Single-ended fault location method based on wavelet theory: Application to a double-circuit transmission line

Within the Wavelet Transform (WT), time and frequency information can be measured simultaneously. This eases the detection of high-frequency transients generated by faults on transmission lines. This paper presents a new single-ended fault location method using WT to capture the fault generated transients and to locate the fault point. The proposed method uses the difference of travelling wave arrival times at one terminal to locate the fault point accurately. The transients reflected from another terminal and the fault point could be distinguished with the adoption of the discrete wavelet transform (DWT) on travelling waves. In order to develop the method based on the wavelet theory, a single line to ground fault is simulated on a 400 kV transmission line model using ATP/EMTP, and the so computed terminal signals are further analysed in Matlab. The impact of transformers and substations on the accuracy of this method is also discussed in this paper.