Control Performance Assessment and Design of Optimal Control to Harvest Ocean Energy

Different approaches exist to design the optimal control strategy to harvest ocean energy with a point absorber. However, the control paradigm changes if the efficiency of the power takeoff (PTO) is taken into account. The motivation of this paper is twofold. The first objective is to develop a framework that includes the PTO efficiency to determine the optimal control strategy. The second objective is to assess the performance of any control strategy given the PTO efficiency. The performance assessment is based on the upper bound of the deliverable electrical energy of the optimal control strategy. As an example, different PTO efficiencies were considered for a given point absorber model, and extensive simulation results show the annual electrical energy delivered to the grid by the optimal control strategy. The performance of a nonoptimal control strategy is assessed with respect to the optimal control strategy.