1 Electrical Machines, The Faculty of Engineering and Science, Aalborg University, VBN2 Department of Energy Technology, The Faculty of Engineering and Science, Aalborg University, VBN3 The Faculty of Engineering and Science, Aalborg University, VBN4 Institute of Electrical and Information Engineering, Hunan University, Changsha, 410082
In this paper, an effective cogging torque reduction method based on shifting the slot-openings is presented. Stator teeth are divided into groups and proper slot-opening shift is applied for each group. The cogging torque can then be greatly reduced while the back-EMF waveforms remain symmetrical. No additional back-EMF harmonic components will be introduced by this method. Analytical analysis revealing the working principle of this method is given, which gives a clear guide about how this method may be applied to different permanent magnet machines.
I E E E Transactions on Magnetics, 2013, Vol 49, Issue 7, p. 4028-4031