• 전기학회논문지
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• 제56권2호
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• pp.301-310
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• 2007

Bidirectional DC-DC converters allow transfer of power between two dc sources, in either direction. Due to their ability to reverse the direction of flow of power, Dey are being increasingly used in many applications such as battery charge/dischargers, do uninterruptible power supplies, electrical vehicle motor drives, aerospace power systems, telecom power supplies, etc. This Paper Proposes a new bidirectional Sepic/Zeta converter. It has low switching loss and low conduction loss due to auxiliary communicated circuit and synchronous rectifier operation, respectively Because of positive and buck/boost-like DC voltage transfer function(M=D/1-D), the proposed converter is very desirable for use in distributed power system. The proposed converter also has both transformer-less version and transformer one.

• 전기학회논문지
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• 제62권12호
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• pp.1688-1693
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• 2013

A small-scale wind power generation system with a switched-mode rectifier(SMR) is proposed. To simplify the converter circuit of the wind power generation system, the synchronous inductors of the permanent magnet synchronous generator(PMSG) replace the inductor for the boost converter. The sensorless maximum power point tracking(MPPT) control is carried out for the wind power generation system with the SMR. The proposed system is verified through the simulations and the experiments.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2012년도 추계학술대회 논문집
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• pp.175-176
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• 2012

본 논문에서는 동기정류 및 부트스트랩 회로를 이용한 Cascade Buck-Boost 컨버터의 전압 제어 및 동작 모드 변경 기법을 제안한다. 제안한 방법은 기존의 제어 방법에 비해 모든 전압 영역에서 안정적으로 승 강압 모드 변경이 가능하며 높은 효율을 갖는다. 이의 검증을 위해 우선 다양한 제어 기법을 소개하고, 각각을 전압 제어 특성 및 효율 측면에서 실험적으로 비교한다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2005년도 전력전자학술대회 논문집
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• pp.549-551
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• 2005

Bidirectional DC/DC converters allows transfer of power between two dc sources, in either direction. Due to their ability to reverse the direction of flow of power, they are being increasingly used in many applications such as battery charger/dischargers, dc uninterruptible power supplies, electrical vehicle motor drives, aerospace power systems, telecom power supplies, etc. This paper proposes a new bidirectional Sepic/zeta converter. It has low swicthing loss and low conduction loss due to auxiliary communicated circuit and synchronous rectifier operation, respectively. Because of positive and buck/boost-like DC voltage transfer function(M=D/1-D), the proposed converter is very desirable for use in distributed power system . The proposed converter also has both transformerless version and transformer one.

• Journal of Power Electronics
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• 제13권2호
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• pp.206-213
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• 2013

In this paper, an improved passive snubber is investigated in a single-phase single-stage full-bridge boost power factor correction (PFC) converter, by which the voltage spike across primary side of the power transformer can be suppressed and the absorbed energy can be transferred to the output side. When compared with the basic passive snubber, the two single-inductors are replaced by a coupled-inductor in the improved snubber. As a result, synchronous resonances in the snubber can be achieved, which can avoid the unbalance of the voltage and current in the snubber. The operational principle of the improved passive snubber is analyzed in detail based on a single-phase PFC converter, and the design considerations of both the snubber and the coupled-inductor are given. Finally, a laboratory-made prototype is built, and the experimental results verify the feasibility of the proposed method and the validity of the theoretical analysis and design method.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2017년도 추계학술대회
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• pp.1-2
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• 2017

본 논문은 영전압 스위칭을 갖는 고승압 캐스케이드 동기정류 부스트 컨버터를 제안한다. 제안된 컨버터는 캐스케이드 부스트 컨버터 기반으로 고승압을 달성하기 위해 결합 인덕터를 적용하였으며 컨버터의 효율 향상을 위해 추가 회로와 동기정류방식을 적용하여 기존 출력 다이오드의 도통 손실이 감소하였으며 영전압 스위칭을 달성하였다. 제안된 컨버터는 이론적 해석과 200[W]급 하드웨어 시작품을 제작하여 검증하였다.

• Journal of Electrical Engineering and Technology
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• 제8권1호
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• pp.97-105
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• 2013

The control method of the bidirectional DC/DC converter for instantaneous regenerative current control is described in this paper. The general method to control the DC/DC converter is the output voltage control. However, the regenerative current cannot be controlled to be constant with this control method. To improve the performance of the conventional control method, the DC-link voltage of the inverter is controlled within the tolerance range by the instantaneous boost and buck operations of the bidirectional DC/DC converter. By the proposed control method, the battery current can be controlled to be constant regardless of the motor speed variation. The improved performance of the DC/DC converter controlled by the proposed control method is verified by the experiment and simulation of the system with the inverter and IPMSM(Interior Permanent Magnet Synchronous Motor) which is operated by the reduced practical speed profile.

• Journal of Electrical Engineering and Technology
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• 제5권4호
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• pp.606-613
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• 2010

This paper proposes a novel current-based maximum power point tracking (CMPPT) method for a single-phase photovoltaic power conditioning system (PV PCS) by using a modified incremental conductance method. The CMPPT method simplifies the entire control structure of the power conditioning system and uses an inherent current source characteristic of solar cell arrays. Therefore, it exhibits robust and fast response under a rapidly changing environmental condition. Digital phase locked loop technique using an all-pass filter is also introduced to detect the phase of grid voltage, as well as the peak voltage. Controllers of dc/dc boost converter, dc-link voltage, and dc/ac inverter are designed for coordinated operation. Furthermore, a current control using a pseudo synchronous d-q transformation is employed for grid current control with unity power factor. A 3 kW prototype PV PCS is built, and its experimental results are given to verify the effectiveness of the proposed control schemes.

• 전기학회논문지
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• 제63권7호
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• pp.916-923
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• 2014

This paper proposes a low-cost switched-mode rectifier (SMR) for a small-scale wind turbine with a permanent magnet synchronous generator (PMSG) system. Also, a sensorless Fuzzy MPPT control is realized by the proposed system. In the PMSG system with the SMR, the synchronous impedance can be replaced as the input inductor of a boost converter. Moreover, the sensorless MPPT control using the Fuzzy technique is carried out by the duty-ratio regulation of the SMR. The relation between the generating power and the duty-ratio is ruled by the chain rule. The wind turbine model is implemented by the squirrel cage induction motor and generated the variable torque when the generator speed is varied. To verify the performance of the proposed system, simulation and experimental results are executed.

• 전력전자학회논문지
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• 제6권6호
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• pp.538-545
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• 2001

본 논문에서는 영구 자석형 동기 전동기를 이용한 고속 엘리베이터 시스템 용 무기어식 구동 시스템의 개발 사례를 소개한다. 엘리베이터 구동원으로서 영구 자석형 동기 전동기의 채택은 에너지 절약, 승차감 향상, 기계실의 하중 부담 감소 및 효율적인 공간 활용 등의여러 장점을 지닌다. 전력 변환 장치로는 기존의 다이오드 정류기와 제동 저항 대신 직류단 전압 제어 회생 운전 그리고 낮은 고조파 함유율이 역률 1 제어가 가능한 승압형 PWM 컴버터를 채택하였다. 제어 시스템은 고속 대용량의 단일 DSP를 사용하여 통합형 제어 시스템을 구축함으로써 전체 제어 시스템의 신뢰성 및 성능을 크게 향상시켰다. 시험 장치로는 고속 엘리베이터용 부사 시뮬레이터 시스템을 개발하여 운전 거리에 대한 제약 없이 구동 시스템의 다양한 시험이 가능해졌다.