This paper investigates the dynamic modeling and robust control of an underactuated floating wind turbine for vibration suppression. The offshore wind turbine is equipped with a tuned mass damper on the floating platform. The Lagrange's equation is employed to establish the limited degree‐of‐freedom dynamic model. A novel disturbance observer‐based hierarchical sliding mode control system is developed for mitigating loads of the underactuated floating wind turbine. In the proposed control scheme, two prescribed performance nonlinear disturbance observers are developed to estimate and counteract unknown disturbances, where the load induced by wave is considered as a mismatched disturbance while the load caused by wind is treated as a matched disturbance. The hierarchical sliding mode controller regulates the states of such an underactuated nonlinear system. In particular, the first‐order sliding mode differentiator is used to avoid the tedious analytic computation in the sliding mode control design. The stability of the whole closed‐loop system is rigorously analyzed, and some sufficient conditions are derived to guarantee the convergence of the states for the considered system. Numerical simulations deployed on both the design model and the National Renewable Energy Laboratory 5‐MW wind turbine model are provided, which demonstrate great effectiveness and strong robustness of the proposed control scheme.

中文翻译：

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欠驱动浮式风力发电机的鲁棒结构控制

本文研究了用于抑制振动的欠驱动浮式风力发电机的动力学建模和鲁棒控制。海上风力涡轮机在浮动平台上配备有调谐质量阻尼器。拉格朗日方程用于建立有限自由度动力学模型。开发了一种新颖的基于扰动观测器的分层滑模控制系统，用于减轻欠驱动浮式风力发电机的负荷。在提出的控制方案中，开发了两个具有规定性能的非线性扰动观测器，以估计和抵消未知扰动，其中由波引起的负载被视为失配扰动，而由风引起的负载被视为匹配扰动。分级滑模控制器调节这种欠驱动的非线性系统的状态。特别是，一阶滑模微分器可避免滑模控制设计中繁琐的解析计算。严格分析了整个闭环系统的稳定性，并推导了一些足够的条件来保证所考虑系统状态的收敛。提供了在设计模型和国家可再生能源实验室5兆瓦风力涡轮机模型上部署的数值模拟，证明了所提出控制方案的巨大有效性和强大鲁棒性。严格分析了整个闭环系统的稳定性，并推导了一些足以保证所考虑系统状态收敛的条件。提供了在设计模型和国家可再生能源实验室5兆瓦风力涡轮机模型上部署的数值模拟，证明了所提出控制方案的巨大有效性和强大鲁棒性。严格分析了整个闭环系统的稳定性，并推导了一些足以保证所考虑系统状态收敛的条件。提供了在设计模型和国家可再生能源实验室5兆瓦风力涡轮机模型上部署的数值模拟，证明了所提出控制方案的巨大有效性和强大鲁棒性。