Zero-Sequence Current Retrieval-Based Robust High-Impedance Fault Location in Resonant Grounding System

To address the limited accuracy and robustness of existing high-impedance fault (HIF) location methods for resonant grounding systems (RGS), which fail to account for the difference in prominence and fluctuations of transient component (TC) at various measurement points under different fault scenarios, this paper introduces a robust HIF location method that eliminates the high requirement for TC extraction. By analyzing the equivalent circuit equations of HIF, the influence mechanism of grounding resistance and the ratio of zero-sequence capacitance upstream of the measurement position to the entire zero sequency system on the differences in main TC is quantitatively analyzed. Meanwhile, a zero-sequence current (ZSC) retrieval model is constructed to classify signals from faulty and healthy regions into ideal separable data unaffected by line parameter deviation and fault conditions. Subsequently, a fault location method via shape-based distance metric is developed to ensure accurate and robust fault feeder selection and fault section location. Finally, extensive case studies validate the effectiveness of the proposed method under different scenarios.