Dépouillements

Design considerations of a direct drive brushless machine with concentrated windings / Wrobel, R. 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. 1 - 8 Titre : Design considerations of a direct drive brushless machine with concentrated windings Type de document : texte imprimé Auteurs : Wrobel, R., Auteur ; Mellor, P.H., Auteur Année de publication : 2008 Article en page(s) : pp. 1 - 8 Note générale : Energy conversion Langues : Anglais (eng) Mots-clés : Brushless  DC  motors;  electric  vehicles;  finite  element  analysis;  genetic  algorithms;  machine  windings;  permanent  magnet  machines Résumé : This paper discusses the performance attributes of the open-slot, modular-wound, external-rotor, topology of electrical machine. Combinations of pole and slot numbers are presented for which the winding factor is maximal and torque ripple is minimal. An optimization of the magnetic circuit design of six promising pole-slot configurations is undertaken using a parametric finite element model (FEM) combined with a genetic algorithm (GA). These designs are benchmarked against a conventional 1.5 slots/pole external-rotor brushless dc machine. These candidate electrical machine versions are characterized by having the same external-rotor diameter, total slot area available for the winding and by equal volumes of permanent magnet (PM). Based on the analysis, the most promising motor structure was selected and a prototype wheel-hub motor has been built for application in a small electrical vehicle. Test data from the prototype is used to validate the findings of the initial analyses and practically demonstrate the attributes of the topology. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4378207&sortType%3Das [...] [article] Design considerations of a direct drive brushless machine with concentrated windings [texte imprimé] / Wrobel, R., Auteur ; Mellor, P.H., Auteur . - 2008 . - pp. 1 - 8. Energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 23 N°1 (Mars 2008) . - pp. 1 - 8 Mots-clés : Brushless  DC  motors;  electric  vehicles;  finite  element  analysis;  genetic  algorithms;  machine  windings;  permanent  magnet  machines Résumé : This paper discusses the performance attributes of the open-slot, modular-wound, external-rotor, topology of electrical machine. Combinations of pole and slot numbers are presented for which the winding factor is maximal and torque ripple is minimal. An optimization of the magnetic circuit design of six promising pole-slot configurations is undertaken using a parametric finite element model (FEM) combined with a genetic algorithm (GA). These designs are benchmarked against a conventional 1.5 slots/pole external-rotor brushless dc machine. These candidate electrical machine versions are characterized by having the same external-rotor diameter, total slot area available for the winding and by equal volumes of permanent magnet (PM). Based on the analysis, the most promising motor structure was selected and a prototype wheel-hub motor has been built for application in a small electrical vehicle. Test data from the prototype is used to validate the findings of the initial analyses and practically demonstrate the attributes of the topology. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4378207&sortType%3Das [...]

Significance of defects inside in-service aged winding insulations / Sumereder, C. 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. 9 - 14 Titre : Significance of defects inside in-service aged winding insulations Type de document : texte imprimé Auteurs : Sumereder, C., Auteur ; Weiers, T., Auteur Année de publication : 2008 Article en page(s) : pp. 9 - 14 Note générale : Energy conversion Langues : Anglais (eng) Mots-clés : Weibull  distribution;  electric  breakdown;  insulation  testing;  machine  insulation;  machine  windings;  mica Résumé : This study aims to gain insight into the consequences of local defects in stator winding insulation; therefore, optical (microscopic) inspections and voltage-endurance tests have been carried out on in-service aged generator bars. In this context, generator bars with mica-bitumen insulations and generator bars with mica-epoxy insulations were investigated. The mica-bitumen insulations had been in service for 43 years in a 12 kV hydro-generator. The generator bars with mica-epoxy insulation had been dismantled from two identically constructed 10.5-kV generators after 35 and 36 years of service. The time to breakdown values obtained from the voltage-endurance tests were evaluated using a Weibull distribution. Apart from the scale parameter, Weibull exponent of this distribution allowed for the identification of early failures. The voltage-endurance tests carried out on replacement bars for these generators did not yield any early failures; such failures, however, were detected on both types of the in-service aged insulations. In particular, these occurred at high levels of electric stress and at delaminations between the copper conductor and the groundwall insulation. It is concluded that the interpretation of the measured time to breakdown values and their scatter depends on the level of electric stress. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4428276&sortType%3Das [...] [article] Significance of defects inside in-service aged winding insulations [texte imprimé] / Sumereder, C., Auteur ; Weiers, T., Auteur . - 2008 . - pp. 9 - 14. Energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 23 N°1 (Mars 2008) . - pp. 9 - 14 Mots-clés : Weibull  distribution;  electric  breakdown;  insulation  testing;  machine  insulation;  machine  windings;  mica Résumé : This study aims to gain insight into the consequences of local defects in stator winding insulation; therefore, optical (microscopic) inspections and voltage-endurance tests have been carried out on in-service aged generator bars. In this context, generator bars with mica-bitumen insulations and generator bars with mica-epoxy insulations were investigated. The mica-bitumen insulations had been in service for 43 years in a 12 kV hydro-generator. The generator bars with mica-epoxy insulation had been dismantled from two identically constructed 10.5-kV generators after 35 and 36 years of service. The time to breakdown values obtained from the voltage-endurance tests were evaluated using a Weibull distribution. Apart from the scale parameter, Weibull exponent of this distribution allowed for the identification of early failures. The voltage-endurance tests carried out on replacement bars for these generators did not yield any early failures; such failures, however, were detected on both types of the in-service aged insulations. In particular, these occurred at high levels of electric stress and at delaminations between the copper conductor and the groundwall insulation. It is concluded that the interpretation of the measured time to breakdown values and their scatter depends on the level of electric stress. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4428276&sortType%3Das [...]

Transient modeling and parameter estimation of field aligned starting / Madawala, U.K. 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. 15 - 24 Titre : Transient modeling and parameter estimation of field aligned starting Type de document : texte imprimé Auteurs : Madawala, U.K., Auteur ; Baguley, C. A., Auteur Année de publication : 2008 Article en page(s) : pp. 15 - 24 Note générale : Energy conversion Langues : Anglais (eng) Mots-clés : Machine  theory;  squirrel  cage  motors;  starting;  transient  analysis Résumé : Field aligned starting (FAS) is a new technique for starting three-phase cage induction motors on single-phase supply lines with minimal inrush currents. It uses a simple energy storage system to generate a very high impulsive torque by which the motor is started before being connected to the mains supply. The spinning motor can then be connected to the mains to operate in a standard Steinmetz connection without incurring high inrush currents, if the moment of mains connection is properly timed. This paper presents a transient model and an accompanying parameter estimation method through which the transient behavior of three-phase induction motors operated with FAS can be analyzed. The proposed model is based on instantaneous symmetrical components and is used to investigate a 3 kW motor started under various operating conditions. The proposed parameter estimation method and the developed transient model are both validated by experimental results. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4358745&sortType%3Das [...] [article] Transient modeling and parameter estimation of field aligned starting [texte imprimé] / Madawala, U.K., Auteur ; Baguley, C. A., Auteur . - 2008 . - pp. 15 - 24. Energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 23 N°1 (Mars 2008) . - pp. 15 - 24 Mots-clés : Machine  theory;  squirrel  cage  motors;  starting;  transient  analysis Résumé : Field aligned starting (FAS) is a new technique for starting three-phase cage induction motors on single-phase supply lines with minimal inrush currents. It uses a simple energy storage system to generate a very high impulsive torque by which the motor is started before being connected to the mains supply. The spinning motor can then be connected to the mains to operate in a standard Steinmetz connection without incurring high inrush currents, if the moment of mains connection is properly timed. This paper presents a transient model and an accompanying parameter estimation method through which the transient behavior of three-phase induction motors operated with FAS can be analyzed. The proposed model is based on instantaneous symmetrical components and is used to investigate a 3 kW motor started under various operating conditions. The proposed parameter estimation method and the developed transient model are both validated by experimental results. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4358745&sortType%3Das [...]

Design and analysis of an interior permanent magnet (IPM) machine with very wide constant power operation range / Dutta, R. 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. 25 - 33 Titre : Design and analysis of an interior permanent magnet (IPM) machine with very wide constant power operation range Type de document : texte imprimé Auteurs : Dutta, R., Auteur ; Rahman, M.F., Auteur Année de publication : 2008 Article en page(s) : pp. 25 - 33 Note générale : Energy conversion Langues : Anglais (eng) Mots-clés : Permanent  magnet  machines;  rotors;  stators Résumé : This paper evaluates the design of a new segmented interior permanent magnet (SIPM) machine with very wide constant power operation range. The machine uses segmentation of the rotor magnets with the help of iron bridges between magnet segments. This provides for an inherent flux-weakening capability to the interior permanent magnet (IPM) machine. A very wide flux-weakening range has been achieved by using a standard distributed stator winding only. The flux-weakening capability of the proposed SIPM motor was compared to a conventional IPM machine. The same stator was used in both machines for direct comparison. The paper also presents the design optimization process and experimental verification of the performance of the proposed machine as a case study of a 42 V alternator operation in which the speed range is from 600 to 6000 r/min. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4362690&sortType%3Das [...] [article] Design and analysis of an interior permanent magnet (IPM) machine with very wide constant power operation range [texte imprimé] / Dutta, R., Auteur ; Rahman, M.F., Auteur . - 2008 . - pp. 25 - 33. Energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 23 N°1 (Mars 2008) . - pp. 25 - 33 Mots-clés : Permanent  magnet  machines;  rotors;  stators Résumé : This paper evaluates the design of a new segmented interior permanent magnet (SIPM) machine with very wide constant power operation range. The machine uses segmentation of the rotor magnets with the help of iron bridges between magnet segments. This provides for an inherent flux-weakening capability to the interior permanent magnet (IPM) machine. A very wide flux-weakening range has been achieved by using a standard distributed stator winding only. The flux-weakening capability of the proposed SIPM motor was compared to a conventional IPM machine. The same stator was used in both machines for direct comparison. The paper also presents the design optimization process and experimental verification of the performance of the proposed machine as a case study of a 42 V alternator operation in which the speed range is from 600 to 6000 r/min. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4362690&sortType%3Das [...]

Characterization of flux rotation and of the ensuing core losses in the stator of induction motors / Diaz, G. 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. 34 - 41 Titre : Characterization of flux rotation and of the ensuing core losses in the stator of induction motors Type de document : texte imprimé Auteurs : Diaz, G., Auteur ; Gonzalez-Moran, C., Auteur ; Arboleya, P., Auteur Année de publication : 2008 Article en page(s) : pp. 34 - 41 Note générale : Energy conversion Langues : Anglais (eng) Mots-clés : Induction  motors;  iterative  methods;  losses;  magnetic  flux;  rotatio;  stators Résumé : A literature survey reveals that the study of rotational power losses in stator cores has been conventionally performed by means of finite-element analysis. This paper proposes an alternative characterization of rotational power losses in the tooth roots - a region that has been long known as a seat of flux rotation - relating some geometric dimensions to the values of flux density of interest to compute the rotational losses over the region. A simplified computation of maximum and minimum flux densities is proposed based on the trajectories of flux at singular time intervals. This enables the calculation using analytical expressions. For that reason, the proposed approach improves the power losses analysis in early design stages, showing the impact of projected geometries on the total loss estimate. Moreover, it consequently provides a tool to include the rotational losses estimate within optimization-oriented iterative searches. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4453983&sortType%3Das [...] [article] Characterization of flux rotation and of the ensuing core losses in the stator of induction motors [texte imprimé] / Diaz, G., Auteur ; Gonzalez-Moran, C., Auteur ; Arboleya, P., Auteur . - 2008 . - pp. 34 - 41. Energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 23 N°1 (Mars 2008) . - pp. 34 - 41 Mots-clés : Induction  motors;  iterative  methods;  losses;  magnetic  flux;  rotatio;  stators Résumé : A literature survey reveals that the study of rotational power losses in stator cores has been conventionally performed by means of finite-element analysis. This paper proposes an alternative characterization of rotational power losses in the tooth roots - a region that has been long known as a seat of flux rotation - relating some geometric dimensions to the values of flux density of interest to compute the rotational losses over the region. A simplified computation of maximum and minimum flux densities is proposed based on the trajectories of flux at singular time intervals. This enables the calculation using analytical expressions. For that reason, the proposed approach improves the power losses analysis in early design stages, showing the impact of projected geometries on the total loss estimate. Moreover, it consequently provides a tool to include the rotational losses estimate within optimization-oriented iterative searches. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4453983&sortType%3Das [...]

Model-based digital generator control unit for a variable frequency synchronous generator with brushless exciter / Rosado, S. 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. 42 - 52 Titre : Model-based digital generator control unit for a variable frequency synchronous generator with brushless exciter Type de document : texte imprimé Auteurs : Rosado, S., Auteur ; Xiangfei Ma, Auteur ; Francis, G., Auteur Année de publication : 2008 Article en page(s) : pp. 42 - 52 Note générale : Energt conversion Langues : Anglais (eng) Mots-clés : Brushless  machines;  digital  control;  digital  signal  processing  chips;  exciters;  synchronous  generators;  voltage  regulators Résumé : This paper presents the design and implementation of a digital signal processor (DSP)-based generator control unit (GCU) for a variable frequency synchronous generator with brush-less exciter. A novel model-based control algorithm is proposed to better account for the wide operating frequency range and various load conditions. In addition to the model-based inner-loop exciter field current regulator and outer-loop generator voltage regulator, the control algorithm also adopts a generator-model-based d-axis current feed-forward loop to compensate for the load disturbance. Simulation and test results show a considerable performance improvement for the new controller when compared to the existing controllers, including better dynamics, better damping stability margin, and more uniform response over the operating range. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4358735&sortType%3Das [...] [article] Model-based digital generator control unit for a variable frequency synchronous generator with brushless exciter [texte imprimé] / Rosado, S., Auteur ; Xiangfei Ma, Auteur ; Francis, G., Auteur . - 2008 . - pp. 42 - 52. Energt conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 23 N°1 (Mars 2008) . - pp. 42 - 52 Mots-clés : Brushless  machines;  digital  control;  digital  signal  processing  chips;  exciters;  synchronous  generators;  voltage  regulators Résumé : This paper presents the design and implementation of a digital signal processor (DSP)-based generator control unit (GCU) for a variable frequency synchronous generator with brush-less exciter. A novel model-based control algorithm is proposed to better account for the wide operating frequency range and various load conditions. In addition to the model-based inner-loop exciter field current regulator and outer-loop generator voltage regulator, the control algorithm also adopts a generator-model-based d-axis current feed-forward loop to compensate for the load disturbance. Simulation and test results show a considerable performance improvement for the new controller when compared to the existing controllers, including better dynamics, better damping stability margin, and more uniform response over the operating range. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4358735&sortType%3Das [...]

Impact of winding layer number and magnet type on synchronous surface PM machines designed for wide constant-power speed range operation / EL-Refaie, A.M. 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. 53 - 60 Titre : Impact of winding layer number and magnet type on synchronous surface PM machines designed for wide constant-power speed range operation Type de document : texte imprimé Auteurs : EL-Refaie, A.M., Auteur ; Jahns, T.M., Auteur Année de publication : 2008 Article en page(s) : pp. 53 - 60 Note générale : Energy conversion Langues : Anglais (eng) Mots-clés : Machine  windings;  permanent  magnet  machines;  synchronous  machines Résumé : This paper thoroughly investigates the impact of the winding layer number and the choice of magnet type on the performance characteristics of surface permanent magnet (SPM) machines with fractional slot concentrated windings designed for wide speed ranges of constant-power operation. This is accomplished by carefully examining the performance characteristics of three different SPM machines designed for the same set of performance requirements drawn from an automotive direct-drive starter/alternator application. These results show that double-layer stator windings yield lower torque ripple and magnet eddy current losses than do single-layer windings, but can contribute to a lower overload torque capability. Although the adoption of sintered magnets leads to the highest machine torque density, bonded magnets result in a significant reduction of the magnet losses because of their much higher value of resistivity. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4374091&sortType%3Das [...] [article] Impact of winding layer number and magnet type on synchronous surface PM machines designed for wide constant-power speed range operation [texte imprimé] / EL-Refaie, A.M., Auteur ; Jahns, T.M., Auteur . - 2008 . - pp. 53 - 60. Energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 23 N°1 (Mars 2008) . - pp. 53 - 60 Mots-clés : Machine  windings;  permanent  magnet  machines;  synchronous  machines Résumé : This paper thoroughly investigates the impact of the winding layer number and the choice of magnet type on the performance characteristics of surface permanent magnet (SPM) machines with fractional slot concentrated windings designed for wide speed ranges of constant-power operation. This is accomplished by carefully examining the performance characteristics of three different SPM machines designed for the same set of performance requirements drawn from an automotive direct-drive starter/alternator application. These results show that double-layer stator windings yield lower torque ripple and magnet eddy current losses than do single-layer windings, but can contribute to a lower overload torque capability. Although the adoption of sintered magnets leads to the highest machine torque density, bonded magnets result in a significant reduction of the magnet losses because of their much higher value of resistivity. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4374091&sortType%3Das [...]

Research on the cooling system of a 4QT prototype machine used for HEV / Ping Zheng 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. 61 - 67 Titre : Research on the cooling system of a 4QT prototype machine used for HEV Type de document : texte imprimé Auteurs : Ping Zheng, Auteur ; Ranran Liu, Auteur ; Thelin, Peter, Auteur Année de publication : 2008 Article en page(s) : pp. 61 - 67 Note générale : Energy conversion Langues : Anglais (eng) Mots-clés : Cooling;  finite  element  analysis;  hybrid  electric  vehicles;  internal  combustion  engines;  torque  control;  transducers;  velocity  control Résumé : A four-quadrant transducer (4QT) is a hybrid electric vehicle (HEV) power train concept. It can enable the internal combustion engine (ICE) to operate at optimum efficiency during all driving conditions with both torque and speed control. The thermal property is a vital problem due to its special configuration. Aiming to find the hot spot and investigate the cooling system of the 4QT, the thermal field is calculated with finite-element method (FEM). The simulation is validated by the comparisons with the experiment. The influences of the forced-air cooling, water cooling, and the distribution of the cooling channels on the cooling performance are discussed, respectively. The stator air ducts are removed, and 12 water channels evenly distributed in the housing are employed. The design principle of the cooling system is presented. The speed impacts of air flow and water flow are discussed and provide a parameter reference for choosing the forced-air cooling fan and water pump properly. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4454002&sortType%3Das [...] [article] Research on the cooling system of a 4QT prototype machine used for HEV [texte imprimé] / Ping Zheng, Auteur ; Ranran Liu, Auteur ; Thelin, Peter, Auteur . - 2008 . - pp. 61 - 67. Energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 23 N°1 (Mars 2008) . - pp. 61 - 67 Mots-clés : Cooling;  finite  element  analysis;  hybrid  electric  vehicles;  internal  combustion  engines;  torque  control;  transducers;  velocity  control Résumé : A four-quadrant transducer (4QT) is a hybrid electric vehicle (HEV) power train concept. It can enable the internal combustion engine (ICE) to operate at optimum efficiency during all driving conditions with both torque and speed control. The thermal property is a vital problem due to its special configuration. Aiming to find the hot spot and investigate the cooling system of the 4QT, the thermal field is calculated with finite-element method (FEM). The simulation is validated by the comparisons with the experiment. The influences of the forced-air cooling, water cooling, and the distribution of the cooling channels on the cooling performance are discussed, respectively. The stator air ducts are removed, and 12 water channels evenly distributed in the housing are employed. The design principle of the cooling system is presented. The speed impacts of air flow and water flow are discussed and provide a parameter reference for choosing the forced-air cooling fan and water pump properly. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4454002&sortType%3Das [...]

Hybrid-state-model-based time-domain identification of synchronous machine parameters from saturated load rejection test records / Wamkeue, R. 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. 68 - 77 Titre : Hybrid-state-model-based time-domain identification of synchronous machine parameters from saturated load rejection test records Type de document : texte imprimé Auteurs : Wamkeue, R., Auteur ; Baetscher, F., Auteur ; Kamwa, I., Auteur Année de publication : 2008 Article en page(s) : pp. 68 - 77 Note générale : Energy conversion Langues : Anglais (eng) Mots-clés : Equivalent  circuits;  parameter  estimation;  power  factor;  rotors;  synchronous  generators;  synchronous  machines;  time-domain  analysis Résumé : This paper presents a suitable method for time-domain identification of synchronous machine parameters from the hybrid state model recently introduced by the authors in a compact matrix form. The saturated version of this model is developed in terms of generator equivalent-circuit parameters. The load rejection test of a combined resistive/inductive load is performed for the parameter identification while the online symmetrical three-phase short-circuit test is carried out for the model cross-validation. For weak power factor initial loads connected to the generator, the rotor speed is quite constant during the full load rejection test. Thus, the mechanical transients do not have any influence on estimated electrical parameters since they are decoupled from the electrical model of the machine. The method is successfully applied for the parameter identification of 380 V, 3 kVmiddotA, four-pole, 50 Hz saturated synchronous generator. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4454001&sortType%3Das [...] [article] Hybrid-state-model-based time-domain identification of synchronous machine parameters from saturated load rejection test records [texte imprimé] / Wamkeue, R., Auteur ; Baetscher, F., Auteur ; Kamwa, I., Auteur . - 2008 . - pp. 68 - 77. Energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 23 N°1 (Mars 2008) . - pp. 68 - 77 Mots-clés : Equivalent  circuits;  parameter  estimation;  power  factor;  rotors;  synchronous  generators;  synchronous  machines;  time-domain  analysis Résumé : This paper presents a suitable method for time-domain identification of synchronous machine parameters from the hybrid state model recently introduced by the authors in a compact matrix form. The saturated version of this model is developed in terms of generator equivalent-circuit parameters. The load rejection test of a combined resistive/inductive load is performed for the parameter identification while the online symmetrical three-phase short-circuit test is carried out for the model cross-validation. For weak power factor initial loads connected to the generator, the rotor speed is quite constant during the full load rejection test. Thus, the mechanical transients do not have any influence on estimated electrical parameters since they are decoupled from the electrical model of the machine. The method is successfully applied for the parameter identification of 380 V, 3 kVmiddotA, four-pole, 50 Hz saturated synchronous generator. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4454001&sortType%3Das [...]

Semiactive and active piezoelectric vibration controls for switched reluctance machine / Mininger, X. 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. 78 - 85 Titre : Semiactive and active piezoelectric vibration controls for switched reluctance machine Type de document : texte imprimé Auteurs : Mininger, X., Auteur ; Lefeuvre, E., Auteur ; Gabsi, M., Auteur Année de publication : 2008 Article en page(s) : pp. 78 - 85 Note générale : Energy conversion Langues : Anglais (eng) Mots-clés : Damping;  machine  control;  noise  abatement;  piezoelectric  devices;  reluctance  machines;  vibration  control Résumé : This paper presents two vibration control approaches using piezoelectric inserts applied to a switched reluctance machine (SRM) in order to reduce acoustic emission. The semiactive approach, called synchronized switch damping, consists of a particular voltage processing that increases the electromechanical energy conversion of the piezoelectric insert and leads to effective vibration energy dissipation. Piezoelectric inserts can also be considered as actuators: the active technique aims at imposing an adequate force in order to compensate the structure strain originated by the electromagnetic forces. These two techniques are compared on a single-phase structure mechanically similar to that of an SRM. Advantages and drawbacks depending on the chosen technique are then discussed. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4453990&sortType%3Das [...] [article] Semiactive and active piezoelectric vibration controls for switched reluctance machine [texte imprimé] / Mininger, X., Auteur ; Lefeuvre, E., Auteur ; Gabsi, M., Auteur . - 2008 . - pp. 78 - 85. Energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 23 N°1 (Mars 2008) . - pp. 78 - 85 Mots-clés : Damping;  machine  control;  noise  abatement;  piezoelectric  devices;  reluctance  machines;  vibration  control Résumé : This paper presents two vibration control approaches using piezoelectric inserts applied to a switched reluctance machine (SRM) in order to reduce acoustic emission. The semiactive approach, called synchronized switch damping, consists of a particular voltage processing that increases the electromechanical energy conversion of the piezoelectric insert and leads to effective vibration energy dissipation. Piezoelectric inserts can also be considered as actuators: the active technique aims at imposing an adequate force in order to compensate the structure strain originated by the electromagnetic forces. These two techniques are compared on a single-phase structure mechanically similar to that of an SRM. Advantages and drawbacks depending on the chosen technique are then discussed. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4453990&sortType%3Das [...]

Motors with buried magnets for medium-speed applications / Kolehmainen, J. 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. 86 - 91 Titre : Motors with buried magnets for medium-speed applications Type de document : texte imprimé Auteurs : Kolehmainen, J., Auteur ; Ikaheimo, J., Auteur Année de publication : 2008 Article en page(s) : pp. 86 - 91 Note générale : Energy conversion Langues : Anglais (eng) Mots-clés : Finite  element  analysis;  permanent  magnet  motors Résumé : A novel type of mechanically robust buried magnet rotor structure is proposed for medium speed permanent magnet machines. A machine utilizing the construction is built, tested, and compared to another machine with traditional V-shaped poles. The machine is also simulated using finite element method and the results are compared to tested values. The obtained results demonstrate the feasibility of the construction. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4453987&sortType%3Das [...] [article] Motors with buried magnets for medium-speed applications [texte imprimé] / Kolehmainen, J., Auteur ; Ikaheimo, J., Auteur . - 2008 . - pp. 86 - 91. Energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 23 N°1 (Mars 2008) . - pp. 86 - 91 Mots-clés : Finite  element  analysis;  permanent  magnet  motors Résumé : A novel type of mechanically robust buried magnet rotor structure is proposed for medium speed permanent magnet machines. A machine utilizing the construction is built, tested, and compared to another machine with traditional V-shaped poles. The machine is also simulated using finite element method and the results are compared to tested values. The obtained results demonstrate the feasibility of the construction. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4453987&sortType%3Das [...]

A current control scheme with an adaptive internal model for torque ripple minimization and robust current regulation in PMSM drive systems / Mohamed, Y.A.-R.I. 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. 92 - 100 Titre : A current control scheme with an adaptive internal model for torque ripple minimization and robust current regulation in PMSM drive systems Type de document : texte imprimé Auteurs : Mohamed, Y.A.-R.I., Auteur ; El-Saadany, E. F., Auteur Année de publication : 2008 Article en page(s) : pp. 92 - 100 Note générale : Energy conversion Langues : Anglais (eng) Mots-clés : Lyapunov  methods;  closed  loop  systems;  electric  current  control;  machine  control;  permanent  magnet  motors;  robust  control;  synchronous  motor  drives;  torque  control Résumé : This paper addresses the problem of uncertainties in practical permanent magnet synchronous motors (PMSMs), and proposes a simple adaptive internal model within the current feedback and reference current generation structure as a solution. Due to the time varying nature and the high-bandwidth property of uncertainties in a practical PMSM drive system, the internal model is simply chosen as the estimated uncertainty function. To provide a high bandwidth estimate of the uncertainty function with high-noise immunity, a simple adaptation law is derived, in the sense of Lyapunov functions, using the nominal current dynamics. The inclusion of the frequency modes of the disturbances to be eliminated (the flux harmonics and voltage disturbances caused by parameter variation) in the stable closed-loop system introduces very high-attenuation at different frequency modes corresponding to uncertainty modes. Therefore, a robust torque ripple minimization and current regulation performances are yielded. To properly tune the proposed scheme, a stability analysis based on a discrete-time Lyapunov function has been used to determine the stability limits of the adaptation gain. Comparative evaluation results are presented to demonstrate the effectiveness of the proposed control scheme under different operating conditions. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4453985&sortType%3Das [...] [article] A current control scheme with an adaptive internal model for torque ripple minimization and robust current regulation in PMSM drive systems [texte imprimé] / Mohamed, Y.A.-R.I., Auteur ; El-Saadany, E. F., Auteur . - 2008 . - pp. 92 - 100. Energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 23 N°1 (Mars 2008) . - pp. 92 - 100 Mots-clés : Lyapunov  methods;  closed  loop  systems;  electric  current  control;  machine  control;  permanent  magnet  motors;  robust  control;  synchronous  motor  drives;  torque  control Résumé : This paper addresses the problem of uncertainties in practical permanent magnet synchronous motors (PMSMs), and proposes a simple adaptive internal model within the current feedback and reference current generation structure as a solution. Due to the time varying nature and the high-bandwidth property of uncertainties in a practical PMSM drive system, the internal model is simply chosen as the estimated uncertainty function. To provide a high bandwidth estimate of the uncertainty function with high-noise immunity, a simple adaptation law is derived, in the sense of Lyapunov functions, using the nominal current dynamics. The inclusion of the frequency modes of the disturbances to be eliminated (the flux harmonics and voltage disturbances caused by parameter variation) in the stable closed-loop system introduces very high-attenuation at different frequency modes corresponding to uncertainty modes. Therefore, a robust torque ripple minimization and current regulation performances are yielded. To properly tune the proposed scheme, a stability analysis based on a discrete-time Lyapunov function has been used to determine the stability limits of the adaptation gain. Comparative evaluation results are presented to demonstrate the effectiveness of the proposed control scheme under different operating conditions. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4453985&sortType%3Das [...]

Novel multiflux level, three-phase, squirrel-cage induction motor for efficiency and power factor maximization / Ferreira, F.J.T.E. 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. 101 - 109 Titre : Novel multiflux level, three-phase, squirrel-cage induction motor for efficiency and power factor maximization Type de document : texte imprimé Auteurs : Ferreira, F.J.T.E., Auteur ; de Almeida, A.T., Auteur Année de publication : 2008 Article en page(s) : pp. 101 - 109 Note générale : Energy conversion Langues : Anglais (eng) Mots-clés : Power  factor;  squirrel  cage  motors;  stators Résumé : In the European Union, the average load factor of electric motors in both industrial and tertiary sectors is estimated to be less than 60%. However, in some industrial sectors, the average load factor for some motor power ranges can be as low as 25%. Most oversized three-phase induction motors operate with low efficiency and power factor, which is, by far, the most important cause for poor power factor in industrial installations. In the low-load operating periods, motor performance can be improved both in terms of efficiency and power factor if the magnetizing flux is properly regulated. In this paper, a multiflux level, three-phase, squirrel-cage induction motor is proposed, in which the efficiency and power factor can be both maximized as a function of load. This novel motor can be a surplus value in industry due to its flexibility, particularly, for variable load applications in which significant energy savings can be obtained, and can also be used as new or rewound general purpose spare motor (with several levels of voltage, magnetizing flux and/or power). The proposed motor has a stator winding with two sets of turns, sharing the same positions in the stator slots (which can be connected either in series or in parallel). Among all the possible stator winding connections, six modes were selected and analyzed (two of which are new). The basic principles for proper connection mode change are discussed. An electronic device and a contactor concept for automatic connection mode change are proposed. As far as the authors know, this concept is described and analyzed for the first time. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4453984&sortType%3Das [...] [article] Novel multiflux level, three-phase, squirrel-cage induction motor for efficiency and power factor maximization [texte imprimé] / Ferreira, F.J.T.E., Auteur ; de Almeida, A.T., Auteur . - 2008 . - pp. 101 - 109. Energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 23 N°1 (Mars 2008) . - pp. 101 - 109 Mots-clés : Power  factor;  squirrel  cage  motors;  stators Résumé : In the European Union, the average load factor of electric motors in both industrial and tertiary sectors is estimated to be less than 60%. However, in some industrial sectors, the average load factor for some motor power ranges can be as low as 25%. Most oversized three-phase induction motors operate with low efficiency and power factor, which is, by far, the most important cause for poor power factor in industrial installations. In the low-load operating periods, motor performance can be improved both in terms of efficiency and power factor if the magnetizing flux is properly regulated. In this paper, a multiflux level, three-phase, squirrel-cage induction motor is proposed, in which the efficiency and power factor can be both maximized as a function of load. This novel motor can be a surplus value in industry due to its flexibility, particularly, for variable load applications in which significant energy savings can be obtained, and can also be used as new or rewound general purpose spare motor (with several levels of voltage, magnetizing flux and/or power). The proposed motor has a stator winding with two sets of turns, sharing the same positions in the stator slots (which can be connected either in series or in parallel). Among all the possible stator winding connections, six modes were selected and analyzed (two of which are new). The basic principles for proper connection mode change are discussed. An electronic device and a contactor concept for automatic connection mode change are proposed. As far as the authors know, this concept is described and analyzed for the first time. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4453984&sortType%3Das [...]

Design and operation of power converter for microturbine powered distributed generator with capacity expansion capability / Pai, Fu-Sheng 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. 110 - 118 Titre : Design and operation of power converter for microturbine powered distributed generator with capacity expansion capability Type de document : texte imprimé Auteurs : Pai, Fu-Sheng, Auteur ; Shyh-Jier, Huang, Auteur Année de publication : 2008 Article en page(s) : pp. 110 - 118 Note générale : Energy conversion Langues : Anglais (eng) Mots-clés : Distributed  power  generation;  gas  turbines;  power  convertors;  turbogenerators Résumé : In this paper, a novel approach for the design of power converter for a microturbine is proposed. In the method, a unified control scheme as well as a novel modular arrangement has been developed such that the inverter circuit is capable of parallel operation of different modules in anticipation of reaching high-capacity requirements. To validate the effectiveness of this proposed approach, scenarios including the loss of grid and grid-connected operation were both tested through the software simulation and experimental validation. From the test results, they have consolidated the feasibility and practicability of the approach for the applications considered. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4358742&sortType%3Das [...] [article] Design and operation of power converter for microturbine powered distributed generator with capacity expansion capability [texte imprimé] / Pai, Fu-Sheng, Auteur ; Shyh-Jier, Huang, Auteur . - 2008 . - pp. 110 - 118. Energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 23 N°1 (Mars 2008) . - pp. 110 - 118 Mots-clés : Distributed  power  generation;  gas  turbines;  power  convertors;  turbogenerators Résumé : In this paper, a novel approach for the design of power converter for a microturbine is proposed. In the method, a unified control scheme as well as a novel modular arrangement has been developed such that the inverter circuit is capable of parallel operation of different modules in anticipation of reaching high-capacity requirements. To validate the effectiveness of this proposed approach, scenarios including the loss of grid and grid-connected operation were both tested through the software simulation and experimental validation. From the test results, they have consolidated the feasibility and practicability of the approach for the applications considered. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4358742&sortType%3Das [...]

Large offshore DFIG-based wind farm with line-commutated HVDC connection to the main grid / Bozhko, Serhiy 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. 119 - 127 Titre : Large offshore DFIG-based wind farm with line-commutated HVDC connection to the main grid : engineering studies Type de document : texte imprimé Auteurs : Bozhko, Serhiy, Auteur ; Asher, G., Auteur ; Risheng Li, Auteur Année de publication : 2008 Article en page(s) : pp. 119 - 127 Note générale : Energy conversion Langues : Anglais (eng) Mots-clés : HVDC  power  convertors;  asynchronous  generators;  commutation;  offshore  installations;  power  system  CAD;  power  system  control;  power  system  simulation;  static  VAr  compensators;  wind  power  plants Résumé : The paper considers a solution for integration of large offshore doubly fed induction generator-based wind farms with a common collection bus controlled by a STATCOM into the main onshore grid using line-commutated high-voltage dc connection. A design procedure is described and the controlled system is validated using PSCAD/EMTDC simulations confirming high performance of the proposed control strategy in both normal operation conditions and faults. Engineering issues related to STATCOM capacitor sizing and reduction of STATCOM rating are considered and their effectiveness is confirmed. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4453977&sortType%3Das [...] [article] Large offshore DFIG-based wind farm with line-commutated HVDC connection to the main grid : engineering studies [texte imprimé] / Bozhko, Serhiy, Auteur ; Asher, G., Auteur ; Risheng Li, Auteur . - 2008 . - pp. 119 - 127. Energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 23 N°1 (Mars 2008) . - pp. 119 - 127 Mots-clés : HVDC  power  convertors;  asynchronous  generators;  commutation;  offshore  installations;  power  system  CAD;  power  system  control;  power  system  simulation;  static  VAr  compensators;  wind  power  plants Résumé : The paper considers a solution for integration of large offshore doubly fed induction generator-based wind farms with a common collection bus controlled by a STATCOM into the main onshore grid using line-commutated high-voltage dc connection. A design procedure is described and the controlled system is validated using PSCAD/EMTDC simulations confirming high performance of the proposed control strategy in both normal operation conditions and faults. Engineering issues related to STATCOM capacitor sizing and reduction of STATCOM rating are considered and their effectiveness is confirmed. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4453977&sortType%3Das [...]

Universal single-stage grid-connected inverter / Prasad, B.S. 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. 128 - 137 Titre : Universal single-stage grid-connected inverter Type de document : texte imprimé Auteurs : Prasad, B.S., Auteur ; Jain, S., Auteur ; Agarwal, V., Auteur Année de publication : 2008 Article en page(s) : pp. 128 - 137 Note générale : Energy conversion Langues : Anglais (eng) Mots-clés : PWM  invertors;  distributed  power  generation;  power  convertors Résumé : A new single-stage grid-connected inverter, suitable for distributed generation applications, is proposed. The inverter is universal in the sense that it can be switched between buck, boost, and buck--boost configurations by appropriately altering the pulse width modular (PWM) control. Discontinuous current mode (DCM) operation is implemented to facilitate shuffling between configurations during the converter operation. Such flexibility ensures maximum benefit of the buck, boost, and the buck--boost operations (e.g., low device stresses, higher efficiency, higher boosting capability, etc.). The PWM is achieved by comparing a high frequency carrier (triangular) waveform with a suitable reference waveform, which is not necessarily sinusoidal, but has a shape specific to the individual configuration and is derived by equating the power fed into the grid with that extracted from the source during each switching cycle. The values of the components (inductors and capacitors) need to be optimized so that DCM is maintained and the required amount of energy is transferred to the grid in all the three configurations during their respective operation. All the design expressions have been derived. A salient feature of this inverter is its compatibility with various types of sources (PV array, fuel cell, etc.) with varying voltage levels and control requirements. Being single-stage, the proposed topology offers additional advantages like modularity, compactness, and low cost. All the details of simulation and experimental work are presented. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4374094&sortType%3Das [...] [article] Universal single-stage grid-connected inverter [texte imprimé] / Prasad, B.S., Auteur ; Jain, S., Auteur ; Agarwal, V., Auteur . - 2008 . - pp. 128 - 137. Energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 23 N°1 (Mars 2008) . - pp. 128 - 137 Mots-clés : PWM  invertors;  distributed  power  generation;  power  convertors Résumé : A new single-stage grid-connected inverter, suitable for distributed generation applications, is proposed. The inverter is universal in the sense that it can be switched between buck, boost, and buck--boost configurations by appropriately altering the pulse width modular (PWM) control. Discontinuous current mode (DCM) operation is implemented to facilitate shuffling between configurations during the converter operation. Such flexibility ensures maximum benefit of the buck, boost, and the buck--boost operations (e.g., low device stresses, higher efficiency, higher boosting capability, etc.). The PWM is achieved by comparing a high frequency carrier (triangular) waveform with a suitable reference waveform, which is not necessarily sinusoidal, but has a shape specific to the individual configuration and is derived by equating the power fed into the grid with that extracted from the source during each switching cycle. The values of the components (inductors and capacitors) need to be optimized so that DCM is maintained and the required amount of energy is transferred to the grid in all the three configurations during their respective operation. All the design expressions have been derived. A salient feature of this inverter is its compatibility with various types of sources (PV array, fuel cell, etc.) with varying voltage levels and control requirements. Being single-stage, the proposed topology offers additional advantages like modularity, compactness, and low cost. All the details of simulation and experimental work are presented. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4374094&sortType%3Das [...]

Position control of induction and DC servomotors / Shahnazi, R. 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. 138 - 147 Titre : Position control of induction and DC servomotors Type de document : texte imprimé Auteurs : Shahnazi, R., Auteur ; H. M. Shanechi, Auteur ; N. Pariz, Auteur Année de publication : 2008 Article en page(s) : pp. 138 - 147 Note générale : Energy conversion Langues : Anglais (eng) Mots-clés : Adaptive  control;  DC  motors;  fuzzy  systems;  induction  motors;  sliding  mode  control  (SMC) Résumé : A position control of a class of servomotors is addressed in this paper via a novel adaptive fuzzy PI sliding mode control. The premise and the consequence parts of the fuzzy rules are tuned with adaptive schemes. To attenuate chattering effectively, the discontinuous control is approximated by an adaptive PI control structure. Moreover, the bound of the discontinuous control term is assumed to be unknown, and an adaptive mechanism is used to estimate this bound. All adaptive laws are derived via Lyapunov synthesis method, thereby guaranteeing the closed-loop stability. The proposed approach has the added advantage that, for external disturbances, it only requires a bound to exist, without needing to know the magnitude of this bound. The proposed controller is applied to control a model of uncertain induction servomotor subject to significant disturbances and a model of DC servomotor with unknown parameters and uncertainty in load condition. The analysis of simulations reveals the effectiveness of the proposed method in controlling servomotors in terms of significant reduction in chattering while maintaining asymptotic convergence. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4392498&sortType%3Das [...] [article] Position control of induction and DC servomotors [texte imprimé] / Shahnazi, R., Auteur ; H. M. Shanechi, Auteur ; N. Pariz, Auteur . - 2008 . - pp. 138 - 147. Energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 23 N°1 (Mars 2008) . - pp. 138 - 147 Mots-clés : Adaptive  control;  DC  motors;  fuzzy  systems;  induction  motors;  sliding  mode  control  (SMC) Résumé : A position control of a class of servomotors is addressed in this paper via a novel adaptive fuzzy PI sliding mode control. The premise and the consequence parts of the fuzzy rules are tuned with adaptive schemes. To attenuate chattering effectively, the discontinuous control is approximated by an adaptive PI control structure. Moreover, the bound of the discontinuous control term is assumed to be unknown, and an adaptive mechanism is used to estimate this bound. All adaptive laws are derived via Lyapunov synthesis method, thereby guaranteeing the closed-loop stability. The proposed approach has the added advantage that, for external disturbances, it only requires a bound to exist, without needing to know the magnitude of this bound. The proposed controller is applied to control a model of uncertain induction servomotor subject to significant disturbances and a model of DC servomotor with unknown parameters and uncertainty in load condition. The analysis of simulations reveals the effectiveness of the proposed method in controlling servomotors in terms of significant reduction in chattering while maintaining asymptotic convergence. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4392498&sortType%3Das [...]

Control algorithm of fuel cell and batteries for distributed generation system / Thounthong, P. 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. 148 - 155 Titre : Control algorithm of fuel cell and batteries for distributed generation system Type de document : texte imprimé Auteurs : Thounthong, P., Auteur ; Raël, S., Auteur ; Davat, B., Auteur Année de publication : 2008 Article en page(s) : pp. 148 - 155 Note générale : Energy conversion Langues : Anglais (eng) Mots-clés : Distributed  power  generation;  electric  vehicles;  energy  storage;  hybrid  power  systems;  power  system  control;  proton  exchange  membrane  fuel  cells;  secondary  cells Résumé : This paper intends to propose a novel control algorithm for utilizing a polymer electrolyte membrane fuel cell (PEMFC) as a main power source and batteries as a complementary source, for hybrid power sources for distributed generation system, particularly for future electric vehicle applications. The control, which takes into account the slow dynamics of a fuel cell (FC) in order to avoid fuel (hydrogen and air) starvation problems, is obviously simpler than state machines used for hybrid source control. The control strategy lies in using an FC for supplying energy to battery and load at the dc bus. The structure is an FC current, battery current, and battery state-of-charge (SOC) cascade control. To validate the proposed principle, a hardware system is realized by analogical circuits for the FC current loop and numerical calculation (dSPACE) for the battery current and SOC loops. Experimental results with small-scale devices (a 500 W PEM FC and 33 Ah, 48 V lead-acid battery bank) illustrate the excellent control scheme during motor drive cycles. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4358732&sortType%3Das [...] [article] Control algorithm of fuel cell and batteries for distributed generation system [texte imprimé] / Thounthong, P., Auteur ; Raël, S., Auteur ; Davat, B., Auteur . - 2008 . - pp. 148 - 155. Energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 23 N°1 (Mars 2008) . - pp. 148 - 155 Mots-clés : Distributed  power  generation;  electric  vehicles;  energy  storage;  hybrid  power  systems;  power  system  control;  proton  exchange  membrane  fuel  cells;  secondary  cells Résumé : This paper intends to propose a novel control algorithm for utilizing a polymer electrolyte membrane fuel cell (PEMFC) as a main power source and batteries as a complementary source, for hybrid power sources for distributed generation system, particularly for future electric vehicle applications. The control, which takes into account the slow dynamics of a fuel cell (FC) in order to avoid fuel (hydrogen and air) starvation problems, is obviously simpler than state machines used for hybrid source control. The control strategy lies in using an FC for supplying energy to battery and load at the dc bus. The structure is an FC current, battery current, and battery state-of-charge (SOC) cascade control. To validate the proposed principle, a hardware system is realized by analogical circuits for the FC current loop and numerical calculation (dSPACE) for the battery current and SOC loops. Experimental results with small-scale devices (a 500 W PEM FC and 33 Ah, 48 V lead-acid battery bank) illustrate the excellent control scheme during motor drive cycles. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4358732&sortType%3Das [...]

Novel circuit configuration for compensating for the reactive power of induction generator / Jinn-Chang Wu 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. 156 - 162 Titre : Novel circuit configuration for compensating for the reactive power of induction generator Type de document : texte imprimé Auteurs : Jinn-Chang Wu, Auteur Année de publication : 2008 Article en page(s) : pp. 156 - 162 Note générale : Energy conversion Langues : Anglais (eng) Mots-clés : Asynchronous  generators;  power  capacitors;  reactive  power;  static  VAr  compensators Résumé : A novel circuit configuration for compensating for the reactive power of an induction generator is proposed in this paper. This reactive power compensator includes an ac power capacitor set serially connected to a small-capacity power converter. The ac power capacitor is adapted to provide basic reactive power and reduce the voltage rating and power capacity of the power converter. Because, the ac power capacitor set can also effectively block the dc voltage generated by the power converter to the utility, the salient point of the proposed reactive power compensator is that only a two-arm structure is required for the power converter in the three-phase three-wire application. Consequently, the required number of power electronic switches for the power converter is reduced. The current, generated by the induction generator system, supplied back to the utility is sinusoidal and in phase with the utility voltage following compensation of the proposed reactive power compensator. A prototype is developed and tested to verify the performance of the proposed reactive power compensator. The experimental results show that the performance of the proposed reactive power compensator is as expected. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4358733&sortType%3Das [...] [article] Novel circuit configuration for compensating for the reactive power of induction generator [texte imprimé] / Jinn-Chang Wu, Auteur . - 2008 . - pp. 156 - 162. Energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 23 N°1 (Mars 2008) . - pp. 156 - 162 Mots-clés : Asynchronous  generators;  power  capacitors;  reactive  power;  static  VAr  compensators Résumé : A novel circuit configuration for compensating for the reactive power of an induction generator is proposed in this paper. This reactive power compensator includes an ac power capacitor set serially connected to a small-capacity power converter. The ac power capacitor is adapted to provide basic reactive power and reduce the voltage rating and power capacity of the power converter. Because, the ac power capacitor set can also effectively block the dc voltage generated by the power converter to the utility, the salient point of the proposed reactive power compensator is that only a two-arm structure is required for the power converter in the three-phase three-wire application. Consequently, the required number of power electronic switches for the power converter is reduced. The current, generated by the induction generator system, supplied back to the utility is sinusoidal and in phase with the utility voltage following compensation of the proposed reactive power compensator. A prototype is developed and tested to verify the performance of the proposed reactive power compensator. The experimental results show that the performance of the proposed reactive power compensator is as expected. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4358733&sortType%3Das [...]

Multistate wind energy conversion system models for adequacy assessment of generating systems incorporating wind energy / Billinton, R. 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. 163 - 170 Titre : Multistate wind energy conversion system models for adequacy assessment of generating systems incorporating wind energy Type de document : texte imprimé Auteurs : Billinton, R., Auteur ; Yi Cao, Auteur Année de publication : 2008 Article en page(s) : pp. 163 - 170 Note générale : Energy conversion Langues : Anglais (eng) Mots-clés : Monte  Carlo  methods;  power  system  reliability;  wind  power Résumé : Wind energy is considered to be a very promising alternative for power generation because of its tremendous environmental, social, and economic benefits. Electrical power generation from wind energy behaves quite differently from that of conventional sources. The fundamentally different operating characteristics of those facilities, therefore, affect the power system reliability in a manner different from that of the conventional systems. This paper is focused on the development of suitable models for wind energy conversion systems, in adequacy assessments of generating systems, using wind energy. These analytical models can be used in the conventional generating system adequacy assessment utilizing analytical or Monte Carlo state-sampling techniques. This paper shows that a five-state wind energy conversion system model can be used to provide a reasonable assessment of the practical power system adequacy studies, using an analytical method, or a state-sampling simulation approach. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4453976&sortType%3Das [...] [article] Multistate wind energy conversion system models for adequacy assessment of generating systems incorporating wind energy [texte imprimé] / Billinton, R., Auteur ; Yi Cao, Auteur . - 2008 . - pp. 163 - 170. Energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 23 N°1 (Mars 2008) . - pp. 163 - 170 Mots-clés : Monte  Carlo  methods;  power  system  reliability;  wind  power Résumé : Wind energy is considered to be a very promising alternative for power generation because of its tremendous environmental, social, and economic benefits. Electrical power generation from wind energy behaves quite differently from that of conventional sources. The fundamentally different operating characteristics of those facilities, therefore, affect the power system reliability in a manner different from that of the conventional systems. This paper is focused on the development of suitable models for wind energy conversion systems, in adequacy assessments of generating systems, using wind energy. These analytical models can be used in the conventional generating system adequacy assessment utilizing analytical or Monte Carlo state-sampling techniques. This paper shows that a five-state wind energy conversion system model can be used to provide a reasonable assessment of the practical power system adequacy studies, using an analytical method, or a state-sampling simulation approach. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4453976&sortType%3Das [...]

Ragone plot comparison of radioisotope cells and the direct sodium borohydride/hydrogen peroxide fuel cell with chemical batteries / Romer, M. 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. 171 - 178 Titre : Ragone plot comparison of radioisotope cells and the direct sodium borohydride/hydrogen peroxide fuel cell with chemical batteries Type de document : texte imprimé Auteurs : Romer, M., Auteur ; Miley, G.H., Auteur ; Nie Luo, Auteur Année de publication : 2008 Article en page(s) : pp. 171 - 178 Note générale : Energy conversion Langues : Anglais (eng) Mots-clés : Cells  (electric);  energy  storage;  fuel  cells;  hydrogen  compounds;  nuclear  power;  sodium  compounds Résumé : Radioisotope cells (RCs) and a direct sodium borohydride/hydrogen peroxide fuel cell ( FC) are compared to conventional chemical batteries through Ragone plots of theoretical (RCs) and experimental (chemical batteries and FC) data. It is found that the RCs are projected to have superior specific energy but inferior specific power, while the borohydride/peroxide FC shows an impressive range for both parameters. Thus, RCs may be especially useful in battery charging, communications, or other applications that require a long-lived, low-power source or periodic pulses of energy. While the borohydride/peroxide FC can be scaled to a variety of high-power applications, it is especially well suited for space and undersea use where air independence is essential. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4453997&sortType%3Das [...] [article] Ragone plot comparison of radioisotope cells and the direct sodium borohydride/hydrogen peroxide fuel cell with chemical batteries [texte imprimé] / Romer, M., Auteur ; Miley, G.H., Auteur ; Nie Luo, Auteur . - 2008 . - pp. 171 - 178. Energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 23 N°1 (Mars 2008) . - pp. 171 - 178 Mots-clés : Cells  (electric);  energy  storage;  fuel  cells;  hydrogen  compounds;  nuclear  power;  sodium  compounds Résumé : Radioisotope cells (RCs) and a direct sodium borohydride/hydrogen peroxide fuel cell ( FC) are compared to conventional chemical batteries through Ragone plots of theoretical (RCs) and experimental (chemical batteries and FC) data. It is found that the RCs are projected to have superior specific energy but inferior specific power, while the borohydride/peroxide FC shows an impressive range for both parameters. Thus, RCs may be especially useful in battery charging, communications, or other applications that require a long-lived, low-power source or periodic pulses of energy. While the borohydride/peroxide FC can be scaled to a variety of high-power applications, it is especially well suited for space and undersea use where air independence is essential. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4453997&sortType%3Das [...]

Feedback-linearization-based nonlinear control for PEM fuel cells / Woon Ki Na 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. 179 - 190 Titre : Feedback-linearization-based nonlinear control for PEM fuel cells Type de document : texte imprimé Auteurs : Woon Ki Na, Auteur ; Bei Gou, Auteur Année de publication : 2008 Article en page(s) : pp. 179 - 190 Note générale : Energy conversion Langues : Anglais (eng) Mots-clés : MIMO  systems;  linearisation  techniques;  nonlinear  control  systems;  proton  exchange  membrane  fuel  cells Résumé : This paper presents a dynamic nonlinear model for polymer electrolyte membrane fuel cells (PEMFCs). A nonlinear controller is designed based on the proposed model to prolong the stack life of the PEM fuel cells. Since it is known that large deviations between hydrogen and oxygen partial pressures can cause severe membrane damage in the fuel cell, feedback linearization is applied to the PEM fuel cell system so that the deviation can be kept as small as possible during disturbances or load variations. A dynamic PEM fuel cell model is proposed as a nonlinear, multiple-input multiple-output system so that feedback linearization can be directly utilized. During the control design, hydrogen and oxygen inlet flow rates are defined as the control variables, and the pressures of hydrogen and oxygen are appropriately defined as the control objectives. The details of the design of the control scheme are provided in the paper. The proposed dynamic model was tested by comparing the simulation results with the experimental data previously published. The simulation results show that PEMFCs equipped with the proposed nonlinear controls have better transient performances than those with linear controls. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4453991&sortType%3Das [...] [article] Feedback-linearization-based nonlinear control for PEM fuel cells [texte imprimé] / Woon Ki Na, Auteur ; Bei Gou, Auteur . - 2008 . - pp. 179 - 190. Energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 23 N°1 (Mars 2008) . - pp. 179 - 190 Mots-clés : MIMO  systems;  linearisation  techniques;  nonlinear  control  systems;  proton  exchange  membrane  fuel  cells Résumé : This paper presents a dynamic nonlinear model for polymer electrolyte membrane fuel cells (PEMFCs). A nonlinear controller is designed based on the proposed model to prolong the stack life of the PEM fuel cells. Since it is known that large deviations between hydrogen and oxygen partial pressures can cause severe membrane damage in the fuel cell, feedback linearization is applied to the PEM fuel cell system so that the deviation can be kept as small as possible during disturbances or load variations. A dynamic PEM fuel cell model is proposed as a nonlinear, multiple-input multiple-output system so that feedback linearization can be directly utilized. During the control design, hydrogen and oxygen inlet flow rates are defined as the control variables, and the pressures of hydrogen and oxygen are appropriately defined as the control objectives. The details of the design of the control scheme are provided in the paper. The proposed dynamic model was tested by comparing the simulation results with the experimental data previously published. The simulation results show that PEMFCs equipped with the proposed nonlinear controls have better transient performances than those with linear controls. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4453991&sortType%3Das [...]

One day ahead prediction of wind speed and direction / El-Fouly, T.H.M. 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. 191 - 201 Titre : One day ahead prediction of wind speed and direction Type de document : texte imprimé Auteurs : El-Fouly, T.H.M., Auteur ; El-Saadany, E. F., Auteur ; Salama, M.M.A., Auteur Année de publication : 2008 Article en page(s) : pp. 191 - 201 Note générale : Energy conversion Langues : Anglais (eng) Mots-clés : Least  squares  approximations;  time  series;  wind  power Résumé : This paper presents a new technique for predicting wind speed and direction. This technique is based on using a linear time-series-based model relating the predicted interval to its corresponding one- and two-year old data. The accuracy of the model for predicting wind speeds and directions up to 24 h ahead have been investigated using two sets of data recorded during winter and summer season at Madison weather station. Generated results are compared with their corresponding values when using the persistent model. The presented results validate the effectiveness and accuracy of the proposed prediction model for wind speed and direction. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4433186&sortType%3Das [...] [article] One day ahead prediction of wind speed and direction [texte imprimé] / El-Fouly, T.H.M., Auteur ; El-Saadany, E. F., Auteur ; Salama, M.M.A., Auteur . - 2008 . - pp. 191 - 201. Energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 23 N°1 (Mars 2008) . - pp. 191 - 201 Mots-clés : Least  squares  approximations;  time  series;  wind  power Résumé : This paper presents a new technique for predicting wind speed and direction. This technique is based on using a linear time-series-based model relating the predicted interval to its corresponding one- and two-year old data. The accuracy of the model for predicting wind speeds and directions up to 24 h ahead have been investigated using two sets of data recorded during winter and summer season at Madison weather station. Generated results are compared with their corresponding values when using the persistent model. The presented results validate the effectiveness and accuracy of the proposed prediction model for wind speed and direction. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4433186&sortType%3Das [...]

Wind–diesel generation using doubly fed induction machines / Pena, R. 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. 202 - 214 Titre : Wind–diesel generation using doubly fed induction machines Type de document : texte imprimé Auteurs : Pena, R., Auteur ; Cardenas, R., Auteur ; Proboste, J., Auteur Année de publication : 2008 Article en page(s) : pp. 202 - 214 Note générale : Energy conversion Langues : Anglais (eng) Mots-clés : Asynchronous  generators;  diesel  engines;  frequency  control;  hybrid  power  systems;  machine  vector  control;  power  generation  control;  voltage  control;  wind  turbines Résumé : In this paper, the modeling and control strategy of a wind-diesel generation system are discussed. In the proposed topology, the diesel engine and the wind turbine are both variable-speed machines, allowing maximum fuel efficiency and optimal energy capture from the wind. A vector-controlled doubly fed induction generator is used in each generation system to provide fixed voltage and frequency to the load. The diesel unit balances the system power and changes the speed according to the power demand in order to minimize the fuel consumption. The electrical torque of the wind system generator is regulated to maximize the energy capture of the wind turbine. The advantages of operating a diesel engine at variable speed are discussed. The dynamic and steady-state operation of the wind-diesel system, including voltage and frequency control, active power balancing, and control of the reactive power supplied to the grid/load are analyzed in this paper. Experimental results, from a 3-kW experimental prototype are presented in this paper. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4453995&sortType%3Das [...] [article] Wind–diesel generation using doubly fed induction machines [texte imprimé] / Pena, R., Auteur ; Cardenas, R., Auteur ; Proboste, J., Auteur . - 2008 . - pp. 202 - 214. Energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 23 N°1 (Mars 2008) . - pp. 202 - 214 Mots-clés : Asynchronous  generators;  diesel  engines;  frequency  control;  hybrid  power  systems;  machine  vector  control;  power  generation  control;  voltage  control;  wind  turbines Résumé : In this paper, the modeling and control strategy of a wind-diesel generation system are discussed. In the proposed topology, the diesel engine and the wind turbine are both variable-speed machines, allowing maximum fuel efficiency and optimal energy capture from the wind. A vector-controlled doubly fed induction generator is used in each generation system to provide fixed voltage and frequency to the load. The diesel unit balances the system power and changes the speed according to the power demand in order to minimize the fuel consumption. The electrical torque of the wind system generator is regulated to maximize the energy capture of the wind turbine. The advantages of operating a diesel engine at variable speed are discussed. The dynamic and steady-state operation of the wind-diesel system, including voltage and frequency control, active power balancing, and control of the reactive power supplied to the grid/load are analyzed in this paper. Experimental results, from a 3-kW experimental prototype are presented in this paper. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4453995&sortType%3Das [...]

Optimal design of an “energy tower” power plant / Omer, E. 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. 215 - 225 Titre : Optimal design of an “energy tower” power plant Type de document : texte imprimé Auteurs : Omer, E., Auteur ; Guetta, R., Auteur ; Ioslovich, I., Auteur Année de publication : 2008 Article en page(s) : pp. 215 - 225 Note générale : Energy conversion Langues : Anglais (eng) Mots-clés : Hybrid  power  systems;  linear  programming;  power  generation  planning;  solar  power Résumé : The energy tower (ET) is a power plant that uses seawater and solar energy accumulated in hot dry desert air to produce electricity. An optimization algorithm was designed and programmed for the design of an ET that also includes water reservoirs, pipes, and pumps. The algorithm is a variant of the block coordinate descent method, where one subproblem is formulated as a linear programming problem, and a second subproblem usually has an analytic solution. If the analytic solution is nonfeasible, a variant of the quasi-Newton algorithm is used instead. The algorithm was tested with input information from the arid area near Eilat, the Red Sea, Israel. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4374093&sortType%3Das [...] [article] Optimal design of an “energy tower” power plant [texte imprimé] / Omer, E., Auteur ; Guetta, R., Auteur ; Ioslovich, I., Auteur . - 2008 . - pp. 215 - 225. Energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 23 N°1 (Mars 2008) . - pp. 215 - 225 Mots-clés : Hybrid  power  systems;  linear  programming;  power  generation  planning;  solar  power Résumé : The energy tower (ET) is a power plant that uses seawater and solar energy accumulated in hot dry desert air to produce electricity. An optimization algorithm was designed and programmed for the design of an ET that also includes water reservoirs, pipes, and pumps. The algorithm is a variant of the block coordinate descent method, where one subproblem is formulated as a linear programming problem, and a second subproblem usually has an analytic solution. If the analytic solution is nonfeasible, a variant of the quasi-Newton algorithm is used instead. The algorithm was tested with input information from the arid area near Eilat, the Red Sea, Israel. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4374093&sortType%3Das [...]

STATCOM impact study on the integration of a large wind farm into a weak loop power system / Chong Han 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. 226 - 233 Titre : STATCOM impact study on the integration of a large wind farm into a weak loop power system Type de document : texte imprimé Auteurs : Chong Han, Auteur ; Huang, A.Q., Auteur ; Baran, M.E., Auteur Année de publication : 2008 Article en page(s) : pp. 226 - 233 Note générale : Energy conversion Langues : Anglais (eng) Mots-clés : SCADA  systems;  power  supply  quality;  power  system  control;  power  system  stability;  static  VAr  compensators;  voltage  control;  wind  power Résumé : Recently, renewable wind energy is enjoying a rapid growth globally to become an important green electricity source to replace polluting and exhausting fossil fuel. However, with wind being an uncontrollable resource and the nature of distributed wind induction generators, integrating a large-scale wind-farm into a power system poses challenges, particularly in a weak power system. In the paper, the impact of static synchronous compensator (STATCOM) to facilitate the integration of a large wind farm (WF) into a weak power system is studied. First, an actual weak power system with two nearby large WFs is introduced. Based on the field SCADA data analysis, the power quality issues are highlighted and a centralized STATCOM is proposed to solve them, particularly the short-term (seconds to minutes) voltage fluctuations. Second, a model of the system, WF, and STATCOM for steady state and dynamic impact study is presented, and the model is validated by comparing with the actual field data. Using simulated PV and QV curves, voltage control and stability issues are analyzed, and the size and location of STATCOM are assessed. Finally, a STATCOM control strategy for voltage fluctuation suppression is presented and dynamic simulations verify the performance of proposed STATCOM and its control strategy. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4358734&sortType%3Das [...] [article] STATCOM impact study on the integration of a large wind farm into a weak loop power system [texte imprimé] / Chong Han, Auteur ; Huang, A.Q., Auteur ; Baran, M.E., Auteur . - 2008 . - pp. 226 - 233. Energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 23 N°1 (Mars 2008) . - pp. 226 - 233 Mots-clés : SCADA  systems;  power  supply  quality;  power  system  control;  power  system  stability;  static  VAr  compensators;  voltage  control;  wind  power Résumé : Recently, renewable wind energy is enjoying a rapid growth globally to become an important green electricity source to replace polluting and exhausting fossil fuel. However, with wind being an uncontrollable resource and the nature of distributed wind induction generators, integrating a large-scale wind-farm into a power system poses challenges, particularly in a weak power system. In the paper, the impact of static synchronous compensator (STATCOM) to facilitate the integration of a large wind farm (WF) into a weak power system is studied. First, an actual weak power system with two nearby large WFs is introduced. Based on the field SCADA data analysis, the power quality issues are highlighted and a centralized STATCOM is proposed to solve them, particularly the short-term (seconds to minutes) voltage fluctuations. Second, a model of the system, WF, and STATCOM for steady state and dynamic impact study is presented, and the model is validated by comparing with the actual field data. Using simulated PV and QV curves, voltage control and stability issues are analyzed, and the size and location of STATCOM are assessed. Finally, a STATCOM control strategy for voltage fluctuation suppression is presented and dynamic simulations verify the performance of proposed STATCOM and its control strategy. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4358734&sortType%3Das [...]

MCMC for wind power simulation / Papaefthymiou, G. 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. 234 - 240 Titre : MCMC for wind power simulation Type de document : texte imprimé Auteurs : Papaefthymiou, G., Auteur ; Klockl, B., Auteur Année de publication : 2008 Article en page(s) : pp. 234 - 240 Note générale : Energy conversion Langues : Anglais (eng) Mots-clés : Markov  processes;  Monte  Carlo  methods;  correlation  methods;  power  system  simulation;  probability;  wind  power Résumé : This paper contributes a Markov chain Monte Carlo (MCMC) method for the direct generation of synthetic time series of wind power output. It is shown that obtaining a stochastic model directly in the wind power domain leads to reduced number of states and to lower order of the Markov chain at equal power data resolution. The estimation quality of the stochastic model is positively influenced since in the power domain, a lower number of independent parameters is estimated from a given amount of recorded data. The simulation results prove that this method offers excellent fit for both the probability density function and the autocorrelation function of the generated wind power time series. The method is a first step toward simple stochastic black-box models for wind generation. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4453993&sortType%3Das [...] [article] MCMC for wind power simulation [texte imprimé] / Papaefthymiou, G., Auteur ; Klockl, B., Auteur . - 2008 . - pp. 234 - 240. Energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 23 N°1 (Mars 2008) . - pp. 234 - 240 Mots-clés : Markov  processes;  Monte  Carlo  methods;  correlation  methods;  power  system  simulation;  probability;  wind  power Résumé : This paper contributes a Markov chain Monte Carlo (MCMC) method for the direct generation of synthetic time series of wind power output. It is shown that obtaining a stochastic model directly in the wind power domain leads to reduced number of states and to lower order of the Markov chain at equal power data resolution. The estimation quality of the stochastic model is positively influenced since in the power domain, a lower number of independent parameters is estimated from a given amount of recorded data. The simulation results prove that this method offers excellent fit for both the probability density function and the autocorrelation function of the generated wind power time series. The method is a first step toward simple stochastic black-box models for wind generation. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4453993&sortType%3Das [...]

Centralized control for optimizing microgrids operation / Tsikalakis, A.G. 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. 241 - 248 Titre : Centralized control for optimizing microgrids operation Type de document : texte imprimé Auteurs : Tsikalakis, A.G., Auteur ; Hatziargyriou, N. D., Auteur Année de publication : 2008 Article en page(s) : pp. 241 - 248 Note générale : Energy conversion Langues : Anglais (eng) Mots-clés : Distributed  power  generation;  optimisation;  power  distribution  control;  power  grids;  power  markets Résumé : Microgrids are low-voltage (LV) distribution networks comprising various distributed generators (DGs), storage devices, and controllable loads that can operate either interconnected or isolated from the main distribution grid as a controlled entity. This paper describes the operation of a central controller for microgrids. The controller aims to optimize the operation of the microgrid during interconnected operation, i.e., maximize its value by optimizing the production of the local DGs and power exchanges with the main distribution grid. Two market policies are assumed including demand-side bidding options for controllable loads. The developed optimization algorithms are applied on a typical LV study case network operating under various market policies and assuming realistic spot market prices and DG bids reflecting realistic operational costs. The effects on the microgrid and the distribution network operation are presented and discussed. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4454000&sortType%3Das [...] [article] Centralized control for optimizing microgrids operation [texte imprimé] / Tsikalakis, A.G., Auteur ; Hatziargyriou, N. D., Auteur . - 2008 . - pp. 241 - 248. Energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 23 N°1 (Mars 2008) . - pp. 241 - 248 Mots-clés : Distributed  power  generation;  optimisation;  power  distribution  control;  power  grids;  power  markets Résumé : Microgrids are low-voltage (LV) distribution networks comprising various distributed generators (DGs), storage devices, and controllable loads that can operate either interconnected or isolated from the main distribution grid as a controlled entity. This paper describes the operation of a central controller for microgrids. The controller aims to optimize the operation of the microgrid during interconnected operation, i.e., maximize its value by optimizing the production of the local DGs and power exchanges with the main distribution grid. Two market policies are assumed including demand-side bidding options for controllable loads. The developed optimization algorithms are applied on a typical LV study case network operating under various market policies and assuming realistic spot market prices and DG bids reflecting realistic operational costs. The effects on the microgrid and the distribution network operation are presented and discussed. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4454000&sortType%3Das [...]

Strategies for wind power trading in competitive electricity markets / S. N. Singh 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. 249 - 256 Titre : Strategies for wind power trading in competitive electricity markets Type de document : texte imprimé Auteurs : S. N. Singh, Auteur ; Erlich, I., Auteur Année de publication : 2008 Article en page(s) : pp. 249 - 256 Note générale : Energy conversion Langues : Anglais (eng) Mots-clés : Power  system  management;  power  system  reliability;  power  system  security;  pricing;  wind  power Résumé : The emergence of independent generators and new technologies over past decades has led to the competition in the electricity sector to encourage development of a more market-based electricity industry. The success of wind energy under new market structures will depend, to a large degree, on the market rules on technical and financial aspects. This paper proposes a suitable trading option for wind power in the emerging electricity market for its sustainable development. Market clearing price with and without wind power has been analyzed in both supply side and demand side bidding scenarios for linear bid and block bid trading models. Several other aspects of wind power in electricity market have also been highlighted. This paper could be a guideline for the policy makers and market operators to promote the wind power with system reliability and security. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4453999&sortType%3Das [...] [article] Strategies for wind power trading in competitive electricity markets [texte imprimé] / S. N. Singh, Auteur ; Erlich, I., Auteur . - 2008 . - pp. 249 - 256. Energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 23 N°1 (Mars 2008) . - pp. 249 - 256 Mots-clés : Power  system  management;  power  system  reliability;  power  system  security;  pricing;  wind  power Résumé : The emergence of independent generators and new technologies over past decades has led to the competition in the electricity sector to encourage development of a more market-based electricity industry. The success of wind energy under new market structures will depend, to a large degree, on the market rules on technical and financial aspects. This paper proposes a suitable trading option for wind power in the emerging electricity market for its sustainable development. Market clearing price with and without wind power has been analyzed in both supply side and demand side bidding scenarios for linear bid and block bid trading models. Several other aspects of wind power in electricity market have also been highlighted. This paper could be a guideline for the policy makers and market operators to promote the wind power with system reliability and security. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4453999&sortType%3Das [...]

Surge analysis on wind farm when winter lightning strikes / Yasuda, Y. 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. 257 - 262 Titre : Surge analysis on wind farm when winter lightning strikes Type de document : texte imprimé Auteurs : Yasuda, Y., Auteur ; Uno, N., Auteur ; Kobayashi, H., Auteur Année de publication : 2008 Article en page(s) : pp. 257 - 262 Note générale : Energy conversion Langues : Anglais (eng) Mots-clés : Power  system  protection;  power  system  simulation;  sensitivity  analysis;  surge  protection;  wind  power  plants;  wind  turbines Résumé : The rapid expansion of wind power generation has brought problems involving lightning strikes to the fore. Many such incidents have damaged not only the wind turbine that was actually struck but also other turbines that were not, a phenomenon that has yet to be fully explained. In this paper, the authors present a case study using a wind farm model with multiple wind turbines connected to a power system. The aim is to clarify the influence of the grounding system on surge propagation from a wind turbine that has been struck to others which have not, during a winter lightning strike. Sensitivity analyses show that the surge propagated to nearby wind turbines can sometimes become large, depending on the conditions of the grounding system, and result in the burnout of surge arresters in turbines that have not been struck, especially during winter lightning strikes. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4378208&sortType%3Das [...] [article] Surge analysis on wind farm when winter lightning strikes [texte imprimé] / Yasuda, Y., Auteur ; Uno, N., Auteur ; Kobayashi, H., Auteur . - 2008 . - pp. 257 - 262. Energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 23 N°1 (Mars 2008) . - pp. 257 - 262 Mots-clés : Power  system  protection;  power  system  simulation;  sensitivity  analysis;  surge  protection;  wind  power  plants;  wind  turbines Résumé : The rapid expansion of wind power generation has brought problems involving lightning strikes to the fore. Many such incidents have damaged not only the wind turbine that was actually struck but also other turbines that were not, a phenomenon that has yet to be fully explained. In this paper, the authors present a case study using a wind farm model with multiple wind turbines connected to a power system. The aim is to clarify the influence of the grounding system on surge propagation from a wind turbine that has been struck to others which have not, during a winter lightning strike. Sensitivity analyses show that the surge propagated to nearby wind turbines can sometimes become large, depending on the conditions of the grounding system, and result in the burnout of surge arresters in turbines that have not been struck, especially during winter lightning strikes. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4378208&sortType%3Das [...]

Modeling and analysis of an FC/UC hybrid vehicular power system using a novel-wavelet-based load sharing algorithm / Uzunoglu, M. 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. 263 - 272 Titre : Modeling and analysis of an FC/UC hybrid vehicular power system using a novel-wavelet-based load sharing algorithm Type de document : texte imprimé Auteurs : Uzunoglu, M., Auteur ; Alam, M. S., Auteur Année de publication : 2008 Article en page(s) : pp. 263 - 272 Note générale : Energy conversion Langues : Anglais (eng) Mots-clés : Fuel  cell  vehicles;  hybrid  electric  vehicles;  power  control;  supercapacitors Résumé : The most critical attribute of a power control strategy for a fuel cell (FC) and ultracapacitor (UC) based hybrid vehicular power system is the sharing of load demand between available power sources. Transients and rapid changes of the power demand may cause drying of the FC membrane resulting in degradation of FC lifetime. The load demand profile of a hybrid electric vehicle (HEV) is a nonstationary fluctuating signal and consists of transients. Wavelet transforms are suitable for analyzing and evaluating such signals for dynamic systems. This paper focuses on the integration of a developed novel-wavelet-based load sharing algorithm and dynamic model of the FC/UC hybrid vehicular power system in order to ensure efficient power flow control strategy. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4407746&sortType%3Das [...] [article] Modeling and analysis of an FC/UC hybrid vehicular power system using a novel-wavelet-based load sharing algorithm [texte imprimé] / Uzunoglu, M., Auteur ; Alam, M. S., Auteur . - 2008 . - pp. 263 - 272. Energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 23 N°1 (Mars 2008) . - pp. 263 - 272 Mots-clés : Fuel  cell  vehicles;  hybrid  electric  vehicles;  power  control;  supercapacitors Résumé : The most critical attribute of a power control strategy for a fuel cell (FC) and ultracapacitor (UC) based hybrid vehicular power system is the sharing of load demand between available power sources. Transients and rapid changes of the power demand may cause drying of the FC membrane resulting in degradation of FC lifetime. The load demand profile of a hybrid electric vehicle (HEV) is a nonstationary fluctuating signal and consists of transients. Wavelet transforms are suitable for analyzing and evaluating such signals for dynamic systems. This paper focuses on the integration of a developed novel-wavelet-based load sharing algorithm and dynamic model of the FC/UC hybrid vehicular power system in order to ensure efficient power flow control strategy. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4407746&sortType%3Das [...]

Optimal wind–thermal generating unit commitment / Chung-Lung Chen 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. 273 - 280 Titre : Optimal wind–thermal generating unit commitment Type de document : texte imprimé Auteurs : Chung-Lung Chen, Auteur Année de publication : 2008 Article en page(s) : pp. 273 - 280 Note générale : Energy conversion Langues : Anglais (eng) Mots-clés : Dynamic  programming;  hybrid  power  systems;  power  generation  scheduling;  thermal  power  stations;  wind  power Résumé : As wind power penetrations increase in isolated power systems, more innovative and sophisticated approaches to system operation will need to be adopted due to the intermittency and unpredictability of wind power generation. In this paper, a hybrid approach of combining branch and bound algorithm with a dynamic programming algorithm is developed to coordinate the wind and thermal generation scheduling problem for operating an isolated hybrid power system reliably and efficiently. Several technique constraints are applied to determine the maximum proportion of wind generator capacity that can be integrated into the system. A simplified dispatch based on the direct search method (DSM) is also introduced to relieve the computational burden further. Numerical experiments are included to understand the wind generator capacity in production cost analysis and to provide valuable information for both operational and planning problems. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4453978&sortType%3Das [...] [article] Optimal wind–thermal generating unit commitment [texte imprimé] / Chung-Lung Chen, Auteur . - 2008 . - pp. 273 - 280. Energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 23 N°1 (Mars 2008) . - pp. 273 - 280 Mots-clés : Dynamic  programming;  hybrid  power  systems;  power  generation  scheduling;  thermal  power  stations;  wind  power Résumé : As wind power penetrations increase in isolated power systems, more innovative and sophisticated approaches to system operation will need to be adopted due to the intermittency and unpredictability of wind power generation. In this paper, a hybrid approach of combining branch and bound algorithm with a dynamic programming algorithm is developed to coordinate the wind and thermal generation scheduling problem for operating an isolated hybrid power system reliably and efficiently. Several technique constraints are applied to determine the maximum proportion of wind generator capacity that can be integrated into the system. A simplified dispatch based on the direct search method (DSM) is also introduced to relieve the computational burden further. Numerical experiments are included to understand the wind generator capacity in production cost analysis and to provide valuable information for both operational and planning problems. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4453978&sortType%3Das [...]

Optimum design of the current-source flyback inverter for decentralized grid-connected photovoltaic systems / Kyritsis, A.Ch. 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. 281 - 293 Titre : Optimum design of the current-source flyback inverter for decentralized grid-connected photovoltaic systems Type de document : texte imprimé Auteurs : Kyritsis, A.Ch., Auteur ; Tatakis, E.C., Auteur ; Papanikolaou, N.P., Auteur Année de publication : 2008 Article en page(s) : pp. 281 - 293 Note générale : Energy conversion Langues : Anglais (eng) Mots-clés : SPICE;  invertors;  photovoltaic  power  systems;  power  conversion Résumé : Two alternative modes of operation for the current-source flyback inverter are investigated in this paper. The discontinuous conduction mode (DCM), where a constant switching frequency (CSF) control method is applied, and the boundary between continuous and DCM (BCM) that is introduced for photovoltaic (PV) applications in this paper (where a variable switching frequency control method is applied). These two control methods are analytically studied and compared in order to establish their advantages as well as their suitability for the development of an inverter for decentralized grid-connected PV applications. An optimum design methodology is developed, aiming for an inverter with the smallest possible volume for the maximum power transfer to the public grid and wide PV energy exploitation. The main advantages of the current-source flyback inverter are very high-power density and high efficiency due to its simple structure, as well as high-power factor regulation. The design and control methodology are validated by personal computer simulation program with integrated circuit emphasis (PSPICE) simulation and experimental results, accomplished on a laboratory prototype. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4358743&sortType%3Das [...] [article] Optimum design of the current-source flyback inverter for decentralized grid-connected photovoltaic systems [texte imprimé] / Kyritsis, A.Ch., Auteur ; Tatakis, E.C., Auteur ; Papanikolaou, N.P., Auteur . - 2008 . - pp. 281 - 293. Energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 23 N°1 (Mars 2008) . - pp. 281 - 293 Mots-clés : SPICE;  invertors;  photovoltaic  power  systems;  power  conversion Résumé : Two alternative modes of operation for the current-source flyback inverter are investigated in this paper. The discontinuous conduction mode (DCM), where a constant switching frequency (CSF) control method is applied, and the boundary between continuous and DCM (BCM) that is introduced for photovoltaic (PV) applications in this paper (where a variable switching frequency control method is applied). These two control methods are analytically studied and compared in order to establish their advantages as well as their suitability for the development of an inverter for decentralized grid-connected PV applications. An optimum design methodology is developed, aiming for an inverter with the smallest possible volume for the maximum power transfer to the public grid and wide PV energy exploitation. The main advantages of the current-source flyback inverter are very high-power density and high efficiency due to its simple structure, as well as high-power factor regulation. The design and control methodology are validated by personal computer simulation program with integrated circuit emphasis (PSPICE) simulation and experimental results, accomplished on a laboratory prototype. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4358743&sortType%3Das [...]

Pumped-storage scheduling using evolutionary particle swarm optimization / Po-Hung Chen 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. 294 - 301 Titre : Pumped-storage scheduling using evolutionary particle swarm optimization Type de document : texte imprimé Auteurs : Po-Hung Chen, Auteur Année de publication : 2008 Article en page(s) : pp. 294 - 301 Note générale : Energy conversion Langues : Anglais (eng) Mots-clés : Decoding;  encoding;  evolutionary  computation;  hydrothermal  power  systems;  particle  swarm  optimisation;  pumped-storage  power  stations;  scheduling Résumé : This paper presents new solution algorithms based on an evolutionary particle swarm optimization (EPSO) for solving the pumped-storage (P/S) scheduling problem. The proposed EPSO approach combines a basic particle swarm optimization (PSO) with binary encoding/decoding techniques as well as a mutation operation. The binary encoding/decoding techniques are adopted to model the discrete characteristics of a P/S plant. The mutation operation is applied to accelerate convergence and escape local optimums. The optimal generation schedules for both P/S and thermal units are concurrently obtained within the evolutionary process of a scoring function. Therefore, hydrothermal iteration is no longer needed. The proposed approach is applied with great success to an actual utility system consisting of four P/S units and 34 thermal units. Experimental results indicate the attractive properties of the EPSO approach in a practical application, namely, a highly optimal solution and robust convergence behavior. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4453979&sortType%3Das [...] [article] Pumped-storage scheduling using evolutionary particle swarm optimization [texte imprimé] / Po-Hung Chen, Auteur . - 2008 . - pp. 294 - 301. Energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 23 N°1 (Mars 2008) . - pp. 294 - 301 Mots-clés : Decoding;  encoding;  evolutionary  computation;  hydrothermal  power  systems;  particle  swarm  optimisation;  pumped-storage  power  stations;  scheduling Résumé : This paper presents new solution algorithms based on an evolutionary particle swarm optimization (EPSO) for solving the pumped-storage (P/S) scheduling problem. The proposed EPSO approach combines a basic particle swarm optimization (PSO) with binary encoding/decoding techniques as well as a mutation operation. The binary encoding/decoding techniques are adopted to model the discrete characteristics of a P/S plant. The mutation operation is applied to accelerate convergence and escape local optimums. The optimal generation schedules for both P/S and thermal units are concurrently obtained within the evolutionary process of a scoring function. Therefore, hydrothermal iteration is no longer needed. The proposed approach is applied with great success to an actual utility system consisting of four P/S units and 34 thermal units. Experimental results indicate the attractive properties of the EPSO approach in a practical application, namely, a highly optimal solution and robust convergence behavior. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4453979&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 [...]

Small-signal stability analysis of an autonomous hybrid renewable energy power generation/energy storage system / Dong-Jing Lee 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. 311 - 320 Titre : Small-signal stability analysis of an autonomous hybrid renewable energy power generation/energy storage system : Part I: time-domain simulations Type de document : texte imprimé Auteurs : Dong-Jing Lee, Auteur ; Wang, Li, Auteur Année de publication : 2008 Article en page(s) : pp. 311 - 320 Note générale : Energy conversion Langues : Anglais (eng) Mots-clés : Battery  storage  plants;  diesel-electric  generators;  energy  storage;  flywheels;  fuel  cells;  power  generation  reliability;  power  system  stability;  renewable  energy  sources;  time-domain  analysis;  wind  turbines Résumé : Small-signal stability analyzed results of an autonomous hybrid renewable energy power generation/energy storage system connected to isolated loads using time-domain simulations is presented in this paper. The companion paper presents frequency-domain analyzed results of the same hybrid system. The proposed renewable energy power generation subsystems include three wind turbine generators (WTGs), a diesel engine generator, two fuel cells (FCs), and a photovoltaic system (PV) while the energy storage subsystems consist of a battery energy storage system and a flywheel energy storage system. An aqua electrolyzer absorbs a part of generated energy from PV or WTGs to generate available hydrogen for FCs. A time-domain approach based on three mathematical models for three studied cases under various operating points and disturbance conditions is performed. It can be concluded from the simulation results that the proposed hybrid power generation/energy storage system feeding isolated loads can be properly operated to achieve system power-frequency balance condition. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4453988&sortType%3Das [...] [article] Small-signal stability analysis of an autonomous hybrid renewable energy power generation/energy storage system : Part I: time-domain simulations [texte imprimé] / Dong-Jing Lee, Auteur ; Wang, Li, Auteur . - 2008 . - pp. 311 - 320. Energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 23 N°1 (Mars 2008) . - pp. 311 - 320 Mots-clés : Battery  storage  plants;  diesel-electric  generators;  energy  storage;  flywheels;  fuel  cells;  power  generation  reliability;  power  system  stability;  renewable  energy  sources;  time-domain  analysis;  wind  turbines Résumé : Small-signal stability analyzed results of an autonomous hybrid renewable energy power generation/energy storage system connected to isolated loads using time-domain simulations is presented in this paper. The companion paper presents frequency-domain analyzed results of the same hybrid system. The proposed renewable energy power generation subsystems include three wind turbine generators (WTGs), a diesel engine generator, two fuel cells (FCs), and a photovoltaic system (PV) while the energy storage subsystems consist of a battery energy storage system and a flywheel energy storage system. An aqua electrolyzer absorbs a part of generated energy from PV or WTGs to generate available hydrogen for FCs. A time-domain approach based on three mathematical models for three studied cases under various operating points and disturbance conditions is performed. It can be concluded from the simulation results that the proposed hybrid power generation/energy storage system feeding isolated loads can be properly operated to achieve system power-frequency balance condition. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4453988&sortType%3Das [...]

Wind turbines based on doubly fed induction generator under asymmetrical voltage dips / Lopez, J. 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. 321 - 330 Titre : Wind turbines based on doubly fed induction generator under asymmetrical voltage dips Type de document : texte imprimé Auteurs : Lopez, J., Auteur ; Gubia, E., Auteur ; Sanchis, P., Auteur Année de publication : 2008 Article en page(s) : pp. 321 - 330 Note générale : Energy conversion Langues : Anglais (eng) Mots-clés : Asynchronous  generators;  wind  power;  wind  turbines Résumé : Many large wind farms employ doubly fed induction generators (DFIGs). The main drawback of these machines is their large sensitivity to grid disturbances, especially to voltage dips. As the penetration of wind energy in the network increases, it becomes more relevant to understand the behavior of these machines under voltage dips. This paper analyzes the operation of the DFIG under asymmetrical voltage dips and explains why such kinds of dips are more harmful than are symmetrical dips. The influence of the dip type and instant of occurrence is also studied. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4453989&sortType%3Das [...] [article] Wind turbines based on doubly fed induction generator under asymmetrical voltage dips [texte imprimé] / Lopez, J., Auteur ; Gubia, E., Auteur ; Sanchis, P., Auteur . - 2008 . - pp. 321 - 330. Energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 23 N°1 (Mars 2008) . - pp. 321 - 330 Mots-clés : Asynchronous  generators;  wind  power;  wind  turbines Résumé : Many large wind farms employ doubly fed induction generators (DFIGs). The main drawback of these machines is their large sensitivity to grid disturbances, especially to voltage dips. As the penetration of wind energy in the network increases, it becomes more relevant to understand the behavior of these machines under voltage dips. This paper analyzes the operation of the DFIG under asymmetrical voltage dips and explains why such kinds of dips are more harmful than are symmetrical dips. The influence of the dip type and instant of occurrence is also studied. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4453989&sortType%3Das [...]

Computer-based study of secondary emission cell (SEC) efficiency compared to that of a vacuum-type direct collection cell / Romer, M. 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. 331 - 341 Titre : Computer-based study of secondary emission cell (SEC) efficiency compared to that of a vacuum-type direct collection cell Type de document : texte imprimé Auteurs : Romer, M., Auteur ; Miley, G.H., Auteur ; Nie Luo, Auteur Année de publication : 2008 Article en page(s) : pp. 331 - 341 Note générale : Energy conversion Langues : Anglais (eng) Mots-clés : Computer  aided  analysis;  energy  conservation;  insulators;  nuclear  power;  power  engineering  computing;  secondary  cells;  secondary  emission Résumé : The concept of directly collecting secondary electrons created by beta emission through an electrical insulator has been proposed as an attractive low-voltage nuclear battery termed a secondary emission cell (SEC). In this paper, a MATLAB computer simulation of an SEC is conducted using Mott scattering, the Penfold-Katz slowing approximation, Bethe's ionization loss expression, and energy and momentum conservation. The goal of the simulation is to compare the efficiency of an SEC to that of a vacuum direct collection cell. It is found that the SEC efficiency is typically les1%. Energy losses in the insulator prevent it from having an efficiency advantage over a vacuum direct collection cell which offers higher efficiencies, especially at high voltages. However, operational simplicity and ease of construction still make the SEC attractive for some applications. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4453998&sortType%3Das [...] [article] Computer-based study of secondary emission cell (SEC) efficiency compared to that of a vacuum-type direct collection cell [texte imprimé] / Romer, M., Auteur ; Miley, G.H., Auteur ; Nie Luo, Auteur . - 2008 . - pp. 331 - 341. Energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 23 N°1 (Mars 2008) . - pp. 331 - 341 Mots-clés : Computer  aided  analysis;  energy  conservation;  insulators;  nuclear  power;  power  engineering  computing;  secondary  cells;  secondary  emission Résumé : The concept of directly collecting secondary electrons created by beta emission through an electrical insulator has been proposed as an attractive low-voltage nuclear battery termed a secondary emission cell (SEC). In this paper, a MATLAB computer simulation of an SEC is conducted using Mott scattering, the Penfold-Katz slowing approximation, Bethe's ionization loss expression, and energy and momentum conservation. The goal of the simulation is to compare the efficiency of an SEC to that of a vacuum direct collection cell. It is found that the SEC efficiency is typically les1%. Energy losses in the insulator prevent it from having an efficiency advantage over a vacuum direct collection cell which offers higher efficiencies, especially at high voltages. However, operational simplicity and ease of construction still make the SEC attractive for some applications. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4453998&sortType%3Das [...]

Numerical validation of parametric average-value modeling of synchronous machine–rectifier systems for variable frequency operation / Jatskevich, J. 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. 342 - 344 Titre : Numerical validation of parametric average-value modeling of synchronous machine–rectifier systems for variable frequency operation Type de document : texte imprimé Auteurs : Jatskevich, J., Auteur ; Pekarek, S.D., Auteur Année de publication : 2008 Article en page(s) : pp. 342 - 344 Note générale : Energy conversion Langues : Anglais (eng) Mots-clés : Nonlinear  functions;  rectifiers;  synchronous  machines Résumé : The derivation of accurate dynamic average-value models for synchronous machine-rectifier systems is challenging. A recently proposed parametric approach uses a computer-aided procedure for constructing the required averaged models, wherein the key nonlinear functions are extracted from a detailed (valve-by-valve) simulation. This letter shows that by using a judicious selection of parametric functions, a model obtained at a fixed generator speed is also valid for variable speeds. This is an important feature that makes this approach applicable to systems where electromechanical dynamics and variable speed operation is required. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4453986&sortType%3Das [...] [article] Numerical validation of parametric average-value modeling of synchronous machine–rectifier systems for variable frequency operation [texte imprimé] / Jatskevich, J., Auteur ; Pekarek, S.D., Auteur . - 2008 . - pp. 342 - 344. Energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 23 N°1 (Mars 2008) . - pp. 342 - 344 Mots-clés : Nonlinear  functions;  rectifiers;  synchronous  machines Résumé : The derivation of accurate dynamic average-value models for synchronous machine-rectifier systems is challenging. A recently proposed parametric approach uses a computer-aided procedure for constructing the required averaged models, wherein the key nonlinear functions are extracted from a detailed (valve-by-valve) simulation. This letter shows that by using a judicious selection of parametric functions, a model obtained at a fixed generator speed is also valid for variable speeds. This is an important feature that makes this approach applicable to systems where electromechanical dynamics and variable speed operation is required. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4453986&sortType%3Das [...]

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