Robust control of oscillating water column (OWC) devices: Power generation improvement

Wave energy composes a direct and easy way of harnessing power from the Ocean. Among the different techniques used, OWC devices stand as one of the most promising ones. NEREIDA MOWC demonstration project is a breakwater wave plant located in the Basque location of Mutriku, using Wells turbines and Doubly Fed Induction (DFI) generators. Since one of the main objectives when dealing with renewable energies is to make them economically viable to compete with fossil fuels and nuclear fission, all technological improvements are particularly welcome. In this context, this paper presents a new Variable Structure (VC) controller for OWC wave power generation plants. Due to the nature of the control law, it allows overcoming uncertainties caused by parametrical errors or system disturbances. The proposed design has been successfully validated and compared with the traditionally used PI-based vector control, improving the power extraction when applied for maximum power generation purposes.