Synchronized measurement based an adaptive distance relaying scheme for STATCOM compensated transmission line

Protection of bulk power delivering transmission line (TL) is very important for power system stability and reliability. The environmental and right of way restrictions delayed the construction of new transmission line to meet the deregulated power demands. Shunt FACTS devices connected in the transmission system enhances the power transfer capability up to its thermal limit. Shunt FACTS devices have the ability to control series impedance, shunt impedance, current, voltage and load angle. STATCOM is one of such shunt FACTS devices which severely affect the protection system installed for TL. This research work is focused on the addressing the issues with distance relaying of STATCOM compensated TL and to overcome these adverse effects, new adaptive relaying algorithm is presented based on synchronized measurement. The proposed algorithm is implemented in PSCAD EMTDC simulation to validate its performance in terms of accuracy and reliability subjected to various faults on TL. Error in the fault location estimation with proposed algorithm is 0.6% for 300 km TL. To claim the superiority and its accuracy, the algorithm is tested in hardware environment with faults in offline mode.