• 전력전자학회:학술대회논문집
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• 전력전자학회 1997년도 전력전자학술대회 논문집
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• pp.276-279
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• 1997

본 논문은 통신용전원장치와 같은 대용량의 DC 전원 장치에 적용하기 위하여 3상용 6 Switch로 구성된 Bridge로써 대용량 DC-DC converter에 적합한 Topology에 관한 것이다. 기본 동작은 기존의 Phase shifted ZVS PWM 방식을 사용하며, Bridge의 바깥쪽 양쪽암의 펄스폭을 제어하는데, 같은 펄스를 동시에 주는 방식과 각각 별도로 제어하는 방식, 두암의 위상을 지연시키는 방식에 관하여 연구하였다. 제안된 Topology들은 컴퓨터 시뮬레이션을 수행하여 그 동작특성을 확인하였고, 대용량에 적용할 수 있음을 확인하였다. 장치의 용량은 출력 500[A]/30[V] 회로를 구성하여 각각의 경우에 대하여 컴퓨터 시뮬레이션 결과를 제시하였다.

• Journal of Power Electronics
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• 제18권5호
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• pp.1501-1512
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• 2018

This paper proposes a three-phase three-switch buck-type converter as the MSC of a wind turbine system. Owing to a novel switching modulation scheme that can eliminate the unwanted diode rectifier mode switching state, the proposed system exhibits a satisfying ac voltage and current waveform quality and torque ripple up to the level of a typical current source rectifier even under a wide power factor operating range. The proposed system has been verified through simulations and HILS tests on a PMSG wind turbine model of 5MW/4160V. The proposed converter has been shown to provide a stator current THD of 3.9% and a torque ripple of 1% under the rated power condition. In addition to the inherent advantage of the reduced switch count of three-phase three-switch buck-type converters, the proposed switching modulation technique can make this converter a viable solution for the MSC placed inside of a nacelle, which is under severe volume, weight and mechanical vibration design limits.

• 전기학회논문지
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• 제58권9호
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• pp.1728-1734
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• 2009

This paper proposes a new power conditioning system for the fuel cell power generation, which consists of a ZVS DC-DC converter and 3-phase inverter. The ZVS DC-DC converter with a digital controller boosts the fuel cell voltage of 26-50V up to 400V, and the grid-tie inverter controls the active power delivered to the grid. The operation of proposed power conditioning system was verified through simulations with PSCAD/EMTDC software. The feasibility of hardware implementation was verified through experimental works with a laboratory prototype, which was built with 1.2kW PEM fuel-cell stack, 1kW DC-DC converter, and 3kW PWM inverter. The proposed system can be utilized to commercialize an interconnection system for the fuel-cell power generation.

• Journal of Power Electronics
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• 제9권3호
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• pp.410-417
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• 2009

This paper represents a design and implementation of a digital controller for a multi-phase synchronous buck converter (SBC) using a digital signal processor (DSP). The multi-phase SBC has generally been used for a voltage regulation module (VRM) of a microprocessor because of its high current handling capability at a low output voltage. The VRM requires high control performance of tight output regulation, high slew rate, and load sharing capability of multiple converters. In order to achieve these requirements, the design and implementation of a digital control system for a multi-phase SBC are presented in this paper. The digital PWM generation, current sensing, and voltage and current controller using a DSP TMS320F2812 are considered. The experimental results are provided to show the validity of the implemented digital control system.

• Journal of Power Electronics
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• 제13권3호
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• pp.339-348
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• 2013

Multiphase dc-dc converters are widely used in modern power electronics applications due to their advantages over single-phase converters. Such advantages include reduced current stress in both the switching devices and passive elements, reduced output current ripple, and so on. Although the output current ripple of a converter can be significantly reduced by virtue of the interleaving effect, the inductor current ripple cannot be reduced even with the interleaving PWM method. One way to solve this problem is to use a coupled inductor. However, care must be taken in designing the coupled inductor to maximize its performances. In this paper, a detailed analysis of a coupled inductor is conducted and the effect of a coupled inductor on current ripple reduction is investigated extensively. From this analysis, a UU core based coupled inductor structure is proposed to maximize the performance of the coupled inductor.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2013년도 전력전자학술대회 논문집
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• pp.275-276
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• 2013

In this paper, we proposed the Z-source four-switch three-phase rectifier. As we know, the conventional Four-Switch Three-Phase Rectifier(FSTPR) has advantages of the lower cost and less complex switching control. However, The conventional FSTPR can only either perform buck or boost operation, it can only attain the buck-boost operation by adding another DC-DC converter. In addition, besides its narrow output voltage region, distortion of the input current is serious either. Thus, we proposed the Z-source FSTPR which has buck-boost function and better input current waveform by applying the Z-impedance network to the conventional FSTPR. The validity of the proposed system was confirmed by experiments.

• 한국방사선학회논문지
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• 제4권3호
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• pp.31-37
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• 2010

본 논문에서는 태양광 발전시스템을 이용한 PWM(Pulse Width Modulation) 전압형 인버터를 전력변환기로 구성하였고, 안정된 변조를 위해서 동기신호와 제어신호를 56F8323 마이크로프로세서에 의해서 처리하였다. PWM 전압형 인버터는 태양전지가 연속 발전할 수 없는 단점을 보완하기 위해 일반 상용전원과 연계함으로써 약 10~20[%]의 전력 절감 효과를 얻을 수 있는 에너지 절약 전원 복합형 전력변환장치로 구성하였다. 그리고 PWM 전압형 인버터와 위상동기를 위해서 계통전압을 검출하고 계통전압과 인버터 출력을 동상 운전하므로 잉여전력을 계통과 연계할 수 있게 하였다. 또한, 고조파를 절감한 출력을 유지함으로써 부하와 계통에 전력이 안정하게 공급될 수 있도록 제어 시스템을 적용하여 좋은 결과를 얻을 수 있었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 추계학술대회 논문집 학회본부
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• pp.138-140
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• 1994

In this paper, a three-phase active power filter using voltage- source PWM converter is designed to eliminate the harmonics and compensate the reactive power in the ac side. The predictive current control method is adopted, which provides constant switching frequency and low current ripple but has inherently one sampling error between the command and the actual current. Here we propose the algorithm which corrects this delay time. The converter voltage obtained from this current control can be accomplished by the space vector modulation method at a voltage-type converter. All control sequences of active filter is executed by a DSP which is designed to calculate floating points at very hight speed. Finally, the validity of this filter using the predictive current control method is demonstrated through experimental results.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2017년도 전력전자학술대회
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• pp.451-452
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• 2017

본 논문에서는 3상 PWM 전압형 컨버터의 LCL필터 설계기법을 제안한다. 3상 전압형 컨버터는 스위칭으로 인한 고조파를 함유하고 있기 때문에, 입력측 고조파 감소를 위한 수동필터가 필수적이며, 용량, 입력역률, 입출력 조건 등 여러 가지 파라미터를 필요하기 때문에 설계하는 데에 어려운 단점이 있다. 이에 본 논문에서는 LCL필터의 최적 설계기준을 제안하며, 이에 대한 유효성을 입증하기 위해 PSIM 시뮬레이션을 통해 검증한다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2019년도 추계학술대회
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• pp.136-137
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• 2019

본 논문에서는 ADALINE (Adaptive-Linear-Neuron) 구조의 ANN(Artificial Neural Network)을 이용한 3상 PWM 컨버터의 개방고장 진단 방법에 대해 제안한다. 3상 PMW 컨버터에서 스위치의 개방고장이 발생한 경우 보호회로에 의해 시스템이 중단되지 않으며, 개방고장으로 인한 상전류의 고조파와 직류 성분에 의해 주변 기기에 고장에 의한 파급효과가 나타날 수 있다. 이에 본 논문에서는 ADALINE을 이용하여 각 상의 THD(Total Harmonics Distortion)와 직류 성분 얻고 대소비교를 통해 개방고장이 발생한 스위치를 진단하는 방법에 대해 제안한다.