Dry type power transformer is a type of electrical equipment that does not use insulating oil. It is mainly used for high-rise buildings, power plants, commercial centers, and other places that require fire, explosion, and moisture protection through natural cooling or air cooling. Its iron core and winding have no oil insulation, and the shell is made of stainless steel, cold-rolled sheet or aluminum alloy, with flame retardant, explosion-proof, and no maintenance requirements.

The common structures of dry-type transformers include open type, closed type, and cast type, each suitable for different environmental conditions to meet diverse usage needs. The cast winding is made of epoxy resin or other resins to achieve the main insulation function; The closed winding is enclosed in a shell and is not directly connected to the outside atmosphere. This design is mainly used for mining equipment, as its sealing and heat dissipation conditions are relatively poor, but it has explosion-proof characteristics.