Oil immersed transformer
Transformer oil is a petroleum liquid, which has the possibility of combustion and has disadvantages in environmental protection. However, because transformer oil has the characteristics of excellent performance and low price, most power transformers still use transformer oil as insulation and cooling medium.
At the end of the 19th century, transformers began to use transformer oil as insulation and cooling medium, and oil immersed transformers appeared. In addition to rich natural storage and low price, transformer oil has been widely used because of its following characteristics.
1) When used with fiber materials, it has good insulation performance, which can reduce insulation distance and cost.
2) Transformer oil has low viscosity and good heat transfer performance.
3) It can well protect the iron core and winding from the influence of moisture in the air.
4) Protect insulating paper and insulating paperboard from oxygen, reduce the aging of insulating materials and prolong the service life of transformer.
Except for some small and medium capacity transformers and gas transformers for special purposes, most large and medium-sized transformers still use transformer oil as cooling and insulation medium.
For transformers impregnated with transformer oil, the insulation heat resistance grade is class A, and the long-term working temperature is 105 ℃.