The difference between dry-type transformers and oil immersed transformers

In the field of electrical engineering, transformers are important equipment used to adjust the magnitude of AC voltage. According to their different cooling and insulation methods, transformers are mainly divided into two types: dry-type transformers and oil immersed transformers. These two types of transformers each have their own characteristics and are suitable for different application scenarios. Below, we will provide a detailed introduction to the differences between dry-type transformers and oil immersed transformers in terms of structure, working principle, and application scenarios.

1、 Structural differences

Dry type transformer: Dry type transformer is mainly composed of iron core, winding, insulation material, and shell. Its winding is usually cast with epoxy resin or other polymer materials to form a solid insulator. The structure of dry-type transformers is relatively simple, with a small volume and relatively easy installation and maintenance.

Oil immersed transformer: The structure of oil immersed transformer is different from that of dry-type transformer. Its iron core and winding are immersed in transformer oil, using transformer oil as insulation and cooling medium. The casing of oil immersed transformers is usually made of welded steel plates, which have strong protective performance.

2、 Working principle

Dry type transformer: The working principle of dry-type transformer is basically the same as that of oil immersed transformer, both of which achieve voltage transformation through electromagnetic induction principle. When AC power is applied to the primary winding, the generated magnetic flux passes through the iron core, inducing a corresponding electromotive force in the secondary winding. During the process of transmitting electrical energy, the insulation material of dry-type transformers plays a crucial role in ensuring their normal operation.

Oil immersed transformer: The working principle of oil immersed transformer is similar to that of dry-type transformer, which also achieves voltage transformation through electromagnetic induction. However, due to the presence of transformer oil, oil immersed transformers have better performance in heat dissipation and insulation. Transformer oil has high insulation strength and good heat dissipation performance, which can effectively reduce the temperature rise of windings and improve the operating efficiency of transformers.

3、 Application scenarios

Dry type transformer: Dry type transformers are widely used in various indoor and outdoor environments due to their compact structure and easy maintenance. Especially in the fields of urban power grid, industry, transportation, and construction, dry-type transformers are favored due to their advantages of environmental protection, energy conservation, and safety. Dry type transformers also have good overload capacity and short-circuit withstand capacity, making them suitable for situations with high power demand.

Oil immersed transformer: Due to its strong heat dissipation performance and high insulation strength, oil immersed transformers are usually used in high voltage and large capacity applications such as large substations and power systems. Oil immersed transformers require regular inspection of the condition of the transformer oil during operation to ensure their normal functioning. Oil immersed transformers also have good overload capacity and short-circuit withstand capacity, which can meet the stable operation requirements of power systems.

4、 Summary

Dry type transformers and oil immersed transformers each have their own characteristics and are suitable for different application scenarios. Dry type transformers have a compact structure and are easy to maintain, suitable for indoor and outdoor environments; Oil immersed transformers have strong heat dissipation performance and high insulation strength, making them suitable for high voltage and large capacity applications such as large substations and power systems. When selecting transformers, it is necessary to comprehensively consider the actual needs and operating environment to ensure the stable operation of the power system.