Faulted feeder selection in neutral non-effectively grounded distribution system using single-phase current traveling wave

Abstract

A novel scheme of single-phase-to-ground fault feeder selection in distribution networks with the application of a wavelet transform technique is presented in this paper. The scheme uses single-phase current traveling wave to identify faulted feeder. The current traveling wave measured by single-phase current transformer of each feeder is decomposed using wavelet multi-resolution analysis. The local modulus maxima of the wavelet transform are extracted and compared in magnitude with each other to determine the faulted feeder. The faulted feeder selection using current traveling waves is independent of the network neutral-point grounding mode. The proposed scheme uses the residual voltage to determine a disturbance as a fault or not. The scheme is implemented and verified using EMTP (Electromagnetic Transients Program) generated signals. The scheme is implemented easily in the field without the need of special zero-sequence current transducer and simple wiring, especially for overhead feeders. The scheme proved to be robust against transients generated during normal events such as feeder energizing and de-energizing as well as capacitor bank switching.