An accurate digital distance protection scheme using neural network in UHV transmission line

This paper describes an accurate digital distance relaying scheme integrated with artificial neural network block is developed using zero sequence component of a fault current and conventional ground impedance values, assuming that the conventional ground impedance always have some error impedance associated in it. The modified scheme is immune to the variation in fault location for under reach and overreach problem caused by sequence current components. Several types of test conducted on a 800kV, 400km transmission line for single phase to ground faults as well as simultaneous open conductor fault in PSCAD/EMTP and Matlab. In the end a comparison has been done with the conventional methods in order to check the accuracy and performance of the proposed scheme which is found to be 97%.