10 kV馈线保护大电流闭锁重合闸失效事件分析

Analysis of Large Current Blocking Reclosing Failure Incident of 10 kV Feeder Protection

对某110 kV变电站10 kV馈线保护大电流闭锁重合闸功能失效事件进行分析。通过现场试验,验证了RCS-9611B保护装置在二次故障电流为70 A,闭重过流保护与速断保护时间均为0 s的情况下存在大电流闭锁重合闸功能失效问题,其失效原因为闭重过流保护动作时间设置不合理,无法满足闭锁条件。为了避免同类事件再次出现,建议厂家对保护装置进行硬件或软件升级,并从继电保护设备管理及运行维护方面提出了防范措施。

The large current blocking reclosing function failure incident of 10 kV feeder protection in an 110 kV substation is analyzed. By field test, it is verified that RCS-9611B protection device has the large current blocking reclosing function failure problem under conditions that the secondary fault current is 70 A and both of the time of blocking reclosing overcurrent protection and instantaneous trip protection are 0 s. The failure reason is the unreasonable setting of the action time of blocking reclosing overcurrent protection which cannot meet the blocking condition. In order to avoid similar incidents happening again, it is suggested that hardware or software of the protection device should be updated by manufactures. Precaution measures are proposed from aspects of management, operation and maintenance of relay protection device.