Research on Thermal Aging Characteristics of Dry-type Transformer Epoxy Resin Based on Dielectric Response and Activation Energy

Since dry-type transformer failure caused by aging of insulating materials has not been fundamentally contained, it is necessary to explore more accurate aging detection techniques and evaluation methods. Activation energy, as an intrinsic characteristic parameter of insulation, can be used to evaluate the deterioration process. It is significance to study the dielectric properties and activation energy variation of insulation materials for the accurate analysis of the aging and state evaluation of the dry-type transformer insulation system . In this paper, the epoxy resin is subjected to accelerated heat aging test at three temperatures. The mass loss and frequency-domain dielectric are periodically tested, and the time of the epoxy reaching the aging failure state is confirmed by the existing mass loss rate standard. Then we calculate the activation energy of the epoxy resin samples in different states We establishe the relationship between the activation energy and the aging time, and the activation energy value of the epoxy resin insulation failure time is established., and analyze the influence of temperature and aging degree on the activation energy . Based on the temperature acceleration factor AFT proposed by Arrhenius, the aging time under laboratory conditions is equivalently converted to the actual transformer running time to achieve life prediction of dry-type transformer.