全相位FFT算法在谐波测量中的应用

Application of All Phase FFT Algorithm in Harmonic Measurement

传统FFT算法的结果可以通过一些算法实现频谱校正,如FFT插值法、比值法等,但在对谐波参数测量时存在一定的误差,精度有限,影响谐波分析结果的准确性。本文在现有的离散频谱校正方法基础上,提出一种全相位FFT算法。该算法实现自动搜索各个谐波峰值,能够有效提高对电网谐波频率、相位和幅值的测量精度。通过matlab仿真工具,将全相位FFT算法与比值法测量结果进行比较,结果表明该算法简单实用,精度高,特别是对间谐波的检测,能有效防止频谱泄露,抗干扰能力强。

The result of the traditional FFT algorithm can be corrected through some methods, such as the FFT window interpolation algorithm, the ratio method and so on. However, the test accuracy is limited and there is one larger measurement error that affect the accuracy of harmonic analysis. Based on the method of discrete spectrum correction, this paper studies a new correction method -All phase FFT algorithm. This algorithm can automatically search for the peak of each harmonic, and it can effectively improve the power of the harmonic frequency, phase and amplitude accuracy. In this paper, with the matlab tool, comparing the two methods, the results show that the All phase FFT algorithm is simple, practical and high precision, especially for the detection of inter-harmonies. It can effectively prevent spectral leakage and has a strong anti-interference ability.