Efficiency Improvement for Multi-Position of Receiver in 13.56 MHz Wireless Power Transfer Coupling System

In the wireless power transfer, the efficiency depends so much on the relative position of transmitter and receiver. Therefore, the efficiency of the electric vehicle dynamic wireless charging is much lower than the optimized design of the transfer system. The solution to improving the charging efficiency automatically matches the system impedance according to the position of the receiver placing on the electric vehicle. The wireless power transfer in this paper using strongly coupled magnetic resonance technology for the coupling system. In order to compensate for the variation from optimized charging distance, the proposed system is able to change the transmitter configuration accordingly the receiver movement by using the lookup data. As the result, the efficiency of the proposed system is increased maximum 56% within 550 mm transfer distance and 400 mm misalignment than a conventional system. The effectiveness of the proposed system is verified by both simulation and experimental results.