基于布莱克曼窗的双窗全相位傅里叶谐波分析

为了提高谐波和间谐波的参数估计精度,本文提出了基于布莱克曼窗的双窗全相位傅里叶新算法。该方法首先将输入数据分为N段,每段数据加两次布莱克曼窗,然后对新形成的N点数据分段进行傅里叶变换;进而,利用全相位傅里叶和传统傅里叶的谱分析结果,对全相位谱分析结果进一步校正,从而得到精度更高的谐波及间谐波估计结果。相比于其他如加汉宁窗的方法,本文提出的新方法有更高的信号参数估计精度。因不受谐波及间谐波频率范围的影响,本文方法可以应用于同步相量测量设备中,实现对于所有谐波的准确检测。仿真结果验证了本文方法的有效性。

Harmonic Analysis Using Double-window All-phase FFT Based on Blackman Window

To improve the parameter estimation accuracy of harmonics and inter-harmonics,a novel double-window allphase fast Fourier transform(apFFT)algorithm based on Blackman window is proposed. First,the input data are divided into N segments,and Blackman window is added to each segment twice. Then,Fourier transform is performed on the newly generated N segments,respectively. Furthermore,the results of the all-phase spectral analysis are corrected by means of the spectral analysis results of the full-phase Fourier and the traditional Fourier,so that the harmonic and inter-harmonic estimation results with higher accuracy can be obtained. Compared with other methods such as adding Hanning window,the novel method has higher accuracy of signal parameter estimation. Since the proposed method is not affected by the harmonic or inter-harmonic frequency range,it can be applied to phasor measurement unit(PMU)to achieve the accurate detection of all harmonics. The effectiveness of the proposed method is verified by simulation results.