Magnetic Coupling Mechanism With Omnidirectional Magnetic Shielding for Wireless Power Transfer

Electromagnetic field is used as medium for wireless power transfer to realize noncontact power transmission, which is hoped to be concentrated in the power transmission channel as much as possible to improve performance and reduce the impact on surrounding environment. A magnetic coupling mechanism (MCM) with omnidirectional magnetic shielding (ODMS) is designed in this article. Ferrite shielding layers are added at the back of power channel to guide more for power transmission and restraint leakage. The reverse-wound magnetic shielding coil and forward-wound power transmitting coil are connected in reverse series to form a bidirectional antiparallel coil, which eliminates the complex control and additional excitation source, and restrict magnetic in the side areas of power channel. Active and passive shielding methods are comprehensively used to improve the magnetic field distribution in the power transmission channel and reduce magnetic in the full space around MCM. The optimal design method of ODMS MCM is summarized, and the experiments are carried out. The results are consistent with the theoretical and simulation analysis. The proposed ODMS MCM can effectively limit magnetic leakage in all directions and improve transmission power and efficiency.