• Proceedings of the KIEE Conference
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• 2007.11b
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• pp.100-102
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• 2007

본 논문에서는 혼합정수 선형계획 법을 이용하여 장기 전력계통 계획수립시 최적의 설비를 투자할 수 있는 기법을 제안하였다. 발전설비와 송변전설비는 하나의 망으로 연결되어 상호 보완적 영향을 주기 때문에 계통계획시 두 설비를 동시에 평가하는 것이 무엇보다 중요하다. 또한 계획기간 전체에 대해 투자비를 고려하여 비용을 최소화해야 한다. 이를 위해 선형계획법을 계통계획에 도입하여 최소비용의 투자비를 가지고 공급 신뢰도 기준를 만족할 수 있는 최적 장기 전력계통 계획 수립기법을 개발하였다. 개발된 기법을 Garver 6모선 계통 및 제3차 전력수급기본계획에 대해 모의하여 결과의 타당성을 검증하였다.

• Proceedings of the KIEE Conference
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• 2007.11b
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• pp.231-233
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• 2007

구조개편 이후 전력수급계획 수립여건이 한전의 독점적 계책에서 사업자 건설의향으로 전환됨에 따라 신규설비 건설계획은 수익성 위주로 전환되었다. 이에 따라 본 논문에서는 기저선비(원자력, 석탄화력) 운전효율성 항상 차원에서 건설되던 양수설비의 적정 설비규모를 계통 공급신뢰도 측면, 에너지 이응 효율성 향상 측면, 전력시장에서의 경제성 측면에서 검토하여 최적전원구성(Best Fuel Mix) 유도론 위한 정책적 방향을 제시하였다.

• Proceedings of the KIEE Conference
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• 2007.11b
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• pp.234-236
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• 2007

전력산업 구조개편에 따라 도입된 새로운 전력시장환경하에서 전력시장가격(SMP)은 시장참여자에게 있어 기존사업 운영 및 신규투자에서의 의사결정을 하는데 가장 중요한 요소로 작용하게 된다. 이에, 본 논문에서는 전력시장 시뮬레이션 모형인 P-Pool 모형을 활용하여 제3차 전력수급기본계획에 기준한 장기 전력시장가격(2007-2020)을 전망하고 이를 시장정보로 제공함으로써 향후 잠재적 시장참여자의 의사결정을 돕고자 한다.

• Proceedings of the KIEE Conference
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• 2007.11b
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• pp.81-83
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• 2007

본 논문은 제3차 전력수급기본계획을 토대로 2010년부터 2020년도까지 우리나라 장기전력계통의 공급신뢰도를 MEXICO 모형을 이용해 전망한 결과를 분석한 것이다. 지금까지 전력계통 신뢰도에 대한 연구들은 주로 발전계통을 대상으로 한 결정론적 신뢰도 산정을 다루었던 반면 MEXICO 모형을 이용한 분석은 발전설비와 송전선로의 불확실성까지 고려한 복합 전력계통을 대상으로 실질적인 신뢰도 평가를 수행하였다는 점에서 의미가 있다. 주요 검토 내용으로는 2010년, 2012년, 2014년, 2020년도에 대한 공급지장에너지 및 공급지장비용분석 등을 다루고 있으며 이번 논문에서 사용된 신뢰도 평가방법은 향후 전력설비(발전 및 송전 설비계획의 복합 부분)의 확충계획 수립에 환웅이 가능할 것이다.

• The Transactions of the Korean Institute of Power Electronics
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• v.18 no.6
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• pp.587-592
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• 2013

In this paper, the performance improvement of the sensorless control of IPMSM employing the active flux concept by the improved current estimator is presented. The accuracy of the current estimator used in a previous report is degraded when the motor parameters are not known exactly. A simple current estimator derived from estimated flux is proposed to improve the position estimation performance. In order to show the usefulness of the proposed estimation method, the simulation results using Matlab/Simulink and the experiment results are presented.

• Proceedings of the KIPE Conference
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• 2011.07a
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• pp.481-482
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• 2011

New discrete time domain models for the peak current controlled (PCC) power LED drivers in continuous conduction mode include for the first time the effects of time delay in the pulse-width-modulator. Realistic amounts of time delay are found to have significant effects on the average output LED current and on the critical inductor value at the boundary between two conduction modes. Especially, the time delay can provide an accurate LED current for the PCC buck converter with a wide input voltage. The models can also predict the critical inductor values at the mode boundary as functions of the input voltage and the time delay.

• Proceedings of the KIPE Conference
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• 2004.07b
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• pp.610-614
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• 2004

Recently, an active-clamp, full-bridge boost converter has been actively studied for high-power applications such as power factor correction and battery discharger. However, DC and AC modeling for this converter has not conquered. In this paper, a DC and small-signal AC modeling for the active-clamp, full-bridge boost converter is described. Based on the operation principle, the ac part of the converter can be replaced by a do counterpart. Then, a conceptual equivalent circuit is derived by rearranging the switches. The equivalent circuit for this converter consists of CCM (Continuous conduction mode) boost and DCM (Discontinuous conduction mode) buck converter. The analyses for the equivalent CCM boost and DCM buck converter are done using the model of PWM switch. The theoretical modeling results are confirmed through experiment or SIMPLIS simulation.

• Proceedings of the KIEE Conference
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• 2001.05a
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• pp.108-111
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• 2001

The electric power industries in Korea are launched into deregulation by introducing the CBP(Cost Based Pool), where generation sector of KEPCO was divided into six generation companies and the other sectors of KEPCO remains vertically integrated system. In deregulated market, participants are concerned with maximization of their profit rather than minimization of system-wide costs. Consequently, there are difficulties in applying the cost minimization for the scheduling of generation resources to CBP, because of the operation of pumped-storage hydroplants. This paper presents an operation method of pumped storage hydroplants which is helpful for the economic operation of power system considering the market in the CBP.

• Proceedings of the KIEE Conference
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• 1993.11a
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• pp.132-134
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• 1993

A new Zero-Current Switched(ZCS) High Power Factor Rectifier for the. power factor correction is proposed. The proposed single phase rectifier enables a zero-current switching operation of all the power devices allowing the circuit to operate at high switching frequencies and high power levels. A dynamic model and a predictive current control technique for the ZCS-High Power Factor Rectifier(HPFR) are proposed. With the proposed dynamic model, an analysis for the internal operational characteristics is explored. With the proposed control technique, the unity power factor.

• Journal of the Korea Society for Simulation
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• v.21 no.2
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• pp.103-112
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• 2012

Traditional system-oriented measures are no longer adequate to describe the availability perceived by the user. In this paper we investigate the service availability model and the user behavior graph. And we propose the simulation model, which determines the sevice availability considering user model, system model and service model at the same time. Through the example, we show how to construct the UBG of user model, system model and service model. And we investigate the effect of the parameters of system model and UBG on the service availability.