多重雷击线路导致开关设备故障分析

介绍220 kV线路遭受连续多重雷击导致开关断口击穿的过程,通过对开关解体处理及继电保护动作行为的分析,确定线路开关遭受雷电冲击断口击穿的原因。多重雷击使开关承受雷电侵入波与其反射波的叠加冲击,导致断口击穿,严重时可使灭弧室瓷套爆炸。SF6气体与空气伏—秒特性差异导致灭弧室内部先于外部瓷瓶击穿。提出在架空线路开关线路侧加装避雷器及进行开关断口雷电冲击、工频耐压试验的防范措施。

Analysis of Breaker Fault Cased by Multiple Lightning Strikes on Transmission Lines

This paper introduced the breakdown of circuit breaker cased by multiple lightning strike fault on 220 kV line. It indicated the reason of the breakdown by analysis of the breaker disintegration and the action process of protection. The addition process of lightning intruding waves and reflect waves made the breakdown of breaker, even made the breaker exploded. The internal arc insulator breakdown is easier than the external because of the difference between SF6 and air＇s Voltage-Time characteristics. The countermeasures are adding substation lightning arresters on terminal of overhead transmission line and carrying out the combined voltage tests of lightning impulse voltage test.