Quantitative Comparison of Dual Permanent Magnet Vernier Machines with Uniform and non-Uniform Permeance

This paper presents and compares two dual-permanent-magnet-excited vernier (DPMEV) machines with uniform and non-uniform permeance. The non-uniform permeance DPMEV machine is newly proposed for a fair comparison with the uniform one. Firstly, through the study of the back EMF, it is proved that the non-uniform permeable structure has a potential advantage in terms of torque. Then, by analyzing and optimizing the parameters of the tooth structure, the motor can achieve optimal performance. Furthermore, with the exploring permeability and conducting a harmonic comparison analysis, the rationale behind the torque increase in the non-uniform permeance machine is elucidated. Finally, the prototypes of DPMEV machine with uniform and non-uniform permeance are manufactured and tested to verify the effectiveness of the analytical results.