• 제목/요약/키워드: Dual-Mode

검색결과 848건 처리시간 0.028초

이중모드 스크램제트 엔진에서 연소와 충격파의 상호작용 (Combustion/Shock Interactions in a Dual-Mode Scramjet Engine)

  • 최정열;노진현;변종렬
    • 한국추진공학회:학술대회논문집
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    • 한국추진공학회 2011년도 제36회 춘계학술대회논문집
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    • pp.367-370
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    • 2011
  • 에틸렌을 연료로하는 직결식 이중모드 스크램제트 연소기에서 연소와 충격파-열 발생 천이 과정에 대한 고해상도 수치 연구를 수행하였다. 연소기의 확산 부에는 질량 유량 공급으로 유효 면적을 줄이고 유속을 아음속으로 낮추어 연료-공기 혼합과 점화를 촉진하기 위하여 air-throttling을 적용하였다. 본 결과는 이중모드 스크램제트 연소기에서 작동 영역의 천이 과정을 잘 이해할 수 있는 상세한 보여주었다.

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Dual Band GSM Handset의 설계 및 구현 (Design and Implementation of Dual Band GSM Handset)

  • 안형근
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2000년도 추계종합학술대회 논문집(1)
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    • pp.129-132
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    • 2000
  • This paper describes how to Implement dual band GSM hand set varying single band GSM phone. The idea can be extended to Triple mode design. Multiband design is important for global roamming and Baseband setup planning. Here H/W and SW issues are briefly described

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PWM/PFM Dual Mode SMPS Controller IC for Active Forward Clamp and LLC Resonant Converters

  • Cheon, Jeong-In;Ha, Chang-Woo
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제7권2호
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    • pp.94-97
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    • 2007
  • The desin and implementation of a CMOS analog integrated circuit that provides dual-mode modulations, PWM for active clamp reset converter and PFM for LLC resonant converter, is described. The proposed controller is capable of implementing programmable soft start and current-mode control with compensating ramp for PWM and frequency shifting soft start for PFM. Also it provides delay time for both modes. PWM mode is implemented by active clamp reset converter and PFM mode is implemented by LLC resonant convereter, respectively. The chip is fabricated using the 0.6um high voltage CMOS process.

전기자동차용 배터리의 CC/CV 충전을 위한 새로운 듀얼 풀브리지 LLC 공진형 컨버터 (A Novel Dual Full-Bridge LLC Resonant Converter for CC/CV Charge of the Battery for Electric Vehicles)

  • 부하이남;최우진
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2016년도 전력전자학술대회 논문집
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    • pp.337-338
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    • 2016
  • This paper introduces a novel dual Full-Bridge LLC(FBLLC)resonant converter for CC/CV Charge of the Battery for Electric Vehicles. One full-bridge LLC resonant converter operates with a fixed-resonant network and the other operates with a variable-resonant network for CC and CV mode operations. The proposed converter can achieve ZVS for all the primary switches and exhibits a highefficiency characteristics like aconventional single FBLLC resonant converter. In addition, the variable-resonant network helps minimize the switching-frequency variation. The dual structure makes the proposed converter possible to achieve ZVS and nearly ZCS for all the primary switches in CC mode operation. Since the proposed converter can operate at a fixed frequency in CV mode, it can minimize the circulating current and achieve nearly ZCS. A 6.6 kW prototype converter is implemented to verify the validity of proposed converter and the maximum efficiency of 98.3% was achieved.

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The Design of Fault Tolerant Dual System and Real Time Fault Detection for Countdown Time Generating System

  • Kim, Jeong-Seok;Han, Yoo-Soo
    • 한국컴퓨터정보학회논문지
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    • 제21권10호
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    • pp.125-133
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    • 2016
  • In this paper, we propose a real-time fault monitoring and dual system design of the countdown time-generating system, which is the main component of the mission control system. The countdown time-generating system produces a countdown signal that is distributed to mission control system devices. The stability of the countdown signal is essential for the main launch-related devices because they perform reserved functions based on the countdown time information received from the countdown time-generating system. Therefore, a reliable and fault-tolerant design is required for the countdown time-generating system. To ensure system reliability, component devices should be redundant and faults should be monitored in real time to manage the device changeover from Active mode to Standby mode upon fault detection. In addition, designing different methods for mode changeover based on fault classification is necessary for appropriate changeover. This study presents a real-time fault monitoring and changeover system, which is based on the dual system design of countdown time-generating devices, as well as experiment on real-time fault monitoring and changeover based on fault inputs.

PZT를 이용한 초소형 광 픽업 엑츄에이터의 슬라이딩 모드 제어 (Sliding mode control of small form factor optical pick-up actuator using PZT)

  • Lee, Woo-Chul;Jung, Dong-Ha;Park, Tae-Wook;Park, No-Cheol;Yang, Hyun-Seok
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2003년도 추계학술대회논문집
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    • pp.424-429
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    • 2003
  • This paper proposes a swing-arm type dual-stage actuator, which consists of a PZT actuator for fine motion and a VCM(Voice Coil Motor) for coarse motion, for SFF ODD(Small Form Factor Optical Disk Drive), in order to achieve fast access speed and precise track following control. We focus our attention on the design and control of the PZT actuator, because there have been a lot of previous researches related to the VCM and dual-stage actuators. Due to the dual cantilever structure, the PZT actuator can generate precise translational tracking motion at its tip where optical pickup is attached at, and the effect of hysteric behavior of the PZT element is reduced. The dynamic model of the PZT actuator is derived by using the Hamilton's principle, and verified by comparing with the experimental frequency response. The sliding mode control is designed in order to be robust against modeling uncertainties. Simulations and experimental results confirm the effectiveness of the suggested control scheme.

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듀얼 스테이지 서보 시스템을 이용한 영상 추적장치의 안정화 제어 (Dual Stage Servo Controller for Image Tracking System)

  • 최영준;강민식;유건환;이승현
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2006년도 춘계학술대회 논문집
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    • pp.45-46
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    • 2006
  • In this paper, a dual stage servo mechanism has been developed for image tracking system to improve transient control performances such as small rise time, small overshoot, small settling time, etc. A secondary stage, a platform, actuated by a pair of electro-magnets is mounted on a conventional elevation gimbal. In this mechanism, the gimbal provides large range but slow motion and the platform provides small range but fast positioning. A sliding mode control is applied to the platform positioning to attain robust performances and stability in the presence of the disturbance related to dynamic coupling of the gimbal and the platform. Results from experiments illustrate that the suggested dual stage mechanism controlled by the sliding mode control is effective in improving transient responses and attenuating the disturbance related with dynamic coupling.

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Initial Firing Angle Control of Parallel Multi-Pulse Thyristor Dual Converter for Urban Railway Power Substations

  • Kim, Sung-An;Han, Sung-Wo;Cho, Yun-Hyun
    • Journal of Electrical Engineering and Technology
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    • 제12권2호
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    • pp.674-682
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    • 2017
  • This paper presents an optimal initial firing angle control based on the energy consumption and regenerative energy of a parallel multi-pulse thyristor dual converter for urban railway power substations. To prevent short circuiting the thyristor dual converter, a hysteresis band for maintaining a zero-current discontinuous section (ZCDS) is essential during mode changes. During conversion from the ZCDS to forward or reverse mode, the DC trolley voltage can be stabilized by selecting the optimal initial firing angle without an overshoot and slow response. However, the optimal initial firing angle is different depending on the line impedance of each converter. Therefore, the control algorithm for tracking the optimal initial firing angle is proposed to eliminate the overshoot and slow response of DC trolley voltage. Simulations and experiments show that the proposed algorithm yields the fastest DC voltage control performance in the transient state by tracking the optimal firing angle.

3.4L 급 농기계용 디젤-천연가스 혼소 엔진 개발 (A Development of an 3.4L-class Diesel-LNG Dual Fuel Engine for Farming Machine)

  • 심주현;고춘식;이상민;이옥재;이창언
    • 한국연소학회:학술대회논문집
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    • 한국연소학회 2012년도 제45회 KOSCO SYMPOSIUM 초록집
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    • pp.187-190
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    • 2012
  • An experimental study was performed to provide the effect of PM reduction and the improvement of diesel alternative ratio utilizing diesel-natural gas dual-fuel combustion mode in a retrofit 3.4-liter diesel engine. In order to achieve the same power as the original diesel engine, engine control unit (ECU) of the dual-fuel engine was calibrated. As a result, diesel alternative ratio was found that the maximum value of diesel alternative ratio was about 96%. Finally PM emission experiment was performed in C1-8 mode cycle and it was shown PM emission was extremely reduced down to $7.42{\ast}10^{-7}g/kWh$ comparing with mechanical diesel engine.

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PZT를 이용한 광 정보저장기기용 엑츄에이터의 추적제어 (Track following control of optical pick-up actuator using PZT)

  • 이우철;양현석;박노철;박영필
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2003년도 춘계학술대회 논문집
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    • pp.664-669
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    • 2003
  • This paper proposes a swing-arm type dual-stage actuator, which consists of a PZT actuator for fine motion and a VCM(Voice Coil Motor) for coarse motion, for SFF ODD(Small Form Factor Optical Disk Drive), in order to achieve fast access speed and precise track following control. We focus our attention on the design and control of the PZT actuator, because there have been a lot of previous researches related to the VCM and dual-stage actuators. Due to the dual cantilever structure, the PZT actuator can generate precise translational tracking motion at its tip where optical pickup is attached at, and the effect of hysteric behavior of the PZT element is reduced. The dynamic model of the PZT actuator is derived by using the Hamilton's principle, and verified by comparing with the experimental frequency response. The sliding mode control is designed in order to be robust against modeling uncertainties. Simulations and experimental results confirm the effectiveness of the suggested control scheme.

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