Performances analysis of interior permanent magnet motors having different rotor iron pole shapes

Abstract

Interior permanent magnet motors (IPMMs) have been increasing in popularity, since the emergence of permanent magnet material with high energy products, i.e. rare earth permanent magnet material. This paper analyses the performances of IPMMs having different rotor iron pole shapes including eccentric, sinusoidal and sinusoidal with 3th order harmonic injected rotor pole arc shapes IPMMs. Cogging torque, static torque, torque ripple, torque-speed and power-speed curves of the mentioned motors have been compared. It must be noted that the mentioned motors have been designed with the same stator, PM shape and the same dimensions, in order to highlight the effect of the rotor pole arc shape on the performance of the such motors. Two-dimensional (2D) finite element analysis (FEA) has been utilized to design and analyze the mentioned machines. It has been found that rotor iron pole shape of the IPM has notably influence on the machine performance, practically on output electromagnetic torque and its ripple. The highest value of average electromagnetic torque as well as torque capability in the constant torque reign is delivered by 3th order harmonic injected rotor pole arc shapes machine, while the lowest torque ripple is obtained by the sinusoidal rotor pole arc machine.