PMU based Distance Protection Methodology to Avert Malfunction due to FACTS controllers

In general, reactive power compensation equipment are used in transmission lines to enhance the power transfer capacity and voltage profile but they affect the performance of distance relays significantly. This paper proposes phasor measurement units (PMUs) based protection technique to avert malfunction of distance relays due to flexible alternating current transmission system (FACTS) controllers, especially static VAr compensator (SVC). The proposed methodology has employed synchronized voltage and current phasor data received at phasor data concentrator (PDC) in system protection center (SPC) to determine the zone of fault detection by the primary and backup relays. The SPC takes appropriate action based on the impedance seen by the primary and backup relays. Performance of the proposed methodology is validated on WSCC-9 bus system in PSCAD/EMTDC environment. The results show that the proposed methodology is successful in averting distance relay malfunction due to FACTS controllers.