Nonlinear Analytical Solution in Axial Flux Permanent Magnet Machines Using Scalar Potential

Analytical model (AM) has significant value in early design stage for electric machines, in terms of both time and accuracy. AM can be developed based on vector or scalar potential, but all AMs for armature reaction are using the vector potential, and it is a difficult matter to model armature reaction by scalar potential. This is the gap that the work here proposed aims to fill. We, for the first time, report the load magnetic field prediction by using magnetic scalar potential. Also, the proposed nonlinear AM is developed for the surface-mounted permanent magnet machine. The proposed model is developed based on the two-dimensional harmonic subdomain approach by solving Maxwell's equations. The magnetic sources, viz., the armature reaction are regarded as line current and solved at the connection boundaries. The comprehensive derivations and calculation algorithm are explained in detail. Moreover, the AM is developed for an axial flux permanent magnet (PM) machine, both finite element model and experiment are verified the correctness of proposed model, and good agreement is achieved. Moreover, a slight modification can also be applied to the radial flux PM machines.