A Novel Flux Focusing Magnetically Geared Machine with Reduced Eddy Current Loss

• Main Authors: Jin Liu, Wenxiang Zhao, Jinghua Ji, Guohai Liu, Tao Tao
• Format: Article
• Language: English
• Published: MDPI AG 2016-11-01
• Series: Energies
• Subjects: finite-element method; eddy current loss; magnetic gear; serial-spoke structure; torque; back-electromotive force
• Online Access: http://www.mdpi.com/1996-1073/9/11/904

This paper proposes a novel flux focusing magnetically geared (MG) machine for wind power generation, considering the permanent magnets (PMs) eddy current loss and the balance between the pull-out torque of MG machine and the back-electromotive force (EMF)of the PM brushless machine. The PM eddy current loss in the two rotors of the conventional surface-mounted MG machine is calculated and analyzed by using finite-element method. By adopting serial-spoke structure in the inner rotor, a novel rotor structure for a MG machine is proposed to reduce the PM eddy current loss. Moreover, in order to balance the pull-out torque and the back-EMF, several serial-spoke structures and the main design parameters are investigated. Then, a quantitative comparison between the proposed topology and the conventional surface-mounted MG machine is performed. The analysis results indicate that the PM eddy current loss of the proposed MG machine can be significantly reduced and its pull-out torque and back-EMF can be balanced well.