scholarly journals Field Quality and Magnetic Center Stability Achieved in a Variable Permanent Magnet Quadrupole for the Ilc

Author(s):  
Y. Iwashita ◽  
T. Mihara ◽  
M. Kumada ◽  
C.M. Spencer
Author(s):  
Sun Jinji ◽  
Bai Guochang ◽  
Yang Lei

To measure current stiffness and displacement stiffness of permanent magnet biased radial magnetic bearing, a new stiffness measurement method is proposed for magnetically suspended flywheel (MSFW). The detailed stiffness measurement method is proposed in this paper. At first, the suspension force and stiffness characteristics of the permanent magnet biased radial magnetic bearing are studied using magnetic circuit method and finite element method (FEM). Second, the detailed stiffness measurement method of permanent magnet biased radial magnetic bearing is proposed. It has two procedures, one is the determination of the magnetic center in radial magnetic bearing when the gravity of rotor is in the +x(+y) direction and −x(−y) direction, respectively, then the current stiffness can be obtained, and the other is the calculation of the displacement stiffness according to the relationship between rotor displacement and current. A prototyped MSFW with angular moments of 50 Nms is manufactured, and the proposed stiffness measurement method of permanent magnet biased radial magnetic bearing is verified by prototyped experiments.


2010 ◽  
Vol 20 (3) ◽  
pp. 1964-1968 ◽  
Author(s):  
Cherrill M Spencer ◽  
Chris Adolphsen ◽  
Martin Berndt ◽  
David R Jensen ◽  
Ron Rogers ◽  
...  

1984 ◽  
Vol 45 (C1) ◽  
pp. C1-285-C1-291 ◽  
Author(s):  
R. Pauthenet
Keyword(s):  

Author(s):  
Jianqi Li ◽  
Yu Zhou ◽  
Jianying Li

This paper presented a novel analytical method for calculating magnetic field in the slotted air gap of spoke-type permanent-magnet machines using conformal mapping. Firstly, flux density without slots and complex relative air-gap permeance of slotted air gap are derived from conformal transformation separately. Secondly, they are combined in order to obtain normalized flux density taking account into the slots effect. The finite element (FE) results confirmed the validity of the analytical method for predicting magnetic field and back electromotive force (BEMF) in the slotted air gap of spoke-type permanent-magnet machines. In comparison with FE result, the analytical solution yields higher peak value of cogging torque.


2020 ◽  
Vol 64 (1-4) ◽  
pp. 959-967
Author(s):  
Se-Yeong Kim ◽  
Tae-Woo Lee ◽  
Yon-Do Chun ◽  
Do-Kwan Hong

In this study, we propose a non-contact 80 kW, 60,000 rpm coaxial magnetic gear (CMG) model for high speed and high power applications. Two models with the same power but different radial and axial sizes were optimized using response surface methodology. Both models employed a Halbach array to increase torque. Also, an edge fillet was applied to the radial magnetized permanent magnet to reduce torque ripple, and an axial gap was applied to the permanent magnet with a radial gap to reduce eddy current loss. The models were analyzed using 2-D and 3-D finite element analysis. The torque, torque ripple and eddy current loss were compared in both models according to the materials used, including Sm2Co17, NdFeBs (N42SH, N48SH). Also, the structural stability of the pole piece structure was investigated by forced vibration analysis. Critical speed results from rotordynamics analysis are also presented.


2020 ◽  
Vol 64 (1-4) ◽  
pp. 1495-1504
Author(s):  
Fangchao Xu ◽  
Yongquan Guo ◽  
Ran Zhou ◽  
Junjie Jin ◽  
Chuan Zhao ◽  
...  

To solve the problem of reduction of suspension force of permanent magnet system with variable magnetic flux path control, according to the structure of the system, suspension principle of the permanent magnet system with variable magnetic flux path control and the generation principle of the load torque, the influence of the mechanical structure of the system on the suspension force is analyzed by changing part of parameters of the system structure. The results show that the existence of magnetic isolation plate is the main reason for the decrease of suspension force, the permanent magnet ring can be thickened to 11.91 mm, the annular gap can be reduced to 1 mm, thickness of the “F” shaped magnetizer can be increased to 9 mm to increase the suspension force.


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