A new fault location technique for radial distribution systems based on high frequency signals

This paper presents a fault location method for distribution systems. The method is based on the traveling wave theory and uses the transient signals recorded during the fault, as a basis for the analysis. According to the traveling wave theory fault transients will have different signatures at the substation terminals depending on the number of network junctions they pass through as they travel towards the substation. Unfortunately, these signatures only show up at high frequency end of the spectrum and will be missed by most methods based on the power frequency signals. The proposed method takes advantage of the special properties of the wavelet transform to differentiate between faults occuring along different laterals of the same main feeder, equal distance away from the main substation. Once the faulted lateral is identified, exact location of the fault is determined by one of the conventional methods developed for strictly radial systems. Simulation results obtained by using ATP/EMTP for a sample distribution system, are included for demonstration of the proposed method.