• 전력전자학회논문지
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• 제20권1호
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• pp.51-58
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• 2015

In order to decrease the size of a switch mode power supply, high switching frequency can be an efficient way to reduce the size of passive components in the converter. In this paper, a 500-kHz high-frequency LLC resonant converter is proposed with an accurate design method of magnetizing inductance, as well as the relationship between the switching frequency and the size of the passive components. Simulation and experimental results are presented to verify the proposed methods and equations, including the temperature data of each passive and active device of the converter. Using those results, dominant power losses in the prototype converter under 500-kHz high-frequency operation are investigated, compared with the results from a 100-kHz converter. In addition, operating waveforms and power conversion efficiency will be shown to obtain design considerations for the high switching frequency LLC resonant converter.

• Journal of Electrical Engineering and Technology
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• 제11권2호
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• pp.383-392
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• 2016

This paper proposes the design considerations of resonant network and transformer magnetics for 500 kHz high switching frequency LLC resonant converter. The high power density can be effectively achieved by adopting high switching frequency which allows small size passive components in the converter. The design methodology of magnetizing inductance is derived for zero voltage switching (ZVS) condition, and the design methodology of the transformer and output capacitance is derived to achieve high power density at high operating frequency. Moreover, the structure of transformer is analyzed to obtain the proper inductance value for high switching operation. To verify the proposed design methodology, simulation and experimental results will be presented including temperature of passive and active components, and power conversion efficiency to evaluate dominant power loss. In addition, the validity of magnetics design will be evaluated with operating waveforms of the prototype converter.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(1)
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• pp.337-340
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• 2003

This paper presented practical details about control-loop design and dynamic analysis for a peak current-mode controlled asymmetrical half-bridge(ASHB) do-to-dc converter, Graphical loop gain method is used to design the feedback compensation and analyze the closed-loop performance of ASHB converter. The results of the control design and closed-loop analysis are validated by experiments on a prototype converter.

• Journal of Power Electronics
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• 제18권2호
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• pp.482-491
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• 2018

The practical design methodology of a three-phase dual active bridge (3ph-DAB) converter applied to low voltage direct current (LVDC) applications is proposed by using a mathematical model based on the steady-state operation. An analysis of the small-signal model (SSM) is important for the design of a proper controller to improve the stability and dynamics of the converter. The proposed lead-lag controller for the 3ph-DAB converter is designed with a simplified SSM analysis including an equivalent series resistor (ESR) for the output capacitor. The proposed controller can compensate the effects of the ESR zero of the output capacitor in the control-to-output voltage transfer function that can cause high-frequency noises. In addition, the performance of the power converter can be improved by using a controller designed by a SSM analysis without additional cost. The accuracy of the simplified SSM including the ESR zero of the output capacitor is verified by simulation software (PSIM). The design methodology of the 3ph-DAB converter and the performance of the proposed controller are verified by experimental results obtained with a 5-kW prototype 3ph-DAB converter.

• 한국전자통신학회논문지
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• 제11권9호
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• pp.869-876
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• 2016

위상변조 풀브리지 컨버터를 설계, 개발하는데 있어, 전력반도체와 그 전력반도체 구동회로, 변압기 및 인덕터, 정류기 등을 포함한 많은 설계 요인들이 존재한다. 그 중에서 위상변조 풀브리지 컨버터의 최적 성능에 매우 큰 영향을 끼치는 것은 변압기 설계이다. 특히 변압기 설계는 대형 컴퓨터 데이터센터에 사용되는 전원장치에서처럼 저전압, 고전류 응용에서 매우 중요하다. 이 논문에서는 위상변조 풀브리지 컨버터의 최적 성능을위한 변압기 설계에 관한 연구 결과를 발표한다. 변압기 설계에 관련된 설계 수식들을 유도하고 세밀한 분석을 한다. 이를 토대로, 12V, 1200W 서버전원장치 응용을 위한 위상변조 풀브리지 컨버터 최적 성능을 위한 변압기 설계를 결과물로 제시한다.

• Journal of Power Electronics
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• 제10권5호
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• pp.461-467
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• 2010

This paper proposes a new soft-switched Sepic converter. It has low switching losses and low conduction losses due to its auxiliary communicated circuit and synchronous rectifier operation, respectively. Because of its positive and buck/boost-like DC voltage transfer function (M=D/(1-D)), the proposed converter is desirable for use in distributed power systems. The proposed converter has versions both with and without a transformer. The paper also suggests some design guidelines in terms of the power circuit and the control loop for the proposed converter.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.523-526
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• 2001

In this paper, we design and fabricate the high-efficiency and low-power switched-capacitor DC-DC converter. This converter consists of internal oscillator, output driver and output switches. The internal oscillator has 100kHz oscillation frequency and the output switches composed of one pMOS transistor and three nMOS transistors. According to the configuration of two external capacitors, the converter has three functions that are the Inverter, Doubler and Divider. The proposed converter is fabricated through the 0.8$\mu\textrm{m}$ 2-poly, 2-metal CMOS process. The simulation and experimental result for fabricated IC show that the proposed converter has the voltage conversion efficiency of 98% and power efficiency more than 95%.

• 조명전기설비학회논문지
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• 제23권7호
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• pp.20-28
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• 2009

This paper presents the design of zero current switching ZCS pulse frequency modulation type DC-DC converter for magnetron power supply. A magnetron serving as the microwave source in a microwave oven is driven by a switch mode power supply (SMPS). SMPSs have the advantages of improved efficiency, reduced size and weight, regulation and the ability to operate directly from the converter DC bus. The demands of the load system and the design of the power supply required to produce constant power at 4[kV]. A magnetron power supply requires the ability to limit the load current under short circuit conditions. The current source series resonant converter is a circuit configuration which can achieve this. The main features of the proposed converter are an inherent protection against a short circuit at the output, a high voltage gain and zero current switching over a large range of output power. These characteristics make it a viable choice for the implementation of a high voltage magnetron power supply.

• Journal of Electrical Engineering and Technology
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• 제9권1호
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• pp.197-204
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• 2014

In this paper an Improved Zero Voltage Zero Current Pulse Width Modulation Forward converter which employs a simple resonance snubber circuit is introduced. A simple snubber circuit consists of a capacitor, an inductor and two diodes. In proposed converter, switch Q1 operates at ZCS turn-on, and ZVS turn-off conditions and all-passive semiconductor devices operate at ZVZCS turn-on and turn-off state. The proposed converter is analyzed and various operating modes of the ZVZCS-PWM forward converter are discussed. Analysis and design considerations are presented and the prototype experimental results of a 100w (40 V/2.5A) proposed converter operating at 30 KHz switching frequency confirm the validity of theoretical analysis.

• Journal of Electrical Engineering and information Science
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• 제2권3호
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• pp.123-131
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• 1997

Design of single stage AC/DC converter with high power factor for low power level applications is proposed. The proposed converter gives the good power factor correction, low line current harmonic distortions, and tight output voltage regulations. This converter also has a high efficiency by employing an active clamp method and synchronous rectifiers. To verify the performances of the proposed converter, a 90W-converter has been designed. The modelling of this proposed converter is power formed using an averaging technique and based on this model a detailed analysis is carried out. This prototype meets the IEC555-2 requirements satisfactorily with nearly unity power factor and high efficiency.