Comparing effects of SVC and STATCOM on distance relay tripping characteristic

This paper presents and compares the measured impedance at the relaying point in the presence of shunt connected flexible alternating current transmission system (FACTS) devices, i.e. static VAr compensator (SVC) and static synchronous compensator (STATCOM). The presence of the shunt connected FACTS devices on a transmission line greatly affects the measured impedance at the relaying point. The measured impedance itself depends on the power system structural conditions, pre-fault loading, and especially the ground fault resistance. In the presence of shunt connected FACTS devices, their structural and controlling parameters as well as their installation position, affects the measured impedance. Here, the measured impedance at the relaying point is calculated due to the mentioned affecting parameters, and compared in the two cases of SVC and STATCOM.