A Multidimensional Misalignment-Tolerant Wireless Power Transfer System Based on Coaxial Split Solenoid Coil for AUV Charging Applications

To tackle the problem of a significant drop in output power and transmission efficiency of the wireless power transfer (WPT) system for autonomous underwater vehicles under multidimensional misalignments, this paper presents a WPT system with multidimensional misalignment-tolerant performance based on the coaxial split solenoid coil structure. The system employs two coaxially arranged and perfectly symmetrical solenoid coils as the energy transmitting coils, both of which are coupled with the single solenoid coil on the receiving side. The combination of this coil structure and the primary-side detuning SS compensation topology facilitates zero voltage switching for the inverter switches and simultaneously averts the risk of overcurrent in the transmitting coils. Furthermore, by rationally designing the parameters, the maximum allowable misalignment range of the WPT system within the preset output power fluctuation range can be achieved. Experimental results demonstrate that within the spatial range of axial misalignment of ±50 mm, air gap misalignment of ±25 mm, and swing misalignment of ±20°, including a full 360° circumferential rotation misalignment, the power fluctuation of the system is consistently within the set 5%, and the transmission efficiency remains above 90%, reaching a maximum of 91.88%.