继电保护二次电压中性点电位漂移在线监测方法探析

Study on the on-line Monitoring Method of Secondary Voltage Neutral Point Potential Drift in Relay Protection

指出了二次回路中性点是继电保护正常运行时的参考点,参考点电位发生漂移变化时,使继电保护感受到的二次电压、电流向量发生偏移,严重情况下会导致保护误动和拒动事故的发生。阐述了由于设计、安装检修作业等原因造成继电保护装置二次中性点丢失的几种情况,探讨了一种基于零序电压、电流原理的二次电压中性点丢失的在线监测方案,实现了各种二次回路丢失中性点情况的在线监测功能。

The neutral point of secondary circuit is the reference point for relay protection. When potential drift at the reference point occurs, the secondary voltage and current vectors that relay protection equipment collect will be shifted. It may lead to protection malfunction and rejection in serious circumstances. This paper discusses several cases of the neutral point signal loss of relay protection devices caused by improper design, installation or maintenance work. An on-line monitoring scheme of neutral point signal loss of secondary voltage based on the principle of zero sequence voltage and current is proposed. The on-line monitoring function of the neutral point signal loss of any secondary circuits is realized.