Oscillation control in offshore wind turbines

In this study, control approaches based on tuned mass dampers were examined to reduce structural oscillations in offshore wind turbines, and the effectiveness of different control methods was evaluated. Both passive and active control strategies were addressed, and the improvements obtained were compared under different conditions. The applied methods were shown to have high potential in controlling the nonlinear and uncertain dynamic behavior of the turbine. In the first part, the standard coefficients of the tuned mass damper found in the literature were optimized using particle swarm optimization. The results of the optimization were compared with the turbine tower's angular displacement, and notable improvements were achieved. In the second part, the delayed resonator was used as an innovative approach in the active control of an offshore wind turbine equipped with a tuned mass damper, and after optimization with a genetic algorithm, its performance was tested with three different inputs. The theoretical basis of the delayed resonator in suppressing undesired vibrations is highly suitable for offshore wind conditions. In line with this suitability, the results confirm that using the delayed resonator in the control of an offshore wind turbine with a tuned mass damper significantly improves turbine performance and structural control. In the final part, the tuned mass damper was controlled by a fuzzy logic controller, with the aim of suppressing the oscillations of the offshore wind turbine. Unlike previous studies, the membership functions and rule base of the fuzzy logic controller were not constructed based on empirical knowledge but were optimized using particle swarm optimization. The results highlighted the success of this innovative approach in the structural control of offshore wind turbines. In conclusion, the findings demonstrate that these different control approaches applied to offshore wind turbines are effective in increasing structural stability, reducing vibrations, and enhancing operational reliability. The study is expected to serve as a pioneering reference for future research in this field.