一起带负荷拉隔离开关事故的分析及其对策

Analysis and Solutions on an Accident of Switching Disconnector with Load

某220kV变电站在进行一次倒母线操作过程中发生带负荷拉隔离开关的事故。分析了此次事故的原因,直接原因是误操作隔离开关,间接原因是隔离开关结构设计不合理,导致电气闭锁回路失效。对此,提出3种防范措施:正常情况下,断开所有隔离开关的电机电源,防止误操作而引发事故;增加隔离开关控制回路切换开关,确保隔离开关操作的唯一性;隔离开关动作结构采用齿轮结构,以解决辅助触头与主触头位置不一致的问题。

An accident caused by switching disconnector with load during shifting bus bar happened in a 220 kV substation.Investigation results showed that the accident was caused directly by the misoperation of disconnector and indirectly by the irrational structural design of disconnector that failed the electric blocking circuit.Three solutions are proposed,i.e.,cutting all motor power of disconnector under normal condition to prevent misoperation and ensuing accident, adding diverter switch to disconnector control circuit to ensure the uniqueness of disconnection operation, and adopting gear structure as the working structure of disconnector to solve the problem of position inconsistency between auxiliary contact and main contact.