550kV断路器合闸电阻及保护管烧损原因分析

Analysis on Burnout of Closing Resistor and Protective Tube in 550kV Circuit Breaker

为了研究某550 kV换流站断路器合闸电阻发生多起烧损事故的原因,避免事故再次发生和扩大,文中通过录波分析、返厂解体分析和仿真计算等手段,获取了较多的支撑原因的证据。研究表明:滑动触指部位涂抹了过多的润滑脂,在触头高速运动过程中,掺杂着银屑的润滑脂随着气流被带到绝缘拉杆和保护管,多次累积引起沿面放电,在触头预击穿的暂态电压下发生了击穿,最终使合闸电阻烧损。

For studying the causes of multiple burnout of the closing resistor of a 550 kV converter circuit breaker and avoiding the reoccurrence and expansion of the fault,the sufficient evidence supporting the fault is obtained by such measures as recording analysis,disintegration analysis at factory and simulation calculation etc.The study shows that excessive grease is applied to the sliding contact finger.During the high-speed movement of the contact,the grease mixed with silver crumbs is brought to the insulation rod and protective tube with the airflow and the multiple accumulation leads to surface discharge.The breakdown is occurred at the transient voltage of contact pre-breakdown and finally the closing resistor is burnt out.