Robust distance protection of mid-point shunt compensated transmission line

Distance relays is exclusively used for the protection of HV and EHV line from last few decades. As a result of extensive research studies the distance relays have been upgraded to a distinct level. Introduction of synchronized measurement in power system has opened the new area of research in protection of transmission line. To enhance the power transfer capability of line the shunt Flexible AC Transmission System (FACTS) devices placed at midpoint are widely used nowadays. The use of shunt compensating devices like Static Var Compensator (SVC) and STATic synchronous COMpensator (STATCOM) have created many issues in distance protection of transmission line. This paper proposes the robust distance protection scheme utilizing the concept of synchronized measurement. The proposed scheme measures the impedance in two parts by utilizing the terminal information of the compensating device. Electro-magnetic Transient Program (EMTP) simulations on two machine system are used to establish the claims. The results prove the excellence of the proposed scheme.