基于EEMD和能量法的谐振接地配电网故障选线研究

提出一种基于集合经验模态分解（EEMD）的谐振接地配电网暂态量选线新方法。提取故障发生后各线路1／4周期暂态零序电流作为数据窗长度，用EEMD将1／4周期暂态零序电流分解为有限个固有模态函数（IMF）分量和一个剩余分量 r；将每条线路的IM F分量与原始信号做相关分析，选出与原始信号相关程度最大的前3个IM F分量作为暂态零序电流特征IM F分量，计算特征IM F分量和剩余分量的能量和作为线路的固有模态能量；计算各线路的固有模态能量权重因子，比较能量权重因子的大小选出故障线路。为了判断母线故障，选出能量权重因子最大的前3条线路做进一步比较。该方法利用暂态量，不受消弧线圈影响，可以同时适用于中性点不接地和谐振接地配电网，而且针对故障条件比较苛刻的高阻接地和小角接地故障同样适用。MATLAB仿真验证了方法的正确性。

Study on fault line selection in resonant earthed distribution network based on EEMD and energy

A transient line selection method in resonant earthed distribution network based on EEMD is proposed . Extract 1/4 period transient zero sequence current of each line as the data window length ,decompose the 1/4 period transient zero sequence current with EEMD into a finite number of intrinsic mode function components IMF and a remaining components r .Do correlation analysis of the IMF component of each line with the original signal ,select three IMF component as the characteristic IMF component which their correlation coefficient is the first biggest ,calculate characteristic IM F components and residual energy as the inherent mode energy of a line .Calculate intrinsic mode energy weighting coefficient of each line ,select the fault line by comparing the size of the energy weighting coefficient .In order to determine the bus fault ,choose the first three lines which their energy weighting factor are biggest for further comparison .The method use the transient signal ,not influenced by arc suppression coil ,applying to the neutral point grounding and resonant grounding distribution network at the same time ,can also applying to high resistance grounding fault and small Angle ground fault .MATLAB simulation verify the validity of the method .