• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.2
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• pp.36-44
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• 2013

This paper proposes the reconfiguration of PV module considering shadow influence of photovoltaic system. The PV system is consisted series-parallel connection of PV module. The voltage and current between PV modules become unbalance when shadow occurs to PV module. If shadow occurs to the series connection PV module, the output current is limited to current of shaded PV module. Also if shadow occurs to the parallel connection PV module, the output voltage is limited to voltage of shaded PV module. These problems are caused power loss. Therefore, the PV module in this paper consist using the fixed module and variable module by shaded conditions. The reconfiguration of PV module can compensates the shadow influence by changing connection of a variable module when shadow is occurred to PV module. A validity of the reconfiguration of PV module proposed in this paper proves through comparing with performance of conventional PV module.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.2
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• pp.31-41
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• 2014

This paper proposes the configuration of photovoltaic(PV) module considering the environment conditions of the PV system. The PV system is consisted of the series-parallel connection of the PV module. When shadows or changes of the radiation or an electrical characteristic in the solar cell are happened to PV system, the serious power loss will occur. If the PV module connected in series has the shadows, the output current is restricted to current of shaded PV module. Also if shadow is occurred to the parallel connection PV module, the output voltage is limited to voltage of shaded PV module. These problems are caused power loss. Therefore, this paper proposes the method that makes the output power of the PV module equalize by reconfiguration of PV module using the switching considering these environment conditions. A validity of the method proposed in this paper proves through comparing with performance of conventional PV module.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.424.2-424.2
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• 2016

Solar cell converts light energy to electric energy. But a solar cell generates low power, PV module is fabricated by connected in series with dozens of solar cell. Owing to solar cell connected in series, power of PV module is influenced by shading or mismatch power of solar cells. To prevent power loss of PV module by shading or mismatch current, Bypass diodes are installed in PV module. Bypass diode operating reverse voltage by shading or mismatch power of solar cells bypass mismatch current. However, bypass diode in module exposed outdoor is easily damaged by surge voltage. In this paper, we confirm characteristics variation of PV module with damaged bypass diode. As a result, power of PV module with damaged bypass diode is reduced and Temperature of that is increased.

• 한국태양에너지학회:학술대회논문집
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• 2008.11a
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• pp.36-41
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• 2008

In this paper, we study The Effects of PV Cell's Electrical Characteristics for PV Module Application. Photovoltaic module consists of serially connected solar cell which has low open circuit voltage and high short circuit current characteristics. The whole current flow of PV module is restricted by lowest current of one solar cell. For the experiment, we make PV module composing the solar cells that have short circuit current difference of 0%, 1%, 3% and Random. The PV module exposed about 35days, its the maximum power drop ratio was 4.282% minimum and 6.657% maximum. And PV module of low current characteristics has electrical stress from other modules. The solar cell temperature of PV module was higher compared to PV cell. To prevent early degradation, it is need to have attention to PV cell selection.

• 한국태양에너지학회:학술대회논문집
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• 2009.11a
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• pp.104-109
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• 2009

If the Photovoltaic(PV) Module should get physical load, the PV module will be warped according to elongation of the front glass and then micro-crack will be occurred in the heat sealed Solar Cell. This micro-crack drops output of the short circuit current and the open circuit voltage of the PV Module. This is because of increase of resistance component by micro-crack. Micro-crack at specific Solar Cell in the module reduces the durability of PV Module such as less output, Hot-Spot in the PV module caused by Solar Cell output mismatch, heat generating as resistance component caused by micro-crack. In this study, among some factors which effect to the output of crystalline PV Module, we will see how the micro-crack caused by mechanical stress effects to the electrical output of PV Module.

• Journal of the Korean Solar Energy Society
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• v.36 no.2
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• pp.65-72
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• 2016

PV module is installed in various outdoor conditions such as solar irradiation, ambient temperature, wind speed and etc. Increase in solar cell temperature within PV module aggravates the behaviour and durability of PV module. It is difficult to measure temperature among respective PV module components during PV module operating, because the temperature within PV module depends on thermal characteristics of PV module components materials as well as operating conditions such as irradiation, outdoor temperature, wind etc. In this paper, simulation by using finite element method is conducted to predict the temperature of each components within PV module installed to outdoor circumstance. PV module structure based on conventional crystalline Si module is designed and the measured values of thickness and thermal parameters of component materials are used. The validation of simulation model is confirmed by comparing the calculated results with the measured temperatures data of PV module. The simulation model is also applied to estimate the thermal radiation of PV module by front glass and back sheet.

• Journal of the Korean Solar Energy Society
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• v.26 no.1
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• pp.73-79
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• 2006

The integration of PV modules into building facades or roof could raise PV module temperature that results in the reduction of electrical power generation. Lowering operating temperature of PV module is important in this respect, and PV module temperature should be considered more accurately, for building-integrated PV(BIPV) systems in predicting their performance. This paper describes a BIPV solar roof design and verifies its performance through experiment In relation to the effect of ventilation in space between PV module and roof surface. The results showed that the ventilation in the space had a positive effect in lowering the module temperature of the BIPV solar roof that enhanced the performance of its electricity generation.

• New & Renewable Energy
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• v.16 no.4
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• pp.76-82
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• 2020

Soiling on the surface of a PV module reduces the amount of light reaching the solar cells, decreasing power performance. The performance of the PV module is generally restored after contaminants on the module surface are washed away by rain, but it accumulates at the bottom of the module owing to the thickness of the module frame, causing an output mismatch on the PV module. Since PV modules are usually installed horizontally or vertically outdoors, soiling can occur at the bottom of the PV module, depending on the installation direction due to external environmental factors. This paper is analyzed the output characteristics of a PV module considering its installation direction and the soiling area. The soiling was simulated to use transparent films with 5% transmittance, and the transmission film was attached to the bottom part of the PV module horizontally and vertically. When the soiling area was 33% of the string at the bottom of the PV module, the power output decreased similarly regardless of installation direction. However, when the soiling area was 66% of the string at the bottom of the PV module, it was confirmed that the output performance decreased sharply when installed vertically rather than horizontally.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.35 no.8
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• pp.177-184
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• 2019

Recently, electric power usages and peak loads from buildings are increasing due to higher outdoor air temperatures and/or abnormal climate during the summer period. As one of the eco-friendly measures, a renewable energy system has been received much attention. Particularly, interest on a photovoltaic (PV) system using solar energy has been rapidly increasing in a building sector due to its broad applicability. In using the PV system, one of important factors is the PV efficiency. The normal PV efficiency is determined based on the STC(Standard Test Condition) and the NOCT(Nominal Operating Cell Temperature) performance test. However, the actual PV efficiency is affected by the temperature change at the module surface. Especially, higher module temperatures generally reduce the PV efficiency, and it leads to less power generation from the PV system. Therefore, the analysis of the relation between the module temperature and PV efficiency is required to evaluate the PV performance during the summer period. This study investigates existing algorithms for calculating module surface temperatures and analyzes resultant errors with the algorithms by comparing the measured module temperatures.

• Journal of the Korean Solar Energy Society
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• v.38 no.6
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• pp.51-63
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• 2018

Nowadays the bifacial PV system market and its applications are increasing rapidly. The performance of the bifacial PV system take advantage of its rear surface irradiance. Also, the ground albedo, PV module tilt and azimuth, PV module installation height, shading effect and module temperature are factors of bifacial PV system performance. This paper investigates how the performance of bifacial PV system is influenced by above factors. First, we analyzed the energy yield depending on PV module installation by simulation. Secondly, we compare energy performance evaluation of monofacial and bifacial module on different weather condition by experiment. Thirdly, we tested the albedo effect and checked operating characteristics using Dupont Tyvek material for the bifacial PV module. Fourthly, we check the shading effect of bifacial PV module on bypass diode operating. Finally, we applied the bifacial PV module in the nearby subway station for the noise reduction barrier using a qualified simulation program. In summary, we confirm that the energy performance superiority of the bifacial PV module has a lot of application use including road. Also, we have confirmed the bifacial module and inverter design should be considered by rear surface irradiance.