High-power factor three-phase ac-dc soft-switched converter incorporating zero-voltage transition topology in modular systems for high-power industry applications

In this study, a three-phase ac-dc converter using three single-phase pulse-width-modulated zero-voltage transition (ZVT), soft-switched boost converter in modular approach is presented. The novelty of the active snubber cell is that, it provides ZVT turn-on and zero-voltage switching (ZVS) turn-off for the main switch without extra current or voltage stress. Auxiliary switch is turned on near zero-current switching without additional voltage stress and turns off near ZVS. The input line current and output voltage are controlled by the proposed power factor correction (PFC) converter in very wide load range. This PFC converter has ease of control as well as a simple structure. In this study, detailed steady-state analysis of proposed converter is presented, and this theoretical analysis is verified exactly by 400-V, 1.5-kW and 100-kHz prototype. This prototype has total efficiency of 97.3- and 0.9996 power factor with input line sinusoidal current at full load.