A High Force Density HTS Tubular Vernier Machine

In this paper, a high force density, high-temperature superconductor dual-stator tubular Vernier machine (HTS-DSTVM) has been proposed for wave energy extraction. The machine adopts dual-stator configuration with spoke-type permanent magnets on the translator. The inner stator does not have any winding, and HTS bulks are placed between the adjacent flux modulation teeth of the inner stator to decrease the leakage flux and improve the force density. The HTS bulks effectively shield the leakage flux of the proposed HTS-DSTVM to improve the force density and power factor. 2-D finite-element method results validate that the proposed HTS-DSTVM yields a higher thrust force density per magnet volume and higher power factor compared with the recently presented flat dual-stator spoke-type linear Vernier machine due to the leakage flux shielding effect of HTS bulks.