What is the chemical composition of transformer mineral oil used in power transformers?

The chemical composition of transformer mineral oil used in power transformers primarily consists of aliphatic and aromatic hydrocarbons. These hydrocarbons are derived from the distillation of crude oil and typically include saturated and unsaturated compounds. The oil is refined to remove impurities and enhance its dielectric properties, ensuring it effectively insulates and cools the transformer while maintaining stability under high temperatures and electrical stress.