500kV断路器失灵保护误动原因分析

盘南电厂500kV电气主接线采用2／3接线方式，1号发电机组由于锅炉炉膛火检闪烙事故停机，发变组保护跳开两个出口断路器，随后中断路器失灵保护误动，出口跳开该串第三个线边断路器并远跳线路对侧500kV相应断路器，造成500kV线路失电，由于断路器失灵保护属于跳多元件重要后备保护，其误动作出口的后果较严重甚至可能导致电网事故，该文对误动原因作筒要介绍和分析。

Analysis on maloperation reasons of 500kV circuit breaker failure protection

500kV main electrical connection of Pannan Power Plant is adopted the 2/3 connection mode, its #1 electric generating unit shutdown because of the flashover of the boiler furnace fire inspection. After the generating unit was shutdown, protection maloperation of the middle breaker by fault, so the 3rd breaker of this series was tripped, and the relevant offside 500kV breaker was tripped remotely. This situation leads to 500kV line loss of power. As the breaker malfunction protection belongs to the important backup devices of multiple components tripping operation, its maloperation can cause serious result or even the power grid accident. This paper provides the introduction and analysis of the maloperation reasons.