Génie électrique
Wind Power Relationships Homer Methodology Calculation
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
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
Wavelet Transform And Envelope Detection For Gear Fault Diagnosis .A Comparative Study
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)
Application of Wavelet Transform for Inner Race Fault (IRF) Diagnosis in Bearings of Rotating Machines
On-line vibration monitoring of Rotary Machines is a fundamental axis of development and industrialresearch. Its purpose is to provide knowledge about the working condition of machines at each moment withoutstopping the production line. This method allows avoiding the production losses related to breakdowns and reducingoverall maintenance costs. Bearing fault diagnosis is important in vibration monitoring of any rotating machine.Early fault detection in machineries can save millions of dollars in emergency maintenance cost. In this paper we areinterested to the vibration signal processing by Application of Wavelet Transform for Inner Race Fault (IRF)Diagnosis in bearings, the suggested Technique is applied to real vibratory signals obtained from the Case WesternReserve University Bearing Data Centre. From the monitoring results, the effectiveness of the Wavelet Transformmethod was proven. Voir les détails
Mots clés : Vibration analysis, Fault Diagnosis, Rotating machines, Wavelet transform, Envelope Detection
Dynamic Response of a Stand Alone AC Side Wind Energy Conversion System
This Paper consists on the study of one part of wind energy system conversion, its ACside. Renewable resources are in constant fluctuation. This situation could put in peril the energizing efficiency towards a given demand requirement. Therefore, in order to maximize the efficiency of the renewable energy system, it is necessary to track the maximum powerpoint of the input source, a study established under MATLAB/Simulink platform. For the wind system, the maximizing is assured while considering the optimal power curve as load characteristic, with the knowledge of the turbine characteristic C_p (λ).Then, this work elaboratesthe analysis and simulation of a low speed Permanent Magnet Synchronous Generator (PMSG) driven by a vertical wind turbine through a Pulse-Width Modulation (PWM) voltage inverter, independently of the DC components of the wind system conversion, usingMATLAB computer simulation. Voir les détails
Mots clés : Wind, Optimal load characteristic, Compensation decoupling, IP regulator, Permanent Magnet Synchronous Generator.
Extraction of weld defects dimension from radiographic images using the level set segmentation without re-initialization
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 of weld defects from radiographic images using level set segmentation. The information would be used in the area of nondestructive testing (NDT). This method is found to be effective and robust. Voir les détails
Mots clés : radiographic method, weld inspection, defect dimensions, Signal processing
Etude conceptuelle d’un système de conditionnement de puissance pour unecentrale hybride PV/Eolien.
En régions isolées, le générateur diesel constitue la source principale d’énergie électrique. Or, le prix d’extension du réseau électrique pour ces régions s’avère prohibitif et le surcoût de l’approvisionnement encombustible augmente radicalement avec l’isolement. Dans ce contexte, l’interconnexion de plusieurs sourcesd’énergie renouvelable (éoliennes, panneaux photovoltaïques, petites centrales hydroélectriques. etc.) dans unSystème d’Energie Hybride (SEH) peut avoir une incidence profitable sur la production d’énergie électrique entermes de coût et de disponibilité. Ainsi, ce travail de mémoire présente une contribution à l’analyse du comportement et la maîtrise desperformances d’un SEH constitué par deux sources d’énergie renouvelable, photovoltaïque et éolienne, associées àun générateur diesel, des batteries de stockage et une technologie de commande. Le système est étudié sur la base de deux aspects : dimensionnement et, maximisation de l’utilisation desressources renouvelables. Le dimensionnement s’est fait sur deux logiciels, Homer et PVsyst avec le non-apport du générateur diesel dans cesecond cas. Les ressources renouvelables sont aléatoires. Situation en mesure de mettre en péril l’efficacité énergétiquevis-à-vis d’une certaine exigence de la demande. Alors, afin de maximiser les performances des systèmes d’énergie renouvelable il est nécessaire depoursuivre le point de puissance maximale « MPPT », de la source d’entrée, étude établie sous l’environnementMatlab/Simulink. - Pour améliorer le rendement de conversion de l’énergie photovoltaïque, une nouvelle méthode de poursuite dupoint de puissance maximale en utilisant la théorie floue est proposée. Elle est basée sur des règles linguistiquesappliquées au hacheur type Boost.- Pour le système éolien, la maximisation est assurée en considérant la courbe de puissance optimale comme caractéristique de charge, avec connaissance de la caractéristique de la voilure Cp(λ). Voir les détails
Mots clés : Système d’Energie Hybride, Photovoltaïque, Eolien, Dimensionnement, simulation, MPPT, Convertisseur DC-DC, contrôleur flou, caractéristique de charge optimale.
Extraction of weld defects dimension from radiographic images using the level set segmentation without re-initialization
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
MULTIPHASE LEVEL SETS MODEL APPLIED TO WELD RADIOGRAPHIC IMAGES SEGMENTATION.
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
INFLUENCES DUES AUX LIGNES AERIENNES DE TRANSPORTD'ENERGIE SUR LES PIPELINES ENTERRESPROBLÈMES ET SOLUTIONS
L'interférence électromagnétique causée par des lignes de transport d'énergie électrique haute tension aux canalisations enterrées de pétrole et de gaz est à l'étude pendant beaucoup d’années. Particulièrement pendant les conditions de panne, et même en fonctionnement normal, des courants et des tensions sont induits sur les canalisations qui peuvent accélérer la corrosion du métal de la canalisation. Les résultats présentés dans ce document illustrent bien la tension induite due au champ magnétique sur les pipelines produits par les lignes électriques de haute tension en fonctionnement normal. Cet effet résulte un processus de corrosion auxquels nous avons proposé certaines solutions. Voir les détails
Mots clés : Ligne électrique HT, champ magnétique, pipelines, tension induite, corrosion, Protection cathodique