Design optimisation of ironless motors based on magnet selection

Greaves, Matthew C., Walker, Geoffrey R., & Walsh, Bernard B. (2002) Design optimisation of ironless motors based on magnet selection. Australian Journal of Electrical and Electronics Engineering, 22(1), pp. 43-48.

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This paper considers the design of a radial flux permanent magnet iron less core brushless DC motor for use in an electric wheel drive with an integrated epicyclic gear reduction. The motor has been designed for a continuous output torque of 30 Nm and peak rating of 60 Nm with a maximum operating speed of 7000 RPM. In the design of brushless DC motors with a toothed iron stator the peak air-gap magnetic flux density is typically chosen to be close to that of the remanence value of the magnets used. This paper demonstrates that for an ironless motor the optimal peak air-gap flux density is closer to the maximum energy product of the magnets used. The use of a radial flux topology allows for high frequency operation and can be shown to give high specific power output while maintaining a relatively low magnet mass. Two-dimensional finite element analysis is used to predict the air-gap flux density. The motor design is based around commonly available NdFeB bar magnet size

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ID Code: 63578
Item Type: Journal Article
Refereed: Yes
Additional Information: 7482348
ironless motors
brushless DC motor
magnet selection
design optimisation
radial flux permanent magnet ironless core motor
toothed iron stator
peak air-gap magnetic flux density
remanence value
optimal peak air-gap flux density
maximum energy product
high frequency operation
high specific power output
relatively low magnet mass
two-dimensional finite element analysis
NdFeB bar magnet size
air-gap flux density
Keywords: air gaps, brushless DC motors, finite element analysis, machine theory, magnetic flux, optimisation, permanent magnet motors
ISSN: 0725-2986
Subjects: Australian and New Zealand Standard Research Classification > ENGINEERING (090000) > AUTOMOTIVE ENGINEERING (090200) > Hybrid Vehicles and Powertrains (090205)
Australian and New Zealand Standard Research Classification > ENGINEERING (090000) > ELECTRICAL AND ELECTRONIC ENGINEERING (090600) > Industrial Electronics (090603)
Divisions: Current > Schools > School of Electrical Engineering & Computer Science
Current > QUT Faculties and Divisions > Science & Engineering Faculty
Copyright Owner: Copyright 2002 Institution of Engineers
Deposited On: 23 Oct 2014 00:51
Last Modified: 23 Oct 2014 00:51

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