Thermal performance evaluation of an insulation system for cast resin power transformers

The thermal performance evaluation study is based on a proper thermal characterization of the PET (polyethylene terephthalate) film to be used as part of the insulation system. The film is tested in conditions similar to the ones present in the intended application and a meaningful set of data is obtained, which makes it possible to draw the relevant thermal life curves and to complete the analysis of the insulation system´s long-term behavior. The results obtained evince a higher thermal performance of the PET film than the ones reported in literature, because of the precautions introduced in segregating the film from air during the thermal agings and in avoiding the application of excessive mechanical stresses during the dielectric tests