Comparison and evaluation of different compound-structure permanent-magnet synchronous machine used for HEVs

A compound-structure permanent-magnet synchronous machine (CS-PMSM) is a hybrid electric vehicle (HEV) power train concept to realize both the torque and speed control of the internal combustion engine (ICE). It is integrated by two permanent-magnet synchronous machines. Different topologies of the CS-PMSM are proposed. The characteristics of different CS-PMSMs are compared and evaluated from the aspects of magnetic coupling, design features and so on. Prototypes of radial-radial flux CS-PMSM and axial-axial flux CS-PMSM were designed and manufactured for the concept validation. The optimization methods of the two prototypes are compared. The performances of the two topologies are evaluated by experiments.