Comparison of synchronous PM machine types for wide constant‐power speed range operation
ISSN: 0332-1649
Article publication date: 12 September 2008
Abstract
Purpose
The purpose of this paper is to provide a comparison of synchronous permanent magnet machine types for wide constant power speed range operation.
Design/methodology/approach
A combination of analytical models and finite element analysis is used to conduct this study.
Findings
The paper has presented a detailed comparison between various types of synchronous PM machines for applications requiring a wide speed range of constant‐power operation. Key observations include: surface permanent magnet (SPM) and interior permanent magnet (IPM) machines can both be designed to achieve wide speed ranges of constant‐power operation. SPM machines with fractional‐slot concentrated windings offer opportunities to minimize machine volume and mass because of their short winding end turns and techniques for achieving high‐slot fill factors via stator pole segmentation. High back‐emf voltage at elevated speeds is a particular issue for SPM machines, but also poses problems for IPM machine designs when tight maximum limits are applied. Magnet eddy‐current losses pose a bigger design issue for SPM machines, but design techniques can be applied to significantly reduce the magnitude of these losses. Additional calculations not included here suggest that the performance characteristics of the inverters accompanying each of the four PM machines are quite similar, despite the differences in machine pole number and electrical frequency.
Research limitations/implications
The paper is targeting traction applications where a very wide speed range of constant‐power operation is required.
Practical implications
Results presented are intended to provide useful guidelines for engineers faced with choosing the most appropriate PM machine for high‐constant power speed ratio applications. As in most real‐world drive design exercises, the choice of PM machine type involves several trade‐offs that must be carefully evaluated for each specific application.
Originality/value
The paper provides a comprehensive comparison between different types of synchronous PM machines, which is very useful in determining the most suitable type for various applications.
Keywords
Citation
EL‐Refaie, A.M. and Jahns, T.M. (2008), "Comparison of synchronous PM machine types for wide constant‐power speed range operation", COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, Vol. 27 No. 5, pp. 967-984. https://doi.org/10.1108/03321640810890717
Publisher
:Emerald Group Publishing Limited
Copyright © 2008, Emerald Group Publishing Limited