• KIEE International Transactions on Power Engineering
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• 제4A권3호
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• pp.122-128
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• 2004

With the advent of distributed generation, power systems are fundamentally impacted in regards to stability and power quality. Distributed generation has a positive impact on system restoration following a fault, higher reliability, and mitigation of effect due to voltage sag. However, distributed generation also has a negative impact on decrease of reliability such as changes of protective device setting and mal-operation. Because bulk power systems consist of various sources and loads, it becomes complicated to analyze a power system with distributed generation. The types of distributed generation are usually classified by both rotating machinery and the inverter-based system. In this paper, distributed generation is designed by rotating machinery, and the distributed system having a model of the distributed generation is simulated using EMTP. In addition, this paper presents the simulation results according to the types of distributed generation.

• KIEE International Transactions on Power Engineering
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• 제4A권4호
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• pp.201-206
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• 2004

With the advent of distributed generation, power systems in general are impacted in regards to stability and power quality. Distributed generation has positive impacts on system restoration following a fault, higher reliability, and mitigation of effect due to voltage sag. However, distributed generation also has negative impacts on the decrease of reliability such as changes of protective device setting and mal-operation. Because bulk power systems consist of various sources and loads, it is complicated to analyze power systems that have distributed generation. The types of distributed generation usually are classified as the rotating machinery system and the inverter-based system. In this paper, distributed generation is designed as a synchronous generator, and the distribution system with its distributed generation model is simulated using EMTP. In addition, this paper shows the simulation results according to the types of distributed generation

• 조명전기설비학회논문지
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• 제20권9호
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• pp.78-83
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• 2006

A new measure, the distributed generation impact factor (DGIF), is used for evaluating the impact of newly introduced distributed generators on a networked distribution or a transmission system. Distribution systems are normally operated in a radial structure. But the introduction of distributed generation needs load flow calculation to analyze the networked system. In the developed framework, the potential share of every generation bus in each line flow of a networked system can be directly evaluated. The developed index does not require the solution of power flow equations to evaluate the effect of the distributed generation. The main advantage of the developed method lies in its capability of considering simultaneous outputs of multiple generation sites.

• 전기학회논문지
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• 제57권8호
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• pp.1349-1355
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• 2008

The paper shows the analysis of operating conflict of OCGR trip events and metering errors in the photovoltaic generation, wind generation distributed generation customers with no defect of the distributed generation facilities, which are connected to 22.9kV distribution lines. To analyze problems with metering errors and OCGR fault event, a power quality analyzer and PSIM program were used to test the field and to simulate in Sun-Cheon photovoltaic generation and Seo-Cheon photovoltaic generation customers. With the trial distribution line, the result of analysis was verified to prove with the same situation of the actual field. This paper suggests short term and long term countermeasures of OCGR fault events, analysis of over and shortage of metering errors in distributed generation customers.

• 전기학회논문지
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• 제67권8호
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• pp.1002-1008
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• 2018

Fault Ride Through(FRT) requirement prevents disconnections of distributed generations during the specific time on disturbance condition for system stability. However, since there is a limitation to the FRT capability of distributed generation, and the protection system needs to clear the fault quickly before the distributed generation is disconnected. Therefore, this paper proposes a novel optimal setting method of directional overcurrent relay considering FRT of distributed generation. The proposed method reduces the probability of disconnections of the distributed generation in disturbance without additional equipment considering the FRT capability of the distributed generation by calculating the optimal relay setting through the Genetic Algorithm(GA).

• 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.

• 신재생에너지
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• 제2권3호
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• pp.15-22
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• 2006

As the distributed generation becomes more reliable and economically feasible, it is expected that a higher application of the distributed generation units would be interconnected to the existing grids. This new market penetration using the distributed generation technology is linked to a large number of factors like economics and performance, safety and reliability, market regulations, environmental issues, or grid connection standards. KEPCO, a government company in Korea, has performed the project to identify and evaluate the performance of Micro Gas Turbine(MGT) technologies focused on 30, 60kW-class grid-connected optimization and combined Heat & Power performance. This paper describes the results for the mechanical, electrical, and environmental tests of MGT on actual grid-connection under Korean regulations. As one of the achievements, the simulation model of Exhaust-gas Absorption Chiller was developed, so that it will be able to analyze or propose new distributed generation system using MGT. In addition, KEPCO carried out the field testing of the MGT Cogeneration system at the R&D Center Building, KEPCO. The field test was conducted in order to respond to a wide variety of needs for heat recovery and utilization. The suggested method and experience for the evaluation of the distributed generation will be used for the introduction of other distributed generation technologies into the grid in the future.

• 전기학회논문지
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• 제62권11호
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• pp.1505-1510
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• 2013

This paper presents a method for determining the optimal placement of distributed generation units considering voltage sags. In general, the existing methods for distributed generation placement do not consider power quality problems such as voltage sags. In this paper, a novel method based on both genetic algorithm and voltage sag assessment is proposed for determining the placement of distributed generation unit. In the proposed method, the optimal placement is determined to minimize voltage sag effects and system losses.

• KEPCO Journal on Electric Power and Energy
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• 제8권1호
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• pp.21-29
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• 2022

Power generated from renewable energy has continuously increased recently. As the distributed generation begins to interconnect in the distribution system, an accurate generation forecasting has become important in efficient distribution planning. This paper explained method and current state of distributed power generation forecasting models. This paper presented selecting input and output variables for the forecasting model. In addition, this paper analyzed input variables and forecasting models that can use as mid-to long-term distributed power generation forecasting.

• 전기학회논문지P
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• 제65권2호
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• pp.94-100
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• 2016

A virtual power plant (VPP) technology is a cluster of distributed generation installations. VPP system is that integrates several types of distributed generation sources, so as to give a reliable overall power supply. Virtual power plant systems play a key role in the smart grids concept and the move towards alternative sources of energy. They ensure improved integration of the renewable energy generation into the grids and the electricity market. VPPs not only deal with the supply side, but also help manage demand and ensure reliability of grid functions through demand response (DR) and other load shifting approaches in real time. In this paper, utilizing a variety of distributed generation resources(such as emergency generator, commercial generator, energy storage device), activation scheme of the virtual power plant technology. In addition, through the analysis of the domestic electricity market, it describes a scheme that can be a virtual power plant to participate in electricity market. It attempts to derive the policy support recommendation in order to obtain the basics to the prepared in position of power generation companies for the commercialization of virtual power plant.