• Proceedings of the KIEE Conference
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• 2003.10b
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• pp.177-180
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• 2003

본 논문에서는 dc-dc convertor의 진단을 위해 buck 컨버터의 등가 모델을 가정하고 주요 파라메터를 시스템 식별 기법을 통해 추정하였으며 추정된 결과가 실제 시스템의 특성을 충실히 반영하는지를 계측기를 통한 주파수 응답 측정 결과와 비교하여 검증하였다. dc-dc 컨버터의 모델 파라메터 추정을 통해 주요 진단지수를 계산할 수 있으며 진단 지수를 이용하여 시스템의 열화 여부를 판단할 수 있음을 확인 하였다.

• Proceedings of the KIPE Conference
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• 2014.07a
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• pp.9-10
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• 2014

자동차 업계는 전장화 가속화와 강화된 환경규제에 대응하기 위해 자동차의 12[V] 전기시스템과 더불어 48[V] 전기 시스템에 대한 도입을 추진하고 있다. 듀얼 전기시스템을 사용할 경우 소모 전력이 적은 부품에 대해서는 기존의 12[V] 시스템을 유지하고 전력 소모가 큰 전동식 조향장치, 브레이크, 공조 시스템은 48[V] 시스템을 사용함으로써 비용을 최소화 하고 연비를 최대 15[%]까지 개선시킬 수 있는 특징을 갖고 있다. 이를 구현하기 위해서는 양방향 DC/DC 컨버터가 필수적 이며 LS그룹 계열사인 자동차부품 전문기업인 대성전기에서는 4-phase Synchronous Buck 구조의 양방향 DC/DC 컨버터를 개발하였다.

• The Transactions of the Korean Institute of Power Electronics
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• v.24 no.3
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• pp.201-206
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• 2019

This study presents the design and experimental result of a GaN-based DC-DC converter with an integrated gate driver. The GaN device is attractive to power electronic applications due to its superior device performance. However, the switching loss of a GaN-based power converter is susceptible to the common source inductance, and converter efficiency is severely degraded with a large loop inductance. The objective of this study is to achieve high-efficiency power conversion and the highest power density using a multiphase integrated half-bridge GaN solution with minimized loop inductance. Before designing the converter, several GaN and Si devices were compared and loss analysis was conducted. Moreover, the impact of common source inductance from layout parasitic inductance was carefully investigated. Experimental test was conducted in buck mode operation at 48 -12 V, and results showed a peak efficiency of 97.8%.

• Proceedings of the KIPE Conference
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• 2014.07a
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• pp.423-424
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• 2014

본 논문에서는 배터리 충 방전을 위한 새로운 고승압 양방향 DC-DC 컨버터를 제안한다. 제안 회로는 하나의 회로로 양방향 스위치가 가능하게 하였다. 기존 DC-DC 컨버터는 고주파 스위칭 동작 시 손실분 저항의 증가로 승압이 어려운 문제점이 있다. 이를 위해 기존 Boost converter 회로 방식보다 승압비가 높은 회로를 제안하였다. 그리고 기존 충전회로는 10배 이상의 입 출력 강압변환 시, 낮은 duty cycle로 소자 스트레스가 높아 고 사양의 소자를 사용해야 했다. 제안회로는 충전 시, Buck converter 동작을 하면서 기존 duty cycle 보다 3배가량 높아 소자 스트레스를 줄였다. 이를 모의실험 및 실험을 통해 타당성을 검증하였다.

• Proceedings of the KIEE Conference
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• 1993.07b
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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.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.10a
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• pp.31-34
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• 2018

This paper presents a low-power buck-boost converter for multi-input energy harvesting systems. The designed circuit combines the energy harvested from three input channels in real time and stores it in a storage capacitor. The structure of the buck-boost converter is simplified by using one external inductor and applying time division technique using an arbiter. In addition, to improve the efficiency of the system, the controller circuits of the converter are designed so that current consumption is minimized. The proposed circuit is designed with $0.35{\mu}m$ CMOS process. Simulation results show that the designed circuit consumes up to 490nA of current when all three input channels are active, and the maximum power efficiency is 92%. The chip area of the designed circuit is $1310{\mu}m{\times}1100{\mu}m$.

• Proceedings of the KIEE Conference
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• 1996.07a
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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.

• Journal of Power Electronics
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• v.8 no.1
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• pp.51-59
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• 2008

This paper addresses several issues concerning the analysis, design, modeling, simulation and development of single-phase, single-switch, power factor corrected AC-DC high frequency switching converter topologies with transformer isolation. A detailed analysis and design is presented for single-switch topologies, namely forward buck, flyback, Cuk, Sepic and Zeta buck-boost converters, with high frequency isolation for discontinuous conduction modes (DCM) of operation. With an awareness of modem design trends towards improved performance, these switching converters are designed for low power rating and low output voltage, typically 20.25W with 13.5V in DCM operation. Laboratory prototypes of the proposed single-switch converters in DCM operation are developed and test results are presented to validate the proposed design and developed model of the system.

• Proceedings of the KIEE Conference
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• 2001.11c
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• pp.338-340
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• 2001

Power factor improved for single-phase buck-converter is studied in the paper. To sinusoidal waveform the input current with a near-unity power factor over a wide variety of operating conditions, the output capacitor is operated with voltage reversibility for the supply by arranging the auxiliary diode and power switching device. Then the output voltage is superposed on the input voltage during on time duration of power switching devices in order to minimize the input current distortion caused by the small input voltage when changing the polarity. The tested setup, using two insulated gate bipolar transistors(IGBT) and a microcomputer, is implemented and IGBT are switched with 20[kHz], which is out of the audible band. Moreover, a rigorous state-space analysis is introduced to predict the operation of the rectifier. The simulated results confirm that the input current can be sinusoidal waveform with a near-unity power factor and a satisfactory output voltage regulation can be achieved.

• The Transactions of the Korean Institute of Power Electronics
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• v.23 no.2
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• pp.121-128
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• 2018

This work proposes a simple control method of a buck-type active power decoupling circuit that can minimize the ripple values in the dc link voltage. The proposed method utilizes a simplified duty calculation method and an optimal compensation gain tracking algorithm with variable-step approach. Thus, the dc link voltage ripple can be effectively reduced through the proposed method along with rapid response in tracking the optimum compensation gain. Moreover, the proposed method has better dynamic responses in the load fluctuation or abnormal situation. MATLAB/Simulink simulation and hardware-in-the-loop-simulation(HILS)-based experimental results are presented to validate the effectiveness of the proposed control method.