某变电所变压器差动保护误动作分析及对策

Analysis of Transformer Differential Protection Misoperation in Substation and Countermeasure

通过对一起变压器比率差动保护误动作事故的分析,指出造成保护误动作的原因是由于直流系统的故障电流流入变压器二次,造成低压侧CT或者变压器铁芯饱和,导致差动保护误动作.针对变压器比率差动保护可能会出现的误动作提出了解决措施.

Through analyzing a misoperation accident in transformer ratio differential protection, point out that the reason is the DC fault current goes into transformer secondary side. As the result, the low voltage side CT or transformer core is saturated, and misoperation of differential protection occurred. Put forward countermeasures to avoid misoperation on transformer ratio differential protection.