秦山二期500kV断路器重动继电器接线的改进

Improvement on Restart Relay Connection of Qinshan Phase Ⅱ 500kV Circuit Breaker

秦山二期原采用500 kV断路器辅助触点组合启动重动继电器的典型设计。当发生输电线路单相瞬时接地故障时,可能使仪控DEH发生误切换,断口闪络保护误动,从而导致发电机停机的严重后果;也会造成厂用电跳闸失电、主变压器冷却器停止运行、应急柴油机误启动等后果。改变断路器的分合闸状态定义,改进500 kV断路器三相辅助触点组合接线后,彻底克服了运行方式变化造成的保护误动情况。

Originally, a typical design of starting restart relay by combined auxiliary contacts of 500kV circuit breaker was used in Qinshan Phase II project. When instantaneous single-phase earth fault occurs, it is possible to cause instrument-controlled DEH false switching and breaker flashover protection misoperation, resulting in generator shutdown; it also causes serious consequences, such as auxiliary power tripping, main transformer cooler stop running, backup diesel generator false start, etc. After changing definitions of breaker switch-off and -on, and improves connections of breakerJs 3- phase auxiliary contact combination, protection misoperation problems are solved totally.