Hybrid-Excited Stator Slot Permanent Magnet Machines—Influence of Stator and Rotor Pole Combinations

The hybrid-excited stator slot permanent magnet (HSSPM) machines have good flux regulation capability due to the dc excitation. This makes them attractive candidates for variable speed applications. In this paper, the choices of stator/rotor pole combinations for an arbitrary number of armature phases are discussed. The three-phase 12-10/11/13/14 stator/rotor poles HSSPM machines with single- and double-layer windings are further investigated. Their open-circuit characteristics, torque, inductances, and unbalanced magnetic forces are comparatively studied using 2-D finite-element analysis (FEA). Finally, the 2-D FEA is experimentally validated.