A LCC-LCC Converter with Near Constant Output Voltage for Autonomous Underwater Vehicles

Autonomous Underwater Vehicles (AUVs) are increasingly employed for underwater activities. To increase the autonomy range of AUVs, underwater wireless charging techniques for AUVs have been extensively researched recently. In this paper, a novel double-sided LCC converter for wireless power transfer (WPT) in AUVs is proposed that can obtain a good efficiency, and maintain the output voltage and current of a constant resistance load within an ideal range despite momentary changes in the distance between the transmitter and receiver coils due to ocean water turbulences. The passive element values of the proposed compensating converter are defined using the nonlinear optimization method through the software GAMS. The magnetic coupler used in this paper is a 200×200 mm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> plate with a coupling coefficient ranging from 0.08 to 0.9. To validate the proposed method, the system parameters are calculated for the proposed and conventional methods in two scenarios with different voltage and power levels, showing significantly lower voltage variations due to the gap changes between the couplers in the proposed method than that in the conventional method.