Dielectric and Mechanical Response of Cold-Curing Epoxy Resin to Hygrothermal Stress

The electrical insulation system plays a pivotal role in the design and operation of electric machines. It is important and it might be crucial to describe the material aging process and subsequently monitor the acting ambient degradation factors as these systems are always exposed to these factors to some extent. Epoxy resin is a typical material used in the electrical insulating systems of rotating electrical machines at various voltage and power ratings. Therefore, epoxy resin is the investigated material in this study. This paper aims to describe the aging process and the material response to the harsh experiment setup of multifactor hygrothermal stress. The results in this study report a decline in all investigated parameters of the specimens including both the dielectric and mechanical properties. It appears that mechanical properties are slightly more suitable for the aging process description even after longer expositions and near-completed saturation. Collected data are further discussed in this study.