WorldWideScience

Sample records for voltage pulse cable

  1. 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.

  2. High voltage pulse cable and connector experience in the kicker systems at SLAC

    Energy Technology Data Exchange (ETDEWEB)

    Harris, K.; Artusy, M.; Donaldson, A.; Mattison, T.

    1991-05-01

    The SLAC 2-mile linear accelerator uses a wide variety of pulse kicker systems that require high voltage cable and connectors to deliver pulses from the drivers to the magnet loads. Many of the drivers in the SLAC kicker systems use cable lengths up to 80 feet and are required to deliver pulses up to 40 kV, with rise and fall time on the order of 20 ns. Significant pulse degradation from the cable and connector assembly cannot be tolerated. Other drivers are required to deliver up to 80 kV, 20 {mu}s pulses over cables 20 feet long. Several combinations of an applicable high voltage cable and matching connector have been used at SLAC to determine the optimum assembly that meets the necessary specifications and is reliable. 14 refs., 3 figs., 1 tab.

  3. High Voltage Pulse Testing Survey.

    Science.gov (United States)

    1985-10-01

    Cryogenic 23 E. Liquids 26 F. Solids 28 1. Polyethylene 28 2. Cross-Linked Polyethylene ( XLPE ) 29 3. Polyimide and Polyvenylchloride (PVC) 31 VI Benefits 35 A...Strength of XLPE Cables 29 vii * 4" I PROGRAM OBJECTIVES The Pulse Test Survey summarizes government, industry, and technical reports on high voltage pulse...system of silicone oil on a XLPE (cross-linked polyethylene) spacer tends to lower the impulse breakdown by approximately 10 percent. The negative impulse

  4. Capacitance of High-Voltage Coaxial Cable in Plasma Immersion Ion Implantation

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Plasma immersion ion implantation (PIII) is an excellent technique for the surface modification of complex-shaped components. Owing to pulsed operation mode of the high voltage and large slew rate, the capacitance on the high-voltage coaxial cable can be detrimental to the processand cannot be ignored. In fact, a significant portion of the rise-time/fall-time of the implantation voltage pulse and big initial current can be attributed to the coaxial cable.

  5. High voltage pulse generator

    Science.gov (United States)

    Fasching, George E.

    1977-03-08

    An improved high-voltage pulse generator has been provided which is especially useful in ultrasonic testing of rock core samples. An N number of capacitors are charged in parallel to V volts and at the proper instance are coupled in series to produce a high-voltage pulse of N times V volts. Rapid switching of the capacitors from the paralleled charging configuration to the series discharging configuration is accomplished by using silicon-controlled rectifiers which are chain self-triggered following the initial triggering of a first one of the rectifiers connected between the first and second of the plurality of charging capacitors. A timing and triggering circuit is provided to properly synchronize triggering pulses to the first SCR at a time when the charging voltage is not being applied to the parallel-connected charging capacitors. Alternate circuits are provided for controlling the application of the charging voltage from a charging circuit to be applied to the parallel capacitors which provides a selection of at least two different intervals in which the charging voltage is turned "off" to allow the SCR's connecting the capacitors in series to turn "off" before recharging begins. The high-voltage pulse-generating circuit including the N capacitors and corresponding SCR's which connect the capacitors in series when triggered "on" further includes diodes and series-connected inductors between the parallel-connected charging capacitors which allow sufficiently fast charging of the capacitors for a high pulse repetition rate and yet allow considerable control of the decay time of the high-voltage pulses from the pulse-generating circuit.

  6. Development of High - voltage Pulse - transmission Electric Cable for Plasma Drill%等离子体钻机高压脉冲传输电缆的研制

    Institute of Scientific and Technical Information of China (English)

    季念迎; 裴彦良; 闫克平; 刘晨光; 章志成

    2012-01-01

    设计了等离子钻机高压脉冲传输电缆的结构,讨论了高压绝缘层的设计及材料选择.在此基础上,开展了高压脉冲传输电缆的绝缘阻抗和波阻抗测试实验.实验测试结果表明,所研制的传输电缆具有较高的绝缘性能和较小的波阻抗,可基本满足等离子体钻机的需要.%The structure of the high - voltage pulse - transmission electric cable was designed. The design of high - voltage insulation layer and the insulation material were discussed. Based on what mentioned above, the insulating resistance and the wave resistance tests of the high - voltage pulse - transmission electric cable were carried out. The test results show that the high - voltage pulse - transmission electric cable has good insulating property and little wave resistance, which meets the challenges of the plasma drill.

  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. Measurements for validation of high voltage underground cable modelling

    DEFF Research Database (Denmark)

    Bak, Claus Leth; Gudmundsdottir, Unnur Stella; Wiechowski, Wojciech Tomasz

    2009-01-01

    This paper discusses studies concerning cable modelling for long high voltage AC cable lines. In investigating the possibilities of using long cables instead of overhead lines, the simulation results must be trustworthy. Therefore a model validation is of great importance. This paper describes...

  9. Study of High Voltage AC Underground Cable Systems

    DEFF Research Database (Denmark)

    da Silva, Filipe Miguel Faria; Bak, Claus Leth; Wiechowski, Wojciech T.

    2010-01-01

    High-Voltage cables are starting to be more often used to transmit electric energy at high-voltage levels, introducing in the electric grid phenomena that are uncommon when using Overhead Lines. Under the phenomena worthy of special attention are those related with the cable energisation and deen...

  10. Calculation Method for Normal Inducedlongitudinal Voltage on Pilot Cable

    Directory of Open Access Journals (Sweden)

    Abdelaziz B.M. Kamel,

    2014-09-01

    Full Text Available In this paper a full study and detailed calculations of the induced voltage in pilot cables are carried out. First an introduction showing the importance of the induced voltage and its effect in pilot cables. The first calculation method Flat Formation. The second calculation method Trefoil Formation. Then the results obtained for both methods and compared. Finally a conclusion is conduct.

  11. Estimation of Medium Voltage Cable Parameters for PD Detection

    DEFF Research Database (Denmark)

    Villefrance, Rasmus; Holbøll, Joachim T.; Henriksen, Mogens

    1998-01-01

    Medium voltage cable characteristics have been determined with respect to the parameters having influence on the evaluation of results from PD-measurements on paper/oil and XLPE-cables. In particular, parameters essential for discharge quantification and location were measured. In order to relate...

  12. Commercialization of Medium Voltage HTS Triax TM Cable Systems

    Energy Technology Data Exchange (ETDEWEB)

    Knoll, David

    2012-12-31

    The original project scope that was established in 2007 aimed to install a 1,700 meter (1.1 mile) medium voltage HTS Triax{TM} cable system into the utility grid in New Orleans, LA. In 2010, however, the utility partner withdrew from the project, so the 1,700 meter cable installation was cancelled and the scope of work was reduced. The work then concentrated on the specific barriers to commercialization of HTS cable technology. The modified scope included long-length HTS cable design and testing, high voltage factory test development, optimized cooling system development, and HTS cable life-cycle analysis. In 2012, Southwire again analyzed the market for HTS cables and deemed the near term market acceptance to be low. The scope of work was further reduced to the completion of tasks already started and to testing of the existing HTS cable system in Columbus, OH. The work completed under the project included: • Long-length cable modeling and analysis • HTS wire evaluation and testing • Cable testing for AC losses • Optimized cooling system design • Life cycle testing of the HTS cable in Columbus, OH • Project management. The 200 meter long HTS Triax{TM} cable in Columbus, OH was incorporated into the project under the initial scope changes as a test bed for life cycle testing as well as the site for an optimized HTS cable cooling system. The Columbus cable utilizes the HTS TriaxTM design, so it provided an economical tool for these of the project tasks.

  13. High Voltage Cable Splicing and Cable Termination Techniques

    Science.gov (United States)

    1976-08-01

    solid dielectric insulations currently used are high-molecular-weight polyethylene (EP) and cross-linked poly- ethylene ( XLPE ). The EP insulation is...rated for 750 C a maximum temperature, and the XLPE insulation is rated for 900C maximum temperature. These insulation materials provide the conductor...The cost of installing PILC with copper conductors is compared to the cost of installing XLPE cable with aluminum conductors in Table 1. The

  14. Compensation of Cable Voltage Drops and Automatic Identification of Cable Parameters in 400 Hz Ground Power Units

    DEFF Research Database (Denmark)

    Borup, Uffe; Nielsen, Bo Vork; Blaabjerg, Frede

    2004-01-01

    In this paper a new cable voltage drop compensation scheme for ground power units (GPU) is presented. The scheme is able to predict and compensate the voltage drop in an output cable by measuring the current quantities at the source. The prediction is based on an advanced cable model that includes...

  15. 30 CFR 75.907 - Design of trailing cables for medium-voltage circuits.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Design of trailing cables for medium-voltage... Medium-Voltage Alternating Current Circuits § 75.907 Design of trailing cables for medium-voltage circuits. Trailing cables for medium-voltage circuits shall include grounding conductors, a ground check...

  16. 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...

  17. 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...

  18. Space charge accumulation in polymeric high voltage DC cable systems

    NARCIS (Netherlands)

    Bodega, R.

    2006-01-01

    One of the intrinsic properties of the polymeric high voltage (HV) direct current (DC) cable insulation is the accumulation of electrostatic charges. Accumulated charges distort the initial Laplacian distribution of the electric field, leading to a local field enhancement that may cause insulation d

  19. Noise signals and carrier modulation arising in electrical cables during nuclear pulse irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Both, E.; Bruemmer, H. P.; Lascaro, C. P.; Newberg, J.; Schlosser, W.

    1963-03-15

    Electrical noise signals generated in coaxial and other cables by pulsed nuclear radiation were measured as a function of applied voltage and exposure history. In consecutive exposures the signal magnitude and polarity was found to be strongly affected by training and memory effects. Unexpectedly large signals in the cable shield were identified as the cause for oscillatory signals in the center conductor and for the occurrence of parasitic leakage currents in nearby conductors. A r-f signal transmitted through RG62 A/U cable undergoes a temporary attenuation during the radiation pulse while it passes through RG59 B/U without measurable degradation. Definite rules are given for minimizing cable noise signals in nuclear pulse radiation measurements. (auth)

  20. 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.

  1. Investigation of pulsed voltage limiters characteristics

    Directory of Open Access Journals (Sweden)

    Karimov A. V.

    2012-06-01

    Full Text Available A new method for measuring the voltage limit is offered. It has been designed to measure high-power pulsed current of voltage limiters. The error of this method is half as much as the error of the known method of direct measurement. The investigation of dependence of power capability of single-crystal and double-crystal voltage limiters and of the pulsed operation time on pulse duration.

  2. Pulse Response Measurement Aiming for Locating Water Tree Degradation in XLPE Cables

    Science.gov (United States)

    Hiei, Susumu; Hozumi, Naohiro; Kurihara, Takashi; Okamoto, Tatsuki; Uchida, Katsumi; Tsuji, Taizo

    Water treeing is a degradation mode of power cable with polymeric insulation. A water tree is composed of small droplets filled with water. As the conductivity in water tree is very high, it leads to dielectric breakdown when it grows up. As inside of the water tree is filled with trap sites, it is polarized with a certain distribution of relaxation time when a DC poling voltage is applied. Although its depolarization process after removing the poling voltage is determined by ambient temperature, applying a “depolarizing voltage” with the opposite polarity can accelerate the process. If a short pulse propagating through the cable is employed as a depolarization voltage, we may locate the water tree through looking at the time-resolved pulse response. This would lead to a diagnosing method with spatial resolution. In order to retain 100 m of spatial resolution, the response should be as sharp as 1 μs. As a preliminary study, a coaxial communication cable was aged to form water trees. A DC poling voltage was applied followed by a pulse voltage with opposite polarity. The rising time of the pulse was several hundreds of microseconds. A sharp pulse current response with 50 μs in width was observed, suggesting that a rapid depolarization took place. No such response was seen when the cable specimen was not aged. We concluded that the technique is quite feasible. As the response was found to be as quick as several microseconds, an experiment using 405 m-long cable, with 5 m of degraded length in the middle, was performed. It was shown that the degraded point was successfully located.

  3. 30 CFR 75.822 - Underground high-voltage longwall cables.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Underground high-voltage longwall cables. 75... MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Underground High-Voltage Distribution High-Voltage Longwalls § 75.822 Underground high-voltage longwall cables. In addition to the high...

  4. Development and testing of a 50 KA, pulsed superconducting cable

    Energy Technology Data Exchange (ETDEWEB)

    Wollan; DeClerc, J.; Hamilton, W.; Zeitlin, B.

    1983-05-01

    Prototype cables for 7.5 T, pulsed field application in tokamak poloidal field coils have been designed, fabricated, and evaluated. Successful fabrication of a 10 m superconducting sample represents the largest superconducting cable ever made. Details of the fabrication, the problems expected and encountered, and the solutions to those problems are discussed. Results of stability measurements on the superconducting prototype also are presented.

  5. Research on influence of high-voltage cable un-homogeneities on process of short waves distribution

    Energy Technology Data Exchange (ETDEWEB)

    Tirsu, M.; Berzan, V.; Rimschi, V. [Power Engineering Institute of Academy of Sciences of Moldova, 5 Academy Street, Kishinev (Moldova); Postolache, P. [University ' ' Politechnics' ' of Bucharest, Street Splaiul Independentei 313, Bucharest (Romania)

    2008-12-15

    The partial discharges (PDs) inside of high-voltage cable insulation negatively influence cable service lifespan. Therefore timely detection and localization of affected areas with the weakened electric insulation is a vital question, in particular - according to measured values of PD parameters before they reach the dangerous stage of their development. Electrical cable is a circuit with the distributed parameters for current and voltage waves, initiated by local PD which changes their starting values with time. These changes can be taken as informative parameters for solving problems of localization of the defect and evaluation of dangers to cable's performance. Clear and detailed understanding of PD pulse distribution features in power cables is the basis for correctly solving cable diagnostics tasks with non-destructive approaches. This article uses the mathematical model of a power cable on the premises of cable equations. The model allows for modeling of wave processes in a non-uniform electric circuit (at sudden change of longitudinal parameters) in view of repeated reflection of PD waves from the ends and un-homogeneities of an electric cable. Results of mathematical modeling were compared to the data received from physical model of 110 kV XLPE electric cable. The cable physical model is realized with the help of the chained circuit consisting of 15 quad-poles. This document shows results of measurements and modeling of wave process caused by PD. Also, details of the wave process as dependent on time and frequency, and practical use of measurements of PD for cable insulation control, are discussed. Practical measurements show high degree of accuracy with regards to the data generated by theoretical model analysis. (author)

  6. Generator of ultrashort megavolt voltage pulses

    CERN Document Server

    Zheltov, K A; Shalimanov, V F

    2002-01-01

    Paper describes approx 3 ns duration and > 1 MW amplitude voltage pulse generator under high-ohmic (approx 450 Ohm) load. Generator comprises pulse transformer with magnetized core, as well as, resonance tuned circuit of high-voltage solenoid and accumulating spaces of a shaping line containing, moreover, spark gap to switch charge in transmitting line. Paper contains the results of voltage measuring in generator basic units

  7. Propylene based systems for high voltage cable insulation applications

    Energy Technology Data Exchange (ETDEWEB)

    Hosier, I L; Vaughan, A S; Swingler, S G [ECS, University of Southampton, Highfield, Southampton, SO17 1BJ (United Kingdom); Cozzarini, L, E-mail: ILH@ecs.soton.ac.u [DMRN, University of Trieste, Via Valerio 6A, 34127 Trieste (Italy)

    2009-08-01

    Crosslinked polyethylene (XLPE) remains the material of choice for extruded high voltage cables, possessing excellent thermo-mechanical and electrical properties. However, it is not easily recyclable posing questions as to its long term sustainability. Whilst both polyethylene and polypropylene are widely recycled and provide excellent dielectric properties, polypropylene has significantly better mechanical integrity at high temperatures than polyethylene. However, while isotactic polypropylene is too stiff at room temperature for incorporation into a cable system, previous studies by the authors have indicated that this limitation can be overcome by using a propylene-ethylene copolymer. Whilst these previous studies considered unrelated systems, the current study aims to quantify the usefulness of a series of related random propylene-ethylene co-polymers and assesses their potential for replacing XLPE.

  8. The thermal regime around buried submarine high-voltage cables

    Science.gov (United States)

    Emeana, C. J.; Hughes, T. J.; Dix, J. K.; Gernon, T. M.; Henstock, T. J.; Thompson, C. E. L.; Pilgrim, J. A.

    2016-08-01

    The expansion of offshore renewable energy infrastructure and the need for trans-continental shelf power transmission require the use of submarine high-voltage (HV) cables. These cables have maximum operating surface temperatures of up to 70 °C and are typically buried 1-2 m beneath the seabed, within the wide range of substrates found on the continental shelf. However, the heat flow pattern and potential effects on the sedimentary environments around such anomalously high heat sources in the near-surface sediments are poorly understood. We present temperature measurements from a 2-D laboratory experiment representing a buried submarine HV cable, and identify the thermal regimes generated within typical unconsolidated shelf sediments—coarse silt, fine sand and very coarse sand. We used a large (2 × 2.5 m2) tank filled with water-saturated spherical glass beads (ballotini) and instrumented with a buried heat source and 120 thermocouples to measure the time-dependent 2-D temperature distributions. The observed and corresponding Finite Element Method simulations of the steady state heat flow regimes and normalized radial temperature distributions were assessed. Our results show that the heat transfer and thus temperature fields generated from submarine HV cables buried within a range of sediments are highly variable. Coarse silts are shown to be purely conductive, producing temperature increases of >10 °C up to 40 cm from the source of 60 °C above ambient; fine sands demonstrate a transition from conductive to convective heat transfer between cf. 20 and 36 °C above ambient, with >10 °C heat increases occurring over a metre from the source of 55 °C above ambient; and very coarse sands exhibit dominantly convective heat transfer even at very low (cf. 7 °C) operating temperatures and reaching temperatures of up to 18 °C above ambient at a metre from the source at surface temperatures of only 18 °C. These findings are important for the surrounding near

  9. On-site Testing and PD Diagnosis of High Voltage Power Cables

    NARCIS (Netherlands)

    Gulski, E.; Cichecki, P.; Wester, F.; Smit, J.J.; Bodega, R.; Hermans, T.J.W.H.; Seitz, P.P.; Quak, B.; De Vries, F.

    2008-01-01

    In addition to after-laying of new-installed high voltage (HV) power cables the use of on-site non-destructive on-site testing and diagnosis of service aged power cables is becoming an important issue to determine the actual condition of the cable systems and to determine the future performances. In

  10. Influences of Excess Oscillation of Voltage Pulse and Discharge Mode on NO Removal Using Barrier-Type Plasma Reactor

    Science.gov (United States)

    Kadowaki, Kazunori; Suzuki, Yoshiaki; Ihori, Haruo; Kitani, Isamu

    This paper presents experimental results of NO removal from a simulated exhausted-gas using a barrier type reactor with screw electrodes subjected to polarity-reversed voltage pulses. The polarity-reversed pulse was produced by direct grounding of a charged coaxial cable because a traveling wave voltage was negatively reflected at the grounding end with a change in its polarity and then it propagated to the plasma reactor at the opposite end. Influence of cable length on NO removal was studied for two kinds of cable connection, single-connected cable and parallel-connected cables. NO removal ratio for a 50m-long cable was lower than that for much shorter cables in both single and parallel connections when the applied voltage became high. Energy efficiency for NO removal also increased with decreasing the cable length. This was because excess discharges during the voltage oscillation caused by the large stored energy in the long cable resulted in reproduction of NO molecules. Energy efficiency was further improved by changing the discharge mode from dielectric barrier discharge (DBD) to surface discharge (SD). Energy efficiency was up to 110g/kWh with 55% NO removal ratio and 34g/kWh with 100% NO removal ratio by using a single 10m-long cable in SD mode.

  11. HEAT TESTS OF POWER CABLES WITH XLPE INSULATION AT DIRECT VOLTAGES UP TO 110 KV

    Directory of Open Access Journals (Sweden)

    T.Yu. Antonets

    2015-12-01

    Full Text Available In this paper, experiment for determining the temperature difference between the elements of cable and in the open air is considered. The formation of a three cables laid in a plane with different spacing between adjacent cables. Tests to heat of cables for XLPE-polyethylene are used as a solid dielectric insulation. The line to 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. When single-core cables are installed in parallel the load current may not share equally between the parallel cables. This is because a significant proportion of the impedance of large conductors is due to self reactance and mutual reactance. Hence the spacing and relative location of each cable will have an effect on the current sharing. Calculation for each cable configuration is necessary. Possibility of using for determining the thermal properties of XLPE-cables a sheath applied over the cable surface with coefficient convection heat transfer between cable surface and the air region about it of equal zero. The work is devoted to creation of a method for calculation of the current rating of high-voltage cables in conditions function.

  12. Current and Voltage Induced on the Cable by Flash of Lightning between Clouds

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Based on the transmission line equations, this paper has developed computing formulas of current and voltage induced on the cable over the ground plane by Flash of Lightning Between Clouds (FBC), and estimated current and voltage on the cable of metal shielded sheath and analyzed the results.

  13. Plasma response to transient high voltage pulses

    Indian Academy of Sciences (India)

    S Kar; S Mukherjee

    2013-07-01

    This review reports on plasma response to transient high voltage pulses in a low pressure unmagnetized plasma. Mainly, the experiments are reviewed, when a disc electrode (metallic and dielectric) is biased pulsed negative or positive. The main aim is to review the electron loss in plasmas and particle balance during the negative pulse electrode biasing, when the applied pulse width is less than the ion plasma period. Though the applied pulse width is less than the ion plasma period, ion rarefaction waves are excited. The solitary electron holes are reviewed for positive pulsed bias to the electrode. Also the excitation of waves (solitary electron and ion holes) is reviewed for a metallic electrode covered by a dielectric material. The wave excitation during and after the pulse withdrawal, excitation and propagation characteristics of various electrostatic plasma waves are reviewed here.

  14. Transfer function-based modelling for voltage oscillation phenomena in PWM motor drives with long feeding cables

    Science.gov (United States)

    Lee, Sang-Choel; Park, Ju H.

    2010-04-01

    In this article, a transfer function-based modelling is proposed to investigate voltage oscillation phenomena, i.e. over-voltage at the motor terminal, associated with pulse-width modulation (PWM) inverter-fed motor drives with long feeding cables. As such, the long feeding cable is assumed to be a distortionless transmission line; then, a bounce diagram and time-harmonic method are utilised to derive a simple model with a minimum computational burden that is easy to realise using the Matlab/Simulink software package. Furthermore, the model takes account of the inverter output and the motor terminal filters, which are commonly used to suppress the motor terminal over-voltage. The model accuracy is verified by a comparison with the circuit-oriented software, OrCAD/PSpice, simulation results.

  15. High-voltage cable insulation online monitoring in coal mine based on pattern recognition

    Science.gov (United States)

    Zhao, Yongmei; Li, Junfeng; Wu, Lingjie; Wang, Yanwen

    2017-03-01

    The single-phase grounding fault is the main electrical fault types of the mine power grid. A new cable insulation online monitoring based on pattern recognition is proposed, in case single-phase grounding fault in coal mine. Firstly, using the pattern recognition method, the insulation state of the cable is divided into three types: "good insulation" and "insulation decline symmetrically" and "insulation decline asymmetrically". Then the cables with "insulation decline asymmetrically" can be further analysed and calculated and its insulation parameter value can be determined. The algorithm is simulated and verified. Simulation result shows that: The zero-sequence voltage and each phase voltage and the zero-sequence current of each cable are taken in the coal mine high-voltage system, and the insulation parameter value of each cable can be calculated accurately by using the pattern recognition method.

  16. 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.

  17. Optical cable in lightning wires of high voltage networks. Optische kabel in bliksemdraden van hoogspanningsnetten

    Energy Technology Data Exchange (ETDEWEB)

    Van Eck, J.T. (NKF Kabel BV, Delft (Netherlands))

    1990-12-01

    The design criteria for OPGW cables, various solutions available in the market and the particular choice of NKF Kabel BV for this type of cable are described. The test program performed to verify the design as well as the results of a number of complementary tests are given. Furthermore some practical considerations with respect to the installation of said cables in the high voltage network have been drawn up. 12 ills., 8 tabs.

  18. Qualification High Voltage Testing of Short Triax HTS Cables in the Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    James, David Randy [ORNL; Sauers, Isidor [ORNL; Ellis, Alvin R [ORNL; Tuncer, Enis [ORNL; Gouge, Michael J [ORNL; Demko, Jonathan A [ORNL; Duckworth, Robert C [ORNL; Rey, Christopher M [ORNL

    2009-01-01

    In order to qualify the electrical insulation design of future HTS cables installed in the electric grid, a number of high voltage qualification tests are generally performed in the laboratory on either single-phase model cables and/or actual three-phase cable samples. Prior to installation of the 200-m Triax HTS cable at the American Electric Power Bixby substation near Columbus, Ohio, in September, 2006, such tests were conducted on both single-phase model cables made at ORNL and tri-axial cable sections cut off from cable made on a production run. The three-phase tri-axial design provides some specific testing challenges since the ground shield and three phases are concentric about a central former with each phase separated by dielectric tape insulation immersed in liquid nitrogen. The samples were successfully tested and qualified for partial discharge inception, AC withstand, and lightning impulse where voltage is applied to one phase with the other phases grounded. In addition one of the phase pairs was tested for dc withstand as a ldquoworst caserdquo scenario to simulate the effect of VLF (Very Low Frequency) tests on the actual cable installed at the Bixby site. The model and prototype cables will be described and the high voltage test results summarized.

  19. 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.

  20. High voltage pulse generator. [Patent application

    Science.gov (United States)

    Fasching, G.E.

    1975-06-12

    An improved high-voltage pulse generator is described which is especially useful in ultrasonic testing of rock core samples. An N number of capacitors are charged in parallel to V volts and at the proper instance are coupled in series to produce a high-voltage pulse of N times V volts. Rapid switching of the capacitors from the paralleled charging configuration to the series discharging configuration is accomplished by using silicon-controlled rectifiers which are chain self-triggered following the initial triggering of the first rectifier connected between the first and second capacitors. A timing and triggering circuit is provided to properly synchronize triggering pulses to the first SCR at a time when the charging voltage is not being applied to the parallel-connected charging capacitors. The output voltage can be readily increased by adding additional charging networks. The circuit allows the peak level of the output to be easily varied over a wide range by using a variable autotransformer in the charging circuit.

  1. Diagnostics and testing of high voltage cable systems

    Energy Technology Data Exchange (ETDEWEB)

    Hyvoenen, P.; Oyegoke, B.; Aro, M.

    2003-07-01

    Reliability demands on electricity generation and distribution are increasing. Power utilities have faced new challenges due to liberalisation of electricity markets, increasing authors regulation and new claims for compensation of unexpected power shut downs. As a result power utilities have to concentrate more on asset management to reduce costs, to postpone investments, to optimise technical management keeping at the same time reliability and power quality at high level. Nowadays it is important to do right things at right place at right time. Maintenance strategy is changing from predictive or repairing maintenance to the condition based maintenance (CBM). Success of CBM depends partly on how good and reliable tools are available to determine condition of electrical apparatus. Cables have been used in electricity distribution since beginning of 20th century. Oldest still in use cables in Finland has been installed late 1940's. Nowadays almost all new distribution systems in urban areas are done using cables. Wide variety of cables are in use. Knowledge of condition and history of cables is not so well documented. Professional skill to install cable systems is disappearing due to outsourcing of maintenance groups. There is a worry about increasing amount of after installation faults due to loosing of professional skills to install cable systems. Wide variety of cable insulation systems and large variety in ages of cables still in use will place hard challenges for cable condition assessment. Earlier studies showed that measurement of insulation resistance is almost only diagnostic measurement performed to cable systems. Knowledge and experience of new diagnostic method is not so widely distributed. Based on previous project, dielectric response (DR) measurement and partial discharge (PD) measurement seemed to be most promising tools for the condition assessment of cable systems. Increased moisture content in oil-paper insulated cable or water trees in

  2. High Voltage AC underground cable systems for power transmission

    DEFF Research Database (Denmark)

    Bak, Claus Leth; Silva, Filipe Miguel Faria da

    2016-01-01

    This paper is a second of two presenting a review of research results in underground cable transmission obtained by the Department of Energy Technology, Aalborg University ET/AAU and Danish TSO Energinet.dk within the last six years. The main core of the results are obtained by PhD students...... researching electrical engineering topics related to using underground cables for power transmission at EHV level and including the 420 kV level. The research topics were laid down by ET/AAU and Energinet.dk in the DANPAC (DANish Power systems with Ac Cables) research project. The main topics are discussed...

  3. High Voltage AC underground cable systems for power transmission

    DEFF Research Database (Denmark)

    Bak, Claus Leth; Silva, Filipe Miguel Faria da

    2016-01-01

    This paper is a first of two presenting a review of research results in underground cable transmission obtained by the Department of Energy Technology, Aalborg University ET/AAU and Danish TSO Energinet.dk within the last 6 years. The main core of the results are obtained by PhD students research......This paper is a first of two presenting a review of research results in underground cable transmission obtained by the Department of Energy Technology, Aalborg University ET/AAU and Danish TSO Energinet.dk within the last 6 years. The main core of the results are obtained by PhD students...... researching electrical engineering topics related to using underground cables for power transmission at EHV level and including the 420 kV level. The research topics were laid down by ET/AAU and Energinet.dk in the DANPAC (DANish Power systems with AC Cables) research project. The main topics are discussed...

  4. High Voltage Testing of a 5-meter Prototype Triaxial HTS Cable

    Energy Technology Data Exchange (ETDEWEB)

    Sauers, Isidor [ORNL; James, David Randy [ORNL; Ellis, Alvin R [ORNL; Tuncer, Enis [ORNL; Pace, Marshall O [ORNL; Gouge, Michael J [ORNL; Demko, Jonathan A [ORNL; Lindsay, David T [ORNL

    2007-01-01

    High voltage tests were performed on a 5-m long prototype triaxial HTS cable (supplied by Ultera) at ORNL in preparation for installation of a 200-m HTS cable of the same design at the AEP utility substation in Columbus, Ohio. The triaxial design comprises three concentric phases and shield around a common former with the phase to phase dielectric at cryogenic temperature. Advantages of this design include increased current density, a reduced amount of HTS tape needed, and reduced heat load. The phase to phase voltage will be 13.2 kVrms (7.6 kVrms to ground). Preliminary testing was done on half-scale and full-scale terminations which successfully passed AC withstand, partial discharge, and impulse tests. High voltage tests conducted on the 5-m cable with the cable straight and after bending 90 degrees were ac withstand to 39 kVrms, partial discharge inception, and a minimum of 10 positive and 10 negative lightning waveform impulses at 110 kV. Phase to phase insulation was tested by applying high voltage to each phase one at a time with all the other phases grounded. Partial discharge data will be presented. The 5-m prototype triaxial HTS cable passed all the HV tests performed, with a PD inception voltage significantly above the required voltage.

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

    Science.gov (United States)

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

    2015-02-01

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

  6. High-voltage, short-risetime pulse generator based on a ferrite pulse sharpener

    Energy Technology Data Exchange (ETDEWEB)

    Seddon, N.; Thornton, E.

    1988-11-01

    A high-voltage, short-risetime pulse generator is described. The generator consists of a Marx bank, which produces an initial high-voltage pulse, and a ferrite pulse sharpener that reduces the risetime of the pulse. The generator delivers 70-kV, 350-ps risetime pulses into a 50-..cap omega.. load.

  7. 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.

  8. PROBLEMS OF ECONOMIC CRITERIA APPLICATION TO CALCULATION AND DESIGN OF HIGH-VOLTAGE PLASTIC-INSULATED POWER CABLES

    Directory of Open Access Journals (Sweden)

    O.V. Golik

    2013-09-01

    Full Text Available Results of cable transmitting capacity calculation for voltage of up to 220 kV are analyzed. The work is devoted to creation of a current rating calculation technique for high-voltage cross-linked polyethylene cables.

  9. Field test and theoretical analysis of electromagnetic pulse propagation velocity on crossbonded cable systems

    DEFF Research Database (Denmark)

    Jensen, Christian Flytkjær; Bak, Claus Leth; Gudmundsdottir, Unnur Stella

    2014-01-01

    In this paper, the electromagnetic pulse propagation velocity on a three-phase cable system, consisting of three single core (SC) cables in flat formation with an earth continuity conductor is under study. The propagation velocity is an important parameter for most travelling wave off- and online...

  10. Development and testing of a 50-kA, pulsed superconducting cable

    Science.gov (United States)

    Wollan, J. J.; Hamilton, W. C.; Declerc, J.; Zeitlin, B. A.

    1982-11-01

    Prototype cables for 7.5-T, pulsed field application in Tokamak poloidal coils were designed, fabricated, and evaluated. Successful fabrication of a 10 m superconducting sample represents the largest superconducting cable ever made. Details of the fabrication, the problems expected and encountered, and the solutions to those problems are discussed. Results of stability measurements on the superconducting prototype also are presented.

  11. Development and testing of a 50-kA, pulsed superconducting cable

    Energy Technology Data Exchange (ETDEWEB)

    Wollan, J.J.; Hamilton, W.C.; DeClerc, J.; Zeitlin, B.A.

    1982-01-01

    Prototype cables for 7.5-T, pulsed field application in tokamak poloidal field coils have been designed, fabricated, and evaluated. Successful fabrication of a 10 m superconducting sample represents the largest superconducting cable ever made. Details of the fabrication, the problems expected and encountered, and the solutions to those problems are discussed. Results of stability measurements on the superconducting prototype also are presented.

  12. High-voltage air-core pulse transformers

    Energy Technology Data Exchange (ETDEWEB)

    Rohwein, G. J.

    1981-01-01

    General types of air core pulse transformers designed for high voltage pulse generation and energy transfer applications are discussed with special emphasis on pulse charging systems which operate up to the multi-megavolt range. The design, operation, dielectric materials, and performance are described. It is concluded that high voltage air core pulse transformers are best suited to applications outside the normal ranges of conventional magnetic core transformers. In general these include charge transfer at high power levels and fast pulse generation with comparatively low energy. When properly designed and constructed, they are capable of delivering high energy transfer efficiency and have demonstrated superior high voltage endurance. The principal disadvantage of high voltage air core transformers is that they are not generally available from commercial sources. Consequently, the potential user must become thoroughly familiar with all aspects of design, fabrication and system application before he can produce a high performance transformer system. (LCL)

  13. Application of Optical Diagnosis to Aged Low-Voltage Cable Insulation in Nuclear Plants

    Science.gov (United States)

    Katagiri, Junichi; Takezawa, Yoshitaka; Shouji, Hiroshi

    We have developed a novel non-destructive optical diagnosis technique for low-voltage cable insulations used in nuclear power plants. The key features of this diagnosis are the use of two wavelengths to measure the change in reflective absorbance (ΔAR), the use of polarized light to measure crystallinity and the use of element volatilizing to measure fluorescence. Chemical kinetics is used to predict the lifetimes of the cable insulations. When cable insulations darken and harden by time degradation, the ΔAR and depolarization parameters increase. This means that the cross-linking density in the cable insulations increases due to deterioration reactions. When the cross-linking density of insulation increases, its elasticity, corresponding to the material's life, increases. Similarly, as the crystallinity increases due to the change in the high-order structure of the insulating resin caused by irradiation, its elongation property decreases. The elongation property of insulation is one of the most important parameters that can be used to evaluate material lifetimes, because it relates to elasticity. The ΔAR correlated with the elongation property, and the correlation coefficient of an accelerated experiment using model pieces was over 0.9. Thus, we concluded that this optical diagnosis should be applied to evaluate the degradation of cable insulations used in nuclear power plants.

  14. Ceramic end seal design for high temperature high voltage nuclear instrumentation cables

    Science.gov (United States)

    Meiss, James D.; Cannon, Collins P.

    1979-01-01

    A coaxial, hermetically sealed end structure is described for electrical instrumentation cables. A generally tubular ceramic body is hermetically sealed within a tubular sheath which is in turn sealed to the cable sheath. One end of the elongated tubular ceramic insulator is sealed to a metal end cap. The other end of the elongated tubular insulator has an end surface which is shaped concave relative to a central conductor which extends out of this end surface. When the end seal is hermetically sealed to an instrumentation cable device and the central conductor is maintained at a high positive potential relative to the tubular metal sheath, the electric field between the central conductor and the outer sheath tends to collect electrons from the concave end surface of the insulator. This minimizes breakdown pulse noise generation when instrumentation potentials are applied to the central conductor.

  15. Voltage spike observation in superconducting cable-in-conduit conductor under ramped magnetic fields. Pt. 1: Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Sangkwon Jeong; Schultz, J.H.; Takayasu, Makoto; Vysotsky, Vitaly; Michael, P.C. [Massachusetts Inst. of Technology, Plasma Fusion Center, Cambridge, MA (United States); Warnes, William [Oregan State Univ., Corvallis, OR (United States); Shen, Stewart [Lawrence Livermore National Lab., Livermore, CA (United States)

    1997-06-01

    A 27-strand hybrid superconducting cable-in-conduit conductor (CICC) was fabricated and tested under quickly-ramped high magnetic fields. When the field increased linearly on the CICC, the voltage signal showed several intermittent spikes before it quenched. This paper describes an observation of peculiar voltage spikes during these ramp-rate limitation experiments. The voltage spikes are interpreted as quench precursors and understood as current redistribution events within the local cable inside the conduit. A quantitative correlation is obtained for the magnetic field at which the first voltage spike occurs during ramping fields. The non-uniform current distribution among the strands and the induced loop current in the cable, which is generated by ramped fields, are found to be responsible for the voltage spikes. (author)

  16. Cable Crosstalk Suppression with Two-Wire Voltage Feedback Method for Resistive Sensor Array.

    Science.gov (United States)

    Wu, Jianfeng; He, Shangshang; Li, Jianqing; Song, Aiguo

    2016-01-01

    Using a long, flexible test cable connected with a one-wire voltage feedback circuit, a resistive tactile sensor in a shared row-column fashion exhibited flexibility in robotic operations but suffered from crosstalk caused by the connected cable due to its wire resistances and its contacted resistances. Firstly, we designed a new non-scanned driving-electrode (VF-NSDE) circuit using two wires for every row line and every column line to reduce the crosstalk caused by the connected cables in the circuit. Then, an equivalent resistance expression of the element being tested (EBT) for the two-wire VF-NSDE circuit was analytically derived. Following this, the one-wire VF-NSDE circuit and the two-wire VF-NSDE circuit were evaluated by simulation experiments. Finally, positive features of the proposed method were verified with the experiments of a two-wire VF-NSDE prototype circuit. The experiment results show that the two-wire VF-NSDE circuit can greatly reduce the crosstalk error caused by the cables in the 2-D networked resistive sensor array.

  17. The characteristics of electrical trees in the inner and outer layers of different voltage rating XLPE cable insulation

    Science.gov (United States)

    Xie, Ansheng; Li, Shengtao; Zheng, Xiaoquan; Chen, George

    2009-06-01

    The statistical initiation and propagation characteristics of electrical trees in cross-linked polyethylene (XLPE) cables with different voltage ratings from 66 to 500 kV were investigated under a constant test voltage of 50 Hz/7 kV (the 66 kV rating cable is from UK, the others from China). It was found that the characteristics of electrical trees in the inner region of 66 kV cable insulation differed considerably from those in the outer region under the same test conditions; however, no significant differences appeared in the 110 kV rating cable and above. The initiation time of electrical trees in both the inner and the outer regions of the 66 kV cable is much shorter than that in higher voltage rating cables; in addition the growth rate of electrical trees in the 66 kV cable is much larger than that in the higher voltage rating cables. By using x-ray diffraction, differential scanning calorimetry and thermogravimetry methods, it was revealed that besides the extrusion process, the molecular weight of base polymer material and its distribution are the prime factors deciding the crystallization state. The crystallization state and the impurity content are responsible for the resistance to electrical trees. Furthermore, it was proposed that big spherulites will cooperate with high impurity content in enhancing the initiation and growth processes of electrical trees via the 'synergetic effect'. Finally, dense and small spherulites, high crystallinity, high purity level of base polymer material and super-clean production processes are desirable for higher voltage rating cables.

  18. The characteristics of electrical trees in the inner and outer layers of different voltage rating XLPE cable insulation

    Energy Technology Data Exchange (ETDEWEB)

    Xie Ansheng; Li Shengtao; Zheng Xiaoquan [State Key Laboratory of Electrical Insulation and Power Equipment, Xi' an Jiaotong University, Xi' an 710049 (China); Chen, George, E-mail: sli@mail.xjtu.edu.c, E-mail: xieansheng@gmail.co, E-mail: xqzheng@mail.xjtu.edu.c, E-mail: gc@ecs.soton.ac.u [School of Electronics and Computer Science, University of Southampton, Southampton SO17 1BJ (United Kingdom)

    2009-06-21

    The statistical initiation and propagation characteristics of electrical trees in cross-linked polyethylene (XLPE) cables with different voltage ratings from 66 to 500 kV were investigated under a constant test voltage of 50 Hz/7 kV (the 66 kV rating cable is from UK, the others from China). It was found that the characteristics of electrical trees in the inner region of 66 kV cable insulation differed considerably from those in the outer region under the same test conditions; however, no significant differences appeared in the 110 kV rating cable and above. The initiation time of electrical trees in both the inner and the outer regions of the 66 kV cable is much shorter than that in higher voltage rating cables; in addition the growth rate of electrical trees in the 66 kV cable is much larger than that in the higher voltage rating cables. By using x-ray diffraction, differential scanning calorimetry and thermogravimetry methods, it was revealed that besides the extrusion process, the molecular weight of base polymer material and its distribution are the prime factors deciding the crystallization state. The crystallization state and the impurity content are responsible for the resistance to electrical trees. Furthermore, it was proposed that big spherulites will cooperate with high impurity content in enhancing the initiation and growth processes of electrical trees via the 'synergetic effect'. Finally, dense and small spherulites, high crystallinity, high purity level of base polymer material and super-clean production processes are desirable for higher voltage rating cables.

  19. 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.

  20. Breakdown voltage of discrete capacitors under single-pulse conditions

    Science.gov (United States)

    Domingos, H.; Scaturro, J.; Hayes, L.

    1981-01-01

    For electrostatic capacitors the breakdown voltage is inherently related to the properties of the dielectric, with the important parameters being the dielectric field strength which is related to the dielectric constant and the dielectric thickness. These are not necessarily related to the capacitance value and the rated voltage, but generally the larger values of capacitance have lower breakdown voltages. Foil and wet slug electrolytics can withstand conduction currents pulses without apparent damage (in either direction for foil types). For solid tantalums, damage occurs whenever the capacitor charges to the forming voltage.

  1. 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.

  2. 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

    2016-11-30

    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.

  3. High-voltage pulsed generator for dynamic fragmentation of rocks.

    Science.gov (United States)

    Kovalchuk, B M; Kharlov, A V; Vizir, V A; Kumpyak, V V; Zorin, V B; Kiselev, V N

    2010-10-01

    A portable high-voltage (HV) pulsed generator has been designed for rock fragmentation experiments. The generator can be used also for other technological applications. The installation consists of low voltage block, HV block, coaxial transmission line, fragmentation chamber, and control system block. Low voltage block of the generator, consisting of a primary capacitor bank (300 μF) and a thyristor switch, stores pulse energy and transfers it to the HV block. The primary capacitor bank stores energy of 600 J at the maximum charging voltage of 2 kV. HV block includes HV pulsed step up transformer, HV capacitive storage, and two electrode gas switch. The following technical parameters of the generator were achieved: output voltage up to 300 kV, voltage rise time of ∼50 ns, current amplitude of ∼6 kA with the 40 Ω active load, and ∼20 kA in a rock fragmentation regime (with discharge in a rock-water mixture). Typical operation regime is a burst of 1000 pulses with a frequency of 10 Hz. The operation process can be controlled within a wide range of parameters. The entire installation (generator, transmission line, treatment chamber, and measuring probes) is designed like a continuous Faraday's cage (complete shielding) to exclude external electromagnetic perturbations.

  4. On the Degradation Mechanism of Low-Voltage Underground Cable with Poly(Vinyl Chloride) Insulation

    Science.gov (United States)

    Tawancy, H. M.; Hassan, M.

    2016-06-01

    A study has been undertaken to determine the degradation mechanism leading to localized short-circuit failures of an underground low-voltage cable with PVC insulation. It is shown that that the insulation of outer sheath and conductor cores has been cracked by thermal degradation involving dehydrochlorination, oxidation, and loss of plasticizers leading to current leakage between the cores. Most evidence points out that overheating due to poor connection of copper wires as well as a chemically active soil has caused the observed degradation.

  5. Treatment of emulsified oils by electrocoagulation: pulsed voltage applications.

    Science.gov (United States)

    Genc, Ayten; Bakirci, Busra

    2015-01-01

    The effect of pulsed voltage application on energy consumption during electrocoagulation was investigated. Three voltage profiles having the same arithmetic average with respect to time were applied to the electrodes. The specific energy consumption for these profiles were evaluated and analyzed together with oil removal efficiencies. The effects of applied voltages, electrode materials, electrode configurations, and pH on oil removal efficiency were determined. Electrocoagulation experiments were performed by using synthetic and real wastewater samples. The pulsed voltages saved energy during the electrocoagulation process. In continuous operation, energy saving was as high as 48%. Aluminum electrodes used for the treatment of emulsified oils resulted in higher oil removal efficiencies in comparison with stainless steel and iron electrodes. When the electrodes gap was less than 1 cm, higher oil removal efficiencies were obtained. The highest oil removal efficiencies were 95% and 35% for the batch and continuous operating modes, respectively.

  6. A PC-controlled voltage pulse generator for electroanalytical applications

    Science.gov (United States)

    Heredia-López, Francisco J.; Góngora-Alfaro, José L.; Alvarez-Cervera, Fernando J.; Bata-García, José Luis

    1997-04-01

    We present the design of a voltage pulse generator controlled by an IBM or compatible AT Personal Computer (PC) capable of synthesizing some of the voltage pulse wave forms commonly used in electrochemical studies. The included signals are: differential pulse voltametry, differential normal pulse voltametry, and differential pulse amperometry. Additionally, a triangular wave form and a constant-voltage signal, used in the pretreatment of carbon fiber microelectrodes for neurochemical analysis, are also available. Operating the generator imposes a minimum of restrictions on the specification of the duration, amplitude, and type of wave shapes. Low-cost PC-based design allows for compatibility, portability, and versatility. The operating ranges of the wave form parameters for the three voltametric signals are: initial voltage, -0.9-+0.9 V; step amplitude, 0.1-900 mV; period, 6 ms-60 s; measuring pulse amplitude, 0.1-900 mV; measuring pulse duration, 2 ms-20 s; prepulse duration, 2 ms-20 s. In the electrode pretreatment mode, the operating ranges are: amplitude, 0-±5 V; duration, unlimited; frequency, 15-240 Hz. The generator uses its own time base for the generation of all signals, thereby rendering it independent of processor clock speed or power-line frequency. The results of the experimental evaluation indicate that the system is accurate within ±10% of the expected values, taking into account the errors associated with the signal synthesis and the digitizing process. The maximum achievable scan rate is 500 V/s, and the highest frequency for the triangular wave form is 240 Hz. Therefore, the pulse generator could be used for fast cyclic voltametry (FCV). FCV and other wave forms could be added through software modules, without any hardware changes. We conclude that the PC-based electrochemistry pulse generator represents an economical and flexible alternative for electroanalytical applications.

  7. 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.

  8. High voltage magnetic pulse generation using capacitor discharge technique

    Directory of Open Access Journals (Sweden)

    M. Rezal

    2014-12-01

    Full Text Available A high voltage magnetic pulse is designed by applying an electrical pulse to the coil. Capacitor banks are developed to generate the pulse current. Switching circuit consisting of Double Pole Double Throw (DPDT switches, thyristor, and triggering circuit is developed and tested. The coil current is measured using a Hall-effect current sensor. The magnetic pulse generated is measured and tabulated in a graph. Simulation using Finite Element Method Magnetics (FEMM is done to compare the results obtained between experiment and simulation. Results show that increasing the capacitance of the capacitor bank will increase the output voltage. This technology can be applied to areas such as medical equipment, measurement instrument, and military equipment.

  9. Influence of Voltage Rise Time for Oxidation Treatment of NO in Simulated Exhausted Gas by Polarity-Reversed Pulse Discharge

    Science.gov (United States)

    Shinmoto, Kazuya; Kadowaki, Kazunori; Nishimoto, Sakae; Kitani, Isamu

    This paper describes experimental study on NO removal from a simulated exhausted-gas using repetitive surface discharge on a glass barrier subjected to polarity-reversed voltage pulses. The very fast polarity-reversal with a rise time of 20ns is caused by direct grounding of a charged coaxial cable of 10m in length. Influence of voltage rise time on energy efficiency for NO removal is studied. Results of NO removal using a barrier-type plasma reactor with screw-plane electrode system indicates that the energy efficiency for the very fast polarity reversal caused by direct grounding becomes higher than that for the slower polarity reversal caused by grounding through an inductor at the cable end. The energy efficiency for the direct grounding is about 80g/kWh for 50% NO removal ratio and is about 60g/kWh for 100% NO removal ratio. Very intense discharge light is observed at the initial time of 10ns for the fast polarity reversal, whereas the intensity in the initial discharge light for the slower polarity reversal is relatively small. To confirm the effectiveness of the polarity-reversed pulse application, comparison of the energy efficiency between the polarity-reversed voltage pulse and ac 60Hz voltage will be presented.

  10. Calculation of harmonic losses and ampacity in low-voltage power cables when used for feeding large LED lighting loads

    Directory of Open Access Journals (Sweden)

    N. J. Milardovich

    2014-10-01

    Full Text Available A numerical investigation on the harmonic disturbances in low-voltage cables feeding large LED loads is reported. A frequency domain analysis on several commercially-available LEDs was performed to investigate the signature of the harmonic current injected into the power system. Four-core cables and four single-core cable arrangements (three phases and neutral of small, medium, and large conductor cross sections, with the neutral conductor cross section approximately equal to the half of the phase conductors, were examined. The cables were modelled by using electromagnetic finite-element analysis software. High harmonic power losses (up to 2.5 times the value corresponding to an undistorted current of the same rms value of the first harmonic of the LED current were found. A generalized ampacity model was employed for re-rating the cables. It was found that the cross section of the neutral conductor plays an important role in the derating of the cable ampacity due to the presence of a high-level of triplen harmonics in the distorted current. The ampacity of the cables should be derated by about 40 %, almost independent of the conductor cross sections. The calculation have shown that an incoming widespread use of LED lamps in lighting could create significant additional harmonic losses in the supplying low-voltage lines, and thus more severely harmonic emission limits should be defined for LED lamps.

  11. Influence of metallic trays on the ac resistance and ampacity of low-voltage cables under non-sinusoidal currents

    Energy Technology Data Exchange (ETDEWEB)

    Demoulias, Charis; Labridis, Dimitris P.; Dokopoulos, Petros; Gouramanis, Kostas [Aristotle University of Thessaloniki, Department of Electrical and Computer Engineering, Thessaloniki (Greece)

    2008-05-15

    This paper investigates the influence of metallic trays on the ac resistance of PVC insulated, low-voltage (0.6/1.0 kV) cables made according to CENELEC standard HD603. The investigation is made with a validated finite element model for the fundamental and higher harmonic frequencies. It is shown that the cable's effective resistance is affected significantly by the relative magnetic permeability and specific conductivity of the tray, while the tray's dimensions do not affect it. The orientation of the cable with respect to the tray also influences the ac resistance of the phase and neutral conductors. An ampacity derating factor is defined and calculated for various cable cross-sections and harmonic loads. The presence of a metallic tray is shown to cause an additional derating of cable's ampacity which is relatively significant at large cable cross-sections. Working examples demonstrate the application of the results in calculating the ampacity of low-voltage cables and in assessing the energy savings that will result from the use of active harmonic filters. (author)

  12. Development of high-voltage pulse-slicer unit with variable pulse duration for pulse radiolysis system

    Science.gov (United States)

    Upadhyay, J.; Sharma, M. L.; Navathe, C. P.; Toley, M. A.; Shinde, S. J.; Nadkarni, S. A.; Sarkar, S. K.

    2012-02-01

    A high-voltage pulse-slicer unit with variable pulse duration has been developed and integrated with a 7 MeV linear electron accelerator (LINAC) for pulse radiolysis investigation. The pulse-slicer unit provides switching voltage from 1 kV to 10 kV with rise time better than 5 ns. Two MOSFET based 10 kV switches were configured in differential mode to get variable duration pulses. The high-voltage pulse has been applied to the deflecting plates of the LINAC for slicing of electron beam of 2 μs duration. The duration of the electron beam has been varied from 30 ns to 2 μs with the optimized pulse amplitude of 7 kV to get corresponding radiation doses from 6 Gy to 167 Gy.

  13. A high current pulsed power generator CQ-3-MMAF with co-axial cable transmitting energy for material dynamics experiments

    Science.gov (United States)

    Wang, Guiji; Chen, Xuemiao; Cai, Jintao; Zhang, Xuping; Chong, Tao; Luo, Binqiang; Zhao, Jianheng; Sun, Chengwei; Tan, Fuli; Liu, Cangli; Wu, Gang

    2016-06-01

    A high current pulsed power generator CQ-3-MMAF (Multi-Modules Assembly Facility, MMAF) was developed for material dynamics experiments under ramp wave and shock loadings at the Institute of Fluid Physics (IFP), which can deliver 3 MA peak current to a strip-line load. The rise time of the current is 470 ns (10%-90%). Different from the previous CQ-4 at IFP, the CQ-3-MMAF energy is transmitted by hundreds of co-axial high voltage cables with a low impedance of 18.6 mΩ and low loss, and then hundreds of cables are reduced and converted to tens of cables into a vacuum chamber by a cable connector, and connected with a pair of parallel metallic plates insulated by Kapton films. It is composed of 32 capacitor and switch modules in parallel. The electrical parameters in short circuit are with a capacitance of 19.2 μF, an inductance of 11.7 nH, a resistance of 4.3 mΩ, and working charging voltage of 60 kV-90 kV. It can be run safely and stable when charged from 60 kV to 90 kV. The vacuum of loading chamber can be up to 10-2 Pa, and the current waveforms can be shaped by discharging in time sequences of four groups of capacitor and switch modules. CQ-3-MMAF is an adaptive machine with lower maintenance because of its modularization design. The COMSOL Multi-physics® code is used to optimize the structure of some key components and calculate their structural inductance for designs, such as gas switches and cable connectors. Some ramp wave loading experiments were conducted to check and examine the performances of CQ-3-MMAF. Two copper flyer plates were accelerated to about 3.5 km/s in one shot when the working voltage was charged to 70 kV. The velocity histories agree very well. The dynamic experiments of some polymer bonded explosives and phase transition of tin under ramp wave loadings were also conducted. The experimental data show that CQ-3-MMAF can be used to do material dynamics experiments in high rate and low cost shots. Based on this design concept, the peak

  14. A high current pulsed power generator CQ-3-MMAF with co-axial cable transmitting energy for material dynamics experiments.

    Science.gov (United States)

    Wang, Guiji; Chen, Xuemiao; Cai, Jintao; Zhang, Xuping; Chong, Tao; Luo, Binqiang; Zhao, Jianheng; Sun, Chengwei; Tan, Fuli; Liu, Cangli; Wu, Gang

    2016-06-01

    A high current pulsed power generator CQ-3-MMAF (Multi-Modules Assembly Facility, MMAF) was developed for material dynamics experiments under ramp wave and shock loadings at the Institute of Fluid Physics (IFP), which can deliver 3 MA peak current to a strip-line load. The rise time of the current is 470 ns (10%-90%). Different from the previous CQ-4 at IFP, the CQ-3-MMAF energy is transmitted by hundreds of co-axial high voltage cables with a low impedance of 18.6 mΩ and low loss, and then hundreds of cables are reduced and converted to tens of cables into a vacuum chamber by a cable connector, and connected with a pair of parallel metallic plates insulated by Kapton films. It is composed of 32 capacitor and switch modules in parallel. The electrical parameters in short circuit are with a capacitance of 19.2 μF, an inductance of 11.7 nH, a resistance of 4.3 mΩ, and working charging voltage of 60 kV-90 kV. It can be run safely and stable when charged from 60 kV to 90 kV. The vacuum of loading chamber can be up to 10(-2) Pa, and the current waveforms can be shaped by discharging in time sequences of four groups of capacitor and switch modules. CQ-3-MMAF is an adaptive machine with lower maintenance because of its modularization design. The COMSOL Multi-physics® code is used to optimize the structure of some key components and calculate their structural inductance for designs, such as gas switches and cable connectors. Some ramp wave loading experiments were conducted to check and examine the performances of CQ-3-MMAF. Two copper flyer plates were accelerated to about 3.5 km/s in one shot when the working voltage was charged to 70 kV. The velocity histories agree very well. The dynamic experiments of some polymer bonded explosives and phase transition of tin under ramp wave loadings were also conducted. The experimental data show that CQ-3-MMAF can be used to do material dynamics experiments in high rate and low cost shots. Based on this design concept, the peak

  15. Numeric modeling of synchronous laser pulsing and voltage pulsing field evaporation

    CERN Document Server

    Zhao, L; Houard, J; Blum, I; Delaroche, F; Vurpillot, F

    2016-01-01

    We have recently proposed an atom probe design based on a femtosecond time-resolved pump-probe setup. This setup unlocks the limitation of voltage pulsed mode atom probe thanks to the occurrence of local photoconductive switching effect . In this paper, we have used a numerical model to simulate the field evaporation process triggered by the synchronous two pulses. The model takes into account the local photoconductive effect and the temperature rise caused by the laser application and the voltage pulse distortion due to the RC effect.

  16. 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.

  17. 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).

  18. 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.

  19. A Novel Electrical Insulating Material for 275 kV High-Voltage HTS Cable with Low Dielectric Loss

    Science.gov (United States)

    Hayakawa, N.; Nishimachi, S.; Maruyama, O.; Ohkuma, T.; Liu, J.; Yagi, M.

    2014-05-01

    In the case of high temperature superconducting (HTS) power transmission cables at high voltage operation, the electrical insulation technique in consideration of the dielectric loss reduction becomes crucial. In this paper, we focused on a Tyvek/polyethylene (PE) sheet, instead of the conventional polypropylene laminated paper (PPLP). We obtained the dielectric characteristics (epsilonr, tanδ) and partial discharge inception strength (PDIE) of PPLP, Tyvek and Tyvek/PE. We pointed out that the dielectric loss of 275 kV HTS cable with Tyvek/PE insulation will be reduced to 21 % of that with PPLP, and the total electrical loss including the AC loss will be reduced to 41 %.

  20. An atmospheric pressure plasma source driven by a train of monopolar high voltage pulses superimposed to a dc voltage

    OpenAIRE

    Stoican, O.S.

    2011-01-01

    Abstract An atmospheric pressure plasma source supplied by an electrical circuit consisting of two voltage sources in parallel connection is reported. One of them is a low-power self-oscillating flyback converter which produces negative voltage pulses with an amplitude of several kilovolts. The high voltage pulses are necessary to ignite an electrical discharge between the electrodes at atmospheric pressure. An additional dc source delivering several hundreds of volts at a few hund...

  1. Identification of problems when using long high voltage AC cable in transmission system II: Resonance & Harmonic resonance

    DEFF Research Database (Denmark)

    Rahimi, Saeed; Wiechowski, W.; Randrup, M.;

    2008-01-01

    cable in transmission system. The objective of this paper and the companion paper is to address the most important problems expected in transmission system with relatively larger share of long HV underground cables. The end goal will be a guideline to special solutions and precautions to avoid dangerous...... over voltage problems and also resonance problems in a transmission network with future increased share of cables. Two major categories of problems are switching transient and resonance problems. In each category of the possible problems, first some theoretical background is provided...... and then the problem and countermeasures are discussed. In this paper most important resonance problems are addressed and discussed. Three main categories of resonance problems are: Near Resonance, Harmonic resonance and Ferroresonance....

  2. 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

  3. 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.

  4. Use of very low frequency technology for diagnostic in medium voltage electric cables; Utilizacao da tecnologia VLF para diagnostico de cabos eletricos de media tensao

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, Flavio Costa; Pinho, Wilson Pereira de [Companhia Siderurgica Nacional (CSN), Volta Redonda, RJ (Brazil). Gerencia de Distribuicao de Energeticos

    2010-07-01

    The present technical contribution presents a new technology used in the Companhia Siderurgica Nacional (CSN) to diagnose operating conditions, useful life and faults in medium voltage electrical cables. The Very Low Frequency is a nondestructive electrical testing, conducted in medium voltage electrical cables, designed to measure the overall state of insulation of the cables, and the precise location of the fault before the failure. Through two types of tests, Delta Tangent and Partial Discharge, it is possible to make a complete diagnosis of insulation performance of the cable and also detect the fault. The implantation of this predictive technique, will monitor the useful life of medium voltage cables, avoiding potential failures in electrical circuits of Usina Presidente Vargas, allowing the intervention of maintenance before the failure, that result in interference in the production process. (author)

  5. Nuclear instrumentation cable end seal

    Science.gov (United States)

    Cannon, Collins P.; Brown, Donald P.

    1979-01-01

    An improved coaxial end seal for hermetically sealed nuclear instrumentation cable exhibiting an improved breakdown pulse noise characteristic under high voltage, high temperature conditions. A tubular insulator body has metallized interior and exterior surface portions which are braze sealed to a center conductor and an outer conductive sheath. The end surface of the insulator body which is directed toward the coaxial cable to which it is sealed has a recessed surface portion within which the braze seal material terminates.

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

    OpenAIRE

    Ye Peng; Tao Liu; Haifeng Gong; Xianming Zhang

    2016-01-01

    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...

  7. Characteristics for electrochemical machining with nanoscale voltage pulses.

    Science.gov (United States)

    Lee, E S; Back, S Y; Lee, J T

    2009-06-01

    Electrochemical machining has traditionally been used in highly specialized fields, such as those of the aerospace and defense industries. It is now increasingly being applied in other industries, where parts with difficult-to-cut material, complex geometry and tribology, and devices of nanoscale and microscale are required. Electric characteristic plays a principal function role in and chemical characteristic plays an assistant function role in electrochemical machining. Therefore, essential parameters in electrochemical machining can be described current density, machining time, inter-electrode gap size, electrolyte, electrode shape etc. Electrochemical machining provides an economical and effective method for machining high strength, high tension and heat-resistant materials into complex shapes such as turbine blades of titanium and aluminum alloys. The application of nanoscale voltage pulses between a tool electrode and a workpiece in an electrochemical environment allows the three-dimensional machining of conducting materials with sub-micrometer precision. In this study, micro probe are developed by electrochemical etching and micro holes are manufactured using these micro probe as tool electrodes. Micro holes and microgroove can be accurately achieved by using nanoscale voltages pulses.

  8. Modelling of long High Voltage AC Cables in the Transmission System

    DEFF Research Database (Denmark)

    Gudmundsdottir, Unnur Stella

    , EMTDC/PSCAD is provided. A typical HV AC underground power cable is formed by 4 main layers, namely; Conductor-Insulation-Screen-Insulation. In addition to these main layers, the cable also has semiconductive screens, swelling tapes and metal foil. For high frequency modelling in EMT-based software...... and field measurement results. This is because of intersheath mode reflecting from the crossbonding points. The second main part of the work deals with improving the cable model based on the findings from analysis of the field measurements. The existing EMT-based models have the configuration for cables...

  9. High Voltage Coaxial Vacuum Gap Breakdown for Pulsed Power Liners

    Science.gov (United States)

    Cordaro, Samuel; Bott-Suzuki, Simon; Caballero Bendixsen, Luis Sebastian

    2015-11-01

    The dynamics of Magnetized Liner Inertial Fusion (MagLIF)1, are presently under detailed study at Sandia National Laboratories. Alongside this, a comprehensive analysis of the influence of the specific liner design geometry in the MagLIF system on liner initiation is underway in the academic community. Recent work at UC San Diego utilizes a high voltage pulsed system (25kV, 150ns) to analyze the vacuum breakdown stage of liner implosion. Such experimental analyses are geared towards determining how the azimuthal symmetry of coaxial gap breakdown affect plasma initiation within the liner. The final aim of the experimental analysis is to assess to what scale symmetry remains important at high (MV) voltages. An analysis of the above will utilize plasma self-emission via optical MCP, current measurements, voltage measurements near the gap, exact location of breakdown via 2D b-dot probe triangulation, as well as measuring the evolution of the B-field along the length of the liner via b-dot array. Results will be discussed along with analytical calculations of breakdown mechanisms

  10. PE/PVC materials in HV cable jackets. Breakdown voltage of PE/PVC materials; PE/PVC-Materialien in Aussenmaenteln von Hochspannungskabeln. Durchschlagspannung von PE/PVC-Materialien

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, Uwe; Xu, Liang; Schufft, Wolfgang [Technische Univ. Chemnitz-Zwickau, Chemnitz (Germany). Fakultaet fuer Elektrotechnik und Informationstechnik

    2010-12-13

    Cables are spaced across increasingly longer distances in HV engineering. Integration of offshore wind farms and the construction of new transmission and distribution grids would be impossible without cables. Voltages and overvoltages in operation are managed according to international standards using overvoltage protection systems. However, there may be instances in which voltage occur that exceed the strength of the cable jacket. (orig.)

  11. A 70 kV solid-state high voltage pulse generator based on saturable pulse transformer.

    Science.gov (United States)

    Fan, Xuliang; Liu, Jinliang

    2014-02-01

    High voltage pulse generators are widely applied in many fields. In recent years, solid-state and operating at repetitive mode are the most important developing trends of high voltage pulse generators. A solid-state high voltage pulse generator based on saturable pulse transformer is proposed in this paper. The proposed generator is consisted of three parts. They are charging system, triggering system, and the major loop. Saturable pulse transformer is the key component of the whole generator, which acts as a step-up transformer and main switch during working process of this generator. The circuit and working principles of the proposed pulse generator are introduced first in this paper, and the saturable pulse transformer used in this generator is introduced in detail. Circuit of the major loop is simulated to verify the design of the system. Demonstration experiments are carried out, and the results show that when the primary energy storage capacitor is charged to a high voltage, such as 2.5 kV, a voltage with amplitude of 86 kV can be achieved on the secondary winding. The magnetic core of saturable pulse transformer is saturated deeply and the saturable inductance of the secondary windings is very small. The switch function of the saturable pulse transformer can be realized ideally. Therefore, a 71 kV output voltage pulse is formed on the load. Moreover, the magnetic core of the saturable pulse transformer can be reset automatically.

  12. Dynamic Voltage Restorer Based on Space Vector Pulse Width Modulation Technique

    Directory of Open Access Journals (Sweden)

    B.N S P Venkatesh

    2011-07-01

    Full Text Available Power Quality problems encompass a wide range of disturbances such as voltage sags, swells, flicker,harmonics distortion and interruptions. The strategic deployment of custom power devices has been proposed asone of the means to protect sensitive loads from power quality problems such as voltage sags and swells. The Dynamic Voltage Restorer (DVR is a power electronic device that is used to inject 3-phase voltage in series and in synchronism with the distribution feeder voltages in order to compensate voltage sag and similarly itreacts quickly to inject the appropriate voltage component (negative voltage magnitude in order to compensate voltage swell. The principal component of the DVR is a voltage source inverter that generates three phase voltages and provides the voltage support to a sensitive load during voltage sags and swells. Pulse Width Modulation Technique is very critical for proper control of DVR. Sinusoidal Pulse Width Modulation (SPWM and Space Vector Pulse Width Modulation (SVPWM control techniques are used for controlling the DVR. Inthis work, the operation of DVR is presented and the control technique used for voltage source inverter is Space Vector PWM technique. Space vector PWM can utilize the better dc voltage and generates the fewer harmonic in inverter output voltage than Sinusoidal PWM technique. This work describes the DVR based on Space Vector PWM which provides voltage support to sensitive loads and is simulated by using MATLAB/SIMULINK. Simulation results show that the control approach is able to compensate for any type of voltage sags and swells.

  13. Condition assessment of power cables using partial discharge diagnosis at damped AC voltages

    NARCIS (Netherlands)

    Wester, F.J.

    2004-01-01

    The thesis focuses on the condition assessment of the distribution power cables, which have a very critical part in the distribution of electrical power over regional distances. The majority of the outages in the power system is related to the distribution cables, of which for more than 60% to inter

  14. Effect of DC voltage pulses on memristor behavior.

    Energy Technology Data Exchange (ETDEWEB)

    Evans, Brian R.

    2013-10-01

    Current knowledge of memristor behavior is limited to a few physical models of which little comprehensive data collection has taken place. The purpose of this research is to collect data in search of exploitable memristor behavior by designing and implementing tests on a HP Labs Rev2 Memristor Test Board. The results are then graphed in their optimal format for conceptualizing behavioral patterns. This series of experiments has concluded the existence of an additional memristor state affecting the behavior of memristors when pulsed with positively polarized DC voltages. This effect has been observed across multiple memristors and data sets. The following pages outline the process that led to the hypothetical existence and eventual proof of this additional state of memristor behavior.

  15. Radiation Testing of a Low Voltage Silicone Nuclear Power Plant Cable.

    Energy Technology Data Exchange (ETDEWEB)

    Bernstein, Robert

    2014-08-01

    This report summarizes the results generated in FY13 for cable insulation in support of DOE's Light Water Reactor Sustainability (LWRS) Program, in collaboration with the US- Argentine Binational Energy Working Group (BEWG). A silicone (SiR) cable, which was stored in benign conditions for %7E30 years, was obtained from Comision Nacional de Energia Atomica (CNEA) in Argentina. Physical property testing was performed on the as-received cable. This cable was artificially aged to assess behavior with additional analysis. SNL observed appreciable tensile elongation values for all cable insulations received, indicative of good mechanical performance. Of particular note, the work presented here provides correlations between measured tensile elongation and other physical properties that may be potentially leveraged as a form of condition monitoring (CM) for actual service cables. It is recognized at this point that the polymer aging community is still lacking the number and types of field returned materials that are desired, but SNL -- along with the help of others -- is continuing to work towards that goal. This work is an initial study that should be complimented with location- mapping of environmental conditions of CNEA plant conditions (dose and temperature) as well as retrieval, analysis, and comparison with in-service cables.

  16. Radiation Testing of a Low Voltage Silicone Nuclear Power Plant Cable.

    Energy Technology Data Exchange (ETDEWEB)

    White II, Gregory Von; Schroeder, John Lee.; Sawyer, Patricia Sue.; Wichhart, Derek; Mata, Guillermo Adrian; Zorrilla, Jorge; Bernstein, Robert

    2014-09-01

    This report summarizes the results generated in FY13 for cable insulation in support of the Department of Energy's Light Water Reactor Sustainability (LWRS) Program, in collaboration with the US-Argentine Binational Energy Working Group (BEWG). A silicone (SiR) cable, which was stored in benign conditions for %7E30 years, was obtained from Comision Nacional de Energia Atomica (CNEA) in Argentina with the approval of NA-SA (Nucleoelectrica Argentina Sociedad Anonima). Physical property testing was performed on the as-received cable. This cable was artificially aged to assess behavior with additional analysis. SNL observed appreciable tensile elongation values for all cable insulations received, indicative of good mechanical performance. Of particular note, the work presented here provides correlations between measured tensile elongation and other physical properties that may be potentially leveraged as a form of condition monitoring (CM) for actual service cables. It is recognized at this point that the polymer aging community is still lacking the number and types of field returned materials that are desired, but Sandia National Laboratories (SNL) -- along with the help of others -- is continuing to work towards that goal. This work is an initial study that should be complimented with location-mapping of environmental conditions of Argentinean plant conditions (dose and temperature) as well as retrieval, analysis, and comparison with in- service cables.

  17. Pulsed voltage electrospray ion source and method for preventing analyte electrolysis

    Science.gov (United States)

    Kertesz, Vilmos; Van Berkel, Gary

    2011-12-27

    An electrospray ion source and method of operation includes the application of pulsed voltage to prevent electrolysis of analytes with a low electrochemical potential. The electrospray ion source can include an emitter, a counter electrode, and a power supply. The emitter can include a liquid conduit, a primary working electrode having a liquid contacting surface, and a spray tip, where the liquid conduit and the working electrode are in liquid communication. The counter electrode can be proximate to, but separated from, the spray tip. The power system can supply voltage to the working electrode in the form of a pulse wave, where the pulse wave oscillates between at least an energized voltage and a relaxation voltage. The relaxation duration of the relaxation voltage can range from 1 millisecond to 35 milliseconds. The pulse duration of the energized voltage can be less than 1 millisecond and the frequency of the pulse wave can range from 30 to 800 Hz.

  18. Note: Complementary metal-oxide-semiconductor high voltage pulse generation circuits.

    Science.gov (United States)

    Sun, Jiwei; Wang, Pingshan

    2013-10-01

    We present two types of on-chip pulse generation circuits. The first is based on CMOS pulse-forming-lines (PFLs). It includes a four-stage charge pump, a four-stacked-MOSFET switch and a 5 mm long PFL. The circuit is implemented in a 0.13 μm CMOS process. Pulses of ~1.8 V amplitude with ~135 ps duration on a 50 Ω load are obtained. The obtained voltage is higher than 1.6 V, the rated operating voltage of the process. The second is a high-voltage Marx generator which also uses stacked MOSFETs as high voltage switches. The output voltage is 11.68 V, which is higher than the highest breakdown voltage (~10 V) of the CMOS process. These results significantly extend high-voltage pulse generation capabilities of CMOS technologies.

  19. Non destructive testing of medium and high voltage cables with a transportable radiography system

    OpenAIRE

    2010-01-01

    A power cable is the most important part in a power transmission system. The cables must be total quality dedicated andcertified for development, manufacturing and installation, however are exposed to a corrosive environment. The purpose ofthis paper is to show that the fast neutron radiography with a transportable system is a solution to find defects in the cablesand reduce the cost of inspection. The design, regarding the materials considered, was compatible with the European UnionDirective...

  20. Comparison between Underground Cable and Overhead Line for a Low-Voltage Direct Current Distribution Network Serving Communication Repeater

    Directory of Open Access Journals (Sweden)

    Jae-Han Kim

    2014-03-01

    Full Text Available This paper compares the differences in economic feasibility and dynamic characteristics between underground (U/G cable and overhead (O/H line for low-voltage direct current (LVDC distribution. Numerous low loaded long-distance distribution networks served by medium-voltage alternative current (MVAC distribution lines exist in the Korean distribution network. This is an unavoidable choice to compensate voltage drop, therefore, excessive cost is expended for the amount of electrical power load. The Korean Electric Power Corporation (KEPCO is consequently seeking a solution to replace the MVAC distribution line with a LVDC distribution line, reducing costs and providing better quality direct current (DC electricity. A LVDC distribution network can be installed with U/G cables or O/H lines. In this paper, a realistic MVAC distribution network in a mountainous area was selected as the target model to replace with LVDC. A 30 year net present value (NPV analysis of the economic feasibility was conducted to compare the cost of the two types of distribution line. A simulation study compared the results of the DC line fault with the power system computer aided design/electro-magnetic transient direct current (PSCAD/EMTDC. The economic feasibility evaluation and simulation study results will be used to select the applicable type of LVDC distribution network.

  1. High-voltage isolation transformer for sub-nanosecond rise time pulses constructed with annular parallel-strip transmission lines.

    Science.gov (United States)

    Homma, Akira

    2011-07-01

    A novel annular parallel-strip transmission line was devised to construct high-voltage high-speed pulse isolation transformers. The transmission lines can easily realize stable high-voltage operation and good impedance matching between primary and secondary circuits. The time constant for the step response of the transformer was calculated by introducing a simple low-frequency equivalent circuit model. Results show that the relation between the time constant and low-cut-off frequency of the transformer conforms to the theory of the general first-order linear time-invariant system. Results also show that the test transformer composed of the new transmission lines can transmit about 600 ps rise time pulses across the dc potential difference of more than 150 kV with insertion loss of -2.5 dB. The measured effective time constant of 12 ns agreed exactly with the theoretically predicted value. For practical applications involving the delivery of synchronized trigger signals to a dc high-voltage electron gun station, the transformer described in this paper exhibited advantages over methods using fiber optic cables for the signal transfer system. This transformer has no jitter or breakdown problems that invariably occur in active circuit components.

  2. Development of high-voltage pulse generator with variable amplitude and duration

    Science.gov (United States)

    Upadhyay, J.; Sharma, M. L.; Ahuja, Aakash B.; Navathe, C. P.

    2014-06-01

    A high voltage pulse generator with variable amplitude (100-3000 V) and duration (100-2000 μs) has been designed and developed. The variable duration pulse has been generated by adopting a simple and novel technique of varying the turn off delay time of a high voltage Metal Oxide Semiconductor Field Effect Transistor (MOSFET) based switch by varying external gate resistance. The pulse amplitude is made variable by adjusting biasing supply of the high voltage switch. The high voltage switch has been developed using a MOSFET based stack of 3 kV rating with switching time of 7 ns.

  3. Voltage-pulsed and laser-pulsed atom probe tomography of a multiphase high-strength low-carbon steel.

    Science.gov (United States)

    Mulholland, Michael D; Seidman, David N

    2011-12-01

    The differences in artifacts associated with voltage-pulsed and laser-pulsed (wavelength = 532 or 355 nm) atom-probe tomographic (APT) analyses of nanoscale precipitation in a high-strength low-carbon steel are assessed using a local-electrode atom-probe tomograph. It is found that the interfacial width of nanoscale Cu precipitates increases with increasing specimen apex temperatures induced by higher laser pulse energies (0.6-2 nJ pulse(-1) at a wavelength of 532 nm). This effect is probably due to surface diffusion of Cu atoms. Increasing the specimen apex temperature by using pulse energies up to 2 nJ pulse(-1) at a wavelength of 532 nm is also found to increase the severity of the local magnification effect for nanoscale M2C metal carbide precipitates, which is indicated by a decrease of the local atomic density inside the carbides from 68 ± 6 nm(-3) (voltage pulsing) to as small as 3.5 ± 0.8 nm(-3). Methods are proposed to solve these problems based on comparisons with the results obtained from voltage-pulsed APT experiments. Essentially, application of the Cu precipitate compositions and local atomic density of M2C metal carbide precipitates measured by voltage-pulsed APT to 532 or 355 nm wavelength laser-pulsed data permits correct quantification of precipitation.

  4. Results of the CESI-CPRI research on extruded cables under DC voltage

    Energy Technology Data Exchange (ETDEWEB)

    Mosca, W.

    1988-10-01

    This paper describes extensive feasibility studies (involving power frequency withstand, partial discharge, short and long duration stress, lighting impulse and polarity reversal tests) on the the use of extruded DC cables for HVDC links. The results indicate that: either XLPe or EPr insulated cables, although not optimized for DC, show dielectric performances under DC stress that may be considered satisfactory (a mean working stress of around 25 kV/mm appears a realistic figure to be attained with proper materials and manufacturing technology); the behaviour under transient stress seems satisfactory (a fundamental role is played by the absence of defects and by the quality of the interfaces between inner/outer semiconductive screen and main insulation); a suitable protection to prevent moisture penetration in the insulation must be provided in order to avoid a significant reduction in cable dielectric performances (the use of a laminated protective covering could be in an interesting solution).

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

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Masayuki [Department of Chemical and Environmental Engineering, Gunma University 1-5-1 Tenjin, Kiryu, Gunma 376-8515 (Japan)], E-mail: mxsato@cee.gunma-u.ac.jp

    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.

  6. Reduction of low voltage power cables electromagnetic field emission in MV/LV substations

    Energy Technology Data Exchange (ETDEWEB)

    Beltran San Segundo, Hector [Dpt. Industrial Systems Engineering and Design, Campus del Riu Sec, Universitat Jaume I, 12071 Castello (Spain); Fuster Roig, Vicente [Instituto de Tecnologia Electrica, Avda. Juan de la Cierva 24, Parc Tecnologic de Valencia, 46980 Paterna (Spain)

    2008-06-15

    In this paper a solution to reduce magnetic field emission levels generated by MV/LV substation power cables is proposed. The reduction is obtained by the arrangement of the phases in a proper way and by shielding the cables with magnetic or conductive materials. The effects introduced by these two options have been analyzed by means of simulations, using finite elements method calculation software, and by experimental measurements. The introduced results allow selecting an optimal arrangement and the best screening material in order to reduce the magnetic fields in those directions required to protect. (author)

  7. Study of Space Charge in SC Shield / XLPE Interface and Mid-Voltage Cable Perfomance

    Directory of Open Access Journals (Sweden)

    Idalberto Tamayo Ávila

    2013-01-01

    Full Text Available Se estudiaron tres cables experimentales de media tensión: C2, C3 y C4; con aislamiento de polietileno reticulado (XLPE denominados: Medio, Alto y Bajo en los test de perforación con tensiones sobre 150 kV. Los tres cables han sido medidos sistemáticamente mediante las técnicas del Pulso Electroacústico (PEA y de las Corrientes de Despolarización Estimuladas Térmicamente (TSDC usando un voltaje de polarización de 120 kV en muestras tal y como se reciben, tratadas térmicamente a 90 oC y 120 oC durante 672 horas. Las medidas de carga interna en el cable C4 son de un orden del doble que en los cables C2 y C3. El fenómeno de carga interfacial ha sido estudiado por espectroscopia infrarroja mediante la técnica de Reflectancia Total Atenuada (ATR y muestra que hay componentes que migran, se difunden y se trasportan desde la capa semiconductora externa hacia el aislamiento de polietileno reticulado durante el tratamiento térmico del cable. Las medidas por PEA usando un campo eléctrico de 120 KV/mm muestran la formación y propagación de paquetes de carga de espacio desde el semiconductor (SC hacia el aislamiento. Estos resultados son coherentes con las medidas mediante TSDC que muestran diferencias entre las áreas bajo la curva de corriente en función de la temperatura para los tres cables C2, C3 y C4 que es el resultado de la carga acumulada. Para resumir, la combinación de las mediciones PEA, TSDC y ATR son herramientas útiles para la comprensión de los procesos de relajación de carga de espacio y la eficiencia de los cables con aislamiento de XLPE.

  8. A Pulsed Power Supply with Sag Compensation using Controlled Gradational Voltage

    Science.gov (United States)

    Suzuki, Akihiro; Yamada, Masaki; Tashiro, Shojirou; Iwata, Akihiko

    A pulsed power supply with sag compensation using controlled gradational voltage to increase the flatness of output waveforms has been developed.The sag compensation circuit consists of compensation units connected in series. Each compensation unit consists of capacitances, diodes, and semiconductor switches. The capacitances of each unit are charged with different voltages by 2n (V0, 2V0, 4V0, ···). The compensation voltages, which has 2n-1 steps, is generated by switching the semiconductor switches of each unit in a binary sequence. Using this method, compensation voltage waveforms up to 6.2kV with 31 steps can be obtained with 5 compensation units. The sag compensation circuit has been adapted to a direct switch type pulsed power supply, which generates 7kV pulsed voltage with a pulse width of 700μs, thus realizing sag compensation.

  9. Non destructive testing of medium and high voltage cables with a transportable radiography system

    Directory of Open Access Journals (Sweden)

    D. V. Bandekas

    2010-01-01

    Full Text Available A power cable is the most important part in a power transmission system. The cables must be total quality dedicated andcertified for development, manufacturing and installation, however are exposed to a corrosive environment. The purpose ofthis paper is to show that the fast neutron radiography with a transportable system is a solution to find defects in the cablesand reduce the cost of inspection. The design, regarding the materials considered, was compatible with the European UnionDirective on “Restriction of Hazardous Substances” (RoHS 2002/95/EC, hence excluding the use of cadmium and lead.Wide width values for the collimator ratio were calculated. With suitable collimator design it was possibly to optimize theneutron radiography parameters. Finally the shielding design was examined closely. The proposed system has been simulatedusing the MCNPX code.

  10. 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.

  11. Ground Return Current Behaviour in High Voltage Alternating Current Insulated Cables

    Directory of Open Access Journals (Sweden)

    Roberto Benato

    2014-12-01

    Full Text Available The knowledge of ground return current in fault occurrence plays a key role in the dimensioning of the earthing grid of substations and of cable sealing end compounds, in the computation of rise of earth potential at substation sites and in electromagnetic interference (EMI on neighbouring parallel metallic conductors (pipes, handrails, etc.. Moreover, the ground return current evaluation is also important in steady-state regime since this stray current can be responsible for EMI and also for alternating current (AC corrosion. In fault situations and under some assumptions, the ground return current value at a substation site can be computed by means of k-factors. The paper shows that these simplified and approximated approaches have a lot of limitations and only multiconductor analysis can show the ground return current behaviour along the cable (not only the two end values both in steady-state regime and in short circuit occurrence (e.g., phase-to-ground and phase-to-phase-to-ground. Multiconductor cell analysis (MCA considers the cable system in its real asymmetry without simplified and approximated hypotheses. The sensitivity of ground return current on circuit parameters (cross-bonding box resistances, substation earthing resistances, soil resistivity is presented in the paper.

  12. DESIGN NOTE: A fast high-voltage pulse generator with variable amplitude and duration

    Science.gov (United States)

    Upadhyay, Jankee; Navathe, C. P.

    2006-07-01

    A high-voltage pulse generator based on a self-matched transmission line with variable pulse amplitude and duration is developed. Two avalanche transistor stacks are used as switches. The pulse width is varied by adjusting the delay in triggering two switches whereas amplitude is adjusted by adjusting load resistance. A pulse with amplitude of 800 V to 3.8 kV and width of 5 ns to 38 ns can be obtained using this circuit.

  13. The Dynamic Fracture Process in Rocks Under High-Voltage Pulse Fragmentation

    Science.gov (United States)

    Cho, Sang Ho; Cheong, Sang Sun; Yokota, Mitsuhiro; Kaneko, Katsuhiko

    2016-10-01

    High-voltage pulse technology has been applied to rock excavation, liberation of microfossils, drilling of rocks, oil and water stimulation, cleaning castings, and recycling products like concrete and electrical appliances. In the field of rock mechanics, research interest has focused on the use of high-voltage pulse technology for drilling and cutting rocks over the past several decades. In the use of high-voltage pulse technology for drilling and cutting rocks, it is important to understand the fragmentation mechanism in rocks subjected to high-voltage discharge pulses to improve the effectiveness of drilling and cutting technologies. The process of drilling rocks using high-voltage discharge is employed because it generates electrical breakdown inside the rocks between the anode and cathode. In this study, seven rock types and a cement paste were electrically fractured using high-voltage pulse discharge to investigate their dielectric breakdown properties. The dielectric breakdown strengths of the samples were compared with their physical and mechanical properties. The samples with dielectric fractured were scanned using a high-resolution X-ray computed tomography system to observe the fracture formation associated with mineral constituents. The fracture patterns of the rock samples were analyzed using numerical simulation for high-voltage pulse-induced fragmentation that adopts the surface traction and internal body force conditions.

  14. Development of the Composite High Voltage Optical Fiber Temperature Measurement Cable%高压光纤复合测温电缆的研制

    Institute of Scientific and Technical Information of China (English)

    金金元

    2012-01-01

    In order to use optical fiber distributed temperature monitoring system to on-line monitor the temperature of the cable in operation; a composite high voltage fiber optic temperature measuring cable is developed independently. The structure design, the production process of building in of the fibers, and the performance testing of the composite high voltage optical fiber temperature measuring cable are described in detail.%为利用光纤分布式温度监测系统对运行电缆的温度进行实时在线监测,自主开发了高压光纤复合测温电缆。对高压光纤复合测温电缆结构设计、光纤内置等制造过程和性能检测进行了较为详细的阐述。

  15. Direct-detect Type Residual Charge Method with Short-term Voltage Up-down for Water Tree Deterioration Diagnosis in XLPE Cable

    Science.gov (United States)

    Ootaka, Iwao; Aoki, Masaru; Togashi, Hirotaka; Tsujimoto, Tomiyuki; Nakade, Masahiko

    Water tree is one of the unique type of deterioration in XLPE cable, which is the primary cause of aging breakdown. Water tree, which bridges between conductor and shield, can be detected easily, such as DC leakage current method. However, 22kV class or above XLPE cable, most of breakdown occurs before water tree bridges, and there used to be no effective method for detecting non-bridged water tree. In this paper, we've found residual charge in harmful water tree relaxes quickly with AC voltage application. To detect this type of residual charge, we've developed new diagnosis method with “direct-detect type residual charge method" and “short-term voltage up-down method". This new method found to be very effective for diagnosing over 22kV class XLPE cable lines.

  16. Comparison of the quantitative analysis performance between pulsed voltage atom probe and pulsed laser atom probe.

    Science.gov (United States)

    Takahashi, J; Kawakami, K; Raabe, D

    2017-01-31

    The difference in quantitative analysis performance between the voltage-mode and laser-mode of a local electrode atom probe (LEAP3000X HR) was investigated using a Fe-Cu binary model alloy. Solute copper atoms in ferritic iron preferentially field evaporate because of their significantly lower evaporation field than the matrix iron, and thus, the apparent concentration of solute copper tends to be lower than the actual concentration. However, in voltage-mode, the apparent concentration was higher than the actual concentration at 40K or less due to a detection loss of matrix iron, and the concentration decreased with increasing specimen temperature due to the preferential evaporation of solute copper. On the other hand, in laser-mode, the apparent concentration never exceeded the actual concentration, even at lower temperatures (20K), and this mode showed better quantitative performance over a wide range of specimen temperatures. These results indicate that the pulsed laser atom probe prevents both detection loss and preferential evaporation under a wide range of measurement conditions.

  17. Finite Element Based Optimal Design Approach for High Voltage Pulse Transformers

    CERN Document Server

    Aguglia, D; Viarouge, P; Cros, J

    2014-01-01

    This paper presents an optimal design methodology of monolithic high voltage pulse transformers based on the direct 2D FEA identification of the electrical equivalent circuit parameters. This method is applied to the preliminary optimal design of the monolithic high voltage pulse transformer for the future CLIC modulators under study at CERN. The feasibility of such a transformer with tight specifications is demonstrated. The predicted performances obtained with the direct 2D FEA optimization process is validated by 3D FEA simulation.

  18. Power cables with extruded insulation and their accessories for rated voltages from 1 kV (Um = 1,2 kV) up to 30 kV (Um = 36 kV) - Part 1: Cables for rated voltages of 1 kV (Um = 1,2 kV) and 3 kV (Um = 3,6 kV)

    CERN Document Server

    International Electrotechnical Commission. Geneva

    2004-01-01

    Specifies the construction, dimensions and test requirements of power cables with extruded solid insulation for rated voltages of 1 kV (Um = 1,2 kV) and 3 kV (Um = 3,6 kV) for fixed installations such as distribution networks or industrial installations. This standard includes cables which exhibit properties of reduced flame spread, low levels of smoke emission and halogen-free gas emission when exposed to fire. Cables for special installation and service conditions are not included, for example cables for overhead networks, the mining industry, nuclear power plants (in and around the containment area), submarine use or shipboard application. The main changes with respect to the first edition relate to insulation and oversheath thickness requirements, and inclusion of constructions and requirements for halogen free cables with reduced flame propagation and low levels of smoke emission.

  19. Initial position estimation method for permanent magnet synchronous motor based on improved pulse voltage injection

    DEFF Research Database (Denmark)

    Wang, Z.; Lu, K.; Ye, Y.

    2011-01-01

    According to saliency of permanent magnet synchronous motor (PMSM), the information of rotor position is implied in performance of stator inductances due to the magnetic saturation effect. Researches focused on the initial rotor position estimation of PMSM by injecting modulated pulse voltage...... vectors. The relationship between the inductance variations and voltage vector positions was studied. The inductance variation effect on estimation accuracy was studied as well. An improved five-pulses injection method was proposed, to improve the estimation accuracy by choosing optimaized voltage vectors...

  20. Correction factor based double model fuzzy logic control strategy of arc voltage in pulsed MIG welding

    Institute of Scientific and Technical Information of China (English)

    Wu Kaiyuan; Huang Shisheng; Meng Yongmin

    2005-01-01

    According to the feature of arc voltage control in welding steel using pulsed MIG welding, a correction factor based double model fuzzy logic controller (FLC) was developed to realize the arc voltage control by means of arc voltage feedback.When the error of peak arc voltage was great, a coarse adjusting fuzzy logic control rules with correction factor was designed,in the controller, the peak arc voltage was controlled by the wire feeding speed by means of arc voltage feedback. When the error of peak arc voltage was small, a fine adjusting fuzzy logic control rules with correction factor was designed, in this controller, the peak arc voltage was controlled by the background time by means of arc voltage feedback. The FLC was realized in a Look-Up Table ( LUT) method. Experiments had been carried out aiming at implementing the control strategy to control the arc length change in welding process. Experimental results show that the controller proposed enables the consistency of arc length and the stabolity of arc voltage and welding process to be achieved in pulsed MIG welding process.

  1. Submerged Medium Voltage Cable Systems at Nuclear Power Plants. A Review of Research Efforts Relevant to Aging Mechanisms and Condition Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Jason [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Bernstein, Robert [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); White, II, Gregory Von [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Glover, Steven F. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Neely, Jason C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Pena, Gary [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Williamson, Kenneth Martin [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Zutavern, Fred J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Gelbard, Fred [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-03-01

    In a submerged environment, power cables may experience accelerated insulation degradation due to water - related aging mechanisms . Direct contact with water or moisture intrusion in the cable insulation s ystem has been identified in the literature as a significant aging stressor that can affect performance and lifetime of electric cables . Progressive reduction of the dielectric strength is commonly a result of water treeing which involves the development of permanent hydrophilic structures in the insulation coinciding with the absorption of water into the cable . Water treeing is a phenomenon in which dendritic microvoids are formed in electric cable insulation due to electrochemic al reactions , electromechanical forces , and diffusion of contaminants over time . These reactions are caused by the combined effect s of water presence and high electrical stress es in the material . Water tree growth follow s a tree - like branching pattern , i ncreasing in volume and length over time . Although these cables can be "dried out," water tree degradation , specifically the growth of hydrophilic regions, is believed to be permanent and typically worsens over time. Based on established research , water treeing or water induced damage can occur in a variety of electric cables including XLPE, TR - XLPE and other insulating materials, such as EPR and butyl rubber . Once water trees or water induced damage form, the dielectric strength of an insulation materia l will decrease gradually with time as the water trees grow in length, which could eventually result in failure of the insulating material . Under wet conditions or i n submerged environments , several environmental and operational parameters can influence w ater tree initiation and affect water tree growth . These parameters include voltage cycling, field frequency, temperature, ion concentration and chemistry, type of insula tion material , and the characteristics of its defects. In this effort, a review of academic

  2. 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.

  3. Submerged Medium Voltage Cable Systems at Nuclear Power Plants. A Review of Research Efforts Relevant to Aging Mechanisms and Condition Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Jason [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Bernstein, Robert [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); White, II, Gregory Von [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Glover, Steven F. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Neely, Jason C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Pena, Gary [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Williamson, Kenneth Martin [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Zutavern, Fred J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Gelbard, Fred [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-03-01

    In a submerged environment, power cables may experience accelerated insulation degradation due to water - related aging mechanisms . Direct contact with water or moisture intrusion in the cable insulation s ystem has been identified in the literature as a significant aging stressor that can affect performance and lifetime of electric cables . Progressive reduction of the dielectric strength is commonly a result of water treeing which involves the development of permanent hydrophilic structures in the insulation coinciding with the absorption of water into the cable . Water treeing is a phenomenon in which dendritic microvoids are formed in electric cable insulation due to electrochemic al reactions , electromechanical forces , and diffusion of contaminants over time . These reactions are caused by the combined effect s of water presence and high electrical stress es in the material . Water tree growth follow s a tree - like branching pattern , i ncreasing in volume and length over time . Although these cables can be "dried out," water tree degradation , specifically the growth of hydrophilic regions, is believed to be permanent and typically worsens over time. Based on established research , water treeing or water induced damage can occur in a variety of electric cables including XLPE, TR - XLPE and other insulating materials, such as EPR and butyl rubber . Once water trees or water induced damage form, the dielectric strength of an insulation materia l will decrease gradually with time as the water trees grow in length, which could eventually result in failure of the insulating material . Under wet conditions or i n submerged environments , several environmental and operational parameters can influence w ater tree initiation and affect water tree growth . These parameters include voltage cycling, field frequency, temperature, ion concentration and chemistry, type of insula tion material , and the characteristics of its defects. In this effort, a review of academic

  4. Research on the Effects of Pulse Waves Through a Long Cable on Motor Terminal Overvoltage%长电缆传输脉冲波对电机端过电压影响的研究

    Institute of Scientific and Technical Information of China (English)

    张椿; 戴鹏; 宗伟林; 潘庆山

    2013-01-01

    基于传输线理论分析了脉冲波在电缆中的反射过程及电机端过电压的产生机理,通过Matlab仿真软件对脉冲波反射过程进行了分析.根据反射原理,对电机端各反射波分量和入射波分量进行叠加,得到电机端电压.通过PSpice仿真软件建立了单个脉冲-无损电缆-电机仿真模型,并对电机端产生过电压临界脉冲传输的时间做了仿真研究;在此基础上建立了PWM脉冲-无损电缆-电机仿真模型,仿真结果验证了PWM脉冲占空比最大时电机端电压达到最大值.%The reflection of pulse waves through a long cable and the mechanism of motor terminal overvoltage using transmission line theory was analyzed.The pulse wave reflection prosses was simulated with Matlab software. According to the reflection principle,motor terminal over-voltage is the piling up of the incident and reflected wave components.Pusle-lossless cable-motor model was set up in PSpice software, while the critical state and the most likely moment occurring motor terminal overvoltage was studied with the model.And then PWM pulse-lossless cable-motor model was set up to verify that motor terminal voltage reached its maximum as PWM pulse duty cycle is the largest.

  5. Evolution of nanosecond surface dielectric barrier discharge for negative polarity of a voltage pulse

    Science.gov (United States)

    Soloviev, V. R.; Krivtsov, V. M.; Shcherbanev, S. A.; Starikovskaia, S. M.

    2017-01-01

    Surface dielectric barrier discharge, initiated by a high-voltage pulse of negative polarity in atmospheric pressure air, is studied numerically and experimentally. At a pulse duration of a few tens of nanoseconds, two waves of optical emission propagate from the high-voltage electrode corresponding to the leading and trailing edges of the high-voltage pulse. It is shown by means of numerical modeling that a glow-like discharge slides along the surface of the dielectric at the leading edge of the pulse, slowing down on the plateau of the pulse. When the trailing edge of the pulse arrives to the high-voltage electrode, a second discharge starts and propagates in the same direction. The difference is that the discharge corresponding to the trailing edge is not diffuse and demonstrates a well-pronounced streamer-like shape. The 2D (in numerical modeling) streamer propagates above the dielectric surface, leaving a gap of about 0.05 mm between the streamer and the surface. The calculated and experimentally measured emission picture, waveform of the electrical current, and deposited energy, qualitatively coincide. The sensitivity of the numerical solution to unknown physical parameters of the model is discussed.

  6. Synthesis gas regeneration electrotechnology using volume high-voltage pulsed discharges: corona and barrier ones

    Directory of Open Access Journals (Sweden)

    M.I. Boyko

    2014-09-01

    Full Text Available Factory testing of a created high-voltage complex (plant has been conducted. The complex consists of two pulse generators with the repetition rate of up to 50,000 pulses per second and load reactors with pulsed discharges - corona and barrier ones. Transistor (IGBT keys are used as energy switches. The efficient mode of coke gas methane conversion (steam reforming to syngas has been obtained with application of the complex created. A unidirectional action of the pulsed discharges, the gas mixture temperature, and a nickel catalyst has reduced the specific energy consumption for synthesis gas regeneration during the conversion. A feasible mechanism of this conversion is described.

  7. Continuous-flow multi-pulse electroporation at low DC voltages by microfluidic flipping of the voltage space topology

    Science.gov (United States)

    Bhattacharjee, N.; Horowitz, L. F.; Folch, A.

    2016-10-01

    Concerns over biosafety, cost, and carrying capacity of viral vectors have accelerated research into physical techniques for gene delivery such as electroporation and mechanoporation. Advances in microfabrication have made it possible to create high electric fields over microscales, resulting in more efficient DNA delivery and higher cell viability. Continuous-flow microfluidic methods are typically more suitable for cellular therapies where a large number of cells need to be transfected under sterile conditions. However, the existing continuous-flow designs used to generate multiple pulses either require expensive peripherals such as high-voltage (>400 V) sources or function generators, or result in reduced cell viability due to the proximity of the cells to the electrodes. In this paper, we report a continuous-flow microfluidic device whose channel geometry reduces instrumentation demands and minimizes cellular toxicity. Our design can generate multiple pulses of high DC electric field strength using significantly lower voltages (15-60 V) than previous designs. The cells flow along a serpentine channel that repeatedly flips the cells between a cathode and an anode at high throughput. The cells must flow through a constriction each time they pass from an anode to a cathode, exposing them to high electric field strength for short durations of time (the "pulse-width"). A conductive biocompatible poly-aniline hydrogel network formed in situ is used to apply the DC voltage without bringing the metal electrodes close to the cells, further sheltering cells from the already low voltage electrodes. The device was used to electroporate multiple cell lines using electric field strengths between 700 and 800 V/cm with transfection efficiencies superior than previous flow-through designs.

  8. Solid-state fast voltage compensator for pulsed power applications requiring constant AC power consumption

    CERN Document Server

    Magallanes, Francisco Cabaleiro; Viarouge, Philippe; Cros, Jérôme

    2015-01-01

    This paper proposes a novel topological solution for pulsed power converters based on capacitor-discharge topologies, integrating a Fast Voltage Compensator which allows an operation at constant power consumption from the utility grid. This solution has been retained as a possible candidate for the CLIC project under study at CERN, which requires more than a thousand synchronously-operated klystron modulators producing a total pulsed power of almost 40 GW. The proposed Fast Voltage Compensator is integrated in the modulator such that it only has to treat the capacitor charger current and a fraction of the charging voltage, meaning that its dimensioning power and cost are minimized. This topology can be used to improve the AC power quality of any pulsed converters based on capacitor-discharge concept. A prototype has been built and exploited to validate the operating principle and demonstrate the benefits of the proposed solution.

  9. Variable Voltage Source Inverter with controlled frequency spectrum based on Random Pulse Width Modulation

    Directory of Open Access Journals (Sweden)

    Muhammad Farrukh Yaqub

    2012-01-01

    Full Text Available This paper presents a new method for single phase variable voltage inverter based on Random Pulse Width Modulation. In Random Pulse Width Modulation based inverter, the frequency spectrum of the output current and voltage waveforms becomes continuous because of the randomization of the switching function of the devices controlling the output voltages. This paper establishes a theory that if the distributions of the random numbers generated by the random source are kept within certain limit with respect to the peak value of reference sinusoidal waveform, the frequency spectrum can be controlled. On the basis of the results, a novel drive using variable tap changing transformer (optional and adaptive random number generator, to control the ratio between the numbers generated by the random source and the reference waveform has been suggested that will guarantee a better power quality profile for a broad range of output voltages.

  10. A compact, low jitter, nanosecond rise time, high voltage pulse generator with variable amplitude

    Science.gov (United States)

    Mao, Jiubing; Wang, Xin; Tang, Dan; Lv, Huayi; Li, Chengxin; Shao, Yanhua; Qin, Lan

    2012-07-01

    In this paper, a compact, low jitter, nanosecond rise time, command triggered, high peak power, gas-switch pulse generator system is developed for high energy physics experiment. The main components of the system are a high voltage capacitor, the spark gap switch and R = 50 Ω load resistance built into a structure to obtain a fast high power pulse. The pulse drive unit, comprised of a vacuum planar triode and a stack of avalanche transistors, is command triggered by a single or multiple TTL (transistor-transistor logic) level pulses generated by a trigger pulse control unit implemented using the 555 timer circuit. The control unit also accepts user input TTL trigger signal. The vacuum planar triode in the pulse driving unit that close the first stage switches is applied to drive the spark gap reducing jitter. By adjusting the charge voltage of a high voltage capacitor charging power supply, the pulse amplitude varies from 5 kV to 10 kV, with a rise time of gas-switch and available capacitor recovery time.

  11. Assembly delay line pulse generators

    CERN Document Server

    1971-01-01

    Assembly of six of the ten delay line pulse generators that will power the ten kicker magnet modules. One modulator part contains two pulse generators. Capacitors, inductances, and voltage dividers are in the oil tank on the left. Triggered high-pressure spark gap switches are on the platforms on the right. High voltage pulse cables to the kicker magnet emerge under the spark gaps. In the centre background are the assembled master gaps.

  12. Pulsed high voltage electric discharge disinfection of microbially contaminated liquids.

    Science.gov (United States)

    Anpilov, A M; Barkhudarov, E M; Christofi, N; Kop'ev, V A; Kossyi, I A; Taktakishvili, M I; Zadiraka, Y

    2002-01-01

    To examine the use of a novel multielectrode slipping surface discharge (SSD) treatment system, capable of pulsed plasma discharge directly in water, in killing micro-organisms. Potable water containing Escherichia coli and somatic coliphages was treated with pulsed electric discharges generated by the SSD. The SSD system was highly efficient in the microbial disinfection of water with a low energy utilization (eta approximately 10-4 kW h l-1). The SSD treatment was effective in the destruction of E. coli and its coliphages through the generation of u.v. radiation, ozone and free radicals. The non-thermal treatment method can be used for the eradication of micro-organisms in a range of contaminated liquids, including milk, negating the use of pasteurization. The method utilizes multipoint electric discharges capable of treating large volumes of liquid under static and flowing regimes.

  13. Bipolar generator of voltage pulses of amplitude + or - 600 kV

    Energy Technology Data Exchange (ETDEWEB)

    Bannikov, A.V.; Dzhavrishvili, A.K.; Kharchilava, A.I.; Lomtadze, T.A.; Vertogradov, L.S.

    1985-09-01

    This paper describes the design of a 25-stage pulsed-voltage generator (+ or - 600 kV) of the Arkad'ev-Marx type. The generator is used in the high-voltage power supply system of a five-meter, three-gap streamer chamber. The values of the Principal parameters of the generator, per arm, are impulse capacitance 0.95 nF, internal resistance 21 ..cap omega.., and internal inductance 1.8 ..mu.. H.

  14. Effects of High-voltage Pulse Electric Field Treatment on the Structure Stability of Konjac Glucomannan

    Institute of Scientific and Technical Information of China (English)

    YAO Min-Na; FAN Lin-Lin; LIU Ya-Nan; CHEN Qing-Ai; ZENG Yuan; JIAN Wen-Jie; PANG Jie

    2011-01-01

    Structures of KGM treated in two high-voltage pulse electric fields were characterized by infrared spectroscopy,Raman spectroscopy,X-ray diffraction and so on.The results showed that intermolecular hydrogen bonding interactions of KGM were reduced after being treated with high-voltage pulse electric field,but there was no significant effect on its fiber chain form and thermal characteristics.Results of the study can provide a useful reference for further study on the structure and property of KGM,and especially can provide theoretical basis for the effect of physical field on the foodstuff deep processing related to KGM.

  15. Hybrid Design Optimization of High Voltage Pulse Transformers for Klystron Modulators

    CERN Document Server

    Sylvain, Candolfi; Davide, Aguglia; Jerome, Cros

    2015-01-01

    This paper presents a hybrid optimization methodology for the design of high voltage pulse transformers used in klystron modulators. The optimization process is using simplified 2D FEA design models of the 3D transformer structure. Each intermediate optimal solution is evaluated by 3D FEA and correction coefficients of the 2D FEA models are derived. A new optimization process using 2D FEA models is then performed. The convergence of this hybrid optimal design methodology is obtained with a limited number of time consuming 3D FEA simulations. The method is applied to the optimal design of a monolithic high voltage pulse transformer for the CLIC klystron modulator.

  16. MOSFET-based high voltage double square-wave pulse generator with an inductive adder configuration

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Xin [State Key Laboratory of Electrical Insulation and Power Equipment, Xi' an Jiaotong University, Xi' an 710049 (China); Zhang, Qiaogen, E-mail: hvzhang@mail.xjtu.edu.cn [State Key Laboratory of Electrical Insulation and Power Equipment, Xi' an Jiaotong University, Xi' an 710049 (China); Long, Jinghua [College of Physics, Shenzhen University, Shenzhen 518060 (China); Lei, Yunfei; Liu, Jinyuan [Institute of Optoelectronics, Shenzhen University, Shenzhen 518060 (China)

    2015-09-01

    This paper presents a fast MOSFET-based solid-state pulse generator for high voltage double square-wave pulses. The generator consists mainly of an inductive adder system stacked of 20 solid-state modules. Each of the modules has 18 power MOSFETs in parallel, which are triggered by individual drive circuits; these drive circuits themselves are synchronously triggered by a signal from avalanche transistors. Our experiments demonstrate that the output pulses with amplitude of 8.1 kV and peak current of about 405 A are available at a load impedance of 20 Ω. The pulse has a double square-wave form with a rise and fall time of 40 ns and 26 ns, respectively and bottom flatness better than 12%. The interval time of the double square-wave pulses can be adjustable by varying the interval time of the trigger pulses.

  17. Optimized Controller Design for a 12-Pulse Voltage Source Converter Based HVDC System

    Science.gov (United States)

    Agarwal, Ruchi; Singh, Sanjeev

    2017-08-01

    The paper proposes an optimized controller design scheme for power quality improvement in 12-pulse voltage source converter based high voltage direct current system. The proposed scheme is hybrid combination of golden section search and successive linear search method. The paper aims at reduction of current sensor and optimization of controller. The voltage and current controller parameters are selected for optimization due to its impact on power quality. The proposed algorithm for controller optimizes the objective function which is composed of current harmonic distortion, power factor, and DC voltage ripples. The detailed designs and modeling of the complete system are discussed and its simulation is carried out in MATLAB-Simulink environment. The obtained results are presented to demonstrate the effectiveness of the proposed scheme under different transient conditions such as load perturbation, non-linear load condition, voltage sag condition, and tapped load fault under one phase open condition at both points-of-common coupling.

  18. Effect of pulsed voltage on electrochemical migration of tin in electronics

    DEFF Research Database (Denmark)

    Verdingovas, Vadimas; Jellesen, Morten Stendahl; Ambat, Rajan

    2015-01-01

    influences the dendritic growth, although a tendency for more hydroxide precipitation was observed for lower duty cycles. The precipitation of tin hydroxides was identified as influencing factor for the reduction of charge transfer under pulsed voltage with low duty cycles, therefore resulting...... in the suppression of dendrite growth....... respectively at 10 and 5 V, while the duty cycle and the pulse width were varied in the range of ms. The results showed that varying of pulse width at fixed duty cycle has a minor effect under investigated conditions, whereas increasing duty cycle significantly reduces the time to short due to dendrite...

  19. Removal of phenol by activated alumina bed in pulsed high-voltage electric field

    Institute of Scientific and Technical Information of China (English)

    ZHU Li-nan; MA Jun; YANG Shi-dong

    2007-01-01

    A new process for removing the pollutants in aqueous solution-activated alumina bed in pulsed high-voltage electric field was investigated for the removal of phenol under different conditions. The experimental results indicated the increase in removal rate with increasing applied voltage, increasing pH value of the solution, aeration, and adding Fe2+. The removal rate of phenol could reach 72.1 % when air aeration flow rate was 1200 ml/min, and 88.2 % when 0.05 mmol/L Fe2+ was added into the solution under the conditions of applied voltage 25 kV, initial phenol concentration of 5 mg/L, and initial pH value 5.5. The addition of sodium carbonate reduced the phenol removal rate. In the pulsed high-voltage electric field, local discharge occurred at the surface of activated alumina, which promoted phenol degradation in the thin water film. At the same time, the space-time distribution of gas-liquid phases was more uniform and the contact areas of the activated species generated from the discharge and the pollutant molecules were much wider due to the effect of the activated alumina bed. The synthetical effects of the pulsed high-voltage electric field and the activated alumina particles accelerated phenol degradation.

  20. The effects of high-voltage pulse electric discharges on ion adsorption on activated carbons

    Science.gov (United States)

    Gafurov, M. M.; Sveshnikova, D. A.; Larin, S. V.; Rabadanov, K. Sh.; Shabanova, Z. E.; Yusupova, A. A.; Ramazanov, A. Sh.

    2008-07-01

    The effects of high-voltage pulse electric discharges (HPED) on sorption of boron and sulfate ions on activated carbons of different kinds (KM-2, BAU, DAK) were investigated. The effect of HPED activation on the sorption characteristics of the systems was found to be similar to the temperature effect.

  1. 中压电缆终端高频电热老化试验装置的研制及分析%Development and analysis of experimental setup under high frequency voltage for medium voltage cable termination

    Institute of Scientific and Technical Information of China (English)

    周凯; 吴迎霞; 陶霰韬; 赵威; 李旭涛

    2011-01-01

    中压电缆终端被广泛应用于柔性交流输电和作为逆变器和电机的连接中,这些电缆终端可能会遭受到高频谐波电压的冲击,从而导致其绝缘迅速失效.本文研制了模拟电网高频谐波电压和工频大电流的电热老化试验装置.首先,通过信号发生器和功率放大器产生低压大电流信号,再通过高频变压器升压获得高频高压;同时通过工频试验变压器产生工频高压,将工频高压和高频高压同时施加到样本上,形成叠加;并分别在两侧加以滤波器阻止高频和工频高压串入到低压系统;最后通过CT(电流互感器)施加150A左右的大电流模拟实际工况.通过实验和红外热成像结果分析,该装置有助于高频电压下的电缆终端绝缘老化研究.%Medium voltage cable terminations are widely used for flexible AC transmission (FACTS) and for con necting terminations for electric motors driven by inverters. These cable terminations are possibly subjected to high electrical stress because of high frequency voltage components. In this paper, an experimental setup was designed to test cable terminations insulation under high frequency sinusoidal voltage. A signal generator and a power ampli fier were used to generate high frequency voltage and larger output power. The voltage was used for the input of high frequency transformer in order to generate high voltage. Also, work frequency high voltage was generated by work frequency transformer. The two kinds of voltages were both applied to specimens at the same time. As a re sult, a superposition waveform by high frequency and work frequency waveform was formed. Two filters composed of LC components were also needed. Furthermore, to simulate working condition, a current transformer is used to obtain 150A current. Through the analysis of experiment and thermal images, the experimental setup has positive effect on investigating insulation characteristics of cable termination.

  2. 电缆绝缘电阻测试仪中高压电源的设计*%Design of High-Voltage Power Supply of Cable Insulation Resistance Tester

    Institute of Scientific and Technical Information of China (English)

    李琳琳; 王二宝; 孙继银; 恒波; 肖明芳

    2013-01-01

      To meet the power requirements of inputting low voltage and outputting high-voltage during cable insulation resistance test, the paper proposes a new type of active clamp voltage multiplying converters by analyzing and improving the technical of analysis active clamp pulse width modulation and voltage double rectifier. It uses main circuit in active clamp technique to achieve magnetic core flux automatic reset and increases core utilization. The clamp capacitor with other components produces resonant achieving opened switch to zero pressure, which reduces the switching loss and voltage stress. Doubling voltage technique is used to reduce transformer step-up requirements and converter bulk. Taking advantage of negative feedback in control loop,input output voltage into PWM chip and control pulse duty cycle can increase power stability and load characteristics. The software simulation result shows that the converter is able to provide a stable high insulation resistance test voltage.%  为满足电缆绝缘电阻测试“低电压输入,高电压输出”的需求,对有源钳位、脉宽调制和倍压整流等技术分析改进,提出一种新型的有源钳位倍压变换器。主回路中利用有源钳位技术实现磁芯磁通自动复位,提高了磁芯利用率,钳位电容与元器件产生谐振实现开关零压开通,减小开关损耗和电压应力;利用倍压技术降低变压器升压要求,减小了变换器体积;在控制回路中利用负反馈将输出电压输入脉宽调制芯片,控制脉冲占空比,提高了电源稳定性和负载特性。用软件仿真结果表明,该变换器能够为绝缘电阻测试提供稳定的高电压。

  3. [An integral chip for the multiphase pulse-duration modulation used for voltage changer in biomedical microprocessor systems].

    Science.gov (United States)

    Balashov, A M; Selishchev, S V

    2004-01-01

    An integral chip (IC) was designed for controlling the step-down pulse voltage converter, which is based on the multiphase pulse-duration modulation, for use in biomedical microprocessor systems. The CMOS technology was an optimal basis for the IC designing. An additional feedback circuit diminishes the output voltage dispersion at dynamically changing loads.

  4. 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

  5. Simultaneously Propagating Voltage and Pressure Pulses in Lipid Monolayers of pork brain and synthetic lipids

    CERN Document Server

    Griesbauer, J; Wixforth, A; Schneider, M F

    2012-01-01

    Hydrated interfaces are ubiquitous in biology and appear on all length scales from ions, individual molecules to membranes and cellular networks. In vivo, they comprise a high degree of self-organization and complex entanglement, which limits their experimental accessibility by smearing out the individual phenomenology. The Langmuir technique, however, allows the examination of defined interfaces, whose controllable thermodynamic state enables one to explore the proper state diagrams. Here we demonstrate that voltage and pressure pulses simultaneously propagate along monolayers comprised of either native pork brain or synthetic lipids. The excitation of pulses is conducted by the application of small droplets of acetic acid and monitored subsequently employing timeresolved Wilhelmy plate and Kelvin probe measurements. The isothermal state diagrams of the monolayers for both lateral pressure and surface potential are experimentally recorded, enabling us to predict dynamic voltage pulse amplitudes of 0,1 to 3mV...

  6. Quantitative relationship between the maximum streamer length and discharge voltage of a pulsed positive streamer discharge in water

    Science.gov (United States)

    Wen, Xiaoqiong; Li, Qian; Li, Jingsen; Ren, Chunsheng

    2017-08-01

    A linear relationship has been realized between the maximum streamer length and discharge voltage of a pulsed positive streamer discharge by measuring the streamer length in water with conductivity of 100 μS cm-1 using high-speed photography. Based on Ohm’s law, a quantitative equation has been derived for the dependence of the maximum streamer length on the discharge voltage of a pulsed positive streamer discharge in water. According to the equation, our results suggest that the streamers spontaneously stop propagating through water due to the voltage at the streamer head dropping below the ignition voltage of a pulsed positive streamer discharge.

  7. Voltage Sag Mitigation Using Pulse Width Modulation Switched Autotransformer through Matlab Simulation

    Directory of Open Access Journals (Sweden)

    P. Shyam Kiran

    2014-04-01

    Full Text Available In this paper, a new voltage sag compensator for critical loads in electrical distribution system discussed. The proposed scheme employs a Pulse width modulation ac-ac converter along with a auto transformer. During a disturbance such as voltage sag, the proposed scheme supplies the missing voltage and helps in maintaining the rated voltage at the terminals of the critical load. Under normal condition the approach work in bypass mode and delivering utility power directly to load. The proposed system has less number of switching devices and has good compensating capability in comparison to commonly used compensators. Simulation analysis of three-phase compensator is performed in MATLAB/SIMULINK and performance analysis of the system is presented for various levels of sag and swell.

  8. 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

  9. Study on coupling effect between lightning electromagnetic field and unshielded multi-core cable

    Directory of Open Access Journals (Sweden)

    Hao WANG

    2015-04-01

    Full Text Available In order to investigate the terminating load voltage of the unshielded multi-core cable coupled with lightning electromagnetic pulse(LEMP, we simulate LEMP within the bounded-wave transmission line which is input with a lightning surge signal produced by WU-800-type MARX generator and conduct the relevant experiments towards multi-core cable lines radiated by LEMP. We can get the respond laws of induced voltage of the load by changing the length of unshielded multi-core cable, angles between LEMP and cable, waveforms of LEMP as well as cable terminal loads including linear and non-linear loads. Results show that the amplitude of induced voltage is mainly determined by rising part of electromagnetic field waveforms and the pulse width has little effect on the induced voltage. The respond amplitude and the respond frequency are obviously affected by the length of cable. The polarization direction of the electric field has a great impact on the amplitude of terminal response, but it does not change the waveforms of the induced voltage. With the termination of test side increasing, the induced voltage is gradually increased, but the load in the other side has no effect on the induced voltage.

  10. High-speed, high-voltage pulse generation using avalanche transistor

    Science.gov (United States)

    Yong-sheng, Gou; Bai-yu, Liu; Yong-lin, Bai; Jun-jun, Qin; Xiao-hong, Bai; Bo, Wang; Bing-li, Zhu; Chuan-dong, Sun

    2016-05-01

    In this work, the conduction mechanism of avalanche transistors was demonstrated and the operation condition for generating high-speed pulse using avalanche transistors was illustrated. Based on the above analysis, a high-speed and high-voltage pulse (HHP) generating circuit using avalanche transistors was designed, and its working principle and process were studied. To improve the speed of the output pulse, an approach of reducing the rise time of the leading edge is proposed. Methods for selecting avalanche transistor and reducing the parasitic inductance and capacitance of printed circuit board (PCB) were demonstrated. With these instructions, a PCB with a tapered transmission line was carefully designed and manufactured. Output pulse with amplitude of 2 kV and rise time of about 200 ps was realized with this PCB mounted with avalanche transistors FMMT417, indicating the effectiveness of the HHP generating circuit design.

  11. High-voltage electrode optimization towards uniform surfacetreatment by a pulsed volume discharge

    OpenAIRE

    Ponomarev, A. V.; Pedos, M. S.; Scherbinin, S. V.; Mamontov, Y. I.; Ponomarev, Sergey Viktorovich

    2015-01-01

    In this study, the shape and material of the high-voltage electrode of an atmospheric pressure plasma generation system were optimised. The research was performed with the goal of achieving maximum uniformity of plasma treatment of the surface of the low-voltage electrode with a diameter of 100 mm. In order to generate low-temperature plasma with the volume of roughly 1 cubic decimetre, a pulsed volume discharge was used initiated with a corona discharge. The uniformity of the plasma in the r...

  12. Attaching single carbon nanotube on tip's apex using dielectrophoresis of DC-pulse voltage

    Institute of Scientific and Technical Information of China (English)

    Hee-Jin JEONG; Yoong-Ho JUNG; Deug-Woo LEE

    2009-01-01

    Single carbon nanotubes (CNTs) are candidates for a number of electronics and sensing applications, provided that single CNTs can be separated from a bundle of CNTs in suspension. Dielectrophoresis has recently been demonstrated as one route for the extraction of desired CNTs. However, previous methods using dielectrophoresis have found it difficult to extract single nanotubes from bundles of CNTs in solution. Here, we show that this restriction can be overcome by using pulsed DC voltage of an electric field, instead of regular AC and DC voltages.

  13. Simultaneously propagating voltage and pressure pulses in lipid monolayers of pork brain and synthetic lipids

    Science.gov (United States)

    Griesbauer, J.; Bössinger, S.; Wixforth, A.; Schneider, M. F.

    2012-12-01

    Hydrated interfaces are ubiquitous in biology and appear on all length scales from ions and individual molecules to membranes and cellular networks. In vivo, they comprise a high degree of self-organization and complex entanglement, which limits their experimental accessibility by smearing out the individual phenomenology. The Langmuir technique, however, allows the examination of defined interfaces, the controllable thermodynamic state of which enables one to explore the proper state diagrams. Here we demonstrate that voltage and pressure pulses simultaneously propagate along monolayers comprised of either native pork brain or synthetic lipids. The excitation of pulses is conducted by the application of small droplets of acetic acid and monitored subsequently employing time-resolved Wilhelmy plate and Kelvin probe measurements. The isothermal state diagrams of the monolayers for both lateral pressure and surface potential are experimentally recorded, enabling us to predict dynamic voltage pulse amplitudes of 0.1-3 mV based on the assumption of static mechanoelectrical coupling. We show that the underlying physics for such propagating pulses is the same for synthetic and natural extracted (pork brain) lipids and that the measured propagation velocities and pulse amplitudes depend on the compressibility of the interface. Given the ubiquitous presence of hydrated interfaces in biology, our experimental findings seem to support a fundamentally new mechanism for the propagation of signals and communication pathways in biology (signaling), which is based neither on protein-protein or receptor-ligand interaction nor diffusion.

  14. Irreversible electroporation ablation area enhanced by synergistic high- and low-voltage pulses

    Science.gov (United States)

    2017-01-01

    Irreversible electroporation (IRE) produced by a pulsed electric field can ablate tissue. In this study, we achieved an enhancement in ablation area by using a combination of short high-voltage pulses (HVPs) to create a large electroporated area and long low-voltage pulses (LVPs) to ablate the electroporated area. The experiments were conducted in potato tuber slices. Slices were ablated with an array of four pairs of parallel steel electrodes using one of the following four electric pulse protocols: HVP, LVP, synergistic HVP+LVP (SHLVP) or LVP+HVP. Our results showed that the SHLVPs more effectively necrotized tissue than either the HVPs or LVPs, even when the SHLVP dose was the same as or lower than the HVP or LVP doses. The HVP and LVP order mattered and only HVPs+LVPs (SHLVPs) treatments increased the size of the ablation zone because the HVPs created a large electroporated area that was more susceptible to the subsequent LVPs. Real-time temperature change monitoring confirmed that the tissue was non-thermally ablated by the electric pulses. Theoretical calculations of the synergistic effects of the SHLVPs on tissue ablation were performed. Our proposed SHLVP protocol provides options for tissue ablation and may be applied to optimize the current clinical IRE protocols. PMID:28253331

  15. Differential-output B-dot and D-dot monitors for current and voltage measurements on a 20-MA, 3-MV pulsed-power accelerator

    Directory of Open Access Journals (Sweden)

    T. C. Wagoner

    2008-10-01

    Full Text Available We have developed a system of differential-output monitors that diagnose current and voltage in the vacuum section of a 20-MA 3-MV pulsed-power accelerator. The system includes 62 gauges: 3 current and 6 voltage monitors that are fielded on each of the accelerator’s 4 vacuum-insulator stacks, 6 current monitors on each of the accelerator’s 4 outer magnetically insulated transmission lines (MITLs, and 2 current monitors on the accelerator’s inner MITL. The inner-MITL monitors are located 6 cm from the axis of the load. Each of the stack and outer-MITL current monitors comprises two separate B-dot sensors, each of which consists of four 3-mm-diameter wire loops wound in series. The two sensors are separately located within adjacent cavities machined out of a single piece of copper. The high electrical conductivity of copper minimizes penetration of magnetic flux into the cavity walls, which minimizes changes in the sensitivity of the sensors on the 100-ns time scale of the accelerator’s power pulse. A model of flux penetration has been developed and is used to correct (to first order the B-dot signals for the penetration that does occur. The two sensors are designed to produce signals with opposite polarities; hence, each current monitor may be regarded as a single detector with differential outputs. Common-mode-noise rejection is achieved by combining these signals in a 50-Ω balun. The signal cables that connect the B-dot monitors to the balun are chosen to provide reasonable bandwidth and acceptable levels of Compton drive in the bremsstrahlung field of the accelerator. A single 50-Ω cable transmits the output signal of each balun to a double-wall screen room, where the signals are attenuated, digitized (0.5-ns/sample, numerically compensated for cable losses, and numerically integrated. By contrast, each inner-MITL current monitor contains only a single B-dot sensor. These monitors are fielded in opposite-polarity pairs. The two

  16. Differential B-dot and D-dot monitors for current and voltage measurements on a 20-MA 3-MV pulsed-power accelerator.

    Energy Technology Data Exchange (ETDEWEB)

    Shoup, Roy Willlam (ITT Industries, Albuquerque, NM); Gilliland, Terrance Leo (Ktech Corporation, Albuquerque, NM); Lee, James R.; Speas, Christopher Shane; Kim, Alexandre A. (High Current Electronic Institute, Russian Academy of Sciences, Tomsk, Russia); Struve, Kenneth William; York, Mathew William; Leifeste, Gordon T.; Rochau, Gregory Alan; Sharpe, Arthur William; Stygar, William A.; Porter, John Larry Jr.; Wagoner, Tim C. (Ktech Corporation, Albuquerque, NM); Reynolds, Paul Gerard (Team Specialty Products Corporation, Albuquerque, NM); Slopek, Jeffrey Scott (Ktech Corporation, Albuquerque, NM); Moore, William B. S.; Dinwoodie, Thomas Albert (Ktech Corporation, Albuquerque, NM); Woodring, R. M. (Ktech Corporation, Albuquerque, NM); Broyles, Robin Scott (Ktech Corporation, Albuquerque, NM); Mills, Jerry Alan; Melville, J. A. (Prodyn Technologies Incorporated, Albuquerque, NM); Dudley, M. E. (Ktech Corporation, Albuquerque, NM); Androlewicz, K. E. (Ktech Corporation, Albuquerque, NM); Mourning, R. W. (Ktech Corporation, Albuquerque, NM); Moore, J. K. (Ktech Corporation, Albuquerque, NM); Serrano, Jason Dimitri (Ktech Corporation, Albuquerque, NM); Ives, H. C. (EG& G, Albuquerque, NM); Johnson, M. F. (Team Specialty Products Corporation, Albuquerque, NM); Peyton, B. P. (Ktech Corporation, Albuquerque, NM); Leeper, Ramon Joe; Savage, Mark Edward; Donovan, Guy Louis; Spielman, R. B. (Ktech Corporation, Albuquerque, NM); Seamen, Johann F.

    2007-12-01

    We have developed a system of differential-output monitors that diagnose current and voltage in the vacuum section of a 20-MA 3-MV pulsed-power accelerator. The system includes 62 gauges: 3 current and 6 voltage monitors that are fielded on each of the accelerator's 4 vacuum-insulator stacks, 6 current monitors on each of the accelerator's 4 outer magnetically insulated transmission lines (MITLs), and 2 current monitors on the accelerator's inner MITL. The inner-MITL monitors are located 6 cm from the axis of the load. Each of the stack and outer-MITL current monitors comprises two separate B-dot sensors, each of which consists of four 3-mm-diameter wire loops wound in series. The two sensors are separately located within adjacent cavities machined out of a single piece of copper. The high electrical conductivity of copper minimizes penetration of magnetic flux into the cavity walls, which minimizes changes in the sensitivity of the sensors on the 100-ns time scale of the accelerator's power pulse. A model of flux penetration has been developed and is used to correct (to first order) the B-dot signals for the penetration that does occur. The two sensors are designed to produce signals with opposite polarities; hence, each current monitor may be regarded as a single detector with differential outputs. Common-mode-noise rejection is achieved by combining these signals in a 50-{Omega} balun. The signal cables that connect the B-dot monitors to the balun are chosen to provide reasonable bandwidth and acceptable levels of Compton drive in the bremsstrahlung field of the accelerator. A single 50-{omega} cable transmits the output signal of each balun to a double-wall screen room, where the signals are attenuated, digitized (0.5-ns/sample), numerically compensated for cable losses, and numerically integrated. By contrast, each inner-MITL current monitor contains only a single B-dot sensor. These monitors are fielded in opposite-polarity pairs. The two

  17. Pulse voltage determination for electrostatic micro manipulation considering surface conductivity and adhesion of glass particle

    Directory of Open Access Journals (Sweden)

    Ryo Fujiwara

    2015-05-01

    Full Text Available A model with surface conductivity and adhesional force is proposed to investigate the mechanism for electrostatic micro manipulation of a dielectric object using a single probe. The manipulation system consists of three elements: a conductive probe as a manipulator, a conductive plate as a substrate, and a dielectric particle as the target object for manipulation. The particle can be successfully picked up/placed if a rectangular pulse voltage is applied between the probe and the plate. The reliability of the picking up/placing operation is improved by applying a pulse voltage that is determined by a theoretical model considering surface conductivity and adhesion. To verify the theoretical prediction, manipulation experiment is conducted using soda-lime glass particles with radii of 20 μm and 40 μm.

  18. 现代架空线输电系统中的高压电缆段%Aspects of High Voltage Cable Sections in Modern Overhead Line Transmission Systems

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Electrical power transmission is dominated by overhead line systems at present. This is mainly based on more than hundred years of experience of utilities in running overhead lines. Furthermore, overhead lines have proven their operational reliability and functional assurance. In the past, cables were used in distribution networks in urban areas for the most part with the exception of direct current submarine cables. New developments of high voltage XLPE cables make it possible to use this technology for EHV level applications in transmission networks. Within this paper, mixed network configurations, consisting of overhead lines and high voltage cables, are investigated. An exemplary EHV transmission line with a total length of about 100 km, which is quite typical for Central Europe, has been studied. Several different line combinations are discussed with varied rates between overhead line sections and cable sections length in practice. The length of the cable sections are ranging from several kilometers up to lengths of 100 km. In this paper the work focuses on the transient behavior of combined 400 kV overhead and cable lines during switching processes and lightning impacts. A number of calculations were carried out to get an overview of the transient stress in numerous network nodes along the transmission system. Numerical programs like ATP/EMTP have been used for these simulations. Peak values and wave shapes of the transient voltage stress have been evaluated, based on different systems and within possible combinations. In respect of the insulation coordination and transient stress at network nodes, the voltage-time trends are also analyzed. The combination of high voltage overhead and cable transmission systems, especially such with lengths of more than about 50 km, are making tightened and extended demands to the network design, to the operational management and of course to the network protection also. As an output of this investigations, the results might

  19. A High Voltage High Frequency Resonant Inverter for Supplying DBD Devices with Short Discharge Current Pulses

    OpenAIRE

    Bonnin, Xavier; Brandelero, Julio; Videau, Nicolas; Piquet, Hubert; Meynard, Thierry

    2014-01-01

    International audience; In this paper, the merits of a high-frequency resonant converter for supplying dielectric barrier discharges (DBD) devices are established. It is shown that, thanks to its high-frequency operating condition, such a converter allows to supply DBD devices with short discharge current pulses, a high repetition rate, and to control the injected power. In addition, such a topology eliminates the matter of connecting a high-voltage transformer directly across the DBD device ...

  20. Initial position estimation method for permanent magnet synchronous motor based on improved pulse voltage injection

    DEFF Research Database (Denmark)

    Wang, Z.; Lu, K.; Ye, Y.

    2011-01-01

    According to saliency of permanent magnet synchronous motor (PMSM), the information of rotor position is implied in performance of stator inductances due to the magnetic saturation effect. Researches focused on the initial rotor position estimation of PMSM by injecting modulated pulse voltage vec....... The experimental results show that the proposed method estimates the initial rotor position reliably and efficently. The method is also simple and can achieve satisfied estimation accuracy....

  1. 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.

  2. Effect of Variation in Voltage on the Synthesis of Ag Nanopowder by Pulsed Wire Evaporation

    Directory of Open Access Journals (Sweden)

    Joon-Woo Song

    2012-01-01

    Full Text Available Nanosized Ag particles were obtained in liquid medium, which is composed of deionized water and sodium hexametaphosphate, using pulsed wire evaporation within hundreds of microseconds from pure initial Ag wire (99.98%, with varying voltage. Changes in powder morphology and microstructure due to change in supply voltage was observed by FE-SEM and HR-TEM, and phase structure of powders was analyzed by XRD. The results revealed that average particle size slightly increased with increasing supply voltage without any impurity and oxide phase, which was explained in terms of addition of stabilizer into the coolant liquid. The experimental results also suggest that addition of sodium hexametaphosphate into the coolant liquid is good for enhancing the dispersibility property of silver nanopowders.

  3. Volume Diffuse Dielectric Barrier Discharge Plasma Produced by Nanosecond High Voltage Pulse in Airflow

    Institute of Scientific and Technical Information of China (English)

    QI Haicheng; GAO Wei; FAN Zhihui; LIU Yidi; REN Chunsheng

    2016-01-01

    Volume diffuse dielectric barrier discharge (DBD) plasma is produced in subsonic airflow by nanosecond high-voltage pulse power supply with a plate-to-plate discharge cell at 6 mm air gap length.The discharge images,optical emission spectra (OES),the applied voltage and current waveforms of the discharge at the changed airflow rates are obtained.When airflow rate is increased,the transition of the discharge mode and the variations of discharge intensity,breakdown characteristics and the temperature of the discharge plasma are investigated.The results show that the discharge becomes more diffuse,discharge intensity is decreased accompanied by the increased breakdown voltage and time lag,and the temperature of the discharge plasma reduces when airflow of small vclocity is introduced into the discharge gap.These phenomena are because that the airflow changes the spatial distribution of the heat and the space charge in the discharge gap.

  4. Volume Diffuse Dielectric Barrier Discharge Plasma Produced by Nanosecond High Voltage Pulse in Airflow

    Science.gov (United States)

    Qi, Haicheng; Gao, Wei; Fan, Zhihui; Liu, Yidi; Ren, Chunsheng

    2016-05-01

    Volume diffuse dielectric barrier discharge (DBD) plasma is produced in subsonic airflow by nanosecond high-voltage pulse power supply with a plate-to-plate discharge cell at 6 mm air gap length. The discharge images, optical emission spectra (OES), the applied voltage and current waveforms of the discharge at the changed airflow rates are obtained. When airflow rate is increased, the transition of the discharge mode and the variations of discharge intensity, breakdown characteristics and the temperature of the discharge plasma are investigated. The results show that the discharge becomes more diffuse, discharge intensity is decreased accompanied by the increased breakdown voltage and time lag, and the temperature of the discharge plasma reduces when airflow of small velocity is introduced into the discharge gap. These phenomena are because that the airflow changes the spatial distribution of the heat and the space charge in the discharge gap. supported by National Natural Science Foundation of China (No. 51437002)

  5. Development and Applications of discharges generated in liquids with short high voltage pulses

    Science.gov (United States)

    Kolb, Juergen; Miron, Camelia; Kruth, Angela; Balcerak, Michal; Bonislawski, Michal; Holub, Marcin

    2016-09-01

    Discharges that are generated within a liquid have been of scientific interest for more than a century. The possibility for a breakdown development that is not mediated by an initial gaseous phase is still disputed. In this respect are especially discharges that are instigated with short high voltage pulses calling for attention. Associated with this specific excitation scheme is a change in plasma development, plasma parameters and reaction mechanisms in the liquid. We have compared discharges in a point-to-plane geometry that were generated with 50-us or 10-ns high voltage pulses. Time-resolved shadowgraphy and spectroscopy were performed to evaluate discharge structures, plasma parameter and reactive species that were formed in distilled water or ethanol. Different propagation modes, with velocities of 6.7 km/s for tree-like streamers and only 50 m/s for bush-like streamers, were observed. Optical emission spectroscopy has shown the formation of molecular bands of nitrogen, as well as strongly broadened atomic hydrogen and oxygen, which are likely to be responsible for the observed surface modifications of polymers. With nanosecond high voltage pulses we found an increase of unsaturated bondings for polyimide surfaces that were exposed in the discharge volume.

  6. Effect of pulsed corona discharge voltage and feed gas flow rate on dissolved ozone concentration

    Energy Technology Data Exchange (ETDEWEB)

    Prasetyaningrum, A., E-mail: ajiprasetyaningrum@gmail.com; Ratnawati,; Jos, B. [Department of Chemical Engineering, Faculty of Engineering, Diponegoro University Jl. Prof. H. Soedarto Tembalang, Semarang, Central Java, Indonesia, 50276 (Indonesia)

    2015-12-29

    Ozonization is one of the methods extensively used for water purification and degradation of organic materials. Ozone (O{sub 3}) is recognized as a powerful oxidizing agent. Due to its strong oxidability and better environmental friendless, ozone increasing being used in domestic and industrial applications. Current technology in ozone production utilizes several techniques (corona discharge, ultra violet radiation and electrolysis). This experiment aimed to evaluating effect of voltage and gas flow rate on ozone production with corona discharge. The system consists of two net-type stainless steel electrode placed in a dielectric barrier. Three pulsed voltage (20, 30, 40 KV) and flow rate (5, 10, 15 L/min) were prepare for operation variable at high frequency (3.7 kHz) with AC pulsed power supply. The dissolved ozone concentration depends on the applied high-voltage level, gas flow rate and the discharge exposure duration. The ozone concentration increases with decreasing gas flow rate. Dissolved ozone concentrations greater than 200 ppm can be obtained with a minimum voltage 40 kV.

  7. End moldings for cable dielectrics

    Energy Technology Data Exchange (ETDEWEB)

    Roose, L.D.

    1993-12-31

    End moldings for high-voltage cables are described wherein the dielectric insulator of the cable is heated and molded to conform to a desired shape. As a consequence, high quality substantially bubble- free cable connectors suitable for mating to premanufactured fittings are made. Disclosed are a method for making the cable connectors either in the field or in a factory, molds suitable for use with the method, and the molded cable connectors, themselves.

  8. High-voltage nanosecond pulses in a low-pressure radiofrequency discharge

    CERN Document Server

    Pustylnik, Mikhail; Ivlev, Alexei; Vasilyak, Leonid; Couëdel, Lenaic; Thomas, Hubertus; Morfill, Gregor; Fortov, Vladimir

    2013-01-01

    An influence of a high-voltage (3-17 kV) 20 ns pulse on a weakly-ionized low-pressure (0.1-10 Pa) capacitively-coupled radiofrequency (RF) argon plasma is studied experimentally. The plasma evolution after pulse exhibits two characteristic regimes: a bright flash, occurring within 100 ns after the pulse (when the discharge emission increases by 2-3 orders of magnitude over the steady-state level), and a dark phase, lasting a few hundreds \\mu s (when the intensity of the discharge emission drops significantly below the steady-state level). The electron density increases during the flash and remains very large at the dark phase. 1D3V particle-in-cell simulations qualitatively reproduce both regimes and allow for detailed analysis of the underlying mechanisms. It is found that the high-voltage nanosecond pulse is capable of removing a significant fraction of plasma electrons out of the discharge gap, and that the flash is the result of the excitation of gas atoms, triggered by residual electrons accelerated in t...

  9. Pulsed Plasma with Synchronous Boundary Voltage for Rapid Atomic Layer Etching

    Energy Technology Data Exchange (ETDEWEB)

    Economou, Demetre J.; Donnelly, Vincent M.

    2014-05-13

    Atomic Layer ETching (ALET) of a solid with monolayer precision is a critical requirement for advancing nanoscience and nanotechnology. Current plasma etching techniques do not have the level of control or damage-free nature that is needed for patterning delicate sub-20 nm structures. In addition, conventional ALET, based on pulsed gases with long reactant adsorption and purging steps, is very slow. In this work, novel pulsed plasma methods with synchronous substrate and/or “boundary electrode” bias were developed for highly selective, rapid ALET. Pulsed plasma and tailored bias voltage waveforms provided controlled ion energy and narrow energy spread, which are critical for highly selective and damage-free etching. The broad goal of the project was to investigate the plasma science and engineering that will lead to rapid ALET with monolayer precision. A combined experimental-simulation study was employed to achieve this goal.

  10. Frequency-Domain Maximum-Likelihood Estimation of High-Voltage Pulse Transformer Model Parameters

    CERN Document Server

    Aguglia, D

    2014-01-01

    This paper presents an offline frequency-domain nonlinear and stochastic identification method for equivalent model parameter estimation of high-voltage pulse transformers. Such kinds of transformers are widely used in the pulsed-power domain, and the difficulty in deriving pulsed-power converter optimal control strategies is directly linked to the accuracy of the equivalent circuit parameters. These components require models which take into account electric fields energies represented by stray capacitance in the equivalent circuit. These capacitive elements must be accurately identified, since they greatly influence the general converter performances. A nonlinear frequency-based identification method, based on maximum-likelihood estimation, is presented, and a sensitivity analysis of the best experimental test to be considered is carried out. The procedure takes into account magnetic saturation and skin effects occurring in the windings during the frequency tests. The presented method is validated by experim...

  11. 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.

  12. 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.

  13. High-voltage electrode optimization towards uniform surface treatment by a pulsed volume discharge

    Science.gov (United States)

    Ponomarev, A. V.; Pedos, M. S.; Scherbinin, S. V.; Mamontov, Y. I.; Ponomarev, S. V.

    2015-11-01

    In this study, the shape and material of the high-voltage electrode of an atmospheric pressure plasma generation system were optimised. The research was performed with the goal of achieving maximum uniformity of plasma treatment of the surface of the low-voltage electrode with a diameter of 100 mm. In order to generate low-temperature plasma with the volume of roughly 1 cubic decimetre, a pulsed volume discharge was used initiated with a corona discharge. The uniformity of the plasma in the region of the low-voltage electrode was assessed using a system for measuring the distribution of discharge current density. The system's low-voltage electrode - collector - was a disc of 100 mm in diameter, the conducting surface of which was divided into 64 radially located segments of equal surface area. The current at each segment was registered by a high-speed measuring system controlled by an ARM™-based 32-bit microcontroller. To facilitate the interpretation of results obtained, a computer program was developed to visualise the results. The program provides a 3D image of the current density distribution on the surface of the low-voltage electrode. Based on the results obtained an optimum shape for a high-voltage electrode was determined. Uniformity of the distribution of discharge current density in relation to distance between electrodes was studied. It was proven that the level of non-uniformity of current density distribution depends on the size of the gap between electrodes. Experiments indicated that it is advantageous to use graphite felt VGN-6 (Russian abbreviation) as the material of the high-voltage electrode's emitting surface.

  14. Investigating the overload capacity of a direct-driven synchronous permanent magnet wind turbine generator designed using high-voltage cable technology

    Energy Technology Data Exchange (ETDEWEB)

    Solum, A.; Leijon, M. [The Angstrom Laboratory, Uppsala (Sweden). Div. of Electricity and Lightning Research

    2007-09-15

    Utilization of wind energy to maximum permissible limits for generating electrical power has become necessary to meet the global energy demands. Under such circumstances the present day conventional wind turbine generators pose a limitation regarding the overload capability, specifically significant when they need to operate in high-energy wind conditions. It is proposed that by employing a completely different generator winding concept, based on high-voltage cable technology, to a specific generator, it is possible to increase the generator overload capabilities and thereby making it operationally efficient in high wind speed situations. Therefore, the possibility of extracting more energy is predicted to increase. Simulations, based on finite-element methods combined with external circuit models for the generator, have been performed. The results demonstrate that under given thermal and electrical restrictions, a direct-driven permanent magnet synchronous wind turbine generator, based on high-voltage cable windings, is capable of being overloaded more than twice the rated power, thus making it very suitable for strong wind situations. (author)

  15. Identification of problems when using long high voltage AC cable in transmission system I: Switching transient problems

    DEFF Research Database (Denmark)

    Rahimi, Saeed; Wiechowski, W.; Randrup, M

    2008-01-01

    Due to political and environmental pressures from the public and government side, upgrading and building new transmission facilities are becoming more and more difficult and in some cases the expansion of overhead transmission lines are impossible. This means that underground cable technology...

  16. Analysis of a modular generator for high-voltage, high-frequency pulsed applications, using low voltage semiconductors (series connected step-up (1:10) transformers

    Science.gov (United States)

    Redondo, L. M.; Fernando Silva, J.; Margato, E.

    2007-03-01

    This article discusses the operation of a modular generator topology, which has been developed for high-frequency (kHz), high-voltage (kV) pulsed applications. The proposed generator uses individual modules, each one consisting of a pulse circuit based on a modified forward converter, which takes advantage of the required low duty cycle to operate with a low voltage clamp reset circuit for the step-up transformer. This reduces the maximum voltage on the semiconductor devices of both primary and secondary transformer sides. The secondary winding of each step-up transformer is series connected, delivering a fraction of the total voltage. Each individual pulsed module is supplied via an isolation transformer. The assembled modular laboratorial prototype, with three 5kV modules, 800V semiconductor switches, and 1:10 step-up transformers, has 80% efficiency, and is capable of delivering, into resistive loads, -15kV/1A pulses with 5μs width, 10kHz repetition rate, with less than 1μs pulse rise time. Experimental results for resistive loads are presented and discussed.

  17. Analysis of a modular generator for high-voltage, high-frequency pulsed applications, using low voltage semiconductors (series connected step-up (1:10) transformers.

    Science.gov (United States)

    Redondo, L M; Fernando Silva, J; Margato, E

    2007-03-01

    This article discusses the operation of a modular generator topology, which has been developed for high-frequency (kHz), high-voltage (kV) pulsed applications. The proposed generator uses individual modules, each one consisting of a pulse circuit based on a modified forward converter, which takes advantage of the required low duty cycle to operate with a low voltage clamp reset circuit for the step-up transformer. This reduces the maximum voltage on the semiconductor devices of both primary and secondary transformer sides. The secondary winding of each step-up transformer is series connected, delivering a fraction of the total voltage. Each individual pulsed module is supplied via an isolation transformer. The assembled modular laboratorial prototype, with three 5 kV modules, 800 V semiconductor switches, and 1:10 step-up transformers, has 80% efficiency, and is capable of delivering, into resistive loads, -15 kV1 A pulses with 5 micros width, 10 kHz repetition rate, with less than 1 micros pulse rise time. Experimental results for resistive loads are presented and discussed.

  18. Modeling of dielectric barrier discharge excimer lamp excited by mono polar voltage pulses

    Science.gov (United States)

    Akashi, Haruaki; Oda, Akinori; Sakai, Yosuke

    2007-10-01

    Filametal discharges in Dielectric Barrier Discharge (DBD) excimer lamp excited by mono polar voltage pulses has been simulated using two dimensional fluid model. And the differences of the filament discharges formations between mono polar case and bipolar case [1] have been examined. Xe gas was used and its pressure is 300Torr. Simulated region is 1cm (gap length) x 3cm (radial length). Periodical boundary conditions are assumed for the radial direction boundaries. The both electrodes are covered with dielectrics and their thickness is 0.2cm. Applied voltage is 5kV trapezoid shape with 50% duty ratio waveform and its repetition rate is 200kpps. First a small amount of electron-ion pair is provided in the middle of the gap for initial condition. Then the voltage starts to apply. In the case of bipolar excitation, the discharge starts from one filament (streamer discharge), and finally, 5 filaments are obtained self-consistently. In the case of mono polar case, as first, similar to bipolar case, the discharge starts from one filament, however, only 3 filaments have been obtained. This result is similar to that of 100kHz bipolar voltage case. [1] H. Akashi et al, IEEE Trans. Plasma Science, Vol.33, No.2 (2005) pp.308-309

  19. Simulation of subnanosecond streamers in atmospheric-pressure air: Effects of polarity of applied voltage pulse

    Science.gov (United States)

    Babaeva, N. Yu.; Naidis, G. V.

    2016-08-01

    Results of simulation of subnanosecond streamer propagation in corona gap configuration, obtained in the framework of 2D fluid model, are presented. Effects related with the polarity of a voltage pulse applied to the stressed electrode are discussed. It is argued that these effects (dependence of the discharge current and propagation velocity on the polarity of applied voltage) observed in experiments can be attributed to the difference in initial (preceding the streamer formation) distributions of charged species inside the gap. This difference can be caused by preionization (at negative polarity) of the gas inside the discharge gap by runaway electrons. Calculated streamers have large widths (up to 1 cm) and move with velocities in the range of 109-1010 cm s-1, similar to experimental data.

  20. A new method for compensation of the effect of charging transformer's leakage inductance on PFN voltage regulation in Klystron pulse modulators

    Science.gov (United States)

    Patel, Akhil; Kale, Umesh; Shrivastava, Purushottam

    2017-04-01

    The Line type modulators have been widely used to generate high voltage rectangular pulses to power the klystron for high power RF generation. In Line type modulator, the Pulse Forming Network (PFN) which is a cascade combination of lumped capacitors and inductors is used to store the electrical energy. The charged PFN is then discharged into a klystron by firing a high voltage Thyratron switch. This discharge generates a high voltage rectangular pulse across the klystron electrodes. The amplitude and phase of Klystron's RF output is governed by the high voltage pulse amplitude. The undesired RF amplitude and phase stability issues arises at the klystron's output due to inter-pulse and during the pulse amplitude variations. To reduce inter-pulse voltage variations, the PFN is required to be charged at the same voltage after every discharge cycle. At present, the combination of widely used resonant charging and deQing method is used to regulate the pulse to pulse PFN voltage variations but the charging transformer's leakage inductance puts an upper bound on the regulation achievable by this method. Here we have developed few insights of the deQing process and devised a new compensation method to compensate this undesired effect of charging transformer's leakage inductance on the pulse to pulse PFN voltage stability. This compensation is accomplished by the controlled partial discharging of the split PFN capacitor using a low voltage MOSFET switch. Theoretically, very high values of pulse to pulse voltage stability may be achieved using this method. This method may be used in deQing based existing modulators or in new modulators, to increase the pulse to pulse voltage stability, without having a very tight bound on charging transformer's leakage inductance. Given a stable charging power supply, this method may be used to further enhance the inter-pulse voltage stability of modulators which employ the direct charging, after replacing the direct charging with the

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

    Science.gov (United States)

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

    2013-06-01

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

  2. Note: Compact high voltage pulse transformer made using a capacitor bank assembled in the shape of primary.

    Science.gov (United States)

    Shukla, Rohit; Banerjee, Partha; Sharma, Surender K; Das, Rashmita; Deb, Pankaj; Prabaharan, T; Das, Basanta; Adhikary, Biswajit; Verma, Rishi; Shyam, Anurag

    2011-10-01

    The experimental results of an air-core pulse transformer are presented, which is very compact (transformer. A high voltage capacitor assembly (pulse-forming-line capacitor, PFL) of 5.1 nF is connected with the secondary of transformer. The transformer output voltage is 160 kV in its second peak appearing in less than 2 μS from the beginning of the capacitor discharge. The primary capacitor bank can be charged up to a maximum of 18 kV, with the voltage delivery of 360 kV in similar capacitive loads.

  3. 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

  4. Different approach to pulsed high-voltage vacuum-insulation design

    Directory of Open Access Journals (Sweden)

    John G. Leopold

    2007-06-01

    Full Text Available A theoretical methodology promising improved design of vacuum insulation in high-voltage pulsed-power systems is described. It consists of shaping the electromagnetic fields within the system in such a way that charged particles which can in principle initiate vacuum surface breakdown are deflected away from the insulator surface, and secondary electrons, if emitted, are prevented from restriking the surface. Thus, vacuum surface breakdown is prevented before it is able to develop. Our methodology is presented here by a set of case studies.

  5. Electron tunnelling through single azurin molecules can be on/off switched by voltage pulses

    Science.gov (United States)

    Baldacchini, Chiara; Kumar, Vivek; Bizzarri, Anna Rita; Cannistraro, Salvatore

    2015-05-01

    Redox metalloproteins are emerging as promising candidates for future bio-optoelectronic and nano-biomemory devices, and the control of their electron transfer properties through external signals is still a crucial task. Here, we show that a reversible on/off switching of the electron current tunnelling through a single protein can be achieved in azurin protein molecules adsorbed on gold surfaces, by applying appropriate voltage pulses through a scanning tunnelling microscope tip. The observed changes in the hybrid system tunnelling properties are discussed in terms of long-sustained charging of the protein milieu.

  6. Electron tunnelling through single azurin molecules can be on/off switched by voltage pulses

    Energy Technology Data Exchange (ETDEWEB)

    Baldacchini, Chiara [Biophysics and Nanoscience Centre, DEB-CNISM, Università della Tuscia, I-01100 Viterbo (Italy); Institute of Agro-Environmental and Forest Biology, CNR, I-05010 Porano (Italy); Kumar, Vivek; Bizzarri, Anna Rita; Cannistraro, Salvatore, E-mail: cannistr@unitus.it [Biophysics and Nanoscience Centre, DEB-CNISM, Università della Tuscia, I-01100 Viterbo (Italy)

    2015-05-04

    Redox metalloproteins are emerging as promising candidates for future bio-optoelectronic and nano-biomemory devices, and the control of their electron transfer properties through external signals is still a crucial task. Here, we show that a reversible on/off switching of the electron current tunnelling through a single protein can be achieved in azurin protein molecules adsorbed on gold surfaces, by applying appropriate voltage pulses through a scanning tunnelling microscope tip. The observed changes in the hybrid system tunnelling properties are discussed in terms of long-sustained charging of the protein milieu.

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

    Directory of Open Access Journals (Sweden)

    E. M. Waisman

    2014-12-01

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

  8. Nuclear Energy Plant Optimization (NEPO) final report on aging and condition monitoring of low-voltage cable materials.

    Energy Technology Data Exchange (ETDEWEB)

    Assink, Roger Alan; Gillen, Kenneth Todd; Bernstein, Robert

    2005-11-01

    This report summarizes results generated on a 5-year cable-aging program that constituted part of the Nuclear Energy Plant Optimization (NEPO) program, an effort cosponsored by the U. S. Department of Energy (DOE) and the Electric Power Research Institute (EPRI). The NEPO cable-aging effort concentrated on two important issues involving the development of better lifetime prediction methods as well as the development and testing of novel cable condition-monitoring (CM) techniques. To address improved life prediction methods, we first describe the use of time-temperature superposition principles, indicating how this approach improves the testing of the Arrhenius model by utilizing all of the experimentally generated data instead of a few selected and processed data points. Although reasonable superposition is often found, we show several cases where non-superposition is evident, a situation that violates the constant acceleration assumption normally used in accelerated aging studies. Long-term aging results over extended temperature ranges allow us to show that curvature in Arrhenius plots for elongation is a common occurrence. In all cases the curvature results in a lowering of the Arrhenius activation energy at lower temperatures implying that typical extrapolation of high temperature results over-estimates material lifetimes. The long-term results also allow us to test the significance of extrapolating through the crystalline melting point of semi-crystalline materials. By utilizing ultrasensitive oxygen consumption (UOC) measurements, we show that it is possible to probe the low temperature extrapolation region normally inaccessible to conventional accelerated aging studies. This allows the quantitative testing of the often-used Arrhenius extrapolation assumption. Such testing indicates that many materials again show evidence of ''downward'' curvature (E{sub a} values drop as the aging temperature is lowered) consistent with the limited

  9. PTF, a new facility for pulse field testing of large scale superconducting cables and joints

    NARCIS (Netherlands)

    Smith, Bradford A.; Hale, J. Richard; Zhukovsky, Alex; Michael, Philip C.; Minervini, Joseph V.; Olmstead, Michael M.; Dekow, Gary L.; Rosati, James; Camille, Richard J.; Gung, Chen-yu; Gwinn, David; Silva, Frank; Fairfax, Stephen A.; Shen, Stewart; Knoopers, H.G.; Wessel, S.; Krooshoop, H.J.G.; Shevchenko, O.A.; Godeke, A.; Kate, ten H.H.J.

    1997-01-01

    A magnetic Pulse Test Facility (PTF), in which samples of CICC electrical joints from each ITER home team will be tested, has been fabricated at the MIT Plasma Fusion Center under an ITER task agreement. Construction of this facility has recently been completed, and an initial test phase on the firs

  10. High voltage pulsed current in collagen realignment, synthesis, and angiogenesis after Achilles tendon partial rupture

    Directory of Open Access Journals (Sweden)

    Érika P. Rampazo

    2016-01-01

    Full Text Available ABSTRACT Objective To verify the efficacy of high voltage pulsed current in collagen realignment and synthesis and in angiogenesis after the partial rupturing of the Achilles tendon in rats. Method Forty male Wistar rats were randomized into four groups of 10 animals each: sham, cathodic stimulation, anodic stimulation, and alternating stimulation. Their Achilles tendons were submitted to direct trauma by a free-falling metal bar. Then, the treatment was administered for six consecutive days after the injury. In the simulation group, the electrodes were positioned on the animal, but the device remained off for 30 minutes. The other groups used a frequency of 120 pps, sensory threshold, and the corresponding polarity. On the seventh day, the tendons were removed and sent for histological slide preparation for birefringence and Picrosirius Red analysis and for blood vessel quantification. Results No significant difference was observed among the groups regarding collagen realignment (types I or III collagen or quantity of blood vessels. Conclusion High voltage pulsed current for six consecutive days was not effective in collagen realignment, synthesis, or angiogenesis after the partial rupturing of the Achilles tendon in rats.

  11. High voltage pulsed current in collagen realignment, synthesis, and angiogenesis after Achilles tendon partial rupture

    Science.gov (United States)

    Rampazo, Érika P.; Liebano, Richard E.; Pinfildi, Carlos Eduardo; Folha, Roberta A. C.; Ferreira, Lydia M.

    2016-01-01

    ABSTRACT Objective To verify the efficacy of high voltage pulsed current in collagen realignment and synthesis and in angiogenesis after the partial rupturing of the Achilles tendon in rats. Method Forty male Wistar rats were randomized into four groups of 10 animals each: sham, cathodic stimulation, anodic stimulation, and alternating stimulation. Their Achilles tendons were submitted to direct trauma by a free-falling metal bar. Then, the treatment was administered for six consecutive days after the injury. In the simulation group, the electrodes were positioned on the animal, but the device remained off for 30 minutes. The other groups used a frequency of 120 pps, sensory threshold, and the corresponding polarity. On the seventh day, the tendons were removed and sent for histological slide preparation for birefringence and Picrosirius Red analysis and for blood vessel quantification. Results No significant difference was observed among the groups regarding collagen realignment (types I or III collagen) or quantity of blood vessels. Conclusion High voltage pulsed current for six consecutive days was not effective in collagen realignment, synthesis, or angiogenesis after the partial rupturing of the Achilles tendon in rats. PMID:27556387

  12. Pulsed Current-Voltage-Induced Perturbations of a Premixed Propane/Air Flame

    Directory of Open Access Journals (Sweden)

    Jacob. B. Schmidt

    2011-01-01

    Full Text Available The effect of millisecond wide sub-breakdown pulsed voltage-current induced flow perturbation has been measured in premixed laminar atmospheric pressure propane/air flame. The flame equivalence ratios were varied from 0.8 to 1.2 with the flow speeds near 1.1 meter/second. Spatio-temporal flame structure changes were observed through collection of CH (A-X and OH (A-X chemiluminescence and simultaneous spontaneous Raman scattering from N2. This optical collection scheme allows us to obtain a strong correlation between the measured gas temperature and the chemiluminescence intensity, verifying that chemiluminescence images provide accurate measurements of flame reaction zone structure modifications. The experimental results suggest that the flame perturbation is caused by ionic wind originating only from the radial positive space-charge distribution in/near the cathode fall. A net momentum transfer acts along the annular space discharge distribution in the reaction zone at or near the cathode fall which modifies the flow field near the cathodic burner head. This radially inward directed body force appears to enhance mixing similar to a swirl induced modification of the flame structure. The flame fluidic response exhibit a strong dependence on the voltage pulse width ≤10 millisecond.

  13. Development and Outlook of Insulating Materials for High Voltage Direct Current Cables%高压直流电缆绝缘材料的发展与展望

    Institute of Scientific and Technical Information of China (English)

    张翀; 查俊伟; 王思蛟; 巫运辉; 闫轰达; 李维康; 陈新; 党智敏

    2016-01-01

    针对高压直流电缆的发展历史,介绍了高压直流电缆的基本原理、应用现状以及技术瓶颈,指出我国研发高压直流电缆的必要性和紧迫性,并对未来高压直流电缆的发展方向进行了展望.%The basic principle, application status, and technical bottlenecks of high voltage direct current (HVDC) cables were introduced according to the history of HVDC cables, and the necessity and urgency for developing HVDC cables were pionted out in China. The future development direction of HVDC cables was prospected.

  14. The Study of Active Atoms in High-Voltage Pulsed Coronal Discharge by Optical Diagnostics

    Institute of Scientific and Technical Information of China (English)

    Liu Feng; Wang Wenchun; Wang Su; Ren Chunsheng; Wang Younian

    2005-01-01

    In this study, the emission spectra of active atoms O (3p5P → 3s5S20 777.4 nm),Ha (3P → 2S 656.3 nm) and N (3p4P → 3s4S0 742.3 nm, 744.2 nm, 746.8 nm) produced by thepositive high-voltage pulsed corona discharge (HVPCD) of N2 and H2O mixture in a needle-platereactor have successfully been recorded against a severe electromagnetic interference coming fromthe HVPCD at one atmosphere. The effects of the peak voltage, the repetition rate of pulseddischarge and the flow rate of oxygen on the production of those active atoms are investigated. Itis found that when the peak voltage and the repetition rate of the pulsed discharge are increased,the emission intensities of those active atoms rise correspondingly. And the emission intensities ofO (3p5P → 3s5S20 777.4 nm), Ha (3P → 2S 656.3 nm) and N (3p4P → 3s4S0 742.3 nm, 744.2 nm,746.8 nm) increase with the flow rate of oxygen (from 0 to 25 ml/min) and achieve a maximumvalue at a flow rate of 25 ml/min. When the flow rate of oxygen is increased further, the emissionintensities of those atoms visibly decrease correspondingly. The main physicochemical processesof interaction involved between electrons, neutrals and ions are also discussed.

  15. Efficiency of high- and low-voltage pulse combinations for gene electrotransfer in muscle, liver, tumor, and skin

    DEFF Research Database (Denmark)

    André, F M; Gehl, J; Sersa, G;

    2008-01-01

    Gene electrotransfer is gaining momentum as an efficient methodology for nonviral gene transfer. In skeletal muscle, data suggest that electric pulses play two roles: structurally permeabilizing the muscle fibers and electrophoretically supporting the migration of DNA toward or across......, but not to liver; and (4) efficient gene electrotransfer was achieved with HV field strengths below the detectability thresholds for permeabilization; and (5) the lag time interval between the HV and LV pulses decreased sensitivity to the HV pulses, enabling a wider HV amplitude range. In conclusion, HV plus LV...... the permeabilized membrane. To investigate this further, combinations of permeabilizing short high-voltage pulses (HV; hundreds of V/cm) and mainly electrophoretic long low-voltage pulses (LV; tens of V/cm) were investigated in muscle, liver, tumor, and skin in rodent models. The following observations were made...

  16. A pulsed-power generator merging inductive voltage and current adders and its switch trigger application example.

    Science.gov (United States)

    Li, Lee; Yafeng, Ge; Heqin, Zhong; Bin, Yu; Longjun, Xie

    2013-07-01

    A pulsed-power generator using inductive adder technology is proposed for the case of a discharge gap. The merit of this generator is to merge the pulsed-voltage and pulsed-current adders via the dual secondary windings with special circuit. For the nonlinear impedance in any discharge gap, the standalone voltage-pulse and current-pulse can be outputted successively by this generator. The proposed generator is especially useful for the common resolution of implementing pulse discharge at less cost. As an application example, a compact trigger prototype was developed to compatibly use in the gas-insulated and vacuum switches. Experiments achieved good results that the triggered switches showed stable performance and long life. If the basic circuit of this proposed generator is regarded as a pulsed-generating unit, a certain number of such units connected in parallel can be expected to form a general device with generating greater breakdown-voltage and sustained-current pulses for discharge gaps.

  17. Determination of the residual strength of PE medium voltage cables. FGH testing of aged PE cables; Bestimmung von Restspannungsfestigkeiten an Polyethylen-Mittelspannungskabeln. FGH-Stufentest an gealterten PE-Kabeln

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, Uwe; Barsch, Dietrich [Technische Univ., Chemnitz (Germany). Professur fuer Energie- und Hochspannungstechnik

    2010-11-15

    Many power transmission grids in East Germany still have PE cables of the NA2YHCaY type (TGL cables) that are more than 30 years old. As the cables are ageing, tests of their residual electric strength become necessary. (orig.)

  18. 高压电缆线路不间断取能电源的研究%Research on Uninterruption Power Sources of High-voltage Cable Line

    Institute of Scientific and Technical Information of China (English)

    殷迪清; 韩跃峻; 胡顺

    2011-01-01

    To solve the power supply problem of secondary equipment application m distribution network field, this paper designs uninterruption power sources of high voltage line. The main part of power supply obtains the induced current of high voltage cable line through open current coil. Solar power and lithium battery with charge and discharge are taken as auxiliary power supply, which can solve the problem of inadequate power supply under the conditions of line small load current The automatic switching mode is used to ensure uninterruption power supply output and seamless switching.%为解决电网二次设备在现场应用中的供电电源问题,提出了一种高压电缆线路的不间断取能电源设计,电源的主供电部分通过开口取能线圈从一次电缆线路的电流上取能,并辅助有太阳能电池供电和锂电池充放电,以解决电网中负荷电流较小情况下的供电不足问题,通过自动切换方式确保电源的不间断输出和元缝隙切换.

  19. [Degradation of 4-chlorophenol in aqueous solution by high-voltage pulsed discharge-ozone technology].

    Science.gov (United States)

    Wen, Yuezhong; Jiang, Xuanzhen; Liu, Weiping

    2002-03-01

    The combination of high voltage pulse discharge and ozonation as an advanced oxidation technology was used to investigate the degradation of 4-chlorophenol (4-CP) in water. The factors that affect the rate of degradation were discussed. The 1.95 x 10(-3) mol/L solutions of 4-CP were almost completely (96%) degraded after the discharge treatment of 30 min. The degradation of 4-CP was investigated as a function of the ozone concentration, radical scavenger and electrode distance. The rate of 4-CP degradation increases with an increase in ozone concentration and a decrease in the electrode distance from 20 mm to 10 mm. The presence of radical scavenger decreased the rate of 4-CP degradation.

  20. An exploding foil shockwave technique for magnetic flux compression and high voltage pulse generation

    CERN Document Server

    Goh, S E

    2002-01-01

    This thesis describes a novel electromagnetic shockwave technique for use in compressing magnetic flux and to serve as the basis for a new approach to producing fast-rising voltage pulses with amplitudes of several hundred kV. The shockwave is produced by an exploding foil driven electric gun that accelerates a Mylar flyer to impact with a sample of aluminium powder. Both Japanese and Russian researchers have previously published experimental results for shockwave magnetic flux compression using an explosive driver. The present research considers replacing the explosive energy of this driver by the electrostatic energy stored in a capacitor bank, thereby enabling experiments to be performed in a laboratory environment. Differences in performance that arise from the use of explosive and electrical driver are examined. A conventional electric gun system in planar geometry is developed to study the insulator-to-metallic transition in shock-compressed aluminium powder. This provides data on the conducting shock f...

  1. Pretreatment of food waste with high voltage pulse discharge towards methane production enhancement.

    Science.gov (United States)

    Zou, Lianpei; Ma, Chaonan; Liu, Jianyong; Li, Mingfei; Ye, Min; Qian, Guangren

    2016-12-01

    Anaerobic batch tests were performed to investigate the methane production enhancement and solid transformation rates from food waste (FW) by high voltage pulse discharge (HVPD) pretreatment. The total cumulative methane production with HVPD pretreatment was 134% higher than that of the control. The final volatile solids transformation rates of FW with and without HVPD pretreatment were 54.3% and 32.3%, respectively. Comparison study on HVPD pretreatment with acid, alkali and ultrasonic pretreatments showed that the methane production and COD removal rates of FW pretreated with HVPD were more than 100% higher than the control, but only about 50% higher can be obtained with other pretreatments. HVPD pretreatment could be a promising pretreatment method in the application of energy recovery from FW.

  2. Effects of the Liquid Conductivity on Pulsed High-voltage Discharge Modes in Water

    Institute of Scientific and Technical Information of China (English)

    Bin YANG; Le Cheng LEI; Ming Hua ZHOU

    2004-01-01

    Spark, stream and corona pulsed high-voltage discharges in water induced by the various initial conductivities have been examined in this paper. The discharge modes changed from spark to corona discharge with the liquid conductivity increasing. The apparent production of OH radical and quantum yield generated by spark discharge in distilled water were 11.57 μmol/L and 0.0978photon/s, respectively. A preliminary study on acid fuchsine (AF) treatment indicated that higher AF removal efficiency has been achieved by spark discharge. The process of degradation showed that the oxidative effects through OH radical oxidation did not play an important role and did increase with the discharge mode changing to spark discharge.

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

    Science.gov (United States)

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

    2013-03-01

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

  4. Investigation of low-voltage pulse parameters on electroporation and electrical lysis using a microfluidic device with interdigitated electrodes.

    Science.gov (United States)

    Morshed, Bashir I; Shams, Maitham; Mussivand, Tofy

    2014-03-01

    Electroporation (EP) of biological cells leads to the exchange of materials through the permeabilized cell membrane, while electrical lysis (EL) irreversibly disrupts the cell membrane. We report a microfluidic device to study these two phenomena with low-voltage excitation for lab-on-a-chip (LOC) applications. For systematic study of EP, we have employed a quantification metric: flow Index (FI) of EP. Simulation and experimental results with the microfluidic device containing interdigitated, coplanar, integrated electrodes to electroporate, and rapidly lyse biological cells are presented. H&E stained human buccal cells were subjected to various pulse magnitudes, pulsewidths, and number of pulses. Simulations show that an electric field of 25 kV/cm with a 20 V applied potential produced 1.3 (°)C temperature rise for a 5 s of excitation. For a 20 V pulse-excitation with pulse-widths between 0.5 to 5 s, EL was observed, whereas for lower excitations, only EP was observed. FI of EP is found to be a direct function of pulse magnitudes, pulsewidths, and numbers of pulses. To release DNA from nucleus, excitation-pulses of 5 s were required. Quantification of EP would be useful for systematic study of EP toward optimization with various excitation pulses, while low-voltage requirement and high yield of EP and EL are critical to develop LOC for drug delivery and cell-sample preparation, respectively.

  5. Numerical simulation of high voltage electric pulse comminution of phosphate ore

    Institute of Scientific and Technical Information of China (English)

    Razavian Seyed Mohammad; Rezai Bahram; Irannajad Mehdi; Ravanji Mohammad Hasan

    2015-01-01

    Numerical simulation of the electrical field distribution helps in-depth understanding of the mechanisms behind the responses and the benefits of the high voltage pulse comminution. The COMSOL Multiphysics package was used to numerically simulate the effect of ore compositions in this study. Regarding phos-phate ore particles shape and composition, the effects of mineral composition, particle size, particle shape and electrodes distance were investigated on the electrical field intensity and distribution. The results show that the induced electrical field is significantly dependent on the electrical properties of minerals, the feed particle size and the location of conductive minerals in ores. The angle of material contact sur-face with the discharge electrode is also an important factor in the intensity of electrical field. Moreover, it is found that the specific liberation effect at the disintegration of phosphate ore by electrical pulses is due to the locality of the electrical field at the interface of mineral components of the phosphate ore aggregates with different permittivities. However, the intensity of the electrical field increases with shar-pening the contact angle. Besides, the electrical discharge in the samples is converted to the elec-trohydraulic discharge across the surrounding water by changing the distance between the discharge electrode and sample surface.

  6. Electron Emission from Ferroelectric/Antiferroelectric Cathodes Excited by Short High-Voltage Pulses

    CERN Document Server

    Benedek, G; Handerek, J; Riege, H

    1997-01-01

    Un-prepoled Lead Zirconate Titanate Lanthanum doped-PLZT ferroelectric cathodes have emitted intense current pulses under the action of a high voltage pulse of typically 8 kV/cm for PLZT of 8/65/35 composition and 25 kV/cm for PLZT of 4/95/5 composition. In the experiments described in this paper, the exciting electric field applied to the sample is directed from the rear surface towards the emitting surface. The resulting emission is due to an initial field emission from the metal of the grid deposited over the emitting surface with the consequent plasma formation and the switching of ferroelectric domains. These electrons may be emitted directly form the crystal or from the plasma. This emission requires the material in ferroelectric phase. In fact, PLZT cathodes of the 8/65/35 type, that is with high Titanium content, showing ferroelectric-paraelectric phase sequence, emit at room temperature, while PLZT cathodes of the 4/95/5 type, that is with low Titanium content, having antiferro-ferro-paraelectric pha...

  7. Dual branch high voltage pulse generator for the beam extraction of the Large Hadron Collider

    CERN Document Server

    Bonthond, J; Ducimetière, L; Jansson, U; Vossenberg, Eugène B

    2002-01-01

    The LHC beam extraction kicker system, MKD, is composed of 15 fast kicker magnets per beam to extract the particles in one turn from the collider and to dispose them, after dilution, on an external absorber. Each magnet is powered by a separate pulse generator. The original single branch generator consisted of a discharge capacitor in series with a solid state closing switch left bracket 1 right bracket operating at 30 kV. In combination with a parallel freewheel diode stack this generator produced a current pulse of 2.7 mus rise time, 18.5 kA amplitude and about 1.8 ms fall time, of which only about 90 mus are needed to dump the beam. The freewheel diode circuit is equipped with a flat top current droop compensation network, consisting of a low voltage, low stray inductance, high current discharge capacitor. Extensive reliability studies have meanwhile suggested to further increase the operational safety of this crucial system by equipping each generator with two parallel branches. This paper presents the re...

  8. A Xenon dielectric barrier discharge lamp (172nm) with a fast-pulse voltage driver: Influence of the voltage waveform on plasma kinetic issues and light output.

    Science.gov (United States)

    Carman, Robert; Ward, Barry; Mildren, Richard; Kane, Deborah

    2003-10-01

    An important class of vacuum-ultraviolet (VUV) excimer lamps based on high pressure rare-gas and rare-gas halogen mixtures utilize the dielectric barrier discharge (DBD) to generate a transient, non-equilibrium plasma that yields high electrical to VUV conversion efficiency. Recent interest has focussed on the use of pulsed voltage excitation techniques (rather than conventional AC sinusoidal waveforms) to alter the physical appearance of the DBD "micro-discharges" from filamentary (AC) to semi-diffuse, conical or homogeneous (pulsed), whilst at the same time dramatically improving the lamp performance and VUV efficiency^1,2. We report results from a combined experimental/computer modelling study of a short-pulse excited co-axial DBD Xe lamp to investigate the influence of the pulsed voltage waveform on the discharge structure, lamp performance, VUV output, and electrical efficiency. The underlying plasma kinetics issues relating to lamp performance, including parasitic collisional processes that act to quench key xenon species population densities, are examined in detail. ^1 Vollkommer F and Hitzschke, US patent 5604410 (1997) ^2 R.P.Mildren and R.J.Carman, J.Phys.D, 34, L1-L6 (2001)

  9. Circuit-field coupled finite element analysis method for an electromagnetic acoustic transducer under pulsed voltage excitation

    Institute of Scientific and Technical Information of China (English)

    Hao Kuan-Sheng; Huang Song-Ling; Zhao Wei; Wang Shen

    2011-01-01

    This paper presents an analytical method for electromagnetic acoustic transducers (EMATs) under voltage excitation and considers the non-uniform distribution of the biased magnetic field. A complete model of EMATs including the non-uniform biased magnetic field, a pulsed eddy current field and the acoustic field is built up. The pulsed voltage excitation is transformed to the frequency domain by fast Fourier transformation (FFT). In terms of the time harmonic field equations of the EMAT system, the impedances of the coils under different frequencies are calculated according to the circuit-field coupling method and Poynting's theorem. Then the currents under different frequencies are calculated according to Ohm's law and the pulsed current excitation is obtained by inverse fast Fourier transformation (IFFT).Lastly, the sequentially coupled finite element method (FEM) is used to calculate the Lorentz force in the EMATs under the current excitation. An actual EMAT with a two-layer two-bundle printed circuit board (PCB) coil, a rectangular permanent magnet and an aluminium specimen is analysed. The coil impedances and the pulsed current are calculated and compared with the experimental results. Their agreement verified the validity of the proposed method. Furthermore, the influences of lift-off distances and the non-uniform static nagnetic field on the Lorentz force under pulsed voltage excitation are studied.

  10. Plasma density enhancement in atmospheric-pressure dielectric-barrier discharges by high-voltage nanosecond pulse in the pulse-on period: a PIC simulation

    Science.gov (United States)

    Sang, Chaofeng; Sun, Jizhong; Wang, Dezhen

    2010-02-01

    A particle-in-cell (PIC) plus Monte Carlo collision simulation is employed to investigate how a sustainable atmospheric pressure single dielectric-barrier discharge responds to a high-voltage nanosecond pulse (HVNP) further applied to the metal electrode. The results show that the HVNP can significantly increase the plasma density in the pulse-on period. The ion-induced secondary electrons can give rise to avalanche ionization in the positive sheath, which widens the discharge region and enhances the plasma density drastically. However, the plasma density stops increasing as the applied pulse lasts over certain time; therefore, lengthening the pulse duration alone cannot improve the discharge efficiency further. Physical reasons for these phenomena are then discussed.

  11. Laser ultrasonic analysis of normal modes generated by a voltage pulse on an AT quartz sensor.

    Science.gov (United States)

    Goossens, Jozefien; Martinez, Loïc; Glorieux, Christ; Wilkie-Chancellier, Nicolas; Ehssein, Chighali Ould; Serfaty, Stéphane

    2006-12-22

    Laser ultrasonic detection is a versatile and highly sensitive tool for the observation of surface waves. In the following study, laser ultrasonic detection is used for the experimental study of spurious normal vibration modes of a disk quartz sensor excited by a voltage pulse. The AT cut crystal (cut of the crystal relative to the the main crystallographic axis is 35.25 degrees) is optimal for generating mainly thickness-shear vibrations (central frequency 6 MHz) on the quartz surface. However, resulting from shear-to-longitudinal and shear-to-surface mode conversion, and from the weak coupling with the other crystallographic axes, other modes (thickness-compressional and bending modes) are always present in the plate response. Since the laser vibrometer is sensitive to normal displacements, the laser investigation shows waves that can be considered as unwanted for the AT quartz used as a shear sensor. The scanned three dimensional (3D) amplitude-space-time signals are carefully analysed using their representation in three dual Fourier domains (space-time, wave number-frequency). Results on the transient analysis of the waves, the normal bending modes and the dispersion curves are shown.

  12. Morphology and Electric Conductance Change Induced by Voltage Pulse Excitation in (GeTe)2/Sb2Te3 Superlattices

    Science.gov (United States)

    Bolotov, Leonid; Saito, Yuta; Tada, Tetsuya; Tominaga, Junji

    2016-09-01

    Chalcogenide superlattice (SL) phase-change memory materials are leading candidates for non-volatile, energy-efficient electric memory where the electric conductance switching is caused by the atom repositioning in the constituent layers. Here, we study the time evolution of the electric conductance in [(GeTe)2/(Sb2Te3)1]4 SLs upon the application of an external pulsed electric field by analysing the structural and electrical responses of the SL films with scanning probe microscopy (SPM) and scanning probe lithography (SPL). At a low pulse voltage (1.6-2.3 V), a conductance switching delay of a few seconds was observed in some SL areas, where the switch to the high conductance state (HCS) is accompanied with an SL expansion under the strong electric field of the SPM probe. At a high pulse voltage (2.5-3.0 V), the HCS current was unstable and decayed in a few seconds; this is ascribed to the degradation of the HCS crystal phase under excessive heating. The reversible conductance change under a pulse voltage of opposite polarity emphasised the role of the electric field in the phase-transition mechanism.

  13. Novel design of high voltage pulse source for efficient dielectric barrier discharge generation by using silicon diodes for alternating current

    Science.gov (United States)

    Truong, Hoa Thi; Hayashi, Misaki; Uesugi, Yoshihiko; Tanaka, Yasunori; Ishijima, Tatsuo

    2017-06-01

    This work focuses on design, construction, and optimization of configuration of a novel high voltage pulse power source for large-scale dielectric barrier discharge (DBD) generation. The pulses were generated by using the high-speed switching characteristic of an inexpensive device called silicon diodes for alternating current and the self-terminated characteristic of DBD. The operation started to be powered by a primary DC low voltage power supply flexibly equipped with a commercial DC power supply, or a battery, or DC output of an independent photovoltaic system without transformer employment. This flexible connection to different types of primary power supply could provide a promising solution for the application of DBD, especially in the area without power grid connection. The simple modular structure, non-control requirement, transformer elimination, and a minimum number of levels in voltage conversion could lead to a reduction in size, weight, simple maintenance, low cost of installation, and high scalability of a DBD generator. The performance of this pulse source has been validated by a load of resistor. A good agreement between theoretically estimated and experimentally measured responses has been achieved. The pulse source has also been successfully applied for an efficient DBD plasma generation.

  14. Morphology and Electric Conductance Change Induced by Voltage Pulse Excitation in (GeTe)2/Sb2Te3 Superlattices

    Science.gov (United States)

    Bolotov, Leonid; Saito, Yuta; Tada, Tetsuya; Tominaga, Junji

    2016-01-01

    Chalcogenide superlattice (SL) phase-change memory materials are leading candidates for non-volatile, energy-efficient electric memory where the electric conductance switching is caused by the atom repositioning in the constituent layers. Here, we study the time evolution of the electric conductance in [(GeTe)2/(Sb2Te3)1]4 SLs upon the application of an external pulsed electric field by analysing the structural and electrical responses of the SL films with scanning probe microscopy (SPM) and scanning probe lithography (SPL). At a low pulse voltage (1.6–2.3 V), a conductance switching delay of a few seconds was observed in some SL areas, where the switch to the high conductance state (HCS) is accompanied with an SL expansion under the strong electric field of the SPM probe. At a high pulse voltage (2.5–3.0 V), the HCS current was unstable and decayed in a few seconds; this is ascribed to the degradation of the HCS crystal phase under excessive heating. The reversible conductance change under a pulse voltage of opposite polarity emphasised the role of the electric field in the phase-transition mechanism. PMID:27618797

  15. Comparative study of SVPWM (space vector pulse width modulation) & SPWM (sinusoidal pulse width modulation) based three phase voltage source inverters for variable speed drive

    Science.gov (United States)

    Ahmed, Waheed; Usman Ali, Syed M.

    2013-12-01

    We have performed comparative studies of Space Vector Pulse Width Modulation (SVPWM) and Sinusoidal Pulse Width Modulation (SPWM) techniques utilizing MATLAB tools. During these investigations, we carried out intensive simulations, comprehensively analyzed the obtained results and compared the harmonic density, power factor (PF), & switching losses of SVPWM and SPWM. It has been observed during investigations that if the switching frequency is high then losses due to harmonics are negligible, thus based on obtained results we suggested that the SVPWM technique is a more reliable solution. Because SVPWM utilizes DC bus voltage more efficiently, generates less Total Harmonic Distortion (THD) and has higher output quality it provides flexible control of output voltage and output frequency for Variable Speed Drive (VSD).

  16. An EMC Evaluation of the Use of Unshielded Motor Cables in AC Adjustable Speed Drive Applications

    DEFF Research Database (Denmark)

    Hanigovszki, Norbert; Poulsen, J.; Spiazzi, G.

    2004-01-01

    -phase applications the occurrence of common-mode voltage is inherent due to asymmetrical output pulses. As a result, for electromagnetic compatibility (EMC) reasons, in most applications shielded cables are used between the inverter and the motor, implying high installation costs. The present paper discusses the use......The most common solution for modern adjustable speed drives (ASD) is the use of induction motors (IM) fed by voltage-source inverters (VSI). The inverter generates a pulsewidth modulated (PWM) voltage, with values of about 6 kV/ dv/dt m s or even more. In three-leg inverters for three...... of cheaper, unshielded cables. A new method for measuring electromagnetic interference (EMI) from unshielded cables is proposed and measurement results are presented. The level of EMI is evaluated in different situations: without an output filter, with a classical LC output filter and with an advanced output...

  17. Cable Diagnostic Focused Initiative

    Energy Technology Data Exchange (ETDEWEB)

    Hartlein, R.A.; Hampton, R.N.

    2010-12-30

    This report summarizes an extensive effort made to understand how to effectively use the various diagnostic technologies to establish the condition of medium voltage underground cable circuits. These circuits make up an extensive portion of the electric delivery infrastructure in the United States. Much of this infrastructure is old and experiencing unacceptable failure rates. By deploying efficient diagnostic testing programs, electric utilities can replace or repair circuits that are about to fail, providing an optimal approach to improving electric system reliability. This is an intrinsically complex topic. Underground cable systems are not homogeneous. Cable circuits often contain multiple branches with different cable designs and a range of insulation materials. In addition, each insulation material ages differently as a function of time, temperature and operating environment. To complicate matters further, there are a wide variety of diagnostic technologies available for assessing the condition of cable circuits with a diversity of claims about the effectiveness of each approach. As a result, the benefits of deploying cable diagnostic testing programs have been difficult to establish, leading many utilities to avoid the their use altogether. This project was designed to help address these issues. The information provided is the result of a collaborative effort between Georgia Tech NEETRAC staff, Georgia Tech academic faculty, electric utility industry participants, as well as cable system diagnostic testing service providers and test equipment providers. Report topics include: •How cable systems age and fail, •The various technologies available for detecting potential failure sites, •The advantages and disadvantages of different diagnostic technologies, •Different approaches for utilities to employ cable system diagnostics. The primary deliverables of this project are this report, a Cable Diagnostic Handbook (a subset of this report) and an online

  18. Application of Partial Discharge Detection Technique in AC Voltage Withstand Test of HV Cable%局放测试技术在高压电缆交流耐压试验中的应用

    Institute of Scientific and Technical Information of China (English)

    罗容波; 詹清华; 王岩

    2013-01-01

      针对交流耐压试验方法在发现电缆缺陷上的不足,提出在高压电缆交流耐压试验中外接局放监视仪来避免耐压试验对电缆造成损伤。通过建立仿真电路和搭建实验室模型,研究了现场干扰信号与电缆自身局放信号的时域、频域、波形和极性的特征,总结出一套适用于高压电缆现场局放测试的方法。应用该方法对新敷设的110 kV高压电缆进行检测,发现了高压电缆终端的缺陷,证实了此测试方法的有效性。%  In view of the shortcomings of AC withstand voltage test method in discovering the faults of HV cable, a partial discharge monitoring instrument is external connected with AC withstand voltage test to avoid the damage of cable. The time domain, frequency domain, waveform and polarity characteristics of the interference signal and the signal of cable were studied by simulation and experimental research, and a method suitable for the partial discharge test of HV cable was summarized. The termination fault of a new HV cable was found by applying the method, which confirms the validity of the method.

  19. Plasma surface treatment to improve surface charge accumulation and dissipation of epoxy resin exposed to DC and nanosecond-pulse voltages

    Science.gov (United States)

    Zhang, Cheng; Lin, Haofan; Zhang, Shuai; Xie, Qin; Ren, Chengyan; Shao, Tao

    2017-10-01

    In this paper, deposition by non-thermal plasma is used as a surface modification technique to change the surface characteristics of epoxy resin exposed to DC and nanosecond-pulse voltages. The corresponding surface characteristics in both cases of DC and nanosecond-pulse voltages before and after the modification are compared and investigated. The measurement of the surface potential provides the surface charge distribution, which is used to show the accumulation and dissipation process of the surface charges. Morphology observations, chemical composition and electrical parameters measurements are used to evaluate the treatment effects. The experimental results show that, before the plasma treatment, the accumulated surface charges in the case of the DC voltage are more than that in the case of the nanosecond-pulse voltage. Moreover, the decay rate of the surface charges for the DC voltage is higher than that for the nanosecond-pulse voltage. However, the decay rate is no more than 41% after 1800 s for both types of voltages. After the plasma treatment, the maximum surface potentials decrease to 57.33% and 32.57% of their values before treatment for the DC and nanosecond-pulse voltages, respectively, indicating a decrease in the accumulated surface charges. The decay rate exceeds 90% for both types of voltages. These changes are mainly attributed to a change in the surface nanostructure, an increase in conductivity, and a decrease in the depth of energy level.

  20. Fault detection on the Large Hadron Collider at CERN: design, simulation and realization of a High Voltage Pulse Generator

    CERN Document Server

    Cavicchioli, C; Biagi, E; Bozzini, D

    2007-01-01

    This project was developed inside the Quality Assurance Plan (ELQA) of the LHC. The superconducting circuits of the collider show a great complexity concerning the control system, because of various reasons: the tunnel is placed around 50 to 175 m underground, the circuits work at temperatures of 1.9 K, all the structure should be perfectly aligned and the electronic part has considerable dimensions. To maximize the running time of the collider, it is necessary to develop methods for the diagnostic of defects and for the precise localization of the segment of the accelerator that contains the fault. From my studies it emerged that a possible way to localize electrical faults in the LHC superconducting circuits is to combine the use of time domain reflectometry methods and high voltage pulses. Therefore, I have designed and realized a high voltage pulse generator that will be an important instrument for the fault location among the accelerator.

  1. Stability and normal zone propagation in YBCO CORC cables

    Science.gov (United States)

    Majoros, M.; Sumption, M. D.; Collings, E. W.; van der Laan, D.

    2016-04-01

    In this work, a two layer conductor on round core cable was tested for stability and normal zone propagation at 77 K in a liquid nitrogen bath. The cable was instrumented with voltage taps and wires on each strand over the cable’s central portion (i.e. excluding the end connections of the cable with the outside world). A heater was placed in the central zone on the surface of the cable, which allowed pulses of various powers and durations to be generated. Shrinking (recovering) and expanding (not recovering) normal zones have been detected, as well as stationary zones which were in thermal equilibrium. Such stationary thermal equilibrium zones did not expand or contract, and hit a constant upper temperature while the heater current persisted; they are essentially a form of Stekly stability. Overall, the cable showed a high degree of stability. Notably, it was able to carry a current of 0.45I c cable with maximum temperature of 123 K for one minute without damage.

  2. Experimental investigation of dielectric barrier discharge plasma actuators driven by repetitive high-voltage nanosecond pulses with dc or low frequency sinusoidal bias

    Science.gov (United States)

    Opaits, Dmitry F.; Likhanskii, Alexandre V.; Neretti, Gabriele; Zaidi, Sohail; Shneider, Mikhail N.; Miles, Richard B.; Macheret, Sergey O.

    2008-08-01

    Experimental studies were conducted of a flow induced in an initially quiescent room air by a single asymmetric dielectric barrier discharge driven by voltage waveforms consisting of repetitive nanosecond high-voltage pulses superimposed on dc or alternating sinusoidal or square-wave bias voltage. To characterize the pulses and to optimize their matching to the plasma, a numerical code for short pulse calculations with an arbitrary impedance load was developed. A new approach for nonintrusive diagnostics of plasma actuator induced flows in quiescent gas was proposed, consisting of three elements coupled together: the schlieren technique, burst mode of plasma actuator operation, and two-dimensional numerical fluid modeling. The force and heating rate calculated by a plasma model was used as an input to two-dimensional viscous flow solver to predict the time-dependent dielectric barrier discharge induced flow field. This approach allowed us to restore the entire two-dimensional unsteady plasma induced flow pattern as well as characteristics of the plasma induced force. Both the experiments and computations showed the same vortex flow structures induced by the actuator. Parametric studies of the vortices at different bias voltages, pulse polarities, peak pulse voltages, and pulse repetition rates were conducted experimentally. The significance of charge buildup on the dielectric surface was demonstrated. The charge buildup decreases the effective electric field in the plasma and reduces the plasma actuator performance. The accumulated surface charge can be removed by switching the bias polarity, which leads to a newly proposed voltage waveform consisting of high-voltage nanosecond repetitive pulses superimposed on a high-voltage low frequency sinusoidal voltage. Advantages of the new voltage waveform were demonstrated experimentally.

  3. Research Progress of Inverse Power Law Applied in Lifetime Design of High Voltage Cable%反幂定律应用于高压电缆寿命设计的研究进展

    Institute of Scientific and Technical Information of China (English)

    廖雁群; 冯冰; 罗潘; 张连杰; 卢志华; 徐阳

    2016-01-01

    本文回顾了反幂定律的发展过程,用Eyring公式对反幂定律的正确性进行了理论解释,总结了反幂定律在确定高压电缆绝缘厚度和在电缆E-t寿命曲线中的应用,给出了温度修正的电老化寿命模型,阐述了温度在高压电缆寿命设计中的重要性。%The development process of the inverse power law was reviewed, and the correctness of inverse power law was theoretical explained with the Eyring equation. The application of the inverse power law in determining the thickness of high voltage cable insulation and the application in the life curves of cable were summarized. Finally, this paper presented the electrical ageing lifetime model revised by temperature and emphasized the importance of temperature in the lifetime design of high voltage cable.

  4. Low Voltage Electrolytic Capacitor Pulse Forming Inductive Network for Electric Weapons

    Science.gov (United States)

    2006-06-01

    reliable high- current, high-energy pulses of many megawatts. Pulsed alternators potentially have the same maintenance issues as other motor...high-energy pulses of many megawatts. Pulsed alternators potentially have the same maintenance issues as other motor-generator sets, so a solid...on an all-electric ship, those challenges are being met. The naval railgun, the army railgun, coilguns , and other electric weapon systems such as

  5. Sub-nanosecond time resolved light emission study for diffuse discharges in air under steep high voltage pulses

    Science.gov (United States)

    Tardiveau, P.; Magne, L.; Marode, E.; Ouaras, K.; Jeanney, P.; Bournonville, B.

    2016-10-01

    Pin-to-plane discharges in centimetre air gaps and standard conditions of pressure and temperature are generated under very high positive nanosecond scale voltage pulses. The experimental study is based on recordings of sub-nanosecond time resolved and Abel-processed light emission profiles and their complete correlation to electrical current waveforms. The effects of the voltage pulse features (amplitude between 20 and 90 kV, rise time between 2 and 5.2 ns, and time rate between 4 and 40 kV · ns‑1) and the electrode configuration (gap distance between 10 and 30 mm, pin radius between 10 and 200 µm, copper, molybdenum or tungsten pin material) are described. A three time period development can be found: a glow-like structure with monotonic light profiles during the first 1.5 ns whose size depends on time voltage rate, a shell-like structure with bimodal profiles whose duration and extension in space depends on rise time, and either diffuse or multi-channel regime for the connection to the cathode plane according to gap distance. The transition of the light from monotonic to bimodal patterns reveals the relative effects and dynamics of streamer space charge and external laplacian field. A classical 2D-fluid model for streamer propagation has been used and adapted for very high and steep voltage pulses. It shows the formation of a strong space charge (streamer) very close to the pin, but also a continuity of emission between the pin and the streamer, and electric fields higher than the critical ionization field (28 kV · cm‑1 in air) almost in the whole gap and very early in the discharge propagation.

  6. Nanosecond pulsed power generator for a voltage amplitude up to 300 kV and a repetition rate up to 16 Hz for fine disintegration of quartz

    Energy Technology Data Exchange (ETDEWEB)

    Krastelev, E. G., E-mail: ekrastelev@yandex.ru; Sedin, A. A.; Tugushev, V. I. [Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation)

    2015-12-15

    A generator of high-power high-voltage nanosecond pulses is intended for electrical discharge disintegration of mineral quartz and other nonconducting minerals. It includes a 320 kV Marx pulsed voltage generator, a high-voltage glycerin-insulated coaxial peaking capacitor, and an output gas spark switch followed by a load, an electric discharge disintegration chamber. The main parameters of the generator are as follows: a voltage pulse amplitude of up to 300 kV, an output impedance of ≈10 Ω, a discharge current amplitude of up to 25 kA for a half-period of 80–90 ns, and a pulse repetition rate of up to 16 Hz.

  7. Electromagnetic transients in power cables

    CERN Document Server

    da Silva, Filipe Faria

    2013-01-01

    From the more basic concepts to the most advanced ones where long and laborious simulation models are required, Electromagnetic Transients in Power Cables provides a thorough insight into the study of electromagnetic transients and underground power cables. Explanations and demonstrations of different electromagnetic transient phenomena are provided, from simple lumped-parameter circuits to complex cable-based high voltage networks, as well as instructions on how to model the cables.Supported throughout by illustrations, circuit diagrams and simulation results, each chapter contains exercises,

  8. Experimental verification of the effect of cable length on voltage distribution in stator winding of an induction motor under surge condition

    Energy Technology Data Exchange (ETDEWEB)

    Oyegoke, B.S. [Helsinki Univ. of Technology, Otaniemi (Finland). Lab. of Electromechanics

    1997-12-31

    This paper presents the results of surge distribution tests performed on a stator of a 6 kV induction motor. The primary aim of these tests was to determine the wave propagation properties of the machine winding fed via cables of different lengths. Considering the measured resorts, conclusions are derived regarding the effect of cable length on the surge distribution within the stator winding of an ac motor. (orig.) 15 refs.

  9. Effect of moisture on the electrical performance of transition-joints for medium voltage paper-insulated cables; Elektrische Beeintraechtigung durch Feuchtigkeit an oelgetraenkten Isolierpapieren. Mittelspannungsuebergangsmuffen

    Energy Technology Data Exchange (ETDEWEB)

    Cardinaels, Jos [Nexans Network Solution, Erembodegem (Belgium). Produktentwicklung; Baesch, Manfred [Nexans Power Accessories Germany, Dortmund (Germany). Produkt- und Qualitaetsmanagement

    2009-06-15

    Paper-insulated cables are constructed with an impervious metallic outer jacket in order to protect them against ingress of moisture. On 'modern' transition-joints to XLPE-insulated cables, this metal barrier is interrupted, hence, a risk of moisture penetration exists. This text presents measurements of water-vapour permeability of used materials and discusses the results of ageing tests. (orig.)

  10. Post-Treatment Process of Extruded Insulation for 400 kV DC High Voltage Cable%400kV直流高压电缆绝缘挤塑后处理工艺

    Institute of Scientific and Technical Information of China (English)

    王坤; 杨德亮; 陆根生

    2013-01-01

    XLPE material is adopted as insulation of most 400 kV DC high voltage cables,but low molecular additives in material become weakness when suffering DC voltage withstanding test,which leads to low yields.The research of post-treatment extruded insulation for 400 kV DC high voltage cable is carried out.The experiment results of low molecular content in XLPE before and after treatment are compared.As a result the post-treatment processing conditions are cleared leading to the yields of finished products being increased from 65 % to 90 %.%400 kV直流高压电缆大多采用交联聚乙烯(XLPE)材料作为绝缘,材料中低分子添加物影响直流耐压试验通过,造成产品成品率较低.为此,针对400 kV直流高压电缆绝缘挤塑后处理工艺开展了研究,通过对处理前后材料中低分子物质含量的检测,明确了后处理工艺条件,产品成品率由65%提高到90%.

  11. Isolated PWM DC-AC SICAM with an active capacitive voltage clamp[Pulse Density Modulated; Pulse Width Modulation

    Energy Technology Data Exchange (ETDEWEB)

    Ljusev, P.

    2004-03-15

    In this report an isolated PWM DC-AC SICAM with an active capacitive voltage clamp is presented. AC-DC power supply is implemented in its simplest form: diode rectifier followed by a medium-size charge-storage capacitors and possibly with an EMC filter on the mains entrance. Isolation from the AC mains is achieved using a high frequency (HF) transformer, whose voltages are not audio-modulated. The latter simplifies the design and is expected to have many advantages over the approach where the transformer voltages are modulated in regards to the audio signal reference. Input stage is built as a DC-AC inverter (push-pull, half-bridge or a full-bridge) and operated with 50% duty cycle, with all the challenges to avoid transformer saturation and obtain symmetrical operation. On the secondary side the output section is implemented as rectifier+inverter AC-AC stage, i.e. a true bidirectional bridge, which operation is aimed towards amplification of the audio signal. In order to solve the problem with the commutation of the load current, a dead time between the incoming and outgoing bidirectional switch is implemented, while a capacitive voltage clamp is used to keep the induced overvoltage to reasonable levels. The energy stored in the clamping capacitor is not wasted as in the dissipative clamps, but is rather transferred back to the primary side for further processing using an auxiliary isolated single-switch converter, i.e. an active clamping technique is used. (au)

  12. 30 CFR 77.606 - Energized trailing cables; handling.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Energized trailing cables; handling. 77.606... COAL MINES Trailing Cables § 77.606 Energized trailing cables; handling. Energized medium- and high-voltage trailing cables shall be handled only by persons wearing protective rubber gloves (see § 77.606-1...

  13. Comparison of atmospheric air plasmas excited by high-voltage nanosecond pulsed discharge and sinusoidal alternating current discharge

    Science.gov (United States)

    Zhang, Shuai; Wang, Wen-chun; Jiang, Peng-chao; Yang, De-zheng; Jia, Li; Wang, Sen

    2013-10-01

    In this paper, atmospheric pressure air discharge plasma in quartz tube is excited by 15 ns high-voltage nanosecond pulsed discharge (HVNPD) and sinusoidal alternating current discharge (SACD), respectively, and a comparison study of these two kinds of discharges is made through visual imaging, electrical characterization, optical detection of active species, and plasma gas temperature. The peak voltage of the power supplies is kept at 16 kV while the pulse repetition rate of nanosecond pulse power supply is 100 Hz, and the frequency of sinusoidal power supply is 10 kHz. Results show that the HVNPD is uniform while the SACD presents filamentary mode. For exciting the same cycles of discharge, the average energy consumption in HVNPD is about 1/13 of the SACD. However, the chemical active species generated by the HVNPD is about 2-9 times than that excited by the SACD. Meanwhile, the rotational and vibrational temperatures have been obtained via fitting the simulated spectrum of N2 (C3Πu → B3Πg, 0-2) with the measured one, and the results show that the plasma gas temperature in the HVNPD remains close to room temperature whereas the plasma gas temperature in the SACD is about 200 K higher than that in HVNPD in the initial phase and continually increases as discharge exposure time goes on.

  14. Superconductor cable

    Science.gov (United States)

    Allais, Arnaud; Schmidt, Frank; Marzahn, Erik

    2010-05-04

    A superconductor cable is described, having a superconductive flexible cable core (1) , which is laid in a cryostat (2, 3, 4), in which the cable core (1) runs in the cryostat (2, 3, 4) in the form of a wave or helix at room temperature.

  15. A simplified method for estimation of iron loss in wound toroidal cores energised by pulse width modulated voltage sources

    Science.gov (United States)

    Tutkun, Nedim; Moses, Anthony J.

    2004-12-01

    Recently the strip wound toroidal cores have increasingly been used in switching mode and uninterruptible power supplies for a wide range of industrial applications. Therefore, the prediction of iron loss increase in such magnetic cores energised by non-sinusoidal voltage excitation is important step in the design of electromagnetic devices. In this investigation, a loss increase was estimated by determination of unknown constants in a previously developed loss separation model using genetic algorithms. Also the skin effect of flux density was taken into account for estimation of power loss under pulse width modulated voltage sources. The results obtained are in good agreement with the measured results in wound toroids at various flux densities.

  16. Development in food nonthermal sterilization with high-voltage pulsed generator%食品冷杀菌用高压脉冲发生器的研制

    Institute of Scientific and Technical Information of China (English)

    杜存臣; 吴清

    2011-01-01

    为开展高压脉冲电场冷杀菌研究,研制高压脉冲发生器,主要由单片机控制单元、AT89S52单片机、脉冲驱动模块、高压脉冲变压器和交流调压单元组成,具备脉冲电压、脉冲频率和脉冲宽度等参数可以同时调节的特点,为开展冷杀菌技术研究的脉冲电源研制提供一种可行的技术途径.%For the development of the high-voltage pulsed electric field P nonthermal sterilization , design and make high-voltage pulsed genera- H tor. It mainly by single-chip microcomputer control unit, AT89S52 SCM, pulse driver modules, high pressure pulse transformer and alternating voltage regulation of elements have pulse voltage and pulse frequency and pulse width and can adjust the parameters such as characteristics, in the nonthermal sterilization technology research development pulse power provides a feasible technology way.

  17. Influence of the Discharge Voltage during Pulse-Plasma Process on the Durability of Edges coated with Superhard Coatings

    Institute of Scientific and Technical Information of China (English)

    Maciej Kupczyk

    2004-01-01

    In the paper the experimental results concerning the functional quality of thin, superhard coatings produced on cutting edges is described. Boron nitride coatings were deposited on insert cutting edges made cemented carbides by the pulse-plasma method. The comparative investigations of mentioned coatings have been concerned of tool life of edges during steel machining. In these investigations for the purpose of additional increase of coated edge durability an interfacial layers were applied. Presented investigations particularly pointed out to essential influence of the values of discharge voltage on the coating structure and durability of edges coated with boron nitride.

  18. Influence of the Discharge Voltage during Pulse-Plasma Process on the Durability of Edges coated with Superhard Coatings

    Institute of Scientific and Technical Information of China (English)

    MaciejKupczyk

    2004-01-01

    In the paper the experimental results concerning the functional quality of thin, superhard coatings produced on cutting edges is described. Boron nitride coatings were deposited on insert cutting edges made cemented carbides by the pulse-plasma method. The comparative investigations of mentioned coatings have been concerned of tool life of edges during steel machining. In these investigations for the purpose of additional increase of coated edge durability an interfacial layers were applied. Presented investigations particularly pointed out to essential influence of the values of discharge voltage on the coating structure and durability of edges coated with boron nitfide.

  19. Study on the Test Method of Initiation Energy Matching for High Voltage Pulse Power Source and Slapper%高压脉冲功率源与冲击片雷管发火能量匹配关系特性试验方法

    Institute of Scientific and Technical Information of China (English)

    韩克华; 王丽萍; 任西; 褚恩义

    2012-01-01

    Aimed at the problem of initiation energy matching for high voltage pulse power source with cable and slapper, the test method of initiation energy matching was put forward. For the cable connected to the output of high voltage pulse power source condition, the data of the short circuit discharge were obtained by the test device, meanwhile, the theoretic analysis and verification test of slapper initiation were carried out The results indicated that when the cable of 100mm was connected to the output of high voltage pulse power source, the initiation voltage of slapper was risen 300V, the corresponding output energy equals to that without cable. The test method not only protect the initiation device and retrench the test cost, but also ensure the reliability of slapper initiation.%针对高压脉冲功率源接入引出电缆后与冲击片雷管发火能量的匹配问题,提出了高压脉冲功率源与冲击片雷管发火能量的匹配关系特性试验方法,通过试验装置测试了接入引出电缆后冲击片雷管短路放电性能参数,并进行了理论分析及冲击片雷管发火验证试验.结果表明:在脉冲功率源输出端增加100mm的引出电缆后,冲击片雷管发火电压需提升300V,此时输出能量等价于未接入引出电缆时的发火能量.该方法在冲击片雷管发火试验以及传爆序列试验中,既能保护起爆装置,节约试验成本,又能保证冲击片雷管可靠起爆.

  20. High Voltage XLPE Cable Becoming Damp and Its Prevention Measures%交联聚乙烯电缆受潮及预防措施分析

    Institute of Scientific and Technical Information of China (English)

    何兴友

    2014-01-01

    由于电缆绝缘材料及结构的特殊性,对电缆的安装、运行及维护都具有特殊的要求。防治电缆受潮就是其主要工作之一,电缆受潮或进水使电缆绝缘电阻降低、绝缘老化等是引起电缆线路发生运行事故重要诱因之一。本文对高压电力电缆受潮原因进行分析,探索有效预防措施。%Due to the characteristics of cable insulation material structure,there are special requirements for cable installation, operation and maintenance. Preventing cable from becoming damp is one of the most important tasks. Cable becoming damp will lead to low insulated resistance,and insulation aging is one of the reasons for operation accident. This article has discussed the reason why the cable becomes damp and the effective prevention measures.

  1. Research on Flow Capacity of Low-voltage Flame Retardant Power Cable%低压阻燃电力电缆通流能力研究

    Institute of Scientific and Technical Information of China (English)

    李炳华

    2015-01-01

    Flow capacity of flame retardant cable is explained in comparative analysis and test from the perspective of design. It is concluded that the current-carrying capacity of cable varies significantly from model to model, such as radiation crosslinking cable of YJF ( E) series and ZG - A isolated flame retardant cable, higher current-carrying capacity, and the larger the size, the greater is the difference of current-carrying capacity; furthermore, the current-carrying capacity of isolated flame retardant cable of the same model and size but from different manufacturers also differs.%从设计角度出发,通过对比分析和试验说明阻燃电缆的通流能力,得出两个结论:①不同类型的电缆载流量差别较大,规格越大载流量差别也越大,辐照交联的YJF (E)系列电缆和ZG-A隔离型阻燃电缆具有较强的载流能力;②相同型号、相同规格、不同厂家的阻燃电力电缆通流能力有所不同。

  2. On the influence of high voltage slope steepness on breakdown and development of pulsed dielectric barrier discharges

    Science.gov (United States)

    Höft, H.; Becker, M. M.; Loffhagen, D.; Kettlitz, M.

    2016-12-01

    The influence of the steepness of the applied high voltage (HV) waveform on the characteristics of pulsed dielectric barrier discharges (DBDs) is investigated using a single-filament arrangement with 1 mm gap in 0.1 vol% O2 in N2 at atmospheric pressure. The slope steepness was varied between 75 V ns-1 and 200 V ns-1. The discharge development was recorded with a combined iCCD and streak camera system accompanied by electrical measurements. The analysis was supported by time-dependent, spatially one-dimensional fluid model calculations. A steeper HV slope leads to a higher transferred charge and electrical energy per cycle. The DBD emission structure in the gap features a shorter ‘dark space’ in front of the cathode for steeper HV pulses. The starting velocity of the positive streamer-like propagation at the rising slope of the HV pulses increases with increasing slope steepness, but without influencing the maximal velocity in front of the cathode. At the falling slope, however, smaller propagation velocities for steeper pulses were measured. The modelling results and the measurements of the emission during the pre-phase suggest that the elevated pre-ionisation and higher electrical energy for steeper HV slopes is responsible for most of the observed effects.

  3. 10kV中压复合电缆和中间接头的结构及性能%The Structure and Properties of 10kV Medium-Voltage Composite Cable and Its connector

    Institute of Scientific and Technical Information of China (English)

    李峰; 胡为进; 金神; 陈博; 吴海生

    2012-01-01

    介绍了光纤复合电缆的结构及性能,把具有特定功能的传感光纤和通信光纤嵌入到电力电缆中,构成具有通信和传感功能的10kV中压复合电力电缆,可以实现对输变电网设备、设施状态的在线监测和数据通信传输功能;阐述了针对此光纤复合电缆开发的直通式中压光纤复合电缆接头结构及性能。%This paper firstly elaborates the structure and function of optical fiber composite cable: 10 kV optical fiber composite cable is constituted with communication and sensing function by embedding the special sensing optical fibers and telecom optical fibers into the power cable,thus,achieving the on-line monitoring function over the power transmission and distribution network equipments and facilities,as well as achieving the data communication and transmission function.Then it introduces the structure and properties of a straight-through connector,specifically developed for this type of medium-voltage optical fiber composite cable.

  4. High-voltage Pulsed Electric Field in.Food Industry%食品高压脉冲电场杀菌技术

    Institute of Scientific and Technical Information of China (English)

    袁丽佳; 何博; 姜彬; 尤涛

    2011-01-01

    High-voltage pulsed electric field is one of the most popular methods in food process. The mechanism of high-voltage pulsed electric field, the device of high-vo]tage pulsed electric field , and the application of it are introduced.%高压脉冲电场(high-voltage pulsed electric field,HPEF)杀菌技术是目前国际上最热门的食品加工技术之一,本文介绍了高压脉冲电场杀菌技术的基本机理,杀菌装置,以及对该技术在食品加工中应用的介绍。

  5. Reactive Power Compensation of a 24 MW Wind Farm using a 12-Pulse Voltage Source Converter

    DEFF Research Database (Denmark)

    Pedersen, Knud Ole Helgesen; Pedersen, Jørgen Kaas

    1998-01-01

    Integration of large wind farms in distribution and transmission systems may have severe influence on the power quality at the connection point and may also influence the voltage controlling capability of the electrical system. The purpose of the described project has been to develop and investig......Integration of large wind farms in distribution and transmission systems may have severe influence on the power quality at the connection point and may also influence the voltage controlling capability of the electrical system. The purpose of the described project has been to develop...... and investigate the use of a STATCOM by modelling and field testing an 8 MVar unit in a 24 MW wind farm....

  6. Space Vector Pulse Width Modulation Scheme for a Seven-Phase Voltage Source Inverter

    Directory of Open Access Journals (Sweden)

    Mohd. Arif Khan

    2011-09-01

    Full Text Available This paper analyses a simple space vector PWM (SVPWM scheme for a seven-phase voltage source inverter. At first the conventional method of producing sinusoidal output voltage  by utilizing six active and a zero space vectors are used to synthesis the input reference and then new PWM scheme called time equivalent space vector PWM is presented.  A comparison of the proposed scheme with the conventional scheme is presented based on various performance indices. Extensive Simulation results are provided to validate the findings

  7. A cable position sorting method for the balance of current distribution of parallel connected cables

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S.Y. [Northern Taiwan Inst. of Science and Technology, Taipei, Taiwan (China); Yu, C.S. [National Defence Univ., Taoyuan, Taiwan (China); Wang, S.C. [Lung Hwa Univ. of Science and Technology, Taoyuan, Taiwan (China); Chen, Y.L. [MingChi Univ. of Technology, Taipei, Taiwan (China)

    2006-07-01

    In order to meet the high ampacity requirement of a low voltage main feeder, single-core power cables are usually connected in parallel in Taiwan's industrial and commercial power distribution systems. However, parallel connected cables can be problematic due to unequal current distributions among cables of the same phase, causing excessive temperature rise in the heavier loading cables, thus reducing the life expectancy of cable insulation. One of the most effective and economical methods of balancing current distributions is a properly designed cable position arrangement. This paper proposed a cable position sorting method for the balance of current distribution of parallel connected cables. A current distribution calculation method was developed based on mutual inductance theorem and the numerical iteration technique. In order to implement the sorting algorithm, two current distribution indices were proposed for the power loss of all cables and for the largest cable current value. The index values of different cable arrangement patterns generated by a novel permutation reduction method were determined and sorted and 3 cable configurations were studied. Recommendations for the arrangement of cable positions, aiming for more balanced current distributions, were also presented. It was concluded that dividing the cables into subgroups, including only one cable per phase in a subgroup, and arranging the cables in symmetric form can achieve a very balanced current distribution. 5 refs., 14 tabs., 7 figs.

  8. OVERLOAD CAPABILITY OF POWER CABLES IN ACTUAL POWER CONSUMPTION SYSTEMS

    Directory of Open Access Journals (Sweden)

    L.A. Szhebenyuk

    2013-09-01

    Full Text Available Results of overload capability calculations for 6-kV power cables are analyzed. The work is aimed at creating a computation system for the current rating of high-voltage cross-linked polyethylene power cables.

  9. Pulsed voltage deposited lead selenide thin film as efficient counter electrode for quantum-dot-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Bin Bin [Key Laboratory of Macromolecular Science of Shaanxi Province & School of Materials Science and Engineering, Shaanxi Normal University, Xi’an 710062 (China); Department of Chemical Engineering, Institute of Chemical Industry, Shaanxi Institute of Technology, Xi’an 710300 (China); Wang, Ye Feng [Key Laboratory of Macromolecular Science of Shaanxi Province & School of Materials Science and Engineering, Shaanxi Normal University, Xi’an 710062 (China); Wang, Xue Qing [Faculty of Chemical, Environmental and Biological Science and Technology, Dalian University of Technology, Dalian 116024 (China); Zeng, Jing Hui, E-mail: jhzeng@ustc.edu [Key Laboratory of Macromolecular Science of Shaanxi Province & School of Materials Science and Engineering, Shaanxi Normal University, Xi’an 710062 (China)

    2016-04-30

    Highlights: • PbSe thin film is deposited on FTO glass by a pulse voltage electrodeposition method. • The thin film is used as counter electrode (CE) in quantum dot-sensitized solar cell. • Superior electrocatalytic activity and stability in the polysulfide electrolyte is received. • The narrow band gap characteristics and p-type conductivity enhances the cell efficiency. • An efficiency of 4.67% is received for the CdS/CdSe co-sensitized solar cells. - Abstract: Lead selenide (PbSe) thin films were deposited on fluorine doped tin oxide (FTO) glass by a facile one-step pulse voltage electrodeposition method, and used as counter electrode (CE) in CdS/CdSe quantum dot-sensitized solar cells (QDSSCs). A power conversion efficiency of 4.67% is received for the CdS/CdSe co-sensitized solar cells, which is much better than that of 2.39% received using Pt CEs. The enhanced performance is attributed to the extended absorption in the near infrared region, superior electrocatalytic activity and p-type conductivity with a reflection of the incident light at the back electrode in addition. The physical and chemical properties were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), energy-dispersive spectroscopy (EDS), reflectance spectra, electrochemical impedance spectroscopy (EIS) and Tafel polarization measurements. The present work provides a facile pathway to an efficient CE in the QDSSCs.

  10. Switching Restrikes in HVAC Cable Lines and Hybrid HVAC Cable/OHL Lines

    DEFF Research Database (Denmark)

    da Silva, Filipe Miguel Faria; Bak, Claus Leth; Balle Holst, Per

    2011-01-01

    The disconnection of HV underground cables may, if unsuccessful, originate a restrike in the circuit breaker, leading to high overvoltages, and potentially damaging the cable and near equipment. Due to the cable high capacitance and low resistance the voltage damping is slow, resulting, half...... a cycle after the disconnection, in a voltage of approximately 2 pu at the circuit breaker terminals. In case of restrike in that instant, it is theoretical possible to attain an overvoltage of 3 pu. The overvoltage can be even larger in hybrid cable-Overhead Lines (OHL), due to voltage magnifications...

  11. The Preceding Voltage Pulse and Separation Welding Mechanism of Electrical Contacts

    DEFF Research Database (Denmark)

    Yang, Xiao Cheng; Huang, Jiang; Li, Zhen Biao

    2016-01-01

    In order to obtain a better understanding of the welding mechanism in contact separation, electrical endurance tests were conducted with AgSnO2 and AgNi contacts on a simulation test device. Waveforms of contact displacement, contact voltage, and current were recorded with LabVIEW during the tests...

  12. Transistorized Marx bank pulse circuit provides voltage multiplication with nanosecond rise-time

    Science.gov (United States)

    Jung, E. A.; Lewis, R. N.

    1968-01-01

    Base-triggered avalanche transistor circuit used in a Marx bank pulser configuration provides voltage multiplication with nanosecond rise-time. The avalanche-mode transistors replace conventional spark gaps in the Marx bank. The delay time from an input signal to the output signal to the output is typically 6 nanoseconds.

  13. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-09-30

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

  15. Recent progress in R&D for long pulse and ultra-high voltage components for the ITER HNB

    Energy Technology Data Exchange (ETDEWEB)

    Kashiwagi, Mieko, E-mail: kashiwagi.mieko@jaea.go.jp; Umeda, Naotaka; Kojima, Atsushi; Yoshida, Masafumi; Tobari, Hiroyuki; Dairaku, Masayuki; Yamanaka, Haruhiko; Maejima, Tetsuya; Yamashita, Yasuo; Shibata, Naoki; Watanabe, Kazuhiro; Hanada, Masaya

    2015-10-15

    Highlights: • Long-pulse acceleration of MeV-class ion beams is demonstrated in JAEA. • The pulse length is extended from 0.4 s to 60 s, successfully. • R&D of 1 MV power supply is in progressed as scheduled. • Feasibility of 1 MV insulating transformer is confirmed in the mockup. - Abstract: Toward ITER, the long-pulse acceleration of MeV-class negative ion beams has been successfully demonstrated and R&Ds and the procurement of high-voltage components of 1 MV power supply system have been progressed. In the accelerator development after the production of 1 MeV beams, an extraction grid, where a water cooling is reinforced and the beam is steered by aperture offset to suppress grid heat loads, has been newly developed to extend the pulse duration of the MeV-class beams. As the result, a total grid heat load has been reduced from 20% to 10% of the total beam power. The beam pulse was successfully increased from 0.4 s to 60 s at 0.68 MeV, 100 A/m{sup 2} and 12 s at 0.89 MeV, 156 A/m{sup 2} beams. As for the procurement of the 1 MV power supply system, 1 MV insulating transformer as the critical component has been developed. In the mock-up, a dc 1.2 MV for 1 h with the margin of 20% was stably sustained. Through the R&Ds of the critical components, design of five power supplies procured by JAEA has been finalized, and out of which a testing power supply has been completed in June 2014.

  16. External Force Damage Simulation of Submarine High-voltage Cable Based on Distributed Fiber Optic Sensor Technology%基于分布式光纤传感技术的高压海底电缆外力损坏仿真

    Institute of Scientific and Technical Information of China (English)

    陆莹; 黄辉

    2012-01-01

    高压海底电缆的安全稳定运行对于海上能源的开发具有重要的作用,海缆电缆的损坏主要由外力引起,针对分布式光纤传感器在线监测高压海底电缆运行状况的方法,利用有限元软件ANSYS建立XLPE高压海底电缆模型,仿真分析海底电缆受到外力损坏时,内部物理量的变化,为分布式光纤传感器在线监测高压海底电缆运行状态提供参考。%Safety and stable operation of submarine high-voltage cable has played an important role in the development of Marine energy. However, submarine high-voltage cable was mainly damaged by external forces. According to the method for operation state of submarine high-voltage cable using on-line monitoring technology based on distributed fiber optic sensor, the model of the XLPE submarine high-voltage cable was gained by using finite element software ANSYS. Then, based on the model, the change of internal physical quantities were researched ,when submarine high-voltage cable was damaged by external force, with the function to provide the practical reference for running state of submarine high-voltage cable monitoring on-line based on distributed fiber optic sensor.

  17. 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

    Gene transfer by electroporation is gaining momentum now that high-level, long-term expression of transgenes is being obtained. Several different pulse regimens are efficient, yet little information is available about the physiological muscular response to gene electrotransfer. This paper provide...

  18. Transcranial low voltage pulsed electromagnetic fields in patients with treatment-resistant depression

    DEFF Research Database (Denmark)

    Martiny, Klaus Per Juul; Lunde, Marianne; Bech, Per

    2010-01-01

    of a new principle using low-intensity transcranially applied pulsed electromagnetic fields (T-PEMF) in combination with antidepressants in patients with treatment-resistant depression. METHODS: This was a sham-controlled double-blind study comparing 5 weeks of active or sham T-PEMF in patients...

  19. Mineral Liberation of Magnetite-Precipitated Copper Slag Obtained via Molten Oxidation by Using High-Voltage Electrical Pulses

    Science.gov (United States)

    Fan, Yong; Shibata, Etsuro; Iizuka, Atsushi; Nakamura, Takashi

    2016-10-01

    Our proposed method, i.e., a controlled molten oxidation process under 1 vol pct oxygen, leads to selective precipitation of magnetite in a copper smelter slag for downstream iron separation. In the present study, the preroasted magnetite precipitated copper slag was treated via magnetite liberation, which was realized by using high-voltage electrical pulses. The mineral distribution was determined by using a laser microscope and its image analysis; and it revealed that the 100- µm under-sieve product contains approximately 70 pct of liberated mineral particles. The study affirms the positive outcome of using this new technology for comminution to obtain micrometer-scale particles that yield monominerals via selective liberation. Using magnetic separation, iron was capable of finally separating into high- and low-iron-bearing concentrate and tailing that can be used in specific applications.

  20. The formation of diffuse discharge by short-front nanosecond voltage pulses and the modification of dielectrics in this discharge

    Science.gov (United States)

    Orlovskii, V. M.; Panarin, V. A.; Shulepov, M. A.

    2014-07-01

    The dynamics of diffuse discharge formation under the action of nanosecond voltage pulses with short fronts (below 1 ns) in the absence of a source of additional preionization and the influence of a dielectric film on this process have been studied. It is established that the diffuse discharge is induced by the avalanche multiplication of charge initiated by high-energy electrons and then maintained due to secondary breakdowns propagating via ionized gas channels. If a dielectric film (polyethylene, Lavsan, etc.) is placed on the anode, then multiply repeated discharge will lead to surface and bulk modification of the film material. Discharge-treated polyethylene film exhibits a change in the optical absorption spectrum in the near-IR range.

  1. Image processing for non-ratiometric measurement of membrane voltage using fluorescent reporters and pulsed laser illumination.

    Science.gov (United States)

    Silve, Aude; Rocke, Sarah; Frey, Wolfgang

    2015-06-01

    The measurement of transmembrane voltages induced by pulsed electric field exposure can be achieved by using fluorescent dyes like ANNINE-6. Such approach requires a quantitative determination of the fluorescence intensity along the cell's membrane by image processing. When high temporal resolution is required, the illumination source is frequently a dye-laser which causes high fluctuations in the intensity of illumination which in turn affects the fluorescence intensity and thus the quality of the results. We propose an image processing technique that allows to overcome the fluctuations and to produce quantitative data. It uses the optical background noise as a correcting factor. Standard deviation in the fluctuations is thus efficiently reduced by at least a factor of 2.5. Additionally we draw attention to the fact that the parasitic component of the laser radiation (ASE) can also suppress fluctuations although it deteriorates wavelength precision.

  2. Design and Experiments of the High Voltage Pulsed Electric Fields Sterilization System

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xihai; FANG Junlong; SHEN Weizheng

    2008-01-01

    This experiment designed the pulsed electric fields (PEF) of high intensity of 100 kV. cml sterilization system. Fluorescent pseudomonas as target cell was operated 180 s in the PEF. By observing the difference of the bacteria before and after the disposal by TEM, it is found that the cell wails of the treated bacteria were broken. Irreversible perforations were formed on the cell membrane. The cell inclusions and cell fragments were leaked. The cell died as a result. The results showed that the PEF sterilization system designed can be used for liquid food sterilization experiments.

  3. DC link current simulation of voltage source inverter with random space vector pulse width modulation

    Directory of Open Access Journals (Sweden)

    Chen Guoqiang

    2016-01-01

    Full Text Available Aiming at analysis complexity, a simulation model is built and presented to analyze and demonstrate the characteristics of the direct current (DC link current of the three-phase two-level inverter with the random space vector pulse width modulation (SVPWM strategy. The developing procedure and key subsystems of the simulation model are given in detail. Several experiments are done using the simulation model. The results verify the efficiency and convenience of the simulation model and show that the random SVPWM scheme, especially the random switching frequency scheme, can efficiently suppress the harmonic peaks of the DC link current.

  4. Discharge ignition in the diaphragm configuration supplied by DC non-pulsing voltage

    Science.gov (United States)

    Hlochová, L.; Hlavatá, L.; Kozáková, Z.; Krčma, F.

    2016-05-01

    This work deals with the ignition of the discharge in the diaphragm configuration generated in water solutions containing supporting NaCl electrolyte. The reactor has volume of 110 ml and it is made of polycarbonate. HV electrodes made of stainless steel are placed in this reactor. Ceramic (Shapal-MTM) diaphragm is placed in the barrier separating the cathode and the anode space. An electric power source supplies the reactor by constant DC voltage up to 4 kV and electric current up to 300 mA. The discharge ignition is compared in the reactor with different sizes of diaphragms. Measurements are carried out in electrolyte solutions with the same conductivity. Images of plasma streamers and bubble formation are taken by an ICCD camera iStar 734. Electrical characteristics are measured by an oscilloscope LeCroy LT 374 L in order to determine breakdown moments at different experimental conditions.

  5. 阻尼振荡波电压和工频电压下XLPE电缆局部放电特性的对比研究%Comparative Study on Partial Discharge Characteristics of XLPE Cable under Damped Oscillating Wave Voltage and AC Voltage

    Institute of Scientific and Technical Information of China (English)

    薛荣; 张龙; 黄志伟; 张伟; 李洪杰

    2015-01-01

    The partial discharge characteristics of four defects in heat-shrinkable cable accessories, which were termination without stress tube, incorrect use of insulation tape as semi-conductive adhesive tape in the middle joint, void and metal particles on the surface of XLPE insulation, were studied by AC volt-age method and damped oscillating wave voltage method. The partial discharge inception voltage and pat-terns under damped oscillating wave voltage and AC voltage were compared. The results show that the two methods are consistent in the study of partial discharge characteristics, and there are obvious differ-ences in the partial discharge statistical characteristics of various defects.%采用工频电压法和阻尼振荡波电压法研究热缩式电缆附件在4种缺陷情况下的局部放电特性,对比分析两种电压情况下的局部放电起始电压和局放模式。结果表明:两种方法在局部放电特性研究中具有一致性,各种缺陷的局部放电统计特征具有较为明显的差异。

  6. [Spectroscopic study on the high voltage fast pulsed discharge of nitrogen, ammonia or their mixture].

    Science.gov (United States)

    Liu, Z P; Wang, P N; Yang, W D; Zheng, J B; Li, F M

    2001-10-01

    The emission spectra from the pulsed discharge plasma of nitrogen, ammonia or their mixture were measured. In the discharge of pure nitrogen gas, as the pressure increased, the discharge volume decreased and more dissociation of nitrogen molecules occurred due to the higher energy density. In the discharge of ammonia, N,N+ and NH+ were observed, but no NH2 and NH3 were detected, indicating that ammonia, which has the lower dissociation and ionization energies as compared to nitrogen, was highly dissociated. The discharge of the mixture of N2 and NH3 was also studied. The dependence of the dissociation of nitrogen on the ratio of nitrogen to ammonia was investigated by emission spectra. The optimal ratio for nitrogen dissociation was obtained. The advantage of using the mixture of nitrogen and ammonia in the synthesis of nitrides was discussed.

  7. Transcranial low voltage pulsed electromagnetic fields in patients with treatment-resistant depression

    DEFF Research Database (Denmark)

    Martiny, Klaus Per Juul; Lunde, Marianne; Bech, Per

    2010-01-01

    BACKGROUND: Approximately 30% of patients with depression are resistant to antidepressant drugs. Repetitive transcranial magnetic stimulation (rTMS) has been found effective in combination with antidepressants in this patient group. The aim of this study was to evaluate the antidepressant effect...... of a new principle using low-intensity transcranially applied pulsed electromagnetic fields (T-PEMF) in combination with antidepressants in patients with treatment-resistant depression. METHODS: This was a sham-controlled double-blind study comparing 5 weeks of active or sham T-PEMF in patients......-resistant depression. Few side effects were observed. Mechanism of the antidepressant action, in light of the known effects of PEMF stimulation to the brain, is discussed....

  8. Degradation of Dye Wastewater by Pulsed High-Voltage Discharge Combined with Spent Tea Leaves

    Science.gov (United States)

    Liu, Yan; Yang, Li; Yang, Gang; Zhang, Yanzong; Zhang, Xiaohong; Deng, Shihuai

    2014-12-01

    Degradation of methylene blue (MB) was performed using the pulsed discharge process (PDP) combined with spent tea leaves (STLs). The effects of STL dosage, concentration of initial solution, and pH were analyzed in the combined treatment. Results showed that the combined treatment was effective for dye wastewater degradation; when the dosage of STLs was 3.2 g/L, the degradation efficiency reached 90% after 15 min treatment, and STLs showed a good repeatability. The degradation rate decreased with increasing initial MB concentration but not related to the solution pH in the combined treatment. Fourier-transform infrared spectra and N2 adsorption suggested that the number of acidic and basic groups in the STL surface increased after the treatment, but the surface area and pore volume remained unchanged.

  9. Cable tensiometer

    Energy Technology Data Exchange (ETDEWEB)

    Park, B.V

    1989-05-30

    This patent describes a weight beam for measuring load on a cable. The weight beam consists of: a beam body; load cell means mounted on the beam body, the load cell means being spaced a predetermined distance from the beam body; clamp means connected to the load cell means and adapted to grip a cable whose tension is to be measured; and adjusting means connected to the load cell to deflect the cable and put the load cell under a tension load, the clamp means and the adjusting means being structurally distinct.

  10. Effects of high voltage nanosecond pulsed plasma and micro DBD plasma on seed germination, growth development and physiological activities in spinach.

    Science.gov (United States)

    Ji, Sang-Hye; Choi, Ki-Hong; Pengkit, Anchalee; Im, Jun Sup; Kim, Ju Sung; Kim, Yong Hee; Park, Yeunsoo; Hong, Eun Jeong; Jung, Sun Kyung; Choi, Eun-Ha; Park, Gyungsoon

    2016-09-01

    In this study, we analyzed seed germination, seedling growth, and physiological aspects after treatment with high voltage nanosecond pulsed plasma and micro DBD plasma in spinach (Spinacia oleracea L.), a green leafy vegetable known to have low germination rate. Both germination and dry weight of seedlings increased after high voltage pulse shots were applied to spinach seeds. However seeds treated with many shots (10 shots) showed a decrease in germination rate and seedling growth. Seeds treated with air DBD plasma exhibited slightly higher germination and subsequent seedling growth than those treated with N2 plasma. Seed surface was degenerated after treated with high voltage pulsed plasma and micro DBD plasma but no significant difference in the degree of degeneration was observed among micro DBD plasma treatment time. Level of GA3 hormone and mRNA expression of an amylolytic enzyme-related gene in seeds were elevated 1 day after treatment with high voltage pulsed plasma. The relative amount of chlorophyll and total polyphenols in spinach seedlings grown from seeds treated with air DBD plasma was increased in 30 s, 1 min, and 3 min treatments. Taken together, our results suggest a possibility that plasma can enhance seed germination by triggering biochemical processes in seeds.

  11. Soft x-ray generation in gases by means of a pulsed electron beam produced in a high-voltage barier discharge

    NARCIS (Netherlands)

    Azarov, A.V.; Peters, P.J.M.; Boller, K.-J.

    2007-01-01

    A large area pulsed electron beam is produced by a high-voltage barrier discharge. We compare the properties of the x-rays generated by stopping this beam of electrons in a thin metal foil with those generated by stopping the electrons directly in various gases. The generation of x-rays was investig

  12. Theory of quantum transport in disordered systems driven by voltage pulse

    Science.gov (United States)

    Zhou, Chenyi; Chen, Xiaobin; Guo, Hong

    2016-08-01

    Predicting time-dependent quantum transport in the transient regime is important for understanding the intrinsic dynamic response of a nanodevice and for predicting the limit of how such a device can switch on or off a current. Theoretically, this problem becomes quite difficult to solve when the nanodevice contains disorder because the calculated transient current must be averaged over many disorder configurations. In this work, we present a theoretical formalism to calculate the configuration averaged time-dependent current flowing through a phase coherent device containing disorder sites where the transient current is driven by sharply turning on and off the external bias voltage. Our theory is based on the Keldysh nonequilibrium Green's function (NEGF) formalism and is applicable in the far from equilibrium nonlinear response quantum transport regime. The effects of disorder scattering are dealt with by the coherent potential approximation (CPA) extended in the time domain. We show that after approximations such as CPA and vertex corrections for calculating the multiple impurity scattering in the transient regime, the derived NEGFs perfectly satisfy a Ward identity. The theory is quantitatively verified by comparing its predictions to the exact solution for a tight-binding model of a disordered two-probe transport junction.

  13. Superconductor cable

    Science.gov (United States)

    Allais, Arnaud; Schmidt, Frank (Langenhagen, DE

    2009-12-15

    A superconductor cable includes a superconductive cable core (1) and a cryostat (2) enclosing the same. The cable core (1) has a superconductive conductor (3), an insulation (4) surrounding the same and a shielding (5) surrounding the insulation (4). A layer (3b) of a dielectric or semiconducting material is applied to a central element (3a) formed from a normally conducting material as a strand or tube and a layer (3c) of at least one wire or strip of superconductive material is placed helically on top. The central element (3a) and the layer (3c) are connected to each other in an electrically conducting manner at the ends of the cable core (1).

  14. DETERMINATION OF ANALYTICAL CALCULATION ERROR OF MAGNETIC FIELD OF HIGH-VOLTAGE CABLE LINES WITH TWO-POINT BONDED CABLE SHIELDS CAUSED BY NON-UNIFORM CURRENT DISTRIBUTION IN THE SHIELDS

    Directory of Open Access Journals (Sweden)

    M. I. Baranov

    2017-06-01

    Full Text Available Purpose. To obtain new calculation correlations, determining approximate energy dissipation and electric erosion of massive basic metallic electrodes in the high-voltage high-current air switchboard (HVCAS of atmospheric pressure, in-use in the bit chain of the high-voltage electrophysics setting (HVES with the powerful capacity store of energy (CSE. Methodology. Electrophysics bases of technique of high-voltage and large impulsive currents (LIC, scientific and technical bases of development and planning of high-voltage heavy-current impulsive electro-devices, including HVES and powerful CSE, and also methods of measuring in their bit chains of LIC of the microsecond temporal range. Results. On the basis of new engineering approach the results of calculation estimation of excretions energy and electric erosion of massive basic metallic electrodes are resulted in probed HVCAS. New correlations are obtained for the approximate calculation of thermal energy, selected in an impulsive air spark and on the workings surfaces of anode and cathode of HVCAS. It is entered and a new electrophysics concept, touching equivalent active resistance of impulsive air spark, is mathematically certain. New formulas are obtained for the approximate calculation of most depth of single round crater of destruction on the workings surfaces of basic metallic electrodes of HVCAS, and also mass of metal, thrown out magnetic pressure from this crater of destruction on the electrodes of switch for one electric discharge through them powerful CSE HVES. It is shown that the radius of the indicated single crater of destruction is approximately equal to the maximal radius of plasma channel of a spark discharge between a cathode and anode of HVCAS. The executed high-current experiments in the bit chain of HVES with powerful CSE validated row of the got and in-use calculation correlations for the estimation of energy dissipation and electric erosion of metallic electrodes in

  15. Avalanche mode of high-voltage overloaded p{sup +}–i–n{sup +} diode switching to the conductive state by pulsed illumination

    Energy Technology Data Exchange (ETDEWEB)

    Kyuregyan, A. S., E-mail: ask@vei.ru [Lenin All-Russia Electrical Engineering Institute (Russian Federation)

    2015-07-15

    A simple analytical theory of the picosecond switching of high-voltage overloaded p{sup +}–i–n{sup +} photodiodes to the conductive state by pulsed illumination is presented. The relations between the parameters of structure, light pulse, external circuit, and main process characteristics, i.e., the amplitude of the active load current pulse, delay time, and switching duration, are derived and confirmed by numerical simulation. It is shown that the picosecond light pulse energy required for efficient switching can be decreased by 6–7 orders of magnitude due to the intense avalanche multiplication of electrons and holes. This offers the possibility of using pulsed semiconductor lasers as a control element of optron pairs.

  16. First Field Experience of On-line Partial Discharge Monitoring of MV Cable Systems with location

    Energy Technology Data Exchange (ETDEWEB)

    Van der Wielen, P.; Steennis, F.

    2009-06-15

    A new measuring system is presented for the on-line monitoring and location of partial discharges (PDs) in medium-voltage power cables. The system uses two inductive sensors, each at one cable end. The measuring system is called PD-OL, which stands for PD detection Online with Location. A pulse injection system is used for the time synchronization of the data intake at both cable ends and for the on-line calibration. PD data is send via internet to the KEMA Control Center for interpretation and final presentation, made visible on a secured website for the network owners. This paper discusses the basics of PD-OL and a number of measurement results.

  17. 30 CFR 75.817 - Cable handling and support systems.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Cable handling and support systems. 75.817... High-Voltage Longwalls § 75.817 Cable handling and support systems. Longwall mining equipment must be provided with cable-handling and support systems that are constructed, installed and maintained to...

  18. Computation of Electric Field and Thermal Properties of 3-Phase Cable

    Directory of Open Access Journals (Sweden)

    Hemsingh Lunavath

    2012-06-01

    Full Text Available The high voltage electric power is generally transmitted by underground cable in urban, considering about the high cost for underground cable, it is necessary for us to get accurately biggest ampacity of cables in order to ensure the operation of cables in safe. The Cross linked polyethylene (XLPE insulated power cables are used for transmission and distribution of electrical power for higher voltage level. In this paper a three phase high voltage power cable buried in soil and it can be used to investigate electrical and thermal properties of cable. An underground cable of 132kV electric field, voltage distribution using finite element method (FEM, analytical method for calculating ampacity of cable and temperature distribution is presented and verified same by using COMSOL multiphysics software.

  19. Characteristics of plasma in culture medium generated by positive pulse voltage and effects of organic compounds on its characteristics

    Science.gov (United States)

    Sato, Y.; Sato, T.; Yoshino, D.

    2016-12-01

    We describe a positive pulse voltage method for generating plasma in culture medium with a composition similar to biological fluids. We also describe the plasma’s characteristics, liquid quality, and the effect of organic compounds in the culture medium on the plasma characteristics through comparisons to a solution containing inorganic salts at the same concentrations as in the culture medium. Light emission with Na and OH spectra was observed within a vapor bubble produced by Joule heating at the tip of the electrode. A downward thermal flow and shock wave were caused by the behavior of the vapor bubble. The culture medium pH gradually increased from 7.9 to 8.3 over the discharge time of 300 s. H2O2 was generated 1.1 mg l-1 in the culture medium after discharge for 300 s, and this value was 0.5 mg l-1 lower than the inorganic salts solution which does not contain organic compounds. This study provides important data that will help facilitate more widespread application of plasma medicine.

  20. Characteristics of temperature rise in variable inductor employing magnetorheological fluid driven by a high-frequency pulsed voltage source

    Science.gov (United States)

    Lee, Ho-Young; Kang, In Man; Shon, Chae-Hwa; Lee, Se-Hee

    2015-05-01

    A variable inductor with magnetorheological (MR) fluid has been successfully applied to power electronics applications; however, its thermal characteristics have not been investigated. To evaluate the performance of the variable inductor with respect to temperature, we measured the characteristics of temperature rise and developed a numerical analysis technique. The characteristics of temperature rise were determined experimentally and verified numerically by adopting a multiphysics analysis technique. In order to accurately estimate the temperature distribution in a variable inductor with an MR fluid-gap, the thermal solver should import the heat source from the electromagnetic solver to solve the eddy current problem. To improve accuracy, the B-H curves of the MR fluid under operating temperature were obtained using the magnetic property measurement system. In addition, the Steinmetz equation was applied to evaluate the core loss in a ferrite core. The predicted temperature rise for a variable inductor showed good agreement with the experimental data and the developed numerical technique can be employed to design a variable inductor with a high-frequency pulsed voltage source.

  1. Characteristics of temperature rise in variable inductor employing magnetorheological fluid driven by a high-frequency pulsed voltage source

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ho-Young; Kang, In Man, E-mail: imkang@ee.knu.ac.kr [School of Electronics Engineering, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Shon, Chae-Hwa [Korea Electrotechnology Research Institute, Changwon 642-120 (Korea, Republic of); Lee, Se-Hee, E-mail: shlees@knu.ac.kr [Department of Electrical Engineering, Kyungpook National University, Daegu 702-701 (Korea, Republic of)

    2015-05-07

    A variable inductor with magnetorheological (MR) fluid has been successfully applied to power electronics applications; however, its thermal characteristics have not been investigated. To evaluate the performance of the variable inductor with respect to temperature, we measured the characteristics of temperature rise and developed a numerical analysis technique. The characteristics of temperature rise were determined experimentally and verified numerically by adopting a multiphysics analysis technique. In order to accurately estimate the temperature distribution in a variable inductor with an MR fluid-gap, the thermal solver should import the heat source from the electromagnetic solver to solve the eddy current problem. To improve accuracy, the B–H curves of the MR fluid under operating temperature were obtained using the magnetic property measurement system. In addition, the Steinmetz equation was applied to evaluate the core loss in a ferrite core. The predicted temperature rise for a variable inductor showed good agreement with the experimental data and the developed numerical technique can be employed to design a variable inductor with a high-frequency pulsed voltage source.

  2. Mechanism of Fast Current Interruption in p -π -n Diodes for Nanosecond Opening Switches in High-Voltage-Pulse Applications

    Science.gov (United States)

    Sharabani, Y.; Rosenwaks, Y.; Eger, D.

    2015-07-01

    Step-recovery diodes operating in the snappy recovery regime are used as opening switches for generating narrow pulses with high-voltage amplitude. Physical modeling of the switching process is complex due to the large number of parameters involved, including diode structure, the extreme physical conditions, and the effect of external driving conditions. In this work, we address the problem by using a physical device simulator for solving the coupled device and electrical driving circuit equations. This method allows deciphering of the physical processes to take place in the diode during the fast current interruption phase. Herein we analyze the complete hard (snappy) reverse recovery process in short-base devices and determine the fast-transition-phase mechanism. It was found that the fast current interruption phase is constructed of two processes; the main parameters governing the switching time duration and the prepulse magnitude are the diode's reverse current density and its base-doping concentration. We describe the dependence of the switching performance in these parameters.

  3. 高压电力电缆接头温度无线检测控制系统设计%Design of High-Voltage Cable Jointed-node Wireless Monitor and Control System

    Institute of Scientific and Technical Information of China (English)

    王学军; 王浩川

    2009-01-01

    It designs a type of high-voltage cable joints' faults monitor and control system based on technol-ogy such as wireless communication, single chip microprocessor, and virtual instrumental technology, etc. The system fulfills temperature data collection underground by low power consumption digital tem-perature sensor TMP100. The single chip microprocessor MSP430F149 analyzes and processes data as central core control unit. Wireless transceiver nRF401 realizes data communication, which the high-volt-age cable joints monitor and control system is carried out. The paper describes system structure, parts of hardware and software design in detail Experiments show that the system performs weU as expoected.%基于无线传输技术、单片机技术、虚拟仪器技术等设计了一种电力电缆中间接头故障检测控制系统,系统利用低功耗数字温度传感器TMP100实现地下电缆接头温度采集,单片机MSP430F149作为中央核心控制单元完成数据分析与处理,并通过nRF401无线收发器实现了数据无线传输.文章对系统部分硬件及软件设计进行了详细介绍.通过实验测试,系统较好地满足了设计要求.

  4. 基于TTL数字电路控制的高压脉冲源%High-voltage pulse source controlled by TTL digital circuit

    Institute of Scientific and Technical Information of China (English)

    李玺钦; 丁明军; 吴红光; 冯莉; 刘云涛; 戴文峰; 黄雷

    2012-01-01

    给出了一种基于TTL数字电路作为高压脉冲源触发控制单元的设计原理和方法.介绍了高压脉冲源的工作原理,设计了一台脉冲输出幅度5 kV、脉冲宽度大于200 μs及脉冲前沿小于30 ns的高压脉冲源.将触发控制单元和前级开关金属氧化物半导体场效应管(MOSFET)组合成一体,控制后级气体高压开关管放电输出高压脉冲信号.实验结果验证了所采用的设计原理及方法的可行性,给出了单次触发情况下的实验结果.%The paper introduces a TTL digital circuit, which is designed as the trigger control system of high power pulse source, and presents the development of a high-voltage pulse source. In the source, the TTL circuit operated after the optical isolation circuit and power driver, and outputs pulse signals to drive MOSFET, which controls the pulse signal output from high-voltage switch. The source can outputs pulses with voltage of 5 kV, pulse-width larger than 200 Ωs and fall-time less than 30 ns. Besides long-distance control and local control mode, it also includes inner trigger and external trigger (one electric signal and one optical signal as the trigger). A series of experiments have been conducted to validate the design, and the one-shot trigger results are presented.

  5. Technologies for Improved Reliability of Shielded Power Cable and Characterization of Capacitor Film Energy Density

    Science.gov (United States)

    Shu, Wen

    Partial Discharge (PD), a partial breakdown of insulation between high voltage electrodes, reduces cable reliability. Understanding electromagnetic propagation of PD-induced pulses in shielded power cable, including attenuation and dispersion, is essential to the application of PD diagnostics and, especially, PD location. Dispersion is caused by the transition of cable semicon-ducting layers (between the cable conductors and dielectric) from "resistive" at low frequency to "capacitive" at high frequency. Methods are presented to compute dispersion as a function of semiconducting material properties and evaluate the effect of dispersion on pulse characteristics (amplitude, shape, and width, etc.) as a function of distance propagated, the results of which are applied to investigate the effects of dispersion for PD detection and location. The location error induced by dispersion can be compensated from calibration. Electrochemical degradation of cable dielectrics, known as "water treeing", is one of the leading cause of premature failures in underground shielded power cable. Silane-based fluid has been used successfully for decades to rejuvenate HMWPE and XLPE dielectric cables to "cure" existing water trees and extend cable life. However the ability of the treatment to inhibit future water tree initiation is not known. A method for silane fluid treatment of un-aged cable insulation and semicon was developed based on the use of GC/MS to determine curing of the fluid within the dielectric. A wet electrical aging test at 5 kV/mm (127 V/mil) based on a sample which includes semicon electrodes on both sides of the XLPE insulation with a water electrode in contact with one semicon layer was used to age untreated samples, samples treated prior to the test, and samples treated at the mid-time of the test (3500 hrs). The result of aging is analyzed by microscopic examination to determine the number, length and types of water trees. The mechanism by which the silane

  6. THE EFFECTS OF PULSE BIAS VOLTAGE AND N2 PARTIAL PRESSURE ON TiAIN FILMS OF ARC ION PLATING (AIP)

    Institute of Scientific and Technical Information of China (English)

    M.S. Li; S.L. Zhu; Fuhui Wang; C. Sun; L.S. Wen

    2001-01-01

    Owing to the characteristics of arc ion plating(AIP) technique, the structure and com-position of TiAlN films can be tailored by controlling of various parameters such ascompositions of target materials, N2 partial pressure, substrate bias and so on. ln thisstudy, several titanium aluminum nitride films were deposited on 1Cr11Ni2 W2Mo Vsteel for compressor blade of areo-engine under different d.c pulse bias voltage and ni-trogen partial pressure. The effects of substrate pulse bias and nitrogen partial pressureon the deposition rate, droplet formation, microstruture and elemental component ofthe films were investigated.

  7. Implementation of computational model for the evaluation of electromagnetic susceptibility of the cables for communication and control of high voltage substations; Implementacao de modelo computacional para a avaliacao da suscetibilidade eletromagnetica dos cabos de comunicacao e controle de subestacoes de alta tensao

    Energy Technology Data Exchange (ETDEWEB)

    Sartin, Antonio C.P. [Companhia de Transmissao de Energia Eletrica Paulista (CTEEP), Bauru, SP (Brazil); Dotto, Fabio R.L.; Sant' Anna, Cezar J.; Thomazella, Rogerio [Fundacao para o Desenvolvimento de Bauru, SP (Brazil); Ulson, Jose A.C.; Aguiar, Paulo R. de [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Bauru, SP (Brazil)

    2009-07-01

    This work show the implementation of a electromagnetic model for supervision cable, protection, communication and high voltage substations control that was investigated in literature and adapted. The model was implemented by using a computational tool in order to obtain the electromagnetic behavior of various cables used in CTEEP substation, subject to several sources of electromagnetic interference in this inhospitable environment, such as lightning strikes, outbreaks of maneuvers switching and the corona effect. The results obtained in computer simulations were compared with results of laboratory tests carried out on a lot of cables that represent those systems that are present in substations 440 kV. This study characterized the electromagnetic interference, ranked them, identified possible susceptible points in the substation, which contributed to the development of a technical procedure that minimizes unwanted effects caused in communication systems and substation control. This developed procedure also assured the maximum reliability and availability in the operation of the electrical power system to the company.

  8. Brookhaven superconducting cable test facility

    Energy Technology Data Exchange (ETDEWEB)

    Forsyth, E.B.; Gibbs, R.J.

    1976-08-17

    Construction has started on an outdoor testing station for flexible ac superconducting power transmission cables. It is intended to serve as an intermediate step between laboratory-scale experiments and qualification testing of prototype-scale cables. The permanent equipment includes a 500 W supercritical helium refrigerator using a screw compressor and multistage turbine expanders. Helium storage for 250,000 cu ft of helium at 250 psi is provided. Initially, the cables will be tested in a horizontal cryostat some 250 ft long. High-voltage 60 Hz tests will be performed with the cable in a series resonant mode with a maximum line to ground capability of 240 kV, this is adequate for a 138 kV system design. Impulse testing up to about 650 kV is planned. The cable conductor will be energized by current transformers, initially at about 4 kA and later up to fault levels of 40 kA. The refrigerator is now at the site and testing on a dummy load will commence in the Fall of 1976. The cryostat will be installed in 1977 followed about a year later by the first cable tests.

  9. Design and measurements of a fast high-voltage pulse generator for the MedAustron Low Energy Transfer line fast deflector

    CERN Document Server

    Fowler, T; Mueller, F; Kramer, T; Stadlbauer, T

    2012-01-01

    MedAustron, a centre for ion-therapy and research, will comprise an accelerator facility based on a synchrotron for the delivery of protons and light ions for cancer treatment. The Low Energy Beam Transfer line (LEBT) to the synchrotron contains an electrostatic fast deflector (EFE) which, when energized, deviates the continuous beam arriving from the ion source onto a Faraday Cup: the specified voltage is ±3.5 kV. De-energizing the EFE for variable pulse durations from 500 ns up to d.c. allows beam passage for multi-turn injection into the synchrotron. To maintain beam quality in the synchrotron, the EFE pulse generator requires rise and fall times of less than 300 ns between 90 % of peak voltage and a ±1 V level. To achieve this, a pulsed power supply (PKF), with high voltage MOSFET switches connected in a push-pull configuration, will be mounted in close proximity to the deflector itself. A fast, large dynamic range monitoring circuit will verify switching to the ±1 V level and subsequent flat bottom pu...

  10. Pulse

    Science.gov (United States)

    ... resting for at least 10 minutes. Take the exercise heart rate while you are exercising. ... pulse rate can help determine if the person's heart is pumping. Pulse ... rate gives information about your fitness level and health.

  11. Energy dispatching analysis of lightning surges on underground cables in a cable connection station

    Energy Technology Data Exchange (ETDEWEB)

    Hong-Chan Chang; Fu-Hsien Chen; Tai-Hsiang Chen [Department of Electrical Engineering, National Taiwan University of Science and Technology, 43, Sec. 4, Keelung Rd., Taipei (China); Cheng-Chien Kuo [Department of Electrical Engineering, St. John' s University, 499, Sec. 4, TamKing Rd., Tamsui, Taipei (China)

    2011-01-15

    The paper aimed to simulate the transient over-voltage phenomena which occur at 345 kV and 161 kV underground cables, when lighting strikes on or near the cable connection station, by using the Electro-Magnetic Transients Program (EMTP). A feasibility study on changing related parameters, as well as cable connections and grounding methods to reduce the impact caused by lightning strikes, will be thoroughly conducted. The various components required for a detailed simulation including; lightning surges, transmission line and tower, arrester, and underground cables are all considered. Then, the transient voltage of the cables will be analyzed under different situations including; connection methods, grounding locations, length of the grounding wire of arrester, and the grounding resistance for different locations. The simulation results show that the length of the grounding wire is more sensitive to the transient over-voltage which occurred when a common grounding topology was adopted. In contrast, the use of an independent grounding topology resulted in a reduction of the grounding resistance, which effectively decreased the over-voltage, thereby avoiding surpassing the shielding voltage level of the cable, caused by the rise of ground voltage. (author)

  12. Energy dispatching analysis of lightning surges on underground cables in a cable connection station

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Hong-Chan, E-mail: hcchang@mail.ntust.edu.t [Department of Electrical Engineering, National Taiwan University of Science and Technology, 43, Sec. 4, Keelung Rd., Taipei, Taiwan (China); Chen, Fu-Hsien, E-mail: fu@mail.sju.edu.t [Department of Electrical Engineering, National Taiwan University of Science and Technology, 43, Sec. 4, Keelung Rd., Taipei, Taiwan (China); Kuo, Cheng-Chien, E-mail: cckuo@mail.sju.edu.t [Department of Electrical Engineering, St. John' s University, 499, Sec. 4, TamKing Rd., Tamsui, Taipei, Taiwan (China); Chen, Tai-Hsiang, E-mail: thchen@yahoo.com.t [Department of Electrical Engineering, National Taiwan University of Science and Technology, 43, Sec. 4, Keelung Rd., Taipei, Taiwan (China)

    2011-01-15

    The paper aimed to simulate the transient over-voltage phenomena which occur at 345 kV and 161 kV underground cables, when lighting strikes on or near the cable connection station, by using the Electro-Magnetic Transients Program (EMTP). A feasibility study on changing related parameters, as well as cable connections and grounding methods to reduce the impact caused by lightning strikes, will be thoroughly conducted. The various components required for a detailed simulation including; lightning surges, transmission line and tower, arrester, and underground cables are all considered. Then, the transient voltage of the cables will be analyzed under different situations including; connection methods, grounding locations, length of the grounding wire of arrester, and the grounding resistance for different locations. The simulation results show that the length of the grounding wire is more sensitive to the transient over-voltage which occurred when a common grounding topology was adopted. In contrast, the use of an independent grounding topology resulted in a reduction of the grounding resistance, which effectively decreased the over-voltage, thereby avoiding surpassing the shielding voltage level of the cable, caused by the rise of ground voltage.

  13. Under Ground Cable Sizing Using MAT LAB

    Directory of Open Access Journals (Sweden)

    B. V. R. Uday Kiran

    2014-06-01

    Full Text Available The main theme of this paper is to explain the procedure to calculate the cross sectional area of a conductor of an underground cable for a specified power & voltage ratings. This paper will also explain one of the simplest ways to calculate the cross section. In this paper we analyzed various factors that effect in deciding the ampacity of the conductor. We developed a Mat lab code to find the cross sectional area by including some of the parameters and also the voltage drop , maximum permissible voltage drop for that size of the conductor and also the number of runs of the cable that are to be laid.

  14. Direct current in the future. HVDC better than a high-voltage alternating current cable; Gelijk in de toekomst. HVDC-verbonding beter dan hoogspanningskabel met wisselstroom

    Energy Technology Data Exchange (ETDEWEB)

    Van Velzen, T.

    2010-10-01

    For the development of a pan-European high-voltage grid the application of direct current (DC) technology is obvious. However, a series of incidents involving a link between the Netherlands and Norway raises questions about the reliability. An alternative conversion method seems more suited for a European supernetwork. DC transmission with insulated-gate bipolar transistor is the technology of the future. [Dutch] Voor de ontwikkeling van een pan-Europees hoogspanningsnet ligt toepassing van gelijkstroomtechnologie voor de hand. Een reeks incidenten met zo'n verbinding tussen Nederland en Noorwegen roept echter vragen op over de betrouwbaarheid. Een alternatieve conversietechniek lijkt echter geschikter voor een Europees supernet. Gelijkstroomtransmissie met 'insulated-gate bipolar' transistors is de techniek van de toekomst.

  15. DC conduction and breakdown characteristics of Al2O3/cross-linked polyethylene nanocomposites for high voltage direct current transmission cable insulation

    Science.gov (United States)

    Park, Yong-Jun; Kwon, Jung-Hun; Sim, Jae-Yong; Hwang, Ju-Na; Seo, Cheong-Won; Kim, Ji-Ho; Lim, Kee-Joe

    2014-08-01

    We have discussed a cross-linked polyethylene (XLPE) nanocomposite insulating material that is able to DC voltage applications. Nanocomposites, which are composed in polymer matrix mixed with nano-fillers, have received considerable attention because of their potential benefits as dielectrics. The nano-sized alumina oxide (Al2O3)/XLPE nanocomposite was prepared, and three kinds of test, such as DC breakdown, DC polarity reversal breakdown, and volume resistivity were performed. By the addition of nano-sized Al2O3 filler, both the DC breakdown strength and the volume resistivity of XLPE were increased. A little homogeneous space charge was observed in Al2O3/XLPE nanocomposite material in the vicinity of electrode through the polarity reversal breakdown test. From these results, it is thought that the addition of Al2O3 nano-filler is effective for the improvement of DC electrical insulating properties of XLPE.

  16. Computation of Electric Field and Thermal Properties of 3-Phase Cable

    National Research Council Canada - National Science Library

    Hemsingh Lunavath; K. Panduranga Vittal; K. Rajagopala

    2012-01-01

    The high voltage electric power is generally transmitted by underground cable in urban, considering about the high cost for underground cable, it is necessary for us to get accurately biggest ampacity...

  17. Full-scale fire experiments on vertical horizontal cable trays

    Energy Technology Data Exchange (ETDEWEB)

    Mangs, J.; Keski-Rahkonen, O. [VTT Building Technology, Espoo (Finland). Building Physics, Building Services and Fire Technology

    1997-10-01

    Two full-scale fire experiments on PVC cables used in nuclear power plants were carried out, one with cables in vertical position and one with cables in horizontal position. The vertical cable bundle, 3 m high, 300 mm wide and 30 mm thick, was attached to a steel cable ladder. The vertical bundle experiment was carried out in nearly free space with three walls near the cable ladder guiding air flow in order to stabilise flames. The horizontal cable experiment was carried out in a small room with five cable bundles attached to steel cable ladders. Three of the 2 m long cable bundles were located in an array, equally spaced above each other near one long side of the room and two correspondingly near the opposite long side. The vertical cable bundle was ignited with a small propane gas burner beneath the lower edge of the bundle. The horizontal cable bundles were ignited with a small propane burner beneath the lowest bundle in an array of three bundles. Rate of heat release by means of oxygen consumption calorimetry, mass change, CO{sub 2}, CO and smoke production rate and gas, wall and cable surface temperatures were measured as a function of time, as well as time to sprinkler operation and failure of test voltage in cables. Additionally, the minimum rate of heat release needed to ignite the bundle was determined. This paper concentrates on describing and recording the experimental set-up and the data obtained. (orig.)

  18. Investigation on a Novel Discontinuous Pulse-Width Modulation Algorithm for Single-phase Voltage Source Rectifier

    DEFF Research Database (Denmark)

    Qu, Hao; Yang, Xijun; Guo, Yougui

    2014-01-01

    -sequence component injection, in order to reduce power loss and increased overall efficiency. And then by reconstructing the other two phase input voltages and currents, the transformation from stationary frame (abc) to rotating frame (dq frame) is designed. Finally, a PI regulator based controller for single......Single-phase voltage source converter (VSC) is an important power electronic converter (PEC), including single-phase voltage source inverter (VSI), single-phase voltage source rectifier (VSR), single-phase active power filter (APF) and single-phase grid-connection inverter (GCI). Single-phase VSC...

  19. High-temperature performance of MoS{sub 2} thin-film transistors: Direct current and pulse current-voltage characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, C.; Samnakay, R.; Balandin, A. A., E-mail: balandin@ee.ucr.edu [Nano-Device Laboratory (NDL), Department of Electrical Engineering, Bourns College of Engineering, University of California—Riverside, Riverside, California 92521 (United States); Phonon Optimized Engineered Materials (POEM) Center, Materials Science and Engineering Program, University of California—Riverside, Riverside, California 92521 (United States); Rumyantsev, S. L. [Department of Electrical, Computer, and Systems Engineering, Center for Integrated Electronics, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States); Ioffe Physical-Technical Institute, St. Petersburg 194021 (Russian Federation); Shur, M. S. [Department of Electrical, Computer, and Systems Engineering, Center for Integrated Electronics, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States)

    2015-02-14

    We report on fabrication of MoS{sub 2} thin-film transistors (TFTs) and experimental investigations of their high-temperature current-voltage characteristics. The measurements show that MoS{sub 2} devices remain functional to temperatures of at least as high as 500 K. The temperature increase results in decreased threshold voltage and mobility. The comparison of the direct current (DC) and pulse measurements shows that the direct current sub-linear and super-linear output characteristics of MoS{sub 2} thin-films devices result from the Joule heating and the interplay of the threshold voltage and mobility temperature dependences. At temperatures above 450 K, a kink in the drain current occurs at zero gate voltage irrespective of the threshold voltage value. This intriguing phenomenon, referred to as a “memory step,” was attributed to the slow relaxation processes in thin films similar to those in graphene and electron glasses. The fabricated MoS{sub 2} thin-film transistors demonstrated stable operation after two months of aging. The obtained results suggest new applications for MoS{sub 2} thin-film transistors in extreme-temperature electronics and sensors.

  20. 高强脉冲电场与臭氧联用降解壳聚糖%Degradation of chitosan by high voltage pulsed electric field and ozone

    Institute of Scientific and Technical Information of China (English)

    罗文波; 唐超; 曾新安; 于淑娟

    2013-01-01

    The vigorous oxidation ability of ozone and the high energy input of pulsed electric field were utilized to degrade the macromolecular chitosan to oligochitosan. The degradation rate was up to 98. 5% after the combined treatment of high voltage pulsed electric field and ozone for 30 minutes in acetic acid homogeneous phase. Three experiment schemes of individual and combined treatments of high voltage pulsed electric field and ozone were designed the results showed that the efficiency of combined treatment was higher than that of single treatments, so the combination of high voltage pulsed electric field and ozone had high synergistic effect. By infrared spectrum analysis, the structure of degraded chitosan was not changed compared to the initial chitosan.%利用臭氧的强氧化性和电场的高能量降解大分子壳聚糖为壳寡糖.在乙酸均相体系中,高强脉冲电场与臭氧联用处理壳聚糖30min时,壳聚糖的降解率达到98.5%.设计了脉冲电场、臭氧单独处理和电场与臭氧联用处理3种实验方案,结果表明:电场与臭氧联用的处理效率要高于分别处理效率,电场与臭氧联用具有协同作用.经红外光谱分析,降解产物与原料壳聚糖结构基本一致.

  1. Energy Efficiency of Induction Motors Running Off Frequency Converters with Pulse-Width Voltage Modulation{sup 1}

    Energy Technology Data Exchange (ETDEWEB)

    Shvetsov, N. K., E-mail: elmash@em.ispu.ru [V. I. Lenin Ivanovo State Power University (Russian Federation)

    2016-11-15

    The results of calculations of the increase in losses in an induction motor with frequency control and different forms of the supply voltage are presented. The calculations were performed by an analytic method based on harmonic analysis of the supply voltage as well as numerical calculation of the electromagnetic processes by the finite-element method.

  2. Research of manufacturing high voltage nanosecond electromagnetic pulse attenuator%高压纳秒电磁脉冲衰减器的研制

    Institute of Scientific and Technical Information of China (English)

    陈炜峰; 宋珂锦

    2012-01-01

    随着电磁脉冲技术的发展,电磁脉冲前沿越来越快,峰值越来越高.针对这些特点,为了减小高压纳秒电磁脉冲传输、衰减过程中电磁波的反射,在输出端得到理想的电磁脉冲波形,设计了一种高压纳秒电磁脉冲衰减器,采用高频电磁场仿真软件HFSS建模仿真,分析驻波比,优化结构尺寸.根据仿真及优化结果,制作了衰减量为30%和40%的衰减器样机.实验表明样机衰减量误差小,传输性能好,可对上升时间2 ns左右,峰值小于40 kV的电磁脉冲实现有效衰减.%With the development of technology of electromagnetic pulse, the rising of electromagnetic pulse is more and more quickly, the peak is higher and higher. According to these characteristics, in order to reduce the reflex of high voltage nanosecond electromagnetic pulse in transmission and attenuation which can output the ideal electromagnetic pulse waveform, design of a high voltage nanosecond electromagnetic pulse attenuator, using high-frequency electromagnetic simulation software HFSS modeling,the size of the structure was optimized base on simulation,and got the simulation of VSWR (voltage standing wave ratio). According to the simulation and structural optimization of results,making attenuation for 30% and 40% of the attenuator prototype. Experimental validation of a prototype performance good, .deviation small,the attenuator had effective attenuation on the electromagnetic pulse which riseing time is about 2 ns,peak of pulse is less than 40 kV.

  3. Impact of pulsed-electric field and high-voltage electrical discharges on red wine microbial stabilization and quality characteristics.

    Science.gov (United States)

    Delsart, C; Grimi, N; Boussetta, N; Miot Sertier, C; Ghidossi, R; Vorobiev, E; Mietton Peuchot, M

    2016-01-01

    In this study, pulsed-electric fields (PEF) and high-voltage electrical discharges (HVED) are proposed as new techniques for the microbial stabilization of red wines before bottling. The efficiency of the treatment was then evaluated. PEF and HVED-treatments have been applied to wine for the inactivation of Oenococcus oeni CRBO 9304, O. oeni CRBO 0608, Pediococcus parvulus CRBO 2.6 and Brettanomyces bruxellensis CB28. Different treatment times (1, 2, 4, 6, 8 and 10 ms) were used at 20 kV cm(-1) for the PEF treatments and at 40 kV for the HVED treatments, which correspond to applied energies from 80 to 800 kJ l(-1) . The effects of the treatments on the microbial inactivation rate and on various characteristics of red wines (phenolic composition, chromatic characteristics and physico-chemical parameters) were measured. The application of PEF or HVED treatments on red wine allowed the inactivation of alteration yeasts (B. bruxellensis CB28) and bacteria (O. oeni CRBO 9304, O. oeni CRBO 0608 and P. parvulus CRBO 2.6). The electric discharges at 40 kV were less effective than the PEF even after 10 ms of treatments. Indeed, 4 ms of PEF treatment at 20 kV cm(-1) were sufficient to inactivate all micro-organisms present in the wines. Also, the use of PEF had no negative impact on the composition of wines compared to the HVED treatments. Contrary to PEF, the phenolics compounds were degraded after the HVED treatment and the physico-chemical composition of wine were modified with HVED. PEF technology seems to be an interesting alternative to stabilize microbiologically wines before bottling and without modifying their composition. This process offers many advantages for winemakers: no chemical inputs, low energy consumption (320 kJ l(-1) ), fast (treatment time of 4 ms) and athermal (ΔT ≈ 10°C). © 2015 The Society for Applied Microbiology.

  4. Influence Factors Analysis of Interface Pressure in High Voltage Cable Accessories%高压电缆附件界面压力的影响因素分析

    Institute of Scientific and Technical Information of China (English)

    柳松; 彭嘉康; 王霞; 王陈诚; 崔浩

    2013-01-01

    The interface pressure between cable accessory and cable insulation is the key to ensure the safety of cable accessory. Based on the interface pressure which determined the discharge characteristics of cable accessory, several influence factors of interface pressure were introduced, that is the roughness between cable accessory and cable insulation, temperature and the stress relaxation characteristics of cable accessory material. The long-term operational reliability of cable accessory can increase by increasing the interface smoothness, controlling the operation temperature rise of cable and selecting the accessory materi-al with relaxation resistance.%电缆附件和电缆绝缘间的界面压力是确保电缆附件安全运行的关键。基于决定电缆附件界面放电特性的界面压力,介绍了影响电缆附件界面压力的几个主要因素:电缆附件和电缆绝缘界面的粗糙度、温度和电缆附件材料的应力松驰特性。得出增加界面光滑度、控制电缆运行温升、选择耐松驰性附件材料等措施可提高电缆附件的长期运行可靠性。

  5. High Voltage Distribution

    Science.gov (United States)

    Norbeck, Edwin; Miller, Michael; Onel, Yasar

    2010-11-01

    For detector arrays that require 5 to 10 kV at a few microamps each for hundreds of detectors, using hundreds of HV power supplies is unreasonable. Bundles of hundreds of HV cables take up space that should be filled with detectors. A typical HV module can supply 1 ma, enough current for hundreds of detectors. It is better to use a single HV module and distribute the current as needed. We show a circuit that, for each detector, measures the current, cuts off the voltage if the current exceeds a set maximum, and allows the HV to be turned on or off from a control computer. The entire array requires a single HV cable and 2 or 3 control lines. This design provides the same voltage to all of the detectors, the voltage set by the single HV module. Some additional circuitry would allow a computer controlled voltage drop between the HV and each individual detector.

  6. Pulsed-voltage atom probe tomography of low conductivity and insulator materials by application of ultrathin metallic coating on nanoscale specimen geometry.

    Science.gov (United States)

    Adineh, Vahid R; Marceau, Ross K W; Chen, Yu; Si, Kae J; Velkov, Tony; Cheng, Wenlong; Li, Jian; Fu, Jing

    2017-10-01

    We present a novel approach for analysis of low-conductivity and insulating materials with conventional pulsed-voltage atom probe tomography (APT), by incorporating an ultrathin metallic coating on focused ion beam prepared needle-shaped specimens. Finite element electrostatic simulations of coated atom probe specimens were performed, which suggest remarkable improvement in uniform voltage distribution and subsequent field evaporation of the insulated samples with a metallic coating of approximately 10nm thickness. Using design of experiment technique, an experimental investigation was performed to study physical vapor deposition coating of needle specimens with end tip radii less than 100nm. The final geometries of the coated APT specimens were characterized with high-resolution scanning electron microscopy and transmission electron microscopy, and an empirical model was proposed to determine the optimal coating thickness for a given specimen size. The optimal coating strategy was applied to APT specimens of resin embedded Au nanospheres. Results demonstrate that the optimal coating strategy allows unique pulsed-voltage atom probe analysis and 3D imaging of biological and insulated samples. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Cable Sliding at Supports in Cable Structures

    Institute of Scientific and Technical Information of China (English)

    魏建东

    2004-01-01

    To develop an effective numerical method for the cable sliding problem in cable structures, two-node catenary cable element was built to model the cables based on analytical solution of elastic catenary. Cooperated with Newton method, continuation method was used to solve the nonlinear equations. This approach is more efficient than using Newton method only and has a wider range to select initial values for the process to converge. The relationship between the tension on a cable segment and its unstrained length was derived and used to calculate the unbalanced cable tensions at the supports. An example is presented to show the correctness and efficiency of the proposed method.

  8. VT Cable Systems 2013

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The VT Cable dataset (CABLE2013) includes lines depicting the extent of Vermont's cable modem broadband system as of 6/30/2013 in addition to...

  9. Quality Assessment of Soft-Switching Based Single-phase Pulse Width Modulated Voltage Source Inverter (PWM VSI

    Directory of Open Access Journals (Sweden)

    Z.A. Jaffery

    2012-10-01

    Full Text Available The authors present the design, simulation and analysis of a single phase voltage source inverter using soft switching techniques. The performance of the inverter has been compared in terms of harmonic contents present in output voltage and current. The research works for a PWM inverter along with a LLCC filter has been investigated. This paper also investigated the performance of the same inverter with a feedback controller with a closed loop feedback path to maintain rated output voltage. This work is helpful for the inverter used in application where high quality ac wave is prime requirement

  10. Frequency Dependent Losses in Transmission Cable Conductors

    DEFF Research Database (Denmark)

    Olsen, Rasmus Schmidt; Holbøll, Joachim; Guðmundsdóttir, Unnur Stella

    2011-01-01

    , such as thermal conditions in and around the cable, as well as the heat generated in conductors, screens, armours etc., taking into account proximity and skin effects. The work performed and presented in this paper is concerned with an improved determination of the losses generated in the conductor, by means...... of better calculation of the AC resistance of transmission cable conductors, in particular regarding higher frequencies. In this way, also losses under harmonics can be covered. Furthermore, the model is suitable for modelling of transient attenuation in high voltage cables. The AC resistance is calculated...

  11. Condition Monitoring of Power Cables

    OpenAIRE

    Lewin, P L; L. Hao; Swaffield, D J; Swingler, S.G.

    2007-01-01

    A National Grid funded research project at Southampton has investigated possible methodologies for data acquisition, transmission and processing that will facilitate on-line continuous monitoring of partial discharges in high voltage polymeric cable systems. A method that only uses passive components at the measuring points has been developed and is outlined in this paper. More recent work, funded through the EPSRC Supergen V, UK Energy Infrastructure (AMPerES) grant in collaboration with UK ...

  12. A Pulse Width Modulation Scheme With Zero-sequence Voltage Injection for Single Phase Three-level NPC Rectifiers

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    A single phase three-level converter (shown in Fig. 1) has been widely applied in high-speed railway electrical traction drive systems. But the main technical drawback of the three-level converter is DC-link neutral point voltage drift. In order to solve this problem, it is important to understand the cause of DC-link neutral point voltage drift.

  13. Cable Television Service; Cable Television Relay Service.

    Science.gov (United States)

    Federal Register, 1972

    1972-01-01

    The rules and regulations of the Federal Communications Commission (FCC) concerning cable television service and cable relay service are presented along with the comments of the National Cable Television Association, the National Association of Broadcasters, the Association of Maximum Service Telecasters, and a major group of program suppliers.…

  14. Propagation of terawatt-femtosecond laser pulses and its application to the triggering and guiding of high-voltage discharges

    OpenAIRE

    Ackermann, Roland

    2006-01-01

    When an ultrashort-terawatt laser pulse is propagating through the atmosphere, long filaments may develop. Their light is confined in an area of about 100 µm over distances up to several hundred meters, and an air plasma is generated along the beam path. Moreover, filamentation leads to a significant broadening of the initial pulse spectrum. These properties open the perspective to improve classical LIDAR techniques as well as to laser lightning control.In the laboratory, we have shown that t...

  15. 变频串联谐振技术在高压电缆交接试验中的应用%Application of Variable-Frequency Series Resonance Technology in Hand-over Acceptance Tests of High Voltage Power Cables

    Institute of Scientific and Technical Information of China (English)

    赵金明; 段肖华

    2012-01-01

    变频串联谐振耐压试验技术是当前高压试验的一种新方法.变频串联谐振的原理、组成及优点等进行了阐述,并对此技术在高压电缆交接试验中的应用进行了分析探讨,通过实例表明:此方法是科学、实用、高效的.%Variable-frequency series resonance withstand voltage technology is a new method widely in high voltage tests. This paper introduces the principle, composition and advantages of the technology, and discusses its applications in the acceptance tests of high voltage power cables. The actual examples show that the method is scientific and practical and efficient.

  16. Technological Aspects: High Voltage

    CERN Document Server

    Faircloth, D C

    2013-01-01

    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.

  17. Cable Tensiometer for Aircraft

    Science.gov (United States)

    Nunnelee, Mark (Inventor)

    2008-01-01

    The invention is a cable tensiometer that can be used on aircraft for real-time, in-flight cable tension measurements. The invention can be used on any aircraft cables with high precision. The invention is extremely light-weight, hangs on the cable being tested and uses a dual bending beam design with a high mill-volt output to determine tension.

  18. LOW-LOSS CABLE AND METHOD OF FABRICATION

    Science.gov (United States)

    McCarthy, R.L. et al.

    1960-09-27

    A radiation-resistant coaxial electrical cable capable of carrying very small currents at high voltages with little leakage is described. The cable comprises an inner axial conductor separated from an outer coaxial tubular conductor by annular layer of fibrous silica insulation. The silica insulation is formed by leaching boron from spun horosilicate glass and then heat treating the silica at a high temperature.

  19. Chemical oxidation of cable insulating oil contaminated soil

    NARCIS (Netherlands)

    Jinlan Xu,; Pancras, T.; Grotenhuis, J.T.C.

    2011-01-01

    Leaking cable insulating oil is a common source of soil contamination of high-voltage underground electricity cables in many European countries. In situ remediation of these contaminations is very difficult, due to the nature of the contamination and the high concentrations present. Chemical oxidati

  20. Distance Protection of Cross-Bonded Transmission Cable-Systems

    DEFF Research Database (Denmark)

    Bak, Claus Leth; F. Jensen, Christian

    2014-01-01

    In this paper the problems of protecting a cross-bonded cable system using distance protection are analysed. The combination of the desire to expand the high voltage transmission grid and the public's opinion towards new installations of overhead lines (OHL), more and more transmission cable syst...

  1. Double Layered Sheath in Accurate HV XLPE Cable Modeling

    DEFF Research Database (Denmark)

    Gudmundsdottir, Unnur Stella; Silva, J. De; Bak, Claus Leth;

    2010-01-01

    This paper discusses modelling of high voltage AC underground cables. For long cables, when crossbonding points are present, not only the coaxial mode of propagation is excited during transient phenomena, but also the intersheath mode. This causes inaccurate simulation results for high frequency ...

  2. Design, manufacture, test and delivery of a 230 kV extruded irradiated crosslinked polyethylene cable. Final report

    Energy Technology Data Exchange (ETDEWEB)

    None

    1978-01-01

    A project was initiated to develop a 230 kV solid dielectric cable for use in underground transmission. The dielectric is to be polyethylene, crosslinked by electron bombardment. Compared to the more conventional chemically crosslinked polyethylene, the irradiated cable is expected to contain less sensitive defects and thus be more suitable for a 230 kV rating. A toroidally shaped diode was developed to provide a uniform radiation dose to a thick-walled coaxial cable. The diode is to receive an output wave form obtained by ringing a Marx generator into a peaking capacitor. Initial evaluation of the toroidal diode was performed on thin plaques and tapes of insulating and semi-conducting polyethylene polymers. Additionally, some miscellaneous ethylene plastics were briefly investigated. Using a 4.8 MV Van de Graaff pulse generator in conjunction with several diode configurations, 15 to 35 kV extruded HMW-PE cables were irradiated. Dose rate, temperature, and pressure effects were evaluated. It was found that with limited dose rate it was possible to produce excellent crosslink density and uniformity at room temperature and atmospheric pressure. A subsequent 60 Hz voltage endurance test on an irradiated cable sample indicated it had long term, high stress capability. An engineering study conducted to determine an acceptable irradiator system design is reported. It was estimated that a 7 MV peak voltage at a rate of 2 to 3 pulse/sec can be provided by a Marx generator/peaking capacitor and should be capable of crosslinking a polyethylene wall thickness of approximately 2.5 cm. Based on the accumulated test results and on the performance of the 7 MV irradiator predicted, it appears feasible to continue the work effort into the next scheduled phase.

  3. Applying Diagnostics to Enhance Cable System Reliability (Cable Diagnostic Focused Initiative, Phase II)

    Energy Technology Data Exchange (ETDEWEB)

    Hartlein, Rick [Georgia Tech Research Corporation (GTRC), Atlanta, GA (United States). National Electric Energy Testing, Research and Applications Center (NEETRAC); Hampton, Nigel [Georgia Tech Research Corporation (GTRC), Atlanta, GA (United States). National Electric Energy Testing, Research and Applications Center (NEETRAC); Perkel, Josh [Georgia Tech Research Corporation (GTRC), Atlanta, GA (United States). National Electric Energy Testing, Research and Applications Center (NEETRAC); Hernandez, JC [Univ. de Los Andes, Merida (Venezuela); Elledge, Stacy [Georgia Tech Research Corporation (GTRC), Atlanta, GA (United States). National Electric Energy Testing, Research and Applications Center (NEETRAC); del Valle, Yamille [Georgia Tech Research Corporation (GTRC), Atlanta, GA (United States). National Electric Energy Testing, Research and Applications Center (NEETRAC); Grimaldo, Jose [Georgia Inst. of Technology, Atlanta, GA (United States). School of Electrical and Computer Engineering; Deku, Kodzo [Georgia Inst. of Technology, Atlanta, GA (United States). George W. Woodruff School of Mechanical Engineering

    2016-02-01

    The Cable Diagnostic Focused Initiative (CDFI) played a significant and powerful role in clarifying the concerns and understanding the benefits of performing diagnostic tests on underground power cable systems. This project focused on the medium and high voltage cable systems used in utility transmission and distribution (T&D) systems. While many of the analysis techniques and interpretations are applicable to diagnostics and cable systems outside of T&D, areas such as generating stations (nuclear, coal, wind, etc.) and other industrial environments were not the focus. Many large utilities in North America now deploy diagnostics or have changed their diagnostic testing approach as a result of this project. Previous to the CDFI, different diagnostic technology providers individually promoted their approach as the “the best” or “the only” means of detecting cable system defects.

  4. Distance and Cable Length Measurement System

    Directory of Open Access Journals (Sweden)

    Jonay Toledo

    2009-12-01

    Full Text Available A simple, economic and successful design for distance and cable length detection is presented. The measurement system is based on the continuous repetition of a pulse that endlessly travels along the distance to be detected. There is a pulse repeater at both ends of the distance or cable to be measured. The endless repetition of the pulse generates a frequency that varies almost inversely with the distance to be measured. The resolution and distance or cable length range could be adjusted by varying the repetition time delay introduced at both ends and the measurement time. With this design a distance can be measured with centimeter resolution using electronic system with microsecond resolution, simplifying classical time of flight designs which require electronics with picosecond resolution. This design was also applied to position measurement.

  5. Distance and Cable Length Measurement System

    Science.gov (United States)

    Hernández, Sergio Elias; Acosta, Leopoldo; Toledo, Jonay

    2009-01-01

    A simple, economic and successful design for distance and cable length detection is presented. The measurement system is based on the continuous repetition of a pulse that endlessly travels along the distance to be detected. There is a pulse repeater at both ends of the distance or cable to be measured. The endless repetition of the pulse generates a frequency that varies almost inversely with the distance to be measured. The resolution and distance or cable length range could be adjusted by varying the repetition time delay introduced at both ends and the measurement time. With this design a distance can be measured with centimeter resolution using electronic system with microsecond resolution, simplifying classical time of flight designs which require electronics with picosecond resolution. This design was also applied to position measurement. PMID:22303169

  6. Effect of heating samples during pulsed electron beam annealing on the open-circuit voltage of silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Laugier, A.; Barbier, D.; Doghmane, M.S.; Chemisky, G. (Institut National des Sciences Appliquees de Lyon, 69 - Villeurbanne (France))

    1983-01-01

    Defects associated with pulsed electron beam annealing of P implanted Si solar cells lead to poor Vsub(oc) (< 500mV). Their nature is discussed on the basic of S.E.M. observations, deep level transient spectroscopy study and degradation of electrical characteristics of Schottky barriers. An improved pulsed electron beam annealing process is determined, characterized by a low mean energy electron beam (10 keV) associated to a starting temperature of 450/sup 0/C and low fluences (<= 1J/cm/sup 2/). Values of Vsub(oc) similar to conventional thermal annealing are obtained.

  7. Field Test and Simulation of a 400 kV Cross-Bonded Cable System

    DEFF Research Database (Denmark)

    Gudmundsdottir, Unnur Stella; Gustavsen, Bjørn; Bak, Claus Leth

    2011-01-01

    This paper discusses cable modeling for long high voltage AC underground cables. In investigating the possibility of using long cables instead of overhead lines, the simulation results must be trustworthy. Therefore, model validation is of great importance. This paper gives a benchmark case...

  8. Analysis of Current Pulses in HeLa-Cell Permeabilization Due to High Voltage DC Corona Discharge.

    Science.gov (United States)

    Chetty, Nevendra K; Chonco, Louis; Ijumba, Nelson M; Chetty, Leon; Govender, Thavendran; Parboosing, Raveen; Davidson, Innocent E

    2016-09-01

    Corona discharges are commonly utilized for numerous practical applications, including bio-technological ones. The corona induced transfer of normally impermeant molecules into the interior of biological cells has recently been successfully demonstrated. The exact nature of the interaction of the corona discharge with a cell membrane is still unknown, however, previous studies have suggested that it is either the electric fields produced by ions or the chemical interaction of the reactive species that result in the disruption of the cell membrane. This disruption of the cell membrane allows molecules to permeate into the cell. Corona discharge current constitutes a series of pulses, and it is during these pulses that the ions and reactive species are produced. It stands to reason, therefore, that the nature of these corona pulses would have an influence on the level of cell permeabilization and cell destruction. In this investigation, an analysis of the width, rise-time, characteristic frequencies, magnitude, and repetition rate of the nanosecond pulses was carried out in order to establish the relationship between these factors and the levels of cell membrane permeabilization and cell destruction. Results obtained are presented and discussed.

  9. Frequency Dependent Losses in Transmission Cable Conductors

    DEFF Research Database (Denmark)

    Olsen, Rasmus Schmidt; Holbøll, Joachim; Guðmundsdóttir, Unnur Stella

    2011-01-01

    Denmark is taking on the exciting project of undergrounding the electricity transmission grid. In 2009 it was decided by the Danish government to underground large parts of the 400 kV and the entire 132-150 kV transmission network before the end of 2030. For ensuring network stability...... and economical gain, such severe network changes necessitate correct estimation and optimisation of load conditions in the cable grid. Both IEC and IEEE have published standards for rating transmission cables' current carrying capacity. These standards are based on assumptions of a number of parameters...... of better calculation of the AC resistance of transmission cable conductors, in particular regarding higher frequencies. In this way, also losses under harmonics can be covered. Furthermore, the model is suitable for modelling of transient attenuation in high voltage cables. The AC resistance is calculated...

  10. Insulation Degradation Diagnostic Technology to XLPE Cable

    Science.gov (United States)

    Uchida, Katsumi; Okamoto, Tatsuki

    XLPE power cables have been in use for long time now and some of them are approaching 30 years of their designed lifetime. However, under the present severe economic situation, it is necessary to use the existing apparatus as long as possible. So, degradation diagnostic methods with high reliability are needed earnestly. This paper explains the insulation degradation mechanism of XLPE power cables and the newest diagnostic methods on each voltage class. In 3.3-77kV classes, fairly high extents of the cable accidents depend on the water-tree degradation. For 3.3-6.6kV class cables, on-line diagnostic methods with high reliability to detect bridged water-trees have been developed and put in practical use. And, for 22-77kV classes, two promising off-line diagnostic methods to detect un-bridged water-trees have begun to carry out in on-site tests.

  11. A small cable tunnel inspection robot design

    Science.gov (United States)

    Zhou, Xiaolong; Guo, Xiaoxue; Huang, Jiangcheng; Xiao, Jie

    2017-04-01

    Modern city mainly rely on internal electricity cable tunnel, this can reduce the influence of high voltage over-head lines of urban city appearance and function. In order to reduce the dangers of cable tunnel artificial inspection and high labor intensity, we design a small caterpillar chassis in combination with two degrees of freedom robot with two degrees of freedom camera pan and tilt, used in the cable tunnel inspection work. Caterpillar chassis adopts simple return roller, damping structure. Mechanical arm with three parallel shafts, finish the up and down and rotated action. Two degrees of freedom camera pan and tilt are used to monitor cable tunnel with 360 °no dead angle. It looks simple, practical and efficient.

  12. Self-contained cable systems offer advantages

    Energy Technology Data Exchange (ETDEWEB)

    Morello, A.S.; Occhini, E.

    1977-05-01

    Low-pressure oil-filled (LPOF) cable systems, while seldom used in this country, have several advantages of interest to engineers. Less oil and insulating paper is required for low-pressure than for the more commonly used high-pressure systems because of the single core. The lower pessure offers safety features in the event of accidental oil loss. LPOF cables are used internationally because of their good thermal characteristics. Applications besides ac transmission lines include underground and submarine cables, such as those connecting islands with mainland facilities. Cooling can be accomplished either by circulating oil inside the central duct or circulating water through parallel nonmetallic pipes. Forced-cooling of the LPOF cables is less complicated, which allows them to have higher current ratings and makes them more adaptable to thermal transients. Conductor cooling, which increases capacity but prohibits overloads in LPOF cables, is the only system available to high voltage (HVDC) cables. Several experimental and demonstration cable systems are described. (DCK)

  13. Safer cables; Des cables plus surs

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2005-02-01

    Sixteen years after its adoption, the European construction products directive (CPD) will have soon a strong impact on the characteristics of electrical and communication cables used in European buildings and facilities. Among the six main requirements of this directive, the fire protection safety is a growing up concern and the electric cables have to be tested with respect to their fire resistance to become conformable with the directive. The cable industry has taken up the challenge. (J.S.)

  14. REGIMES ANALYSIS OF THE VOLTAGE PULSE REGULATORS ON THE BASIC OF THE INVARIANCE PROPERTY OF THE CONTROL CHARACTERISTICS

    Directory of Open Access Journals (Sweden)

    Penin A.A.

    2009-04-01

    Full Text Available Regime characteristic values are determined relative to character values of regulation curve of switching regulator. Regime changing and the correspondence between various regime parameters are examined as a geometric (projective transformation. This makes possible to validate the regime definition, to restrict the range of their variation on the rising area of the control characteristic, to realize the linearization of this characteristic, to compare different pulse regulators.

  15. Land cable systems for the connection of wind farms

    Energy Technology Data Exchange (ETDEWEB)

    Brakelmann, Heinrich; Brueggmann, Jan [Duisburg-Essen Univ., Duisburg (Germany). Inst. of Energy Transport and -Storage; Frisch, Walter [IFK Gesellschaft m.b.H., Salzburg (Austria). CEO

    2011-07-01

    This paper reports about the application of earth ploughs for the installation of high-voltage and extra-high-voltage cables. In the first part, there is a general description of the ploughing process with its features, the plough and the plough-cavity itself as well as some impressions of installation process. The second part analyzes the current rating of a cable system, installed by earth ploughs. Beside steady-state loads, time varying loads are assumed. The temperature profile in the soil is displayed and conclusions for the moisture content of the soil are drawn. The application of new filling materials for cables in pipes is introduced. (orig.)

  16. Estudio de la cargabilidad de cables de alta tensión de aislamiento sólido con las variaciones periódicas de la carga; Study of the current capacity of solid insulation high voltage cables with periodical changes of load

    Directory of Open Access Journals (Sweden)

    Juan F Zuñinga

    2011-02-01

    Full Text Available Se plantean los resultados obtenidos al introducir una corrección al método desarrollado en el CIPEL para elcálculo de la cargabilidad de cables soterrados considerando las variaciones periódicas de la curva de cargadiaria y la impedancia compleja del medio que rodea a la instalación a partir del empleo de funciones Bessel yHankel. La validación de la corrección propuesta se realizó mediante el cálculo, con y sin la corrección planteada,de la temperatura superficial de cables en servicio por el método de cálculo propuesto y su comparación conlos medidos en la superficie de dichos cables  This work presents the results obtaines after the introduction of a correction to the method developed in theCIPEL to calculate the current capacity of underground cables considering the periodical chnages of the loadchanges of the daily load curve and the complex impedance of the enviroment sorrounding the installation usingBessel and Hankel funtions.The validity of the proposed correction was carried out calculating the surfacetemperature of the cables in service by means of the calculating method  with and whithout the correction  andthe  comparison of these values with the temperature mesured on the surface of the cables

  17. Can undersea voltage measurements detect tsunamis?

    Digital Repository Service at National Institute of Oceanography (India)

    Manoj, C.; Kuvshinov, A.; Neetu, S.; Harinarayana, T.

    The movement of electrically conducting ocean water in the ambient geomagnetic field induces secondary electric and magnetic fields in the oceans. Ocean water transport is now routinely inferred from undersea cable voltage data. We try to answer...

  18. 晶体管驱动的阶跃二极管大幅度窄脉冲源%Narrow Pulse Source of High-voltag Based on Step Recovery Diode Driven by Transistor

    Institute of Scientific and Technical Information of China (English)

    杨金钢; 谢嘉; 李红英; 和先孟; 周祖国

    2012-01-01

    Current ways of generating narrow pulse is difficult to generate a high-voltage narrow-pulse or a narrow-pulse of voltage higher than working voltage. This paper presented a method to generate a high-voltage narrow-pulse by using a step recovery diode at low voltage which was driven by bipolar transistor. The basic principle of this method was to realize the generation of a high-voltage narrow-pulse by using step characteristic of step recovery diode, and the excitation source form was redesigned based on bipolar driving. Simulation results showed that the circuit's output pulse voltage was not lower than working voltage and had advantages of simple circuit,adjustable pulse width,prone to be integrated,etc. This method was suitable to generate narrow-pulse for ultra-wideband communication system and played an important role in increasing the detecting distance of ultra-wideband fuze.%目前纳秒级窄脉冲源的实现方法有很多,但很难用低电源产生大幅度窄脉冲,或是实现输出脉冲幅度大于其工作电压.提出了一种采用阶跃恢复二极管在双极型晶体管驱动下实现工作于低电压的大幅度纳秒级窄脉冲源的方法.该方法利用阶跃管的阶跃特性,同时利用晶体管的驱动,对阶跃管的激励源形式进行改进设计,实现大幅度窄脉冲.仿真和测试结果表明:该电路具有输出脉冲幅度不小于工作电压的特点,并具有电路简单、脉宽可调、易于集成等优点,适用于超宽带通信系统中窄脉冲信号的产生.

  19. UtilityTelecom_CABLE2005

    Data.gov (United States)

    Vermont Center for Geographic Information — The VT Cable System dataset (CABLE2005) includes lines depicting the extent of Vermont's cable system as of 12/31/2005. Numerous cable companies provide service in...

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

    Science.gov (United States)

    Bearden, Douglas

    2012-01-01

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

  1. Simulations of atmospheric pressure discharge in a high-voltage nanosecond pulse using the particle-in-cell Monte Carlo collision model in noble gases

    Science.gov (United States)

    Shi, Feng; Wang, Dezhen; Ren, Chunsheng

    2008-06-01

    Atmospheric pressure discharge nonequilibrium plasmas have been applied to plasma processing with modern technology. Simulations of discharge in pure Ar and pure He gases at one atmospheric pressure by a high voltage trapezoidal nanosecond pulse have been performed using a one-dimensional particle-in-cell Monte Carlo collision (PIC-MCC) model coupled with a renormalization and weighting procedure (mapping algorithm). Numerical results show that the characteristics of discharge in both inert gases are very similar. There exist the effects of local reverse field and double-peak distributions of charged particles' density. The electron and ion energy distribution functions are also observed, and the discharge is concluded in the view of ionization avalanche in number. Furthermore, the independence of total current density is a function of time, but not of position.

  2. Effects of adsorbed proteins, an antifouling agent and long-duration DC voltage pulses on the impedance of silicon-based neural microelectrodes.

    Science.gov (United States)

    Sommakia, Salah; Rickus, Jenna L; Otto, Kevin J

    2009-01-01

    The successful use of implantable neural microelectrodes as neuroprosthetic devices depends on the mitigation of the reactive tissue response of the brain. One of the factors affecting the ultimate severity of the reactive tissue response and the in vivo electrical properties of the microelectrodes is the initial adsorption of proteins onto the surface of the implanted microelectrodes. In this study we quantify the increase in microelectrode impedance magnitude at physiological frequencies following electrode immersion in a 10% bovine serum albumin (BSA) solution. We also demonstrate the efficacy of a common antifouling molecule, poly(ethylene glycol) (PEG), in preventing a significant increase in microelectrode impedance. In addition, we show the feasibility of using long-duration DC voltage pulses to remove adsorbed proteins from the microelectrode surface.

  3. Concept design of the high voltage transmission system for the collider tunnel

    Science.gov (United States)

    Norman, L. S.

    1992-03-01

    In order to provide electrical service to the Superconducting Super Collider Laboratory (SSCL) 54-mile-circumference collider of 125 MVA at 69 kV or 155 MVA at 138 kV of distributed power, it must be demonstrated that the concept design for a high-voltage transmission system can meet the distribution requirements of the collider electrical system with its cryogenic system's large motor loads and its pulsed power technical systems. It is a practical design, safe for operating personnel and cost-effective. The normal high-voltage transmission techniques of overhead and underground around the 54-mile collider tunnel could not be applied because of technical and physical constraints, or was environmentally unacceptable. The approach taken to solve these problems is the installation of 69-kV or 138-kV exposed solid dielectric transmission cable inside the collider tunnel with the superconducting magnets, cryogenic piping, electrical medium, and low-voltage distribution systems, and electronic/instrumentation wiring systems. This mixed-use approach has never been attempted in a collider tunnel. Research into all aspects of the engineering and installation problems and consultation with transmission cable manufacturers, electrical utilities, and European entities with similar installations--such as the Channel Tunnel--demonstrate that the concept design is feasible and practical. This paper presents a history of the evolution of the concept design. Design studies are underway to determine the system configuration and voltages. Included in this report are tunnel transmission cable system considerations and evaluation of solid dielectric high-voltage cable design.

  4. High- voltage Pulsed Electric Field Sterilization Equipment and Flow Control%高压脉冲电场灭菌设备及其流量控制

    Institute of Scientific and Technical Information of China (English)

    林荣华; 李伟光

    2012-01-01

    In order to optimize the sterilization effect of high-voltage pulsed electric field sterilization equipment, this paper analyzes its function according the tactors of the enfluence on the system, designs the overall structure and PLC-based flow control system by the way of frequency control of motor speed, describes the structure and principle of high-voltage pulse generator and the theory and realization of the flow control based on frequency control as well as the realization of communication between inverters and PLC with RS-485. The result shows that the equipment is able to control and adjust key process parameters well, comtro the flow by a simple and reliable way, and achieve high effective and fast sterilization.%为优化高压脉冲电场灭菌设备的灭菌效果,根据其影响因素进行了系统功能需求分析,设计了设备的总体架构,采用变频调速的方法,设计了基于PLC的流量控制系统.简述了高压脉冲发生器的结构及原理,重点介绍了基于变频调速的流量控制原理与实现,变频器与PLC的RS - 485通信的实现.实验表明,设备实现了关键工艺参数可调可控,运行效果良好,简单可靠地实现了流量的控制,实现了快速高效灭菌.

  5. 振荡电压下电缆典型缺陷局部放电的统计特征及定位研究%Statistical Characteristic and Location of Partial Discharge Caused by Typical Defects in Power Cable Under Damped Oscillation Voltage

    Institute of Scientific and Technical Information of China (English)

    常文治; 葛振东; 时翔; 马国明; 陈志勇; 崔潇; 李成榕; 陈雪薇; 唐志国

    2013-01-01

    Oscillating wave test system (OWTS) possesses such advantages as calibratable detection results,not causing deterioration in power cable insulation,especially suitable to field testing and so on while it is utilized to detect partial discharge (PD) occurred at the position of power cable,where defects exist,under damped oscillation voltage.To research statistical characteristic of PD caused by power cable defects under damped oscillation voltage,four circumstances are preset to simulate four typical cable defects,they are:A) incorrect winding-up of insulation adhesive tape at intermediate joint core,B) a nadel at the surface of conductor core pricking into insulation layer of cable,C) breakage of outer semiconducting layer of cable body and D) a extrinsic metal pin pricking into main insulation layer of cable but not touching with both surfaces of conductor core and inner semiconducting layer.Using self-developed OWTS,the PD signals caused by preset circumstances are measured,and then the phasic statisticalcircumstances are measured,and then the phasic statistical characteristics of PD caused by the four circumstances with different severities are analyzed by the phase analysis of oscillation voltage.Analysis results show that all location errors of the four preset circumstances do not exceed 10cm.The PD signals caused by circumstance A concentrate within two phase intervals of oscillation voltage from 20° to 70° and from 200° to 280° respectively and the densest distribution appears nearby 230°,and in grey image they sparsely distribute in triangle shape,and the discharge density in the negative half-cycle is slightly denser than in positive half-cycle; the PD signals caused by circumstance B concentrate within two phase intervals of oscillation voltage from 20° to 110° and from 200° to 280° respectively and in grey image they symmetrically distribute in rectangular shape,and the distribution densities in positive and negative half-cycle are basically

  6. Demonstration of InAlN/AlGaN high electron mobility transistors with an enhanced breakdown voltage by pulsed metal organic chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Xue, JunShuai, E-mail: junshuaixue@hotmail.com; Zhang, JinCheng; Hao, Yue [Key Laboratory of Wide Band Gap Semiconductor Materials and Devices, School of Microelectronics, Xidian University, Xi' an 710071 (China)

    2016-01-04

    In this work, InAlN/AlGaN heterostructures employing wider bandgap AlGaN instead of conventional GaN channel were grown on sapphire substrate by pulsed metal organic chemical vapor deposition, where the nominal Al composition in InAlN barrier and AlGaN channel were chosen to be 83% and 5%, respectively, to achieve close lattice-matched condition. An electron mobility of 511 cm{sup 2}/V s along with a sheet carrier density of 1.88 × 10{sup 13 }cm{sup −2} were revealed in the prepared heterostructures, both of which were lower compared with lattice-matched InAlN/GaN due to increased intrinsic alloy disorder scattering resulting from AlGaN channel and compressively piezoelectric polarization in barrier, respectively. While the high electron mobility transistor (HEMT) processed on these structures not only exhibited a sufficiently high drain output current density of 854 mA/mm but also demonstrated a significantly enhanced breakdown voltage of 87 V, which is twice higher than that of reported InAlN/GaN HEMT with the same device dimension, potential characteristics for high-voltage operation of GaN-based electronic devices.

  7. Demonstration of InAlN/AlGaN high electron mobility transistors with an enhanced breakdown voltage by pulsed metal organic chemical vapor deposition

    Science.gov (United States)

    Xue, JunShuai; Zhang, JinCheng; Hao, Yue

    2016-01-01

    In this work, InAlN/AlGaN heterostructures employing wider bandgap AlGaN instead of conventional GaN channel were grown on sapphire substrate by pulsed metal organic chemical vapor deposition, where the nominal Al composition in InAlN barrier and AlGaN channel were chosen to be 83% and 5%, respectively, to achieve close lattice-matched condition. An electron mobility of 511 cm2/V s along with a sheet carrier density of 1.88 × 1013 cm-2 were revealed in the prepared heterostructures, both of which were lower compared with lattice-matched InAlN/GaN due to increased intrinsic alloy disorder scattering resulting from AlGaN channel and compressively piezoelectric polarization in barrier, respectively. While the high electron mobility transistor (HEMT) processed on these structures not only exhibited a sufficiently high drain output current density of 854 mA/mm but also demonstrated a significantly enhanced breakdown voltage of 87 V, which is twice higher than that of reported InAlN/GaN HEMT with the same device dimension, potential characteristics for high-voltage operation of GaN-based electronic devices.

  8. Parametric study on coupling loss in subsize ITER Nb3Sn cabled specimen

    NARCIS (Netherlands)

    Nijhuis, Arend; Kate, ten Herman H.J.; Bruzzone, Pierluigi; Bottura, Luca

    1996-01-01

    The cable in conduit conductors for the various ITER coils are required to function under pulse conditions and fields up to 13 T. A parametric study, restricted to a limited variation of the reference cable lay out, is carried out to clarify the quantitative impact of various cable parameters on the

  9. Potential applications of cable television (CATV) to the FEMA (Federal Emergency Management Agency) communications mission

    Science.gov (United States)

    Gilligan, D. D.; Abtahi, H.; Becker, J. R., Jr.; Frantz, S. W.

    1983-07-01

    The history, technology, economics, regulation and vulnerability to electromagnetic pulse (EMP) effects of cable television are examined. Recommendations are made concerning FEMA integration of cable television systems into the FEMA emergency communications system and the protection of cable television systems for EMP effects.

  10. Parametric studh on coupling loss in subsize ITER Nb3Sn cabled specimens

    NARCIS (Netherlands)

    Nijhuis, Arend; ten Kate, Herman H.J.; Bruzzone, Pierluigi; Bottura, Luca

    1996-01-01

    The cable in conduit conductors for the various ITER coils are required to function under pulse conditions and fields up to 13 T. A parametric study, restricted to a limited variation of the reference cable lay out, is carried out to clarify the quantitative impact of various cable parameters on the

  11. Vacuum breakdown limit and quantum efficiency obtained for various technical metals using dc and pulsed voltage sources

    CERN Document Server

    Le Pimpec, F; Paraliev, M; Ganter, R; Hauri, C; Ivkovic, S; 10.1116/1.3478300

    2010-01-01

    For the SwissFEL project, an advanced high gradient low emittance gun is under development. Reliable operation with an electric field, preferably above 125 MV/m at a 4 mm gap, in the presence of an UV laser beam, has to be achieved in a diode configuration in order to minimize the emittance dilution due to space charge effects. In the first phase, a DC breakdown test stand was used to test different metals with different preparation methods at voltages up to 100 kV. In addition high gradient stability tests were also carried out over several days in order to prove reliable spark-free operation with a minimum dark current. In the second phase, electrodes with selected materials were installed in the 250 ns FWHM, 500 kV electron gun and tested for high gradient breakdown and for quantum efficiency using an ultra-violet laser.

  12. Efficiency enhancement of TiO2 (active material) solar cell by inserting copper particles grown with pulse voltage electroplating method

    Science.gov (United States)

    Rokhmat, Mamat; Sutisna; Wibowo, Edy; Khairurrijal; Abdullah, Mikrajuddin

    2017-01-01

    Here, we report the manufacture of a solar cell using TiO2 nanoparticles as photon absorbers and copper bridges inserted between the TiO2 particles. The copper bridges were synthesized by the pulse voltage electroplating method, and the effect of the pulse duty cycle was explored. The amount of copper deposited between TiO2 particles can be controlled by varying the duty cycles and the deposition time. We found that the cell fabricated by the deposition of copper at duty cycles of 60% and a deposition time of 30 s exhibited the highest efficiency (2.21%). Efficiency was improved to 3.5% following the post-treatment of the cell with NaOH. We also proposed a simple mathematical model to explain the dependence of the efficiency on the amount of copper. Efficiencies of more than 3% for solar cells made by a simple method and using inexpensive materials make these solar cells promising competition for the current commercial solar cells.

  13. Tuning and Cold Test of a Four-Vane RFQ with Ramped Inter-Vane Voltage for the Compact Pulsed Hadron Source

    Science.gov (United States)

    Xing, Qing-Zi; Du, Lei; Zheng, Shu-Xin; Guan, Xia-Ling; Li, Jian; Cai, Jin-Chi; Gong, Cun-Kui; Wang, Xue-Wu; Tang, Chuan-Xiang; James, Billen; James, Stovall; Lloyd, Young

    2013-05-01

    A four-vane radio-frequency quadrupole (RFQ) accelerator is under construction for the Compact Pulsed Hadron Source (CPHS) project at Tsinghua University. The 3 m-long RFQ will accelerate a 50keV proton beam from the ECR source to 3MeV, and deliver it to the downstream drift tube linac (DTL) with a peak current of 50mA, pulse length of 0.5 ms and beam duty factor of 2.5%. The inter-vane voltage is designed to increase with the longitudinal position to produce a short RFQ. Coupling plates are therefore not necessary. The cavity cross section and vane-tip geometry are tailored as a function of the longitudinal position, while limiting the peak surface electric field to 1.8 Kilpatrick. The RFQ is designed, manufactured, and installed at Tsinghua University. We also present the tuning and cold test results of the RFQ accelerator. After final tuning, the relative error of the quadrupole field is within 2%, and the admixture of the two dipole modes are less than 2% of the quadrupole mode.

  14. Cable Television: Franchising Considerations.

    Science.gov (United States)

    Baer, Walter S.; And Others

    This volume is a comprehensive reference guide to cable television technology and issues of planning, franchising, and regulating a cable system. It is intended for local government officials and citizens concerned with the development of cable television systems in their communities, as well as for college and university classes in…

  15. Cable Television: Franchising Considerations.

    Science.gov (United States)

    Baer, Walter S.; And Others

    This volume is a comprehensive reference guide to cable television technology and issues of planning, franchising, and regulating a cable system. It is intended for local government officials and citizens concerned with the development of cable television systems in their communities, as well as for college and university classes in…

  16. Colleges and Cable Franchising.

    Science.gov (United States)

    Glenn, Neal D.

    After noting issues of audience appeal and financial and philosophical support for educational broadcasting, this paper urges community colleges to play an active role in the process of cable franchising. The paper first describes a cable franchise as a contract between a government unit and the cable television (CATV) company which specifies what…

  17. Cable Supported Bridges

    DEFF Research Database (Denmark)

    Gimsing, Niels Jørgen

    Cable supported bridges in the form of suspension bridges and cable-stayed bridges are distinguished by their ability to overcome large spans.The book concentrates on the synthesis of cable supported bridges, covering both design and construction aspects. The analytical part covers simple methods...

  18. Negative differential mobility for negative carriers as revealed by space charge measurements on crosslinked polyethylene insulated model cables

    Science.gov (United States)

    Teyssedre, G.; Vu, T. T. N.; Laurent, C.

    2015-12-01

    Among features observed in polyethylene materials under relatively high field, space charge packets, consisting in a pulse of net charge that remains in the form of a pulse as it crosses the insulation, are repeatedly observed but without complete theory explaining their formation and propagation. Positive charge packets are more often reported, and the models based on negative differential mobility(NDM) for the transport of holes could account for some charge packets phenomenology. Conversely, NDM for electrons transport has never been reported so far. The present contribution reports space charge measurements by pulsed electroacoustic method on miniature cables that are model of HVDC cables. The measurements were realized at room temperature or with a temperature gradient of 10 °C through the insulation under DC fields on the order 30-60 kV/mm. Space charge results reveal systematic occurrence of a negative front of charges generated at the inner electrode that moves toward the outer electrode at the beginning of the polarization step. It is observed that the transit time of the front of negative charge increases, and therefore the mobility decreases, with the applied voltage. Further, the estimated mobility, in the range 10-14-10-13 m2 V-1 s-1 for the present results, increases when the temperature increases for the same condition of applied voltage. The features substantiate the hypothesis of negative differential mobility used for modelling space charge packets.

  19. Design and construction of double-Blumlein HV pulse power supply

    Indian Academy of Sciences (India)

    Deepak K Gupta; P I John

    2001-10-01

    A double Blumlein pulse generator is constructed using a coaxial cable. This power supply is capable of providing a voltage up to 20 kV across a matched load and 40kV across an open load with a charging voltage of 10 kV. It is designed to provide a pulse width of 110ns. A rise time of ∼10ns is obtained with present spark gap. A rotating spark gap is also designed and constructed to get a pulse repetition rate of 25Hz. Although, in the present work this pulse generator is used to study the streamer discharge in air, it is useful in many other applications also.

  20. Cu2O/Ag co-deposited TiO2 nanotube array film prepared by pulse-reversing voltage and photocatalytic properties

    Science.gov (United States)

    Ding, Qi; Chen, Suiyuan; Shang, Fanmin; Liang, Jing; Liu, Changsheng

    2016-12-01

    In this experiment, Cu2O/Ag co-deposition TiO2 nanotube array (Cu2O-Ag-TNT) film was prepared on pure Ti substrate with the method of combining anodic oxidation and electrodeposition by pulse-reversing voltage power supply in the electrolyte of NH4F, ethylene glycol, CuNO3 · 3H2O and AgNO3. The morphology, phase, chemical composition, photocatalytic property and mechanism of the nanotube array film were studied by means of scanning electron microscopy, energy dispersive x-ray spectroscopy, x-ray diffraction, x-ray photoelectron spectroscopy, transmission electron microscopy, UV-vis diffuse reflectance spectra, photoluminescence and photocatalytic degradation under visible light. The results showed that the depositional Cu2O and Ag existed in two forms, being the small-particle dispersion and large-particle sedimentary phase in the nanotube arrays: Cu2O-Ag-TNTs for different doping amounts of Ag could be prepared by adjusting the concentration of AgNO3 and the reverse voltages; with changing of the doping amount of Ag, the band gap and photo-generated electron-hole pair recombination rate also changed, and under the conditions of annealing and the optimized process parameter, the band gap of the nanotube arrays narrowed 0.49 eV and the rate of electron and pair recombination decreased noticeably; the nanotube array film for the concentration of 0.5 cm2 ml-1 degraded the methylene blue of 8 mg L-1, and the degradation rate reached above 98%. The co-deposition Cu2O-Ag-TNT film prepared by the one-step method performed well in the field of photocatalysis under visible light.

  1. SVPWM Technique with Varying DC-Link Voltage for Common Mode Voltage Reduction in a Matrix Converter and Analytical Estimation of its Output Voltage Distortion

    Science.gov (United States)

    Padhee, Varsha

    Common Mode Voltage (CMV) in any power converter has been the major contributor to premature motor failures, bearing deterioration, shaft voltage build up and electromagnetic interference. Intelligent control methods like Space Vector Pulse Width Modulation (SVPWM) techniques provide immense potential and flexibility to reduce CMV, thereby targeting all the afore mentioned problems. Other solutions like passive filters, shielded cables and EMI filters add to the volume and cost metrics of the entire system. Smart SVPWM techniques therefore, come with a very important advantage of being an economical solution. This thesis discusses a modified space vector technique applied to an Indirect Matrix Converter (IMC) which results in the reduction of common mode voltages and other advanced features. The conventional indirect space vector pulse-width modulation (SVPWM) method of controlling matrix converters involves the usage of two adjacent active vectors and one zero vector for both rectifying and inverting stages of the converter. By suitable selection of space vectors, the rectifying stage of the matrix converter can generate different levels of virtual DC-link voltage. This capability can be exploited for operation of the converter in different ranges of modulation indices for varying machine speeds. This results in lower common mode voltage and improves the harmonic spectrum of the output voltage, without increasing the number of switching transitions as compared to conventional modulation. To summarize it can be said that the responsibility of formulating output voltages with a particular magnitude and frequency has been transferred solely to the rectifying stage of the IMC. Estimation of degree of distortion in the three phase output voltage is another facet discussed in this thesis. An understanding of the SVPWM technique and the switching sequence of the space vectors in detail gives the potential to estimate the RMS value of the switched output voltage of any

  2. Cable Television for Librarians. Cable Television Primer

    Science.gov (United States)

    Briscoe, Wallace C.

    1973-01-01

    The development of cable television, its present state, and future prospects, including a possible role for libraries, are discussed. (Other conference materials are LI 503071 and 503073 through 503084.) (SJ)

  3. Simulation Analysis of the Electro-Magnetic Transient on High Voltage Submarine Cable of the Offshore Wind Farms%海上风电场海底高压电缆电磁暂态过程的仿真分析

    Institute of Scientific and Technical Information of China (English)

    黄辉; 郑明; 蓝锦标; 李迪

    2012-01-01

    In order to better determine the selection requirements of the high voltage submarine cable of the wind farms, the corresponding submarine cable simulation model is built using PSCAD/EMTDC software. The simulation is made for frequency overvoltage, switching overvoltage and lightning overvaltage with different characteristics of the transient process. Effects of the three kinds of overvoltage on the cable insulation are also considered in different system conditions. For switching overvoltage, the study is focused on the influence of the closing resistance on the overvoltage, while for lightning overvoltage focused on the lightning intruding to transmission lines. The simulation results show that the submarine cable structure parameters of each layer exert different impacts on the submarine cable electro-magnetic transient, and the conductor layer, insulation layer and HDPE layer have more remarkable impacts. In addition, the material of the sheath layer and the main insulation layer have impacts on the electro -magnetic transient.%为了能更好地确定海上风电场海底高压电缆的选型要求,使用PSCAD/EMTDC软件建立相应的海上风电场仿真计算模型.针对海上风电场工频过电压、操作过电压和雷电过电压这3种电磁暂态过程的不同特点,进行仿真,并且考虑了不同的系统条件下上述3种过电压对电缆绝缘的影响.在操作过电压中,重点研究了合闸电阻对过电压的影响;而在雷电过电压中重点研究的是架空线路受雷电侵入波的过电压.仿真结果表明,海底电缆各层的结构参数对海底电缆的电磁暂态有着不同程度的影响,其中导体层、绝缘层、HDPE层对海底电缆的电磁暂态影响尤为明显.另外,海底高压电缆的护套层材料和主绝缘层材料也对电磁暂态有影响.

  4. Cable Tester Box

    Science.gov (United States)

    Lee, Jason H.

    2011-01-01

    Cables are very important electrical devices that carry power and signals across multiple instruments. Any fault in a cable can easily result in a catastrophic outcome. Therefore, verifying that all cables are built to spec is a very important part of Electrical Integration Procedures. Currently, there are two methods used in lab for verifying cable connectivity. (1) Using a Break-Out Box and an ohmmeter this method is time-consuming but effective for custom cables and (2) Commercial Automated Cable Tester Boxes this method is fast, but to test custom cables often requires pre-programmed configuration files, and cables used on spacecraft are often uniquely designed for specific purposes. The idea is to develop a semi-automatic continuity tester that reduces human effort in cable testing, speeds up the electrical integration process, and ensures system safety. The JPL-Cable Tester Box is developed to check every single possible electrical connection in a cable in parallel. This system indicates connectivity through LED (light emitting diode) circuits. Users can choose to test any pin/shell (test node) with a single push of a button, and any other nodes that are shorted to the test node, even if they are in the same connector, will light up with the test node. The JPL-Cable Tester Boxes offers the following advantages: 1. Easy to use: The architecture is simple enough that it only takes 5 minutes for anyone to learn how operate the Cable Tester Box. No pre-programming and calibration are required, since this box only checks continuity. 2. Fast: The cable tester box checks all the possible electrical connections in parallel at a push of a button. If a cable normally takes half an hour to test, using the Cable Tester Box will improve the speed to as little as 60 seconds to complete. 3. Versatile: Multiple cable tester boxes can be used together. As long as all the boxes share the same electrical potential, any number of connectors can be tested together.

  5. 高压脉冲电场对微生物的灭活作用研究进展%Research Progress in the Effect of High-voltage Pulsed Electric Field on Microorganism Inactivation

    Institute of Scientific and Technical Information of China (English)

    陈新梅; 薛文静; 赵元

    2016-01-01

    Objective:To review the inactivation effect of high-voltage pulsed electric field on microorganism to provid theoretical basis for the further research and sterilization application of high-voltage pulsed electric field. Methods:The combination of high-volt-age pulse electric field, microbiology and pulse electric field as the keywords, the research results of high-voltage pulsed electric field on microbial inactivation in PubMed, CNKI, VIP Chinese journal full text database and Wanfang database during 2010 and 2015 were retrieved, summarized and reviewed. Results:As a non-thermal sterilization technology, high-voltage pulsed electric field not only had the characteristics of short sterilization time, narrow increasing extent of temperature and low energy consumption, but also could keep the original flavor of food. Conclusion:With the development of related technology, high-voltage pulsed electric field is expected to re-alize industrialization.%目的::综述高压脉冲电场对微生物的灭活作用,为进一步研究和应用高压脉冲电场灭菌提供理论基础。方法:以“高压脉冲电场”、“微生物”、“Pulse Electric Field”等组合为关键词,检索2010~2015年PubMed、中国知网、维普中文期刊全文数据库、万方数据库中有关高压脉冲电场对微生物的灭活作用的研究成果,进行总结和综述。结果:高压脉冲电场作为一种非热灭菌技术,不仅具有灭菌时间短、升温幅度小、耗能少的特点,还能保持食品原有风味不变。结论:随着相关技术的发展,高压脉冲电场有望实现产业化。

  6. Generalized cable theory for neurons in complex and heterogeneous media.

    Science.gov (United States)

    Bédard, Claude; Destexhe, Alain

    2013-08-01

    Cable theory has been developed over the last decade, usually assuming that the extracellular space around membranes is a perfect resistor. However, extracellular media may display more complex electrical properties due to various phenomena, such as polarization, ionic diffusion, or capacitive effects, but their impact on cable properties is not known. In this paper, we generalize cable theory for membranes embedded in arbitrarily complex extracellular media. We outline the generalized cable equations, then consider specific cases. The simplest case is a resistive medium, in which case the equations recover the traditional cable equations. We show that for more complex media, for example, in the presence of ionic diffusion, the impact on cable properties such as voltage attenuation can be significant. We illustrate this numerically, always by comparing the generalized cable to the traditional cable. We conclude that the nature of intracellular and extracellular media may have a strong influence on cable filtering as well as on the passive integrative properties of neurons.

  7. VLF Tan Delta Measurement for Used XLPE Power Cables

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Woo Sang; Ha, Che Wung; Joo, Kwang Ho [Korea Hydro and Nuclear Power Co., Daejeon (Korea, Republic of)

    2011-05-15

    Medium voltage power cables in nuclear power plants are currently managed through the visual inspection or by monitoring environmental factors such as the temperature and radiation levels. However, these methods are insufficient to monitor aging degradation of power cables. The NRC requires an additional monitoring program to detect the aged degradation, especially for safety-related power cables which are inaccessible or installed underground. EPRI suggested that very low frequency (VLF) tan {delta} test be included in MV power cable diagnostic programs. In addition, the VLF tan {delta} test was recently adopted for domestic submarine distribution cable diagnostics. KEPRI suggested that the impacts of leakage current should be controlled in VLF tan {delta} test for the submarine cables. As a pre-process to develop such a program, tan {delta} tests have been performed for 4.16 kV cables which were removed from the domestic nuclear power plant after approximate 30 years of service to analyze the degradation of long time serviced cables and the effect of leakage current from the both ends of cables

  8. 高压脉冲电场灭菌方法研究概况%Research on the High-voltage Pulsed Electric Field Sterilization Method

    Institute of Scientific and Technical Information of China (English)

    陈新梅; 李莹; 陈新华

    2014-01-01

    The high-voltage pulsed electric field (PEF) sterilization has significant advantages such as a short process-ing time,low energy consumption,small temperature rise,high sterilization rate and not affecting the effective components of drugs,and so on. Based on the review of the mechanism of PEF sterilization,sterilization devices and the possible influ-encing factors,and the comparison of other sterilization methods,the evaluation of the PEF sterilization method was made and the existing problems and commercial prospects in the fields of food and pharmaceuticals were discussed.%高压脉冲电场灭菌具有处理时间短、耗能低、升温小、灭菌率高、不影响药物的有效成分等显著优点,本文通过对高压脉冲电场灭菌作用机理、灭菌装置、可能的影响因素总结及与其他灭菌方式的比较,对高压脉冲电场灭菌方式进行评价,并探讨其现存问题及在食品、药品领域的应用前景。

  9. A new technique to study transient conductivity under pulsed monochromatic light in Cr-doped GaAs using acoustoelectric voltage measurement

    Science.gov (United States)

    Tabib-Azar, Massood

    1991-01-01

    The transient conductivity of high-resistivity Bridgman-grown Cr-doped GaAs under pulsed monochromatic light is monitored using transverse acoustoelectric voltage (TAV) at 83 K. Keeping the photon flux constant, the height and transient time constant at the TAV are used to calculate the energy dependence of the trap density and its cross section, respectively. Two prominent trap profiles with peak trap densities of approximately 10 to the 17th/cu cm eV near the valence and the conduction bands are detected. These traps have very small capture cross sections in the range of 10 to the -23 to 10 to the -21st cm sq. A phenomenon similar to the persistent photoconductivity with transient time constants in excess of a few seconds in high-resistivity GaAs at T = 83 K is also detected using this technique. These long relaxation times are readily explained by the spatial separation of the photo-excited electron-hole pairs and the small capture cross section and large density of trap distribution near the conduction band.

  10. Development of cable fed flash X-ray (FXR) system

    Science.gov (United States)

    Menon, Rakhee; Mitra, S.; Patel, A. S.; Kumar, R.; Singh, G.; Senthil, K.; Kumar, Ranjeet; Kolge, T. S.; Roy, Amitava; Acharya, S.; Biswas, D.; Sharma, Archana

    2017-08-01

    Flash X-ray sources driven by pulsed power find applications in industrial radiography, and a portable X-ray source is ideal where the radiography needs to be taken at the test site. A compact and portable flash X-ray (FXR) system based on a Marx generator has been developed with the high voltage fed to the FXR tube via a cable feed-through arrangement. Hard bremsstrahlung X-rays of few tens of nanosecond duration are generated by impinging intense electron beams on an anode target of high Z material. An industrial X-ray source is developed with source size as low as 1 mm. The system can be operated from 150 kV to 450 kV peak voltages and a dose of 10 mR has been measured at 1 m distance from the source window. The modeling of the FXR source has been carried out using particle-in-cell and Monte Carlo simulations for the electron beam dynamics and X-ray generation, respectively. The angular dose profile of X-ray has been measured and compared with the simulation.

  11. Electrical power cable engineering

    CERN Document Server

    Thue, William A

    2011-01-01

    Fully updated, Electrical Power Cable Engineering, Third Edition again concentrates on the remarkably complex design, application, and preparation methods required to terminate and splice cables. This latest addition to the CRC Press Power Engineering series covers cutting-edge methods for design, manufacture, installation, operation, and maintenance of reliable power cable systems. It is based largely on feedback from experienced university lecturers who have taught courses on these very concepts.The book emphasizes methods to optimize vital design and installation of power cables used in the

  12. Total Magnetic Field Signatures over Submarine HVDC Power Cables

    Science.gov (United States)

    Johnson, R. M.; Tchernychev, M.; Johnston, J. M.; Tryggestad, J.

    2013-12-01

    Mikhail Tchernychev, Geometrics, Inc. Ross Johnson, Geometrics, Inc. Jeff Johnston, Geometrics, Inc. High Voltage Direct Current (HVDC) technology is widely used to transmit electrical power over considerable distances using submarine cables. The most commonly known examples are the HVDC cable between Italy and Greece (160 km), Victoria-Tasmania (300 km), New Jersey - Long Island (82 km) and the Transbay cable (Pittsburg, California - San-Francisco). These cables are inspected periodically and their location and burial depth verified. This inspection applies to live and idle cables; in particular a survey company could be required to locate pieces of a dead cable for subsequent removal from the sea floor. Most HVDC cables produce a constant magnetic field; therefore one of the possible survey tools would be Marine Total Field Magnetometer. We present mathematical expressions of the expected magnetic fields and compare them with fields observed during actual surveys. We also compare these anomalies fields with magnetic fields produced by other long objects, such as submarine pipelines The data processing techniques are discussed. There include the use of Analytic Signal and direct modeling of Total Magnetic Field. The Analytic Signal analysis can be adapted using ground truth where available, but the total field allows better discrimination of the cable parameters, in particular to distinguish between live and idle cable. Use of a Transverse Gradiometer (TVG) allows for easy discrimination between cable and pipe line objects. Considerable magnetic gradient is present in the case of a pipeline whereas there is less gradient for the DC power cable. Thus the TVG is used to validate assumptions made during the data interpretation process. Data obtained during the TVG surveys suggest that the magnetic field of a live HVDC cable is described by an expression for two infinite long wires carrying current in opposite directions.

  13. Overcurrent experiments on HTS tape and cable conductor

    DEFF Research Database (Denmark)

    Tønnesen, Ole; Jensen, Kim Høj; Træholt, Chresten;

    2001-01-01

    their critical current. In this light, it is important to investigate the response of HTS tapes and cable conductors to overcurrents several times the critical current. A number of experiments have been performed on HTS tapes and cable conductors, with currents up to 20 times the critical current. During...... overcurrent experiments, the voltage, and the temperature were measured as functions of time in order to investigate the dynamic behavior of the HTS tape and cable conductor. After each experiment, damage to the superconductors was assessed by measuring the critical current. Preliminary results show...... that within seconds an HTS tape (critical current=17 A) heats above room temperature with an overcurrent larger than 140 A. Similar overcurrent experiments showed that a HTS cable conductor could sustain damage with overcurrents exceeding 10 times the critical current of the cable conductor....

  14. Electric Propulsion Cables For Milli-Newton Thrusters

    Science.gov (United States)

    Jakob, Manfred; Bertrand, Arnaud; El-Idrissi, Mohamed; Schaper, Wolfgang, , Dr.

    2011-10-01

    AXON' Kabel GmbH, is developing and manufacturing cables and connectors up to complete interconnect systems for all types of applications needed in Space. As a request from ESA, AXON has developed a new generation of cables suitable for current and future applications to feed electric propulsion thruster systems in spacecraft with electric power. Under this project the main objectives were to find and select materials for the composition to produce a cable withstanding quite strongrequirements for operating temperature, radiation resistance, high voltage application and in variants to various current ratings (A); the cable construction will also include ESD immunisation. The paper will summarise the specification achieved and will give an overview on the test results with the prototype cables.

  15. Analytical Calculation of Current Distribution in Multistrand Superconducting Cables

    CERN Document Server

    Bottura, L; Fabbri, M G

    2003-01-01

    In recent years the problem of current distribution in multistrand superconducting cables has received increasing attention for large scale superconductivity applications due to its effect on the stability of fusion magnets and the field quality of accelerator magnets. A modelling approach based on distributed parameters has revealed to be very effective in dealing with long cables made of some tens or hundreds of strands. In this paper we present a fully analytical solution equation for a distributed parameters model in cables made of an arbitrary number of strands, whose validity is subjected to symmetry conditions generally satisfied in practical cables. We give in particular analytical formulae of practical use for the estimation of the maximum strand currents, time constants and redistribution lengths as a function of the cable properties and the external voltage source.

  16. A 245 kV XLPE (X-Linked PolyEthylene) cable systems. 245 kV XLPE kabelsystemen

    Energy Technology Data Exchange (ETDEWEB)

    Schoonakker, P.; Willems, H.M.J. (Hoogspannings Research Laboratorium, Nederlandse Kabel Fabriek BV (NKF), Waddinxveen (Netherlands))

    1991-12-01

    High-voltage extruded cables up to and including 170 kV have acquired a good service record in the Netherlands during the last decade. These cables are rapidly replacing the conventional paper-insulated cables. The next step is the introduction of extruded cable systems for 245 kV. The Dutch Cable Factory (NKF) started the development of a 245 kV XLPE cable system several years ago. The development is based on well-defined design parameters, a controlled production, a sound test program, and a good quality control system. 12 figs., 1 tab.

  17. Study on Impedance Characteristics of Aircraft Cables

    Directory of Open Access Journals (Sweden)

    Weilin Li

    2016-01-01

    Full Text Available Voltage decrease and power loss in distribution lines of aircraft electric power system are harmful to the normal operation of electrical equipment and may even threaten the safety of aircraft. This study investigates how the gap distance (the distance between aircraft cables and aircraft skin and voltage frequency (variable frequency power supply will be adopted for next generation aircraft will affect the impedance of aircraft cables. To be more precise, the forming mechanism of cable resistance and inductance is illustrated in detail and their changing trends with frequency and gap distance are analyzed with the help of electromagnetic theoretical analysis. An aircraft cable simulation model is built with Maxwell 2D and the simulation results are consistent with the conclusions drawn from the theoretical analysis. The changing trends of the four core parameters of interest are analyzed: resistance, inductance, reactance, and impedance. The research results can be used as reference for the applications in Variable Speed Variable Frequency (VSVF aircraft electric power system.

  18. Coil-Type Asymmetric Supercapacitor Electrical Cables.

    Science.gov (United States)

    Yu, Zenan; Moore, Julian; Calderon, Jean; Zhai, Lei; Thomas, Jayan

    2015-10-21

    Cable-shaped supercapacitors (SCs) have recently aroused significant attention due to their attractive properties such as small size, lightweight, and bendability. Current cable-shaped SCs have symmetric device configuration. However, if an asymmetric design is used in cable-shaped supercapacitors, they would become more attractive due to broader cell operation voltages, which results in higher energy densities. Here, a novel coil-type asymmetric supercapacitor electrical cable (CASEC) is reported with enhanced cell operation voltage and extraordinary mechanical-electrochemical stability. The CASECs show excellent charge-discharge profiles, extraordinary rate capability (95.4%), high energy density (0.85 mWh cm(-3)), remarkable flexibility and bendability, and superior bending cycle stability (≈93.0% after 4000 cycles at different bending states). In addition, the CASECs not only exhibit the capability to store energy but also to transmit electricity simultaneously and independently. The integrated electrical conduction and storage capability of CASECS offer many potential applications in solar energy storage and electronic gadgets. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. UtilityTelecom_CABLE2013

    Data.gov (United States)

    Vermont Center for Geographic Information — The VT Cable dataset (CABLE2013) includes lines depicting the extent of Vermont's cable modem broadband system as of 6/30/2013 in addition to those companies who do...

  20. Influence of Cable Vibrations on Connectors Used in Automotive Applications

    OpenAIRE

    AMEL Bouzera; ROCHDI El Abdi; ERWANN Carvou; NOUREDDINE Benjemâa; LAURENT Tristani; EL MOSTAFA Zindine

    2012-01-01

    In order to determine the influence of cable vibrations on the contact resistance of connectors, the cable resonant frequency and the resulting movement of both parts of the connector have been studied. The increase of contact voltage, followed by rapidfluctuations generated by wear particles, has been analysed. A test bench designed to monitor wire vibrations was used while the transferred amplitude was measured by a high sensitivity displacement sensor. The contact interface was made of cop...

  1. Development of (RE)BCO cables for HTS power transmission lines

    Science.gov (United States)

    Mukoyama, S.; Yagi, M.; Masuda, T.; Amemiya, N.; Ishiyama, A.; Kashima, N.; Nagaya, S.; Aoki, Y.; Yoshizumi, M.; Yamada, Y.; Izumi, T.; Shiohara, Y.

    2009-10-01

    High-temperature superconducting (HTS) power cables transmit bulk power with lower loss than conventional cables. Moreover, HTS cables are expected to be constructed as a new underground cable in urban areas at lower cost compared to a high voltage XLPE cable. To put promising HTS cables to practical use, we need (RE)BCO tapes with long length, high critical current, and low cost. Recently many organizations have improved the performance of the (RE)BCO tapes, such as YBCO tapes, or other coated conductor tapes that are made with a variety of different processes. We have fabricated the conductors for the HTS power cable that was constructed of different kinds of (RE)BCO tapes and measured the I c and AC losses. We achieved significantly low AC loss of 0.1 W/m at 1 kA in the HTS conductor using narrow slit tapes that were cut by laser. Moreover, a 20 m long HTS power cable model and a cable intermediate joint were developed. Short circuit current tests were conducted on the cable system that consisted of two 10 m cables, a cable joint, and two terminations. The cables and the joint withstood the short circuit current of 31.5 kA for 2 s without damage.

  2. Development of (RE)BCO cables for HTS power transmission lines

    Energy Technology Data Exchange (ETDEWEB)

    Mukoyama, S., E-mail: mukoyama@ch.furukawa.co.j [Furukawa Electric Co. Ltd., Ichihara 290-8555 (Japan); Yagi, M. [Furukawa Electric Co. Ltd., Ichihara 290-8555 (Japan); Masuda, T. [Sumitomo Electric Industries, Ltd., Osaka 554-0024 (Japan); Amemiya, N. [Kyoto University, Kyoto 615-8510 (Japan); Ishiyama, A. [Waseda University, Tokyo 169-8555 (Japan); Kashima, N.; Nagaya, S. [Chubu Electric Power Co. Inc., Nagoya 459-8522 (Japan); Aoki, Y. [Showa Cable System Co. Ltd., Sagamihara 229-1133 (Japan); Yoshizumi, M.; Yamada, Y.; Izumi, T.; Shiohara, Y. [Superconductivity Research Laboratory, Tokyo 135-0062 (Japan)

    2009-10-15

    High-temperature superconducting (HTS) power cables transmit bulk power with lower loss than conventional cables. Moreover, HTS cables are expected to be constructed as a new underground cable in urban areas at lower cost compared to a high voltage XLPE cable. To put promising HTS cables to practical use, we need (RE)BCO tapes with long length, high critical current, and low cost. Recently many organizations have improved the performance of the (RE)BCO tapes, such as YBCO tapes, or other coated conductor tapes that are made with a variety of different processes. We have fabricated the conductors for the HTS power cable that was constructed of different kinds of (RE)BCO tapes and measured the I{sub c} and AC losses. We achieved significantly low AC loss of 0.1 W/m at 1 kA in the HTS conductor using narrow slit tapes that were cut by laser. Moreover, a 20 m long HTS power cable model and a cable intermediate joint were developed. Short circuit current tests were conducted on the cable system that consisted of two 10 m cables, a cable joint, and two terminations. The cables and the joint withstood the short circuit current of 31.5 kA for 2 s without damage.

  3. Compact repetitive high voltage nanosecond pulse generator%紧凑型重复频率高压纳秒脉冲电源及其仿真模型

    Institute of Scientific and Technical Information of China (English)

    庞磊; 陈纲亮; 何堃; 任保忠; 张乔根

    2012-01-01

    纳秒脉冲等离子体在诸多实际的工程应用中依赖于小型化且可靠的纳秒脉冲电源实现.设计了一种紧凑型全固态高压纳秒脉冲电源,该电源主要由直流电源部分、绝缘栅双极晶体管及其驱动控制电路、可饱和脉冲变压器、磁脉冲压缩网络等组成.通过理论计算分析、PSpice电路仿真以及实验研究表明,其最终可以在800 Ω的输出负载阻抗上获得幅值40 kV、脉冲宽度100 ns左右、脉冲上升沿约50 ns的高电压脉冲,重复频率最高可达5 kHz.%The application of nanosecond discharge plasma in many fields depends greatly on a compact repetitive high voltage nanosecond pulse generator. In this paper. a compact high voltage nanosecond pulse generator is presented > which is constructed with all-solid-state components. The pulse generator consists of DC module, insulated-gate bipolar transistors and its drivers, saturable pulse transformer and magnetic switch and so on. Simulation analysis and experimental investigation show that, the pulse generator can output pulsed voltage of 40 kV with duration about 100 ns and rise-time of 50 ns. Its highest repetitive frequency can be up to 5 kHz.

  4. Multichannel computerized control system of current pulses in LIU-30 electron accelerator

    CERN Document Server

    Gerasimov, A I; Kulgavchuk, V V; Pluzhnikov, A V

    2002-01-01

    In LIU-30 power linear pulsed induction electron accelerator (40 MeV, 10 kA, 25 ns) 288 radial lines with water insulation serve as energy accumulators and shapers of accelerating voltage pulses. The lines are charged simultaneously up to 500 kV using a system comprising 72 Arkadiev-Marx screened generators. To control parameter of synchronous pulses of charging current with up to 60 kA amplitude and 0.85 mu s duration in every of 72 charging circuits one applies a computer-aided system. Current pulse is recorded at output of every generator using the Rogowski coil signal from which via a cable line is transmitted to an analog-digital converter, is processed with 50 ns sampling and is recorded to a memory unit. Upon actuation of accelerator the signals are sequentially or selectively displayed and are compared with pulse typical shape

  5. Modified Blumlein pulse-forming networks for bioelectrical applications.

    Science.gov (United States)

    Romeo, Stefania; Sarti, Maurizio; Scarfì, Maria Rosaria; Zeni, Luigi

    2010-07-01

    Intense nanosecond pulsed electric fields (nsPEFs) have been shown to induce, on intracellular structures, interesting effects dependent on electrical exposure conditions (pulse length and amplitude, repetition frequency and number of pulses), which are known in the literature as "bioelectrical effects" (Schoenbach et al., IEEE Trans Plasma Sci 30:293-300, 2002). In particular, pulses with a shorter width than the plasma membrane charging time constant (about 100 ns for mammalian cells) can penetrate the cell and trigger effects such as permeabilization of intracellular membranes, release of Ca(2+) and apoptosis induction. Moreover, the observed effects have led to exploration of medical applications, like the treatment of melanoma tumors (Nuccitelli et al., Biochem Biophys Res Commun 343:351-360, 2006). Pulsed electric fields allowing such effects usually range from several tens to a few hundred nanoseconds in duration and from a few to several tens of megavolts per meter in amplitude (Schoenbach et al., IEEE Trans Diel Elec Insul 14:1088-1109, 2007); however, the biological effects of subnanosecond pulses have been also investigated (Schoenbach et al., IEEE Trans Plasma Sci 36:414-422, 2008). The use of such a large variety of pulse parameters suggests that highly flexible pulse-generating systems, able to deliver wide ranges of pulse durations and amplitudes, are strongly required in order to explore effects and applications related to different exposure conditions. The Blumlein pulse-forming network is an often-employed circuit topology for the generation of high-voltage electric pulses with fixed pulse duration. An innovative modification to the Blumlein circuit has been recently devised which allows generation of pulses with variable amplitude, duration and polarity. Two different modified Blumlein pulse-generating systems are presented in this article, the first based on a coaxial cable configuration, matching microscopic slides as a pulse-delivery system

  6. Arc tracking energy balance for copper and aluminum aeronautic cables

    Science.gov (United States)

    André, T.; Valensi, F.; Teulet, P.; Cressault, Y.; Zink, T.; Caussé, R.

    2017-04-01

    Arc tracking tests have been carried out between two voluntarily damaged aeronautic cables. Copper or aluminum conductors have been exposed to short circuits under alternating current. Various data have been recorded (arc voltage and current, radiated power and ablated mass), enabling to determine a power balance, in which every contribution is estimated. The total power is mainly transferred to the cables (between 50 and 65%, depending on the current and the cable type), and causes the melting and partial vaporization of the metallic core and insulating material, or is conducted or radiated. The other part is deposited into the arc column, being either radiated, convected or conducted.

  7. Electrical Aging Phenomena of Power Cables Aged by Switching Impulses

    Institute of Scientific and Technical Information of China (English)

    L.Cao; A.Zanwar; S.Grzybowski

    2013-01-01

    Due to the insufficient information regarding the aging phenomenon of cables caused by switching impulses,we aged 15 kV XLPE and EPR cable samples by 10000 switching impulses in experiments and tested them.Plus in order to compare the aging phenomenon under multi-stress conditions,additional EPR cable samples were aged by rated AC voltage and current with switching impulses superimposed.We used measurements of partial discharge parameters to monitor the cables' conditions during their aging process,and the AC breakdown voltages measurement to evaluate the cables after aging.Moreover,the Fourier transform infrared (FTIR) spectroscopy measurements revealed the changes of insulation materials after aging.The measurement results confirm that the accelerated aging of cable samples had taken place.The impacts of each individual aging factor are shown through the selected measurements and comparison.The study also helps to assess the reliability of the XLPE and EPR cables under similar condition while serving in power systems.

  8. Multistrand superconductor cable

    Science.gov (United States)

    Borden, Albert R.

    1985-01-01

    Improved multistrand Rutherford-type superconductor cable is produced by using strands which are preformed, prior to being wound into the cable, so that each strand has a variable cross section, with successive portions having a substantially round cross section, a transitional oval cross section, a rectangular cross section, a transitional oval cross section, a round cross section and so forth, in repetitive cycles along the length of the strand. The cable is wound and flattened so that the portions of rectangular cross section extend across the two flat sides of the cable at the strand angle. The portions of round cross section are bent at the edges of the flattened cable, so as to extend between the two flat sides. The rectangular portions of the strands slide easily over one another, so as to facilitate flexing and bending of the cable, while also minimizing the possibility of causing damage to the strands by such flexing or bending. Moreover, the improved cable substantially maintains its compactness and cross-sectional shape when the cable is flexed or bent.

  9. Partial discharge pulse shape recognition using an inductive loop sensor

    Science.gov (United States)

    Martínez-Tarifa, J. M.; Robles, G.; Rojas-Moreno, M. V.; Sanz-Feito, J.

    2010-10-01

    Partial discharges (PD) are a clear ageing agent on insulating materials used in high-voltage electrical machines and cables. For this reason, there is increasing interest in measuring this phenomenon in an effort to forecast unexpected failures in electrical equipment. In order to focus on harmful discharges, PD pulse shape analysis is being used as an insulation defect identification technique. In this paper, a simple, inexpensive and high-frequency inductive loop sensor will be used to detect and acquire PD pulses. Several measurements will be made on some controlled test cell geometries in order to characterize PD pulse shapes for different discharge sources. The sensor identification capability has been checked in an insulation system where two simultaneous PD sources were active.

  10. Design of sewage treatment system based on high-voltage pulsed electric field technology%基于高压脉冲电场技术的污水处理系统研究设计

    Institute of Scientific and Technical Information of China (English)

    李唐; 王亚伟; 赵振良; 尤丽华

    2013-01-01

    针对污水处理厂剩余污泥含水率高,达到70%-80%,不利于进一步处理的问题,根据污水成分及其处理工艺特点,提出了一种基于高压脉冲电场技术的污水处理的方法.本文从理论上系统地阐述了高压脉冲电场处理装置的研制,设计了低成本高压脉冲电源,最高电压10 kV,最大电流50A,并且能方便的调节电场参数.%Contrary to the problem that the high moisture content of the excess sludge of the sewage treatment plant, up to 70% to 80% , the paper proposed a sewage treatment method based on the high-voltage pulse electric field (HPEF) technology, according to the composition of sewage and the feature of its treatment technology.The paper systematically expounded of how to design a pulsed electric field theoretically,and design a low-cost high-voltage pulse power supply with the peak impulse voltage 10 kV and impulse current to 50 A, which also can easily adjust the electric field parameters.

  11. Low Beam Voltage, 10 MW, L-Band Cluster Klystron

    Energy Technology Data Exchange (ETDEWEB)

    Teryaev, V.; /Novosibirsk, IYF; Yakovlev, V.P.; /Fermilab; Kazakov, S.; /KEK, Tsukuba; Hirshfield, J.L.; /Yale U. /Omega-P, New Haven

    2009-05-01

    Conceptual design of a multi-beam klystron (MBK) for possible ILC and Project X applications is presented. The chief distinction between this MBK design and existing 10-MW MBK's is the low operating voltage of 60 kV. There are at least four compelling reasons that justify development at this time of a low-voltage MBK, namely (1) no pulse transformer; (2) no oil tank for high-voltage components and for the tube socket; (3) no high-voltage cables; and (4) modulator would be a compact 60-kV IGBT switching circuit. The proposed klystron consists of four clusters containing six beams each. The tube has common input and output cavities for all 24 beams, and individual gain cavities for each cluster. A closely related optional configuration, also for a 10 MW tube, would involve four totally independent cavity clusters with four independent input cavities and four 2.5 MW output ports, all within a common magnetic circuit. This option has appeal because the output waveguides would not require a controlled atmosphere, and because it would be easier to achieve phase and amplitude stability as required in individual SC accelerator cavities.

  12. High Voltage Power Transmission for Wind Energy

    Science.gov (United States)

    Kim, Young il

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

  13. Comparison of Bergeron and Frequency-dependent cable models for the simulation of electromagnetic transients

    DEFF Research Database (Denmark)

    Silva, Filipe Miguel Faria da

    2016-01-01

    analyses the simulation errors of different Bergeron models to a reference frequency-dependent model for a 150kV cable. The simulations consider flat and trefoil installation, both-ends bonding and cross-bonding, ideal voltage source and modelling of the area around the cable. The Bergeron model...... the modelling of the area around the cable being energised, the Bergeron model has a small error if tuned for the right frequency....

  14. Superconductors for the medium-voltage grid. A superconducting power cable running through the inner city of Essen passes a two-year field test; Supraleiter fuer das Mittelspannungsnetz. Ein supraleitendes Stromkabel quer durch die Essener Innenstadt besteht zweijaehrigen Feldtest

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Franz

    2017-04-01

    Scientists are testing the longest high-temperature superconducting cable in the world under real conditions in Essen. One kilometre long, it connects two substations in the inner city. It replaces a conventional 110 kV line and renders one substation in the inner city obsolete. After two years of testing, it has passed the field test. It could be a blueprint for the future power supply system in urban areas. [German] Wissenschaftler testen in Essen das laengste Hochtemperatur-Supraleiterkabel der Welt unter realen Bedingungen. Mit einer Laenge von einem Kilometer verbindet es zwei Umspannstationen quer durch die Innenstadt. Es ersetzt eine konventionelle 110-kV-Leitung und macht eine Umspannanlage im Stadtzentrum ueberfluessig. In einer zweijaehrigen Erprobung hat es den Praxistest bestanden. Es koennte eine Blaupause fuer die kuenftige Stromversorgung in Ballungsraeumen sein.

  15. XLPE电缆电树枝二次生长特性分析%Analysis on Secondary Growth Characteristics of Electrical Trees in XLPE Cable

    Institute of Scientific and Technical Information of China (English)

    周湶; 陈仕军; 廖瑞金

    2009-01-01

    In order to study the growth characteristics of electrical trees in XLPE cable under secondary applied volt- age, a short cable metal needle defect test device is adopted to study the growth characteristics of the new trees after the electrical trees in XLPE cable under the action of the voltage of 12 kV are influenced by secondary applied volt- age (15 kV). The research results show that influenced by secondary applied voltage and voltage increase rate, there will be a peculiar "bush-branch" electrical tree in XLPE cable insulation layer and the new trees under secondary ap- plied voltage have the characteristics of short initiation time, fast growth rate and narrow discharge channel, etc, which shows that secondary applied voltage has a great effect on the secondary initiation and growth of electrical trees in XLPE cable and it is an important factor of accelerating cable aging and breakdown.

  16. Cable Television; A Bibliographic Review.

    Science.gov (United States)

    Schoenung, James

    This bibliographic review of publications in the field of cable television begins with an introduction to cable television and an outline of the history and development of cable television. Particular attention is given to the regulatory activities of the Federal Communications Commission and the unfulfilled potential of cable television. The…

  17. Application Research Progress of Nano-filler in Polyethylene Composites for High Voltage Direct Current Cable%纳米填料在高压直流电缆用聚乙烯复合材料应用中的研究进展

    Institute of Scientific and Technical Information of China (English)

    胡阳; 廖霞; 戢菁

    2013-01-01

    综述了纳米填料在改善聚乙烯高压直流电缆绝缘材料的空间电荷、电荷捕获、介电常数以及提高其耐电压能力和电气强度方面的最新国内外研究进展,并讨论了不同填料的加入、纳米粒子表面处理和水分对纳米复合材料电绝缘性能的影响及其机理,并展望了今后的研究重点。%The latest research progress of nano-filler in improving the space charge, charge trapping, di-electric constant, voltage endurance and breakdown strength of polyethylene high voltage direct current (HVDC) cable insulation at home and aboard was reviewed. The effects of various kinds of nano-fillers, surface treatment of nano particle and moisture on the electrical insulating properties and the mechanism were discussed, and the future research emphasis was prospected.

  18. Testing of an HTS Power Cable Made from YBCO Tapes

    Energy Technology Data Exchange (ETDEWEB)

    Gouge, Michael J [ORNL; Duckworth, Robert C [ORNL; Demko, Jonathan A [ORNL; Rey, Christopher M [ORNL; Lindsay, David T [ORNL; Roden, Mark L [ORNL; Tolbert, Jerry Carlton [ORNL

    2007-01-01

    Oak Ridge National Laboratory (ORNL) has designed, built, and tested a 1.25-m-long, prototype high temperature superconducting (HTS) power cable made from second-generation YBa2Cu3Ox (YBCO)-coated conductor tapes. Electrical tests of this cable were performed in liquid nitrogen at 77 K. DC testing of the HTS cable included determination of the V-I curve with a critical current of about 2100 A, which was consistent with the critical currents of the two layers of 4.4-mm wide YBCO tapes. AC testing of the cable was conducted at currents up to about 1500 Arms. The ac losses were determined calorimetrically by measuring the response of a calibrated temperature sensor placed on the former and electrically by use of a Rogowski coil with a lock-in amplifier. Over-current testing was conducted at peak current values up to 4.9 kA for pulse lengths of 0.3-0.5 s. Test results are compared to earlier data from a 1.25-m-long power cable made from 1-cm-wide YBCO tapes and also comparable BSCCO cables. This commercial-grade HTS cable demonstrated the feasibility of second-generation YBCO tapes in an ac cable application.

  19. 49 CFR 234.243 - Wire on pole line and aerial cable.

    Science.gov (United States)

    2010-10-01

    ... Maintenance, Inspection, and Testing Maintenance Standards § 234.243 Wire on pole line and aerial cable. Wire... transmission line operating at voltage of 750 volts or more shall be placed not less than 4 feet above the... 49 Transportation 4 2010-10-01 2010-10-01 false Wire on pole line and aerial cable....

  20. Influence of Frequency Converters on Insulation of Power Supply Cables at Oil-Producing Stations

    Directory of Open Access Journals (Sweden)

    D. I. Zalizny

    2011-01-01

    Full Text Available The paper considers consequences of negative frequency converter influence on insulation of  power supply cables used for submersible installations of electric-centrifugal pumps at oil-producing stations. The possible approaches to the solution of the problem are proposed on the basis of a harmonic analysis of actually measured voltages and currents in a cable.  

  1. ESTIMATION CRITERIA FOR DEGREE OF PAPER-IMPREGNATED INSULATED POWER CABLE AGEING

    Directory of Open Access Journals (Sweden)

    G.V. Bezprozvannych

    2013-09-01

    Full Text Available Correlation between parameters characterizing mechanical and thermal ageing of paper-impregnated insulation of medium voltage power cables is revealed. On the basis of linear and exponential regression analysis at confidence coefficient of 0.95, critical values of dielectric loss tangent of wrapping and phase insulation corresponding to the cable life termination are found.

  2. Comparative studies on extraction of laminarin by high voltage pulsed electric fields and traditional method%高压脉冲电场和传统热水法提取海带多糖的比较研究

    Institute of Scientific and Technical Information of China (English)

    刘航; 冯立强; 刘兴江

    2016-01-01

    Orthogonal tests are carried out to determine optimal laminarin extraction technologies by the high voltage pulsed electric fields and the traditional hot water method.The mechanism of the high voltage pulsed electric fields is preliminarily discussed.The optimal conditions of traditional method are:1∶50 of material-liquid ratio,60 ℃ of extraction temperature and 40 minutes of extraction time.The optimal conditions of high voltage pulsed electric fields are:1 ∶ 30 of material-liquid ratio,20 minutes of pulse time,10 kV of electric field intensity and 50 Hz of pulse frequency.Compared with traditional hot water extraction method,the extraction time is shortened by 50% and the extraction ratio is increased by 45% for high voltage pulsed electric field method.%利用正交试验确定了高压电脉冲电场和传统热水法提取海带多糖的方法的最佳工艺,并对2种工艺进行了比较,初步探讨高压脉冲的作用机理.结果表明,传统热水法提取海带多糖的最佳工艺为:海带粉与去离子水的料液比为1∶50,提取温度为60℃,提取时间为40 min.高压脉冲电场的最佳工艺为:海带粉与去离子水的料液比为1∶30,脉冲时间为20 min,脉冲电压为10 kV,脉冲频率为50 Hz.提取时间仅为传统热水法时间的1/2,海带多糖提取率比传统热水法提高45%.

  3. Simple buck/boost voltage regulator

    Science.gov (United States)

    Paulkovich, J.; Rodriguez, G. E.

    1980-01-01

    Circuit corrects low or high supply voltage, produces regulated output voltage. Circuit has fewer components because inductory/transformer combination and pulse-width modulator serve double duty. Regulator handles input voltage variation from as low as one half output voltage to as high as input transistor rating. Solar arrays, fuel cells, and thermionic generators might use this regulator.

  4. Determining the Number of Parallel RC Branches in Polarization / Depolarization Current Modeling for XLPE Cable Insulation

    Directory of Open Access Journals (Sweden)

    S. Sulaiman

    2017-06-01

    Full Text Available An important element in the electric power distribution system is the underground cable. However continuous applications of high voltages unto the cable, may lead to insulation degradations and subsequent cable failure. Since any disruption to the electricity supply may lead to economic losses as well as lowering customer satisfaction, the maintenance of cables is very important to an electrical utility company. Thus, a reliable diagnostic technique that is able to accurately assess the condition of cable insulation operating is critical, in order for cable replacement exercise to be done. One such diagnostic technique to assess the level of degradation within the cable insulation is the Polarization / Depolarization Current (PDC analysis. This research work attempts to investigate PDC behaviour for medium voltage (MV cross-linked polyethylene (XLPE insulated cables, via baseline PDC measurements and utilizing the measured data to simulate for PDC analysis. Once PDC simulations have been achieved, the values of conductivity of XLPE cable insulations can be approximated. Cable conductivity serves as an indicator to the level of degradation within XLPE cable insulation. It was found that for new and unused XLPE cables, the polarization and depolarization currents have almost overlapping trendlines, as the cable insulation’s conduction current is negligible. Using a linear dielectric circuit equivalence model as the XLPE cable insulation and its corresponding governing equations, it is possible to optimize the number of parallel RC branches to simulate PDC analysis, with a very high degree of accuracy. The PDC simulation model has been validated against the baseline PDC measurements.

  5. Design considerations for high-power VHF radar transceivers: Phase matching long coaxial cables using a cable radar

    Science.gov (United States)

    Johnson, P. E.; Ecklund, W. L.

    1983-01-01

    The Poker Flat 49.92-MHz MST radar uses 64 phase-controlled transmitters in individual shelters distributed throughout the antenna array. Phase control is accomplished by sampling the transmitted pulse at the directional coupler of each transmitter and sending the sample pulse back to a phase-control unit. This method requires phase matching 64 long (256 meter) coaxial cables (RG-213) to within several electrical degrees. Tests with a time domain reflectometer showed that attenuation of high frequency components in the long RG-213 cable rounded the leading edge of the reflected pulse so that the cables could only be measured to within 50 cm (about 45 deg at 49.92 MHz). Another measurement technique using a vector voltmeter to compare forward and reflected phase required a directional coupler with unattainable directivity. Several other techniques were also found lacking, primarily because of loss in the long RG-213 cables. At this point it was realized that what was needed was a simple version of the phase-coherent clear-air radar, i.e., a cable radar. The design and operation of this cable are described.

  6. Volume transport data from a submarine cable in the Florida Strait in 2014 (NODC Accession 0125429)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Daily mean and raw voltage volume transport data of the Florida Current collected with a submarine cable spanning from South Florida to the Grand Bahama Island in...

  7. Volume transport data from a submarine cable in the Florida Strait in 2013 (NODC Accession 0115895)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Daily mean and raw voltage volume transport data of the Florida Current collected with a submarine cable spanning from South Florida to the Grand Bahama Island in...

  8. Volume transport data from a submarine cable in the Florida Strait from 2015 (NCEI Accession 0140278)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Daily mean and raw voltage volume transport data of the Florida Current collected with a submarine cable spanning from South Florida to the Grand Bahama Island in...

  9. Robotic Arm Biobarrier Cable

    Science.gov (United States)

    2008-01-01

    This image, taken by the Surface Stereo Imager on NASA's Phoenix Mars Lander on the 14th Martian day of the mission (June 7, 2008), shows the cable that held the Robotic Arm's biobarrier in place during flight has snapped. The cable's springs retracted to release the biobarrier right after landing. To the lower right of the image a spring is visible. Extending from that spring is a length of cable that snapped during the biobarrier's release. A second spring separated from the cable when it snapped and has been photographed on the ground under the lander near one of the legs. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  10. Robotic Arm Biobarrier Cable

    Science.gov (United States)

    2008-01-01

    This image, taken by the Surface Stereo Imager on NASA's Phoenix Mars Lander on the 14th Martian day of the mission (June 7, 2008), shows the cable that held the Robotic Arm's biobarrier in place during flight has snapped. The cable's springs retracted to release the biobarrier right after landing. To the lower right of the image a spring is visible. Extending from that spring is a length of cable that snapped during the biobarrier's release. A second spring separated from the cable when it snapped and has been photographed on the ground under the lander near one of the legs. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  11. Triaxial HTS Cable for the AEP Bixby Project

    Energy Technology Data Exchange (ETDEWEB)

    Demko, Jonathan A [ORNL; Gouge, Michael J [ORNL; Lindsay, David T [ORNL; Roden, Mark L [ORNL; Tolbert, Jerry Carlton [ORNL

    2007-01-01

    Ultera has installed a single 200-meter long high temperature superconducting (HTS) 3-phase triaxial design cable at the American Electric Power (AEP) Bixby substation in Columbus, Ohio. The cable connects a 132/13.8 kV transformer to the distribution switchgear serving seven outgoing circuits. It was designed to carry 3000 Arms. Testing of 3- to 5-meter length prototype cables, including a 5-meter prototype with full scale terminations tested at ORNL was conducted prior to the manufacture and installation of the AEP triaxial cable. These prototypes were used to demonstrate the crucial operating conditions including steady state operation at the 3000 Arms design current, high voltage operation, high voltage withstand and 110 kV impulse, and overcurrent fault capability. A summary of the results from the thermal analysis and testing conducted by Ultera and ORNL will be presented. Some analysis of the cable thermal-hydraulic response based on the testing that were used to determine some of the cable cryogenic system requirements are also presented.

  12. Buoyant Cable Antenna System

    Science.gov (United States)

    2008-07-02

    comprise a mechanical jacket surrounding a hollow core enclosing the seismic sensor and signal transfer means. Elongated axial stress elements for...to S. H. Bittleston, discloses a semi-dry marine seismic streamer cable that consists of a number of connected streamer cable sections which each...transmitting axial loads and a radial reinforcement member for relieving radial loads are provided in the jacket . The core is filled with a fluid or fluid

  13. Modeling of cable vibration effects of cable-stayed bridges

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The analysis of dynamic responses of cable-stayed bridges subjected to wind and earthquake loads generallyconsiders only the motions of the bridge deck and pylons. The influence of the stay cable vibration on the responses of the bridgeis either ignored or considered by approximate procedures. The transverse vibration of the stay cables, which can be significant insome cases, are usually neglected in previous research. In the present study, a new three-node cable element has been developed tomodel the transverse motions of the cables. The interactions between the cable behavior and the other parts of the bridgesuperstructure are considered by the concept of dynamic stiffness. The nonlinear effect of the cable caused by its self-weight isincluded in the formulation. Numerical examples are presented to demonstrate the accuracy and efficiency of the proposed model.The impact of cable vibration behavior on the dynamic characteristics of cable-stayed bridges is discussed.

  14. Aerodynamic stability of cable-supported bridges using CFRP cables

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xin-jun; YING Lei-dong

    2007-01-01

    To gain understanding of the applicability of carbon fiber reinforced polymer (CFRP) cable in cable-supported bridges, based on the Runyang Bridge and Jinsha Bridge, a suspension bridge using CFRP cables and a cable-stayed bridge using CFRP stay cables are designed, in which the cable's cross-sectional area is determined by the principle of equivalent axial stiffness.Numerical investigations on the aerodynamic stability of the two bridges are conducted by 3D nonlinear aerodynamic stability analysis. The results showed that as CFRP cables are used in cable-supported bridges, for suspension bridge, its aerodynamic stability is superior to that of the case using steel cables due to the great increase of the torsional frequency; for cable-stayed bridge,its aerodynamic stability is basically the same as that of the case using steel stay cables. Therefore as far as the wind stability is considered, the use of CFRP cables in cable-supported bridges is feasible, and the cable's cross-sectional area should be determined by the principle of equivalent axial stiffness.

  15. AC Cable: Yokohama Project

    Science.gov (United States)

    Masuda, Takato

    High Temperature Superconducting (HTS) cables can transmit large amounts of electricity in a compact size with minimal losses. Therefore, they are expected to save the construction cost of underground lines in urban areas and decrease transmission losses. Several HTS cables have recently been demonstrated in networks around the world, and full-scale commercialization is expected in the near future. In Japan, the development of compact HTS cables suitable for urban deployment has been underway since the early 1990s. In 2007, a national project was started to verify their operational performance and long-term reliability in the grid. An HTS cable 240 m long was installed at the Asahi substation of the Tokyo Electric Power Company (TEPCO) in Yokohama; then a joint, terminations and cooling system was constructed in 2011. After successful performance tests, the cable was connected to the grid for the first time in Japan, and started to deliver electricity to 70,000 households in October 2012. This trouble-free in-grid service continued for over a year. We can conclude that the HTS cable system performs well and has the stability required for long-term in-grid operations.

  16. Test of Cable Products in Respect of Thermal and Dynamic Stability

    Directory of Open Access Journals (Sweden)

    M. A. Коrotkevich

    2010-01-01

    Full Text Available The paper considers conditions for selection of  power supply of the unit which is used for testing samples of cable products by thermal and dynamic stability currents. It has been shown that while conducting testing by thermal and dynamic stability currents at nominal cable voltage it is more justifiable to use a percussive energy accumulator, and in the case when the voltage is low an inductive energy accumulator is used.

  17. A dual-cable noise reduction method for Langmuir probes

    Science.gov (United States)

    Yang, T. F.; Zu, Q. X.; Liu, Ping

    1995-07-01

    To obtain fast time response plasma properties, electron density and electron temperature, with a Langmuir probe, the applied probe voltage has to be swept at high frequency. Due to the RC characteristics of coaxial cables, an induced noise of a square-wave form will appear when a sawtooth voltage is applied to the probe. Such a noise is very annoying and difficult to remove, particularly when the probe signal is weak. This paper discusses a noise reduction method using a dual-cable circuit. One of the cables is active and the other is a dummy. Both of them are of equal length and are laid parallel to each other. The active cable carries the applied probe voltage and the probe current signal. The dummy one is not connected to the probe. After being carefully tuned, the induced noises from both cables are nearly identical and therefore can be effectively eliminated with the use of a differential amplifier. A clean I-V characteristic curve can thus be obtained. This greatly improves the accuracy and the time resolution of the values of ne and Te.

  18. 30 CFR 77.605 - Breaking trailing cable and power cable connections.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Breaking trailing cable and power cable... OF UNDERGROUND COAL MINES Trailing Cables § 77.605 Breaking trailing cable and power cable connections. Trailing cable and power cable connections between cables and to power sources shall not be...

  19. Stator insulation systems for medium voltage PWM drives fed motors

    Energy Technology Data Exchange (ETDEWEB)

    Gao, G.; Chen, W. [TECO-Westinghouse Motor Co., Round Rock, TX (United States)

    2005-07-01

    Adjustable speed drives (ASD) are commonly used in power electronics and control systems. It is estimated that more than 15 per cent of medium voltage motors are currently fed by such drives worldwide. A research project was conducted to examine the influence of medium voltage pulse width modulated (PWM) ASD on motor stator insulation systems. The findings, based on accelerated laboratory tests, have helped designers to improve the capabilities of the insulation system used for ASD-fed motors. Repetitive, high magnitude voltage spikes with fast rise time create significant stress on insulation systems. Gradual deterioration and premature failure of the motor insulation can result from surge voltages which generate surface discharges between phase windings/end windings, or partial discharges between stator turns. However, there is no industrial standard to evaluate motor insulation life under ASD-cable-motor conditions. Several material manufacturers have developed their own version of corona resistant material. However, the insulation life of ASD-fed motors does not depend solely on the raw materials. Rather, it depends on the complete insulation system, including the stator manufacturing process. In order to address this problem, TECO-Westinghouse Motor Company has developed special design criteria and manufacturing practices in order to reduce winding insulation temperature and to compensate for the additional heat generated by high frequency contents in the PWM voltage waveform. A patent pending new cooling system should reduce winding temperature by 15 to 20 degrees C. This paper presented design considerations for turn insulation, groundwall insulation, and a voltage stress grading system. A new thermal class H insulation system was also described. 6 refs., 2 tabs., 5 figs.

  20. Electrical Model of Balanced AC HTS Power Cable

    Science.gov (United States)

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

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

  1. HEAT TRANSFER EXPERIMENTS AND ANALYSIS OF A SIMULATED HTS CABLE

    Energy Technology Data Exchange (ETDEWEB)

    Demko, J. A. [Oak Ridge National Laboratory (ORNL); Duckworth, R. C. [Oak Ridge National Laboratory (ORNL); Gouge, M. J. [Oak Ridge National Laboratory (ORNL); Knoll, D. [Oak Ridge National Laboratory (ORNL)

    2010-01-01

    Long-length high temperature superconducting (HIS) cable projects, over 1 km, are being designed that are cooled by flowing liquid nitrogen. The compact counter-flow cooling arrangement which has the supply and return stream in a single cryostat offers several advantages including smallest space requirement, least heat load, and reduced cost since a return cryostat is not required. One issue in long length HIS cable systems is the magnitude of the heat transfer radially through the cable. It is extremely difficult to instrument an HIS cable in service on the grid with the needed thermometry because of the issues associated with installing thermometers on high voltage components. A 5-meter long test system has been built that simulates a counter-flow cooled, HIS cable using a heated tube to simulate the cable. Measurements of the temperatures in the flow stream and on the tube wall can be made and compared to analysis. These data can be used to benchmark different HIS cable heat transfer and fluid flow analysis approaches.

  2. Test Results For a 25-m Prototype Fault Current Limiting HTS Cable for Project Hydra

    Energy Technology Data Exchange (ETDEWEB)

    Rey, Christopher M [ORNL; Duckworth, Robert C [ORNL; Demko, Jonathan A [ORNL; Ellis, Alvin R [ORNL; Gouge, Michael J [ORNL; James, David Randy [ORNL; Tuncer, Enis [ORNL

    2010-01-01

    The Oak Ridge National Laboratory (ORNL) has tested a 25-m long prototype High Temperature Superconducting (HTS) cable with inherent Fault-Current Limiting (FCL) capability at its recently upgraded HTS cable test facility in Oak Ridge, TN. The HTS-FCL cable and terminations were designed and fabricated by Ultera, which is a joint venture of Southwire and nkt cables with FCL features and HTS wire provided by American Superconductor Corporation. The overall project is sponsored by the U.S. Department of Homeland Security. The ultimate goal of the 25-m HTS-FCL cable test program was to verify the design and ensure the operational integrity for the eventual installation of a ~ 200-m fully functional HTS-FCL cable in the Consolidated Edison electric grid located in downtown New York City. The 25-m HTS-FCL cable consisted of a three-phase (3- ) Triax design with a cold dielectric between the phases. The HTS-FCL cable had an operational voltage of 13.8 kV phase-to-phase and an operating current of 4000 Arms per phase, which is the highest operating current to date of any HTS cable. The 25-m HTS-FCL cable was subjected to a series of cryogenic and electrical tests. Test results from the 25-m HTS-FCL cable are presented and discussed.

  3. High voltage testing for the MAJORANA DEMONSTRATOR

    Energy Technology Data Exchange (ETDEWEB)

    Abgrall, N. [Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Arnquist, I.J. [Pacific Northwest National Laboratory, Richland, WA (United States); Avignone, F.T. [Department of Physics and Astronomy, University of South Carolina, Columbia, SC (United States); Oak Ridge National Laboratory, Oak Ridge, TN (United States); Barabash, A.S. [National Research Center “Kurchatov Institute” Institute for Theoretical and Experimental Physics, Moscow (Russian Federation); Bertrand, F.E. [Oak Ridge National Laboratory, Oak Ridge, TN (United States); Bradley, A.W. [Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Brudanin, V. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Busch, M. [Department of Physics, Duke University, Durham, NC (United States); Triangle Universities Nuclear Laboratory, Durham, NC (United States); Buuck, M. [Center for Experimental Nuclear Physics and Astrophysics, and Department of Physics, University of Washington, Seattle, WA (United States); Byram, D. [Department of Physics, University of South Dakota, Vermillion, SD (United States); Caldwell, A.S. [South Dakota School of Mines and Technology, Rapid City, SD (United States); Chan, Y-D. [Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Christofferson, C.D. [South Dakota School of Mines and Technology, Rapid City, SD (United States); Chu, P.-H. [Los Alamos National Laboratory, Los Alamos, NM (United States); Cuesta, C., E-mail: ccuesta@uw.edu [Center for Experimental Nuclear Physics and Astrophysics, and Department of Physics, University of Washington, Seattle, WA (United States); Detwiler, J.A.; Doe, P.J. [Center for Experimental Nuclear Physics and Astrophysics, and Department of Physics, University of Washington, Seattle, WA (United States); and others

    2016-07-01

    The MAJORANA Collaboration is constructing the MAJORANA DEMONSTRATOR, an ultra-low background, 44-kg modular high-purity Ge (HPGe) detector array to search for neutrinoless double-beta decay in {sup 76}Ge. The phenomenon of surface micro-discharge induced by high-voltage has been studied in the context of the MAJORANA 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 the MAJORANA 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.

  4. High voltage testing for the MAJORANA DEMONSTRATOR

    Science.gov (United States)

    Abgrall, N.; Arnquist, I. J.; Avignone, F. T.; Barabash, A. S.; Bertrand, F. E.; Bradley, A. W.; Brudanin, V.; Busch, M.; Buuck, M.; Byram, D.; Caldwell, A. S.; Chan, Y.-D.; Christofferson, C. D.; Chu, P.-H.; Cuesta, C.; Detwiler, J. A.; Doe, P. J.; Dunagan, C.; Efremenko, Yu.; Ejiri, H.; Elliott, S. R.; Fu, Z.; Galindo-Uribarri, A.; Giovanetti, G. K.; Goett, J.; Green, M. P.; Gruszko, J.; Guinn, I. S.; Guiseppe, V. E.; Henning, R.; Hoppe, E. W.; Howard, S.; Howe, M. A.; Jasinski, B. R.; Keeter, K. J.; Kidd, M. F.; Konovalov, S. I.; Kouzes, R. T.; LaFerriere, B. D.; Leon, J.; Li, A.; MacMullin, J.; Martin, R. D.; Massarczyk, R.; Meijer, S. J.; Mertens, S.; Orrell, J. L.; O'Shaughnessy, C.; Poon, A. W. P.; Radford, D. C.; Rager, J.; Rielage, K.; Robertson, R. G. H.; Romero-Romero, E.; Shanks, B.; Shirchenko, M.; Snyder, N.; Suriano, A. M.; Tedeschi, D.; Thompson, A.; Ton, K. T.; Trimble, J. E.; Varner, R. L.; Vasilyev, S.; Vetter, K.; Vorren, K.; White, B. R.; Wilkerson, J. F.; Wiseman, C.; Xu, W.; Yakushev, E.; Yu, C.-H.; Yumatov, V.

    2016-07-01

    The MAJORANA Collaboration is constructing the MAJORANA 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 the MAJORANA 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 the MAJORANA 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.

  5. 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.

  6. Geometrical Configuration of Cabling as Factor Influencing the Reproducibility of EMC Immunity Tests

    Directory of Open Access Journals (Sweden)

    I. Szolik

    2006-12-01

    Full Text Available The paper deals with analysis of the influence of geometrical configuration of device cabling upon voltages induced in cable interfaces. The analyzed properties are the cable height and the cable length for common mode disturbance, and the loop width for differential mode disturbance. The analysis is solved both by analytical calculation and by numerical simulation. Achieved results are compared mutually as well as with results obtained by measurements performed according to standardized procedures. Finally the analyzed parameters are ordered in correspondence of their importance for objectivity and reproducibility of immunity tests against electromagnetic field.

  7. 关节式电分相过电压致线索烧损分析及对策%Caused of Cables Burn-out of The Over-voltages of Articulated Phase Insulator and Prevention Measures

    Institute of Scientific and Technical Information of China (English)

    裴涛

    2011-01-01

    This paper analyses the causes of the over-voltages of articulated phase insulator,it supplies the prevention measures of how to resolve the problems according to the practice work in XiangFan Power Supply Station.%对接触网的关节式电分相出现过电压的原因进行了分析,并结合襄樊供电段现场实际情况,提出了具体的防治对策。

  8. Enhanced analogue front-end for the measurement of the high state of wide-band voltage pulses with 87 dB common-mode rejection ratio and ±0.65 ppm 1-day offset stability

    Science.gov (United States)

    Arpaia, Pasquale; Baccigalupi, Carlo; Martino, Michele

    2015-09-01

    An improved analogue front-end for measuring the high state of trapezoidal voltage pulses with transition duration of 3 μs is presented. A new measurement system, composed by a front-end and the state-of-the-art acquisition board NI PXI-5922, has been realized with improved Common Mode Rejection Ratio (CMRR) of more than 87 dB at DC and 3-sigma stability of ±0.65 ppm over 1 day. After highlighting the main design enhancements with respect to state-of-the-art solutions, the CMRR measurement is reported. The output drift due to temperature and humidity is assessed to be negligible. Finally, the worst-case repeatability is measured both with shorted-to-ground inputs and with an applied common-mode voltage of 10 V, which represents the nominal working condition.

  9. Enhanced analogue front-end for the measurement of the high state of wide-band voltage pulses with 87 dB common-mode rejection ratio and ±0.65 ppm 1-day offset stability

    CERN Document Server

    AUTHOR|(SzGeCERN)712364; Arpaia, Pasquale; Martino, Michele

    2015-01-01

    An improved analogue front-end for measuring the high state of trapezoidal voltage pulses with transition duration of 3 μs is presented. A new measurement system, composed by a front-end and the state-of-the-art acquisition board NI PXI-5922, has been realized with improved Common Mode Rejection Ratio (CMRR) of more than 87 dB at DC and 3-sigma stability of }0.65 ppm over 1 day. After highlighting the main design enhancements with respect to state-of-the-art solutions, the CMRR measurement is reported. The output drift due to temperature and humidity is assessed to be negligible. Finally, the worst-case repeatability is measured both with shorted-to-ground inputs and with an applied common-mode voltage of 10 V, which represents the nominal working condition.

  10. Cable-Dispensing Cart

    Science.gov (United States)

    Bredberg, Alan S.

    2003-01-01

    A versatile cable-dispensing cart can support as many as a few dozen reels of cable, wire, and/or rope. The cart can be adjusted to accommodate reels of various diameters and widths, and can be expanded, contracted, or otherwise reconfigured by use of easily installable and removable parts that can be carried onboard. Among these parts are dispensing rods and a cable guide that enables dispensing of cables without affecting the direction of pull. Individual reels can be mounted on or removed from the cart without affecting the other reels: this feature facilitates the replacement or reuse of partially depleted reels, thereby helping to reduce waste. Multiple cables, wires, or ropes can be dispensed simultaneously. For maneuverability, the cart is mounted on three wheels. Once it has been positioned, the cart is supported by rubber mounts for stability and for prevention of sliding or rolling during dispensing operations. The stability and safety of the cart are enhanced by a low-center-of-gravity design. The cart can readily be disassembled into smaller units for storage or shipping, then reassembled in the desired configuration at a job site.

  11. Brillouin distributed temperature sensing system for monitoring of submarine export cables of off-shore wind farms

    Science.gov (United States)

    Marx, Benjamin; Rath, Alexander; Kolm, Frederick; Schröder, Andreas; Buntebarth, Christian; Dreß, Albrecht; Hill, Wieland

    2016-05-01

    For high-voltage cables, the maximum temperature of the insulation must never be exceeded at any location and at any load condition. The local temperatures depend not only on the cable design and load history, but also on the local thermal environment of the cable. Therefore, distributed temperature monitoring of high-voltage cables is essential to ensure the integrity of the cable at high load. Especially, the load of the export cables of wind farms varies strongly in dependence on weather conditions. In this field study, we demonstrate the measurement performance of a new, robust Brillouin distributed temperature sensing system (Brillouin-DTS). The system is based on spontaneous Brillouin scattering and does not require a fibre loop. This is essential for long submarine high-voltage cables, where normally no loop can be formed in the seabed. It is completely passively cooled and does not contain any moving or wearing parts. The instrument is dedicated for use in industrial and other rough environments. With a measuring time below 10 min, the temperature resolution is better than 1 °C for distances up to 50 km. In the field study, the submarine export cable of an off-shore wind farm has been monitored. The temperature profile of the export cable shows several hot spots, mostly located at cable joints, and also several cold spots.

  12. 高压脉冲电参数对果蔬介电特性的影响机理分析%Influence Mechanism of High-voltage Pulsed Electric Parameters on Dielectric Properties of Fruits and Vegetables

    Institute of Scientific and Technical Information of China (English)

    马飞宇; 郭玉明

    2013-01-01

    The high voltage pulse electric field pretreatment can improve the freeze-drying rate of fruits and vegetables and reduce energy consumption .But when researching fruit and vegetable dielectric property about the changes of on -line monitoring freeze-dried moisture content ,high-voltage pulsed electric field should be considered the influence of electri-cal parameter on dielectric properties of fruit and vegetable .In the cellular level , high-voltage pulsed electric fields effects fruits and vegetables , analyzing the influence of electric parameters on dielectric properties of fruit and vegetable . For equivalent circuit model of fruits and vegetables biological tissue , electrical parameters influence on dielectric proper-ties of fruit and vegetable , such as fruit and vegetable equivalent capacitance and equivalent impedance , which were summarized and analyzed about mechanism to provide a reference on high voltage pulse electric field pretreatment fruit and vegetable processing parameters optimization .%高压脉冲电场预处理果蔬可以提高果蔬冻干速率、降低能耗。但研究运用果蔬介电特性在线监测冻干水分变化时,需要考虑高压脉冲电场电参数对果蔬介电特性的影响。为此,针对高压脉冲电场作用果蔬细胞层面,分析了电参数对果蔬介电特性的影响,对果蔬生物组织等效电路模型和电参数对果蔬等效电容、等效阻抗等介电特性的影响等方面进行了综述分析及机理分析,为高压脉冲电场预处理果蔬工艺参数优化提供了参考。

  13. 应用负高压脉冲技术提高植物空气净化能力的探讨%Application of Negative High-voltage Pulse Technology to Improve Air Purification Ability of Plants

    Institute of Scientific and Technical Information of China (English)

    杨运经; 习岗; 刘锴; 张晓辉

    2011-01-01

    现代城市中的室内空气污染日益严重,室内空气污染的净化与治理已成为社会发展中迫切需要解决的关键科技问题之一.为此,根据植物电信号的低频特征与电共振原理,利用极低频负高压脉冲连续刺激盆栽吊兰植物的根际土壤,使吊兰叶片产生了显著的空气负离子倍增效应.在此基础上依据评价空气质量的常用指标:单极系数q、安培空气质量评价系数CI、空气负离子系数P和森林空气离子评价指数FCI,对应用负高压脉冲技术提高植物的空气净化能力进行了计算与分析.结果表明,极低频负高压脉冲电场可以有效地提高植物的空气净化能力,提出了极低频负高压脉冲电场介导的植物空气净化新技术.%Purification of indoor air pollution has become one of the key technologies of social development. An extremely low frequency high voltage pulse generator was designed according to the characteristics of plants electrical signals and the principle of electrical resonance. The soil of potted broadleaf bracket-plant (Chlorophytum como-sum) was continuously stimulated by negative high voltage pulses with very low frequency, the high concentration of negative air ions appeared around the plant leaves, and the multiplier effect of negative air ion from leave of broadleaf bracket-plant was produced. Then, the ability of plant air purification was calculated and analyzed according to common evaluation indicators of air quality such as single polar factor q, air quality assessment coefficient CI, negative ion air coefficient P and the forest air ion evaluation index FCI. The results show that the extremely low-frequency negative high voltage pulse can enhance the ability of plant to air purification. A new technology of indoor air pollution control and restoration based on negative high-voltage pulse technology is proposed.

  14. On the submarine communication cable JASC ground self-potential stability

    Science.gov (United States)

    Starjinsky, S. S.; Nikiforov, V. M.

    2005-09-01

    This investigation was undertaken for searching the source of linear trends in JASC submarine cable data over the time interval of 6 years and estimating the electrode noise level. One of the reasons for a trend is probably the potential instability in the cable ground, which happened because the titanium electrodes of the ground were placed in sea water that is electrochemically active. To study this phenomenon, we have registered the voltage variations of three titanium JASC cable electrodes, which were closely spaced (~15 cm) and placed at a depth of ~15 m near the coast for 70 days, synchronously with JASC cable voltage observations. The electrode noise level and coherence between channels were estimated and linear trends in electrode pair voltage variation were revealed. The estimated linear trend magnitude is about 0.28 mV/day, which is comparable with 0.21 mV/day earlier observed in JASC submarine cable data. We concluded that the linear trend in JASC cable data is, at least partly, probably caused by the titanium electrodes potential variations. This linear trend should be registered simultaneously with JASC cable voltage observation, keeping in mind the possibility of finding a procedure for removing it, in order to enhance the signal/noise ratio in data.

  15. Beamlet pulsed-power system

    Energy Technology Data Exchange (ETDEWEB)

    Larson, D.

    1996-06-01

    The 13-MJ Beamlet pulsed-power system provides power to the 512 flash lamps in the cavity and booster amplifiers. Since the flash lamps pump all of the apertures in the 2 x 2 amplifier array, the capacitor bank provides roughly four times the energy required to pump the single active beam line. During the 40 s prior to the shot, the capacitors are charged by constant-current power supplies. Ignitron switches transfer the capacitor energy to the flash lamps via coaxial cables. A preionization system triggers the flash lamps and delivers roughly 1 % of the capacitor energy 200 {mu}s prior to the main discharge. This is the first time flash-lamp preionization has been used in a large facility. Preionization improves the amplifier efficiency by roughly 5% and increases the lifetime of the flash lamps. LabVIEW control panels provide an operator interface with the modular controls and diagnostics. To improve the reliability of the system, high-energy-density, self-healing, metallized dielectric capacitors are used. High-frequency, voltage-regulated switching power supplies are integrated into each module on Beamlet, allowing greater independence among the modules and improved charge voltage accuracy, flexibility, and repeatability.

  16. Negative differential mobility for negative carriers as revealed by space charge measurements on crosslinked polyethylene insulated model cables

    Energy Technology Data Exchange (ETDEWEB)

    Teyssedre, G., E-mail: gilbert.teyssedre@laplace.univ-tlse.fr; Laurent, C. [Université de Toulouse, UPS, INPT, LAPLACE (Laboratoire Plasma et Conversion d' Energie), 118 route de Narbonne, F-31062 Toulouse cedex 9 (France); CNRS, LAPLACE, F-31062 Toulouse (France); Vu, T. T. N. [Université de Toulouse, UPS, INPT, LAPLACE (Laboratoire Plasma et Conversion d' Energie), 118 route de Narbonne, F-31062 Toulouse cedex 9 (France); Electric Power University, 235 Hoang Quoc Viet, 10000 Hanoi (Viet Nam)

    2015-12-21

    Among features observed in polyethylene materials under relatively high field, space charge packets, consisting in a pulse of net charge that remains in the form of a pulse as it crosses the insulation, are repeatedly observed but without complete theory explaining their formation and propagation. Positive charge packets are more often reported, and the models based on negative differential mobility(NDM) for the transport of holes could account for some charge packets phenomenology. Conversely, NDM for electrons transport has never been reported so far. The present contribution reports space charge measurements by pulsed electroacoustic method on miniature cables that are model of HVDC cables. The measurements were realized at room temperature or with a temperature gradient of 10 °C through the insulation under DC fields on the order 30–60 kV/mm. Space charge results reveal systematic occurrence of a negative front of charges generated at the inner electrode that moves toward the outer electrode at the beginning of the polarization step. It is observed that the transit time of the front of negative charge increases, and therefore the mobility decreases, with the applied voltage. Further, the estimated mobility, in the range 10{sup −14}–10{sup −13} m{sup 2} V{sup −1} s{sup −1} for the present results, increases when the temperature increases for the same condition of applied voltage. The features substantiate the hypothesis of negative differential mobility used for modelling space charge packets.

  17. VT Cable Modem Systems 2013

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The VT Cable Modem dataset (CABLEMOD2013) includes lines depicting the extent of Vermont's cable modem broadband system as of 6/30/2013. This data...

  18. VT Cable Modem Systems 2005

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The VT Cable Modem dataset (CABLEMOD2005) includes lines depicting the extent of Vermont's cable modem broadband system as of 12/31/2005. This...

  19. Cable historical operating temperature estimator

    Energy Technology Data Exchange (ETDEWEB)

    Leon de, F.; St-Roch, P.; Beauregard, C. [Cyme International, St-Bruno, PQ (Canada)

    2006-07-01

    A tool designed to accurately determine the thermal age of underground cables was described. The cable historical operating temperature estimate (CHOTE) is a software application designed to identify which cables have exceeded their normal and emergency operating temperatures. CHOTE is also capable of predicting when cables are likely to reach their maximum design temperature in the future. The system operates by processing archived loading information from data acquisition systems in order to automatically analyze all the thermal sections of a system. Cables that exceed their emergency and normal temperatures for the longest amount of time are ranked first, and outputs display when and where the hot spots have occurred. CHOTE is also able to study the impact of the addition of new cables and to determine the remaining ampacity of cables installed in a given duct bank. It was concluded that the CHOTE system can help in the efficient management of cable repairs and installations. 28 refs., 7 figs.

  20. Space Flight Cable Model Development

    Science.gov (United States)

    Spak, Kaitlin

    2013-01-01

    This work concentrates the modeling efforts presented in last year's VSGC conference paper, "Model Development for Cable-Harnessed Beams." The focus is narrowed to modeling of space-flight cables only, as a reliable damped cable model is not yet readily available and is necessary to continue modeling cable-harnessed space structures. New experimental data is presented, eliminating the low-frequency noise that plagued the first year's efforts. The distributed transfer function method is applied to a single section of space flight cable for Euler-Bernoulli and shear beams. The work presented here will be developed into a damped cable model that can be incorporated into an interconnected beam-cable system. The overall goal of this work is to accurately predict natural frequencies and modal damping ratios for cabled space structures.

  1. Simple Program to Investigate Hysteresis Damping Effect of Cross-Ties on Cables Vibration of Cable-Stayed Bridges

    Directory of Open Access Journals (Sweden)

    Panagis G. Papadopoulos

    2012-01-01

    Full Text Available A short computer program, fully documented, is presented, for the step-by-step dynamic analysis of isolated cables or couples of parallel cables of a cable-stayed bridge, connected to each other and possibly with the deck of the bridge, by very thin pretensioned wires (cross-ties and subjected to variation of their axial forces due to traffic or to successive pulses of a wind drag force. A simplified SDOF model, approximating the fundamental vibration mode, is adopted for every individual cable. The geometric nonlinearity of the cables is taken into account by their geometric stiffness, whereas the material nonlinearities of the cross-ties include compressive loosening, tensile yielding, and hysteresis stress-strain loops. Seven numerical experiments are performed. Based on them, it is observed that if two interconnected parallel cables have different dynamic characteristics, for example different lengths, thus different masses, weights, and geometric stiffnesses, too, or if one of them has a small additional mass, then a single pretensioned very thin wire, connecting them to each other and possibly with the deck of the bridge, proves effective in suppressing, by its hysteresis damping, the vibrations of the cables.

  2. 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).

  3. Development of an improved extruded dielectric cable rated 230 kV

    Energy Technology Data Exchange (ETDEWEB)

    Blais, L D; Traut, R T; Bolden, G N

    1977-05-01

    Work performed on developing an improved 230 kV extruded solid dielectric cable, the techniques of jointing such cables and the testing of terminations suitable for operation at that voltage level are described. Difficulties were encountered during manufacture in applying the semi-conducting extruded conductor shield. A new higher melt point compound solved the problem. A joint capable of operating at the 230 kV level was developed but showed a deficiency under voltage impulse testing while the conductor was at elevated temperature. A reduction in contract scope terminated this effort. Two terminals rated for 230 kV were found to be commercially available from domestic manufacturers. The limited testing performed showed them to be compatible with the cable cross-linked polyethylene insulation and electrically sound under 60 Hertz testing. No direct voltage or impulse voltage testing was performed on the terminations. A sample circuit, consisting of cable and joint, was subjected to impulse voltages at both room temperature and normal conductor operating temperature of 90/sup 0/C. While the cable only was able to withstand voltage impulses in excess of the Basic Impulse Level (BIL) at room temperature, it failed at BIL while conductor was heated to 90/sup 0/C. In like manner, a cable and joint circuit was assembled. Similar voltages were impressed at room temperature without incident. The joint failed at 90/sup 0/C conductor temperature. Cable, joint and termination were assembled in a simulated circuit and subjected to conductor loading to elevate temperature while 60 Hz voltages in excess of normal operating levels were continuously applied.

  4. An Analysis and Administration System for Cable Partial Discharge Data Based on Oscillatory Wave Voltage Method%基于振荡波电压法的电缆局部放电数据分析与管理系统

    Institute of Scientific and Technical Information of China (English)

    熊俊; 陆国俊

    2013-01-01

    基于振荡波电压法,考虑了局部放电信号的入射波形与反射波形时间限制、相似性、时频衰减性等因素,开发了一个电缆局部放电数据分析与管理系统。该系统与现场采集的原始数据兼容,具有定位算法精度高、数据分散性较小的特点,且系统能够实现电缆局部放电信息台账管理、状态评估与风险管理及打印报表等。%Based on the oscillatory wave voltage method, and taking the factors into account such as the time limit, similarity, time-frequency attenuation of incident wave and reflected wave in partial discharge signal, this paper develops an analysis and administration system for cable partial discharge data. The system is compatible with the original data collected from spot, and has the characteristics of high positioning accuracy and low data dispersion, and is able to realize the functions such as the account management of partial discharge informationt, condition assessment, risk management and report printing.

  5. Power Capability in Low Voltage DC Distribution Systems

    Directory of Open Access Journals (Sweden)

    C.O. Gecan

    2009-12-01

    Full Text Available Recent developments in power electronics components enable the use of power electronics in Low Voltage (LV networks. This development makes the model of a Low Voltage Direct Current (LVDC distribution system possible. The technical and economical benefits of this technology make possible the alternative hypothesis of using DC instead of AC distribution systems. Some aspects, such as increasing the capability of the existing lines, interconnecting distributed generation units and even supplying in DC some loads are creating additional requirements of using a LVDC distribution system. The paper presents some general considerations regarding cables used in a LVAC distribution system and different line reconfigurations witch enable the use of cobles in a LVDC distribution system. The reconfigurations are presented in respect of the DC network topologies: unipolar and bipolar. The central aim of this paper is to investigate capability of power transmission and to calculate the transmission distance for cables used in Low Voltage AC and DC distribution systems. Capability computation is considered in respect of two constrains imposed in the cables cross section selection: cable thermal limit and the maximum allowable voltage drop. Cable thermal limit is represented in calculations by the maximum rated current. The equations used to calculate the power capability are presented for single-phase and threephase AC networks and unipolar and bipolar DC networks. Based on these equations, comparisons between power capability of cables with different cross sections used in Low Voltage DC and AC distribution systems are realized and presented.

  6. Temperature Distribution and Critical Current of Long HTS Cables Cooled with Subcooled Liquid Nitrogen

    Science.gov (United States)

    Vyatkin, V. S.; Ivanov, Y. V.; Watanabe, H.; Chikumoto, N.; Yamaguchi, S.

    2017-07-01

    Cooling of the long HTS power transmission lines performs by pumping of subcooled liquid nitrogen (LN2) along the cable. The temperature of LN2 along the cable increases due to the heat losses of the cryostat and heat generation in the HTS cable. The experiment using test cable line in Ishikari shows that flow rate of 35 L/min retains increasing of LN2 temperature by 1 K per 1 km of length. The technology when the back flow of LN2 cools the radiation shield surrounding the cable pipe is also applied in Ishikari-2 project. In this case the ambient heat flow into cable pipe is 50 times less than that without radiation shield. Back flow of LN2 removes almost all heat coming from the environment. When transport current is close to the critical value the Joule heat of HTS cable is significant. This heat additionally increases the temperature of LN2 flowing along the HTS cable. Near the outlet the temperature of HTS cable is maximal and the local critical current is minimal. The current matching critical current criterion of average electrical field of E 0 = 10-4 V/m provides the voltage drop and significant Joule heat at the hot end of the cable. It can lead the damage of the cable. The present work contains analysis of temperature distribution along the cable and the way to achieve the fail-safe operation of long HTS cable cooled by subcooled LN2. We also performed extrapolation of obtained results for several times longer cable lines by decreasing the LN2 flow rate.

  7. The Danish Superconducting Cable Project

    DEFF Research Database (Denmark)

    Tønnesen, Ole

    1997-01-01

    The design and construction of a superconducting cable is described. The cable has a room temperature dielectric design with the cryostat placed inside the electrical insulation.BSCCO 2223 superconducting tapes wound in helix form around a former are used as the cable conductor. Results from...

  8. High Temperature Superconducting Underground Cable

    Energy Technology Data Exchange (ETDEWEB)

    Farrell, Roger, A.

    2010-02-28

    The purpose of this Project was to design, build, install and demonstrate the technical feasibility of an underground high temperature superconducting (HTS) power cable installed between two utility substations. In the first phase two HTS cables, 320 m and 30 m in length, were constructed using 1st generation BSCCO wire. The two 34.5 kV, 800 Arms, 48 MVA sections were connected together using a superconducting joint in an underground vault. In the second phase the 30 m BSCCO cable was replaced by one constructed with 2nd generation YBCO wire. 2nd generation wire is needed for commercialization because of inherent cost and performance benefits. Primary objectives of the Project were to build and operate an HTS cable system which demonstrates significant progress towards commercial progress and addresses real world utility concerns such as installation, maintenance, reliability and compatibility with the existing grid. Four key technical areas addressed were the HTS cable and terminations (where the cable connects to the grid), cryogenic refrigeration system, underground cable-to-cable joint (needed for replacement of cable sections) and cost-effective 2nd generation HTS wire. This was the world’s first installation and operation of an HTS cable underground, between two utility substations as well as the first to demonstrate a cable-to-cable joint, remote monitoring system and 2nd generation HTS.

  9. Economical Aspects of Superconducting Cable

    Science.gov (United States)

    Ohya, Masayoshi

    High-temperature superconducting (HTS) cables are expected to resolve technical problems with power grids because they put large-capacity, low-loss power transmission into a compact package. One problem is replacing old 275-kV oil filled (OF) cables with cross-linked polyethylene insulated vinyl sheath cables (XLPE cables). This is difficult because XLPE cable has a lower transmission capacity than OF cable. In addition, the high concentration of public infrastructure underground makes it extremely difficult to build new ones. However, if 66-kV HTS cables can be installed inside existing underground conduits and can achieve a power capacity equivalent to conventional 275-kV cables, construction costs could be significantly reduced. Moreover, if XLPE cables are used for a 1,000 MVA-class transmission line, then three circuits of nine 275-kV single-core cables would be required, which would incur a transmission loss of 90 W/m/cct. Three circuits of three 66-kV Three-in-One HTS cables, however, with an AC loss of 1 W/m/ph@3 kA, heat invasion of 2 W/m, and cooling system efficiency of 0.1, would reduce transmission loss to less than three-fifths that of XLPE cables.

  10. 30 CFR 75.607 - Breaking trailing cable and power cable connections.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Breaking trailing cable and power cable... LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Trailing Cables § 75.607 Breaking trailing cable and power cable connections. Trailing cable and power cable connections...

  11. Modeling of long High Voltage AC Underground

    DEFF Research Database (Denmark)

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

    2010-01-01

    This paper presents the work and findings of a PhD project focused on accurate high frequency modelling of long High Voltage AC Underground cables. The project is cooperation between Aalborg University and Energinet.dk. The objective of the project is to investigate the accuracy of most up to date...

  12. Pediatrics and Cable Television.

    Science.gov (United States)

    Wallerstein, Edward; And Others

    The Department of Community Medicine of the Mount Sinai School of Medicine (New York City), in cooperation with the TelePrompTer Corporation and with funding from the Health Services and Mental Health Administration of the Department of Health, Education, and Welfare, has developed a bidirectional television system using coaxial cable which links…

  13. Cable Aerodynamic Control

    DEFF Research Database (Denmark)

    Kleissl, Kenneth

    to a categorization of the different control technics together with an identification of two key mechanisms for reduction of the design drag force. During this project extensive experimental work examining the aerodynamics of the currently used cable surface modifications together with new innovative proposals have...

  14. Comparison of cable ageing

    Science.gov (United States)

    Plaček, Vít; Kohout, Tomáš

    2010-03-01

    Two cable types, which currently are used in nuclear power plants (NPP) and which are composed by jacket/insulation materials, i.e. PVC/PVC and PVC/PE, were exposed to accelerated ageing conditions, in order to simulate their behavior after 10 years in service. The cables were aged under two different test conditions: With relatively high accelerating ageing speed:Radiation ageing was carried out at room temperature at a dose rate of 2900 Gy/h, followed by thermal ageing at 100 °C. This accelerated ageing condition was fairly fast, but still in compliance with the standards. With moderate ageing speed:The radiation and thermal ageing was performed simultaneously (superimposed) at a dose rate of 2.7-3.7Gy/h and a temperature of 68-70 °C. Such a test condition seems to be very close to the radiation and temperature impact onto the cables in the real NPP service. Finally, mechanical properties were measured to characterize the ageing status of the cables. The purpose of this study was to compare degradation effects, derived from both ageing methods, and to demonstrate that results obtained from high values of accelerating parameters and from fast ageing simulation can be very different from reality. The observed results corroborated this assumption.

  15. Lightweight Electric Power Cable.

    Science.gov (United States)

    1982-09-01

    8I~ .4 111 162 MICROCi Pi RL’ LUHION TESI CHARI "LIGHTWEIGHT ELECTRIC POWER CABLE" FINAL TECHNICAL REPORT SEPTEMBER 30, 1981 to SEPTEMBER 30, 1982... Vulcanized by heat to crosslink. TPE (Thermoplastic Elastomer) - Polymers having elastomeric proper- ties. Used as thermoplastics - melt formed by

  16. Handbook for photovoltaic cabling

    Energy Technology Data Exchange (ETDEWEB)

    Klein, D. N.

    1980-08-01

    This volume, originally written as part of the Interim Performance Criteria Document Development Implementation Plan and Procedures for Photovoltaic Energy Systems, is an analysis of the several factors to be considered in selecting cabling for photovoltaic purposes. These factors, correspoonding to chapter titles, are electrical, structural, safety, durability/reliability, and installation. A glossary of terms used within the volume is included for reference.

  17. Signal enhancement in laser-induced breakdown spectroscopy using fast square-pulse discharges

    Science.gov (United States)

    Sobral, H.; Robledo-Martinez, A.

    2016-10-01

    A fast, high voltage square-shaped electrical pulse initiated by laser ablation was investigated as a means to enhance the analytical capabilities of laser Induced breakdown spectroscopy (LIBS). The electrical pulse is generated by the discharge of a charged coaxial cable into a matching impedance. The pulse duration and the stored charge are determined by the length of the cable. The ablation plasma was produced by hitting an aluminum target with a nanosecond 532-nm Nd:YAG laser beam under variable fluence 1.8-900 J cm- 2. An enhancement of up to one order of magnitude on the emission signal-to-noise ratio can be achieved with the spark discharge assisted laser ablation. Besides, this increment is larger for ionized species than for neutrals. LIBS signal is also increased with the discharge voltage with a tendency to saturate for high laser fluences. Electron density and temperature evolutions were determined from time delays of 100 ns after laser ablation plasma onset. Results suggest that the spark discharge mainly re-excites the laser produced plume.

  18. 用于等离子体离子辐照的新型阶梯型脉冲高压电路研制%Novel Circuit Producing Pulsed High Voltage with Discrete Steps for Ion Bombardment in Plasma Immersion

    Institute of Scientific and Technical Information of China (English)

    石经纬; 田修波; 巩春志; 杨士勤

    2011-01-01

    为满足等离子体离子辐照和复合表面改性处理技术的发展,提出了基于Marx发生器,通过调节驱动信号延时,实现放电IGBT开关不同时导通,从而获得阶梯型脉冲高压输出的电路设计思想,并验证了其可行性.试验结果显示,该电路可输出脉冲峰值电压10 kV,峰值电流30 A,脉冲宽度3~30μs,脉冲频率20~500 Hz,最大电压阶数10阶的高压脉冲.1个原边、10个副边结构的驱动高压隔离变压器及延时驱动电路结构紧凑,抗干扰能力强.IGBT驱动反向偏置脉冲电压能够满足IGBT快速关断和过流保护的要求.等离子体负载下电路特性测试结果表明,该电路能够适应实际的工作环境,为复合处理技术的发展提供技术支持.该电路结构通过Marx单元叠加可以拓展到更高的脉冲电压输出.%A novel circuit which is capable of producing pulsed high voltage with discrete steps based on Marx generator has been developed for ion bombardment in plasma immersion, and it is realized by means of each discharge IG-BT switching on at different time by adjusting the delay time of drive signals. A compact and robust circuit is designed, using a high-voltage isolation transformer with one primary winding and ten secondary windings for control signal and designed delay drive unit, to meet the requirements of rapidity of switch off and overcurrent protection of IGBT. A pulsed high voltage with amplitude of 10kV, peak current of 30A, pulse width of 3~30 μs, frequency of 20~500 Hz and voltage steps of 10 are achieved. The developed circuit with several kinds of output voltage waveforms is applied to the plasma load with high reliability, and possesses the practicability for ion bombardment or hy-. Brid surface modification in plasma immersion mode. The higher pulse voltage may be achieved using more Marx link with the same control mode for wide application.

  19. Simulation and Modeling of 24-Pulse STATCOM in EMTDC/PSCAD Program in Order to Regulate Voltage and Dynamic Stability Improvement

    Directory of Open Access Journals (Sweden)

    Naser Parhizgar

    2012-02-01

    Full Text Available This study starts from the proof of Low Frequency Oscillation (LFO and then points out that there are many ways to study the LFO including its rejection measures. Also in this study one control system is planned in order to regulate voltage at common coupling point (PCC in where STATCOM is installed. This research present a single-machine infinite-bus system with one static synchronous compensator (STATCOM asymmetrically installed as a current source. Together with a classical generator model, the simplest power equation is obtained to give direct and clear physical concepts on synchronizing and damping torque factors. According to the primary equations, some basic issues, such as the relationship of voltage gain control and damping control, operating conditions, and the installation of STATCOM, are investigated in this research. Then, with assistance of proportional controller for voltage regulation and damp control, the digital simulation indicate the necessity of control of STATCOM in damping power system oscillations and supplying regulated voltage support.

  20. Flat conductor cable commercialization project

    Science.gov (United States)

    Hogarth, P.; Wadsworth, E.

    1977-01-01

    An undercarpet flat conductor cable and a baseboard flat conductor cable system were studied for commercialization. The undercarpet system is designed for use in office and commercial buildings. It employs a flat power cable, protected by a grounded metal shield, that terminates in receptacles mounted on the floor. It is designed to interface with a flat conductor cable telephone system. The baseboard system consists of a flat power cable mounted in a plastic raceway; both the raceway and the receptacles are mounted on the surface of the baseboard. It is designed primarily for use in residential buildings, particularly for renovation and concrete and masonry construction.

  1. High voltage pulse electron beam control strategy and influence on weld bead shape%高压脉冲电子束的控制及其对焊缝形貌影响

    Institute of Scientific and Technical Information of China (English)

    许海鹰; 余伟; 左从进

    2011-01-01

    研制出一台150 kV/30 kW高压脉冲电子束焊机,介绍了控制脉冲束流产生的偏压脉冲电源拓扑电路结构及脉冲束流频率、占空比、束流基值、束流峰值的调节控制技术.在0~1 kHz频率范围内,该电源可输出最大幅值200 mA的脉冲电子束束流,且工艺参数调节方便.分别采用脉冲束流与连续束流电子束工艺焊接了1Cr18Ni9Ti奥氏体不锈钢,对不同工艺的焊缝形貌进行了对比分析.与连续束流电子束焊接工艺相比,采用脉冲电子束焊接工艺的焊缝熔深增加,深宽比增大;对于脉冲电子束焊接工艺,占空比给定时,随着束流频率增加,焊接缺陷减少.试验结果表明:脉冲束流频率、占空比是影响焊缝成形的关键工艺参数;脉冲调制方式控制偏压是获得高压脉冲电子束的理想控制技术之一.%A 150 kV/30 kW high voltage pulse electron beam welding power source was developed.The bias pulse power source topology and control technique about base beam current,peak beam current,pulse beam duty,pulse beam frequency were introduced.Not only the biggest peak beam current up to 200 mA has been exported by this power source at 0-1 kHz,but also weld technology parameters are expediently adjusted.The 1Cr18Ni9Ti stainless steel work pieces had been welded by electron beam welding and pulse electron beam welding.These weld bead shapes had been studied and analyzed.In contrast with electron beam welding,weld penetration will be increased by pulse electron beam welding introduced.At the immovable pulse beam duty,the weld faults will be reduced with the pulse beam frequency being increased.Through these weld tests,besides beam frequency and duty are substantiated key technique parameters for weld shapes,it also shows that pulse modulated bias power source technique is an applicable technology to achieve high voltage pulse electron beam.

  2. A superconducting transformer system for high current cable testing.

    Science.gov (United States)

    Godeke, A; Dietderich, D R; Joseph, J M; Lizarazo, J; Prestemon, S O; Miller, G; Weijers, H W

    2010-03-01

    This article describes the development of a direct-current (dc) superconducting transformer system for the high current test of superconducting cables. The transformer consists of a core-free 10,464 turn primary solenoid which is enclosed by a 6.5 turn secondary. The transformer is designed to deliver a 50 kA dc secondary current at a dc primary current of about 50 A. The secondary current is measured inductively using two toroidal-wound Rogowski coils. The Rogowski coil signal is digitally integrated, resulting in a voltage signal that is proportional to the secondary current. This voltage signal is used to control the secondary current using a feedback loop which automatically compensates for resistive losses in the splices to the superconducting cable samples that are connected to the secondary. The system has been commissioned up to 28 kA secondary current. The reproducibility in the secondary current measurement is better than 0.05% for the relevant current range up to 25 kA. The drift in the secondary current, which results from drift in the digital integrator, is estimated to be below 0.5 A/min. The system's performance is further demonstrated through a voltage-current measurement on a superconducting cable sample at 11 T background magnetic field. The superconducting transformer system enables fast, high resolution, economic, and safe tests of the critical current of superconducting cable samples.

  3. Research of reduced common-mode voltage technique with nonzero vector pulse width modulation for three-phase inverters%三相逆变器的无零矢量共模电压抑制技术研究

    Institute of Scientific and Technical Information of China (English)

    章勇高; 邝光健; 龙立中

    2013-01-01

    The common-mode suppression techniques with nonzero vector pulse width modulation (NZPWM) for three-phase inverters are studied. They are random state pulse width modulation (RSPWM), active zero state PWM1 (AZSPWM1), active zero state PWM3 (AZSPWM3) and near state PWM (NSPWM). Firstly, the operation areas of modulation factor and reference voltage vector with different modulation strategies are analyzed. The results show that RSPWM has a smaller operation area than other three NZPWM and is suitable for the application with lower modulation ratio. Secondly, the DC voltage utilization rate and output harmonic of different NZPWM are researched and compared with that of traditional space vector modulation (SVM) by using theoretical analysis and simulation. The results show that AZPWM1, AZPWM3 and NSPWM can not only suppress the common mode voltage of three-phase inverters efficiently, but also maintain high DC voltage utilization rate. However, three-phase inverters with NSPWM have the higher output harmonic comparing with the traditional SVM. The research results provide theoretical basis and instruction for the selection of common mode voltage suppression technique with NZPWM for three-phase inverters and its further study.%  研究了三相逆变器的 RSPWM、AZSPWM1、AZSPWM3和 NSPWM 无零矢量共模电压抑制技术。首先,分析了不同调制策略的调制因数和参考电压矢量的工作区间,说明了 RSPWM 的工作区间较小,适用于低调制比工作场合。再次,利用理论分析和仿真方法,研究了无零矢量调制策略的直流电压利用率和输出谐波特性,并与传统 SVM 调制策略比较。结果表明,AZSPWM1、AZSPWM3和 NSPWM 调制策略能够有效地抑制三相逆变器共模电压,同时保持了较高的直流电压利用率。但相对 SVM 调制策略,三相逆变器的输出谐波含量有所增大。研究结果为三相逆变器的无零矢量共模电压抑制技术的选用及进一步研究提供了理论依据和指导。

  4. Analysis and simulation of switching surge generation when disconnecting a combined 400 kV cable/overhead line with shunt reactor

    DEFF Research Database (Denmark)

    Bak, Claus Leth; Wiechowski, Wojciech Tomasz; Søgaard, Kim

    2007-01-01

    400 kV power system and initiated by Danish TSO Energinet.dk after having measured the voltage of the cable/overhead line after disconnection. A particular decaying dynamic phase voltage containing voltages higher than the voltage before disconnection appeared. A simulation model for the entire system...

  5. Tapping the television cable.

    Science.gov (United States)

    Clarke, M; Findlay, A; Canac, J F; Vergez, A

    1996-01-01

    Immediate access to patient data is essential to support good clinical decision making and support. However, away from the surgery, the doctor is currently unable to have any access to the clinical database. Solutions exist to support remote access, such as modems or radio data networks, but these are slow, with typical speeds in the 2-10 kbaud region. We propose a novel solution, to use the TV cable already installed in many homes. Using this technology, a suitably equipped computer (RF modern) is capable of connecting at speeds in excess of 500 kbaud and will run applications in exactly the same way as if connected to a surgery network: the cable TV becomes a LAN, but on a metropolitan scale. Brunel University, in collaboration with the Cable Corporation, has been piloting such a network. Issues include not only levels of service, but also security on the network and access, since the data are being effectively received in every home. However, close scrutiny of channel use can create closed networks reserved for specific users. The technology involves use of an RF modem to transmit data on a reverse channel (based at 16 MHz) on each subnet to a router at the head end of the cable network. This frequency translates the packet and retransmits it to all the subnets on a forward channel (based at 178 MHz). Each channel occupies the bandwidth normally allocated to one TV channel. Access is based on a modified CSMA/CD protocol, so treating the cable network as single multiple access network. The modem comes as a standard card installed in a PC and appears much as an ethernet card, but at reduced speed. With an NDIS driver it is quite able to support almost any network software, and has successfully demonstrated Novell and TCP/IP. We describe the HomeWorker network and the results from a pilot study being undertaken to determine the performance of the system and its impact on working practice.

  6. 基于固体开关器件的新型高压脉冲驱动源%New high-voltage pulse driving source based on solid switch device

    Institute of Scientific and Technical Information of China (English)

    陈静; 周晓青

    2012-01-01

    The the circuit of the pulse source is introduced briefly. The switch theory of the power MOSFET is expatiated emphatically. The overdriving technique of the power MOSFET grid is investigated to improve the switch speed of the power MOSFET by simulation and experiments. Power MOSFET is used as a switch element in the technology. The ways of improving the output power of the pulse source are analyzed through integrating the techniques of several power MOSFETs in series or in parallel. A high-voltage wide pulse source with the amplitude of output pulse larger than 4 kv, the rise time less than 10 ns and the pulse width wider than 100 ns was obtained.%从MOSFET的开关基理,以仿真与电路实验相结合的方法,研究出了MOSFET栅极的“过”驱动技术,以此来提高MOSFET的开关速度.并结合多个MOSFET的串并联的级联技术,采用多管串联方法来提高脉冲源的输出脉冲幅度,采用多管并联方法来提高脉冲源的其输出脉冲功率,从而得到较大的脉冲宽度.在此研制出了输出脉冲幅度大于4kV、前沿小于10ns、脉冲宽度大于100ns的高压快脉冲源.

  7. Statistical Distribution of Energization Overvoltages of EHV Cables

    DEFF Research Database (Denmark)

    Ohno, Teruo; Bak, Claus Leth; Ametani, Akihiro

    2013-01-01

    those on the overhead lines with respect to maximum, 2%, and mean values. As the minimum value is almost at the same level, standard deviations are smaller for the cables. The obtained statistical distributions in this paper are of a great importance in considering insulation levels of cable systems.......Statistical distributions of switching overvoltages have been used for decades for the determination of insulation levels of extremely high voltage (EHV) systems. Existing statistical distributions obtained in the 1970s are for overhead lines, and statistical distributions of switching overvoltages...

  8. Programmable pulse generator

    CERN Document Server

    Xue Zhi Hua; Duan Xiao Hui

    2002-01-01

    The author introduces the design of programmable pulse generator that is based on a micro-controller and controlled by RS232 interface of personal computer. The whole system has good stability. The pulse generator can produce TTL pulse and analog pulse. The pulse frequency can be selected by EPLD. The voltage amplitude and pulse width of analog pulse can be adjusted by analog switches and digitally-controlled potentiometers. The software development tools of computer is National Instruments LabView5.1. The front panel of this virtual instrumentation is intuitive and easy-to-use. Parameters can be selected and changed conveniently by knob and slide

  9. A Pulsed Electric Field (PEF) bench static system to study bacteria inactivation

    Energy Technology Data Exchange (ETDEWEB)

    Cortese, Pietro; Dellacasa, Giuseppe; Gemme, Roberto [Department of Science and Advanced Technology, Eastern Piedmont University, Viale Teresa Michel 11, 15121-Alessandria (Italy); Bonetta, Sara; Bonetta, Silvia; Carraro, Elisabetta; Motta, Francesca [Department of Environmental and Life Science, Eastern Piedmont University, Viale Teresa Michel 11, 15121-Alessandria (Italy); Paganoni, Marco; Pizzichemi, Marco [Physics Department G. Occhialini, University of Milano-Bicocca, Piazza della Scienza 3, 20126-Milano (Italy)

    2011-06-15

    Pulsed Electric Fields (PEF) technology is a promising non-thermal processing method for inactivation of microorganisms. A small PEF bench system able to treat a 0.4 ml static liquid volume has been built and tested at the laboratories of the Universita del Piemonte Orientale in Alessandria, Italy. The technique used to produce the required fields consists of charging high voltage cables of various lengths and subsequently discharge them on a cylindrical cell. The pulse intensity can be adjusted to reach a maximum electric field in the cell of about 35 kV/cm and the pulse frequency can reach 10 Hz. We describe the PEF system in some detail and, as a benchmark of its performances, we report preliminary results obtained on Escherichia coli (ATCC 25922) at 10{sup 9} Cfu/ml concentration suspended in a McIlvaine buffer (pH 7.2).

  10. Bilinear slack span calculation model. Slack span calculations for high-temperature cables; Bilineares Berechnungsmodell fuer Durchhangberechnungen. Durchhangberechnungen bei Hochtemperaturleitern

    Energy Technology Data Exchange (ETDEWEB)

    Scheel, Joerg; Dib, Ramzi [Fachhochschule Giessen-Friedberg, Friedberg (Germany); Sassmannshausen, Achim [DB Energie GmbH, Frankfurt (Main) (Germany). Arbeitsgebiet Bahnstromleitungen Energieerzeugungs- und Uebertragungssysteme; Riedl, Markus [Eon Netz GmbH, Bayreuth (Germany). Systemtechnik Leitungen

    2010-12-13

    Increasingly, high-temperature cables are used in high-voltage grids. Beyond a given temperature level, their slack span cannot be calculated accurately by conventional simple linear methods. The contribution investigates the behaviour of composite cables at high operating temperatures and its influence on the slack span and presents a more accurate, bilingual calculation method. (orig.)

  11. [Computation of the cross-sectional area of the cable in the power circuit of the X-ray machine].

    Science.gov (United States)

    Meng, Xin-min; Feng, Da-yu

    2007-01-01

    The source impedance of the power circuit in the x-ray machine is analyzed in the paper and based on the voltage drop generated by the impedance, the cross-sectional area of the cable is calculated. In the end, the cross-sectional areas of the cables, corresponding to their respective distances between the transformers and the switchboards are given.

  12. Derivation of Theoretical Formulas of the Frequency Component Contained in the Overvoltage Related to Long EHV Cables

    DEFF Research Database (Denmark)

    Ohno, Teruo; Bak, Claus Leth; Ametani, Akihiro;

    2012-01-01

    Recent studies of long extremely high-voltage (EHV) cables show the importance of performing temporary overvoltage analyses. As the switching of EHV cables can trigger temporary overvoltages, it is important to find the dominant frequency component contained in the switching overvoltages of these...

  13. 110 kV电缆中间接头及本体典型缺陷局部放电特征分析%Partial Discharge Characteristics Analysis of Typical Defects for 110 kV Cable and Joint

    Institute of Scientific and Technical Information of China (English)

    廖雁群; 惠宝军; 夏荣; 徐阳

    2014-01-01

    Six kinds of artificial typical defects of 110 kV cable and joint were produced, and high frequency current transformer (HFCT) was used to couple the PD signals. The PD pulse of different defects in time domain and frequency domain were analyzed. The monocycle pulse waveform and frequen-cy spectrum at different discharge moments of the same defects under the same voltage were studied, and the changes of PD parameters of the cable bulk defects with different degree of damage were analyzed. The results show that when the corrugated aluminum is damaged but the insulation of the cable is undamaged, these defects could not be detected by PD detection. Once the insulation of the cable is damaged, the PD can be detected under lower voltage, but the cable can pass through the with-stand voltage experiment. With the increase of the depth of insulation damage, the initial partial discharge voltage decrease linearly.%针对110 kV XLPE电缆中间接头及本体制作了6种人工典型缺陷,并利用高频电流互感器耦合局部放电信号。对各类缺陷放电脉冲进行时域、频域特征分析,研究同一缺陷相同电压下不同放电时刻单脉冲波形和频谱规律,并对不同受损程度的电缆本体缺陷局部放电参数的变化进行分析。结果表明:当本体电缆波纹铝破损但未伤及主绝缘时,局部放电无法发现该类缺陷;当主绝缘破损时,在较低电压下便可检测到局部放电,但耐压试验依然可以通过,且随着主绝缘破损深度的增加,局部放电起始电压呈线性递减。

  14. Design and Evaluation of 275 kV-3 kA HTS Power Cable

    Science.gov (United States)

    Yagi, M.; Mukoyama, S.; Mitsuhashi, T.; Jun, T.; Liu, J.; Nakayama, R.; Hayakawa, N.; Wang, X.; Ishiyama, A.; Amemiya, N.; Hasegawa, T.; Saitoh, T.; Ohkuma, T.; Maruyama, O.

    A 275 kV 3 kA high temperature superconducting (HTS) cable has been developed in the Materials & Power Applications of Coated Conductors (M-PACC) project. The cable is expected to be put to practical use as the backbone power line in the future because the capacity of 1.5 GW is about the same as overhead transmission lines. The 30 m cable has been designed on the basis of design values that had been obtained by various voltage tests, AC loss measurement tests, short circuit tests, and other elementary tests. Cable insulation was determined by the design stresses and test conditions based on IEC, JEC (Japan electrical standards), and other HTS demonstrations. This cable was also designed to withstand the short circuit test of 63 kA for 0.6 seconds and to have low losses, including AC loss and dielectric loss of 0.8 W/m at 3kA, 275 kV. Based on the design, a 30 m cable was manufactured, and short samples during this manufacturing process were confirmed to have the designed characteristics. Furukawa Electric prepared a demonstration of the 30 m cable with two terminations and a cable joint. The long-term test under a current of 3 kA, and test voltage determined from 30 years of insulation degradation has been conducted since November 2012 at Shenyang in China.

  15. Use of Fourier Transformation for Detection of Faults in Underground Power Cables

    Institute of Scientific and Technical Information of China (English)

    Abhishek Pandey; Nicolas H. Younan

    2011-01-01

    An analysis of underground power cables is performed using Fourier analysis with the objective of detecting fault and average life of the cables. Three types of cables are used in this experiment: a normal cable, a shorted cable, and a cable with holes. The impedance in each case is computed and Fourier transformation is applied so that the re- suiting impedance magnitude and impedance phase can be examined in the frequency domain. Various windowing tech- niques are applied to the experimental data to eliminate any interference. Fourier analysis is then applied to the imped- ance data calculated from both the sending end voltage and differential voltage. This analysis reveals differences in the frequency response of the three different types of a cable and can eventually be used as a measure for fault detection. Preliminary results reveal the differences in the frequency response. Accordingly, Fourier type methods can be effectively used as low cost and viable solutions to identify and detect faults in underground cables.

  16. Elimination of DC-Link Current Ripple for Modular Multilevel Converters With Capacitor Voltage-Balancing Pulse-Shifted Carrier PWM

    DEFF Research Database (Denmark)

    Deng, Fujin; Chen, Zhe

    2015-01-01

    The modular multilevel converter (MMC) is attractive for medium- and high-power applications because of its high modularity, availability, and power quality. In this paper, the current ripple on the dc link of the three-phase MMC derived from the phase-shifted carrier-based pulse-width modulation...

  17. High Frequency Tan Delta Measurement Method for 132kV Transmission Underground Cables

    Directory of Open Access Journals (Sweden)

    A.R. Avinash

    2015-07-01

    Full Text Available Tangent Delta is a measurement technique to investigate cables insulation strength. Current techniques utilize Very Low Frequency (VLF at 0.1 Hz and power frequency at 50 Hz. However, high voltages are required, thus requiring larger space and cost. Proposed method of tangent delta testing utilizes High frequency Low voltage diagnoses. The phase between the current and the voltage is utilized to determine the tangent delta (tan δ. The aim of this study is to develop a low voltage high frequency tangent delta measurement method and test if it can discriminate manufactured 132 kV good conditioned cable sample from defect induced cables with void, scotched and contamination in its insulation. Impurities are clearly discriminated using this method. Comparison of Tangent Delta of cables manufactured simultaneously in good condition and defect induced is performed using High Frequency Tangent Delta method and in 50 Hz conventional method to validate the effectiveness of the measurement technique. The High Frequency AC setup utilizes a small testing environment which can sample small lengths with minimum 1 m length of cable. The small lengths will result in the reduction of total capacitance of the cable but using High Frequency induces high electric stress on XLPE layer thus resulting in measureable dielectric current.

  18. Power cables and transmission lines. A special issue; Kabels en lijnen. Special

    Energy Technology Data Exchange (ETDEWEB)

    Franken, B. [Vakgroep Electrische Energiesystemen, Technische Universiteit Eindhoven, Eindhoven (Netherlands); Hendriks Boers, M.H.A.J.; Bloemhof, G.A.; Pultrum, E.; Van der Wey, A.H.; Cremers, R. [KEMA Transport en Distributie, Arnhem (Netherlands); Rogier, J. [Dienst Methoden - Technische Assistentie, Departement Netten, Tractebel, Brussels (Belgium); Wiersma, J.A. [Regionale Energiemaatschappij Utrecht REMU, Utrecht (Netherlands); Birkhoelzer, W.A.; Lommen, P.P.C. [MEGA Limburg, Maastricht (Netherlands); Van Oirsouw, P. [KEMA Procesautomatisering en Informatietechnologie, Arnhem (Netherlands); Emous, K. [ed.

    1996-10-01

    In 8 articles several aspects with regard to cables and lines, applied in the electric power industry, are discussed. In the first article attention is paid to a new detection method for weak spots in cables. In the second article it is discussed that loading cables in a power distribution network more heavily has an impact on the reliability of the power supply. In article three the reliability of systems to protect the network against power failures is dealt with. The concept of a KEMA-developed computer program (PRORANK or Protection Reliability Analysis KEMA) is described and illustrated by two case studies. In article four the activities of CIGRE to realize a standard format for a database to maintaine and manage above-ground transmission lines are outlined. In article five the most important results and conclusions of a CIGRE working group on high-voltage cables and high-voltage lines are summarized. In the sixth article the developments with regard to discharge measurements for the diagnosis of cables are discussed, as well as the option of distributed optical measurement in high-voltage transmission cables. In article seven the so-called Power-Donut{sup TM} system is described by which the conductor temperature in high-voltage transmission lines can be determined. In the last article a KEMA-developed computer program (GAIA) for safety grounding analysis is discussed

  19. Method to improve superconductor cable

    Science.gov (United States)

    Borden, A.R.

    1984-03-08

    A method is disclosed of making a stranded superconductor cable having improved flexing and bending characteristics. In such method, a plurality of superconductor strands are helically wound around a cylindrical portion of a mandrel which tapers along a transitional portion to a flat end portion. The helically wound strands form a multistrand hollow cable which is partially flattened by pressure rollers as the cable travels along the transitional portion. The partially flattened cable is impacted with repeated hammer blows as the hollow cable travels along the flat end portion. The hammer blows flatten both the internal and the external surfaces of the strands. The cable is fully flattened and compacted by two sets of pressure rollers which engage the flat sides and the edges of the cable after it has traveled away from the flat end portion of the mandrel. The flattened internal surfaces slide easily over one another when the cable is flexed or bent so that there is very little possibility that the cable will be damaged by the necessary flexing and bending required to wind the cable into magnet coils.

  20. EIGENFREQUENCY ANALYSIS OF CABLE STRUCTURES WITH INCLINED CABLES

    Institute of Scientific and Technical Information of China (English)

    William Paulsen; Greg Slayton

    2006-01-01

    The approximate eigenfrequencies for the in-plane vibrations of a cable structure consisting of inclined cables, together with point masses at various points were computed. It was discovered that the classical transfer matrix method was inadequate for this task, and hence the larger exterior matrices were used to determine the eigenfrequency equation. Then predictions of the dynamics of the general cable structure based on the asymptotic estimates of the exterior matrices were made.

  1. 14 CFR 23.689 - Cable systems.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Cable systems. 23.689 Section 23.689... Systems § 23.689 Cable systems. (a) Each cable, cable fitting, turnbuckle, splice, and pulley used must meet approved specifications. In addition— (1) No cable smaller than 1/8 inch diameter may be used...

  2. Improved Method for PD-Quantification in Power Cables

    DEFF Research Database (Denmark)

    Holbøll, Joachim T.; Villefrance, Rasmus; Henriksen, Mogens

    1999-01-01

    n this paper, a method is described for improved quantification of partial discharges(PD) in power cables. The method is suitable for PD-detection and location systems in the MHz-range, where pulse attenuation and distortion along the cable cannot be neglected. The system transfer function...... was calculated and measured in order to form basis for magnitude calculation after each measurements. --- Limitations and capabilities of the method will be discussed and related to relevant field applications of high frequent PD-measurements. --- Methods for increased signal/noise ratio are easily implemented...

  3. Cable networks, services, and management

    CERN Document Server

    2015-01-01

    Cable Networks, Services, and Management is the first book to cover cable networks, services, and their management, in-depth, for network operators, engineers, researchers, and students. Thirteen experts in various fields have contributed their knowledge of network architectures and services, Operations, Administration, Maintenance, Provisioning, Troubleshooting (OAMPT) for residential and business services, cloud, Software Defined Networks (SDN), as well as virtualization concepts and their applications as part of the future directions of cable networks. The book begins by introducing architecture and services for Data Over Cable Service Interface Specification (DOCSIS) 3.0/ 3.1, Converged Cable Access Platform (CCAP), Content Distribution Networks (CDN, IP TV, and Packet Cable and Wi-Fi for Residential Services. Topics that are discussed in proceeding chapters include: operational systems and management architectures, service orders, provisioning, fault manageme t, performance management, billing systems a...

  4. Technology for long cable erection of a thousand-meter scale cable-stayed bridge

    Institute of Scientific and Technical Information of China (English)

    Rao Huarong; Deng Huibin

    2009-01-01

    In the background of the construction of Sutong Yangtze River Bridge (short as Sutong Bridge), the cable construction method and techniques of a thousand-meter scale cable-stayed bridge are introduced. Some key construction techniques, such as outspreading cable on deck, installing cable at pylon, pulling and fixing cable at the attachment with decks and cable PE sheath protection are discussed.

  5. DOE-sponsored aging management guideline for electrical cable and terminators

    Energy Technology Data Exchange (ETDEWEB)

    Gazdzinski, R.F. [Ogden Enviromental and Energy Services, Inc., Blue Bell, PA (United States)

    1996-03-01

    The DOE-sponsored Aging Management Guideline (AMG) for Electrical Cable and Terminations provides an analysis of the potential age-related degradation mechanisms and effects for low-voltage and medium-voltage extruded cables and associated terminations used in commercial nuclear power plants. The AMG examined historical industry failure data and correlated this with postulated aging mechanisms and effects. Existing and developmental testing and condition monitoring techniques were evaluated, as well as current industry practices, in order to assess whether all significant aging mechanisms/effects are being effectively managed. Results of the study indicate that some aging mechanisms and effects are not directly addressed by current industry maintenance and surveillance practices; however, empirical evidence indicates that low- and medium-voltage cable and terminations are in general very reliable. A limited number of nondestructive (or essentially nondestructive) techniques currently available are potentially useful for evaluating low-voltage cable condition; however, such techniques do not currently exist for monitoring medium-voltage cable. Troubleshooting or diagnostic techniques are available to identify certain types of degradation.

  6. Mitigation of Manhole Events Caused by Secondary Cable Failure

    Science.gov (United States)

    Zhang, Lili

    "Manhole event" refers to a range of phenomena, such as smokers, fires and explosions which occur on underground electrical infrastructure, primarily in major cities. The most common cause of manhole events is decomposition of secondary cable initiated by an electric fault. The work presented in this thesis addresses various aspects related to the evolution and mitigation of the manhole events caused by secondary cable insulation failure. Manhole events develop as a result of thermal decomposition of organic materials present in the cable duct and manholes. Polymer characterization techniques are applied to intensively study the materials properties as related to manhole events, mainly the thermal decomposition behaviors of the polymers present in the cable duct. Though evolved gas analysis, the combustible gases have been quantitatively identified. Based on analysis and knowledge of field conditions, manhole events is divided into at least two classes, those in which exothermic chemical reactions dominate and those in which electrical energy dominates. The more common form of manhole event is driven by air flow down the duct. Numerical modeling of smolder propagation in the cable duct demonstrated that limiting air flow is effective in reducing the generation rate of combustible gas, in other words, limiting manhole events to relatively minor "smokers". Besides manhole events, another by-product of secondary cable insulation breakdown is stray voltage. The danger to personnel due to stray voltage is mostly caused by the 'step potential'. The amplitude of step potential as a result of various types of insulation defects is calculated using Finite Element Analysis (FEA) program.

  7. Dynamic testing of cable structures

    Directory of Open Access Journals (Sweden)

    Caetano Elsa

    2015-01-01

    Full Text Available The paper discusses the role of dynamic testing in the study of cable structures. In this context, the identification of cable force based on vibration measurements is discussed. Vibration and damping assessment are then introduced as the focus of dynamic monitoring systems, and particular aspects of the structural behaviour under environmental loads are analysed. Diverse application results are presented to support the discussion centred on cable-stayed bridges, roof structures, a guyed mast and a transmission line.

  8. Cable Bacteria in Freshwater Sediments

    OpenAIRE

    Risgaard-Petersen, Nils; Kristiansen, Michael; Frederiksen, Rasmus B.; Dittmer, Anders Lindequist; Bjerg, Jesper Tataru; Trojan, Daniela; Schreiber, Lars; Damgaard, Lars Riis; Schramm, Andreas; Nielsen, Lars Peter

    2015-01-01

    In marine sediments cathodic oxygen reduction at the sediment surface can be coupled to anodic sulfide oxidation in deeper anoxic layers through electrical currents mediated by filamentous, multicellular bacteria of the Desulfobulbaceae family, the so-called cable bacteria. Until now, cable bacteria have only been reported from marine environments. In this study, we demonstrate that cable bacteria also occur in freshwater sediments. In a first step, homogenized sediment collected from the fre...

  9. Long duration immersion tests on cross-linked polyethylene insulated MV cables; Essais de longue duree en immersion de cables HTA isoles au polyethylene reticule

    Energy Technology Data Exchange (ETDEWEB)

    Leroy, J.H.; Pinet, A. [Electricite de France, 92 - Clamart (France). Direction des Etudes et Recherches; Simeon, E. [Alcatel, 75 - Paris (France); Audoux, C.; FOndeur, J.H.

    1996-12-31

    Although the MV cable used in France possesses a high degree of radial and longitudinal watertightness, it has been subjected to further investigations to assess its behaviour when the insulation is in presence of water. The selected test methods consist mainly of ageing the cable in water at 50 deg. C under 4 times its rated voltage, with the dielectric residual strength being measured after 6 months, one year and two years. It appears that a drop in the residual voltage strength occurs chiefly during the first 6 months of ageing. The detailed results are given in this report. Finally, aspects relating to the standardization of such tests are also mentioned. (authors)

  10. STATIC ANALYSIS OF CABLE STRUCTURE

    Institute of Scientific and Technical Information of China (English)

    HUANG Yan; LAN Wei-ren

    2006-01-01

    Based on the nonlinear geometric relation between strain and displacement for flexible cable, the equilibrium equation under self-weight and influence of temperature was established and an analytical solution of displacement and tension distribution defined in Eulerian coordinate system was accurately obtained. The nonlinear algebraic equations caused by cable structure were solved directly using the modified Powell hybrid algorithm with high precision routine DNEQNE of Fortran. For example, a cable structure consisting of three cables jointly supported by a vertical spring and all the other ends fixed was calculated and compared with various methods by other scholars.

  11. Study of the impact of board orientation on radiated emissions due to common-mode currents on attached cables

    DEFF Research Database (Denmark)

    Sørensen, Morten; Hubing, Todd H.; Jensen, Kim

    2016-01-01

    Common-mode current on attached cables is a typical source for radiated emission. Several models have been made for conversion of the intended differential signal to unwanted common-mode current on cables. In this paper we refine a method for identifying the radiation sources arising from a long...... microstrip. This method is used to show that the radiated emission from a PCB with attached cable(s) caused by a long trace depends on whether the trace is facing up or down with different result for voltage and current sources....

  12. Phenol wastewater treatment by needle-plate pulsed high voltage discharge in gas-liquid two phase%针-板式高压脉冲气液两相放电降解废水中的苯酚

    Institute of Scientific and Technical Information of China (English)

    董冰岩; 张鹏; 聂亚林; 谢寅寅; 何俊文; 王晖

    2016-01-01

    为了提高脉冲放电对有机物的降解效果,以苯酚为处理对象建立了单针-板电极形式的脉冲放电体系,考察了各因素对苯酚降解的影响并分析了降解过程中间产物及其浓度变化。结果表明,脉冲电压、电极间距、针-液间距、脉冲频率、曝气量等影响因素对苯酚降解率有很大影响;随着脉冲电压的增大,苯酚降解率增大,电压达到一定值后,苯酚降解率增大不再明显,趋于稳定;随着电极间距、针-液间距、脉冲频率、曝气量的增大,苯酚降解率增大,但当这些因素达到一定值后继续增大,苯酚降解率反而降低。100mL浓度为100mg/L的苯酚废水在电极间距10mm、针-液间距7.5mm、脉冲电压26kV、脉冲频率70Hz、曝气量1.5L/min的最佳条件下,放电60min时苯酚降解率为64.63%,放电140min时达到了85.02%。中间产物间苯二酚、对苯二酚、对苯醌、邻苯二酚在放电过程中浓度随着放电时间的延长先增大后减小,最后浓度都趋于零。其中,间苯二酚浓度最低并且分段出现,对苯醌浓度最大,邻苯二酚最先消失,考察产物变化规律以提高苯酚降解的彻底性。%In order to enhance the effect of pulse discharge on degradation of organic matter,a pulse discharge system of single needle-plate electrode aimed at phenol was established. The paper investigated the effect of various factors on phenol degradation and analyzed the degradation of intermediate products and their concentrations in the degradation process. Such factors,as pulse voltage,electrode spacing,needle-liquid spacing,pulse frequency,and air volume,had a great influence on the degradation rate of phenol. Phenol degradation rate increased with the increase of pulse voltage and tended to stablize while pulse voltage reached a specific value. With the increase of electrode spacing,needle-liquid spacing,pulse frequency,air volume,degradation rate of

  13. 150kV全固态高压脉冲发生器设计%Design of 150 kV all-solid-state high voltage pulsed power generator

    Institute of Scientific and Technical Information of China (English)

    雷宇; 邱剑; 刘克富

    2012-01-01

    The paper presents a design of all-solid-state pulsed power generator based on Marx generator with MOSFET semiconductor switch devices. Charging resistance is replaced by fast recovery diode in the circuit, which reduces power loss in charging process. Drive circuit is integrated in and gets power supply from main circuit. Optical fiber is used to deliver the drive signal so as to protect it from the interference of discharging. A clockwise/counter-clockwise ring-shaped compact configuration is applied, which reduces the loop inductance, and makes the generator modularized and compact. The proposed generator is com-posed of 180 Marx unites in series, each of which is charged at a low voltage of 900 V, and generates a fast output pulse of voltage 150 kV, rise time less than 500 ns and duration adjustable between 1 and 5 Ωs. Some experimental results of the pulsed power generator are listed, with a load of 50 kΩ resistance and 5 pF capacitance in parallel. Through comparison and analysis, some factors affecting the rise time of output pulses are summarized, including loop inductance, drive voltage of MOSFET and distributed capacitance of main circuit. Approaches for pulse rise time improvement are also discussed.%设计了一种基于全固态MOSFET半导体开关器件的Marx脉冲发生器.充电回路用快恢复二极管代替充电电阻,减小了充电部分功率损耗;将主电路和驱动电路集成在一起,采用自取电模式给驱动电路供电;由光纤传输驱动信号,抑制了放电回路对触发信号的干扰;采用顺/逆时针方向环形分布的紧凑型拓扑结构,不仅减小了回路电感,而且实现了脉冲发生器的小型化与模块化.所设计的Marx发生器充电部分仅需提供900 V低压,用180级单元串联,获得最高幅值为150 kV、脉宽1~5 μs可调的高压快脉冲,前沿控制在500ns以内.利用该脉冲发生器在50 kΩ电阻和5 pF电容并联的等效负载上进行了一系列实验;比

  14. Current Redistribution around the Superconducting-to-normal Transition in Superconducting Nb-Ti Rutherford Cables

    CERN Document Server

    Willering, G P; ten Kate, H H J

    2008-01-01

    Sufficient thermal-electromagnetic stability against external heat sources is an essential design criterion for superconducting Rutherford cables, especially if operated close to the critical current. Due to the complex phenomena contributing to stability such as helium cooling, inter-strand current and heat transfer, its level is difficult to quantify. In order to improve our understanding, many stability tests were performed on different cable samples, each incorporating several point-like heaters. The current redistribution around the heat front is measured after inducing a local normal zone in one strand of the cable. By using voltage taps, expansion of the normal zone is monitored in the initially quenched strand as well as in adjacent strands. An array of Hall probes positioned at the cable edge is used to scan the selffield generated by the cable by which it becomes possible to estimate the inter-strand current transfer. In this paper it is demonstrated that two different stability regimes can be disti...

  15. Cable Damage Detection System and Algorithms Using Time Domain Reflectometry

    Energy Technology Data Exchange (ETDEWEB)

    Clark, G A; Robbins, C L; Wade, K A; Souza, P R

    2009-03-24

    This report describes the hardware system and the set of algorithms we have developed for detecting damage in cables for the Advanced Development and Process Technologies (ADAPT) Program. This program is part of the W80 Life Extension Program (LEP). The system could be generalized for application to other systems in the future. Critical cables can undergo various types of damage (e.g. short circuits, open circuits, punctures, compression) that manifest as changes in the dielectric/impedance properties of the cables. For our specific problem, only one end of the cable is accessible, and no exemplars of actual damage are available. This work addresses the detection of dielectric/impedance anomalies in transient time domain reflectometry (TDR) measurements on the cables. The approach is to interrogate the cable using time domain reflectometry (TDR) techniques, in which a known pulse is inserted into the cable, and reflections from the cable are measured. The key operating principle is that any important cable damage will manifest itself as an electrical impedance discontinuity that can be measured in the TDR response signal. Machine learning classification algorithms are effectively eliminated from consideration, because only a small number of cables is available for testing; so a sufficient sample size is not attainable. Nonetheless, a key requirement is to achieve very high probability of detection and very low probability of false alarm. The approach is to compare TDR signals from possibly damaged cables to signals or an empirical model derived from reference cables that are known to be undamaged. This requires that the TDR signals are reasonably repeatable from test to test on the same cable, and from cable to cable. Empirical studies show that the repeatability issue is the 'long pole in the tent' for damage detection, because it is has been difficult to achieve reasonable repeatability. This one factor dominated the project. The two-step model

  16. Cable Damage Detection System and Algorithms Using Time Domain Reflectometry

    Energy Technology Data Exchange (ETDEWEB)

    Clark, G A; Robbins, C L; Wade, K A; Souza, P R

    2009-03-24

    This report describes the hardware system and the set of algorithms we have developed for detecting damage in cables for the Advanced Development and Process Technologies (ADAPT) Program. This program is part of the W80 Life Extension Program (LEP). The system could be generalized for application to other systems in the future. Critical cables can undergo various types of damage (e.g. short circuits, open circuits, punctures, compression) that manifest as changes in the dielectric/impedance properties of the cables. For our specific problem, only one end of the cable is accessible, and no exemplars of actual damage are available. This work addresses the detection of dielectric/impedance anomalies in transient time domain reflectometry (TDR) measurements on the cables. The approach is to interrogate the cable using time domain reflectometry (TDR) techniques, in which a known pulse is inserted into the cable, and reflections from the cable are measured. The key operating principle is that any important cable damage will manifest itself as an electrical impedance discontinuity that can be measured in the TDR response signal. Machine learning classification algorithms are effectively eliminated from consideration, because only a small number of cables is available for testing; so a sufficient sample size is not attainable. Nonetheless, a key requirement is to achieve very high probability of detection and very low probability of false alarm. The approach is to compare TDR signals from possibly damaged cables to signals or an empirical model derived from reference cables that are known to be undamaged. This requires that the TDR signals are reasonably repeatable from test to test on the same cable, and from cable to cable. Empirical studies show that the repeatability issue is the 'long pole in the tent' for damage detection, because it is has been difficult to achieve reasonable repeatability. This one factor dominated the project. The two-step model

  17. Investigation of mechanism of breakdown in XLPE cables. Final report

    Energy Technology Data Exchange (ETDEWEB)

    McKean, A.L.

    1976-07-01

    The basic hypothesis that microporosity plays a significant role in the mechanism of breakdown of XLPE cable is explored. The potential improvement achieved by impregnating the microporous regions of the cable core with a neutral liquid is evaluated, with relation to ac voltage life and impulse strength. The effect at higher frequency is also demonstrated. A similar test program is pursued on model cables, designed to explore the effects of gas pressure and gas type on breakdown and life, since it is reasonable to expect that only the microporous regions of the insulation should be sensitive to the gas-pressure environment. Comparison of gas-pressurized model breakdown stress (and related microvoid size) with basic Paschen curves demonstrates reasonably good agreement, indicating that partial discharge is the basic mechanism of fatigue and breakdown. The form of the voltage life curve above and below the discharge inception level is proposed, and evidence is presented indicating breakdown originates in the bulk insulation as well as at the shield interface. It is also shown that model cable discharge energies are below 0.1 pC, even at very high stress, and cannot be measured with modern detectors. Results with liquid or gas impregnation suggest a possible approach to dielectric improvement.

  18. The Design of Partial Discharge On-Line Monitoring System for XLPE Power Cable

    OpenAIRE

    Chen Rui-Long; Qian Yong; Ye Hai-Feng; Sheng Ge-Hao; Jiang Xiu-Chen

    2013-01-01

    Partial discharge detection is an important means to assess the situation of XLPE power cable’s insulation. This study has developed an on-line monitoring system which applies to the medium voltage XLPE cable on partial discharge, described its working principle, components of hardware, software designing and program implementation in details. Through monitoring the partial discharge signal in grounding lines of the XLPE cable’s shield, the system integrated assess the situation of XLPE cable...

  19. New Passive Methodology for Power Cable Monitoring and Fault Location

    Science.gov (United States)

    Kim, Youngdeug

    studies. Finally, the noise levels of real voltage and current signals, which are acquired from an operating power plant, are estimated and the resonant frequencies are extracted by applying window functions, and these results prove that the resonant frequency can be used as an assessment for the internal changes in power cable parameters such as defects and faults.

  20. AC Loss of Ripple Current in Superconducting DC Power Transmission Cable

    Science.gov (United States)

    Yoshitomi, K.; Otabe, E. S.; Vyatkin, V. S.; Kiuchi, M.; Matsushita, T.; Hamabe, M.; Yamaguchi, S.; Inada, R.

    As a method of largely reducing the transmission loss in the electric power grid, superconducting direct current (DC) power transmission cable has been investigated. Using superconducting DC power transmission cables, large amounts of current and energy can be transferred compared to conventional copper cables. In this case, an alternating current (AC) is converted to DC and superposed AC which is known as ripple current, and the energy loss by the ripple current is generated. Therefore it is desired to estimate the energy loss density for the case of DC current and superposed AC current for a design of DC transmission cable system. In this study, the hysteresis loss for DC current of 2 kA rectified from 60 Hz alternating current is calculated using the Bean model, and coupling loss was also estimated. The diameter of the cable was 40 mm. The ripple currents generated by multi-pulse rectifiers, 6-pulse, 12-pulse, and 24-pulse were considered. It is found that the total AC loss including the hysteresis loss and the coupling loss is considerably smaller than the supposed heat loss of 0.5 W/m which is obtained with a newly developed cable.