Optimal Design for Bipolar Reverse-Wound Magnetic Coupler in Wireless Power Transfer Systems Considering Misalignment Tolerance and Wire Consumption

To address the issue of transmission performance degradation caused by misalignment between the transmitting and receiving coils in wireless power transfer (WPT) systems, the optimal design for a bipolar reverse-wound magnetic coupler is proposed in this paper, considering both misalignment tolerance and wire consumption. Firstly, a bipolar reverse-wound magnetic coupler employing two concentric circular coils connected in reverse series is introduced. The calculation method for the mutual inductance between the transmitter and receiver coils of the proposed mechanism is investigated. Secondly, a circuit model for the WPT system based on this magnetic coupler is established. Subsequently, considering the mutual inductance variation characteristics and coil wire consumption, the design method based on particle swarm optimization for the bipolar reverse-wound magnetic coupler is proposed to enhance its misalignment tolerance. Simulation and experimental results demonstrate that, with the proposed optimization method, the receiving coil is permitted to misalign within a range covering 60% of the transmitter radius while maintaining mutual inductance fluctuations below ±5%. Compared to the conventional single circular transmitter, the proposed magnetic coupler achieves an approximately 20% improvement in misalignment tolerance under similar transmitter coil wire consumption conditions. The maximum receiving power of the experimental prototype is 203.67 W, while the DC-DC efficiency is 89.33%.