配网自动化系统小电流接地故障暂态定位技术

Small-current grounding fault location based on transient signals of distribution automation system

分析了小电流接地故障的暂态过程、暂态电流分布特征,以及配网自动化(DA)系统实现接地故障定位面临的问题。介绍了暂态功率方向定位方法和暂态电流相似性定位方法的原理和特点,提出了综合利用两者特点确定故障区段的方法:利用前者大致估计故障所在区段,利用后者确定具体的位置。最后阐述了故障选线装置接入DA系统的必要性,给出了DA系统接地故障定位流程。静态模拟试验和现场运行结果均表明,基于所提方法的DA系统故障定位功能成功率高,且可有效辨识故障和扰动。

The transient process and the transient current distribution of small-current grounding fault are analyzed and the difficulties of its location by DA（Distribution Automation） system are discussed. The principles and features of transient reactive power direction location method and transient grounding fault current similarity location method are introduced and a hybrid method is proposed,which applies the former method to estimate roughly the fault section and the latter to confirm exactly the fault location. The necessity of integrating the faulty line selector into DA system is explained and its location flowchart is given. The results of static simulation and field operation show that,the proposed fault location function of DA system has high success rate,which can effectively distinguish the disturbances from the faults.