一种新的谐波、间谐波参数估计算法

A New Algorithm to Estimate Parameters of Harmonics and Interharmonics

加窗插值算法是谐波、间谐波分析的常用方法,能显著提高谐波检测精度。以单峰谱线插值算法为例,分析了常规插值算法的不足,并提出了相应的解决方法。首先,提出一种用多项式逼近求极值的谐波、间谐波频率估计算法,减小了求取频率校正系数的计算复杂度;其次,考虑邻近谐波、间谐波间频谱泄漏的影响,利用矩阵求逆的方法修正谐波谱线的幅值和相位;最后,对所提算法进行了仿真研究,结果表明,本文算法在频率波动和白噪声干扰下都能准确地估计谐波参数,有效地提高了谐波的检测精度。

The windowed and interpolation algorithm is the common used method to estimate parameters of harmonics and interharmonics to evidently improve the detection accuracy of harmonics. Taking single peak spectral lines interpolation algorithm for example, the insufficiency of conventional interpolation algorithms is analyzed and corresponding solution is put forward. Firstly, an algorithm to estimate frequencies of harmonics and interharmonics, which is based on polynomial approximation and the extremum can he achieved, is proposed to reduce the calculation complexity for frequency correction factor; secondly, taking the impact of spectral leakage of adjacent harmonics and interharmonics into account, the amplitudes and phases of harmonic spectrum lines are corrected by matrix inversion; finally, the simulation research on the proposed algorithm is performed. Simulation results show that using the proposed algorithm the parameters of both harmonics and interharmonics can be correctly estimated under frequency fluctuation and white noise, so the proposed algorithm can effectively improve detection accuracy of harmonics.