Evaluations on AC electrical characteristics of no-insulation coil for power devices

This paper deals with the ac electrical characteristics of high temperature superconducting pancake coils without turn-to-turn insulation (no-insulation coils). Several research groups have done studies of the electrical characteristics of no-insulation coils. However, most of the studies have been done with respect to the dc electrical characteristics, and studies with respect to the ac electrical characteristics are rare. In this paper, we evaluated the ac electrical characteristics, such as the fault current, recovery time, and ac loss of the no-insulation coil. The results can be expected to suggest useful data for the application of no-insulation coils in the area of power devices.