高压断路器分合闸过程触头间隙C_(4)F_(7)N/CO_(2)混合气体动态绝缘特性实验研究  

Experimental Study on Dynamic Insulation Properties of C_(4)F_(7)N/CO_(2) Gas Mixtures in Contact Gap of High Voltage Circuit Breaker During Closing and Opening Process

作　　者：张佳[1] 林莘[1] 徐建源[1] 张友鹏 庚振新[1] 钟建英 ZHANG Jia;LIN Xin;XU Jianyuan;ZHANG Youpeng;GENG Zhenxin;ZHONG Jianying(School of Electric Engineering,Shenyang University of Technology,Shenyang 110870,Liaoning Province,China;Pinggao Group Co.,Ltd.,Pingdingshan 467001,Henan Province,China)

机构地区：[1]沈阳工业大学电气工程学院,辽宁省沈阳市110870 [2]平高集团有限公司,河南省平顶山市467001

出　　处：《中国电机工程学报》2021年第22期7871-7880,共10页Proceedings of the CSEE

基　　金：国家重点研发计划项目(2017YFB0902500);国家自然科学基金项目(51777130);国家电网有限公司总部科技项目(环保型管道输电关键技术)。

摘　　要：高压断路器分合闸过程中触头间隙介质的绝缘强度及其变化是断路器结构设计的重要性能指标。搭建高压断路器触头间隙介质绝缘特性实验回路,测量C_(4)F_(7)N/CO_(2)混合气体断路器空载分合闸过程中不同压强、不同C4F7N含量时触头间隙介质的动态击穿电压,研究C_(4)F_(7)N/CO_(2)混合气体断路器的关合预击穿特性和分闸绝缘特性。实验发现,断路器空载分合闸过程中C_(4)F_(7)N/CO_(2)混合气体动态击穿电压存在“低电压击穿”现象;合闸过程中,动态击穿电压分散性较大,C_(4)F_(7)N/CO_(2)混合气体断路器的关合预击穿特性显著劣于SF6断路器,增大压强或增加C4F7N含量对混合气体动态击穿电压分散性的改善不大;正、负极性条件下0.7MPa时9%C_(4)F_(7)N/91%CO_(2)混合气体的分闸平均绝缘强度上升率(rate of rise of dielectric strength,RRDS)分别为49.8kV/ms和42.7kV/ms,具有“反极性”效应;分闸过程中,“低电压击穿”现象主要出现在刚分后2ms(开距约6mm)范围以内,断路器若在此时间(开距)范围内熄弧,极易发生弧后重击穿现象,因此,C_(4)F_(7)N/CO_(2)混合气体断路器结构设计时应避免在此范围内熄弧。Dielectric insulation strength between contact gap and its corresponding variation during travel process are two important performance indexes for the structural design of a high voltage circuit breaker.An experimental circuit was built to investigate the dielectric insulation characteristics between the contacts in a high voltage circuit breaker.The dynamic breakdown voltage between the contacts was measured in C_(4)F_(7)N/CO_(2) at different pressures and different C_(4)F_(7)N contents during no current flows or no arc burns closing and opening process.The closing pre-breakdown and opening insulation characteristics of the C_(4)F_(7)N/CO_(2) circuit breaker was studied as well.It was firstly found that“low voltage breakdown”appeared in the dynamic breakdown voltage of C_(4)F_(7)N/CO_(2) contact gap during this process.In the closing process,the dispersion of dynamic breakdown voltage was large,as a result,the closing pre-breakdown characteristics of C_(4)F_(7)N/CO_(2) circuit breaker were significantly lower than SF6 circuit breaker.With increasing the contents of C4F7N or the pressures in the circuit breaker,no significant improvement could be found in the breakdown voltage dispersion property of the C_(4)F_(7)N/CO_(2).Moreover,under the positive and negative polarity conditions,the average rate of rise of dielectric strength(RRDS)of 9%C4F7N/91%CO_(2) mixture at 0.7MPa were 49.8kV/ms and 42.7kV/ms,respectively,with an“reverse polarity”effect.The phenomenon of“low voltage breakdown”mainly concentrated within 2ms(about 6mm contact gap)after the contacts separation during opening process,restrike was easy to occur after the arc extinguishing in this range.Thus,the structural design of C_(4)F_(7)N/CO_(2) filled circuit breaker should avoid arc extinguishing in this rang.

关 键 词：C_(4)F_(7)N/CO_(2)混合气体 动态击穿电压 关合预击穿特性 分闸绝缘特性 高压断路器 

分 类 号：TM561.2[电气工程—电器]