A Combined Rectangular/Circular Power Pad for Electric Vehicles Wireless Charging

Inductive power transfer (IPT) technology enables electric vehicles to be charged safely and effectively without physical connection. A main element in IPT system is the magnetic coupler (power pads) structures that contributes to the power transmission capability and efficiency. In addition, the coupler must show robustness against misalignment between receiver and transmitter coupling coils. Therefore, this paper presents a novel charging pad named Rectangular/Circular (RC) that integrates the traditional rectangular and circular pads. The proposed pad is compared to the double-D (DD) pad in terms of the misalignment effect and the coupling coefficient. A three-dimensional finite-element analysis based on the ANSYS MAXWELL software is used to design and evaluate the system performance. The results show that the proposed pad requires less wire than DD structure, and is less sensitive to different lateral and rotational misalignments. To more studying the RC charging pad performance, a WPT1 (3.7 kVA)/Z1 magnetic gap IPT model is built by using MATLAB Simulink. A power transfer efficiency (PTE) of 98.85% for the designed charger has been achieved.