• Current Photovoltaic Research
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• 제11권2호
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• pp.44-48
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• 2023

In heterojunction technology (HJT) solar cells, low-temperature curing paste is used because the passivation layer deteriorates at high temperatures of 200℃ or higher. However, manufacturing HJT photovoltaic (PV) modules is challenging due to the weak peel strength between busbar electrodes and cells after soldering process. For this issue, the electrode thicknesses of the busbars of the HJT solar cell were analyzed, and the peel strengths between electrodes and wires were measured after soldering using an infrared (IR) lamp. As a result, the electrodes printed by the screen printing method had a difference in thickness due to screen mask. Also, as the thickness of the electrode increased, the peel strength of the wire increased.

• Transactions on Electrical and Electronic Materials
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• 제17권6호
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• pp.359-362
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• 2016

In the PV (Photovoltaic) power system, a junction box collects the DC voltage generated from the PV module and transfers it to the PCS (power conditioning system). The junction box prevents damage caused by the voltage difference between the serially connected PV modules and provides convenience while repairing or inspecting the PV array. In addition, the junction box uses the diode to protect modules from the inverse current when the PV power system and electric power system are connected for use. However, by using the reverse blocking diode, heat is generated within the junction box while generating electric power, which decreases the generating efficiency, and causes short circuit and electric leakage. In this research, based on the purpose of improving the performance of the PV module by decreasing the heat generation within the junction box, a junction box with a built-in bypass circuit was designed/manufactured so that a certain capacity of current generated from the PV module does not run through the reverse blocking diode. The manufactured junction box was used to compare the electric power and heating power generated when the circuit was in the bypass/non-bypass modes. It was confirmed that the electric power loss and heat generation indicated a decrease when the circuit was in the bypass mode.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2006년도 전력전자학술대회 논문집
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• pp.488-491
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• 2006

In this paper proposed method of maximum power point tracking using boost converter for a connected single phase inverter with photovoltaic system. The maximum power point tracking control is based on generated circuit control MOSFET switch of boost converter and single phase inverter uses predicted current control to control four IGBT's switch in full bridge. The predicted current control provide current with sinusoidal wave shape and inphase with voltage. The generation control circuit allows each photovoltaic module to operate independently at peak capacity, simply by detecting of the output power of the system. Furthermore, the generation control circuit attenuates low-frequency ripple voltage, which is caused by the full-bridge inverter, across the photovoltaic modules. Consequently, the output power of system is increased due to the increase in average power generated by the photovoltaic modules. The effectiveness of the proposed inverter system is confirmed experimentally and by means of simulation.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2009년도 추계학술발표대회 논문집
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• pp.303-308
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• 2009

In 2008, the global photovoltaic(PV) market reached 5.6GW and the cumulative PV power installed totalled almost 15GW compared to 9GW in 2007. Due to a favourable feed-in-tariff, Korea emerged in 2008 as the 4th largest PV market worldwide. PV power installation rose 495.5 percent to 268MW in 2008 compare to 45MW in 2007. However many PV systems are not installed in suitable part which is concerned about geometrical factor. It is generally recognized that the actual output of PV system in field is a function of orientation, tilt angle, irradiance, temperature, soiling and various system-related losses. Thus this paper shows that a experimental result of PV modules(A group) with uniform azimuth angle and PV modules(B group) with non-uniform azimuth angle. As a result, the electrical output of B group is decreased 48.8% as compared with electrical output of A group.

• 세라미스트
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• 제22권2호
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• pp.122-132
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• 2019

Wearable electronic devices with batteries must be lightweight, flexible and highly durable. Most importantly, the battery should be able to self-generate to operate the devices without having to be too frequently charged externally. An eco-friendly energy harvesting technology from various sources, such as solar energy, electromagnetic energy and wind energy, has been developed for a self-charging flexible battery. Although the energy harvesting from such sources are often unstable according to the surrounding environment, the energy harvesting from body movements and vibrations has been less affected by the surrounding environment. In this regard, flexible piezoelectric modules are the most attractive solution for this issue, because they convert mechanical energy to electrical energy and harvest energy from the human body motions. Among the various flexible piezoelectric modules, piezoelectric nanofibers have advantages when used as an energy harvester in wearable devices, due to their simple manufacturing process with good applicability to polymers and ceramics. This review focused on diverse flexible piezoelectric nanofibers and discusses their applications as various energy harvesting systems.

• 한국전기전자재료학회논문지
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• 제33권6호
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• pp.439-444
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• 2020

An increase in the temperature of photovoltaic (PV) modules causes reduced power output and shorter lifetime. Because of these characteristics, demands for the heat dissipation of PV modules are increasing. In this study, we attached a heat dissipation sheet to the back sheet of a shingled PV module and observed the temperature changes. The PV shingled module was tested under Standard Test Conditions (STCs; irradiance: 1,000 W/㎡, temperature: 25℃, air mass: 1.5) using a solar radiation tester, wherein the temperature of the PV module was measured by irradiating light for a certain duration. As a result, the temperature of the PV module with the heat dissipation sheet decreased by 3℃ compared to that without a heat dissipation sheet. This indicated that the power loss was caused by a temperature increase of the PV module. In addition, it was confirmed that the primary parameter contributing to the reduced PV module output power was the open circuit voltage (Voc).

• 한국멀티미디어학회논문지
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• 제22권2호
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• pp.194-202
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• 2019

In the information society represented by the Fourth Industrial Revolution, various types of data and information that are difficult to see are produced, processed, and processed and circulated to enhance the value of existing goods. The IoT(Internet of Things) paradigm will change the appearance of individual life, industry, disaster, safety and public service fields. In order to implement the IoT paradigm, several elements of technology are required. It is necessary that these various elements are efficiently connected to constitute one system as a whole. It is also necessary to collect, provide, transmit, store and analyze IoT data for implementation of IoT platform. We designed and implemented a big data processing IoT platform for IoT service implementation. Proposed platform system is consist of IoT sensing/control device, IoT message protocol, unstructured data server and big data analysis components. For platform testing, fixed IoT devices were implemented as solar power generation modules and mobile IoT devices as modules for table tennis stroke data measurement. The transmission part uses the HTTP and the CoAP, which are based on the Internet. The data server is composed of Hadoop and the big data is analyzed using R. Through the emprical test using fixed and mobile IoT devices we confirmed that proposed IoT platform system normally process and operate big data.

• 한국태양에너지학회 논문집
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• 제39권5호
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• pp.1-10
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• 2019

Recently, the installation capacity of PV (photovoltaic) systems has been increasing not only field installation but also floating PV, farm land, BIPV/BAPV. For this reason, the new design and materials of PV module are needed. In particular, in order to apply a PV system to a building, lightweight of the PV module is essential. PV modules made of generally used texturing glass are excellent in output and reliability, but there is a limit to the weight that can be reduced. For the lightweight of the PV module, it necessary to use a film instead of a glass. However, the application of film rather than a glass may cause various problems such as decrease in photocurrent by decrease in transmittance and a increase of CTM (cell to module) loss, a degradation of the reliability, and so on. In this paper, PV modules using Ultra barrier film, which is recently a lot of interest as a substitute for a glass, its characteristic analysis and reliability test were conducted. The transmittance and UV characteristics of each material were verified, and the output of the fabricated 1 cell PV module was measured. In addition, 24 cell PV modules were fabricated at the lab-scale and its reliability tests were conducted. As a result of the experiment, the reliability characteristics of the ultra barrier film PV module were excellent, and it was confirmed that it could be used as the front material of the PV module instead of glass

• 마이크로전자및패키징학회지
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• 제26권4호
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• pp.75-82
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• 2019

유연 태양 전지는 최근 휴대용 배터리, 웨어러블 소자, 로봇, 드론 및 비행기와 같은 광범위한 응용 분야로 인해 큰 주목을 받고 있다. 특히, 고효율 및 높은 신뢰성을 갖는 유연 실리콘 및 화합물 반도체 태양 전지의 요구가 계속 증가하고 있다. 본 연구에서는 유연 InGaP/GaAs 2중 접합 태양전지 모듈을 개발하였다. 특히 제작된 유연 태양전지 모듈의 신뢰성을 확보하기 위하여, 풍속 및 주위 온도가 태양 전지 작동 온도에 미치는 영향을 수치해석으로 분석하였다. 3종류의 풍속(0 m/s, 2.5 m/s 및 5 m/s) 및 2종류의 주변 온도 조건(25℃ 및 33℃)에 대하여 태양 전지 모듈의 온도 분포를 해석하였다. 유연 태양전지 모듈의 유연성은 굽힘 시험 및 굽힘 수치해석을 통하여 평가하였다. 25℃ 온도조건에서 풍속이 0 m/s 일 때, 태양 전지 셀의 최대 온도는 149.7℃이다. 풍속이 2.5 m/s로 증가되었을 경우, 태양 전지의 온도는 66.2℃로 크게 감소되었다. 또한 풍속이 5 m/s 인 경우, 태양 전지의 온도는 48.3℃로 급격히 감소함을 알 수 있었다. 주변 온도 또한 태양 전지의 작동 온도에 영향을 미친다. 2.5 m/s의 풍속에서 주변 온도가 33℃로 증가할 경우, 태양 전지의 온도는 74.2℃로 약간 증가하였다. 따라서 태양 전지 셀의 온도에 영향을 미치는 가장 중요한 인자는 풍속으로 인한 열 방출 효과임을 알 수 있었다. 또한 태양 전지의 최대 온도는 사용된 소재들의 유리 전이 온도보다 낮기 때문에, 열 변형 및 모듈의 열화 가능성은 매우 낮을 것으로 예측된다. 제작된 태양전지 모듈은 굽힘 반경 7 mm까지 굽힐 수 있어 비교적 우수한 유연성을 갖고 있었다. 또한 향후 neutral plane 해석을 통하여 태양전지 셀을 neutral plane에 위치시키면 유연성이 크게 증가할 것으로 예측된다.

• 한국인터넷방송통신학회논문지
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• 제20권3호
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• pp.129-134
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• 2020

최근 태양전지 모듈 내부에 습기 침투 및 EVA Sheet의 배부름 현상, 프레임 Seal이 녹아내리는 현상, 설치 후 1년 지난 모듈에서 발전성능이 저하되는 현상 등이 발생하고 있다. 국내에 5~7년 이전에 설치된 태양전지 모듈에서 백화현상 및 전극 부식 현상, 절연파괴 현상 등이 나타나기 시작하여 발전성능 저하로 이어지고, 장기 신뢰성 및 장수명 기술에 대한 커다란 문제점이 대두되고 있다. 따라서 이러한 문제점들을 해결하기 위해 태양전지 모듈의 내구성 확보 및 노화 진행을 모니터링할 수 있는 기능을 포함하는 마이크로 인버터 (MiCrco Inverter Converter, 이하 MiC) 개발 및 MiC에서 모니터링 데이터를 기반으로 태양전지 모듈의 노화를 판단할 수 있는 스마트 모니터링 프로그램이 제시되고 있다. 또한, 태양전지 모듈의 모니터링 기능을 강화한 MiC와 IT 융합을 통한 체계적 운영 관리를 통한 고효율 태양광 스마트 감시 시스템이 되기 위해서는 MiC 내의 SoC (System On Chip)는 태양전지 모듈에 대한 환경정보를 복합적으로 감지하고 필요시 통신 및 제어를 수행할 수 있는 기능들이 요구되고 있다. 이러한 요구사항들을 기반으로 본 논문에서는 SoC 기반 보급형 MIC 스마트 태양광발전시스템 기술개발을 목적으로 연구하고자 한다.