Kana Padinharu, D.K., Li, G.-J. orcid.org/0000-0002-5956-4033, Zhu, Z.Q. orcid.org/0000-0001-7175-3307 et al. (3 more authors) (2022) AC losses in form-wound coils of surface mounted permanent magnet Vernier machines. IEEE Transactions on Magnetics, 58 (6). 8105315. ISSN 0018-9464
Abstract
Surface mounted permanent magnet Vernier (SPM-V) machines, because of their high torque density and multi-pole structure, are promising candidates for low speed direct-drive applications. To achieve high torque density, the SPM-V machines are generally designed with high gear ratios. Therefore, their operating frequencies can be much higher than those of the conventional SPM machines. This potentially increases the alternating current (AC) winding losses, especially those with form-wound coils proposed for high power applications. This paper investigates the AC losses (including skin effect, proximity effect, rotor PM induced and circulating current losses) in form-wound stator coils of a 3 MW direct-drive SPM-V machine with different slot/pole number combinations. The study reveals that the SPM-V machines have significantly higher AC winding losses than their conventional SPM counterparts for similar operating conditions. To reduce the AC winding losses in SPM-V machines, a novel flux shunt concept is proposed along with other conventional techniques such as increasing the number of turns/coil (with terminal voltage being kept constant) and parallel strands/turn, providing extra clearance at slot opening, etc. With the loss reduction techniques implemented, the SPM-V machines can achieve comparable efficiency but much higher torque density than their conventional counterparts. Moreover, the proposed flux shunt was also found to be very effective in reducing the potential risk of permanent magnet (PM) irreversible demagnetization, a key issue for SPM-V machines at high power ratings.
Metadata
Item Type: | Article |
---|---|
Authors/Creators: |
|
Copyright, Publisher and Additional Information: | © 2022 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works. Reproduced in accordance with the publisher's self-archiving policy. |
Keywords: | AC loss; circulating current; efficiency; form-wound coil; Vernier machine |
Dates: |
|
Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Engineering (Sheffield) > Department of Electronic and Electrical Engineering (Sheffield) |
Funding Information: | Funder Grant number Engineering and Physical Sciences Research Council EP/R004900/1 Siemens PLC n/a |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 27 Apr 2022 08:57 |
Last Modified: | 26 Apr 2023 00:13 |
Status: | Published |
Publisher: | Institute of Electrical and Electronics Engineers |
Refereed: | Yes |
Identification Number: | 10.1109/TMAG.2022.3170658 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:186031 |