Torque-speed characteristics of superconducting synchronous reluctance motors with DyBCO bulk in the rotor

Several kinds of superconducting motors have been proposed, Among them the superconducting synchronous reluctance motor (SCSynRM) is expected to develop. The maximum output characteristics of traditional synchronous reluctance motor are basically determined by the relation between the reluctances on d-q axes of the compound rotor. In the conventional synchronous reluctance motor, it is achieved by using the compound rotor of magnetic and nonmagnetic materials. In the SCSynRM nonmagnetic materials are replaced by DyBCO bulk, which possesses diamagnetic properties. Therefore its output characteristics will be improved. In this paper, toward the same stator, we made four types of rotors, which are a salient rotor, an aluminum rotor, a plastic rotor, and a DyBCO rotor. The stator has laminated iron core and three-phase copper windings in the twelve slots. Each rotor has 38 mm diameter and 35 mm axial length, in which the slot, the aluminum, the plastic, or the DyBCO occupies about 37% of total rotor volume. The torque-speed characteristics under the same condition were measured. Through comparison of four motors, the output characteristics of SCSynRM were discussed.