Dépouillements

Online sensorless induction motor temperature monitoring / Sonnaillon, M.O. in IEEE transactions on energy conversion, Vol. 25 N° 2 (Juin 2010) 

Public ISBD [article]  in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 273 - 280 Titre : Online sensorless induction motor temperature monitoring Type de document : texte imprimé Auteurs : Sonnaillon, M.O., Auteur ; Bisheimer, G., Auteur ; De Angelo, C., Auteur Année de publication : 2010 Article en page(s) : pp. 273 - 280 Note générale : energy conversion Langues : Anglais (eng) Mots-clés : computerised  monitoring;  electric  machine  analysis  computing;  induction  motor  drives;  signal  processing;  temperature  measurement Résumé : A sensorless internal temperature monitoring method for induction motors is proposed in this paper. This method can be embedded in standard motor drives, and is based on the stator windings resistance variation with temperature. A small AC signal is injected to the motor, superimposed to the power supply current, in order to measure the stator resistance online. The proposed method has the advantage of requiring a very low-level monitoring signal, hence the motor torque perturbations and additional power losses are negligible. Furthermore, temperature estimations do not depend on the knowledge of any other motor parameter, since the method is not based on a model. This makes the proposed method more robust than model-based methods. Experimental results that validate the proposal are also presented. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5437206&sortType%3Das [...] [article] Online sensorless induction motor temperature monitoring [texte imprimé] / Sonnaillon, M.O., Auteur ; Bisheimer, G., Auteur ; De Angelo, C., Auteur . - 2010 . - pp. 273 - 280. energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 273 - 280 Mots-clés : computerised  monitoring;  electric  machine  analysis  computing;  induction  motor  drives;  signal  processing;  temperature  measurement Résumé : A sensorless internal temperature monitoring method for induction motors is proposed in this paper. This method can be embedded in standard motor drives, and is based on the stator windings resistance variation with temperature. A small AC signal is injected to the motor, superimposed to the power supply current, in order to measure the stator resistance online. The proposed method has the advantage of requiring a very low-level monitoring signal, hence the motor torque perturbations and additional power losses are negligible. Furthermore, temperature estimations do not depend on the knowledge of any other motor parameter, since the method is not based on a model. This makes the proposed method more robust than model-based methods. Experimental results that validate the proposal are also presented. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5437206&sortType%3Das [...]

Improved moving coil electric machine for internal combustion linear generator / Zhaoping, Xu in IEEE transactions on energy conversion, Vol. 25 N° 2 (Juin 2010) 

Public ISBD [article]  in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 281 - 286 Titre : Improved moving coil electric machine for internal combustion linear generator Type de document : texte imprimé Auteurs : Zhaoping, Xu, Auteur ; Siqin, Chang, Auteur Année de publication : 2010 Article en page(s) : pp. 281 - 286 Note générale : energy conversion Langues : Anglais (eng) Mots-clés : distributed  power  generation;  emergency  power  supply;  hybrid  electric  vehicles;  internal  combustion  engines;  linear  machines;  magnetic  circuits Résumé : This paper investigates the use of moving coil linear machines (MCLM) in the internal combustion linear generator (ICLG), which is a novel solution for series hybrid electric vehicles, distributed generation, and emergency power supply. According to the analysis of the basic structure of MCLM, an improved tubular MCLM equipped with quasi-Halbach magnetized magnets is suggested and analyzed with a proposed equivalent magnetic circuit (EMC) model. Measurements on a 4-kN prototype show good agreement with the results from the EMC model. Compared with the reported moving magnet linear machines (MMLM) for the same application, the proposed machine has the merit of less moving mass, faster response, and better controllability. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5409649&sortType%3Das [...] [article] Improved moving coil electric machine for internal combustion linear generator [texte imprimé] / Zhaoping, Xu, Auteur ; Siqin, Chang, Auteur . - 2010 . - pp. 281 - 286. energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 281 - 286 Mots-clés : distributed  power  generation;  emergency  power  supply;  hybrid  electric  vehicles;  internal  combustion  engines;  linear  machines;  magnetic  circuits Résumé : This paper investigates the use of moving coil linear machines (MCLM) in the internal combustion linear generator (ICLG), which is a novel solution for series hybrid electric vehicles, distributed generation, and emergency power supply. According to the analysis of the basic structure of MCLM, an improved tubular MCLM equipped with quasi-Halbach magnetized magnets is suggested and analyzed with a proposed equivalent magnetic circuit (EMC) model. Measurements on a 4-kN prototype show good agreement with the results from the EMC model. Compared with the reported moving magnet linear machines (MMLM) for the same application, the proposed machine has the merit of less moving mass, faster response, and better controllability. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5409649&sortType%3Das [...]

Effect of voltage and load variations on efficiencies of a motor-pump system / Kini, P.G. in IEEE transactions on energy conversion, Vol. 25 N° 2 (Juin 2010) 

Public ISBD [article]  in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 287 - 292 Titre : Effect of voltage and load variations on efficiencies of a motor-pump system Type de document : texte imprimé Auteurs : Kini, P.G., Auteur ; Bansal, R. C., Auteur Année de publication : 2010 Article en page(s) : pp. 287 - 292 Note générale : energy conversion Langues : Anglais (eng) Mots-clés : centrifuges;  induction  motor  drives;  pumps Résumé : Centrifugal pumps are the most widely used ac-motor-driven pump systems mainly for water pumping applications. Due to increasing and varying load demand, voltage variation and unbalance is a reality and has to be dealt with carefully. Studies on motor-driven systems under conditions of voltage unbalance have either neglected or maintained constant magnitude of the rotational loss component and focused only on the motor performance while system side performances have not been discussed generally. This paper presents the experimental results of a three-phase induction motor-pump system subjected to voltage and load variations with a view to justify that knowledge of voltage and load variations are very much essential for better result analysis. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5350688&sortType%3Das [...] [article] Effect of voltage and load variations on efficiencies of a motor-pump system [texte imprimé] / Kini, P.G., Auteur ; Bansal, R. C., Auteur . - 2010 . - pp. 287 - 292. energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 287 - 292 Mots-clés : centrifuges;  induction  motor  drives;  pumps Résumé : Centrifugal pumps are the most widely used ac-motor-driven pump systems mainly for water pumping applications. Due to increasing and varying load demand, voltage variation and unbalance is a reality and has to be dealt with carefully. Studies on motor-driven systems under conditions of voltage unbalance have either neglected or maintained constant magnitude of the rotational loss component and focused only on the motor performance while system side performances have not been discussed generally. This paper presents the experimental results of a three-phase induction motor-pump system subjected to voltage and load variations with a view to justify that knowledge of voltage and load variations are very much essential for better result analysis. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5350688&sortType%3Das [...]

Winding configurations and optimal stator and rotor pole combination of flux-switching PM brushless AC machines / Chen, J. T. in IEEE transactions on energy conversion, Vol. 25 N° 2 (Juin 2010) 

Public ISBD [article]  in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 293 - 302 Titre : Winding configurations and optimal stator and rotor pole combination of flux-switching PM brushless AC machines Type de document : texte imprimé Auteurs : Chen, J. T., Auteur ; Zhu, Z.Q., Auteur Année de publication : 2010 Article en page(s) : pp. 293 - 302 Note générale : energy conversion Langues : Anglais (eng) Mots-clés : AC  machines;  electric  potential;  finite  element  analysis;  permanent  magnet  machines;  rotors;  stators;  torque Résumé : A simple analytical method is developed to compare the combinations of stator and rotor pole numbers in flux-switching permanent magnet (PM) machines in terms of back electromotive force (EMF) and electromagnetic torque. The winding connections and winding factors of machines having all poles and alternate poles wound, and different numbers of phases, from two to six, are determined by the coil-EMF vectors. Their differences from analyzing the conventional fractional-slot PM machines with concentrated nonoverlapping windings are highlighted. The general conditions are established for balanced symmetrical back-EMF waveform. It shows that the optimized rotor pole number should be close to the number of stator poles, whereas larger torque can be obtained by the machine with relatively higher rotor pole number. The analysis is validated by finite-element analyses and experiment. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5340616&sortType%3Das [...] [article] Winding configurations and optimal stator and rotor pole combination of flux-switching PM brushless AC machines [texte imprimé] / Chen, J. T., Auteur ; Zhu, Z.Q., Auteur . - 2010 . - pp. 293 - 302. energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 293 - 302 Mots-clés : AC  machines;  electric  potential;  finite  element  analysis;  permanent  magnet  machines;  rotors;  stators;  torque Résumé : A simple analytical method is developed to compare the combinations of stator and rotor pole numbers in flux-switching permanent magnet (PM) machines in terms of back electromotive force (EMF) and electromagnetic torque. The winding connections and winding factors of machines having all poles and alternate poles wound, and different numbers of phases, from two to six, are determined by the coil-EMF vectors. Their differences from analyzing the conventional fractional-slot PM machines with concentrated nonoverlapping windings are highlighted. The general conditions are established for balanced symmetrical back-EMF waveform. It shows that the optimized rotor pole number should be close to the number of stator poles, whereas larger torque can be obtained by the machine with relatively higher rotor pole number. The analysis is validated by finite-element analyses and experiment. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5340616&sortType%3Das [...]

Performance of an isolated nduction generator under unbalanced loads / Idjdarene, K. in IEEE transactions on energy conversion, Vol. 25 N° 2 (Juin 2010) 

Public ISBD [article]  in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 303 - 311 Titre : Performance of an isolated nduction generator under unbalanced loads Type de document : texte imprimé Auteurs : Idjdarene, K., Auteur ; Rekioua, D., Auteur ; Rekioua, T., Auteur Année de publication : 2010 Article en page(s) : pp. 303 - 311 Note générale : energy conversion Langues : Anglais (eng) Mots-clés : asynchronous  generators;  Park  model;  saturation  effect;  self-excited  induction  generator  (SEIG);  unbalanced  load Résumé : In this paper, the performance of an isolated self-excited induction generator driven by a wind turbine under unbalanced loads is studied. First, the whole system, including the induction generator, the capacitors, and the loads, is modeled. The model used for the isolated induction generator is a diphase one obtained, using the Park transformation. This model allows the saturation effect to be taken into account, assuming certain simplifying hypotheses. Then, the developed model is validated comparing simulation and experiment results at no load and for balanced load cases. Finally, the same model is used to study the performance of the isolated induction generator under unbalanced load cases. Compared to the experiments, the simulation results show a good prediction of the electrical variable waveforms. Furthermore, it can be seen that the magnitude and frequency of the voltages do not vary a lot even if the load is hardly unbalanced. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5353693&sortType%3Das [...] [article] Performance of an isolated nduction generator under unbalanced loads [texte imprimé] / Idjdarene, K., Auteur ; Rekioua, D., Auteur ; Rekioua, T., Auteur . - 2010 . - pp. 303 - 311. energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 303 - 311 Mots-clés : asynchronous  generators;  Park  model;  saturation  effect;  self-excited  induction  generator  (SEIG);  unbalanced  load Résumé : In this paper, the performance of an isolated self-excited induction generator driven by a wind turbine under unbalanced loads is studied. First, the whole system, including the induction generator, the capacitors, and the loads, is modeled. The model used for the isolated induction generator is a diphase one obtained, using the Park transformation. This model allows the saturation effect to be taken into account, assuming certain simplifying hypotheses. Then, the developed model is validated comparing simulation and experiment results at no load and for balanced load cases. Finally, the same model is used to study the performance of the isolated induction generator under unbalanced load cases. Compared to the experiments, the simulation results show a good prediction of the electrical variable waveforms. Furthermore, it can be seen that the magnitude and frequency of the voltages do not vary a lot even if the load is hardly unbalanced. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5353693&sortType%3Das [...]

Fault detection by means of Hilbert–Huang transform of the stator current in a PMSM with demagnetization / Espinosa, A.G. in IEEE transactions on energy conversion, Vol. 25 N° 2 (Juin 2010) 

Public ISBD [article]  in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 312 - 318 Titre : Fault detection by means of Hilbert–Huang transform of the stator current in a PMSM with demagnetization Type de document : texte imprimé Auteurs : Espinosa, A.G., Auteur ; Rosero, J.A., Auteur ; Cusido, J., Auteur Année de publication : 2010 Article en page(s) : pp. 312 - 318 Note générale : energy conversion Langues : Anglais (eng) Mots-clés : Hilbert  transforms;  demagnetisation;  fault  diagnosis;  finite  element  analysis;  permanent  magnet  motors;  stators;  synchronous  motors;  time-frequency  analysis Résumé : This paper presents a novel method to diagnose demagnetization in permanent-magnet synchronous motor (PMSM). Simulations have been performed by 2-D finite-element analysis in order to determine the current spectrum and the magnetic flux distribution due to this failure. The diagnostic just based on motor current signature analysis can be confused by eccentricity failure because the harmonic content is the same. Moreover, it can only be applied under stationary conditions. In order to overcome these drawbacks, a novel method is used based upon the Hilbert-Huang transform. It represents time-dependent series in a 2-D time-frequency domain by extracting instantaneous frequency components through an empirical-mode decomposition process. This tool is applied by running the motor under nonstationary conditions of velocity. The experimental results show the reliability and feasibility of the methodology in order to diagnose the demagnetization of a PMSM. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5404255&sortType%3Das [...] [article] Fault detection by means of Hilbert–Huang transform of the stator current in a PMSM with demagnetization [texte imprimé] / Espinosa, A.G., Auteur ; Rosero, J.A., Auteur ; Cusido, J., Auteur . - 2010 . - pp. 312 - 318. energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 312 - 318 Mots-clés : Hilbert  transforms;  demagnetisation;  fault  diagnosis;  finite  element  analysis;  permanent  magnet  motors;  stators;  synchronous  motors;  time-frequency  analysis Résumé : This paper presents a novel method to diagnose demagnetization in permanent-magnet synchronous motor (PMSM). Simulations have been performed by 2-D finite-element analysis in order to determine the current spectrum and the magnetic flux distribution due to this failure. The diagnostic just based on motor current signature analysis can be confused by eccentricity failure because the harmonic content is the same. Moreover, it can only be applied under stationary conditions. In order to overcome these drawbacks, a novel method is used based upon the Hilbert-Huang transform. It represents time-dependent series in a 2-D time-frequency domain by extracting instantaneous frequency components through an empirical-mode decomposition process. This tool is applied by running the motor under nonstationary conditions of velocity. The experimental results show the reliability and feasibility of the methodology in order to diagnose the demagnetization of a PMSM. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5404255&sortType%3Das [...]

A coaxial magnetic gear with Halbach permanent-magnet arrays / Linni Jian in IEEE transactions on energy conversion, Vol. 25 N° 2 (Juin 2010) 

Public ISBD [article]  in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 319 - 328 Titre : A coaxial magnetic gear with Halbach permanent-magnet arrays Type de document : texte imprimé Auteurs : Linni Jian, Auteur ; Chau, K. T., Auteur Année de publication : 2010 Article en page(s) : pp. 319 - 328 Note générale : energy conversion Langues : Anglais (eng) Mots-clés : finite  element  analysis;  gears;  magnetic  fields;  permanent  magnets;  rotors;  torque Résumé : This paper proposes a coaxial magnetic gear that offers higher torque density, lower cogging torque, and lower iron losses than its counterparts. The key is to newly employ a Halbach permanent-magnet (PM) array to constitute the PM poles in the inner rotor and a partial Halbach array (two segments per pole) for the outer rotor. The corresponding magnetic field distributions, torque transmission, and torque ripples are analytically discussed. Then, the corresponding performances are quantitatively assessed by using the finite-element method. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5467346&sortType%3Das [...] [article] A coaxial magnetic gear with Halbach permanent-magnet arrays [texte imprimé] / Linni Jian, Auteur ; Chau, K. T., Auteur . - 2010 . - pp. 319 - 328. energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 319 - 328 Mots-clés : finite  element  analysis;  gears;  magnetic  fields;  permanent  magnets;  rotors;  torque Résumé : This paper proposes a coaxial magnetic gear that offers higher torque density, lower cogging torque, and lower iron losses than its counterparts. The key is to newly employ a Halbach permanent-magnet (PM) array to constitute the PM poles in the inner rotor and a partial Halbach array (two segments per pole) for the outer rotor. The corresponding magnetic field distributions, torque transmission, and torque ripples are analytically discussed. Then, the corresponding performances are quantitatively assessed by using the finite-element method. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5467346&sortType%3Das [...]

Incorporating motion in mesh-based magnetic equivalent circuits / Bash, M. L. in IEEE transactions on energy conversion, Vol. 25 N° 2 (Juin 2010) 

Public ISBD [article]  in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 329 - 338 Titre : Incorporating motion in mesh-based magnetic equivalent circuits Type de document : texte imprimé Auteurs : Bash, M. L., Auteur ; Williams, J.M., Auteur ; Pekarek, S.D., Auteur Année de publication : 2010 Article en page(s) : pp. 329 - 338 Note générale : energy conversion Langues : Anglais (eng) Mots-clés : air  gaps;  electric  machines;  equivalent  circuits;  magnetic  circuits;  mesh  generation;  rotors;  synchronous  machines Résumé : Recent research has compared the numerical efficiency of magnetic equivalent circuit (MEC) models based upon Kirchhoff's voltage law (mesh equations) and Kirchhoff's current law (nodal equations). For stationary magnetic components, it was shown that mesh-based methods converge in significantly fewer iterations. Although the numerical advantages would seemingly apply to electric machines, two issues have limited the application of mesh-based MEC models to electric machines. With movement, the number of meshes (unlike the number of nodes) is position dependent. Additionally, the loss of an airgap element creates an infinite reluctance. In this paper, both issues are addressed. Specifically, it is first shown that a relatively straightforward algorithm can be used to dynamically update meshes with rotor position. In addition, it is shown that the mesh model remains stable for very large values of tube reluctance. Tube reluctance values that are large enough to cause numerical issues can be easily avoided by excluding a very narrow range of rotor positions. Based upon these results, a mesh-based MEC model of a wound-rotor synchronous machine is developed and is shown to provide a significant advantage over its nodal-based model equivalent. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5378586&sortType%3Das [...] [article] Incorporating motion in mesh-based magnetic equivalent circuits [texte imprimé] / Bash, M. L., Auteur ; Williams, J.M., Auteur ; Pekarek, S.D., Auteur . - 2010 . - pp. 329 - 338. energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 329 - 338 Mots-clés : air  gaps;  electric  machines;  equivalent  circuits;  magnetic  circuits;  mesh  generation;  rotors;  synchronous  machines Résumé : Recent research has compared the numerical efficiency of magnetic equivalent circuit (MEC) models based upon Kirchhoff's voltage law (mesh equations) and Kirchhoff's current law (nodal equations). For stationary magnetic components, it was shown that mesh-based methods converge in significantly fewer iterations. Although the numerical advantages would seemingly apply to electric machines, two issues have limited the application of mesh-based MEC models to electric machines. With movement, the number of meshes (unlike the number of nodes) is position dependent. Additionally, the loss of an airgap element creates an infinite reluctance. In this paper, both issues are addressed. Specifically, it is first shown that a relatively straightforward algorithm can be used to dynamically update meshes with rotor position. In addition, it is shown that the mesh model remains stable for very large values of tube reluctance. Tube reluctance values that are large enough to cause numerical issues can be easily avoided by excluding a very narrow range of rotor positions. Based upon these results, a mesh-based MEC model of a wound-rotor synchronous machine is developed and is shown to provide a significant advantage over its nodal-based model equivalent. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5378586&sortType%3Das [...]

Induction machine modeling approach based on 3-D magnetic equivalent circuit framework / Amrhein, M. in IEEE transactions on energy conversion, Vol. 25 N° 2 (Juin 2010) 

Public ISBD [article]  in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 339 - 347 Titre : Induction machine modeling approach based on 3-D magnetic equivalent circuit framework Type de document : texte imprimé Auteurs : Amrhein, M., Auteur ; Krein, P.T., Auteur Année de publication : 2010 Article en page(s) : pp. 339 - 347 Note générale : energy conversion Langues : Anglais (eng) Mots-clés : asynchronous  machines;  electric  machine  CAD;  equivalent  circuits Résumé : Developments in power electronics technology, materials, and changing application requirements are driving advances in electric machines. Limitations of standard motor design, particularly for induction machines, restrict performance capabilities in drive applications. Current computer-aided design tools are inadequate to overcome these limitations. Lumped-parameter and finite-element models have limited accuracy and heavy computational effort, respectively. Magnetic equivalent circuits (MEC) avoid these limitations. This paper presents an induction machine MEC model geared toward design and based on a 3-D MEC framework introduced in previous work. A matrix formulation suitable for computation is described. Details of mesh generation for the MEC approach are provided. Force and performance estimation are discussed. Simulations based on this approach are able to track dynamic effects, such as rotor slot torque ripple contributions. Comparisons are made to a 500 W purpose-built machine. Results from lumped-parameter and finite-element models and measurements indicate that MECs, corrected for local saturation, are a promising option for design tools. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5467361&sortType%3Das [...] [article] Induction machine modeling approach based on 3-D magnetic equivalent circuit framework [texte imprimé] / Amrhein, M., Auteur ; Krein, P.T., Auteur . - 2010 . - pp. 339 - 347. energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 339 - 347 Mots-clés : asynchronous  machines;  electric  machine  CAD;  equivalent  circuits Résumé : Developments in power electronics technology, materials, and changing application requirements are driving advances in electric machines. Limitations of standard motor design, particularly for induction machines, restrict performance capabilities in drive applications. Current computer-aided design tools are inadequate to overcome these limitations. Lumped-parameter and finite-element models have limited accuracy and heavy computational effort, respectively. Magnetic equivalent circuits (MEC) avoid these limitations. This paper presents an induction machine MEC model geared toward design and based on a 3-D MEC framework introduced in previous work. A matrix formulation suitable for computation is described. Details of mesh generation for the MEC approach are provided. Force and performance estimation are discussed. Simulations based on this approach are able to track dynamic effects, such as rotor slot torque ripple contributions. Comparisons are made to a 500 W purpose-built machine. Results from lumped-parameter and finite-element models and measurements indicate that MECs, corrected for local saturation, are a promising option for design tools. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5467361&sortType%3Das [...]

Adjustable flux three-phase AC machines with combined multiple-step star–delta winding connections / Cistelecan, M.V. in IEEE transactions on energy conversion, Vol. 25 N° 2 (Juin 2010) 

Public ISBD [article]  in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 348 - 355 Titre : Adjustable flux three-phase AC machines with combined multiple-step star–delta winding connections Type de document : texte imprimé Auteurs : Cistelecan, M.V., Auteur ; Ferreira, F.J.T.E., Auteur ; Popescu, M., Auteur Année de publication : 2010 Article en page(s) : pp. 348 - 355 Note générale : energy conversion Langues : Anglais (eng) Mots-clés : AC  machines;  machine  control;  permanent  magnet  motors;  squirrel  cage  motors;  stators;  synchronous  generators Résumé : In this paper, a complete theory and analysis method for combined star-delta three-phase windings from the point of view of magnetomotive force spatial harmonics content and equivalent winding factors calculation is developed. The method allows for any spatial angle and any coils percentage distribution between star and delta balanced winding systems. It is proven that connecting the inner delta in the clockwise or counterclockwise direction leads to two different space angles between the star and delta systems and two different steps in the flux level control. It means that, compared to what is known and applied up to now, using n winding sections in each phase, it is possible to obtain 2 n steps (instead of n + 1) in the flux level. To check the analysis validity, two experimental tests are reported on both squirrel-cage, integer-winding, induction motor, and permanent magnet, low-speed, fractional-winding, synchronous generator with a specially designed stator winding, allowing multiple-step air-gap flux regulation. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5353678&sortType%3Das [...] [article] Adjustable flux three-phase AC machines with combined multiple-step star–delta winding connections [texte imprimé] / Cistelecan, M.V., Auteur ; Ferreira, F.J.T.E., Auteur ; Popescu, M., Auteur . - 2010 . - pp. 348 - 355. energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 348 - 355 Mots-clés : AC  machines;  machine  control;  permanent  magnet  motors;  squirrel  cage  motors;  stators;  synchronous  generators Résumé : In this paper, a complete theory and analysis method for combined star-delta three-phase windings from the point of view of magnetomotive force spatial harmonics content and equivalent winding factors calculation is developed. The method allows for any spatial angle and any coils percentage distribution between star and delta balanced winding systems. It is proven that connecting the inner delta in the clockwise or counterclockwise direction leads to two different space angles between the star and delta systems and two different steps in the flux level control. It means that, compared to what is known and applied up to now, using n winding sections in each phase, it is possible to obtain 2 n steps (instead of n + 1) in the flux level. To check the analysis validity, two experimental tests are reported on both squirrel-cage, integer-winding, induction motor, and permanent magnet, low-speed, fractional-winding, synchronous generator with a specially designed stator winding, allowing multiple-step air-gap flux regulation. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5353678&sortType%3Das [...]

Integral sliding-mode direct torque control of doubly-fed induction generators under unbalanced grid voltage / Si Zhe, Chen in IEEE transactions on energy conversion, Vol. 25 N° 2 (Juin 2010) 

Public ISBD [article]  in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 356 - 368 Titre : Integral sliding-mode direct torque control of doubly-fed induction generators under unbalanced grid voltage Type de document : texte imprimé Auteurs : Si Zhe, Chen, Auteur ; Cheung, N. C., Auteur ; Ka Chung, Wong, Auteur Année de publication : 2010 Article en page(s) : pp. 356 - 368 Note générale : energy conversion Langues : Anglais (eng) Mots-clés : asynchronous  generators;  machine  control;  power  grids;  reactive  power;  torque  control;  variable  structure  systems Résumé : An integral sliding-mode direct torque control (ISM-DTC) scheme with space-vector modulation for wind-energy conversion systems based on doubly-fed induction generators (DFIGs) under unbalanced grid voltage is proposed. The torque and power pulsations at twice the grid frequency caused by unbalanced grid voltage can be minimized by the proposed ISM-DTC scheme. Compared with existing control schemes of DFIGs under unbalanced grid voltage, the parametric uncertainties are included into the design procedure of sliding-mode controller, which guarantees the robustness of the controller. Because the torque and reactive power are directly controlled by the rotor voltage, the measurement, coordinate transformation, and symmetrical component extraction of rotor current are eliminated, which simplifies the structure of the controller. Simulation and hardware implementation results validate the effect and parametric robustness of the proposed ISM-DTC scheme. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5353677&sortType%3Das [...] [article] Integral sliding-mode direct torque control of doubly-fed induction generators under unbalanced grid voltage [texte imprimé] / Si Zhe, Chen, Auteur ; Cheung, N. C., Auteur ; Ka Chung, Wong, Auteur . - 2010 . - pp. 356 - 368. energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 356 - 368 Mots-clés : asynchronous  generators;  machine  control;  power  grids;  reactive  power;  torque  control;  variable  structure  systems Résumé : An integral sliding-mode direct torque control (ISM-DTC) scheme with space-vector modulation for wind-energy conversion systems based on doubly-fed induction generators (DFIGs) under unbalanced grid voltage is proposed. The torque and power pulsations at twice the grid frequency caused by unbalanced grid voltage can be minimized by the proposed ISM-DTC scheme. Compared with existing control schemes of DFIGs under unbalanced grid voltage, the parametric uncertainties are included into the design procedure of sliding-mode controller, which guarantees the robustness of the controller. Because the torque and reactive power are directly controlled by the rotor voltage, the measurement, coordinate transformation, and symmetrical component extraction of rotor current are eliminated, which simplifies the structure of the controller. Simulation and hardware implementation results validate the effect and parametric robustness of the proposed ISM-DTC scheme. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5353677&sortType%3Das [...]

Optimization of magnet segmentation for reduction of eddy-current losses in permanent magnet synchronous machine / Wan-Ying Huang in IEEE transactions on energy conversion, Vol. 25 N° 2 (Juin 2010) 

Public ISBD [article]  in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 381 - 387 Titre : Optimization of magnet segmentation for reduction of eddy-current losses in permanent magnet synchronous machine Type de document : texte imprimé Auteurs : Wan-Ying Huang, Auteur ; Bettayeb, M., Auteur ; Kaczmarek, R., Auteur Année de publication : 2010 Article en page(s) : pp. 381 - 387 Note générale : energy conversion Langues : Anglais (eng) Mots-clés : eddy  current  losses;  finite  element  analysis;  machine  theory;  permanent  magnet  machines;  synchronous  machines Résumé : Rare earth permanent magnet synchronous machines with the pulsewidth modulated supply are exposed to magnets' heating due to harmonic fields, which rotate in relation to rotor. In cases when skin effect is negligible, the corresponding eddy-current losses in magnets can be reduced by segmentation of magnets. In this paper, we propose an analytical method to evaluate the effect of both circumferential and axial segmentations on losses' reduction in various conditions, concerning the skin effect. With the skin effect operating, the magnets' division may lead to increase rather than decrease of the eddy-current losses. A criterion to determine range of parameters leading to this unexpected situation is presented. Finite-element calculation confirms the results of the analysis. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5378552&sortType%3Das [...] [article] Optimization of magnet segmentation for reduction of eddy-current losses in permanent magnet synchronous machine [texte imprimé] / Wan-Ying Huang, Auteur ; Bettayeb, M., Auteur ; Kaczmarek, R., Auteur . - 2010 . - pp. 381 - 387. energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 381 - 387 Mots-clés : eddy  current  losses;  finite  element  analysis;  machine  theory;  permanent  magnet  machines;  synchronous  machines Résumé : Rare earth permanent magnet synchronous machines with the pulsewidth modulated supply are exposed to magnets' heating due to harmonic fields, which rotate in relation to rotor. In cases when skin effect is negligible, the corresponding eddy-current losses in magnets can be reduced by segmentation of magnets. In this paper, we propose an analytical method to evaluate the effect of both circumferential and axial segmentations on losses' reduction in various conditions, concerning the skin effect. With the skin effect operating, the magnets' division may lead to increase rather than decrease of the eddy-current losses. A criterion to determine range of parameters leading to this unexpected situation is presented. Finite-element calculation confirms the results of the analysis. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5378552&sortType%3Das [...]

Steady-state analysis of a permanent-magnet-assisted salient-pole synchronous generator / Fukami, T. in IEEE transactions on energy conversion, Vol. 25 N° 2 (Juin 2010) 

Public ISBD [article]  in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 388 - 393 Titre : Steady-state analysis of a permanent-magnet-assisted salient-pole synchronous generator Type de document : texte imprimé Auteurs : Fukami, T., Auteur ; Hayamizu, T., Auteur ; Matsui, Y., Auteur Année de publication : 2010 Article en page(s) : pp. 388 - 393 Note générale : energy conversion Langues : Anglais (eng) Mots-clés : losses;  magnetic  cores;  permanent  magnet  generators;  synchronous  generators Résumé : This paper presents a simple mathematical model for the steady-state analysis of a permanent-magnet-assisted salient-pole synchronous generator (PMa-SG). The PMa-SG is a new type of salient-pole SG that has PMs between the adjacent pole shoes. The developed model takes into account the magnetic saturation and core loss, and enables quantitative predictions of load characteristics from the no-load test data. The validity of the developed model is confirmed experimentally. The effect of the PMs on the performance characteristics of the PMa-SG is also investigated. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5467350&sortType%3Das [...] [article] Steady-state analysis of a permanent-magnet-assisted salient-pole synchronous generator [texte imprimé] / Fukami, T., Auteur ; Hayamizu, T., Auteur ; Matsui, Y., Auteur . - 2010 . - pp. 388 - 393. energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 388 - 393 Mots-clés : losses;  magnetic  cores;  permanent  magnet  generators;  synchronous  generators Résumé : This paper presents a simple mathematical model for the steady-state analysis of a permanent-magnet-assisted salient-pole synchronous generator (PMa-SG). The PMa-SG is a new type of salient-pole SG that has PMs between the adjacent pole shoes. The developed model takes into account the magnetic saturation and core loss, and enables quantitative predictions of load characteristics from the no-load test data. The validity of the developed model is confirmed experimentally. The effect of the PMs on the performance characteristics of the PMa-SG is also investigated. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5467350&sortType%3Das [...]

MRAS sensorless vector control of an induction motor using new sliding-mode and fuzzy-logic adaptation mechanisms / Gadoue, S.M. in IEEE transactions on energy conversion, Vol. 25 N° 2 (Juin 2010) 

Public ISBD [article]  in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 394 - 402 Titre : MRAS sensorless vector control of an induction motor using new sliding-mode and fuzzy-logic adaptation mechanisms Type de document : texte imprimé Auteurs : Gadoue, S.M., Auteur ; Giaouris, Damian, Auteur ; Finch, J.W., Auteur Année de publication : 2010 Article en page(s) : pp. 394 - 402 Note générale : energy conversion Langues : Anglais (eng) Mots-clés : fuzzy  control;  induction  motors;  machine  vector  control;  model  reference  adaptive  control  systems;  rotors;  variable  structure  systems Résumé : In this paper, two novel adaptation schemes are proposed to replace the classical PI controller used in model reference adaptive speed-estimation schemes that are based on rotor flux. The first proposed adaptation scheme is based on sliding-mode theory. A new speed-estimation adaptation law is derived using Lyapunov theory to ensure estimation stability, as well as fast error dynamics. The other adaptation mechanism is based on fuzzy-logic strategy. A detailed experimental comparison between the new and conventional schemes is carried out in both open- and closed-loop sensorless modes of operation when a vector control drive is working at very low speed. Superior performance has been obtained using the new sliding-mode and fuzzy-logic adaptation mechanisms in both modes of operations. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5357459&sortType%3Das [...] [article] MRAS sensorless vector control of an induction motor using new sliding-mode and fuzzy-logic adaptation mechanisms [texte imprimé] / Gadoue, S.M., Auteur ; Giaouris, Damian, Auteur ; Finch, J.W., Auteur . - 2010 . - pp. 394 - 402. energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 394 - 402 Mots-clés : fuzzy  control;  induction  motors;  machine  vector  control;  model  reference  adaptive  control  systems;  rotors;  variable  structure  systems Résumé : In this paper, two novel adaptation schemes are proposed to replace the classical PI controller used in model reference adaptive speed-estimation schemes that are based on rotor flux. The first proposed adaptation scheme is based on sliding-mode theory. A new speed-estimation adaptation law is derived using Lyapunov theory to ensure estimation stability, as well as fast error dynamics. The other adaptation mechanism is based on fuzzy-logic strategy. A detailed experimental comparison between the new and conventional schemes is carried out in both open- and closed-loop sensorless modes of operation when a vector control drive is working at very low speed. Superior performance has been obtained using the new sliding-mode and fuzzy-logic adaptation mechanisms in both modes of operations. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5357459&sortType%3Das [...]

Thermal performance of an open-slot modular-wound machine with external rotor / Wrobel, R. in IEEE transactions on energy conversion, Vol. 25 N° 2 (Juin 2010) 

Public ISBD [article]  in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 403 - 411 Titre : Thermal performance of an open-slot modular-wound machine with external rotor Type de document : texte imprimé Auteurs : Wrobel, R., Auteur ; Mellor, P.H., Auteur ; McNeill, N., Auteur Année de publication : 2010 Article en page(s) : pp. 403 - 411 Note générale : energy conversion Langues : Anglais (eng) Mots-clés : brushless  DC  motors;  permanent  magnet  motors;  rotors;  thermal  analysis;  traction  motors;  windings Résumé : This paper describes the thermal analysis of an external-rotor brushless permanent-magnet motor used in a traction application. The machine has a nonstandard open-slot stator lamination and is wound with a single-layer concentrated ``modular'' winding. This structure potentially has several heat transfer advantages compared to the more traditional double-layer concentrated winding. An analytical lumped-parameter thermal model has been developed for the machine to gain an understanding of the main cooling mechanisms and to investigate the potential heat transfer advantages. The thermal advantage of the modular winding over the more conventional 1.5-slot-per-pole design is presented. Results from the developed thermal model have been validated experimentally on a prototype wheel hub motor. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5467351&sortType%3Das [...] [article] Thermal performance of an open-slot modular-wound machine with external rotor [texte imprimé] / Wrobel, R., Auteur ; Mellor, P.H., Auteur ; McNeill, N., Auteur . - 2010 . - pp. 403 - 411. energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 403 - 411 Mots-clés : brushless  DC  motors;  permanent  magnet  motors;  rotors;  thermal  analysis;  traction  motors;  windings Résumé : This paper describes the thermal analysis of an external-rotor brushless permanent-magnet motor used in a traction application. The machine has a nonstandard open-slot stator lamination and is wound with a single-layer concentrated ``modular'' winding. This structure potentially has several heat transfer advantages compared to the more traditional double-layer concentrated winding. An analytical lumped-parameter thermal model has been developed for the machine to gain an understanding of the main cooling mechanisms and to investigate the potential heat transfer advantages. The thermal advantage of the modular winding over the more conventional 1.5-slot-per-pole design is presented. Results from the developed thermal model have been validated experimentally on a prototype wheel hub motor. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5467351&sortType%3Das [...]

Harmonics mitigation in LCI-fed synchronous motor drives / Singh, B. in IEEE transactions on energy conversion, Vol. 25 N° 2 (Juin 2010) 

Public ISBD [article]  in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 369 - 380 Titre : Harmonics mitigation in LCI-fed synchronous motor drives Type de document : texte imprimé Auteurs : Singh, B., Auteur ; Singh, S., Auteur ; Hemanth Chender, S.P., Auteur Année de publication : 2010 Article en page(s) : pp. 369 - 380 Note générale : energy conversion Langues : Anglais (eng) Mots-clés : AC-DC  power  convertors;  commutator  motors;  synchronous  motor  drives Résumé : A load-commutated inverter (LCI) fed synchronous motor (SM) is operated as an adjustable speed drive (ASD) in high-power applications. These drives are known as commutatorless motor (CLM) drives and posses many promising features like high efficiency, economic operation, and flexibility of control in high-power ratings. The CLM drives are used in compressors, blowers, fans, pumps, and mill drives for a range of industries as mining, water treatment plants, chemical, paper, textile, cement, rolling mills, and petrochemical plants. However, the power quality (PQ) problems at ac mains have been the concerns in these drives as the LCI has front-end thyristor converter injecting harmonics in the supply. This paper investigates various topologies for the mitigation of PQ problems in LCI-fed SM drives using multipulse ac-dc converters. A set of hybrid topologies is proposed, which use a combination of a passive filter with a multipulse converter to feed CLM. A basis for selection of a suitable ac-dc converter is presented for PQ improvement at the input mains of the LCI-fed SM drives. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5409650&sortType%3Das [...] [article] Harmonics mitigation in LCI-fed synchronous motor drives [texte imprimé] / Singh, B., Auteur ; Singh, S., Auteur ; Hemanth Chender, S.P., Auteur . - 2010 . - pp. 369 - 380. energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 369 - 380 Mots-clés : AC-DC  power  convertors;  commutator  motors;  synchronous  motor  drives Résumé : A load-commutated inverter (LCI) fed synchronous motor (SM) is operated as an adjustable speed drive (ASD) in high-power applications. These drives are known as commutatorless motor (CLM) drives and posses many promising features like high efficiency, economic operation, and flexibility of control in high-power ratings. The CLM drives are used in compressors, blowers, fans, pumps, and mill drives for a range of industries as mining, water treatment plants, chemical, paper, textile, cement, rolling mills, and petrochemical plants. However, the power quality (PQ) problems at ac mains have been the concerns in these drives as the LCI has front-end thyristor converter injecting harmonics in the supply. This paper investigates various topologies for the mitigation of PQ problems in LCI-fed SM drives using multipulse ac-dc converters. A set of hybrid topologies is proposed, which use a combination of a passive filter with a multipulse converter to feed CLM. A basis for selection of a suitable ac-dc converter is presented for PQ improvement at the input mains of the LCI-fed SM drives. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5409650&sortType%3Das [...]

A fault-tolerant induction generator system based on instantaneous torque control (ITC) / Yuwen, Hu in IEEE transactions on energy conversion, Vol. 25 N° 2 (Juin 2010) 

Public ISBD [article]  in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 412 - 421 Titre : A fault-tolerant induction generator system based on instantaneous torque control (ITC) Type de document : texte imprimé Auteurs : Yuwen, Hu, Auteur ; Lanhong Zhang, Auteur ; Wenxin Huang, Auteur Année de publication : 2010 Article en page(s) : pp. 412 - 421 Note générale : energy conversion Langues : Anglais (eng) Mots-clés : asynchronous  generators;  fault  tolerance;  switching  convertors;  torque  control Résumé : A fault-tolerant scheme of an induction generator using instantaneous torque control (ITC) is proposed in this paper. In the case that a power switch of the converter goes wrong, the system can be reconfigured to a four-switch three-phase (FSTP) generator system and continue supplying some power. In the reconfigured system, the ITC strategy can also be applied; the only differences lie in the available voltage space vectors and optimal switching-table. There are only two bridges working in the post-failure operation, which results in halved output power compared with that of prefailure six-switch three-phase system. This paper also investigates the special issues of the voltage ripples and drifts of the midpoint voltage of the dc bus capacitor of the FSTP system. The optimization of capacitor and the improvement of ITC strategy can effectively solve the two issues. In order to further improve the quality of the output dc voltage, the space vector modulation -ITC strategy is examined by modeling and experimental tests, which can greatly reduce the fluctuations of output voltage. Its voltage ripple is only 0.5 V on the output voltage of 270 V dc. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5437315&sortType%3Das [...] [article] A fault-tolerant induction generator system based on instantaneous torque control (ITC) [texte imprimé] / Yuwen, Hu, Auteur ; Lanhong Zhang, Auteur ; Wenxin Huang, Auteur . - 2010 . - pp. 412 - 421. energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 412 - 421 Mots-clés : asynchronous  generators;  fault  tolerance;  switching  convertors;  torque  control Résumé : A fault-tolerant scheme of an induction generator using instantaneous torque control (ITC) is proposed in this paper. In the case that a power switch of the converter goes wrong, the system can be reconfigured to a four-switch three-phase (FSTP) generator system and continue supplying some power. In the reconfigured system, the ITC strategy can also be applied; the only differences lie in the available voltage space vectors and optimal switching-table. There are only two bridges working in the post-failure operation, which results in halved output power compared with that of prefailure six-switch three-phase system. This paper also investigates the special issues of the voltage ripples and drifts of the midpoint voltage of the dc bus capacitor of the FSTP system. The optimization of capacitor and the improvement of ITC strategy can effectively solve the two issues. In order to further improve the quality of the output dc voltage, the space vector modulation -ITC strategy is examined by modeling and experimental tests, which can greatly reduce the fluctuations of output voltage. Its voltage ripple is only 0.5 V on the output voltage of 270 V dc. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5437315&sortType%3Das [...]

A series-dynamic-resistor-based converter protection scheme for doubly-fed induction generator during various fault conditions / Jin Yang in IEEE transactions on energy conversion, Vol. 25 N° 2 (Juin 2010) 

Public ISBD [article]  in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 422 - 432 Titre : A series-dynamic-resistor-based converter protection scheme for doubly-fed induction generator during various fault conditions Type de document : texte imprimé Auteurs : Jin Yang, Auteur ; Fletcher, J.E., Auteur ; O'Reilly, J., Auteur Année de publication : 2010 Article en page(s) : pp. 422 - 432 Note générale : energy conversion Langues : Anglais (eng) Mots-clés : DC  motor  protection;  asynchronous  generators;  machine  control;  overcurrent  protection;  power  system  CAD Résumé : This paper proposes a new converter protection method, primarily based on a series dynamic resistor (SDR) that avoids the doubly-fed induction generator (DFIG) control being disabled by crowbar protection during fault conditions. A combined converter protection scheme based on the proposed SDR and conventional crowbar is analyzed and discussed. The main protection advantages are due to the series topology when compared with crowbar and dc-chopper protection. Various fault overcurrent conditions (both symmetrical and asymmetrical) are analyzed and used to design the protection in detail, including the switching strategy and coordination with crowbar, and resistance value calculations. PSCAD/EMTDC simulation results show that the proposed method is advantageous for fault overcurrent protection, especially for asymmetrical faults, in which the traditional crowbar protection may malfunction. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5404230&sortType%3Das [...] [article] A series-dynamic-resistor-based converter protection scheme for doubly-fed induction generator during various fault conditions [texte imprimé] / Jin Yang, Auteur ; Fletcher, J.E., Auteur ; O'Reilly, J., Auteur . - 2010 . - pp. 422 - 432. energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 422 - 432 Mots-clés : DC  motor  protection;  asynchronous  generators;  machine  control;  overcurrent  protection;  power  system  CAD Résumé : This paper proposes a new converter protection method, primarily based on a series dynamic resistor (SDR) that avoids the doubly-fed induction generator (DFIG) control being disabled by crowbar protection during fault conditions. A combined converter protection scheme based on the proposed SDR and conventional crowbar is analyzed and discussed. The main protection advantages are due to the series topology when compared with crowbar and dc-chopper protection. Various fault overcurrent conditions (both symmetrical and asymmetrical) are analyzed and used to design the protection in detail, including the switching strategy and coordination with crowbar, and resistance value calculations. PSCAD/EMTDC simulation results show that the proposed method is advantageous for fault overcurrent protection, especially for asymmetrical faults, in which the traditional crowbar protection may malfunction. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5404230&sortType%3Das [...]

Study of a novel energy efficient single-phase induction motor with three series-connected windings and two capacitors / Xiuhe, Wang in IEEE transactions on energy conversion, Vol. 25 N° 2 (Juin 2010) 

Public ISBD [article]  in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 433 - 440 Titre : Study of a novel energy efficient single-phase induction motor with three series-connected windings and two capacitors Type de document : texte imprimé Auteurs : Xiuhe, Wang, Auteur ; Hui, Zhong, Auteur ; Yubo, Yang, Auteur Année de publication : 2010 Article en page(s) : pp. 433 - 440 Note générale : energy conversion Langues : Anglais (eng) Mots-clés : energy  conservation;  induction  motors;  machine  windings Résumé : This paper presents a novel energy efficient single-phase induction motor with three series-connected windings and two capacitors. By suitable selection of capacitors, the currents in three windings are approximately symmetrical, and thus, the motor can operate approximately symmetrically from single-phase supply. Based on the symmetrical components method, the condition for balanced operation is studied, and the method for determining capacitances is proposed. The performance analysis method is put forward to calculate the steady performances. Performance tests are performed on the proposed motor and three-phase induction motor. It is proved that their rated efficiency is approximately the same, while the power factor of the former is higher than that of the latter. In comparison with the ordinary single-phase induction motor, it has the advantages of higher efficiency and smaller volume, thus can take the place of the latter in some applications. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5444911&sortType%3Das [...] [article] Study of a novel energy efficient single-phase induction motor with three series-connected windings and two capacitors [texte imprimé] / Xiuhe, Wang, Auteur ; Hui, Zhong, Auteur ; Yubo, Yang, Auteur . - 2010 . - pp. 433 - 440. energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 433 - 440 Mots-clés : energy  conservation;  induction  motors;  machine  windings Résumé : This paper presents a novel energy efficient single-phase induction motor with three series-connected windings and two capacitors. By suitable selection of capacitors, the currents in three windings are approximately symmetrical, and thus, the motor can operate approximately symmetrically from single-phase supply. Based on the symmetrical components method, the condition for balanced operation is studied, and the method for determining capacitances is proposed. The performance analysis method is put forward to calculate the steady performances. Performance tests are performed on the proposed motor and three-phase induction motor. It is proved that their rated efficiency is approximately the same, while the power factor of the former is higher than that of the latter. In comparison with the ordinary single-phase induction motor, it has the advantages of higher efficiency and smaller volume, thus can take the place of the latter in some applications. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5444911&sortType%3Das [...]

Reducing harmonic eddy-current losses in the stator teeth of interior permanent magnet synchronous machines during flux weakening / Seok-Hee Han in IEEE transactions on energy conversion, Vol. 25 N° 2 (Juin 2010) 

Public ISBD [article]  in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 441 - 449 Titre : Reducing harmonic eddy-current losses in the stator teeth of interior permanent magnet synchronous machines during flux weakening Type de document : texte imprimé Auteurs : Seok-Hee Han, Auteur ; Soong, W.L., Auteur ; Jahns, Thomas M., Auteur Année de publication : 2010 Article en page(s) : pp. 441 - 449 Note générale : energy conversion Langues : Anglais (eng) Mots-clés : eddy  current  losses;  finite  element  analysis;  harmonics  suppression;  machine  theory;  permanent  magnet  machines;  synchronous  machines Résumé : Interior permanent magnet (IPM) synchronous machines can experience large harmonic eddy-current losses in the stator teeth under flux-weakening operation, significantly depressing the efficiency of these machines at high operating speeds. This paper presents a new analytical/finite-element hybrid design approach to reduce the harmonic eddy-current losses in IPM machine stator teeth during flux-weakening operation. The proposed technique achieves this objective by three steps: 1) developing an analytical index for the harmonic eddy-current losses in IPM machine stator teeth; 2) designing the spatial distribution of the rotor MMF to minimize the analytical index; and 3) synthesizing the rotor geometry to implement the desired rotor MMF function while maintaining the basic machine characteristics unchanged. It will be shown that two-layer rotors, if properly optimized, are significantly more effective than one-layer rotors for the purpose of reducing the harmonic eddy-current losses in IPM machine stator teeth during flux-weakening operation at high speeds. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5467352&sortType%3Das [...] [article] Reducing harmonic eddy-current losses in the stator teeth of interior permanent magnet synchronous machines during flux weakening [texte imprimé] / Seok-Hee Han, Auteur ; Soong, W.L., Auteur ; Jahns, Thomas M., Auteur . - 2010 . - pp. 441 - 449. energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 441 - 449 Mots-clés : eddy  current  losses;  finite  element  analysis;  harmonics  suppression;  machine  theory;  permanent  magnet  machines;  synchronous  machines Résumé : Interior permanent magnet (IPM) synchronous machines can experience large harmonic eddy-current losses in the stator teeth under flux-weakening operation, significantly depressing the efficiency of these machines at high operating speeds. This paper presents a new analytical/finite-element hybrid design approach to reduce the harmonic eddy-current losses in IPM machine stator teeth during flux-weakening operation. The proposed technique achieves this objective by three steps: 1) developing an analytical index for the harmonic eddy-current losses in IPM machine stator teeth; 2) designing the spatial distribution of the rotor MMF to minimize the analytical index; and 3) synthesizing the rotor geometry to implement the desired rotor MMF function while maintaining the basic machine characteristics unchanged. It will be shown that two-layer rotors, if properly optimized, are significantly more effective than one-layer rotors for the purpose of reducing the harmonic eddy-current losses in IPM machine stator teeth during flux-weakening operation at high speeds. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5467352&sortType%3Das [...]

Synchronous reluctance motor with form blocked rotor / Kolehmainen, J. in IEEE transactions on energy conversion, Vol. 25 N° 2 (Juin 2010) 

Public ISBD [article]  in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 450 - 456 Titre : Synchronous reluctance motor with form blocked rotor Type de document : texte imprimé Auteurs : Kolehmainen, J., Auteur Année de publication : 2010 Article en page(s) : pp. 450 - 456 Note générale : energy conversion Langues : Anglais (eng) Mots-clés : finite  element  analysis;  reluctance  motor  drives;  rotors;  synchronous  machines Résumé : A novel type of mechanically robust synchronous reluctance rotor structure is proposed for medium speed synchronous reluctance machines. A machine utilizing the construction is built, tested, and compared to another machine with the common synchronous reluctance rotor structure. The machine is also simulated using the finite element method and the results are compared to the tested values. The obtained results demonstrate the feasibility of the construction. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5404253&sortType%3Das [...] [article] Synchronous reluctance motor with form blocked rotor [texte imprimé] / Kolehmainen, J., Auteur . - 2010 . - pp. 450 - 456. energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 450 - 456 Mots-clés : finite  element  analysis;  reluctance  motor  drives;  rotors;  synchronous  machines Résumé : A novel type of mechanically robust synchronous reluctance rotor structure is proposed for medium speed synchronous reluctance machines. A machine utilizing the construction is built, tested, and compared to another machine with the common synchronous reluctance rotor structure. The machine is also simulated using the finite element method and the results are compared to the tested values. The obtained results demonstrate the feasibility of the construction. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5404253&sortType%3Das [...]

Effects of fan blade forward-swept and inclined amounts in electric motors / Nakahama, T. in IEEE transactions on energy conversion, Vol. 25 N° 2 (Juin 2010) 

Public ISBD [article]  in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 457 - 464 Titre : Effects of fan blade forward-swept and inclined amounts in electric motors Type de document : texte imprimé Auteurs : Nakahama, T., Auteur ; Ishibashi, F., Auteur ; Sato, K., Auteur Année de publication : 2010 Article en page(s) : pp. 457 - 464 Note générale : energy conversion Langues : Anglais (eng) Mots-clés : blades;  electric  motors;  fans;  numerical  analysis Résumé : This paper studies the effects of blades' forward-swept amount in the rotation direction and forward-inclined amount in the intake direction on the flow around the fan blades of a large open-type motor. The authors have previously clarified this flow separation on the blade surface under high ventilation resistance from flow analysis and visualization experiments. To prevent flow separation, they proposed forward-swept and inclined blades, together with reduction of the air path's ventilation resistance. In this study, numerical fluid analyses were performed on the flow around forward-swept and inclined blades of axial fans for large open-type motors. Several combinations of forward-swept and inclined amounts were studied. The relationship between forward-swept and inclined amounts and flow was evaluated quantitatively, and an ideal combination was obtained. The study revealed that an axial fan with this combination showed much higher flow rate than a conventional fan without forward-swept and inclined blades. Furthermore, it significantly decreased fluid noise and axis power. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5467360&sortType%3Das [...] [article] Effects of fan blade forward-swept and inclined amounts in electric motors [texte imprimé] / Nakahama, T., Auteur ; Ishibashi, F., Auteur ; Sato, K., Auteur . - 2010 . - pp. 457 - 464. energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 457 - 464 Mots-clés : blades;  electric  motors;  fans;  numerical  analysis Résumé : This paper studies the effects of blades' forward-swept amount in the rotation direction and forward-inclined amount in the intake direction on the flow around the fan blades of a large open-type motor. The authors have previously clarified this flow separation on the blade surface under high ventilation resistance from flow analysis and visualization experiments. To prevent flow separation, they proposed forward-swept and inclined blades, together with reduction of the air path's ventilation resistance. In this study, numerical fluid analyses were performed on the flow around forward-swept and inclined blades of axial fans for large open-type motors. Several combinations of forward-swept and inclined amounts were studied. The relationship between forward-swept and inclined amounts and flow was evaluated quantitatively, and an ideal combination was obtained. The study revealed that an axial fan with this combination showed much higher flow rate than a conventional fan without forward-swept and inclined blades. Furthermore, it significantly decreased fluid noise and axis power. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5467360&sortType%3Das [...]

Key technical challenges for the electric power industry and climate change / Beard, L. M. in IEEE transactions on energy conversion, Vol. 25 N° 2 (Juin 2010) 

Public ISBD [article]  in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 465 - 473 Titre : Key technical challenges for the electric power industry and climate change Type de document : texte imprimé Auteurs : Beard, L. M., Auteur ; J. B. Cardell, Auteur ; Dobson, I., Auteur Année de publication : 2010 Article en page(s) : pp. 465 - 473 Note générale : energy conversion Langues : Anglais (eng) Mots-clés : greenhouses;  power  generation  planning;  power  systems;  renewable  energy  sources Résumé : This paper, prepared by the Climate Change Technology Subcommittee, a subcommittee of the Power and Energy Society Energy Development and Power Generation Committee, identifies key technical issues facing the electric power industry, related to global climate change. The technical challenges arise from: 1) impacts on system operating strategies, configuration, and expansion plans of emission-reducing technologies; 2) power infrastructure response to extreme weather events; 3) effects of government policies including an expanded use of renewable and alternative energy technologies; and 4) impacts of market rules on power system operation. Possible lessons from other industries' responses to climate change are explored. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5353612&sortType%3Das [...] [article] Key technical challenges for the electric power industry and climate change [texte imprimé] / Beard, L. M., Auteur ; J. B. Cardell, Auteur ; Dobson, I., Auteur . - 2010 . - pp. 465 - 473. energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 465 - 473 Mots-clés : greenhouses;  power  generation  planning;  power  systems;  renewable  energy  sources Résumé : This paper, prepared by the Climate Change Technology Subcommittee, a subcommittee of the Power and Energy Society Energy Development and Power Generation Committee, identifies key technical issues facing the electric power industry, related to global climate change. The technical challenges arise from: 1) impacts on system operating strategies, configuration, and expansion plans of emission-reducing technologies; 2) power infrastructure response to extreme weather events; 3) effects of government policies including an expanded use of renewable and alternative energy technologies; and 4) impacts of market rules on power system operation. Possible lessons from other industries' responses to climate change are explored. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5353612&sortType%3Das [...]

Neural network modeling of proton exchange membrane fuel cell / Puranik, S.V. in IEEE transactions on energy conversion, Vol. 25 N° 2 (Juin 2010) 

Public ISBD [article]  in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 474 - 483 Titre : Neural network modeling of proton exchange membrane fuel cell Type de document : texte imprimé Auteurs : Puranik, S.V., Auteur ; Keyhani, A., Auteur ; Khorrami, F., Auteur Année de publication : 2010 Article en page(s) : pp. 474 - 483 Note générale : energy conversion Langues : Anglais (eng) Mots-clés : neural  nets;  proton  exchange  membrane  fuel  cells Résumé : This paper proposes a neural network model of a 500-W proton exchange membrane (PEM) fuel cell. The nonlinear autoregressive moving average model of the PEM fuel cell with external inputs is developed using the recurrent neural networks. The data required to train the neural network model is generated by simulating the nonlinear state space model of the 500-W PEM fuel cell. It is shown that the two-layer neural network, with a hyperbolic tangent sigmoid function, as an activation function, in the first layer, and a pure linear function, as an activation function, in the second layer can effectively model the nonlinear dynamics of the PEM fuel cell. After model is trained and validated, it is used to analyze the dynamic behavior of the PEM fuel cell. Finally, the effect of measurement noise on the performance of the neural network model is investigated, and the results are shown. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5437311&sortType%3Das [...] [article] Neural network modeling of proton exchange membrane fuel cell [texte imprimé] / Puranik, S.V., Auteur ; Keyhani, A., Auteur ; Khorrami, F., Auteur . - 2010 . - pp. 474 - 483. energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 474 - 483 Mots-clés : neural  nets;  proton  exchange  membrane  fuel  cells Résumé : This paper proposes a neural network model of a 500-W proton exchange membrane (PEM) fuel cell. The nonlinear autoregressive moving average model of the PEM fuel cell with external inputs is developed using the recurrent neural networks. The data required to train the neural network model is generated by simulating the nonlinear state space model of the 500-W PEM fuel cell. It is shown that the two-layer neural network, with a hyperbolic tangent sigmoid function, as an activation function, in the first layer, and a pure linear function, as an activation function, in the second layer can effectively model the nonlinear dynamics of the PEM fuel cell. After model is trained and validated, it is used to analyze the dynamic behavior of the PEM fuel cell. Finally, the effect of measurement noise on the performance of the neural network model is investigated, and the results are shown. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5437311&sortType%3Das [...]

A biological swarm chasing algorithm for tracking the PV maximum power point / Liang-Rui Chen in IEEE transactions on energy conversion, Vol. 25 N° 2 (Juin 2010) 

Public ISBD [article]  in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 484 - 493 Titre : A biological swarm chasing algorithm for tracking the PV maximum power point Type de document : texte imprimé Auteurs : Liang-Rui Chen, Auteur ; Chih-Hui Tsai, Auteur ; Yuan-Li Lin, Auteur Année de publication : 2010 Article en page(s) : pp. 484 - 493 Note générale : energy conversion Langues : Anglais (eng) Mots-clés : maximum  power  point  trackers;  particle  swarm  optimisation Résumé : In this paper, a novel photovoltaic (PV) maximum power point tracking (MPPT) based on biological swarm chasing behavior is proposed to increase the MPPT performance for a module-integrated PV power system. Each PV module is viewed as a particle, and as a result, the maximum power point is viewed as the moving target. Thus, every PV module can chase the maximum power point (MPP) automatically. A 525 W prototype constructed by three parallel-connected 175 W PV modules is implemented to assess the MPPT performance. Comparing with a typical perturb and observe (P & O) MPPT method, the MPPT efficiency ??MPPT is improved about 12.19% in transient state by the proposed MPPT as theoretical prediction. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5404251&sortType%3Das [...] [article] A biological swarm chasing algorithm for tracking the PV maximum power point [texte imprimé] / Liang-Rui Chen, Auteur ; Chih-Hui Tsai, Auteur ; Yuan-Li Lin, Auteur . - 2010 . - pp. 484 - 493. energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 484 - 493 Mots-clés : maximum  power  point  trackers;  particle  swarm  optimisation Résumé : In this paper, a novel photovoltaic (PV) maximum power point tracking (MPPT) based on biological swarm chasing behavior is proposed to increase the MPPT performance for a module-integrated PV power system. Each PV module is viewed as a particle, and as a result, the maximum power point is viewed as the moving target. Thus, every PV module can chase the maximum power point (MPP) automatically. A 525 W prototype constructed by three parallel-connected 175 W PV modules is implemented to assess the MPPT performance. Comparing with a typical perturb and observe (P & O) MPPT method, the MPPT efficiency ??MPPT is improved about 12.19% in transient state by the proposed MPPT as theoretical prediction. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5404251&sortType%3Das [...]

Output power control for variable-speed variable-pitch wind generation systems / Hua Geng in IEEE transactions on energy conversion, Vol. 25 N° 2 (Juin 2010) 

Public ISBD [article]  in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 494 - 503 Titre : Output power control for variable-speed variable-pitch wind generation systems Type de document : texte imprimé Auteurs : Hua Geng, Auteur ; Geng Yang, Auteur Année de publication : 2010 Article en page(s) : pp. 494 - 503 Note générale : energy conversion Langues : Anglais (eng) Mots-clés : neural  nets;  power  control;  power  system  control;  three-term  control;  wind  power  plants;  wind  turbines Résumé : A robust pitch control strategy for the output power control of wind generator systems in wide-wind-speed range is presented in this paper. The corresponding controller is designed, which consists of a nominal inverse-system controller and a robust compensator. The advantages of the proposed strategy include the simple implementation, tolerance of turbine parameter or some nonparametric uncertainties, and robust control of the generator output power with wind-speed variations. Theoretical analyses, simulation, and experimental results show that the proposed controller can work better in a wide-wind-speed range compared with the traditional proportional-integral-derivative controller. It has similar performance with the neural network controller, but less complexity. Additionally, it can be easily adapted to other wind generator systems. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5378554&sortType%3Das [...] [article] Output power control for variable-speed variable-pitch wind generation systems [texte imprimé] / Hua Geng, Auteur ; Geng Yang, Auteur . - 2010 . - pp. 494 - 503. energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 494 - 503 Mots-clés : neural  nets;  power  control;  power  system  control;  three-term  control;  wind  power  plants;  wind  turbines Résumé : A robust pitch control strategy for the output power control of wind generator systems in wide-wind-speed range is presented in this paper. The corresponding controller is designed, which consists of a nominal inverse-system controller and a robust compensator. The advantages of the proposed strategy include the simple implementation, tolerance of turbine parameter or some nonparametric uncertainties, and robust control of the generator output power with wind-speed variations. Theoretical analyses, simulation, and experimental results show that the proposed controller can work better in a wide-wind-speed range compared with the traditional proportional-integral-derivative controller. It has similar performance with the neural network controller, but less complexity. Additionally, it can be easily adapted to other wind generator systems. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5378554&sortType%3Das [...]

Optimal operation of offshore wind farms with line-commutated HVDC link connection / Montilla-DJesus, M.E. in IEEE transactions on energy conversion, Vol. 25 N° 2 (Juin 2010) 

Public ISBD [article]  in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 504 - 513 Titre : Optimal operation of offshore wind farms with line-commutated HVDC link connection Type de document : texte imprimé Auteurs : Montilla-DJesus, M.E., Auteur ; Santos-Martin, D., Auteur ; Arnaltes, S., Auteur Année de publication : 2010 Article en page(s) : pp. 504 - 513 Note générale : energy conversion Langues : Anglais (eng) Mots-clés : HVDC  power  convertors;  HVDC  power  transmission;  asynchronous  generators;  offshore  installations;  optimisation;  wind  power Résumé : This paper aims to calculate the optimal operation of offshore wind farms (OWF) working with wind turbines based on doubly fed induction generator (DFIG) technologies, and with a high-voltage dc transmission connection. The objective of the optimization problem is to maximize the active power output of the arrangement, while considering certain factors, i.e., the restrictions imposed by the available wind power, the capability curve of the DFIG, the dc-link model, and the operative conditions. The accomplishment of this aim implies setting, adjusting, and operating the system under study in order to produce a reliable and cost-efficient electric energy supply. A realistic simulation test case is performed to evaluate the proposed method, and the optimal operation analysis takes into account different wind speeds and high-voltage dc-link lengths. The results show the effectiveness of the proposed method, demonstrating the advantages of using the reactive control performed by the DFIG to manage the operational requirements of the dc link. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5378553&sortType%3Das [...] [article] Optimal operation of offshore wind farms with line-commutated HVDC link connection [texte imprimé] / Montilla-DJesus, M.E., Auteur ; Santos-Martin, D., Auteur ; Arnaltes, S., Auteur . - 2010 . - pp. 504 - 513. energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 504 - 513 Mots-clés : HVDC  power  convertors;  HVDC  power  transmission;  asynchronous  generators;  offshore  installations;  optimisation;  wind  power Résumé : This paper aims to calculate the optimal operation of offshore wind farms (OWF) working with wind turbines based on doubly fed induction generator (DFIG) technologies, and with a high-voltage dc transmission connection. The objective of the optimization problem is to maximize the active power output of the arrangement, while considering certain factors, i.e., the restrictions imposed by the available wind power, the capability curve of the DFIG, the dc-link model, and the operative conditions. The accomplishment of this aim implies setting, adjusting, and operating the system under study in order to produce a reliable and cost-efficient electric energy supply. A realistic simulation test case is performed to evaluate the proposed method, and the optimal operation analysis takes into account different wind speeds and high-voltage dc-link lengths. The results show the effectiveness of the proposed method, demonstrating the advantages of using the reactive control performed by the DFIG to manage the operational requirements of the dc link. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5378553&sortType%3Das [...]

Transient performance improvement of wind turbines with doubly fed induction generators using nonlinear control strategy / Rahimi, M. in IEEE transactions on energy conversion, Vol. 25 N° 2 (Juin 2010) 

Public ISBD [article]  in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 514 - 525 Titre : Transient performance improvement of wind turbines with doubly fed induction generators using nonlinear control strategy Type de document : texte imprimé Auteurs : Rahimi, M., Auteur ; Parniani, M., Auteur Année de publication : 2010 Article en page(s) : pp. 514 - 525 Note générale : energy conversion Langues : Anglais (eng) Mots-clés : asynchronous  generators;  machine  control;  nonlinear  control  systems;  transient  analysis;  voltage  control;  wind  turbines Résumé : This paper first discusses dynamic characteristics of wind turbines with doubly fed induction generator (DFIG). Rotor back electromotive force (EMF) voltages in DFIG reflect the effects of stator dynamics on rotor current dynamics, and have an important role on rotor inrush current during the generator voltage dip. Compensation of these voltages can improve DFIG ride-through capability and limit the rotor current transients. It is found that the electrical dynamics of the DFIG are in nonminimum phase for certain operating conditions. Also, it is shown that the dynamics of DFIG, under compensation of rotor back EMF and grid voltages, behave as a partially linearizable system containing internal and external dynamics. The internal and external dynamics of DFIG include stator and rotor dynamics, respectively. It is found that under certain operating conditions, the internal dynamics, and thus, the entire DFIG system becomes unstable. This phenomenon deteriorates the DFIG postfault behavior. Since the DFIG electrical dynamics are nonlinear; the linear control scheme cannot properly work under large voltage dips. We address this problem by means of a nonlinear controller. The proposed approach stabilizes the internal dynamics through rotor voltage control, and improves the dynamic behavior of the DFIG after clearing the fault. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5306105&sortType%3Das [...] [article] Transient performance improvement of wind turbines with doubly fed induction generators using nonlinear control strategy [texte imprimé] / Rahimi, M., Auteur ; Parniani, M., Auteur . - 2010 . - pp. 514 - 525. energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 514 - 525 Mots-clés : asynchronous  generators;  machine  control;  nonlinear  control  systems;  transient  analysis;  voltage  control;  wind  turbines Résumé : This paper first discusses dynamic characteristics of wind turbines with doubly fed induction generator (DFIG). Rotor back electromotive force (EMF) voltages in DFIG reflect the effects of stator dynamics on rotor current dynamics, and have an important role on rotor inrush current during the generator voltage dip. Compensation of these voltages can improve DFIG ride-through capability and limit the rotor current transients. It is found that the electrical dynamics of the DFIG are in nonminimum phase for certain operating conditions. Also, it is shown that the dynamics of DFIG, under compensation of rotor back EMF and grid voltages, behave as a partially linearizable system containing internal and external dynamics. The internal and external dynamics of DFIG include stator and rotor dynamics, respectively. It is found that under certain operating conditions, the internal dynamics, and thus, the entire DFIG system becomes unstable. This phenomenon deteriorates the DFIG postfault behavior. Since the DFIG electrical dynamics are nonlinear; the linear control scheme cannot properly work under large voltage dips. We address this problem by means of a nonlinear controller. The proposed approach stabilizes the internal dynamics through rotor voltage control, and improves the dynamic behavior of the DFIG after clearing the fault. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5306105&sortType%3Das [...]

Design and control strategies of an induction-machine-based flywheel energy storage system associated to a variable-speed wind generator / Cimuca, G. in IEEE transactions on energy conversion, Vol. 25 N° 2 (Juin 2010) 

Public ISBD [article]  in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 526 - 534 Titre : Design and control strategies of an induction-machine-based flywheel energy storage system associated to a variable-speed wind generator Type de document : texte imprimé Auteurs : Cimuca, G., Auteur ; Breban, S., Auteur ; Radulescu, Mircea M., Auteur Année de publication : 2010 Article en page(s) : pp. 526 - 534 Note générale : energy conversion Langues : Anglais (eng) Mots-clés : asynchronous  machines;  flywheels;  machine  control;  torque  control;  wind  power Résumé : Flywheel energy storage systems (FESSs) improve the quality of the electric power delivered by wind generators, and help these generators contributing to the ancillary services. Presently, FESSs containing a flux-oriented controlled induction machine (IM) are mainly considered for this kind of application. The paper proposes the direct torque control (DTC) for an IM-based FESS associated to a variable-speed wind generator, and proves through simulation and experimental results that it could be a better alternative. This DTC application entails two specific aspects: 1) the IM must operate in the flux-weakening region, and 2) it must shift quickly and repeatedly between motoring and generating operation modes. DTC improvement for increasing the FESS efficiency, when it operates at small power values, is discussed. Some aspects concerning the flywheel design and the choice of the filter used in the FESS supervisor are also addressed. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5467354&sortType%3Das [...] [article] Design and control strategies of an induction-machine-based flywheel energy storage system associated to a variable-speed wind generator [texte imprimé] / Cimuca, G., Auteur ; Breban, S., Auteur ; Radulescu, Mircea M., Auteur . - 2010 . - pp. 526 - 534. energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 526 - 534 Mots-clés : asynchronous  machines;  flywheels;  machine  control;  torque  control;  wind  power Résumé : Flywheel energy storage systems (FESSs) improve the quality of the electric power delivered by wind generators, and help these generators contributing to the ancillary services. Presently, FESSs containing a flux-oriented controlled induction machine (IM) are mainly considered for this kind of application. The paper proposes the direct torque control (DTC) for an IM-based FESS associated to a variable-speed wind generator, and proves through simulation and experimental results that it could be a better alternative. This DTC application entails two specific aspects: 1) the IM must operate in the flux-weakening region, and 2) it must shift quickly and repeatedly between motoring and generating operation modes. DTC improvement for increasing the FESS efficiency, when it operates at small power values, is discussed. Some aspects concerning the flywheel design and the choice of the filter used in the FESS supervisor are also addressed. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5467354&sortType%3Das [...]

Analytical approach for well-being assessment of small autonomous power systems with solar and wind energy sources / Khatod, D.K. in IEEE transactions on energy conversion, Vol. 25 N° 2 (Juin 2010) 

Public ISBD [article]  in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 535 - 545 Titre : Analytical approach for well-being assessment of small autonomous power systems with solar and wind energy sources Type de document : texte imprimé Auteurs : Khatod, D.K., Auteur ; Pant, V., Auteur ; Sharma, Jaydev, Auteur Année de publication : 2010 Article en page(s) : pp. 535 - 545 Note générale : energy conversion Langues : Anglais (eng) Mots-clés : Monte  Carlo  methods;  power  systems;  renewable  energy  sources;  solar  power;  wind  power Résumé : This paper presents a systematic analytical approach for the well-being assessment of small autonomous power systems (SAPSs) with wind and solar energy sources. The proposed technique accounts for the uncertainties associated with solar irradiance, wind speed, demand, and outages of various generating units. The impact of wind power fluctuation on the system stability is also assessed by limiting the wind power dispatch to a certain percentage of system load. Well-being assessment and production costing simulation for SAPS are performed using proposed analytical approach and Monte Carlo simulation (MCS) method, and then, obtained results are compared in terms of accuracy and computational time. The comparison shows that the developed technique requires less computational time than MCS method, with reasonable accuracy, and thus, validates the usefulness of proposed analytical method. The impact of renewable energy penetration on a SAPS is also analyzed using the proposed method. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5353679&sortType%3Das [...] [article] Analytical approach for well-being assessment of small autonomous power systems with solar and wind energy sources [texte imprimé] / Khatod, D.K., Auteur ; Pant, V., Auteur ; Sharma, Jaydev, Auteur . - 2010 . - pp. 535 - 545. energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 535 - 545 Mots-clés : Monte  Carlo  methods;  power  systems;  renewable  energy  sources;  solar  power;  wind  power Résumé : This paper presents a systematic analytical approach for the well-being assessment of small autonomous power systems (SAPSs) with wind and solar energy sources. The proposed technique accounts for the uncertainties associated with solar irradiance, wind speed, demand, and outages of various generating units. The impact of wind power fluctuation on the system stability is also assessed by limiting the wind power dispatch to a certain percentage of system load. Well-being assessment and production costing simulation for SAPS are performed using proposed analytical approach and Monte Carlo simulation (MCS) method, and then, obtained results are compared in terms of accuracy and computational time. The comparison shows that the developed technique requires less computational time than MCS method, with reasonable accuracy, and thus, validates the usefulness of proposed analytical method. The impact of renewable energy penetration on a SAPS is also analyzed using the proposed method. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5353679&sortType%3Das [...]

An intelligent power plant fault diagnostics for varying degree of severity and loading conditions / Liangyu Ma in IEEE transactions on energy conversion, Vol. 25 N° 2 (Juin 2010) 

Public ISBD [article]  in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 546 - 554 Titre : An intelligent power plant fault diagnostics for varying degree of severity and loading conditions Type de document : texte imprimé Auteurs : Liangyu Ma, Auteur ; Yongguang Ma, Auteur ; K. Y. Lee, Auteur Année de publication : 2010 Article en page(s) : pp. 546 - 554 Note générale : energy conversion Langues : Anglais (eng) Mots-clés : fault  diagnosis;  feedforward  neural  nets;  power  engineering  computing;  thermal  power  stations Résumé : Practical fault diagnosis of a thermal system is very important in ensuring safe and reliable operation of a power plant. However, it is a difficult task due to the structural complexity of a thermal system, varying degree of severity of a fault, and the wide range of operation of the power generating unit. An artificial neural network combined with optimal zoom search is proposed in this paper for recognizing varying degrees of faults in a power plant thermal system operating at different load level. The zoom search technology is based on the similarity rules of the feature variables to a same fault with different severity when the system topological structure does not change with fault or with different loading conditions. Two different types of symptoms, a trend symptom and a semantic symptom, are calculated and jointly used for on-line fault recognition, which results in a faster and more stable fault diagnosis. A feedforward neural network structure is adopted and an improved training method is introduced. A high-pressure feedwater heater system is taken as a target system for investigation. Several simulation tests for diagnosing a multidegree fault under different operating conditions are carried out on a 300-MW power plant simulator to demonstrate the validity of the method. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5401094&sortType%3Das [...] [article] An intelligent power plant fault diagnostics for varying degree of severity and loading conditions [texte imprimé] / Liangyu Ma, Auteur ; Yongguang Ma, Auteur ; K. Y. Lee, Auteur . - 2010 . - pp. 546 - 554. energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 546 - 554 Mots-clés : fault  diagnosis;  feedforward  neural  nets;  power  engineering  computing;  thermal  power  stations Résumé : Practical fault diagnosis of a thermal system is very important in ensuring safe and reliable operation of a power plant. However, it is a difficult task due to the structural complexity of a thermal system, varying degree of severity of a fault, and the wide range of operation of the power generating unit. An artificial neural network combined with optimal zoom search is proposed in this paper for recognizing varying degrees of faults in a power plant thermal system operating at different load level. The zoom search technology is based on the similarity rules of the feature variables to a same fault with different severity when the system topological structure does not change with fault or with different loading conditions. Two different types of symptoms, a trend symptom and a semantic symptom, are calculated and jointly used for on-line fault recognition, which results in a faster and more stable fault diagnosis. A feedforward neural network structure is adopted and an improved training method is introduced. A high-pressure feedwater heater system is taken as a target system for investigation. Several simulation tests for diagnosing a multidegree fault under different operating conditions are carried out on a 300-MW power plant simulator to demonstrate the validity of the method. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5401094&sortType%3Das [...]

Stability analysis of a wave-energy conversion system containing a grid-connected induction generator driven by a wells turbine / Wang, Li in IEEE transactions on energy conversion, Vol. 25 N° 2 (Juin 2010) 

Public ISBD [article]  in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 555 - 563 Titre : Stability analysis of a wave-energy conversion system containing a grid-connected induction generator driven by a wells turbine Type de document : texte imprimé Auteurs : Wang, Li, Auteur ; Zan-Jia Chen, Auteur Année de publication : 2010 Article en page(s) : pp. 555 - 563 Note générale : energy conversion Langues : Anglais (eng) Mots-clés : asynchronous  generators;  power  system  stability;  stators;  turbines;  wave  power  generation Résumé : This paper presents the dynamic-stability analyzed results of both dynamic simulations and steady-state performance of a wave-energy power generation system containing a grid-connected induction generator (IG) driven by a Wells turbine. The stator windings of the IG are connected directly to a power grid through a step-up transformer and a transmission line. A d-q axis equivalent-circuit model is employed to establish the IG, the transmission line, and the grid to derive the complete dynamic equations of the studied system under three-phase balanced loading conditions. A frequency-domain approach based on eigenvalue analysis and a time-domain scheme based on nonlinear-model simulations are both carried out to systematically determine the dynamic stability of the studied system under various operating conditions. It can be concluded from the simulation results that the studied wave-energy power generation system subject to different disturbance conditions can maintain stable operation. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5353611&sortType%3Das [...] [article] Stability analysis of a wave-energy conversion system containing a grid-connected induction generator driven by a wells turbine [texte imprimé] / Wang, Li, Auteur ; Zan-Jia Chen, Auteur . - 2010 . - pp. 555 - 563. energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 555 - 563 Mots-clés : asynchronous  generators;  power  system  stability;  stators;  turbines;  wave  power  generation Résumé : This paper presents the dynamic-stability analyzed results of both dynamic simulations and steady-state performance of a wave-energy power generation system containing a grid-connected induction generator (IG) driven by a Wells turbine. The stator windings of the IG are connected directly to a power grid through a step-up transformer and a transmission line. A d-q axis equivalent-circuit model is employed to establish the IG, the transmission line, and the grid to derive the complete dynamic equations of the studied system under three-phase balanced loading conditions. A frequency-domain approach based on eigenvalue analysis and a time-domain scheme based on nonlinear-model simulations are both carried out to systematically determine the dynamic stability of the studied system under various operating conditions. It can be concluded from the simulation results that the studied wave-energy power generation system subject to different disturbance conditions can maintain stable operation. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5353611&sortType%3Das [...]

Hardware-in-the-loop-based simulator for a class of variable-speed wind energy conversion systems / Munteanu, I. in IEEE transactions on energy conversion, Vol. 25 N° 2 (Juin 2010) 

Public ISBD [article]  in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 564 - 576 Titre : Hardware-in-the-loop-based simulator for a class of variable-speed wind energy conversion systems : design and performance assessment Type de document : texte imprimé Auteurs : Munteanu, I., Auteur ; Bratcu, A.I., Auteur ; Seddik Bacha, Auteur Année de publication : 2010 Article en page(s) : pp. 564 - 576 Note générale : energy conversion Langues : Anglais (eng) Mots-clés : machine  control;  permanent  magnet  generators;  power  grids;  rotors;  synchronous  generators;  wind  power Résumé : This paper focuses on the design, building, error evaluation, and performance assessment of a physical simulator for a variable-speed wind energy conversion system (WECS). Such simulator, dedicated to control algorithms validation, must replicate the dynamical behavior of the WECS physically in real time. To this end, software parts, which model subsystems of the plant, and hardware parts, taken as they are from the plant, are closed-loop connected, thus implementing a hardware-in-the-loop (HIL) simulator. The simulator interacts with a software-simulated environment-in this case, the wind velocity-in order to run experiments under controllable conditions. Controllers to be tested interact directly with the hardware part of the simulator, thus better approaching the behavior of the real-world WECS. A complete grid-connected generation chain employing a horizontal-axis fixed-pitch three-bladed rotor permanent-magnet-synchronous-generator-based WECS is chosen as example for the design and performance assessment of an HIL simulator, both in frequency and time domain. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5437239&sortType%3Das [...] [article] Hardware-in-the-loop-based simulator for a class of variable-speed wind energy conversion systems : design and performance assessment [texte imprimé] / Munteanu, I., Auteur ; Bratcu, A.I., Auteur ; Seddik Bacha, Auteur . - 2010 . - pp. 564 - 576. energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 564 - 576 Mots-clés : machine  control;  permanent  magnet  generators;  power  grids;  rotors;  synchronous  generators;  wind  power Résumé : This paper focuses on the design, building, error evaluation, and performance assessment of a physical simulator for a variable-speed wind energy conversion system (WECS). Such simulator, dedicated to control algorithms validation, must replicate the dynamical behavior of the WECS physically in real time. To this end, software parts, which model subsystems of the plant, and hardware parts, taken as they are from the plant, are closed-loop connected, thus implementing a hardware-in-the-loop (HIL) simulator. The simulator interacts with a software-simulated environment-in this case, the wind velocity-in order to run experiments under controllable conditions. Controllers to be tested interact directly with the hardware part of the simulator, thus better approaching the behavior of the real-world WECS. A complete grid-connected generation chain employing a horizontal-axis fixed-pitch three-bladed rotor permanent-magnet-synchronous-generator-based WECS is chosen as example for the design and performance assessment of an HIL simulator, both in frequency and time domain. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5437239&sortType%3Das [...]

Sequential reliability forecasting for wind energy / Callaway, D. S. in IEEE transactions on energy conversion, Vol. 25 N° 2 (Juin 2010) 

Public ISBD [article]  in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 577 - 585 Titre : Sequential reliability forecasting for wind energy : temperature dependence and probability distributions Type de document : texte imprimé Auteurs : Callaway, D. S., Auteur Année de publication : 2010 Article en page(s) : pp. 577 - 585 Note générale : energy conversion Langues : Anglais (eng) Mots-clés : Gaussian  distribution;  anemometers;  power  generation  reliability;  time  series;  wind  power Résumé : Sequential wind simulation models have been developed to forecast effective load-carrying capability (ELCC), but they produce data that follow a Gaussian distribution, which can be considerably different from real wind-speed distributions, and they do not explicitly model the influence of temperature on the evolution of wind speed. The latter issue is of significant importance considering the strength of correlation between electricity load and temperature and the influence electricity load shapes have on system reliability. This paper presents a new approach to reliability estimation of wind facilities that models wind-speed distributions nonparametrically and includes the effect of temperature on the evolution of wind speed. A relatively long tall tower anemometer dataset is then used to test whether or not the model output produces ELCC distributions that are statistically similar to observed distributions. Results indicate that, relative to temperature independent models, temperature-dependent time-series models are better at both short-term wind-speed forecasting and long-term reliability forecasting. Results also show that reliability forecasts are relatively unaffected by the shape of the wind-speed distribution. Finally, it is apparent that model performance is robust to variation in the average wind power in the years used for model parameterization. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5464365&sortType%3Das [...] [article] Sequential reliability forecasting for wind energy : temperature dependence and probability distributions [texte imprimé] / Callaway, D. S., Auteur . - 2010 . - pp. 577 - 585. energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 577 - 585 Mots-clés : Gaussian  distribution;  anemometers;  power  generation  reliability;  time  series;  wind  power Résumé : Sequential wind simulation models have been developed to forecast effective load-carrying capability (ELCC), but they produce data that follow a Gaussian distribution, which can be considerably different from real wind-speed distributions, and they do not explicitly model the influence of temperature on the evolution of wind speed. The latter issue is of significant importance considering the strength of correlation between electricity load and temperature and the influence electricity load shapes have on system reliability. This paper presents a new approach to reliability estimation of wind facilities that models wind-speed distributions nonparametrically and includes the effect of temperature on the evolution of wind speed. A relatively long tall tower anemometer dataset is then used to test whether or not the model output produces ELCC distributions that are statistically similar to observed distributions. Results indicate that, relative to temperature independent models, temperature-dependent time-series models are better at both short-term wind-speed forecasting and long-term reliability forecasting. Results also show that reliability forecasts are relatively unaffected by the shape of the wind-speed distribution. Finally, it is apparent that model performance is robust to variation in the average wind power in the years used for model parameterization. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5464365&sortType%3Das [...]

Direct torque control for doubly fed induction machine-based wind turbines under voltage dips and without crowbar protection / Abad, G. in IEEE transactions on energy conversion, Vol. 25 N° 2 (Juin 2010) 

Public ISBD [article]  in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 586 - 588 Titre : Direct torque control for doubly fed induction machine-based wind turbines under voltage dips and without crowbar protection Type de document : texte imprimé Auteurs : Abad, G., Auteur ; Rodriguez, M.A., Auteur ; Poza, J., Auteur Année de publication : 2010 Article en page(s) : pp. 586 - 588 Note générale : energy conversion Langues : Anglais (eng) Mots-clés : asynchronous  machines;  power  system  control;  rotors;  stators;  torque  control;  wind  turbines Résumé : This letter proposes a rotor flux amplitude reference generation strategy for doubly fed induction machine based wind turbines. It is specially designed to address perturbations, such as voltage dips, keeping controlled the torque of the wind turbine, and considerably reducing the stator and rotor overcurrents during faults. In addition, a direct torque control strategy that provides fast dynamic response accompanies the overall control of the wind turbine. Despite the fact that the proposed control does not totally eliminate the necessity of the typical crowbar protection for this kind of turbines, it eliminates the activation of this protection during low depth voltage dips. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5437318&sortType%3Das [...] [article] Direct torque control for doubly fed induction machine-based wind turbines under voltage dips and without crowbar protection [texte imprimé] / Abad, G., Auteur ; Rodriguez, M.A., Auteur ; Poza, J., Auteur . - 2010 . - pp. 586 - 588. energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 25 N° 2 (Juin 2010) . - pp. 586 - 588 Mots-clés : asynchronous  machines;  power  system  control;  rotors;  stators;  torque  control;  wind  turbines Résumé : This letter proposes a rotor flux amplitude reference generation strategy for doubly fed induction machine based wind turbines. It is specially designed to address perturbations, such as voltage dips, keeping controlled the torque of the wind turbine, and considerably reducing the stator and rotor overcurrents during faults. In addition, a direct torque control strategy that provides fast dynamic response accompanies the overall control of the wind turbine. Despite the fact that the proposed control does not totally eliminate the necessity of the typical crowbar protection for this kind of turbines, it eliminates the activation of this protection during low depth voltage dips. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5437318&sortType%3Das [...]

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