线路引流线断线导致机组异常停机分析及处理

Analysis and Treatment of Unit Shutdown Caused by Break of Line Lead Wire

在110kV电力系统中,由于输电线路引流线断线故障概率极低(线路其他部分断线一般会造成短路或接地),目前110kV输电网未配备专门的断线保护,当发生电网引流线断线故障时,主要依靠调度人员进行处理。同时输电线路引流线断线在电站侧很少见,未能引起发电站高度重视,导致值班人员在处置此类事件时经验不足,不能及时做出判断,错失最佳处理机会,导致机组非计划停机,全站失压的不安全事件。分析觉巴水电站发生过的110kV输电线路引流线断线引起机组反时限负序过负荷保护动作停机的原因,介绍其处理过程。

In 110kV power system,due to the extremely low probability of breaking the lead line of transmission line(other parts of the line will generally cause short circuit or grounding),there is no special breaking protection for 110 kV transmission network at present.When breaking the lead line of power grid occurs,it mainly relies on dispatchers to deal with it.At the same time,power transmission line diversion line break is rare on the side of the power plant,which fails to attract great attention of the power plant.As a result,the operator on duty has insufficient experience in handling such events,can not make timely judgments,and misses the best treatment opportunity,resulting in unplanned unit shutdown and unstable voltage loss of the whole station.This paper analyses the cause of unit reverse time-limit negative-sequence overload protection action shutdown caused by 110 kV transmission line diversion line break in Jueba Hydropower Station and introduces its treatment process.