• 제목/요약/키워드: linear phase

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비선형 부하의 운전시 유도전동기의 특성 해석 (Characteristics Analysis of Induction Motor by Operation of Non-lineal Loads)

  • 김종겸;박영진;이은웅
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2006년도 학술대회 논문집 전문대학교육위원
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    • pp.147-153
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    • 2006
  • Voltage unbalance will be generated by the load unbalance operation such as combination operation of single & three phase load and current unbalance will be more severe by the deteriorated voltage quality. Under the these unbalance conditions, all power electronic converters used in different types of electronic systems can increase harmonic disturbances by injecting harmonic currents directly into the feeder grid of three phase 4-wire. Harmonic current may cause torque to decrease. it may also overheat or become noisy and torque oscillation in the rotor can lead to mechanical resonance and vibration. This paper presents a scheme on the characteristics of induction motor under the combination of linear & non-linear loads at the three phase 4-wire power distribution system by the unbalance and harmonic components. It was able to confirm that the number of torque pulsation decreased and torque ripple values increased by the harmonics that reduction was difficult by five harmonics filters at additional driving time of single-phase non-linear load.

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Linear Stepping Motor의 시동특성 개선에 관한 연구 (A Study on improving of starting characteristics in Linear Stepping Motor)

  • 배진호;정도영;원규식;이상호;서진우;오흥석
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1996년도 하계학술대회 논문집 A
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    • pp.98-100
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    • 1996
  • In this paper, the Two-Double 1-2phase exciting driver circuit, in order to improving the starting characteristics of Linear Stepping Motor(LSM), is designed. And the static thrust forces of LSM is measured through the chopper constant current method according to the 2 phase, the Double 1-2phase, and the Two-Double 1-2phase exciting method.

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3상 4선식에서 비선형 부하의 운전시 유도전동기의 특성 해석 (Characteristics Analysis of Induction Motor by Operation of Non- linear Loads under the 3-phase 4-wire grid system)

  • 김종겸;박영진;이은웅
    • 한국조명전기설비학회:학술대회논문집
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    • 한국조명전기설비학회 2006년도 춘계학술대회 논문집
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    • pp.43-48
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    • 2006
  • This paper presents a scheme on the characteristics of induction motor under the combination of linear & non-linear loads at the three phase 4-wire power distribution system. Under the combination operation of single & three phase load, voltage unbalance will be generated and current unbalance will be more severe by the dropped voltage quality. All power electronic converters used in different types of electronic systems can increase harmonic disturbances by injecting harmonic currents directly into the feeder grid of three phase 4-wire. Harmonic current may cause torque to decrease. Moors may also overheat or become noisy and torque oscillation in the rotor can lead to mechanical resonance and vibration.

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고차스펙트럼을 이용한 선체 종동요의 비선형적 거동에 관한 해석 (Higher Order Spectral Analysis of Non-linear Pitching Motion)

  • 강병호;;김태호;박준모;공길영
    • 한국항해항만학회지
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    • 제41권1호
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    • pp.1-8
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    • 2017
  • 선체의 비선형적 동요현상은 선박의 감항성 확보와 관련하여 최근 활발하게 연구가 이루어지는 분야들 중 하나이다. 본 연구에서는 고차 스펙트럼 해석방법들 중 하나인 바이스펙트럼 해석방법과 바이코히어런스 해석방법을 적용하여 선체의 비선형적인 동요 현상을 해석하였다. 본 연구를 통해 기존에 알려진 추파상황에서의 비선형적 선체 종동요 현상과 더불어 추사파 및 우현 횡파 상황에서도 선체 종동요의 비선형 위상 동조 현상이 일어나는 것을 확인하였다. 또한, 바이코히어런스 방법을 통해 주파수간 비선형적 간섭현상을 수치화 하여 주파수 대역별로 위상 동조 현상을 비교할 수 있었다. 이를 통해 선체 종동요의 파워스펙트럼상의 피크 주파수 이외의 주파수 대역에서 비선형적 위상결합이 더 강하게 일어난다는 사실을 확인하였다. 이에 더하여, 바이코히어런스 해석방법은 정규화 방법에 크게 영향을 받지 않는 다는 사실 또한 확인하였다.

Study of Retention of Mono-Substituted Phenols in Reversed-Phase Liquid Chromatography Based on the Linear Solvation Energy Relationships Using the Solvatochromic Parameters for Mobile Phases, ${\pi}_m^{\ast}, {\alpha}_m$ and ${\beta}_m$

  • Park, Jung-Hag;Jang, Myung-Duk;Kim, Sang-Tae
    • Bulletin of the Korean Chemical Society
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    • 제11권4호
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    • pp.297-302
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    • 1990
  • Retention of mono-substituted phenols in reversed-phase liquid chromatography has been studied based on the linear solvation energy relationships using the solvatochromic mobile phase parameters, ${\pi}_m^{\ast}, {\alpha}_m$ and ${\beta}_m$. It has been observed that retention behavior of phenols in RPLC were well represented by regression equations vs. solvatochromic mobile phase parameters even though the equations may be incomplete due to lack of an explicit cavity term. Dependence of retention of monosubstituted phenols on the mobile phase properties were varied depending on the type of the organic cosolvent in the mobile phase, e.g., ${\beta}_m$ and {\alpha}_m$ in methanol-water system, but ${\pi}_m^{\ast} and ${\beta}_m$ in THF-water system. It has been suggested that retention of phenols in methanol-water system is controlled by the solvophobicity of the mobile phase.

근사 복원 IIR/FIR QMF 필터뱅크에서 지연요소 변화에 따른 특성에 관한 연구 (A Study on the Characteristics of Delay Parameter Change in Approximately Reconstruction IIR/FIR QMF Filter Banks)

  • 이상준;김남수;김남호
    • 융합신호처리학회 학술대회논문집
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    • 한국신호처리시스템학회 2003년도 하계학술대회 논문집
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    • pp.296-299
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    • 2003
  • This paper shows a novel and simple IIR/FIR QMF(quadrature mirror filter) filter banks, mixed IIR and FIR structure. Here, FIR filters used for phase compensation. In this paper, we introduced analysis and synthesis filter banks, which used FIR linear phase filters and all pass filters. In result, phase response of analysis and synthesis filter banks become approximately linear characteristic. Simultaneously, a liasing distortion can be completely canceled.

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Limitations of the Linear Solvation Energy Relationships in Reversed Phase Liquid Chromatography

  • Cheong, Won-Jo;Choi, Jang-Duck
    • Bulletin of the Korean Chemical Society
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    • 제15권10호
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    • pp.868-873
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    • 1994
  • We have re-examined the linear solvation energy relationships in reversed phase liquid chromatography by considering various solutes including quite a number of compounds of strong hydrogen bond capability. We observed that solutes of strong hydrogen bond ability should be excluded in order to obtain resonable correlations between In k' and solute polarity parameters and that inclusion of one or two such solutes causes severe distortions of correlation results. This anomaly may be due to existence of residual silanol groups in the stationary phase, that is, their specific interactions with solutes.

PCM/FM 전송에서 가변 컷오프 특성을 갖는 선형위상 필터 블록의 펄스 성형에 관한 연구 (A Study on Pulse Shaping of Linear Phase filter block with Variable Cutoff Frequency in PCM/FM transmission)

  • 이상래;나성웅
    • 한국통신학회논문지
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    • 제31권1C호
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    • pp.65-73
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    • 2006
  • 본 연구의 목적은 PCM/FM 전송시스템에서 RF 대역제한을 위해 사용되는 가변 컷오프 및 선형위상 특성을 갖는 pre-modulation 필터의 설계 및 주파수 응답을 분석하는데 있다. 이러한 필터를 구현하기 위해서 디지털 FIR 필터, DAC 및 가변 2차 LPF의 필터 블록을 구성하였으며 각 스테이지별 진폭 주파수 응답 분석을 통해서 아날로그 7차 베셀 필터의 요구조건에 만족하도록 필터블록의 감쇄특성을 효과적으로 할당하여 설계하였다. 또한 필터블록의 선형위상 특성을 살펴보았으며 가변 2차 LPF에 대해서는 실제 구현할 소자를 적용하여 시뮬레이션을 수행하여 고정 대역폭의 2차 베셀 필터의 그룹지연과 비교하여 통과 주파수 대역에서 선형성 조건에 합당한지 분석하였다.

토크분배함수를 이용한 SRM의 적접토크제어기법 (Direct Torque Control Scheme of Switched Reluctance Motor using Novel Torque Sharing Function)

  • 안진우;이동희;김태형
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2007년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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    • pp.138-140
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    • 2007
  • A novel non-linear logical torque sharing function (TSF) is presented. To improve efficiency and to reduce torque ripple in commutation region, only a phase torque under commutation is regulated to produce a uniform torque. And the torque developed by the other phase remains with the previous state under a current limit of the motor and drive. If the minimum change of a phase torque reference can not satisfy the total reference torque, two-phase changing mode is used. Since a phase torque is constant and the other phase torque is changed at each rotor position, total torque error can be reduced within a phase torque error limit. And the total torque error is dependent on the change of phase torque. To consider non-linear torque characteristics and to suppress a tail current at the end of commutation region, the incoming phase current is changed to torque increasing direction, but the outgoing phase current is changed to torque decreasing direction. So, the torque sharing of the outgoing phase and incoming phase can be smoothly changed with a minimum current cross over. The proposed control scheme is verified by some computer simulations and experimental results.

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