• Proceedings of the KIEE Conference
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• 2006.07a
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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.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.54 no.5
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• pp.251-258
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• 2005

Recently, the domestic and foreign power trends are the supply of high quality power and environment conservation technology based on the new energies development. So, the dispersed generation systems, such as photovoltaic, fuel cell, and battery are to be introduced in distribution systems. According to the situation change, power of high Quality and reliability are required in distribution systems with dispersed generation. Up to now, the voltage in distribution systems are regulated by ULTC of substation and pole transformer of primary feeders. These days, Step Voltage Regulator(SVR) is getting established at distribution feeders to regulate effectively voltage of primary ffeders that voltage drop exceeds $5\%$. But, because SVR is operated independently with ULTC of substation, SVR can not take play to its full effectivity. Under these circumstances, in order to deliver suitable voltages to as many customers as possible, new optimal voltage regulation algorithms are required in distribution system. So, this paper presents optimal voltage regulation algorithm to regulate voltage effectively for ULTC and SVR in distribution systems with dispersed generation systems.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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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.

• Proceedings of the KIEE Conference
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• 1999.07c
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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.

• Journal of Energy Engineering
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• v.11 no.3
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• pp.216-223
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• 2002

Generation facilities of the power system are mainly classified into large-scale concentrated generation and small-scale dispersed generation, but generation planning of the Korea power system has been focusing on the large-scale generation so far. Recently, however, applications of dispersed generation sources including solar cell, fuel cell, wind power, etc. have been rapidly increasing and being strongly promoted, and such generation sources should be comprehensively considered in both planning and operating. Since it is not always possible that the dispersed generation alone meets all the load interconnected to it is especially when a fault occurs, interconnection into the existing utility is desirable and recommended. In relation to wind power generation systems interconnected at the low and extra high voltage levels, this paper performs the simulation and analysis of the system protection and suggests protection coordination plans on various faults which possibly occur.

• Proceedings of the KIEE Conference
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• 1997.07c
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• pp.933-935
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• 1997

This paper presents a new approach to dispersed generation installation planning based on a Hereford Ranch Algorithm in a subtransmission system. A method to optimally locate dispersed generations in a meshed network for maximizing the potential benefits is outlined using Hereford Ranch Algorithm and its improvement in this paper. The benefit expressed as a performance index can be minimization of losses. The proposed method was tested for several sample power systems.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.6
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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.

• KIEE International Transactions on Power Engineering
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• v.2A no.4
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• pp.166-173
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• 2002

Dispersed Generation (DG) units significantly effect the existing distribution protection practices. Therefore, new protection practices of the distribution system interconnected with DG units should be reevaluated and developed. In this paper, a new inter-tie protection scheme of DG units for distribution automatic reclosing is proposed. The impact of DG units on existing radial-sectionaliser coordination is analyzed. And the effects of the distribution reclosing type (radial and passive reclosing) on DG dynamics are analyzed and classified. From the results of the DG dynamic responses by the reclosing type, i.e. radial and passive reclosing, the inter-tie protection schemes of DG are introduced to improve the reliability and availability of utility interactive DG. The proposed schemes are proved and evaluated by a case study using PSCAD/EMTDC simulation.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.11a
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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.

• Proceedings of the KIEE Conference
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• 2000.11a
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• pp.113-115
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• 2000

So far, it was very difficult to simulate the dispersed generation system including PV generation system using EMTP or EMTDC because the source of the dispersed generation system has a particular VI characteristic equation. In this paper, a novel simulation method of PV generation system has proposed and a new solar cell component for EMTDC is also developed. The VI characteristic equation of solar cell is used in order to realize the solar generation system in EMTDC simulation. Consequently the simulation of PV power generation system using field data is realized and acceptable results, which show close match between the real data of PV panel and the simulated data, were obtained.