Investigation of the ambient temperature effects on transformer's insulation life.

The insulation hot spot temperature (HST) represents the most important limiting factor of a transformer insulation life. Ambient temperature involved in the HST computations in all transformer thermal models affects insulation life-time directly or indirectly. Regarding the importance of the ambient temperature in transformer's insulation life, in this paper a new thermal model for the estimation of HST in transformers has been proposed and using this thermal model, the effect of the ambient temperature on HST and transformer insulation life is investigated. The proposed model has been validated using real data gathered from a 180 MVA transformer. [ABSTRACT FROM AUTHOR]