• Journal of information and communication convergence engineering
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• 제5권4호
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• pp.358-361
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• 2007

We report on a new type dc-dc converter design that combines the advantage of dc ripple noise elimination and high efficiency. As potential low cost solar cells, DSC module and the panel's system efficiency and stability are still critical problems to the way of marketing. In this study, a new three-step dc-dc converter scheme with the phase-shift-carrier technology is proposed to apply for solar power system. We have achieved power conversion efficiency around 94.88%.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2016년도 추계학술대회 논문집
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• pp.63-64
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• 2016

This paper deal with single module design of 13.2kVrms/10kVA solid state transformers exchanging conventional transformer. We can design compact hardware system to reduce size and get higher switching frequency by using SiC devices. As a result by comparing simulation results with experiment result, it is verified.

• 조명전기설비학회논문지
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• 제20권7호
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• pp.74-80
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• 2006

본 논문은 새로운 태양광 에너지 변환 기술에 의한 연계형 단상 인버터 제어기술을 나타내었다. 최대전력 점 추적제어는 두 부스터 컨버터의 MOSFET 스위치 제어 발생회로에 기초하고 단상 인버터는 풀 브리지의 4개 IGBT 스위치에 의해 전류 추종제어 된다. PV 모듈의 발생전력 제어회로는 PV 모듈의 출력 전압, 전류 검출에 의해 최대전력 점 제어한다. 결국 PV 모듈 양단은 인버터 입력전압으로 낮은 리플 전압을 유지하고 출력은 증가한다. 제안한 태양광 인버터 시스템의 효과가 시뮬레이션과 실험을 통하여 입증되었다.

• 전력전자학회논문지
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• 제23권6호
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• pp.433-439
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• 2018

This study considers the design of a submodule test circuit for the modular multi-level converter (MMC)-based HVDC systems. A novel submodule test circuit is proposed to provide not only an AC but also a DC component to the submodule current. However, the current waveforms depend on the capacitor voltages. Therefore, determining the capacitance value of the test circuit is important. Finding a proper capacitance value is easy when the proposed analysis method is used. Simulation and experimental results show the usefulness of the proposed method.

• 전력전자학회논문지
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• 제25권6호
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• pp.425-432
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• 2020

The phase-shifted, full-bridge (PSFB) DC-DC converter is widely used in electric vehicles (EVs) to charge a low-voltage (12 V) battery from a high-voltage battery. A Photovoltaic (PV) module-integrated PSFB converter is proposed for the EV power conversion system. The converter is useful because solar energy can be utilized to extend the driving range. The buck converter circuit is simply realized by adding one switch to the conventional PSFB converter's secondary side. For the inductor and diode, the existing components in the PSFB converter are shared. The proposed converter can charge a low-voltage battery from the PV module with maximum power point tracking. In addition, the two power sources can be used simultaneously, and efficiency is increased by reducing the circulating current, which is a problem for the conventional PSFB converter.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.1146-1147
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• 2008

PV Power Conditioning System (PCS) must have high conversion and low cost. Generally, PV PCS uses either a single converter or multilevel module integrated converter (MIC). Each of these approaches has both advantage and disadvantage. For a high conversion efficiency and low cost of PV module, this paper proposes series connection of module integrated DC-DC converter's output with PV panel. Output voltage of PV panel is connected to the output capacitor of flyback converter. Thus, converter's output voltage is added to the output voltage of PV panel. Isolated DC-DC converter generates only the difference voltage between the PV panel voltage and the required total output voltage. This method reduces power level of DC-DC converter and enhances the energy conversion efficiency compared with conventional DC-DC converter.

• 전력전자학회논문지
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• 제22권2호
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• pp.109-117
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• 2017

This paper describes the design and implementation of a unit module for a 10 kVA class 13.2 kV/220 V unidirectional solid-state transformer (SST) with silicon-carbide metal-oxide-semiconductor field-effect transistors. The proposed module consists of an active-front-end (AFE) converter to interface 1320 V AC voltage source to 2500 V DC link and an isolated resonant DC-DC converter for 500 V low-voltage DC output. The design approaches of the AFE and the isolated resonant DC-DC converters are addressed. The control structures of the converters are described as well. The experiments for the converters are performed, and results verify that the proposed unit module can be successfully adopted for the entire SST operation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 A
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• pp.181-183
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• 2003

This paper presents an operator training simulator for power system restoration against massive black-out. The system is designed especially focused on the generality and convenient setting up for initial condition of simulation. The former is accomplished by using on line calculation methodology, and PSS/E data is used to define the initial situation. The proposed simulator consists of three major components - the Power flow(PF) module, data conversion(CONV) module and CUI subsystem. PF module calculates power flow, and then checks overvoltage of buses and overflow of lines. CONV module composes an Y-Bus array and a data base at each restoration action. The initial Y-Bus array is constructed from PSS/E data. The user friendly GUI module is developed including graphic editor and built-in operation manual. As a result, the maximum processing time for one step operation is 15 seconds, which is adequate for training purpose. Comparison with PSS/E simulation proves the accuracy and reliability of the training system.

• Journal of Power Electronics
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• 제13권2호
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• pp.296-303
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• 2013

This paper proposes a high efficiency three-phase cascaded phase shifted H-bridge multi-level inverter without DC/DC converters for grid-tied multi string photovoltaic (PV) applications. The cascaded H-bridge topology is suitable for PV applications since each PV module can act as a separate DC source for each cascaded H-bridge module. The proposed phase shifted H-bridge multi-level topology offers advantages such as operation at a lower switching frequency and a lower current ripple when compared to conventional two level topologies. It is also shown that low ripple sinusoidal current waveforms are generated with a unity power factor. The control algorithm permits the independent control of each DC link voltage with a maximum power point for each string of PV modules. The use of the controller area network (CAN) communication protocol for H-bridge multi-level inverters, along with localized PWM generation and PV voltage regulation are implemented. It is also shown that the expansion and modularization capabilities of the H-bridge modules are improved since the individual inverter modules operate more independently. The proposed topology is implemented for a three phase 240kW multi-level PV power conditioning system (PCS) which has 40kW H-bridge modules. The experimental results show that the proposed topology has good performance.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 A
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• pp.35-42
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• 2003

We have studied DC energy conversion of RF card by wireless communication. In order to attain an objective, it used the system which is a Rectenna. The main purpose of energy conversion system is the operation of the circuits at RF-ID system. The proposed RF-ID system is a lot classified with the reader and tag. Reader is a kind of the base station role supporting RF energy. And priority tag convert RF energy from the reader it was delivered with a wireless to DC energy. The energy which is converted like Tag. It transmits to the reader characteristic ID of each card. The tag is mainly divided into rectifier, power module, memory and controller. The FRAM maintains the data like a ROM in no-power situation. And the advantage is a low power element compared with other EEPROM. There are two considerations, when RF energy is converted into DC source by wireless. One is energy amount supported from the reader, the other is high power efficiency. This paper presents a study of simulation and experiments on the RF-DC conversion circuit in tag by the power efficiency concentrated.