School of Electrical Engineering,Qingdao University
Project Supported by National Natural Science Foundation of China (51877113)
As the crucial component of wireless charging system, magnetic coupler is composed of energy transmitting coil, energy receiving coil and electromagnetic shielding layer. At present, a large quantity of ferrite and aluminum materials are used in the shielding layer to enhance the coupling performance of the system and reduce electromagnetic leakage, which causes the problem of large volume, heavy weight and high cost of the magnetic coupler. In addition, ferrite is fragile and easily saturated, which seriously restricts the promotion and application of wireless electric vehicle charging technology. In order to solve above problems, a composite shielding layer composed of iron-based nanocrystalline strip, ferrite and aluminum foil is proposed. Based on the detailed analysis of the characteristics of nanocrystalline strip, the pretreatment process of nanocrystalline strip is given. Using MAXWELL and other simulation software, the advantages of composite shielding layer are described from the comparison of coil static parameters, the improvement of ferrite saturation problem, shielding efficiency and misalignment tolerance. Finally, the prototype is built and verified.