500kV线路瓷绝缘子雷击断串故障分析  

Fault Analysis for Lightning Strike-caused String Fracture of 500kV Line Porcelain Insulators

作　　者：李岳 周路遥 李特 邵先军 初金良 高磊 LI Yue;ZHOU Luyao;LI Te;SHAO Xianjun;CHU Jinliang;GAO Lei(State Grid Gansu Electric Economy Research Institute,Lanzhou 730000,China;State Grid Zhejiang Electric Power Research Institute,Hangzhou 310014,China;State Grid Zhejiang Lishui Power Supply Company,Lishui Zhejiang 323000,China)

机构地区：[1]国网甘肃省电力有限公司经济技术研究院,兰州730000 [2]国网浙江省电力有限公司电力科学研究院,杭州310014 [3]国网浙江省电力有限公司丽水供电公司,浙江丽水323000

出　　处：《浙江电力》2020年第4期17-21,共5页Zhejiang Electric Power

基　　金：国网浙江省电力有限公司科技项目(5211DS190033)。

摘　　要：在机电负荷、污秽及环境温湿度等多重环境影响下,盘型悬式瓷绝缘子瓷件内微孔可能会逐渐扩展,直至开裂受潮,导致其机械强度和绝缘性能减弱,在遭受雷击或污闪时极有可能导致绝缘子炸裂、断串等恶性事故发生。针对一起500 k V线路瓷绝缘子雷击断串故障,结合雷电定位系统、线路分布式故障定位系统进行了线路耐雷水平分析。通过绝缘子试验,可判定故障原因为故障前已存在多片低零值绝缘子,当雷电绕击C相造成绝缘子串闪络后,大部分工频续流能量从低零值绝缘子头部瓷件内部放电通道泄放,产生的热量导致绝缘子炸裂脱开并引发断串。建议对线路低零值绝缘子进行排查,并合理采用疏导型防雷措施,对多雷区塔位优先安装线路避雷器。Under multiple environmental impacts of electromechanical load, pollutants, ambient temperature and humidity, the micropores in cap and pin porcelain insulators may gradually expand or even crack and get damp, resulting in mechanical strength and insulation performance deterioration. When subjected to a lightning strike or pollution flashover, it is likely to cause vicious accidents such as explosion or insulator string fracture. In this paper, a lightning strike-caused fault of 500 k V line cap and pin porcelain insulators is introduced based on lightning positioning system, distributed line fault location system to analyze lightning resistance of the lines. It is concluded that there are several low(zero) resistance insulators in the string before the accident;after the insulator string flashover caused by a lightning strike on phase C, most of the power fre quency freewheeling current is discharged from the low(zero) value insulator in the porcelain discharge channel, and the heat generated causes the insulator explosion and string fracture. It is recommended to check the low(zero) value insulators and adopt leading-type lightning protection measures and install line arrester in intensive lightening areas.

关 键 词：低零值绝缘子 雷击闪络 绕击 绝缘电阻 瓷件 

分 类 号：TM72[电气工程—电力系统及自动化]