Independent primary-side controller applied to wireless chargers for electric vehicles

Electric vehicles rely on batteries that need to be frequently recharged. As an alternative to conductive charging, wireless chargers provide a higher reliability to pollution and electric failures and they also extend the situations and places where the recharge could be available without user´s intervention (e.g. parking spaces, on-road). In order to optimize the performance of a wireless charger, its configuration should be dynamically adapted to the varying battery´s electrical features. Towards this goal, controllers are incorporated into the system to modify the behavior of some switching devices belonging to the power electronics blocks. This paper presents a controller that acts in the DC/DC structure placed in the primary side. As a novelty, the controller infers the instantaneous battery power demands by exclusively measuring voltage and current in the primary side. In this way, there is no need for communicating (via wired or wireless links) the primary and the secondary sides. The simulation results show the ability of the controller to adapt to different battery states.