失灵保护在主变代路运行时存在的问题及解决方案

对于配置电磁型或微机型保护的220kV主变,在高压侧开关停电检修并由旁路开关代路运行的情况下,如不切换其高压侧失灵保护启动回路,则无法正确启动断路器失灵保护。以两个实际的220kV变电站为例,介绍了主变失灵保护的启动原理,分析了失灵保护无法正确启动的原因,并提出了220kV旁路及主变失灵启动回路的改造方案。

Protection against faulty operation in bypassing transformer's breaker

For the 220 kV transformers equipped with electromagnetic or microcomputer protection, when the higher voltage breaker replaced by bypass one is shutdown for inspection, the breaker failure protection may start up incorrectly, if the startup circuit of higher voltage breaker failure protection is not switched on. Taking example for two 220 kV substations, the startup principle of circuit breaker failure protection and the reasons why the breaker failure protection starts incorrectly are discussed. It brings forward modified scheme to the startup circuit of failure protection for 220 kV transformers and their bypass breakers.