Preliminary Analysis of Core Losses and Performance of an Axial Flux Motor with High Temperature Superconducting Tapes on the Rotor

This work presents a novel electric motor with a rotor built by high-temperature superconducting (HTS) tapes. The motor is of axial flux (disc) type, in a double stator topology integrating conventional (copper) coils. The motor has as many coils as slots in the stator, and each is controlled independently. Due to this topology, the number of poles of the stator can be electronically changed, by adjusting the phase shifts of the voltages in each coil of the stator. A commutator was thus developed to vary the configuration of the poles of the motor and to evaluate its performance. Since HTS materials trap magnetic flux, one of the research questions of the work is to assess the viability of dynamically changing the poles configuration trapped in the rotor, i.e., under operation. The obtained results show that the HTS motor can have its polar formation reconfigured during operation without the need for the HTS material to transition to the normal state, losing superconductivity and the flux trapping ability. Experimental and numerical simulation results are presented in the paper, to demonstrate the viability of the proposed concept. Experimental tests allowed measuring electromagnetic quantities and collecting motor operating data in different configurations of poles. The stator losses were calculated in two different configurations using the finite element method.