Fault Location Estimation Based on Wavelet Analysis of Traveling Waves

Improved fault location techniques are important particularly in EHV transmission lines and those subject to relatively high incidence of contingency faults over difficult terrain. Traveling wave based single end data techniques generally assume near total reflections at the fault point as well as line terminals. However, in practice effective impedances at the fault point and line terminals may not be significantly lesser than the line surge impedance. With this in view, a new traveling wave based algorithm, which does not assume near total reflections at discontinuities, and therefore more accurate over the wide range of variable parameters, is presented in this paper. Discrete wavelet transform was used to analyze the fault induced traveling waves. MATLAB/Simulink software was used to test and validate the proposed fault location approach. Various fault conditions were simulated by varying fault type, fault resistance, fault location and fault inception time, on a given power system model. The results showed that the proposed method for fault location was able to locate the faults on the transmission line rapidly and correctly.