中文摘要：

长期以来，水轮发电机组的激烈振动现象严重影响电站的正常安全稳定工作。在高水头、大流量水流和强电磁场的共同作用下，其规律十分神秘，是一个至今仍未彻底解决的难题。文中以混流式水轮发电机组主轴系统为研究对象，首先根据发电机、水轮机主轴和水轮机转轮的特点，分别建立发电机单元、水轮机主轴单元和水轮机转轮单元，然后在发电机单元、水轮机主轴单元和水轮机转轮单元的基础上，应用有限单元法建立混流式水轮发电机组主轴系统的非线性全局耦合动力学方程。所建方程较好地体现该系统动态性能与其水力参数、电磁参数和结构参数之间的实际关系，表达以往方程未能反映的动态性能，为进一步深入研究混流式水轮发电机组主轴系统的动力学特性与系统的水力参数、电磁参数和结构参数之间的内在联系奠定基础。

英文摘要：

For a long time, the severe vibration phenomenon of hydraulic turbine-generator units occurs frequently, which strongly affects the normal, safe and stable work of hydropower station. Under the combination action of high head, high flow rate and strong electromagnetic field, the vibration law of Francis turbine-generator units is quite mysterious, which hasn＇t been thoroughly discovered. Taking the main shaft system of a hydraulic turbine-generator unit as object, based on the characters of generator, turbine shaft and turbine nmner, generator element, turbine shaft element and turbine nmner element are established, then the nonlinear global coupling dynamic equations of the main shaft system by using finite element method is established. The coupling dynamic equations reflect the real relationship between the dynamic characteristics of system with fluid parameters, structural parameters and electromagnetic parameters, which is the base of further study of the relationship between the dynamic characteristics of the main shaft system of hydraulic turbine-generator units with fluid parameters, structural parameters and electromagnetic parameters.