Combined Modulation and Harmonic Suppression

The output of pulse width modulation includes harmonics with invariable frequencies and invariable magnitudes, which are sources of conducted interference and load resonance. Based on the spectrum analysis of switching modulation and sinusoidal pulse width modulation (SPWM), frequency modulation and low frequency amplitude modulation are combined to make a nonlinear swing for the modulated frequencies, to spread the harmonics frequencies broader, to reduce the average amplitudes of various harmonics, and the experimental results are also given out in this paper