• Proceedings of the KIPE Conference
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• 2018.07a
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• pp.189-191
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• 2018

This paper introduces a novel ZVS interleaved totem-pole PFC with the reduced circulating current and the reverse recovery current of the diodes. With the help of a simple auxiliary inductor, both ZVS turn-on of the main switches and soft turn-off of the body diodes can be achieved. In the proposed totem-pole PFC topology since the switching losses and the reverse recovery losses can be significantly reduced, the typical Si MOSFETs can be employed. In addition the circulating current is reduced by adjusting the switching frequency. The proposed PFC topology can be a low cost solution to achieve high efficiency in high power PFC applications. The validity and the feasibility of the proposed topology is verified by the experimental results with a 3.3kW interleaved totem-pole PFC converter.

• Journal of Power Electronics
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• v.4 no.4
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• pp.197-204
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• 2004

Two-stage Power-Factor-Correction (PFC) converters are the most common circuits for drawing sinusoidal and in phase current waveforms from an ac source with a good regulated output voltage. The first stage is a boost PFC converter with average-current-mode control for achieving the near-unity power factor and the second stage is a forward converter with voltage-mode control to regulate the output voltage. Stability analysis and design methods of two-stage PFC converters have previously been discussed using linear models. Recently, new nonlinear phenomena have been detected in pre-regulator boost PFC circuits and a new nonlinear model has been proposed for pre-regulated PFC converters. Therefore, investigation of two-stage PFC converters from the nonlinear viewpoint becomes important because the second stage DC/DC converter adds more complexity to the circuit. So, this paper introduces a study of the stability of two-stage PFC converters. A novel nonlinear model of two-stage PFC converters is proposed. Then, a stability analysis is made based upon this nonlinear model. The high correspondence between the simulated and experimental results confirms our analysis.

• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.150-154
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• 2000

This paper proposes PFC boost converter with soft switching for harmonics decrement and analyzes characteristics of PFC boost converter. In this technique power factor correction(PFC) is usually obtained by operating the PFC stage in the discontinuous current mode(DCM) Switching devices are operated for reducing current stress and electronical noise. As a result eliminate 3rd harmonic component and high power factor(PF) of the input line are verified by characteristics analysis and experimental results.

• Proceedings of the IEEK Conference
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• 2002.06e
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• pp.311-314
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• 2002

In recent years, various power factor correction(PFC) circuits for the electronic ballasts have been proposed. In this paper, we have studied several passive PFC and compared with their characteristics, used in the electronic ballast for fluorescent. Especially, Improved Valley Fill Circuit (IVF) and the circuit IVF PFC combined with Charge Pumping Capacitors(CPCs) have been reaserched for High Power Factor. In conclusion, we have researched characteristics of Passive PFC and proposed the most effective PFC method.

• Proceedings of the KIPE Conference
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• 2016.11a
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• pp.145-146
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• 2016

일반적인 boost PFC 컨버터는 한 개의 스위칭 소자를 사용하고 구조가 간단하지만 높은 도통손실과 스위칭 손실 때문에 낮은 효율을 갖는다. bridgeless boost PFC 컨버터는 일반적인 boost PFC 에 비해 낮은 손실을 갖는 이점이 있다. 또한 컨버터의 동작 모드 중 CRM 방식은 낮은 스위칭 손실을 갖는 이 점이 있다. 본 논문에서는 이러한 CRM 모드로 동작하는 bridgeless boost PFC 컨버터를 해석하는 경우 기존의 방법으로 해석하여 구현하면 주파수가 커지는 영역에서 오차가 커지게 된다. 따라서 본 논문에서는 반도체 스위치의 기생 커패시터를 추가하여 해석하는 것을 제안하였다.

• Proceedings of the KIPE Conference
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• 2010.11a
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• pp.44-45
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• 2010

In this paper a new PFC Controller for 3-Phase Modular UPS is proposed. The PFC circuit for 3-Phase Modular UPS is implemented using three 1-phase 3-level boost PFC circuits. To control DC output voltage and AC input current, single voltage controller considering imbalance of two capacitor voltages and three independent current controllers are used in proposed PFC controller.

• Proceedings of the KIPE Conference
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• 2011.07a
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• pp.555-556
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• 2011

본 논문은 중, 고용량 통신용 정류기에 적합한 고효율 PFC Topology를 선정하여 특성 및 성능을 비교한다. 선정회로는 Conventional Average Current Mode PFC, Back-To-Back Bridgeless PFC, Semi-Bridgeless PFC, Interleaved PFC 이다. 통신용 1U 표준사이즈의 2kw PFC 정류기 제작 및 시험을 통해 각 Topology의 성능 차이점을 확인한다.

• Proceedings of the KIPE Conference
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• 2019.11a
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• pp.122-123
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• 2019

본 논문은 전기차량용 Onboard Charger(OBC)의 3병렬 운전시 3개의 단상 PFC와 3상 PFC 두가지 입력단 PFC 토플로지에 대하여 비교 및 분석을 진행하였다. 9.9kW급 OBC에서는 입력단 전원을 3상 전원으로 사용하여야 하기 때문에 PFC단에는 단상 PFC 3개를 모듈화하여 병렬로 사용할 수도 있고 3상 PFC를 하나로 구성할 수 있다. 각 토플로지 방식에서 인덕턴스 입력전류리플, DC단 커패시터 전류리플 등 면에서 이 두가지 구성방식에 대하여 비교분석을 진행하였다.

• Proceedings of the KIPE Conference
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• 2015.07a
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• pp.471-472
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• 2015

본 논문에서는 PFC(Power Factor Correction) 컨버터가 초기 구동시 발생하는 돌입전류를 제어하기 위한 새로운 PFC 컨버터를 제안한다. 기존 Boost 구조를 갖는 PFC 컨버터는 안정적인 출력 전압을 생성하기 위해 출력단에 큰 커패시터가 필수적이지만 방전된 커패시터에 AC 전압이 인가되면 단락 상태가 되어 큰 돌입전류가 발생하게 된다. 이를 해결하기 위해 본 논문에서는 시뮬레이션을 통해 기존 PFC 컨버터의 돌입전류 문제점을 파악하고 제안된 PFC 컨버터로 돌입전류를 제어함으로써 안정적인 동작 상태와 효율적인 PFC 컨버터의 타당성을 검증하였다.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.4 no.2
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• pp.161-170
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• 2006

PFC(Perfluorocarbon) decontamination process is one of best methods to remove hot particulate adhered on the inner surface of hot cell and surface of equipment in hot cell. It was necessary to develop a filtration equipment to reuse the PFC waste solution generated on PFC decontamination due to the high cost of PFC solution and for minimization of the volume of second waste solution. The filtration equipment was developed to remove hot particulate in PFC waste solution. It was made suitable size and weight in consideration of hot cell gate and crane. And it has wheels for easy movement. Flux of the filtration equipment decreased with particulate concentration increase. It consists of pre-filter($1.4{\mu}m$) and final-filter($0.2{\mu}m$) for protection of the flux decrease along filtration time. It treatment capacity of waste solution is 0.2 L/min.