Preliminary test results of radial-type sintered Sm-123 bulk motor

We designed and fabricated a radial-type motor with a high temperature superconducting bulk rotor. The fabricated motor has 3-phase and 4-pole armature winding, and then generates rotating magnetic field at the speed of 1800 rpm under the condition of 3-phase, 60 Hz electric power. Sintered Sm-123 bulk was utilized for the solid rotor in this study. The performance of the sintered Sm-123 bulk motor was evaluated by no-load, locked-rotor and load test. Test results showed that the motor generated a little torque and rotated with large slip, even if the motor was applied 165 V_rms of the phase voltage (the stator current is 18 A_rms). Because of small magneto-motive-force and spatial harmonic components in the air-gap, magnetic flux was prevented from penetrating into the HTS bulk rotor. Therefore, the screening current in the rotor flowed only at the surface of the rotor and generated torque is remained in a little value.