Results 31 to 40 of about 370 (172)
南方能源建设, 2022 [Introduction] Massive usage of gas-insulated metal-enclosed switchgear (GIS) has caused serious electromagnetic interference, especially when the isolating switch in GIS is operated with small capacitive current, it does not have arc extinguishing ...
LI Jiahui
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Gaoya dianqi, 2023 抽水蓄能电站与传统GIS电站相比，因开关操作更为频繁，产生VFTO概率更大，同时抽水蓄能电站由于地理环境限制需通过高压长电缆连接地上与地下两部分，接线形式的不同也会使产生的VFTO具有不同的特性。由于VFTO会严重威胁GIS设备、变压器和二次设备的运行安全，尤其是VFTO的幅值是导致设备绝缘损坏的重要因素，因此有必要对抽水蓄能GIS电站的VFTO幅值影响因素与权重进行深入研究。文中以某500 kV抽水蓄能GIS电站为例，采用仿真的方法计算分析了电站中VFTO幅值的影响因素和影响权重 ...
郝国文 +8 more
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Dianci bileiqi, 2022 GIS中的隔离开关操作将会产生高幅值的VFTO,从而损害其设备造成系统故障。为了更加经济地抑制VFTO,提出了基于粒子群优化算法来抑制VFTO最佳铁氧体磁环尺寸的方法。通过模拟GIS中磁环对于VFTO抑制效果的分析，得出了磁环模型等效电阻和等效电感的取值范围；建立磁环尺寸参数的数学模型，利用粒子群优化算法优化得出最小的磁环尺寸。最后基于ATP-EMTP软件对某一1 100 kV GIS进行建模仿真，对比磁环优化前后对于VFTO幅值抑制效果。结果表明：优化前磁环和优化后磁环都能达到相同的抑制效果 ...
刘子英, 刘洋
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The Study of VFTO Distribution in the Insulation System of IOCT Used in Traction Network
, 2022 The FDS (Frequency-domain Dielectric Spectroscopy) of oil-immersed insulation paper, and semi-conductive paper with different moisture content, has been measured.
Zhonghuan Su +5 more
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Study of the behavior of low voltage ZnO varistors against very fast transient overvoltages (VFTO). [PDF]
, 2021 IlustracionesCaracterización de varistores de ZnO ante sobretensiones transitorias con tiempo de frentes muy rápidos (VFTO) Este trabajo presenta la caracterización de un tipo de varistores de ZnO ante sobretensiones transitorias con tiempo de frente muy
Rojo Ceballos, Clara Rosa
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The Journal of Engineering, Volume 2019, Issue 4, Page 3418-3424, April 2019., 2019 This study analyses a gas insulated switchgear explosion accident caused by a failure of the circuit breaker (CB) in a thermal power plant, which resulted in the explosion of the CB and the burning of the potential transformer (PT). Through X‐ray detection and disassemble examination of the damaged CB, it is found that the A‐phase moveable contact was ...
Xun Zhang +6 more
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Modeling of Common Mode Interference of Secondary Side of Potential Transformer in VFTO Excitation
Shanghai Jiaotong Daxue xuebaoVery fast transient overvoltage (VFTO) is generated during the operation of isolation switches and circuit breakers in substations, which can affect the safe and reliable operation of power secondary equipment through cable transmission and spatial ...
PANG Fubin, JI Jianfei, WU Xianqiang, ZHOU Mengxia, YAN Wei, XU Dong
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Multi-spark modeling of very fast transient overvoltages for the purposes of developing HV and UHV gas-insulated switchgear and of conducting insulation co-ordination studies [PDF]
, 2017 Very fast transient overvoltages (VFTO) originate from steep voltage breakdowns in SF6gas that are inherent to operation of any switching device of the gas-insulated switchgear (GIS) type.
M. Szewczyk, Szewczyk, M.
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The electromagnetic effect study of GIS enclosure under high‐frequency electromagnetic pulse
The Journal of Engineering, Volume 2019, Issue 16, Page 2837-2841, March 2019., 2019 In gas insulated switchgear (GIS) substation, due to the operation of disconnect switch and circuit breaker, as well as short‐circuit fault, SF6 will break down very rapidly. The superposition of refraction and reflection of high‐frequency travelling waves will cause the very fast transient electromagnetic pulse (EMP).
Shu Chen +6 more
wiley +1 more source
Very Fast Transient Overvoltage Analysis on 245 kV Gas Insulated Substation
, 2022 Gas-insulated Substations play an important role in power systems today but are adversely affected by the generation of Very Fast Transient Overvoltages (VFTO).
Anuj Paul +4 more
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