1.事故情况 我局某新建60kV变电所在运行中多次发生越级跳闸。无论是哪条10kV线路故障,虽然其断路器跳闸,但都同时引发主变过流保护动作,造成越级跳闸,以至全所停电。这类事故给我们查找事故原因带来了很大困难, 2.查找经过 我局的继电保护人员去现场进行了全面的分析,估计有以下几种原因可能 1. Accident I Bureau of a new 60kV substation in the operation occurred more than tripped. No matter what 10kV line fault, although the circuit breaker trip, but all while triggering the main transformer overcurrent protection action, resulting in extra-trip, so that the whole power outage. This kind of accident has brought us great difficulty in finding out the cause of the accident, 2. After looking through my bureau’s relay protection personnel to the scene to carry on the comprehensive analysis, estimated that may have the following several possible reasons