Design and Fabrication of a Flux Shunt DC Motor with an Anti-Demagnetization Mechanism
Date Issued
2009
Date
2009
Author(s)
Wu, Cheng-Ju
Abstract
High energy product rare earth magnets are widely used in high performance permanent magnet machines to replace the current excitation methods and to improve machine efficiency. However, the magnetic field provided by a permanent magnet cannot be adjusted and the price of rare earth magnets is high. If the machine adopts low grade permanent magnet, there is a high risk of irreversible demagnetization. To address this problem, a novel DC commutator machine that incorporates the concepts of hybridagnetomotive force and flux shunt is proposed in this research. The hybrid magnetomotive force is provided by a low grade permanent magnet and an additional field winding to form an adjustable magnetic field, which is connected in the flux shunt magnetic circuit. The design procedures of this machine are presented in the following order: magnetic circuit model construction, optimization, and finite element analysis verification. Finally, a conceptual prototype is fabricated. The experimental results showhat increases in the field winding current can increase the machine efficiency and torque, while the armature voltage is kept constant. Moreover, the machine speed can also be changed by controlling the field winding current at constant armature voltage. This excellent machine characteristic could be applied to a continuous speed variation servo drive system.
Subjects
Demagnetization
magnetic circuits
permanent magnet
DC machine
flux shunt
hybrid excitation
Type
thesis
File(s)![Thumbnail Image]()
Loading...
Name
ntu-98-R96522803-1.pdf
Size
23.53 KB
Format
Adobe PDF
Checksum
(MD5):038ceb108709d5127cc738e048b0718d