Application of wavelet multiresolution analysis for classification of faults on transmission lines

This paper presents a new method for classification of faults based on wavelet multiresolution analysis (MRA). Daubechies eight (D-8) wavelet transforms of the three phase currents on a transmission line fed from both ends are used. The summations of the 3rd 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 also examined. Extensive simulations are carried out to generate time domain input signal using EMTP (Microtran) on a 230 kV, 200 km long line fed from both ends and simulation results show that the proposed method is a simple, effective and robust method suitable for high impedance faults also.