Study on the Insulation Aging Performance of Dry-Type Bushing Resin-Impregnated Paper Capacitor Cores

The main insulation component of dry-type bushings' capacitor cores is constructed from crepe paper impregnated with epoxy resin under high temperatures. During actual operation, thermal stresses can degrade the performance of epoxy insulation materials, and the resulting aging issues have become a significant factor affecting the stable operation of electrical equipment. To elucidate the impact of thermal aging on the epoxy resin in impregnated paper bushings, this study employs a sample preparation platform and thermal aging experimental setup to obtain epoxy resin and epoxy-impregnated paper specimens. Thermal aging experiments are conducted, with periodic assessments of mass loss and infrared spectroscopy of the aged samples. Results indicate that specimens experience rapid mass loss over 24-48 hours, while mass loss increases linearly from 48 to 288 hours. Infrared spectroscopy results reveal that the functional groups on the surface of the epoxy insulation material undergo corresponding changes, leading to significant alterations in the peak values of the absorption spectra.