Performance of a U-OWC – PTO coupled system using different control laws

The problem of maximizing the performances of a U-OWC wave energy converter in a variety of environmental conditions is investigated. Specifically, the paper compares two control strategies coupling the U-OWC – PTO system. Two approaches are discussed. The first relies on the tracking of the Maximum Power Points of the system, and empirical relations between the optimal PTO performances and the energy content of the incident sea state are estimated. Secondly, an analytical formulation linking the operational conditions of the turbine to the instantaneous air pressure inside the pneumatic chamber is identified. Results show that a sea state-based controller works better than a wave-to wave fast-acting control