Effects of voltage transformer connection point on measured impedance at relaying point in presence of SSSC for inter phase faults

This paper presents the measured impedance at the relaying point in the presence of static synchronous series compensator (SSSC), one of the series connected flexible alternating current transmission system (FACTS) devices, in the case of inter phase, phase to phase and three phase, faults. The presence of SSSC on a transmission line has a great influence on the measured impedance at the relaying point. The measured impedance itself depends on the power system structural conditions, pre-fault loading, and especially the fault resistance. In the presence of SSSC at the near end of the line, its structural and controlling parameters as well as the distance relay voltage transformer connection point affects the measured impedance at the relaying point. Here, the measured impedance is calculated in the case of inter phase faults due to concerning parameters.