252kV GIS隔离开关特快速暂态过电压试验中触头间隙重复击穿过程研究  

Research on Repeated Breakdown Process of Disconnector Contact Gap During Very Fast Transient Overvoltage Test of Overall Switching Process of Disconnector in 252 kV GIS

作　　者：詹花茂[1] 姚林志 李志兵[2] 段韶峰[1] 李成榕 赵琳 

机构地区：[1]高电压与电磁兼容北京市重点实验室(华北电力大学),北京市昌平区102206 [2]中国电力科学研究院,北京市海淀区100192 [3]新能源电力系统国家重点实验室(华北电力大学),北京市昌平区102206

出　　处：《电网技术》2014年第9期2570-2574,共5页Power System Technology

基　　金：国家重点基础研究发展计划项目(973项目)(2011CB-209405);国家电网公司科技项目(SGKJ[2010]151)~~

摘　　要：为深入研究气体绝缘开关设备(gas insulated switchgear,GIS)中隔离开关分合空载短母线产生的触头间隙重复击穿现象,实现隔离开关操作全过程特快速暂态过电压(very fast transient overvoltage,VFTO)的准确仿真,建立了252 kV GIS试验平台,对GIS隔离开关分合产生的间隙重复击穿过程及影响因素进行了试验研究。通过同步测量触头间隙电压及长度,获得了隔离开关分合操作中触头间隙击穿电压与间隙长度的统计关系。统计结果表明,操作过程中间隙击穿电压与间隙长度的关系与工频电压下各长度的击穿电压基本吻合,且具有极性效应。每次间隙放电产生的空间电荷促进了后续击穿的发生,且首次放电越剧烈,这种趋势越明显。负载侧残余电压衰减时间常数约为160 min,仿真时可不计重复击穿间歇残余电压的衰减。相同的触头间隙恢复电压下,接地腔体对间隙电场分布影响不大。基于上述研究结果建立了隔离开关操作全过程VFTO仿真模型,仿真结果与实测结果基本吻合。To research the phenomena of repeated breakdown of contact gap of the disconnector in 252 kV gas insulted switchgear （GIS） thoroughly when the disconnector is used to switch on/off no-load short bus and to implement accurate simulation of very fast transient overvoltage （VFTO） during the whole switching process of the disconnector, a test platform for 252 kV GIS is constructed to perform experimental research on repeated breakdown process of the disconnector contact gap and its influencing factors. Through synchronously measuring the gap voltage and the length of contact clearance, the statistic relationship between the breakdown voltage of contact gap and the length of contact clearance during the switching on/off of the disconnector is obtained. Statistical results show that the relationship between contact gap breakdown voltages and the lengths of contact clearance during the switching on/off process basically agrees with the breakdown voltages of corresponding lengths under power frequency voltage, and there exists the polarity effect. The space charge produced by every time of gap discharge promotes the occurrence of follow-up breakdown, and the more violent the first time of discharge is, the more obvious this trend will he. The attenuation time constant of residual voltage at load side is about 160 min, so the attenuation of residual voltage in the intermittence between the repeated breakdownscan not be taken into account in the simulation. Under the same restoring voltage of the contact gap the residual voltage at the load side does not obviously influence the electric field distribution in the gap. Based on above-mentioned research results, a VFTO simulation model of the whole switching on/off process of the disconnector is built, and the simulation results basically coincide with the measured results.

关 键 词：气体绝缘组合电器 特快速暂态过电压 隔离开关 重复击穿 空间电荷 残余电压 

分 类 号：TM86[电气工程—高电压与绝缘技术]