For prototype test and vibration source analysis on abnormal vibration of3# hydro generating set at Tianshengqiao first cascaded power station, it is useful to find out the vibration source by finite element computation for upper bracket.

• 对天生桥一级电厂3%23组上机架异常振动进行了真机实测及原因分析,得到的结果是:振动过大的主要原因是发电机转子质量不平衡,次要原因是机组轴线不直。