基于VMD的电力系统谐波检测方法研究

Research on Harmonic Detection Method of Power System Based on VMD

针对当前的电力系统谐波检测问题,提出了一种基于变分模态分解(variational mode decomposition,VMD)与希尔伯特变换结合的方法。首先,提出一种模态混叠比较方法,来确定最优模态数;其次,将稳态谐波用两种方法分解,并加入30 dB高斯白噪声,将VMD后的结果与经验模态分解(empirical mode decomposition,EMD)后的结果进行对比分析,说明VMD克服了EMD算法中容易出现模态混叠和虚假分量等不足之处,在噪声鲁棒性、准确度、分解精度方面都要优于EMD方法。

In view of the current problems of harmonic detection in power system, this paper introduces several traditional harmonic detection methods, and analyzes the advantages and disadvantages of the traditional methods.A method based on the combination of variational mode decomposition(VMD) and Hilbert transform is proposed for the detection and analysis of harmonic signals.Firstly, a mode aliasing comparison method is proposed to determine the optimal number of modes.Secondly, the steady-state harmonics are decomposed by two methods, and 30 dB white Gaussian noise is added.The results of VMD and empirical mode decomposition(EMD) are compared and analyzed.This indicates that VMD overcomes the shortcomings of EMD algorithm such as mode aliasing and false components, the VMD is superior to the EMD in noise robustness, accuracy and decomposition accuracy.