Application occasions and advantages and disadvantages of dry-type transformers and oil-immersed transformers

Dry-type transformers are widely used in local lighting, high-rise buildings, airports, terminals, CNC machinery and other places. Simply speaking, dry-type transformers are transformers whose cores and windings are not immersed in insulating oil.

The oil-immersed transformer adopts a full oil-filled sealed type. The corrugated oil tank housing is a permanently sealed oil tank with its elasticity to accommodate the expansion of oil. Oil-immersed transformers have been widely used in various power distribution equipment.

1 Appearance

Different package types, dry-type transformers can directly see the iron core and coils, while oil-type transformers can only see the transformer shell.

2. Different lead forms

Different dry-type transformers mostly use silicone rubber sleeves, while oil-type transformers mostly use porcelain sleeves.

3. Different capacity and voltage

Dry-type transformers are generally used for power distribution. The capacity is mostly below 1600KVA, and the voltage is below 10K. Some can also achieve 35KV voltage level, while oil-type transformers can achieve the full capacity from small to large, and the voltage level also achieves all voltages. The ultra-high voltage 1000KV test circuit under construction in China is generally an oil-type transformer.

4. Applicable places

Dry-type transformers are mostly used in places that require “fire and explosion-proof”, and are generally easy to adopt on large buildings and high-rise buildings. Oil-type transformers are likely to be used outdoors because of oil spray or leakage due to “incidents”, and There are places for digging “accident oil pools”.

5. Insulation and heat dissipation are not the same

Dry-type transformers are generally insulated with resin, relying on natural air cooling, large-capacity cooling by fans, and oil-type transformers are insulated by insulating oil, and the circulation of the insulating oil inside the transformer transfers the tropical heat generated by the coils to the heat sink of the transformer for heat dissipation .

6. different cost

For transformers of the same capacity, the purchase price of dry-type transformers is much higher than the price of oil-type transformers. Models of dry-type transformers generally start with SC, epoxy cast-encapsulated, SCR non-epoxy cast solid insulation-encapsulated, and SG open-type. Different dry-type transformers mostly use silicone rubber sleeves, while oil-type transformers mostly use Porcelain casing.

7.Different load carrying capacity

Generally dry-type transformers should run at rated capacity, while oil-type transformers have better overload capacity.

8. In terms of price, dry change becomes more expensive than oil. In terms of capacity, oil with large capacity becomes more than dry.

It is necessary to use dry transformers in complex buildings (basements, floors, roofs, etc.) and in densely populated areas. The oil transformer is used in an independent transformer substation. The transformer inside the box transformer is generally dry transformer, and the outdoor transformer is usually used for temporary power. Choose dry and oil changes according to the space during construction. Choose oil changes when the space is large, and dry changes when the space is crowded.


Post time: Jun-06-2019