Affiliations: [a] Engineering Research Center for Motion Control of MOE, Southeast University, Nanjing, Jiangsu, China | [b] Electrical and Computer Engineering Department, Portland State University, Portland, OR, USA
Correspondence:
[*]
Corresponding author: Heyun Lin, Engineering Research Center for Motion Control of MOE, Southeast University, Nanjing, Jiangsu, China. E-mail:hyling@seu.edu.cn
Abstract: Permanent magnet vernier machine (PMVM) based on flux modulation principle
has attracted increasing attention in low-speed direct-drive applications
due to its high torque capability. A dual-stator PMVM topology with
sandwiched spoke-array PM rotor is presented to produce higher air-gap flux
density and larger torque in this paper, and the space utilization and the
energy conversion efficiency are improved significantly. Two representative
dual-stator PMVMs (DS-PMVMs) are designed with this topology, the pole/slot
combinations and gear ratios of which are 18 slots/30 poles and
18 slots/28 poles, 5 and 3.5, respectively. In order to reveal the advantages
of the proposed topology and assess the torque characteristics of the proposed machines with different pole/slot combinations, the electromagnetic
characteristics of these two machines are quantitatively compared and analyzed by
using finite element method (FEM). The results demonstrate that the
18 slots/28 poles DS-PMVM can offer higher output torque, lower torque
ripples, lower cogging torque and higher power factor owing to its optimal
pole/slot combination. In addition, the unbalanced magnetic pulls (UMPs) of
the two machines are also investigated, and the UMP of the 18 slots/30 poles
DS-PMVM is smaller than that of its counterpart due to its symmetrical
winding.
