An algorithm of windowing interpolation FFT harmonic analysis

It is difficult to realize the synchronized sampling and integral period truncation.Therefore,the analisis accuracy of algorithm is affected when FFT algorithm is applied to analysis of harmonic signal in power system because of the spectral leakage and fence effect.The windowed interpolating fast Fourier transform(FFT) is the effective method to restrain spectral leakage and eliminate fence effect.A harmonic analysis method based on 3-term 3-derivative Nuttall interpolation FFT is proposed in this paper.The formula of interpolation coefficients,and the estimation formulas of frequency,amplitude and phase of each harmonic are derived.The comparison with the Hanning and Blackman interpolation FFT methods is conducted by Matlab simulation.It verifies that the algorithm has higher analysis accuracy.