一起程序缺陷导致防跳回路失灵的故障分析

Analysis of an Anti-trip Circuit Failure Caused by Program Defect

某电厂在主变充电时合高压侧断路器,因保护装置无法避开励磁涌流使主变差动保护动作,断路器跳开后又立刻合上。针对这一异常状况,通过分析防跳回路和监控合闸程序并进行故障模拟试验,发现是由于合闸程序存在缺陷导致防跳回路失去作用,最后通过修改合闸程序来解决问题。

HV-side circuit breaker is closed when main transformer is charging in a power plant. Protection device is failed to avoid magnetizing inrush current, which causes differential protection act of main transformer. So the circuit breaker closes immediately after tripping. In view of this abnormal condition, it is necessary to analyze anti-trip circuit, monitor closing program and carry out fault simulation test; finally, it is found that the failure of anti-trip circuit is caused by defect of closing program, and solved through modification of closing program.