A Novel Magnetic Shielding Structure for Inductive Wireless Power Transfer Systems Based on Constraint of Magnetic Flux

With the development of inductive wireless power transfer technology (IPT), electromagnetic compatibility (EMC) of the IPT system has attracted much attention. In this paper, the equivalent AC impedance model of LCC/S topology is established, and the conclusion that the output characteristics and power transfer efficiency (PTE) are related to mutual inductance M is obtained. To solve the problem of excessively large magnetic flux leakage of loosely coupling transformer (LCT), magnetic coupler with vertical and horizontal shielding is designed based on the method of magnetic flux constraint, and its finite element analysis (FEA) 3D model is established. A prototype is built for experiments. The maximum transmission efficiency of the prototype is 90.33%, and the minimum transmission efficiency is 88.20%. The FEA simulation and experimental results verify the feasibility of the magnetic shielding structure design method. The results show that the novel proposed magnetic shielding structure increases the strength of magnetic field, effectively reduces the eddy current loss caused by magnetic field leakage, and increases the anti-misalignment ability of the system.