ELECTRICAL MOTOR WITH BULK Y-BA-CU-O PELLETS

The interaction between a magnetic field and a superconducting (SC) bu lk sample produces not only levitation forces but also transverse ones . They may be used in an electromagnetic coupling device to transmit a torque or in an electrical motor to produce a torque. We have designe d and built a disk type motor (vertical axial gap) with a static three phase armature resistive winding and a rotating part composed by eigh t YBaCuO pellets immersed in a liquid nitrogen vessel. The SC samples are melt textured using the Top Seed Melt Texturing method, The armatu re winding is fed by a power converter. Then the supplied frequency an d the speed of rotation are variable. The motor was tested in differen t conditions and operated without magnetizing the SC samples, It works in a way as a variable reluctance motor even if the hysteresis behavi our of the SC pellets complicates the operation, Other experiments wer e carried out magnetizing the SC samples before their use as inductor. The operation is close then to a permanent magnet motor. The experime ntal set up and the different tests are reported.