• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.485-487
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• 2001

Electric power has traditionally been supplied to the demander through power generation, its transmission, and final distribution system. It is, however, expected that the various dispersed power system will be located near demanders and act as a power source based on the efficient management of electric power demanders and the optimal utilization of substitute energy. More stable electric power and efficient utilization of various power sources can be guranteed through the connection of the dispersed power system into the existing power system. It is the purpose of this study that, in the case of the connection of dispersed power system into the existing distribution line, effects of the connection on the power quality and plans for protection of power equipments are discussed and solutions of them are proposed.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 A
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• pp.541-542
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• 2006

The dispersed generation is recently increased introduction for the energy supply rationalization and effective management of power system. But the dispersed generation causes to the various trouble that isn't occurred in the past, for example, the two way systems have an effect on the mistake action of protection equipment and the power quality. In this paper, we research the influence on the harmonic when the dispersed generation is interconnected with distribution system. To achievement, we construct the interconnecting dispersed generation and distribution system which is applied to the permission of harmonic emission. After that, we simulate about the harmonic of distribution system interconnection dispersed generation by the PSCAD/EMTDC analyzing transient state of the power system.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.800-804
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• 2005

Load flow and short circuit fault transients of a power distribution system with wind turbines as dispersed generation units is presented. Usage of renewable energies such as wind is already a small part of total installed power system in medium and low voltage networks. In this paper, a radial power distribution system with wind turbines is simulated using DIgSILENT PowerFactory software for their influence on load flow and short circuit fault transients. Short fault occurring in dispersed generation systems causes some problems for the system and costumers such as fault level increase or the problems of sudden fluctuations in the current, voltage, power and torque of the double fed induction machine utilized in the wind turbines which have been studied and investigated.

• 대한전기학회논문지:전력기술부문A
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• 제48권6호
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• pp.692-698
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• 1999

This paper analyzes the effect of DGS(Dispersed Generation System) on the voltage regulation of the traditional distribution system of which the voltage is controlled by the bank LDC(Line Drop Compensator). Through the simulation results for 22.9kV class distribution system with DGSs, some general relationships among the operating power factor and introduction limit of DGS, and the sending-end reference voltage determined by internal setting coefficients of the LDC are derived. Those relationships are that the introduction limit of DGS increases as the power factor of DGS goes from lagging to leading and also as the allowance of the sending-end reference voltage increases. From the relationships, a operation method of the power distribution system integrated with DGSs is proposed from the view point of the operating power factor of DGS and new voltage regulation method.

• 전기학회논문지
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• 제66권2호
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• pp.300-304
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• 2017

Due to the introduction of various types of dispersed generations (DGs) with larger capacity in a power distribution system, the short-circuit current is expected to be increased, which more requires for the effective fault current limiting methods. As one of the promising countermeasures, the superconducting fault current limiter (SFCL) has been noticed. However, the decreased fault current by SFCL affects the operation of the overcurrent relay (OCR), representative protective device in a power distribution system. In this paper, the operation of the overcurrent relay due to the application of a SFCL in a power distribution system with DG linked by its bus line was analysed through the short-circuit tests. To analyze the effect of the SFCL application in a power distribution system with DG, the experimental simulated circuits were designed and the short-circuit tests for the power distributed system assembled with the DG, the OCR and the SFCL were carried out. Through the analysis on the short-circuit tests, the application of the SFCL in a power distribution system with DG could be confirmed to be contributed to the operational improvement of overcurrent relay.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 추계학술대회 논문집 Vol.15
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• pp.569-572
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• 2002

The reduction method of harmonic currents is very important, when harmonic influences of the systems connections of AC power lines with dispersed generations like solar energy and wind power generation etc, increase more and more. Which the influences of harmonic currents bring not only the drop of power quality but also many trouble occurrences of various systems. Recently, the necessity about application development of new substitute energy has gone up, and the development and practical use of dispersed power lines are proceeding now. Henceforth, a counterplan against harmonic influences must be devised for more practical use of new substitute energy. In this paper, we studied the harmonic influences and new devices for that connections and defined the calculating methods for hamonic currents of those systems.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 C
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• pp.1453-1455
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• 1999

This paper presents an economical generation planning for operating power systems with dispersed generation. As dispersed generation introduced into an electric power distribution system, the power system will be complicated and have much variable aspects. So there is need for developing new generation scheduling. In this paper, the proposed method is tested for distribution system with two battery storage resources. Optimal generation planning of 15 thermal units in 24-hours is achieved by improved genetic algorithm. Also, to show its effectiveness, the results are compared with those of not including battery storage resources.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1992년도 하계학술대회 논문집 A
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• pp.126-129
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• 1992

Compared to other sources of electricity such as Thermal and Nuclear power plant, dispersed storage and generation system (DSG) is environmentally clean, quiet and efficient, thus this source is expected to be introduced In urban area by the utilities and customers. If a great number of DSG will be applied to electric power system in the rear future (around 2000, in Korea), these will give a great influence on the existing power system. In other words, the interconnection to electric power system of these source may bring many problems such as system operation, protection coordination, and service quality related with voltages (110${\pm}$6V, 220${\pm}$13V), harmonics (5%) and pour factor (90% over). So, this analysis of the interconnection to power system of DSG is required

• 전기학회논문지
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• 제57권6호
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• pp.944-950
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• 2008

When small cogenerators are operated in connected with power system, there are many positive aspects such as the reduction of power plant construction, making a improvement of power security etc. At the same time, there are some negative effects or difficulties such as we should make sure of protective coordination, especially, Actually these are not fault, but it is likely to consider the current as the fault. This is one of major causes of malfunctions for protective relays in power distribution system which is including interconnection point. Thus, in this paper, We showed that the directional protection is necessary to the dispersed generation system which is including connection point. We also executed contingency analysis to find out the magnitude of fault current and direction which are classified by fault points, length of line and kinds of faults using ETAP power system analysis program.

• 에너지공학
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• 제11권3호
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• pp.216-223
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• 2002

전력계통의 전원설비 방식은 대규모 집중전원방식과 소규모 분산전원방식으로 크게 분류할 수 있으나 지금까지의 우리나라의 전원방식은 대규모집중방식 위주로 전원계획을 수립하여 왔다. 그러나 최근에 신에너지 전원설비인 태양광, 연료전지 및 풍력발전 등의 환경 친화적인 전원방식이 급증하고 있는 추세이고 국가적으로도 이러한 전원설비를 장려하고 있다. 그러나 이러한 신에너지 전원방식은 독자적으로 모든 부하를 충당할 수 없으며 고장시 전원공급에 차질이 발생할 우려가 있어 전력계통과의 연계가 필수적이다. 따라서 본 논문에서는 이러한 여러 형태의 신에너지 전원설비 중 풍력발전시스템을 저압 및 특별고압계통에 연계하는 경우에 발생하는 보호문제에 대해서 시뮬레이션과 분석을 통해 각종 사고에 대한 보호방식과 협조방안에 대한 방안을 제시하였다.