Application of the latching control on a wave energy converter

Abstract

Initially, an optimization process is proposed to determine the optimum dimensions of a control-free point absorber wave energy converter (WEC). The methodology is based on frequency domain simulation of the WEC oscillations and a statistical analysis method called “design of experiment” (DOE). Then, using the preliminary results, an approach based on a series of time domain analyses is adapted to obtain the optimum dimensions of a point absorber controlled by a constant-delay latching. The optimization goal is to maximize both WEC absorbed power and absorption bandwidth when providing a natural period close to the predominant wave periods of the sea site. In addition, a wave-to-wire numerical model is developed to address the performance of the COPPE/Seahorse device in the nearshore Rio de Janeiro. The code is adapted to model a specific PTO system consisting of a gearbox and a rotational generator. An adapted constant-delay latching control aiming at the optimization of the WEC power generation is proposed and the results are compared to the control-free model.