Design, Fabrication, and Experiment of Proto-Type Miniature Cylindrical Bulk YBCO Induction Motor for Cryogen Pump

The conceptual design, prototype fabrication, and experimental evaluation of a pipe-integrated cryogenic pump motor using a bulk YBCO superconductor in the rotor were conducted. An induction -type topology was adopted, utilizing a commercial copper-wound stator. The cylindrical bulk YBCO, mounted as the rotor, was designed under the assumption of liquid nitrogen flowing through a pipeline, allowing for direct cooling of the rotor. A locked-rotor experiment was performed on the fabricated prototype in a liquid nitrogen bath, and the equivalent critical current density was calculated through the finite element method (FEM) analysis based on the measured voltage and current data. Using the fitted parameters, the torque and output power characteristics of the motor were calculated, and the motor had approximately 50 W of output power under the given operating conditions.