基于WPT和参数优化的VMD谐波检测方法

VMD harmonic detection method based on WPT and parameter optimization

针对变分模态分解(Variational Mode Decomposition,VMD)在谐波检测中易受噪声影响、分解模态个数K难以确定的问题,提出一种基于小波包降噪(WPT)和参数优化的VMD谐波检测方法。利用WPT对谐波信号进行降噪处理,将降噪后信号进行VMD预分解,根据解析分量瞬时频率均值变化选取最优K值,对降噪后信号进行最优K值VMD分解并提取频率,采用希尔伯特变换进行幅值检测。仿真结果与对比表明,文章算法有效地降低了噪声影响,实现最优K值VMD分解,谐波参数检测精度有较好的提高。

Aiming at the problem that the variational mode decomposition(VMD)is susceptible to noise and the mode decomposition number(MDN)is difficult to be determined in harmonic detection,a VMD harmonic detection method based on wavelet packet transform(WPT)de-noising and parameter optimization is proposed in this paper.WPT is utilized to reduce the noise of harmonic signal,VMD is utilized to pre-decompose the de-noised signal,and the optimal K value is selected according to the instantaneous frequency mean of analytical component,VMD is adopted to decompose the de-noised signal under the optimal K value,and the amplitude of harmonic parameters is detected by the Hilbert transform.The simulation and comparison results show that the proposed method can effectively reduce the impact of noise,achieve the VMD decomposition of optimal K value,and improve the detection accuracy of harmonic parameters.