Cogging torque and torque ripple analysis of permanent magnet flux-switching machine having two stators

The analysis of cogging torque, torque ripple and total harmonic distortion of a permanent magnet (PM) flux-switching machine having separate excitation stators is presented in this study. Further, the effect of unbalanced magnetic force (UMF) on the rotor of this machine is also investigated. A comparison of the analysed machine having different rotor pole configurations is also given. The analysis shows that the largest cogging torque, torque ripple as well as total harmonic distortion (THD) are obtained in the four-rotor-pole machine while the least of THD and torque ripple effects is seen in the thirteen-rotor-pole machine. Furthermore, the evaluation of the radial magnetic force of the machines having an odd number of rotor poles shows that the investigated machine having a five-rotor-pole number exhibits the highest value of UMF, while the smallest amount of UMF is obtained in an eleven-rotor-pole machine. Similarly, it is observed that the machines having an even number of rotor poles exhibit a negligible amount of UMF compared to the ones of the odd number of rotor poles.