Magnetic energy regulation of wireless power transfer systems based on coordinate transformation principle

Aiming at the problem that the magnetic field of magnetic coupling wireless power transfer (MC-WPT) cannot be regulated arbitrarily as required, a magnetic field regulation method based on coordinate transformation principle is proposed in this paper. This method can adjust the magnetic field as needed, which can effectively improve the system performance, including the power, efficiency and transfer range. Firstly, the coordinate transformation principle is introduced and the parameter design criterion of magnetic field regulating material is deduced. Secondly, according to the expected magnetic field distribution of the MC-WPT system, the corresponding electromagnetic parameters are designed and the design steps of magnetic energy regulation are derived. Finally, the proposed method and the designed material are verified by using COMSOL software. The simulation results show that the proposed method can regulate magnetic field as expected. The mutual inductance between coils is doubled after adding this material to MC-WPT system, and the transmission distance and transmission efficiency of the system are greatly improved.