继电保护误动跳闸原因分析及处理

按实际情况整定保护定值是避免保护误动的关键。通过分析现场数据，查找到雷电引起启备变差动保护误动作的原因为：启备变差动保护定值整定不尽合理。得出启备变差动保护基准侧额定电流定值应按变压器总容量进行整定，相应的启动电流、拐点设置应按考虑设备正常运行工况下不误动的原则进行计算的结论，并提出了整改措施。

Analysis and Treatment of Relay Protection Trip Misoperation

The key to avoid protection misoperation is to set protection value on the basis of the real situation. By analyzing the field data,the misoperation reason of differential protection of startup/standby transformer caused by thunder is found which the unreasonable protection value setting is. Conclusions are obtained which is that the normal side rate current value setting of the differential protection of startup/standby transformer should set according to the total capacity of the transformer, and the startup current, the inflection point should he calculated based on the principle that the protection should not operate under ordinary operation conditions of the device. Modification measures are also proposed.