Analysis of distance relay performance on shunt FACTS-compensated transmission lines

Flexible Alternating Current Transmission System (FACTS) are widely and increasingly used in recent years to enhance transmission line capability and reliability. FACTS devices such as STATCOM can impact distance relay performance due to the fact that it changes power system quantities such as line impedances. Distance relay will mal-operate when STATCOM is connected and the transmission lines will lose the main objectives of using FACTS devices which are enhancement of capability and reliability. In this paper, we present detailed modeling and simulation of digital distance relay with three zones mho characteristics. We also verify the proposed model under a variety of fault types and fault locations. Analytical study on the effects of STATCOM on distance relay performance is examined. Analytical and simulation results are used to discuss the impact on the performance of distance relay for different modes and different STATCOM locations on transmission lines.