Current-based directional relaying scheme to protect series compensated transmission lines used to transmit bulk power produced by power electronics interfaced renewable energy power plants
© 2019 The Institution of Engineering and Technology. Exploiting series compensated transmission lines (SCTLs) to transfer bulk power produced by power electronicsinterfaced renewable energy power plants (PE-REPPs) to the load canters has been accepted as an economical solution as well as the practical approach. However, SCTLs impose some difficulties on protective relays, especially conventional directional relaying which mainly employ phase angle difference between voltage and current signals to discriminate between forward and reverse faults and can jeopardize their operation, leading to a false trip and unjustified isolation of REPPs. To solve this problem, an efficient current-based directional relaying scheme is presented for the protection of SCTLs. In SCTLs due to the presence of series capacitance in the fault loop, voltage inversion (VI) and current inversion (CI) phenomena occur. The proposed directional relaying scheme can tackle CI and VI problems. Since the proposed method merely uses the phase angle of fault current, it can retain its proper operation during close-in faults where conventional directional relaying lose their proposer performance due to CCVT transients as well. Therefore, the resilience offered by SCTLs during the integration of REPPs will be attained. The performance of the proposed relaying scheme is evaluated under various operating conditions, and obtained results prove its efficiency.