Analysis On Rotor's Multi Direction Force Under Different Air Gap Eccentric Faults Of Generator

In this thesis,taking the SDF-9 type non-salient pole synchronous fault simulating generator as researched object,the unbalanced magnetic pull(UMP)characteristics of rotor in different directions(include radial,axial and circumferential)caused by the radial static air-gap eccentricity(SAGE),the axial static air-gap eccentricity(AAGE),the radial dynamic air-gap eccentricity(DAGE)and the radial mixed air-gap eccentricity(MAGE)in the generator are researched.The main achievements obtained in the thesis can be drawn up as follows.(1)The formulas of the radial UMP under the normal condition,the SAGE fault,the DAGE fault and the MAGE fault are deduced.The formulas of the axial UMP and the electromagnetic torque(EMT)under the AAGE fault are also deduced.Then the relationship between the key characteristic component of UMP and the different types of air-gap eccentricity is obtained(2)The physical solving model and coupling circuit model for the normal condition and four different types of eccentricity fault of the SDF-9 type fault simulating generator is built in Ansoft Maxwell,the time domain waveform and spectrum of the UMP under different operating conditions are calculated.(3)The radial vibration characteristics cause by the radial UMP under the normal condition and the SAGE fault is verified by the experiment results of the SDF-9 type non-salient pole synchronous fault simulating generator(7.5k W).In addition,the axial UMP data under the AAGE fault of a five pairs pole generator(1600k W)in South Korea Hanyang University and the stator current spectrum data under the DAGE fault of a brushless DC motor(1.5k W)in South Korea Ulsan University are used to verify the theory.The experiment results agree well with the theoretical analysis and the FEA results.(4)Taking the double times rotating frequency as the key characteristic component of SAGE and the fundamental rotating frequency as the key characteristic component of DAGE to distinguish between various types of SAGE and DAGE separately,and the sensitivity of different types of air-gap eccentricity fault to the UMP is obtained.The study in this thesis provides a theoretical reference and application basis for improving the diagnostic accuracy of the SAGE fault,the DAGE fault and the MAGE fault in the generator.