• 대한전기학회:학술대회논문집
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• 대한전기학회 1990년도 추계학술대회 논문집 학회본부
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• pp.267-271
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• 1990

This paper describes a 3-Phase Quasi-Resonant DC Link Inverter (3-phase QRI), which has two operating modes, ie. inverting mode and rectifying mode. First the 3-Phase QRI is simplified and the resonant circuit is analyzed in comparison with two resonant DC-to-DC converters. This analysis shows that the maximum voltage of resonant capacitor is limited to twice the input voltage irrespective of operating modes. A new simple control method in rectifying mode is suggested, which does not require any other element in power circuit. The characteristic of 3-Phase Quasi Resonant Inverter has been verified by simulation using the proposed control method.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제50권11호
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• pp.568-574
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• 2001

This paper describes a current fed high frequency resonant inverter can be used as the power supply for wax-sealing. This circuit configuration is composed of conventional two unit inverter of single ended current find type in parallel. The proposed inverter can realize ZVS operation by using resonant capacitor to ZVS capacitor and has merits not only reduction of switch current distribution but also extension of load range in comparison with the conventional single-ended current fed high frequency resonant inverter. This analysis of proposed circuit uses normalized parameter and characteristic estimation which is needed in each step before design is generally described according to normalized frequency($\mu$), normalized resistance(λ) and parameters. On the basis of characteristic values, a method of the circuit design is presented. Also, the theoretical analysis is proved through experiment and this proposed circuit shows that it can be practically used as the power supply system for wax-sealing and DC-DC converter.

• 조명전기설비학회논문지
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• 제17권1호
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• pp.86-93
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• 2003

본 논문은 출력전류를 증가하기 위해서 L과 C를 공진 탱크회로로 구성하는 고주파 공진을 이용한 전류형 고주파 공진 U-U 컨버터를 보여주고 있다. 이 회로구성은 L과 C를 공진 탱크회로로 구성하였고, 스위칭 양단에 커패시터를 삽입하여 공진과 ZVS(Zero Voltage Switching) 커패시터로 동시에 사용하였다. 따라서, 컨버터는 턴ㆍ온, 턴ㆍ오프에서 스위칭 손실과 집음, 전압 스트레스를 줄일 수 있고, U전원 공급으로부터 리플이 적은 일정한 전류를 공급하기 위한 U 리액터는 공진 리액터와 연결되어 있기 때문에 부하 단락시 안정하게 동작하는 장점이 있다. 본 컨버터의 회로해석은 무차원화 파라미터 기법을 도입하여 행하였고, 또한 ZVS영역특성, 출력전력특성, 출력전압특성, 출력전류특성 등 여러 특성평가를 하였다. 여러 특성평가를 바탕으로 설계하였고, 실험을 통한 실험치와 이론치를 비교하여 이론해석의 정당성도 입증하였다.

• 전력전자학회논문지
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• 제18권5호
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• pp.458-465
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• 2013

This paper proposes a novel soft-switched auxiliary resonant circuit to provide a Zero-Voltage-Transition at turn-on for a conventional PWM boost converter in a PFC application. The proposed auxiliary circuit enables a main switch of the boost converter to turn on under a zero voltage switching condition and simultaneously achieves both soft-switched turn-on and turn-off. Moreover, for the purpose of an intelligent multi-chip power module fabrication, the proposed circuit is designed to satisfy several design constraints including space saving, low cost, and easy fabrication. As a result, the circuit is easily realized by a low rated MOSFET and a small inductor. Detail operation and the circuit waveform are theoretically explained and then simulation and experimental results are provided based on a 1.8 kW prototype PFC converter in order to verify the effectiveness of the proposed circuit.

• 대한전기학회논문지
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• 제35권7호
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• pp.272-277
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• 1986

The system that follows to the resonance frequency of high frequency MOSFET inverter and varies according to the changes of load characteristics is proposed. Also we suggested a method how to select the resonant load type between series and parallel circuit for a given inverter type. It leads to the conclusion that in the case of high impedance loads, parallel resonant circuits are preferable, on the other hand, for low impedance loads, series resonant circuits are more preferable. For frequency tracking, a PLL circuit is used as main control element to detect the phase difference of current and voltage of load. The realized apparatus composed of control circuit and voltage type full-bridged MOSFET elements as main parts of inverter. A stable frequency follow-up characteristics are obtained for 1.2MHz, 1.5KW high frequency output and power is always supplied to the load with unity power factor.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2003년도 학술대회논문집
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• pp.311-314
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• 2003

In this paper, proposed circuit proposes that Active-Clamp-Circuits basis of a current-fed inverter linked type high frequency resonant dc-dc converter of conventional. and the paper the most of characteristics of the reduced high voltage stress main switches with active clamp circuits and output current constant with the resonant part consists of L, C resonant tank circuit. Also, the capacitor (C$_1$, C$_2$) connected in switches are a common using by resonance capacitor and ZVS capacitor. and circuit analysis used state equation of each part modes. Also we conform a rightfulness theoretical analysis by comparing a parameters values and simulation values obtained from simulation using Power MOS-FET as switching devices.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 A
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• pp.360-364
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• 1995

A zero voltage switching (ZVS) three level resonant pole inverter is presented for high power GTO inverters. The concept of auxiliary resonant commutated pole(ARCP) for two level inverter is extended to the three level inverter. The proposed auxiliary commutation circuit consists of one resonant inductor and two bi-directional switches, which provides ZVS condition to the main devices without increasing device voltage or current stresses. The auxiliary device operates with zero current switching(ZCS) which enables use of the low cost thyristors. The proposed circuit can handle higher voltage and higher power(1-10MVA) comparing to the two level one. Operation and analysis of the proposed circuit are illustrated. Experimental results with 10 KW, 4 kHz prototype are presented to verify the principle of operation.

• 전력전자학회논문지
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• 제10권2호
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• pp.194-202
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• 2005

본 연구는 새로운 AC PDP(Plasma Display Panel)용 멀티레벨 에너지 회수회로에 관한 연구로서, 기존 멀티레벨 구동회로의 장점을 그대로 유지하면서 문제점을 해결한 새로운 멀티레벨 구동회로를 제안한다. 기존의 멀티레벨 구동회로는 Weber회로의 하드스위칭 문제를 개선하였지만 공진 인덕터에 기생공진전류가 존재하고 Vs/2유지구간이 존재한다. 제안한 회로는 기존 회로에 비해 인덕터의 수를 반으로 줄여 회로를 간단히 하고 공진 인덕터의 기생 공진전류와 Vs/2유지구간을 제거하였으며 CIM(Current Injection Method)을 사용하여 하드스위칭 문제를 해결하였다. 또한 풀브리지 구동회로에 직렬 연결된 스위칭 소자에 NPC(Neutral Point Clamping)기법을 적용하여 각 스위칭 소자에 전압이 균등하게 분배되도록 하였다. 그리고 제안회로의 동작을 모드별로 해석하였으며, PSpice 프로그램으로 시뮬레이션하고 회로를 구성하여 실험함으로써 제안한 회로의 유용성을 입증하였다.

• Journal of Power Electronics
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• 제13권4호
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• pp.626-635
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• 2013

An analysis of the junction capacitance in resonant rectifiers which has a significant impact on the operating point of resonance circuits is studied in this paper, where the junction capacitance of the rectifier diode is to decrease the resonant current and output voltage in the circuit when compared with that in an ideal rectifier diode. This can be represented by a simplified series resonant equivalent circuit and a voltage transfer function versus the normalized operating frequency at varied values of the resonant capacitor. A low voltage to high voltage push-pull DC/DC resonant converter was used as a design example. The design procedure is based on the principle of the half bridge class-DE resonant rectifier, which ensures more accurate results. The proposed scheme provides a more systematic and feasible solution than the conventional resonant push-pull DC/DC converter analysis methodology. To increase circuit efficiency, the main switches and the rectifier diodes can be operated under the zero-voltage and zero-current switching conditions, respectively. In order to achieve this objective, the parameters of the DC/DC converter need to be designed properly. The details of the analysis and design of this DC/DC converter's components are described. A prototype was constructed with a 62-88 kHz variable switching frequency, a 12 $V_{DC}$ input voltage, a 380 $V_{DC}$ output voltage, and a rated output power of 150 W. The validity of this approach was confirmed by simulation and experimental results.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 B
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• pp.1065-1066
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• 2006

The multi-resonant converter minimizes the parasitic oscillations using the resonant tank circuit absorbed parasitic reactances in a converter. So the converter can be operated at a high frequency and it provides a high efficiency because the switching power losses are reduced effectively. However, the high resonant voltage stress of semiconductors leads to the conduction loss. In this paper, it is proposed the novel flyback multi-resonant converter. The converter input is divided by two series input capacitors. And also the resonant stress is reduced to 2-3 times input voltage without any complexity and it provides the various circuit schemes in lots of applications. The proposed converters are verified through simulation and experiment.