Inverted Sine Carrier Pulse Width Modulation for Fundamental Fortification in DC-AC Converters

This paper deals with a novel natural sampled pulse width modulation (PWM) switching strategy for voltage source inverter (VSI) through carrier wave modification. The proposed inverted sine carrier PWM (ISCPWM) method uses a sinusoidal reference signal and an inverted sine carrier which has better spectral quality and higher output limit as compared to the conventional sinusoidal PWM (SPWM), without any pulse dropping. The ISCPWM strategy reduces the total harmonic distortion (THD) without hampering device switching losses. It also enhances the fundamental output voltage particularly at lower modulation index. The paper also presents mathematical analysis to bring out the salient features of the proposed scheme. The detailed comparison of ISCPWM and SPWM has been also presented.