A Novel Bipolar Cubic Magnetic Coupler for Multidirectional and Multiload WPT System in Cluster AUVs

Recently, most wireless power transfer (WPT) systems for autonomous underwater vehicle (AUV) employ one to one charging method, leading to low system utilization rate and degree of freedom. A novel bipolar cubic magnetic coupler (BC-MC) for multidirectional and multiload WPT system is proposed. Specifically, the presented BC-MC transmitting coil is composed of four L-shaped coils connected in series, which can supply power to multiple bipolar arc-shaped receiving coils positioned around it. The most attractive feature is that, each side of the BC-MC is equivalent to a bipolar coil which can produce an annular magnetic field with a strong magnetic field confinement effect. A multi-objective genetic algorithm is employed to optimize the coil parameters, aiming to achieve enhanced coupling and reduced volume. In addition, an LCC-S compensation topology is adopted to stabilize the current in Tx coil under dynamic load variations. An experimental WPT prototype is built and the effectiveness of the proposed BC-MC was verified by the measurement results. While satisfying optimal load, the system can achieve 92.45% efficiency at a power level of 200 W for four AUVs. Meanwhile, strong anti-offset capability of BC-MC is also validated.