• 한국정밀공학회지
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• 제22권12호
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• pp.34-41
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• 2005

There is a strong demand fur the contactless transportation device fur a hard disk and silicon wafer without contaminating and damaging them. To fulfill this requirements, A transportation device fur them has been proposed. But the device needs many of costly displacement sensors positioned along the transportation interval and possesses a very complicated controller and driving scheme. To overcome those kinds of drawback, in this paper, we present a very simple and cost-effective transportation device which only consists of a linear guide, very simple electrostatic suspension system and driving circuit of stepping motor. The principle of stable suspension by relay feedback control, derivation of lateral restoring force, the design of transportation system are described, fellowed by the experimental system. Experimental results show that a 3.5-inch hard disk has been transported with a speed of approximately 20mm/s while being suspended stably at a gap of 0.25mm.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 추계학술대회논문집
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• pp.136-139
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• 2006

In this paper we propose a small form factor actuator using an inclined motion guide for auto-focusing and zoom motions for mobile information devices. The novel structure using the inclined motion guide and a lens-supporting beam converts the circular motion by an ultrasonic motor into the linear motion of the optical lens. The proposed actuator has a simple structure to minimizing the mechanical tolerance, and the stroke is easy to modify by controlling the inclined angle. Experiments using a prototype verify the validity of the model as small form factor optical actuator.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.74-76
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• 2006

This paper presents the experiment and characteristics analysis of electromagnetic pump using linear induction motor(LIM). The electromagnetic pump is used to transfer the molten metals by electromagnetic force of LIM. The characteristics of LIM pump for molten metals: zinc, tin, aluminum are analysed solving the magnetohydrodynamics at constant magnetic flux. The molten zinc is used in the experiment and the experimental results are compared with the analysis.

• 조명전기설비학회논문지
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• 제24권12호
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• pp.71-77
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• 2010

A discontinuity of magnetic circuits according to the end effect is generated in PMLSM. And magnetic state of the 3 phase coils becomes unbalanced. Due to the unbalanced magnetic state, the unbalanced flux linkage, back electro-magnetic force and inductance of the 3 phase coils appear. In result, the circulating current is generated by unbalanced inductance even if the input voltages are in balanced state. Then the thrust and efficiency are decreased because of the circulating current. Therefore, in this paper, the unbalanced inductance and the thrust reduction according to discontinuity of magnetic circuits are analyzed by FEA(2D). To demonstrate the validity of the analysis results, the experiment results are compared with analysis results.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2017년도 추계학술대회
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• pp.65-66
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• 2017

본 논문은 자기부상열차 시스템의 부상 신뢰도 향상을 위한 선형 유도전동기의 순시 제어기법을 제안한다. 선형 유도전동기는 자기부상열차의 추진을 담당하며, 운전 속도와 입력 주파수에 따른 슬립 특성이 존재한다. 이 슬립 특성은 전동기에서 발생되는 수직력과 밀접한 관련을 보이며, 이는 부상 시스템에 외란으로 작용된다. 따라서 본 논문에서는 선형 유도전동기의 특성을 FEM 해석을 통해 정확히 분석하고, 이를 반영한 최적 슬립 주파수 간접벡터제어 기법을 통해 부상 신뢰도 향상을 위한 새로운 순시 제어기법을 제안 하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.812_813
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• 2009

본 논문에서 로프리스 엘리베이터용 영구자석형(PM) 선형동기전동기(LSM)의 디텐트력을 저감하기 위하여 반응표면법(RSM)을 이용한 디텐트력의 최소화 설계 방법을 제안하였다. RSM을 이용하여 정수 슬롯형과 분수 슬롯형 PM-LSM의 설계변수를 추론하고 유한요소법(FEM)으로 디텐트력을 구하였다. 반응표면법과 유한요소법의 해석결과를 토대로 분수 슬롯형 PM-LSM이 주어진 체적의 엘리베이터 시스템에 적합한 형상임을 입증한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.165-167
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• 2007

영구자석 선형 동기 전동기(PMLSM)는 코깅력과 단부력에 의한 큰 추력 리플을 갖는 문제점이 있다. 본 논문에서는 영구자석 선형 동기 전동기의 디텐트력을 줄이기 위해 영구자석의 극수와 전기자의 슬롯수의 비를 변경한 새로운 구조의 단 1차형 영구자석 선형동기 전동기를 제안하였으며, 단부력을 줄이기 위하여 전기자의 길이 조정 및 챔퍼링을 통하여 영구자석 선형 동기 전동기를 설계하였다.

• 조명전기설비학회논문지
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• 제12권3호
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• pp.59-66
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• 1998

In this paper, the thrust control of PWM Inverter-Fed SLIM(Single-sided Linear Induction Motor) is achieved with Space Vector control and PI control. The trembling of air gap length which is occurred between the primary winding core and the secondary structure of the SLIM must be minimized in order to get quick response characteristics. First, the equivalent circuits and voltage equations of SLIM are shown on th suitable d-q axis which analyze characteristics of the thrust and the normal force. Also, modeling and analysis of the equivalent circuits transferred d-q axis are able to make robust transient torque from the current regulation in the equivalent circuit. These results exemplified the direct drive of SLIM with the reference speed and torque were verified by experiments.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2004년도 전력전자학술대회 논문집(1)
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• pp.316-320
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• 2004

This paper presents an advanced method for an initial pole position estimation of a PMLSM (Permanent Magnet Linear Synchronous Motor) that has an incremental encoder for servo applications but does not have Hall sensors as a magnetic pole sensor. The proposed algorithm finds either of two zero force positions and then the correct d-axis by appropriately using the secant method as a numerical method. It only requires the tuned current controller and the relative position information and so it can be simply applicable to a rotary PMSM. The experimental results show the validity of the proposed method with respect to accurate pole position estimation under the minimal moving distance during estimation process.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 B
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• pp.883-885
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• 2001

This paper deals with a comparison between the secondary Halbach array and conventional array of permanent magnets(PMs) in linear synchronous motor(LSM). The finite element method(FEM) is employed for characteristic analysis of the machine. Two types of PMLSM are analyzed and compared, with reference to the following parameters as variables: magnetic field, detent force, static thrust and thrust/secondary weight ratio.