Modeling and Efficiency Optimization Design of Underwater Capacitive Power Transfer System

In underwater environments, existing capacitive power transfer (CPT) systems only consider the capacitance or conductivity of the coupling plate when analyzing transfer efficiency. This is inconsistent with the characteristics of the underwater coupler. Thus, it would lead to inaccurate efficiency models and difficult efficiency optimization design. To address the above issue, this paper models the underwater CPT system by simultaneously considering the capacitance and conductivity of the coupler in the efficiency model, so a more accurate efficiency model of CPT system in the underwater environment is derived. On this basis, the efficiency optimization design of the underwater CPT system is carried out, and the optimization design process is provided. Finally, the accuracy of the proposed efficiency model and the effectiveness of the design method have been demonstrated through simulation and experimentation. With the proposed optimization method, the underwater CPT system achieves a transfer efficiency of 82% within a load range of 10 Omega to 60 Omega at a plate spacing of 100 mm. The maximum transfer efficiency reaches 90%.