Optimal design of Permanent Magnet Linear Motor for reducing cogging force

Reducing the thrust ripple is one of the important analysis and research contents of Permanent Magnet Linear Motor (PMLM). The thrust ripple was mainly caused by the cogging force and the end force. In this paper, in order to reduce cogging force in PMLM, the mechanism of cogging force was analyzed. And the analytical expression of the cogging force was got using energy method and Fourier expansion. Based on the expression, the effect of slot-poles number, pole-arc coefficient and slot-opening coefficient on cogging force is studied by using Ansoft. The optimized motor parameters of reducing cogging force have been listed. The results show that the optimized motor parameters make the cogging force improved. And the effect is very significant.