Improving the Misalignment Tolerance of Wireless Charging System by Uniforming Magnetic Field of Double-D Coil

The wireless power transmission system can transmit energy from the excitation side to the load side under the condition of complete electrical isolation, which is flexible, convenient and safe. Reasonably designing the structure and parameters of the system coupling coil can produce a relatively uniform magnetic field in a certain area and improve the anti offset performance of the system. In this paper, the uniformity of magnetic field corresponding to different structures of double-D coil is analyzed through finite element simulation. After finding out the optimal situation, ferrite is added for magnetic shielding, and its shielding effect is studied. The experimental results show that with the proposed optimizing method, the uniformity index of the magnetic field can be improved 10.2% and the mutual inductance fluctuation rates can be decreased 5%.