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In current engineering, the skewing slots approach is commonly used for permanent magnet synchronous motor (PMSM) to reduce torque ripple and electromagnetic vibration. However, this approach may limit the axial length of the motor and increase the manufacturing cost. This article studies a segmented rotor with different pole widths approach to mitigate torque ripple and electromagnetic vibration for PMSM, which has a lower implementation cost and facilitates mechanized production. The mapping relationship between geometric dimensions and torque performance is obtained, and the optimal dimensions are determined. An 8-pole/48-slot V-shaped PMSM is taken as the original motor, and the influence of engineering error on the torque performance of the presented approach is discussed. The electromagnetic performances and vibration responses of the motor with the presented approach are compared with that of the skewing slot motor to verify the effectiveness of the presented approach. Finally, prototypes are built, and intensive experimental tests are carried out to verify the analysis and comparison. [ABSTRACT FROM AUTHOR]

In this article, an increasing interest for permanent magnet synchronous machines with low torque ripple and low vibration is observed. The purpose of this article is to investigate the topology of nonuniformly distributed teeth and its influence on cogging torque, tooth ripple harmonics, and torque ripple of permanent magnet synchronous machines. The topologies with different numbers of nonuniformly distributed teeth are investigated. Analytical procedure is developed to illustrate the impacts of nonuniformly distributed teeth on cogging torque and unbalanced magnetic pull, and then identify the appropriate nonuniformly distributed teeth. A commercial 10 kW 8-pole 48-slot V-shaped interior permanent magnet (IPM) machine is taken as the reference base machine. The machines with two and six nonuniformly distributed teeth are chosen to make an overall comparison with the well-known skewing slots. The machine with two nonuniformly distributed teeth is finally chosen to be fabricated. Intensive experiments, including cogging torque, back electromotive force, load current, efficiency, and instantaneous torque, are done. [ABSTRACT FROM AUTHOR]

This article presents a new rotor configuration for V-shaped interior permanent magnet machine to reduce torque ripple and electromagnetic vibration. The proposed rotor structure consists of two segments staggered mechanically 180°. In each segment, the intersection angle between two magnets of one V-shaped pole is different to the others, resulting in a different pole arc to pole pitch ratio. The dimensions and total volumes of magnets keep unchanged. Benefitting from the two opposing segments, unbalanced magnetic pull can be offset. Machine performances in terms of back-EMF, d-&q-axis inductance, radial and axial force and instantaneous torque ripple are intensively compared and evaluated to the conventional machine with skewing slots, which is often used in mass production. Comprehensive models using coupled multiphysic fields are established and the comparative study of electromagnetic vibration aspects are done. Two machines, i.e., the proposed machine and the conventional machine with slot skewing are prototyped. Extensive experiments are carried out and compared in terms of back-EMF, current, modal frequency, static average torque, instantaneous torque, and efficiency. [ABSTRACT FROM AUTHOR]