Various New Magnet Arrangements Used in Dual-Stator Permanent-Magnet Vernier Machine for Large Telescope Drive

Various new magnet arrangements used in dual-stator permanent-magnet vernier machine (DSPMVM) are proposed that develop dual-excitation conditions on both sides of the machine’s airgaps (either stator-stator or stator-rotor) in order to increase the torque production by enhancing the airgap flux density in the inner and outer machine layers. The DSPMVM with sandwiched rotor combines features of the dual-stator and vernier structures. As a result, the proposed machine topologies are able to deliver high torque production by taking advantage of rich modulated harmonics. The topologies, operating principles, and the key design parameters of all the four DSPMVM configurations are presented. The electromagnetic performance of the proposed topologies including back electromotive force, airgap flux density, and torque characteristics are investigated and compared using 2D finite element analysis. The results show that the DSPMVM with flux-reversal magnets arrangement delivers high average torque with low cogging and ripple torque which are desired features for the telescope application.