Reduction of Torque Ripple for Outer-Rotor-Type Segment PM motor with Ferrite Magnet

• Published in: Transaction of the Magnetics Society of Japan Special Issues Vol. 9; no. 1; pp. 66 - 71
• Main Authors: Yoshida, Y., Tajima, K., Sakurai, S.
• Format: Journal Article
• Language: Japanese
• Published: The Magnetics Society of Japan 01.05.2025; 公益社団法人 日本磁気学会
• Subjects: Ferrite magnet; PM motor; Segmented rotor; Torque ripple
• ISSN: 2432-0471
• DOI: 10.20819/msjtmsj.25TR901

  Drones have been used for limited purposes such as aerial photography and pesticide spraying, but now they are expected to be used for logistics and transportation. On the other hand, the drones are operated for a short time about 40 to 60 minutes, and they have a low payload weight of less than 10 kg. To improve these, the battery capacity can be increased, but the weight is also increased and the payload weight is decreased. So, improvement of the motor is necessary. This paper presented a novel outer-rotor-type permanent magnet (PM) motor with a segment-shaped rotor for high power density and low cost. It can be used a magnet flux effectively because it has backyoke iron, and improving output can be expected. However, the torque ripple is increased. So, the improvement of torque ripple is proved using an asymmetry rotor and Ferrite magnet.