• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.615-616
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• 2012

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.11a
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• pp.503-504
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• 2010

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.19 no.4
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• pp.553-561
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• 2010

In flat panel display or semiconductor industries, they install the equipments with fine line width and high throughput for fabrication and inspection. The equipments are required to have the linear stage which can position the work-piece with high speed, fine resolution on wide range of motion. In this paper, a precision planar linear XY stage is proposed. The stage has a symmetric planar window configuration and is guided by air-bearings on granite plate. The symmetric planar window configuration makes the stage has robustness against dynamic and thermal disturbances. The air-bearings let the stage move smooth on straight guide bar and flat granite surface. The stage is actuated by linear motor with Halbach magnet array (HMA). HMA generates more confined magnetic flux than conventional array. The linear motors are optimized by using sequential quadratic programming (SQP) with the several constraints that are thermal dissipation, required power, force ripple and so on. The planar linear XY stage with the symmetric planar configuration and the linear motors is implemented and then the performance such as force ripple, resolution and stroke are evaluated.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.3B no.4
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• pp.179-187
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• 2003

In the machine tool industry, direct drive linear motor technology is of increasing interest as a means to achieve high acceleration and to increase reliability. This paper analyzes and compares the characteristics of the tubular linear actuator with the cylindrical Halbach and radial array, respectively. A tubular linear actuator with cylindrical Halbach array, consisting of parallel magnetized arc segments instead of ideal radial and axial magnetized rings, is manufactured. The magnetic field solutions due to the PMs and to the currents are established analytically in terms of vector potential, using the 2-D cylindrical coordinate system. Motor thrust, flux linkage and back emf are then derived. Thrust characteristics according to such design parameters as magnet height and air gap length are also given. The results are validated extensively by comparison with finite element analysis (FEA). Test results such as thrust measurements are also given to confirm the analysis.

• Journal of Electrical Engineering and Technology
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• v.13 no.1
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• pp.352-361
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• 2018

This paper proposes a sensing system of the Halbach array permanent magnet spherical motor(PMSM). The rotor position can be obtained by solving three rotation angles, which revolves around 3 reference axes of the stator. With the development of 3-D hall sensor, the position identification problem of the Halbach array PMSM based on rotor magnetic field is studied in this paper. A nonlinear and serious coupling relationship between the rotation angles and the measured magnetic flux density is established on the basis of the rotation transformation theory and the magnetic field model. In order to get rid of the influence on position detection caused by the harmonics of rotor magnetic field and the stator coil magnetic field, a sensor location combination scheme is proposed. In order to solve the nonlinear equation fast and accurately, a new position solution algorithm which combines the merits of gradient projection and particle swarm optimization(PSO) is presented. Then the rotation angles are obtained and the rotor position is identified. The validity of the sensing system is verified through the simulation.

• Journal of the Korean Magnetics Society
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• v.25 no.2
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• pp.58-65
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• 2015

This paper deals with the generating characteristic analysis of permanent magnet linear generator (PMLG) with double-sided Halbach magnet array mover and three phases concentrated stator windings by using analytical method. On the basis of a magnetic vector potential and Maxwell's equations, governing equations are obtained, and magnetization modeling for Halbach magnet array is performed analytically by using the Fourier series. And then, we obtain electrical parameters such as back-EMF constant, resistance, and coil inductance based on magnetic field calculations. Finally, analytical results for generating performance are confirmed by comparing with finite element analysis results.

• Journal of the Korean Magnetics Society
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• v.24 no.5
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• pp.152-159
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• 2014

Magnetic gear can transmit torque without any mechanical contact among rotational parts in rotating mechanical systems. Especially, magnetic gear using rare-earth PMs can be used in variety of industry application because of their great power efficiency. Thus, recent trend shows that magnetic gear can be replaced with common mechanical gear. This paper deals with comparison and torque analysis for magnetic gears with parallel and Halbach magnetization according to various design parameters. Using a two dimensional (2D) finite element (FE) analysis, suitable gear ratio is selected. We performed analysis for magnetically connected inner and outer torque with respect to various design parameters including thickness of inner and outer PM, steel pole angle, segments of Halbach array and magnetization pattern of inner and outer PMs. Finally, we can obtain improved design model having parallel and Halbach magnetization with larger torque, compared with an initial design model.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.5B no.2
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• pp.154-161
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• 2005

In the machine tool industry, direct drive linear motor technology is an interesting means to achieve high acceleration, and to increase reliability. This paper analyzes and compares the characteristics of a tubular linear motor with Halbach and radial magnet array, respectively. First, the governing equations are established analytically in terms of the magnetic vector potential and two dimensional cylindrical coordinate systems. Then, we derive magnetic field solutions due to the PMs and the currents. Motor thrust, flux linkage and back emf are also derived. The results are shown to be in good conformity with those obtained from the commonly used finite element method. Finally, control parameters are obtained from analytical solutions.

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.679-681
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• 2002

본 논문에서는 해석적 기법을 적용하여, 추진력과 부상력을 동시 제어하는 Planar Motor의 정밀 특성 해석을 나타내었다. 특히, 본 해석 모델은 가동자의 요크를 제거하기 위한 Halbach Array를 적용하였으며, 이에 대한, 정밀한 특성 해석을 위해 공간고조파 해석법도 제안한다. 또한, 해석해 검증을 위하여 유한 요소해석법에 의한 결과와 비교 분석을 하며, 이를 토대로 한 해석 모델의 동작 특성을 살펴본다.

• Proceedings of the KIEE Conference
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• 2008.04c
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• pp.86-88
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• 2008

The rotational loss is one of the most important problems for the practical use of the high power Flywheel Energy Storage System (FESS). This rotational loss is divided as the mechanical loss by windage and bearing and iron loss by hysteresis loop and eddy current in the part of the magnetic field. So, In this paper, a double-sided PMSM/G without the iron loss is designed by analytical method of the magnetic field and estimation of the back-EMF constant represented as the design parameter. This design model consists of the double-sided PM rotor with Halbach magnetized any and coreless 3-phase winding stator. The results show that the double-sided PMSM/G without iron loss can be applicable to the high power FESS.