Documents disponibles écrits par cet auteur

Development of a MATLAB/simulink model of a single-phase grid-connected photovoltaic system / Ropp, M. E. in IEEE transactions on energy conversion, Vol. 24 N°1 (Mars 2009) 

Public ISBD [article]  in IEEE transactions on energy conversion > Vol. 24 N°1 (Mars 2009) . - pp. 195 - 202 Titre : Development of a MATLAB/simulink model of a single-phase grid-connected photovoltaic system Type de document : texte imprimé Auteurs : Ropp, M. E., Auteur ; S. González, Auteur Année de publication : 2009 Article en page(s) : pp. 195 - 202 Note générale : energy conversion Langues : Anglais (eng) Mots-clés : Invertors;  photovoltaic  power  systems;  power  grids;  power  system  simulation Résumé : Because of their deployment in dispersed locations on the lowest voltage portions of the grid, photovoltaic (PV) systems pose unique challenges to power system engineers. Computer models that accurately simulate the relevant behavior of PV systems would thus be of high value. However, most of today's models either do not accurately model the dynamics of the maximum power point trackers (MPPTs) or anti-islanding algorithms, or they involve excessive computational overhead for this application. To address this need, a Matlab/Simulink model of a single-phase grid-connected PV inverter has been developed and experimentally tested. The development of the PV array model, the integration of the MPPT with an averaged model of the power electronics, and the Simulink implementation are described. It is experimentally demonstrated that the model works well in predicting the general behaviors of single-phase grid-connected PV systems. This paper concludes with a discussion of the need for a full gradient-based MPPT model, as opposed to a commonly used simplified MPPT model. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4785259&sortType%3Das [...] [article] Development of a MATLAB/simulink model of a single-phase grid-connected photovoltaic system [texte imprimé] / Ropp, M. E., Auteur ; S. González, Auteur . - 2009 . - pp. 195 - 202. energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 24 N°1 (Mars 2009) . - pp. 195 - 202 Mots-clés : Invertors;  photovoltaic  power  systems;  power  grids;  power  system  simulation Résumé : Because of their deployment in dispersed locations on the lowest voltage portions of the grid, photovoltaic (PV) systems pose unique challenges to power system engineers. Computer models that accurately simulate the relevant behavior of PV systems would thus be of high value. However, most of today's models either do not accurately model the dynamics of the maximum power point trackers (MPPTs) or anti-islanding algorithms, or they involve excessive computational overhead for this application. To address this need, a Matlab/Simulink model of a single-phase grid-connected PV inverter has been developed and experimentally tested. The development of the PV array model, the integration of the MPPT with an averaged model of the power electronics, and the Simulink implementation are described. It is experimentally demonstrated that the model works well in predicting the general behaviors of single-phase grid-connected PV systems. This paper concludes with a discussion of the need for a full gradient-based MPPT model, as opposed to a commonly used simplified MPPT model. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4785259&sortType%3Das [...]

Enhanced mechanical properties due to structural changes induced by devitrification in Fe–Co–B–Si–Nb bulk metallic glass / J. Fornell in Acta materialia, Vol. 58 N° 19 (Novembre 2010) 

Public ISBD [article]  in Acta materialia > Vol. 58 N° 19 (Novembre 2010) . - pp. 6256–6266 Titre : Enhanced mechanical properties due to structural changes induced by devitrification in Fe–Co–B–Si–Nb bulk metallic glass Type de document : texte imprimé Auteurs : J. Fornell, Auteur ; S. González, Auteur ; E. Rossinyol, Auteur Année de publication : 2011 Article en page(s) : pp. 6256–6266 Note générale : Métallurgie Langues : Anglais (eng) Mots-clés : Metallic  glass  Annealing  Nanoindentation  Transmission  electron  microscopy  Acoustic  methods Résumé : Fe36Co36B19.2Si4.8Nb4 bulk glassy rods were synthesized by copper mould casting. The effects of annealing treatments on the microstructure, elastic and mechanical properties of this alloy are investigated. Annealing below the glass transition temperature induces the formation of atomic clusters with pseudo-tenfold symmetry with a close relationship to the Fe23B6 phase. Annealing at sufficiently high temperatures promotes the formation of stable Fe2B and FeB phases and Fe(Co) solid solution. The as-cast alloy exhibits ultra-high hardness (H > 14 GPa), high reduced Young’s modulus (Er > 200 GPa) and good wear resistance. These properties are further enhanced after thermal treatments (H > 18 GPa and Er > 260 GPa are achieved in the fully crystallized sample). The mechanical hardening is accompanied with an increase of the elastic recovery and a decrease of the Poisson’s ratio. The different microstructural mechanisms responsible for these annealing-induced changes in mechanical and elastic properties are discussed. DEWEY : 669 ISSN : 1359-6454 En ligne : http://www.sciencedirect.com/science/article/pii/S135964541000491X [article] Enhanced mechanical properties due to structural changes induced by devitrification in Fe–Co–B–Si–Nb bulk metallic glass [texte imprimé] / J. Fornell, Auteur ; S. González, Auteur ; E. Rossinyol, Auteur . - 2011 . - pp. 6256–6266. Métallurgie Langues : Anglais (eng) in Acta materialia > Vol. 58 N° 19 (Novembre 2010) . - pp. 6256–6266 Mots-clés : Metallic  glass  Annealing  Nanoindentation  Transmission  electron  microscopy  Acoustic  methods Résumé : Fe36Co36B19.2Si4.8Nb4 bulk glassy rods were synthesized by copper mould casting. The effects of annealing treatments on the microstructure, elastic and mechanical properties of this alloy are investigated. Annealing below the glass transition temperature induces the formation of atomic clusters with pseudo-tenfold symmetry with a close relationship to the Fe23B6 phase. Annealing at sufficiently high temperatures promotes the formation of stable Fe2B and FeB phases and Fe(Co) solid solution. The as-cast alloy exhibits ultra-high hardness (H > 14 GPa), high reduced Young’s modulus (Er > 200 GPa) and good wear resistance. These properties are further enhanced after thermal treatments (H > 18 GPa and Er > 260 GPa are achieved in the fully crystallized sample). The mechanical hardening is accompanied with an increase of the elastic recovery and a decrease of the Poisson’s ratio. The different microstructural mechanisms responsible for these annealing-induced changes in mechanical and elastic properties are discussed. DEWEY : 669 ISSN : 1359-6454 En ligne : http://www.sciencedirect.com/science/article/pii/S135964541000491X