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This project presents a strategy of field control then sliding mode control put in to the conversion process of wind energy containing an asynchronous generator with double fed (DFAG; DFIG). A model was developed for each component of the wind turbine (turbine, DFAG and cascade rectifier-inverter). MPPT device must be introduced in order to obtain maximum energy efficiency so that PI-MPPT method is made. The objective is to apply this command to control independently the active and reactive powers generated by the asynchronous generator uncoupled by orientation from the flow. The results of digital simulations obtained show the improvement of the performances of the sliding control compared to the field control, also it has provided information on the commands available techniques as reference tracking and robustness.

wind energy features prominently as a supplementary energy booster. It does not pollute and is inexhaustible. However, its high cost is a major constraint, especially on the less windy sites. The purpose of wind energy systems is to maximize energy efficiency, and extract maximum power from the wind speed. In This case, the MPPT control becomes important. To realize this control, strategy conventional Proportional and Integral (PI) controller is usually used. However, this strategy cannot achieve better performance. This paper proposes other control methods of a turbine which optimizes its production such as fuzzy logic, sliding mode control. These methods improve the quality and energy efficiency. The proposed Sliding Mode Control (SMC) strategy and the fuzzy controllers have presented attractive features such as robustness to parametric uncertainties of the turbine, simplicity of its design and good performances. The simulation result under Matlab\Simulink has validated the performance of the proposed MPPT strategies.

The objective of this paper is to study the dynamic response of the wind energy conversion system (WECS) based on the Doubly Fed Induction Generator (DFIG). The DFIG rotor is connected to the grid via a converter. The active and reactive power control is realized by the DFIG rotor variables control, using the field oriented control (FOC). The vector control of DFIG is applied by the use of tow regulators PI and the neural network regulator (NN). The generator mathematical model is implemented in Matlab/ Simulink software to simulate a DFIG of 1.5 MW in order to show the efficiency of the performances and robustness of the studied control systems. The simulation obtained results shows that the robustness and response time of the neural network regulator is better than those obtained by the PI classical regulator.

Direct Torque Control (DTC) is a method, which is used to control the flux and torque of a motor. This method uses a flux and torque estimator and two hysteresis controllers. The major problem that is usually associated with DTC drive is the high torque ripple. The stator resistance is used in the flux and torque estimator. So the stator resistance deviation from its set value, might affect fuzzy-DTC performance especially at low speed. To overcome these problems, this paper presents an improved direct torque control based on fuzzy logic technique, where the torque and flux hysteresis controllers are replaced by fuzzy controllers and we also used a fuzzy stator resistance estimator The fuzzy proposed controller is shown to be able to reducing the torque and flux ripples and to improve performance DTC especially at low speed.

The active power filter has been proved to be an effective method to mitigate harmonic currents generated by nonlinear loads as well as to compensate reactive power. The main objective of this work is to develop a new control strategy to improve the performances of shunt active power filter for mitigating current harmonics under balanced and unbalanced sinusoidal source voltage conditions. To achieve this objective a shunt active power filter (SAPF) is proposed with a sliding mode control (SMC) strategy for the DC bus capacitor voltage regulation and currents reference estimation. The analysis and simulation results using Matlab/Simulink are presented and discussed showing the effectiveness of the control algorithm and confirm performance improvement of fuzzy logic technique used for the source current control which provides flexibility, high precision and fast response.

Wind energy features prominently as a supplementary energy booster since the wind speed varies. Evaluation of control schemes for electrical generator is hard with wind turbine. For similar environment of turbine, a wind turbine emulator (WTE) is used. The purpose of systems is to maximize energy efficiency, and extract maximum power from the wind speed. In This case, the MPPT control becomes important. Conventional proportional and integral (PI) controller is usually used to realize this control. However, this strategy has limitation and cannot achieve better performances. This paper proposes other solutions such as fuzzy logic, sliding mode control. The proposed sliding mode control strategy with fuzzy controller presented attractive features such as robustness against parameter variation of the turbine. The proposed strategies have been simulated with wind turbine emulator. The simulation results under Matlab\Simulink show better dynamic performances of the proposed MPPT strategy.

Not available, aLa thèse porte sur l'étude et la réalisation d'un cycloconvertisseur à commande entièrement numérique destine à la commande vectorielle d'une machine synchrone. Dans la première partie, après avoir brièvement rappelé les différentes structures des changeurs de fréquence, nous décrivons le cycloconvertisseur étudié et présentons les principes généraux relatifs au système de commande. La seconde partie est consacrée à la modélisation et a la simulation numérique de l'ensemble cycloconvertisseur-machine synchrone. Nous présentons les principes généraux d'une nouvelle méthodologie de modélisation des ensembles comprenant des convertisseurs à liaison directe. Par la suite, nous appliquons la méthodologie de simulation développée au système étudié. La dernière partie s'intéresse à la réalisation du système de puissance et en particulier a la formalisation et a la mise en œuvre de la commande numérique du cycloconvertisseur. Nous utilisons une méthode de conception permettant une approche globale des problèmes à résoudre, basée sur le concept de réseaux de pétri interprétés. A partir de la formalisation du cahier des charges, nous obtenons un bilan de toutes les fonctions à accomplir. Pour cela, le système est découpé en blocs fonctionnels regroupant un certain nombre de fonctions bien identifiées. Les taches élémentaires ainsi obtenues sont ensuite reparties entre diverses technologies afin d'aboutir à une solution hybride dans laquelle le microcalculateur tient un rôle dominant pour les calculs et les traitements d'algorithmes nécessaires au contrôle du système