An approach to power transformer protection based on wavelet transform

A transformer model considering the hysteresis effect is presented first and magnetic inrushes and short-circuit faults are simulated with this model. The wavelet transform is a powerful tool in the analysis of power transformer transient phenomena because of its ability to extract information from transient signals simultaneously in both the time and frequency domains. This paper proposes a new wavelet-based method to identify an internal fault and distinguish it from an inrush current or an external fault. The simulation results demonstrated effectiveness and feasibility of the presented method