小电流接地选线跳闸技术分析探讨与试点建设

针对当前小电流接地配电网系统中电缆线路不断增多,传统中性点接地方式及人工拉路方法难以满足现代城市电网安全要求的形势,梳理了灵活并小电阻选线跳闸、灵活并中电阻选线跳闸、主动干预灭弧、分布式选线跳闸、集中式选线跳闸共5种接地选线后作用于跳闸方案的动作逻辑及主要优缺点。并通过某电力公司试点建设的动作数据及运行经验,推荐已投运设备选择集中式单相接地选线跳闸方案,新建与改造设备选择分布式单相接地选线跳闸方案。

Analysis and Pilot Construction of Grounding Line Selection Tripping Technology in Single-phase Grounding System

Due to the increase of cable lines in small-current grounding distribution systems currently, traditional neutral point grounding modes and manual pulling method now is difficult to meet the security requirements of modern urban power grid. The action logic, main advantages and disadvantages of five kinds of grounding line selection tripping schemes are sorted ou, that is,: parallel small resistance line selection, parallel medium resistance line selection, active intervention of arc extinction, distributed line selection and centralized line selection. Through the actual data and operation experiences of a electric power company, the centralized single-phase grounding line selection tripping scheme is recommended if the electrical equipment is already in operation, and the distributed single-phase grounding line selection tripping scheme can be selected if the equipment has not been put into operation.