一起ABB低压开关越级跳闸原因分析及改进措施

Reasons and countermeasures for an ABB low-voltage switch override trip

万安水电厂厂用电系统的400V馈线发生了一起越级跳闸事故,处于该馈线上下级的3台ABB自动空气开关同时跳闸。对事故的原因进行分析后,发现越级跳闸的原因与该馈线上下级的ABB自动空气开关的保护配置不合理有关,通过对事故原因的分析,该厂技术人员提出了事故防范措施,并根据ABB自动空气开关技术说明书上提供的反时限的过载、过流曲线,对反时限的过载、过流保护的选择性与灵敏性进行了校核,防止了同类事故的发生。

There was a 400 kV override trip accident happened in plant power supply system of Wan＇an Hydropower Plant. The paper analyzed reasons and proposed countermeasures according to the instruction. Moreover, the ABB automatic air switch was testified in order to prevent similar accidents.