变载荷激励下风电行星齿轮系统动力学特性

为了更准确地分析风电行星齿轮系统的动力学特性,在同时考虑风速变化和发电机电磁转矩变化引起的外部载荷激励,齿轮时变啮合刚度、轴承时变刚度以及行星齿轮啮合相位差等引起的内部激励的条件下,建立了风电行星齿轮系统的动力学模型。在此基础上,采用Runge-Kutta数值积分方法求解了某兆瓦级半直驱风电行星齿轮系统的动态响应,分析了上述激励对系统动态特性的影响规律。结果表明：外部变载荷的激励使系统的响应频率具有明显的低频成分,各构件的扭转振动位移与外部合力矩有相似的变化趋势;行星轮啮合相位差的激励使系统的结构频率成分增多且频率减小,增加了系统共振的可能性;轴承时变刚度使系统的高阶响应频率产生较大波动,增加了系统动态响应的复杂性。
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Dynamics Characteristic of Planetary Gear System of Wind Turbines under Varying Load

A dynamics model of the planetary gear system of a wind turbine under varying load was established in order to analyse the dynamics characteristic of the planetary gear system more accurately. The external load excitations caused by varying wind speed and the varying electromagnetic torque,as well as the internal excitations caused by time-varying mesh stiffness,the meshing phase of the planetary gear pairs and time-vary stiffness of rolling element bearing were considered in the model. On the basis of that, the Runge-Kutta numerical method was used to solve the dynamics model of planetary gear system of a MW wind turbine with multibrid technology,and the influences of the above proposed excitations on the dynamics characteristics of the system were analyzed. The results show that there are distinct lower-frequency components in system response frequencies and the torsion vibration displacements of each component have similar varying tendency as the external total moment. Influenced by planet gears meshing phase, the amount of structure frequencies increases and their values decrease in the system,therefore the possibility of resonance of system is increased. The dynamic responses become very complicated because of the time-varying stiffness of the rolling element bearing. 