Design and Optimization of a Novel Slot-PM-Assisted Variable Flux Reluctance Generator for Hybrid Electric Vehicles

Xing Zhao, Shuangxia Niu

Research output: Journal article publicationJournal articleAcademic researchpeer-review

27 Citations (Scopus)


This paper proposes a new slot-permanent-magnet (PM)-assisted variable flux reluctance generator (VFRG) for the hybrid electric vehicles. Compared with the existing dc-excited VFRG, auxiliary PMs are introduced into stator slots, which can fully utilize the redundant harmonics excited by single-layer concentrated armature winding and boost power density significantly. In this paper, the generator structure, operation principle as well as the winding restriction are discussed. Different slot pole combinations are fully compared in terms of both no-load and on-load characteristics. Some important design parameters are redefined for this slot-PM-assisted topology based on a sensitivity analysis. To release cost burden, both rare-earth-magnet and ferrite-magnet-assisted designs are considered into optimization. The feasibility of this new topology is verified by using finite element analysis and prototype testing.

Original languageEnglish
Article number8385135
Pages (from-to)2102-2111
Number of pages10
JournalIEEE Transactions on Energy Conversion
Issue number4
Publication statusPublished - 1 Dec 2018


  • Power density
  • redundant winding harmonics
  • slot-permanent-magnet (PM) assistance
  • variable flux reluctance generator

ASJC Scopus subject areas

  • Energy Engineering and Power Technology
  • Electrical and Electronic Engineering

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