接线错误引起高压电机零序过流保护误动的原因分析

Cause Analysis of Misoperation of Zero Sequence Overcurrent Protection of High Voltage Motor Caused by Wiring Error

高压电机发生多次零序过流保护误动作后,对二次回路接线进行了全面检查,发现施工人员将相电流互感器与零序电流互感器的二次回路接地线共用,且有接线松动。对保护误动的原因进行了分析,提出电流回路应接线可靠,两者的接地线应严格分开设置。

After the zero-sequence overcurrent protection of the high-voltage motor malfunctioned for many times,a comprehensive inspection of the secondary circuit wiring was carried out.It was found that the construction personnel shared the phase current transformer with the secondary circuit grounding wire of the zero-sequence current transformer,and the wiring was loose.The reasons for the protection malfunction are analyzed,and it is proposed that the current loop should be connected reliably,and the grounding wires of the two should be strictly separated.