A novel concentric circular ring structure applied in AUV’s inductive power transfer system for resisting the disturbance of ocean current

Inductive power transfer (IPT) realizes no physical connection and make it possible to be a substitute for conductive charging in autonomous underwater vehicle (AUV) power feeding applications. However, in marine environment, the seawater stream vibration could bring disturbance and change the primary and secondary parameters, which reduces the stability of the power transmission system. This paper proposes a concentric circular ring structure applied in AUV’s IPT system for resisting the disturbance of ocean current. The study focuses on its misalignment tolerance. It is found that the 3rd coupler (19:24 turns) has better tolerance on axial misalignment among the three couplers with different secondary winding turns. It improves the coupling coefficient reduction from 34.7% to 23.6% when the axial misalignment varies from 0 to 50 mm and the radial displacement almost has no influence on coupling coefficient if radial misalignment is much smaller than the diameter of coils. Experiment results show that the system efficiency drops from 93.2% to 82.4%, when the axial misalignment changes from 0 to 50 mm.