Harmonic Detection Algorithm Based on Kaiser Window

Aiming at the problems of large-scale error such as spectrum leakage and non-synchronous sampling use the method of the Fast Fourier Transform (FFT) in the harmonic detection of power system, in this paper put forward the method Kaiser window with FFT and the way harmonic analysis of window function restoration coefficient for reducing amplitude error. The magnitude recovery coefficient of the window function is calculated by simulation, when the signal of Kaiser window analyzed by FFT can suppressed the spectral leakage and multiplied by the amplitude recovery coefficient of window function corresponding to value of β in order to get the amplitude value of each harmonic. The simulation results show that the method of window FFT analysis and amplitude recovery can be realized by using 20 harmonic signals, when β = 10, the amplitude error of Kaiser window is lower than that of triangular window, Hanning window and Blackman window; when β = 30, the harmonic amplitude error of Kaiser window is less than 4%. By comparing the magnitude error of others window functions and different β values, can reduced the amplitude error of harmonic analysis by improved the β value of Kaiser window.