A Rotation-Free Wireless Power Transfer System With Stable Output Power and Efficiency for Autonomous Underwater Vehicles

This letter proposes a rotation-free wireless power transfer system based on a new coil structure to achieve stable output power and efficiency against rotational misalignments for charging autonomous underwater vehicles. The new coil structure has two decoupled receivers composed of two reversely wound receiver coils and the magnetic flux directions of the two receivers are perpendicular to each other, guaranteeing a relatively constant total mutual inductance and a decoupled characteristic under rotational misalignments. The proposed coil structure is verified via finite element analysis based on ANSYS Maxwell. A rotation-free LCC-LCC compensated WPT prototype is built and the experimental results verify the theoretical analysis and simulations. The system can deliver 664 W with a dc-dc efficiency of 92.26% under the best case and 485 W with a 92.10% dc-dc efficiency under the worst case.