基于变分模态分解的变压器有载分接开关振动信号去噪分析

De-noising analysis of vibration signal of transformer on-load tap-changer based on variational mode decomposition

针对变压器有载分接开关振动信号中的环境噪声影响后续特征提取与识别的问题,提出了基于变分模态分解(Variational Mode Decomposition,VMD)与小波包阈值的去噪算法。首先对信号进行VMD分解,得到一系列窄带、中心频率区分度较好的模态分量。然后对各模态分量分别进行小波包阈值处理,利用均方根误差、信噪比及平滑度构成的复合评价指标确定最佳分解层数,得到最优的去噪效果。最后重构得到去噪后的振动信号。在变压器有载分接开关模拟试验平台上进行试验,并对采集的振动信号进行去噪分析,结果表明该方法的效果优于常用的去噪方法。

Aiming at the problem that the subsequent feature extraction and recognition of vibration signal of transformer on-load tap-changer are affected by the environmental noise,the de-noising method based on the variational mode decomposition(VMD)and the wavelet packet threshold algorithm is proposed in this paper.Firstly,the vibration signal is decomposed by VMD method into a series of modal components with narrow band and distinguishing center frequency.Then,the modal components are processed by the wavelet packet threshold algorithm separately,and a composite evaluation index constituted by root-mean-square error,signal-to-noise ratio and smoothness is used to determine the optimal wavelet decomposition level in order to obtain the best de-noising result.Finally the signal is restructured to get the de-noised vibration signal.An experiment is conducted on the transformer on-load tap-changer simulation experimental platform and the de-noising analysis on the collected vibration signal is processed,which shows the effect of the proposed method is better than that of several common de-noising methods.