Affiliations: [a] School of Electrical Engineering, Shandong University, Jinan, Shandong, China | [b] Department of Electronic Systems Engineering, Hanyang University, Ansan, Korea
Correspondence:
[*]
Corresponding author: Byung-Il Kwon, Department of Electronic Systems Engineering, Hanyang University, Sangnok-gu, Ansan, Gyeonggi-do 426-791, Korea. Tel.: +82 10 6211 5165; Fax: +82 31 409 1277; E-mail:bikwon@hanyang.ac.kr
Abstract: This paper proposes a novel permanent magnet (PM) shape
for surface-mounted PM (SPM) machines, with the aim of not only improving
the sinusoidal quality of back electromotive force (EMF) and reducing
cogging torque as well as torque ripple, but also saving on the magnet
material cost. The proposed PM shape is designed to be trapezoidal and
symmetrical in the axial direction, and the pieces from breaking the magnets
for the trapezoidal shape can be used to create a new pole resulting in a
significant reduction of magnet material cost. The design principle of the
proposed cost-effective PM shape with two alternatives is illustrated in
detail. To highlight the advantages of the proposed PM shape in SPM
machines, two conventional rectangular PM shapes and a previously reported
sinusoidal PM shape are adopted for performance comparison, based on a 3-D
finite element method (FEM) using JMAG-Designer.
Keywords: Back electromotive force (EMF), cogging torque, cost-effective, finite element method (FEM), surface-mounted permanent magnet (SPM), machines, torque ripple
