Mutual Inductance Calculation of Rectangular Coils at Arbitrary Position With Bilateral Finite Magnetic Shields in Wireless Power Transfer Systems

Horizontal or rotational misalignment between the transmitting and receiving coils with magnetic shielding is inevitable during the wireless charging process, which leads to mutual inductance changes between the coils with magnetic shielding. However, there is no literature report on the mutual inductance calculation method for rectangular coils with bilateral finite magnetic shielding at arbitrary position. Therefore, the mutual inductance formulation of the rectangular coil at vertical misalignment is first obtained by the subdomain partition method (SPM). Then, the mutual inductance formulation of the rectangular coil with bilateral finite magnetic shielding at arbitrary position is obtained by the proposed vector coordinate transformation method (VCTM). Finally, this article presents the design of a wireless power transfer system's receiving and transmitting device according to the model of this article. The results of mutual inductance are compared between computational, simulation, and experimental results, and the results show that the mutual inductance error rate is within 4.79%. Moreover, the mutual inductance calculation time is not more than 12 s, which is 11 times faster than the finite element simulation time. The accuracy and rapidity of the proposed method in this article are verified