• 제목/요약/키워드: Operating mode

검색결과 1,464건 처리시간 0.028초

EMTDC를 이용한 8.5 MVA급 Magnetic Power Supply의 전력공급 시스템 분석 (Analysis of Power Supply System for 8.5 MVA Magnetic Power Supply Using EI)

  • 정응후;노의철;김인동;최정완
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2002년도 하계학술대회 논문집 B
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    • pp.1114-1116
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    • 2002
  • The characteristics of voltage drop and THD for parallel operating 11 PCRs (Phase Controlled Rectifiers) are analysed. The PCRs are used to drive high current (1.6 kA ${\sim}$ 3.7 kADC) electromagnetic coils for electromagnets. All the PCRs operate simultaneously in pulsed mode, and the pulse shot occurs every 150 seconds. During the pulse operation the PCR output current ramps up for 4 seconds, and then keeps flat top state for 2 seconds, and finally ramps down for 4 seconds. For the flat top mode a severe voltage drop and distortion appear in the power system because transformers for the PCRs are designed considering pulsed mode operation. It is expected that the analysis method can be applied to improve the system performance including power factor and design of high power pulsed mode operating power supply systems.

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A Fast Response Integrated Current-Sensing Circuit for Peak-Current-Mode Buck Regulator

  • Ha, Jung-Woo;Park, Byeong-Ha;Kong, Bai-Sun;Chun, Jung-Hoon
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제14권6호
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    • pp.810-817
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    • 2014
  • An on-chip current sensor with fast response time for the peak-current-mode buck regulator is proposed. The initial operating points of the peak current sensor are determined in advance by the valley current level, which is sensed by a valley current sensor. As a result, the proposed current sensor achieves a fast response time of less than 20 ns, and a sensing accuracy of over 90%. Applying the proposed current sensor, the peak-current-mode buck regulator for the mobile application is realized with an operating frequency of 2 MHz, an output voltage of 0.8 V, a maximum load current of 500 mA, and a peak efficiency of over 83%.

Implementation of a Sliding Mode Controller for Single Ended Primary Inductor Converter

  • Subramanian, Venkatanarayanan;Manimaran, Saravanan
    • Journal of Power Electronics
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    • 제15권1호
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    • pp.39-53
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    • 2015
  • This paper presents the regulation of the output voltage and inductor currents in a Single Ended Primary Inductor Converter (SEPIC), operating in the continuous conduction mode (CCM) using a sliding mode controller. Owing to the time varying nature of the SEPIC converter, designing a feedback controller is a challenging task. In order to improve the dynamic performance of the SEPIC, a Sliding Mode Controller (SMC) is developed. The developed SMC is designed by using a state space average model. The performance of the developed controller with the SEPIC converter is validated at different working conditions through Matlab simulations. It is also compared with the performance while using a PI controller. The results show that the designed controller gives very good output voltage regulation under different operating conditions such as a varying input voltage, changes in the load and component variations. A 48V, 46W experimental setup for has been developed in an analog platform to validate the performance of the proposed SMC.

이산 시간 영역 해석에 기반한 벅 AC/DC LED 구동기의 슬로프 보상 설계 (Slope Compensation Design of Buck AC/DC LED Driver Based on Discrete-Time Domain Analysis)

  • 김만고
    • 전력전자학회논문지
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    • 제24권3호
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    • pp.207-214
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    • 2019
  • In this study, discrete-time domain analysis is proposed to investigate the input current of a buck AC/DC light-emitting diode (LED) driver. The buck power factor correction converter can operate in both discontinuous conduction mode (DCM) and continuous conduction mode (CCM). Two discontinuous and two continuous conduction operating modes are possible depending on which event terminates the conduction of the main switch in a switching cycle. All four operating modes are considered in the discrete-time domain analysis. The peak current-mode control with slope compensation is used to design a low-cost AC/DC LED driver. A slope compensation design of the buck AC/DC LED driver is described on the basis of a discrete-time domain analysis. Experimental results are presented to confirm the usefulness of the proposed analysis.

Particular aspects of drivers for VCSELs operating at multi-Gb/s

  • Kyriakis-Bitzaros, Efstathios D.;Katsafouros, Stavros G.;Halkias, George
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제2권1호
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    • pp.82-86
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    • 2002
  • It is demonstrated that the conventional current-pulse laser drivers are not adequate in driving VCSELs operating at multi-Gb/s speeds. Simulation results, including the bonding parasitics, show that high-performance VCSELs are more efficiently driven using voltage-pulse mode of operation. The optical output power is almost doubled in the voltage-mode of operation, while the total electrical power consumption of the transmitter decreases by 20%.

KTX 열차 운전 모드에 따른 정차소음 특성 (Characteristics of Braking Noise in accordance with Operating Mode of KTX High Speed Vehicle)

  • 이찬우;김재철;조준호
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2005년도 추계학술대회 논문집
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    • pp.816-822
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    • 2005
  • High speed trains with maximum speed of 300km/h, named KTX, have started revenue services since April 2004. Is becoming big problem where currently the KTX train because excessive braking noise at a station platform. The KTX braking noise follows in operating mode of KTX train and important railroad station where the quality appears different, the quality against hereupon from the commerce vehicle from the research which it sees it executes and comparison to analyze.

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BSCCO Magnet 제작 및 영구전류모드에서의 전류 보상 운전 특성 (Fabrication of a BSCCO Magnet and its Operating Characteristics of Current Compensation in Persistent Current Mode)

  • 조현철;장기성;장재영;김형준;정윤도;윤용수;고태국
    • 한국초전도ㆍ저온공학회논문지
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    • 제12권1호
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    • pp.56-60
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    • 2010
  • Recently, many researches have been carried out for a high temperature superconducting (HTS) magnet which is advantageous in high critical current density and critical temperature. In HTS magnet, however, critical current is decreased by perpendicular magnetic field and persistent current is hard to maintain due to a low index value and high joint resistance compared with low temperature superconducting (LTS) magnet. In this paper, the HTS magnet using BSCCO wire was simulated through finite element method (FEM) and manufactured. we experimentally investigated operating characteristics of the compensating mode of the HTS magnet for current decay and made a comparison between persistent current mode and compensating mode. A feedback control unit was used to sustain current within specified ranges with defined upper and lower limits.

동시냉난방 열펌프 시스템의 냉방전용 및 냉방주체 운전모드에서의 실내기온 변화에 따른 성능특성에 관한 실험적 연구 (An Experimental Study on the Performance of a Simultaneous Heating and Cooling Heat Pump in the Cooling-only and Cooling-main Operation Mode with the Variation of the Indoor Air Temperature)

  • 안재환;주영주;강훈;정현준;김용찬;최종민
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2008년도 추계학술대회B
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    • pp.2165-2170
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    • 2008
  • The cooling load in winter season is significant in many commercial buildings and hotels because of the usage of office equipments and the high efficiency of wall insulation. Therefore, the development of a multi-heat pump which can cover heating and cooling simultaneously for each indoor unit is required. In this study, the characteristics and performance of a simultaneous heating and cooling heat pump in the cooling-only and cooling-main operating mode was investigated experimentally with a variation of indoor air dry bulb temperature which is from $21^{\circ}C$ to $35^{\circ}C$. EEV opening was adjusted from 20% to 24% during the tests. When the indoor air temperature varied, the performance in the cooling-only mode was more sensitive to the temperature than in the cooling-main mode. The total capacity and COP were increased by 53.8% and 48.1%, respectively, in the cooling-main, while those were increased by 19.6% and 19.3% in the cooling-only mode. The performance differences between the two operating modes became larger at lower temperatures, especially for the COP.

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전투기 AESA 레이더 운용모드의 최적 계층구조 설계 방법론 (Optimal Hierarchical Design Methodology for AESA Radar Operating Modes of a Fighter)

  • 김흥섭;김성호;장우석;설현주
    • 산업경영시스템학회지
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    • 제46권4호
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    • pp.281-293
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    • 2023
  • This study addresses the optimal design methodology for switching between active electronically scanned array (AESA) radar operating modes to easily select the necessary information to reduce pilots' cognitive load and physical workload in situations where diverse and complex information is continuously provided. This study presents a procedure for defining a hidden Markov chain model (HMM) for modeling operating mode changes based on time series data on the operating modes of the AESA radar used by pilots while performing mission scenarios with inherent uncertainty. Furthermore, based on a transition probability matrix (TPM) of the HMM, this study presents a mathematical programming model for proposing the optimal structural design of AESA radar operating modes considering the manipulation method of a hands on throttle-and-stick (HOTAS). Fighter pilots select and activate the menu key for an AESA radar operation mode by manipulating the HOTAS's rotary and toggle controllers. Therefore, this study presents an optimization problem to propose the optimal structural design of the menu keys so that the pilot can easily change the menu keys to suit the operational environment.

발전소 급수용 펌프 배관계의 음향학적 현상 고찰 (Acoustic Investigation on BFP Piping System in a Power Plant)

  • 양경현;조철환;배춘희
    • 한국소음진동공학회논문집
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    • 제21권11호
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    • pp.1029-1035
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    • 2011
  • Pressure pulsation of exciting sources that generally occurs on the piping system connected to the discharge of BFP(boiler feed water pump) in power plants causes wave reflection, wave interference, resonance, standing wave and so on. But if the operating speed of the pump is changed, the state of the noise and vibration can be done because characteristics of the exciting source are changed. This paper is to investigate the cause of the noise and vibration occurring on the piping system when the operating speed of BFP is down in accordance with lowering of the power generation. It is approached to two points of view ; Firstly, it is examined whether the pulsation source impacts on the shell mode vibration that vibrates radially across the cross-section of the pipe. But it doesn't affect the shell mode as much as the resonance occurs. Secondly, to find the relation between the pulsation source and the acoustic mode of the piping system, analysis for the piping system by indirect BEM(boundary element method) is carried out. Therefore it is investigated that the mechanism of the noise and vibration relates with acoustic mode of the piping system.