• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 학술대회 논문집 정보 및 제어부문
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• pp.528-529
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• 2008

Proposed buck converter includes load current sensing circuit to compensate load regulation. Because error amp has finite gain, there is load regulation in SMPS. In this paper we use variable current source that is added to positive input of comparator and current of current source is changed by sensed load current. The simulation result shows that proposed buck converter has improved load regulation than conventional buck convertor.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제55권1호
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• pp.47-53
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• 2006

In this paper, a simple scheme compensating for the effect of dc-link ripple voltages on output voltage of two-leg and three-phase PWM inverters is proposed, where single-phase half-bridge PWM convertor and two-leg inverter are used. The voltage at neutral point of the dc-link is controlled so that the upper-half of do-link voltage is equal to the lower-half voltage in average concept. However, the effect of the do-link ripple voltage results in the inverter output voltage and current distortion. This effect can be eliminated by introducing a compensation voltage in switching time calculation. Also, the inverter dead time should be compensated for sinusoidal output waveform. The proposed scheme has been verified by experimental results which were obtained from the V/F constant operation of the induction motor fed by two-leg inverter.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2012년도 전력전자학술대회 논문집
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• pp.431-432
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• 2012

The proposed dc-dc convertor for a battery energy storage system(BESS) can reduce the power rating and bidirectional power flow. This system consist soft-switching bidirectional dc-dc converter so it can reduce the energy loss when charging and discharging mode. Thus it can achieve high efficiency. Also, overall system utilizes the voltage compensation circuit. It is composed of small size and low cost due to reducing the power rating. In this paper, we proposed system about verified by simulation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.122-124
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• 2006

This paper deals with the dynamic analysis of wind power systems with permanent magnet generator (PMG). The dynamic modeling for wind turbines, PMG and dc-dc convertor are performed. On the basis of dynamic simulation model simulation results are obtained. Finally, test results such as cp vs. TSR and generated voltage are given to confirm the analysis.

• 한국태양에너지학회 논문집
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• 제32권spc3호
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• pp.282-288
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• 2012

Proton exchange membrane fuel cell (PEMFC) is the most promising energy source for the robot applications because it has unique advantages such as high energy density, no power drop during operating, and easy to make compact size. However, PEMFC has intrinsic disadvantages which are delay to start up and difficulty to correspond drastic load changes. These disadvantages can be compensated by hybrid operating with a Li-poly battery. This study is focus to build and understand the hybrid system for the robot system. In this study, we build the PEMFC hybrid system using EOS-320 PEMFC stack, Li-poly battery and G-Philos FDX1-250BU dc-dc converter. The hybrid system is accurately monitored by CAN and RS485. The system was studied under two conditions such as non-loaded and loaded operating conditions. The results show that the system has delay to start up without hybrid operating and it can be compensated with the hybrid operating.

• Journal of Power Electronics
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• 제14권1호
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• pp.194-201
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• 2014

To increase the capacity of secondary cells, an appropriate serial composition of the battery modules is essential. The unbalance that may occur due to the series connection in such a serial composition is the main cause for declines in the efficiency and performance of batteries. Various studies have been conducted on the use of a passive or active topology to eliminate the unbalance from the series circuit of battery modules. Most topologies consist of a complex structure in which the Battery Management System (BMS) detects the voltage of each module and establishes the voltage balancing in the independent electrical power converters installed on each module by comparing the module voltage. This study proposes a new magnetic flux sharing type DC/DC converter topology in order to remove voltage unbalances from batteries. The proposed topology is characterized by a design in which all of the DC/DC convertor outputs connected to the modules converge into a single transformer. In this structure, by taking a form in which all of the battery balancing type converters share magnetic flux through a single harmonic wave transformer, all of the converter voltages automatically converge to the same voltage. This paper attempts to analyze the dynamic properties of the proposed circuit by using a Programmable Synthesizer Interface Module (PSIM), which is useful for power electronics analysis, while also attempting to demonstrate the validity of the proposed circuit through experimental results.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2012년도 춘계학술발표대회 논문집
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• pp.229-233
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• 2012

Proton exchange membrane fuel cell (PEMFC) is the most promising energy source for the robot applications because it has unique advantages such as high energy density, no power drop during operating, and easy to make compact size. However, PEMFC has intrinsic disadvantages which are delay to start up and difficulty to correspond drastic load changes. These disadvantages can be compensated by hybrid operating with a Li-poly battery. This study is focus to build and understand the hybrid system for the robot system. In this study, we build the PEMFC hybrid system using EOS-320 PEMFC stack, Li-poly battery and G-Philos FDX1-250BU dc-dc converter. The hybrid system is accurately monitored by CAN and RS485. The system was studied under two conditions such as non-loaded and loaded operating conditions. The results show that the system has delay to start up without hybrid operating and it can be compensated with the hybrid operating.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2010년도 춘계학술대회
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• pp.665-667
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• 2010

본 논문에서는 주파수 하향 변환기를 이용한 전력증폭기의 혼변조 성분 검출 방법을 제안하였다. 전력증폭기 출력 신호의 일부를 전력분배기를 통해 2개의 경로로 나누어 변환기의 RF, LO 단자에 각각 인가한 뒤 그 차 주파수를 얻고, 얻어진 차 주파수 중 필요한 성분인 3차와 5차의 차 성분만 여파기로 걸러 내어 이를 DC 전압으로 변환함으로써 전력 증폭기 출력 신호의 혼변조 성분의 크기를 알 수 있었다. 3W 전력증폭기의 Vgs를 변화시켜서 3차 혼변조 성분이 -26.4~+2.15dBm, 5차 혼변조 성분이 -34.2~-12.89dBm으로 변화하였을 때, 검출된 DC 전압 크기는 +0.72~+0.9V의 변화를 보였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 심포지엄 논문집 정보 및 제어부문
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• pp.135-136
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• 2008

본 연구에서는 USB(Universal Serial Bus)통신과 전기적 절연을 이용하여 생체신호계측이 가능한 USB 데이터 수집(DAQ, Data acquisition)보드를 설계 및 구현한 것이다. 대부분의 데이터 수집보드는 전기적 절연이 되어 있지 않기 때문에 의용계측에 있어서 적합하지 않다. 보드를 평가하기 위해 설계한 USB DAQ 보드와 PC를 사용하여 사인파와 램프신호 그리고 생체신호중 하나인 ECG 신호를 측정하였다. 제안한 USB 데이터 수집보드는 AD변환부, 전기적 절연부, 전송부, 디지털 입 출력부 그리고 DC-DC변환기(DC DC Convertor)로 구성되었고, 최대 1KHz의 샘플링 주파수와 12비트 분해능과 8채널의 성능을 가진다.

• 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.