• Journal of the Korean Solar Energy Society
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• v.33 no.2
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• pp.42-49
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• 2013

Recently, the attention to renewable energy has increased globally because of the environmental issue and the global energy crisis. Accordingly, south korea is focused on increasing the renewable energy usage. And the government enforced a law to the public buildings to install the renewable energy facilities. In this study, the building to evaluate renewable energy consumption and supply ratio was selected. This building has 9.79% of renewable energy supply ratio by PV system. In this study, the method for improving renewable energy supply ratio was analyzed using additional PV system. And The 5 methods to increasing electricity were evaluated. The method of increase 4.24 times PV arrays area is most efficient way to increase the renewable supply ratio. The case 1, show that the increasing renewable energy supply ratio of 39.2% compared to exsiting PV system. The result of the above, consider the additional supply of renewable energy.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.6
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• pp.1099-1106
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• 2017

In this paper, a three phase inverter control methodology for photovoltaic generation system, which is a renewable energy source, was studied. The voltage source inverter type of the constant voltage supply type was selected as the three phase photovoltaic inverter, and SWPM method was selected as control technique. a small capacity three phase photovoltaic inverter system, which has a DSP with powerful high speed data processing ability as the main controller and a solar controller as current controller to supply a certain amount of current to charge the battery, was made and tested for SPWM function.

• Proceedings of the Materials Research Society of Korea Conference
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• 2009.05a
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• pp.59.1-59.1
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• 2009

레독스 흐름 배터리 (Redox Flow Battery)는 외부의 탱크 등에 저장해 둔 활성물질(이온 가수가 변화는 금속) 의 용액을 펌프로 전해셀에 공급하여 충전 방전하는 배터리로 신재생 에너지인 풍력과 태양광 발전, 야간의 잉여 전력 저장 등 대용량 전력 저장 장치로 관심이 높아지고 있다. 대표적인 레독스 흐름 배터리로 알려진 바나듐 레독스 흐름 배터리는 이온 교환막 사용으로 인하여 전기전도도, 기계적 강도, 투과도 및 전해질 내의 화학적 안정성 등 여러 가지 문제점과 함께 비용 문제점을 야기한다. 하지만 새로운 용해 납 레독스 흐름 배터리는 이온 교환막을 사용하지 않아 바나듐 레독스 흐름 배터리의 문제점 및 시설비가 절약되는 장점이 있어 새로이 연구되지고 있다. 본 연구는 레독스 흐름 배터리에 주로 이용되는 카본 전극재료의 따라 형성되는 Pb, $PbO_2$ 박막의 미세 구조를 및 에너지 효율 특성을 분석하였다. 실험은 half-cell로 이루어졌으며 작업전극은 Carbon felt, Ordered Graphite, Disordered Graphite, Glassy Carbon 등을 여러 카본 재료를 사용하였고, 상대전극은 Pt, 기준전극으로 Ag/AgCl를 사용하여 Cyclic Voltammetry특성과 충방전 특성을 연구하였다. 전해질은 Lead Carbonate ($PbCO_3$)+Methanesulfonic acid ($CH_3SO_3H$) 들어간 수용성 전해질을 교반을 통해 이용하였다. 여러 carbon 전극재료와 생성된 Pb, $PbO_2$ 막의 표면구조, 미세구조, 상들의 변화는 XRD, SEM, EDX, Raman등을 통하여 분석하였으며, 전기화학 공정의 변수와 전극에 따른 에너지 효율특성에 대하여 고찰해 보았다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.12
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• pp.1777-1783
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• 2021

The use of drones is gradually increasing for the efficient maintenance of large-scale renewable energy power generation complexes. For a long time, photovoltaic panels have been photographed with drones to manage panel loss and contamination. Various approaches using artificial intelligence are being tried for efficient maintenance of large-scale photovoltaic complexes. Recently, semantic segmentation-based application techniques have been developed to solve the image classification problem. In this paper, we propose a classification model using semantic segmentation to determine the presence or absence of failures such as arcs, disconnections, and cracks in solar panel images obtained using a drone equipped with a thermal imaging camera. In addition, an efficient classification model was implemented by tuning several factors such as data size and type and loss function customization in U-Net, which shows robust classification performance even with a small dataset.

• Journal of Adhesion and Interface
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• v.25 no.1
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• pp.143-151
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• 2024

Organic photovoltaics (OPVs) have shown great potential as a new generation of energy harvesters because they possess many unique properties, including mechanical flexibility, lightweight, semi-transparency, and low-fabrication costs. Recent advancements in molecular structure and device engineering have led to achieving power conversion efficiency (PCE) exceeding 19%. However, these highly efficient active layer materials have been hampered in their commercialization by complex synthesis steps that result in high manufacturing costs. To address this issue, research is actively underway on low-cost active layer materials with simple structures. This paper introduces such cost-effective active layer materials and strategies for their synthesis.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.11
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• pp.672-682
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• 2020

The Korea Nowadays, which is research on digital twin technology for efficient operation in various industrial/manufacturing sites, is being actively conducted, and gradual depletion of fossil fuels and environmental pollution issues require new renewable/eco-friendly power generation methods, such as wave power plants. In wave power generation, however, which generates electricity from the energy of waves, it is very important to understand and predict the amount of power generation and operational efficiency factors, such as breakdown, because these are closely related by wave energy with high variability. Therefore, it is necessary to derive a meaningful correlation between highly volatile data, such as wave height data and sensor data in an oscillating water column (OWC) chamber. Secondly, the methodological study, which can predict the desired information, should be conducted by learning the prediction situation with the extracted data based on the derived correlation. This study designed a workflow-based training model using a machine learning framework to predict the pressure of the OWC. In addition, the validity of the pressure prediction analysis was verified through a verification and evaluation dataset using an IoT sensor data to enable smart operation and maintenance with the digital twin of the wave generation system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.9
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• pp.1808-1818
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• 2015

Recently, the wind power has experienced great attentions and growths among many renewable energy sources. To increase the power generation performance and economic feasibility, the size of wind turbine (WT) is getting bigger and most of wind power plants are being constructed on offshore. Therefore, the maintenance cost is relatively high because boats or helicopters are needed operators to reach the WT. In order to combat this kind of problem, remote monitoring and control system for the WT is needed. In this paper, the small-scale WT monitoring and control system is implemented using wireless sensor network technologies. To do this, sensor devices are installed to measure and send the WT status and control device is installed to receive control message for specific operation. The WT is managed by control center through graphic user interface (GUI) based monitoring and control software. Also, smart device based web-program is implemented to make the remote monitoring of the WT possible even though operators are not in control room.

• Journal of Ocean Engineering and Technology
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• v.26 no.4
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• pp.37-41
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• 2012

Due to global warming, the need to secure alternative resources has become more important nationally. Because of the very strong current on the west coast, with a tidal range of up to 10 m, there are many suitable sites for the application of TCP (tidal current power) in Korea. In the southwest region, a strong current is created in the narrow channels between the numerous islands. A rotor is an essential component that can convert tidal current energy into rotational energy to generate electricity. The design optimization of a rotor is very important to maximize the power production. The performance of a rotor can be determined using various parameters, including the number of blades, shape, sectional size, diameter, etc. There are many offshore jetties and piers with high current velocities. Thus, a VAT (vertical axis turbine) system, which can generate power regardless of flow direction changes, could be effectively applied to cylindrical structures. A VAT system could give an advantage to a caisson-type breakwater because it allows water to circulate well. This paper introduces a multi-layer vertical axis tidal current power system. A Savonius turbine was designed, and a performance analysis was carried out using CFD. A physical model was also demonstrated in CWC, and the results are compared with CFD.

• Journal of Advanced Navigation Technology
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• v.18 no.2
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• pp.165-169
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• 2014

Digital load is increasing suddenly for various reasons, such as easy control and management. Accordingly, a consumption pattern of load is becoming DC. However, the power supply is supplied by AC power. The load power supply substantially needs DC power. AC power has to be converted to DC power. Renewable energy sources like solar, wind, fuel cells are DC power generation, but the transfer needs to through by AC power, thus DC power has to be converted to AC power. Resultantly, a multi-stage conversion loss is constantly increasing. The power distribution system of DC-based is required for effective use of these energy sources. This requires a DC load, as well as is necessary to develop DC ELCB which are able to detect DC leakage current for implementing protection. In this study, it realize detection algorithm about DC leakage current to verify the performance of the sensor and apply it to the ELCB which is based on DC. Therefore, it is expected to protect operating of DC power distribution system.

• Journal of Advanced Navigation Technology
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• v.19 no.3
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• pp.250-256
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• 2015

Digital load is increasing suddenly for various reasons, such as easy control and management. Accordingly, a consumption pattern of load is becoming DC. However, the power supply is supplied by AC power. The load power supply substantially needs DC power. AC power has to be converted to DC power. Renewable energy sources like solar, wind and fuel cells are DC power generation, but the transfer needs to through by AC power, thus DC power has to be converted to AC power. Resultantly, a multi-stage conversion loss is constantly increasing. The power distribution system of DC-based is required for effective use of these energy sources. This requires a DC load, as well as is necessary to develop DC breaker. This study is expect for system and equipment for reliable DC power distribution through the study of the arc extinguish technology for direct current a hybrid arc extinguishing technology with permanent magnets technology.