柔性支承下风力机传动系统动态特性及轴承疲劳寿命分析

发布时间：2018-10-14 10:53

【摘要】：在世界各地,大型风力机发电逐渐成为风能转化的主要利用形式,并带动风力发电机的需求量与生产量持续增长。随着我国对能源需求以及环保力度的加大,对成熟风电技术的需求与依赖不断增加。目前,我们与国外先进风电技术相比,依然存在较大差距,与我国当前风电产业迅猛增长的技术需求量产生矛盾。随着大型风力机基础支承结构的高度增加,支承结构柔性对系统的影响也随之增大。在随机风载荷的作用下,支承结构产生弹性形变,从而影响机到舱内的齿轮箱传动系统,使其内部构件发生耦合运动,使系统的动载荷加剧,系统的动力学响应也随之有所变化。实际情况中,在基础柔性高、瞬时载荷变化大等因素的影响下,风力机的实际使用寿命远低于其二十年的设计寿命,说明传统的在刚性支承下风力机传动系统设计方法和理念在分析系统动力学特性及可靠性时存在不足。因此深入研究塔架的柔性支承、随机风载条件下大型风力机传动系统动力学特性及关键部件疲劳寿命,对提升风力发电机齿轮箱的整机性能,解决风机寿命等瓶颈问题具有重要意义,对我国风力机传动系统动力学及可靠性分析等研究具有一定参考价值。本文考虑塔架柔性支承和随机风载对大型风力机的影响,对风力机齿轮箱传动系统建立动力学耦合模型,同时考虑时变啮合刚度、啮合误差等内部激励,求解出柔性支承下齿轮箱传动系统动态响应;在此基础上,计算各齿轮副的动态啮合力和低速轴轴承动态载荷;对轴承进行静力学分析,分析得出滚动体与内圈接触区域的外侧倒角处接触应力最大;结合准静态学分析法及数理统计理论,得到轴承应力谱,基于Miner线性累积损伤法则对低速轴轴承的疲劳寿命进行估算,所得结果对风力机动力学分析、故障维修安排及可靠性设计研究等具有一定参考价值。
[Abstract]:In all parts of the world, large-scale wind turbine power generation has gradually become the main form of wind energy conversion, and the demand and production of wind turbines have continued to increase. With the increase of energy demand and environmental protection in China, the demand and dependence on mature wind power technology is increasing. At present, compared with advanced wind power technology abroad, there is still a big gap between us and the demand of wind power industry in China. With the increase of the height of large wind turbine foundation support structure, the influence of supporting structure flexibility on the system also increases. Under the action of random wind load, the supporting structure produces elastic deformation, which affects the gearbox transmission system from the machine to the cabin, causes the coupling movement of its internal components, and makes the dynamic load of the system worse. The dynamic response of the system changes with it. The actual service life of the wind turbine is much lower than its design life in 20 years under the influence of the high flexibility of the foundation and the great change of the instantaneous load. It is shown that the traditional design method and concept of wind turbine drive system under rigid support are insufficient in analyzing the dynamic characteristics and reliability of the system. Therefore, the flexible support of tower, the dynamic characteristics of large wind turbine transmission system under random wind load and fatigue life of key components are studied in order to improve the performance of wind turbine gearbox. It is of great significance to solve the bottleneck problems such as the life of wind turbine, and has certain reference value for the study of dynamics and reliability analysis of wind turbine transmission system in China. In this paper, the influence of tower flexible support and random wind load on large wind turbine is considered, and the dynamic coupling model of wind turbine gearbox transmission system is established, and the internal excitation such as time-varying meshing stiffness and meshing error are considered. The dynamic response of gearbox transmission system under flexible support is solved. On this basis, the dynamic meshing force of each gear pair and the dynamic load of the low-speed shaft bearing are calculated, and the static analysis of the bearing is carried out. The results show that the contact stress at the outer corner of the contact region between the rolling body and the inner ring is the largest, and the bearing stress spectrum is obtained by combining the quasi-static analysis method and the mathematical statistics theory. The fatigue life of low speed shaft bearing is estimated based on Miner linear cumulative damage rule. The results are valuable for wind turbine dynamic analysis, fault maintenance arrangement and reliability design.
【学位授予单位】：太原科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM315

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