叶片刚度对风力发电机组载荷的影响

为了研究受叶片刚度变化影响的载荷灵敏度问题,提出利用柔性多体动力方程对全耦合风机进行建模的方法,并考虑叶片旋转时产生的空气动力、重力及离心力作用对叶片进行模态分析,求解叶片的气动阻尼.运用Newmark法对风力发电机组叶片进行动态分析计算,得到总的动态响应载荷.以某3 MW风力发电机组为例,计算叶片在不同刚度下的载荷敏感度,仿真其在额定风速下的正常发电情况,获得其叶根、塔底、偏航轴承以及轮毂的载荷.仿真结果表明,叶片刚度降低导致叶根载荷减小,但是塔底、偏航轴承载荷增加;叶根XY、塔底Z、偏航轴承Y及轮毂Z方向载荷变化较为敏感.

Influence of blade stiffness on loads of wind turbine

In order to study the load sensitivity problem affected by the change of blade stiffness, a modeling method for the fully coupled wind turbine with the flexible multi body dynamic equations was proposed, and the modal analysis for the blade was performed with considering the effect of aerodynamic force, gravity and centrifugal force, which were generated during the rotation of blade. The aerodynamic damping of blade was solved. In addition, the dynamic analysis and calculation for the blade of wind turbine were conducted with the Newmark method, and the total dynamic response load was obtained. With taking the 3MW wind turbine as an example, the load sensitivity of blade under different stiffness was calculated, the normal power generation status at the rated wind speed was simulated, and the loads of blade root, tower bottom, yaw bearing and hub were attained. The simulated results show that with reducing the blade stiffness, the load of blade root decreases, but the loads of both tower bottom and yaw bearing increase. Furthermore, the load variation in such directions as blade root XY, bottom Z, yaw bearing Y and hub Z is more sensitive.