Comparative study of a new structure of HTS-bulk axial flux-switching machine

A high-temperature superconducting (HTS) axial flux permanent magnet (AFPM) machine was designed, using superconducting bulks over the rotor surface and rare-earth magnets in the middle of the stator teeth. Because of diamagnetic behavior of the HTS bulks and zero field cooling, leakage flux significantly reduces in the proposed machine compared to the existing machine with mounting rare-earth magnets. Three-dimensional finite element (FE) modelling was used to validate the design performance. The magnetic flux distribution, induced electromotive force (EMF), inductance, PM flux, losses, total harmonic distribution and cogging torque are computed and compared in two structures. The results show that the proposed machine structure is more efficient than the existing one