Study to determine the potential use of silicone fluids in transformers

The family of silicone fluids, were surveyed to determine which fluids could be used in place of conventional hydrocarbon transformer fluids, and to study the effect of molecular structure and composition on the dielectric properties. Forty-one fluids were surveyed. Very few of the silicone fluids have dielectric strengths equal to transformer mineral oil or askarels at room temperature, although they can be operated at higher temperature. Some silicones are used in special applications, such as railway and precipitator transformers, but wide applications are unlikely. The most attractive silicones (except for cost) are methyl decyl polysiloxane, methyldodecyl siloxane, and methyldecylmethylethyl copolymer.