Dual-Frequency Modulation to Achieve Power Independent Regulation for Dual-Load Underwater Wireless Power Connector

The power supply of underwater devices can be realized by the nonelectrical contact wireless power transfer (WPT) technology. The diversity and flexibility of devices carried by the remotely operated vehicle (ROV) can be increased by the WPT which can achieve convenient and safe device switching. Power independent regulation is a key for the underwater wireless power connector (UWPC) with multiload, and a superimposed dual-frequency modulation (SDFM) method is proposed in this article to achieve the load power independent regulation. The equal-area rule is first applied to SDFM, which can use one inverter to generate SDFM current at the transmitter. The theory of decoupled power transfer is analyzed in detail for the SDFM UWPC with dual-load (DL). All the above analyses are verified in a DL UWPC system prototype. The experimental results show that the SDFM current is generated using one inverter, and the load power can be independently regulated by adjusting the output voltage of the inverter. Furthermore, the load power is still independent and controllable under the conditions of load switching and mutual inductances changing. The DL UWPC system power can reach 50 W and dc-dc efficiency is about 68.73%.