• Journal of Electrical Engineering and Technology
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• 제11권1호
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• pp.38-46
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• 2016

This study analyzes the economic efficiency of the virtual power plant (VPP) model that aims to integrate a number of emergency generators installed at the consumer end and operate them as a single power plant. Several factors such as the demand response benefits from VPP operation and costs incurred for converting emergency generators into VPP are considered to assess the economic efficiency of the proposed VPP model. Scenarios for yearly VPP conversion are prepared based on the installed capacities of the emergency generators distributed in South Korea, while the costs and benefits are calculated from the viewpoints of participants and power companies in accordance with California Test Methods. Furthermore, a sensitivity analysis is conducted on the cost factors among those affecting the economic efficiency of VPP business because these two factors have a great impact on benefits.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 하계종합학술대회논문집
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• pp.223-226
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• 1998

The control objective of steam generator water level in the secondary circuit of a nuclear power plant is to regulate the water level at the desired set point. The dynamics of steam generators is non-linear in nature. The task of modelling such plant is very difficult and especially so when plant operating conditions change frequently. In these reasons, conventional PI gains over all pover range will not work efficiently and a manual control is generally used in low power operation. Therefore the robust H$\infty$ controller design method should be required. In this paper, we design the robust H$\infty$ controller for water level control of steam generator using a mixed H$\infty$ optimization with model-matching method. Firstly we choose the desired model that has good disturbance rejection performance. Secondly we design a stabilizing controller to keep the model-matching error small and also provide sufficiently large stability margin against additive perturbations of the nominal plant.

• 한국안전학회지
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• 제21권1호
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• pp.1-5
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• 2006

The damage of important equipments for the nuclear power plant by the earthquake brings the loss of human lives and economic losses. Therefore safety-related equipment of nuclear power plant must be proved that function must be designed and structural integrity so that it can be maintained also from accident condition of various kinds. In this study, the computer room air conditioner to be delivered at the nuclear power plant applied to this qualification, try to develop an optimum model. This model ended up with good results which were under suitably allowable conditions about structurally safe earthquake.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2005년도 동계학술발표대회 논문집
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• pp.235-240
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• 2005

Recently urban utility plants in urban areas of Korea, such as energy supply systems, municipal waste incineration systems, sewage treatment systems and so on, have caused some critical troubles, for instance the insensitive response to the seasonal or daily variation of loads, the low system efficiency and inefficient use of energy because of the large-scale system located a great distance. Therefor the design method of optimal integrated system model of various urban utility plants proposed in this study suitably to the present situation of Korea. Also, the effect analysis for the introduction of compound utility plants was studied for a new town model on a 60,000 persons scale. As the results we found that the complex plant was superior to individual urban utility plant in side of the initial investment expenses, the operating cost and other reasons.

• Journal of Electrical Engineering and Technology
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• 제6권5호
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• pp.706-712
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• 2011

Necessary and sufficient conditions for the existence of diagonal, block-diagonal, and triangular decoupling controllers in linear multivariable systems for the most general setting are presented. The plant model in this study is sufficiently general to accommodate non-square plant and non-unity feedback cases with one-degree-of-freedom (1DOF) or two-degree-of-freedom (2DOF) controller configuration. The existence condition is described in terms of rank conditions on the coefficient matrices in partial fraction expansions.

• Mycobiology
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• 제45권4호
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• pp.233-239
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• 2017

Drosophila melanogaster is a useful model organism that offers essential insights into developmental and cellular processes shared with humans, which has been adapted for large scale analysis of medically important microbes and to test the toxicity of heavy metals, industrial solvents and other poisonous substances. We here give a brief review of the use of the Drosophila model in medical mycology, discuss the volatile organic compounds (VOCs) produced by the opportunistic human pathogen, Aspergillus fumigatus, and give a brief summary of what is known about the toxicity of some common fungal VOCs. Further, we discuss the use of VOC detection as an indirect indicator of fungal growth, including for early diagnosis of aspergillosis. Finally, we hypothesize that D. melanogaster has promise for investigating the role of VOCs synthesized by A. fumigatus as possible virulence factors.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 19-21 Oct. 1992
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• pp.490-495
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• 1992

A neural model predictive control strategy combining a neural network for plant identification and a nonlinear programming algorithm for solving nonlinear control problems is proposed. A constrained nonlinear optimization approach using successive quadratic programming cooperates with neural identification network is used to generate the optimum control law for the complicate continuous/batch chemical reactor systems that have inherent nonlinear dynamics. Based on our approach, we developed a neural model predictive controller(NMPC) which shows excellent performances on nonlinear, model-plant mismatch cases of chemical reactor systems.

• 제어로봇시스템학회논문지
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• 제4권3호
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• pp.392-399
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• 1998

A full-scope replica type simulator whose MCR(main control room) has the same features and operation functions as MCR of the reference power plant has been developed for a fossil power plant. This simulator was developed with the model of Poryung Fossil Power Plant #3,4 which is the standard model of the Korean fossil power plant. It is the first localized simulator for the supercritical, variable boiler pressure type fossil power plant. The simulator provides various kinds of accidents which are in normal plant operation and thus enables operators to recover or reduce possible damages. To design and develop this kind of simulator, we need to integrate high technologies such as system analysis, plant operation and system integration of mechanics, physics, computer science. CASE(Computer Aided Software Engineering) tools were used to develop the dynamic model. This simulator will greatly contribute to the improvement of the safety and efficiency of the fossil power plant by implementing operator training. In this paper, the outline of software and hardware configuration and characteristics of the simulator are described, and the results of 30%, 50%, 75%, 100% load operation test will be discussed.

• 한국지진공학회논문집
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• 제21권2호
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• pp.95-103
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• 2017

In order to modeling seismic isolation system such as lead-rubber bearing (LRB), bilinear model is widely used by many researchers. In general, an actual force-displacement relationship for LRB has a smooth hysteretic shape. So, Bouc-Wen model with smooth hysteretic shape represents more accurately actual hysteretic shape than bilinear model. In this study, seismic responses for seismically isolated nuclear power plant (NPP) with LRB modelled by Bouc-Wen and bilinear models are compared with those of NPP without seismic isolation system. To evaluate effect of earthquake characteristics for seismic responses of NPP isolated by LRB, 5 different site class earthquakes distinguished by Geomatrix 3rd Letter Site Classification and artificially generated earthquakes corresponding to standard design spectrum by Reg. Guide 1.60 are used as input earthquakes. From the seismic response results of seismically isolated NPP, it can be observed that maximum displacements of seismic isolation modelled by Bouc-Wen model are larger than those by bilinear model. Seismic responses of NPP with LRB is significantly reduced than those without LRB. This reduction effect for seismic responses of NPP subjected to Site A (rock) earthquakes is larger than that to Site E (soft soil) earthquakes.

• 한국농림기상학회:학술대회논문집
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• 한국농림기상학회 2011년도 학술발표회
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• pp.33-33
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• 2011