基于节点阻抗矩阵和电压暂降的故障定位新方法

配电网线路发生故障时,将导致用户停电,直接影响供电连续性和可靠性,及时准确的故障定位对及时排除故障,缩短停电时间,提高供电质量有重要意义。当线路发生故障时,一方面将在全系统内引起电压暂降,给系统内的敏感负荷带来损失；另一方面,利用该特征可识别故障类型并判断故障位置,为此提出利用电压暂降数据识别故障类型,基于节点阻抗矩阵实现配电网故障定位的新方法,并结合网络参数和离线仿真分析,建立不同故障类型和故障情况下的节点电压数据库,当检测到故障后,将采集到的电压暂降数据在节点电压数据库中进行搜索匹配,确定故障区间和故障点。该方法直接利用搜索结果确定故障位置,不用增加其它算法或变换,原理简单,计算迅速。最后,利用电力系统计算机辅助设计（power system computer aided design,PSCAD）仿真软件和实验室搭建实际电路进行测试,验证所提方法的正确性和可靠性。

New Method for Fault Positioning Based on Nodal Impedance Matrix and Voltage Sag

Faults of lines of power distribution network may cause power outages and directly affect power supply continuity and reliability.Timely and correct fault positioning plays important roles in removing faults,shortening power outage time and improving power supply quality.When fault happening to the line,voltage sag was occurred in the system which might cause loss in sensitive load in the system.In addition,it was able to recognize fault types and adjust fault position by using this feature and therefore,a new method for realizing fault positioning of the power distribution network based on nodal im-pedance matrix and by using voltage sag data was proposed.Combining network parameters and off-line simulation analysis, node voltage data base with different fault types was established.When detecting fault,it was able to carry out search and match for collected voltage sag data in the node voltage data base in order to confirm fault intervals and fault points.This method directly used search results to confirm fault position instead of increasing other algorithm or transformation which was provided with advantages of simple principle and rapid calculation.By means of power system computer aided design simulation software and practical circuit in lab,accuracy and reliability of this method was proved and verified.