Prediction of open-circuit airgap field distribution in brushless machines having an inset permanent magnet rotor topology

A 2-dimensional analytical model for predicting the open-circuit airgap field distribution in radial-field brushless machines having an inset permanent magnet rotor is developed. It accounts for flux focusing and inter-pole leakage effects and arbitrary pole-arc/pole-pitch ratios, and is also applicable to machines having a surface mounted magnet rotor. Predicted results are compared with finite element analyses, and are shown to be in good agreement.>