罐式断路器瓷套沿面闪烙对保护动作的影响

Effect of tank circuit breaker porcelain surface flashover on protection

运行发现LW13-363型SF6罐式断路器在断路器瓷套表面发生闪烙接地短路时,除了对电网一次系统造成冲击外,还会导致看似保护动作区外的继电保护装置误动作跳闸,直接扩大事故范围。通过调取误动保护装置的录波图和采样值进行分析,发现误动的保护装置其故障采样值确实在保护正方向动作范围内并非是装置原因。结合断路器放电位置和内部结构进一步分析研究,确认造成保护装置误动的原因是由于这种断路器自身结构所致。分析的结果使我们可以采取相对应的防范措施和对这种断路器结构进行改进,避免发生类似的问题。

It is found that when the breaker bush ofLW13-363 SF6 tank circuit breaker surface flashover ground short, it would cause imapct for the primary system of power system, in addition, this would cause the malfunction of relay protection device outside of the protection function area, and expand the scope of incident. Through analyzing the filter wave figures and sampling value of the malfunction protection device, we find that the malfunction sampling value of protection device is in the right scope of protection function, it is not the fault of device. Combined analysis of the circuit breaker discharge position and internal structure, we find that the reason that caused the malfunction of protection device is the breaker structure. The result shows that we could take corresponding preventive measures and improve the structure of breaker to avoid these incidents.