中文摘要：

针对三峡地下电站中各种结构的封闭母线的固有频率进行了计算。对于垂直段母线，建立了单自由度的振动模型，并直接地求出其固有频率；对于水平面地段母线的固有频率的计算，建立了一个多自由度的振动模型，并利用Lagrange方程进行了求解；而对于空间的复杂结构的母线固有频率的计算，则采用有限单元法，并利用了ANSYS的有限元软件进行计算处理。计算表明根据不同母线结构采用不同的方法可以使母线满足工程设计的要求。

英文摘要：

The free frequency of the closed busbar used in Three Gorges Underground Power Station is calculated. For the only vertically laid busbar wire, the simple freedom vibration model is established and its free frequency can be calculated directly. For the horizontally laid busbar wire, the many freedom vibration model is established and the free frequency is calculated by Lagrange formula. For the complicated spacial structural busbar , it is an effectual method to calculate the free frequency by the finite element. The finite element model for these busbar wire is established and the free frequency and the viabrlat.