Compact and Misalignment Tolerance IPT System Based on Sine-Cosine Coupling Superposition for Autonomous Underwater Vehicle Applications

This article presents a novel inductive power transfer (IPT) system for autonomous underwater vehicles (AUVs). A magnetic coupler based on a curved quadruple-coil transmitter and a cuboid dipole receiver is innovatively proposed. The transmitter forms a stable magnetic field on the inner surface of the AUV. The principle of sine-cosine coupling superposition is creatively proposed and adopted on the two-phase vertically crossed receiver, which participates in power transfer against misalignments in a complementary way. The receiver is designed to be self-decoupled and compact, with a small surface occupancy of 49 cm2. LCC-SS compensation topologies are analyzed and selected to improve the transmission performance. Finally, an experimental prototype is built, and the theoretical feasibility is verified. Experiments have proven that the system can wirelessly charge the AUV with a stable power of 1 kW and the dc-dc efficiency can reach 91.35%. Meanwhile, the system can effectively cope with rotational misalignment of [−30°, 30°] and axial misalignment of [−55, 55 mm] for smooth power transmission.