What is the oil used for transformer cooling in power transformers?

The oil used for transformer cooling in power transformers is typically mineral oil or synthetic ester. This oil serves as both an insulator and a coolant, effectively dissipating heat generated during operation. The thermal conductivity and heat capacity of the oil are crucial for maintaining optimal operating temperatures, ensuring the reliability and longevity of the transformer. Additionally, the oil’s dielectric properties prevent electrical breakdown, enhancing safety and performance.