• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.622-625
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• 1999

This paper introduces a novel zero-voltage switching (ZVS)) pulse width modulation (PWM) active clamping dc-to-dc boost converter. This technique presents ZVS commutation without additional voltage stress and a significant increase in the circulating reactive energy throughout the converter. Therefore, all of the losses for the switches are minimized, and high power density system can be realized. The characteristics are verified through simulation and experimental results.

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.327-332
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• 1999

In this paper, six harmonic injection PWM method for reducing total harmonic distortion in single switch three phase discontinuous conduction mode boost converter is presented. In the proposed method, periodic six harmonic voltage is injected in the control circuit to vary the duty ratio of the converter switch within a line cycle so that the fifth order harmonic of the input current is reduced. Experimental results are verified by converter operating at 400V/6kW with three phase 140V~220V input.

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.646-649
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• 1999

A new isolated boost dc to dc convertor suitable for a low input voltage application is proposed. The proposed convertor features the low switch current stresses, the wide input voltage range operation, and the inherent inrush current protection characteristics, essential to design a low to high voltage conversion circuit. A comparative analysis and experimental results are presented to show the validity of the proposed convertor.

• Proceedings of the KIPE Conference
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• 1998.07a
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• pp.149-153
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• 1998

In this paper A switched mode AC/DC three phase boost converter with high power factor and sinusoidal input current waveform is analyzed and simulated. The proposed converter retain high power factor and sinusoidal input current waveform even under electric arc welder load. It is shown that experimental result and simulation waveform yield a sinusoidal input current waveform at high power factor.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.52 no.4
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• pp.170-176
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• 2003

This paper introduces an improved pulse generator using power semiconductors and L-C circuit. The proposed circuit consists of the series connected boost converter structure. In the presented circuits, high voltage pulse is generated by series-connection of capacitors and IGBTs. The charging of capacitors and voltage balance of IGBTs are obtained automatically. To verify the proposed circuit, 1.8㎸, 40A pulse generator is manufactured and tested.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.22 no.1
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• pp.135-140
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• 2022

In addition to the stack that directly generates electricity by the reaction of hydrogen and oxygen, the fuel cell power generation system has a reformer that generates hydrogen from various fuels such as methanol and natural gas. It also consists of a power converter that converts the DC voltage generated in the stack into a stable AC voltage. The fuel cell output of such a system is direct current, and in order to be used at home, an inverter device that converts it into alternating current through a power converter is required. In addition, a DC-DC step-up converter is used to boost the fuel cell voltage to about 30~70V, which is the inverter operating voltage, to about 380V. The DC-DC step-up converter is a DC voltage variable device that exists between the fuel cell output and the inverter. Accordingly, since a constant output voltage of the converter is generated in response to a change in the output voltage of the fuel cell, the inverter can receive constant power regardless of the voltage change of the fuel cell. Therefore, in this paper, we discuss the detailed hardware design of the full-bridge converter, which is the main power source of the inverter that receives the fuel cell output voltage (30~70V) as an input and is applied to the grid among the members of the fuel cell power generation system.

• Proceedings of the KIEE Conference
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• 2006.04b
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• pp.219-222
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• 2006

Recently, the high frequency boost DC-DC converter has been widely used for the PCS system because of its small size and low cost. In this paper, the experimental results of the boost DC/DC converter using LLC series resonant converter are verified on the simulation based on the theoretical analysis and the lkW experimental prototype.

• Proceedings of the KIPE Conference
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• 2001.12a
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• pp.119-123
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• 2001

In this paper, a DCM operated boost integrated single-stage forward-flyback converter is proposed. This proposed converter has high power factor, low harmonic distortion, and tight output regulation. To increase efficiency, zero voltage switching with asymmetrical control is used. This converter also give low voltage stress in switch and this results in low conduction loss with low turn-on resistance.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1650_1651
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• 2009

DC/DC 승압 컨버터는 인덕터 내부 저항으로 인하여 부하 저항의 변화가 시스템 동작점에 영향을 미치게 되며, 이로 하여 제어기 설계의 기준이 되는 선형화된 모델은 불확실성을 가지게 된다. 본 논문은 인덕터의 내부 저항과 출력단의 부하 변동으로 인한 불확실성에 대하여 출력 전압의 강인성을 향상시키기 위해 PI 관측기 기반 적분형 상태 변수 궤환 제어기를 제안한다. PI 관측기는 불확실한 시스템 제어에 널리 사용되는 오차의 적분항을 Luenberger 관측기에 추가한 형태로써 불확실성에 강인한 추정 성능을 보인다. 모의실험을 통해 불확실성이 존재하는 경우 제안된 제어기의 강인성을 확인하고 설계된 관측기가 Luenberger 관측기에 비해 상태변수 추정 성능이 우수함을 보인다.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.55 no.8
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• pp.423-429
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• 2006

Recently, the high frequency isolated boost DC/DC converter has been widely used for the PCS (Power Conditioning System) system because of its small size and low cost. However, the high frequency isolated boost DC/DC converters applied the conventional voltage-fed converter and current-fed converter have the problems such as the high conduction losses and the surge voltage due to the high circulating current and the leakage inductance, respectively. To overcome this problems, in this paper the secondary LLC resonant converter is proposed, and the experimental results of the secondary LLC series resonant converter for boost DC/DC converter are verified on the simulation based on the theoretical analysis and the 700W experimental prototype.