A quantitative comparison study of power-electronic-driven flux-modulated machines using magnetic field and thermal field co-simulation

Longnv Li, Weinong Fu, Siu Lau Ho, Shuangxia Niu, Yan Li

Research output: Journal article publicationJournal articleAcademic researchpeer-review

26 Citations (Scopus)


Low-speed flux-modulated permanent-magnet (PM) machines do not need to conform to the conventional design rule which requires identical number of pole-pairs in both stator and rotor. In flux-modulated machines, special ferromagnetic segments in the airgap are used to modulate the magnetic field. In this paper, a general rule to compare different types of electric machines as well as measures to improve the torque density in these machines are presented. In this paper, the energy conversion capacity of different machines with the same physical size and the same operating temperature-rise are compared. An adaptive-order method for modeling the load - temperature-rise relationship is presented to reduce the computing time for this inverse problem. Three power-electronic-driven PM electric machines, which are, namely, a traditional PM machine, a radial-flux-modulated machine (RFMM), and an axial-flux-modulated machine (AFMM), are analyzed and compared based on their temperature distribution and electromagnetic torque density using magnetic field and thermal field computation. Experimental results of an AFMM prototype are used to validate the temperature-rise which is computed using 3-D finite-element method (3-D FEM).
Original languageEnglish
Article number2420039
Pages (from-to)6076-6084
Number of pages9
JournalIEEE Transactions on Industrial Electronics
Issue number10
Publication statusPublished - 1 Oct 2015


  • Electric machine
  • finite element method
  • flux modulation
  • low speed drive
  • magnetic field
  • permanent magnet
  • thermal field
  • torque density

ASJC Scopus subject areas

  • Control and Systems Engineering
  • Computer Science Applications
  • Electrical and Electronic Engineering

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