虚拟气隙在轴向磁通永磁电机三维有限元计算中的应用研究

Thanks to the complex structure of axial flux permanent magnet (AFPM) machine, 2 dimensional finite element analysis (2D FEA) is hard to be employed. 3D FEA is precise but very time-consuming. A virtual air gap was proposed and adopted in the 3D FEA of AFPM machines in this paper. The virtual air gap will be achieved by changing the length and relative permeability of the actual air gap. In this way, the length of air gap can be random selected and the mesh of air gap is flexible. The air-gap flux density and back electromotive force (EMF) of machines were calculated and compared to show the influence of virtual air gap and mesh setting. The results show that the adoption of virtual air gap can reduce the mesh elements and accelerate the solving process. Meanwhile, the accuracy of results can be guaranteed by the control of mesh setting. The adoption of virtual air gap gives new ideas of 3D FEA of AFPM machines.