对一起220kV母线差动失灵保护动作的分析

某220kV变电站甲220kV线路乙A相接地故障，线路两侧双高频保护快速动作，变电站甲侧线路乙开关A相跳闸随后三跳，紧接着母线失灵保护动作跳开220kV母联开关，最后母线差动保护B相动作，跳开220kV正母线上的所有开关。对上述故障发展过程及保护动作行为进行了详尽、深入的剖析，并对这次复杂的、多重故障下的保护动作行为做出了“正确动作”的判断。

Analysis of 220 kV Busbar Differential Breaker Failure Protection

An earth fault on a 220 kV line＇s phase A in 220 kV substation is occured, the dual pilot protection on both sides of line operated quickly. The following actions happen serially： switch of phase A trips and three trips happen continually, then the bus breaker failure protection operates to trip the 220 kV bus coupler, finally, bus differential protection operates to trip all breakers of 220 kV bus. In this paper, both the fault developing process and the protections operation are analyzed in details, and the correct action is suggested for these complicated and multiple faults.