Optimal Solutions for Underwater Capacitive Power Transfer.

Area of Science:

• Electrical Engineering
• Power Electronics
• Wireless Power Transfer

Background:

• Capacitive power transfer (CPT) is gaining traction for charging electric vehicles, autonomous underwater vehicles, and electric ships.
• High power transfer capability and efficiency are critical for CPT system performance.

Purpose of the Study:

• To propose and analyze three solutions for CPT systems: maximum efficiency, maximum power, and conjugate matching.
• To express load power and efficiency as functions of capacitive coupling parameters.
• To derive the necessary source and load admittances for optimal CPT operation.

Main Methods:

• Theoretical analysis of CPT system parameters.
• Derivation of load and source admittances for different optimization goals.
• Experimental validation of proposed solutions.

Main Results:

• The study derived expressions for available load power and efficiency based on capacitive coupling parameters.
• Experimental results indicate that CPT power and efficiency decrease with increasing frequency (300 kHz to 1 MHz) and separation distance (100 mm to 300 mm).
• Maximum efficiency reached 83% at 300 kHz and 100 mm distance; maximum power yielded a normalized power of 0.994 under the same conditions.

Conclusions:

• CPT systems can be effectively utilized for charging electric ships and underwater vehicles across considerable separation distances and low frequencies.
• The proposed solutions provide a framework for optimizing CPT systems for specific applications, balancing efficiency and power transfer.
• Performance is sensitive to frequency and distance, necessitating careful system design and parameter selection.