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.

This paper investigates the possibilities for developing a pole-changing winding with a pole ratio of 3:4 with improved electromagnetic properties. Such a winding can be used in two-speed induction motors for turbo mechanisms. The scheme of the new winding was obtained by using a discretely-specified spatial function method developed at the Tashkent State Technical University. A comparison of the parameters obtained for a similar winding received by the pole amplitude modulation method has been presented. Design of a new motor with a new winding is developed based on the standard induction motor. The paper presents results of laboratory tests, too.