This paper proposes a strategy to improve the efficiency of a low-frequency Wireless Power Transfer (WPT) system used to charge the battery of an Autonomous Underwater Vehicle (AUV) through an Inductive Power Transfer (IPT). The IPT system uses a Split-Core Transformer (SCT) to transfer power from the docking base to the AUV, without electric contact. Under gap variation, the efficiency is changed because the variation of SCT parameters. Therefore, the input frequency is changed in order to improve the efficiency of the system trough the Maximum Efficiency Point Tracking algorithm (MEPT) without communication between primary and secondary sides. Experimental results are presented to validate the theoretical analysis and to demonstrate the behaviour of the transformer under different values of gap and excitation frequency.

中文翻译：

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低频水下无线电力传输：最高效率跟踪策略

本文提出了一种提高低频无线电力传输 (WPT) 系统效率的策略，该系统用于通过感应功率传输 (IPT) 为自主水下航行器 (AUV) 的电池充电。IPT 系统使用分芯变压器 (SCT) 将电源从对接底座传输到 AUV，无需电接触。在间隙变化下，效率会因为 SCT 参数的变化而改变。因此，通过最大效率点跟踪算法 (MEPT) 改变输入频率以提高系统效率，而无需原边和副边之间的通信。实验结果用于验证理论分析并证明变压器在不同间隙和励磁频率值下的行为。