Génie électrique

Nombre total de résultats : 78
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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)

Real Time Implementation of Shunt ActivePower Filter (SAPF) for Harmonic suppressionand Power Quality Improvement

B. Babes, L. Rahmani, A. Bouafassa, N. Hamouda  (2013)
Article de conférence

In this paper, A Shunt Active Power Filter (SAPF) is implemented using a dSPACE DS1104 processorto compensate harmonics and reactive power produced by nonlinear load. The reference source currentis computed based on the measurement of harmonics in the supply voltage and load current.A hysteresis based current controller has been implemented in a DSP processor for injecting thecompensating current into the power system, so that SAPF allows suppression of the harmonics andreactive power component of load current, resulting in a supply current that is purely sinusoidal.Simulation and experimental results of the proposed SAPF to meet the IEEE-519 standards arepresented. Voir les détails

Mots clés : Harmonics, Power quality, Active power filter, Hysteresis comparator, Real-time control

Wind Power Relationships Homer Methodology Calculation

Fouzia BRIHMAT, Said MEKHTOUB  (2013)
Article de conférence

This paper simplifies the evaluating designs task ofpower systems for a variety of applications. When we design a power system, we should make many decisions about the configuration of the system, a task that Homer takes in hand.HOMER simulates the operation of a system by making energy balance calculations for each of the 8,760 hours a year.In this work, stages of wind energy conversion system are given through a mathematical formulation, knowing that wind power is probably the most promising sustainable energy resource. The wind is a clean and inexhaustible resource available all over the world. Voir les détails

Mots clés : wind layer, wind turbine output power, mathematical formulation, calculation, Homer.

Technico-Economical Sizing of Stand Alone Hybrid System for Rural Electrification in an Algerian Territory—a Case Study

Fouzia BRIHMAT, Said MEKHTOUB  (2013)
Article de conférence

The Tindouf region in Algeria enjoys an average windspeed of 4.3 m/s at 10 m elevation and an average daily solar radiation of 5.9 kWh/m2/d. Within this perspective, a remote rural village in Tindouf region within ten homes can readily be expected to have more than enough potential for its load demand to be supplied with a stand-alone hybrid renewable energy system. For this purpose, a wind-pv-diesel hybrid power system has been designed. The study found a wind-pv-diesel hybrid power system with 74% renewable energy penetration (26% wind and 48% solar PV) to be the feasible system with cost of energy of 0.433 US$/kWh. The proposed system was comprised of one wind turbine of 3 kW, 3.5kW of PV panels, and one diesel generating set of 5.5 kW rated power. The system was able to meet the energy requirements (AC primary load of 9.49 MWh/y)of the village with 289 kWh/y energy in excess. The annual contributions of wind, solar pv and the diesel generating set were 3 234, 5 958, and 3 274 kWh, respectively. The proposed hybrid power system resulted in avoiding addition of 16.26 t/y of CO2 gas in to the local atmosphere of the village and conservation of 6176.15 liters of fossil fuel annually. Voir les détails

Mots clés : Wind-pv-diesel hybrid system, Homer, optimum system sizing, Net Present Cost, Algeria

Technico-economical Feasibility Study of a PV Power System for a Village

Fouzia BRIHMAT, Said MEKHTOUB  (2014)
Article de conférence

Algeria being enriched with higher level of solar radiation is a prospective candidate for deployment of solar PV systems.The aim of this study is to analyze long-term solar radiation data of Tindouf (South-West of, Algeria to assess the techno-economic feasibility of utilizing PV–battery power system to meet the load of a typical residential building (with annual electrical energy demand of 9490 kWh). The monthly average daily solar global radiation ranges from 3.61 to 7.96 kwh/m 2 . PVSyst and National Renewable Energy Laboratory’s (NREL) Hybrid Optimization Model for Electric Renewable (HOMER) softwares have been employed to respectively carry out the technical and the economical present study. Voir les détails

Mots clés : Algeria, Homer, Net Present Cost, optimum system sizing, PVsyst, PV system.

Formulation of Mumford and Shah problem by level set

N. Ramou, M. Halimi  (2014)
Article de conférence

The limitations of the active contour based on borders have directed the research towards solutions wherethe contour is built from all the information contained in the image. They are known as region-based active contours. More robust to the noise and less sensitive to the position of the initial curve, the models based on regions have for general principle to develop a curve so that in the convergence, we realize a partition of the image in two homogeneous regions.We obtain two regions because a single curve bounds only two domains in image. The region-based active contours base generally on statistical. Voir les détails

Mots clés : Level set, Mumford-Shah, weld defect

Extraction of weld defects dimension from radiographic images using the level set segmentation without re-initialization

N. Ramou, Y. Boutiche, M. Halimi  (2012)
Article de conférence

Radiographic images segmentation is the major interest for the weld defect diagnosis and monitoring in the field of industry. In this work we present a method that takes ownership of local segmentation geodesic active contours. The goal of the method presented in this paper is to automate the process of extracting dimension characteristics from radiographic images using level set segmentation to provide information which is used in the area of nondestructive testing (NDT). This method is found to be effective and robust. Voir les détails

Mots clés : Level set segmentation, Radiographic weld defect, weld defects Dimension, NDT


Y. Boutiche, N. Ramou, M. Halimi  (2012)
Article de conférence

This paper is devoted to a crucial task in image analysis which is segmentation. Our aim is to give the structural form of industrial radiographic images. In this purpose, we have used an implicit region oriented deformable model. In this context the criteria to stop the curves’ evolution is the statistical information of the image grey level, this gives many advantages compared to those that used the gradient.The functional is minimized via a piecewise constant approximation and Multiphase level set. In this situation we need n level set function to represent up to 2n segments or regions. The model avoids automatically the problems of vacuum and overlap. The numerical results for synthetic and weld radiographic images are satisfactory. Voir les détails

Mots clés : Weld Radiographic image, image segmentation, Level Set Methods, Chan-Vese Model, Multiphase segmentation