Optimisation of wave energy extraction with the Archimedes Wave Swing

• Published in: Ocean engineering Vol. 34; no. 17; pp. 2330 - 2344
• Main Authors: VALERIO, Duarte, BEIRIAO, Pedro, SA DA COSTA, José
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Ltd 01.12.2007; Elsevier
• Subjects: Applied sciences; Archimedes; Archimedes Wave Swing; Buildings. Public works; Energy; Energy of waters: ocean thermal energy, wave and tidal energy, etc; Exact sciences and technology; Feedback linearisation control; Hydraulic constructions; Latching control; Marine; Natural energy; Offshore structure (platforms, tanks, etc.); Phase and amplitude control; Reactive control; Renewable energy; Wave energy; Wave energy; Latching control; Renewable energy; Reactive control; Archimedes Wave Swing; Phase and amplitude control; Feedback linearisation control; Ocean energy; Performance evaluation; Linear model; Optimization; Simulation; System description; Feedback linearization; Dynamic model; Offshore structure; Optimal control (mathematics)
• ISSN: 0029-8018; 1873-5258
• DOI: 10.1016/j.oceaneng.2007.05.009

This paper addresses the Archimedes Wave Swing (an offshore wave energy converter, which produces electricity from sea waves). It compares the performances of latching control (a discrete, highly non-linear, intrinsically sub-optimum control strategy), of reactive control, of phase and amplitude control (two optimum control strategies that involve non-causal transfer functions, which have to be implemented with approximations, thus rending the control sub-optimum), and of feedback linearisation control (a non-linear control strategy). From extensive simulations it is concluded that the latter performs clearly better irrespective of the sea state, and leads to a significant increase of absorbed wave power.