A Novel Magnetic-Geared Tubular Linear Machine with Halbach Permanent-Magnet Arrays for Tidal Energy Conversion

S. L. Ho, Qingsong Wang, Shuangxia Niu, W. N. Fu

Research output: Contribution to journalArticle

30 Citations (Scopus)


This paper proposes a novel magnetic-geared tubular linear machine for tidal and wave energy conversion. The key of the proposed machine is to embed the armature windings into slots adjacent to the modulating segments of a linear magnetic gear (LMG). The compact component designed can serve simultaneously as the modulating poles in the LMG and the armature stator in the generator. When compared with its existing counterparts, the proposed machine has an improved force density and a simpler mechanical structure by virtue of its gearing effect. Moreover, Halbach permanent-magnet (PM) array is used to build up the PM arrays in both the inner mover and outer mover of the LMG, resulting in increase in thrust force density, reduction in cogging force, and high machine efficiency. The working principle of the proposed machine is introduced, and the electromagnetic performance is investigated quantitatively using the time-stepping finite-element method.
Original languageEnglish
Article number8113604
JournalIEEE Transactions on Magnetics
Issue number11
Early online date29 Jun 2015
Publication statusPublished - 1 Nov 2015
Externally publishedYes



  • Energy conversion
  • Halbach permanent magnet (PM)
  • finite-element method (FEM)
  • tubular linear machine

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