Abstract
Dry-type transformers are quite popular in commercial and industrial applications. The IEEE and IEC standards on dry-type transformer loading provide a significant guideline and recommendation for transformer aging rate calculation. In this study, the fundamental information in these standards are used to develop a real-time dry-type transformer thermal model and evaluate transformer insulation performance in different conditions. Thermal model of the transformer can help to determine proper transformer operation condition, transformer aging rate, and approximately demonstrate transformer lifespan. Simulation studies show that increasing of transformer load and ambient temperature sampling frequency rates will lead to the increase of the accuracy of aging rate calculation and more precise lifespan estimation.