基于固有模态能量的暂态量选线方法

摘要

针对基于小波分析的煤矿电网故障选线方法由于分解效果取决于基函数的选择,不能保证最优分解效果的问题,提出了一种基于固有模态能量的暂态量选线方法.该方法利用经验模态分解对信号局部特征的自适应性,对单相接地故障零序电流的暂态特征进行分析,定义固有模态能量和能量权重因子作为故障特征参数,实现对故障暂态量信息的数据挖掘;求取故障后各馈线的零序暂态电流的固有模态能量,计算各馈线的能量权重因子,通过比较各馈线能量权重因子辨识出故障线路,即能量权重因子最大的线路就是故障线路.理论分析和仿真结果表明,该方法不受接地电阻、故障时间等故障条件的影响,能够准确可靠地实现煤矿高压电网故障选线.%In view of problem that fault line selection method based on wavelet analysis of coal mine power grid can't guarantee the optimal decomposition effect due to the decomposition effect depends on choice of primary function,the paper presented a fault line selection method with transient state based on intrinsic mode energy.The method uses adaptivity of empirical mode decomposition to signal local feature to analyze transient characteristics of zero sequence current for single-phase grounding fault,and defines intrinsic mode energy and energy weight factor as parameters of fault characteristics,so as to realize data mining of fault information of transient state.It obtained intrinsic mode energy of zero sequence transient current of each line after fault and calculated energy weight factor,then determined fault line by comparing the energy weight factors,namely,the line with the biggest energy weight factor is fault line.The theoretical analysis and simulation results show that the method is not affected by transition resistance,fault time and other fault conditions,and can accurately achieve fault line selection of coal mine high-voltage power grid.