Development History Of Oil-immersed Transformers

Transformer oil is a petroleum-based liquid that has the potential to burn and has disadvantages in terms of environmental protection. However, due to the excellent performance and low price of transformer oil, the vast majority of power transformers still use transformer oil as the insulation and cooling medium.
At the end of the 19th century, transformers began to use transformer oil as the insulation and cooling medium, and oil-immersed transformers appeared. In addition to its abundant natural storage and low price, transformer oil has been widely used because of its following characteristics.
1) Used in conjunction with fiber materials, it has good insulation performance, can reduce the insulation distance and reduce costs.
2) Transformer oil has low viscosity and good heat transfer performance.
3) It can well protect the core and windings from the influence of moisture in the air.
4) Protect insulating paper and insulating cardboard from the effects of oxygen, reduce the aging of insulating materials, and extend the life of the transformer.
Except for some special-purpose small and medium-capacity transformers and gas transformers, the vast majority of large and medium-sized transformers still use transformer oil as a cooling and insulating medium.
The insulation heat resistance grade of a transformer impregnated with transformer oil is Class A, and the long-term operating temperature is 105°C.