In order to improve the efficiency of dynamic balance and reduce the number of startup

pre-balancing method of shaft system for turbo-generator unit was proposed.Based on the history and characteristics of the unit vibration

shis method pre-evaluated the influence of factors such as maintenance and installation

on the vibration condition of shaft system

and pre-weighed the shaft system before the unit starting.Validation of the pre-balancing method of shaft system was done on a 600 MW unit.Results show that

this method is applicable to the dynamic balance of vibration with critical speed

to the balance compensation of bended rotor

and to the elimination of unbalance mass caused by fracture repair of turbine blade or shroud ring.