Electrotechnique

Nombre total de résultats :121
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Early detection of short circuit between turns in stator winding of induction machines via multivariate statistics

Aouabdi Salim, Merabet hichem  (2015)
Article de conférence

Online monitoring of induction machine health is of increased interest, as the industrial processes that depend on the machines becomes more complex and as performance to cost ration of monitoring technology. Several efforts have been directed towards developing methods that use the conventional signal processing and pattern classification techniques. This paper focuses on fault diagnosis in induction machines operating under transient conditions. A new tool of anomaly detection based on multi-scale entropy MSE of Park vector approach and information theory combined with current trajectory mass center with principal component analysis (PCA) are proposed. The faults study in this paper is short circuit between turns  in stator winding of induction machine. Simulation results show that the proposed method are able to detect short circuit between turns in stator winding of induction machine in the permanent period. Voir les détails

Mots clés : Induction machine, Fault Diagnosis, Multi-scale entropy, principal component analysis, Current trajectory mass center

Parameters Identification for Jiles-AthertonModel using Genetic Algorithms

M. Zergoug, M. Amir, Y. BENNEDJOUE  (2015)
Article de conférence

The aims of this work is the modeling of the hysteresis loop in ferromagneticmaterials, and allowed to highlight of the difficulty that exists in the choice of an model,both accurate and fast, for implantation in a calculation code field. Through this work, wetried to implement the means to incorporate the hysteresis phenomenon; we proposed aprocedure for the identification and optimization of the hysteresis loop by geneticalgorithms (GA). The obtained results by this method permit to get the hysteresis loopusing numerical simulation techniques. Experimental cycles on different samples allowedto us to identify the different optimized parameters and determine the GA approach on thecalculation of various parameters of the hysteresis loop. Voir les détails

Mots clés : Hysteresis Loop, Ferromagnetic Materials, genetic algorithms (GA), Jiles-Atherton Model.

Parameters Identification for Jiles-Atherton Model using Genetic Algorithms

M. Zergoug, M. Amir, Y. BENNEDJOUE  (2015)
Article de conférence

The aims of this work is the modeling of the hysteresis loop in ferromagnetic materials, and allowed to highlight of the difficulty that exists in the choice of an model, both accurate and fast, for implantation in a calculation code field. Through this work, we tried to implement the means to incorporate the hysteresis phenomenon; we proposed a procedure for the identification and optimization of the hysteresis loop by genetic algorithms (GA). The obtained results by this method permit to get the hysteresis loop using numerical simulation techniques. Experimental cycles on different samples allowed to us to identify the different optimized parameters and determine the GA approach on the calculation of various parameters of the hysteresis loop. Voir les détails

Mots clés : Hysteresis Loop, Ferromagnetic Materials, genetic algorithms (GA), Jiles-Atherton model

Répartition de champ électrique dans un système pointe-plan avec barrière isolante

BENHARAT Samira, Slimane Bouazabia  (2015)
Article de conférence

The objective of our work is the study by numerical simulation of the distribution of the electric field according to geometric measurements of the insulating barrier and its position in the inter-electrodes gap Voir les détails

Mots clés : Electrical discharge, insulating barrier, finite element, electrical field

An advanced control approach for current harmonic cancellation using shunt active power filter

N. Hamouda, K. E. Hemsas, H. Benalla, A. Boutaghane  (2015)
Publication

Generally, low harmonic frequencies such as the harmonic of the order 5 and 7 have agreat influence to deteriorate the network current and interim the grid power factor. The objectiveis; to cancel out the selected harmonic order from the network current. The shapes of waves andthe values of the THD of the network current before and after applying the proposed techniqueare introduced. The system is simulated and investigated using MATLAB/Simulink. The resultsprove the effectiveness of the design and control strategy (α-β). This paper deals with design,analysis and simulation of a three phase three wire shunt selective active power filter. Itcompensates the harmonic currents selectively under balanced power network. In order toimprove, the power factor of the supply network, an advanced control approach based on amultivariable filter is adopted. The novelty of the proposed control approach developed in thispaper is to use a multi-variable filter (MVF), which can extract the harmonics content of loadcurrent reference, according to the axis of Concordia. Voir les détails

Mots clés : harmonic, shunt selective active power filter control, power factor, multi-variable filter, MVF, axis of Concordia, THD

Condition Monitoring and Fault Detection in Wind Turbine Based on DFIG by the Fuzzy Logic

H.MERABET, T. BAHI, N. HALEM  (2015)
Publication

oubly-fed induction generator is widely used in wind turbine conversion systems. Several research works are being made to efficiently approve existing condition monitoring and fault detection techniques for these systems. The condition monitoring ofthese systems becomes more and more important, the main obstacle in this task is the lack of an accurate analytical model to describe a faulty DFIG in the majority of the research tasks. In this paper, we present the monitoring strategy of short-circuit fault between turns of the stator windings and open stator phases in doubly-fed induction generator by fuzzy logic technique. The stator condition monitoring is diagnosed based on the root mean square values of current magnitude in addition to the knowledgeexpressed in rules and membership function. The proposed strategy is verified using simulations performed via the model of Doubly-fed induction generator built in MatLab ® SIMULINK. Voir les détails

Mots clés : Wind turbine, DIFG, Monitoring, Detection fault, Fuzzy logic.

Fault Diagnosis of an Induction Generator ina Wind Energy Conversion System Using SignalProcessing Techniques

Issam ATTOUI; Amar OMEIRI  (2015)
Publication

In this article, a contribution to fault diagnosis of an in-duction machine in a wind energy conversion system in closed-loopoperation using a combination between short-time Fourier transformand discrete wavelet transform algorithms is proposed. An on-linefault diagnostic technique based on stator currents analysis of thesquirrel-cage induction generator is proposed to detect and localizeabnormal electrical conditions that indicate, or may lead to, a statoror rotor failure in a squirrel-cage induction generator. This techniquealso permits identification of a fault severity factor and consequentlyhelps to determine the best choice of correctivemaintenance. Further-more, a generalized model of the squirrel-cage induction generatoris used to simulate both the rotor and stator faults, taking iron losses,main flux, and cross-flux saturation into account. The efficiency ofdiagnostic procedure in closed-loop operation of the wind energyconversion system under non-stationary operating conditions is illus-trated with simulation results. Voir les détails

Mots clés : fault diagnosis;, Induction Generator;, Wind Energy Conversion System;, Signal Processing Techniques

Sensor Monitoring of the Concentrations of Different Gases Present in Synthesis of Ammonia Based On Multi-Scale Entropy and Multivariate Statistics

Aouabdi Salim, Taibi Mahmoud  (2015)
Publication

This paper presents powerful techniques for the development of a new monitoring method based on multi-scale entropy (MSE) in order to characterize the behaviour of the concentrations of different gases present in the synthesis of Ammonia and soft-sensor based on Principal Component Analysis (PCA). Voir les détails

Mots clés : Ammonia synthesis, Concentrations of different gases, Soft sensor, Multi-scale entropy, multivariate statistics.

Modélisation électromagnétique d’un système de contrôle non destructif par courant de Foucault

Oualid SEMAOUN, Kahina MERMOURI  (2014)
Mémoire de Master

Nous avons étudié dans ce mémoire un modèle électromagnétique du contrôle non destructif par courant de Foucault d’un système sonde-pièce d’une géométrie 2D axisymétrique. Notre recherche bibliographique étendue, nous a permis de consulter assez de modèles physiques récents, ainsi que les méthodes numériques exploitées dans la résolution de la formulation magnétodynamique en régime fréquentiel. Pour notre cas, on a opté pour l’application champ magnétique du module AC/DC de COMSOL à la base des éléments finis, à fin de calculer le potentiel vecteur magnétique azimutal représentant une variable principale pour la détermination de toutes les autres grandeurs électromagnétiques et électriques du système. Partant d’une source d’excitation sinusoïdale du capteur placé à proximité d’une pièce à matériau conducteur, on est arrivé au calcul de la variation d’impédance aux bornes du capteur. Cette grandeur électrique, résultante de la topologie de perturbation des lignes de courant de Foucault, nous informe sur l’existence des défauts à la surface de la pièce. Expérimentalement, nous avons pratiqué un balayage de la sonde sur une pièce à deux défauts distants et de profondeur différente, l’impédance mesurée est plus grande lorsque le défaut est plus profond. Ces résultats ont été comparés avec ceux obtenus numériquement, et l’erreur relative a été de l’ordre 3%. Voir les détails

Mots clés : contrôle non destructif, Courant de Foucault, Électromagnétisme, méthode des éléments finis, Impédance d’un capteur, Défauts.

CORROSION RESISTANCE EVALUATION OF DUPLEX STAINLESS STEEL 2205 INACIDIC AND CHLORIDE ENVIRONMENT

ZIOUCHE Aicha, ZERGOUG Mourad, DEHCHAR Cherif, MOKHTARI Madjda, YOUNES Abdrahmane  (2014)
Article de conférence

This work is mainly devoted to the study ofelectrochemical performance anticorrosive of stainless steel,2205 duplex by immersion in different study at roomtemperature and different concentrations of corrosive speciesenvironments. The chemical composition and morphologicalstructure of the stainless steel material, respectively, arecharacterized by X-ray fluorescence and by optical microscopy.Electrochemical tests are performed in three electrolytes,namely sodium chloride (NaCl) at 3 %, hydrochloric acid (HCl)3% and hydrochloric acid (HCl) 5%. The techniques used inthis study are potentiometric open circuit (OCP), linearpolarization (LP) and electrochemical impedance spectroscopy(EIS). The impedance spectra and the current - potential curvesobtained allowed the estimation of the rate of corrosion indifferent electrolytes and showed a change of the polarizationresistance (Rp) and the degradation kinetics of this materialdepending on the composition of the study areas. Voir les détails

Mots clés : duplex stainless steel, Pitting corrosion, PREN, Electrochemical impedance spectroscopy