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 airga p field distribution in radial-field brushless machines having an inse t permanent magnet rotor is developed. It accounts for flux focusing a nd inter-pole leakage effects and arbitrary pole-arc/pole-pitch ratios , and is also applicable to machines having a surface mounted magnet r otor. Predicted results are compared with finite element analyses, and are shown to be in good agreement.