Wavelet based energy function for symmetrical fault detection during power swing

Fault during power swing is one of the challenging task for the distance relay functioning. This paper focuses on developing Wavelet Energy (WE) based function for symmetrical fault detection during power swing. The process starts at retrieving the current signal samples during power swing and processes it through Wavelet Transform to derive detailed coefficient of wavelet d1 to d7, used to find out energy of the signal, and called Wavelet Energy (WE). In the case study, the three-phase symmetrical fault is created in the transmission line and proposed algorithm detects the fault with in one and half cycles for 60 Hz system. Simulation results demonstrate the effectiveness of the proposed approach under time-varying conditions.