基于Rife-Vincent自卷积窗三谱线插值FFT电力谐波分析

Harmonic analysis of power system based on Rife-Vincent self-convolution window triple-spectral-line interpolation FFT

加窗和插值算法可以有效抑制快速傅里叶变换(FFT)在非同步采样和非整周期截断时产生的频谱泄露和栅栏效应,提高谐波检测精度。在比较不同Rife-Vincent窗、经典窗的频谱特性的基础上,选择五项Rife-Vincent窗做母窗,构建了五项Rife-Vincent自卷积窗的时域、频域函数,并分析五项Rife-Vincent自卷积窗的主瓣特性以及自卷积阶数对旁瓣性能的影响。建立了基于五项Rife-Vincent自卷积窗三谱线插值频谱校正算法。采用多项式拟合的方式推导了简单实用的三谱线插值修正公式。通过仿真,验证了非同步采样时,与其他加窗插值相比,该算法具有更高的计算精度。

Utilization of windows and interpolation algorithm can effectively restrain the spectrum leakage and fence effect which caused by FYF in the non-synchronous sampling and non integer period truncation, and can improve the accuracy of harmonic detection. On the basis of comparison of the spectral characteristics of different Rife- Vincent windows and classical windows, five-term Rife-Vincent window is chosen as the parent window, then the time domain and frequency domain functions of five-term Rife-Vincent self-convolution window are constructed. The characteristics of the main lobe of five-term Rife-Vincent self-convolution windows and the effect of the selfconvolution order on the side-lobe performance are analyzed. And five-term Rife-Vincent self-convolution window triple-spectral-line interpolation FFF is constructed. Simple and practical three spectral line interpolation correction formulas are obtained by fitting of polynomials. The simulation results demonstrate that the proposed algorithm has better precision than other window interpolated FFT algorithm.