Lateral and Angular Misalignments of Coil in Wireless Power Transfer System

Wireless power transfer requires the transmission and reception of energy through coils arranged coaxially and the direction does not change to ensure maximum transmission efficiency and power. However, in actual working environments, coils have lateral and angular misalignments, thereby reducing the transmission performance. In this study, we investigate the transmission efficiency of coils and the mutual inductance of the lateral and angular misalignments theoretically. Coils with lateral and angular misalignments are modeled with the Maxwell simulation software. Finally, a 3D test experimental platform is built. The experimental results show that the use of a magnetic isolation material on the coil can effectively improve the electromagnetic field intensity of the system. The coupling coefficient of the two coils is increased by more than 15%. At a coupling distance of 5 mm, the coupling mechanism with ferrite is approximately 10% more efficient than that without ferrite. Furthermore, it shows that when the misalignment is large, the magnetic isolation material can significantly improve the efficiency of the wireless charging system.