Effects of Rotor Skew Angle on Flux Switching Permanent Magnet (FSPM) Machines Characteristics

Abstract

Not only does rotor skewing as a cost-effective technique reduce the cogging torque, but also it affects machines performance too. Hence, this paper studies the torque, back-EMF and loss characteristic of a Flux Switching Permanent Magnet (FSPM) machine with rotor skewing. The cogging torque, torque profile, induced EMF and iron core losses of a 10/12 FSPM machine with various degrees of rotor skewing are calculated and compared using three dimensional finite element analysis. First and foremost, the results have shown that the torque oscillation is totally eliminated when skew angle is equal to 6 degrees. In addition, the peak value of both output torque and back-EMF does not change significantly, and they reduce at most 5%. Finally, the influences of rotor skewing on the iron core losses are carried out using Bertotti formula and it is discovered that by increasing the skew angle, core losses almost do not vary.