Results 41 to 50 of about 229 (144)
Modelling and validation of metal oxide surge arrester for very fast transients
Metal oxide surge arrester models that are currently on rounds suffer from certain deficiencies and as a consequence, they are not in position to portray accurately the arrester residual voltages. This drawback is mainly attributed to their inherent features.
Kannadasan Raju, Valsalal Prasad
wiley +1 more source
Abstract As voltage measuring devices are widely used in the high voltage power system with a primary‐secondary‐fusion structure, electronic voltage transformers are directly connected to the primary conductor and would face much more serious electromagnetic environments than general secondary equipment.
Houda Zhu +5 more
wiley +1 more source
GIS隔离开关在操作过程中会产生VFTO,对设备的安全稳定运行构成威胁,因此,研究隔离开关操作过程中VFTO的抑制措施具有重要意义。文中首先开展了隔离开关操作顺序对VFTO影响的理论分析,以某抽水蓄能500kVGIS由于VFTO引起的故障案例,通过仿真计算分析了优化操作顺序降低VFTO的效果。最后,对该措施的进一步推广应用进行了展望。
刘凯 +6 more
doaj
合闸电阻对1000 kV GIS高压隔离开关VFTO的抑制研究
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
doaj
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
doaj
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
The influence of VFTO on SCSR windings with an equivalent PEEC model
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
openaire +1 more source
Influence of Switching Conditions on the VETO Magnitudes in a GIS [PDF]
Estimation of very fast transient overvoltage (VFTO) has been carried out using EMTP for various switching conditions in a 420 kV gas-insulated substation (GIS). The variation of the VFTO peak along the GIS bus nodes for disconnector and circuit breaker switching operations, as well as the variation of VFTO peak with different magnitudes of trapped ...
Kumar, VV, Thomas, JM, Naidu, MS
openaire +2 more sources
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
doaj
GIS站操作隔离开关时会产生特快速暂态过电压(VFTO),对GIS站和相邻电气设备安全会造成严重威胁,必须采取措施对其进行抑制。用PSCAD软件对某550 kV典型GIS变电站建立了仿真模型,指出可通过抑制VFTO中主导频率分量以降低VFTO的能量,进而达到抑制VFTO峰值的目的。通过分析MOA位置与主导频率分量幅值之间的关系,确定了MOA的最佳位置,以最大程度降低VFTO。研究结果对于GIS站的设计、运维和设备保护具有一定的指导意义。
李宜, 张彼德
doaj

