Harmonic phasor calculation based on ten terms cosine window and interpolated FFT

An interpolated FFT algorithm based on a ten-terms cosine window is proposed. The characteristics of cosine window and the advantages of sidelobe peak are firstly analyzed,then the ten-terms cosine window of a low sidelobe peak is used,next the formulas of interpolated FFT algorithm based on the ten-terms cosine window is derived. Simulation results demonstrate that the amplitude error is less than 0. 001%,and that the phase error is less than 0. 001%. The comparison of the measurement result of this new interpolated FFT algorithm with the measurement results of interpolated FFT algorithm based on Hannning window and Blackman window,is verified that this algorithm enhances the measuring accuracy of power system harmonics and has actual application value.