Abstract
Increasing power densities of electric vehicle traction drive systems necessitates combining the electric motor and the power electronics into one unit. A compact, integrated traction drive unit with fewer components also drives production costs down, enabling wider adoption of electric vehicles. However, the integration of power electronics in the electric machine is associated with challenges of designing an effective thermal management solution for the combined traction drive system. This paper focuses on the thermal management approach selected for Oak Ridge National Laboratory's outer-rotor-motor-based integrated traction drive and evaluates its potential performance. The outer-rotor-motor configuration provided an opportunity for integration of the six-phase inverter in the available space in the central cavity of the internal stator. A cylindrical inverter enclosure with integrated coolant (water-ethylene glycol) channels in its walls was designed to enable heat removal from the power electronics. Numerical thermal-fluid modeling and initial channel/fin optimization results for the cylindrical heat sink are presented here. As permanent magnets are integrated in a high-speed (20 000 RPM) outer rotor, forced air convection provides cooling for the magnets. The magnets were segmented axially to mitigate the eddy current losses. Heat generated in the stator windings and laminations is removed by water-ethylene glycol coolant circulating in interpolar T-shape ceramic heat exchangers inserted between windings. General design concepts and numerical thermal-fluid simulations illustrating the electric motor thermal management solution are also presented.
| Original language | English |
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| Title of host publication | Proceedings of ASME 2024 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems, InterPACK 2024 |
| Publisher | American Society of Mechanical Engineers |
| ISBN (Electronic) | 9780791888469 |
| DOIs | |
| State | Published - 2024 |
| Event | ASME 2024 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems, InterPACK 2024 - San Jose, United States Duration: Oct 8 2024 → Oct 10 2024 |
Publication series
| Name | Proceedings of ASME 2024 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems, InterPACK 2024 |
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Conference
| Conference | ASME 2024 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems, InterPACK 2024 |
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| Country/Territory | United States |
| City | San Jose |
| Period | 10/8/24 → 10/10/24 |
Funding
The authors would like to acknowledge the support provided by Susan Rogers, Technology Manager of the Electric Drive Technologies Program, Vehicle Technologies Office, U.S. Department of Energy Office of Energy Efficiency and Renewable Energy. This work was authored in part by the National Renewable Energy Laboratory, operated by Alliance for Sustainable Energy, LLC, for the U.S. Department of Energy (DOE) under Contract No. DE-AC36-08GO28308. Funding was provided by U.S. Department of Energy Office of Energy Efficiency and Renewable Energy Vehicle Technologies Office. The views expressed in the article do not necessarily represent the views of the DOE or the U.S. Government. The U.S. Government retains and the publisher, by accepting the article for publication, acknowledges that the U.S. Government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this work, or allow others to do so, for U.S. Government purposes.
Keywords
- Integrated traction drive
- electric motor cooling
- inverter cooling
- outer-rotor motor
- power electronics