A Complete Quasi-3-D Analytical Model of No-Load Magnetic Field of Double-Sided Slotted AFPMMs Considering End Effect

This paper presents a complete quasi-3-D analytical model combining the solution of Maxwell’s equations and the magnetic equivalent circuit for the determination of no-load magnetic field distributions of slotted axial flux permanent magnet machines (AFPMMs) considering the end effect without using 3-D finite element method (FEM). The effect of end effect on the air gap magnetic field distributions along the radial direction of AFPMMs is considered by introducing the end function. Moreover, based on the proposed analytical model, the method of adjusting the pole-arc ratio along the radial direction is adopted to solve the local saturation problem of the stator teeth at the inner radius when adopting the parallel slot structure. The relationship between the inner pole-arc ratio and the outer pole-arc ratio is obtained when the tooth flux densities are consistent along the radial direction. Finally, taking two AFPMM prototypes as examples, the analytical calculation results, 3-D FEM analyses and experiment results are compared to validate the accuracy of the analytical model.