基于VMD和相关性聚类的谐振接地系统单相接地故障选线

Single-phase grounding fault line selection in a resonant grounding system based on VMD and correlation clustering

通过分析谐振接地系统的故障暂态零序电流组成及特性,提出了一种基于暂态非工频分量相关性聚类的故障选线方法。首先,将变分模态分解和快速傅里叶变换相结合,准确分离暂态零序电流中的工频分量和噪声信号,得到暂态非工频分量。然后,采用局部加权回归算法对各出线的非工频分量进行平滑处理,获得线路非工频分量的整体趋势,计算各出线的相关系数矩阵。最后,通过免阈值设定的K-means聚类算法实现故障选线。仿真结果表明,所提出的选线方法能够准确选取故障线路,选线结果不受故障电阻、故障初相角等因素的影响,且具有较好的抗噪能力。

By analyzing the composition and characteristics of fault transient zero sequence current in a resonant grounding system,a fault line selection method based on correlation clustering of transient non-power frequency components is proposed.First,the power frequency component and noise signal in the transient zero sequence current are separated accurately by combining the variational mode decomposition with the fast Fourier transform,and the transient non-power frequency component is obtained.Then,a local weighted regression algorithm is used to smooth the non-power frequency component of each outgoing line to obtain the overall trend of the line non-power frequency component,and calculate the correlation coefficient matrix of each outgoing line.Finally,the fault line selection is realized by a K-means clustering algorithm without threshold setting.The simulation results show that the fault line selection method proposed can accurately select the fault line,and the fault line selection result is not affected by fault resistance,fault initial phase angle and other factors,and has good anti noise ability.