Event-Triggered H-Infinity Pitch Control for Floating Offshore Wind Turbines
Ya Zhao, Xiyun Yang, Yanfeng Zhang, Qiliang Zhang
Abstract
The complex wind and wave environment can lead to increased external disturbances and power fluctuations of floating offshore wind turbines, posing a significant challenge to their stable operation. To cope with this issue, this paper formulates an event-triggered H-infinity pitch control strategy for floating offshore wind turbines. Firstly, a linear parameter varying model of floating offshore wind turbines is proposed, utilizing the dynamic characteristics of subsystems while considering the combined external disturbances from wind and wave. Then, the event-triggered control strategy is introduced into the H-infinity pitch control of floating offshore wind turbines. Based on this, a criterion for the asymptotic stability and H-infinity norm boundedness of floating offshore wind turbines is derived. Furthermore, an algorithm is presented for designing feedback gain matrices of the event-triggered H-infinity pitch control, which can effectively reduce the update frequency of the controller. Finally, a simulation is conducted on the IEA 15 MW Reference Wind Turbine by integrating OpenFAST with MATLAB/Simulink. The simulation results provide a comparative analysis of the event-triggered H-infinity pitch control strategy and the continuous-time pitch control strategy, demonstrating the superiority of the method proposed in this paper.