• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 A
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• pp.443-445
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• 1995

Since the residential load is an AC load, while the output of solar cell is a DC power, the photovoltaic system needs the DC/AC converter to utilize solar cell and must provide the sinusoidal wave current and voltage with unity power factor in the case of driving to Interact with utility line. It is always necessary for the output of solar cell to operate in the vicinity of maximum power point, since it is greatly fluctuated by insolation. This paper treats that we will constitute a single phase PWM voltage source inverter and trace the modulation index which always maximize the output of solar cell in propotion to insolation variation and prove it by simulation that we can provide current wave, which is nearly sinusoidal wave with unity power factor, for load and utility line.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2005년도 춘계학술대회
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• pp.117-122
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• 2005

This paper proposes an inverter for the grid-connected photovoltaic system based on the transformer-less inverter. This system consists of a high frequency converter bridge, high frequency transformer, diode bridge rectifiers, a DC filter, a low frequency inverter bridge, and an AC filter. The high frequency converter bridge switching at 20kHz is used to generate bipolar PWM pulse, and the high frequency transformer raise its voltage twice, which is subsequently rectified by diode bridge rectifiers to result in a full-wave rectified sine wave. Finally, it is unfolded by a low frequency inverter bridge to result in a 60Hz sine wave power output. Even though the high frequency link system needs more power semiconductors, a reduced size, light weight, and saved parts cost make this system more comparative than the other systems due to elimination of 60Hz transformer.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 추계학술대회 논문집 전력기술부문
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• pp.89-91
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• 2007

In this paper, a remote monitoring system of wind-photovoltaic hybrid generation system using mobile phone and internet has been developed. Many kinds of data can be acquired, analyzed and saved automatically by this system. The hybrid system is composed of 1[kW] PV with DC/DC converter, battery banks and 5[kW] wind power system with power inductor and AC/DC converter. In addition, wind monitoring sensors, voltage and current meters, current transformers and potential transformers are used as accessory instruments. All of these signals are fed into DAQ (Data Acquisition) board after converting the data which have been processed by many types of converters, dividing circuits and signal conditioning circuits. These data can not only be displayed on a computer, transmitted using the server program to remote computer and saved on a computer as a file day by day but also be sent as a CDMA message. The monitored-data can be downloaded, analyzed and saved from server program in real-time via mobile phone or internet at a remote place. All of the programs were designed with LabVIEW software.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2010년도 하계학술대회 논문집
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• pp.291-292
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• 2010

The main purpose of this study is to design and develop the grid connected 4kW photovoltatic PCS(Power Conditioning System) targeting for Japanese market. To make this task, the development of DC to DC converter, one phase inverter and EMI filters, and the research on connection between inverter and utility line are made. The developed 4kW PCS has fully carried out performance verifications and evaluation works and acquired the JET(Japan Electrical Safety & Environment Technology Laboratories) certification for safety and performance.

• ETRI Journal
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• 제45권6호
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• pp.996-1006
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• 2023

Renewable energy is promoted massively to overcome problems that fossil fuel power plants generate. One popular renewable energy type that offers easy installation is a photovoltaic (PV) system. However, the energy harvested through a PV system is not optimal because influenced by exposure to solar irradiance in the PV module, which is constantly changing caused by weather. The maximum power point tracking (MPPT) technique was developed to maximize the energy potential harvested from the PV system. This paper presents the MPPT technique, which is operated on a new high-gain voltage DC/DC converter that has never been tested before for the MPPT technique in PV systems. Fuzzy logic (FL) was used to operate the MPPT technique on the converter. Conventional and adaptive perturb and observe (P&O) techniques based on variables step size were also used to operate the MPPT. The performance generated by the FL algorithm outperformed conventional and variable step-size P&O. It is evident that the oscillation caused by the FL algorithm is more petite than variables step-size and conventional P&O. Furthermore, FL's tracking speed algorithm for tracking MPP is twice as fast as conventional P&O.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.1039_1040
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• 2009

본 논문에서는 특성이 다른 두 에너지원인 연료전지와 태양광을 최적의 조건으로 복합발전할 수 있도록 새로운 단일 컨버터 및 단일 인버터 구조 및 전력제어 알고리즘을 제안한다. 제안된 회로 및 알고리즘의 타당성을 컴퓨터 시뮬레이션과 실험을 통해 검증한다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2012년도 전력전자학술대회 논문집
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• pp.269-270
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• 2012

이 논문에서는 Fly-Back-Converter로 Interleaving 동작하는 계통연계형 마이크로 인버터를 연구하고 200W급 태양전지 모듈에서 발생되는 전기에너지를 효율적으로 이용하여 계통에 연계하기 위한 전력변환시스템 개발을 목표로 하고 있다. 저렴하면서 효율이 높은 계통연계 인버터를 실현하기 위해서는 기존의 중앙집중식 인버터 구조와 다른 접근이 필요하다. 따라서 영전위 소프트 스위칭이 가능한 2병렬 인터리빙 구동의 Fly-Back DC/DC 컨버터 토폴로지로 입력 단 회로를 구성하여 모든 전력변환 동작이 일어나도록 한다. 출력전류를 사인파 open loop로 제어를 하고 CRM(Critical Conduction Mode) 스위칭 동작으로 높은 효율로 작동을 실현시켰다. 이 논문에서는 인터리빙으로 동작하였을 시 200W급 출력으로 나올 수 있는 전류 최대치를 계산 하였고 출력 전류가 사인파로 동작하게 제어방법을 기재하였다.

• 전기전자학회논문지
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• 제19권2호
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• pp.201-209
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• 2015

본 논문에서는 빛에너지 하베스팅을 이용한 MPPT(Maximum Power Point Tracking) 제어 기능을 갖는 배터리 충전기를 제안한다. 제안된 회로는 MPPT를 이용하여 빛 에너지를 PV(photovoltaic) 셀로부터 수확하고, 수확한 에너지를 배터리에 연결하여 충전한다. 배터리 관리 회로에서 출력되는 신호에 따라, 배터리의 충전 상태가 조절된다. MPPT 제어는 PV 셀의 개방회로 전압과 MPP 전압간의 비례관계를 이용하여, 보조(pilot) PV 셀로 하여금 주(main) PV 셀의 MPP를 실시간 추적할 수 있도록 설계하였다. 제안된 회로는 $0.35{\mu}m$ CMOS 공정으로 설계하였으며, 모의실험을 통해 성능을 검증하였다. 설계된 회로의 최대 효율은 86.2%이며 칩 면적은 패드를 포함하여$1.35mm{\times}1.2mm$이다.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2012년도 춘계학술발표대회 논문집
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• pp.153-159
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• 2012

In photovoltaic system, the characteristic of photovoltaic module such as open circuit voltage and short circuit current will be changed because of cell temperature and solar radiation. Therefore, a boost converter of the PV system connects between the output of photovoltaic system and DC link capacitor of grid connected inverter as controlling duty ratio for maximum power point tracking(MPPT). This paper shows the dynamic characteristic of the boost converter by comparing single-loop control algorithm and two-loop control algorithm using both analog and digital control. The proposed both compensation method has been verified with computer simulation and simulation results obtained demonstrate the validity of the proposed control schemes.

• Journal of Advanced Marine Engineering and Technology
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• 제28권6호
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• pp.916-921
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• 2004

This paper describes microprocessor-based control of photovoltaic power conditioning system. where the microprocessor is responsible for control of output power in accordance with the generated array DC power. The microprocessor includes the control algorithm of maximum power point tracking and converter control algorithm. In this power, we have designed a MPPT(Maximum Power Point Tracker) algorithm with environment factors and a PWM(Pulse Width Modulation) algorithm for high efficiency. The controller has been tested in the laboratory with the power conditioner and shows excellent performance.