Analysis and Design of Dual-Mode Wireless Battery Charging System Based on Trajectory Optimization and Matching Network Integration

High-frequency megahertz (MHz) wireless power transfer (WPT) system has great advantages in special application fields due to its miniaturization characteristics. However, the traditional unidirectional impedance compression method limits the system functional output performance to a certain extent, such as battery charging. To this end, this article proposes a constant current (CC)/constant voltage (CV) bidirectional impedance trajectory design method. In this process, the dual-mode compression network parameter integration and device reuse mechanism are utilized. The CC/CV functional output is completed without reducing the system power density. A 40V/1A experimental prototype was built with a peak efficiency of 90.4%.