A dual-stage pwm dc to ac inverter with reduced harmonic distorsion and switching losses

Abstract

In conventional pulse width modulated full bridge dc to ac inverters, all power devices are switched at high  frequency and are consequently subject to significant power losses. This paper presents a modified dc to ac  inverter topology where the high frequency switching is performed by a single device in a pre-converter stage,  while the bridge switches are controlled at the low frequency of the load voltage. The proposed inverter is shown to have smaller device losses and higher power transfer efficiency than commonly used control schemes, while producing a lower harmonic distortion in the ac output voltage.

Keywords: Dc to ac inverter, Pulse Width Modulation