Properties of impregnated superconducting coils made from YBCO coated conductor using different technology of impregnation.

Superconducting coils are very important components in various applications like e.g. superconducting magnets, superconducting magnetic energy storage systems (SMES), superconducting fault current limiters, transformers, motors and generators. There is a strong worldwide effort to use the high temperature superconductors in these applications. The aim of the authors' work is to build a self-contained coil without coil frame by resin impregnation. In addition, impregnation is necessary for conduction-cooled systems. In this article, they present the properties of three superconducting coils made from YBCO coated conductor. These coils have identical inner diameter and number of turns while the thicknesses of windings are slightly different. Their inner diameter is 60 mm and they have 10 turns. The coils were impregnated using different resins and technologies of impregnation. Coils were characterized in the liquid nitrogen bath and their parameters like the critical currents, E(I) characteristics, inductances and AC losses at frequencies 36, 72 and 144 Hz were compared. In conclusion, none of the impregnation techniques disqualifies the coils for AC applications. However, for one impregnation method the coil is not rigid.