Design and Simulation of Wireless Power Transfer for Electric Vehicle Charging

The Wireless Power Transfer (WPT) technology has evolved rapidly as the preferred technology of charging electric vehicles safely, conveniently and easily outdoors since plugging poses certain issues to users and to the vehicles. This paper gives the design and simulation details of an inductive WPT system optimized to be used in EV charging. System architecture Utilizing inductive coupling, the system architecture enables high-efficiency energy transfer across a 20 centimeter air gap, as would exist between a vehicle and ground coils. It is designed with sophisticated coil shape and Litz wire to maintain the resistance low and increase the quality factor of the circuit. Electromagnetic analysis is performed in ANSYS Maxwell to calculate system performance and compensation efficiency and load dynamics are calculated by circuit simulation in MATLAB/Simulink. Since a Series-Parallel (SP) topology has been selected in the proposed system, the reactive power loss on the primary side and the robustness of the voltage on the secondary side is kept quite well. The simulation results depict that the power efficiency within the system exceeds 90% at 3.3 kW, thus the system meets performance indicators of typical EV chargers. Moreover, the design considers both thermal and electromagnetic safety, meaning that it conforms to the international regulations of ICNIRP and SAE J2954. Due to the above characteristics, the WPT system presented in this paper can be implemented in the future smart charging networks of electric vehicles.