Design and implementation of high power closed-loop AC-DC resonant converter for wireless power transfer

This paper presents a high power AC-DC converter for wireless power transfer (WPT) using series resonant magnetic coupling technique. Large signal model and small signal model of the converter are analyzed. According to the small signal model, an analog compensator for closed loop control of the converter is designed. In order to realize high efficiency, zero voltage switching technique is applied in the converter. Design considerations and procedures are stated to meet different demands. Finally, a 3.5KW, 175KHz closed loop series resonant converter, with over 85% efficiency and over 200mm air gap between sending and receiving coils is built to verify the design.