谐波测量的改进FFT插值算法研究

Improved FFT Interpolation Algorithm for Harmonic Measurement

为满足对谐波分析的计算速度和计算精度均有较高要求的应用场合的需要,文中提出了一种改进的基于谱能量重心法的双峰插值算法。利用各谐波分量附近的两根离散谱线的值,该算法可简单快速地实现对信号频率、幅值和相位的准确插值校正计算。文中给出了该算法的任意阶余弦窗函数的系数和参数校正的计算公式。计算机仿真计算结果表明,这种算法的计算精度不逊于目前常用的多项式拟合插值算法,而在计算速度上则提高了10%以上,且适用于包括间谐波在内的所有谐波分量的校正计算。

To raise calculation speed and analyzing precision of harmonic analysis for special applications,an improved double-spectrum-line interpolation algorithm based on spectral energy centroid method is proposed, and the formulas for calculating the coefficient of arbitrary order cosine window function and parameters correction are deduced. Making use of the values of two discrete spectral lines near each harmonic component, this algorithm can realize the accurate interpolation correction calculation of the signal frequency, amplitude and phase simply and rapidly. Computer simulation results show that the accuracy of the proposed algorithm is comparable to the current polynomial fitting interpolation algorithm,and its calculation is accelerated by more than 10%. The proposed algorithm is suitable for the correction of all harmonic components, including interharmonic component. Experiments prove the effectiveness and practicability of the algorithm.