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M’Sila, Algeria

Silvestre S.,Polytechnic University of Catalonia | Kichou S.,Polytechnic University of Catalonia | Chouder A.,University Msila | Nofuentes G.,University of Jaen | Karatepe E.,Dokuz Eylul University
Energy | Year: 2015

To ensure the optimization of the energy generated by grid connected PV (photovoltaic) systems is necessary to plan a strategy of automatic fault detection. The analysis of current and voltage indicators have demonstrated effectiveness in the detection of permanent faults in the PV array in real time as short-circuits or open circuits present in the system. In this paper, the analysis of the evolution of these indicators is focused on the detection of temporary faults due to partial shade on the PV array or disconnection of the inverter in case of grid fluctuations of voltage or frequency to prevent islanding. These situations can be identified by observation of the evolution of both indicators and power losses due to these effects can be evaluated from them. The analysis and experimental validation were carried out in two grid connected PV systems in Spain and Algeria. © 2015 Elsevier Ltd. Source


Bouabdallah K.,University Msila | Balland P.,University of Savoy
Annales de Chimie: Science des Materiaux | Year: 2013

Straining of the Al-Mg alloys in a certain range of strain rate and temperature can lead up to the apparition of mechanical instabilities known as Portevin-Le-Chatelier effect (PLC effect). In flat specimen traction test, these instabilities can generate characteristic bands where the deformation is localised. This behaviour cane compromises the quality of the product in deforming process. The aim of the present study is to evaluate the influence of the length of the specimen on the parameters of PLC instability in traction test. The tests are performed at ambient temperature using various lengths of flat specimens cut out in the rolling direction. The local evolution of the deformation field components is obtained using an image correlation technique. © Lavoisier, Paris Effet PLC dans un alliage Al-Mg. Source


Silvestre S.,Polytechnic University of Catalonia | Silva M.A.D.,Polytechnic University of Catalonia | Chouder A.,University Msila | Guasch D.,Polytechnic University of Catalonia | Karatepe E.,Ege University
Energy Conversion and Management | Year: 2014

In this work we present a new procedure for automatic fault detection in grid connected photovoltaic (PV) systems. This method is based on the evaluation of new current and voltage indicators. Thresholds for these indicators are defined taking into account the PV system configuration: number of PV modules included and series and parallel interconnection to form the array. The procedure to calculate the thresholds that allow the identification of the faults is described. A simulation study was carried out to verify the evaluation of current and voltage indicators and their corresponding thresholds for a set of PV systems with different sizes and different configurations of interconnection of PV modules. The developed method was experimentally validated and has demonstrated its effectiveness in the detection of main faults present in grid connected applications. The computational analysis has been reduced and the number of monitoring sensors minimized. The fault detection procedure can be integrated into the inverter without using simulation software or additional external hardware. © 2014 Elsevier Ltd. All rights reserved. Source


Kichou S.,Polytechnic University of Catalonia | Abaslioglu E.,Polytechnic University of Catalonia | Silvestre S.,Polytechnic University of Catalonia | Nofuentes G.,University of Jaen | And 2 more authors.
Energy Conversion and Management | Year: 2016

The analysis of the degradation of tandem Micromorph thin-film photovoltaic (TFPV) modules and its impact on the output power of a PV array under outdoor long term exposure located in Jaén (Spain) is addressed in this work. Furthermore, the evolution of main solar cell model parameters is evaluated by means of parameters extraction techniques from monitored data of the PV system in real operation of work. The degradation rate and the stabilization period of micromorph TFPV modules are evaluated. The analysis of the degradation rate, together to results obtained for the evolution of each of the solar cell model parameters along the outdoor long-term exposure allow a better understanding of changes in performance of micromorph TFPV modules and the behavior of the output power of the PV generator. © 2016 Elsevier Ltd. All rights reserved. Source


Kichou S.,Polytechnic University of Catalonia | Silvestre S.,Polytechnic University of Catalonia | Nofuentes G.,University of Jaen | Torres-Ramirez M.,University of Jaen | And 2 more authors.
Energy | Year: 2016

The analysis of the degradation of thin-film single junction a-Si PV (photovoltaic) modules and its impact on the output power of a PV array under outdoor long term exposure located in Jaén (Spain), a relatively dry and sunny inland site with a Continental-Mediterranean climate is addressed in this paper. Furthermore, a new procedure of solar cell model parameters extraction experimentally validated is presented. The parameter extraction procedure allows obtaining main model parameters of the solar cells forming the PV array from monitored data of the PV system in real operation of work. Results obtained of the evolution of each one of the solar cell model parameters along the PV system outdoor long term exposure campaign are analysed in order to achieve a better understanding of the performance changes of the PV modules and the behaviour of the output power of the PV array. © 2015 Elsevier Ltd. Source

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