Realistic energy-maximising control of cyclorotor wave energy converters using estimator, predictor, and nonlinear MPC

• The first integrated estimator-predictor-NMPC for cyclorotor WEC control. • Evaluation under site-specific irregular sea states. • Realistic estimates of cyclorotor WEC annual energy output. • Quantification of energy capture losses due to estimation and prediction inaccuracies. This study presents the first realistic control design for cyclorotor-based Wave Energy Converters (WECs) to maximise energy conversion. The selected approach incorporates a relative foil-fluid velocity estimator and predictor with a nonlinear model predictive controller for a cyclorotor WEC operating in irregular waves. The performance of the proposed realistic controller is compared with that of an idealised case, which assumes perfect knowledge of the relative foil-fluid velocity. Realistic and idealised control are assessed by calculating the annual energy production in two representative ocean regions, and the associated energy losses due to estimation and prediction inaccuracies are quantified. Simulation results indicate that the impact of estimation and prediction errors on energy capture remains within acceptable limits, while realistic estimates of cyclorotor energy output are obtained for the first time.