• Proceedings of the KIPE Conference
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• 2013.07a
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• pp.477-478
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• 2013

This paper presents the control mehtod of a photovoltaic(PV) hybrid generation with energy storage system(ESS). To stabilize power control between PV generation system with ESS and local load, the proposed control method performs grid-connected and islanding operations. Through the simulation results the theoretical analysis of proposed method is verified.

• Proceedings of the KIPE Conference
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• 2001.07a
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• pp.135-137
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• 2001

Recently, according to developing industry and life style, power consumption have been increased year after year. Currently these much power demand from power consumer weakening the allowable power reverse margin in summer. As on of the remedies about this problem, the small scale grid-connected photovoltaic system is considered for auxiliary power source. Generally, grid-connected Inverter have a isolation transformer for electrical isolation from utility. This paper proposed transformerless system topology an inquiry validity simulation.

• Proceedings of the KAIS Fall Conference
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• 2010.05a
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• pp.67-70
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• 2010

국가차원의 신 재생에너지 활성화 방안에 따라 태양광, 풍력발전 등의 대규모 분산전원 단지의 도입이 이루어지고 있으며, 현재 배전계통의 전압조정 방법은 배전용 변전소의 부하시 탭 절환기(Under Load Tap Changer, 이하 ULTC)와 배전선로의 선로전압조정장치(Step Voltage Regulator, 이하 SVR)로 수용가에 규정전압(220${\pm}$6%)을 만족시키는 전압을 공급한다. 하지만 대규모의 태양광, 풍력 등의 분산 전원이 배전계통에 도입되는 경우, 전력품질[과전압/저전압]의 문제가 발생된다. 본 논문에서는 부하율에 따라 변화된 LDC 정정치를 적용 및 시뮬레이션을 통한 수용가 직하 및 말단의 규정전압(220${\pm}$6%) 즉 207V이하의 저전압, 233V이상의 과전압 여부를 검증함으로써 전력품질을 유지 할 수 있는 태양광전원이 연계된 배전계통의 최적전압운용 알고리즘을 개발하였다.

• Proceedings of the KIPE Conference
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• 2008.10a
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• pp.121-123
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• 2008

A high efficiency soft switching boost converter is proposed in this paper. The conventional boost converter generates switching losses at turn on and off. Because of those, the whole system efficiency is reduced. The proposed converter utilizes soft switching method using resonant circuit with an auxiliary switch. Therefore, the proposed converter reduces switching losses lower than the hard switching. The proposed soft switching boost converter can be applied to photovoltaic system, power factor correction circuit and etc.

• Proceedings of the KIPE Conference
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• 2014.07a
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• pp.217-218
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• 2014

전력 계통에 연계하는 신재생에너지 분산형 전원의 보급량이 지속적으로 늘어나면서 저압 계통의 공통 연계점에 다수대의 PCS(Power Conditioning System)가 집중적으로 설치되는 사례가 증가하고 있다. 최근 일본전기공업회(JEMA)는 계통 사고나 계획 정전 등으로 변전소 차단기가 개방되었을 때, 복수대 PCS의 능동방식이 서로 간섭을 일으켜 정해진 시간 내에 단독운전 검출기능이 작동하지 않게 되는 상황을 방지하기 위해 표준형 단독운전 능동적 방식을 공표하였다. 본 논문에서는 일본 단독운전 검출방식의 표준으로 지정된 스텝주입이 있는 주파수피드백 방식의 원리와 특징을 살펴보고, 이를 적용하여 연계 보호기능의 안전성 확보와 분산형 전원 보급에 기여하는 효과에 대해 소개하였다.

• Proceedings of the KIEE Conference
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• 2005.10c
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• pp.311-313
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• 2005

태양광 발전 시스템과 풍력 발전 시스템의 운전 특성을 분석하기 위해서 적용되는 방법은 매우 다양하다. 본 논문에서는 다양한 측정 분석 방법 중 원격지에 있는 시스템의 출력 및 운전 특성을 Compact Field Point라는 하드웨어와 제어계측 전문 Tool인 LabVIEW를 이용한 프로그래밍을 통하여 출력을 원격 모니터링하고 지장, 분석 할 수 있는 시스템을 구현하였다. 본 논문에서 구현된 시스템은 400W 규모의 소형 태양광/풍력 발전 시스템의 모니터링 시스템으로서 전압/전류/온습도/풍향/풍속 등의 다양한 환경을 측정 할 수 있도록 하였다.

• Proceedings of the KIPE Conference
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• 2002.07a
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• pp.571-575
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• 2002

Generation of electrical energy faces many problems today. Solar power converters were used to convert the electrical energy from the solar arrays to a stable and reliable power source. The object of this paper is to analyze and design DC-DC converters in a solar energy system to investigate the performance of the converters. A DC-DC converter can be commonly used to control the power flow from solar cell to load and to achieve maximum power point tracking(MPPT), DC-AC converter can also be used to modulate the DC power to AC power being applied on common utility load. A DC-DC converter is used to boost the solar cell voltage to constant 360(V) DC link and to ensure operation at the maximum power point tracking, If a wide input voltage range has to be covered a boost converter is required. In this paper, author described that simulation and experimental results of PV system contain solar modules, a DC-DC converter(boost type chopper), a DC-AC converter (3-phase inverter) and resistive loads.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.10
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• pp.1370-1374
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• 2018

A heterojunction $SnS_2/p-Si$ photodetector was fabricated by RF magnetron sputtering system. $SnS_2$ was formed with 2-inch $SnS_2$ target. Al was applied as the front and the back metal contacts. Rapid thermal process was conducted at $500^{\circ}C$ to enhance the contact quality. 2D material such as $SnS_2$, MoS2 is very attractive in various fields such as field effect transistors (FET), photovoltaic fields such as photovoltaic devices, optical sensors and gas sensors. 2D material can play a significant role in the development of high performance sensors, especially due to the advantages of large surface area, nanoscale thickness and easy surface treatment. Especially, $SnS_2$ has a indirect bandgap in the single and bulk states and its value is 2 eV-2.6 eV which is considerably larger than that of the other 2D material. The large bandgap of $SnS_2$ offers the advantage for the large on-off current ratio and low leakage current. The $SnS_2/p-Si$ photodetector clearly shows the current rectification when the thickness of $SnS_2$ is 80 nm compared to when it is 135 nm. The highest photocurrent is $19.73{\mu}A$ at the wavelength of 740 nm with $SnS_2$ thickness of 80 nm. The combination of 2D materials with Si may enhance the Si photoelectric device performance with controlling the thickness of 2D layer.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.3
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• pp.549-557
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• 2012

In this paper an on-chip photo energy harvesting system with MPPT(Maximum Power Point Tracking) control is proposed. The ISC(Integrated Solar Cell) is implemented using p-diff/n-well diodes available in CMOS processes. MPPT control is implemented using the linear relationship between the open-circuit voltage of a PV(Photovoltaic) cell and its MPP(Maximum Power Point) voltage such that a small pilot PV cell can track the MPP of a main PV cell in real time. Simulation results show that the designed circuit with the MPPT control delivers the MPP voltage to load even though the load is heavy such that the load circuit can operate properly. The proposed circuit is designed in 0.18um CMOS process. The designed main PV cell and pilot PV cell occupy $8mm^2$ and $0.4mm^2$ respectively.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.159-159
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• 2011

Among the semiconductor ternary compounds in the I-III-$VI_2$ series, $CulnS_2$ ($CulnSe_2$) are one of the promising materials for photovoltaic applications because of the suitability of their electrical and optical properties. The $CuInS_2$ thin film is one of I-III-$VI_2$ type semiconductors, which crystallizes in the chalcopyrite structure. Its direct band gap of 1.5 eV, high absorption coefficient and environmental viewpoint that $CuInS_2$ does not contain any toxic constituents make it suitable for terrestrial photovoltaic applications. A variety of techniques have been applied to deposit $CuInS_2$ thin films, such as single/double source evaporation, coevaporation, rf sputtering, chemical vapor deposition and chemical spray pyrolysis. This is the first report that $CuInS_2$ thin films have been prepared by Aerosol Jet Deposition (AJD) technique which is a novel and attractive method because thin films with high deposition rate can be grown at very low cost. In this study, $CuInS_2$ thin films have been prepared by Aerosol Jet Deposition (AJD) method which employs a nozzle expansion. The mixed fluid is expanded through the nozzle into the chamber evacuated in a lower pressure to deposit $CuInS_2$ films on Mo coated glass substrate. In this AJD system, the characteristics of $CuInS_2$ films are dependent on various deposition parameters, such as compositional ratio of precursor solution, flow rate of carrier gas, stagnation pressure, substrate temperature, nozzle shape, nozzle size and chamber pressure, etc. In this report, $CuInS_2$ thin films are deposited using the deposition parameters such as the compositional ratio of the precursor solution and the substrate temperature. The deposited $CuInS_2$ thin films will be analyzed in terms of deposition rate, crystal structure, and optical properties.