Evaluation of travelling wave fault location methods based on field measurements

Travelling wave recorders (TWRs) are used throughout the world to accurately find the location of different faults in transmission networks. In this paper, TWR signals are recorded and the minimum travel time of the travelling wave has been calculated considering shortest path algorithm to select the nearest TWR to the faulted line. Digital wavelet transform (DWT) is used to find the details at several high frequency bands of the travelling wave signals. The best selection from several mother wavelets was used to decompose the fault transient signal and extract the feature vector. The fault location is determined by accurately time- tagging the arrival of the travelling wave at the monitored substations and comparing the time difference to the total propagation time of the lines. A small number of fault cases from the Finnish transmission network have been analysed. Comparing the simulated and recorded fault cases, the algorithm gives a good results and the method can be applied using the minimum number of TWR in the transmission network.