The epoxy resin samples were placed in thermal aging environments of 100

130

and 160 ℃ for aging test so as to research the aging characteristics of epoxy resin of dry-type transformer in high temperature environments.The thermal mass loss

AC breakdown voltage

and dielectric properties of samples were tested

and 3 parameters such as the mass loss

breakdown voltage and dielectric loss were analyzed under different aging time and temperature.The results show that

with aging time and temperature increasing

the mass loss rate

dielectric constant

and dielectric loss of samples will increase.With the increase of aging time

the breakdown voltage trends to increase-decrease-increase-decrease-increase

and its changing rate increases with the aging temperature.Under a high temperature environment

the molecular chain of the epoxy resin sample will break and oxidative decomposition occurr

thus the mass and breakdown voltage of aged samples will be reduced.And the increase of dipole concentration and polarization loss in aged samples will increase the dielectric constant and dielectric loss.In the increase process of dielectric loss tangent and mass loss rate

the breakdown voltage decreases rapidly

which provides an insulation status judgment basis of dry-type transformer by the non-destructive testing parameter

such as mass loss and dielectric loss.