Minimizing the Rebar Impact on Power Dissipation in Dynamic Wireless Power Transfer Systems

Dynamic wireless charging of Electric Vehicles (EVs) is realized by embedding magnetic transmitter (Tx) pads into concrete roads. However, the surrounding material may affect the performance of the Tx pads. This paper studies the extra power losses caused by the rebar inserted in the reinforced concrete road behind Tx pads. Furthermore, it is investigated and proved that an aluminum shield can reduce losses in the pad - rebar system. By employing 3-D Finite Element Analysis (FEA), the aluminum shield is optimized such that the losses in the rebar, aluminum sheet, and ferrite core are minimized. A 1.75-m long Tx pad is considered when analyzing the performance of the aluminum shield. It is experimentally validated that the aluminum shield can reduce the transmitter side no-load losses by more than 30% in a 3.7-kW system. Finally, using a reference 3.7-kW receiver (Rx) pad, it is demonstrated that the proposed aluminum shield does not impact the mutual inductance between Tx and Rx pads significantly.