• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.203-204
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• 2011

There is a growing interest on Electric Vehicles due to global warming and greenhouse gas emission issue. Recently, new technologies of EV fast charging are continually being developed and power supply infrastructure technologies are being developed widely. In general, the fast charging system consists of AC-DC converter, DC-DC converter, and filters. This paper performs modeling of Electric Vehicle fast charging system using EMTP(Electromagnetic transient program).

• 한국군사과학기술학회지
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• 제14권5호
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• pp.818-824
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• 2011

In this paper, we proposed a phase noise model of a frequency synthesizer for a radar system. Especially, it was proposed a phase noise model in a DAS(Direct Analog Synthesizer) and a frequency up converter system using Leeson's model. The proposed phase noise model was derived from the measurement data of model 1 and evaluated by adapting to model 2 and model 3 frequency synthesizers. The prediction phase noise by modeling was totally matched to the measured data and the effective analysis of the phase noise was done in a frequency synthesizer and a frequency converter of radar system.

• Journal of Power Electronics
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• 제8권1호
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• pp.51-59
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• 2008

This paper addresses several issues concerning the analysis, design, modeling, simulation and development of single-phase, single-switch, power factor corrected AC-DC high frequency switching converter topologies with transformer isolation. A detailed analysis and design is presented for single-switch topologies, namely forward buck, flyback, Cuk, Sepic and Zeta buck-boost converters, with high frequency isolation for discontinuous conduction modes (DCM) of operation. With an awareness of modem design trends towards improved performance, these switching converters are designed for low power rating and low output voltage, typically 20.25W with 13.5V in DCM operation. Laboratory prototypes of the proposed single-switch converters in DCM operation are developed and test results are presented to validate the proposed design and developed model of the system.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2003년도 추계종합학술대회
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• pp.749-753
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• 2003

본 논문에서는 Custom Power의 전력품질의 향상을 위하여 PWM Buck-Boost AC-AC 컨버터를 사용, 항상 일정한 출력전압을 얻는 시스템을 보이고 제어를 위한 동적 모델링 및 제어기 설계의 일례를 보였다. 그 결과, 시스템 상태방정식을 유도하였고 전달함수를 구였으며 일정한 동작점 하에서 출력전압을 기준전압으로 regulation 제어하기 위한 제어기에 대하여 다루었다. 끝으로, 실험을 통하여 제안된 모델링과 시스템 설계가 타당함을 확인하였다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1998년도 Proceedings ICPE 98 1998 International Conference on Power Electronics
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• pp.713-718
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• 1998

Due to high power ratings and low conduction loss, the IGBT has become more attractive in high power applications. However, its slower characteristics than those of MOSFET cause severe switching losses and switching frequency limitation. This paper proposes the IGBT's soft switching concept with the help of MOSFET, where each of the IGBT and MOSFET plays its role during on-periods and switching instants. Also, the switching losses are analyzed by using the linearized modeling and the modeling and the operations of a converter are investigated to confirm the soft switching of IGBT's.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1988년도 전기.전자공학 학술대회 논문집
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• pp.109-112
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• 1988

All parasitics such as switch conduction voltages, conduction resistances, switching times and ESR''s of capacitors are counted in the new state-space modeling based on non-ideal switching functions. An equivalent simplified model is derived from the complex circuit with parasitics. Hence the results are very simple and exact, which are very important features of modelings. The pole frequency, dc voltage gain, and efficiency of the general converter, the buck-boost converter are analyzed and verified by the experiments with good agreements with the theories. This may be a good summary for the previous works concerned with parasitics.

• Journal of Power Electronics
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• 제8권3호
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• pp.239-247
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• 2008

This paper presents the design of 1 kW prototype high frequency link boost half bridge inverter-fed DC-DC power converters with bridge voltage-doublers suitable for small scale PEM fuel cell systems and associated control schemes. The operation principle of this converter is described using fuel cell modeling and some operating waveforms. The switching mode equivalent circuits are based on simulation results and a detailed circuit operation analysis at soft-switching conditions.

• 전기학회논문지
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• 제59권3호
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• pp.555-561
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• 2010

In this paper, the constant current controller is designed to regulate the driving current of a power LED. The controller design model of the power LED including its driving circuit is proposed to design the constant current controller. A buck converter is also introduced to drive the power LED. The PI-based digital controller is implemented to validate the proposed strategy for the power LED driving.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 하계종합학술대회 논문집(5)
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• pp.9-12
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• 2000

This paper describes the modeling and experimental results of coreless printed circuit board (PCB) based transformer that can be used for power conversion at high frequency operation. The principle of using coreless PCB based transformer in 2MHz, 10W class ZVS Flyback DC-DC converter has been successfully demonstrated. The maximum power conversion efficiency is 79%. Even for high operating frequency, an efficiency greater than 70% can be obtained with under 1% regulation error.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2002년도 전력전자학술대회 논문집
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• pp.533-537
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• 2002

A fast time domain modeling and simulation is performed for the input-series-output-parallel connected 2-switch forward converter Steady-state and large-signal transient responses due to a step load change are simulated. The simulation results are verified through experiments.