Abstract:

Aiming at the output and switching problem of wireless power transmission system,the adaptive switching of battery constant current and constant voltage charging mode under fixed resonant frequency is realized by using compound LCC topology.Firstly,it is concluded that the composite LCC compensation topology has the ability of constant current and constant voltage output; furthermore,a constant current/constant voltage control strategy based on the basic theory of reflection impedance is proposed,which only needs to detect the voltage at both ends of the primary transmitting coil and the current flowing through the primary transmitting coil to control the switch to switch the constant current and constant voltage charging modes adaptively.This method does not need communication between primary side and secondary side and additional DC-DC converter,which reduces the design cost and control complexity of the whole system.Finally,a 6.6 kW system simulation platform and a 66 W experimental prototype are built to verify that the proposed method has the ability of adaptive switching constant current/constant voltage charging.

Key words: constant current, constant voltage, adaption, composite topology WPT system