随机风作用下风力发电机齿轮传动系统动载荷计算及统计分析

Dynamic Load Calculation and Statistical Analysis of Gear Transmission System of Wind Turbine under Stochastic Wind Loading

针对风力发电机齿轮传动系统在随机风作用下失效率高的问题,在模拟真实风速的基础上,建立考虑外部随机风载及内部齿轮时变啮合刚度、轴承时变刚度及综合传递误差等激励因素的风力发电机齿轮传动系统齿轮轴承耦合动力学模型,通过对动力学模型进行仿真计算,得到各齿轮副的动态啮合力和各支承轴承的动态接触力。结合有限单元法和赫兹接触理论,得到关键零部件的应力时间历程,采用雨流计数法对应力时间历程进行统计分析,得到传动系统各关键零部件承受载荷的应力谱及概率分布函数。研究结果为风力发电机齿轮传动系统的动态可靠性分析和疲劳寿命预测奠定基础。

Aiming at the problems of high failure rate of wind turbines gear transmission system under the stochastic wind speed conditions, a dynamics model of gear transmission system coupled with bearing of wind turbine was established on the basis of simulating real wind speed, and the exter- nal random wind load and internal excitations such as time-varying mesh stiffness of gear pair, timevarying stiffness of rolling element bearings and integrated transmission errors were considered in the model. Numerical method was used to simulate the dynamics model, the dynamic meshing forces of each gear pair as well as the dynamic contact forces of each bearing were obtained. Then, the stress spectrum and the probability distribution function of the loads acting on the key parts of transmission system were obtained by statistic the stress-time history curves which was obtained by using the finite element method and the Hertz contact theory. This research results lay a foundation for dynamic relia bility analysis and fatigue life prediction of the gear transmissionsystem of a wind turbine.