Cogging torque and operation torque ripple reduction of interior permanent magnet synchronous machines by using asymmetric flux-barriers

This paper presents three configurations of flux-barriers in a V-shaped interior permanent magnet synchronous machine (PMSM) to reduce cogging torque and operation torque ripple. While maintaining the average electromagnetic torque, torque performances in dual rotation directions are analyzed with finite element method (FEM), showing that one of the configurations can achieve good performance in dual rotation directions while the other two are suitable for one rotation direction only. Furthermore, frozen permeability method (FPM) is employed to compare the influence on PM torque and reluctance torque, and comes to a conclusion that two configurations have little impact on the reluctance torque while the other can enhance the reluctance torque slightly.