Modelling and Control of the Wavestar Prototype

In the field of wave energy it is well known that control of point absorbers is essential in order to increase energy capture from waves. Correspondingly, advanced control is an integrated part of the Wavestar design. This paper presents the control method, referred to as the Wave Power Extraction Algorithm (WPEA), applied to the full-scale Wavestar Prototype for maximizing energy extraction. The WPEA is optimized based on simulations of the point absorbers in different sea states. Hence, a presentation of a hydrodynamic model of the Wavestar is included in the paper. A simplified Power Take-Off (PTO) is also added to the model, enabling the optimization of the WPEA to take into account the PTO constraints of PTO bandwidth and force limitations. The predicted results of the optimized WPEA are compared to real measurements from theWavestar Prototype, showing good compliance.