Influence of pole ratio and winding pole numbers on the performances and optimal parameters of the surface permanent magnet vernier machines

Vernier machine is becoming a new generation of direct drive motor due to its feature of high torque at low speed based on the so-called “magnetic gear effect”. This paper investigates the winding pole number and the pole ratio defined as rotor pole number/winding pole number of the surface permanent magnet vernier machines (SPMVM) for performances of torque, power factor, etc. The variation of design parameters with pole ratio and winding pole number, such as split ratio, slot opening and permanent magnet thickness, while SPMVM reaches maximum torque are also analyzed based on the finite element analysis (FEA) tools. Some simulation results will be experimentally validated by prototypes being manufactured in the future.