Pulsating torque analysis & reduction methods on a sine-wave PM machine

In order to decrease the magnitude of cogging torque and torque ripple in a specific sine-wave PM machine to meet a certain demand, in this paper, the mechanisms of cogging torque and torque ripple is illustrated. Furthmore, study on the relationship between pole / slot combination and pulsating torque, optimum design of the major structure may influence torque pulsating, e.g. pole arc, tooth width, etc., and discussion on specially designed structures e.g. dummy teeth with different width and depth for minimizing pulsating torque are also investigated. On this basis, a 3-D prototype model is built to fit the requirement, which valid the conclusions from the pulsating torque reduction methods, cogging torque especially, analysis above.