Liste des publications

Nombre total de résultats : 646
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Dynamic Response of a Stand Alone AC Side Wind Energy Conversion System

Fouzia BRIHMAT, Said MEKHTOUB  (2013)

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.

Effect of the austenite hot deformation on the transformation microstructural mechanics parameters of a microalloyed steel

D. BERDJANE, Pr M. L. Fares, G. Goldhahn  (2012)

This study was established to optimize the heat treatments - mechanical and improve the mechanical properties of microalloyed steel with Nb-Ti-V for the production of hot rolled strip. A database of the main parameters of deformation of this steel was developed by dilatometer-plastometer tests. The cooling experiments were used to simulate sequences of the industrial process. The results of these investigations used to analyze the effect of deformation parameters on the evolution of the ferritic structure and mechanical properties of steel. The conditions of rolling deformation bands must be simulated by experimental investigations in order to find a favorable microstructure while choosing the appropriate technological parameters. The microstructural evolution during hot rolling is a dominant factor for achieving the optimal properties. The chemical composition can predict the limits of the desired properties, but these limits depend significantly thermomechanical conditions imposed. A good adaptation of these conditions with the performance of the material allows for a high quality finished product. These investigations will be the basis for determining in advance of the microstructure, mechanical properties for subsequent monitoring of the industrial process. Voir les détails

Mots clés : Microalloyed steel, Austenite, hot deformation, mechanical properties, structure

Effet du niobium sur la résistance à l’usure d’une fonte au chrome traitée thermiquement


RésuméLes fontes au chrome sont bien connues pour leurs propriétés à l’usure. Elles sont utilisées dans les domaines miniers, cimentiers ainsi que tant d’autres. Leurs facultés de résister à l’usure sont principalement dues à leur microstructure qui est constituée d’un réseau de carbure eutectique du type M7C3 contenu dans une matrice austénitique ou martensitique. Plusieurs chercheurs ont exploré la possibilité d’améliorer les propriétés à l’usure de ces fontes en agissant sur la microstructure, la morphologie des composants microstructuraux ainsi que sur leur distribution. Le présent travail consiste à étudier l’effet du niobium sur le comportement à l’usure d’une fonte au chrome. Des caractérisations par microscopie optique, usure par abrasion et par frottement sont réalisées dans le but de déterminer la résistance à l’usure de cette fonte et le type de microstructure ayant été à l’origine de cette amélioration. Les résultats obtenus montrent que la fonte étudiée est une fonte à 15 % de chrome. L’addition du niobium a eu un effet sur la microstructure ainsi que sur les résistances par abrasion et par frottement des échantillons de fontes traitées. La résistance à l’usure augmente avec l’accroissement de la teneur en niobium. Voir les détails

Mots clés : Fontes au chrome, usure, carbures eutectiques, éléments d’alliages

PV Cell Temperature/ PV Power Output Relationships Homer Methodology Calculation

Fouzia BRIHMAT, Said MEKHTOUB  (2014)

Because of the intermittent solar irradiation whichhighly influences the resulting energy production, the majoraspects in the design of PV power generation systems are thereliable power supply of the consumer under varyingatmospheric conditions and the corresponding total system cost.Thus it is necessary to select the number of PV modules andbatteries, and their installation details such as the power will beuninterruptedly supplied to the electrical load, andsimultaneously the minimum system cost would be achieved.But it’s especially so judicious to take into account the wholesystem parameters such as cell temperature, a task ensured byseveral software tools as Homer from the NREL Laboratory.As known, meteorological parameters especially the arraytemperature, do not remain constant the whole day long, butchange considerably. Then, it is worth investigating the influenceof the daily average temperature variation on the predictedperformances of the optimized system.It’s so important to seize how such software proceeds to get around any result calculation and a possible problem at the same time.So, the goal achieved through this study is to investigate theinfluence of the cell temperature and head changing effects onthe system performances. So an approach by a mathematical formalism is then indispensable. Voir les détails

Mots clés : solar layer, PV cell temperature, PV power output, mathematical formulation, calculation, Homer.

MPPT Control of a Small PV Generation System under Diverse Weather Conditions

Fouzia BRIHMAT, Said MEKHTOUB  (2014)

The power induced in the photovoltaic modules is influenced by the intensity of solar cell irradiation, temperature of solar cells and moreover by the load. Therefore, to maximize the efficiency of the renewable energy system, it is necessary to track the maximum power point of the input source. In this work, we tie to present the constituent of a weak power PV chain dedicated to the storage on battery. The battery bank is connected to the DC network via a DC/DC boost converter, called the storage converter, used for controlling the network.Indeed, the battery is only imperative buffer storage in this case. The PV units are connected to the DC network via its own DC/DC converter, called PV converter, to ensure the required power flow. The purpose of the proposed model is the simulation of the complete system behavior from the electric and energy point of view. A maximum power point tracker (MPPT) scheme is applied through the boost converter to improve the energy conversion efficiency. Fuzzy algorithm based on linguistic rules describing the operator’s control strategy is applied to control the step-up converter for MPPT. On the other hand, Fuzzy logic control based on coarse and fine mode is incorporated in order to reduce not only the time required to track the maximum power point but also power fluctuation. A confrontation with a P and O method performed. Another fuzzy battery-charge controller is also applied. Simulation results show that the proposed fuzzy controller exhibits a better performance than the controller based upon the P and O method. Voir les détails

Mots clés : Photovoltaic, simulation, MPPT; DC-DC converter, Fuzzy controller

Removal of AY99 from an aqueous solution using an emulsifiedliquid membrane. Application of Plackett-Burman Design

Lynda BAHLOUL, Fadhel Ismail, Mohamed El-Hadi SAMAR, Hazem MERADI  (2014)

Water contaminated with dyes presents serious environmental problems. An important quantity of dyes is released asindustrial waste in nature. As part of the recovery and the regeneration of these complexes, the extraction of a cationic dye AcidYellow 99 has been the subject of this work. To removal dyes from industrial wastewater, the technique of extraction byemulsion liquid membrane could provide an industrial success. The membrane used in this study consisted of SPAN80 asemulsifier and aliquat 336 as extractant. The stability of the emulsified liquid membrane has a very important role in theextraction. A study of the effects of different components of the membrane is necessary. The process parameters were studiedusing a statistical method of experimental Plackett-Burman design, This method allows us to study the effects of different factorssimultaneously and determines which factors are most important parameters. The modeling was done by a mathematical modelrepresenting the extraction yield according to various factors. The most significant factors on the elimination of the acid yellow99by the emulsion liquid membrane were then studied. Voir les détails

Mots clés : emulsified liquid membrane, modeling, recovery, acid yellow, design of experiment (DOE).

AC Corrosion Induced by High Voltage Power Line on Cathodically Protected Pipeline

Ouadah M‘hamed, ZERGOUG Mourad, ZIOUCHE Aicha, Touhami Omar, Ibtiouen Rachid, Bouyegh Saida, DEHCHAR Cherif  (2014)

The implications of the influence of alternating currents on buried pipelines are of great concern to all pipeline owners in world. The relevance of the interference is always increasing for operational personnel and for the protection of buried metallic structures from corrosion. The paper studies the electromagnetic interference problem between an existing high voltage power line and a newly designed underground pipeline cathodically protected. Induced voltages and currents are evaluated for steady state operating conditions of the power line. It is found that on pipelines suffering from A.C. interference traditional pipe-to-soil potential measurements do not guarantee efficient cathodic protection against corrosion. A specific approach to assess the effectiveness of cathodic protection should be adopted. Voir les détails

Mots clés : Induced Voltages, Electric Power Transmission Lines, pipeline, AC Corrosion, cathodic protection, soil resistivity, AC interference

A numerical investigation of both thermal and texturing surface effects on the journal bearings static characteristics

Nacer Tala-Ighil, Michel FILLON  (2015)

Journal bearing characteristics modellization has been investigated in this paper for both cases of texture presence or absence onto the bearing surface. The thermal effect has been studied. The used numerical approach in this analysis is finite difference method. The textured bearing performance enhancement passes essentially by a minimum film thickness and a friction torque improvement through an appropriate surface texture geometry and right texture distribution on the bearing surface. It is found that the simulations results are in good concordance with those issued from the literature. The obtained results by considering the temperature effect are more realistic. Voir les détails

Mots clés : Journal bearings, Reynolds equation, Hydrodynamic lubrication, Stribeck curve, texture

Effet du titane, manganèse et molybdène sur le comportement à l’usure des fontes au chrome traitées


Les fontes à haute teneur en chrome sont largement utilisées dans les domaines où la résistance à l’usure est recommandée. Elles constituent la troisième génération d’alliage après les fontes ordinaires et les fontes au nickel. Le présent travail étudie l’effet de l’addition des éléments carburigènes sur le comportement à l’usure d’une fonte au chrome légèrement hypoeutectique. L’objectif visé est un compromis entre les propriétés de la matrice et des phases eutectiques constituant la microstructure de la fonte étudiée en vue d’atteindre un comportement optimal en cours d’usure caractérisé par de faibles pertes de masse en cours d’exploitation. La méthodologie utilisée consiste à introduire des éléments fortement carburigènes tel que le titane, le manganèse et le molybdène. L’utilisation du titane a été variée entre 0 et 3% par contre le manganèse et le molybdène ont été introduits à des proportions de l’ordre de 0,5% combinés avec le titane (Ti+Mn ; Ti+Mo et Ti+Mn+Mo). La microscopie optique et électronique à balayage ainsi la diffraction des rayons X complétée par affinement Rietveld du diffractogramme expérimental ont été utilisées pour mettre en évidence les précipitations secondaires ainsi que les principales phases microstructurales de cette fonte. Les résultats discutés en terme de comportement à l’usure montrent que la plus faible perte de masse a été obtenue pour l’alliage titrant 3% de titane. Ceci est justifié par le fait que la microstructure de la fonte est composée d’une fine martensite renforcée par des carbures du type MC (TiC) et des carbures secondaires du type M7C3 et d’un carbure eutectique allié. Voir les détails

Mots clés : fonte au chrome, carbures, usure, eutectique

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

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

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