• 제목/요약/키워드: 홍정표

검색결과 622건 처리시간 0.024초

3차원 와전류 해석을 위한 등가자기회로방법의 개발 (Development of Equivalent Magnetic Circuit Network Method for 3 Dimentional Eddy current Analysis)

  • 허진;홍정표;현동석
    • 대한전기학회논문지:전기기기및에너지변환시스템부문B
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    • 제51권5호
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    • pp.228-233
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    • 2002
  • A computational method for analysis of the 3 dimensional electro-magnetic induction problems has been developed. The developed method is capable of modeling the induced current and analyzing its characteristics using only scalar Potential at each node. A benchmark model of asymmetrical conductor with a hole is analyzed to verify the application of the developed method. The calculated value of magnetic flux density are compared with the measured value, and the results indicate that the developed method is valid. Also, Comparing with 3-D finite element method (FEM) results, we conformed effectiveness of the developed method for the accuracy and computation times.

단상 직립 기동형 영구자석 동기기의 회로정수에 따른 특성 해석 (Characteristic Analysis of Single Phase Line-start Permanent Magnet Synchronous Motor Considering Circuit Parameters)

  • 강규홍;홍정표
    • 대한전기학회논문지:전기기기및에너지변환시스템부문B
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    • 제52권6호
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    • pp.262-270
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    • 2003
  • In this paper, the characteristics of single-phase line-start permanent magnet synchronous motor driven by constant voltage are analyzed on d-q axis vector diagram and compared with that of current controlled motor. The coupled method of symmetrical coordinates and d-q axis voltage equation are applied to the analysis method like the analysis of single-phase induction motor. From the result of the analysis, it is seen that motors driven by constant voltage source have effects on not only the amplitude of current and torque but also current and current phase angle, so overall characteristics such as power factor and load angle are affected by circuit parameters. For precise analysis and design of single-phase line-start synchronous motor, its characteristics should be analyzed on d-q axis vector plan in consideration of the variation of circuit parameters.

초고주파전류가 흐르는 코일의 표피효과와 전류분포특성 - 핀치효과 개선용 4각단면 중공코일의 전류흐름특성 - (The skin effect and current distribution characteristics of a coil streaming with high frequency)

  • 장석명;서진호;이현구;홍정표;이진형
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1996년도 하계학술대회 논문집 A
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    • pp.222-224
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    • 1996
  • This paper treats the stream phenomena of high frequency current on the solid-loop coil of which consists the hollow conductor. The governing equation is derived from electromagnetic field theory and the characteristics are analyzed by FEM with 2-D and 3-D. The results may be available data on designing the optimum shape of the coil for the improved pinch effect.

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단상유도전동기의 도체바 개수 변경에 따른 특성해석 (Analysis of Characteristics of a Single-phase Induction Motor by changing of Conductor-bar number)

  • 류호길;남혁;홍정표;차현록;박성우
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2003년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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    • pp.3-5
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    • 2003
  • This paper deals with the characteristics of a capacitor-run single-phase induction motor by changing of conductor bar numbers. The Finite Element Method (FEM) is used to analyze the starting characteristics according to the rotor initial starting point about conduction bar and the characteristic analysis at the rated condition is calculated by equivalent circuit based on symmetry coordinate theory Finally, the analysis results of the analysis models have different conductor bars in their rotor are compared.

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초정밀 구동용 영구자석 선형 동기전동기(PMLSM)의 자기회로 설계 (Magnetic Circuit Design of Permanent Magnet Linear Synchronous Motor(PMLSM) for Super Precision Control System)

  • 김성일;하재평;남혁;이지영;홍정표;조한익
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2003년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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    • pp.39-41
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    • 2003
  • This paper deals with the characteristics of the permanent magnet type linear synchronous motors(PMLSMs). Firstly, the structures and the characteristics of a slotted type and a slotless type PMLSM are compared. Secondly, the analyses and the design methods of each motor are presented. Finally, slotted type PMLSM and slotless type PMLSM are designed using the presented design method.

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횡자속 선형전동기를 적용한 수령형 스토크 시스템의 설계 및 해석 (Design and analysis of horizontal stocker using transverse flux linear motor)

  • 장정환;정수진;강도현;이지영;홍정표
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2003년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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    • pp.30-32
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    • 2003
  • 본 논문은 LCD 제조 공정 라인에서 LCD용 원판을 다른 여러 공정으로 이송하는데 사용하기 위한 수평형 스토크 시스템의 설계 및 제작에 관한 연구이다. 구동원으로 제작된 영구 자석 여자 횡자속형 전동기는 높은 공극 자속 밀도를 얻을 수 있는 구조로 일반 선형 유도 전동기나 선형 등기기에 비해 단위 체적당 높은 출력 밀도를 얻을 수 있는 장점을 가지고 있다. 3차원 등가 자기 회로망법을 사용하여 기자력 변화에 따른 추력 및 흡인력과 같은 특성을 해석하였으며 정특성 실험을 통하여 설계 및 해석의 타당성을 검토하였다.

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가변구조제어 이론을 이용한 유도 서보 전동기의 위치제어 (Position Control for Induction Servo Motors Using a Theory of Variable Structure Control)

  • 홍순일;홍정표
    • Journal of Advanced Marine Engineering and Technology
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    • 제29권1호
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    • pp.132-139
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    • 2005
  • This paper describes the application of sliding mode control based on the variable structure control(VSC) concept for high-performance position control of an induction servo motor A design method based on external load parameters has been developed for the robust control of AC induction servo drive. Also, a slip frequency vector control with software current control technique has been adopted to achieve fast response of an induction motor drive The position control scheme is comprised of a variable structure controller and slip frequency vector control for inverter fed induction servo motor. Simulated results are given to verify the proposed design method by adoption of sliding mode and show robust control for a change of shaft inertia, viscous friction and torque disturbance.

음성구간검출을 위한 비정상성 잡음에 강인한 특징 추출 (Robust Feature Extraction for Voice Activity Detection in Nonstationary Noisy Environments)

  • 홍정표;박상준;정상배;한민수
    • 말소리와 음성과학
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    • 제5권1호
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    • pp.11-16
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    • 2013
  • This paper proposes robust feature extraction for accurate voice activity detection (VAD). VAD is one of the principal modules for speech signal processing such as speech codec, speech enhancement, and speech recognition. Noisy environments contain nonstationary noises causing the accuracy of the VAD to drastically decline because the fluctuation of features in the noise intervals results in increased false alarm rates. In this paper, in order to improve the VAD performance, harmonic-weighted energy is proposed. This feature extraction method focuses on voiced speech intervals and weighted harmonic-to-noise ratios to determine the amount of the harmonicity to frame energy. For performance evaluation, the receiver operating characteristic curves and equal error rate are measured.

반응표면법을 이용한 초전도 전동기의 마그넷 형상 최적화 (Shape Optimization of the Magnet for Superconducting Motor by Using RSM)

  • 이지영;김성일;김영균;홍정표;권영길
    • 한국초전도ㆍ저온공학회논문지
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    • 제6권1호
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    • pp.18-21
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    • 2004
  • This paper presents the optimization for shape design of a field coil used High Temperature Superconducting Motor (HTSM). In materials of HTSM, critical current Ic is more sensitive to magnetic fields directed along the axis or the unit cell ($B_{\bot}$). Thus, in the shape design of the HTS magnet. the maximum $B_{\bot}$ should be reduced to limit Ic. In order to reduce the maximum $B_{\bot}$, the shape optimization of the magnet, which is used for the field coil of HTSM, is necessary. It can be accomplished by using Response Surface Methodology (RSM). Finally, the result of RSM is verified by comparison with these experimental results.