In current years, together with the improvement of ciry building, energy transformers which might be installed in buildings, railways, airports as well as other areas which have higher needs for fire protection demand to utilize oil-free gear. So that you can meet the requirement of fire protection, oil-free energy transformers, namely dry form transformers arises in the historic moment. Early on, the perform components of distribution transformers are exposed within the air. As a way to resolve the issue that moisture absorption will lower the insulation amount of fibrous insulation, transformer winding should really be soaked in phenolic varnish and dry. To additional enhance the insulation degree of combined transformer and resolve its thermal difficulties throughout the operating procedure, we should boost the distance among layers and interturn as air flue. On occasion, an air blower can also be ought to be installed to force convection air cooling heat dissipation. But, when utilizing, also needs that the transformer installation web-site will have to possess a decent hyperlink. In order to possess a ventilation program, to help keep the air relative humidity of not greater than 70% significantly less than 40 ??, atmosphere temperature, and so forth. Early operate dry variety transformer to run a whole lot of inconvenience, and limits the improvement of higher voltage sizeable capacity transformer items. At present, the air self-cooling of dry form transformer is only put to use in voltage below 500 v grade, unique goal dry type transformer manufacturer. Because the industry would be the want for disaster prevention sort transformer, within the 1960 s Germany TU organization has created a type of steel wire, higher and low voltage winding of glass fiber-reinforced epoxy resin casting dry-type transformer. Epoxy resin includes a flame retardant and self-extinguishing characteristic, make the transformer from the disaster prevention capability is tremendously enhanced. Immediately after the solution available on the market, user interest, was welcomed by the customers. Several nations on the planet also subsequently created or introduction of patent technologies production, kind epoxy resin casting dry-type transformer occupied practically the entire from the dry form transformer industry. In 1979 in China started to introduce epoxy resin casting dry-type transformer technologies, production of epoxy resin casting transformer.