Development of a High Efficiency Primary Side Controlled 7kW Wireless Power Charger

The aim of this paper is to present the design of a primary side controlled 7kW wireless charging system for electric vehicles (EVs). A systematic design procedure and practical design considerations are discussed for a high efficiency level 2 wireless charger. The fundamental design consideration of the bipolar magnetic coupler is introduced. The double-sided LCC compensation circuit is chosen based on its characteristic analysis. For single pickup applications, the fixed-frequency primary-side current-controlled is feasible to regulate the delivering power due to the merits of the double-sided LCC compensation. Consequently, the on-board secondary circuits can be downsized as an uncontrolled rectifier since a decoupling converter is not necessary. The front-stage AC/DC converter consists of a boost-type power factor correction and buck converter for the primary side control. Simulation and experimental results are presented for a prototype with up to 7kW output power for electric vehicles (EV) charger. A peak efficiency of 93% from the grid to the battery load is achieved at rated operation condition.