Abstract：The bus-differential protection of a 500kV 3/2 connection substation reported 5053 circuit breaker branch TA break, check found to be due to 5053 circuit breaker branch three-phase current imbalance caused by the zero sequence current to meet the bus protection TA off Line logic criterion. The main circuit of the 5053 circuit breaker branch circuit A-phase main circuit isolation switch contact resistance is too large, resulting in 5053 circuit breaker three-phase main circuit resistance imbalance, resulting in the 3/2 system zero sequence circulation. The simulation of the zero sequence circulation generated by 3/2 system of 3-phase main circuit resistance imbalance of 5053 circuit breaker is simulated by Simulink model. It is also reminded to pay attention to the unbalance of the three-phase resistance in the maintenance test deviation.
冯顺, 曲欣, 王毅, 葛琳朝, 陈思思. 某变电站500kV母线保护TA断线保护闭锁分析[J]. 电气技术, 2017, 18(7): 113-116.
Feng Shun, Qu Xin, Wang Yi, Ge Linzhao, Chen Sisi. The Analysis on 500kV Bus-differential Protection Latch of a Substation because of TA Break. Electrical Engineering, 2017, 18(7): 113-116.
2017, Vol. 18 
