• 전력전자학회:학술대회논문집
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• 전력전자학회 2017년도 전력전자학술대회
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• pp.180-181
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• 2017

Recently as distributed source has increased, the distribution system has changed from unidirectional power flow to bi-directional power flow. This power flow causes the PCC voltage variation, which can adversely affect voltage sensitive loads. In this paper, the relation between the active power, reactive power and PCC voltage of the distributed source is analyzed, and the PCC voltage control scheme by reactive power compensation is proposed in the distributed source itself. In addition, limitations and conditions according to the standard for interconnecting distributed resources are specified and verified through simulation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.95_96
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• 2009

In this paper, a new algorithm of Integrated Volt/Var Control (IVVC) is proposed using Volt/Var control for the Distribution Automation System (DAS) based on the modeling of the distributed load and the distributed current. In the proposed, the load flow based on the modeling of the distributed load with Distributed Generation and the distributed current are estimated from constants of four terminals using the measurement of the current and power factor from a Feeder Remote Terminal Unit (FRTU). For Integrated Volt/Var Control (IVVC), the gradient method is applied to find optimal solution for tap and capacity control of OLTC (On-Load Tap Changers), SVR (Step Voltage Regulator), and SC (Shunt Condenser). What is more Volt/Var control method is proposed using moving the tie switch as well as IVVC algorithm using power utility control. In the case studies, the estimation and simulation network have been testified in Matlab Simulink.

• Journal of Electrical Engineering and Technology
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• 제13권2호
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• pp.620-630
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• 2018

In this paper, a positioning method of distributed power system is proposed to minimize the average voltage variation of a DC microgrid through voltage sensitivity analysis. The voltage sensitivity under a droop control depends on the position of the distributed power system. In order to acquire a precise voltage sensitivity under a droop control, we analyzed the power flow by introducing a droop bus with the considerations of the droop characteristics. The results of the positioning method are verified through PSCAD/EMTDC simulation.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2001년도 유체기계 연구개발 발표회 논문집
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• pp.347-353
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• 2001

A combined cycle, 'HYBRID', is emerging as a new power generation technology that is particularly suitable for the distributed power generation system, with high energy efficiency and low pollutant emission. Currently micro gas turbines and fuel cells are attracting a lot of attention to meet the future needs in the distributed power generation market. This hybrid system may have every advantages of both systems because a gas turbine is synergistically combined with a fuel cell into a unique combined cycle. The hybrid system is believed to become a leading runner in the distributed power generation market. This paper introduces a current plan associated with the development of the hybrid system which consists of a micro gas turbine and a solid-oxide fuel cell(SOFC).

• 한국통신학회논문지
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• 제42권5호
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• pp.1093-1101
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• 2017

스마트 그리드를 구성하는 기본 단위 요소인 마이크로그리드(Microgrid)는 전력의 중앙 공급방식에서 벗어나 독립된 하나의 체계를 이룬다. 본 논문은 전력변환장치(Power Conditioning System)를 기반으로 마이크로그리드를 계통으로부터 전기적으로 독립시키고, 신재생 에너지원과 에너지 저장장치(Energy Storage System) 등의 분산자원(Distributed Energy Resource)을 활용하여 효과적으로 독립 상태를 유지하고 운영할 수 있는 방법을 제안한다. 계통의 위상검출과 동기화를 통해 계통에 연계하거나 독립 시에 부하에 미치는 영향을 최소화할 뿐만 아니라 계통의 정전 상황에서도 안정적으로 운영이 가능하다.

• 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.

• 전기학회논문지
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• 제59권2호
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• pp.298-305
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• 2010

In this paper, a new algorithm of optimal Volt/Var Control is proposed using Volt/Var control for the Distribution Automation System (DAS) with Distributed Generation (DG) based on the modeling of the distributed load and the distributed current. In the proposed, algorithm based on the modeling of the distributed load and the distributed current are estimated from constants of four terminals using the measurement of the current and power factor from a Feeder Remote Terminal Unit (FRTU) and DG data from RTU for DG. For the optimal Volt/Var Control, the gradient method is applied to find optimal solution for tap, capacity and power control of OLTC (On-Load Tap Changers), SVR (Step Voltage Regulator), PC (Power Condenser) and DG (Distributed Generation). In the case studies, the estimation and control of the voltages have been testified in a radial distribution system with DG using matlab program.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제4B권4호
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• pp.217-224
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• 2004

A novel anti-islanding method for the distributed power generation system (DPGS) is proposed in this paper. Three different islanding scenarios are explored and presented based on the analysis of real and reactive power mismatch. It is shown via investigation that islanding voltage is a function of real power alone, where its frequency is a function of both real and reactive power. Following this analysis, a robust anti-islanding algorithm is developed. The proposed algorithm continuously perturbs ($\pm$5%) the reactive power supplied by the DPGS while simultaneously monitoring the utility voltage and frequency. In the event of islanding, a measurable frequency deviation takes place, upon which the real power of the DPGS is further reduced to 80%. A drop in voltage positively confirms islanding and the DPGS is then safely disconnected. This method of control is shown to be robust: it is able to detect islanding under resonant loads and is also fast acting (operable in one cycle). Possible islanding conditions are simulated and verified through analysis. Experimental results on a 0.5kW fuel cell system connected to a utility grid are discussed.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 심포지엄 논문집 정보 및 제어부문
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• pp.90-92
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• 2005

In this paper, we design a digital protection IED(Intelligent Electric Device) for a distributed power system in connection with power grid. The device can measure various elements for protection and communicate with another devices through network. The protection IED is composed of specific function modules: signal process module which converts analog signal from PT and CT handle algorithm to digital one; communication module for connection with another IEDs; input/output module for user-interfaces; main control module for control the whole modules. A general purpose DSP board with TMS320C2812 is used in the IED. Experiments with the power system simulator DOBLE have been made to verily the proposed hardware system.

• 한국인터넷방송통신학회논문지
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• 제21권6호
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• pp.163-171
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• 2021

본 논문은 분산형 전력 시스템에서 심층강화학습 기반의 전력 생산 환경 및 수요와 공급을 예측하며 자원 할당 알고리즘을 적용해 전력거래 시스템 연구의 최적화된 결과를 보여준다. 전력 거래시스템에 있어서 기존의 중앙집중식 전력 시스템에서 분산형 전력 시스템으로의 패러다임 변화에 맞추어 전력거래에 있어서 공동의 이익을 추구하며 장기적인 거래의 효율을 증가시키는 전력 거래시스템의 구축을 목표로 한다. 심층강화학습의 현실적인 에너지 모델과 환경을 만들고 학습을 시키기 위해 날씨와 매달의 패턴을 분석하여 데이터를 생성하며 시뮬레이션을 진행하는 데 있어서 가우시안 잡음을 추가해 에너지 시장 모델을 구축하였다. 모의실험 결과 제안된 전력 거래시스템은 서로 협조적이며 공동의 이익을 추구하며 장기적으로 이익을 증가시킨 것을 확인하였다.