带地方小水电的局部电网故障分析与仿真研究

Fault analysis and simulation research of local power grid with local small hydropower

对于接有地方小水电110kV终端变电站,当110kV联络线路发生瞬时故障时,需要先解列本站小电源,然后以检母线无压方式重合。梧州电网太平变电站在发生110kV联络线路瞬时故障时,出现了因故障解列装置动作延迟而造成联络线路断路器无法重合情况。本文根据故障录波数据,分析了110kV太平变电站故障解列装置动作行为及联络线路断路器重合闸失败原因,针对频率异常闭锁问题,给出了装置逻辑和整定方面的解决方案。通过对带小电源的局部电网故障仿真测试,验证了所提方案的可行性。

For 110kV terminal substation with small hydropower, when transient fault occurs in 110kV tie line, local small source needs to be disconnected, and then the responding circuit breaker will be reclosed to restore power supply when the condition of bus non-voltage is satisfied. There was an accident of circuit breaker reclosing failure in Taiping substation of Wuzhou power grid because of the action delay of fault disconnection device when a transient fault occurred in 110kV tie line. The action process of fault disconnection device and the reason of circuit breaker reclosing failure of tie line in 110kV Taiping substation were analyzed according to recorded fault data. Considering the problem of abnormal frequency locking, some solutions of improving device logic and settings were put forward and verified through fault simulation of local power grid with small source.