Comparative Study of Dual-Rotor Slotless Axial-Flux Permanent Magnet Machines with Equidirectional Toroidal and Conventional Concentrated Windings

TY - JOUR

T1 - Comparative Study of Dual-Rotor Slotless Axial-Flux Permanent Magnet Machines with Equidirectional Toroidal and Conventional Concentrated Windings

AU - Si, Jikai

AU - Zhang, Tianxiang

AU - Nie, Rui

AU - Gan, Chun

AU - Hu, Yihua

N1 - (c) 2021 IEEE. This is an author-produced version of the published paper. Uploaded in accordance with the publisher’s self-archiving policy. Further copying may not be permitted; contact the publisher for details

PY - 2023/2

Y1 - 2023/2

N2 - Axial-flux permanent magnet (AFPM) machines are gaining popularity in low speed and high torque applications due to their high torque density, high efficiency and compact structure. In this paper, a dual-rotor slotless (DRS) AFPM machine equipped with equidirectional toroidal winding (EDTW) is proposed and compared with that equipped with conventional single layer and double layer concentrated windings (SL and DLCWs). Firstly, the differences between the DRSAFPM machine with EDTW and that with conventional CWs in coil layout, electromotive force (EMF) and winding magnetomotive force (MMF) are revealed. Considering the special coil layout of the EDTW, the coil factor and size equations of the DRSAFPM machines with EDTW and conventional CWs are presented. Secondly, the electromagnetic performance including air-gap field, back-EMF, torque and efficiency of the DRSAFPM machines with EDTW and conventional CWs are analyzed based on the three-dimensional finite element method (3D-FEM). The simulation results validate the correctness of the coil factor and size equations and indicate the EDTW-DRSAFPM machine has superiority in back-EMF amplitude and torque density. Finally, a prototype of the EDTW-DRSAFPM machine is manufactured and tested, which validates the feasibility of the EDTW-DRSAFPM machine and the correctness of the analysis.

AB - Axial-flux permanent magnet (AFPM) machines are gaining popularity in low speed and high torque applications due to their high torque density, high efficiency and compact structure. In this paper, a dual-rotor slotless (DRS) AFPM machine equipped with equidirectional toroidal winding (EDTW) is proposed and compared with that equipped with conventional single layer and double layer concentrated windings (SL and DLCWs). Firstly, the differences between the DRSAFPM machine with EDTW and that with conventional CWs in coil layout, electromotive force (EMF) and winding magnetomotive force (MMF) are revealed. Considering the special coil layout of the EDTW, the coil factor and size equations of the DRSAFPM machines with EDTW and conventional CWs are presented. Secondly, the electromagnetic performance including air-gap field, back-EMF, torque and efficiency of the DRSAFPM machines with EDTW and conventional CWs are analyzed based on the three-dimensional finite element method (3D-FEM). The simulation results validate the correctness of the coil factor and size equations and indicate the EDTW-DRSAFPM machine has superiority in back-EMF amplitude and torque density. Finally, a prototype of the EDTW-DRSAFPM machine is manufactured and tested, which validates the feasibility of the EDTW-DRSAFPM machine and the correctness of the analysis.

KW - Axial flux

KW - coil factor

KW - comparative study

KW - concentrated windings

KW - equidirectional toroidal windings

KW - Force

KW - Layout

KW - permanent magnet machine

KW - Rotors

KW - size equation

KW - Stator cores

KW - Stator windings

KW - Torque

KW - Windings

UR - http://www.scopus.com/inward/record.url?scp=85127057336&partnerID=8YFLogxK

U2 - 10.1109/TIE.2022.3159956

DO - 10.1109/TIE.2022.3159956

M3 - Article

AN - SCOPUS:85127057336

SN - 0278-0046

VL - 70

SP - 1216

EP - 1228

JO - IEEE Transactions on Industrial Electronics

JF - IEEE Transactions on Industrial Electronics

IS - 2

ER -