Research on the Influence of Distributed Static Series Compensator on the Line Distance Relay Protection

As a series flexible control device, the distributed static series compensator (DSSC) can effectively and flexibly adjust the parameters of the power line, improving the stability of the new power system. In this paper, the topological structure of DSSC is analyzed, and the control method of DSSC device is derived. Subsequently, the influence of DSSC on distance relay is studied Through theoretical analysis, the impact of additional impedance generated by DSSC device operating in different compensation states on the measured impedance is obtained. Through simulation verification, it has been proven that the connection of DSSC has an undeniable impact on the ground impedance relay. The operation of DSSC in inductive compensation state will increase the risk of refusing action of relay protection device, while the operation of DSSC in capacitive compensation state may cause the relay protection device to malfunction and the larger the output voltage of DSSC, the more obvious the impact.