Vernier Machine Analysis and Analytical Design for Traction Applications

Surface permanent magnet machines gain more and more attention over recent years due to their high power density and high efficiency. This paper compares the Vernier machine and surface permanent magnet synchronous machine in electromagnetic structure, operating principle, and steady-state performances. FEA results are used to verify the analytical equations for comparing Vernier machine and SPM machine performance, with the exact dimensions, in terms of back-EMF, cogging torque, torque generation capability, and torque ripple. Moreover, the machine's back-EMF and torque performances regarding magnet thickness show that the Vernier machine utilizes magnets better than the surface PM machine.