Electric vehicle traction based on a PM assisted synchronous reluctance motor

Abstract

It is recently demonstrated that the synchronous reluctance motor is well suited for electric as well as for hybrid electric vehicles. Of course, a proper rotor design is necessary, since the main torque is due to the rotor anisotropy, that is, the permeance difference between the direct- and the quadrature-axis. The flux barrier ends are placed so as to reduce the torque ripple due to the slot harmonics. The torque ripple is also reduced adopting rotor asymmetries. The impact of the rotor design on the motor performance is presented deeply, showing several experimental test results carried out on synchronous reluctance motors with different rotor geometries. Permanent magnet can be inset in the flux barriers to assist the synchronous reluctance motor improving its capabilities. The main advantages and drawbacks of the permanent magnet adoption are highlighted.