负荷电流下主变后备保护误动分析

Analysis on Misoperation of Main Transformer Backup Protection at Load Current

以一起35 kV变电站低压侧出线故障导致主变高后备保护误动为例,分析了主变低压侧发生相间故障时主变两侧的电气量关系,结合录波波形及理论分析,得出高后备保护误动的原因,并提出解决建议,可为类似事故的分析和处理提供参考。

Taking a fault of the main transformer’s high-voltage backup protection misoperation due to the low-voltage side of 35 kV substation fails as an example,analyses are carried out on the relationship of electrical variables at both sides of the main transformer when the interphase fault occurs at the low-voltage side.In combination with the recorded waveform and theoretical analysis,the reason for the high-voltage backup protection misoperation is found,and several suggestions are put forward so as to provide a certain reference for the analysis and treatment of similar accidents.