Analysis method and application of rotor dynamic balance test for large hydropower units

The spindle runout of unit 2 in a hydropower plant seriously exceeded the standard during the startup test, and its main frequency was consistent with the conversion frequency, which did not meet the startup test acceptance specification. Through the analysis of the variable speed test data of the unit, it is judged that the reason for the excessive runout is the mass imbalance of the generator rotor, which affects the vibration of the shafting and the frame. A dynamic balance test analysis method is proposed to determine the counterweight weight and orientation, which is the same centrifugal force with the equivalent in the state. In this method, the weight of the trial counterweight and the total unbalanced mass is calculated by using the trial counterweight empirical formula and dynamic balance equation respectively, and the second counterweight test is carried out after calculation. Through the application in unit 2 of the power plant, the serious problem of excessive runout of the unit can be completely solved. The analysis method of the rotor dynamic unbalance test for large hydropower units proposed in this paper can provide a technical reference for similar problems.