• 전력전자학회논문지
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• 제5권3호
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• pp.209-214
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• 2000

본 논문에서는 FB ZVT PWM DC-DC 컨버터에서 영전압 스위칭에 도달하기 위해 두 개의 보조 스위치 대신에 가포화 인덕터를 사용한다. 기존의 고주파 위상 변위 FB ZVT PWM DC-DC 컨버터는 프리휠링 주기동안 고주파 변압기와 스위칭 소자를 통해 흐르는 순환전류를 갖으며, 이러한 순환전류로 인해 컨버터의 도전손실이 증가한다. 이러한 손실을 줄이기 위해 변압기의 2차측에 도전손실저감회로를 제안한다. 컨버터의 동작원리를 자세하게 설명하고 제안된 회로를 시뮬레이션과 실험을 통해 검증하였다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 Proceedings ICPE 01 2001 International Conference on Power Electronics
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• pp.484-488
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• 2001

The grid voltage of commercial utility power source hi Japan and USA is 100rms, but in China and European countries, it is 200rms. In recent years, In Japan 200Vrms out putted single phase three wire system begins to be used for high power applications. In 100Vrms utility AC power applications and systems, an active voltage clamped quasi-resonant Inverter circuit topology using IGBTs has been effectively used so far for the consumer microwave oven. In this paper, presented is a half bridge type voltage-clamped high-frequency Inverter type AC-DC converter using which is designed for consumer magnetron drive used as the consumer microwave oven in 200V utility AC power system. This zero voltage soft switching Inverter can use the same power rated switching semiconductor devices and three-winding high frequency transformer as those of the active voltage clamped quasi-resonant Inverter using the IGBTs that has already been used for 100V utility AC power source. The operating performances of the voltage source single ended push pull type Inverter are evaluated and discussed for consumer microwave oven. The harmonic line current components In the utility AC power side of the AC-DC power converter operating at ZVS­PWM strategy reduced and improved on the basis of sine wave like pulse frequency modulation and sine wave like pulse width modulation for the utility AC voltage source.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 A
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• pp.395-399
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• 1996

The Clamp Mode(CM) Forward Zero Voltage Switching Multi Resonant Converter(ZVS-MRC) with self-driven synchronous rectifier in studied. The loss at the synchronous rectification stage of the converter is analyzed using MOSFET linear model and is compared with the loss at the conventional schottky diode rectification stage of the converter. From the results of the analysis, it is known that the use of MOSFETs as a synchronous rectifier reduces the loss at the rectification stage over the whole load range comparing the use of schottky diodes as a conventional rectifier in the converter. In order to verify the validity of the analysis, we have built a 33W(3.3V/10A) CM Forward ZVS-MRC with self-driven synchronous rectifier, in which switching frequency is 1MHz, and tested. From the experimental results, it is known that the synchronous rectification achieved about 1W improvement in the loss at the rectification stage and about 3% in the efficiency at the converter as compared with the conventional schottky diode rectification.

• 전력전자학회논문지
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• 제23권3호
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• pp.161-167
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• 2018

In battery-operated systems, an isolated converter is used to interface the utility grid with the system to increase stability when charging and discharging batteries. Systems such as vehicle-to-grids (V2Gs), on-board chargers, and energy storage systems (ESSs) have recently become popular, and the roles of isolated converters have become important considerations in fabricating such devices. A fixed-frequency LLC converter, which is a type of isolated converter, presents the advantages of high efficiency and high power density by performing zero-voltage switching (ZVS) over wide frequency ranges. However, the magnetizing inductance of the LLC converter should be designed to enable ZVS in all switching devices. Therefore, in this study, the operating characteristics of the LLC circuit are analyzed, and an optimal design method for ZVS operation is established. Moreover, an 8 kW LLC high-efficiency and high-power-density resonant converter is designed and tested for ESS application. The LLC converter achieves 98% efficiency at rated power.

• 전력전자학회논문지
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• 제10권5호
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• pp.518-525
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• 2005

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.

• 조명전기설비학회논문지
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• 제29권5호
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• pp.57-64
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• 2015

This paper proposes a new switching algorithm for an controllable clamp snubber to improve the efficiency of a fly-back converter system. This system uses an controllable clamp method for the snubber circuit for the efficiency and reliability of the system. However, the active clamp snubber circuit has the disadvantage that system efficiency is decreased by switch operating time because of heat loss in resonance between the snubber capacitor and leakage inductance. To address this, this paper proposes a new switching algorithm. The proposed algorithm is a technique to reduce power consumption by reducing the resonance of the snubber switch operation time. Also, the snubber switch is operated at zero voltage switching by turning on the snubber switch before main switch turn-off. Experimental results are presented to show the validity of the proposed controllable clamp control algorithm.

• 조명전기설비학회논문지
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• 제27권7호
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• pp.67-75
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• 2013

In this paper, parallel input/serial output dual converter is designed appropriately for fuel cell hybrid power system. In case of proposed converter, zero voltage switching condition is designed without additional resonance device using leakage inductance of transformer and output capacitance of switch, and zero voltage switching method is used. Also, the system method is for increasing power by connecting half-bridge in parallel and increasing output voltage by connecting secondary output of transformer in serial. Through this method we can increase power and decrease volume of system. So in this paper, dual converter is designed. 1.5kW fuel cell hybrid power system was implemented, and system operation and stability was verified through experiment.

• 한국정보전자통신기술학회논문지
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• 제12권1호
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• pp.99-105
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• 2019

전기 자동차의 배터리 충전용 OBC는 주로 PFC회로와 절연형 DC-DC 컨버터 회로를 포함한 2단으로 구성된다. 일반적으로 PFC 회로로는 구조가 간단한 비절연형 부스트 컨버터가 사용되고, 절연형 DC-DC 컨버터로는 ZVS(Zero Voltage Switching)가 가능한 공진형 컨버터가 이용되고 있다. 전기자동차의 주행거리 증가에 따른 넓은 배터리 출력에 대응하기 위해서는 OBC의 넓은 출력범위가 필요하지만, 이러한 시스템 회로 구성에서는 ZVS를 위한 회로설계의 한계와 제어기 구성이 복잡해지기 때문에 배터리 충전에 요구되는 넓은 범위의 출력에 효과적으로 대응하기에는 어려움이 있다. 본 논문에서는 절연형 전류원 방식의 PFC 회로와 벅 DC-DC 컨버터로 구성된 OBC를 제안하였다. 제안된 OBC는 회로 및 제어기 구성이 용이하고, 넓은 출력범위에 대한 대응이 가능하다. 제안된 회로의 유효성을 검증하기 위해 3.3㎾급 시작품을 제작 하였으며, 동작결과 출력전압 150V~400V에서 동작안정성 및 정격 부하 조건에서 최대 효율 94.4%, 최대 역률 99.2%를 확인하였다.

• Journal of Power Electronics
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• 제6권4호
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• pp.298-306
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• 2006

A high efficiency and low cost sustain driver for a plasma display panel (PDP) utilizing a current pumping method is proposed. The main concept of the proposed circuit is using the current source to charge and discharge the panel. As a result, all power switches can achieve zero voltage switching (ZVS) and every auxiliary switch can also achieve zero current switching (ZCS). Since the inductor current can compensate for the discharge current, the current stress of all the power switches can be reduced considerably. Furthermore, it has features such as a simpler structure, less mass, lower cost, and lower electromagnetic interference than in previous circuits.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.159-162
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• 2004

The paper proposes the coupled inductor rectifier of Three Level DC/DC converter CICDR-TL(Coupled Inductor Current Doubler Rectifier-Three Level) achieves Zero Voltage Switching (ZVS) for the switches in a wide load range and Zero Current Switching (ZCS) in a light load range. Advantages and disadvantages of this topology compared to the conventional Center Tapped TL Converter are discussed. Experimental evaluation results obtained on a 27V 60A DC/DC converter prototype for the 1.8kW 40kHz IGBT based experimental circuit.