谐波影响下电容器组差压保护动作分析及对策

Analysis and Countermeasures of Differential Protection for Capacitors Based on Influence of Harmonics

结合某变电站供电片区频繁发生的电压波动事件,分析了附近工厂冲击负荷产生的高次谐波是造成站内并联电容器组差压保护频繁动作的原因。变电站10kV母线电压和电流的监测数据分析表明,母线电压和电流波形发生较大畸变,母线电压谐波造成电容器组差压保护回路放电线圈二次侧较大的高次谐波电压,引起差压保护出口电压达到整定值动作,多组电容器连续跳闸导致10kV母线供电片区电压产生较大波动。针对工厂供电路径迁改困难的问题,提出了在并联电容器组二次回路加装高通滤波器的措施,改造后未发生差压保护动作事件,实施效果良好。

Combining with Voltage fluctuation events of some power supply area, this paper analyzed action reason of differential protection for capacitors,which was caused by impact load produce from the factory. Monitoring voltage and current data showed that distortion appeared in voltage and current waves. Bus bar voltage harmonics caused differential protection loop secondary side higher harmonic, which triped the capacitors. Under the difficulty of path moved,this paper raised the measure of adding high pass filter in differential protection loop,which was efficient.