Windowed FFT interpolation correction algorithm based on Blankman-harris window

Fast Fourier transform;  spectrum analysis;  window functions;  Blankman-harris

There is a large error in the direct use of FFT for power system harmonic analysis, and the interpolation correction algorithm can better improve the measurement accuracy. In view of the excellent performance of Blankman-harris window in suppressing long-range leakage in spectral analysis, the principle of double spectral line interpolation correction is adopted, the Blankman-harris window double spectral line interpolation correction formula is derived, and the MATLAB polynomial approximation function is used to find a concise and practical approximation polynomial based on the Blankman-harris window interpolation correction formula. Simulation analysis shows that the algorithm of modified polynomial is easy to implement and has high accuracy.