The function of transformer oil is 1, and it has insulation function. Transformer oil is a kind of fluid, which can fill any space between components in the transformer and avoid the insulation degradation caused by the contact between components and air. Because the insulation strength of transformer oil is higher than that of air, it can maintain good insulation between windings, between windings and iron core, and between windings and oil tank shell, which increases the insulation strength of transformer.

2. During the heat dissipation operation, the heat generated by the loss in the iron core and winding makes the temperature of transformer oil rise, the volume expands, and it rises due to the decrease of its specific gravity. After being cooled by the cooling device, it enters the bottom of transformer oil tank to form oil circulation. The oil circulates to cool the winding and iron core, which improves the working conditions.

3. Arc extinguishing function. Transformer oil can not only play the above role, but also accelerate the arc extinguishing in transformer shell under special operating conditions.