• 한국정보통신학회논문지
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• 제4권5호
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• pp.1117-1125
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• 2000

벅 컨버터 회로 평균모델를 이용하고 한주기 응답 기법을 적용한 전류모드 PWM 기법을 제안하였다. 이 제어기는 비선형 PWM 제어기로 스위칭 변수와 응답 기준과의 오차를 각 주기에서 0이 되도록 구현하였다. 그 결과, 시스템 전달함수는 폐루프 극점의 함수가 되어 설계가 용이하며 폐루프 특성이 향상되었다. 이 제어기에서 인덕터 전류의 상태 변수를 구현하기 위하여 전류모드를 이용하여 컨버터를 제어하였다. 제안한 PWM제어는 인덕터 전류 센서를 생략할 수 있으며 잡음 특성, 동특성이 기존 전류 모드 제어기에 비하여 많은 장점을 갖는다. 시뮬레이션 및 실험을 통하여 타당성을 입증하였다.

• 전력전자학회논문지
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• 제8권1호
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• pp.1-8
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• 2003

전력품질 문제를 해결할 때 직류전기아크로의 선인장치고서 높은 역률을 갖는 컨버터가 요구된다. 본 논문에서는 계통전압의 각 주기에서 커패시터와 인덕터의 공진회로가 부하변수에 따라서 직렬연결상태에서 병력연결상태로, 혹은 그 반대로 전환하면서 고역율을 유지하는 50(60)Hz 교류에서 직류로 변환하는 공진형컨버터가 묘사된다. 직렬연결과 병렬연결의 기간과 변환비는 부하에 따라서 결정되면 병력 공진회로는 단락회로를 제한한다. 이 공진형컨버터는 무부하에서 단락회로의 범위까지 높은 역률을 가지며 아크로에 전원공급을 하는 장치로 매우 적당하다.

• 한국철도학회논문집
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• 제14권5호
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• pp.411-415
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• 2011

DC/DC컨버터는 임의의 직류전원을 부하가 요구하는 형태의 직류전원으로 변환시키는 전력변환기이다. 전압모드 DC/DC 컨버터는 주기적으로 입력측에서 출력측으로 전달되는 에너지를 제어하는 기능을 수행하기 위해 MOSFET(산화물-반도체 전계 효과 트랜지스터), 인덕터, PWM 제어기(오실레이터, 연산증폭기, 비교기로 구성)를 이용한다. 본 논문에서 PWM(펄스폭 변조) 모듈과 스위칭모드로 제어하는 기본적인 승압과 강압컨버터를 연구하고, 전기적 특성을 SPICE로 시뮬레이션을 수행하며, 전력의 효율을 각 소자의 변화와 사양에 따라 분석하는데 있다.

• Journal of Power Electronics
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• 제7권3호
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• pp.246-256
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• 2007

In this paper, a novel type auxiliary active edge resonant snubber assisted zero current soft switching pulse modulation Single-Ended Push Pull (SEPP) series load resonant inverter using IGBT power modules is proposed for cost effective consumer high-frequency induction heating (IH) appliances. Its operating principle in steady state is described by using each switching mode's equivalent operating circuits. The new multi resonant high-frequency inverter with series load resonance and edge resonance can regulate its high frequency output power under a condition of a constant frequency zero current soft switching (ZCS) commutation principle on the basis of the asymmetrical pulse width modulation (PWM) control scheme. Brand-new consumer IH products using the proposed ZCS-PWM series load resonant SEPP high-frequency inverter using IGBTs is evaluated and discussed as compared with conventional high-frequency inverters on the basis of experimental results. In order to extend ZCS operation ranges under a low power setting PWM as well as to improve efficiency, the high frequency pulse density modulation (PDM) strategy is demonstrated for high frequency multi-resonant inverters. Its practical effectiveness is substantially proved from an application point of view.

• Journal of Power Electronics
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• 제14권4호
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• pp.661-670
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• 2014

A new DC/DC converter with zero voltage switching is proposed for applications with high input voltage and high load current. The proposed converter has two circuit modules that share load current and power rating. Interleaved pulse-width modulation (PWM) is adopted to generate switch control signals. Thus, ripple currents are reduced at the input and output sides. For high-voltage applications, each circuit module includes two half-bridge legs that are connected in series to reduce switch voltage rating to $V_{in}/2$. These legs are controlled with the use of asymmetric PWM. To reduce the current rating of rectifier diodes and share load current for high-load-current applications, two center-tapped rectifiers are adopted in each circuit module. The primary windings of two transformers are connected in series at the high voltage side to balance output inductor currents. Two series capacitors are adopted at the AC terminals of the two half-bridge legs to balance the two input capacitor voltages. The resonant behavior of the inductance and capacitance at the transition interval enable MOSFETs to be switched on under zero voltage switching. The circuit configuration, system characteristics, and design are discussed in detail. Experiments based on a laboratory prototype are conducted to verify the effectiveness of the proposed converter.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 추계학술대회 논문집 학회본부A
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• pp.125-127
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• 1998

The widely used power supply (Switched Mode Power Supply : SMPS) as a source in order to stabilize direct current for electronics or communication systems has merits, when it is compared to the existing source for stability, such as high efficiency, small size, light weight by means of switching process of the semiconductor device which controls the flow of power. However, due to existence of inductors and capacitors used for charging energy, the source part in electronic or communication systems hasn't reached the speed, that is supposed to get, for achieving smaller size and lighter weight. In order to got smallness in size, it is necessary to increase switching frequency. And that makes devices for measuring energy smaller. Nevertheless, the rise switching frequency brings increases in switching loss, inductor loss, and power loss. Also, the occurrence of surge and noise caused by high frequency switching is setting higher. The resonant converter has been considered as one of methods that give solutions for the problems of SMPS and that method has been paid attention as a source technology in electronics and communication.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.247.1-247.1
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• 2014

The capacitive coupled plasma is used widely in the semiconductor industries. Especially, the uniformity of the industrial plasma is heavily related with defect ratio of devices. Therefore, the industries need the capacitive coupled plasma source which can generate the uniform plasma and control the plasma's uniformity. To achieving the uniformity of the large area plasma, we designed multi-powered electrodes. We controlled the uniformity by controlling the power of each electrode. After this work, we started to research another concept of the plasma device. We make the plasma chamber that has multi-ground electrodes imaginary (CST microwave studio) and simulate the electric field. The shape of the multi-ground electrodes is ring type, and it is same as the shape of the multi-power electrodes that we researched before. The diameter of the side electrode's edge is 300mm. We assumed that the plasma uniformity is related with the impedance of ground electrodes. Therefore we simulated the imaginary chamber in three cases. First, we connected L (inductor) and C (capacitor) at the center of multi-ground electrodes. Second, we changed electric conductivity of multi-ground electrode. Third, we changed the insulator's thickness between the center ground electrode and the side ground electrode. The driving frequency is 2, 13.56 and 100 MHz. We switched our multi-powered electrode system to multi-ground electrode system. After switching, we measured the plasma uniformity after installing a variable vacuum capacitor at the ground line. We investigate the effect of ground electrodes' impedance to plasma uniformity.

• 조명전기설비학회논문지
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• 제17권1호
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• pp.116-123
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• 2003

본 논문에서는 SMPS의 교류 입력측 역률을 개선시킬 수 있는 전치 레귤레이터로서 interleaved 승압형 컨버터를 관하여 연구하였다. Interleaved 승압형 역률보상 컨버터(IBPFC)는 입력전류를 두 개의 스위칭 소자에 의하여 50%씩 나누어져 흐르게 함으로써, 내부 전류제어 루프 얼이 전압제어 루프만으로 제어계를 구성하여 입력전류 리플을 줄일 수 있다. 즉, IBPFC를 구성하는 각각의 부스트 컨버터 cell을 불연속 전류모드로 동작시키더라도 전체적인 입력전류의 파형은 연속이 되어 입력전류 리플이 감소하게 된다. 불연속 전류모드로 동작하는 IBPFC를 해석하기 위하여 스위칭 상태에 따라서 6개의 모드로 구분하여 상태방정식을 구하였다. 또한, 각 상태방정식을 상태공간 평균화법을 이용하여 모델링하고, 미소변동분을 고려한 소신호 해석을 통하여 제어전달함수를 구할 수 있다. 또한, 제어전달함수를 이용하여 단일 전압제어 루프를 가지는 제어계를 설계하였으며, 이러한 해석 및 설계를 바탕으로 실험을 통하여 IBPFC의 역률개선 및 리플저감을 확인하였다.

• 조명전기설비학회논문지
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• 제25권8호
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• pp.8-19
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• 2011

This paper was compared for the output voltage and efficiency of the single-phase Z-source inverter(ZSI) according to shoot through duty ratio D. The eight single-phase ZSI in this study are typical ZSI, Embedded ZSI(EZSI), Improved ZSI(IZSI), Quasi ZSI(QZSI), Series ZSI, Trans ZSI(TSI), Switched inductor ZSI(SL-ZSI) and Extended boost ZSI (exZSI). The eight ZSI are divided into two Groups. ; Group-1 which is ZSI with the ordinary voltage boost factor B, and Group-2 which is ZSI with the maximum voltage boost factor B. For the execution of the proposed study, the PSIM simulation was achieved under the condition of input DC voltage=150[V] of ZSI, load =30[${\Omega}$] and 60[Hz] output filter. The output voltage and efficiency of each ZSI were calculated within the limits of D=0.1~0.4. As a result, the output peak voltage of Group-2 was suddenly increased in a specified duty ratio D, and its efficiency was rapidly decreased. On the contrary, Group-1 shown the output and efficiency characteristics without sudden change compared to Group-2 despite the duty ratio increase. The efficiency of the Group-2 was sharply declined at duty ratio D of the most output voltage, but, in case of Group-1, the efficiency was slightly declined. Finally, the input DC current of ZSI with DCM and CCM was discussed.