Integrated analysis of hybrid control for offshore wind turbines: A case study in wave resonance prone wind farms

For wind farms situated in resonance-prone environments, exemplified by the Xiangshan wind farm in China, where wave-induced resonance impacts most of the operating time, designing offshore wind turbines (OWT) is an urgent engineering challenge. Given the scarcity of solutions lowering resonance response while balancing power generation, this study provides a hybrid control strategy to facilitate OWT operation for optimal power capture at low wind speeds and safeguard structural integrity by mitigating fatigue loads at high speeds. This is achieved through the integration of a maximum power point tracking (MPPT) generator torque controller and a PID-based blade pitch controller, which incorporate wind speed feedforward and tower acceleration feedback. The tangible effects of hybrid control are demonstrated through the simulation of the Xiangshan wind farm employing an integral OWT model within the aero-hydro-servo-elastic-soil framework. The results show that the hybrid controller achieves a trade-off between energy capture efficiency and long-term structural stabilization. The hybrid control strategy presents effective regulation under varying environmental conditions and significantly extends the lifetime of OWT foundation while incurring minimal power production reductions. Enabling to satisfy power generation and load reduction, this research signals a promising potential for the OWT design in wave resonance-prone areas. •Dynamic responses of offshore wind turbines could be interactively influenced by wave resonance, foundation, and controller.•A hybrid controller is formulated by integrating MPPT torque control and feedback-feedforward blade pitch control.•The hybrid controller can satisfy fatigue loading mitigation and power production compensation.