基于D-PMU的配电网故障选线和定位方法

Fault Line Selection and Location Method Based on Synchrophasor Measurement Unit for Distribution Network

配电网发生单相接地故障时,故障信号微弱且易受噪声干扰,准确选线和故障定位困难。为此,提出一种基于配电网同步相量测量装置(D-PMU)的故障选线和定位新方法。研制了D-PMU功能扩展模块——行波故障采集模块;搭建了配电网故障选线和定位系统;依据全网波头时差构建故障前、后时间特征矩阵,并引入最小二乘法模型以消除行波波头到达时刻标定误差。通过分析得出故障前、后时间特征矩阵中元素的变化规律,实现配电网故障选线和精确定位。仿真分析及现场试验结果表明,D-PMU现场运行稳定,所提方法不受线路参数和网络拓扑结构的影响且实用性强。

Single-phase grounding fault signal in distribution network is weak and is susceptible to noise interference.Therefore,it is very difficult to accurately select fault lines and locate faults.Therefore,a new method of fault line selection and location based on synchrophasor measurement units for distribution network(D-PMU)is proposed.Firstly,the function expansion module of DPMU,namely acquisition module of fault traveling wave,is developed.The fault line selection and location system of distribution network is built,and the time characteristic matrix before and after the fault is constructed according to the time difference of traveling wave front in the whole distribution network.The least square method model is introduced to eliminate the calibration error of arrival time of traveling wave front.The variation characteristics of elements in time characteristic matrix before and after fault are analyzed,and the fault line selection and precise location of distribution network are realized.Simulation analysis and field test results show that D-PMU runs stably in the field,and the proposed method is immune to the influence of line parameters and network topology and is highly practical.