• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.1309_1310
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• 2009

The topology of active clamp forward converter provides ZVS characteristic and also the stress of voltage and current is smaller than that of the conventional forward converters. The benefits of this technique include a higher efficiency at a high switching frequency, lower EMI/RFI. In this paper, the active clamp forward converter is designed for operation in wide range voltage and has 19.5V/120W ratings with efficiency more than 90%.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.205-207
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• 2007

Isolated Current fed full-bridge converter with active clamp is analyzed in this paper. An active clamp branch is used for limiting the voltage overshoot in the bridge switches and rectifier diodes. Zero voltage switching(ZVS) is also realized by using the energy stored in the transformer leakage inductance. To analyze the converter, 6 modes of operation are introduced and investigated. For each of the modes, voltage and current equations are derived together with corresponding equivalent circuits. 200W prototype dc-dc converter is assembled and verifies the effectiveness of the analysis and simulation.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2004년도 전력전자학술대회 논문집(2)
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• pp.519-523
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• 2004

In this paper, a simple power control scheme of Class-D inverter, which is varied duty cycle of fixed frequency to desired output power. It is more suitable and acceptable for high-frequency induction heating (IH) jar applications. The proposed control scheme has the advantages of not only wide power regulation range but also ease to control output power. Also it can achieve the stable and efficient Zero-Voltage-Switching (ZVS) in whole load range. The control principles of proposed method are described in detail and its validity is verified trough simulations results on 38.5kHz IGBT for induction heating rated on 1.6kW with constant frequency variable power.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제49권6호
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• pp.441-449
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• 2000

Analysis, design and practical implementation of a single-stage electronic ballast for compact fluorecent lamps are presented in this paper. The proposed topology is based on a single-stage ballast which combines a boost converter and a half-bridge series resonant inverter. High power factor is achieved by using the boost semi-stage operating in discontinuous conduction mode, and inverter semi-stage operated above resonant frequency to provide zero voltage switching is employed to ballast the fluorescent lamp. Analytical and experimental results from the ballast system with 36W fluorescent lamps have demonstrated the feasibility of the proposed single-stage electronic ballast.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제52권12호
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• pp.655-660
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• 2003

This paper proposes new single stage power factor correction (PFC) full bridge converter. The proposed converter is combined previous ZVS full bridge DC/DC converter with two inductors, two diodes, two magnetic coupling transformer for PFC. This process of power is isolated from the source and also regulate stable DC output voltage in a category. In this topology, the voltage stress of main switches is reduced by zero voltage switching. Moreover, the proposed converter doesn't need active PFC switch and auxiliarly circuits, like control and gating board, so it could decrease the size and cost and increase the efficiency.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2012년도 추계학술대회 논문집
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• pp.107-108
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• 2012

This paper presents design and implementation of the LDC(1.8 kW DC-DC Converter for Electric Vehicles). For Implementation of the LDC, the adapted topology is ZVS(Zero Voltage Switching) PSFB(Phase Shift Full Bridge) with Digital Control is adopted. Also, for the purpose of stable operation of the LDC in vehicle with variable electrical load condition, Continuous Voltage and Current Limit Control scheme based on PI controller are developed. According to real-car test mode, the prototype of proposed the LDC is verified with performance and stability. Thus, optimizing design and implement of the LDC are discussed, and experimental results are presented.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 F
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• pp.2508-2511
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• 1999

A non-contact battery charger which transfers energy using magnetic field without any electrical contacts is designed using half-bridge series resonant converter. This converter utilizes series resonance to reduce the undesirable effect of large leakage inductance of the non-contact transformer and ZVS operation can reduce switching losses. In this paper. analysis and design procedure of half-bridge series resonant converter with non-contact transformer is presented. Input voltage is 85VAC ${\sim}$ 270VAC, output voltage and current is 4.1V and 800mA, respectively. Furthermore, a method for calculating the secondary current of the transformer to control battery charging current in constant current charging mode which is required for litium-ion battery is proposed and the performance is verified from experiments.

• 전기학회논문지
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• 제58권8호
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• pp.1551-1558
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• 2009

This paper proposes a new power conditioning system for the fuel cell power generation, which consists of a LLC resonant DC-DC converter and 3-phase inverter. The LLC resonant converter boosts the fuel cell voltage of 26-48V up to 400V, using the hard-switching boost converter and the high-frequency ZVS half-bridge converter. The operation of proposed power conditioning system was verified through simulations with PSCAD/EMTDC software. The feasibility of hardware implementation was verified through experimental works with a laboratory prototype, which was built with 1.2kW PEM fuel-cell stack, 1kW LLC resonant converter, and 3kW PWM inverter. The proposed system can be utilized to commercialize a real interconnection system for the fuel-cell power generation.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1998년도 Proceedings ICPE 98 1998 International Conference on Power Electronics
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• pp.1018-1023
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• 1998

This paper presents an effective control scheme incorporated in the voltage-fed half-bridge series resonant inverter for induction heating applications, which is based upon a load-adaptive tuned frequency tracking control strategy using PLL(Phase Locked Loop) and its peripheral control circuit. The proposed control strategy ensures a stable operation characteristics of overall inverter system and ZVS(Zero Voltage Switching0 operation in spite of sensitive load parameters variation as well as power regulation, specially in the non-magnetic heating loads. The simulation results and the performance characteristics in the steady-state are shown as compared with the experimental results for a prototype induction cooking system rated at 1.2kW.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2006년도 전력전자학술대회 논문집
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• pp.22-24
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• 2006

Of all the proposed resonant techniques, the well-known phase-shifted full bridge converter remains one of the most attractive because it offers an easy way of achieving ZVS with a minimum of extra components added, which is essential for the high power applications. This paper describes the design of a digital controller for a Phase Shifted Full-bridge PWM Converter. The small-signal model is derived incorporating the effects of phase-shift control and the utilization of the transformer leakage inductance and power FET junction capacitances to achieve the zero-voltage resonant switching. Based on the derived small-signal model, the digital controller is designed in the discrete domain. The performance of designed controller is verified through the simulation.