A sequential reclosing strategy for distribution lines with permanent fault identification capability

Identifying fault properties before reclosing mitigates secondary impacts caused by traditional three-phase automatic reclosing onto permanent faults in distribution networks. While existing literature proposes detection-based reclosing for identification, low sensitivity and the influence of neutral grounding modes remain problematic. This paper proposes a sequential reclosing strategy with permanent fault identification capability for both grounding and phase-to-phase faults. First, an analytical model for detection-based reclosing is developed to demonstrate that the fault current surge from single-phase reclosing is substantially lower than that of three-phase reclosing. Second, zero-sequence impedance expressions are derived for grounding faults; a criterion is then established based on the characteristic phase angle differences between transient and permanent faults. For phase-to-phase faults, a criterion utilizing the average Hausdorff distance algorithm is proposed to quantify line voltage waveform similarities. Finally, RTDS-based closed-loop tests under low-resistance grounding, ungrounded, and arc-suppression-coil grounding systems verify that the proposed scheme can reliably identify fault properties, tolerate high fault resistance, and remain independent of neutral grounding modes.