• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 학술대회 논문집 전문대학교육위원
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• pp.14-16
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• 2004

This paper describes a boost converter to be operated at the boundary of continuous current mode(CCM) and discontinuous current mode(DCM) for power factor correction and low cost. A control method to be utilized in simulation is a average Current mode method in case of operating in CCM. The simulation results show that Better is the CCM converter then the DCM converter in harmonic content and input current waveform. And A Double-boost converter is superior to single-boost converter for input-current harmonic.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.112-115
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• 2002

Previous AC/DC PFC Boost Converter perceives feed forward signal of input and feedback signal of output for average current-mode control. Previous Boost Converter, the quantity of input current will be decreased by the decrease of output current in light load, and also power factor comes to be decreased. Also the efficiency of converter will be decreased by the decrease of power factor. The proposed converter presents the good PFC(Power Factor Correction), low line current hormonic distortions and tight output voltage regulations using non-dissipative snubber. The proposed converter also has a high efficiency by non-dissipative snubber circuit. To show the superiority of this converter is verified through the experiment with a 640W, 100kHz prototype converter.

• Journal of Power Electronics
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• 제14권5호
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• pp.899-907
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• 2014

This paper proposes a single-phase bidirectional AC/DC converter topology applied in V2G systems, which consists of an inverter and a bidirectional non-inverting buck-boost converter. This topology can operate in four modes: buck charging, boost charging, buck discharging and boost discharging with high input current quality and unity input power factor. The inverter switches at line frequency, which is different from conventional voltage source inverters. A bidirectional buck-boost converter is utilized to adapt to a wider charging voltage range. The modulation and control strategy is introduced in detail, and the switching patterns are optimized to reduce the current ripple. In addition, the semiconductor losses are analyzed. Simulation and experimental results demonstrate the validity and effectiveness of the proposed topology.

• Journal of Power Electronics
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• 제5권3호
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• pp.212-217
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• 2005

In order to correct the power boost topology has been used for easy control. But conventional boost topology has the following drawbacks: switching voltage surge, cross conduction current and right-half-plane zero of its control transfer function. Furthermore, in this topology the output voltage is always higher than the input voltage. As a result, a first-stage boost PFC converter needs to be connected with a second-stage DC-DC converter. A new topology which can be used as single stage PFC converter is proposed in this paper.

• 조명전기설비학회논문지
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• 제26권6호
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• pp.16-28
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• 2012

This paper proposes a quasi Z-source converter(QZSC) with a diode-capacitor output filter to improve the output DC voltage boost ability. The proposed converter has the same quasi Z-source network topology compared with the conventional converter. But the proposed method is adopted a diode-capacitor filter as its output filter, since the conventional method is used an inductor-capacitor as its output filter. Under the condition of the same input-output DC voltage, the proposed method has more lower shoot-through duty ratio than the conventional method. Also, because the proposed converter has same voltage boost factor under lower shoot-through duty ratio compared with the conventional converter, the proposed converter can be operated with the lower capacitor voltage of Z-source network and the lower input current. To confirm the validity of the proposed method, PSIM simulation and a DSP based experiment were performed to acquire the output DC voltage 120[V] under the input DC voltage 80[V]. And the capacitor voltage and inductor current in Z-source network, the output voltage of each converter were compared and discussed.

• 전력전자학회논문지
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• 제5권2호
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• pp.176-183
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• 2000

본 논문에서는 단일 스위치 3상 승압형 컨버터 입력전류의 왜형을 개선하기 위한 6고조파 주입 PWM 방식이 제안디었다. 주기적인 6고조파 전압이 한 스위칭 사이클 내에 컨버터 스위치의 듀비티를 가변하도록 제어회로에 주입되었다. 그 결과 입력 상전류는 입력전압을 따라가고 거의 1에 가까운 역률을 얻었다. 실험결과는 3상 입력 AC 140∼220V, 400V∼6kW 저항부하와 3상 AC 220V, 비선형 부하인 CO2 아크 용접기에 의하여 입증하였다.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제52권7호
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• pp.343-351
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• 2003

In this paper, interleaved boost converter is applied as a first-stage converter in switch mode power supply. The first-stage converter plays a role to improve power factor. Interleaved Boost Power Factor Corrector(IBPFC) can reduce input current ripple as a single voltage control loop only without inner current loop, because input current is divided each 50% by two switching devices. Each converter cell is also operated in discontinuous current mode and inductor current of each converter is discontinuous. Total input current which is composed by each converter cell is continuous current. Thus, IBPFC is able to improve input current ripple. IBPFC operating in discontinuous current mode can be classified as six modes from switching state and be carried out state space averaging small signal modeling. A control transfer function is obtained according to the modeling. Not only steady-state characteristics but also dynamic characteristics is considered. Single voltage control loop is also constructed by the control transfer function. From experimental result, improvement of power factor and input current ripple are verified.

• 전력전자학회논문지
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• 제12권6호
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• pp.465-471
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• 2007

본 논문에서는 새로운 소프트 스위칭형 PFC 벅-부스트 AC-DC 컨버터에 대해 연구된다. 제안된 컨버터에 사용된 제어스위치의 턴-온과 턴-오프는 부분공진 동작에 의해 소프트 스위칭으로 되어 스위칭 손실을 줄이고, 입력전류는 듀티율 일정제어에 의한 교류 입력전압의 크기에 비례된 불연속적 유사 펄스열의 정현파 형태를 가진다. 그 결과 컨버터는 효율이 증대되고 입력역률이 증대되는 효과를 가진다. 또한 제안된 컨버터의 출력전압은 제어스위치의 PWM 제어에 의해 조정되고 벅-부스트용 인덕터에 흐르는 전류는 불연속모드로 제어되어 제어회로와 제어기법이 간단한 장점이 주어진다. 제안된 PFC 벅-부스트 컨버터는 기존의 PFC 벅-부스트 컨버터와 비교되어 해석되고 컴퓨터 시뮬레이션과 실험을 통해 그 해석적 타당성이 입증된다.

• Journal of Power Electronics
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• 제10권2호
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• pp.132-137
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• 2010

Interleaving techniques are widely used to reduce input/output ripples and to increase the power capacity of boost converters operating in critical conduction mode. Two types of phase-shift control schemes are studied in this paper, the turn-on time shifting method and the turn-off time shifting method. It is found that although the turn-off time shifting method exhibits better performance, it suffers from sub-harmonic oscillations at high input voltages. To solve this problem, an intensive quantitative analysis of the sub-harmonic oscillation phenomenon is made in this paper. Based upon that, a novel modified turn off time shifting control scheme for interleaved boost converters operating in critical conduction mode is proposed. An important advantage of this scheme is that both the master phase and the slave phase can operate stably in critical conduction mode without any oscillations in the full input voltage range. This method is implemented with a FPGA based digital PWM control platform, and tests were carried out on a two-phase interleaved boost PFC converter prototype. Experimental results demonstrated the feasibility and performance of the proposed phase-shift control scheme.

• 전기학회논문지
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• 제62권3호
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• pp.355-364
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• 2013

Respect to the input AC voltage and output DC voltage, conventional three-phase PWM rectifier is classified as the voltage type rectifier with boost capability and the current type rectifier voltage with buck capability. Conventional PWM rectifier can not at the same time the boost and buck capability and its bridge is weak in the shoot- through state. These problems can be solved by Z-source PWM rectifier which has all characteristic of voltage and current type PWM rectifier. By shoot-through duty ratio control, the Z-source PWM rectifier can buck and boost at the same time, also, there is no need to consider the dead time. This paper proposes the input AC voltage sensorless control method of a three-phase Z-source PWM rectifier in order to accomplish the unity input power factor and output DC voltage control. The proposed method is estimated the input AC voltage by using input AC current and output DC voltage, hence, the sensor for the input AC voltage detection is no needed. comparison of the estimated and detected input AC voltage, estimated phase angle of the input voltage, the output DC voltage response for reference value, unity power factor, FFT(Fast Fourier Transform) of the estimated voltage and efficiency are verified by PSIM simulation.