一起750 kV 罐式SF6压气式断路器损坏故障的原因分析

Analysis of the Failure of a 750 kV Tank Type SF6 Compressed Gas Circuit Breaker

根据系统运行方式、ABB高压断路器灭弧室原理、SF6气体的特性、串联式合闸电阻的特点进行分析,发现由于断路器在切断短路电流时故障电流中非周期分量较大,波形偏移至时间轴下侧,波形在断路器有效灭弧的时间内没有过零,断路器灭弧失败,在断路器内部形成弧光短路现象,造成母线跳闸、断口烧损、合闸电阻热容量崩溃等事故。

According to the operation mode of the system,the principle of ABB high-voltage circuit breaker interrupter,the characteristics of SF6 gas,and the characteristics of series closing resistors are analyzed,and the cause of the accident is found out because the circuit breaker cuts off the short-circuit current.The component is large,the waveform shifts to the lower side of the time axis,the waveform does not cross zero within the effective arc extinguishing time of the circuit breaker,the circuit breaker fails to extinguish the arc,and an arc short circuit is formed inside the circuit breaker,causing the bus to trip,the fracture is burned,and the circuit is closed The heat capacity of brake resistor collapsed and other accidents.