风电机组变桨轴承的动态柔性特性研究

Dynamic and flexible characteristics of pitch bearing in wind turbine

针对传统变桨轴承方法中的刚性假设不能反应变桨轴承动态运行特点的问题,引入了在线测试与仿真分析技术,对变桨轴承动态柔性特性进行了研究。分析了变桨轴承运行的受载特点,提出了一种基于应变载荷测试与位移传感器的在线测试方法,以测试风电机组不同功率下变桨轴承内外圈轴向位移、径向位移和载荷;建立了考虑周边结构与变桨轴承柔性的变桨系统有限元模型,并以在线测试所得载荷作为有限元分析输入载荷,进行了仿真分析;最终对不同功率下的变桨轴承轴向位移、径向位移测试数据与仿真数据进行了对比分析。研究结果表明:变桨轴承载荷、变桨轴承内外圈轴向位移、径向位移随风轮转动呈现周期性交替变化规律,不同位置变化规律特点不同,体现了变桨轴承的动态柔性特性;该特性可应用于变桨轴承可靠性的研究。

Aiming at the problem that the dynamic characteristics of pitch bearing could not be reflected with traditional pitch bearing analyzing method due to the rigid assumption,online test and numerical simulation techniques were introduced to study the dynamic and flexible characteristics of pitch bearing.The characteristics of load distribution in working pitch bearing were studied,and an online test method based on strain-load measurement and displacement sensor was proposed,to measure the axial and radial displacements of internal and external rings,and the load of pitch bearing at various powers.A finite element model of pitch system was developed with the flexibilities of pitch bearing and surrounding structures incorporated,and finite element analyses were performed with the tested loads as inputs.Finally the tested and simulated dataofthe axial and radial displacements at different positions of pitch bearing at different powers were compared.The results indicate that the load,axial and radial displacementsof pitch bearing change regularly at different positions with different characteristicsas the wind rotor operates,which shows the dynamic and flexible characteristics of the pitch bearing,and such characteristics can be used to guide the study of pitch bearing reliability.