• Title, Summary, Keyword: power cut

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Development of Adaptive Home Power Peak-Cut Control System Using Power Line Communication (전력선통신을 이용한 소규모 주택용 맞춤형 전력피크 제어시스템 개발)

  • Kim, Sang-Dong;Park, Ji-Ho;Kim, Dong-Wan
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.65 no.1
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    • pp.219-226
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    • 2016
  • In this paper, adaptive home power peak-cut control system is developed using PLC. The developed scheme provides monitoring of power usage, power peak-cut control and additional function. In test bed, zone is presented by bedroom, living room, kitchen and bathroom. And individual load is presented by lighting, heater and fan in zone. In developed scheme, zone control is implemented by single PLC modem. And individual load control is implemented by key-map table. In addition, power peak-cut control system S/W, which can perform setting of power peak, power peak-cut control and monitoring of power usage.

Utility Interactive PV Systems with Power Shaping Function for Increasing Peak Power Cut Effect

  • Choe, Gyu-Ha;Kim, Hong-Sung;Heo, Hye-Seong;Jeong, Byong-Hwan;Choi, Young-Ho;Kim, Jae-Chul
    • Journal of Power Electronics
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    • v.8 no.4
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    • pp.371-380
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    • 2008
  • This paper describes the Utility Interactive PV (UIPV) system which can improve the peak-cut effect by adding an energy storage device of batteries to the power converter. The proposed system has three possible operation modes depending on relative condition of PV output, which can have the power shaping function covering the peak power for 3 hours. A new power circuit and an application algorithm have been applied to the UIPV system which is based on working PV system during a 3-hour peak time. The energy relationship by the proposed system is analyzed theoretically and experimentally. The proposed system is evaluated at the viewpoint of cost and total spacing, which enables the proposed UIPV system to have the reduction of the peak power demand and hence to improve the power capacity of peak cut.

Output Characteristics of Peak-Cut Saver System with Energy Storage Device (에너지 저장장치를 갖는 피크컷 세이버 시스템의 출력특성 연구)

  • Seo, Hyou-Uk;Han, D.H;Lee, Y.J;Chun, T.W;Choe, Gyu-Ha
    • Proceedings of the KIPE Conference
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    • pp.231-232
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    • 2011
  • It is very important thing to efficiently utilize the solar power. The conventional solar power system has no energy storage device. So the conventional system cannot cut the peak load. In this paper, the solar power system with the energy storage device and the operation algorithm of peak cut function was proposed to cut the peak load. The algorithm principle is proposed based on the insolation curve and load curve. The simulation and experiment was performed to demonstrate the validity of the peak cut algorithm.

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Effects of Laser Parameters and Workpiece Conditions on Cutting Characteristics of Solid Wood and Wood-based Panel(II) - Specific Cutting Energy and Surface Qualities - (레이저변수(變數)와 피삭재조건(被削材條件)이 목재(木材) 및 목질(木質)보드의 절삭특성(切削特性)에 미치는 영향(影響)(II) - 비절삭(比切削)에너지와 절삭면(切削面)의 품질(品質) -)

  • Sim, Jae-Hyeon;Jung, Hee-Suk
    • Journal of the Korean Wood Science and Technology
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    • v.26 no.1
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    • pp.38-50
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    • 1998
  • Laser cutting tests were conducted to investigate the laser cutting characteristics of solid woods such as 25mm-thick white oak(Quercus acutissima) and maple(Acer mono), and wood-based panels such as 15mm-thick medium density fiberboard and particleboard. Test variables were laser power, cutting speed, grain direction, and moisture content. Specific cutting energy was measured and the qualities of cut surface were estimated in constant laser power. Specific cutting energy of white oak was larger than that of maple, and specific cutting energy of medium density fiberboard was smaller than that of particleboard. For both white oak and maple, specific cutting energy of green wood was smaller than that of air-dried wood because weight loss of moisture evaporation in green wood was larger than that in air-dried wood. In laser-cut surface, wood cells were not deformed and damaged, but in circular saw-cut surface fibers were pushed out and cut, and wood cells were deformed severely. However, mechanical surface roughness of saw-cut surface was smoother than that of laser-cut surface because of the existence of undeformed cell cavity in laser-cut surface.

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Control Method for Cut-out of Shorted Load in the Auxiliary Power Supply (보조전원장치의 단락부하 차단기 개방을 위한 제어방법)

  • 황광철;조국춘;최종묵
    • Proceedings of the KSR Conference
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    • pp.249-254
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    • 1998
  • This paper describes the control methods to cut out the NFB(No Fuse Breaker) of shorted load in the auxiliary power supply, Generally, when the short-circuit occurs in the load of the auxiliary power supply, the auxiliary power supply stops the operation according to the protection sequence. Finally, the other auxiliary power supply stops the operation by the same fault, To resolve this problem, we suggest the control method to trip the NFB of shorted load. That is, when the short circuit occurs, the controller changes control mode from voltage mode to current mode without the operation of output contactor(SIVK) in the auxiliary power supply. The auxiliary power supply provides a large current for the short-circuit load. After some time, the NFB of the short-circuit load is cut off and the auxiliary power supply Provides stable voltage for the loads except for the short-circuit load.

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A Study on the Reliability Evaluation of Start-up Power Supply in Fossil Power Plant by Minimal Cut-Set Method (최소 컷셋법에 의한 화력발전소 기동전원의 신뢰도 예측에 관한 연구)

  • Choe, Gyu-Sik
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.48 no.4
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    • pp.358-364
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    • 1999
  • The auxiliary transformers or start-up/stand-by transformer(s) are installed against the start-up and shut-down of generator and emergency status in fossil power plant. The on-site power supply configuration using these transformers must be determined, considering configuration requirements, site characteristics, reliability and availability severely because it is remarkably important for safety and ecfonomy of plant. The auxiliary or start-up/stand-by power supply configuration has been determined considering only safety requirements and construction cost until now in Korea. This paper presents general theorems for the reliability estimation and proposes 2-unit based 4 alternatives for the start-up power supply stystem of 500㎿ standardized fossil power plant. The reliability and unavailability of equipment, system and configuration are determined using minimal cut-set methodology. The optimized plan of 4 alternatives is determined based on this ultimate reliability and unavailability.

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Solar ESS Peak-cut Simulation Model for Customer (수용가 대응용 태양광 ESS 피크컷(Peak-cut) 시뮬레이션 모델)

  • Park, Seong-Hyeon;Lee, Gi-Hyun;Chung, Myoung-Sug;Chae, U-ri;Lee, Joo-Yeuon
    • Journal of Digital Convergence
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    • v.17 no.7
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    • pp.131-138
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    • 2019
  • The world's electricity production ratio is 40% for coal, 20% for natural gas, 16% for hydroelectric power, 15% for nuclear power and 6% for petroleum. Fossil fuels also cause serious problems in terms of price and supply because of the high concentration of resources on the earth. Solar energy is attracting attention as a next-generation eco-friendly energy that will replace fossil fuels with these problems. In this study, we test the charge-operation plan and the discharge operation plan for peak-cut operation by applying the maximum power demand reduction simulation. To do this, we selected the electricity usage from November to February, which has the largest amount of power usage, and applied charge / discharge logic. Simulation results show that the contract power decreases as the peak demand power after the ESS Peak-cut service is reduced to 50% of the peak-target power. As a result, the contract power reduction can reduce the basic power value of the customer and not only the economic superiority can be expected, but also contribute to the improvement of the electric quality and stabilization of the power supply system.

Modal acoustic power of broadband noise by interaction of a cascade of flat-plate airfoils with inflow turbulence (평판 에어포일 캐스케이드와 입사 난류의 상호작용에 의한 광대역 소음의 모달 음향 파워)

  • Cheong, Cheol-Ung;Jurdic, Vincent;Joseph, Phillip
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.1467-1475
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    • 2007
  • This paper investigates the modal acoustic power by a cascade of flat-plate airfoils interacting with homogeneous, isotropic turbulence. Basic formulation for the acoustic power upstream and downstream is based on the analytical theory of Smith and its generalization due to Cheong et al. The acoustic power spectrum has been expressed as the sum of cut-on acoustic modes, whose modal power is the product of three terms: a turbulence series, an upstream or downstream power factor and an upstream or downstream acoustic response function. The effect of these terms in the modal acoustic power has been examined. For isotropic turbulence gust, the turbulent series are only reducing factor of the modal acoustic power. The power factor tends to reduce the modal acoustic power in the upstream direction, although the power factor is liable to increase the modal acoustic power in the downstream direction. The modes close to cut-off are decreasing strongly, especially in the downstream direction. Therefore the modes close to cut-off don't contribute highly to the radiated acoustic power in the downstream direction, although the modal acoustic pressure is high for these modes.

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Characteristics of Modal Acoustic Power of Broadband Noise by Interaction of a Cascade of Flat-plate Airfoils with Inflow Turbulence (평판 에어포일 캐스케이드와 입사 난류의 상호작용에 의한 광대역 소음의 모달 음향 파워 특성)

  • Cheong, Cheol-Ung;Jurdic, Vincent;Joseph, Phillip
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.18 no.1
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    • pp.61-70
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    • 2008
  • This paper investigates the modal acoustic power by a cascade of flat-plate airfoils interacting with homogeneous, isotropic turbulence. Basic formulation for the acoustic power upstream and downstream is based on the analytical theory of Smith and its generalization due to Cheong et al. The acoustic power spectrum has been expressed as the sum of cut-on acoustic modes, whose modal power is the product of three terms: a turbulence series, an upstream or downstream power factor and an upstream or downstream acoustic response function. The effect of these terms in the modal acoustic power has been examined. For isotropic turbulence gust, the turbulent series are only reducing factor of the modal acoustic power. The power factor tends to reduce the modal acoustic power in the upstream direction, although the power factor is liable to increase the modal acoustic power in the downstream direction. The modes close to cut-off are decreasing strongly, especially in the downstream direction. Therefore the modes close to cut-off don't contribute highly to the radiated acoustic power in the downstream direction, although the modal acoustic pressure is high for these modes.

Analysis of Noise Reduction Performance for Noise Cut Transformer (Noise Cut Transformer의 노이즈 억제성능 분석)

  • Lee, Jae-Bok;Huh, Chang-Su;Lee, Ki-Chul;Myung, Sung-Ho;Ha, Tae-Hyun
    • Proceedings of the KIEE Conference
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    • pp.1784-1786
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    • 1996
  • It is necessary to eliminate the broad band noise which frequency is in a few kHz to MHz in the AC line to supply the power to electrical and electronic control equipments. Because this kind of noise could damage the device or could be a source of malfunction, many devices like a filter and surge suppressor are developed to cut off the noise. But those device could not disconnected from the power line, so it remain some problem and on be used in limited area, In this paper, we present performance test results NCT(noise Cut Transformer) with excellent performance for reducing the high frequency noise and surge existing in the power line.

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