Design of Magnetic Coupler for Wireless Power Transmission System Based on Magnetic Field Reconstruction

This article proposes a novel wireless charging transmitter structure with a high rotational misalignment tolerance. It addresses the issue of reduced power transfer efficiency due to the rotating deviation in receiving coils, such as solenoid and Double D coils, which are constrained by the range of operating angles. The proposed transmitter is also compatible with unipolar coils such as circular and orthogonal magnetic structure receiving coils through magnetic field reconfiguration. The article also proposes an optimization method for the new structure and compares the optimized coupler with three typical couplers for compatibility and angular misalignment tolerance. Through the simulation and experimental verification, the DCDC transmission efficiencies are 84.4%, 84.6%, 84.0%, and 88.9% when the receiving coils are flat solenoid, Double D, orthogonal magnetic structures, and circular, respectively, with the transmission power of 100 W. Under 360° rotational misalignment, without the additional control circuitry, the system output voltage fluctuates less than 5% compared to when it is aligned.