This paper proposes a new high power density permanent magnet (PM) motor design for traction applications to achieve the 50kW/L target set by the US Department of Energy by increasing the torque capability and operating speed compared to conventional PM machine topologies. A large-scale multi-objective design optimization based on 2D finite element analysis (FEA) and differential evolution algorithm was conducted to achieve the best trade-off among high efficiency, high power density and high power factor. The torque-speed envelopes are also checked for the Pareto front designs to make sure they have a constant power speed ratio of at least 3:1. An open frame lab prototype (OFLP) motor has been fabricated and tested to validate the principle of operation and design optimization approach, and to identify the potential challenges in manufacturing and testing. Ongoing work on further pushing the electromagnetic performance to the limit and improving the manufacturing and cooling techniques are also discussed.

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Conference Proceeding

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Published in Proceedings, IEEE Energy Conversion Congress and Exposition.

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The document available for download is the authors’ manuscript version accepted for publication. The final published version is copyrighted by IEEE and available as: Han P., Kesgin M. G., Ionel D. M., Gosalia R., Shah N., Flynn J. F., Goli C. S., Essakiappan S., and Manjrekar M. “Design Optimization of a Very High Power Density Motor with a Reluctance Rotor and a Modular Stator Having PMs and Toroidal Windings,” Proceedings, IEEE Energy Conversion Congress and Exposition (ECCE), Vancouver, Canada, pp.1-7, Oct 2021.

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Funding Information

This work was supported by the Vehicle Technologies Office, U.S. Department of Energy, under award no. DEEE0008871. The material presented in this paper do not necessarily reflect the views of the U.S. Department of Energy. The authors would also like to gratefully acknowledge the direct support provided by QM Power, Inc and Ansys, Inc.