• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.113-115
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• 2005

본 연구는 저전압 교류 전류원으로부터 직류 부하에 에너지를 공급하기 위하여, 새로운 컨버터를 제안한다. 컨버터는 풀브리지 MOSFET 정류기와 플라이백 컨버터의 2단 구조로 구성되어 있으며, LC공진을 이용하여 AC/DC 전력변환을 수행한다. 컨버터 효율 개선을 위하여 컨버터 회로 내의 스위칭 소자는 3상한에서 동작한다. 제안된 컨버터의 동작원리 및 동작모드를 해석하고, 시뮬레이션을 통해 해석결과를 검증하였다.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.1
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• pp.87-94
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• 2008

A method for improving current THD of Valley-fill rectifier is proposed in this paper. The proposed topology combines a boosting inductor with Valley-fill rectifier which carry out AC/DC conversion and PFC simultaneously The boosting effect by PWM switching makes low THD current and improve of Valley-fill rectifier. The operation modes and THD of input current are analyzed as applied the boosting inductor, and the optimum value of boosting inductor is determined A 100[W] single-stage converter has been designed and tested. Experimental results are resented to verify the validity of the proposed method.

• The Transactions of the Korean Institute of Power Electronics
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• v.10 no.3
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• pp.274-281
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• 2005

A new resonant pulse converter for energy harvesting is proposed. The converter transfers energy from a low-voltage AC current to a battery. The low-voltage AC current source is an equivalent of the piezoelectric generator, which converts the mechanical energy to the electric energy. The converter consists of a full-bridge rectifier having four N-type MOSFETs and a boost converter haying N-type MOSFET and P-type MOSFET instead of diode. Switching of MOSFETs utilizes the capability of the $3^{rd}$ regional operation. The operational principles and switching method for the power control of the converter are investigated with the consideration of effects of the parasitic capacitances of MOSFETs. Simulation and experiment are performed to prove the analysis of the converter operation and to show the possibility of the $\mu$W energy harvesting.

• Proceedings of the KIPE Conference
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• 2012.07a
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• pp.373-374
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• 2012

본 논문에서는 전력변환장치의 고효율화 시대에 맞추어 AC-DC단에는 브릿지리스 PFC, DC-DC단에는 Full-Bridge LLC 공진형 컨버터를 적용하여 전부하 ZVS 동작영역 확보를 통한 고효율의 저전압, 대전류 AC-DC 정류기를 제안하였다. 제안된 AC-DC 정류기는 그린 PC용 전력변환 장치로써 단말형 중앙 집중식 PC rack 시스템에 사용된다. 따라서 19 [V], 105 [A] (2KW) Full-bridge LLC 공진형 컨버터를 설계 및 제작하여 실험을 통해 제안된 토폴로지의 타당성을 검증하였다.

• The Transactions of the Korean Institute of Power Electronics
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• v.16 no.6
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• pp.533-541
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• 2011

This paper studies modeling of Jeju 80kV HVDC system and its controller by using PSCAD/EMTDC program. Reduced ac network is applied to verify interaction between ac network and dc system. Design parameter is applied to the converter transformer, harmonic filter and dc transmisstion line to simulate dc system. HVDC controller is divided into a rectifier controller and a inverter controller according to the converter operating mode. The inverter controller is composed of current control, voltage control and extingtion angle control. The rectifier controller is composed of current control and voltage control. Both controller has VDCOL characteristics so that current order is dependant on voltage variation. Step response, ac network single phase fault, three phase fault is simulated to verify the dynamic performance of controller model in both transient state and steady state.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2009.10a
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• pp.319-321
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• 2009

일반적으로 가장 간단한 구조의 배터리 충전장치는 교류를 직류로 변환하기 위한 다이오드 정류기와 직류의 크기를 변환하기 위한 컨버터로 구성되어 있다. 하지만, 이러한 구조로 되어있는 충전장치의 경우 입력단 역률저하로 인하여 전력변환장치에 과도전류나 파형의 왜곡 현상 등을 초래하게 되고, 정류기와 컨버터로 구성되는 2단 전력변환구조이기 때문에 효율에도 좋지 않은 영향을 미치게 된다. 따라서 본 논문에서는 역률제어가 가능한 단일 컨버터 구조를 갖는 플러그인 하이브리드 전기자동차용 42V 배터리 충전장치를 연구하였다. 본 논문에서 연구한 배터리 충전장치는 PWM 방식의 AC-DC Buck 컨버터를 이용한 전력 변환장치와 입력단 역률제어 및 컨버터 출력을 제어하기위한 제어기로 구성되어있다. 본 논문에서 연구한 배터리 충전장치는 시뮬레이션을 통하여 역률제어 및 컨버터 출력을 확인하고 그 타당성을 검토하였다.

• Journal of the Korean Society of Marine Environment & Safety
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• v.16 no.2
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• pp.235-240
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• 2010

In order to substitute incandescent lamps, a power supply device for 7W class LED lamps which are environmentally friendly and energy saving is designed LED lamps consist of a multitude of chip LED connected in parallel and series. 11ms it is necessary to supply LED lamps with DC voltage and current. However, when LED lamps are in use, they are connected directly to AC 220V. This is why we need to have AC/DC, DC/DC power converters including a control system of voltage and current. For this, a transformerless and simple LED lamp driver is designed 조ich can control the current and output voltage for LED string of LED lamp.

• Proceedings of the KIEE Conference
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• 2004.10a
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• pp.131-133
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• 2004

본 연구는 출력단에 패캐시터를 갖고 있는 AC 전류원으로부터, 밧데리 충전을 위한 새로운 AC/DC 컨버터 회로를 제안한다. 영전압과 영전류 스위칭을 사용하여 컨버터의 소형화 및 고효율화를 추구하였고, 풀브리지 MOSFET 정류기와 Buck-boost 컨버터가 결합된 새로운 토폴로지의 회로를 구성하였다. 제안된 컨버터의 동작원리 및 동작모드를 해석하고, PSpicc 시뮬레이션을 통해 해석결과를 검증하였다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2001.05a
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• pp.431-436
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• 2001

Boost converter operating at the boundary region CCM and DCM is designed. Boost converter is incorporated behind rectifier as an equivalent resistance. Also for a high efficiency and PF, a switch turn-on time is controlled by using the capacitor filter effect. To verify a validity of the designed boost converter 100[W] boost converter is fabricated and also experiment are carried out.

• The Transactions of the Korean Institute of Power Electronics
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• v.5 no.6
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• pp.592-600
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• 2000

In this paper, a novel control scheme of three-phase PWM rectifiers using only dc-side sensors is proposed. The phase currents are reconstructed from switching states of the rectifier and the dc output current. For effective current control, the currents are estimated by a predictive state observer. Also, both the phase angle and the magnitude of the source voltage are estimated by controlling the deviation between the model current and the system current to be zero. The validity of the proposed ac phase and current sensorless technique has been verified by experimental results.