Liste des publications
Comparative Study of Wind Energy Conversion SystemDriven by Matrix Converter and AC/DC/AC Converter
In this work we presents comparative study of avariable speed wind energy conversion system (WECS) basedon the doubly fed induction generator (DFIG) driven by twoAC/DC/AC converters and WECS driven by matrix converter(MC). The whole system is presented in d-q-synchronousreference frame. For this purpose, the control of the activeand reactive power using PI controller is verified usingsoftware Matlab/Simulink, studies on a 1.5 MW DFIG windgeneration system. Simulation results obtained are presentedand analyzed. The results show the high performance andimprove the electric energy of the control strategy adopted inthe WECS based on a DFIG driven by a MC. Voir les détails
Mots clés : wind systems, doubly fed induction generator, matrix converter, simulation
Assessment and analysis of wind energy generation and power control ofwind turbine system
This study concerns the evaluation of wind power potential and the choice of a wind turbine to be installed nearRabah Bitat international airport of Annaba. Furthermore, the performances of power control of this turbine aredeveloped. For this, the wind speed data measured by meteorological station of the airport are used. At the firsttime, a statistical analysis of wind characteristics and the extrapolation of weibull parameters are presented.Otherwise, the analysis of the power produced and the capacity factor led to the choice of the wind turbineEnercon E-82/2000 whose characteristics: Rated wind speed (13m / s), the cut-in wind speed (2.5m / s) and arated power of 2000kW. Finally, the control of the active and reactive power, by adaptive fuzzy gain schedulingof proportional integral controller is simulated using software Matlab/Simulink, studies on a 2 MW DFIG windgeneration system. Performance and robustness results obtained are presented and analyzed. Voir les détails
Mots clés : Wind energy, wind speed, weibull distribution, capacity factor, power output.
Oi and Cs Impurities Study on the Edge of Si-mc Ingot for Photovoltaic Applications
The objective of this work is determining the substitutional carbon ([Cs]) and interstitial oxygen ([Oi]) concentrations in the edge of the multicrystalline silicon ingot (mc-Si) for photovoltaic applications obtained by the heat exchanger method (HEM). Some calculations of [Cs] and [Oi] was obtain by the Fourier Transform InfraRed spectroscopy (FTIR). The results obtained for [Cs] give an increase of bottom-up of the ingot: 130 ppm to 150 ppm. The results obtained for the [Oi] give constant concentrations throughout the edge of the ingot with an author of concentration 325 ppm. Voir les détails
Mots clés : Crystallization, mc-Si, HEM, FTIR, [Cs], [Oi]
Evaluation of surface quality by Fractal Dimension and VolumeParameters
This study aims, the evaluation of the surface quality by the fractal dimension "D" and volume settings (Vmp,Vmc, Vvv). Experimental work was conducted by process of surface mechanical treatment; in this case ballburnishing was applied on a commercial aluminum alloy material. Three parameters of regime were considered:"burnishing feed f", "burnishing force Py" and "burnishing ball diameter Db". Mathematical models wereidentified using the plans of multifactorial experiments "Box-Behnken" for prediction of fractal dimension "D"and volume parameters. Experimental and simulation results have enabled to show than the large diameter ballunder low loads and medium feed speeds, favors the elimination of peaks and reduction of fractal dimensionwhence quality improvement of surface. Voir les détails
Mots clés : burnishing, volume parameters, fractal dimension, experimental designs
Improvement of surface finish by ball burnishing:approach by fractal dimension
The surface roughness significantly affects the quality of parts and their functional properties suchas contact surface, as well as coating adhesion. The machined surface quality is evaluated byarithmetic deviation Ra which does not suffice to describe the surface irregularities. In order toapprehend these deficiencies a new technique based on fractal geometry was introduced. Toapply this concept an experimental work was carried out to characterise surface quality byfractal dimension ‘D’. The operations of burnishing ball were performed according to plans ofexperiments of ‘Box–Behnken’, an optimal regime was obtained and a mathematical model wascleared for predicting the fractal dimension ‘D’ as a function of treatment regime parameters.Furthermore, the application of optimal regime under several passes ‘i’ has enabled to examinethe evolution of ‘D’. The results confirm that fractal dimension ‘D’ has impact on surface qualityand tribological parameters. Voir les détails
Mots clés : roughness, fractal dimension, Burnishing process, Designs of experiments
THE CONTRIBUTION OF DIRECT TORQUE CONTROL WITH APPLICATION OFFUZZY LOGIC ON THE PERFORMANCE OF A MULTI-LEVEL INVERTER FED INDUCTION MACHINEWITH A FAULT TOLERANCE
Today it is possible to obtain induction machine performances similar to those of dc machines through the mastering of power electronics and control.Moreover, there are new methods of control for sensorless speed traction-type applications already studied particularly those related to the Direct Torque Control technique (DTC). This study consists at optimizing the three-level DTC algorithm fed from an NPC structure multilevel inverter with fault tolerant using are the configurable redundant spare arm to increase the average value of the torque. The results obtained in the DTC are further improved by applying the technique of fuzzy logic Voir les détails
Mots clés : Multilevel Inverter, DTC, NPC, Fault tolerance, Fuzzy logic.
One-dimensional Parametric Study of Damage Detection in a Solid Material using a Nonlinear Wave Modulation Spectroscopy (NWMS) Technique.
Nonlinear Wave Modulation Spectroscopy (NWMS) is one of the most powerful techniques used to detect damage in materials. It consists in simultaneously applying two continuous waves with different frequencies, the one high, f2, and the other low, f1. When the material is damaged, the frequency spectrum exhibits harmonics and sidebands which are located at (f2 + f1) and (f2 - f1). This paper presents a parametric simulation study of the nonlinear propagation of elastic waves in solid media, which can be represented by a one dimensional mass-spring system. The system of motion equations is resolved by a fourth order Runge-Kutta iterative method. A quadratic nonlinearity can be introduced locally in the system at any spring. The objective of the paper is to highlight the ability of the nonlinear acoustic methods, especially the NWMS (Nonlinear Wave Modulation Spectroscopy), to detect damages in solid material. The study of the evolution of the sidebands amplitude, according to the low frequency of the wave (pump wave), f1, in cracked and intact material will be presented. It is shown that this amplitude reaches a maximum when the pump frequency corresponds to a resonance frequency of the system. In addition, the study shows the strong dependency of the resulting frequency spectrum of the received signal upon the nonlinearity magnitude as well as the rigidity of the simulating crack spring. Voir les détails
Mots clés : Nonlinear Modulation Spectroscopy, Damage detection, nonlinear wave propagation simulation
Study of physico-chemical properties ofdiatomite Algeria: Application to thethermal insulation of liquid steel bath
The purpose of this paper is tocharacterize and to evaluate the diatomitepowder of Sig region (West Algeria) withoutfluorine by powder generally used in tundish tothermal insulation of steel bath contain fluorine,that affecting the environment and health ofworkers. Thermal and physicochemicalcharacterization showed different endothermicand exothermic peaks. The scanning microscopymethod was used and a large porosity wasobserved, which is very beneficial for improvingthe thermal conductivity of the product. The trialindustrial in steelwork with diatomite powder,showed a weak loss temperature of steel (10 °Cmax), and filled fully function in thermalinsulation of the steel bath Voir les détails
Mots clés : diatomite, fluorine, Tundish, steelwork, thermal insulation, DSC
Diagnosis of AC corrosion on the buried pipeline due to the high voltage power line
This paper studies the electromagnetic effect of the high voltage power line on the X70 Steel pipeline and the factors affecting this interference. The induced voltage onto the pipeline was calculated for different separation distance between conductors, the existence of the earth wire, separation distance between transmission line and pipeline and the parallelism length. The induced AC current density was calculated function to the induced voltage, the soil resistivity, and the holiday diameter. The electrochemical characters of the X70 steel with and without influence of the alternating currents were studied in simulated soil solution. The results indicate that the AC density accelerate the corrosion degree of X70 steel in simulated soil solution comparing with that in the absence of the AC density. Voir les détails
Mots clés : Power lines, interference, induced voltage, induced current density, AC corrosion.
Study and analysis of mechanical and viscoelasticbehavior in flexure of laminated composites
In the present paper, seven laminated composites were thesubject of an experimental study to determine their mechanical and viscoelastic properties by means of dynamic mechanical analysis in a bending configuration. The influenceof the frequency, fiber type and fiber orientation on dynamic mechanical properties of different system composites were investigated. Carbon/epoxy laminates exhibit agreat stiffness when fibers are oriented along the axis ofthe clamps, and the maximum modulus was reported forunidirectional carbon/epoxy laminate [08 plies] with56.4 GPa. The glass transition temperature was found to decrease with the incorporation of fibers and increase with increased frequency. For the Kevlar/epoxy laminate, an increase of 12.5 8C in glass transition temperature wasobserved. This is related to a better interfacial adhesion between epoxy matrix and Kevlar fibers Voir les détails
Mots clés : Composite laminate, Dynamic mechanical analysis, Fiber/matrice interface, glass transition temperature