DETECTION AND LOCATION OF FAULTS IN THREE PHASE UNDER GROUND POWER CABLE USING WAVELET TRANSFORM

Power system fault location and identification of t he different faults on a underground power cable system for quick & reliable operation of protection scheme. Fault location estimation is very important issue in power system in order to clear faults quickly & restore power supply but the location of fault can be analyzed only with wavelet transform. Wavelet transform, which is very fast and sensitive to noise, is used to extract transients in the line currents for fault detection. The de - noising process rejects noise by thresholding in th e wavelet domain and also improves the quality of the signal. Three wavelet functions ("db", "coif" a nd "sym") and three different thresh holding methods are “Rigsure”, “Sqtwolog” and “Minimax” use d to de-noise the noise signal.