A feasibility study and experiments on a cryoresistive transformer cooled at -150 degree c with fluorocarbon

The feasibility of a new type cryoresistive transformer, which is operated at -150°C and has a higher efficiency and some weight and size merits compared to the conventional oil cooled transformer, is examined. This transformer has a new cooling system in which the latent heat of evaporation of L.N.G. is used instead of a refrigerator. In addition, because of the low operating temperature, some new materials which are not commonly used in oil cooled transformer, such as liquid fluorocarbon 12 and a composite paper made of a non-woven cloth and apolyethylene film, are adopted. A 1200 KVA experimental transformer wsa built and from the experimental results, it may be concluded that this new type cryoresistive transformer can be used as a power transformer.