Nombre total de résultats : 116
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PredictiveControl of a Grid Connected PVSystemsIncorporating Active Power FilterFunctionalities

N. Hamouda, B. Babes, S. Kahla, Y. Soufi, J. PETZOLDT, T. Ellinger  (2019)
Article de conférence

This paper presents a multifunction operation of adouble stage grid connected photovoltaic system, with insertionthe active power filter (APF) functionalities. This system is usedto compensate the reactive power, suppression harmonicscurrents supply the nonlinear loads and inject the active powerinto grid. Our work is focused on the grid side, a perturbationand observation control is used to reach the maximum powerpoint tracking (MPPT) regardless of solar radiation. On the gridside, a modified instantaneous active and reactive poweralgorithm (P-Q) based on a multi-variable filter (MVF) is usedin order to identify the harmonics currents reference underdistorted source voltage condition, also a modified predictivecurrent control (PCC) algorithm is used to control the sourcevoltage inverter in order to ensure compensate reactive powerand harmonic currents, feed the non linear load and inject thesurplus generated power into the grid. In Matlab/Simulinksoftware, the proposed control scheme is investigated under loadchange and radiation change conditions. Simulation resultsshows that the proposed PCC of the APF guarantees a flexiblesettlement of real power amounts exchanges with the grid with ahigh power factor operation. Furthermore, the grid currentrecovers its sinusoidal waveform with a total harmonic distortion(THD) meet to IEEE-519 standard Voir les détails

Mots clés : Photovoltaic system (PV), activ power filter (APF), Predictive current control (PCC), active and reactive power theory (P-Q), multivariable filter (MVF), total harmonic distortion (THD)

Electric Field Distribution in point-insulating barrier-Plane System using experimental and Theoretical method

S.Benharat, S.Bouazabia, S.BELGACEM  (2019)
Article de conférence

The present paper deals with the influence of insulating barriers on the breakdown and the electric field distribution in the Point –insulating barrier- plane air gap system. An experimental investigation on the influence of different parameters such as gap distance between electrodes and barrier dimensions, under AC voltage, have been studied. The results show that the width and thickness of the insulating barrier effect the electric field variation which increases with increasing applied voltage. The experimental results are compared with a numerical model. Voir les détails

Mots clés : Electric field, Finite Element Method, breakdown voltage, insulating barrier, point- plane system

Corrosion E?ects on the Magnetic Behavior of Magnetic Circuitof an Induction Machine

ALLOU Djilali, KHORCHEF Mohamed, M’hamed Ouadah, Omar TOUHAMI, Rachid IBTIOUEN  (2018)

In This paper, the e?ect of corrosion on the magnetic behavior of a magnetic material usedas a magnetic circuit in the induction machines is studied. With this objective, the magnetic propertiesof the samples with corrosion and without corrosion were evaluated by the study of hysteresis loopsusing a homemade vibrating sample magnetometer (VSM). The magnetic parameters extracted from thehysteresis loops such as saturation magnetization, coercive, remanent magnetization, squareness ratio,magnetic permeability, and hysteresis area were analyzed. It was shown that more energy is required todemagnetize the sample with corrosion than the sample without corrosion, and the hysteresis loss in thecase of the sample with corrosion is more than the case of the sample without corrosion. These meanthat when the corrosion is presented in the magnetic circuits of the induction machine, the hysteresisloss increases, consequentially reducing the machine e?ciency. Voir les détails

Mots clés : corrosion, magnetic behavior, hysteresis loops

Amélioration de la Qualité du Réseau Electrique à l’Aide deCompensateurs Actifs

Hamouda Noureddine (2018)
Thèse de doctorat

This thesis falls within the framework of harmonic depollution of the low voltage electrical networks usingan active power compensators, this pollution is caused by the unlimited use of non-linear loads. The causes, theeffects of these harmonic disturbances and the international standards imposed to protect the consumers againstthese disturbances are presented. Also, several traditional and modern solutions against the harmonic pollution arepresented. We have focused our study on the development of the control techniques of shunt active power filter, Forthis reason, we have based on the development of methods for determining harmonic reference currents based on amultivariable filter (MVF), These new methods are able to correctly extract the reference harmonic currentsnecessary to control the SAPF, after that, we have implemented the modified (p-q) method on the power active filterin order to carry out a global active compensation of the harmonics currents, the behavior and quality of filtering ofthe APF are evaluated with two kinds of electric loads, with different types of electrical network and with aphotovoltaic power source. Then, we have developed two harmonic selective identification methods based onmultivariable filter, which are implemented in real time, in order to realise a selective active compensation ofspecific harmonic currents under low DC link voltage, this work was closed by an experimental validation of anactive power filter (APF) fed by a PMSG-based wind system, for this we implemented three controllers to controlthis system, which are the predictive current controller, Type-2 fuzzy logic controller, and an ANFIS controller. Theexperimental results obtained show that this system is capable of compensating for harmonics and reactive power,and also injected active power into the electrical network. Voir les détails

Mots clés : Harmonic pollution, APF, MVF, global active filter, selective active filter, wind system, PMSG


Omar Fethi BENAOUDA, Azzedine Bendiabdellah, KAHLA SAMI  (2019)

This paper proposes a new diagnostic technique based on Park vectors associated with polar coordinates for the detection and location of open circuit (OC) faults, as well as the integration of fault-tolerant reconfigurable inverter in order to enable continuity of service of the wind farm system. The model used is that of a variable speed wind turbine coupled to a double-fed induction generator (DFIG) connected to the power grid via a fault-tolerant converter to improve performance after the appearance of the fault. This converter is used based on IGBT to obtain an acceptable accuracy with high switching frequencies. This model is well suited for the observation of harmonics and the dynamic performance of the control system over relatively short periods of time (typically hundreds of milliseconds to one second). This method allows extracting the maximum wind energy during a low wind speed by optimizing the turbine speed while minimizing the mechanical stress on the turbine during gusts of wind. To illustrate the diagnostic improvement of fault-tolerant inverter open circuit faults, several results are presented and discussed in this article. Voir les détails

Mots clés : DFIG Turbine, Inverter, diagnosis, Detection, Location, Reconfiguration, fault, Open-Circuit, IGBT

Diagnosis Method for GTO Open Switch FaultApplied to Reconfigurable Three-Level 48-PulseSTATCOM

Omar Fethi BENAOUDA, Azzedine BENBIABDELLAH, Bilal Djamal Eddine CHERIF  (2019)

In the recent years, several research worksare focusing on the use of STATCOM in electrical net-works because it is used to regulate the voltage, to im-prove the dynamic stability of the power system be-sides allowing better management of the power ?ow.All these positive tasks have guaranteed an importantposition of STATCOM within a family of Flexible Al-ternating Current Transmission System (FACTS). Inthis paper study, the control and operation of a threelevels 48-pulse GTO based STATCOM is implementedwith series connected transformers. The system may,unfortunately, be prone to GTO switch faults and there-fore may a?ect reactive power transiting. In this pa-per, a new diagnostic approach is proposed based onthe Single-Sided Amplitude Spectrum (SSAS) methodof the three-leg converter currents for detection and lo-calization of open-circuit faults. The integration of theSTATCOM recon?gurable fault tolerant to the systemis also considered to ensure service continuity. Sev-eral results are presented and discussed in this paperto illustrate the performance of the STATCOM fault-tolerant diagnostic. Voir les détails

Mots clés : Detection, diagnosis, FACTS, GTO, open switch fault, recon?guration, SSAS, STATCOM

A Study of the Behavior of Water Droplets Under The Influence of Non-Uniform Electric Field in Silicon Rubber

S.Benharat, S.Bouazabia, A. Haddad  (2017)
Article de conférence

Water droplets on the surface of silicon rubberwere investigated under the influence of non-uniform electricfields. Several parameters of water droplets were investigated,such as the positioning of the droplets regarding the electrodes.The most striking conclusion is that the flashover voltage andelectric field distribution depends on the positioning of thedroplets from the electrodes. Voir les détails

Mots clés : water droplets, non uniform Electric field, COMSOL, finite element, insulating barrier, silicon rubber

Behaviour of the electric arc for different times and for different values of welding currents

S.Benharat, A.Boutaghane  (2016)
Article de conférence

Welding is a permanent joiningprocess used to join different materials like metals, alloysor plastics, togetherat their contacting surfacesby application of heat and or pressure. The study of welding processes currently appears as an area of research both open and complex because it requires to share of knowledge in different fields of physics and mechanics.Thus, the description of one of the most commonly used processes,the arc welding, involves physical phenomena as varied as the study of plasmas, magnetic and hydrodynamic interactions, the description and quantification of heat transfer, etc. The aim of our work is the treatment of the influence of welding time and welding current on the form of the arc, voltage and current density in the GTWA process. For this, we realize a numerical study to determine the arc forms, the voltage and the current density, in which we use the finite element method for the calculation, using Comsol software. The Main results obtained are: 1-The arc shape and evolution of isothermal change with increasing weld time.2-The distribution of the voltage and the current density between the torch and the plate weld obtained by simulation are the same with the results presented in the literature. Voir les détails

Mots clés : arc welding, GTAW process, welding current, modeling, Finite elements method, COMSOL Multiphysics

Répartition de champ électrique dans un système pointe-plan avec barrière isolante

BENHARAT Samira, Slimane Bouazabia  (2015)
Article de conférence

The objective of our work is the study by numerical simulation of the distribution of the electric field according to geometric measurements of the insulating barrier and its position in the inter-electrodes gap Voir les détails

Mots clés : Electrical discharge, insulating barrier, finite element, electrical field

Fault tolerant control of energy processes

boutasseta nadir (2019)
Thèse de doctorat

This work deals with the control of energy systems subject to faults. The objective is toaccommodate faults by the design of a control law that takes into account the existence ofinternal faults and dysfunctions caused by external environment.Energy systems are characterized by the dependence of their performance on energyefficiency, the total efficiency is the result of the operation of elementary energy processesto verify the final objective which is the production of energy in its final form. Thesupervision of these processes and tolerance to faults allow the improvement of individualperformances and the achievement of global efficiency at a lower cost.In this context, renewable energy conversion processes are characterized by the aspect oftheir dependence on climatic conditions and direct exposure to outdoor environment,resulting in the occurrence of different types of faults and dysfunctions. Solar photovoltaicrenewable energy generation systems are considered in this work as they dominaterenewable electricity capacity expansion. The study of the effect of various abnormalevents and degraded operating modes of solar photovoltaic systems is performed and afault-tolerant control law is proposed to enhance the efficiency of these energy processes.A reconfiguration of controller is designed to switch between an improved current-basedparticle swarm optimization technique and the incremental conductance algorithm.Practical implementation of the proposed approach shows excellent performance in realoperating conditions when compared to traditional maximum power point algorithms. Voir les détails

Mots clés : fault-tolerant control, energy systems, renewable energy, Solar energy, Photovoltaic, Maximum Power Point Tracking, Particle Swarm Optimization