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1.
Koji Michishita Hiroaki Sato Shigeru Yokoyama Seiji Furukawa 《Electrical Engineering in Japan》2015,190(3):37-44
For the effective and efficient insulation design of a power line, the return‐stroke current waveform parameters are indispensable. Charge transfer is one of the important parameters when damage to equipment on a power line due to the energy of lightning is discussed. The amount of charge transfer associated with a lightning flash or individual strokes can be estimated by using the electric field change obtained with a slow antenna. The authors observed the electric field waveforms in south Kyushu for the purpose of efficient acquisition of return‐stroke current parameters. In this paper, the authors discuss the relation between the negative first return‐stroke current peaks and the impulse charge transfer based on the observed electric field waveforms. 相似文献
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地表近场LEMP与回击电流的近似性 总被引:2,自引:2,他引:2
由于闪电近区电磁场的瞬时性和高强度的特点,致使其不易测试,其波形也难以捕捉。为了对闪电近场电磁波进行模拟,从理论上对雷电电磁脉冲(LEMP)的地表近区波形和回击通道底部电流的波形进行了探索。用解析方法近似推导近区LEMP的表达式得出,近区LEMP波形与回击通道底部电流波形近似;用偶极子法精确计算近区LEMP的结果表明,在100 m以内磁场波形与近似计算结果基本吻合,在50 m以内,电场波形与近似计算结果基本吻合。计算结果验证了解析推导近似的可行性,证明<50 m的地表近区,LEMP场波形与回击通道底部电流波形相似。这为闪电地表近场电磁波的模拟提供了理论依据。 相似文献
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Masaru Ishii Mikihisa Saito Fumiyuki Fujii Michihiro Matsui Naoki Itamoto 《Electrical Engineering in Japan》2010,170(1):8-15
Lightning electric‐field waveforms related to power line faults in winter have been identified. Most of those waveforms appear to be associated with upward lightning discharges with absolute peak currents of over 100 kA. They are quite different from common return‐stroke waveforms, and the lightning discharges which produce these characteristic waveforms are called GC (Ground to Cloud) flashes. These high‐current lightning discharges are distributed around the coastline in different ways depending on their polarities. The spatial distributions of high‐current lightning discharges around Japan are also investigated. It is revealed that the region of Honshu Island along the coastline of the Sea of Japan belongs to the area in which the density of high‐current lightning flashes is the highest in Japan through the year. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 170(1): 8–15, 2010; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20874 相似文献
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F. Delfino R. Procopio A. Andreotti L. Verolino 《Electrical Engineering (Archiv fur Elektrotechnik)》2002,84(1):41-50
An inverse procedure is presented for identifying and reconstructing the waveform of the lightning return stroke current.
It is based only on the acquisition of the electromagnetic field radiated by the discharge channel in various locations on
the ground and at various frequencies, and requires no information about the channel base current. The fundamental idea is
shown to come from an electrostatic problem in which the linear charge density of a vertical thin wire is determined starting
from the measured field. Three versions of this procedure have been developed: in the first, the identification is carried
out by means of the measurement of the electric field at various distances from the lightning channel at a given frequency;
in the second, only two sensors for the electric field are necessary, but various sampling frequencies; in the third, only
one observation point is needed, for the measurement of both the electric and the magnetic field. A simulated validation of
all the approaches is provided as well as a detailed analysis of their numerical accuracy.
Received: 4 April 2001/Accepted: 30 April 2001 相似文献
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Lightning-induced voltage waveforms on an overhead wire are analyzed by solving the Telegrapher's equation, in combination with numerical calculations of electric fields from return stroke currents as inducing sources. Based on an equivalent circuit newly developed for an explanation of this method, the roles of the vertical and horizontal electric fields in generating the induced voltage are studied, respectively. By numerical calculations, it is pointed out that the crest value of the lightning-induced voltage waveform at the end of the line is greatly affected by the ground conductivity and the lightning striking points. The accuracy of the computed results is ensured by comparison with the experimental results obtained from a geometrical model on a finitely conducting ground 相似文献
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对自然闪电条件下氧化锌避雷器的残压波形特征进行了分析。通过线路过电压和快电场的变化,对记录的12次自然闪电引起的避雷器残压波形进行了分析。分析结果表明,自然闪电条件下的避雷器残压持续时间约330 μs,明显长于实验室用8/20 μs波形电流冲击得到的几十微秒残压持续时间,波形宽度过长可能会造成压敏电阻体的熔化穿孔。其次,避雷器上残压波形与闪电放电过程紧密相关,具有较多的不规则性。此外,避雷器对前端埋地50 m的线路过电压有一定的抑制作用,对闪电首次回击引起的过电压抑制作用较弱,对继后回击引起的过电压抑制作用较强。 相似文献
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To improve the insulation specification of gas‐insulated switchgear (GIS), it is necessary to recognize the insulation characteristics of SF6 gas during actual surges (called nonstandard lightning impulse waveforms) occurring at field substations. The authors observed the insulation characteristics of SF6 gas gap under various types of nonstandard lightning impulse waveforms and compared them quantitatively with those obtained with standard lightning impulse waveforms. The experimental results were used to derive an evaluation method for real surges, which was applied to typical surges for various UHV and 500‐kV systems. In the preceding study, therefore, only the case of a quasi‐uniform electric field (with a typical range of field utilization factors in the bus of a GIS) was investigated. In the present investigation, the insulation characteristics of an SF6 gas gap for a nonuniform electric field were observed experimentally and an evaluation method for converting nonstandard lightning impulse waveforms equivalently to the standard lightning impulse waveform was investigated. © 2011 Wiley Periodicals, Inc. Electr Eng Jpn, 177(1): 11–18, 2011; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21144 相似文献
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光纤复合架空地线(OPGW)以其独特的优越性在电力系统智能状态监测领域得到了快速发展和应用,文章对OPGW光偏振态雷击故障定位方法中光纤传感雷击信号波形问题进行研究。首先利用ATP-EMTP软件建立输电线路模型仿真得到雷击OPGW时的电气数据,然后基于法拉第磁光效应原理将电信号转换为OPGW内部光纤中的光偏振态信号,此方法可用于仿真计算出雷击OPGW时光信号传播数据。实际输电线路上安装的OPGW雷击定位系统数据验证了仿真结果的准确性,结果表明OPGW光传感输电线路雷击波形受雷电流大小影响较大且不同于传统的电流行波雷击波形。 相似文献
10.
Yokoyama Shigeru Miyake Kunihiko Mitani Hiroshi Yamazaki Nobuharu 《Power Delivery, IEEE Transactions on》1986,1(2):129-139
Waveforms of induced voltage from lightning strokes to a high stack of the power plant have been measured simultaneously with the current waveforms of lighting stroke to the stack since December 1980. This paper shows the lightning stroke current waveforms and the lightning induced voltage waveforms over a 3 year period from December 1981 through March 1984. The combination of polarities for waveforms of lightning induced voltage and lightning stroke current is indicated below: (1) Seven cases of positive induced voltage in response to negative lightning stroke current were observed. (2) Four cases of negative induced voltage in response to positive lightning stroke current were observed. Distribution of lightning induced voltages along the distribution line length was also demonstrated. 相似文献
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Hiromitsu Taniguchi Hitoshi Sugimoto Shigeru Yokoyama 《Electrical Engineering in Japan》2000,130(4):66-75
In order to study lightning problems of low‐voltage power distribution lines, lightning overvoltage waveforms were observed inside the homes of customers. The cause of lightning overvoltages was examined from observation of striking points by still cameras. Lightning overvoltages of 62 waveforms were recorded by observation over a period of about 3 1/2 years. Observed waveforms can be classified into three types of single polarity (positive or negative), both polarities (which change from positive to negative or negative to positive), and pulsive waveform. The causes of these lightning overvoltages which were estimated from striking points are shown as follows: (1) Induced lightning overvoltages on low‐voltage distribution lines. (2) Electric potential rise due to discharge of surge arresters or current of overhead ground wire. (3) Shift of lightning overvoltages from high‐voltage side of transformer to low‐voltage side, which is due to electromagnetic induction. © 2000 Scripta Technica, Electr Eng Jpn, 130(4): 66–75, 2000 相似文献
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为了计算架空配电线路雷电感应过电压,利用Nucci提出的雷电回击通道模型(MTLE模型),计算雷电回击电流产生的空间电磁场,采用Cooray-Rubinstein公式计算大地电导率影响的水平电场分量,并改进Agrawal场线耦合模型,建立架空配电线路雷电感应过电压方程,基于时域有限差分(FDTD)法,计算10 kV架空线路的雷电感应过电压数值。结果表明,大地电导率对计算结果影响较大,大地电导率使线路上的感应电压幅值降低接近20 kV;不同回击传播速率也影响感应雷过电压的数值。定量计算雷电感应过电压,需要分析各种因素对计算感应雷击过电压的影响,完善计算方法,保障计算准确性,使理论与计算方法适用于实际的配电线路防雷设计,提供有价值的参考依据。 相似文献
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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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研究和识别输电线路雷击干扰的暂态特征对研制基于暂态量的保护及提高其可靠性具有十分重要的意义。数学形态学多尺度形态分解可以将复杂信号分解为具有物理意义的各部分,并且能凸显波形的局部特征。基于此,运用数学形态学对±800 kV特高压直流输电线路的雷击未故障、雷击故障和其他原因接地故障的暂态电流进行多尺度分解,提取高、低频段上的谱能量,并用这2个谱能量的比值构成主判据,实现雷击干扰与故障状态的识别。根据电流首波头的第2尺度和第6尺度分解波形的电流幅值最大值的比,进一步判别是雷击故障还是其他原因接地故障。通过大量的仿真验证了该方法是正确和有效的。 相似文献
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Okabe S. Yuasa S. Kaneko S. 《Dielectrics and Electrical Insulation, IEEE Transactions on》2008,15(2):407-415
To lower the insulation specifications (specifically, the lightning impulse withstand voltage) of a gas insulated switchgear (GIS) and thus cut the equipment cost while maintaining the high reliability of its insulation performance, it is necessary to define in an organized way the insulation characteristics for non-standard lightning impulse voltage waveforms that represent actual surge waveforms in the field and compare them with the characteristics for the standard lightning impulse waveform quantitatively. In the preceding paper, lightning surge waveforms and disconnector switching surge waveforms at UHV, 500 kV, and 275 kV substations were analyzed and five to six non-standard lightning surge waveforms with basic frequencies of 0.6 to 5.0 MHz were identified. In this paper, the dielectric breakdown voltage - time characteristics were measured under several different conditions mainly for the quasi-uniform SF6 gas gaps that represent an insulation element of a GIS toward four kinds of non-standard lightning impulse waveforms associated with lightning surges. As a result, in the tested range, the dielectric breakdown values for nonstandard lightning impulse waveforms were higher than for the standard lightning impulse waveform by 3% to 32%. 相似文献
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输电线路杆塔对雷电流监测结果的影响 总被引:2,自引:2,他引:0
在输电线路上实际测量雷电是进一步了解雷电流各种参数的有效手段,但实际测量到的结果是受被击物体影响后的雷电流。为了通过测量结果得到雷电流的原始波形,在输电线路杆塔模型中考虑了雷电波在杆塔传播过程中的衰减、畸变以及杆塔冲击接地电阻等因素,采用电磁暂态分析程序PSCAD对两种不同的输电杆塔进行了仿真计算,并对是否装设避雷线的情况进行了比较分析。结果表明避雷线对于雷电波的传播有很明显的影响,雷击输电线路杆塔时塔顶和塔底的雷电流波形有显著的区别,塔底电流随着杆塔的增高而变大。 相似文献