Intelligent differential relay for power transformer protection

Abstract

This paper presents intelligent differential protection scheme for power transformer which is based on pattern recognition and classification using artificial neural network (ANN). In order to avoid tripping on magnetizing inrush and over-excitation conditions, second-cum fifth harmonic restraint is used. The proposed relay can easily classify the patterns. It restrains during inrush, over-excitation and normal conditions and trip only during internal faults.