500kV断路器断口击穿故障与防护措施分析  

Research on Breaker Breakdown and Protecting Measures of 500 kV Circuit Breakers

作　　者：徐党国 李雨 孙云生 刘平 骆立实 张恩伟 

机构地区：[1]冀北电力有限责任公司电力科学研究院,北京100045 [2]冀北电力有限公司,北京100053 [3]冀北电力有限公司检修分公司,北京102488

出　　处：《高压电器》2013年第3期59-63,68,共6页High Voltage Apparatus

摘　　要：通过对几起500 kV断路器断口击穿故障的分析表明,断路器断口发生击穿后,无论是灭弧室内部断口击穿还是断口外绝缘表面闪络,故障电弧均不能自行熄灭,同时由于断口闪络电流较小且没有对地故障,各种保护装置均不能快速动作。持续燃烧数秒钟的电弧使灭弧室严重发热,劣化SF6气体,并引发断路器爆炸等更严重的设备故障。带有并联电抗器的线路断路器及发变组断路器发生断口闪络故障的风险较高。笔者在对断口闪络故障的原因进行分析的基础上,认为对断路器加装断口闪络保护可避免断口闪络引发设备故障,并分别针对带有并联电抗器的线路断路器和发变组断路器,对断口闪络保护的策略及保护定值进行了分析。Four breaker breakdown are discribed in this paper. Either insulation defect or mechanical error may cause breaker breakdown of circuit breakers. And the faults cannot be cleared automatically when breakdown happened due to the system voltage. The fault current of breaker breakdown is quite small than the short circuit current as there is no phase to ground fault. None protection operates immediately when breaker breakdown happens and the electric-arc buries between breakers for few seconds. The circuit breaker and the SF6 gas may until the breakdown between be damaged during the are buries. The protecting devices do not operate contacts becomes a phase-to-ground and the fault current increases rapiddly. The circuit breakers of EHV transmission line with parralle reactor and breakers of generator-transformer unit have higher risk of breaker flashover than other circuit breakers. The reason of breaker flashover of circuit breakers are analyzed in this paper. Breaker flashover protection of circuit breaker are introduced to protect the circuit breakers from The protection setting and time delay of breaker flashover lines and generator-transformers are discussed respectively. damagement during breaker breakdown faults. protection for circuit breaker of transmission

关 键 词：断路器 断口闪络 闪络保护 

分 类 号：TM561[电气工程—电器]