• Title/Summary/Keyword: Electric Capacity

검색결과 1,250건 처리시간 0.035초

An examples of a 6-inch GTO inverter drive system applied for rougher mills

  • Kawasaki, Muneo;Okayama, Hideo;Koyama, Masato;Mitsuhashi, Masamichi;Masuda, Hiroyuki
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1996년도 Proceedings of the Korea Automatic Control Conference, 11th (KACC); Pohang, Korea; 24-26 Oct. 1996
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    • pp.25-28
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    • 1996
  • Recently, AC variable-speed motors are used for many steel rolling mill drive systems, because of their low maintenance and enhanced control performance. We have been applied GTO inverters for these AC motor drive systems since 1993. We have developed world largest 6-inch diameter GTO and large capacity 3-level GTO inverter up to 20000(kVA). As an example, in this paper, we describe the main circuit, system arrangement and control features of the 6-inches GTO inverters to drive rougher mills for hot strip mill of Pohang Iron & Steel Co., Ltd. The motor capacity is 6000(kW), and it's overload is 250(%).

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심야전력을 이용한 Cascade Heat Pump Cycle의 운전결과 분석 (Analysis on Cascade Cycle Heat Pump Application as Night Storage Heater)

  • 정훈;황성욱;이철희
    • 한국기계기술학회지
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    • 제13권1호
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    • pp.113-118
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    • 2011
  • To analyze and verify the effect of replacing thermal storage heater by a cascade cycle heat pump using midnight electricity was installed and tested at a customer's house in Wonju, Korea. The electric night storage heater is consist of 30kW electric heater and 2,700 liters of thermal storage water tank to supply hot water for warming house floor. The power for electric heater was cut off and hot water was only generated by cascade cycle heat pump. Current thermal storage water tank was not eliminated and electric heater wiring was modified. Some operation logic of the heat pump was also modified for proper operation. The required capacity of the heat pump and hot water temperature for given warming condition were estimated. The estimated capacity of heat pump was about 19kW and estimated hot water temperature for proper heating was at least $75^{\circ}C$.

직류 1500V 전기철도용 변전소의 회생인버터 용량 및 설치위치 선정 방법 (Determining the Capacity and Installation Positions of Regenerative Inverters at DC 1500V Electric Railway Substations)

  • 배창한;한문섭;김용기;권삼영;박현준
    • 대한전기학회논문지:전기기기및에너지변환시스템부문B
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    • 제55권9호
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    • pp.478-484
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    • 2006
  • The paper presents methods of determining the capacity and installation positions of regenerative inverters installed in DC 1500V electric railway system. We suggested a method that approximates using parameters related to substations where regenerative inverters are installed, railway lines and operating motor cars, and another that calculates using regenerative power obtained from Train performance Simulation (TPS) and Power Flow Simulation (PFS). We carried out TPS and PFS for Seoul Subway Line $5{\sim}8$, calculating regenerative power and determining substations where regenerative inverters would be installed and the optimal capacity and number of inverters to be installed.

건물의 활하중을 고려한 소형풍력발전시스템의 최대 설비용량 선정기법 (Determining the Maximum Capacity of a Small Wind Turbine System Considering Live Loads of Buildings)

  • 이여진;김성열
    • 전기학회논문지P
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    • 제65권3호
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    • pp.165-170
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    • 2016
  • Due to environmental issues such as global warming, the reduction of greenhouse gas emissions has become an inevitable measure to be taken. Among others, the building sector accounts for 50% of total carbon dioxide emissions, which is significantly high. Therefore, in order to reduce carbon dioxide emissions of the buildings, improving the energy efficiency by utilizing wind power among renewable energy sources is recommended. In case of buildings in the planning stage, it is possible to take the load of wind power generation systems into consideration when determining installed capacity. Already completed buildings, however, should be connected to small wind electric systems according to the live loads of the buildings based on the architectural design criteria. In order to connect to a building that has already been completed, it is necessary to consider the load of the small wind electric system as well as the live load of building. In addition, we need to generate the maximum electricity possible by determining the maximum installed capacity in a small area. In this paper, we propose the method for determining maximum capacity for building integrated small wind electric systems, which takes into account the considerations associated with connecting small wind electric systems to completed buildings. This can be developed into a system linked to solar power, which makes it possible to improve the energy independence of the building. In addition, carbon dioxide reduction by improving energy efficiency is expected.

The Study on the Efficient HVDC Capacity Considering Extremely Low Probability of 765kV Double Circuit Transmission Lines Trip

  • Moon, Bong-Soo;Ko, Boyung;Choi, Jin-San
    • Journal of Electrical Engineering and Technology
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    • 제12권3호
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    • pp.1046-1052
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    • 2017
  • The load on the power grid of South Korea is expected to grow continuously until the late 2020s, and it is necessary to increase the transfer capacity from the Eastern grid to the Seoul-Gyeonggi region by reinforcing the transmission network for the electric power system to remain stable. To this end, the grid reinforcement by two bipole LCC HVDC transmission systems have been considered on account of the public acceptability and high growth of the fault current level, even though an additional 765kV system construction is more economical. Since the probability of the existing 765kV double circuit transmission line trip is extremely low, a dynamic simulation study was carried out to estimate the efficient HVDC capacity able to stabilize the transient stability by utilizing the HVDC overload capability. This paper suggests the application plan to reduce the HVDC construction capacity with ensuring the transient stability during the 765kV line trip.

태양열 집열기 기능을 갖는 BIPV 시스템의 응용 (Application of BIPV System Functioned as Solar Collector)

  • 민성혜;서승직
    • 대한설비공학회:학술대회논문집
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    • 대한설비공학회 2006년도 하계학술발표대회 논문집
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    • pp.953-958
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    • 2006
  • Perimeter zone has been reinforced by active systems, such as fan-coil units, because it causes an increase in heating and cooling loads, dew condensation in winter, or discomfort with cold-draft to residents in buildings, through poor insulation by light-weighed skin due to progressing multi-storied buildings and skyscrapers. However, because these active systems raise Its capacity so that fossil fuel is used as much as they are added, and ultimately, greenhouse effect is urged, we proposed BIPV system functioned as solar collector which can substitute active system. As an early stage, heat balance equation in steady-state by Fortran was used not only for pre-heating effect and electric power capacity during the day in winter, but also for electric power capacity during day in slimmer and sky radiation effect during night in summer. Especially, we should have considered shading on PV, since even a little bit of it makes the efficiency too low for the PV to work. Still, when the flux of pre-heated air was increased to make air-barrier, its temperature was not enough to make it because the speed of heat exchange was too fast to warm up the air, thus the capacity to meet the condition was evaluated, and electric power from PV was made used for it.

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동결농축법을 이용한 폐수처리시스템의 에너지 효율 향상에 관한 연구 (A study on energy efficiency improvement of waste-water treatment system by freeze concentration method)

  • 김정식;임승택;오철
    • Journal of Advanced Marine Engineering and Technology
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    • 제37권5호
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    • pp.467-476
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    • 2013
  • 동결농축법은 열역학적 효율이 높고 에너지 소비량이 작으며 처리수를 재활용할 수 있는 장점을 가지고 있다. 본 연구에서는 중소규모로 상용화 가능한 동결농축폐수처리시스템을 설계하고, 각 시스템의 에너지 소비효율과 일일처리량을 비교하여 시스템 개발방향을 제안하고자 하였다. 시스템을 완속운전시스템과 급속운전시스템으로 각각 모델링하고 해석을 통해 소비동력과 운전시간을 계산하여 비교한 다음 설계처리량에 따른 변화를 추가 검토하였다. 연구결과 급속운전시스템의 소비전력량비가 0.6 Wh/kg 만큼 다소 높으나 일일처리량은 19 % 증가하였으며, 설계처리량이 큰 시스템일수록 소비전력량비가 작아지고 일일처리량이 큰 결과를 얻었다.

Development of high capacity stirling cryocooler

  • Ko, Junseok;Yeom, Hankil;Kim, Hyobong;Hong, Yong-Ju;In, Sehwan;Park, Seong-Je
    • 한국초전도ㆍ저온공학회논문지
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    • 제17권3호
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    • pp.51-56
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    • 2015
  • Cryogenic cooling system for HTS electric power devices requires a reliable and efficient high-capacity cryocooler. A Striling cryocooler with a linear compressor can be a good candidate. It has advantages of low vibration and long maintenance cycle compared with a kinematic-driven Stirling cryocooler. In this study, we developed dual-opposed linear compressor of 12 kW electric input power with two 6 kW linear motors. Electrical performance of fabricated linear compressor is verified by experimental measurement of thrust constant. The developed Stirling cryocooler has gamma-type configuration. Piston and displacer are supported with flexure spring. A slit-type heat exchanger is adopted for cold and warm-end, and the generated heat is rejected by cooling water. In cooling performance test, waveforms of voltage, current, displacement and pressure are obtained and their amplitude and phase difference are analysed. Moreover, temperatures of cooling water, housing and linear motor are recorded and electric power parameters of driving circuit are also obtained. The developed Stirling cryocooler reaches to 47.8 K within 23.4 min. with no-load. From heat load tests, it shows cooling capacity of 440 W at 78.1 K with 6.45 kW of electric input power and 19.4 of % Carnot COP.

펄스파워를 이용한 현장타설말뚝의 지지력 특성 (Bearing Capacity of In-situ Pile Installed using Pulse Power)

  • 김태훈;채수근;정규점
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2005년도 지반공학 공동 학술발표회
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    • pp.521-527
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    • 2005
  • In the past decades, complain about ground vibration and noise induced by pile driving has been quickly increased. Because of that, auger drilled piling methods have frequently used specially in urban area. However, the present auger drilled piling methods induce inevitable ground disturbance as well as a certain degree of vibration and noise due to the final hammering. For these reasons, a new auger drilled piling method is required to be developed. This paper introduces PDT(Pulse Discharge Technology) piling method and presents the characteristics of bearing capacity. The PDT piling method is to install in-situ piles using electric power so called Pulse. The pile installed by PDT appears to be able to develop shaft and end bearing capacity efficiently.

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냉각수 보급이 가정용 흡수식 냉난방기의 성능에 미치는 영향 (Effect on Household Absorption Chiller by the Supply of the Cooling Water)

  • 이호생;김동휘;최병권;김재돌;윤정인
    • 한국마린엔지니어링학회:학술대회논문집
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    • 한국마린엔지니어링학회 2002년도 춘계학술대회논문집
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    • pp.267-272
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    • 2002
  • The electric heat pump requiring HCFCs as a refrigerant has been for most residential air-conditioners in Korea. They cause a surge up electric power demand during summer. Moreover, the use of HCFCs and HFCs causes a serious problem to the global environment such as global warming and ozone layer destruction. An absorption chiller and heater could solve such problems. It was built and tested for analyzing the performance of the absorption chiller/heater. Experiment was done with a 1.5RT household absorption chiller and heater. It was experimented that the cooling capacity, gas capacity, COP were researched by the temperature of cooling water. The change of the cooling water temperature have effect the temperature(or pressure) of the parts on absorption chiller The result of the change of the cooling water temperature have the effects of the absorption chillers. This data will help to operate the household absorption chiller and heater.

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