Modular Spoke-Type Permanent-Magnet Machine for In-Wheel Traction Applications

Hengliang Zhang, Wei Hua, Zhongze Wu

Research output: Contribution to journalArticlepeer-review

34 Citations (SciVal)


This paper proposes a novel modular spoke-type permanent-magnet machine for in-wheel traction applications. First, the topology and the operating principle are briefly introduced. Then, an analytical model of the proposed machine is deduced based on conformal mapping. A three-phase 48-slot 52-pole modular spoke-type permanent-magnet (PM) machine is designed based on the deduced mathematical model where the dimensions and power source are constrained the same as those of a commercial three-phase surface PM machine in electric motorcycles. Electromagnetic performance comparisons among the proposed machine, the commercial machine, and a conventional spoke-type PM machine are conducted based on finite-element analysis (FEA) with respect to magnetic field, back electromotive force (EMF), flux-weakening capability, torque capability, machine efficiency, etc. The results indicate that the proposed machine has an improved torque, a higher efficiency, and an extremely better flux-weakening capability than the conventional in-wheel machine. Finally, a prototype machine is manufactured and tested to verify both the analytically and FEA predicted results.

Original languageEnglish
Pages (from-to)7648-7659
Number of pages12
JournalIEEE Transactions on Industrial Electronics
Issue number10
Early online date8 Feb 2018
Publication statusE-pub ahead of print - 8 Feb 2018


  • AC machines
  • brushless machines
  • conformal mapping
  • electric vehicles
  • finite-element analysis (FEA)
  • permanent-magnet (PM) machines

ASJC Scopus subject areas

  • Control and Systems Engineering
  • Electrical and Electronic Engineering


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