全球能源互联网（英文）2021，Vol.4Issue(6)：564-575,12.DOI:10.14171/j.2096-5117.gei.2021.06.004
基于零序电流比值系数的小电阻接地系统单相接地故障保护方法
Single-phase-to-ground fault protection based on zero-sequence current ratio coefficient for low-resistance grounding distribution network
摘要
Abstract
Definite-time zero-sequence over-current protection is presently used in systems whose neutral point is grounded by a low resistance (low-resistance grounding systems). These systems frequently malfunction owing to their high settings of the action value when a high-impedance grounding fault occurs. In this study, the relationship between the zero-sequence currents of each feeder and the neutral branch was analyzed. Then, a grounding protection method was proposed on the basis of the zero-sequence current ratio coefficient. It is defined as the ratio of the zero-sequence current of the feeder to that of the neutral branch. Nonetheless, both zero-sequence voltage and zero-sequence current are affected by the transition resistance, The influence of transition resistance can be eliminated by calculating this coefficient. Therefore, a method based on the zero-sequence current ratio coefficient was proposed considering the significant difference between the faulty feeder and healthy feeder. Furthermore, unbalanced current can be prevented by setting the starting current. PSCAD simulation results reveal that the proposed method shows high reliability and sensitivity when a high-resistance grounding fault occurs.关键词
小电阻接地系统/高阻接地故障/接地保护/零序电流比值系数Key words
Low-resistance grounding system/High-impedance grounding fault/Grounding protection/Zero-sequence current ratio coefficient引用本文复制引用
李建蕊,李永丽,王永欢,宋金钊..基于零序电流比值系数的小电阻接地系统单相接地故障保护方法[J].全球能源互联网（英文）,2021,4(6):564-575,12.基金项目
This work was supported in part by National Key Research and Development Program of China(2016YFB0900603)and Technology Projects of State Grid Corporation of China(52094017000W). （2016YFB0900603）
