Results 51 to 60 of about 370 (172)
Simulation on VFTO by Phase-Selection Technology in Low Voltage [PDF]
Proceedings of the 2016 6th International Conference on Machinery, Materials, Environment, Biotechnology and Computer, 2016 Disconnector(DS) operations in GIS may generate very fasttransient overvoltage (VFTO), which is characterized by its high peak value, short rise time, and high frequencies. However,most studies on VFTO are based on statistical data, which cannot show the impact of different phases to VFTO.In this paper, we use a relay with MCU as the Phase-Selection ...
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Analysis of influential factors in determining very fast transient overvoltages of GIS substations [PDF]
, 2014 High voltage Gas Insulated Substation (GIS) is threatened by Very Fast Transient Overvoltage (VFTO) which is high amplitude and high frequency transient within the range from 100 kHz up to 50 MHz in power systems. Operation of Disconnecting Switch is the
Nourirad, Ghasem +5 more
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Computation of Very Fast Transient Overvoltages (VFTO) in a 1000 kV Gas Insulated Substation
, 2017 Very fast transient overvoltages (VFTO) generated in a gas insulated substation (GIS) during disconnector switching operations is one of the major concerns in insulation design of the GIS. Such over voltages can cause malfunctioning of the protection and
M. A. Haseeb +3 more
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Gaoya dianqi, 2015 影响快速暂态过电压（very fast transient overvoltage,VFTO）因素很多,其中气体变电站（GIS）设备模型的选择对VFTO计算结果精确度的影响不可忽略。笔者采用考虑弧道电感特性的电弧电阻模型,结合国外某1 000 k V GIS变电站,详细计算了GIS内部的VFTO,分析了GIS内部关键设备处VFTO的极值。结果表明,用考虑弧道电感特性的电弧电阻模型模拟隔离开关的电弧的物理过程,进而对VFTO研究是适用的。最后还研究了入口电容、静态电感、GIS支路长度对VFTO的影响。
刘德东 +3 more
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合闸电阻对1000 kV GIS高压隔离开关VFTO的抑制研究
Gaoya dianqi, 2021 为了得到合闸电阻在GIS高压隔离开关VFTO抑制中更加合理的值,采用双曲线电阻模型、2～5Ω的定值电阻模型、Mayr电弧模型组合成一个动态电弧模型来描述高压隔离开关电弧燃弧模型的预击穿阶段、稳态燃烧阶段和熄弧阶段,并通过改变合闸电阻在动态电弧模型各个阶段的电阻值来求得电弧各个阶段的最佳VFTO抑制值,再通过取各个阶段的最佳电阻值的平均值作为合闸电阻的最优电阻值。并结合了某1 000 kV特高压变电站分析了其内部关键设备处VFTO的极值 ...
刘子英, 张靖, 吴文辉
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The influence of VFTO on SCSR windings with an equivalent PEEC model
International Journal of Electrical Power & Energy Systems, 2019 Abstract Stepped Controlled Shunt Reactors (SCSRs) have advantages of flexible control and reliable compensation and are likely to become widely used in Ultra-High-Voltage/Extra-High-Voltage (UHV/EHV) transmission systems. Very fast transients that occur in such systems will generate a Very Fast Transient Overvoltage (VFTO) in the SCSR.
Hongshun Liu +5 more
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, 2023 This paper investigates the impact of trapped charges on Very Fast Transient Overvoltages (VFTOs) in 400 kV Gas Insulated Substations (GIS) systems. VFTOs pose significant challenges to the design, insulation coordination, and long-term reliability of ...
Alhazmi, Mohammed +3 more
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Development of a square wave response experimental device for VFTO sensor calibration [PDF]
, 2019 LAUREA MAGISTRALENegli switchgear a isolamento gassoso (in inglese gas insulated switchgear, GIS), operazioni di commutazione o guasti a terra possono causare sovratensioni transitorie molto veloci (in inglese very fast transient overvoltages, VFTO), e i
CHEN, SHUO
core
Dianci bileiqi, 2020 GIS变电站中隔离开关和断路器的操作会产生波头极陡并伴有高频振荡的快速暂态过电压（VFTO）,对GIS设备运行的可靠性以及内外绝缘构成很大的威胁。现有研究表明GIS变电站拓扑结构对VFTO的幅值及频率特性有着较大的影响,而工程上主要关注VFTO沿线最大峰值的变化规律。为此从GIS变电站简化模型着手,分析研究VFTO的幅值以及频率特性随母线、分支母线长度变化的一般规律。在此基础上,通过ATP-EMTP电磁暂态仿真软件对青海某750 kV ...
蒋玲 +6 more
doaj
Dianci bileiqi, 2023 超高压GIS中隔离开关的开闭合可能产生特快速暂态过电压(Very Fast Transient Overvoltage, VFTO),而VFTO会对GIS及其相连设备造成破坏，因此如何削弱VFTO对其他设备的影响迫在眉睫。以某500 kVGIS变电站为研究对象，对隔离开关开闭过程进行仿真建模，模拟VFTO的产生并对其波形进行分析，随后对避雷器的抑制效果进行了仿真验证，然后对只加装阻塞特定频带的阻波器进行了特性仿真，最后对阻尼母线方法进行优化。通过对比不同措施下的VFTO仿真结果 ...
李佰霖 +3 more
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