1.School of Automation and Information Engineering, Xi’an University of Technology, Xi’an710048, China;2.State Grid Shaanxi Electric Power Research Institute, Xi’an710100, China;3.Anhui Onesky Electric Technology Company Limited, Hefei230088, China
This work is supported by National Natural Science Foundation of China (No. U1766208).
To solve the problem of single-phase grounding fault processing for neutral point non-effective grounding in distribution network, an automatic processing scheme for single-phase grounding faults in distribution network based on fault-phase grounding approach is proposed. The automation system consists of a fault-phase grounding arc-extinguishing line selection device in the substation and fault-phase grounding start-up protection devices deployed to the feeder switches. By adopting the fault-phase grounding method to achieve the reliable arc-extinguishing of single-phase grounding faults, the characteristics of zero-sequence voltage and zero-sequence current variations before and after the fault-phase grounding disconnection are used to achieve the line selection, location and isolation of permanent single-phase grounding fault and power restoration of sound district. By analyzing the variations of zero-sequence voltage and zero-sequence current of the system before and after the fault-phase grounding disconnection, a single-phase grounding line selection and location criterion based on the fundamental zero-sequence current ratio before and after the fault-phase grounding disconnection is constructed. The key technical problems, such as the start-up criterion for single-phase grounding fault processing, the detecting of the fault-phase grounding disconnection moment, and the necessity of throwing in a resistance to the neutral point before the fault-phase grounding disconnection are discussed in detail. Combined with an example, the proposed processing process for single-phase grounding fault is explained and experimental verification is carried out. The results show the feasibility and effectiveness of the proposed method
LIU Jian,ZHANG Zhihua,LI Yunge,et al.Automatic Processing of Single-phase Grounding Fault in Distribution Network Based on Fault Phase Grounding[J].Automation of Electric Power Systems,2020,44(12):169-177.DOI:10.7500/AEPS20190730008Copy