The influence of Thyristor controlled series capacitor on distance protection relay and its mitigation

Abstract: In modern power transmission systems suffering from large voltage drop and transfer capability of power reduces due to the line reactance and thermal limits. Therefore, Thyristor Controlled Series Capacitor (TCSC) has been used to improve the power transfer capability of transmission line by changing the reactive power distribution in the power system. This paper discusses the effect of TCSC for power enhancement capability. Further, the effect of TCSC on distance protection relay of transmission lines due to the fast response time of thyristor controllers with respective that of the protective devices is also investigated.

Keywords: Transmission line protection, distance relay, FACTS Devices, active power, reactive power, TCSC