Génie électrique

Nombre total de résultats : 75
Pertinence Titre A-Z Plus récents Plus anciens
10 25 50
Année de publication
et

A Comparative Study of Various Methodsof Bearing Faults Diagnosis Using the CaseWestern Reserve University Data.

Adel Boudiaf . Abdelkrim Moussaoui . Amine Dahane . Issam Atoui (2016)
Article de journal

Bearing is probably one of the most criticalcomponents of rotating machinery. They are employed toguide and support the shafts in rotating machinery.Therefore, any fault in the bearings can lead to losses onthe level of production and equipments as well as potentiallyunsafe. For these reasons, the bearing fault diagnosishas received considerable attention from the research andengineering communities in recent years. The purpose ofthis study is to review the vibration analysis techniques andto explore their capabilities, advantages, and disadvantagein monitoring rolling element bearings.Voir les détails

Mots clés : Vibration analysis, bearing Fault diagnosis, Temporal analysis, Cepstrum analysis

Contribution au Diagnostic des Défauts dans les MachinesTournantes par Analyse Multirésolution

Adel BOUDIAF (2016)
Thèse de doctorat

La fonction principale de la surveillance vibratoire des machines tournantes est de fournirdes connaissances sur l’état de fonctionnement réel de la machine à chaque moment sansarrêter la ligne de production. Ceci permet d’éviter les pertes de production et améliore lafiabilité et la sécurité.La transformée en ondelettes (TO) est l’une des techniques les plus importantes detraitement du signal vibratoire qui peut être utilisé pour détecter et diagnostiquer les défautsdes machines tournantes. Néanmoins, les limites de cette technique sont les suivants: Il fautune présélection de l’ondelette mère convenable et le niveau approprié de décomposition quicontient les informations nécessaires pour le diagnostic des défauts .Afin de résoudre cesproblèmes, une nouvelle approche de diagnostic de défauts de roulements sera développéedans ce travail. Cette nouvelle méthode a l’avantage de ne pas souffrir des limitations destechniques de diagnostic usuelles. Voir les détails

Mots clés : analyse vibratoire, diagnostiquer les défauts de roulement, Transformée de Fourier Rapide, Analyse temporelle, l'analyse de Cepstre, l'analyse de l'enveloppe, transformées en ondelettes

Longitudinal P191 Single Ceramic Piezoelectric Transformer : Comparison between 3D Simulations and Experimental Results

Faiza Boukazouha, Mohamed Laid Tadjine (2016)
Article de conférence

In present study, three longitudinal piezoelectric transformers with size of 18.5×3.5×2 mm3, 26×3×1.5 mm3 and 24×3×2 mm3 are fabricated and tested with a soft PZT (P191) piezoelectric ceramic. The input and the output part vibrate in longitudinal extensional mode. Three configurations of the input and the output voltage are proposed. The electrical measurements results are successfully compared to a three dimensional (3D) Finite Element Analysis using COMSOL Multiphysics software. A step-up voltage of about 16 is obtained for unloaded transformers at the second mode.Voir les détails

Mots clés : Piezoelectric transformer, 3D simulation, longitudinal vibration, Experimental characterisation

DIAGNOSIS OF THE AC CURRENT DENSITIES EFFECT ON THE CATHODIC PROTECTION PERFORMANCE OF THE STEEL X70 FOR A BURIED PIPELINE DUE TO ELECTROMAGNETIC INTERFERENCE CAUSED BY HVPTL

OUADAH.M, Touhami.O, Ibtiouen.R (2016)
Article de journal

This paper diagnosis the effect of the AC current densities induced by the electromagnetic interference between high voltage power line and buried power line on the cathodic protection performance of the X70 steel in simulated soil. First, the induced AC voltage onto the pipeline was calculated for different power line configuration, separation distances between transmission line and pipeline and parallelism lengths. The induced AC current density was calculated function to the induced AC voltage, soil resistivity, and holiday diameter. Then, the electrochemical characters of the X70 steel at various AC current densities are measured using the potentiodynamic method. The electrochemical parameters obtained by the electrochemical tests are used as boundary conditions in the cathodic protection simulation model. The results indicate that, under influence of AC current densities, the X70 steel is more susceptible to corrosion, and the cathodic protection is unable to maintain the protection potential.Voir les détails

Mots clés : cathodic protection, electromagnetic interference, AC Corrosion

Diagnosis of the pipeline corrosion due to the inductive interference between high voltage power line and buried pipeline

Touhami Omar, Ibtiouen Rachid, Ouadah M'hamed (2015)
Article de conférence

In this paper, we study the interference between high voltage power transmission line and buried pipeline. The induced voltage onto the pipeline was calculated for the horizontal and the vertical configuration of the power line, the existence of the earth wire, various separation distances between conductors of the power line, and various separation distances between power line and pipeline. This effect results in a corrosion process which we have proposed some solutions.Voir les détails

Mots clés : Power lines, interference, induced voltage, induced current density, pipeline, AC Corrosion .

Modélisation des machines électriques avec défauts électriques et mécaniques en tenant compte des harmoniques

Mhamed OUADAH (En préparation)
Thèse de doctorat

Il s’agit d’élaborer un modèle de machines asynchrones permettant de tenir compte des défauts électriques et mécaniques. Les résultats obtenus par ce modèle seront comparés à ceux issus de l’approche des circuits multiples couplés magnétiquement. Il est également tenu compte des harmoniques d’espace et de les identifier par rapport à ceux traduisant les défauts électriques et mécaniques. L’analyse de traitement des signaux relevés lors des tests expérimentaux sera effectuée pour la confirmation et la validation des modèles élaborés. Il va sans dire que cette procédure pourrait être utilisée dans la surveillance en ligne des installations industrielles comportant des systèmes d’entraînement électrique à vitesse variable. Voir les détails

Mots clés : modélisation, défauts mécaniques et électriques, Eléments finis

Vibration-Based Gearbox Fault Diagnosis by DWPT and PCA Approaches and an Adaptive Neuro-Fuzzy Inference System

Issam Attoui; Adel Boudiaf; Nadir Fergani; Brahim Oudjani; Nadir Boutasseta; and Adel Deliou (2015)
Article de conférence

In a wide variety of configurations in all sorts of rotating machines, gearboxes which can be subject to breakdowns or dysfunctions in its time-of-use, represents an essential part to transfer rotating power source to other devices and provide speed and torque conversions. The gearbox faults are a critical defect in rotating machinery that may have a direct influence on the availability of the machine itself and also on those of the surrounding systems. Hence, the continuous condition assessment and estimation of the state of this component is very important issue to increase production with quality assurance as per given specification at a reasonable cost and avoid unanticipated breakdowns and equipment failures. In this paper, a particular interest is carried to the analysis and diagnosis of these defects which can appear in the gear and bearing with various combinations under different speeds and loads. This paper consists of the application of the Wavelet Packet Transform WPT and Principal Component Analysis PCA to extract the features of the different sub-bands frequencies in the vibration signal from a rotating machine. These parameters will be used by the Adaptive Neural Fuzzy Inference System ANFIS to automate the fault detection and diagnosis process. Experimental results show that the proposed procedure can classify with precision various types of faults according to the fault location and type.Voir les détails

Mots clés : gear faults;, vibration signal;, fault diagnosis;, ANFIS;, DWPT;, FFT

Vibration-based bearing fault diagnosis by an integrated DWT-FFT approach and an adaptive neuro-fuzzy inference system

I. Atoui, N. BOUTASSETA, N. Fergani, B. Oudjani, A. Deliou (2015)
Article de conférence

The rotating machine, which can be subject to breakdowns or dysfunctions in its time-of-use, represents an essential part in the majority of industrial applications. Hence, their reliability, productivity, safety and availability are very important issues that are imposed to increase production with quality assurance as per given specification at a reasonable cost. Furthermore, because the bearing faults are the most frequent and critical defects in rotating machinery that may have a direct influence on the availability of the machine itself and also on those of the surrounding systems, a particular interest is carried in this paper to the analysis and diagnosis of these defects which can appear in the bearing's ball, inner race and outer race with various fault severity and rotating speed. This paper consists of the application of the Discrete Wavelet Transform DWT and Fast Fourier Transform FFT theories to extract the amplitude of the fundamental bearing defect frequencies in the vibration signal from a rotating machine. These parameters will be used by the Adaptive Neural Fuzzy Inference System ANFIS to automate the fault detection and diagnosis process. Experimental results show that the proposed procedure can classify with precision various types of bearing faults according to the fault location and severity.Voir les détails

Mots clés : bearing faults, vibration signal, Fault Diagnosis, ANFIS, DWT, FFT

Modélisation de la Corrosion par Courants Vagabonds – Cas Continu

Fouzia BRIHMAT, M. Ouadah, S. Bouyegh (2015)
Article de conférence

D'un point de vue corrosion, l'équipement industriel alimenté par une source continue est à l’origine des courants vagabonds. Toute structure métallique enterrée dans le sol tel qu'un pipeline, représente un chemin peu résistant dont la réponse est fonction de trois éléments : 1) l'emplacement de la structure par rapport au champ électrique généré par la source du courant vagabond (dispositif de protection), 2) l'amplitude du champ électrique et 3) la réaction électrochimique de la structure à l'interférence (protection). Si l'amplitude du courant vagabond est connue, il est dans ce cas possible d'estimer les dommages de corrosion résultants sur une période. Plusieurs recherches ont été menées pour déterminer La technique de modélisation la plus appropriée pour étudier le comportement des courants vagabonds. Les systèmes de traction sont par nature imposants, des systèmes 1-D, la distribution du courant dans le sol est un phénomène typiquement 3-D, d’où se relèvent les difficultés. Un compromis précision-difficulté de mise en œuvre s’impose. Le modèle de résistances s’avère relativement simple, il fera l’œuvre de notre étude.Voir les détails

Mots clés : courants vagabonds, systèmes de traction, rails, structures métalliques, modélisation

Wavelet Transform And Envelope Detection For Gear Fault Diagnosis .A Comparative Study

A.boudiaf, Z.Mentouri, S.Ziani, A.boudiaf (2013)
Article de conférence

On-line vibration monitoring of Rotary Machinesis is a fundamental axis of development and industrial research. Itspurpose is to provide knowledge about the working condition ofmachines at each moment without stopping the production line.This method allows avoiding the production losses related tobreakdowns and reducing overall maintenance costs.Bearing fault diagnosis is important in vibration monitoringof any rotating machine. Early fault detection in machineries cansave millions of dollars in emergency maintenance cost.This paper presents the comparison results of Fault diagnosisTechniques of gear fault using two methods: Envelope Detection(ED) and Wavelet Transform (WT) using Morlet Wavelet thecomparative study is applied to real vibratory signals.Voir les détails

Mots clés : Vibration analysis, Fault Diagnosis, Wavelet Transform (WT), Envelope Detection (ED)