1200 MW级汽轮发电机定子绕组端部模态分析

Modal Analysis of the 1200 MW Turbo-generator Stator End Windings

以1 200 MW汽轮发电机定子绕组端部为研究对象,利用有限元方法计算其模态。采用正交各向异性材料建立复合材料大锥环模型,基于接触静力学分析确定定位支架与锥环之间的等效刚度,利用优化分析方法建立线棒-胶体结构的均匀化等效模型。综合各部件形成整体结构模型,完成模态分析计算并结合实验模态分析验证有限元模型。给出1阶模态频率对材料参数和几何参数的灵敏度,明确影响汽轮发电机定子端部模态的关键因素,为定子端部的结构设计提供指导意见。

Modal analysis of the 1 200 MW turbo-generator stator end windings are performed by finite element method. The composite conical ring structure of the stator is made up of orthotropic material. The equivalent stiffness between the positioning bracket and the conical ring is obtained based on the statics contact analysis. Later on, the homogenization equivalent model of the bar-colloid structure is established by optimization analysis method. The whole finite element model is formed by integrating all the components and its modal simulation result is verified by experimental modal analysis. The sensitivity of the first-order modal frequency to the material parameters and geometric parameters is provided. The key factors that influence the modals of the stator end of the turbo-generator are clearly defined, which provides guidance for the design of the stator end windings.