基于VMD的井下变频系统漏电保护误动研究

针对变频器使用给煤矿井下漏电保护带来的误动问题,提出了一种基于变分模态分解（Variational Mode Decomposition，VMD）的煤矿井下变频系统漏电保护新方法。利用VMD分解算法对馈电线路零序电流进行分解，得到数个固有模态分量，计算各个模态分量的能量比重，选择最佳模态分量作为特征分量，比较特征分量能量比重，区分正常情况下由变频器产生的零序电流和故障下零序电流，即筛选出故障零序电流。通过Matlab仿真实验分析可知，该方法能够有效解决变频器带来的漏电保护误动问题。

Research on Leakage Protection Misoperation of Underground Frequency Conversion System Based on VMD

In order to solve the misoperation caused by the use of frequency converter to leakage protection of underground mine,a new method based on variational mode decomposition (VMD) for leakage protection under frequency load of coal mine is proposed.The zero sequence current signal was successfully decomposed into a series of intrinsic mode components by the VMD,the obtained intrinsic mode energy was calculated,and the appropriate modal component was selected as the characteristic component.By comparing the ratio of the characteristic component energy,the zero sequence current generated by frequency converter under normal conditions and under fault conditions was distinguished,and the fault zero sequence current was screened out.Through the Matlab simulation analysis,this method can effectively solve the problem of leakage protection misoperation caused by the inverter.