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This paper shows the influence of the shift phase angle ψ between phase currents and back-electromotive forces on magnetic radial forces and torque ripple for a specific low power permanent magnet synchronous machine. This influence is firstly demonstrated through analytical development considering only the first harmonic values. Then, magnetic pressure harmonics versus space and frequency as well as torque ripple are evaluated on the studied motor for different angles using finite element approach. The aim is to establish a good compromise between consumed current, torque and radial force harmonics at the origin of the electromagnetic noise. Experimental measurements with a sensorless field-oriented control are detailed.

Purpose This paper deals with the study of the influence of the phase shift between currents and back-electromotive forces (back-EMF) on torque ripple and radial magnetic forces for a low power synchronous machine supplied with 120 degrees square-wave currents. This paper aims to establish a good compromise between efficiency, harmonics of torque and harmonics of radial forces at the origin of the electromagnetic noise. Design/methodology/approach Based on a finite element approach, torque and magnetic pressure harmonics versus space and frequency are evaluated for different angle values. The evolutions of the different harmonics against the load angle are analyzed and compared to those of experimental measurements. Findings Depending on the load torque, field-weakening or field-boosting can be used to reduce current harmonics contributing the most to the radial magnetic forces responsible for the noise. Besides, a compromise can be found to avoid deteriorating too much the performances of the machine, thus being suitable with an industrial application. Research limitations/implications This study concerns low power permanent magnet synchronous machines with concentrated windings and driven with a trapezoidal control, while having sinusoidal back-EMF. Originality/value The use of a simple mean and suitable with a large-scale manufacturing industry to reduce the identified electromagnetic-borne noise of a specific electric drive makes the originality.

This paper deals with the study of the influence of the phase shift between currents and back-electromotive forces on torque ripple and radial magnetic forces for a low power synchronous machine supplied with 120 degrees square-wave currents. Based on a finite element approach, torque and magnetic pressure harmonics versus space and frequency are evaluated for different angle values. The aim is to establish a good compromise between efficiency, harmonics of torque and harmonics of radial forces at the origin of the electromagnetic noise. The evolutions of the different harmonics against the load angle are analyzed and compared to those of experimental measurements.

This paper shows the impact of the shift phase angle ψ between phase currents and back-electromotive forces (back-EMFs) on torque and radial forces for a low power synchronous machine (20 W). Pressure harmonics versus space and frequency on our motor and torque are evaluated with different angles with finite element approach. The aim is to establish a good compromise between consumed current, harmonics of torque and harmonics of radial forces linked to the electromagnetic noise for two strategies: maximum torque per ampere (MTPA) control and field weakening (FW) control. The evolution of each harmonic versus ψ are compared for both strategies. Experimental measurements in sinusoidal case are detailed.

Permanent magnet brushed DC motors are used in several applications such as home automation or automotive industry. This is mainly due to their lightweight, low cost and compact structure. Thus, the importance to study the sources of noise and vibration in these motors, which is often complicated and can be attributed to many factors. In this paper, the cogging torque and electromagnetic forces are studied in the case of a small permanent magnet brushed DC motor with 2 poles and 3 slots. Addition of dummy slots on the rotor side is described with its effect on the evolution of both aspects. The aim of this study is to give the quantitative effect about torque ripple and radial forces for each harmonic in relation with these dummy slots.

The aim of this paper concerns the design with these targets for low power motors that offer a good compromise in terms of performance: speed, torque, current, and noise linked to the radial forces. Different low power machines and topologies are studied with the same constraints in term of volume for the same value of the torque. The study is carried out on a PMSM with surface permanent magnet ‘SPM’ and with insert permanent magnet ‘IPM’. In order to reduce the cost, a synchronous reluctance machine ‘SynRM’ is also designed and studied. 2D and 3D Finite Element modeling are used to compare the performance of the three different topologies. In addition, the best solutions are realized and tested.

This paper studies different low power machines and topologies with the same constraints in term of volume for the same value of the torque. The aim of this paper concerns the design with these targets for low power motors that offer a good compromise in terms of performance: speed, torque, current, and noise linked to the radial forces. The study is carried out on a PMSM with surface permanent magnet ‘SPM’ and with insert permanent magnet ‘IPM’. In order to reduce the cost, a synchronous reluctance machine ‘SynRM’ is also designed and studied. 2D and 3D Finite Element modeling are used to compare the performance of the three different topologies.

L’objectif de ce papier concerne la problématique de dimensionnement de machines synchrones de faible puissance sous contraintes de diamètre extérieur, de couple et vitesse, de courant et de bruit émis. Une machine synchrone à aimants en surface avec un bobinage sur dents est comparée à deux machines synchro-réluctantes avec ou sans assistance d’aimants avec le même type de bobinage. L’objectif visé est de réduire le cout en essayant de conserver les mêmes performances sous contraintes. Des simulations éléments finis 3D permettent d’évaluer et de comparer les différentes structures proposées ainsi que des résultats expérimentaux. Mots-clefs : machine synchrone à aimants, machine synchro-réluctante, harmoniques de couple, harmoniques de forces radiales.