• 한국전자통신학회논문지
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• 제15권5호
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• pp.889-896
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• 2020

일반적으로 스텝 업(Step-up) 컨버터는 Boost 컨버터, Buck-Boost 컨버터, Flyback 컨버터, Push-Pull 컨버터 등 다양하며 이 중에서 Boost 컨버터는 매우 간단한 형태로 가장 널리 사용되는 스텝 업(Step-up) 컨버터이다. 하지만, Boost 컨버터는 DCM 동작, 큰 리플 문제 및 RHPZ 문제 등을 가지고 있다. 이러한 문제를 해결하기 위해 새로운 Topology를 적용한 컨버터들이 제시되었는데 그 중 KY 컨버터는 Boost 컨버터의 DCM 동작, 큰 리플 문제 및 RHPZ 문제 등을 개선하였다. 그러나 기존의 KY 컨버터는 Boost 컨버터보다 전압 이득이 상대적으로 낮은 단점이 있다. 따라서 본 논문에서는 기존의 KY 컨버터의 장점이 있으면서 낮은 전압 이득 문제를 해결한 새로운 Topology의 KY 컨버터를 제안하였다.

• 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.

• 전력전자학회논문지
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• 제10권2호
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• pp.169-176
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• 2005

본 논문에서는 능동 클램프 풀브릿지 Boost 컨버터에 관한 DC 모델링과 AC 모델링 과정에 대하여 기술한다. 동작 원리로부터 이 컨버터의 교류 부분을 등가의 직류 부분으로 바꾸고 반도체 스위치를 재배치하여 개념적인 등가 회로가 유도된다. 유도된 등가회로는 CCM(Continuous conduction mode) Boost 컨버터와 DCM(Discontinuous conduction mode) Buck 컨버터로 표현된다. 유도된 등가회로의 각 스위치 부분을 PWM 스위치 모델로 대체하여 DC 모델 및 AC 모델이 완성된다. 이론적인 DC 및 AC 모델링 결과는 실험이나 SIMPLIS 시뮬레이션을 통해 검증된다.

• 전력전자학회논문지
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• 제23권6호
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• pp.389-396
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• 2018

This study proposes a control method using a repetitive controller for a boost-type PFC rectifier with an APD circuit structure to improve the current distortion caused by DCM condition. Conventional proportional integral controllers have bandwidth limitations in DCM conditions. The performance improvement of the APD controller in the DCM region is verified through simulations and experiments on the compensation of harmonics by the repetitive controller.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제54권9호
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• pp.431-436
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• 2005

This paper studies a novel boost DC-DC converter operated high efficiency for discontinuous current mode (DCM) control. The converter worked in DCM eliminates the complicated circuit control requirement, reduces a number of components, and reduces the used reactive components size. In the general DCM converter, the switching devices are turned-on the zero current switching (ZCS), and the switching devices must be switched-off at a maximum reactor current. To achieve the zero voltage switching (ZVS) at the switching turn-off, the proposed converter is constructed by using a new loss-less snubber circuit. Soft-switched operation of the proposed boost converter is verified by digital simulation and experimental results. A new boost converter achieves the soft-switching for all switching devices without increasing their voltage and current stresses. The result is that the switching loss is very low and the efficiency of boost DC-DC converter is high.

• Journal of Power Electronics
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• 제7권4호
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• pp.318-327
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• 2007

The design and performance analysis of a power factor corrected (PFC), single-phase, single switch flyback buck-boost ac-dc converter is carried out for low power battery charging applications. The proposed configuration of the flyback buck-boost ac-dc converter consists of only one switch and operates in discontinuous current mode (DCM), resulting in simplicity in design and manufacturing and reduction in input current total harmonic distortion (THD). The design procedure of the flyback buck-boost ac-dc converter is presented for the battery charging application. To verify and investigate the design and performance, a simulation study of the flyback buck-boost converter in DCM is performed using the PSIM6.0 platform. A laboratory prototype of the proposed single switch flyback buck-boost ac-dc converter is developed and test results are presented to validate the design and developed model of the system.

• 전기학회논문지
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• 제59권1호
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• pp.88-95
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• 2010

In this paper, the variation of phase current and input current ripple of interleaved boost converter at DCM for fuel cell applications are theoretically analyzed. Also, based on the detailed analysis, numerical formula of input current ripple expressed in rising and falling slope magnitude, D, and $D_A$ is proposed. In order to verify proposed formulas, simulation and experimental results are compared with theoretical data and validity of proposed theory is established.

• 전기학회논문지P
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• 제65권4호
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• pp.303-308
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• 2016

A light-emitting diode (LED) has been increasingly applied to various industrial fields and general lightings because of its high efficiency, low power consumption, environment-friendly characteristic and long lifetime. To drive this LED lighting, various types of power converters have been applied. Also, power factor correction (PFC) techniques play an important role in the power supply technology. In this paper, design and control of a DCM interleaved boost PFC converter is discussed. The proposed converter can reduce current ripples at input and output side by cancelling an each phase of inductor currents. Since the IC does not require the auxiliary winding of inductor for current detection, simple PFC circuit is achieved. Therefore, it contributes to increase efficiency and downsize the whole system volume, cost. Also, the performance of the proposed system is demonstrated through experiments.

• 전력전자학회논문지
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• 제19권3호
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• pp.220-226
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• 2014

Input current ripple and harmonic components of the power device are main causes of electromagnetic interference (EMI). Although the discontinuous conduction mode (DCM) operation can reduce harmonic components of the power device by reducing reverse recovery current of diode and turn-off voltage spikes of the switch, input current ripple increases due to high peak to peak inductor current. Therefore, in this paper, frequency control algorithm is proposed to reduce the input current ripple of DCM operated interleaved boost converter. In the proposed algorithm, duty ratio is fixed either 0.33 or 0.67 to minimize the input current ripple and the switching frequency is controlled according to operating conditions. 600 W 3-phase interleaved boost converter prototype system is built to verify proposed algorithm.

• Journal of Electrical Engineering and Technology
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• 제5권3호
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• pp.477-483
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• 2010

This paper is studied on a novel buck-boost isolated converter for high efficiency and high power factor. The switching devices in the proposed converter are operated by soft switching technique using a new quasi-resonant circuit, and are driven with discontinuous conduction mode (DCM) according to pulse width modulation (PWM). The quasi-resonant circuit makes use of a step up-down inductor and a loss-less snubber capacitor. The proposed converter with DCM also simplifies the requirement of control circuit and reduces a number of control components. The input ac current waveform in the proposed converter becomes a quasi sinusoidal waveform in proportion to the magnitude of input ac voltage under constant switching frequency. As a result, it is obtained by the proposed converter that the switching power losses are low, the efficiency of the converter is high, and the input power factor is nearly unity. The validity of analytical results is confirmed by some simulation results on computer and experimental results.