DC and AC Current Transport Characteristics of the HTS Stator Coils in an HTS Induction/Synchronous Motor

We developed and characterized an especially designed stator for a 50 kW class high-temperature superconducting induction/synchronous motor (HTS-ISM). The so-called ring windings are introduced for the stator in order to increase the critical current in the iron slots. DC and ac current transport tests are carried out in liquid nitrogen (77 K). It is found that the stator can carry a large dc current and show adequately small ac loss at low frequencies. Our report shows the possibility of the further improvements of efficiency and torque density in fully HTS-ISM.