Title :
Analysis and Reduction of Magnet Loss by Deepening Magnets in Interior Permanent-Magnet Machines With a Pole/Slot Ratio of 2/3
Author :
Junlong Li ; Yongxiang Xu ; Jibin Zou ; Qian Wang ; Weiyan Liang
Author_Institution :
State Key Lab. of Robot. & Syst., Harbin Inst. of Technol., Harbin, China
Abstract :
Interior permanent-magnet (IPM) machines are desirable for electrical vehicles due to high power density and good flux-weakening capability. This paper focuses on the approaches to reduction of magnet eddy-current loss in IPM machines with a pole/slot ratio of 2/3, taking a 16-pole/24-slot machine as an example. By comparing permanent-magnet losses between a surface-mounted magnet machine and an IPM machine, the spatial filter effect on even-order stator magnetomotive force space harmonics is highlighted. Thereafter, the effect of magnet depth on magnet eddy-current loss is investigated. Moreover, the constraints on reduction effect of magnet´s depth, such as copper loss and torque ripple, are analyzed. A 16-pole/24-slot IPM machine prototype is manufactured after the tradeoff design. The experimental results validate the effect of magnet depth on reducing magnet losses.
Keywords :
copper; eddy current losses; permanent magnet machines; stators; Cu; copper loss; deepening magnets; electrical vehicles; even-order stator; flux-weakening capability; interior permanent magnet machines; magnet eddy-current loss; magnet loss; magnetomotive force; pole-slot ratio; power density; space harmonics; spatial filter effect; surface-mounted magnet machine; torque ripple; Eddy currents; Harmonic analysis; Magnetic flux; Power harmonic filters; Rotors; Stators; Temperature measurement; IPM machines; Interior permanent-magnet (IPM) machines; magnet depth; magnet loss reduction; tradeoff design;
Journal_Title :
Magnetics, IEEE Transactions on
DOI :
10.1109/TMAG.2015.2445787
