【作者】 李超；

【导师】 秦大同；

【作者基本信息】 重庆大学 ， 机械设计及理论， 2011， 硕士

【摘要】 风能是一种清洁无污染的新能源,合理开发利用风能可以解决日益严峻的能源短缺以及环境污染问题。变速风力发电机由于发电量大、振动噪声低等优点,已成为未来大型风力发电机的主要发展方向。大型风力发电机叶片的转速通常都很低,为了达到发电机工作所需的转速就需要在叶轮和发电机之间连接一个增速齿轮箱。齿轮箱传动系统是风力发电机的关键部件之一,其可靠性的高低以及动力学特性的优劣都直接决定着风力发电机正常工作与否。由于变速风力发电机通常工作在较为恶劣的环境条件下,受复杂随机动载荷的影响并且处于高空架设状态,这些都对变速风力发电机齿轮传动系统的可靠性和动力学特性都提出了很高的要求。因此,对变载荷下变速风力发电机齿轮传动系统的可靠性和动力学特性进行研究显得尤为必要。本文受国家自然科学基金项目的资助,以2MW变速风力发电机传动系统为研究对象,对其进行了可靠性评估和动力学特性分析。主要研究工作如下:①建立了基于双参数威布尔分布的随机风速模型。根据实际风场风速的平均值以及方差值,求得了威布尔分布的形状参数和尺度参数,建立了随机风速模型,对自然风场中随机变化的风速进行了模拟;②得到了变速风力发电机齿轮箱实际运行时的时变输入转矩和转速。将通过随机风速模型获得的风载荷作为齿轮传动系统的外部激励,分析了变速风力发电机实际运行时齿轮箱输入功率与风速之间的关系,通过推导得到了齿轮箱输入转矩与风速、输入转速与风速之间的分段函数关系,在此基础上对随机风载荷进行变换得到了齿轮箱时变输入转矩和转速;③对变速风力发电机齿轮传动系统进行了可靠性评估。对齿轮失效的主要形式进行了分析,求得了齿轮传动系统的可靠度,对系统进行了可靠性评估;④建立了齿轮传动系统的动力学模型。在考虑齿轮副时变啮合刚度、轴承刚度和啮合误差等内部激励的基础上,采用集中质量法建立了传动系统的动力学模型;⑤分析了传动系统的动态响应特性。利用matlab求得了传动系统在时变输入转矩和内部激励共同作用下各齿轮的振动位移、振动速度和各齿轮副的动态啮合力,对变风载下变速风力发电机齿轮传动系统的动力学特性进行了分析,所得结果对变速风力发电机齿轮箱的设计和分析具有参考价值。更多还原

【Abstract】 Wind energy is a clean and non-pollution new energy, exploiting wind energy properly can solve the increasing energy and environmental problems. Because of high power and low vibration, the variable speed wind generator has been the main developing generator type of high-power wind generator in the future. The blade rotation speed of high-power wind generator is usually very low, so we should place a increasing-speed gear box between blade and generator in order to gain the speed for generating electricity. The gear box transmission system is a key part of wind generator, its reliability and dynamics level both directly decide the correct operation of wind generator. Because of the bad working environment, complex time-varying wind load and high erection, the gear transmission system of variable speed wind generator must have a high reliability and good dynamic characteristics. So, it is necessary to study on the reliability and dynamic characteristics of variable speed generator transmission system under varying wind load.The thesis is supported by National Natural Science Foundation, it investigated the reliability evaluation and dynamic performance of the 2MW wind generator transmission system. This paper mainly did following works:①A random wind model basing on the two parameters Weibull distribution is built. According to the average value and variance of wind speed, the shape parameter and scale parameter of Weibull distribution is estimated, the random wind model is built and the nature varying wind is simulated.②Realistic time-varying input torque and speed of variable speed wind generator gear box is got. The varying wind speed which is got from the random wind model is used to be the external excitation of gear transmission system. The relation between wind speed and realistic input power of variable speed wind generator gear box is analyzed; the function of input torque and wind speed and the function of input speed and wind speed are both got according to inference. On this foundation, the wind speed is changed into the input torque and speed of variable speed wind generator gear box.③Reliability evaluation of gear box transmission system is done. The main gear failure types are analyzed, the reliability of gear transmission system is got, and the reliability evaluation of gear system is done.④Dynamic model of gear transmission system is built. Considering the internal excitations such as the time-varying meshing stiffness, bearing stiffness and the meshing error, a dynamic model is built by using lumped-parameter method.⑤Dynamic characteristics of gear transmission system are studied. The vibration speed, displacement of gears and mesh force of each gear pair of the variable speed wind generator transmission system which is under the interaction of time-varying input torque and internal excitations are got by using Matlab, and the dynamic characteristics of gear transmission system under varying wind load are studied. The research results provide some references for design and analysis of the variable speed wind generator gear box.更多还原