Permanent Fault Identification Scheme for Distribution Feeders Using Detection-Based Reclosing

To mitigate secondary damage caused by reclosing a distribution line with a permanent fault, a highly sensitive fault property identification scheme using detection-based reclosing is proposed in this paper. Firstly, the analytical model for single-phase detection-based reclosing in distribution networks is established to reveal the differences between transient and permanent faults. Given that the equivalent fault resistance of permanent ground faults differs significantly from the insulation resistance of transient faults, an equivalent fault resistance calculation method is proposed to improve the sensitivity of fault property identification. Furthermore, to reduce the impact of fault resistance and load capacity on phase-to-phase fault property identification sensitivity, a permanent fault identification method utilizing the line voltage ratio is proposed. Finally, a comprehensive detection-based reclosing scheme is developed. Validation results based on PSCAD simulations and RTDS closed-loop tests demonstrate that the proposed scheme exhibits both wide applicability across various scenarios and high sensitivity.