Experimental study of passive cooling techniques in an oil-immersed transformer building

Transformer is a critical component of electrical power systems, and its failure can disrupt the power supply. Additionally, the high investment cost of transformers emphasizes the importance of maintenance and improved service life. The transformer losses cause increased temperature in various parts of the equipment, particularly in the hot-spot temperature, which leads to insulation aging and decreases the service life of the transformer. This study investigates passive cooling techniques for an oil-immersed transformer by experimenting with four methods: shield (T-shield), photovoltaic panel canopy and cooling fan (T-PV/Fan), two heat pipes (T-Heat Pipe) and nanofluid (T-Nano Fluid) in a laboratory transformer with a 1750-W power. The bulk and hot-spot temperature of the oil tank are compared, and the results demonstrate that all techniques improve thermal management and expand the service life of the transformer. The photovoltaic panel and cooling fan (T-PV/Fan) have the highest effect and are expected to prolong the existing system's lifespan up to 48 years based on the IEC 60076 standard.