Comprehensive study on tree-contact single-phase-to-ground faults: Modelling, risk analysis, and detection recommendations

Abstract

Tree-contact single-phase-to-ground faults (TSFs) present a significant fire hazard in electrical distribution systems, and research on the development, modelling, and monitoring is insufficient. This article investigates the electro-thermal coupling mechanisms during the current rise of TSFs, constructing a simplified power–frequency model that leverages actual physical parameters like tree size for prolonged simulations of the first TSF stage zero-sequence current. Validated through full-scale testing, the model enables digital simulations across various tree sizes, concluding that the detection sensitivity for grounding faults should not exceed 0.5 A to mitigate fire risks effectively. This approach surpasses the limitations of traditional high-impedance fault models reliant on empirical parameters and the shortcomings of generalised conclusions from experimental inductions, offering a new paradigm for TSF research that enhances the predictive accuracy and applicability of fault analysis in electrical distribution networks.