Identification and classification of faults on transmission lines using wavelet multiresolution analysis

This article presents a new method for identification and classification of faults based on wavelet multiresolution analysis (MRA). Daubechies eight (D-8) wavelet transforms of the three phase currents on a transmission line are used. The peak absolute value, the mean of the peak absolute values, and summation of the third level output of MRA detail signals of current in each phase extracted from the original signals are used as the criterion for the analysis. The effects of fault distance, fault inception angle and fault impedance are examined. Extensive simulations are carried out to generate time domain input signal using EMTP (Microtran) on a 400 W, 300 km long line and simulation results show that the proposed method is a simple, effective and robust method suitable for high impedance faults also.