What is the composition of transformer oil?

Transformer oil composition primarily consists of mineral oil, which is derived from refining crude oil and is characterized by its high dielectric strength and stability at elevated temperatures. It includes aliphatic hydrocarbons, aromatic hydrocarbons, and various additives such as anti-oxidants, corrosion inhibitors, and foam suppressants to enhance performance and longevity. In some cases, synthetic esters might also be used for improved environmental properties. Overall, the transformer oil’s composition is carefully engineered to ensure effective insulation and cooling in electrical transformers, minimizing the risk of electrical breakdown.