• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.850-851
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• 2008

This paper compares and investigates the vibration and noise characteristics through simulations of 12/8 and 6/4 switched reluctance motors (SRMs). The radial force which is the main source of vibration is computed from two-dimensional(2D) transient magnetic finite element analysis (FEA) and compared in both time and frequency domain. At the same output power, the radial force of 6/4 SRM is found to be more than two times as that one of 12/8 SRM. Three-dimensional structural finite-element analysis (3D FEA) is used to study the mechanical characteristics. It can be concluded from static structural analysis that the maximum total deformation could be reduced to 1/26 if the motor is designed with 12/8 structure instead of 6/4. The dominant vibration modes are verified by modal analysis.

• 한국초전도ㆍ저온공학회논문지
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• 제16권2호
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• pp.47-53
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• 2014

In this paper, the general electromagnetic design process of a 10-MW-class high-temperature superconducting (HTS) synchronous generator that is intended to be utilized for large scale offshore wind generator is discussed. This paper presents three-dimensional (3D) electromagnetic design proposal and electrical characteristic analysis results of a 10-MW-class HTS synchronous generator for wind power. For more detailed design by reducing the errors of a two-dimensional (2D) design owing to leakage flux in air-gap, we redesign and analyze the 2D conceptual electromagnetic design model of the HTS synchronous generator using 3D finite element analysis (FEA) software. Then electrical characteristics which include the no-load and full-load voltage of generator, harmonic contents of these two load conditions, voltage regulation and losses of generator are analyzed by commercial 3D FEA software.

• 전기학회논문지
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• 제60권5호
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• pp.942-948
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• 2011

This paper deals with characteristic analysis of axial flux permanent magnet (AFPM) machines with axially magnetized PM rotor using quasi-3-D analysis modeling. On the basis of magnetic vector potential and a two-dimensional (2-D) polar-coordinate system, the magnetic field solutions due to various PM rotors are obtained. In particular, 3-D problem, that is, the reduction of magnetic fields near outer and inner radius of the PM is solved by introducing a special function for radial position. And then, the analytical solutions for back-emf and torque are also derived from magnetic field solutions. The predictions are shown in good agreement with those obtained from 3-D finite element analyses (FEA). Finally, it can be judged that analytical solutions for electromagnetic quantities presented in this paper are very useful for the AFPM machines in terms of following items : initial design, sensitivity analysis with design parameters, and estimation of control parameters.

• Journal of Electrical Engineering and Technology
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• 제9권3호
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• pp.926-931
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• 2014

This paper presents the torque calculation and parametric analysis of synchronous permanent magnet couplings (SPMCs). Based on a magnetic vector potential, we obtained the analytical magnetic field solutions produced by permanent magnets (PMs). Then, the analytical solutions for a magnetic torque were obtained. All analytical results were extensively validated with the non-linear a two-dimensional (2D) finite element analysis (FEA). In particular, test results such as torque measurements are presented that confirm the analysis. Finally, using the derived analytical magnetic torque solutions, we carried out a parametric analysis to determine the influence of the design parameters on the SPMC's behavior.

• The Journal of Advanced Prosthodontics
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• 제13권4호
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• pp.216-225
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• 2021

PURPOSE. The aim of this study is to evaluate the effects of canine guidance occlusion and group function occlusion on the degree of stress to the bone, implants, abutments, and crowns using finite element analysis (FEA). MATERIALS AND METHODS. This study included the implant-prosthesis system of a three-unit bridge made of monolithic zirconia and hybrid abutments. Three-dimensional (3D) models of a bone-level implant system and a titanium base abutment were created using the original implant components. Two titanium implants, measuring 4 × 11 mm each, were selected. The loads were applied in two oblique directions of 15° and 30° under two occlusal movement conditions. In the canine guidance condition, loads (100 N) were applied to the canine crown only. In the group function condition, loads were applied to all three teeth. In this loading, a force of 100 N was applied to the canine, and 200-N forces were applied to each premolar. The stress distribution among all the components of the implant-bridge system was assessed using ANSYS SpaceClaim 2020 R2 software and finite element analysis. RESULTS. Maximum stress was found in the group function occlusion. The maximum stress increased with an increase in the angle of occlusal force. CONCLUSION. The canine guidance occlusion with monolithic zirconia crown materials is promising for implant-supported prostheses in the canine and premolar areas.

• 전기학회논문지
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• 제60권11호
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• pp.2035-2042
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• 2011

In this paper, we proposed the outer-rotor type of FSPM motor for high speed operation and optimized motor shape. First of all, combinations of pole and slot numbers are examined for the optimal back-EMF and cogging torque, then optimizes the better shape design of the permanent magnet, rotor pole width. Further, The winding turns are obtained by circle of the voltage limit equation and motor parameters to minimize the current and to improve the efficiency. As a result, the performance of the designed model is satisfied, and it is verified through a two-dimensional finite element method (2D-FEA).

• 대한기계학회논문집A
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• 제25권6호
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• pp.1004-1014
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• 2001

The fully automatic algorithm from initial finite element mesh generation to remeshing in two dimensional geometry is introduced using bubble packing method (BPM) for finite element analysis. BPM determines the node placement by force-balancing configuration of bubbles and the triangular meshes are made by Delaunay triangulation with advancing front concept. In BPM, we suggest two node-search algorithms and the adaptive/recursive bubble controls to search the optimal nodal position. To use the automatically generated mesh information in FEA, the new enhanced bandwidth minimization scheme with high efficiency in CPU time is developed. In the remeshing stage, the mesh refinement is incorporated by the control of bubble size using two parameters. And Superconvergent Patch Recovery (SPR) technique is used for error estimation. To verify the capability of this algorithm, we consider two elasticity problems, one is the bending problem of short cantilever beam and the tension problem of infinite plate with hole. The numerical results indicate that the algorithm by BPM is able to refine the mesh based on a posteriori error and control the mesh size easily by two parameters.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.1210-1211
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• 2011

The inherent drawback of iron-core type permanent magnet linear synchronous motor (PMLSM) is detent force that is dependent on several major factors such as PM length, slot clearance, and skewing. To minimize the detent force, this paper proposes a structure optimization using the combination computation of two dimensional (2-D) finite element analysis (FEA) and response surface methodology (RSM). The RSM, that is a collection of the statistical and mathematical techniques, is utilized to predict the global optimal solution based on the FEA calculated results of the detect forces for different combinations of factors. With the help of the combination computation the high capacity iron-core type PMLSM with more than 12000 N propulsion forces only contains less than 3 N detent forces.

• 전기학회논문지
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• 제64권4호
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• pp.545-551
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• 2015

This paper deals with torque analysis of magnetic spur gear with radial magnetized permanent magnets based on analytical method. The analysis is implemented in three parts: First, on the basis of magnetic vector potential and a two-dimensional (2D) polar-coordinate system, the magnetic field solution due to permanent magnet of source gear are obtained. And by using derived magnetic field solutions, the analytical solutions for external magnetic field distribution which affects load gear are obtained. Second, by using coordinate conversion, external magnetic field which is on the primary coordinate system is converted to the secondary coordinate system. Finally, the load gear is reduced to equivalent current densities, and the torque is computed on these currents in the external field of the source magnet. These analytical results are validated by comparing with the 2-D finite element analysis (FEA).

• 조명전기설비학회논문지
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• 제27권9호
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• pp.44-52
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• 2013

This paper presents the development of 10 kW permanent magnet synchronous generator (PMSG) for small hydropower plants considering flow rates and net head. The initial and detailed design are determined using a load distribution method (LDM) which is a well-known method for designing an electric machine and a 2D-FEA which is performed for more accurate analysis of PMSG. The characteristic analysis results of proposed model with straight line magnet are satisfied with the initial model with curved magnet. Finally, the analysis and the design results are confirmed by the experimental results.