偏航速度对风力机功率及叶片应力的影响研究

通过实验测试,以动态旋转平台模拟风力机风向变化及偏航对风,研究不同偏航速度及偏航延时时间对风力机叶片应力及功率的影响。结果表明：动态偏航对风过程中,应力值基本呈由前缘向后缘、叶根向叶尖递减的趋势,在叶展方向0.67R及0.75R处,叶根弦向方向0.25c及0.50c处出现应力集中现象,偏航延时时间的加入可有效抑制叶片应力波动,过慢的偏航速度会导致功率曲线出现较大波动。引入一无量纲系数,该系数为风力机功率及叶片应力的比值,通过分析得知在仅考虑风力机叶片应力及功率时,风力机最佳偏航速度为0.5°/s。

RESEARCH ON INFLUENCE OF YAW SPEED ON POWER AND BLADE STRESS OF WIND TURBINE

Through the experimental tests, the dynamic rotating platform is used to simulate the wind direction change and the yaw motion of the wind turbine. The effects of different yaw speed and yaw delay time on blade stress and power were studied. The results show that In the process of dynamic yaw motion, the stress value decreases gradually from the leading edge to the trailing edge of the blade and from the blade root to the tip. The stress concentration occurs at 0.67R and 0.75R in blade spanwise direction, 0.25c and 0.5c in chord direction of blade root. The yaw delay time can effectively suppress the blade stress fluctuation. Too slow yaw speed will lead to large fluctuation of power curve. The dimensionless coefficient is introduced, which is the ratio of power and blade stress. Through analysis, it is known that when only the stress and power of wind turbine blade are considered, the optimal yaw speed of wind turbine is 0.5°/s.