基于能量与相关性的谐振接地系统选线新方法

New line selection method of resonant grounding system based on energy and correlation

针对谐振接地系统单一选线方法易发生误判、易受训练样本影响等问题,提出基于能量与相关性的谐振接地系统选线新方法。首先计算线路各相电流突变量和每条线路的综合相关系数,然后用经验模态分解算法计算每条线路相电流突变量所对应的固有模态能量权重系数,取每条线路三相固有模态能量权重系数中的最大值作为本线路的综合能量系数值,最后通过二维判据求取特征距离。仿真结果表明,基于能量与相关性的谐振接地系统选线新方法实现了母线故障判别,且在一定程度上提高了判据裕度,适用范围更广。

In view of problem that single line selection method of resonant grounding system prones to misjudgment and is easily affected by the training samples,new line selection method of resonant grounding system based on energy and correlation was proposed.Firstly,current mutation of each phase and comprehensive correlation coefficient of each line are calculated;then EMD algorithm is used to calculate weight coefficient of intrinsic mode energy corresponding to phase current mutation of each line,and the maximum value of weight coefficient of intrinsic mode energy of three phases in each line is taken as the comprehensive energy coefficient value of the line;finally,feature distance of each line is obtained according to the two-dimensional criterion.The simulation results show that the new line selection method of resonant grounding system based on energy and correlation achieves bus fault diagnosis,improves criterion margin in a certain extent,and has wide scope of application.