Analysis On Mechanical Properties Of Stator And Stator Windings Of Generator Under Three-dimensional Air Gap Eccentricity

Static air gap eccentricity is one of the common faults of generators.In severe cases,it will cause great harm to the normal operation of generators.This paper mainly studies the mechanical properties of the stator and the stator windings under normal condition,radial static air gap eccentricity(RSAGE)and axial static air gap eccentricity(ARAGE)by the research method combining theoretical analysis,simulation calculation and analysis and experimental verification,and explore the change law in the mechanical properties of the stator and the stator windings before and after RSAGE and ASAGE.Firstly,the detail formulas of the air gap magnetic flux density under normal condition,RSAGE and ASAGE are theoretically derived.Based on this,the expression of the magnetic pull per unit area(MPPUA)of the stator is obtained using Maxwell’s law.The expression of the axial unbalanced magnetic pull(AUMP)of the stator is obtained by using conductive paper model method.The expression of the electromagnetic force(EMF)of the stator windings is obtained by using the law of electromagnetic induction and Ohm’s law.The change law in the stator force and the stator windings force before and after RSAGE and ASAGE is qualitatively analyzed.Then taking CS-5 generator as the simulation object,finite element simulation calculation is carried out.The frequence components and the amplitude of each frequence component of the stator force and the stator windings force under normal condition,RSAGE and ASAGE are obtained.The change law in stator force and the stator windings force before and after RSAGE and ASAGE is quantitatively analyzed.Finally,the CS-5 generator is used as the analysis object for response analysis.The finite element analysis is performed on the stator and the stator windings.The mechanical responses of the stator and the stator windings under normal condition,RSAGE and ASAGE are obtained.The change law of the mechanical responses of the stator and the stator windings before and after RAGEA and ASAGE is analyzed.Then the vibration responses of the stator and the stator windings under normal condition,RSAGE and ASAGE are obtained.The change law of the vibration responses of the stator and the stator windings before and after RAGEA and ASAGE is analyzed.Through theoretical analysis,simulation calculation and analysis and experimental verification,the trends of the change are basically consistent.The results of the paper provide a theoretical reference and basis for the preventive insulation manufacturing of stator windings in actual production,and lay a certain foundation for the monitoring and diagnosis of three-dimensional hybrid static air gap eccentricity.