Insulation systems for liquid filled transformers

Liquid dielectrics have been successfully used for many years for the major insulation system impregnate for transformer applications above 10–25 KV operating levels. Extensive use of liquid insulants is based primarily on their ability to satisfy the prime design requirements of low cost, long service life with a minimum of maintenance, good dielectric, thermal properties and compatibility with other materials. Not all insulating fluids meet these individual requirements to the same degree, therefore, the selection of a particular liquid solid system should represent the best compromise in these desired properties.