Design and analysis of dual-stator hybrid brushless vernier motor for direct-drive applications

This paper introduces a new dual stator hybrid brushless vernier motor. The rotor is of hybrid nature i.e. it has windings as well as the magnets. To make it brushless for the rotor winding, an already developed brushless technique is employed. Two different configurations for placement of magnets are discussed, interior permanent magnet (IPM) and surface permanent magnet (SPM). Hence, the topologies under investigation are dual stator hybrid interior permanent magnet vernier motor (DSH-IPMVM) and dual stator hybrid surface permanent magnet vernier motor (DSH-SPMVM) intended for direct drive applications. The inner stator contains two windings (Main three-phase "ABC" winding and an additional single phase "X" winding) while the outer stator contains only three phase "ABC" winding. The rotor has two sides; the inner side of the rotor has windings placed on it while the outer side has PMs (either interior or surface mounted). The inclusion of both brushless windings and PMs allow for hybrid configuration which helps to increase the overall torque of the machine. Simulation results in ANSYS Maxwell demonstrate that the DSH-SPMVM achieves a superior average torque of 44.19 Nm at low speed (524 rpm), while the DSH-IPMVM offers a 31.58 Nm torque output with a significant reduction in torque ripple, achieving nearly 89% less ripple at high speeds (1200 rpm). Both models maintain high efficiency levels above 90% under rated conditions. To validate and compare the models, both designs are analyzed using computer simulations in ANSYS Maxwell.