A high-performance permanent-magnet-free machine for wide load ranges

Longya Xu, Hongyu Wang, Philip T. Krein

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

This paper presents the design and operational analysis of a high-performance squirrel-cage induction machine intended for wide load range applications, including electric traction and highly dynamic industrial loads. High performance operation and high torque density are achieved through a combination of four strategies: (1) An inverter-dedicated design in which stator and rotor configurations are based on low slip; (2) High-performance materials including high flux cobalt alloy and copper rotor bars; (3) Optimized pole counts with relatively high frequency stator operation to avoid field weakening in most load ranges; (4) Adaptive flux control to maintain high efficiency over a 10:1 or more load range. Based on the high cost of rare-earth permanent magnets, the cost tradeoffs for cobalt alloys become plausible and feasibility is studied. The design and operation of the induction machine's broad motor behavior are discussed, and simulation results are used to validate its application in electric vehicles. It is verified that the design achieves 4x higher torque density than conventional machines of the same size. At the same time, nominal efficiency of the design is greater than 96% over a wide load range, and the machine is capable of peak efficiency as high as 98%.

Original languageEnglish (US)
Title of host publication2017 IEEE International Electric Machines and Drives Conference, IEMDC 2017
PublisherInstitute of Electrical and Electronics Engineers Inc.
ISBN (Electronic)9781509042814
DOIs
StatePublished - Aug 3 2017
Event2017 IEEE International Electric Machines and Drives Conference, IEMDC 2017 - Miami, United States
Duration: May 21 2017May 24 2017

Publication series

Name2017 IEEE International Electric Machines and Drives Conference, IEMDC 2017

Other

Other2017 IEEE International Electric Machines and Drives Conference, IEMDC 2017
CountryUnited States
CityMiami
Period5/21/175/24/17

Keywords

  • cobalt alloys
  • copper cage
  • eddy current loss
  • electric vehicles
  • finite-element analysis
  • high-performance
  • induction machine
  • power density
  • torque density
  • wide load range

ASJC Scopus subject areas

  • Energy Engineering and Power Technology
  • Electrical and Electronic Engineering
  • Mechanical Engineering

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  • Cite this

    Xu, L., Wang, H., & Krein, P. T. (2017). A high-performance permanent-magnet-free machine for wide load ranges. In 2017 IEEE International Electric Machines and Drives Conference, IEMDC 2017 [8002080] (2017 IEEE International Electric Machines and Drives Conference, IEMDC 2017). Institute of Electrical and Electronics Engineers Inc.. https://doi.org/10.1109/IEMDC.2017.8002080