• Proceedings of the KIPE Conference
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• 2013.11a
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• pp.137-138
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• 2013

능동 클램프 포워드 컨버터의 2차단에 전류 증배 정류회로를 사용할 경우 2차단에서의 도통 손실을 줄일 수 있다. 뿐만 아니라 상대적으로 큰 자화 인덕턴스와 작은 누설 인덕턴스를 이용하여 영전압 스위칭을 달성할 수 있으므로 회로 전체 동작 측면에서 바람직하다. 본 논문에서는 제안된 회로의 동작 설명과 함께 영전압 스위칭을 위한 조건을 다루었고 240W급 (12-V/20-A) 프로토타입 회로를 통해 분석 결과의 타당성을 검증하였다.

• Proceedings of the KIPE Conference
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• 2013.11a
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• pp.101-102
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• 2013

본 논문은 dual half bridge converter와 full-bridge converter가 결합된 절연형 양방향 컨버터를 제안하였다. 기존의 전류원 컨버터는 스위치가 턴-오프 시 전압 스파이크 문제가 발생한다. 이와 같은 문제를 해결하기 위해 절연형 양방향 컨버터에 공진 커패시터와 공진 인덕터를 추가하였다. 추가된 공진 소자들에 의해 준공진이 발생하고 이를 이용하여 스위치의 zero voltage switching (ZVS)조건을 충족시킬 수 있다. 그 결과 제안된 컨버터의 모든 스위치는 소프트 스위칭을 달성하고 전압 스파이크 문제를 해결 할 수 있다. 이를 이론적인 분석과 시뮬레이션을 통해 검증하였다.

• Proceedings of the KIPE Conference
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• 2011.11a
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• pp.44-45
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• 2011

Research on photovoltaic (PV) generation is taking a lot of attention due to its infinity and environment-friendliness with decrease of price per PV cell. While central inverters connect group of PV modules to utility grid in which maximum power point tracking (MPPT) for each module is difficult, micro inverter is attached on each module so that MPPT for individual modules can be easily achieved. Moreover, energy generation and consumption efficiency can be much improved by employing direct current (DC) distribution system. In this paper, a digitally controlled PV micro converter interfacing PV to DC distribution system is proposed. Boundary conduction mode (BCM) is utilized to achieve zero voltage switching (ZVS) of active switch and eliminate reverse recovery problem of passive switch. A 120W prototype boost PV micro converter is implemented to verify the feasibility and experimental results show higher than 98% efficiency at peak power and 97.29% of European efficiency.

• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.461-463
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• 1996

A FB-ZVS(Full Bridge Zero Voltage Switching) PWM DC/DC converter for electric vehicles is analyzed in this paper. The converter considered is a step-down DC/DC converter with the ratings of 3l2/I3.5V and 1.35kW. The steady state analysis of this converter is divided into six operating modes. Digital simulations using PSPICE are carried out to verify the steady-state analysis.

• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.318-320
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• 1996

This paper describes a new dc/ac inverter system, which makes use of parallel loaded high frequency resonant inverter consisting of full bridge, for achieving sinusoidal ac waveform. Because current throughout switch at turn-on is always zero in proposed inverter, low stress and low switching loss is achieved. Operating characteristic of proposed system is analyzed in per unit system using computer simulation. Output voltage of it include low harmonics and almost close tn sine wave.

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.140-145
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• 2001

This paper proposes to use a 20[kHz] phase­shifted Full-Bridge (FB) Zero-Voltage-Switched (ZVS) PWM converter in order to drive a 600[W] magnetron, and analyzes the operational modes in a switching period. Additionally, the controller of the average anode current is designed. Simulation studies and experiments verify that the proposed converter and the average anode current controller shows good performance to drive the magnetron.

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.304-308
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• 2001

This paper presents a novel prototype of ZCS-PFM high frequency series resonant inverter using IGBT power module for electromagnetic induction eddy current-heated roller in copy and printing machines. The operating principle and unique features of this voltage source half bridge inverter with two additional soft commutation inductor snubber are presented including the transformer modeling of induction heated rolling drum. This soft switching inverter can achieve stable zero current soft commutation under a discontinuous and continuous resonant load current for a widely specified power regulation processing. The experimental results and computer-aided analysis of this inverter are discussed from a practical point of view.

• Proceedings of the KIPE Conference
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• 2003.07a
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• pp.73-76
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• 2003

A zero voltage soft switching inverter using active clamp is presented for induction heating application. This converter have long been attractive because of its simplicity, high efficiency, and low cost compared to other schemes. In addition to those merits, Input power factor can be improved with a variable frequency control. In this paper, it describe the control method and operational principle to improve a power factor with a single stage US converter using active clamp for induction heating application.

• Proceedings of the KIEE Conference
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• 2003.04a
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• pp.157-162
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• 2003

This paper presents the loss analysis of Phase-Shift Full-Bridge Converter. Full-Bridge DC/DC Converter presented in this paper used a phase shift control in the primary side to achieve ZVS (Zero-Voltage-Switching) for main switch. Phase-Shaft Full-Bridge converter have an effect on the high power system. This paper analyses the loss of each component and the various losses in the circuit assessed. The result of the analysis are verified using 2.5kW, 50kHz prototype.

• Proceedings of the KIEE Conference
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• 1994.07a
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• pp.542-546
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• 1994

The objective of the study is to design and develope a 13kW zero voltage switching DC-DC Converter far high power application. Due to using the snubber capacitor in the right leg instead of increasing transformer leakage inductance, DC characteristics and the total efficiency in the proposed ZVS DC-DC converter is increased mere than in the conventional ZVS DC-DC converter by reduction of the circulating current when the load current is large. Also, this paper includes simulation and experimental results of the proposed ZVS FB DC-DC converter.