A novel synchronous PWM method for three-phase AC/DC/AC converter without DC-link capacitor

Three-phase AC/DC/AC converter without DC-link capacitor provides decreased switching loss on inverter side of the converter, in the price of slightly increased conduction loss on additional four diodes. Comparing with conventional back-toback PWM converter, the total efficiency of the AC/DC/AC converter can be con or pro, depending on the operation conditions of the both converters. This paper proposed a novel synchronous PWM algorithm for rectifier and inverter side of the AC/DC/AC converter, by which the high efficiency operation of the converter is extended from high power factor load to any power factor load in inverter side.