• Title/Summary/Keyword: Induction Phenomena

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Characteristics of the Voltages between the Communication Lines and Ground Induced by the Adjacent Artificial High-Voltage or Current ELF Source

  • Lee, Sang-Mu;Choi, Mun-Hwan;Cho, Pyung-Dong;Eun, Chang-Soo;Gimm, Yoon-Myoung
    • Journal of electromagnetic engineering and science
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    • v.9 no.4
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    • pp.175-181
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    • 2009
  • The measurements were performed to verify experimentally that the voltage arising on a telecommunication line by a power line is due to the induction phenomena because there has been an opinion that the arising voltage on a telecommunication line is not by induction, but by other causality. The voltage appeared on the telecommunication line by way of an electric field or magnetic field generated by the source apparatus that had been artificially made to provide intentional constant high-voltage or current in ELF, that is, 60 Hz as an emulated commercial power.

Analysis of the Transient Phenomena of a Squirrel-Cage Induction Motor by means of the Spiral Vector method and the Phase Segregation method (감쇠회전 벡터법과 상 분리법에 의한 농형 유도 전동기의 과도현상해석)

  • Jeong, Jong-Ho;Lee, Eun-Woong;Choi, Jae-Young
    • Proceedings of the KIEE Conference
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    • 2000.07b
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    • pp.644-646
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    • 2000
  • An induction motor can be controlled like a separately excited do motor by field oriented control(or vector control). In vector control, Because the transformation of the stator's 3-phase current into two orthogonal current is required. the control scheme is complicated. But, Yamamura proposed a field acceleration method(FAM) without the phase transformation. FAM simplify an implementation control scheme for induction motors. In this paper, the analysis of transient phenomena of a squirrel-cage induction motor was achieved by the spiral vector method and the phase segregation method. It simplified control schemes more than those of vector control.

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Analysis of the torque transient performance of the induction motor by means of phase segregation method (상분리법에 의한 유도전동기의 토오크 과도특성해석)

  • Jeong, Jong-Ho;Lee, Eun-Woong;Choi, Jae-Young
    • Proceedings of the KIEE Conference
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    • 2000.11b
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    • pp.247-249
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    • 2000
  • Transient phenomena cause delay in control response and must be studied and eliminated, if possible, suppressed. The difficulty in analyzing transient phenomena in ac machines comes from the large number of windings involved. But, it is possible that only one phase is used to represent three phases of the induction motor as called phase segregation method. The phase segregation method provides equivalent circuits for both the steady and transient states of induction motor. In this paper, analysis of the torque transient of the induction motor be carried out the phase segregation method and confirmed in the possibility of transientless torque control.

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Simulation of Line Heating by High frequency Induction Heating (고주파 유도 가열에 의한 선상가열 시뮬레이션)

  • 김호경;장창두
    • Journal of Ocean Engineering and Technology
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    • v.17 no.1
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    • pp.80-85
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    • 2003
  • In this study, we developed an analysis method of plate forming by induction heating, verifying the effectiveness of the present method through a series of experiments. The phenomena of the induction heating involves a 3D transient problem, coupled with electromagnetic, heat transfer, and elastoplastic large deformation analyses. To solve the problem, or present an appropriate model and an integrated system. Using the present analysis model, or can estimate the plate deformation in heating without experiments and simulate the plate bending process of induction heating.

Prediction and Measurement of Induction Phenomena in the 765 kV Double Circuit Transmission Line operated with two voltage grades (765 kV 송전선로에서의 이종 전압등급 병행 운전시의 유도현상 예측 및 실측 결과)

  • Kwak, J.S.;Kang, Y.W.;Shim, E.B.;Jeon, M.R.;Woo, J.W.;Bang, H.G.
    • Proceedings of the KIEE Conference
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    • 2003.07a
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    • pp.208-211
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    • 2003
  • The western route of KEPCO's 765 kV transmission line has been tentatively operating as 345 kV voltage before commercial operation. KEPCO decided to operate the 765 kV line for commercial operation after completing the test operation of 765 kV substation in 2002. In the process of energizing the line as 765 kV voltage, double circuit transmission line will be operated with two voltage grades of 765 kV and 345 kV. As the earthing switches are installed on both ends of the line, electrostatic induction voltage and electromagnetic induction current were calculated prior to the line energizing in order to confirm the ratings. The induced voltage and current are important for the maintenance of the parallel circuit. This paper presents the simulation results of electrical phenomena such as electrostatic induction voltage and electromagnetic induction current from the parallel line. The transmission line was modeled by EMTP (Electro-Magnetic Transient Program). The simulation results were compared with the measured results at the field.

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High Frequency Model of Inverter-fed Induction Motor (인버터 구동 유도 전동기 고주파 모델링)

  • Hong, Sun-Ki
    • Proceedings of the KIEE Conference
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    • 2001.07b
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    • pp.795-797
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    • 2001
  • Voltage varing Fate dv/dt which is applied to induction motor usually makes unnegligible leakage current and it flows through stator winding and motor frame. This kind of harmonic leakage current makes effect on power source and cuases electromagnetic trouble because the motor frame has earth. Therefore in this study, a high frequency induction motor model is developed and analyze the motor performance to explain the phenomena. Inverter model is also developed and is combined with the motel model to prepare the basis of the high frequency effects on inverter fed induction motor.

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Numerical Analysis of Plate Deformation by Induction Heating (고주파 유도 가열에 의한 판 변형의 간이 수치 해석)

  • 장창두;김호경;하윤석
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2002.04a
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    • pp.311-318
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    • 2002
  • In this study, we developed an analysis method of plate forming by induction heating and verified the effectiveness of the present method through a series of experiments. The phenomena of the induction heating is a 3D transient problem coupled with electromagnetic, heat transfer, and elastoplastic large deformation analyses. To solve the problem, we suggest a proper model and an integrated system. Using the present analysis model, we can estimate the plate deformation in heating without experiments and simulate the plate bending process of induction heating.

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Transient Simulation of a Self-Excited Induction Generator during Grid Faults

  • Kim, Chan-Ki;Choy, Young-Do;Lim, Seong-Joo
    • Journal of Power Electronics
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    • v.7 no.2
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    • pp.89-96
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    • 2007
  • This paper deals with the transient performance of an induction generator in a wind power plant. An induction generator and grid equipment may be damaged when a sudden disturbance occurs, for example, a sudden disconnection from the utility grid. The reasons for this are over-voltage and over speed. This paper analyzes this phenomena using PSCAD/EMTDC and coincides with its corresponding mathematical equation.

The Effects of Tunable Helmholtz Resonators on the Volumetric Efficiency in a Multi-cylinder Diesel Engine (가변 헬름홀츠 공진기가 다기통 디젤기관의 체적효율에 미치는 영향)

  • Kang, H.Y.;Koh, D.K.;Ahn, S.K.
    • Journal of Power System Engineering
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    • v.9 no.3
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    • pp.26-32
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    • 2005
  • The volumetric efficiency is significantly affected by the behavior of pressure wave in induction system and exhaust pipe. By the motion of the piston, there exist pressure fluctuation in induction system which produce waves. Waves are propagated along a pipe bi-directional as they propagated through it, making compression wave and rare-faction(expansion) wave. These wave phenomena can affect to the volumetric efficiency. As a method of improvement of the volumetric efficiency, fuel economy and pollutant emission reduction particularly in low engine speeds, a side-branch additional tunable helmholtz resonator on the secondary pipe of intake system is proposed by use of their acoustic vibrations. Some of results are presented which deal with their physical phenomena for the wave action of intake system in a four-stroke three cylinders diesel engine.

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Design of Sliding Mode Controller for Induction Motor to Remove Chattering (채터링 제거를 위한 유도 전동기의 슬라이딩 모드 제어기 설계)

  • 김성읍;곽군평;안호균
    • The Transactions of the Korean Institute of Power Electronics
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    • v.3 no.3
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    • pp.240-245
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    • 1998
  • This paper presents an improved sliding mode controller design for induction motor. In place of the discontinuous control inputs, continuous inputs are proposed in order to remove the undesirable chattering phenomena, which represent major drawbacks of the sliding mode controller. The design strategy is illustrated with a microprocessor based implementation for the velocity control of an induction motor. An induction motor is operated under sling mode control such that the motor angular velocity follows a predetermined trajectory. The experimental results confirm the validity of the proposed method.

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