Documents disponibles écrits par cet auteur

An integrated hybrid power supply for distributed generation applications fed by nonconventional energy sources / Jain, S. in IEEE transactions on energy conversion, Vol. 23 n°2 (Juin 2008) 

Public ISBD [article]  in IEEE transactions on energy conversion > Vol. 23 n°2 (Juin 2008) . - pp. 622 - 631 Titre : An integrated hybrid power supply for distributed generation applications fed by nonconventional energy sources Type de document : texte imprimé Auteurs : Jain, S., Auteur ; Agarwal, V., Auteur Année de publication : 2008 Article en page(s) : pp. 622 - 631 Note générale : Energy conversion Langues : Anglais (eng) Mots-clés : DC-DC  power  convertors;  distributed  power  generation;  fuel  cell  power  plants;  hybrid  power  systems;  photovoltaic  power  systems Résumé : A new, hybrid integrated topology, fed by photovoltaic (PV) and fuel cell (FC) sources and suitable for distributed generation applications, is proposed. It works as an uninterruptible power source that is able to feed a certain minimum amount of power into the grid under all conditions. PV is used as the primary source of power operating near maximum power point (MPP), with the FC section (block), acting as a current source, feeding only the deficit power. The unique "integrated" approach obviates the need for dedicated communication between the two sources for coordination and eliminates the use of a separate, conventional dc/dc boost converter stage required for PV power processing, resulting in a reduction of the number of devices, components, and sensors. Presence of the FC source in parallel (with the PV source) improves the quality of power fed into the grid by minimizing the voltage dips in the PV output. Another desirable feature is that even a small amount of PV power (e.g., during low insolation), can be fed into the grid. On the other hand, excess power is diverted for auxiliary functions like electrolysis, resulting in an optimal use of the energy sources. The other advantages of the proposed system include low cost, compact structure, and high reliability, which render the system suitable for modular assemblies and "plug-n-play" type applications. All the analytical, simulation, and experimental results of this research are presented. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4488040&sortType%3Das [...] [article] An integrated hybrid power supply for distributed generation applications fed by nonconventional energy sources [texte imprimé] / Jain, S., Auteur ; Agarwal, V., Auteur . - 2008 . - pp. 622 - 631. Energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 23 n°2 (Juin 2008) . - pp. 622 - 631 Mots-clés : DC-DC  power  convertors;  distributed  power  generation;  fuel  cell  power  plants;  hybrid  power  systems;  photovoltaic  power  systems Résumé : A new, hybrid integrated topology, fed by photovoltaic (PV) and fuel cell (FC) sources and suitable for distributed generation applications, is proposed. It works as an uninterruptible power source that is able to feed a certain minimum amount of power into the grid under all conditions. PV is used as the primary source of power operating near maximum power point (MPP), with the FC section (block), acting as a current source, feeding only the deficit power. The unique "integrated" approach obviates the need for dedicated communication between the two sources for coordination and eliminates the use of a separate, conventional dc/dc boost converter stage required for PV power processing, resulting in a reduction of the number of devices, components, and sensors. Presence of the FC source in parallel (with the PV source) improves the quality of power fed into the grid by minimizing the voltage dips in the PV output. Another desirable feature is that even a small amount of PV power (e.g., during low insolation), can be fed into the grid. On the other hand, excess power is diverted for auxiliary functions like electrolysis, resulting in an optimal use of the energy sources. The other advantages of the proposed system include low cost, compact structure, and high reliability, which render the system suitable for modular assemblies and "plug-n-play" type applications. All the analytical, simulation, and experimental results of this research are presented. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4488040&sortType%3Das [...]

Development and validation of a battery model useful for discharging and charging power control and lifetime estimation / Agarwal, V. in IEEE transactions on energy conversion, Vol. 25, N° 3 (Septembre 2010) 

Public ISBD [article]  in IEEE transactions on energy conversion > Vol. 25, N° 3 (Septembre 2010) . - pp. 821 - 835 Titre : Development and validation of a battery model useful for discharging and charging power control and lifetime estimation Type de document : texte imprimé Auteurs : Agarwal, V., Auteur ; Uthaichana, K., Auteur ; DeCarlo, R. A., Auteur Année de publication : 2011 Article en page(s) : pp. 821 - 835 Note générale : energy conversion Langues : Anglais (eng) Mots-clés : Battery  management  systems;  battery  powered  vehicles;  lead  acid  batteries Résumé : Accurate information on battery state-of-charge, expected battery lifetime, and expected battery cycle life is essential for many practical applications. In this paper, we develop a nonchemically based partially linearized (in battery power) input-output battery model, initially developed for lead-acid batteries in a hybrid electric vehicle. We show that with properly tuned parameter values, the model can be extended to different battery types, such as lithium-ion, nickel-metal hydride, and alkaline. The validation results of the model against measured data in terms of power and efficiency at different temperatures are then presented. The model is incorporated with the recovery effect for accurate lifetime estimation. The obtained lifetime estimation results using the proposed model are similar to the ones predicted by the Rakhmatov and Virudhula battery model on a given set of typical loads at room temperature. A possible incorporation of the cycling effect, which determines the battery cycle life, in terms of the maximum available energy approximated at charge/discharge nominal power level is also suggested. The usage of the proposed model is computationally inexpensive, hence implementable in many applications, such as low-power system design, real-time energy management in distributed sensor network, etc. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5552150&sortType%3Das [...] [article] Development and validation of a battery model useful for discharging and charging power control and lifetime estimation [texte imprimé] / Agarwal, V., Auteur ; Uthaichana, K., Auteur ; DeCarlo, R. A., Auteur . - 2011 . - pp. 821 - 835. energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 25, N° 3 (Septembre 2010) . - pp. 821 - 835 Mots-clés : Battery  management  systems;  battery  powered  vehicles;  lead  acid  batteries Résumé : Accurate information on battery state-of-charge, expected battery lifetime, and expected battery cycle life is essential for many practical applications. In this paper, we develop a nonchemically based partially linearized (in battery power) input-output battery model, initially developed for lead-acid batteries in a hybrid electric vehicle. We show that with properly tuned parameter values, the model can be extended to different battery types, such as lithium-ion, nickel-metal hydride, and alkaline. The validation results of the model against measured data in terms of power and efficiency at different temperatures are then presented. The model is incorporated with the recovery effect for accurate lifetime estimation. The obtained lifetime estimation results using the proposed model are similar to the ones predicted by the Rakhmatov and Virudhula battery model on a given set of typical loads at room temperature. A possible incorporation of the cycling effect, which determines the battery cycle life, in terms of the maximum available energy approximated at charge/discharge nominal power level is also suggested. The usage of the proposed model is computationally inexpensive, hence implementable in many applications, such as low-power system design, real-time energy management in distributed sensor network, etc. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5552150&sortType%3Das [...]

MATLAB-based modeling to study the effects of partial shading on PV array characteristics / Patel, H. in IEEE transactions on energy conversion, Vol. 23 N°1 (Mars 2008) 

Public ISBD [article]  in IEEE transactions on energy conversion > Vol. 23 N°1 (Mars 2008) . - pp. 302 - 310 Titre : MATLAB-based modeling to study the effects of partial shading on PV array characteristics Type de document : texte imprimé Auteurs : Patel, H., Auteur ; Agarwal, V., Auteur Année de publication : 2008 Article en page(s) : pp. 302 - 310 Note générale : Energy conversion Langues : Anglais (eng) Mots-clés : DC-DC  power  convertors;  distributed  power  generation;  mathematics  computing;  photovoltaic  power  systems;  solar  cell  arrays Résumé : 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. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4453994&sortType%3Das [...] [article] MATLAB-based modeling to study the effects of partial shading on PV array characteristics [texte imprimé] / Patel, H., Auteur ; Agarwal, V., Auteur . - 2008 . - pp. 302 - 310. Energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 23 N°1 (Mars 2008) . - pp. 302 - 310 Mots-clés : DC-DC  power  convertors;  distributed  power  generation;  mathematics  computing;  photovoltaic  power  systems;  solar  cell  arrays Résumé : 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. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4453994&sortType%3Das [...]

MPPT scheme for a PV-fed single-phase single-stage grid-connected inverter operating in CCM with only one current sensor / Patel, H. 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. 256 - 263 Titre : MPPT scheme for a PV-fed single-phase single-stage grid-connected inverter operating in CCM with only one current sensor Type de document : texte imprimé Auteurs : Patel, H., Auteur ; Agarwal, V., Auteur Année de publication : 2009 Article en page(s) : pp. 256 - 263 Note générale : energy conversion Langues : Anglais (eng) Mots-clés : Electric  sensing  devices;  invertors;  photovoltaic  power  systems;  power  grids Résumé : The cost and efficiency of a photovoltaic (PV)-based grid-connected system depends upon the number of components and stages involved in the power conversion. This has led to the development of several single-stage configurations that can perform voltage transformation, maximum power point tracking (MPPT), inversion, and current shaping-all in one stage. Such configurations would usually require at least a couple of current and voltage sensors and a relatively complex control strategy. With a view to minimize the overall cost and control complexity, this paper presents a novel MPPT scheme with reduced number of sensors. The proposed scheme is applicable to any single-stage, single-phase grid-connected inverter operating in continuous conduction mode (CCM). The operation in CCM is desirable as it drastically reduces the stress on the components. Unlike other MPPT methods, which sense both PV array's output current and voltage, only PV array's output voltage is required to be sensed to implement MPPT. Only one current sensor is used for shaping the buck-boost inductor current as well as for MPPT. The information about power output of the array is obtained indirectly from array's voltage and the inductor current amplitude. Detailed analysis and the flowchart of the algorithm for the proposed scheme are included. Simulation and experimental results are also presented to highlight the usefulness of the scheme. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4783113&sortType%3Das [...] [article] MPPT scheme for a PV-fed single-phase single-stage grid-connected inverter operating in CCM with only one current sensor [texte imprimé] / Patel, H., Auteur ; Agarwal, V., Auteur . - 2009 . - pp. 256 - 263. energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 24 N°1 (Mars 2009) . - pp. 256 - 263 Mots-clés : Electric  sensing  devices;  invertors;  photovoltaic  power  systems;  power  grids Résumé : The cost and efficiency of a photovoltaic (PV)-based grid-connected system depends upon the number of components and stages involved in the power conversion. This has led to the development of several single-stage configurations that can perform voltage transformation, maximum power point tracking (MPPT), inversion, and current shaping-all in one stage. Such configurations would usually require at least a couple of current and voltage sensors and a relatively complex control strategy. With a view to minimize the overall cost and control complexity, this paper presents a novel MPPT scheme with reduced number of sensors. The proposed scheme is applicable to any single-stage, single-phase grid-connected inverter operating in continuous conduction mode (CCM). The operation in CCM is desirable as it drastically reduces the stress on the components. Unlike other MPPT methods, which sense both PV array's output current and voltage, only PV array's output voltage is required to be sensed to implement MPPT. Only one current sensor is used for shaping the buck-boost inductor current as well as for MPPT. The information about power output of the array is obtained indirectly from array's voltage and the inductor current amplitude. Detailed analysis and the flowchart of the algorithm for the proposed scheme are included. Simulation and experimental results are also presented to highlight the usefulness of the scheme. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4783113&sortType%3Das [...]

A novel scheme for rapid tracking of maximum power point in wind energy generation systems / Agarwal, V. in IEEE transactions on energy conversion, Vol. 25 N° 1 (Mars 2010) 

Public ISBD [article]  in IEEE transactions on energy conversion > Vol. 25 N° 1 (Mars 2010) . - pp. 228 - 236 Titre : A novel scheme for rapid tracking of maximum power point in wind energy generation systems Type de document : texte imprimé Auteurs : Agarwal, V., Auteur ; Aggarwal, R. K., Auteur ; Patidar, P., Auteur Année de publication : 2010 Article en page(s) : pp. 228 - 236 Note générale : energy conversion Langues : Anglais (eng) Mots-clés : matrix  convertors;  power  grids;  wind  power Résumé : This paper presents a novel maximum power point (MPP) tracking (MPPT) algorithm for grid-connected wind energy generation systems (WEGS). This is a rapid tracking algorithm that uses the fact that the value of ????,?? an intermediate variable, especially defined for the purpose, remains constant ( =??MPP ) for a given WEGS at the MPP irrespective of the wind velocity. The value of ??MPP is known in advance. The algorithm works in two stages. In the first stage, it uses large steps to quickly drive the operating point to lie within a narrow band with limits ??max and ??min. In the second stage, exact MPP is tracked using the ??perturb and observe?? method. No extra hardware or measurements (sensors) are required compared to the existing algorithms. Hence, the cost is not increased. Application of the proposed algorithm to an example WEGS shows that the time taken by the system to reach MPP is much smaller compared to most of the existing algorithms. A prototype matrix converter has been developed for grid interfacing and the proposed MPPT scheme has been implemented in conjunction with Venturini and space-vector-modulation-based switching schemes. All the results of this study are presented. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5350683&sortType%3Das [...] [article] A novel scheme for rapid tracking of maximum power point in wind energy generation systems [texte imprimé] / Agarwal, V., Auteur ; Aggarwal, R. K., Auteur ; Patidar, P., Auteur . - 2010 . - pp. 228 - 236. energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 25 N° 1 (Mars 2010) . - pp. 228 - 236 Mots-clés : matrix  convertors;  power  grids;  wind  power Résumé : This paper presents a novel maximum power point (MPP) tracking (MPPT) algorithm for grid-connected wind energy generation systems (WEGS). This is a rapid tracking algorithm that uses the fact that the value of ????,?? an intermediate variable, especially defined for the purpose, remains constant ( =??MPP ) for a given WEGS at the MPP irrespective of the wind velocity. The value of ??MPP is known in advance. The algorithm works in two stages. In the first stage, it uses large steps to quickly drive the operating point to lie within a narrow band with limits ??max and ??min. In the second stage, exact MPP is tracked using the ??perturb and observe?? method. No extra hardware or measurements (sensors) are required compared to the existing algorithms. Hence, the cost is not increased. Application of the proposed algorithm to an example WEGS shows that the time taken by the system to reach MPP is much smaller compared to most of the existing algorithms. A prototype matrix converter has been developed for grid interfacing and the proposed MPPT scheme has been implemented in conjunction with Venturini and space-vector-modulation-based switching schemes. All the results of this study are presented. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5350683&sortType%3Das [...]

A single-stage single-phase transformer-less doubly grounded grid-connected PV interface / Patel, H. in IEEE transactions on energy conversion, Vol. 24 N°1 (Mars 2009) 

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Universal single-stage grid-connected inverter / Prasad, B.S. in IEEE transactions on energy conversion, Vol. 23 N°1 (Mars 2008) 

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