Influence of stator/rotor-pole combination on electromagnetic performance in all/alternate poles wound partitioned stator doubly salient permanent magnet machines
In this study, the influence of stator/rotor-pole combinations on electromagnetic performance in partitioned stator doubly salient permanent magnet (PS-DSPM) machines is investigated, in terms of open-circuit flux-linkage, back-electromotive force (EMF), cogging torque and on-load torque characteristics. Analytical deduction shows that by modifying the all poles wound winding to alternate poles wound winding in the 12/11- and 12/13 stator/rotor-pole PS-DSPM machines, the fundamental distribution factor and hence the fundamental winding factor can be enhanced, resulting higher torque density. Consequently, among the 12-stator-pole all and alternate poles wound PS-DSPM machines, the 10- and 11-rotor-pole machines exhibit the highest torque density, respectively. However, the 12/10- and 12/14-pole alternate poles wound PS-DSPM machines suffer from higher phase back-EMF even harmonics, resulting larger torque ripple. The 12/10- and 12/11-pole all and alternate poles wound prototypes are built and tested to verify the finite-element analysis.