Exact analytical method for magnetic field computation and cogging torque of SPM motors

This paper presents an exact analytical method to computer the air-gap magnetic field of SPM motors for being evaluated slotting effects accurately. The Laplace equations or Poisson equations of the sub-domains are contacted by boundary conditions, and then solved by exact analytical method. The actual height of slot and distance between slots are taken into account in the computation. Magnetic field distributions and cogging torque computed with the proposed analytical method are compared with those issued from two-dimensional finite-element method(FEM), the comparison results are consistent and show the correctness and effectiveness of the proposed analytical method.