• 대한전자공학회논문지SD
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• 제43권9호
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• pp.23-30
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• 2006

본 논문은 전류 감지 feedback 기법을 사용한 고효율 CMOS DC-DC boost 변환기의 설계에 관한 것이다. 펄스-폭 변조 방식의 스위칭 동작을 위해 인덕터를 통해 흐르는 전류의 양을 감지하는 고해상도 전류 감지 회로를 설계하였다. 이를 통하여 외부 소자나 큰 면적을 차지하는 주파수 보상 회로 없이 안정적으로 동작하는 변환기 성능을 얻을 수 있다. 또한 외부 저항 열을 사용하여 다양한 입력/출력 전압 특성을 얻을 수 있다. 설계한 DC-DC 변환기는 thick gate oxide 옵션이 포함된 0.18-um CMOS 표준 공정으로 제작하였다. 부하 전류 200mA 이상에 대하여 3.3V의 출력을 얻는 변환기에서 최대 효율은 90% 이상, load regulation은 100mA의 변화에 대하여 1.15%의 특성을 나타낸다.

• 전기전자학회논문지
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• 제18권2호
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• pp.220-227
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• 2014

이 논문은 Dead-time을 갖는 톱니파 발생기를 이용하여 공통모드와 차동모드 피드백 루프를 구현한 Single-Inductor Dual-Output DC-DC Converter 설계에 관한 내용을 제시하고 있다. 제어회로에는 공통모드와 차동모드 피드백 루프를 Dead-time을 갖는 톱니파 발생기를 이용하여 동시에 사용하였다. 차동모드 피드백 루프에서 duty를 생성하기 위해서 전류 분배기 회로를 사용하여 공통모드 피드백에 의한 duty에 따라 dead-time이 유동적으로 변하는 톱니파형을 만드는 회로인 Dead-time을 갖는 톱니파 발생기를 추가하여 차동모드 피드백 회로를 구성하였다. 0.35um 공정을 사용하여 설계한 SIDO DC-DC Converter는 2.5V 입력으로부터 2.8V와 4.2V의 전압을 출력하며 최대 전력변환 효율은 95%이다. 출력간의 Cross regulation은 출력전류가 2배씩 증가할 경우 Boost1과 Boost2의 출력전압은 각각 3.57%, 4% 수준을 보이고 있다.

• Journal of Power Electronics
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• 제9권1호
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• pp.124-131
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• 2009

This paper presents a PWM dc-ac converter regulation using a Single Input Fuzzy PI Controller (SIFPIC). The SIFPIC is derived from the signed distanced method, which is a simplification of a conventional fuzzy controller. The simplification results in a one-dimensional rule table, that allows its control surface to be approximated by a piecewise linear relationship. The controller multi-loop structure is comprised of an outer voltage and an inner current feedback loop. To verify the performance of the SIFPIC, a low power PWM dc-ac converter prototype is constructed and the proposed control algorithm is implemented. The experimental results show that the SIFPIC performance is comparable to a conventional Fuzzy PI controller, but with a much reduced computation time.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1993년도 하계학술대회 논문집 B
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• pp.850-852
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• 1993

A buck-boost zero current switched(ZCS) series resonant AC to DC converter for the DC output voltage regulation together with high power factor is proposed. A dynamic model for this AC to DC converter is developed and an analysis for the internal operational characteristics is explored. With the proposed control technique, the unity power factor and the DC output voltage regulation without a current overshoot can be obtained.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 A
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• pp.447-449
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• 1996

The main objective of this paper is to increase the efficiency, to eliminate the harmonics wave and to acomplish the zero voltage regulation of the output voltage. To accomplish the goal, DC-to-DC converter model with ERS(Energy Recovery Snubber) is developed. And, to realize the detail purpose, we are used ZVS soft switching snubber, ripple steering filter and, function control law etc.. So, we presented to show superior operation of this convertor with the zero voltage regulation function.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2019년도 전력전자학술대회
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• pp.467-468
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• 2019

This paper proposes an improved bus voltage regulation scheme in filter-based reference current generation of power management for DC home grid with photovoltaics (PV), battery, and ultracapacitor (ultracap) by using feedforward terms instead of the filter output to produce the ultracap reference current. Simulation results have proved the effectiveness of the proposed scheme.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2014년도 추계학술대회 논문집
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• pp.9-10
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• 2014

최근 신재생에너지 및 전기자동차, 통신 IT 서버 전원 및 가전기기 등의 발전에 따라 고 전력밀도(High Power Density), 고 응답(Fast Transient Response) 및 고정밀(Tight Regulation) 출력제어를 위한 다 출력 절연형 DC/DC 컨버터가 개발 및 연구되고 있다. 본 논문에서는 개별적인 정밀제어를 요구하는 다 출력 DC-DC 컨버터에 대한 내용으로 위상천이(Phase-shift) DC-DC 컨버터와 LLC 공진컨버터 제어개념을 하나의 주회로를 사용하여 위상천이제어(Phase-shifted Modulation, PM)와 가변주파수제어(Variable Frequency Modulation, FM)를 통해서 개별적으로 정밀 제어할 수 있는 하이브리드 다 출력 3레벨 DC-DC 컨버터에 관한 내용이다.

• BMB Reports
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• 제35권6호
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• pp.623-628
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• 2002

The Th1 vs. Th2 balance is critical for the maintenance of immune homeostasis. Therefore, the genes that are selectively-regulated by the Th1 and Th2 cytokines are likely to play an important role in the Th1 and Th2 immune responses. In order to search for and identify the novel target genes that are differentially regulated by the Th1/Th2 cytokines, the human PBMC mRNAs differentially expressed upon the stimulation with IL-4 or IL-12, were screened by employing the differential display-polymerase chain reaction. Among a number of clones selected, DC21 was identified as a novel target gene that is regulated by IL-4 and IL-12. The DC21 gene expression was up-regulated either by IL-4 or IL-12, yet counter-regulated by co-treatment with IL-4 and IL-12. DC21 is a dendritic cell protein with an unknown function. The sequence analysis and conserved-domain search revealed that it has two AU-rich motifs in the 3'UTR, which is a target site for the regulation of mRNA stability by cytokines, and that it belongs to the N-acetyltransferase family. The induction of DC21 by IL-12 peaked around 8-12 h, and lasted until 24 h. LY294002 and SB203580 significantly suppressed the IL-12-induced DC21 gene expression, which implies that PI3K and p38/JNK are involved in the IL-12 signal transduction pathway that leads to the DC21 expression. Furthermore, tissue blot data indicated that DC21 is highly expressed in tissues with specialized-resident macrophages, such as the lung, liver, kidney, and placenta. Together, these data suggest a possible role for DC21 in the differentiation and maturation of dendritic cells regulated by IL-4 and IL-12.

• Journal of Power Electronics
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• 제11권4호
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• pp.561-567
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• 2011

This paper presents a high-efficiency power conditioning system (PCS) for grid-connected photovoltaic (PV) modules. The proposed PCS consists of a step-up DC-DC converter and a single-phase DC-AC inverter for the grid-connected PV modules. A soft-switching step-up DC-DC converter is proposed to generate a high DC-link voltage from the low PV module voltage with a high-efficiency. A DC-link voltage controller is presented for constant DC-link voltage regulation. A half-bridge inverter is used for the single-phase DC-AC inverter for grid connection. A grid current controller is suggested to supply PV electrical power to the power grid with a unity power factor. Experimental results are obtained from a 180 W grid-connected PV module system using the proposed PCS. The proposed PCS achieves a high power efficiency of 93.0 % with an unity power factor for a 60 Hz / 120 Vrms AC power grid.

• Journal of Power Electronics
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• 제7권2호
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• pp.124-131
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• 2007

In this paper, a novel type of auxiliary switched capacitor assisted edge resonant soft switching PWM resonant DC-DC converter with two simple auxiliary commutation lossless inductor snubbers is presented. The operation principle of this converter is described using the switching mode equivalent circuits. This newly developed multi resonant DC-DC converter can regulate its DC output AC power under a principle of constant frequency edge-resonant soft switching commutation by an asymmetrical PWM duty cycle control scheme. The high frequency power regulation and actual power characteristics of the proposed soft switching PWM resonant DC-DC converter are evaluated and discussed. The operating performances of the newly proposed soft switching inverter are represented based on simulation results from an applications point of view.