Standard Source Harmonic Analysis Algorithm Based on Nuttall Window Function and Interpolation FFT

The power standard source is used to outputting standard signals for power instrument testing,and it’s output accuracy mainly determined by the feedback accuracy.There are difficulties in performing synchronized sampling and integral period truncation when analyzing harmonic of standard source output with the Fast Fourier Trans-form(FFT),this will cause frequency leakage and bring harmonic analysis a big error.Aiming at the above problems,a dual spectral lines interpolation algorithm for four item three orders Nuttall window are proposed in this paper based on the principle of the interpolation algorithm,and the correction formulas of the harmonic amplitude,phase and frequency parameters are obtained corresponding.The simulation and experiment results have verified that the proposed algorithm can effectively suppress frequency leakage,obviously improve the output accuracy of standard source.