Electrotechnique
Conception et commande d'une machine de soudage de type TIG
TIG welding machine are higly used in mostof industries.this work consists of the desing and engineering of a welding machine. Voir les détails
Mots clés : arc welding, TIG generator, DC/DC convertor
Diagnostic des défauts et contrôle non destructif des tôles magnétiques des transformateurs de puissance Pratique : Centre de Recherche en Technologies Industrielles
Les transformateurs de puissance sont des éléments clés des systèmes électriques et leurs défaillances sont très coûteuses. Cette thèse présente une étude comparative entre les caractéristiques électromagnétiques et thermiques d’une tôle magnétique saine d’un transformateur et une tôle corrodée. Les paramètres magnétiques extraits des boucles d'hystérésis telles que l'aimantation à saturation, l'aimantation coercitive, rémanente, la perméabilité magnétique et la zone d'hystérésis ont été analysées. Il a été démontré que la perte d'hystérésis dans le cas de l'échantillon avec corrosion est supérieure au cas de l'échantillon sans corrosion. Les paramètres électriques et thermiques sont également dégradés. Voir les détails
Mots clés : transformateur de puissance, corrosion, pertes, champ magnétique, distribution de la température.
Novel and simplified model representing Current-Output Phase-Shift Full-Bridge DC-DC LCLC Resonant Converter in Arc Welding Application
In this paper, a novel and simplified model representing current-output phase-shift full-bridge DC-DC LCLC resonant converter in arc welding application is thoroughly presented. First, a switched model written in state space representation and featuring a bilinear form is proposed. The latter facilitates the derivation of both the reduced and full order averaged models in continuous conduction mode (ROAM and FOAM). Although the FOAM can be employed in linear or nonlinear control schemes and the derivation of steady state behavior, in this paper the ROAM is considered in designing both voltage mode control and current mode control by using the classical PID and the fractional order PID controllers. Simulation confirms that the switched model, ROAM and FOAM are quite accurate compared to the circuit simulation using SimPowerSystem toolbox of MATLAB/SIMULINK. Results clearly showed that depending on the switching frequency, the proposed topology can be applied either in constant voltage characteristic or dropped characteristic welding machines fulfilling either zero current Switching (ZCS) or zero voltage switching (ZVS). Besides, the fractional order PID controller seems to be more adapted for arc welding application than its traditional version. Voir les détails
Mots clés : LCLC resonant converter, switched model, reduced order averaged model, full order averaged model, arc welding, FOPID, IGWO
State Feedback Control of DC-DC Converter Using LQR Integral Controller and Kalman Filter Observer
In this paper, the linear state feedback control using LQR controller for a DC/DC converter in the case of negative voltages topology is presented in order to achieve a particular desired behavior. To guarantee a zero steady-state error, we introduce an integral action, which will work out this problem by assuring that the steady-state error will end up to zero. For filtering and state estimation with a low cost and less complexity a state observer is obtained based a Kalman Filter observer. Detailed simulation study is presented to demonstrating the robustness and effectiveness of the proposed control scheme. Voir les détails
Mots clés : Linear quadratic regulator, DC/DC Buck-Boost Converter, Kalman filter, Static error
New Optimal Control of Permanent Magnet DC Motor for Photovoltaic Wire FeederSystems
This article aims to improve the permanent magnet DC (PMDC) motor performance forphotovoltaic (PV) wire-feeder systems (PVWFSs) of arc welding machines. Theconsidered technique is designed by direct speed control based on optimal Fractional-orderFuzzy PID FO-Fuzzy-PID controller. The purpose is to ensure optimal control of wire feedspeed reference to reduce torque ripples and hence, the performance of the WFS isimproved. The dynamic reaction of the proposed solar PVWFS relies upon the scalingfactors of FO-Fuzzy-PID controller, which are optimized by using teaching-learningalgorithm based on Particle Swarm Optimization (PSO) method. The maximum powerpoint tracking (MPPT) is achieved using an intelligent FO-Fuzzy-PID current controllerbased Perturb and Observe (P&O) MPPT algorithm. The PVWFS system incorporatingthe proposed method is tested and compared with the conventional PID control schemeunder different weather conditions. The simulation of the proposed system byMATLAB\SIMULINK is carried out. The simulation results indicate the effectiveness ofthe considered control strategy in terms of the reduction in torque oscillations, optimizingelectrical power and wire feed speed. Voir les détails
Mots clés : Solar photovoltaic (PV) module, wire feeder systems (WFSs), DC-DC buck converter, MPPT control, FO-Fuzzy PID controller, Particle Swarm Optimization (PSO) algorithm
Sensorless Control of DC-DC Converter Using Integral State Feedback Controller and Luenberger Observer
This paper presents a design of linear state feedback control of DC-DC Boost converters, in order to achieve a particular desired behavior. To guarantee a zero steady state error, we introduce an integral action, which will work out this problem by assuring that the steady state error will end up to zero. If it is supposed that both the voltage and current are measured, so much more sensors are needed then and consequently causing a high cost, so that to estimate the voltage and current with a low cost and less complexity it is preferred to introduce a state observer. An observer or estimator is a dynamic system that uses the available information on a real system, according to the inputs and outputs of the real process and estimate the system state. Simulations results demonstrate the robustness and effectiveness of the proposed control scheme. Voir les détails
Mots clés : Boost converter, observer, Static error, Feedback control
An Enhanced MPPT Method CombiningFractional-Order and Fuzzy Logic PIDController for a Photovoltaic-Wire FeederSystem (PV-WFS)
The use of photovoltaic (PV) module as a power source for wirefeeder systems (WFSs) of arc welding machines is one of the promisingdomains in the solar PV applications. This paper provides a new kind of weldingWFS and investigates the PV penetrated power systems. The considered systemconsists of a PV module, a DC-DC buck converter, and PMDC motor. Thepower of the PV-WFS can be widely enhanced by using a Fractional-orderFuzzy PID (FO-Fuzzy-PID) controller based P&O MPPT algorithm. In thiswork, a FO-Fuzzy-PID controller is also proposed for PMDC motor drivenWFS. This will lead consequently to optimize the mechanical motor speed of theWFS. The dynamic response of the PV-WFS relies upon the parameters of theseFO-Fuzzy-PID controllers, which are optimized by using Particle SwarmOptimization (PSO) algorithm. Simulation results found are satisfactory andprove the stability, accuracy and dynamic response of the synthesized optimizedwire feeder regulating system and the proposed intelligent MPPT algorithm. Voir les détails
Mots clés : Solar photovoltaic (PV) module, Wire feeder system (WFS), Arc welding machines, DC-DC buck converter, MPPT control, FO-Fuzzy PID controller, Particle Swarm Optimization (PSO) algorithm
Predictive Control of a Grid Connected PV System Incorporating Active power Filter functionalities
This article proposes a multifunction of a double stage grid connected photovoltaic (PV) system, with insertion the active power filter (APF) functionalities. This system is used to compensate the harmonics currents, compensate reactive power, supply the nonlinear loads and inject the PV system's active power into grid. This study is based on grid side, a perturb and observe algorithm is used to extract the maximum power point tracking (MPPT) from the PV array regardless of solar irradiance. On the grid side, a modified instantaneous active and reactive power theory (P-Q) based on a multi-variable filter (MVF) is applied to correctly identify the harmonics currents reference under distorted source voltage condition, also a modified predictive current control (PCC) algorithm is used to generate the switching signals for the source voltage inverter in order to ensure compensate reactive power and harmonic currents, feed the non linear load and inject the surplus of active powerinto the grid. In Matlab/Simulink™ software environment, the performance of the proposed control scheme is investigated under load change and irradiance change conditions. Simulations results demonstrate that the proposed PCC of the APF ensure a manage of active power exchanges with the grid with power factor correction. Furthermore, the grid current recovers 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)
Design and real?time implementation of an adaptive fast terminalsynergetic controller based on dual RBF neural networks for voltagecontrol of DC–DC step?down converter
In this study, an improved Adaptive Fast Terminal Synergetic Controller (AFTSC) using Dual Radial Basis Function (RBF)Neural Networks (NNs) for output voltage control of an uncertain DC/DC step-down converters is proposed. Using theconsidered AFTSC, the with new manifold proposed here enables the DC/DC step-down converter’s state variables to trackthe preferred reference voltage in presence of disturbances from any initial condition with proper precision and limited time.To rendering the design more robust, a sort of dual RBFNNs are utilized to approximate in real-time unknown converternon-linear dynamics and reduce the modeling error without calling upon usual model linearization and simplifcations. Thestability of the closed-loop system is assured by means of the Lyapunov method. Considering the PWM DC–DC step-downconverter as an example, the considered adaptive RBFNN-FTSC law is studied in detail and implemented on a dSPACEds1103 card. All the simulation and experimental results illustrate the efciency and feasibility of the suggested controller. Voir les détails
Mots clés : Synergetic control (SC), Radial basis function neural network (RBFNN), · Fast terminal technique, Limited time, DC/DC step-down converter
A novel nature-inspired maximum power point tracking (MPPT) controller based on ACO-ANN algorithm for photovoltaic (PV) system fed arc welding machines
In this paper, a metaheuristic optimized multilayer feed?forward artificial neural network (ANN) controller is proposed to extract the maximum power from available solar energy for a three-phase shunt active power filter (APF) grid connected photovoltaic (PV) system supplying an arc welding machine. Firstly, in order to improve the maximum power point (MPP) delivered by PV arrays and to overcome the drawbacks in the conventional MPPT method under irradiation variation, a hybrid MPPT controller is designed, in which the input parameters include the PV array voltage and current, and the output parameter is the duty cycle of the DC/DC boost converter. The proposed approach abbreviated as ANN-ACO MPPT controller is based on an ant colony optimization (ACO) algorithm which is useful to train the developed ANN and to evolve the connection weights and biases to get the optimal values of duty cycle converter corresponding to the MPP of a PV array. Secondly, aiming to meet the various grid requirements such as power quality improvement, distortion free signals etc., a three-phase shunt APF is utilized, and a direct power control algorithm is designed for distributing the solar energy between the DC-link capacitor, arc welding machine and the AC grid. Finally, the performance of proposed control system is confirmed by simulation tests on a 12.2 kW PV system. Both simulation and experimental results have demonstrated that the deigned ANN-ACO MPPT controller can provide a better MPP tracking with a faster speed and a high robustness with a minimal steady-state oscillation than those obtained with the conventional INC method. Also, with the use of a three-phase shunt APF, all the power fluctuations from the arc welding machine disturbances are damped out and the output active and reactive power become controllable. Voir les détails
Mots clés : Solar Photovoltaic (PV) system, DC/DC boost converter, three-phase shunt APF, Hybrid ACO-ANN MPPT control, Feed-forward artificial neural network (ANN), Ant Colony Optimization (ACO) algorithm, Arc welding machine