Two-Step Width Modulation Sinusoidal Inverter with Modulation Switching and Frequency Spectra.

The pulse width modulation (PWM) in the inverter is an extremely important in power electronics. One of the problems in the PWM inverter is the existence of unwanted harmonics by switching. In this paper, a method to reduce this unwanted harmonic component, a modulation switching method, is proposed in which the modulation method is switched at the locations such as the peak of the reference sinusoidal signal. The PWM wave train is analyzed by a computer simulation as well as the theoretical analysis by the double fourier series expansion. It is show that the present method is effective in the reduction unwanted harmonic. Next, the characteristics of the modulation switching two-stage PWN sinusoidal inverter are investigated. [ABSTRACT FROM AUTHOR]