Analysis of Stator Vibration Characteristics in Synchronous Generators Considering Inclined Static Air Gap Eccentricity

Abstract

This paper mainly focuses on the impact of inclined static air gap eccentricity (ISAGE) on the electromagnetic characteristics and mechanical performances (vibration, deformation, strain and stress). Considering different ISAGE fault types in the theoretical and finite element analysis (FEA) model of synchronous generators, the effects of intersection position of the rotor center axis and stator center axis, rotor inclined angle, and the combination of the previous two fault types on MFD, phase current and radial magnetic pulling per unit area (MPPUA) are analyzed and compared. Then, based on the stator model used uniformly in three physical fields, the harmonic response and mechanical response are investigated with loads imported by the electromagnetic field. Finally, the stator radial vibration measurement experiments are carried out to verify the results obtained by theoretical analysis and FEA. It is shown that ISAGE will considerably enlarge the fluctuation of MPPUA and intensify the radial vibration of the stator, especially at the 2nd harmonic. The probability of failure at tooth tip and inner slot wall of the stator will increase.

Keywords

• Synchronous generator
• inclined static air gap eccentricity
• magnetic pulling force per unit area
• stator vibration