An Optimal Wireless Battery Charger for Electric Vehicle using EF2 Inverter at 6.78 MHz

An optimal wireless battery charger for Electric Vehicle (EV) charging application is presented in this paper. The proposed charger taps power from the AC grid performing power factor correction and charges the EV battery pack wirelessly with constant current-constant voltage (CC-CV) technique. The complete charger consists of four stages: i) AC-DC conversion, ii) DC-high frequency AC (HFAC) inversion, iii) wireless power transfer, and iv) HFAC-DC rectification. This uses an EF2 inverter operated at 6.78MHz to generate HFAC that is used at the transmitting side. The proposed charger charges the battery in CC mode when the inverter is excited with a DC voltage and the same charger operates in CV mode when excited with a DC current source. In order to execute this, an optimal charging scheme is implemented to ensure CC-CV charging without having any local controller at the vehicle end. The WPT coils are simulated using Ansys Maxwell and the results are used while simulating the charger for a 24V, 30Ah battery pack in PSIM simulation platform.