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Journal ArticleDOI

Experimental study of mismatch and shading effects in the I-V characteristic of a photovoltaic module

15 Feb 2006-Solar Energy Materials and Solar Cells (North-Holland)-Vol. 90, Iss: 3, pp 329-340
TL;DR: In this article, a conventional photovoltaic module has been prepared with the purpose of accessing its cells either individually or associated, and measurements of every cell and of the whole module have been performed in direct and reverse bias, with the objective of documenting the scattering in cell parameters, working point of the cells and shading effects.
About: This article is published in Solar Energy Materials and Solar Cells.The article was published on 2006-02-15. It has received 354 citations till now. The article focuses on the topics: Shading.
Citations
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Journal ArticleDOI
TL;DR: In this paper, a MATLAB-based modeling and simulation scheme is presented for studying the I-V and P-V characteristics of a PV array under a nonuniform insolation due to partial shading.
Abstract: The performance of a photovoltaic (PV) array is affected by temperature, solar insolation, shading, and array configuration. Often, the PV arrays get shadowed, completely or partially, by the passing clouds, neighboring buildings and towers, trees, and utility and telephone poles. The situation is of particular interest in case of large PV installations such as those used in distributed power generation schemes. Under partially shaded conditions, the PV characteristics get more complex with multiple peaks. Yet, it is very important to understand and predict them in order to extract the maximum possible power. This paper presents a MATLAB-based modeling and simulation scheme suitable for studying the I-V and P-V characteristics of a PV array under a nonuniform insolation due to partial shading. It can also be used for developing and evaluating new maximum power point tracking techniques, especially for partially shaded conditions. The proposed models conveniently interface with the models of power electronic converters, which is a very useful feature. It can also be used as a tool to study the effects of shading patterns on PV panels having different configurations. It is observed that, for a given number of PV modules, the array configuration (how many modules in series and how many in parallel) significantly affects the maximum available power under partially shaded conditions. This is another aspect to which the developed tool can be applied. The model has been experimentally validated and the usefulness of this research is highlighted with the help of several illustrations. The MATLAB code of the developed model is freely available for download.

1,139 citations


Cites background from "Experimental study of mismatch and ..."

  • ...[5] have experimentally obtained the I–V characteristics of the PV module and the constituent cells to study the effect of partial shading....

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Journal ArticleDOI
TL;DR: The luminescent solar concentrator (LSC) is a simple device at its heart, employing a polymeric or glass waveguide and luminecent molecules to generate electricity from sunlight when attached to a photovoltaic cell as mentioned in this paper.
Abstract: Research on the luminescent solar concentrator (LSC) over the past thirty-odd years is reviewed. The LSC is a simple device at its heart, employing a polymeric or glass waveguide and luminescent molecules to generate electricity from sunlight when attached to a photovoltaic cell. The LSC has the potential to find extended use in an area traditionally difficult for effective use of regular photovoltaic panels: the built environment. The LSC is a device very flexible in its design, with a variety of possible shapes and colors. The primary challenge faced by the devices is increasing their photon-to-electron conversion efficiencies. A number of laboratories are working to improve the efficiency and lifetime of the LSC device, with the ultimate goal of commercializing the devices within a few years. The topics covered here relate to the efforts for reducing losses in these devices. These include studies of novel luminophores, including organic fluorescent dyes, inorganic phosphors, and quantum dots. Ways to limit the surface and internal losses are also discussed, including using organic and inorganic-based selective mirrors which allow sunlight in but reflect luminophore-emitted light, plasmonic structures to enhance emissions, novel photovoltaics, alignment of the luminophores to manipulate the path of the emitted light, and patterning of the dye layer to improve emission efficiency. Finally, some possible ‘glimpses of the future’ are offered, with additional research paths that could result in a device that makes solar energy a ubiquitous part of the urban setting, finding use as sound barriers, bus-stop roofs, awnings, windows, paving, or siding tiles.

779 citations

Journal ArticleDOI
TL;DR: In this article, a procedure of simulation and modelling solar cells and PV modules, working partially shadowed in Pspice environment, is presented, where simulation results have been contrasted with real measured data from a commercial PV module of 209 Wp from Siliken.

448 citations

Journal ArticleDOI
TL;DR: In this article, a novel maximum power point tracking (MPPT) system is proposed for partially shaded PV array using artificial neural network (ANN) and fuzzy logic with polar information controller.
Abstract: The one of main causes of reducing energy yield of photovoltaic systems is partially shaded conditions. Although the conventional maximum power point tracking (MPPT) control algorithms operate well under uniform insolation, they do not operate well in non-uniform insolation. The non-uniform conditions cause multiple local maximum power points on the power-voltage curve. The conventional MPPT methods cannot distinguish between the global and local peaks. Since the global maximum power point (MPP) may change within a large voltage window and also its position depends on shading patterns, it is very difficult to recognise the global operating point under partially shaded conditions. In this paper, a novel MPPT system is proposed for partially shaded PV array using artificial neural network (ANN) and fuzzy logic with polar information controller. The ANN with three layer feed-forward is trained once for several partially shaded conditions to determine the global MPP voltage. The fuzzy logic with polar information controller uses the global MPP voltage as a reference voltage to generate the required control signal for the power converter. Another objective of this study is to determine the estimated maximum power and energy generation of PV system through the same ANN structure. The effectiveness of the proposed method is demonstrated under the experimental real-time simulation technique based dSPACE real-time interface system for different interconnected PV arrays such as series-parallel, bridge link and total cross tied configurations.

353 citations

Journal ArticleDOI
TL;DR: A new two-diode model is utilized to represent the PV cell in a comprehensive MATLAB Simulink simulator for photovoltaic (PV) system that supports a large array combination that can be interfaced to MPPT algorithms and power electronic converters.

353 citations

References
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Journal ArticleDOI
TL;DR: The results indicate that with obstacles of irregular shape being close to the photovoltaic array, simulation estimates the shadowing losses rather imprecise, but at array positions mainly suffering from a reduction of the visible horizon by obstacles far away from the photvoltaic arrays, a simulation returns good results.

439 citations

Journal ArticleDOI
TL;DR: In this article, an outdoor test facility has been prepared for the evaluation of the thermal and electrical effects caused by outdoor hot-spot testing in crystalline silicon modules, and five module types have been subjected to a test program with the purpose of analysing their hotspot endurance, and the worst-case cell in each module type has been detected by laboratory characterisation under reverse bias operation of all the individual cells included in the module.
Abstract: An outdoor test facility has been prepared for the evaluation of the thermal and electrical effects caused by outdoor hot-spot testing in crystalline silicon modules. Five module types have been subjected to an outdoor test programme with the purpose of analysing their hot-spot endurance. The worst-case cell in each module type has been detected by laboratory characterisation under reverse-bias operation of all the individual cells included in the module. These cells, encapsulated within the module, have been operated at different shading fractions with bypass diodes around 18 or 24 cells. A data acquisition system has monitored temperatures and current flows during the day, completing the tests via infrared characterisation during the hours of maximum irradiance. The influence of the type of module, the number of cells per bypass diode, the position and amount of shading and the leakage current of the cell is presented. This information is useful for cell and module manufacturers and system installers who must select the necessary protection criteria to guarantee long lifetimes for PV systems; it also helps to clarify hot-spot testing procedures in international standards. Copyright © 2003 John Wiley & Sons, Ltd.

81 citations

Proceedings ArticleDOI
29 Sep 1997
TL;DR: In this article, reverse I-V characteristics and infrared thermal images have been analyzed for commercial silicon solar cells of 12 manufacturers, and the impact on blocking diode concepts and maximum cell temperatures, as compared to EVA cure temperatures, is discussed.
Abstract: For commercial silicon solar cells of 12 manufacturers, reverse I-V characteristics (10 cells each to obtain statistics) and infrared thermal images have been analysed. Except for one cell type, there is a large scatter. Even within batches, cell behaviour varies strongly between avalanche breakdown and thermal breakdown. The impact on blocking diode concepts and maximum cell temperatures, as compared to EVA cure temperatures, is discussed. Some module designs may have to be reviewed.

30 citations

Book ChapterDOI
01 Jan 1982
TL;DR: In this paper, an analysis of the maximum power dissipation in reverse biased shadowed (or faulty) cells is presented for different series-parallel configurations; for each case, the bias point of the shadowed cell is determined as a function of the "shadowing degree", defined as the ratio between the I of a shadowed node and I of the illuminated node.
Abstract: An analysis has been made of the maximum power dissipation in reverse biased shadowed (or faulty) cells. The results of the analysis are presented for different series-parallel configurations; for each case the bias point of the shadowed cell is determined as a function of the “shadowing degree”, defined as the ratio between the I of the shadowed cell and the I of the illuminated ones. The maximum power dissipation allowable for the cell in a given module is computed by using the NOCT values of the module itself.

29 citations

Journal ArticleDOI
TL;DR: In this article, direct measurements of cell reverse bias stress as well as power loss for different configurations of connections and shadowing have been analyzed, using a specially designed photovoltaic (policrystal silicium) module that allows inside measurements of any single cell's power and temperature.

9 citations