Resonant wireless charging scheme

Abstract

In order to reduce the number of switching devices and passive components in the hybrid topology charging system based on resonant power transmission technology, and simplify the control strategy of primary and secondary sides, a hybrid self switching resonant topology based on LCL-LCL/S is proposed. The structure does not need primary and secondary side communication and adds any passive components, and only changes the topology network through the self switching operation of LCL structure can be realized constant current and constant voltage switching of wireless charging system. Then, according to the characteristics of battery charging curve, resonant current threshold and voltage jump threshold, a parameter optimization design method for hybrid resonant topology network is proposed, which can avoid the parameter uncertainty caused by the limitation of empirical selection of resonant network parameters, and provide theoretical basis for parameter selection. In the constant current and constant voltage mode, the input impedance is pure resistance, and the zero phase angle(ZPA) is between the input current and the voltage. The experimental results show that the hybrid self switching wireless charging system with optimized resonant network parameters has better constant current and constant voltage output characteristics. The system realizes ZPA and constant frequency soft switching characteristics, which meets the requirements of constant current and constant voltage charging.

Keywords

• Magnetically coupled resonant wireless power transfer(MCR-WPT)
• Hybrid topology
• Parameter design
• ZPA