Metal Influence Suppression Method for Rotating Wireless Power Transfer System Based on Toroidal Double-D Coil

The wireless power transfer technology provides a feasible solution for scenarios where there is a demand for rotating power transfer. However, the rotating power transfer system is located in a small space and the design of each part is too compact, and when it is too close to the surrounding metal parts, the influence of the metal will cause the system parameters to change and reduce the energy transfer efficiency, and the eddy current loss generated in the metal will lead to temperature rise and affect the safe operation of the system. In this paper, we take an electrically excited motor as the application scenario, establish the equivalent influence model of the system lateral to the metal of different spacing and material, conduct circuit parameters and magnetic field analysis, and propose a toroidal DD structured coil for the design of wireless power transfer system according to the need to suppress the influence of metal and anti-rotation deflection.Based on the finite element method, a simulation model is established to analyze the transmission performance and the surrounding magnetic field of the toroidal DD coil under metal disturbance and to compare the metal influence and rotational offset resistance of the wireless power transfer Finally, an experimental platform of the rotating wireless power transfer system with a toroidal DD coil under the influence of metal at the end of the simulated motor is built to experimentally verify the theoretical and simulation models. The experimental results show that the proposed toroidal DD coil structure has better resistance to metal influence and rotational offset than other power transfer coil structures.