基于经验模态分解差分谱的故障选线新方法

A novel fault line selection method based on empirical mode decomposition and differential spectrum

提出了一种基于经验模态分解差分谱的小电流接地系统单相接地故障选线新方法。该方法采用经验模态分解方法分解故障发生后各条线路的暂态零序电流,提取出各条线路的高频IMF1分量,并根据差分谱和波动值的定义,求出各条线路的IMF1分量差分谱及IMF1分量波动值;通过比较各条线路的IMF1分量波动值,得出IMF1分量波动值最大的线路,则该线路即为故障线路。仿真结果表明,该方法具有较高的选线准确度,适用于不同接地电阻与不同故障初相角情况下的小电流接地系统故障选线。

The paper proposed a novel single-phase grounding fault line selection method of small current grounding system based on EMD and differential spectrum.The method uses EMD method to decompose transient zero-sequence current and extract high-frequency IMF1 component of each line,obtained differential spectrum and fluctuation value of IMF1 component of each line according to definitions of differential spectrum and fluctuation value,and found out the fault line which has the maximum fluctuation value of IMF1 component by comparing fluctuation values of IMF1 component of each line.The experiment results showed that the method has higher accuracy of line selection and is suitable for fault line selection of small current grounding system under different grounding resistances and different fault initial phase angles.