Signal Processing Applications to Current Traveling Wave Fault Locators for EHV Transmission Networks

Traveling waves recorders (TWRs) are used to accurately find the location of different faults in power transmission networks. These recorders are installed at few high voltage buses where current traveling waves (CTWs) can be extracted. The CTW signals´ time delay of the initial wave is recoded at each TWR. In this paper, the minimum travel time of the CTW has been calculated considering Dijkstra algorithm to select the nearest TWRs to the fault point. Wavelet transform is used to find the highest energy of the details frequency band of the CTW signals. Optimum details level is extracted based on its energy content. The mean delay is calculated from the first packet of details´ power profile for each TWR to be used in a double-end fault location algorithm. Time delay at the maximum power delay profile shows good results compared to the mean time delay.