Design of A Rotational Misalignment Resistant Three-phase Wireless Power Transfer Coil for AUVs

Wireless power transfer (WPT) has emerged as a convenient and efficient method for charging autonomous underwater vehicles (AUVs). Compared to single-phase WPT, implementing three-phase WPT on AUVs may take advantages of the three-phase system which has enhanced power transfer capabilities. However, traditional three-phase wireless charging encounters power reduction issues with rotational misalignments, especially in close-coupled conditions like AUVs. This paper proposes a rotational misalignment resistant three-phase wireless power transfer coil. In the proposed design, windings are evenly distributed to mitigate the output voltage reduction caused by rotational misalignment. The design permits AUVs to dock at arbitrary angles with underwater wireless charging stations. Experimental verification shows that the proposed design can transfer power with output dc voltage fluctuations of less than 5% under rotational misalignment conditions.