The Difference Between Dry-type Transformer And Oil-immersed Transformer

The difference between Dry Type Transformer and oil-immersed transformers is mainly reflected in the structure, working principle, cooling method, application occasions, advantages and disadvantages.

‌Structural differences‌:

Dry-type transformer: It is mainly composed of iron core, winding, insulation material and shell. The winding is usually cast with epoxy resin or other polymer materials to form a solid solid insulator. 1. Its structure is relatively simple and small in size.
Oil-immersed transformer: The iron core and winding are immersed in transformer oil, and transformer oil is used as insulation and cooling medium. The shell is usually welded with steel plates and has strong protective performance.
‌Working principle‌:

Both realize voltage conversion through the principle of electromagnetic induction. When the primary winding is passed with alternating current, the magnetic flux generated passes through the iron core, thereby inducing the corresponding electromotive force in the secondary winding.
When the dry-type transformer is working, the heat is naturally dissipated through the air.
Oil-immersed transformers are cooled by the heat dissipation of insulating oil. The oil not only has good insulation properties, but also has strong thermal conductivity, which can help quickly remove the heat generated inside the transformer.
‌Cooling method‌:

Dry-type transformers: Mainly rely on the circulation of natural air to achieve cooling, or use fans, coolers and other equipment to enhance air flow. This method is relatively simple, but the heat dissipation capacity is limited.
Oil-immersed transformers: Indirect heat dissipation through the combination of insulating oil and coolers can withstand higher loads and maintain a relatively stable temperature.
‌Application occasions‌:

Dry-type transformers: Due to their compact structure, easy maintenance, environmental protection, energy saving, safety and other advantages, they are widely used in various environments such as indoors and outdoors, especially in urban power grids, industry, transportation, construction and other fields. It is also suitable for application scenarios that require cleanliness, pollution-free and easy maintenance.
Oil-immersed transformers: Due to their strong heat dissipation performance and high insulation strength, they are usually used in high-voltage and large-capacity occasions such as large substations and power systems. It is also suitable for high-power, high-voltage, high-temperature and high-insulation performance requirements.
‌Advantages and Disadvantages‌:

Dry-type transformer:
Advantages: No fire risk caused by leakage, safer; oil-free, environmentally friendly and easy to handle; lightweight, small size, suitable for places with limited indoor space; easy maintenance and easy to clean‌.
Disadvantages: Relatively poor heat dissipation performance, easy to overheat; high manufacturing cost; high operating noise‌.
Oil-immersed transformer:
Advantages: Excellent insulation and heat dissipation performance; low manufacturing cost; strong short-circuit resistance; long service life‌.
Disadvantages: It is necessary to check the oil level, oil quality, oil temperature, etc. regularly, and the machine needs to be shut down for processing if problems are found; high maintenance cost; during use, it is significantly affected by pollution and is prone to oil leakage and leakage‌.
In summary, dry-type transformers and oil-immersed transformers have significant differences in structure, working principle, cooling method, application occasions, advantages and disadvantages. Which type of transformer to choose depends on the specific application requirements and working environment.