Practical Design of Synchronization Control for a Wireless Battery Charger

This paper presents the design and implementation of a closed-loop control to synchronize the switching actions of an active rectifier (AR), as the onboard receiver of a wireless battery charger, with the offboard transmitter. A discrete time model of the wireless charger is used to model the synchronization dynamics. A compensator is designed to achieve stable performance over the full load range. The synchronization controller is designed to achieve a stable transition from passive to active rectification, and to reduce susceptibility to noise. To validate the control design, a GaN-based prototype is constructed and stable startup and low-noise synchronization experimentally demonstrated.