一起110kV电容式电压互感器二次零序电压异常波动故障分析

Fault analysis of secondary zero-sequence voltage abnormal fluctuation of 110kV capacitive voltage transformer

本文针对一起110kV电容式电压互感器二次零序电压异常波动故障进行分析,通过查看现场故障录波波形、检查二次电压回路、电压互感器本体状况,最终查明故障原因是电压互感器末端N端子与开口三角绕组(二次零序电压回路)之间绝缘击穿,电压互感器一次侧产生的放电电流在开口三角绕组中流通,从而引起二次零序电压异常波动。最后,针对本起事件所暴露出的问题,提出关于二次设备日常巡视工作的思考及建议。

This paper analyzes the abnormal fluctuation of secondary zero-sequence voltage in 110kV capacitive voltage transformer.By viewing the field fault record waveforms and checking the condition of the secondary voltage loop voltage transformer,it is found that the fault is caused by insulation breakdown between the terminal N of the voltage transformer and the open triangular winding(secondary zero-sequence voltage loop).The discharge current generated in the primary side of the voltage transformer circulates in the open triangular winding,which causes abnormal fluctuation of the secondary zero-sequence voltage.In view of the problems exposed by this incident,some thoughts and suggestions on routine inspection of secondary equipment are given at last.