Investigation of a novel hybrid radial and axial magnetic circuit permanent magnet motor with flux weakening capability for EVs

This paper investigates a novel hybrid axial- and radial-magnetic circuit permanent magnet synchronous machine with flux weakening capability. The presented machine consists of a solid rotor and two stators, i.e. radial stator and axial stator. The PMs are radially buried in the solid rotor so that the flux flows into both radial and axial stator. This paper describes the principle of the presented machine and designs a prototype machine. First, influence of some key structural parameters on flux control capability of this machine is investigation by using equivalent magnetic circuits. Then a 3-D FEM model is established for magnetic analysis. The results indicate that the presented machine exhibits higher power density and good capability for flux weakening thus can be a good candidate for PMSM with large scale of running speed.