Automatique
Study and control of PWM arc welding inverter based on a microcontroller
This paper presents an arc welding inverter, based on a microcontroller device for generate PWM pulse. An IGBT inverter was established by applying several control techniques. This system improves the power factor of welding machine and reduce the harmonics. Simulations results are presented to show the operation of proposed system. Voir les détails
Mots clés : are welding inverter, microcontroller, PWM, IGBT inverter
Selection of Wavelet Decomposition Levels for Vibration Monitoring of Rotating Machinery
The vibration signal of a rotating machine always carries the dynamic information of the machine. Its analysis is very useful for the condition monitoring and fault diagnosis. Many signal analysis methods are able to extract useful information from vibration data. In this paper, bearing fault diagnosis is performed using Wavelet Transform (WT) and Parseval’s theorem. The WT is used to decompose the original signal into several signals in order to obtain multiple data series at different resolutions. The fault can be detected from a given level of resolution. For this purpose, Parseval’s theorem is used as an evaluation criterion to select the optimal level. Associated to envelope analysis, it allows clear visualization of fault frequencies. Vibration signals from a pilot scale are used to demonstrate the usefulness of the proposed method. The results of the application in inner and outer races bearing diagnosis are satisfactory. Voir les détails
Mots clés : fault diagnosis; wavelet transform; Parseval’s theorem; bearing.
Commande Predictive non Lineaire d’une Station de Production d’eau Froide à Base de Reseaux de Neurones Artificiels
Cet article présente la commande prédictive non linéaire (CPNL) avec une application sur une station de production d’eau froide . La modélisation de la station a été réalisée à l’aide des Réseaux de Neurones Artificielles (RNA). Le développement des modèles RNA des différents composants de la station à savoir compresseur, évaporateur, condenseur et détendeur ont été réalisés séparément et regroupés par la suite pour donner le modèle complet de la station. L’objectif principal de ce travail est de maintenir les sorties de la commande du système de production proches d’une valeur désirée ou alors de poursuivre une référence donnée par la température d’un produit. Pour cela la commande prédictive non linéaire a été implémenté avec comme modèle interne. Le modèle neuronal développé est validé à l’aide de données entrées/sorties de la station. La commande a été réalisée en utilisant comme variable de commande la température et/ou le débit du fluide frigorigène. Voir les détails
Mots clés : Commande prédictive non linéaire (CPNL), station de production d’eau froide, Réseaux de Neurones Artificielles (RNA)
Nonlinear Model Predictive Control of Quadcopter
In this paper, a quadcopter is controlled by a nonlinear model predictive controller, NMPC, for trajectory tracking in presence of an external perturbation. The nonlinear model predictive control was basically confined to slow processes. Applications to fast processes such as robots are rare because the time for the solution may exceed the sampling period. Metaheuristics have been used for solving many difficult problems. In this work, we consider the application of the Particle Swarm Optimization algorithm to the NMPC optimisation problem model applied for the quadcopter tracking trajectory with presence of an external perturbation. Results show that NMPC-PSO provides a fast solution and can be used in real time. Voir les détails
Mots clés : quadcopter, nonlinear model predictive control, Particle Swarm Optimization, tracking trajectory
Adaptive backstepping control using combined direct and indirect adaptation for a single-link flexible-joint robot
In this paper, a new tuning functions based adaptive backstepping controller using combined direct and indirect adaptation for a single-link flexible-joint robot is presented. In this approach, the parameter estimation is driven by a weighted combination of tracking and identification errors. At first, the x-swapping filter identifier with a gradient-type update law is presented for a class of parametric strict-feedback nonlinear systems. Then, the main steps of the controller design for a single-link flexible-joint robot manipulator model are described. The closed-loop error dynamics is shown to be globally stable by using the Lyapunov stability approach. Finally, simulation results are given to illustrate the tracking performance of a single-link flexible-joint robot manipulator with the proposed adaptive control scheme Voir les détails
Mots clés : Backstepping control, direct and indirect adaptive control, combined adaptation, Lyapunov stability, flexible joint manipulators
Adaptive Fuzzy Gain Scheduling of PI Controller for control of theWind Energy Conversion Systems
In this work, the Wind Energy Conversion Systems (WECS) based on doubly fed induction generator (DFIG) model is built.First, we consider the vector control strategy of the active and reactive powers in order to ensure an optimum operation. Thewhole system is presented in d-q-synchronous reference frame. After, the design of Adaptive Fuzzy Gain Scheduling ofProportional Integral Controller (AFGPI) for WECS is described, where the optimization by Fuzzy rules is utilized online toadjust the parameters of PI controller based on the error and its first derivative. Finally, the control of the active and reactivepower using fuzzy-PI controller is simulated using software Matlab/Simulink, studies on a 1.5 MW DFIG wind generationsystem compared with conventional proportional integral controller. Performance and robustness results obtained are presentedand analyzed. Voir les détails
Mots clés : wind systems, doubly fed induction generator, fuzzy control, fuzzy gain scheduling control, fuzzy PI control, PI controller.
Robust Control of Doubly Fed Induction Generator for WindTurbine Under Sub-Synchronous Operation Mode
This paper presents a modeling and a robust control of doubly fed induction generator for wind generation system. The wholesystem is presented in d-q-synchronous reference frame. The regulation of the electromagnetic torque , stator reactive powercontrol and neuronal controller are applied in order to control the rotor currents of the DFIG. For to improve the controllerrobustness, the study is validated through simulation using software Matlab/Simulink, studies on a 1.5 MW DFIG windgeneration system compared with conventional proportional integral controller. Performance and robustness results obtained willbe presented and analyzed. Voir les détails
Mots clés : wind power generation, modeling, Control, doubly fed induction generator, Neuronal controller, performances.
On-Off control based particle swarm optimization for maximum power point tracking of wind turbine equipped by DFIG connected to the grid with energy storage
In this paper, particle swarm optimization (PSO) is proposed to generate an On-Off Controller. On-Off Control scheme based maximum power point tracking is proposed to control the rotor side converter of wind turbine equipped with doubly fed induction generator connected to the grid with battery storage. The Grid Side Converter (GSC) is controlled in such a way to guarantee a smooth DC voltage and ensure sinusoidal current in the grid side. Simulation results show that the wind turbine can operate at its optimum power point for variable speed and power quality can be improved. Voir les détails
Mots clés : DFIG, Energy storage, Maximum Power Point Tracking, On-Off Control, Particle Swarm Optimization (PSO)
Energy storage based on maximum power pointtracking in photovoltaic systems: A comparisonbetween GAs and PSO approaches
In this paper, a comparison between GAs and PSO Approaches is considered to select andgenerate an optimal duty cycle which varies with photovoltaic parameter in order toextract the maximum Power from Photovoltaic System using real values of temperatureand insolation. The energy storage has very important role in renewable energy. To illustratethe energy storage, we have used a battery type lead-acid simulated in Matlab/Simulink. The obtained simulations results show the effectiveness and the robustness ofthe proposed approaches. Voir les détails
Mots clés : Photovoltaic systems, Chopper, MPPT, PSO, GAs, Energy storage
Commande adaptative par backstepping d’une classe des systèmes non linéaires incertains
Dans ce travail, on s’est intéressé à l’étude et le développement de stratégies de commande adaptatives directe, indirecte et combinée directe/indirecte par backstepping d’une classe des systèmes non linéaires ayant la forme triangulaire inférieure paramétrique. Le problème principal de l’approche de commande adaptative par backstepping est la complexité de ces lois de commande causée par la dérivation des commandes virtuelles. L’utilisation de l’approche de commande de surface dynamique (DSC) qui introduit un filtrage des commandes virtuelles a permis de pallier à ce problème de complexité. De plus, l’analyse de la stabilité des structures de commande proposées est effectuée par l’approche de Lyapunov. Pour chaque approche de commande, des résultats de simulation sont présentés pour montrer ses performances. Voir les détails
Mots clés : Commande par backstepping, commande adaptative par backstepping, adaptation directe et indirecte, stabilité de Lyapunov, systèmes non linéaires