A Novel Distance Relaying Scheme to Mitigate Phase Faults on Doubly Fed Transmission Lines

摘要

Conventional non-pilot distance relaying schemes having the facility of series compensated transmission line were found to fail in providing requisite protection to the transmission line during phase faults. A new novel distance relaying scheme is proposed to mitigate the misinterpretations that occur in the conventional methods due to the capacitor used, infeed/outfeedsources, pre-fault system condition, non -linear behaviour of Metal Oxide Varistor(MOV) and arc resistance The proposed method provides an elaborate study of the apparent impedance seen from its relaying point and measures the accurate value of impedance of the faulted line using symmetrical components of voltages and currents. This method has been validated through the simulations carried out on a 400 kV, doubly fed 300 km series compensated long transmission line using MATLAB/SIMULINK software. Finally an evaluation is done by comparing the conventional and the new proposed scheme is done and effectiveness of the proposed method is inferred.