Experimental assessment of Generalised Super-Twisting control for optimal reference tracking in wave energy systems

FACUNDO D. MOSQUERA; NICOLÁS FAEDO; PAUL F. PULESTON; CAROLINA A. EVANGELISTA

Yokohama

Congreso; 22nd IFAC World Congress; 2023

Maximising wave energy extraction is essential for the successful operation of wave energy converters, and appropriate control strategies play a vital role in achieving this objective. This paper presents a control scheme for an experimental wave energy converter setup. The strategy combines an optimal moment-based reference generation technique with a higher-order sliding mode tracking controller, which provides robust tracking of the associated reference, regardless of the uncertainty present in the experimental operation. The device is tested with two different irregular sea states, and results show that the control structure effectively deals with the system's underlying uncertainty, achieving excellent tracking performance while guiding the system to the corresponding surface following the theoretical phase plot convergence. Furthermore, the comparison with a PID tracking control structure indicates that a proper modification of the tracking element of the loop can improve energy extraction. Finally, consistent tracking error and phase plot evolution behaviour are observed for both sea states.