Letteratura scientifica selezionata sul tema "Générateur à induction à six phases"

This thesis presents a re-designed conventional three phase 5-hp squirrel cage, 4-pole, 48 slots induction motor to a six-phase induction motor (SPIM). It also presents the in-depth of a single layer winding of a three-phase motor that was re-design to the six-phase split winding layout which was practically explained to the understanding of both the engineers and the technicians who normally find it difficult with windings of electrical machines. The optimized re-designed SPIM is presented in the MATLAB/Simulink environment to perform a comparative assessment of the different phase loss scenarios of the six-phase configuration with respect to the six-phase healthy case and its conventional three-phase induction motor. The result shows a comparative benefit of the six-phase induction motor over the three-phase induction motor; in such that in the near future because of its effective way to provide a higher reliability and sustainability under the loss of phase/phases condition it will be practically applied in the power driven devices/machines like in the area of Electric Vehicles, etc.

ABSTRACT Several fimbriated phases of Vibrio cholerae O139 strains were selectively induced and compared immunologically and biochemically with those of V. cholerae O1. Fimbrial antigens were detected on the surfaces of vibrio cells colonizing the epithelial cells of a rabbit small intestine. Convalescent-phase sera from six individuals infected with V. cholerae O139 revealed the development of antibody against the fimbrillin. These findings suggest that the fimbriae of V. cholerae O1 and O139 are expressed in vivo during infection and that consideration must be given to the use of fimbrial antigens as components of vaccines against cholera.

In order to reduce the costs of implementing the radial position control system of a three-phase bearingless machine with split winding, this article proposes a driving method that uses only two phases of the system instead of the three-phase traditional one. It reduces from six to four the number of inverter legs, drivers, sensors, and current controllers necessary to drive and control the system. To justify the proposal, this new power and control configuration was applied to a 250 W machine controlled by a digital signal processor (DSP). The results obtained demonstrated that it is possible to carry out the radial position control through two phases, without loss of performance in relation to the conventional three-phase drive and control system.

Industry is the primary application for induction machines. As such, it is essential to calculate the induction devices’ electrical properties accurately. With DC testing, no-load rotor tests, and locked rotor tests, one may empirically evaluate the electrical variables of induction motors. These tests are expensive and difficult to conduct, however. The information supplied by machine makers can also be used to accurately approximate the equivalent variables of the circuits in induction machines. This article has successfully predicted motor reactance (Xm) for both double- and single-cage models using artificial neural networks (ANN). Although ANNs have been investigated in the literature, the ANN structures were trained to use unmemorized training. Besides ANN, six other approaches have been suggested to address this issue: heap-based optimization (HBO), leagues championship algorithm (LCA), multi-verse optimization (MVO), osprey optimization algorithm (OOA), cuckoo optimization algorithm (COA), and sooty tern optimization algorithm (STOA). The efficaciousness of the suggested approaches was compared with each another. Regarding the obtained outcomes, the suggested MVO- multi-layer perceptron (MLP) technique performed better than the other five methods regarding reactance prediction, with R2 of 0.99598 and 0.9962, and RMSE of 20.31492 and 20.80626 in the testing and training phases, respectively. For the projected model, the suggested ANNs have produced great results. The novelty lies in the mentioned methods’ ability to tackle the complexities and challenges associated with induction motor reactance optimization, providing innovative approaches to finding optimal or near-optimal solutions. As researchers continue to explore and refine these techniques, their impact on motor design and efficiency will likely grow, driving advancements in electrical engineering.

This study aimed to evaluate electroencephalography (EEG) and cardiovascular changes associated with propofol constant rate of infusion (CRI) anesthesia in dogs. Six dogs were each given propofol CRI to induce different anesthetic phases including induction (1 mg/kg/min for 10 min), and decremental maintenance doses of 2.4 mg per kg per min, 1.6 mg per kg per min, and 0.8 mg per kg per minute over 45 min. Processed EEG indices including patient state index (PSI), (burst) suppression ratio (SR), and spectral edge frequency (95%) were obtained continuously until the dogs recovered to sternal recumbency. The dogs were intubated and ventilated. Cardiovascular and EEG index values were compared between anesthetic phases. The PSI, SR, mean arterial blood pressure, and subjective anesthetic depth scores were highly correlated throughout anesthetic depth changes. The PSI decreased from 85.0 ± 17.3 at awake to 66.0 ± 29.0 at induction, and then sharply reduced to 19.7 ± 23.6 during maintenance and returned to 61.5 ± 19.2 at extubation. The SR increased from 15.4 ± 30.9% at induction to 70.9 ± 39.8% during maintenance and decreased to 3.4 ± 8.9% at extubation. We concluded that EEG indices can be used to aid in tracking ongoing brain state changes during propofol anesthesia in dogs.

This paper presents a modified space-vector pulse width modulation (SVPWM) technique for a five-level inverter that provides complete control over the multiple space-vector voltages of a six-phase inverter. This technique involves splitting six phases into two three-phase five-level inverters connected in parallel. A six-phase induction motor (SPIM) drive with a distributed neutral is considered as the load. This paper also presents a comparative analysis between the proposed and conventional SVPWM inverter-fed SPIM drives. To investigate the analytical developments and voltage limits, MATLAB/Simulink environment was used in this study. A prototype was developed in the laboratory for analyzing the harmonic components of the phase voltages and currents. The efficacy of the proposed technique was validated by means of comprehensive experiments, and the results discussed herein.

La génératrice à induction à cage d'écureuil joue un rôle important dans diverses applications éoliennes. Dans cette thèse, une génératrice à induction à six phases à cage d'écureuil présentant 24 pôles a été étudiée. Cette génératrice peut continuer de fonctionner même lorsque 1, 2 ou 3 phases statoriques ou bras d'onduleur sont défaillants. Un modèle de la génératrice à induction dit macroscopique est proposé basé sur les équations standard de tension de la machine et des équations générales du couple et de la vitesse rotorique dans le repère abcdef. Ses paramètres sont similaires à ceux des modèles αβ et dq. Lors de l'ouverture d'un enroulement statorique, ce modèle peut fonctionner comme un modèle à circuit interne équivalent en ouvrant ou en fermant un commutateur tout en nécessitant beaucoup moins de temps de calcul. Associé au système de commande indirecte du champ rotorique, ce modèle a été simulé avec succès. Un système de contrôle par logique floue des courants basé sur la matrice MacVicar-Whelan a été mis au point pour éliminer les oscillations de puissance apparaissant lors de l'ouverture d'une phase statorique. Pour valider la méthode proposée préalablement simulée, des tests ont été effectués sur un banc d'essais constitué d'un prototype de machine à induction hexaphasée de 24 kW
The squirrel cage induction generator plays a significant role in various wind turbine applications. In this dissertation, the squirrel cage six-phase induction generator (SC6PIG) with 24 poles has been studied. This generator can operate even 1, 2 or 3 phases of the stator windings or inverter legs are lost. The proposed model of the SC6PIG is arranged based on the basic voltage equations of the induction machine and the general torque and rotor speed equations which use axis abcdef. Its parameters use similar to the parameters of αβ and dq models to apply the model in healthy and faulty conditions. When a stator winding opens, this model can work as an internal circuit-oriented model by opening or closing a switch but requires less computation time. Associated to the indirect rotor field oriented control (IRFOC), this model has been simulated successfully. Then a fuzzy logic control (FLC) system which uses MacVicar-Whelan matrix has been established in order to eliminate the power ripples that occur when one phase is missing. To validate the proposed method that has been previously simulated, tests have been carried out on the 24 kW prototype induction generator of the wind turbine

La machine à induction est considérée comme l'une des machines électriques les plus utilisées dans les applications industrielles en raison de sa structure ferme, de sa robustesse, de sa simplicité, de son coût raisonnable, de sa longue durée de vie et de sa grande fiabilité. La machine à induction multiphasée, en particulier une machine à six phases, est une solution judicieuse pour augmenter la fiabilité par rapport à une machine à induction triphasée pour des applications telles que les véhicules électriques. L'augmentation du nombre de phases sur la machine peut entraîner une baisse de capacité en cas de perte d'une ou plusieurs phases. En outre, la configuration multiphasée offre d'autres avantages, tels qu'une capacité de gestion de puissance élevée en divisant la puissance requise entre les phases, des pulsations de couple réduites, des pertes de cuivre de stator réduites et des courants harmoniques de rotor réduits. Une autre solution pour améliorer les performances de la machine à induction consiste à utiliser un enroulement concentré car il présente de nombreux avantages tels que l'extrémité des spires plus courte sans chevauchement, une capacité de tolérance de panne plus élevée et une procédure de fabrication plus facile. Cependant, le principal inconvénient du bobinage concentré est la densité de flux d’entrefer de faible qualité. Compte tenu de l'inconvénient mentionné ci-dessus, l'application d'un enroulement concentré sur des moteurs à induction détériore considérablement leurs performances, ce qui rend inefficaces les avantages du bobinage concentré. Dans ce travail de recherche, l'objectif principal est d'améliorer les performances des moteurs asynchrones à six phases à enroulements concentrés. À cette fin, un nouveau schéma d'enroulement concentré réalisable, à savoir un enroulement pseudo-concentré, est proposé en utilisant une analyse de la fonction d'enroulement, qui a un harmonique fondamental plus élevé de la densité de flux d'entrefer par rapport aux enroulements concentrés conventionnels. L'utilisation de l'enroulement pseudo-concentré au lieu de l'enroulement conventionnel améliore considérablement les paramètres de performance du moteur à induction à six phases tels que la puissance de sortie, le rendement et le facteur de puissance. Pour améliorer encore les performances du moteur, un nouveau moteur à induction à six phases optimal équipé de l'enroulement pseudo-concentré est conçu et fabriqué en tenant compte des caractéristiques d'enroulement telles que l'extrémité d'enroulement plus courte et l'harmonique fondamental inférieur de la densité de flux d'entrefer par rapport à la distribution de l’enroulement conventionnel. Les résultats de performance du moteur montrent que le moteur à induction à six phases équipé de l'enroulement pseudo-concentré peut avoir des paramètres de performance élevés même par rapport au moteur équipé de l'enroulement distribué. Compte tenu des faits précités, il semble que l'utilisation d'un moteur à induction équipé du bobinage pseudo-concentré puisse être une solution appropriée pour une application de véhicule électrique. Pour en savoir plus, un moteur à induction à six phases à rotor extérieur équipé du bobinage pseudo-concentré est conçu et optimisé pour les véhicules électriques légers de faible puissance. Comme prévu, le moteur à induction à six phases à rotor externe optimal fabriqué fournit des performances acceptables pour une application dans la roue
Electrical Machine is an important research area in electrical engineering with numerous industrial applications. Induction machine is considered as one of the most employed electrical machines in industrial applications because of its firm structure, robustness, simplicity, reasonable cost, long lifetime, and high reliability. Multiphase induction machine, especially the six-phase one, is a sensible solution to increasing reliability compared to a three-phase induction machine for applications such as an electric vehicle. Increasing the number of phases on the machine can result in the ride through capability in case of loss of one or more phases. Furthermore, the multiphase configuration provides other advantages, such as high power-handling capability by dividing the required power between phases, reduced torque pulsations, reduced stator copper losses, and reduced rotor harmonic currents. Another solution in the way of improving induction machine performance is using concentrated winding because it has many advantages such as shorter non-overlapping end turns, higher fault-tolerant capability, and easier manufacturing procedure. The main drawback of concentrated winding, however, is its low-quality air gap flux density, which usually limits the winding application to permanent magnet synchronous machines. Considering the aforementioned drawback, applying concentrated winding to induction motors deteriorates their performances significantly, which renders the concentrated winding advantages ineffective. In this research work, the main goal is to improve the performance of the six-phase induction motors with concentrated windings. For this purpose, a new feasible concentrated winding layout, namely pseudo-concentrated winding, is proposed using winding function analysis, which has a higher fundamental harmonic of the air gap flux density compared to the conventional concentrated windings. Using the pseudo-concentrated winding instead of the conventional one enhances the performance parameters of the six-phase induction motor such as output power, efficiency, and power factor significantly. To enhance the motor performance, even more, a new optimum six-phase induction motor equipped with the pseudo-concentrated winding is designed and fabricated considering the winding features such as shorter end winding and lower fundamental harmonic of air gap flux density compared to the conventional distributed winding. The performance results of the motor show that the six-phase induction motor equipped with the pseudo-concentrated winding could have high-performance parameters even compared to the motor equipped with the distributed winding. Considering the aforementioned facts, it seems that using an induction motor equipped with the pseudo-concentrated winding can be an appropriate solution for electric vehicle application. To investigate more, an outer rotor six-phase induction motor equipped with the pseudo-concentrated winding is designed and optimized for light-duty low-power electric vehicles. As expected, the fabricated optimum outer rotor six-phase induction motor provides acceptable performance for the in-wheel application. In this research work, a novel pseudo-concentrated winding is introduced with better magnetic characteristics compared to the conventional concentrated windings, which allows applying it to the induction motors without having a noticeable performance drop compared to the distributed winding. The pseudo-concentrated winding has a lower air gap flux density amplitude compared to the distributed winding; therefore, for using this winding layout in induction motor application, a new stator lamination should be designed considering the magnetic characteristics of the pseudo-concentrated winding to achieve acceptable performance parameters