基于EEMD及能量变化曲线的配电网故障选线

Fault Line Selection of Distribution Network Based on EEMD and Energy Variation Curve

针对配电网发生单相接地故障后,各线路零序电流具有非线性和非平稳等复杂特征,提出一种集合经验模态分解(Ensemble Empirical Mode Decomposition,EEMD)和能量变化曲线相结合的配电网故障选线方法。EEMD算法本身具有较强的自适应性,可以通过数据自驱动完成信号分解,而能量曲线可以直观的对故障线路进行筛选。首先,用EEMD算法对故障后各线路零序电流进行分解;其次,提取出各线路分解后的第一固有模态函数并计算相应的能量曲线;最后,计算所构造的信心度函数,完成故障选线。通过试验算例证明,所提方法能够准确选择故障线路。

Aiming at the complex characteristics of nonlinear and non-stationary zero sequence current of each line after single-phase grounding fault in distribution network,a set empirical mode decomposition EEMD(Ensemble Empirical Mode Decomposition)is proposed.The fault line selection method of distribution network is based on the combination of EEMD and energy change curve.EEMD algorithm itself has a strong self-adaptability,which can complete signal decomposition through data self-drive,and the energy curve can intuitively screen the fault line.Firsly,the zero sequence current of each line after fault is decomposed by EEMD algorithm.Secondly,the first inherent mode function of each line is extracted and the corresponding energy curve is calculated.Finally,the confidence function is calculated to complete the fault line selection.The experimental example shows that the proposed method can select the fault line accurately.