Dielectric measurements on HTS insulation systems for electric power equipment

Since the development of flexible high temperature superconducting multifilament wires superconductive coils were constructed for the application in electric power equipment. The dielectric behaviour of conventional technology is well known, but this experience can only be partially applied to superconducting insulation systems. Some prototypes of cables, power and traction transformers and current limiters were built, but there is not sufficient knowledge about optimum dielectric structures and ageing. This paper gives a view to the criterions for liquid nitrogen as coolant and insulating medium of low temperature insulating systems for electric power equipment and shows the results of dielectric measurements tested with different structures