极端风况下风力机的动态失速研究

Study of dynamic stall of wind turbine under extreme wind condition

根据IEC标准与GL准则定义极端风速模型对某1.5 MW的水平轴风力机进行数值模拟计算,研究极端风况下风轮转矩、空气动力系数等的变化规律.研究发现,风力机在非稳态工况下运行时,高风速时风轮的转矩与低风速时风轮的转矩变化规律相比有明显差异,叶根到叶尖产生不同程度的失速.在风速增大和减小的不同过程中,非稳态工况下风轮转矩、升力系数和阻力系数随攻角的变化有显著地差别,叶轮的升力系数和阻力系数的最大值均高于稳态下的系数.

Based on the extreme wind speed model defined by ICE standard and GL criterion, the numerically simulative computation is carried out for a 1.5 MW horizontal-axis wind turbine and the variation rule of rotor by investigation torque and aerodynamic coefficients are investigated under extreme wind condition. It is found that when the turbine operates under unsteady-state condition, the rotor torque at high wind speed will have a remarkable deviation from that at low wind speed and the stall from blade root to tip will take place to a different extent. In the process of increase and decrease of torque, and blade lift and drag coefficients with wind speed under unsteady-state condition, the variation of rotor attack angel of oncoming wind will be apparently different and the maximum of blade lift and drag coefficients will be larger than that under steady-state condition.