A new pilot relaying technique for the STATCOM compensated transmission line

Abstract

With the inclusion of STATCOM in the transmission line (TL) causes maloperation of both the local end and both ends data-based relaying techniques. In this work, a differential impedance is derived using both ends synchronized phase voltage and current data which is equal to zero during normal conditions and high for internal faults. Moreover, the computation of accurate fault distance is an added superiority of the proposed scheme with due reliable fault classification. To validate the proposed technique, a STATCOM compensated 400 kV, 60 Hz and 9- Bus 230 kV, 50 Hz systems are simulated using PSCAD/EMTDC and MATLAB19a. The simulation results illustrate that the proposed technique successfully discriminates, classifies and locate the faults. Further, this technique is robust against variations in fault resistance, source impedance, fault location, mutual coupling between phases under asymmetrical faults and CT saturation. The comparative results reveal the superiority of the proposed technique against recently proposed schemes. Finally, the results under Indian Real-Time field data of a line having 144 km between Ranchi-Rourkela show the authenticity of the proposed scheme for practical implementation.