Abstract: In small current grounding system, determining singlephase grounding fault lines is quick a key question for realizing protection of power distribution net. Studies at the paper as follows was outspreads: a method of malfunction lineselection using the size and direction of zero sequence full current was advanced in neutral point indirect grounding system on the base of studying malfunction lineselection methods. Besides, a new method of lineselection using zero sequence transient electric charges for identifying singlephase grounding fault was put forward. This method is suit for neutral point to the ground via arcsuppression coil system. Computer simulation results indicate that the method has the merit of high lineselection accuracy rate and is propitious to implement microcomputer lineselection devices.

Key words: Small current grounding system , Singlephase earth fault , Transient electriccharges , Lineselection

摘要： 在小电流接地系统中,迅速判定单相接地故障线路是实现配电网保护的关键问题。在分析研究现有
故障选线方法的基础上,提出了利用零序全电流的大小和方向进行故障选线的方法。在此研究的基础上,提出了利
用零序暂态电荷实现故障选线的新方法,此方法适用于主变中性点经消弧线圈接地系统。经计算机仿真验证,此方
法具有选线准确率高、利于微机选线装置实现的优点。

关键词: 小电流接地系统 , 单相接地 , 暂态电荷 , 选线