Transient mechanism analysis and research of a single-phase grounding fault causing transient tripping of the distribution network line

Abstract

This article presents an in-depth analysis of the transient process of power transmission line tripping due to 66kV single-phase grounding faults in the power system. Based on the characteristics of neutral-point non-direct grounding methods, it explores the formation mechanisms of fault current and voltage transients, as well as the key factors in the tripping process. By combining theoretical analysis with practical cases, a transient equivalent circuit model was established, and the transient current expression of the fault path was derived. The research results indicate that if single-phase grounding faults are not addressed promptly, they can easily lead to phase-to-phase short circuits, equipment insulation breakdown, and protection tripping, resulting in power grid accidents. This article provides theoretical support and practical reference for fault diagnosis and protection strategy optimization in distribution networks.