Modulation Schemes With Enhanced Switch Thermal Distribution for Single-Phase AC–DC–AC Reduced-Switch Converters

Modulation schemes can significantly change the performance of a converter in the steady state. They have, thus, been extensively studied, but directed more at three-phase topologies, where triplen offsets are added. Single-phase systems, including ac-dc-ac, are less widely pursued, even though various topologies have since been proposed. The intention of this paper is, thus, to study two promising single-phase ac-dc-ac converters using reduced number of switches, and subsequently proposes modulation schemes for them. The proposed schemes help the converters to achieve better thermal spread among their switches, while keeping their dc-link voltages low. Single points of failure are thus minimized, allowing the converters to have longer lifetimes. Simulation and experimental results have demonstrated the intended performances, hence verifying the analyses presented in this paper.