Dry-type power transformers are based on the principle of electromagnetic induction manufacturing electrical equipment, so have the ability to efficiently use the electromagnetic induction of the core and winding. Oil-immersed transformers are mainly composed of iron core, group, heat resistant tape, fuel tank and so on. Due to the difference in structure, the dry-type power transformer has no fuel tank, mainly composed of iron core, coil, insulation material and related accessories.
 At present, dry-type power transformers are mainly epoxy resin (including pouring and around the package). The early immersion type is changed from oil change, and the high voltage winding is usually the cake winding. Epoxy resin type dry type transformer adopts high-voltage winding and adopts the layer winding and pours. The low-voltage winding adopts spiral winding and pouring and box type Winding. The type of dry-type power transformers in the external structure of the larger differences, while the core structure is basically the same.