Fault line selection method for high-resistance ground faults in asymmetric distribution networks with ne utral point voltage source connection

Authors

• Tao Tang, State Key Laboratory of Disaster Prevention and Reduction for Power Grid ， Changsha University of Science & Technology ， Changsha 410114 ， ChinaFollow
• Silin Xiang, State Key Laboratory of Disaster Prevention and Reduction for Power Grid ， Changsha University of Science & Technology ， Changsha 410114 ， China
• Qilong Rong, State Key Laboratory of Disaster Prevention and Reduction for Power Grid ， Changsha University of Science & Technology ， Changsha 410114 ， China
• Kangjian Yuan, State Grid Loudi Power Supply Company ， Loudi 417000 ， China

Keywords

fault line selection, high-resistance ground fault, asym metric distribution network, equivalent model for zero-sequence networks

Abstract

A fault line selection method based on neutral point voltage source connection for single-phase high-resistance ground faults is proposed to address the challenge of single-phase high-resistance ground fault identification in asymmetric distribution networks.Firstly，the zero-sequence current component characteristics of lines in asymmetric distribution networks are analyzed，and an equivalent model for the zero-sequence network of asymmetric distribution networks is built.Secondly，when the zero-sequence voltage exceeds its limit，a high-frequency voltage source is connected to the system neutral point，with the influence of asymmetric parameters of each line eliminated by calculating the asymmetric current.The ratio of the power frequency component to the high-frequency component of the line zero-sequence current is denoted as the power-to-high ratio （PHR ）.It is found that the PHR of the fault line is significantly higher than that of the healthy line；the line with the largest PHR is identified as the fault line；the high-resistance fault line selection can be realized.At the same time，the influence of transition resistance and the neutral point connection on the line selection criterion is analyzed，with simulation analysis carried out based on case studies.The results demonstrate that the proposed method effectively eliminates the influence of three-phase distribution parameter asymmetry in high-resistance fault line selection，and exhibits robust resilience against transition resistance.Moreover，it is not affected by the neutral point connection and has certain applicability to arc high-resistance grounding.

DOI

10.19781/j.issn.1673-9140.2026.04.005

First Page

51

Last Page

60

Recommended Citation

Tang, Tao; Xiang, Silin; Rong, Qilong; and Yuan, Kangjian (2026) "Fault line selection method for high-resistance ground faults in asymmetric distribution networks with ne utral point voltage source connection," Journal of Electric Power Science and Technology: Vol. 41: Iss. 4, Article 5.
DOI: 10.19781/j.issn.1673-9140.2026.04.005
Available at: https://jepst.researchcommons.org/journal/vol41/iss4/5