Experimental Study on Model Predictive Control for a Point Absorber Type Wave Energy Converter With a Linear Generator

This paper presents the experimental evaluation results of power production efficiency of model predictive control (MPC) on a wave energy converter (WEC) with a linear generator in regular and irregular waves. A bottom-fixed WEC of point absorber type was subjected to the WEC model in this paper. To compare the power production efficiency, the power production efficiency of the approximate complex-conjugate control with considering the copper loss (ACL) was also evaluated. In regular waves, the MPC performance was comparable to the ACL one in the power-production amount reasonably. In irregular waves which have narrow band spectral distribution, a same trend as the trend in regular waves was obtained. On the other hand, in irregular waves which have broadband spectral distribution, the MPC was more effective than the ACL. Moreover, Experiments in regular and irregular waves were carried out in the MPC under the constraint of the small heave displacement. The constraint of the displacement was approximately satisfied by the MPC. This is useful in practical operation. It is also investigated experimentally how time horizon affects the performance of the MPC. When the time horizon is short, the power production amount of the MPC increases.