A Nonferromagnetic Metal-Insensitive Robust Wireless Power Transfer System

Magnetic resonance-based wireless power transfer (WPT) has shown great potential in a variety of applications. However, in the actual operation process, the metallic object between transmitting coil and receiving coil will lead to frequency detuning. In this letter, the impact of the metal on transfer performance is theoretically analyzed. For performance enhancement, a frequency-insensitive nonlinear WPT system is designed to cope with the problem caused by the copper plate. The mathematical modeling of the proposed system is presented. Simulation and experimental validations are conducted. At the operating frequency, a dramatic variation of transfer efficiency is observed for the linear system. Comparatively, transfer efficiency of the proposed nonlinear system is much more stable.