo Alto, CA (United States); Thompson, K. [Thompson, Stangenes Industries, Palo Alto, CA (United States)

    2015-05-03

    A prototype of a high average current polarized electron funneling gun as an eRHIC injector has been built at BNL. The gun was assembled and tested at Stangenes Incorporated. Two beams were generated from two GaAs photocathodes and combined by a switched combiner field. We observed the combined beams on a YAG crystal and measured the photocurrent by a Faraday cup. The gun has been shipped to Stony Brook University and is being tested there. In this paper we will describe the major components of the gun and recent beam test results. High voltage conditioning is discussed as well.

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

    Science.gov (United States)

    Birchenough, Arthur; Hervol, David

    2008-01-01

    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.

  10. Simulation study on transient electric shock characteristics of human body under high voltage ac transmission lines

    Science.gov (United States)

    Huang, Tao; Zou, Yanhui; Lv, Jianhong; Yang, Jinchun; Tao, Li; Zhou, Jianfei

    2017-09-01

    Human body under high-voltage AC transmission lines will produce a certain induced voltage due to the electrostatic induction. When the human body contacts with some grounded objects, the charges transfer from the body to the ground and produce contact current which may cause transient electric shock. Using CDEGS and ATP/EMTP, the paper proposes a method for quantitatively calculating the transient electric shock characteristics. It calculates the human body voltage, discharge current and discharge energy under certain 500kV compact-type transmission lines and predicts the corresponding human feelings. The results show that the average root value of discharge current is less than 10mA when the human body is under the 500kV compact-type transmission lines and the human body is overall safe if the transmission lines satisfy the relevant design specifications. It concludes that the electric field strength above the ground should be limited to 4kV/m through the residential area for the purpose of reducing the electromagnetic impact.

  11. A High-Efficiency Voltage Equalization Scheme for Supercapacitor Energy Storage System in Renewable Generation Applications

    Directory of Open Access Journals (Sweden)

    Liran Li

    2016-06-01

    Full Text Available Due to its fast charge and discharge rate, a supercapacitor-based energy storage system is especially suitable for power smoothing in renewable energy generation applications. Voltage equalization is essential for series-connected supercapacitors in an energy storage system, because it supports the system’s sustainability and maximizes the available cell energy. In this paper, we present a high-efficiency voltage equalization scheme for supercapacitor energy storage systems in renewable generation applications. We propose an improved isolated converter topology that uses a multi-winding transformer. An improved push-pull forward circuit is applied on the primary side of the transformer. A coupling inductor is added on the primary side to allow the switches to operate under the zero-voltage switching (ZVS condition, which reduces switching losses. The diodes in the rectifier are replaced with metal-oxide-semiconductor field-effect transistors (MOSFETs to reduce the power dissipation of the secondary side. In order to simplify the control, we designed a controllable rectifying circuit to achieve synchronous rectifying on the secondary side of the transformer. The experimental results verified the effectiveness of the proposed design.

  12. High voltage 4H SiC rectifiers using Pt and Ni metallization

    Energy Technology Data Exchange (ETDEWEB)

    Saxena, V.; Steckl, A.J. [Cincinnati Univ., OH (United States). Nanoelectronic Lab.

    1998-08-01

    We have fabricated high voltage 4H SiC rectifier diodes using Ni and Pt as metals for the Schottky contacts. At a current density of 100 A/cm{sup 2}, these diodes had a forward voltage drop of 1.76 and 1.86 V, respectively. Both Ni- and Pt-SiC diodes had breakdown voltages >1000 V. Pt-based SiC diodes exhibited a higher on-off current ratio (>10{sup 8}) and lower ideality factor (1.11) at room temperature than the Ni-based diodes (>10{sup 6} and 1.29). The diodes were operated at elevated temperatures up to 450 C for forward bias and 300 C for reverse bias. The room temperature barrier height of Ni on 4H SiC was determined to be 1.31 eV and the specific on-resistance of the diodes was found to be {proportional_to}8 m{Omega}-cm{sup 2}. (orig.) 9 refs.

  13. Cavity voltage phase modulation to reduce the high-luminosity Large Hadron Collider rf power requirements

    Science.gov (United States)

    Mastoridis, T.; Baudrenghien, P.; Molendijk, J.

    2017-10-01

    The Large Hadron Collider (LHC) radio frequency (rf) and low-level rf (LLRF) systems are currently configured for constant rf voltage to minimize transient beam loading effects. The present scheme cannot be extended beyond nominal LHC beam current (0.55 A dc) and cannot be sustained for the high-luminosity (HL-LHC) beam current (1.1 A dc), since the demanded power would exceed the peak klystron power. A new scheme has therefore been proposed: for beam currents above nominal (and possibly earlier), the voltage reference will reproduce the modulation driven by the beam (transient beam loading), but the strong rf feedback and one-turn delay feedback will still be active for loop and beam stability. To achieve this, the voltage reference will be adapted for each bunch. This paper includes a theoretical derivation of the optimal cavity modulation, introduces the implemented algorithm, summarizes simulation runs that tested the algorithm performance, and presents results from a short LHC physics fill with the proposed implementation.

  14. Cavity voltage phase modulation to reduce the high-luminosity Large Hadron Collider rf power requirements

    Directory of Open Access Journals (Sweden)

    T. Mastoridis

    2017-10-01

    Full Text Available The Large Hadron Collider (LHC radio frequency (rf and low-level rf (LLRF systems are currently configured for constant rf voltage to minimize transient beam loading effects. The present scheme cannot be extended beyond nominal LHC beam current (0.55 A dc and cannot be sustained for the high-luminosity (HL-LHC beam current (1.1 A dc, since the demanded power would exceed the peak klystron power. A new scheme has therefore been proposed: for beam currents above nominal (and possibly earlier, the voltage reference will reproduce the modulation driven by the beam (transient beam loading, but the strong rf feedback and one-turn delay feedback will still be active for loop and beam stability. To achieve this, the voltage reference will be adapted for each bunch. This paper includes a theoretical derivation of the optimal cavity modulation, introduces the implemented algorithm, summarizes simulation runs that tested the algorithm performance, and presents results from a short LHC physics fill with the proposed implementation.

  15. 3D MHD modelling of low current-high voltage dc plasma torch under restrike mode

    Science.gov (United States)

    Lebouvier, A.; Delalondre, C.; Fresnet, F.; Cauneau, F.; Fulcheri, L.

    2012-01-01

    We present in this paper a magnetohydrodynamic (MHD) modelling of the gliding arc behaviour of a dc plasma torch operating with air under low current and high voltage conditions. The low current leads to instabilities and difficulties with simulating the process because the magnetic field is not sufficient to constrict the arc. The model is 3D, time dependent and the MHD equations are solved using CFD software Code_Saturne®. Although the arc is definitively non-local thermodynamic equilibrium (LTE), the LTE assumption is considered as a first approach. The injection of air is tangential. A hot gas channel reattachment model has been used to simulate the restriking process of the arc root. After the description of the model, the most appropriate electrical voltage breakdown parameter has been selected in comparing with experimental results. A typical operating point is then studied in detail and shows the helical shape of the arc discharge in the nozzle. Finally, the mass flow rate and the current have been varied in the range 0.16-0.5 g s-1 and 100-300 mA, respectively, corresponding to typical glidarc operating points of our experimental plasma torch. The model shows good consistency with experimental data in terms of global behaviour, arc length, mean voltage and glidarc frequency.

  16. Simulation Model solves exact the Enigma named Generating high Voltages and high Frequencies by Tesla Coil

    OpenAIRE

    Simo Janjanin

    2016-01-01

    Simulation model of Tesla coil has been successfully completed, and has been verified the procedure and functioning. The literature and documentation for the model were taken from the rich sources, especially the copies of Tesla patents. The oscillating system‟s electrical scheme consists of the voltage supply 220/50 Hz, Fe transformer, capacitor and belonging chosen electrical components, the air gap in the primary Tesla coil (air transformer) and spark gap in the exit of the coil. The inves...

  17. IEDF distortion and resolution considerations for RFEA operation at high voltages

    Science.gov (United States)

    Talley, M. L.; Shannon, S.; Chen, L.; Verboncoeur, J. P.

    2017-12-01

    Retarding field energy analyzers (RFEA) have been used extensively to measure the ion flux energy distribution function of plasmas. For consistency, the ion flux energy distribution function is referred to as the ion energy distribution function (IEDf) even though it more accurately represents the one-dimensional ion velocity distribution function. In the past, these devices have operated at voltages less than 1 kV. Higher operating voltages (>2 kV) are currently desired. For an RFEA to operate at these voltages, design changes are necessary that impact the energy resolution and cause space charge build-up. To investigate the effect the design changes have for a high voltage RFEA, electromagnetic simulations and particle-in-cell (PIC) simulations were used to analyze the electric field between the grids, the potential drop in the grid holes, and space charge build-up between the grids. Non-unique optimized dimensions for the RFEA increased the electric field uniformity. The optimization minimizes the electric field from distorting the IV curve or adversely affecting the energy resolution. It was found that a larger grid gap distance and smaller grid hole diameter decreases the potential drop in the grid holes improving energy resolution. IV curves from the PIC simulation were used to obtain space charge distorted IEDfs. The point at which space charge distorts the IV curve is dependent on the grid gap distance and incoming flux. Space charge build-up was found to only affect low energy ions which manifested by cutting off the low energy portion of the IEDf. To fix space charge distortions, the flux into the probe can be limited or it may be possible to account for the distortion when calculating the IEDf.

  18. Electronics drivers for high voltage dielectric electro active polymer (DEAP) applications

    Science.gov (United States)

    Zhang, Zhe; Andersen, Michael A. E.

    2015-04-01

    Dielectric electro active polymer (DEAP) can be used in actuation, sensing and energy harvesting applications, but driving the DEAP based actuators and generators has three main challenges from a power electronics standpoint, i.e. high voltage (around 2.5 kV), nonlinearity, and capacitive behavior. In this paper, electronics divers for heating valves, loud speakers, incremental motors, and energy harvesting are reviewed, studied and developed in accordance with their corresponding specifications. Due to the simplicity and low power capacity (below 10W), the reversible Fly-back converters with both magnetic and piezoelectric transformers are employed for the heating valve and incremental motor application, where only ON/OFF regulation is adopted for energy saving; as for DEAP based energy harvesting, the noisolated Buck/Boost converter is used, due to the system high power capacity (above 100W), but the voltage balancing across the series-connected high voltage IGBTs is a critical issue and accordingly a novel gate driver circuitry is proposed and equipped; due to the requirements of the audio products, such as low distortion and noise, the multi-level Buck converter based Class-D amplifier, because of its high control linearity, is implemented for the loud speaker applications. A synthesis among those converter topologies and control techniques is given; therefore, for those DEAP based applications, their diversity and similarity of electronics drivers, as well as the key technologies employed are analyzed. Therefore a whole picture of how to choose the proper topologies can be revealed. Finally, the design guidelines in order to achieve high efficiency and reliability are discussed.

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

    DEFF Research Database (Denmark)

    Blank, Tobias; Thomas, Stephan; Roggendorf, Christoph

    2010-01-01

    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...... 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...

  20. High Current, Low Voltage Power Converter [20kA, 6V] LHC Converter Prototype

    CERN Document Server

    Jørgensen, H E; Dupaquier, A; Fernqvist, G

    1998-01-01

    The superconducting LHC accelerator requires high currents (~12.5kA) and relatively low voltages (~10 V) for its magnets. The need to install the power converters underground is the driving force for reduced volume and high efficiency. Moreover, the LHC machine will require a very high level of performance from the power converters, particularly in terms of DC stability, dynamic response and also in matters of EMC. To meet these requirements soft-switching techniques will be used. This paper describes the development of a [20kA,6V] power converter intended as a stable high-current source for D CCT calibration and an evaluation prototype for the future LHC converters. The converter is made with a modular concept with five current sources [4kA,6V] in parallel. The 4kA sources are built as plu g-in modules: a diode rectifier on the AC mains with a damped L-C passive filter, a Zero Voltage Switching inverter working at 20 kHz and an output stage (high frequency transformers, Schottky rectifi ers and output filter...

  1. Charge and fluence lifetime measurements of a dc high voltage GaAs photogun at high average current

    Directory of Open Access Journals (Sweden)

    J. Grames

    2011-04-01

    Full Text Available GaAs-based dc high voltage photoguns used at accelerators with extensive user programs must exhibit long photocathode operating lifetime. Achieving this goal represents a significant challenge for proposed high average current facilities that must operate at tens of milliamperes or more. This paper describes techniques to maintain good vacuum while delivering beam, and techniques that minimize the ill effects of ion bombardment, the dominant mechanism that reduces photocathode yield of a GaAs-based dc high voltage photogun. Experimental results presented here demonstrate enhanced lifetime at high beam currents by: (a operating with the drive laser beam positioned away from the electrostatic center of the photocathode, (b limiting the photocathode active area to eliminate photoemission from regions of the photocathode that do not support efficient beam delivery, (c using a large drive laser beam to distribute ion damage over a larger area, and (d by applying a relatively low bias voltage to the anode to repel ions created within the downstream beam line. A combination of these techniques provided the best total charge extracted lifetimes in excess of 1000 C at dc beam currents up to 9.5 mA, using green light illumination of bulk GaAs inside a 100 kV photogun.

  2. Charge and fluence lifetime measurements of a dc high voltage GaAs photogun at high average current

    Energy Technology Data Exchange (ETDEWEB)

    J. Grames, R. Suleiman, P.A. Adderley, J. Clark, J. Hansknecht, D. Machie, M. Poelker, M.L. Stutzman

    2011-04-01

    GaAs-based dc high voltage photoguns used at accelerators with extensive user programs must exhibit long photocathode operating lifetime. Achieving this goal represents a significant challenge for proposed high average current facilities that must operate at tens of milliamperes or more. This paper describes techniques to maintain good vacuum while delivering beam, and techniques that minimize the ill effects of ion bombardment, the dominant mechanism that reduces photocathode yield of a GaAs-based dc high voltage photogun. Experimental results presented here demonstrate enhanced lifetime at high beam currents by: (a) operating with the drive laser beam positioned away from the electrostatic center of the photocathode, (b) limiting the photocathode active area to eliminate photoemission from regions of the photocathode that do not support efficient beam delivery, (c) using a large drive laser beam to distribute ion damage over a larger area, and (d) by applying a relatively low bias voltage to the anode to repel ions created within the downstream beam line. A combination of these techniques provided the best total charge extracted lifetimes in excess of 1000 C at dc beam currents up to 9.5 mA, using green light illumination of bulk GaAs inside a 100 kV photogun.

  3. X-ray microanalysis of biological specimens by high voltage electron microscopy.

    Science.gov (United States)

    Nagata, Tetsuji

    2004-01-01

    For the purpose of analyzing and imaging chemical components of cells and tissues at the electron microscopic level, 3 fundamental methods are available, chemical, physical and biological. Among the physical methods, two methods qualifying and quantifying the elements in the structural components are very often employed. The first method is radioautography which can demonstrate the localization of radiolabeled compounds which were incorporated into cells and tissues after the administration of radiolabeled compounds. The second method is X-ray microanalysis which can qualitatively analyze and quantify the total amounts of elements present in cells and tissues. We have developed the two methodologies in combination with intermediate high or high voltage transmission electron microscopy (200-400 kV) and applied them to various kinds of organic and inorganic compounds present in biological materials. As for the first method, radioautography, I had already contributed a chapter to PHC (37/2). To the contrary, this review deals with another method, X-ray microanalysis, using semi-thin sections and intermediate high voltage electron microscopy developed in our laboratory. X-ray microanalysis is a useful method to qualify and quantify basic elements in biological specimens. We first quantified the end-products of histochemical reactions such as Ag in radioautographs, Ce in phosphatase reaction and Au in colloidal gold immunostaining using semithin sections and quantified the reaction products observing by intermediate high voltage transmission electron microscopy at accelerating voltages from 100 to 400 kV. The P/B ratios of all the end products Ag, Ce and Au increased with the increase of the accelerating voltages from 100 to 400 kV. Then we analyzed various trace elements such as Zn, Ca, S and Cl which originally existed in cytoplasmic matrix or cell organelles of various cells, or such elements as Al which was absorbed into cells and tissues after oral administration

  4. PIEZOELECTRIC WAVEGUIDE SENSOR FOR MEASURING PULSE PRESSURE IN CLOSED LIQUID VOLUMES AT HIGH VOLTAGE ELECTRIC DISCHARGE

    Directory of Open Access Journals (Sweden)

    V. G. Zhekul

    2017-10-01

    Full Text Available Purpose. Investigations of the characteristics of pressure waves presuppose the registration of the total profile of the pressure wave at a given point in space. For these purposes, various types of «pressure to the electrical signal» transmitters (sensors are used. Most of the common sensors are unsuitable for measuring the pulse pressure in a closed water volume at high hydrostatic pressures, in particular to study the effect of a powerful high-voltage pulse discharge on increasing the inflow of minerals and drinking water in wells. The purpose of the work was to develop antijamming piezoelectric waveguide sensor for measuring pulse pressure at a close distance from a high-voltage discharge channel in a closed volume of a liquid. Methodology. We have applied the calibration method as used as a secondary standard, the theory of electrical circuits. Results. We have selected the design and the circuit solution of the waveguide pressure sensor. We have developed a waveguide pulse-pressure sensor DTX-1 with a measuring loop. This sensor makes it possible to study the spectral characteristics of pressure waves of high-voltage pulse discharge in closed volumes of liquid at a hydrostatic pressure of up to 20 MPa and a temperature of up to 80 °C. The sensor can be used to study pressure waves with a maximum amplitude value of up to 150 MPa and duration of up to 80 µs. According to the results of the calibration, the sensitivity of the developed sensor DTX-1 with a measuring loop is 0.0346 V/MPa. Originality. We have further developed the theory of designing the waveguide piezoelectric pulse pressure sensors for measuring the pulse pressure at a close distance from a high-voltage discharge channel in a closed fluid volume by controlling the attenuation of the amplitude of the pressure signal. Practical value. We have developed, created, calibrated, used in scientific research waveguide pressure pulse sensors DTX-1. We propose sensors DTX-1 for sale

  5. The Effect of Current-Limiting Reactors on the Tripping of Short Circuits in High-Voltage Electrical Equipment

    Energy Technology Data Exchange (ETDEWEB)

    Volkov, M. S.; Gusev, Yu. P., E-mail: GusevYP@mpei.ru; Monakov, Yu. V.; Cho, Gvan Chun [National Research University “Moscow Power Engineering Institute,” (Russian Federation)

    2016-01-15

    The insertion of current-limiting reactors into electrical equipment operating at a voltage of 110 and 220 kV produces a change in the parameters of the transient recovery voltages at the contacts of the circuit breakers for disconnecting short circuits, which could be the reason for the increase in the duration of the short circuit, damage to the electrical equipment and losses in the power system. The results of mathematical modeling of the transients, caused by tripping of the short circuit in a reactive electric power transmission line are presented, and data are given on the negative effect of a current-limiting resistor on the rate of increase and peak value of the transient recovery voltages. Methods of ensuring the standard requirements imposed on the parameters of the transient recovery voltages when using current-limiting reactors in the high-voltage electrical equipment of power plants and substations are proposed and analyzed.

  6. A very low noise, high accuracy, programmable voltage source for low frequency noise measurements

    Science.gov (United States)

    Scandurra, Graziella; Giusi, Gino; Ciofi, Carmine

    2014-04-01

    In this paper an approach for designing a programmable, very low noise, high accuracy voltage source for biasing devices under test in low frequency noise measurements is proposed. The core of the system is a supercapacitor based two pole low pass filter used for filtering out the noise produced by a standard DA converter down to 100 mHz with an attenuation in excess of 40 dB. The high leakage current of the supercapacitors, however, introduces large DC errors that need to be compensated in order to obtain high accuracy as well as very low output noise. To this end, a proper circuit topology has been developed that allows to considerably reduce the effect of the supercapacitor leakage current on the DC response of the system while maintaining a very low level of output noise. With a proper design an output noise as low as the equivalent input voltage noise of the OP27 operational amplifier, used as the output buffer of the system, can be obtained with DC accuracies better that 0.05% up to the maximum output of 8 V. The expected performances of the proposed voltage source have been confirmed both by means of SPICE simulations and by means of measurements on actual prototypes. Turn on and stabilization times for the system are of the order of a few hundred seconds. These times are fully compatible with noise measurements down to 100 mHz, since measurement times of the order of several tens of minutes are required in any case in order to reduce the statistical error in the measured spectra down to an acceptable level.

  7. Superconcentrated electrolytes for a high-voltage lithium-ion battery

    Science.gov (United States)

    Wang, Jianhui; Yamada, Yuki; Sodeyama, Keitaro; Chiang, Ching Hua; Tateyama, Yoshitaka; Yamada, Atsuo

    2016-01-01

    Finding a viable electrolyte for next-generation 5 V-class lithium-ion batteries is of primary importance. A long-standing obstacle has been metal-ion dissolution at high voltages. The LiPF6 salt in conventional electrolytes is chemically unstable, which accelerates transition metal dissolution of the electrode material, yet beneficially suppresses oxidative dissolution of the aluminium current collector; replacing LiPF6 with more stable lithium salts may diminish transition metal dissolution but unfortunately encounters severe aluminium oxidation. Here we report an electrolyte design that can solve this dilemma. By mixing a stable lithium salt LiN(SO2F)2 with dimethyl carbonate solvent at extremely high concentrations, we obtain an unusual liquid showing a three-dimensional network of anions and solvent molecules that coordinate strongly to Li+ ions. This simple formulation of superconcentrated LiN(SO2F)2/dimethyl carbonate electrolyte inhibits the dissolution of both aluminium and transition metal at around 5 V, and realizes a high-voltage LiNi0.5Mn1.5O4/graphite battery that exhibits excellent cycling durability, high rate capability and enhanced safety. PMID:27354162

  8. PI and Fuzzy Control Strategies for High Voltage Output DC-DC Boost Power Converter - Hardware Implementation and Analysis

    DEFF Research Database (Denmark)

    Padmanaban, Sanjeevi Kumar; Blaabjerg, Frede; Siano, Pierluigi

    2016-01-01

    This paper presents the control strategies by Proportional-Integral (P-I) and Fuzzy Logic (FL) for a DC-DC boost power converter for high output voltage configuration. Standard DC-DC converters are traditionally used for high voltage direct current (HVDC) power transmission systems. But, lack its...... converter with inbuilt voltage-lift technique and overcome the aforementioned deficiencies. Further, the control strategy is adapted based on proportional-integral (P-I) and fuzzy logic, closed-loop controller to regulate the outputs and ensure the performances. Complete hardware prototype of EHV converter...

  9. A Dual Active Bridge Converter with an Extended High-Efficiency Range by DC Blocking Capacitor Voltage Control

    DEFF Research Database (Denmark)

    Qin, Zian; Shen, Yanfeng; Loh, Poh Chiang

    2017-01-01

    A Dual Active Bridge (DAB) converter can achieve a wide high-efficiency range when its input and output voltages are equal, assuming a 1:1 turns ratio for its isolation transformer. If its input or output voltage is doubled, efficiency of the DAB will drop significantly, because of the introduction...... of hard switching and high circulating power. Thus, a new modulation scheme has been proposed, whose main idea is to introduce a voltage offset across the dc blocking capacitor connected in series with the transformer. Operational principle of the proposed modulation has been introduced, before analyzing...

  10. Determination of exposure to electric fields in extra high voltage substations.

    Science.gov (United States)

    Lövstrand, K G

    1976-09-01

    Electrophysical effects related to extra high voltage are surveyed for the determination of the exposure of personnel to electric fields in substations. It is concluded that the electric field strengths and the electrical discharges to the personnel are the important electrophysical factors. Instruments for measuring the field strength at grounded surfaces and at nonzero potentials were constructed. Results are presented of measurements with these instruments in substations. A dummy was used for the measurement of the distribution of capacitive currents to a man. The dummy can also be used for measuring the effectiveness of special shielding clothes.

  11. Human-rated Safety Certification of a High Voltage Robonaut Lithium-ion Battery

    Science.gov (United States)

    Jeevarajan, Judith; Yayathi, S.; Johnson, M.; Waligora, T.; Verdeyen, W.

    2013-01-01

    NASA's rigorous certification process is being followed for the R2 high voltage battery program for use of R2 on International Space Station (ISS). Rigorous development testing at appropriate levels to credible off-nominal conditions and review of test data led to design improvements for safety at the virtual cell, cartridge and battery levels. Tests were carried out at all levels to confirm that both hardware and software controls work. Stringent flight acceptance testing of the flight battery will be completed before launch for mission use on ISS.

  12. Estimation of Transformer Parameters and Loss Analysis for High Voltage Capacitor Charging Application

    DEFF Research Database (Denmark)

    Thummala, Prasanth; Schneider, Henrik; Ouyang, Ziwei

    2013-01-01

    In a bi-directional DC-DC converter for capacitive charging application, the losses associated with the transformer makes it a critical component. In order to calculate the transformer losses, its parameters such as AC resistance, leakage inductance and self capacitance of the high voltage (HV......) winding has to be estimated accurately. This paper analyzes the following losses of bi-directional flyback converter namely switching loss, conduction loss, gate drive loss, transformer core loss, and snubber loss, etc. Iterative analysis of transformer parameters viz., AC resistance, leakage inductance...

  13. Thermocleavable Materials for Polymer Solar Cells with High Open Circuit Voltage-A Comparative Study

    DEFF Research Database (Denmark)

    Tromholt, Thomas; Gevorgyan, Suren; Jørgensen, Mikkel

    2009-01-01

    The search for polymer solar cells giving a high open circuit voltage was conducted through a comparative study of four types of bulk-heterojunction solar cells employing different photoactive layers. As electron donors the thermo-cleavable polymer poly-(3-(2-methylhexyloxycarbonyl)dithiophene) (P3...... in terms of substrate design and device processing, a substantial spread in the photovoltaic properties was generally observed. This spread could not be correlated with the optical properties of the solar cells, the thickness of the photo active layer or the electrode deposition conditions of the aluminum...... top electrode....

  14. Positron annihilation spectroscopy study of high-voltage polydimethylsiloxane (PDMS) insulators

    Energy Technology Data Exchange (ETDEWEB)

    Mallon, P.E.; Greyling, C.J.; Vosloo, W.; Jean, Y.C. E-mail: jeany@umkc.edu

    2003-11-01

    Polydimethylsiloxane (PDMS) compounds are used in outdoor high-voltage applications. Pure PDMS and compounds containing silica and aluminum trihydrate are studied using a mono-energetic positron beam. Large changes in the S parameter profiles as a function of depth from the surface are observed after samples are exposed to corona discharge. In addition, there are significant changes in the profiles on increasing relaxation time after corona treatment. Evidence is found for a silica-like layer at the surface after corona treatment. It is shown that the positron beam technique can provide important information on the mechanism of hydrophobicity loss and recovery that the samples show after corona treatment.

  15. Characteristics of plasma sterilizer using microwave torch plasma with AC high-voltage discharge plasma

    Science.gov (United States)

    Itarashiki, Tomomasa; Hayashi, Nobuya; Yonesu, Akira

    2016-01-01

    Microwave plasma sterilization has recently been attracting attention for medical applications. However, it is difficult to perform low-temperature sterilization in short time periods. Increasing the output power shortens the time required for sterilization but causes the temperature to increase. To overcome this issue, we have developed a hybrid plasma system that combines a microwave torch plasma and a high-voltage mesh plasma, which allows radicals to be produced at low temperatures. Using this system, successful sterilization was shown to be possible in a period of 45 min at a temperature of 41 °C.

  16. Trap Healing for High-Performance Low-Voltage Polymer Transistors and Solution-Based Analog Amplifiers on Foil.

    Science.gov (United States)

    Pecunia, Vincenzo; Nikolka, Mark; Sou, Antony; Nasrallah, Iyad; Amin, Atefeh Y; McCulloch, Iain; Sirringhaus, Henning

    2017-06-01

    Solution-processed semiconductors such as conjugated polymers have great potential in large-area electronics. While extremely appealing due to their low-temperature and high-throughput deposition methods, their integration in high-performance circuits has been difficult. An important remaining challenge is the achievement of low-voltage circuit operation. The present study focuses on state-of-the-art polymer thin-film transistors based on poly(indacenodithiophene-benzothiadiazole) and shows that the general paradigm for low-voltage operation via an enhanced gate-to-channel capacitive coupling is unable to deliver high-performance device behavior. The order-of-magnitude longitudinal-field reduction demanded by low-voltage operation plays a fundamental role, enabling bulk trapping and leading to compromised contact properties. A trap-reduction technique based on small molecule additives, however, is capable of overcoming this effect, allowing low-voltage high-mobility operation. This approach is readily applicable to low-voltage circuit integration, as this work exemplifies by demonstrating high-performance analog differential amplifiers operating at a battery-compatible power supply voltage of 5 V with power dissipation of 11 µW, and attaining a voltage gain above 60 dB at a power supply voltage below 8 V. These findings constitute an important milestone in realizing low-voltage polymer transistors for solution-based analog electronics that meets performance and power-dissipation requirements for a range of battery-powered smart-sensing applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. High-voltage zones within the pulmonary vein antra: Major determinants of acute pulmonary vein reconnections after atrial fibrillation ablation.

    Science.gov (United States)

    Nagashima, Koichi; Watanabe, Ichiro; Okumura, Yasuo; Iso, Kazuki; Takahashi, Keiko; Watanabe, Ryuta; Arai, Masaru; Kurokawa, Sayaka; Nakai, Toshiko; Ohkubo, Kimie; Yoda, Shunichi; Hirayama, Atsushi

    2017-08-01

    Recurrence of atrial fibrillation (AF) after pulmonary vein isolation (PVI) is mainly due to PV reconnections. Patient-specific tissue characteristics that may contribute remain unidentified. This study aimed to assess the relationship between the bipolar electrogram voltage amplitudes recorded from the PV-left atrial (LA) junction and acute PV reconnection sites. Three-dimensional LA voltage maps created before an extensive encircling PVI in 47 AF patients (31 men; mean age 62 ± 11 years) were examined for an association between the EGM voltage amplitude recorded from the PV-LA junction and acute post-PVI PV reconnections (spontaneous PV reconnections and/or ATP-provoked dormant PV conduction). Acute PV reconnections were observed in 17 patients (36%) and in 24 (3%) of the 748 PV segments (16 segments per patient) and were associated with relatively high bipolar voltage amplitudes (3.26 ± 0.85 vs. 1.79 ± 1.15 mV, p voltage (137 [106, 166] vs. 295 [193, 498] gs/mV, p voltage and FTI/PV-LA bipolar voltage for acute PV reconnections (areas under the curve: 0.86 and 0.89, respectively); the best cutoff values were >2.12 mV and ≤183 gs/mV, respectively. The PV-LA voltage on the PV-encircling ablation line and FTI/PV-LA voltage were related to the acute post-PVI PV reconnections. A more durable ablation strategy is warranted for high-voltage zones.

  18. Performance and Environmental Test Results of the High Voltage Hall Accelerator Engineering Development Unit

    Science.gov (United States)

    Kamhawi, Hani; Haag, Thomas; Huang, Wensheng; Shastry, Rohit; Pinero, Luis; Peterson, Todd; Mathers, Alex

    2012-01-01

    NASA Science Mission Directorate's In-Space Propulsion Technology Program is sponsoring the development of a 3.5 kW-class engineering development unit Hall thruster for implementation in NASA science and exploration missions. NASA Glenn and Aerojet are developing a high fidelity high voltage Hall accelerator that can achieve specific impulse magnitudes greater than 2,700 seconds and xenon throughput capability in excess of 300 kilograms. Performance, plume mappings, thermal characterization, and vibration tests of the high voltage Hall accelerator engineering development unit have been performed. Performance test results indicated that at 3.9 kW the thruster achieved a total thrust efficiency and specific impulse of 58%, and 2,700 sec, respectively. Thermal characterization tests indicated that the thruster component temperatures were within the prescribed material maximum operating temperature limits during full power thruster operation. Finally, thruster vibration tests indicated that the thruster survived the 3-axes qualification full-level random vibration test series. Pre and post-vibration test performance mappings indicated almost identical thruster performance. Finally, an update on the development progress of a power processing unit and a xenon feed system is provided.

  19. High-ratio voltage conversion in CMOS for efficient mains-connected standby

    CERN Document Server

    Meyvaert, Hans

    2016-01-01

    This book describes synergetic innovation opportunities offered by combining the field of power conversion with the field of integrated circuit (IC) design. The authors demonstrate how integrating circuits enables increased operation frequency, which can be exploited in power converters to reduce drastically the size of the discrete passive components. The authors introduce multiple power converter circuits, which are very compact as result of their high level of integration. First, the limits of high-power-density low-voltage monolithic switched-capacitor DC-DC conversion are investigated to enable on-chip power granularization. AC-DC conversion from the mains to a low voltage DC is discussed, enabling an efficient and compact, lower-power auxiliary power supply to take over the power delivery during the standby mode of mains-connected appliances, allowing the main power converter of these devices to be shut down fully. Discusses high-power-density monolithic switched-capacitor DC-DC conversion in bulk CMOS,...

  20. New controller for high voltage converter modulator at spallation neutron source

    Energy Technology Data Exchange (ETDEWEB)

    Wezensky, Mark W [ORNL; Brown, David L [ORNL; Lee, Sung-Woo [ORNL; Zhukov, Alexander P [ORNL; Geng, Xiaosong [ORNL

    2017-01-01

    The Spallation Neutron Source (SNS) has developed a new control system for the High Voltage Convertor Modulator (HVCM) at the SNS to replace the original control system which is approaching obsolescence. The original system was based on controllers for similar high voltage systems that were already in use [1]. The new controller, based on National Instruments PXI/FlexRIO Field Programmable Gate Array (FPGA) platform, offers enhancements such as modular construction, flexibility and non-proprietary software. The new controller also provides new capabilities like various methods for modulator pulse flattening, waveform capture, and first fault detection. This paper will discuss the design of the system, including the human machine interface, based on lessons learned at the SNS and other projects. It will also discuss performance and other issues related to its operation in an accelerator facility which requires high availability. To date, 73% of the operational HVCMs have been upgraded to with the new controller, and the remainder are scheduled for completion by mid-2017.