다수 및 소수캐리어 소자에 적용 가능한 영전압영전류 스위칭 컨버터

안희욱,김학성,Ahn Hee-Wook,Kim Hack-Sung 전력전자학회 2005 전력전자학회 논문지 Vol.10 No.5

제안된 회로는 하나의 보조스위치를 이용하여 주 스위치와 정류용 다이오드가 턴-온/턴-오프 시 동시에 영전압과 영전류 조건을 만족시킨다. 그리고 이 회로에 사용되는 주 스위치는 다수 캐리어 소자뿐만 아니라 소수 캐리어 반도체 소자까지 사용할 수 있는 장점을 가지고 모든 PWM 컨버터에 적용 가능하다. 그리고 제안된 보조 스위치와 공진회로가 주 전력 경로에 존재하지 않으므로 주 스위치와 다이오드에 더 이상의 전압/전류 스트레스가 없게 된다. 제안된 컨버터의 유효성을 이론적 분석과 실험을 통하여 입증하였다. The paper proposes a novel ZVZCS PWM converter. It enables the main switch to be turned on/off with both zero voltage and zero current, the auxiliary switch to be turned on/off with ZCS, the rectifier diode to be turned on/off with ZVS. Moreover, this proposed soft switching technique is suitable for not only minority carrier device but also majority carrier semiconductor device. Since auxiliary resonant circuit of the proposed boost converter is placed out of the main power path, therefore, there are no voltage and current stresses on the main switch and diode. The operation of the proposed boost converter is explained and analyzed theoretical and experimentally, from a prototype operating at 100KHz.

광결합 절연증폭기를 이용한 아날로그 센서회로 연구

안희욱,정훈주 금오공과대학교 2006 論文集 Vol.27 No.-

전기절연이 가능하면서 교류신호 뿐만 아니라 직류신호도 전달할 수 있는 선형 광결합 소자가 최근에 소개되었다. 정보처리시스템과 전원장치 등에 많이 사용되는 절연형 증폭기로서 활용될 가능성이 높으므로 관심이 증가하고 있다. 본 논문에서는 선형 광결합 증폭기의 특성과 설계방법을 살펴본 후에, 응용 예에 대한 실험과 시뮬레이션을 통하여, 증폭기의 문제점을 분석하고 그 해결책을 제안한다. 대표적인 문제점으로서 발진현상이 발견되었으며, 광결합 소자의 극점이 루프 전달함수에 추가되어 위상마진이 악화된 때문임을 밝혔다. Linear opto-coupler devices that can transfer isolated DC signals as well as AC signals have been introduced recently. The device is expected to be widely used for isolated amplifiers included in information processing system and power supplies. In this paper, the characteristics of the device and circuit design techniques are surveyed. Problems of the amplifier circuit, if any, are analyzed by experiment, and solutions for the problem are proposed. A typical problem found is oscillatory response, the cause of which is analyzed by PSPICE simulation. The analysis result shows that the phase margin in loop transfer function of the feedback control loop is decreased due to a pole introduced by the device.

벅형 프리레귤레이터를 가진 일정주파수 직렬공진변환기를 위한 새로운 준최적제어기 설계

안희욱,고정호,윤명중 제어로봇시스템학회 1990 제어로봇시스템학회 국내학술대회 논문집 Vol.1990 No.10

어린이 보호구역내 통학로의 보행환경에 관한 연구 -구미시 초등학교를 중심으로-

안희욱,이재림 (사)한국교육녹색환경연구원 2009 교육·녹색환경연구 Vol.8 No.2

The purpose of this study is to suggest a scheme to provide children safer and more comfortable walking circumstances by survey current walking circumstances of school zone ways. First, to avoid pedestrian roads being interrupted and to expand waiting space near school zone ways, several measures are needed including fixing roads, using schools' unemployed spaces and building additional gateway. Second, pedestrian crossings in front of school gate should be located at least 23.16m away from the left side of the gate. Third, on narrow path which cross main streets, the interval of pedestrian signal should be extended as against of the moment. And traffic calming facilities should be built on accurate position. Fourth, to secure pedestrians' safety and field of view, trees lining streets and any obstacles located within 10m from bus stop sign should be removed. Finally, education system about school zone ways should be improved to help children get used to more complicated roads' conditions. The purpose of this study is to suggest a scheme to provide children safer and more comfortable walking circumstances by survey current walking circumstances of school zone ways. First, to avoid pedestrian roads being interrupted and to expand waiting space near school zone ways, several measures are needed including fixing roads, using schools' unemployed spaces and building additional gateway. Second, pedestrian crossings in front of school gate should be located at least 23.16m away from the left side of the gate. Third, on narrow path which cross main streets, the interval of pedestrian signal should be extended as against of the moment. And traffic calming facilities should be built on accurate position. Fourth, to secure pedestrians' safety and field of view, trees lining streets and any obstacles located within 10m from bus stop sign should be removed. Finally, education system about school zone ways should be improved to help children get used to more complicated roads' conditions.

공진형 전력변환기를 위한 Phase-Locked Loop (PLL)의 특성 해석

안희욱,김학성,김상희 금오공과대학교 산업기술개발연구원 2000 産業技術開發硏究 Vol.16 No.-

For high efficiency and low noise operation of power converters, soft switching strategies are required. The resonant converters and/or inverters are suitable candidates for these purpose. Generally the PLL(Phase-Locked Loop) techniques are employed to make the switching frequency of resonant converters follow the resonant frequency which may vary due to the load variations. The conventional design guide of PLL is not suitable in these cases since the characteristics of converters or inverters are not considered. In this paper, the phase characteristics of a resonant inverter is analysed and added to the closed loop. And the design of PLL with digital phase detector is illustrated for the output frequency to track the resonant frequency of the inverter. The validity of the proposed scheme is verified by PSPICE simulation for the PLL system.

벅형 프리레귤레이터를 가진 일정주파수 직렬공진 변환기를 위한 새로운 준최적제어기 설계 ( A Sub-Optimal Controller Design for Constant - Frequency Series Resonant Converter With Buck Type Pre - Regulator )

안희욱,고정호,윤명중 대한전자공학회 1990 대한전자공학회 학술대회 Vol.1990 No.01

변압기-결합형 직렬공진 인버터의 델타변조 전류제어

안희욱,김학성 전력전자학회 1999 전력전자학회 논문지 Vol.4 No.3

변압기로써 결합된 직렬공진 부하를 가진 전압원-인버터(Voltage-Source Inverter)가 공진주파수로 작동되는 경우에 출력 전류를 제어하는 기법으로서, 개선된 전류조절형 델타변조(Current-Regulated Delta Modulator; CRDM)방식을 제안한다. 일반적인 CRDM은, 전류편차가 상당한 크기로 나타난다는 문제가 있으며, 특히 유도가열장치와 같이 부하가 변압기를 통하여 연결되는 경우에는 변압기의 자속포화 문제가 발생하므로 실제 사용에 한계가 있다. 이러한 문제를 해결하기 위하여, 자속포화 현상을 분석하고 이를 방지하기 위한 간단한 방법을 제안하며, 전류편차를 제거하기 위한 적분형 CRDM을 적용한다. 그리고 슬라이딩 모드 제어의 개념을 이용하여, 안정된 동작을 보장하는 적분기 이득의 상한치를 회로특성치로부터 구하는 방법을 제안하고, 제안된 기법의 효용성을 시뮬레이션과 실험으로써 확인한다. An improved version of current-regulated delta modulator (CRDM) is investigated for the output cunent control of v voltage-source inverters that have transformer-coupled series resonant load and are operated at the resonant frequency. Conventional CRDM has not only CUlTent offset problem but also transformer flux saturation problem when i it is applied to induction heating systems that have transformel-coupled loads. To cope with these problems, the effect of flux saturation is analysed, and simple method to av이d the problem is proposed. And integral type of CRDM is a adopted to remove the cunent offset. The boundaries of integrator gain for stable operation is calculated using the c concept of sliding mode controL The validity of proposed strategy is vel퍼ed through simulations and prototype e experiments.

ZVS-PWM 방식을 이용한 DC-DC 컨버터의 설계

박재화,김학성,안희욱 金烏工科大學校 産業技術開發硏究院 1999 産業技術開發硏究 Vol.15 No.-

A Zero-Voltage Switched(ZVS) PWM boost converter in this thesis is proposed. It runs the ZVS as constructing a circulation-tank by connecting parallel with a capacitor for a standard voltage source and auxiliary switch at the resonant inductor. The sub-switch voltage can be small as a dropped-voltage of the inductor makes zero. The voltage of sub-switch is negative value of a standard voltage because the capacitor and the switch are parallel as the resonant inductor voltage is zero. If it is applied to a high voltage converter, it can be realized very high power density system. As a switch time-delay is short, the power dissipation is minimized.

MOSFET를 사용한 고주파 인버터의 제어방식에 따른 전력손실 비교 : 위상변이 제어와 펄스농도 제어

김학성,안희욱 金烏工科大學校 産業技術開發硏究院 1999 産業技術開發硏究 Vol.15 No.-

The power losses are calculated and compared in high frequency voltage source inverters that are operated by two different types of control method : phase-shift control (PSC) and pulse-density modulation (PDM). MOSFET is considered to be used as a switching device for high frequency operation. The calculation procedure of power losses in the inverter stage is proposed. And its example is discussed for comparison of performance of the two types of control in terms of power loss. The results shows that differences in power losses between the two types are mainly due to the switching loss at turn-off instant and that PDM type has less power loss than PSC especially in high frequency operation.

태양광 PV 스트링에서의 모듈 부정합 손실의 분석 및 개선 기법 타당성 연구

안희욱(Ahn Hee-Wook) 한국태양에너지학회 2009 한국태양에너지학회 논문집 Vol.29 No.1

In this paper, the power loss due to PV module mismatch in PV string is analyzed and a mismatch compensation method is proposed to improve the efficiency of PV system. The analysis of mismatch loss using PV model simulation reveals that the mismatch module may decrease the total efficiency because the MPPT function of power conditioner make the PV system operate at the local maximum point. The mismatch loss can be severe if the maximum power point current of mismatch module is less than that of string. The proposed compensation method which is simply implemented with a buck type conveter shows the possibility to remove the mismatch loss. The effectiveness of the analysis and compensation method is verified by a prototype experiment.