Traveling-wave based fault location for phase-to-ground fault in non-effectively earthed distribution networks

This paper presents a multi-terminal traveling-wave-based fault location method for phase-to-ground fault in non-effectively earthed distribution systems. To improve the accuracy of fault location, a two-terminal approach is used to identify the faulty branch and a single-ended approach is followed to determine the fault distance based on the arrival time of reflected traveling waves. Wavelet decomposition is employed to extract the time-frequency component of the aerial-mode traveling waves. Magnitude and polarity of the wavelet coefficients are used to estimate the fault distance starting from the propagation fault point to the branch terminal. In addition, the network is divided into several sub-networks in order to reduce the number of measurement units. The effectiveness of this approach is demonstrated by simulations considering the phase-to-ground fault that happens at different positions in the distribution network.