Nine-phase interior permanent magnet motor for electric vehicle drive

Interior permanent magnet motors have desirable characteristics for electric vehicle drive like high efficiency, wide speed range for flux weakening, relative ease for sensorless control as rotor position information can be obtained from saliency and the possibility of reluctance torque usage in the field weakening range. This paper presents a model and analysis of a nine-phase IPM motor for electric vehicle application. It demonstrates the high torque capability of the IPM motor using controlled third, fifth and seventh harmonic currents and possibility of controlling an n-pole IPM motor as a 6n-pole, 10n-pole or 14n-pole machine which is desirable for low speed range sensorless control.