• Title/Summary/Keyword: induction mechanism

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Transverse flux circumferential induction method as a driving principle of the contact-free revolving stage (비접촉 회전 스테이지에의 구동 원리로서의 횡자속 원주형 유도 방법)

  • Kim, Hyo-Jun;Jung, Kwang-Suk
    • Journal of the Korean Society for Precision Engineering
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    • v.22 no.10 s.175
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    • pp.72-79
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    • 2005
  • Compared with linear induction principle, the transverse flux circumferential induction principle is suggested as a driving mechanism of the revolving stage, which can rotate contactlessly without any supporting structure. The stage realizes the integrated motion of levitation, rotation, and planar perturbation, using the two-axis forces, normally directed force of the air-gap and tangential force, of the induction drivers mounted on the stator uniformly. In this paper, the force generating mechanism of the stage is described in detail. First, the various core shapes generating the transverse flux are analyzed to guarantee the proper thrust force. And the vector force intensity of the circumferential induction driver constituting the stage is compared with that of the linear induction driver. Especially it is shown that the magnetic force of the suggested system can be modeled with the linear equivalent model, including the test verification.

An Analysis on the Performance of a Twin Stator Single-Phase Induction Manchine (단상 Twin sSator유도기의 특성해석에 관한 연구)

  • Young Moon Hwang
    • 전기의세계
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    • v.21 no.3
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    • pp.7-18
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    • 1972
  • An analysis is made for the performance of twin stator single-phase induction machine having any movable asymmetrical angle of stator windings, with any symmetrical or asymmetrical magnetizing reactance and winding turn-ratio between two stators, provided that asymmetrical common squirrel cage rotor is utilized. This mechanism is a new type, which has the advantage of mading only not the performance prediction in applications as a single-phase electromagnetic driving mechanism but also the analysis prediction of single-phase induction motor with not in quadrature axis. The basis of the analyses are lead by Kron's primitive machine matrix and Morrill's double-revolving field concept. All the performances can be calculated from the test values and design details of the asymmetrical magnetizing reactance twin stator single-phase induction machine and verified by test. And its validity is still demonstrated to the pure twin stator single-phase induction machine.

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The Prevention of The Longitudinal Deformation due to Fillet Welding by using Induction Heating (고주파가열에 의한 Built-up재의 용접종굽힘 변형방지)

  • Park Jeong-Ung;Chang Kyong-Ho;Lee Hae-Woo;An Gyu-Baek
    • Journal of Welding and Joining
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    • v.23 no.3
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    • pp.47-53
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    • 2005
  • Longitudinal deformation is produced by fillet welding during the fabrication of built-up beams and decreases productivity and quality because it needs an extra correcting process. The deformation is caused by welding moment, which is the value multiplied the welding shrinking farce by the distance from the neutral axis. This welding moment can be offset by generating a moment in the same magnitude and in an opposite direction by induction heating. The location and quantity of the induction heating are decided via experiments and simple equations. This study, first, clarifies the creation mechanism of the longitudinal deformation with FEM analysis. Then, we presents the preventive method of this deformation by induction heating basing on the mechanism and verifies its validity through analysis and experiments.

The Prevention of the Longitudinal Deformation on the Built­Up Beam by using Induction Heating

  • Park, J.U.;Lee, C.H.;Chang, K.H.
    • International Journal of Korean Welding Society
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    • v.3 no.2
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    • pp.7-14
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    • 2003
  • During the manufacture of a ship, longitudinal deformation is produced by fillet welding on the Built­Up beam used to improve the longitudinal strength of a ship. This deformation needs a correcting process separate from a manufacture process and decreases productivity and quality. This deformation is caused by welding moment, which is the value multiplied the shrinking force due to welding by the distance from the neutral axis on a cross section of Built­Up beam. This deformation can be offset by generating a moment which is the same magnitude with and is located in an opposite direction to the welding moment on web plate by induction heating. Accordingly, this study clarifies the creation mechanism of the longitudinal deformation on Built­Up beam with FEM analysis and presents the preventative method of this deformation by induction heating basing the mechanism and verifies its validity through analysis and experiments. The induction heating used here is performed by deciding its location and quantity with experiments and simple equations and by applying them to a real structure.

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MRAC Fuzzy Control for High Performance of Induction Motor Drive (유도전동기 드라이브의 고성능 제어를 위한 MRAC 퍼지제어)

  • 정동화;이정철
    • The Transactions of the Korean Institute of Power Electronics
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    • v.7 no.3
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    • pp.215-223
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    • 2002
  • This paper investigates the adaptive control of a fuzzy logic based speed and flux controller fur a vector controlled induction motor drive. A model reference adaptive scheme is proposed in which the adaptation mechanism is executed by fuzzy logic based on the error and change of error measured between the motor speed and output of a reference model. The control performance of the model reference adaptive control(MRAC) fuzzy controller is evaluated by simulation for various operating conditions. The validity of the Proposed MRAC fuzzy controller is confirmed by performance results for induction motor drive system.

MRAS Based Speed Estimator for Sensorless Vector Control of a Linear Induction Motor with Improved Adaptation Mechanisms

  • Holakooie, Mohammad Hosein;Taheri, Asghar;Sharifian, Mohammad Bagher Bannae
    • Journal of Power Electronics
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    • v.15 no.5
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    • pp.1274-1285
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    • 2015
  • This paper deals with model reference adaptive system (MRAS) speed estimators based on a secondary flux for linear induction motors (LIMs). The operation of these estimators significantly depends on an adaptation mechanism. Fixed-gain PI controller is the most common adaptation mechanism that may fail to estimate the speed correctly in different conditions, such as variation in machine parameters and noisy environment. Two adaptation mechanisms are proposed to improve LIM drive system performance, particularly at very low speed. The first adaptation mechanism is based on fuzzy theory, and the second is obtained from an LIM mechanical model. Compared with a conventional PI controller, the proposed adaptation mechanisms have low sensitivity to both variations of machine parameters and noise. The optimum parameters of adaptation mechanisms are tuned using an offline method through chaotic optimization algorithm (COA) because no design criterion is given to provide these values. The efficiency of MRAS speed estimator is validated by both numerical simulation and real-time hardware-in-the-loop (HIL) implementations. Results indicate that the proposed adaptation mechanisms improve performance of MRAS speed estimator.

Development of an Induction Motor Vector Control System Using Simulink/RTW (Simulink/RTW를 이용한 유도전동기 벡터제어시스템 개발)

  • 강문호
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.119-119
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    • 2000
  • In this research an induction motor vector control system was developed using Simulink and RTW(Real Time Workshop). On the Simulink window, control system is designed in the form of block diagrams, program codes are produced automatically with the RTW, then c compiler compiles the program codes. With this automatic real time program producing mechanism rapid prototyping is realized without the time-consuming manual program coding procedures. To show effectiveness of the proposed designing scheme a DSP-based induction motor vector control system was constructed and implemented

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THE PREVENTION OF THE LONGITUDINAL DEFORMATION DUE TO FILLET WELDING BY USING INDUCTION HEATING

  • Park, Jeong-Ung;Lee, Chin-Hyung;Chang, Kyong-Ho
    • Proceedings of the KWS Conference
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    • 2002.10a
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    • pp.816-825
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    • 2002
  • During the manufacture of a ship, longitudinal deformation is produced by fillet welding on the BuiltUp beam used to improve the longitudinal strength of a ship. This deformation needs a correcting process separate from a manufacture process and decreases productivity and quality. This deformation is caused by welding moment, which is the value multiplied the shrinking force due to welding by the distance from the neutral axis on a cross section of Built-Up beam. This deformation can be offset by generating a moment which is the same magnitude with and is located in an opposite direction to the welding moment on web plate by induction heating. Accordingly, this study clarifies the creation mechanism of the longitudinal deformation on Built-Up beam with FEM analysis and presents the preventative method of this deformation by induction heating basing the mechanism and verifies its validity through analysis and experiments. The induction heating used here is performed by deciding its location and quantity with experiments and simple equations and by applying them to areal structure.

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Study on Damage Mechanism Analysis and Recovery Characteristic of the Large Scale Steam Turbine Cased by Water Induction (대형 증기터빈 물유입에 의한 손상메커니즘 분석과 원상복구특성 연구)

  • Kim, D.Y.;Park, G.H.;Lee, B.H.
    • Journal of Power System Engineering
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    • v.15 no.5
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    • pp.22-29
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    • 2011
  • In this study, the damage mechanism of large scale steam turbine due to water induction was analyzed and recovery characteristics were reviewed. A turbine consists of the rotating rotor and the stationary casing, and the clearance between them is very small for the efficiency enhancement. If water induction, while relatively cold steam or water is introduced into turbine, occurs, the considerable humping is caused at the casing near the initial water induction point and that induces the rubbing between rotor and casing. Finally, it leads to the catastrophic failure. Bowed rotor has the different characteristics in the recovery depending on damage degree. The elastic deformation due to light rubbing is recovered by turning the rotor with 3 rpm under normal operation condition, but most plastic deformation due to rubbing deforms the local microstructure and that results in permanent deformation which could not be recovered under normal operation condition. Bowed rotor has diverse characteristics depending on the recovery method, and the method is empirical and needs the cutting edge technology. Careful recovery treatment of the rotor will eliminate the risks and secure the high quality rotor similar to new rotor. If any critical error is made during the recovery, the rotor would not be recovered permanently and it should be scrapped.