3/2接线中断路器合闸后电流不平衡问题分析

3/2接线为500kV变电站的主要接线形式。针对某500kV变电站第2串中间的断路器在合闸运行后该串3组电流互感器(TA)均产生电流不平衡的问题,构建了电路模型并结合实际回路电阻的情况进行了分析,指出产生三相电流不平衡的原因为站内或电源至站内的三相阻抗不平衡所致,针对不平衡电流造成的影响等因素,提出了运维措施和建议。

Analysis of Current Imbalance After Circuit Breaker Switching-In of 3/2 Main Wiring

The 3/2 main wiring is the main connection form of 500kV substation. Aiming at the problem that after the circuit breaker in the second string of 500kV substation closing, the three groups current transformers of the string all generated current imbalance, this paper constructed the circuit model and combined with the actual circuit resistance to analyze the causes of three-phase current imbalance from the inside of substation or from the three-phase impedance imbalance between power supply and the inside of substation. According to the inlfu-encing factors caused by imbalance current, maintenance measures and recommendations are proposed.