• Title/Summary/Keyword: LIM

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Light-Weight Linear Induction Motor for Light Railway Train (경량전철 추진시스템용 Linear Induction Motor의 경량화)

  • Kim, K.C.;Lee, K.J.;Lee, J.I.;Park, J.T.;Kwon, J.L.;Kim, J.K.
    • Proceedings of the KIEE Conference
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    • 1999.11b
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    • pp.40-42
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    • 1999
  • In this paper, light-weight system of linear induction motor(LIM) for light railway train is presented, and is compared with former type of LIM. For the light-weight system without modification of motor size the material of primary core(silicon steel) is changed with iron-cobalt alloy and the material of primary winding(copper) is changed with aluminium. The characteristics of LIM are analyzed. Specially, the air gap magnetic flux density distribution due to end effect is showed with motor velocity, we will present papers continuously through designing and testing a trial product.

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Effect on characteristics of thrust force of LIM by Rotational type tester (회전기 타입의 시험기가 LIM의 추력 특성에 미치는 영향)

  • Ham, Sang-Hwan;Won, Sung-Hong;Lee, Sung-Gu;Cho, Su-Yeon;Kim, Yoon-Sung;Lee, Ju
    • Proceedings of the KIEE Conference
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    • 2008.07a
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    • pp.643-644
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    • 2008
  • This paper is analyzed the effect on characteristics of thrust force of linear induction motor(LIM) by rotational type tester. Many kinds of tester have a rotational shape because of a finite length of railroad. Whereas effects by using rotational type tester are generally unknown. For reason of that, this paper will be analyzed the effect on characteristics by rotational type tester using 2D finite element method(FEM), and then will be compared a thrust force between linear type tester and rotational type tester.

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An extension of the hong-park version of the chow-robbins theorem on sums of nonintegrable random variables

  • Adler, Andre;Rosalsky, Andrew
    • Journal of the Korean Mathematical Society
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    • v.32 no.2
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    • pp.363-370
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    • 1995
  • A famous result of Chow and Robbins [8] asserts that if ${X_n, n \geq 1}$ are independent and identically distributed (i.i.d.) random variables with $E$\mid$X_1$\mid$ = \infty$, then for each sequence of constants ${M_n, n \geq 1}$ either $$ (1) lim inf_{n\to\infty} $\mid$\frac{M_n}{\sum_{j=1}^{n}X_j}$\mid$ = 0 almost certainly (a.c.) $$ or $$ (2) lim sup_{n\to\infty}$\mid$\frac{M_n}{\sum_{j=1}^{n}X_j}$\mid$ = \infty a.c. $$ and thus $P{lim_{n\to\infty} \sum_{j=1}^{n}X_j/M_n = 1} = 0$. Note that both (1) and (2) may indeed prevail.

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Vector Control Simulation of Single Sided Linear Induction Motor (편측형 선형유도전동기의 벡터제어 시뮬레이션)

  • Chung Byung-Ho;Lim Hong-Woo;Choi Youn-Ok;Cho Geum-Bae;Baek Hyung-Lae;Oh Geum-Gon
    • Proceedings of the KIPE Conference
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    • 2002.07a
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    • pp.209-212
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    • 2002
  • LIM have mainly different point considering rotary induction motor, that is end effect. In this paper described that, end effect, adding to the rotary induction motor, They can be designed because of affects magnetizing inductance and series resistance in the d-axis circuit. After LIM modeling, using SVPWM, apply to vector control this model. We can verify feasibility of field onented control technology can control speed by simulation.

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Air Gap Change of a Maglev Vehicle at the Moment a Linear Induction Motor Runs (자기부상열차 가속 순간 부상공극 변화)

  • Shin, Hyeon-Jae;Han, Hyung-Suk;Kim, Dong-Sung;Kim, Bong-Seup
    • Proceedings of the KSR Conference
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    • 2009.05a
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    • pp.1218-1223
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    • 2009
  • LIM(Linear induction motor)s are the main type of motors used for urban Maglev vehicles because they are less expensive to operate at a lower speed than linear synchronous motors. An LIM generates an attraction force while running, which perturbs the air gap of the electromagnet. This undesirable air gap variation could result in the mechanical contact of an electromagnet with the reaction plate. For this reason, the magnitude of the air gap variation must be limited within a certain range. The air gap changes when running the 1/2 vehicle under development for testing are analyzed through a test on the test track at KIMM. The results from this study could be used to minimize the air gap variations due to attraction force from LIM.

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Chlorakali Electrolysis에서 한계전류밀도의 변화

  • 황민재;민병렬
    • Proceedings of the Membrane Society of Korea Conference
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    • 1995.10a
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    • pp.52-53
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    • 1995
  • 전해질용액에 있는 이온교환막을 통해 전류가 흐를 때 막표면에는 경계층이 형성된다. 희석실쪽 막표면에서 전해질의 농도는 감소하고 농축실쪽에서 증가 하는 농도분극현상이 일어난다. 이와 같은 농도분극현상은 전류밀도에 벼놔를 주어 에너지 소비를 증가시키고 막표면에 스케일을 형성할 수도 있다. ED에서는 농축실보다는 희석실쪽의 농도분극현상이 더 많은 관심을 갖게 되며 이 부분 연구가 활발하게 진행된다. 따라서 전기 투석을 이용한 물질분리는 항상 한계전류밀도이하에서 이루어져야 하는데 i$_{lim)$은 막자체의 성능 외에도 용액의 종류및 농도, 온도, pH, 전압등에 의해 변화한다. 따라서 i$_{lim)$이 각 변수에 의해 얼마만큼 변화하는지를 살펴봄으로써 임의의 환경에서 i$_{lim)$을 추정할 수 있는 모델을 제시하고자 한다.

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Study on Hybrid Control for Motion Control of Mobile Robot Systems (이동로봇의 동작 제어를 위한 하이브리드 시스템 제어에 관한 연구)

  • Lim, Mee-Seub;Lim, Jin-Mo;Lim, Joon-Hong;Oh, Sang-Rok
    • Proceedings of the KIEE Conference
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    • 1998.07g
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    • pp.2348-2350
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    • 1998
  • The hybrid control system for a wheeled mobile robot with nonholonomic constraints to perform a cluttered environment maneuver is proposed. The proposed hybrid control system consists of a continuous state system for the trajectory control, a discrete state system for the motion and orientation control, and an interface control system for the interaction process between the continuous dynamics and the discrete dynamics The continuous control systems are modeled by the switched systems with the control of driving wheels, and the digital automata for motion control are modeled and implemented by the abstracted motion of mobile robot. The motion control tasks such as path generation, motion planning, and trajectory control for a cluttered environment are investigated as the applications by simulation studies.

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Test for the Dynamic Characteristics of Inverter-fed LIMs (유도형 리니어모터의 인버터 운전시의 동특성 시험)

  • Jang, S.M.;Jeong, S.S.;Lee, S.L.;Yang, H.S.;Jung, R.K.;Park, C.I.
    • Proceedings of the KIEE Conference
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    • 1998.07a
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    • pp.284-286
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    • 1998
  • In this paper, the experiment on the dynamic characteristics of arch-type LIM is treated. The LIM has been experimented by using the rotational drum type system, which has a motionless short primary propelling a drum. Tests were performed by a PC-based data acquisition system. The input voltage of LIM driven by PWM inverter involves time harmonics. Therefore, the performance of inverter was analyzed for test and simulation.

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