某500kV主变压器失灵保护拒动原因分析

Analysis on reason causing the 500 kV main transformer breaker failure protection to refuse to trip

某500 kV变电站在调试传动过程中,发现500 kV主变压器高压侧断路器失灵保护动作后联跳、主变压器三侧功能不能实现。对该回路故障进行了分析,指出图纸设计错误是造成主变压器失灵保护拒动的主要原因,提出了解决方案,从而有效避免了某500 kV主变电站失灵保护的拒动和误动。

It was found that after the 500 kV main transformer breaker failure protection acted,the function of intertrip of the switches in three sides of the main transformer can not be realized in the transmission debug process of a 500 kV substation.The fault in this circuit was analyzed,and it was pointed out that the main reason of this fault is the design error which result the malfunction of the 500 kV main transformer breaker failure protection to refuse to trip.A solution was proposed to avoid effectively refusing to trip and tripping improperly.