Variable magnetization machine in electrified vehicle application

Takashi Fukushige, Takashi Kato, Kan Akatsu, Robert D. Lorenz

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)


This paper describes variable magnetization machines, which are capable of varying the magnetization state of permanent magnets during operation. A pulse current on the stator windings creates a magnetic field on the rotor; this can be used to manipulate the magnetization state of the rotor magnets. Regulating the magnetization state according to the machine operating condition can reduce machine losses. A proof-of-principle machine was designed and fabricated. A series of experiments was conducted to evaluate the torque-speed envelope and efficiency contours of the fabricated machine. A full-scale machine was then designed with a modified magnetic circuit for application to an electric vehicle and evaluated using finite element analysis. A control strategy for the magnetization state during machine operation is proposed, and the losses during a driving cycle with the strategy were evaluated.

Original languageEnglish
Pages (from-to)922-928
Number of pages7
JournalIEEJ Transactions on Industry Applications
Issue number9
Publication statusPublished - 2015 Sept 1


  • Efficiency
  • Flux intensifying machine
  • Memory motor
  • Permanent magnet synchronous machine
  • Variable flux machine

ASJC Scopus subject areas

  • Industrial and Manufacturing Engineering
  • Electrical and Electronic Engineering


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