STUDY ON AGING CHARACTERISTICS OF STATOR INSULATION IN GENERATOR

Accelerated aging test to the epoxy/mica insulation of stator bars in generator is presented in this paper. The parameters of non destructive testing, such as dielectric loss factor, capacity and the voltage at which the charging current increases abruptly, are measured in the different aging stage. The destructive limit, namely residual breakdown voltage (BDV), is determined through the breakdown test. Finally the correlation factors between these non-destructive parameters and destructive parameter are analyzed, which is used to estimate aging characteristics of epoxy/mica stator insulation in generator.