Comparative study of current control methods for a 5kW wireless EV charging system

Abstract

In this paper, a 5kW wireless electric vehicles (EV) charger is introduced and modeled in time-frequency domain. Base on the function of the charging current, two current control methods are discussed. It is found that the DC-link voltage control can make the voltage source inverter (VSI) work under soft switching mode but the adjustable range of the charging current is limited. The phase shift control method has a wider adjustable range while it may lead to switching loss and EMI when the phase shift angle is less than 180°. A combined current control strategy is proposed to deal with the problem. Simulation and experiments verify the validity of the proposed strategy.