针对110 kV万茜变电站35 kV侧线路遭受雷击, 线路保护电流一段动作现象, 使用录波分析软件分析故障前的电流相位、差动动作值和C相动作轨迹。在分析主变差动保护动作原因的基础上, 得出了在单相接地故障状况下, 主变高压侧出现三相电流幅值基本相同以及相位基本一致的结果。证实了此次故障是一起典型的B相区外故障, 差动B相可靠不动; C相区内故障, 差动C相正确动作。C相区内故障, 主要是一体化电流互感器遭受高电压, 绝缘被击穿, 导致区内C相接地。通过分析主变差动动作原因和总结经验, 提出改进措施, 旨在更好地完善变压器保护的运行和维护。

For WanQian of 110 kV substation 35 kV side of the line being struck by lightning, line protection current phenomenon for some action, the use of recorded wave analysis software pre-fault current phase, the differential action value and the C-phase motion trajectory. In the analysis of the main transformer protection action on the basis of reason, obtained in the single-phase ground fault conditions, the main transformer high side appear essentially the same three-phase current amplitude and phase are basically the same results. Confirmed the failure is a typical B-phase external fault, the differential phase B reliably fixed; C phase fault zone, the differential phase C the correct action. C phase fault zone, the main subject is the integration of high voltage current transformer, insulation breakdown, leading to the region C phase to ground. Changes made through the main cause analysis and lessons learned, the improved measures designed to better improve the operation and maintenance of transformer protection.