Parametric analysis of a fully coupled USV-type wave energy converter: An approach based on wave-to-grid modelling

The integration of the wave energy converter and the unmanned surface vehicle (USV), which has the power generation capability and the mobile capability, is attracting increasing attention in concept design, control, and parametric study, as the integrated system can play a crucial role in the maritime sectors of commerce, science, and military. Enhancing the power generation of a USV-integrated wave energy converter contributes to prolonged USV operations or grid supply, but the power generation performance of this new-type device is significantly influenced by its various coupled subsystems, which requires a systematic methodology for distinguishing key design parameters. To address that problem, a comprehensive wave-to-grid model that reflects all subsystem coupling, energy losses, and constraints is developed to comprehensively describe system dynamics, and then a Taguchi method is employed to investigate the influence of selected design parameters on electric power generation. Results reveal that the piston area of the hydraulic cylinder and the accumulator pressure are the two most influential parameters affecting the time-averaged electric power of the proposed USV-type wave energy converter. The proposed methodology provides guidelines for technicians on how to design wave energy converters optimally.