Improvement of Torque Characteristics of An OuterRotor U-Shape Permanent Magnet Motor UsingRotor Structure Modification

Some affirmative traits of permanent magnetmotors including high torque density, high efficiency, and highreliability makes them attractive for various applications suchas robotics, electrical vehicles, machine tools and so on. Coggingtorque in these motors which causes output ripple, noise andvibration is an important challenge that should be addressed. Inthis article, an outer rotor U-shape permanent magnet motor isinvestigated and the proposed model with amendment of itsrotor structure by creating proper flux barriers on it isintroduced. Then the proposed model is optimized using Designof Experiment (DOE) to gain the best performance of it. Finally,the Finite Element Method (FEM) is used to calculate the torqueaccurately and make comparison between the proposed modeland previous works. The results show that the proposed modelhas lower cogging torque and torque ripple while the otheroutput parameters are in an acceptable range.

Keywords:

permanent magnet motor , cogging torque , torqueripple , flux barriers , optimization