Performance characteristics of single-stage AC-DC full-bridge converter

A single-stage ac-dc converter consisting of full-bridge converter is proposed for battery charger applications. Desired feature for the battery charger such as a low cost, small volume, high efficiency and high reliability are achieved by means of the proposed solution. The proposed approach is superior to conventional two-stage ac-dc converter widely used for EV charger applications. The two-stage ac-dc converter is apt to be costly and large. However a single-stage ac-dc converter is suitable to a low cost, small volume due to a reduced number of components. In this paper, a digital control single-stage ac-dc converter consisting of full-bridge converter and series connection of secondary transformer is presented in order to achieve downsizing, high efficiency, high power factor and high reliability for a battery charger. The feasibility and practical value of the proposed approach are verified by the experimental results from a 0.8 / 1.6kW product prototype.