金属微粒对GIS中绝缘子冲击闪络特性的影响  

Influence of Metal Particle on Impulse Flashover Characteristics of Insulator in GIS

作　　者：张璐 王森 孙蕾[2] 郭安祥 张乔根[3] 王荆 ZHANG Lu;WANG Sen;SUN Lei;GUO Anxiang;ZHANG Qiaogen;WANG Jing(State Grid Shaanxi Electric Power Research Institute,Xi＇an 710100,China;Power China Xibei Engineering Corporation Limited,Xi＇an 710065,China;School of Electrical Engineering,Xi＇an Jiaotong University,Xi＇an 710049,China)

机构地区：[1]国网陕西省电力公司电力科学研究院,西安710100 [2]中国电建集团西北勘测设计研究院有限公司,西安710065 [3]西安交通大学电气工程学院,西安710049

出　　处：《高电压技术》2018年第9期2807-2814,共8页High Voltage Engineering

基　　金：国家自然科学基金(51177132);国家电网公司科技项目(5226SX15001T)~~

摘　　要：高电压等级电力系统中,特快速瞬态过电压（VFTO）引起的GIS绝缘事故日益严重。为探究冲击电压下绝缘子沿面闪络特性和机理,研制了陡前沿冲击试验装置。研究了微粒附着位置及微粒尺寸对绝缘子冲击闪络特性的影响规律。结果表明：正常绝缘子在VFTO下闪络电压较雷电冲击闪络电压高;工程运行气压下,500 k V正常绝缘子VFTO闪络电压较雷电冲击高13%,附着微粒绝缘子的VFTO闪络电压会比雷电冲击闪络电压低近10%。附着微粒位于近高压导体侧时绝缘子闪络电压最低;微粒位于盆式绝缘子沿面一定位置时,随其长度增加,绝缘子闪络电压降低,当微粒大于一定临界长度时,负极性VFTO闪络电压低于负极性雷电冲击闪络电压。VFTO下,附着微粒绝缘子的沿面闪络可用先导和＂逆放电＂机理来解释。空间电荷积聚和能量注入是形成先导放电的必要条件,高频位移电流和＂逆放电＂促进了绝缘子沿面闪络过程。The insulation accidents of gas insulated switchgear（GIS） induced by very fast transient overvoltage（VFTO） become more and more serious in high voltage level power system. Therefore, we developed steep-fronted impulse voltage test equipment for studying the surface discharge characteristics and mechanisms of insulator under impulse voltages. Moreover, we researched the influence laws of metal particle position and length on impulse flashover characteristics of insulator. It was found that the flashover voltage of normal insulator under VFTO was higher than that under lightning impulse（LI）, the flashover voltage of 500 k V insulator under VFTO was higher than that under LI by 13%. The flashover voltage of metal-contaminated insulator under VFTO was less than that under LI by 10%. The flashover voltage was the lowest when the particle was attached nearby high voltage electrode of insulator. When the particle attached on some position of insulator surface, the flashover voltage of insulator decreased with increasing of particle length. The flashover voltage for negative VFTO was lower than that for negative LI when the particle length was bigger than some critical value. The surface flashover of metal-contaminated insulator under VFTO can be explained by leader and ‘back discharge＇ mechanism. The accumulation of space charge and energy injection are necessary conditions for leader discharge,and the high frequency displacement current and ‘back discharge＇ promote the process of surface flashover of insulator.

关 键 词：气体绝缘开关设备 特快速瞬态过电压 绝缘子 金属微粒 闪络 逆放电 

分 类 号：TM216[一般工业技术—材料科学与工程]