For region‐2 operation of wind turbines in practice, the optimal torque gain can deviate from the nominal value because of the variations in turbine and wind conditions. The extremum‐seeking control (ESC) has shown its potential as a model‐free region‐2 control solution in some recent work; however, the ESC with rotor power feedback suffers from undesirable convergence under fluctuating wind. In this paper, we propose to use an estimated power coefficient as the objective function for the torque‐gain ESC, where the hub‐height free‐stream wind speed (FSWS) is estimated with the nacelle anemometer measurement on the basis of the so‐called nacelle transfer function (NTF) between the nacelle anemometer and met‐tower measurement. A sensitivity analysis is performed to quantify the impact of the wind speed estimation error on the estimation of power coefficient. An ESC integrated interregion switching scheme is proposed to avoid the load increase. Simulation results show that, compared with the power feedback‐based ESC, the proposed method can greatly improve the convergence rate of ESC under fluctuating wind, even under relatively large wind speed estimation error. Evaluation for the fatigue loads of wind turbine shows that the proposed control strategy induces mild increase of the wind turbine load.

中文翻译：

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基于机舱风速计测量的极值搜索风力涡轮机2区控制可提高波动风的收敛性

实际上，对于风力涡轮机的2区运行，由于涡轮机和风力条件的变化，最佳转矩增益可能会偏离标称值。极值搜索控制（ESC）在最近的一些工作中显示出了其作为无模型2区控制解决方案的潜力。然而，具有转子功率反馈的电调在风起伏不定的情况下会出现不希望的收敛。在本文中，我们建议将估计的功率系数用作扭矩增益ESC的目标函数，其中根据机舱风速计的测量结果估算轮毂高度自由流风速（FSWS）机舱风速计与塔式测量之间的机舱传递函数（NTF）。进行灵敏度分析以量化风速估计误差对功率系数估计的影响。为了避免负载增加，提出了一种ESC集成的区域间切换方案。仿真结果表明，与基于功率反馈的电调相比，即使在风速估计误差较大的情况下，该方法也可以大大提高电调在风速波动下的收敛速度。对风力涡轮机疲劳载荷的评估表明，所提出的控制策略可引起风力涡轮机载荷的适度增加。即使在相对较大的风速估计误差下。对风力涡轮机疲劳负载的评估表明，所提出的控制策略可引起风力涡轮机负载的适度增加。即使在相对较大的风速估计误差下。对风力涡轮机疲劳载荷的评估表明，所提出的控制策略可引起风力涡轮机载荷的适度增加。