In current years, using 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 work with oil-free gear. So as to meet the requirement of fire protection, oil-free energy transformers, namely dry variety transformers arises in the historic moment. Early on, the perform components of electrical switchgear manufacturer are exposed within the air. As a way to resolve the issue that moisture absorption will minimize the insulation amount of fibrous insulation, transformer winding really should be soaked in phenolic varnish and dry. To additional boost the insulation amount of oil immersed distribution transformerand resolve its thermal troubles through the operating method, we should boost the distance among layers and interturn as air flue. On occasion, an air blower can also be have to be installed to force convection air cooling heat dissipation. Nonetheless, when utilizing, also calls for that the transformer installation web-site should possess a beneficial hyperlink. If you wish to possess a ventilation program, to maintain the air relative humidity of not greater than 70% much less than 40 ??, atmosphere temperature, and so on. Early operate dry kind transformer to run a good deal of inconvenience, and limits the improvement of higher voltage massive capacity transformer solutions. At present, the air self-cooling of dry form transformer is only employed in voltage below 500 v grade, unique objective distribution transformers. Because the market place would be the want for disaster prevention kind transformer, inside the 1960 s Germany TU firm has created a form 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 on the disaster prevention capability is tremendously enhanced. Right after the item in the marketplace, user interest, was welcomed by the customers. Lots of nations on the planet also subsequently created or introduction of patent technologies production, variety epoxy resin casting dry-type transformer occupied nearly the entire with the dry kind transformer market place. In 1979 in China started to introduce epoxy resin casting dry-type transformer technologies, production of epoxy resin casting transformer.