加8项余弦窗插值FFT算法

An interpolation FFT algorithm based on 8-term cosine window

采用加8项余弦窗函数插值FFT算法的谐波分析方法可以进一步提高电力系统谐波的测量精度。为了引入加8项余弦窗函数的插值FFT算法,首先比较分析了5到8项余弦窗的频谱特性,然后推导了8项余弦窗函数插值FFT算法的计算公式,并采用三次样条插值函数计算频率修正系数和复振幅的修正系数,减少了计算量。仿真计算结果表明,相比其他加余弦窗插值FFT算法,加8项余弦窗函数插值FFT算法具有更高的精度,从而验证了该算法的有效性与实用性。

An approach for power harmonic analysis based on 8-term cosine window interpolation FFT algorithm can further improve the precision of harmonics measurement, and the paper provides a new interpolation FFT algorithm based on 8-term cosine window. It firstly analyzes the spectrum characteristics of 5 to 8-term cosine window and then deduces the interpolation algorithm on 8-term cosine window in detail, the cubic spline function is adopted to calculate the frequency and the harmonic amplitude modification coefficient, and calculating burden is reduced. The results show that, compared to other cosine window interpolation FFT algorithm, the interpolation FFT algorithm based on 8-term cosine window has higher accuracy, and the results verify the effectiveness and practicality of the proposed algorithm.