Design of an Improved Dual-Stator Ferrite Magnet Vernier Machine to Replace an Industrial Rare-Earth IPM Machine

This paper develops an improved dual-stator Vernier machine using ferrite magnet materials, aiming to replace an industrial interior permanent magnet machine with rare earth magnets in a low speed industrial application. The improved Vernier machine design adapts the single winding dual-stator topology with an empty inner stator core mainly to improve the torque density and eliminate the heat from the inner stator windings of conventional dual-stator Vernier machines. A drum rotor is also proposed to provide mechanical and structural enhancements. This paper compares the performance of the improved Vernier machine design against an industrial interior permanent magnet machine with rare earth magnets. The comparison shows that the improved design using ferrite magnets has even higher torque density and efficiency than those exhibited in the industrial interior permanent magnet machine with rare earth magnets. The improved Vernier machine design has considerable potential to replace industrial rare earth interior permanent magnet machines in low speed applications.