一起主变差动保护误动事故分析

Analysis of Main Transformer Differential Protection Malfunction Accident

介绍了某电厂主变差动保护误动作的原因、故障的查找过程以及采取的措施。1号机组在满负荷试运期间主变差动保护误动,经查找发现发电机机端CT回路二次电缆芯线破损瞬时接地,经过专业人员模拟试验分析,证实了保护动作的原因。

This paper describes the cause of main transformer differential protection malfunction in a power plant, the search process of the failure,and the measures taken. During unit 1 full load trial operation the main transformer dif-ferential protection malfunction was found ,the cause was the generator terminal CT loop secondary cable wire breakage resulted in the instantaneous ground, the professionals analog test analysis confirmed the reasons of protective action.