Analysis and Design of New Composite HTS Magnet With Active Magnetic Shield

The magnetic field modulated superconducting (SC) machines (FMSCMs) with advantages of stationary seal of coolant and brushless current transmission have become a research hotpot in the field of superconducting electrical machine. However, the complex airgap magnetic field in the FMSCM greatly affects the current-carrying capacity and AC losses of the HTS coils, further affecting the electromagnetic performance of the FMSCM. As a result, it is necessary to take measures to suppress the effect of the airgap magnetic field on the HTS coil. To overcome the problem faced by the FMSCM, a new composite HTS magnet with active magnetic shield is proposed and designed in this paper for a kind of distributed HTS armature winding permanent magnet machine (DHTSAW-PMM) belonging to FMSCM. In this paper, the topology of DHTSAW-PMM and the composite HTS magnet are illustrated in detail and their electromagnetic performances are comprehensively analyzed. The results show that the proposed composite HTS magnet can effectively suppress the effect of the complex airgap magnetic field on the HTS coil in the DHTSAW-PMM.