Mediterranean Journal of Modeling and Simulation

7

Authors: M. Kachi, L. Dascalescu

Les forces électriques s’exerçant sur des polymères granulaires chargés sont mises à profit dans plusieurs processus électrostatiques. La dynamique de charges de surface de ces matériaux est très importante pour ce type de processus. Le but de ce papier est d’analyser l’écoulement des charges à la surface de couches compactes de polymères granulaires, en interprétant les mesures sans contact réalisées par trois sondes de potentiel, de champ et de charge, ayant chacune une taille différente. Des mesures du profile de potentiel à différents instants sont également réalisées afin d’expliquer les différences entre les vitesses de déclin de potentiel, de champ et de charge mesurées par les trois sondes. Les résultats mettent en évidence un écoulement transversal et longitudinal de la charge surfacique.

12

Authors: S. Bouhedma, M. Ouali, A. Mahieddine

Piezoelectric materials are subject to a great deal of research in recent years, whether for mechanical purposes for their potential applications in the fields of mechanical engineering, as a tool of control and regulation, or for technological purposes in electronics such as crystal oscillators areas. They can also be used as actuators as well as vibration sensors. The study of the behavior of piezoelectric beams is the subject of our work. We propose to solve the equations of motion obtained by a variational method, applying the NEWMARK approach and based on a finite element discretization. A MATLAB code is developed to simulate and compare the results of a system formed by a piezoelectric and an elastic beam.

21

Authors: B. Chaouchi

We will investigate the Dirichlet problem for Laplace equation set in an singular domain with cuspidal point. We look to describe the behavior of the unique solution near the cuspidal point in the framework of the little Hölder space h2σ (Ω) with σ ∈ ]0,1/2[.

9

Authors: F. Slama, A. Chouder, H. Radjeai

This paper presents the mathematical and the total Matlab-simulink model of the various components, of the photovoltaic power station connected to a network, (PSCN), namely the model of the photovoltaic generator. It is a comprehensive behavioural study which performed according to varying conditions of solar insulation and temperature. The photovoltaic generator and the inverter of single-phase current are modeled. The former by using a mathematical model that gives the values of maximum power according to the variation of the weather conditions, and the latter by a source of voltage controlled by voltage in order to inject a sinusoidal current and to estimate or predict the energy injected monthly or annually into the network.

9

Authors: Karim Negadi, Abdellah Mansouri, Mokhtar Touam

Cette étude concerne l'observation et la commande du moteur asynchrone sans capteur mécanique. L'objectif est de proposer une loi de commande sans capteur mécanique utilisant un observateur adaptatif estimant la vitesse, sur la base d’un mécanisme d’adaptation de Kubota. Le but principal est de parvenir à un contrôle simple, adaptatif et performant, ce qui va nous permettre de tester et d'évaluer les performances de l’observateur proposé, associé à la commande sans capteur du moteur asynchrone, en ayant comme informations disponibles les courants et les tensions statoriques. L’algorithme proposé consiste en un observateur reconstruisant les composantes du flux rotorique et un mécanisme basé sur un l’algorithme de Kubota, et générant la loi d’adaptation pour l’estimation de la vitesse. Des tests sont effectués et validés par voie expérimentale, les résultats obtenus illustrent de bonnes performances en terme de robustesse, vis-à-vis des variations des paramètres du moteur et montrent l’excellente qualité de la loi de commande associée à l'observateur, malgré les problèmes d'observabilité lorsque le moteur fonctionne à basse vitesse.

10

Authors: Noureddine Hamouda, Kamel Eddine Hemsas, Hocine Benalla

To minimize the total harmonic distortion (THD) and improve the power factor (PF), this paper presents a comparative study between two techniques of shunt power active filter (SPAF) by a selective action of harmonics. These two techniques are based on the SAPF of certain low frequency harmonics (5th and 7th) whose identification of the harmonics of references of the first is made by the axis synchronous d-q of the Park, and the second is done by the approach of self-tuning filter (STF) Thereafter, The active simultaneously filtering of the 5th and 7th harmonics of the current of load catches. The shapes of the signals and the THD values resulting from the results of digital simulations (Matlab-Simulink) elaborate the effectiveness and the best technique of this type of filtering.

11

Authors: Ahlem Boumaiza, Fayçal Arbaoui, Med Larbi Saïdi

The wind energy participates strongly in the electric power production in the industrial world. As all industrial systems, the wind turbine can be threatened by anomalies that are likely to cause damages of its performances or even to provoke a total stop of the installation. Therefore the fault diagnosis methods are necessary. In this article, in order to anticipate the apparition of a dysfunction, either to avoid them, or to limit the consequences, we used a model-based fault diagnosis technique to detect and isolate sensor and actuator faults in the pitch systems of the wind turbine blades. It is about an observer applied on a "Benchmark'' model for fault detection and isolation faults (FDI) in a wind turbine, the results of simulation by MATLAB / SIMULINK are presented to validate the efficiency of this diagnosis method.

12

Authors: A.Yahiou, A. Bayadi

The inrush currents generated during an energization of power transformer can reach very high values and may cause many problems in power system. This magnetizing inrush current which occurs at the time of energization of a transformer is due to temporary overfluxing in the transformer core. Its magnitude mainly depends on switching parameters such as the resistance of the primary winding and the point-on-voltage wave (switching angle). This paper describes a system for measuring the inrush current which is composed principally of an acquisition card (EAGLE), and LabVIEW code. The system is also capable of presetting various combinations of switching parameters for the energization of a 2 kVA transformer via an electronic card. Moreover, an algorithm for calculating the saturation curve is presented taking the iron core reactive losses into account, thereby producing a nonlinear inductance. This curve is used to simulate the magnetizing inrush current using the ATP-EMTP software.