• Journal of Electrical Engineering and Technology
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• 제13권1호
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• pp.105-113
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• 2018

This paper proposes pre-analysis on planning of high-voltage direct current (HVDC) transmission system applied to Korea electric power grid. HVDC transmission system for interface lines has been considered as alternative solution for high-voltage AC transmission line in South Korea since constructing new high-voltage AC transmission lines is challenging due to political, environmental and social acceptance problems. However, the installation of HVDC transmission system as interface line in AC grid must be examined carefully. Thus, this paper suggests three scenarios to examine the influences of the installation of HVDC transmission system in AC grid. The power flow and contingency analyses are carried out for the proposed scenarios. Power reserves in metro area are also evaluated. And then the transient stability analysis focusing on special protection scheme (SPS) operations is analyzed when critical lines, which are HVDC lines or high voltage AC lines, are tripped. The latest generic model of HVDC system is considered for evaluating the impacts of the SPS operations for introducing HVDC system in the AC grid. The analyses of proposed scenarios are evaluated by electromechanical simulation.

• 전기학회논문지
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• 제63권9호
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• pp.1219-1226
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• 2014

This paper introduces a hardware simulator for the LVRT operation analysis of the grid-tied PMSG wind power system with a power dissipation circuit. The power dissipation circuit, which is composed of chopper and resistor, suppresses the sudden increase of DC-link voltage in the back-to-back converter of the grid-tied PMSG wind power system. The LVRT operation was first analyzed using computer simulations with PSCAD/EMTDC. A wind power simulator including the power dissipation circuit and the fault simulator composed of variac and IGBT were built to analyze the LVRT operation. Various experiments were conducted to verify the effectiveness of the power dissipation circuit for the LVRT operation. The developed hardware simulator can be extensively utilized for the analysis of various LVRT operations of the grid-tied wind power system.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 추계학술대회 논문집
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• pp.736-741
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• 2005

This paper presents electric characteristics analysis and safe configuration for extension power supply between existent 6.6kV ungrounded distribution system and establishment and improvement 22.9kV direct grounding distribution system. For this, we model 6.6kV ungrounded and 22.9kV direct grounding distribution system of urban underground, ground region. and rural electrical, unelectrical region using PSCAD/EMTDC and analyze voltage drop, charging current, ground and short fault through simulation. To analyze electric characteristics of extension power supply, we simulate extension power supply of overhead line of 6.6kV ungrounded system and underground line of 22.9kV direct grounding system of rural electrical region and propose operation condition for safe extension power supply through result of analysis. Characteristics of voltage drop, charging current, ground and short fault appear almost similarly with electrical characteristic of direct power supply. However, because unbalance of phases may cause relay's malfunction of ungrounded system and ground fault current of direct grounding system may demage facilities of ungrounded system, we propose safe system configuration such as impedance grounding system of neutral point.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 추계학술대회 논문집 전력기술부문
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• pp.128-130
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• 2003

Recently, with the increasing use of power semiconductors and microprocessors which are very sensitive to little change of power quality and power market being formed according to the reorganization of the power market, power providers and consumers show much interest in the power quality problem. This situation makes the demand creation of integrated system for power quality analysis and monitoring based on speedy and powerful functions by the growth of computer hardware and information technology, and besides advanced corporation already have created and employed power quality analysis and monitoring system. In this papers, it will be introduced that power quality database design-database is essential to integrated system-for managing effectively and confidently data from the power quality meters(PQM).

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 전력전자학술대회 논문집
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• pp.446-449
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• 2001

This paper presents the results of the power system analysis and power loss breakdown peformed on a 40-inch ac plasma display panel (PDP) TV set. The architecture and function of power system is reviewed. The power flow inside the PDP TV set is presented, and the distribution of the power loss is analyzed. It was found that the sustain driver circuit and power factor correction (PFC) circuit are the two major sources of the power loss. The results of this paper can be used as a preliminary guideline to improve the architecture and efficiency of power systems for ac PDP application systems.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 B
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• pp.1316-1318
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• 2002

A methodology for reliability and economic analysis of wind embedded electric power system is presented in this paper. This is done by evaluating the reliability index, loss of load expectation (LOLE), for the power system with and without integration of wind system in the overall electric power system. Economic analysis of the wind energy embedded electric system is done in terms of conventional fuel saving assessment due to the use of wind power generation units.

• KIEE International Transactions on Power Engineering
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• 제5A권4호
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• pp.322-330
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• 2005

This paper proposes methods to incorporate station related aging failures in composite system reliability assessment. Aging failures of station components, such as circuit breakers and bus bars, are a major concern in composite power system planning and operation as an increasing number of station components approach the wear-out phase. This paper presents probabilistic models for circuit breakers involving aging failures and relevant evaluation techniques to examine the effects of station related aging outages. The technique developed to incorporate station related aging failures are illustrated by application to a small composite test system. The paper illustrates the effects of circuit breaker aging outages on bulk system reliability evaluation and examines the relative effects of variations in component age. System sensitivity analysis is illustrated by varying selected component parameters. The results show the implications of including component aging failure considerations in the overall analysis of a composite system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 추계학술대회 논문집 전력기술부문
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• pp.127-130
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• 2002

Recently, with the increasing use of power semiconductors and microprocessors which are very sensitive to little change of power quality and for coping positively with anticipating power quality disputes between power providers and consumers which are possible to occur by of power market being formed, the power quality problem has gained preponderance among the contemporary research areas. To serve these purposes, the integrated system has been researched and developed for power quality analysis and monitoring, which provides speedy and powerful functions by the growth of computer hardware and information technology. But the advent of fast and lower price hardware make little difference in an application on many systems. As a result, the key issues of constructing power quality monitoring system are in the management of data obtained, accurate algorithms, graphic representation and user-friendly-environment for easy and clear analysis results. So, in this paper it will be introduced that the standard of user-friendly-GUI(Graphic User Interface) and analysis graphic representation for intuitive understanding of results from power quality analysis based on consideration of several systems currently being in use.

• KIEE International Transactions on Power Engineering
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• 제5A권1호
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• pp.56-61
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• 2005

This paper presents an evaluation of the interruption costs for commercial customers in Korea using customer survey methodology. When various research results are examined, the evaluation of direct interruption costs becomes much more simplified. Especially, in the case of commercial customers, it is known that the evaluation of direct interruption costs is more useful. Accordingly, this paper selected the customer survey method to evaluate the interruption costs for commercial customers in Korea considering interruption and customer characteristics.

• 전기학회논문지P
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• 제63권3호
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• pp.131-137
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• 2014

It is expected that there will be delay of scheduled transmission network reinforcement and huge investment of renewable energy resources in Korea. As transmission capacity expansion delayed, supplying power to Seoul metropolitan area will not be increased as scheduled. In addition, uncertain renewable energy out of Seoul metropolitan area can cause transmission congestion in the future power system. These two combining effects will make the difference in locational marginal prices(LMP) and congestion costs increase. In that sense, this paper will analyze how much the congestion costs for Korea power system are incurred in the future power system. Most of previous approaches to analyze the congestion costs for electric power system are based on the optimal power flow model which cannot deal with hourly variation of power system. However, this study attempted to perform the analysis using market simulation model(M-Core) which has the capability of analyzing the hourly power generation cost and power transmission capacity, and market prices by region. As a result, we can estimate the congestion costs of future power system considering the uncertainty of renewable energy and transmission capacity.