Dry-type transformer (foreign language name: dry-type transformer) refers to the transformer whose iron core and winding are not impregnated in insulating oil, [1] widely used in local lighting, high-rise buildings, airports, wharves CNC machinery equipment, etc. Dry type transformer is mainly divided into open type, closed type, pouring type three forms. The cooling methods are divided into natural air cooling (AN) and forced air cooling (AF). Dry transformer safety, fire prevention, no pollution, high mechanical strength, strong short-circuit resistance, small partial discharge, good thermal stability, high reliability, long service life