Power Transfer Capacity Improvement of AUV IPT Systems via Impedance Transformation

Autonomous underwater vehicles (AUVs) are extensively utilized for underwater resource exploration, requiring inductive power transfer (IPT) systems with large output power to achieve quick charging. However, underwater positioning errors result in significant variations in the coupling coefficient of the IPT system. Moreover, AUVs employ diverse battery types and voltages, exacerbating the issue of decreased transferred power when the coupling coefficient and battery voltage are low, thereby prolonging the AUVs' charging time. To address this challenge, this paper proposes an impedance transformation method based on a π-network to improve power transfer capacity, which can also enhance the system efficiency under low battery voltage conditions. Firstly, the paper presents the proposed topology and analyzes its characteristics. Subsequently, the eddy current losses (ECL), zero-voltage switching (ZVS) condition, the parameters design of the π-network, and the power losses of the system are derived.Finally, a 5-kW prototype with a maximum DC-DC efficiency of 93.1% is built to validate the effectiveness of the proposed topology.

自主水下航行器（AUVs）在海底资源勘探中得到了广泛的应用，这要求配备具有大功率输出的感应式电力传输（IPT）系统以实现快速充电。然而，水下定位误差导致了感应式电力传输系统耦合系数的显著变化。此外，AUVs使用不同类型的电池和电压，进一步加剧了耦合系数和电池电压较低时传输功率降低的问题，从而延长了AUVs的充电时间。为了应对这一挑战，本文提出了一种基于π网络的阻抗变换方法，以提高电力传输能力，该方法亦能在电池电压较低的情况下提升系统效率。首先，文章介绍了所提出的拓扑结构并分析了其特性。随后，推导了涡流损耗（ECL）、零电压切换（ZVS）条件、π网络的参数设计以及系统的功率损耗。最后，构建了一个最大直流-直流转换效率为93.1%的5-kW原型系统，以验证所提出拓扑结构的有效性。