High-impedance fault detection technology based on transient information in a resonant grounding system

Abstract

High-impedance faults (HIFs) occur frequently in resonant grounding systems and are difficult to detect. Thus, an effective HIF feeder identification technology is urgently in demand. An HIF equivalent circuit in a resonant grounding system is established. The magnitude and phase relationships of transient zero-sequence currents among the faulty feeder, healthy feeders, detection points, and fault point, as well as the relationships between their projection coefficients with respect to the transient zero-sequence voltage are analysed. A novel HIF detection method based on the comparison of the magnitude and polarity of the transient zero-sequence current’s projection coefficient is proposed. The accuracy of the proposed method is verified by simulations and field data.