Modeling and simulation the impacts of STATCOMs on distance protection

This paper provides a study on the impacts of a static synchronous compensator (STATCOM) on a transmission line distance protection. An emtp-type model has been developed to simulate the power system and the STATCOM device. A simulated distance relay model with supervisory elements is used. The effective impedance seen by the distance relay is investigated and evaluated with and without the presence of the STATCOM. The results show that the distance relay performance is affected by the fault location relative to the location of the STATCOM. During a capacitive current injection, the simulation results show that the mho relay underreaches for faults applied beyond STATCOM.