大于切出风速的大型风力机运行控制策略研究

运用非定常叶素动量(BEM)理论计算气动载荷,叠加重力载荷和惯性载荷,建立并数值求解全机动力学模型。基于快速非支配排序遗传算法(NSGA),在切出风速以上,优化得到变速变桨和定速变桨两种控制规律曲线,实现大型风力机在25m/s~40m/s风速之间正常运行的目的。比较两种控制策略的输出功率、风轮推力和转矩,得出变速变桨控制策略更适合于25m/s~40m/s之间风力机运行控制的结论。计算稳态工况时8种叶根载荷的极限值,由各载荷的变化趋势可知,Fy在25m/s之后增大9%,其他载荷均安全。

Control strategy for operation of large-scale wind turbines above cut-out wind speeds

The dynamic equation of wind turbines,in which the blade loads including the unsteady aerodynamic loads by using the blade element momentum (BEM) theory,the gravity loads and the inertial loads,is developed.The variable-speed variable-pitch and the constant-speed variable-pitch control strategies are studied for operation of the large-scale wind turbines above cut-out wind speeds.The pitch angle and rotor speed regular curves from 25 m/s to 40 m/s are obtained based on the fast and elitist non-dominated sorting genetic algorithm (NSGA).From the output electric power,rotor thrust and low speed shaft torque,it is clear that the variable-speed variable-pitch control strategy is more suitable for the wind turbine above cut-out wind speeds.Eight types of blade root ultimate loads under the steady cases are predicted.F_y increases by 9% and other loads are safe by observing their variation trends.