학술논문

Optimization of Coaxial Magnetic Gear Design and Magnet Material Grade at Different Temperatures and Gear Ratios
Document Type
Periodical
Source
IEEE Transactions on Energy Conversion IEEE Trans. Energy Convers. Energy Conversion, IEEE Transactions on. 36(3):2493-2501 Sep, 2021
Subject
Power, Energy and Industry Applications
Geoscience
Rotors
Magnetic gears
Magnetoacoustic effects
Magnetic flux
Torque
Prototypes
Aircraft
End effects
finite element analysis
genetic algorithm
magnetic gear
magnet grade
NdFeB
permanent magnet
SmCo
specific torque
temperature
torque density
Language
ISSN
0885-8969
1558-0059
Abstract
Magnetic gears, like mechanical gears, transform power between different speeds and torques; however, magnetic gears’ contactless nature provides inherent potential benefits over mechanical gears. A genetic algorithm was used to optimize magnetic gears at different temperatures across a range of gear ratios. Using different magnet material grades on the different rotors and for the tangentially and radially magnetized magnets can slightly increase the specific torque relative to designs with a single magnet material. The high pole count rotor requires a magnet material with higher coercivity than that of the low pole count rotor magnet material, especially for designs with a large gear ratio. While increasing the temperature produces an exponential decay in the achievable specific torque, with a compounding reduction of about 0.4% for each degree Celsius, the temperature does not significantly affect the optimal geometric parameters and primarily affects the optimal materials. The gear ratio significantly affects the optimal geometric parameters and can impact the optimal magnet materials. Additionally, the genetic algorithm was employed to characterize the impact of stack length using 3D finite element analysis. Designs with shorter stack lengths favored thinner magnets and higher pole counts and may be able to use magnet materials with lower coercivities.