Impact of static synchronous compensator (STATCOM) on performance of distance relay

In this paper impact of static synchronous compensator (STATCOM) on performance of distance relay is investigated both with analytic and simulation methods. At the first step the complete model of STATCOM with a 48-pulsed voltage source converter and its control circuit are described. At the next step, using analytic computations, the impact of STATCOM on the impedance calculated by the relay is investigated. Finally the impact of different factors like settings of STATCOM, type of faults, the place in which faults are occurred, load angle and the level of system short circuit on the relay impedance are examined using simulations in MATLAB/Simulink environment.