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Since 1986, the authors have been taking part in triggered lightning experiments in winter, at Okushishiku, Ishikawa, for the purpose of observing the entire lightning current waveforms with coaxial shunt resistors and an electro‐optical measuring system. Extra‐fast current changes of the order of 1,000 kA/μs were recognized by sharp pulse records superposed on the positive current waveform obtained by a shunt resistor of relatively high residual inductance. This was not the case with a resistor of lower inductance. Furthermore, a positive lightning current waveform which looks like the composite result of bi‐polar discharges has been observed by an advanced measuring system of high performance. This paper deals with these current‐related topics of triggered lightning discharges, which will be analyzed hereafter in detail. © 1999 Scripta Technica, Electr Eng Jpn, 128(2): 18–23, 1999 相似文献
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中国首次大容量试验短路电流测量国际比对 总被引:1,自引:0,他引:1
为解决大容量试验短路电流测量系统量值溯源的难题,西安高压电器研究所(XIHARI)率先参加了国际短路试验联盟(STL)在全球大容量实验室中组织的短路电流测量国际比对技术活动。通过比对,建立了中国第1个大容量试验短路电流标准测量系统,共进行了线性度、刻度系数、高频电流、干扰、电阻值测量5个项目的比对试验。比对电流有效值最高达90kA,最大峰值213kA,比对结果为:XIHARI短路电流标准测量系统与STL短路电流标准测量系统之间最大偏差为0.3%。 相似文献
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Tatsuo Kawamura Eiichi Haginomori Yutaka Goda Tetsuya Nakamoto 《IEEJ Transactions on Electrical and Electronic Engineering》2007,2(5):516-522
The Short‐circuit Testing Liaison (STL) is the organization that consists of high power testing laboratories of the world. Member laboratories perform short‐circuit tests under uniform interpretations of the IEC standards agreed through technical discussions and information exchanges among them. One of the recent projects that the STL has been working on is to establish uncertainty and traceability of high current measurement by international comparison tests with reference shunts. In concert with this project, the IEC Working Group is preparing the new standard for high current measurements. Copyright © 2007 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. 相似文献
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A high‐order curvature‐corrected CMOS bandgap voltage reference with constant current technique 下载免费PDF全文
Junfeng Geng Yiqiang Zhao Hongliang Zhao 《International Journal of Circuit Theory and Applications》2014,42(1):43-52
A high‐order curvature‐corrected complementary metal–oxide–semiconductor (CMOS) bandgap voltage reference (BGR), utilizing the temperature‐dependent resistor and constant current technique, is presented. Considering the process variation, a resistor trimming network is introduced in this work. The circuit is implemented in a standard 0.35‐µm CMOS process. The measurement results have confirmed that the proposed BGR operates with a supply voltage of 1.8 V, consuming 45 μW at room temperature (25 °C), and the temperature coefficient of the output voltage reference is about 5.5 ppm/°C from −40 °C to 125 °C. The measured power supply rejection ratio is −38.8 dB at 1 kHz. The BGR is compatible with low‐voltage and low‐power circuit design when the structure of operational amplifiers and all the devices in the proposed bandgap reference are properly designed. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
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Masaaki Kando Norasage Pattanadech 《IEEJ Transactions on Electrical and Electronic Engineering》2015,10(6):723-725
A new concept of an electrical shunt with two rectangular holes in a copper plate (ESRP) has been developed to be used for measuring a large current with a short‐duration steep wave in a high‐voltage field. The ratio of the input current to the output current is 106, as obtained from a DC voltage test circuit. The electrical shunt has a special configuration. To verify the shunt current ratio of ESRP in a real application, the shunt current was connected to a sphere‐to‐sphere electrode breakdown test circuit with a 10 mm gap to measure the large damping current (8.4 kA) of a DC breakdown voltage. The voltage signal from the shunt was transmitted to excite two light‐emitting diodes (max. 50 mA, 4 V), which were reverse‐connected in series. The light‐emitting diodes operated properly and were illuminated, which validated the capability of the newly designed electrical shunt. © 2015 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. 相似文献
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连续导通交错式功率因数校正(PFC)具有纹波电流小与转换效率高等优点,在家电领域得到了广泛的应用。然而,由于交错式PFC既要实现总输入电流的谐波抑制,也要实现分支电路电流的平衡控制,因而常规交错式PFC方案需要多个电流采样电路,导致成本上升与可靠性下降。针对此问题,本文提出一种低成本的交错式PFC控制的全新电路与方法。通过MCU对采样电阻的电压在特定时刻进行采样,并根据采样值重构出总电流与支路电流,可实现单电阻的交错式PFC控制。实验结果表明,该方法可实现低成本的交错式PFC,输入电流谐波得到有效抑制,且支路电流达到均衡的效果。 相似文献
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笔者介绍了一套在高电压、大电流、强电磁场环境下,安全隔离、抗强电磁干扰、准确采集试验数据的新一代大容量试验测量系统。该系统通过配置性能先进的波形记录仪、多种高性能的电流、电压传感器提高了大容量试验的波形质量和测量准确度;测试软件性能达到了STL的技术指标;设计了符合标准和STL导则要求的报告页面;构建了网络交互平台实现试验信息交换;依据最新IEC电流、电压标准和STL导则完成了测量不确定度的评定;该测量系统完成了百万伏断路器、发电机断路器等几十种典型产品大容量试验,系统运行稳定可靠。系统还通过了STL国际专家的现场评审。 相似文献
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提出了一种基于多MOSFET并联均流的高稳定度大电流恒流源研究方案,输出电流最高可达30 A且连续可调,输出30 A时,30分钟内电流稳定度优于5 ppm。文中详细分析了恒流源基本稳流电路的工作原理,并对电路中关键元器件的选型进行了分析说明。通过高精度基准电压芯片和基于大功率精密电阻采样的电流串联负反馈方法提高系统的稳流精度,通过多只功率MOSFET并联均流工作作为调整管,实现了输出大电流的高稳定度,同时对影响功率MOSFET并联工作的因素进行了系统分析。提出的恒流源方案,对高稳定度直流电源的设计具有一定的参考价值。 相似文献
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智能建筑弱电线缆性能测试仪 总被引:2,自引:0,他引:2
杜晓通 《电子测量与仪器学报》2002,16(2):50-55
本文介绍了一种能对智能建筑弱电线缆的通、断、错接、允许传输的波特率、线路的阻抗、模拟信号衰减的性能进行测试的便携式仪器设计思路,讨论了用数模转换器(DAC),而不是模数转换器(ADC)对模拟量进行量化,以简化电路设计提高测试效率的方法。 相似文献
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针对国内35kV与20kV系统真空断路器开断并联电抗器系统事故多发情况,开展35kV系统工况下的现场试验,分析了开断后的暂态过程及过电压的机理,并在实验室进行了20kV系统真空断路器在额定电流下投切电抗器的截流试验,研究截流值和过电压规律。结果表明:截流过电压幅值远小于重燃过电压,多次重燃过电压是真空断路器开断并联电抗器频繁出现高过电压的主要原因;在系统典型额定工况下,300A负载电流下的截流值比100A负载电流下小,真空断路器的截流值随着开断电流的增大而减小的理论在系统额定电流下同样成立。 相似文献
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直流断路器作为未来基于电压源换流器的柔性直流输电(voltage source converter based high voltage direct current,VSC-HVDC)系统组网的关键设备,可以在出现短路故障时快速切断故障电流并使故障部分退出运行,避免停运整个直流系统。提出了一种适用于柔性直流输电系统的固态直流断路器技术方案,建立了IGBT串联的固态直流断路器仿真模型,研究了IGBT栅极电阻、拖尾电流和门极电荷等差异对IGBT串联均压特性的影响。仿真结果表明,静态和动态均压电路可有效改善IGBT间的均压效果。最后搭建了10个IGBT串联的直流断路器样机及实验回路,并完成了直流母线电压10 kV、峰值电流5.1 k A的关断实验,验证了基于IGBT串联技术固态直流断路器方案的可行性。 相似文献