The change of microstructure of epoxy mica insulation in multi-stress aging

Author

Jia, Z.D. ; Xie, H.K.

Author_Institution

Tsinghua Univ., Beijing, China

fYear

2001

fDate

2001

Firstpage

693

Lastpage

696

Abstract

The epoxy mica insulation system has been in service as the main insulation of large generator since 1960s. The real stator bars of an 18 kV/300 MW generator are used for accelerated multi-stress aging experiments to investigate their changes of microstructure of epoxy mica insulation. The stator insulation of a large generator is a composition system composed of epoxy resin, mica and glassfiber. A study on interface of the composite is significant for overall comprehension of its properties. A scanning electronic microscope is used to observe the pattern of interface during the aging process, and it is brought up that change in interface is the main reason of aging. The variation of components in insulation is also analyzed by the technique of infrared spectrum and X-ray energy spectrum. The results of experiment show that the epoxy resin causes hydrolytic reaction, the mica undergoes structural change

Keywords

X-ray spectroscopy; ageing; composite insulating materials; crystal microstructure; electric generators; epoxy insulation; infrared spectroscopy; insulation testing; machine insulation; mica; scanning electron microscopy; 18 kV; 300 MW; X-ray energy spectrum; epoxy mica insulation; generator; glassfiber; hydrolytic reaction; infrared spectrum; interface pattern; microstructure change; multi-stress aging; scanning electronic microscope; stator bars; stator insulation; structural change; Aging; Conducting materials; Epoxy resins; Insulation; Microstructure; Scanning electron microscopy; Stator bars; Testing; Thermal degradation; Thermal stresses;

fLanguage

English

Publisher

ieee

Conference_Titel

Electrical Insulating Materials, 2001. (ISEIM 2001). Proceedings of 2001 International Symposium on

Conference_Location

Himeji

Print_ISBN

4-88686-053-2

Type

conf

DOI

10.1109/ISEIM.2001.973772

Filename

973772