Fault location in combined overhead line and underground cable distribution networks using fault transient based mother wavelets

This paper presents an optimized fault location approach in combined overhead line and underground cable distribution networks. Continuous wavelet transform (CWT) is employed for analyzing fault originated travelling waves. The transient voltage waveform is recorded at a measuring point and then analyzed using both standard and fault transient inferred mother wavelets. This approach rely on the relationship between typical frequencies of CWT signal energies and certain paths in the network passed by travelling waves produced by faults. In order to identify characteristic frequencies directly related to the previously mentioned paths, the continuous frequency spectrum of fault transients must be determined. Fault location is then detected using this frequency domain data. The frequency domain data along with the theoretically obtained characteristic frequencies specify the fault position. In order to verify this procedure, the IEEE 34-bus test distribution network is modeled by EMTP-RV software and the relevant transient signal analyses are executed in MATLAB programming environment.