抑制分布式静止串联补偿器对线路保护影响的方法研究

Method of suppressing the influence of distributed static series compensator on line protection

分布式静止串联补偿器(distributed static series compensator,DSSC)通过调节注入线路的电压可改变线路功率,优化电网潮流分布。针对现有交流线路保护算法难以适应DSSC串入线路运行的问题,提出了抑制DSSC对线路保护影响的方法。首先,分析了DSSC对交流线路保护的影响,证明了DSSC注入电压可能改变距离保护的阻抗测量值,导致距离保护有拒动或误动的风险。然后,提出了利用DSSC本体过流保护快速将DSSC旁路、或基于故障辅助判据主动将DSSC注入电压降为0的方法,以抑制不同类型的线路故障时DSSC对线路保护的影响。最后,基于硬件在环RTDS实时仿真平台以及浙江湖州DSSC示范工程现场进行试验,验证了所提抑制DSSC对交流线路保护影响的方法的有效性。

A distributed static series compensator(DSSC)can change the power of a transmission line by adjusting the voltage injected into the line to optimize the power flow distribution of the power grid.In response to the problem that existing AC line protection algorithms are difficult to adapt to the operation of a DSSC,a method to suppress the influence of the DSSC on line protection is proposed.First,the impact of a DSSC on AC line protection is analyzed,and it is proved that the injection voltage of the DSSC may change the impedance measurement value of distance protection,leading to the risk of the protection rejecting or mis-operating.Then,a method to quickly bypass the DSSC using the overcurrent protection of the DSSC,or to actively reduce the injection voltage of the DSSC to 0 based on fault auxiliary criteria is proposed.This is to suppress the impact of the DSSC on line protection during different types of line faults.Finally,based on the hardware-in-the-loop RTDS real-time simulation platform and on-site testing of the Zhejiang Huzhou DSSC demonstration project,the effectiveness of the proposed method is verified.