Harmonic and interharmonic detection algorithm based on all-phase FFT triple spectrum line correction
TAN Baohua1， ZHANG Wenyu1， HUANG Chengxu2， ZHENG Peitian1， HE Jiaqi3
(1.School of Science， Hubei University of Technology， Wuhan 430068， China；2.School of Physics and Optoelectronic Engineering， Yangtze University， Jingzhou， Hubei 434023， China；3.School of Mechanical Engineering， Hubei University of Technology， Wuhan 430068， China)
Abstract：In power grid harmonic detection， the spectrum leakage of traditional FFT algorithm affects the harmonic detection accuracy. To solve this problem， the differences between the all-phase FFT algorithm and the FFT algorithm are analyzed and compared， and a triple spectrum line correction method is extended to the all-phase FFT algorithm. And an all-phase FFT triple spectrum line correction algorithm is proposed. The algorithm uses the information of three spectral lines around the peak frequency point to construct the frequency offset correction formula to obtain the amplitude and frequency correction of the all-phase FFT.The phase invariance of all phase FFT is used to obtain the signal phase directly.Compared with the FFT triple spectrum line interpolation algorithm， the all-phase FFT double spectrum line correction algorithm and the all-phase FFT double spectrum line interpolation algorithm， the results show that the proposed algorithm has better detection accuracy of harmonics and inter-harmonics， and stronger anti-white noise ability.
2021, Vol. 55 
