• Title/Summary/Keyword: combined system

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Research and Development Trends of PV Thermal Combined Systems (PV Thermal 복합시스템의 국내외 연구 개발 동향)

  • Kim, Jin-Hee;Lee, Kang-Rock;Yang, Youn-Wan;Kim, Jun-Tae
    • 한국신재생에너지학회:학술대회논문집
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    • 2006.06a
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    • pp.588-592
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    • 2006
  • PV Thermal combined system produces the electricity and thermal energy which are needed for buildings. The system removes heat from PV module through air or liquid, so that its efficiency will be improved. The heat as the forms of hot air or hot water can be utilized for building use, like space heating and hot water. This paper describes the concept of PV Thermal combined system and its research and development trend at local and international levels. This materials can be used as a fundamental study source about PV Thermal combined system to apply fur building space heating.

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Combined test of Power Supply System for Korean High Speed Train (고속전철용 보조전원장치 시스템 조합시험)

  • Cho, Hyun-Wook;Kim, Yuen-Chung;Kim, Tae-Hwan;Jang, Kyung-Hyun;Kim, Chul-Ho
    • Proceedings of the KSR Conference
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    • 2008.11b
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    • pp.619-625
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    • 2008
  • Electrical Power supply System conditions of korea high speed train consists of main transformer, four AC-DC PWM converter of Auxiliary Block, Battery Charger in Power Car and Trailer Car, Trailer Inverter, Auxiliary inverter. Main transformer, at nominal voltage of 25kv supplied to secondary winding nominal output Voltage 383Vac, The Auxiliary block consists of AC-DC converters for generating 670VDC power, Auxiliary inverters for ventilation and air compressor, Trailer car inverter provide three phase power supplies at 440Vac for air conditioning and heating. The Battery charger Trailer and Power car supplies 72VDC all necessary equipment to energize the trainset equipment and suppy essential control. This Paper introduces the combined test results of the power supply system for korea high speed train. The main purpose of this combined test is to verify the performance of the power supply system that is designed to operate up to full load test.

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Proper Cable Arrangement Selection by Induced Voltage Evaluation of DC Cable in AC/DC Hybrid Combined Transmission Systems (AC/DC 하이브리드형 혼합송전계통에서 DC 케이블의 유도전압평가에 의한 적정배열 선정)

  • Son, Yong-Dae;Lee, Jong-Beom
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.64 no.5
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    • pp.680-688
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    • 2015
  • Hybrid type combined transmission systems is being operated by AC and DC line at the same space will be expanded instead of the overhead line. However, such hybrid type combined system has problem like the arrangement selection of DC cable for effective system operation. In this paper, to select the proper arrangement of DC cable, induced voltage of DC cable influenced by AC cable was analyzed in case of several type arrangement of DC cable. Such induced voltage is in detailed analyzed not only in case of steady, but transient state. The arrangement which has the lowest induced voltage is selected as the proper one. EMTP/ATPDraw is used for modeling and analysis of hybrid type combined transmission system.

The Usage Intention of Combined Guard System - Focusing on GOP Scientific Guard System - (통합경계시스템의 이용의도에 미치는 영향 요인 분석 - 한국군 GOP 과학화 경계시스템을 중심으로 -)

  • Jang, Jin-Hyuk;Moon, Hee-Jin;Lee, Choong-J.
    • The Journal of Information Systems
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    • v.19 no.4
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    • pp.183-206
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    • 2010
  • The technology acceptance model (TAM) is a lot of cited in information technology adoption and usage researches. But TAM has been conducted primarily in volitional environments of the adoption of new technology. This paper discusses technology acceptance in accounting information systems to examine TAM with Characteristics of Organizations and Individuals in mandated using Combined Guard System. Combined Guard System is a scientific guard system that is composed of automated surveillance system, automated sensing system and control system. GOP Scientific Guard System is operated by GOP unit in Korean Army O Division from 2006. In this study, using the extended technology acceptance model, we have analyzed factors which affect the usage intention of GOP Scientific Guard System in mandated using environment. Based upon previous researches, we have selected Support of management unit, Training, Perceived Risk, Subjective Knowledge and Computer Self-efficacy, perceived usefulness, perceived ease of use, and usage intention as variables and proposed a research model. We collected 253 survey questionnaires from Korean army officer and soldier who are serviced at GOP unit in O Division, and analyzed the data using SPSS 12.0 and SmartPLS 2.0M3. According to the results by PLS analysis, According to the results by PLS analysis, Training and Subjective Knowledge did not affect Perceived usefulness, but the other hypotheses were accepted. And Perceived usefulness, and Ease of use influenced the Usage intention. The results of this study will increase Characteristics of Organizations and Individuals on GOP Scientific Guard System and eventually contribute to establishing the activation of Combined Guard System.

A Sduty on the Vulcanization Characteristic of Combined Accelerators in SBR compounds. (SBR의 가황촉진제(加黃促進劑) 병용효과(倂用效果)에 의한 가황특성(加黃特性) 연구(硏究))

  • Choi, Jae-Woon;Lee, Ki-Jong
    • Elastomers and Composites
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    • v.17 no.3
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    • pp.151-158
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    • 1982
  • The purpose of this study is to get comparitive results on the combined accelerator systems comprised of MBT, MBTS, DPG and CBS with TMTD, TMTM, Zn-MDC and DPG to SBR compound. Vulcanization characterstics and physical properties of the combined accelerators have been studied by mean of the Mooney viscometer, tensile testing machine, aging chamber and so on. According to the test results, TMTD with DPG system has shown faster Mooney scorch time than other system. The vulcanizate comprise of Zn-MDC with DPG and TMTD with DPG accelerator system has taken advantage of heat resistance.

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A Study on Calculation of Combined Heat and Power on Standpoint of Nation and Independent Power Producers (국가 및 전력회사의 관점에서 열병합발전의 편익산정에 관한 연구)

  • Kim, Yong-Ha;Lee, Pyong-Ho;Kim, Young-Gil;Jo, Hyun-Mi;Woo, Sung-Min
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.5
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    • pp.905-912
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    • 2011
  • In this paper, the method on calculating benefits of combined heat and power is introduced for standard evaluation in electrical power system. This paper calculates benefits about new national viewpoint and viewpoint of independent power producers and assesses benefits of combined heat and power in Korea and In Seoul national capital area. Benefit costs are composed of avoid cost of centralized generation, line upgrading adjustment, loss adjustment and electrical power trade cost per year in earlier study, in addition trade cost of $CO_2$, construction cost of combined heat and power for accurate calculation. Benefit of combined heat and power is calculated by simulation results of real electrical power system.

On the consideration of the masses of helical springs in damped combined systems consisting of two continua

  • Gurgoze, M.;Zeren, S.;Bicak, M.M.A.
    • Structural Engineering and Mechanics
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    • v.28 no.2
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    • pp.167-188
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    • 2008
  • This study is concerned with the establishment of the characteristic equation of a combined system consisting of a cantilever beam with a tip mass and an in-span visco-elastic helical spring-mass, considering the mass of the helical spring. After obtaining the "exact" characteristic equation of the combined system, by making use of a boundary value problem formulation, the characteristic equation is established via a transfer matrix method, as well. Further, the characteristic equation of a reduced system is obtained as a special case. Then, the characteristic equations are numerically solved for various combinations of the physical parameters. Further, comparison of the results with the massless spring case and the case in which the spring mass is partially considered, reveals the fact that neglecting or considering the mass of the spring partially can cause considerable errors for some combinations of the physical parameters of the system.

Performance Analysis of Multicarrier DS/CDMA System Employing Combined Modulation techniques in a Nakagami Fading Channel (나카가미 페이딩 채널에서 합성변조 기법을 채용한 다중반송파 DS/CDMA 시스템 성능 분석)

  • 양원일;강희조
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.5 no.1
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    • pp.52-60
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    • 2001
  • In this paper proposes a multi-carrier MFSK-DPSK/DS-CDMA combined modulation techniques in Nakagami fading environment. Also, multi-carrier DS-CDMA combined system is a promising technique for mobile communications systems, since it has a strong immunity to multipath fading and increasing bandwidth efficiency. The modulations under consideration are noncoherent M-ary frequency shift keying (MFSK)and an MFSK based joint frequency phase modulation utilizing differential phase shift keying (DPSK). With the result, performance improvement of power efficiency and bandwidth efficiency combined system in multi-carrier MFSK-DPSK/DS-CDMA are better then conventional communication system.

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System Configuration Studies on Gas Turbine Combined Cycle Power Plants - Application to Processes for Carbon Capture System (가스 터빈 복합화력 발전 플랜트의 시스템 구성 제안 - CO2 포집 대안 별 비교 평가)

  • Kim, Seungjin;Choi, Sangmin
    • 한국연소학회:학술대회논문집
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    • 2013.06a
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    • pp.15-17
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    • 2013
  • In the design of combined cycle power plants, the design parameters considered mainly could be changed and added for performance evaluation with change on the design objective and method. Therefore, the design criteria considering the different objectives and type of power plant were needed. Thermodynamic and economic analyses of various types of gas turbine combined cycle power plants with demand on generation of power and heat and carbon capture system from high pressure flue gas have been performed to establish criteria for optimization of power plants.

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Lightning Surge Analysis on Underground System in DC Combined Distribution System (DC 혼합배전시스템에서 지중계통의 뇌과전압 해석)

  • An, Chun-Yong;Lee, Jong-Beom
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.62 no.6
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    • pp.737-743
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    • 2013
  • This paper describes the overvoltage through lightning surge analysis on underground system in DC combined distribution systems. It is considered that operating micro grid including distributed generation with smart grid can make possibility of composing new distribution system different from existing one. However, there are many papers about low voltage DC distribution in grids or buildings but not many about replacement or distributing 22.9kV AC distribution system to DC system. Among many research need for DC system development, overvoltage is studied in this paper. Overvoltage is simulated on DC cable when lightning strikes to overhead grounding wire which is installed at the nearest location from power cable section. Analysis as well as modeling is performed in EMTP/ATPDraw. It is evaluated that analysis results can be used to design of DC underground distribution power cable system.