# Dynamic evaluation in motors of variable magnetic flux magnets

https://mdr.nims.go.jp/datasets/50b395fa-e67b-4804-96b5-d85a27de8b4b

## File

- [REPM2025_P1-39_Takeda.pdf](https://mdr.nims.go.jp/filesets/a4dc64b2-cff9-4201-bbff-e05b622f6652/download) ([Detail](https://mdr.nims.go.jp/filesets/a4dc64b2-cff9-4201-bbff-e05b622f6652.md))
- [(abstract) P1-39_Figure.jpeg](https://mdr.nims.go.jp/filesets/70745545-1cda-476b-adce-72e207045a49/download) ([Detail](https://mdr.nims.go.jp/filesets/70745545-1cda-476b-adce-72e207045a49.md))

## Id

50b395fa-e67b-4804-96b5-d85a27de8b4b

## Local identifier



## Visibility

open_to_public

## State

published

## Created at

2025-08-25T08:10:29.466867Z

## Updated at

2025-09-11T07:31:05.657994Z

## Published at

2025-09-11T07:20:06.776167Z

## Doi

https://doi.org/10.48505/nims.5671

## First published url



## Date published



## Recorded date published



## Resource type

conference_poster

## Manuscript type

na

## Collection

- id: d28f086a-61aa-4bc7-bcae-5a1078cbc6c7
  identifier: https://mdr.nims.go.jp/pid/d28f086a-61aa-4bc7-bcae-5a1078cbc6c7
  title: The 28th International Workshop on Rare Earth and Future Permanent Magnets
    and Their Applications (REPM2025)

## Title

- title: Dynamic evaluation in motors of variable magnetic flux magnets
  title_type: original
  lang: en

## Description

- description: "The variable magnetic flux permanent magnet synchronous motor (VMF-PMSM)
    is one of the next-generation technologies to improve the efficiency of PMSM.
    The VMF-PMSM is expected to achieve high efficiency over a wide operating range
    by switching the magnetization states of the VMF-magnet, which has a low coercive
    field, through the application of the magnetic field from an armature coil. Achieving
    the desired torque in the VMF-PMSM requires to accurately grasp the relationship
    between the electrical control of the motor and the operating point of the magnet
    embedded in a rotating rotor, which is difficult to be measured. This presentation
    will show the approach for directly measuring the operating point of the VMF-magnet.\r\nThe
    VMF-PMSM with the system for real-time measurement of the magnetic field and the
    temperature of the rotor magnet was constructed (Fig. (a)). The rotor magnet consisted
    of a series lamination of the VMF-magnet [1] and the high coercive field magnets.
    The sensor probe with a Hall element and an NTC thermistor on a flexible printed
    circuit board was fixed on the surface of the rotor magnet and was electrically
    connected to a signal conditioner mounted on the rotor shaft, which includes a
    micro-controller and a Bluetooth module, enabling measurement and wireless communication.
    For driving the VMF-PMSM, a DSP (PE-Expert3) and an inverter unit (MWINV-2022A)
    manufactured by Myway Plus Corporation were used.\r\nFigure (b) shows the current
    angle β dependence of torque during 3 Arms load rotation after magnetizing and
    demagnetizing the VFM-magnet with a d-axis current of ±60 A and an energizing
    time of 50 ms during a 600 rpm rotation at 26℃. The magnet torque in the magnetized
    state at β = 0° after a field weakening operation up to β = 90° decreased by 3.8%
    compared to before. This corresponded to a 4% decrease in the magnetic field of
    the rotor magnet, which was measured simultaneously during the same operation
    as mentioned above. In the presentation, the relationship between the electrical
    control of the motor and the operating point of the VMF-magnet will be considered
    using the measurement results of the torque and the magnet field."
  description_type: abstract
  lang: en

## Creator

- name: Kenji Takeda
  role: author
  organization: Technology and Intellectual Property HQ, TDK Corporation, Japan
- name: R. Fujiwara
  role: author
  organization: Technology and Intellectual Property HQ, TDK Corporation, Japan
- name: T. Shinji
  role: author
  organization: Technology and Intellectual Property HQ, TDK Corporation, Japan
- name: S. Miyazaki
  role: author
  organization: Technology and Intellectual Property HQ, TDK Corporation, Japan
- name: T. Kajita
  role: author
  organization: Technology and Intellectual Property HQ, TDK Corporation, Japan
- name: Y. Enokido
  role: author
  organization: Technology and Intellectual Property HQ, TDK Corporation, Japan
- name: K. Akatsu
  role: author
  organization: Department of Faculty of Engineering, Yokohama National University,
    Japan

## Contact agent



## Publisher

organization: National Institute for Materials Science (NIMS)

## Managing organization



## Keyword

- subject: REPM2025
  schema: not_defined
- subject: motors
  schema: not_defined

## Rights

- identifier: https://creativecommons.org/licenses/by/4.0/

## Other identifier(s)



## Data origin

- data_origin_type: other

## Embargo



## Journal



## Conference

name: REPM2025
start_date: 2025-07-27
end_date: 2025-07-31
identifier: https://www.nims.go.jp/mmu/repm2025/

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## Instrument



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## Measurement method



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## Fileset

- id: a4dc64b2-cff9-4201-bbff-e05b622f6652
  filename: REPM2025_P1-39_Takeda.pdf
  content_type: application/pdf
  size: 1296897
  md5: e70bfdbfc285fe89514e11fd5ca63039
- id: 70745545-1cda-476b-adce-72e207045a49
  filename: "(abstract) P1-39_Figure.jpeg"
  content_type: image/jpeg
  size: 39665
  md5: 16ef2d607609e2a73cdb715287f26509

## Thumbnail

fileset_id: a4dc64b2-cff9-4201-bbff-e05b622f6652
filename: REPM2025_P1-39_Takeda.pdf