基于有限单元法的大型水轮发电机组自振特性研究

Research of self-oscillation characteristics of large hydroelectric machines based on finite element method

基于有限单元法,建立了考虑各种影响因素的大型水轮发电机组自振特性的计算模型,推导了用有限元法求解临界转速的计算公式.使用ANSYS和MATLAB等大型软件,对工程实例进行了计算,讨论了陀螺效应、不平衡磁拉力、导轴承刚度等因素对机组临界转速的影响及影响程度.计算结果的合理性,说明该计算模型和计算方法可用于水电机组的自振特性计算和振动设计,也可为其他转子动力学问题的研究提供参考.

Based on finite element method, a self-oscillation characteristics calculation model of large hydroelectric machines considering all kinds of affecting factors is established. The calculating formula of the critical speed is developed. Through using the large softwares ANSYS and MATLAB, an example is computed. The influences and influence degree of various factors such as gyroscopic effect, unbalanced electromagnetic forces, stiffness of bearings are discussed. The rational calculating results show that the model and the method is fit for vibration calculation and vibration design of hydroelectric machines, and that can be referenced to the research of other rotor systems.