The vibration characteristic indicators reflecting operation status of steam turbines can be applied to monitor and evaluate the current vibration state of the steam turbine.Generally

more than one characteristic indicator are needed to completely reflect the vibration status of steam turbine from different aspects.However

it is difficult to evaluate the steam turbine's vibration status directly by multiple indicators.To solve this problem

a comprehensive evaluation function was established

on the basis of principal component analysis.The turbine's vibration state was evaluated by comprehensive scores

and the results were verified by experimental data from rotor test rig.The results show this method can evaluate the steam turbines' vibration state quantitatively on the premise of a smaller amount of information loss.