A high-precision two-window three-spectral line interpolation harmonic detection algorithm

In order to improve the detection accuracy of harmonic and inter-harmonic parameters of power system, to reduce the effect of fence effect and spectrum leakage, the interpolated harmonic detection algorithm of the three-spectral line of nuttall window is proposed. First, the algorithm calculates the base wave frequency by using the magnitude of three adjacent spectral lines near the base wave frequency point, deduces the correction formula of the harmonic amplitude and frequency parameters, and then, based on all-phase FFT, apFFT, The phase invariance, using the base wave frequency point near the main spectral line and side spectral line amplitude to calculate the ratio, the two-window apFFT interpolation spectrum correction algorithm, and then proposed the addition of Nuttall window three-spectrum line interpolation detection frequency and amplitude, Nuttall window double window apFFT correction detection phase combination algorithm. The simulation experiments show that compared with other interpolation algorithms, the algorithm can reduce the detection error of harmonic parameters more effectively and measure higher accuracy.