• 전력전자학회논문지
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• 제16권2호
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• pp.114-121
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• 2011

본 논문에서는 고승압.대전력 응용에 적합한 소프트스위칭 인터리빙 부스트 컨버터를 제안한다. 제안하는 컨버터는 동일 듀티로 기존 부스트 컨버터보다 약 2배의 승압비를 얻을 수 있고 스위치와 다이오드의 전압정격은 약 1/2로 감소되어 $R_{DS(ON)}$과 전압 강하가 작은 소자 사용으로 도통손실을 감소시킬 수 있다. 또한 수동소자의 전압정격이 감소되어 전체 에너지량도 1/2로 감소된다. 더욱이 CCM에서도 스위치의 ZVS 턴온이 가능하고 다이오드의 ZCS 턴오프 동작으로 역방향 회복에 의한 서지가 거의 없어 스위칭 손실이 감소된다. 2kW의 시작품으로 제안하는 컨버터의 타당성을 검증하였다.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2008년도 춘계학술대회 논문집
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• pp.53-56
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• 2008

In this paper, we propose the battery charging device for electric bicycle using photovoltaic power. DC voltage from the solar cells is low, it needs to be step-up by the power conversion device. The power conversion device applied to this paper is phase-shift full-bridge converter. This converter steps-up from 12${\sim}$22[Vdc] to 36[Vdc] for charging the battery of electric bicycle. Phase-shift full-bridge converter(PSFB) can obtain twice as much DC voltage compared with half-bridge converter, thus it has lower current stress less than half-bridge converter. It is simulated and tested the battery charging device using photovoltaic power.

• Journal of Electrical Engineering and Technology
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• 제8권4호
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• pp.911-919
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• 2013

This paper reports the development of test bed with the energy recovering technique using two-step boost converter. The device is utilized for LDC aging test of Hyundai Motor's LPI AVANTE HEV in mass production. The developed power recycle type test bed is designed as 1.5 kW class to test up to the maximum load power of LDC and is also designed to supply scant power supply up to 500 W after power recycle. The theoretical design analysis and operational characteristics analysis results of test bed are reported, and its practicality and reliability are verified through the test result. Also, the finally developed test bed confirms approximately 79~85 % energy saving effect compared to the usual traditional aging test system.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제51권11호
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• pp.635-644
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• 2002

Many generating units can be in parallel connection to one battery and inverter. However, one of the biggest problems we encountered is that wind speed is fluctuated sharply in accordance with the unstable weather conditions. To solve this problem, we need energy storage equipment such as storage lead-acid battery. We design a system and analyze its modeling so that it supplies a stable power to the load through DC-AC inverter part. In this paper, we applied dual step-up/down buck-boost converter and dual high-frequency half-bridge converter to the proposed system. These converters are used to store energy in the battery regardless of the change of the wind speed. The operation process of two proposed types of converters for high-power battery charging is discussed along with simulation and experimental result. We design a charging circuit which is applicable in the actual wind power generation system for 30kw and confirm the circuit's validity.

• 반도체디스플레이기술학회지
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• 제7권2호
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• pp.7-12
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• 2008

This paper proposed DC-DC converter for fuel cell that have high voltage and high current output characteristics. It is required step-up converter to use by general power supply, because the general rated voltage of fuel cell is low about 20$\sim$50V. The miniaturization of converter and DC link voltage can be controlled and high quality of output voltage uses mainly DC-DC converter. The boost converter and buck-boost converter do not get high boosting ratio. It is that proposed boost-flyback converter. Through simulation and an experiment, it could get high boosting ratio and efficiency more than 90%.

• Journal of Power Electronics
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• 제13권5호
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• pp.829-840
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• 2013

The modified sinusoidal pulse-width modulation (SPWM) is one of the PWM techniques used in three-phase AC-DC buck converters. The modified SPWM works without the current sensor (the converter is current sensorless), improves production of sinusoidal AC current, enables obtainment of near-unity power factor, and controls output voltage through modulation gain (ranging from 0 to 1). The main problem of the modified SPWM is the huge starting current and voltage (during transient) that results from a large step change from the reference voltage. When the load changes, the output voltage significantly drops (through switching losses and non-ideal converter elements). The single-input single-output (SISO) approach with minor-loop voltage feedback controller presented here overcomes this problem. This approach is created on a theoretical linear model and verified by discrete-model simulation on MATLAB/Simulink. The capability and effectiveness of the SISO approach in compensating start-up current/voltage and in achieving zero steady-state error were tested for transient cases with step-changed load and step-changed reference voltage for linear and non-linear loads. Tests were done to analyze the transient performance against various controller gains. An experiment prototype was also developed for verification.

• Journal of Electrical Engineering and Technology
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• 제10권4호
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• pp.1578-1588
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• 2015

In this paper, an improved KY converter is presented, which is constructed mainly by one charge pump capacitor and one central-tapped coupling inductor. Besides, a passive clamping snubber is added to this converter to improve the efficiency above half load. As compared to the KY converter, the voltage conversion ratio of the proposed converter is upgraded significantly. In this paper, the basic operating principles and mathematical deductions of the proposed converter are described, along with some experimental results provided to demonstrate the feasibility and effectiveness of the proposed converter.

• 전력전자학회논문지
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• 제14권4호
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• pp.315-322
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• 2009

기존의 부스트 컨버터는 출력 전압이 커질수록 스위치와 다이오드의 전압, 전류 스트레스가 커지고 다이오드 역 방향회복에 의한 서지로 인해 실제 사용 가능한 승압비가 제한된다. 본 논문에서는 고승압 응용에 적합한 새로운 비절연 부스트 컨버터를 제안한다. 제안한 컨버터는 듀티비 0.5로 약 6배의 승압비를 가지며 CCM에서도 ZVS 스위칭이 가능하므로 넓은 ZVS 영역을 갖는다. 또한 스위치와 다이오드 전압정격이 출력전압의 1/3로 작고 인터리빙이 가능하여 입출력 수동소자의 정격도 작다. 다이오드도 ZCS 턴오프 동작으로 인해 역방향 회복에 의한 서지가 거의 없다. 제안하는 컨버터의 동작원리를 설명하였고 이론적 해석과 시뮬레이션 및 실험을 통해 타당성을 검증하였다.

• Journal of Advanced Marine Engineering and Technology
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• 제29권7호
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• pp.744-749
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• 2005

This paper describes the performance improvement of power control system of magnetron (MGT) for microwave oven. The MGT is used extensively in household microwave oven and industrial microwave heating devices, and is operated by 3.0[kV] $\∼$5.0[kV] dc high voltage. The proposed power supply is consisted of a bridge rectifier, step-up converter(SUC) and its controller, half bridge inverter(HBI) and its controller, and full wave double voltage rectifier(DVR). In the proposed system, a good power factor can be obtained by the SUC' switching method that the inductor current waveforms follows that of the rectified voltage, and a line input power can be controlled to a range of 17.5[$\%$] by duty ratio (DR) adjustment of the HBI.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1988년도 추계학술대회 논문집 학회본부
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• pp.283-286
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• 1988

This paper describes the PWM cycloconverter which can provide step-up ac-ac direct conversion in a wide output frequency range. With input reactor and output capacitor. the input and output ports are exchanged. And sine PWM scheme is applied to the converter. To analyze the converter operation the state equations are derived using dq transformation. Simulated results show that both the output voltage and frequency can be controlled by adjusting the modulating functions.