Effects of SMES equipped SSSC on distance relay tripping characteristic

This paper presents the measured impedance at the relaying point in the presence of one of the series connected flexible alternating current transmission system (FACTS) devices, i.e. static synchronous series compensator (SSSC) which is equipped with a superconductor magnetic energy storage (SMES). The presence of SMES equipped SSSC on a transmission line greatly influences the tripping characteristic of distance relays. Distance relay tripping characteristic itself depends on the power system structural conditions, pre-fault loading, and especially the ground fault resistance. In the presence of SMES equipped SSSC, its structural and controlling parameters as well as its connection point affect the tripping characteristic. Here, the measured impedance at the relaying point is calculated due to the mentioned parameters.