A thermal improvement technique for phase windings of electrical machines

In electrical machines, a higher torque/force density can usually be achieved by increasing the current density in the windings. However, the resulting increase in copper losses leads to higher temperatures in the coils, especially in the centre of the slots where the thermal resistance to the ambie...

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Main Authors: Galea, Michael, Gerada, C., Raminosa, Tsarafidy, Wheeler, Patrick
Format: Article
Published: IEEE 2012
Subjects:
Online Access:https://eprints.nottingham.ac.uk/44153/
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author Galea, Michael
Gerada, C.
Raminosa, Tsarafidy
Wheeler, Patrick
author_facet Galea, Michael
Gerada, C.
Raminosa, Tsarafidy
Wheeler, Patrick
author_sort Galea, Michael
building Nottingham Research Data Repository
collection Online Access
description In electrical machines, a higher torque/force density can usually be achieved by increasing the current density in the windings. However, the resulting increase in copper losses leads to higher temperatures in the coils, especially in the centre of the slots where the thermal resistance to the ambient/cooling surfaces is highest. In this paper a novel, simple technique is presented in which a higher thermal conductivity path between the centre of the slot and the cooling arrangement is created, thus increasing the heat flow away from the slot centre. A lumped parameter thermal model is presented and used along with finite element analysis to investigate the effectiveness of the proposed technique. The lumped parameter model is also used for optimizing the high conductivity path for maximum air-gap shear stress and to obtain a compromise between the reduced slot area and the improved temperature distribution. Experimental validation is then presented to compare the predicted results with the measured results on a purposely built instrumented set-up.
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spelling nottingham-441532020-05-04T16:32:06Z https://eprints.nottingham.ac.uk/44153/ A thermal improvement technique for phase windings of electrical machines Galea, Michael Gerada, C. Raminosa, Tsarafidy Wheeler, Patrick In electrical machines, a higher torque/force density can usually be achieved by increasing the current density in the windings. However, the resulting increase in copper losses leads to higher temperatures in the coils, especially in the centre of the slots where the thermal resistance to the ambient/cooling surfaces is highest. In this paper a novel, simple technique is presented in which a higher thermal conductivity path between the centre of the slot and the cooling arrangement is created, thus increasing the heat flow away from the slot centre. A lumped parameter thermal model is presented and used along with finite element analysis to investigate the effectiveness of the proposed technique. The lumped parameter model is also used for optimizing the high conductivity path for maximum air-gap shear stress and to obtain a compromise between the reduced slot area and the improved temperature distribution. Experimental validation is then presented to compare the predicted results with the measured results on a purposely built instrumented set-up. IEEE 2012-01-31 Article PeerReviewed Galea, Michael, Gerada, C., Raminosa, Tsarafidy and Wheeler, Patrick (2012) A thermal improvement technique for phase windings of electrical machines. IEEE Transactions on Industry Applications, 48 (1). pp. 79-87. ISSN 1939-9367 Permanent magnet machines Electrical machine windings High current density Thermal improvements http://ieeexplore.ieee.org/document/6074939/ doi:10.1109/TIA.2011.2175470 doi:10.1109/TIA.2011.2175470
spellingShingle Permanent magnet machines
Electrical machine windings
High current density
Thermal improvements
Galea, Michael
Gerada, C.
Raminosa, Tsarafidy
Wheeler, Patrick
A thermal improvement technique for phase windings of electrical machines
title A thermal improvement technique for phase windings of electrical machines
title_full A thermal improvement technique for phase windings of electrical machines
title_fullStr A thermal improvement technique for phase windings of electrical machines
title_full_unstemmed A thermal improvement technique for phase windings of electrical machines
title_short A thermal improvement technique for phase windings of electrical machines
title_sort thermal improvement technique for phase windings of electrical machines
topic Permanent magnet machines
Electrical machine windings
High current density
Thermal improvements
url https://eprints.nottingham.ac.uk/44153/
https://eprints.nottingham.ac.uk/44153/
https://eprints.nottingham.ac.uk/44153/