蒲石河抽水蓄能电站机墩结构刚度分析

Study on Stiffness of Generator Pedestals in Pushihe Pumped Storage Power Station

机墩结构是水轮发电机组的主要支承构件,其刚度对于机组的运行稳定性有重要的控制作用。以蒲石河抽水蓄能电站地下厂房为计算实例,建立包括机墩结构的厂房整体三维有限元模型,对机墩结构的静力刚度和动力刚度进行了复核。复核结果表明,机墩的水平静力刚度和动力刚度均满足设计要求。计算结果还表明,随着机组荷载频率的变化,机墩的动力刚度,动力刚度和静力刚度的大小关系,最大动位移(或最小动力刚度)出现的荷载组合均出现了变化,说明机墩的动力刚度与荷载频率密切相关,因此机墩动力刚度是十分必要的。

The generator pedestal is a main member supporting the hydraulic turbine generator unit, whose stiffness plays a decisive effect on the operation stability of hydroelectric sets. Taking Pushihe Pumped Storage Power Station for example, a three-di- mensional model of the whole hydropower house including the generator pedestal structure is created, and the static stiffness and dynamic stiffness of the generator pedestal are checked. The results indicate that both the static stiffness and dynamic stiffness of the generator pedestal structure could meet the design requirements. The results also show that the dynamic stiffness value, the relative relation between the static stiffness and dynamic stiffness and the load combinations inducing the maximum dynamic displacement （or the minimum dynamic stiffness） would vary with the load frequency without exception. It is proved that the dynamic stiffness of the generator pedestal is closely related to the load frequency, therefore the dynamic stiffness of the generator pedestal is necessary.