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  • Title/Summary/Keyword: 펌프 제어

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Current Status of Development Test of 75 tonf Engine System for KSLV-II (한국형발사체 75톤급 엔진 개발 시험 현황)

  • Kim, SeungHan;Kim, SeungRyong;Kim, SungHyuk;Kim, ChaeHyung;Seo, DaeBan;Woo, SeongPil;Yu, ByungIl;So, YoonSeok;Lee, KwangJin;Lee, SeungJae;Lee, JungHo;Lim, JiHyuk;Jeon, JunSoo;Cho, NamKyung;Hwang, ChangHwan;Park, Jea-Young;Han, YeongMin
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2017.05a
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    • pp.99-103
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    • 2017
  • As a development test of the 75-tonf LOx/Kerosene liquid rocket engine for KSLV-II first Stage Engine, hot firing test of 75-tonf engine are performed. The current status of development test on first stage 75-tonf engine system including combustion chamber, turbopump, gas generator, propellant supply system are presented. During the 75tonf engine test campaign, the development of startup sequence of LOx-Kerosene engine system, engine startup using pyrostarter, ignition of gas generator, steady operation and engine shutdown is successfully performed. As a passenger test during engine hot firing tests, Thrust Vector Control system (TVC) of the engine are also evaluated during engine hot firing test. The results of hot firing test of 75-tonf thrust engine system will be used for the design confirmation and performance evaluation of 75 tonf engine system for KSLV-II first Stage.

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A Design Method of Three-phase IPMSM and Clamping Force Control of EMB for High-speed Train (고속철도차량의 EMB 적용을 위한 3상 IPMSM의 설계 및 제동압부력 제어)

  • Baek, Seung-Koo;Oh, Hyuck-Keun;Kwak, Min-ho;Kim, Seog-Won
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.4
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    • pp.578-585
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    • 2018
  • This paper proposes a design method for a 3-phase interior permanent magnet synchronous motor (IPMSM) and clamping force control method for an electro-mechanical brake (EMB) using co-simulation for a high-speed train (HST). A traditional pneumatic brake system needs much space for the compressor, brake reservoir, and air pipe. However, an EMB system uses up to 50% less space due to the use of a motor and electric wires for controlling the brake caliper. In addition, it can reduce the latency time for brake control because of the fast response and precise control. A train that has many brakes is advantageous for safety because of the control by sharing the braking force. In this paper, a driving method for a cam-shaft-type EMB is modeled. It is different from the ball-screw-type brakes that are widely used in automobiles. In addition, a co-simulation method is proposed using JMAG and Matlab/Simulink. The IPMSM was designed and analyzed with the JMAG tool, and the control system was simulated using Matlab/Simulink. The effectiveness of the co-simulation results of the mechanical clamping force and braking force was verified by comparison with the clamping force specifications of a HEMU-430X HST.

A Micro Solar Energy Harvesting Circuit with MPPT Control (MPPT 제어기능을 갖는 마이크로 빛에너지 하베스팅 회로)

  • Yoon, Eun-Jung;Park, Jong-Tae;Yu, Chong-Gun
    • Journal of the Institute of Electronics and Information Engineers
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    • v.50 no.6
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    • pp.105-113
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    • 2013
  • In this paper a micro solar energy harvesting system with MPPT(Maximum Power Point Tracking) control using a miniature PV(photovoltaic) cell of which the output is less than 0.5V is proposed. The MPPT control is implemented using linear relationship between the open-circuit voltage of a PV cell and its MPP(Maximum Power Point) voltage such that a pilot PV cell can track the MPP of the main PV cell in real time. The proposed circuit is designed in 0.18um CMOS process. The designed chip area is 900um×1370um including a load charge pump and pads. Measured results show that the designed system can track the MPP voltage changes with variations of light intensity. The designed circuit with MPPT control delivers MPP voltages to load even though the load is heavy such that it can supply more power when the MPPT control is applied. The proposed circuit does not require any precharged battery resulting in more suitability for miniaturized self-powered systems compared to the existing works.

Atmosphere and Green Pepper Quality Influenced by Active Air Flushing in Fresh Produce Container Controlled in Real-time O2 Concentration (실시간 O2 농도 제어 풋고추 용기에서 능동기체치환 시스템이 기체조성과 품질보존에 미치는 효과)

  • Jo, Yun Hee;An, Duck Soon;Lee, Dong Sun
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.20 no.2
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    • pp.29-33
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    • 2014
  • Active air flushing mini-pumps were installed in a rigid polypropylene container (32cm\time23cm\time18cm) containing 900 g of fresh green peppers for effectively controlling its O2 concentration on real time basis to preserve the product quality. The performance of the constructed system was compared to that of the modified atmosphere (MA) container system with gas diffusion tube controlled in close/open cycles responding to real time O2 concentration at 10 and 20C. In the control logic, the O2 concentration was programmed to be located exactly at 13% or stay in the range of 13-15%. The active air flushing system could control the O2 concentration in the desired level or range at both temperatures, while the passive diffusion system could work only under the low temperature condition of 10C. At higher temperature of 20C, the passive diffusion system could not manage the produce respiration increased more highly than the gas transfer through the diffusion tube, resulting in too low O2 concentration and too high CO2 concentration which would be injurious to the green pepper. When tested at 20C, the MA container system could preserve the green pepper better than the perforated air package in terms of weight loss, ascorbic acid and chlorophyll contents and firmness.

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Research and Development of a 2.9 Liter Light-duty DME Truck Using Common Rail Fuel Injection Systems (커먼레일 연료분사 시스템을 장착한 2.9 리터급 경량 DME 트럭의 연구 및 개발)

  • Jeong, Soo-Jin;Park, Jung-Kwon;Oh, Se-Doo;Lee, Gee-Soo;Lim, Ock-Taek;Pyo, Young-Dug
    • Transactions of the Korean Society of Automotive Engineers
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    • v.20 no.6
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    • pp.107-116
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    • 2012
  • In this study, the trucks(2.9-liter) have been developed to use DME as fuel, and performance test of the vehicle's DME engine, power, emissions, fuel economy and vehicle aspects was conducted. For experiments, the fuel system(common-rail injectors and high-pressure pump included) and the engine control logic was developed, and ECU mapping was performed. As a result, the rail pressure from 40MPa to approximately 65% increase compared to the base injector has been confirmed that. Also, the pump discharge flow is 15.5 kg/h when the fuel rail pressure is 400rpm(40MPa), and the pump discharge flow is 92.1 kg/h when the fuel rail pressure is 2,000rpm(40MPa). The maximum value of full-load torque capability is 25.5 kgfm(based on 2,000 rpm), and more than 90% compared to the level of the diesel engine were obtained. The DME vehicle was developed in this study, 120 km/h can drive to the stable, and calculated in accordance with the carbon-balance method of fuel consumptions is 5.7 km/L.

네트웍 기반 자기베어링용 전력 증폭기 설계

  • 진재호;박종권;경진호;노승국
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2003.10a
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    • pp.115-115
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    • 2003
  • 최근 회전기계에 대한 세계적인 기술추세를 볼 때 해를 거듭할수록 더욱 정밀해지고 고속화에 대한 요구가 한층 증대되고 있으며 이러한 측면에서 여러 분야에 우수한 장점을 지니고 있는 능동적 자기베어링의 회전축계 활용에 대한 연구가 활발히 진행되고 있다. 특히 프랑스를 중심으로 한 미국, 일본 등이 이에 대한 연구를 활발하게 수행하여 고속 공작기계 스핀들을 비롯한 고진공 펌프 및 각종 터어빈, 압축기 등에 실용화시키는 단계에 있다. 그러나 국내 관련기술에 대한 연구는 연구소, 학계를 중심으로 실험실적인 기초연구로서 부분적으로 수행하는 단계에 있으며 관련분야 활용을 위한 본격적인 연구는 수행되지 못하고 있는 실정이고 이를 실용화시키기 위한 일환으로 능동적 자기 베어링의 회전 축계를 구성하고 있는 요소기술 중 하나인 전력 증폭기의 개발이 이뤄져야 할 필요성이 있는데 본 논문에서는 네트웍 기반 전력 증폭기 개발을 시도하였다. 전력 증폭기는 크게 리니어 앰프와 스위칭 앰프로 구분된다. 리니어 앰프의 경우 회로가 간단하고 노이즈가 비교적 작다는 장점이 있지만 전력손실 및 발열이 크기 때문에 에너지 측면에서 저 효율이라는 점과 따로 방열판을 부착해야 한다는 단점을 가지고 있고, 스위칭 앰프의 경우 전력손실이 작은 반면, 회로가 비교적 복잡하고 노이즈의 발생 가능성이 높다는 단점이 있다. 본 논문에선 위 두 가지 방식을 혼합한 혼합형 전력 증폭기로 설계하였다. 또한 기존에 전력증폭기의 경우 상위 주제어기로부터 제어량을 아날로그 신호로 통신하기 때문에 발생할 수 있는 EMI 노이즈신호에 대한 대책을 세워야 하는데 본 연구를 통해 개발된 전력증폭기는 따로 보조제어기(TMS320LF2406A)를 두어 상위 주제어기에 전력증폭기의 상태값을 궤환할 수 있도록 명령 신호체계를 전체 시스템의 샘플링 시간을 고려하여 비교적 전송 속도가 빠른 CAN(Controller Area Network)으로 구축하여 주제어기와 전력 증폭기간에 양방향 통신이 가능하도록 하였다. 이로써 전력증폭기의 상태정보를 알 수 있다. 따라서 본 논문에서는 칩 설계기술의 발전으로 가격대 성능비가 우수한 DSP(TMS320LF2406A)를 이용하여 과거의 아날로그 방식의 명령신호체계를 디지털 신호체계로 바꿈으로써 네트웍을 통해 전력증폭기의 상태진단 가능성을 검증한다.

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Study on the Development Trend of Pressurization System for Propulsion System of Launch Vehicle (발사체 추진기관 가압시스템 개발 사례 연구)

  • Shin, Dong-Sun;Kim, Byung-Hun;Han, Sang-Yeop
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2011.11a
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    • pp.721-724
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    • 2011
  • A system to pressurize propellants stored in propellant tanks is necessary to feed liquid-propellants into combustion devices at the required pressure and flowrate without having cavitation in turbo-pumps. A pressurization system can be categorized into pre-pressurization stage and main-pressurization stage. This report is regarding to a main-pressurization system. Pressurization methods for propellant tanks are divided into pressurant gas generating method and pressurant gas feeding method. One of pressurant gas generating methods uses the vaporized oxygen gas from cryogenic liquid oxygen and non-flammable gas. In this report, both advantages and disadvantages for pressurization methods and types of pressurization systems are compared. Especially the characteristics and principle of pressurization system using impulsive control strategy applied in launch vehicles are introduced. Additionally the structure, schematics, and specifications of heat exchanger, which is one of main units in pressurization system are also discussed. This paper can be utilized to generate the conceptual requirements and to design preliminary configuration of pressurization system during the development of launch vehicle.

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2-Channel DC-DC Converter for OLED Display with RF Noise Immunity (RF 노이즈 내성을 가진 OLED 디스플레이용 2-채널 DC-DC 변환기)

  • Kim, Tae-Un;Kim, Hak-Yun;Choi, Ho-Yong
    • Journal of IKEEE
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    • v.24 no.3
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    • pp.853-858
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    • 2020
  • This paper proposes a 2-ch DC-DC converter for OLED display with immunity against RF noise inserted from communication device. For RF signal immunity, an input voltage variation reduction circuit that attenuates as much as the input voltage variation is embedded. The boost converter for positive voltage VPOS operates in SPWM-PWM dual mode and has a dead time controller to increase power efficiency. The inverting charge pump for negative voltage VNEG is a 2-phase scheme and operates in PFM using VCO to reduce output ripple voltage. Simulation results using 0.18 ㎛ BCDMOS process show that the overshoot and undershoot of the output voltage decrease from 10 mV to 2 mV and 5 mV, respectively. The 2-ch DC-DC converter has power efficiency of 39%~93%, and the power efficiency of the boost converter is up to 3% higher than the conventional method without dead time controller.

Design of a CMOS PLL with a Current Pumping Algorithm for Clock Syncronization (전류펌핑 알고리즘을 이용한 클락 동기용 CMOS PLL 설계)

  • 성혁준;윤광섭;강진구
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.25 no.1B
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    • pp.183-192
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    • 2000
  • In this paper, the dual looped CMOS PLL with 3-250MHz input locking range at a single 13.3V is designed. This paper proposed a new PLL architecture with a current pumping algorithm to improve voltage-to-frequencylinearity of VCO(Voltage Controlled Oscillator). The designed VCO operates at a wide frequency range of75.8MHz-lGHz with a high linearity. Also, PFD(Phase frequency Detector) circuit preventing voltage fluctuation of the charge pump with loop filter circuit under the locked condition is designed. The simulation results of the PLL using 0.6 um N-well single poly triple metal CMOS technology illustrate a locking time of 3.5 us, a power dissipation of 92mW at 1GHz operating frequency with 125MHz of input frequency. Measured results show that the phase noise of VCO with V-I converter is -100.3dBc/Hz at a 100kHz offset frequency.

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Power Generation and Control System Using Differential Pressure of District Heating Pipeline in a Substation (지역난방 사용자기계실 내 열수송관 차압을 이용한 발전 및 제어 기술)

  • Kim, Kyung Min;Park, Sung Yong;Oh, Mun Sei
    • Journal of Energy Engineering
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    • v.26 no.3
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    • pp.90-96
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    • 2017
  • When the hot water is supplied through the district heating (DH) pipeline, a pressure differential control valve (PDCV) protects the DH user equipment from the high pressure DH water and helps to supply DH water to long distance. It also controls the temperature and adjust the pressure in the main district heating pipeline. However, cavitation occurs in PDCV due to the use of high pressure DH water. It causes frequent failures and many problems. It also causes energy loss and complaints to both operators and users. In order to solve these problems, we will introduce the energy saving technology to replace the primary side PDCV with hydraulic turbine, convert the differential pressure into electricity, and utilize electricity as the power of the secondary side pump.