Comparison of Thermal Aging in Distribution Transformers of Tropical Regions Based on Insulation and Cooling Systems

In areas with high ambient temperatures and intense solar radiation, the hot-spot temperature of distribution transformer windings may exceed permissible limits, accelerating insulation degradation and reducing transformer lifespan. Transformers specifically designed for tropical regions, with enhanced heat transfer capabilities and reduced temperature rise, along with thermally upgraded paper-insulated transformers, offer promising solutions for lifespan extension in hot climates. This paper utilizes the IEC thermal model to estimate and compare the lifespan of standard Kraft paper-insulated transformers, tropical-design transformers, and thermally upgraded paper transformers under variable loading and realistic ambient temperature conditions. To enhance accuracy, the model incorporates The impact of sunlight and wind on transformer temperature.