中文摘要：

当风速大于额定风速时,通过调节桨距角可以限制输入气动功率和风轮转速,使等效在低速轴上的发电机转速更好地跟踪风轮转速,从而减小低速轴扭矩,实现风机叶片、塔筒和传动链的动态载荷控制。文章基于线性矩阵不等式（Linear Matrix Inequality,LMI）设计多目标鲁棒H_∞/H_2状态反馈变桨距控制器。设计变桨距控制器时充分考虑了海上机组的运行环境,分析了海浪对机组产生的影响,控制目标选取机组的功率和机组的关键部位疲劳载荷,在保证功率稳定输出、减小功率波动同时,减小机组载荷。使用MATLAB和FAST软件进行联合仿真,仿真结果表明新型控制策略可以有效平稳风电机组输出功率并降低机组载荷,实现了优化H_∞/H_2鲁棒控制性能。

英文摘要：

Pitch control system is used to limit the aerodynamic power and rotor speed at above rated wind speed region. The torque equivalent in the low shaft from generator torque can track the rotor torque rapidly, and then dynamic load of blade,tower and drive-train can be controlled. A multi-objective robust H_2/H_∞ state feedback controller based on linear matrix inequalities（Linear Matrix Inequality, LMI） is proposed,the controller design takes full account of complex operating condition of offshore wind turbine,especially the effect of waves. The power output and dynamic load on key component are chosen as the multi-objective goals, which can ensure stable output power and slow wind turbine loads of key units by adjusting the pitch angle. The MATLAB and FAST simulation results show that the new control strategy can effectively smooth wind turbine power output and reduce fatigue loads, the H_2/H_∞ robust control performance is also optimized.