基于Daubechies小波的谐波分析算法

Harmonic Estimation Method Based on Daubechies Wavelet

针对基于傅里叶变换(FFT)的谐波分析方法易受噪声干扰和对暂态谐波处理精度差的缺点,提出了一种基于小波包变换的谐波分析算法。该算法能实现信号频带的均匀划分,通过选择适当的采样频率和小波包分解树,可使所关心的谐波频率落在小波包频带的中心,从而减少频谱泄露,有效提高频谱分析精度。通过对比研究表明该算法抗干扰能力明显优于FFT方法,仿真和实验结果进一步表明了该算法的有效性。

This paper presents a method to estimate voltage and current harmonics using the wavelet-packet transform. The proposed method overcomes the shortcomings of FFT-based method such as sensitivity to noise and inaccurate performance in non-stationary environments. This method divides the frequency bands linearly, with constant bandwidth to separate each harmonic. Based on simulation studies, performance of the method is presented and its accuracy is compared with FFT-based method.