油田电力系统小电流单相接地故障选线研究

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。

Study on Small Current Single-Phase Earth Fault Line-Selection Principle to Oilfield Power System

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 are-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.