The optimal shape design of claw-pole for PM stepping motor considering magnetic saturation and leakage flux

This paper presents the optimal design method for shape of claw-pole in a PM stepping motor. The shape design of claw-pole must consider a magnetic saturation and leakage flux. The best solution is 3-Dimensional FEM, but it needs too much computation time and computer resources. So, in this paper, numerical techniques applied to classical magnetic equivalent circuit method to consider the magnetic saturation and the leakage flux. Key points of this proposed method are B-H curve of material approximated by fitting function and iteration routine. To verify the proposed method, flux linkage calculated by this method was compared with the result of 3-Dimensional FEM.