【摘要】 河北南网一条220kV线路发生单相接地故障，引发了多套微机保护不正确动作，进而又导致3／2开关接线一个开关失灵保护设动作的同时启动另一开关失灵保护设动作的罕见事故。原因是11系列微机保护的重合闸不适应3／2接线的特殊情况，一台保护装置出口延时返回，开关失灵电流判别继电器卡。通过对上述情况进行详尽分析，提出了相应的对策。更多还原

【Abstract】 in Southern Hebei Power Network, a line-to-ground fault once occurred on a 220kV transmission line. This caused malfunction of more than one computer-based protections,and led to initiation of one of the circuit--breaker-failure protections in three one-and-a-half breaker scheme lines, and to the malfunction of another breaker-failure protection. This is a rare accident,and the causes of itare: the re--closing function of series 11 computer--based protection is not suitable for one-and-a-half breaker scheme,a time delay return of the exit relay of one protection,and bite up of discriminating relay in the breaker--failure protection. Through detailed discussion of the above mentioned situation,th& countermeasures are proposed.更多还原