2012 IEEE International Power Modulator and High Voltage Conference (IPMHVC)最新文献

{"title":"Simulation of delivery of subnanosecond electric pulses into biological tissues","authors":"S. Xiao, F. Guo, J. Li, G. Hou, K. Schoenbach","doi":"10.1109/IPMHVC.2012.6518798","DOIUrl":"https://doi.org/10.1109/IPMHVC.2012.6518798","url":null,"abstract":"Delivery of subnanosecond pulses into biological tissue can be undertaken by an impulse radiating antenna (IRA). Previous analysis shows that it is important to add a dielectric lens, which reduces the abrupt change of dielectric constant from air to tissue and therefore increases the transmission of the pulses. As a proof of concept, we have simulated subnanosecond pulsed radiation focused into a tissue simulant which consists of homogeneous, hemisphere tissues using 3-D electromagnetic solver, CST Microwave Studio. The simulation of an IRA in conjunction of a lens indicates subnanosecond pulses can be focused 6 cm below tissue surface with a spot diameter approximately 1 cm. The focal point coincides with the geometric focus of the IRA. However, this result is only valid for a tissue with a low conductivity (σ<; 0.3 S/m). For lossier tissues, the electric field decreases from the surface monotonically as the subnanosecond pulses penetrate in depth. Two approaches were proposed to solve this problem. One was to use an inhomogeneous dielectric lens, with lossy material partially filled, to attenuate the incident field in the small azimuthal angles but to spare the field in the larger azimuthal angels. A desirable focusing was observed. The second approach was to use a dipole antenna in conjunction with the impulse radiating antenna. The dipole antenna decreases the surface field intensity generated by the aperture antenna, but at the destination, the field will be mostly given by the aperture antenna, resulting in a focusing.","PeriodicalId":228441,"journal":{"name":"2012 IEEE International Power Modulator and High Voltage Conference (IPMHVC)","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132049860","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Initiation mechanism of negative pulsed discharge in supercritical carbon dioxide","authors":"T. Furusato, T. Ihara, T. Kiyan, S. Katsuki, M. Hara, H. Akiyama","doi":"10.1109/IPMHVC.2012.6518676","DOIUrl":"https://doi.org/10.1109/IPMHVC.2012.6518676","url":null,"abstract":"The initiation mechanism of a negative pulsed discharge in pressurized carbon dioxide including supercritical (SC) phase was studied using pulsed Schlieren and photomultiplier techniques. The appearance of the negative streamer at its initial stage was quite different from the positive one: a bush of negative polarity and a filament of positive polarity. A clear discontinuity existed around the sub-critical phase, characterized by streamer initiation voltage versus medium condition: The streamer initiation voltage increased with the medium density in gas phase, but was mostly independent of the medium density in SC and liquid phases. Calculation of field emission current according to Fowler-Nordheim equation suggested that the streamer initiation in both SC and liquid phases was caused by field emission, while within gas phase, initial electrons might be supplied by electron detachment from CO2- ions.","PeriodicalId":228441,"journal":{"name":"2012 IEEE International Power Modulator and High Voltage Conference (IPMHVC)","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128085126","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Injector system for the polish synchrotron radiation facility ‘SOLARIS’","authors":"P. Tracz, C. Bocchetta, P. Goryl, L. Walczak, A. Wawrzyniak, J. Wiechecki, M. Eriksson, D. Kumbaro, L. Malmgren, J. Modéer, S. Thorin","doi":"10.1109/IPMHVC.2012.6518844","DOIUrl":"https://doi.org/10.1109/IPMHVC.2012.6518844","url":null,"abstract":"SOLARIS, the new synchrotron radiation (SR) facility is being built in Krakow, Poland. Solaris will be equipped with a linear injector and a storage ring operated at electron beam energy of 1.5GeV. The Solaris injector will be constructed in a modular way. It will be divided into three RF stations. Each station consists of an S-band klystron with a solid-state pulsed power modulator, followed by a SLED unit and a power divider. The modulator delivers RF power of 35 MW with a pulse length of 4.5 μs and will have a repetition rate that can be up to 100Hz. The three RF stations will feed six S-band linear accelerating structures each giving an energy gain of 100 MeV. The electron source will be a 3 GHz thermionic RF-gun and a magnetic energy filter will be used. The SOLARIS injector will initially be operated at the electron beam energy of 550 MeV with options for a full energy (1.5GeV) upgrade with supplementary RF stations and accelerating structures. The SOLARIS synchrotron radiation facility is based on a copy of the 1.5 GeV storage ring being concurrently built for the MAX-IV project in Lund, Sweden.","PeriodicalId":228441,"journal":{"name":"2012 IEEE International Power Modulator and High Voltage Conference (IPMHVC)","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127977623","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Compact 600 kV multi-primary windings resonant transformer to drive an electromagnetic source","authors":"R. Pecquois, L. Pécastaing, M. Rivaletto, A. D. de Ferron, L. Caramelle, J-M. Duband, R. Vezinet","doi":"10.1109/IPMHVC.2012.6518824","DOIUrl":"https://doi.org/10.1109/IPMHVC.2012.6518824","url":null,"abstract":"Modern pulsed power applications of high power microwave technology require compact power-amplifier. In each case, the high pulsed power generator is made up of a primary energy source and a load, separated by the power-amplification system that forwards the energy from this source to the load. Usually a Marx generator or a Tesla transformer is used as the power-amplifier. Our structure uses an innovative and very compact resonant transformer to drive a dipole antenna. Our complete pulsed power source, named MOUNA, is composed of a set of batteries, a dc/dc converter to charge four capacitors, four synchronized spark gap switches, a resonant transformer generating 600 kV/265 ns pulses, an oil peaking switch and a dipole antenna. The device must transmit waveforms with a wide frequency band and a high figure-of-merit. The paper describes the compact 600 kV multi-primary windings resonant transformer developed in common by Université de Pau and Hi Pulse Company. The resonant transformer is made of four primary windings, two secondary windings in parallel and a Metglas® 2605SA1 amorphous iron magnetic core. An innovative biconic specific geometry makes it possible to optimize the leakage inductance. The transformer mechanical characteristics are: 6 kg weight, 3.4 liters volume, 20 cm diameter and 11 cm width. Design details are explained accurately. Each feature is justified. Calculations of leakage inductance and stray capacitance between primary and secondary windings are presented. Core losses and saturation induction are studied. An LTspice-based study of the power-amplifier is proposed. Finally, the results from two experimental studies are presented. Firstly, the resonant power-amplifier loaded by a compact capacitive charge associated to a homemade capacitive voltage probe specially developed is studied. Secondly, an integrated V-dot probe measures the power-amplifier output inside the electromagnetic source. To conclude, the experimental results are compared to the LTspice simulations and discussed.","PeriodicalId":228441,"journal":{"name":"2012 IEEE International Power Modulator and High Voltage Conference (IPMHVC)","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129513268","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An empirical study on assessment method for aging medium & large oil-immersed power transformers","authors":"Jeong-Ho Chang, Seungtaek Oh, Heung-Ho Lee","doi":"10.1109/IPMHVC.2012.6518849","DOIUrl":"https://doi.org/10.1109/IPMHVC.2012.6518849","url":null,"abstract":"There has been fewer new hydraulic power plants being built in Korea, and the existing power equipment has gradually been aged. Understandably, older plants require more maintenance to keep up the system performance. An effective asset management of power equipment has become a great necessity from both economical and technical aspects. This paper investigated a Risk-Based Maintenance (RBM) method that consists of technical assessment and economical assessment to make an efficient reliability assessment.","PeriodicalId":228441,"journal":{"name":"2012 IEEE International Power Modulator and High Voltage Conference (IPMHVC)","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129574108","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparison of nonuniform transmission lines with Gaussian and exponential impedance profiles for z-pinch","authors":"Rui Zhang, C. Mao, K. Huang, X. Zou, Xinxin Wang","doi":"10.1109/IPMHVC.2012.6518720","DOIUrl":"https://doi.org/10.1109/IPMHVC.2012.6518720","url":null,"abstract":"The circuit simulation of nonuniform transmission lines that were under consideration for the next generation of pettawatt-class z-pinch drivers was performed. It was confirmed that the power-transport efficiency of the designed radial transformer with an exponential impedance profile is higher than that with Gaussian profiles. Based on the Fourier's theorem and the principle of superposition, it was found that there are considerable low-frequency components for an input voltage of half-sine wave with an angular frequency of 14MRad/s. Compared to the exponential transformer, the Gaussian transformers amplify the low-frequency components to a lower extent, which makes the difference in power efficiency between the two types of the transformers. The radial transformer also serve as a passive high-pass filter and the Gaussian transformer may give better performance than that the exponential transformer does if the signal transport rather than the power transport is concerned.","PeriodicalId":228441,"journal":{"name":"2012 IEEE International Power Modulator and High Voltage Conference (IPMHVC)","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129885480","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fault diagnosis and testing of induction machine using Back Propagation Neural Network","authors":"N. Rajeswaran, T. Madhu, M. Kalavathi","doi":"10.1109/IPMHVC.2012.6518788","DOIUrl":"https://doi.org/10.1109/IPMHVC.2012.6518788","url":null,"abstract":"The recent developments with AI (Artificial Intelligence) are extremely intricate and are useful in a wide range of domestic and industrial applications. In real time environment, operating the induction motor at variable speeds is a severe constraint. The electrical and mechanical faults can impose unacceptable conditions and protective devices are therefore provided to quickly disconnect the motor from grid. In order to ensure that electrical machines receive adequate protection, extensive testing is performed to verify the high quality of assembly. Fault diagnosis and testing of induction machine is attempted under various load conditions and verified by using Field Programmable Gate Array (FPGA). Back Propagation Neural (BPN) Network is used to calculate the error and correct/regulate the induction motor. This technique has resulted in increased speed and improved fault coverage area of the induction machine.","PeriodicalId":228441,"journal":{"name":"2012 IEEE International Power Modulator and High Voltage Conference (IPMHVC)","volume":"92 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121115589","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Performance and optimization of a 50 kV silicon carbide photoconductive semiconductor switch for pulsed power applications","authors":"C. Hettler, W. Sullivan, J. Dickens, A. Neuber","doi":"10.1109/IPMHVC.2012.6518682","DOIUrl":"https://doi.org/10.1109/IPMHVC.2012.6518682","url":null,"abstract":"A 50 kV silicon carbide photoconductive semiconductor switch (PCSS) is presented. The SiC PCSS device is fabricated from semi-insulating 4H-SiC in a newly-proposed rear-illuminated, radial switch structure. The improved structure reduces the peak electric field within the switch, extending the blocking voltage to over 50 kVdc. Electrostatic field simulations of the PCSS are presented along with experimental blocking curves. The PCSS demonstrated low on-state resistance, delivering over 27 MW of peak power into a 31 Ω load. Device modeling was performed to further optimize the switch for peak efficiency when illuminated with 355 nm light, a common laser wavelength. The switch structure was modified for peak operation at 355 nm and the experimental and theoretical results are compared.","PeriodicalId":228441,"journal":{"name":"2012 IEEE International Power Modulator and High Voltage Conference (IPMHVC)","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121064662","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A simulation of breakdown parameters of High Power Microwave induced plasma in atmospheric gases","authors":"P. Ford, J. Krile, H. Krompholz, A. Neuber","doi":"10.1109/IPMHVC.2012.6518732","DOIUrl":"https://doi.org/10.1109/IPMHVC.2012.6518732","url":null,"abstract":"Surface flashover induced by a High Power Microwave fast rise-time pulse causes a significant drop in transmitted power, along with reflections that can damage the source. Momentum transfer collision rates in the range of 100s of GHz (for pressures exceeding 5 kPa) lead to low plasma conductivity, corresponding to absorption levels of up to 60 % of the incident power. A simulation algorithm was developed using the finite-difference time-domain (FDTD) method in order to model the growth and transport of the electron density near a dielectric surface, and the resulting interaction with the microwave pulse. The time-dependent plasma parameters are governed by empirical and simulated scaling laws for ionization and collision rates, along with diffusion coefficients; the resulting frequency-dependent plasma permittivity is transformed to a discrete algorithm to describe the spatially resolved plasma in the FDTD algorithm. A plasma thickness of up to 2 mm is simulated that compares with side-on ICCD imaging of surface flashover. Breakdown parameters, such as delay times and breakdown electric fields, in nitrogen, air and argon, are compared with experimental data on surface flashover across a polycarbonate window at atmospheric pressures; the simulated results correlate well with measured, and the model exhibits low computational complexity when simulating a pulse on the order of microseconds, making it a good alternative to standard particle-in-cell codes. The source is a S-band magnetron that produces a 2.5 MW peak power, 50 ns rise-time pulse with 3 μs duration at 2.85 GHz center frequency.","PeriodicalId":228441,"journal":{"name":"2012 IEEE International Power Modulator and High Voltage Conference (IPMHVC)","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115615075","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modeling of the dielectric recovery of hot air in insulating nozzles","authors":"A. Kurz, P. Nikolic, M. Seeger, D. Eichhoff, A. Schnettler","doi":"10.1109/IPMHVC.2012.6518758","DOIUrl":"https://doi.org/10.1109/IPMHVC.2012.6518758","url":null,"abstract":"In standard high voltage gas circuit breakers -important safety elements in today's power grids-, a small surface layer of polytetrafluoroethylene (PTFE) vaporizes at the high temperatures occurring in the arcing zone during the high current phase of the interruption process. This ablation continues even some hundred microseconds after the arc has been quenched and it actually changes the total gas composition as well as the temperature profile in the arcing zone. Therefore it delays the fast cooling of the arcing zone, which is necessary to prevent dielectric failures. The experimental determination of the dielectric recovery of hot air in insulating nozzles was investigated previously with focus on the substitution of SF6 (sulfur hexafluoride) in circuit breakers for future power grids. The present investigation gives a physical model for the calculation of the previously measured recovery characteristics. CFD-simulations (computational fluid dynamics) are performed for the determination of the relevant physical properties of the decaying quenching gas (density, temperature etc.). These properties serve as input parameters for the developed model. Based on the gas properties resulting from the CFD-simulations it is possible to calculate the effective ionization coefficients and thus the breakdown voltage applying the streamer criterion. Afterwards the calculated breakdown voltages are compared to the measured recovery characteristics. The comparison shows a good agreement between the measurements and the calculation.","PeriodicalId":228441,"journal":{"name":"2012 IEEE International Power Modulator and High Voltage Conference (IPMHVC)","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122497278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}