Reducing Cogging Torque in Surface-mounted Permanent Magnet Motors by Teeth Notching

Based on the analytical formulation for cogging torque derived in this paper, the effects of stator teeth notching on cogging torque are studied. When the method of teeth notching is adopted, the most important is to decide how many notches are needed. When k notches are adopted on one stator tooth, only Fourier coefficients G_n(n is the multiple of k+1) are not zero, and the value of these G_n increases by k+1 times. In order to reduce cogging torque effectively, the G_k+1 should have no effect on the cogging torque. At the end, the method is validated by finite element method.