• 한국전자거래학회지
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• 제17권2호
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• pp.105-114
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• 2012

최근 지구 온난화와 에너지 고갈 및 환경파괴로 인한 환경 문제에 대하여 세계 각국에서 심각하게 고민하고 있으며, 전기자동차의 상용화를 앞두고 이산화탄소 배출의 저감 및 효율적인 에너지 사용이 중요시 되고 있다. 또한, IT 기술의 발달과 함께 독점적인 전력공급에서 수요자가 참여하는 양방향 커뮤니케이션의 스마트 그리드의 개념이 도입되었다. 주요 국가들에서는 스마트 미터의 보급과 함께 에너지 사용의 효율성 개선을 위하여, 전력 경쟁시장에서 소비자의 수요반응의 활성화를 위한 인센티브의 지급 등의 정책도입이 요구되고 있다. 이에, 본 연구에서는 머지않아 등장할 소매전력시장에서 소비자의 수요반응을 증진하여 소비자의 전기 사용 비용을 절감하며 소매사업자의 이익을 최대화하는 전력 가격결정 모델을 제시하였다. 소비자 수요반응 참여율과 가격 탄성률에 따른 시뮬레이션을 시행하여 수요 반응을 나타내는 소비자 별 탄성률을 모든 소비자가 시간대별 고정 값을 사용하는 것과 소비자 별 탄성률을 예측하는 것을 비교하였다. 이를 통하여 전력 소매 시장에서 소비자의 에너지 사용을 줄이고 소매업자의 이익을 최대화할 수 있음을 밝혔다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2019년도 학술발표회
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• pp.160-160
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• 2019

Water is a limited source that needs to be properly managed and distributed to the ever-growing population of the world. Rapid urbanization and development have increased the overall water demand of the world drastically. However, there is loss of billions of liters of water every year due to leakages in water distribution systems. Such water loss means significant financial loss for the utilities as well. World bank estimates a loss of $14 billion annually from wasted water. To address these issues and for the development of efficient and reliable leakage management techniques, high efforts have been made by the researchers and engineers. Over the past decade, various techniques and technologies have been developed for leakage management and leak detection. These include ideas such as pressure management in water distribution networks, use of Advanced Metering Infrastructure, use of machine learning algorithms, etc. For leakage detection, techniques such as acoustic technique, and in recent yeats transient test-based techniques have become popular. Smart Water Grid uses two-way real time network monitoring by utilizing sensors and devices in the water distribution system. Hence, valuable real time data of the water distribution network can be collected. Best results and outcomes may be produced by proper utilization of the collected data in unison with advanced detection and management techniques. Long term reduction in Non Revenue Water can be achieved by detecting, localizing and repairing leakages as quickly and as efficiently as possible. However, there are still numerous challenges to be met and future research works to be conducted in this field.

• 한국태양에너지학회 논문집
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• 제33권4호
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• pp.39-45
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• 2013

This paper presents the estimation of minimum BESS capacity for regulating the output of wind farms considering power grid operating condition in Jeju Island. To analyze the characteristics of wind farm outputs with a BESS, the real data of wind farms, Sung-San, Sam-dal and Hang-Won wind farm, located in the eastern part of Jeju island is considered. The wind farms are connected to Sung-san substation to transfer the electric power to Jeju power grid. Consequently, at PCC (Point of Common Coupling), it can see a huge wind farm connected to the substation and thus it can be expected that the smoothing effect is affected by not only the different wind speeds for each area but also the different mechanical inertia of wind turbines. In this paper, two kinds of simulation have been carried out. One is to analyze the real data of wind farm outputs during a winter season, and the other is to connect a virtual BESS to eliminate the unintended generating power changes by the uncontrolled wind farm outputs as shown in the former data. In the conclusion, two kinds of simulation results show that BESS installed in the substation is more efficient than each wind farms with BESS, respectively.

• Journal of Electrical Engineering and Technology
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• 제5권1호
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• pp.61-69
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• 2010

This paper presents a study of a DFIG wind power generation system for real-time simulations. For real-time simulations, the Real-Time Digital Simulator (RTDS) and its user friendly interface simulation software RSCAD are used. A 2.2MW grid-connected variable speed DFIG wind power generation system is modeled and analyzed in this study. The stator-flux oriented vector control scheme is applied to the stator/rotor side converter control, and the back-to-back PWM converters are implemented for the decoupled control. The real-wind speed signal extracted by an anemometer is used for a realistic, reliable and accurate simulation analysis. Block diagrams, a mathematical presentation of the DFIG and a control scheme of the stator/rotor-side are introduced. Real-time simulation cases are carried out and analyzed for the validity of this work.

• Management Science and Financial Engineering
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• 제14권2호
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• pp.89-104
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• 2008

Growth curves including Bass, Logistic and Gompertz functions are widely used in forecasting the market demand. Nonlinear least square method is often adopted for estimating the model parameters but it is difficult to set up the starting value for each parameter. If a wrong starting point is selected, the result may lead to erroneous forecasts. This paper proposes a method of selecting starting values for model parameters in estimating some growth curves by nonlinear least square method through grid search and transformation into linear regression model. Resealing the market data using the national economic index makes it possible to figure out the range of parameters and to utilize the grid search method. Application to some real data is also included, where the performance of our method is demonstrated.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2009년도 추계학술발표논문집
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• pp.834-836
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• 2009

The authors have been discussed the optimal voltage regulation method and on-line real time method using artificial neural networks in the distribution system interconnected with Distributed Generation and Storage(DSG) systems. However, these methods have difficulty in dealing with the random load variations and operation characteristics of a number of DSG systems. To overcome these problems, this paper shows the basic concepts of smart grid system which is considered as one of the power delivery system in the near future and presents an evaluation method on the impacts of customer voltages by the operation of smart grid system. The smart grid system can change the system configuration in a flexible manner by using the static switches and offer the different power qualities in power services through the power quality control centers.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.1139_1141
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• 2009

Distributed Generation (DG) is predicted to play a important role in electric power system in the near future. insertion of DG system into existing distribution network has great impact on real-time system operation and planning. It is widely accepted that micro turbine generation (MTG) systems are currently attracting lot of attention to meet customers need in the distributed power generation market In order to investigate the performance of MT generation systems, their efficient modeling is required. This paper presents the modeling and simulation of a MT generation system suitable for grid-connected operation. The system comprises of a permanent magnet synchronous generator driven by a MT. A brief description of the overall system is given, and mathematical models for the MT and permanent magnet synchronous generator are presented. Also, the use of power electronics in conditioning the power output of the generating system is demonstrated. Simulation studies with MATLAB/Simulink have been carried out in grid-connected operation mode of a DG system. The control strategies for grid connected operation mode of DG system is also presented.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2007년도 추계 종합학술대회 논문집
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• pp.527-529
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• 2007

초고속 파일 전송을 위한 GridFTP 서버를 구축 하고 WAN상에서 최적의 성능을 내기위한 파라미터를 테스트 한다. production 레벨에서의 서비스 시 발생할 수 있는 여러가지 문제점들을 테스트를 통해 찾아내고 실제로 상용 서비스가 가능한 구성을 제안한다.

• 조명전기설비학회논문지
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• 제27권8호
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• pp.67-74
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• 2013

Major utilities have been focusing on R&D and nationwide business of AMI system which plays a vital role in SmartGrid whose concept is to maximize energy efficiency and optimize electric power facility management with exchanging real time information between utilities and consumers based on ICT technologies in power grid. In this paper, we suggest a power loss monitoring method using KEPCO's AMI system which is operating in fields and with the acquisition of AMI data and analyses verify the validation of a power loss monitoring method.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2008년도 하계학술대회 논문집
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• pp.247-249
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• 2008

There are many types of grid-connected inverter controllers; Synchronous Reference Frame (SRF)-based controller is the most popular methods. SRF-based controller is capable for reducing both of zero-steady state error and phase delay. However, SRF-based controller has a complex algorithm to apply in real application such as digital processor. Resonant controller is also reduced zero-steady state error, but its transfer function has a high order. In this paper, a simple proportional control is applied for grid connected inverter with LCL filter. LCL filter is a third order system. Applying a simple proportional controller is not increased the order of closed loop transfer function. By this technique, the single phase model is easily obtained. To reduce steady state error, proportional gain is set as high as possible, but it may produce instability. To compromise between a minimum steady state error and stability, the single phase model is evaluate through Root Locus and Bode diagram. PSIM simulation is used to verify the analysis.