• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2002년도 학술대회논문집
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• pp.287-291
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• 2002

This paper presents active-clamp class-E high frequency resonant inverter with single-stage. The proposed circuit is integrated active-clamp class-E circuit to boost converter with the function of power factor correction. Boost converter is operated in positive and negative half cycle respectively at line frequency(60Hz), Such a operating in discontinuous conduction mode(DCM) of boost converter performs high power factor. By adding active-clamp circuit in class-E inverter, main switch of inverter part is operated not only ZVS(Zero Voltage Switch) but also reduced the switching voltage stress of main switch. This paper shows that simulation result using Psim 4.1 prove the validity of theoretical analysis. This proposed inverter will be able to be practically used as a power supply in various fields as induction heating applications, DC-DC converter etc.

• Journal of Electrical Engineering and Technology
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• 제10권6호
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• pp.2307-2314
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• 2015

In this paper, a discontinuous conduction mode (DCM) frequency control algorithm is proposed to reduce the input current ripple of a multi-phase interleaved boost converter. Unlike conventional variable duty and constant frequency control, the proposed algorithm controls the switching frequency to regulate the output voltage. By fixing the duty ratio at 1/N in the N-phase interleaved boost converter, the input current ripple can be minimized by ripple cancellation. Furthermore, the negative effects of the diode reverse recovery current are eliminated because of the DCM characteristic. A frequency controller is designed to employ the proposed algorithm considering the magnetic permeability change. The proposed algorithm is analyzed in the frequency domain and verified by a 600 W three-phase boost converter prototype that achieved 57% ripple current reduction.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2004년도 전력전자학술대회 논문집(2)
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• pp.547-550
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• 2004

An interleaved single-stage power-factor-correction (PFC) AC/DC converter is presented in this paper. The proposed converter is combined by two single-stage AC/DC converters based on flyback converter Each PFC stage operates in discontinuous conduction mode (DCM). By exploiting the interleaving technique, the input ripple current and output ripple voltage are reduced. The proposed converter complied with EN/1EC61000-3-2 harmonic regulations achieves high efficiency and low cost. The performance of the proposed converter was evaluated on a 180W $(90W\times2,\;24V,\;7.5A)$ experimental prototype.

• Journal of Power Electronics
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• 제15권6호
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• pp.1577-1583
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• 2015

In this research, a combined adaptive-robust current controller is developed for non-minimum-phase DC-DC converters in a wide range of operations. In the proposed nonlinear controller, load resistance, input voltage and zero interval of the inductor current are estimated using developed adaptation rules and knowing the operating mode of the converter for the closed-loop control is not required; hence, a single controller can be employed for a wide load and line changes in discontinuous and continuous conduction operations. Using the TMS320F2810 digital signal processor, the experimental response of the proposed controller is presented in different operating points of the buck/boost converter. During transition between different modes of the converter, the developed controller has a better dynamic response compared with previously reported adaptive nonlinear approach. Moreover, output voltage steady-state error is zero in different conditions.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제49권6호
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• pp.441-449
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• 2000

Analysis, design and practical implementation of a single-stage electronic ballast for compact fluorecent lamps are presented in this paper. The proposed topology is based on a single-stage ballast which combines a boost converter and a half-bridge series resonant inverter. High power factor is achieved by using the boost semi-stage operating in discontinuous conduction mode, and inverter semi-stage operated above resonant frequency to provide zero voltage switching is employed to ballast the fluorescent lamp. Analytical and experimental results from the ballast system with 36W fluorescent lamps have demonstrated the feasibility of the proposed single-stage electronic ballast.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 B
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• pp.1129-1131
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• 2001

A new low cost single stage high power factor electronic ballast for fluorescent lamps is presented in this paper. The proposed topology is based on integration of two-boost converter and LC type high frequency resonant converter. A ballast is obtained by simple construction, because full bridge rectifier diode is eliminated and simple control circuits is applied. Using two boost converter operating positive and negative half cycle respectively at line frequency (60Hz), operating in discontinuous conduction mode performs high power factor. The simulated and experimental results for 64W fluorescent lamps operating at 45kHz switching frequency and 110V line voltage have been obtained.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1999년도 전력전자학술대회 논문집
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• pp.278-281
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• 1999

In a utility interactive photovoltaic system, a PWM inverter is used for the connection between the photovoltaic arrays and the utility. The DC current becomes pulsated causes the distortion of the AC current waveform. This paper presents the reduced pulsation of DC input current by operating the inverter with buck-boost chopper in the discontinuous conduction mode. The DC current with contains harmonics component is analyzed by means of separating into two terms of a ripple component and a direct component. The constant DC current without pulsation is supplied from photovoltaic array to the inverter. The proposed inverter system provide a sinusoidal AC current for domestic loads and the utility line with unity power factor.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1999년도 전력전자학술대회 논문집
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• pp.639-642
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• 1999

An integrated zero current switching(ZCS) quasi-resonant converter(QRC) for power factor correction and high efficiency with single switch is proposed in this thesis. Boost integrated circuit operating discontinuous conduction mode(DCM) and QRC are used for power factor correction and reducing switching loss, respectively. A prototype converter has been designed and experimented. At rated condition, the THD in the input current waveform of this prototype has approximately 18%. The efficiency is obtained about 70%, the power factor is about 0.985 as well. Therefore, the proposed converter is suitable for a low power level converter with operating switching frequency above several hundred KHz.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 학술대회 논문집 전문대학교육위원
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• pp.149-153
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• 2003

This paper presents a current-source-inverter based on a buck-boost configuration and its application for residential photovoltaic system. The proposed circuit has five switches. Among them, only one switch acts as chopping, and the other determine the polarity of output; therefore, it can reduce the switching loss. Because the input inductor current is operated on the discontinuous conduction mode, high power factor can be achieved without additional input current controller. So the overall system shows a simple structure. The operational modes are analysed in depth, and then it was verified through the experimental results using a 150 [W] prototype equipped with digital signal processor TMS320F241.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 학술대회 논문집 전문대학교육위원
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• pp.154-157
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• 2003

This paper presents a current-source-inverter based on a buck-boost configuration and its application for residential photovoltaic system. The proposed circuit has five switches. Among them, only one switch acts as chopping, and the other determine the polarity of output; therefore, it can reduce the switching loss. Because the input inductor current is operated on the discontinuous conduction mode, high power factor can be achieved without additional input current controller, So the overall system shows a simple structure. The operational modes are analysed in depth, and then it was verified through the experimental results using a 150 [W] prototype equipped with digital signal processor TMS320F241.