Faulty Feeder Detection for Successive Single Phase-to-Ground Faults Based on Line Model Recognition and Correlation Comparison

Abstract

When a single phase-to-ground (SPG) fault occurs in distribution networks, the over-voltages in non-fault phases may cause insulation damage to entire networks, potentially leading to a secondary SPG fault in feeders. Existing detection methods fail to explore the underlying mechanisms of SPG faults, resulting in unsatisfactory detection performance in practical applications. Moreover, they cannot identify the second faulty feeder under successive SPG (SSPG) faults, thereby increasing the risks of bushfires and casualties. This paper proposes a faulty-feeder detection method for SSPG faults based on line model recognition and correlation comparison. Firstly, the fault characteristics under SPG and SSPG faults are analyzed, revealing that differences in the equivalent line models are essential for distinguishing between faulty and healthy feeders. Secondly, the derivative of zero-sequence voltage reflecting the capacitance characteristics is compared with the measured zero-sequence currents from the perspectives of similarity and distance. The first faulty feeder is detected using cosine similarity comparison, while the second faulty feeder is identified using Euclidean distance comparison. Thirdly, a comprehensive detection criterion is constructed based on the cooperation of the similarity comparison method and distance comparison method. The feasibility and applicability are verified using various simulation data, field tests, and practical data tests.