Faulty Phase Identification Using Probability Tail Function for EHV Transmission Systems

-In this paper, a novel simplified probabilistic technique is investigated to identify the faulty phase. Estimating the faulty phase enhances the operation of single-pole autoreclosure which is applied in Europe countries. The proposed technique is based on the probability tail functions applied on the standard deviations of Discrete Wavelet Transforms (DWT) of the phase currents. An adaptive setting is proposed to be suitable for different faulty phase. The setting signal is selected as the maximum standard deviation of the DWT of phase currents. The earth faults and phase faults are correctly discriminated. Validation of the proposed algorithm is verified via ATP/EMTP simulation. Test results corroborate evidence of the efficacy of proposed technique.