Performance comparison of a doubly-salient motor with multi-V-shape ferrite magnets

Abstract

International audienceThis paper presents the analysis of a novel doubly salient structure with concentrated tooth winding and multi-V shape ferrite magnets. Permanent Magnet Synchronous Machines (PMSM) have been universally used with rare-earth magnets or with ferrite magnets and distributed winding. The proposed topology is presented as an improvement to PMSM for high torque and low-speed applications. It has low copper losses due to its short end-winding and benefits from a low cost by virtue of its lack of rare earth materials. This paper presents two slot/pole combinations: the 18/16 and the 12/10. A 2D Finite Element Analysis is used to investigate the average torque, the power factor and the torque ripple of each structure. It is shown that high performance is achieved for both motors. However, a parametric- analysis is performed on the 18/16 motor and shows that the saliency torque cannot be improved without reducing the torque and the power factor. As for the 12/10 motor, its main drawback is its high torque ripple. The torque ripple is reduced using two techniques; a rotor step skew and the use of an asymmetric pole shape. In this paper, a combination of both methods is proposed in order to reduce specific torque harmonics. Finally a comparison of the two motors is presented in order to determine which one is more suitable for the high torque and low speed application

Multiphysics Design of a V-Shape IPM Motor

“…The discrepancy is below 2% [14]. The 18/16 structure allows the development of a smooth torque [6]. Thus, the calculation of the torque ripple is not included in the AM.…”

“…The previously studied structures were generally designed with conventional distributed winding. However, novel doubly salient topologies with multi-V shape interior permanent magnets and concentrated tooth winding were recently studied and the results showed that they are capable of developing a high torque at low rotational speed [6]. Besides, the concentrated Paul winding reduces the length of the end-winding which decreases the copper losses and may improve the efficiency.…”

Multi-physics modeling and optimization of a multi-V-shape IPM with concentrated winding

“…The average torque (Tavg), the internal power factor (PFint) and the internal voltage (Vint) are calculated at 4 static positions for an accurate estimation [7]. They are expressed by (4), (5) and (6) respectively.…”

“…Non-rareearth permanent magnets such as ferrite were used as an additional torque source in synchronous reluctance motors [4], [5]. The previously mentioned structures are generally designed with distributed winding but more novel topologies with multi-V shape interior permanent magnets and concentrated tooth winding were also capable of developing a high torque at low rotational speed [6].…”

“…1). It is able to deliver a smooth, high torque [6]. Besides, the concentrated winding reduces the length of the end-winding which decreases the copper losses and may improve the efficiency.…”