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(Ed.)
—Ocean wave energy is a renewable energy which remains costly for large-scale electricity generation. Although the oscillating water column (OWC) wave energy converter (WEC) is a promising device type with a rectifying air turbine and generator which convert alternating airflow induced by the water motion into kinetic energy then to electric energy, there are still several challenges to overcome to achieve commercial energy production. A first step is deploying multiple devices close to each other in WEC parks, to save cost associated with mooring lines and power transmission cables and a second step is applying control at each stage of energy conversion to increase the electric energy output of the devices and ensure a safe operation. Herein, we first present a state-space model of a park of seven hydrodynamically interacting floating OWC WECs in all degrees of freedom with nonlinear PTO dynamics and a shared, quasi-static mooring model. The electric power flow is modeled by considering the conversion losses from the AC generators over a DC link, including a storage unit to the grid connection. Secondly, the OWC WEC park is expressed from a higher hierarchical level as an automaton driven by discrete events. Finally, we use a standard supervisory control approach to enable different local control schemes to ensure a save operation of the individual WEC and the park. The supervisor has good adaptability potential for different WECs and the incorporation of safety mechanisms.
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