Fractional-slot concentrated-winding (FSCW) consequent pole (CP) permanent magnet vernier (PMV) machines have received increasing attention due to their less magnet consumption but larger torque capability. However, the permanent magnet (PM) magnetomotive force (MMF) distribution is asymmetric in the CP structure. Thus, even-order air-gap flux density and back-electromotive force (back EMF) harmonics are generated, which increases torque ripples. In this article, to eliminate the even-order back EMF harmonics and the resulting torque ripples, a comprehensive investigation on even-order flux density and back EMF harmonics of five-phase FSCW CP PMV machines was presented, and then the general design rules without even-order back EMF harmonics were summarized. First, considering single-layer (SL) and double-layer (DL) windings, the effects of slot/pole number combination and flux modulator (FL) distribution on even-order flux density and back EMF harmonics were analyzed. Second, the optimal slot/pole number combinations were selected, and then the rules for eliminating even-order back EMF harmonics of CP PMV machines were summarized. As an extension, it was revealed that the harmonic elimination mechanism of CP PMV machines is applicable to CP-Halbach PMV machines. According to the summarized general design rules, the five-phase CP and CP-Halbach PMV machines with $S= 20/P_{r}= 21/z_{f}= 10$ were proposed. Their detailed performance has been comparatively analyzed and then the optimal one was selected for prototyping. Both finite element analysis (FEA) and experiments were carried out to validate theoretical analyses.
Analysis and Comparison of Even-Order Back EMF Harmonics of Fractional-Slot Concentrated-Winding Consequent Pole Permanent Magnet Vernier Machines
IEEE Transactions on Transportation Electrification ; 10 , 1 ; 1969-1981
01.03.2024
3698923 byte
Aufsatz (Zeitschrift)
Elektronische Ressource
Englisch