Five-phase interior permanent magnet motor with low torque pulsation

High torque pulsation is the major disadvantage of most IPM motor configurations. Choosing proper number of stator slots and winding distribution as well as increasing number of phases are among the possible solutions for reducing torque pulsation. In this paper, five-phase interior permanent magnet motor with fractional-slot stator is studied. It is shown that despite other IPM motors; the proposed five-phase IPM motor with fractional slot has a very low torque pulsation. For comparison purposes, a five-phase IPM motor with 20 stator slots which is a common configuration for four pole five-phase motors is also considered. It is shown that the torque pulsation of the proposed fractional-slot five-phase IPM motor is much lower than the five-phase IPM motor with 20 stator slots. Nonlinear finite element method is used to analyze different machine configuration. A prototype four pole, five-phase IPM motor with 15 stator slots has been built and is used for experimental verification.