Impact Of Three-dimensional Static Air-Gap Eccentricity On Thermal Responses Of Stator Winding Insulation In Synchronous Generators

Synchronous generator is the key equipment of the power system.As the most common mechanical fault of the generator,the three-dimensional static air-gap eccentricity will cause vibration and temperature rise,reduce the operation efficiency.Hence,it is of great significance to carry out the research of the generator characteristics under the air gap eccentric fault.The paper takes the electrically excited synchronous generator as the research object under the radial static air-gap eccentricity,the axial static air-gap eccentricity and the hybrid static air-gap eccentricity.The main work and the achievements are as follows:(1)The electromagnetic characteristics of the generator are analyzed under the three air-gap eccentricity.And the loss model of the stator core and the winding are established under different eccentricity conditions.Further,the temperature rise of the core and the winding caused by the eccentricity is obtained.(2)The 3D finite element model of the stator-winding system is established by using ANSYS Electromagnetics under different eccentric conditions with CS-5synchronous generator as the analysis object.The temperature distribution of the stator core and the winding is obtained.The thermal wear responses of the stator winding insulation are studied under the unbalanced magnetic heat source of the external core and the heterogeneous electric heat source of the internal winding.(3)The temperature test of the stator core and the stator winding under different eccentricity categories and different eccentricity degrees.The experimental results are consistent with the theoretical analysis and the finite element numerical calculation;This paper obtains the thermal wear distribution rules of the armature winding insulation under the three-dimensional static air-gap static eccentricity.The three damage positions are provided.Further,the basic data and the scientific support are provided for the winding insulation damage prevention,the reverse design optimization and the manufacturing process improvement.