基于EMD的配电网故障定位仿真研究

Simulation Study of Fault Location Based on EMD Algorithm for Distribution Network

在ATP中建立小电流接地系统单相接地故障模型并进行仿真,通过对沿线路安装的各检测装置检测到的暂态零模功率信号进行EMD分解,利用得到的最高频IMF分量部分进行一阶向后差分运算,通过分析各检测点的一阶差分波形可以得出:位于故障位置同侧两检测点的差分波形相似度极高,而位于故障位置两侧2点的差分波形相似度低,以故障点为中心,两侧各点的差分波形对称度极高。已经证明,一阶差分波形的特征信息不随过渡电阻值的变化而变化,因此,利用差分波形的故障特征信息可以为小电流接地系统的故障定位研究工作提供新思路。

It established single-phase to ground fault model of small current to ground system,and simulated model,according to decomposed by EMD algorithm for transient zero-mode power signal of every detection point along line installed.It utilized high-frequency IMF components got to subtract backward first-order,according to analyze differential waveforms of every detection point,it got differential waveforms similarity degree of two detection point located the same side of fault point is higher,while differential waveforms similarity degree of two detection point located two sides of fault point is lower.If fault point was center,differential waveform symmetry of two sides of fault point is higher.It has shown that characteristic information of first-order differential waveform was not varied by transition resistance＇ changement.So it utilized characteristic information of differential waveform to provide a new ideas for fault location of small current to ground system.