基于EEMD和能量法的谐振接地配网故障选线方法

在分析谐振接地配电网发生单相接地故障时暂态电流特征的基础上,首先利用集合经验模态分解法对各条线路首端的零序电流进行分解,然后提取各线路零序电流较高频率的谐波分量和衰减的直流分量,进而求取各线路的能量权重系数.通过比较各线路能量权重系数之间的关系可选出故障线路.若某条线路的能量权重系数最大,且其能量权重系数超过所设定的阈值,则此条线路发生了故障;若所有线路的能量权重系数都没有超过所设定的阈值,则母线发生了故障.仿真和实验表明,该方法可适用于高阻接地故障、小角接地故障等不利于实现选线的故障,且该方法的选线准确度较高.

A fault line-selection method in resonant earthed distribution network based on EEMD and energy theory

While single phase ground fault occurring in resonant earthed system, the frequency of transient capacitance current is many times larger than the frequency of transient inductance current, and they cannot offset each other. In addition, the elements of transient state current of fault feed line have much greater variety than the in non-fault line. This paper used EEMD to extract high frequency and residual component of zero sequence current of each lines, and calculated the energy weighting coefficient of each line, then selected the fault line through comparing the line energy weighting coefficient. The proposed method can be proved to select the fault line accurately and reliably through simulations and experiments.