High-Efficiency WPT System for CC/CV Charging Based on Double-half-bridge Inverter Topology with Variable Inductors
Xiao Zhu, Xing Zhao, Yong Li, Shunpan Liu, Huanyu Yang, Jihao Tian, Jiefeng Hu, Ruikun Mai, Zhengyou He
Abstract
Efficiency remains a key challenge in wireless charging in academia and industry. In this paper, a new wireless power transfer (WPT) system based on a double-half-bridge (DHB) inverter with two variable inductors (VIs) is proposed. Compared with conventional full-bridge (FB) inverters, the DHB inverter can reduce the current through the MOSFETs under the same output power and thus, reduce the conduction loss. Next, by adjusting the inductances of the VIs instead of using phase shift (PS) method, the output voltage or current can be controlled, while the circulating current can be eliminated and wide-range zero voltage switching (ZVS) operation can be achieved. Consequently, the power loss can be further reduced. Circuit analysis, VI design, as well as hardware imple-mentation, are provided in detail. A laboratory prototype is built to verify the feasibility of the proposed method. Close agreement is obtained between simulation and experimental results. The maximum efficiency can reach 92.4%, which is 3.65% higher than traditional PS control.