Analysis of three-phase surface-mounted magnet modular permanent magnet machines

This paper discusses the relative merits of feasible slot/pole number combinations for three-phase surface-mounted magnet modular permanent brushless machines, and presents an analytical method for establishing the open-circuit and armature reaction magnetic field distributions, which allow the prediction of the torque, the phase emf, and the self- and mutual winding inductances in closed forms. In turn, these provide a basis for comparative studies, design optimisation and machine dynamic modelling. Analytically predicted results are validated by comparison with finite element calculations.