In current years, using the improvement of ciry building, energy transformers which can be installed in buildings, railways, airports and also other places which have higher needs for fire protection call for to utilize oil-free gear. In an effort to meet the requirement of fire protection, oil-free energy transformers, namely dry kind transformers arises in the historic moment. Early on, the function components of dry form transformers 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 should really be soaked in phenolic varnish and dry. To additional strengthen the insulation degree of power transformersand resolve its thermal matters through the operating approach, we ought to boost the distance among layers and interturn as air flue. On occasion, an air blower can also be should be installed to force convection air cooling heat dissipation. Yet, when working with, also demands that the transformer installation web page will have to possess a decent hyperlink. In order to possess a ventilation method, to maintain the air relative humidity of not greater than 70% significantly less than 40 ??, atmosphere temperature, and so on. Early perform dry kind transformer to run a good deal of inconvenience, and limits the improvement of higher voltage sizeable capacity transformer merchandise. At present, the air self-cooling of dry kind transformer is only utilised in voltage below 500 v grade, particular objective low voltage transformer. Because the marketplace will be the have to have for disaster prevention kind transformer, inside the 1960 s Germany TU provider 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 capacity is significantly improved. Following the item available on the market, user interest, was welcomed by the customers. Countless nations on the planet also subsequently created or introduction of patent technologies production, variety epoxy resin casting dry-type transformer occupied virtually the entire on the dry sort transformer industry. In 1979 in China started to introduce epoxy resin casting dry-type transformer technologies, production of epoxy resin casting transformer.