A Novel Conformal Coil Structure Design of Wireless Power Transfer System for Autonomous Underwater Vehicles

A coil structure that is compatible with the structure of the autonomous underwater vehicles (AUVs) and preventing the rotational misalignment is proposed for stabilizing the output power of a wireless power transfer (WPT) system. The transmitting coil and the receiving coil are wound on the structure of the energy base station and the AUV in a spiral tube type, respectively. This arrangement not only guarantees a constant mutual inductance when the AUV rotates, but it also maintains the efficient transmission of energy when the receiving coil is conformal with the AUV by optimizing the size of the magnetic core and the distance between the coil and the metal structure. The performance of the proposed coil structure is experimentally evaluated by building an inductor–capacitor–capacitor series (LCC-S)-compensated WPT prototype. It was found that the system can stably deliver a 2 kW power with a dc–dc efficiency of 92.7%.