A new vibration suppression method for a fractional-slot distributed winding permanent magnet synchronous machine (FSDW-PMSM) is proposed by considering the influence of the radial force modulation effect on FSDW-PMSMs. First, the vibration source of the FSDW-PMSMs is analyzed, and the principle of radial force modulation is revealed. Afterwards, the radial force distribution characteristics are studied, and the radial force component that contributes to the dominant vibration is identified. The PM flux density harmonics in the air gap are suppressed using the harmonic injection method to reduce vibrations. Additionally, dual three-phase techniques are used to enhance the fundamental armature flux density, thereby improving torque capability. Consequently, the vibration performance of the FSDW-PMSM is improved without sacrificing the torque. Finally, the proposed method is validated through simulations and experiments.

This study examines the impact of circulating currents on copper loss in alternating current systems and introduces a method to reduce these losses. Initially, a circuit model for the winding is developed to analyze the magnetic leakage field in the stator slot. Subsequently, an equivalent model based on this magnetic leakage field is constructed to assess the magnetic linkage of the strand as the conductor’s position within the slot varies. Comparisons of circulating currents in two different winding configurations are presented. Based on these analyses, a specific winding arrangement designed to reduce circulating current losses is proposed. The effectiveness of this design is then corroborated through experimental validation.

In a dual three-phase open-winding permanent magnet synchronous motor (DTP-OW-PMSM) system sharing a common DC bus, dual zero-sequence current (ZSC) loops are inherent, leading to increased inverter capacity usage, losses, and degraded operational performance. To mitigate ZSC, the dual zero-sequence equivalent circuit of the DTP-OW-PMSM system is established, and zero-vector combinations with significant zero-sequence voltage amplitudes are employed. Since the two sets of ZSC loops are independent, four zero-vector combinations can be determined. A ZSC suppression strategy utilizing hysteresis controllers is proposed. Compared with the PI controller, hysteresis controllers offer wider bandwidth and simplify control parameter tuning. Additionally, 180-degree decoupling streamlines vector selection for multiphase open-winding topologies. Furthermore, the modulation range of the proposed strategy is investigated. Finally, experiment in a direct-drive motor is implemented, and experimental results confirming its effectiveness.

Inverter-fed Permanent Magnet Synchronous Machines (PMSMs) are subject to substantial current harmonic excitations, which critically affect their electromagnetic vibration and noise characteristics. The accurate modeling and efficient computation of these effects have emerged as key research focuses in recent years. While the conventional finite element method offers high precision, its complex implementation procedures and substantial computational costs limit its applicability, particularly during the early stages of motor development where rapid iteration is essential. Consequently, there is a pressing need for modeling and computational approaches that can achieve favorable balance between accuracy and efficiency in the analysis of electromagnetic vibration and noise in inverter-fed PMSMs. To address this issue, this paper presents a comprehensive review of the state-of-the-art modeling and computational techniques for electromagnetic vibration and noise analysis in inverter-fed PMSMs. The review systematically examines key factors such as current harmonic types, electromagnetic force generation, structural modal behavior, vibration responses, and radiated noise. For each aspect, the underlying principles, methodological strengths and weaknesses, and recent research advances are summarized. Finally, future research directions are discussed to highlight opportunities for further theoretical development and practical application in the field.

This study investigates the negative influence of an eccentric permanent-magnet (PM) design on high-frequency electromagnetic vibration in fractional-slot concentrated-winding (FSCW) PM machines. First, an analytical expression for the sideband current harmonics was derived using the double Fourier series expansion method. Then, the characteristics of the flux-density harmonics are studied from the perspective of the space-time distribution and initial phase relationship. The influence of the eccentric PM design on high-frequency electromagnetic and concentrated forces was studied based on the electromagnetic force modulation effect. Consequently, an eccentric PM design is not conducive to reducing the 2p^th-order high-frequency electromagnetic forces. Finally, two FSCW PM machines with conventional and eccentric PM designs are manufactured and tested to verify the theoretical analysis. The results show that the eccentric PM design worsens high-frequency vibrations.

This study aimed to improve the vibration and torque of an integral-slot surface-mounted permanent magnet (SPM) machine by optimizing the shape of the harmonically injected permanent magnet (PM). First, the effect of the third harmonic injected into the sinusoidal PM shape on the electromagnetic performance of a 36-slot/12-pole SPM machine was investigated, including the torque performance and vibration response. It was found that the Sin+3rd harmonic-shaped PM had a contrary effect on the torque and vibration performance of the integral-slot machine, which improved the torque capability but worsened the vibration performance. Second, the response surface model and Barebones multi-objective particle swarm optimization algorithm based on a trade-off between the average torque and vibration were implemented to determine the optimal harmonic injection. Subsequently, the performances of the optimal Sin+3rd-shaped and eccentric PM machines were compared, showing the excellent torque and vibration performance of the adopted method. Finally, a prototype was manufactured and tested to verify the results of the theoretical analysis.

A novel dual-side primary permanent-magnet vernier linear (DS-PPMVL) motors is proposed. The novelty of the proposed motors is the design of asymmetric consequent poles on the mover, which can effectively enforce the flux-modulation effect and improve the thrust force performance. First, the topologies and operation principle are introduced. Subsequently, the structure relationships between the existing and proposed motors are discussed. Then, a unified analytical model is built. Accordingly, the magnetic field generated by the consequent pole is calculated. Meanwhile, the performance improvement mechanism with the asymmetric consequent pole is analyzed. To improve the efficiency of motor optimization, multi-objective optimization method is adopted to obtain the global optimal solution combination of structure parameters. The proposed motors exhibit higher thrust force, higher force density, less PM consumption, and better overload performance than the existing DS-PPMVL motor. Finally, experiments are conducted based on the existing prototype to verify the accuracy of the design and analysis.