International Journal of Applied Electromagnetics and Mechanics - Volume 20, issue 2

Authors: Jung, Sang-Yong | Jung, Hyun-Kyo

Article Type: Research Article

Abstract: This paper reports the methodological approaches to detent force reduction in the steel-cored Permanent Magnet Linear Synchronous Motor (PMLSM). For the detail investigations and overviews on the detent force, analytic solutions considering the various reluctances in the air-gap were obtained using the Space Harmonic Method. The validity of this method was confirmed by comparing the results of the FEM. With the thorough investigation of the causes of detent force, the reduction methods that minimize the force …ripple under the consideration of manufacturing feasibility are introduced, and certified by experimentation of the test machine. Show more

DOI: 10.3233/JAE-2004-293

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 20, no. 2, pp. 57-70, 2004

Authors: Tan, Qing Chang | Kou, Zun Quan | Li, Wei | Pei, Yong Chen

Article Type: Research Article

Abstract: In the present work, the distribution of non-uniform magnetization of magnetic rings is experimentally measured and analyzed. The effects of non-uniform magnetization and the soft-magnetic material on the performance of a magnetic bearing are investigated using the theory of magnetic charges, and a model for predicting magnetic force of magnetic-thrust bearings constructed from permanent magnets is developed. The model is verified using the experimental rig built. From the model, fluctuations of the magnetic force and …bearing stiffness caused by the non-uniform magnetization are calculated and analyzed. Show more

Keywords: magnetic bearing, magnetic force, magnetization, friction, bearing stiffness

DOI: 10.3233/JAE-2004-296

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 20, no. 2, pp. 71-80, 2004

Authors: Lin, Hsien-Mou | Lin, Chun-Bo | Chen, Shin-Cheng

Article Type: Research Article

Abstract: The magnetoelastic problem of curvilinear cracks lying along the interface between two dissimilar ferromagnetic materials under remote uniform magnetic induction is considered. On the basis of the Hilbert formulation and a special technique of analytical continuation, the solutions of the magnetic and the magnetoelastic stress fields either in the matrix or in the inclusion are expressed in a general form. Just like the pure elastic problem of curved cracks or the magnetoelastic problem of straight cracks …in bonded dissimilar media, the trig-log character for the singularity of magnetoelastic stresses is found in this paper. Both the explicit solutions and the numerical results for the illustrating case of a single circular-arc crack in bi-material plate with typical ferromagnetic materials are given to elucidate the use of the present study. It is noted that the stress intensity factors are obtained and verified by comparison with the existing ones under special cases. The validity of the crack opening condition is also discussed. Show more

DOI: 10.3233/JAE-2004-298

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 20, no. 2, pp. 81-103, 2004

Authors: Im, Chang-Hwan | Jung, Hyun-Kyo | Kim, Ji-Hoon | Hahn, Song-Yop | Hahn, Sung-Chin

Article Type: Research Article

Abstract: In this paper, a modular toroid-type SMES was optimized using a recently developed constrained optimization technique named co-evolutionary augmented Lagrangian method (CEALM). The objective of the optimization was to minimize the total length of HTS superconductor satisfying some equality and inequality constraints. The constraints were calculated using 3-D magnetic field analysis techniques and an automatic tetrahedral mesh generator. Optimized results were verified by 3D finite element method (FEM).

Keywords: constrained optimization, co-evolutionary augmented lagrangian method (CEALM), finite element method (FEM), superconducting magnetic energy storage (SMES)

DOI: 10.3233/JAE-2004-299

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 20, no. 2, pp. 105-114, 2004