• Proceedings of the KIEE Conference
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• 2001.04a
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• pp.393-396
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• 2001

According to the development of power electronic element(GTO, IGBT) and material for electrical machines(permanent magnet, super conductor), the technology for electrical machines is nowaday rapidly developing. Here with, a novel electrical machine, based on the new conception of transverse flux configuration leads to a considerable Increase in power density and enables simultaneously high efficiency. The transverse flux machine with PM excitation will be applied to gearless direct drives for railway traction system and magnetic levitation system. The designed and measured performance of transverse machine for railway traction system and magnetic levitation system revealed a great potential of system improvements to reduce linear motor mass and increase efficiency.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.6
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• pp.987-994
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• 2016

In this paper, we present a comparative analysis of surface-mounted permanent magnet synchronous motors (SPMSM) and interior permanent magnet synchronous motors (IPMSM). First, we use 2D finite element analysis (FEA) to analyze models satisfying the same rated conditions according to the torque-speed curve characteristics, which are determined from the operating conditions. Next, we manufacture an SPMSM and IPMSM having good performances from an electromagnetic perspective based on analysis results, namely the cogging torque, torque ripple, and efficiency. We analyze both of the manufactured machines when they are connected back-to-back and when they are used as a motor and a generator, respectively. The motor is driven by a commercial inverter and the generator is connected to a three-phase resistance load bank. Finally, based on experimental results, which include the total harmonic distortion (THD) of the back electro-motive force (EMF), cogging torque, efficiency, and mass, we determine the motor that is most suitable under requirements.

• Proceedings of the KIEE Conference
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• 2009.04b
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• pp.38-40
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• 2009

In order to achieve a gearless construction of the wind energy conversion system(WECS), a low-speed generator should be used. Of the various candidate machine types, radial-field, multi-pole, permanent magnet, synchronous machines may be used for low-speed applications. So, this paper deals with the design of direct-coupled, multi-pole radial field machines with permanent magnet(PM) excitation for wind power applications for cogging torque reduction through the determination of optimum pole arc/pitch ratio. On the basis of an equivalent magnetic circuit method(EMCM) and a space harmonic method(SHM), an initial design is performed considering restricted conditions. And then, a detailed design is made using a non-linear finite element analyses(FEA). Finally, test results concerning generating characteristics are given to confirm the validation of the design.

• Proceedings of the KIEE Conference
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• 2011.07a
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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.

• The Transactions of the Korean Institute of Power Electronics
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• v.13 no.4
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• pp.295-302
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• 2008

This paper examines the design and the performance of a PMA-RSM(permanent-magnet assisted reluctance synchronous motor) for washing machine. A FEM(finite element method) is used to analyze performance and maximum torque characteristic of the proposed PMA-RSM. The designed motor is a combination of salient poles, which is making reluctance torque, and permanent magnet which are located on the air-gap of rotor to get a enough torque during low speed resign. Typical flux barrier type reluctance synchronous motor and the effects of adding magnet into the flux barrier of the rotor of a PMA-RSM are compared and examined. Also the maximum torque point of the reluctance torque by reluctance and reaction torque by magnetic alignment torque, which is in barrier, of the proposed PMS-RSM are derived through simulation. Using this results, the characteristics analysis of a performance, an average torque and a torque ripple of flux barrier RSM and the proposed PMA-RSM are performed through FEM under the saturation effect respectively.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.882-883
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• 2011

This paper deals with comparison on Electromagnetic losses of slotted and slotless high-speed PM Machine for Micro Turbine. Losses are consist of core losses, copper losses and eddy current losses. We are using both analytical method and 2D Finite Element Method for more detailed losses analysis. And then We compare Electromagnetic losses of slotted and slotless PM synchronous machine. This machine has designed of a generator of 800W, 400000rpm and a starter of 400W, 200000rpm.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.1
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• pp.688-695
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• 2017

This paper deals with characteristics analysis of a permanent magnet (PM) linear generator using analytical methods for wave energy harvesting. The wave energy is carried out from the movement of a yo-yo system. A linear generator using permanent magnets to generate a magnetic force itself does not require a separate power supply and has the advantage of simple maintenance. In addition to the use of a rare earth, a permanent magnet having a high-energy density can be miniaturized and lightweight, and can obtain high energy-conversion efficiency. We derived magnetic field solutions produced by the permanent magnet and armature reaction based on 2D polar coordinates and magnetic vector potential. Induced voltage is obtained via arbitrary sinusoidal input. In addition, electrical parameters are obtained, such as back-EMF constant, resistance, and self- and mutual-winding inductances. The space harmonic method used in this paper is confirmed by comparing it with finite element method (FEM) results. These facilitate the characterization of the PM-type linear generator and provide a basis for comparative studies, design optimization, and machine dynamic modeling.

• Journal of international Conference on Electrical Machines and Systems
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• v.3 no.1
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• pp.72-77
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• 2014

To help machine designers to make precise design of large permanent magnet (PM) machines, this paper presents a set of design considerations that are very often ignored by machine designers. These considerations are categorized into several aspects: electromagnetic (EM) performance, losses and efficiency, fault and stability, and some other issues. The effects of various practical factors are presented and some corresponding design methods are introduced.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1080-1082
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• 2005

This paper presents the system design of permanent magnet linear synchronous machine with double-side PM mover and slotless iron-cored stator in the required speed and thrust. in this paper, the design of manufacturing motor is optimized by characteristics of motor parameters with the variation of PM size and coil turns. And, the permissible operating range of manufactured motor by determination of base speed and base thrust according to switching scheme of DC link voltage are offered. Finally, the results of analytical solutions are verificated by finite element analysis and experiment.

• Proceedings of the KIEE Conference
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• 2001.10a
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• pp.9-11
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• 2001

This paper deals with design and characteristic analysis of a permanent magnet linear synchronous motor for magnetic levitation stage of semi-conductor manufacture machine. In order to improve the control performance by detent force minimization, skew and PM offset method are used.