• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.1400-1401
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• 2011

RPS(Renewable Portfolio Standard) recently with the introduction of a new solar power development as the market expands, land shortage of solar power as an alternative site for installing solar water development has emerged. Solar water dams, reservoirs and water by taking advantage of available solar power development a new concept of private forest land in a way does not involve destruction of the forest land and water resources through efficient use of environmentally friendly energy production and water quality improvement There are a variety of benefits. This paper won the nation's first solar power to enforce the selection of the optimal location for solar power's award for planning theory and research techniques are intended to establish. Award of the solar system through the analysis of a few research-related materials and renewable energy systems project implementation process to establish an initial investigation techniques as well as the existing dam located about fitness will be assessed. In this study, solar water conducting business in the current analysis with considerable planning and installation of solar installation for the economic and environmental cost of the evaluation period and is expected to be able to give you one.

• 조명전기설비학회논문지
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• 제17권6호
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• pp.23-30
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• 2003

본 논문에서는 계통과 원활히 동작할 수 있는 계통 연계형 태양광 발전시스템에 대한 특성을 해석하고 이론을 바탕으로 제작된 실 시스템을 적용$.$운용시 시스템의 운전특성 및 발전량을 비교 분석하였다. 그 결과로서 구조적인 문제점과 관리적인 문제점을 도출하고, 이러한 문제점에 대한 대책으로서 설치될 장소의 장기적인 일사량 측정 데이터수집을 동하여 최적의 일사량을 얻을 수 있는 지역설정과 최적의 설치형태를 설계함으로서 발전효율을 높일 수 있다. 또한, 운영시스템 및 모니터링 관리가 현행의 OS시스템으로서는 해결이 불가능한것을 전용의 OS개발과 데이터 백업 시스템을 구축함으로서 실 시스템 운용상의 문제점을 해결할 수 있었다.

• 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 Electrical Engineering and Technology
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• 제10권3호
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• pp.786-794
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• 2015

In this paper, a new power control strategy for the bipolar-type low voltage direct current (LVDC) distribution system is being proposed. The dc distribution system is considered as an innovative system according to the increase of dc loads and dc output type distribution energy resources (DERs) such as photovoltaic (PV) systems and energy storage systems (ESS). Since the dc distribution system has many advantages such as feasible connection of DERs, reduction of conversion losses between dc output sources and loads, no reactive power issues, it is very suitable solution for new type buildings and residences interfaced with DERs and ESSs. In the bipolar-type, if it has each grid-interfaced converter, both sides (upper, lower-side) can be operated individually or collectively. A complementary power control strategy using two ESSs in both sides for effective and reliable operation is proposed in this paper. Detailed power control methods of the host controller and local controllers are described. To verify the performances of the proposed control strategy, simulation analysis using PSCAD/EMTDC is being performed where the results show that the proposed strategy provides efficient operations and can be applied to the bipolar-type dc distribution system.

• 전력전자학회논문지
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• 제18권1호
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• pp.54-62
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• 2013

This paper proposes a high-efficiency DC-DC converter with improved dynamic response characteristics for modular photovoltaic power conversion. High power efficiency is achieved by reducing switching power losses of the DC-DC converter. The voltage stress of power switches is reduced at primary side. Zero-current switching of output diodes is achieved at secondary side. A modified proportional and integral controller is suggested to improve the dynamic responses of the DC-DC converter. The performance of the proposed converter is verified based on a 200 [W] modular power conversion system including the grid-tied DC-AC inverter. The proposed DC-DC converter achieves the efficiency of 97.9 % at 60 [V] input voltage for a 200 [W] output power. The overall system including DC-DC converter and DC-AC inverter achieves the efficiency of 93.0 % when 200 [W] power is supplied into the grid.

• Current Photovoltaic Research
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• 제6권1호
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• pp.17-20
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• 2018

The dependency of the photovoltaic performance of p-/n-type silicon solar-cells on the metallic contaminant type (Fe, Cu, and Ni) and concentration was investigated. The minority-carrier recombination lifetime was degraded with increasing metallic contaminant concentration, however, the degradation sensitivity of recombination lifetime was lower at n-type than p-type silicon wafer, which means n-type silicon wafer have an immunity to the effect of metallic contamination. This is because heavy metal ions with positive charge have a much larger capture cross section of electron than hole, so that reaction with electrons occurs much more easily. The power conversion efficiency of n-type solar-cells was degraded by 9.73% when metallic impurities were introduced in the silicon bulk, which is lower degradation compared to p-type solar-cells (15.61% of efficiency degradation). Therefore, n-type silicon solar-cells have a potential to achieve high efficiency of the solar-cell in the future with a merit of immunity against metal contamination.

• 전력전자학회논문지
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• 제15권3호
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• pp.179-187
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• 2010

본 논문에서는 무효전력변동기법을 사용하여 단독운전을 검출을 하기 위해서 선행되어야 하는 주파수 검출 방법 중에서 개선된 이산푸리에변환(Discrete Fourier Transform; DFT), 즉 Goertzel 알고리즘을 이용한 단독운전 검출기법을 제안한다. 실제 태양광 발전 시스템의 설치를 위해서는 전기사고나 시스템에 악영향을 유발하는 단독운전 검출기법의 연구가 선행되어야 한다. 적용하는 주파수 검출방법은 Goertzel 알고리즘을 이용한 기법으로 기존의 영점검출기법과 가상의 2상 PLL(Phase Locked Loop)에 비하여 외란의 영향에 강인하며 빠른 검출이 가능하다. 시뮬레이션 및 실험을 통하여 기존의 주파수검출기법인 영점검출기법과 가상의 2상 PLL을 이용한 주파수 검출과 제안하는 알고리즘을 비교하고 그의 우수성을 검증하였다.

• Current Photovoltaic Research
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• 제3권1호
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• pp.1-4
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• 2015

In this study, we analyzed the correlation between mechanical and electrical properties of low-temperature conductive film (LT-CF) bonded silicon solar cells by a quadrant analysis (horizontal axis (peeling strength), vertical axis (power loss)). We found that a series of points with various bonding parameters such as bonding temperature, pressure and time were distributed in the different three regimes; weak regime (Q2: weak bonding strength and high power loss), moderate regime (Q4 : strong bonding strength and low power loss) and hard regime (Q3 : weak bonding strength and low power loss). Using this analogous technique, it was possible to fabricate the LT-CF bonded silicon solar cells with the various conditions displayed in Q3 of the quadrant plots, possessing the peeling strength of ~ 1N/mm and power loss of 2~3%.

• Current Photovoltaic Research
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• 제6권4호
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• pp.109-118
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• 2018

Silicon (Si) solar cells are the most successful technology which are ruling the present photovoltaic (PV) market. In that essence, multijunction (MJ) solar cells provided a new path to improve the state-of-art efficiencies. There are so many hurdles to grow the MJ III-V materials on Si substrate as Si with other materials often demands similar qualities, so it is needed to realize the prospective of Si tandem solar cells. However, Si tandem solar cells with MJ III-V materials have shown the maximum efficiency of 30 %. This work reviews the development of the III-V/Si solar cells with the synopsis of various growth mechanisms i.e hetero-epitaxy, wafer bonding and mechanical stacking of III-V materials on Si substrate. Theoretical approaches to design efficient tandem cell with an analysis of state-of-art silicon solar cells, sensitivity, difficulties and their probable solutions are discussed in this work. An analytical model which yields the practical efficiency values to design the high efficiency III-V/Si solar cells is described briefly.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2019년도 전력전자학술대회
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• pp.11-13
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• 2019

This paper proposes a novel high step-up non-isolated DC-DC converter, suitable for regulating dc bus in various inherent low voltage micro sources especially for photovoltaic (PV) and fuel cell sources. This novel high voltage Non-isolated Boost DC-DC converter topology is best replacement, where high voltage conversion ratio is required without the transformer and also need continuous input current. Since the proposed topology utilizes the stack-based structure, the voltage gain, and the efficiency are higher than other conventional non-isolated converters. Switches in this topology is easier to control since its control signal is grounding reference. Also, there is no need of extra gate driver and extra power supply for driver circuit, which reduces the cost and size of system. In order to show the feasibility and practicality of the proposed topology principle operation, steady state analysis and simulation result is presented and analyzed in detail. To verify the performance of proposed converter and theoretical analysis 360W laboratory prototype is implemented.