一起220kV断路器单相拒合故障分析及防范措施

Analysis of 220 kV circuit breaker single-phase closing failure and its countermeasures

针对某次220 kV线路保护装置定期检验过程中出现断路器c相拒合故障进行了调查,发现是由于断路器机构合闸线圈接触不良造成的。通过设计合闸保护回路,增加了合闸回路延时断开功能,并验证了该方法可以有效解决当断路器出现拒合故障时烧毁合闸线圈和操作箱合闸插件的问题。从现场作业的角度阐述了采用快速切断操作电源、测量分析合闸回路电阻、做好定期检验工作等措施来防止此类故障的发生。

Phase-c closing failure of a circuit breaker is found during the regular inspection for a 220 kV line protection,which is caused by the poor connection of circuit breaker＇s closing winding.A protective circuit is designed to add delayed-trip function to the closing circuit,which effectively prevents the burning of closing winding and intermediate relay when closing failure of circuit breaker occurs.The countermeasures are proposed：quickly switch off the operating power;measure the resistance of closing circuit;inspect regularly.