Experimental validation of a nonlinear mpc strategy for a wave energy converter prototype

One of the major limitations to the development of advanced wave energy converters (WECs) control strategies are the associated computational costs. For instance, model predictive control (MPC) strategies have the potential to obtain almost optimal performance, provided that the imperfect power conversion in the power take-off (PTO) system is correctly taken into account in the optimization criterion and that the incoming wave force can be estimated and forecast. However, demanding computational requirements as well as the unresolved issue of wave force estimation have so far prevented real-time implementation and validation of such MPC strategies. In this paper, we present the successful experimental results obtained on a scaled-down prototype of the well-known Wavestar machine. Performance comparisons are provided for nonlinear MPC versus a reference PI controller.