The vibration mechanism and characteristics of stator housing in nuclear power turbo-generators under different excitation forces are investigated

and an analysis and treatment method for the stator housing vibration fault is proposed. Moreover

analysis and verification is conducted by using three nuclear power turbo-generator units as examples. The results show that

the main cause of excessive stator housing vibration is the structure resonance resulting from the natural frequency of the stator housing being close to the rotating frequency or its double. The structure resonance caused by rotor excitation force can be controlled in two ways: by reducing the excitation force through field dynamic balance

or by adjusting the natural frequency of the stator housing through adjustment of the stator bottom bracing load distribution. Performing on-site dynamic balancing can effectively reduce the rotor excitation force. Adjusting the natural frequency of the stator housing can be realized through load distribution adjustment of the stator feet. However

due to the limited adjustment range of the magnetic pulling force

it is necessary to control the structure resonance caused by magnetic pulling force by adjusting the natural frequency of the stator housing. To prevent structure resonance of the stator housing

it is important to adjust the stator bottom bracing load distribution during installation or maintenance of the turbo-generators to keep the natural frequency of the stator housing away from the rotating frequency and electromagnetic force frequency.