Comparative analysis of hybrid and traditional resonators for magnetically coupled wireless power transfer

Wireless power transfer has triggered a great deal of research interest in the fields of various applications. It has been revealed that magnetically coupling wireless power transfer (MC‐WPT) is the most effective approach in wireless energy charging. However, frequency splitting phenomena, observed widely in MC‐WPT, reduces the transfer efficiency. In this article, hybrid resonators with a novel coil structure are presented to suppress the frequency splitting. Different from the traditional two‐coil structure, an inner resonant coil is introduced inside an outer coil and are performed together as the transmitter. The equivalent circuit model of the proposed hybrid MC‐WPT system is analyzed and the transfer efficiency is calculated. Simulation is performed to investigate the feasibility of the proposed resonators in suppressing the frequency splitting and compared with the traditional resonators. In addition, experiments are carried out to validate the proposed hybrid coil structure.