Harmonic Analysis Based on Kaiser Window Interpolation FFT and Its Application

The fundamental windows such as the rectangular window and triangular window and generalized cosine windows can be used to eliminate the errors caused by spectral leakage and picket fence effect under the non-integral period truncation conditions, but effect is restricted by the performance of the fixed side lobes of these windows. The free characteristics of the major lobe and side lobes of the Kaiser window are discussed in this paper, and an approach for the harmonic analysis based on Kaiser window interpolation fast Fourier transform (FFT) is proposed. The mathematic models of odd and even harmonic solutions and the rectification formulas of the interpolation were established. The arithmetic expressions of fundamental and harmonic frequencies, amplitudes and initial phases were deduced. The simulation and test results show that the approach based on Kaiser window interpolation FFT can be designed and realized easily and restrain spectral leakage effectively. The error of fundamental active power measurement on the three-phase multi-functional harmonic energy meter based on this approach is below or equal to 0.2% and the error of fundamental reactive power measurement below or equal to 1%. Data results of the harmonic analysis meet the accuracy requirement according to GB/T 14549—1993.