A wavelet-based restricted earth-fault power transformer differential protection

This paper proposes a restricted earth fault protection based on the wavelet transform (REFW) for detecting ground faults close to transformer neutral point (turn-to-ground faults) and supporting conventional phase differential protection, which presents limitations in this kind of faults. The proposed REFW uses only high-frequency components instead phasor estimation, speeding up detection turn-to-ground A performance comparison between wavelet-based earth-fault respective (REF) unit was accomplished considering simulated faults, involving few winding turns. method is more efficient faster than one, reaching success rate 100%.