Electrotechnique
Type-2 Fuzzy Logic Predictive Control of a Grid Connected Wind Power Systems with Integrated Active Power Filter Capabilities
This paper proposes a real-time implementation of an optimal operation of a double stage grid connected wind power system incorporating an active power filter (APF). The system is used to supply the nonlinear loads with harmonics and reactive power compensation. On the generator side, a new adaptive neuro fuzzy inference system (ANFIS) based maximum power point tracking (MPPT) control is proposed to track the maximum wind power point regardless of wind speed fluctuations. Whereas on the grid side, a modified predictive current control (PCC) algorithm is used to control the APF, and allow to ensure both compensating harmonic currents and injecting the generated power into the grid. Also a type 2 fuzzy logic controller is used to control the DC-link capacitor in order to improve the dynamic response of the APF, and to ensure a well-smoothed DC-Link capacitor voltage. The gained benefits from these proposed control algorithms are the main contribution in this work. The proposed control scheme is implemented on a small-scale wind energy conversion system (WECS) controlled by a dSPACE 1104 card. Experimental results show that the proposed T2FLC maintains the DC-Link capacitor voltage within the limit for injecting the power into the grid. In addition, the PCC of the APF guarantees a flexible settlement of real power exchanges from the WECS to the grid with a high power factor operation. Voir les détails
Mots clés : Active power filter (APF), Adaptive neuro fuzzy inference system (ANFIS), Maximum Power Point Tracking (MPPT), Predictive current control (PCC), Type-2 fuzzy logic controller (T2FLC)
Waveguide Filter Modeling and Simulation using Mode-matching, FullwaveNetwork Analysis and Swarm Optimization
This paper presents the modeling ofwaveguide bandpass filter synthesis. It consists of acombination of the most appropriate and reliablemethods and techniques of analysis, simulation andoptimization used in determined order and leading to afast and accurate method of filter synthesis. An exampleof a forth-order filter synthesis is given, employing asymmetric configuration and symmetric response. Theobtained results, reference measurement and commercialsoftware simulator results are compared for validation. Voir les détails
Mots clés : filter, waveguide, Coupling matrix, Mode-matching, Segmentation method, Optimization techniques.
Contribution à la modélisation de structures et dispositifs passifs microondes basée sur l’utilisation de différentes techniques d’optimisation : Application aux filtres en guides d’ondes rectangulaires métalliques
In this work, we proposed a method for the synthesis of hollow waveguides filters. It consists of a combination of several calculations, simulations and optimizations techniques classified in a defined order to result in band-pass filters. It is a question of: First, to generate the coupling matrix starting from the filter specifications. Deduce the equivalent circuit and then convert it into a microwave structure, which consists of replacing the resonators and inverters of the circuit by resonant cavities and couplers. Once the circuit has been converted to a microwave structure, we need an analysis method to ensure the right conversion. For this, we used the segmentation method, which consists in fragmenting the structure into several basic elements (junction, bend and T-junction). Each element is analyzed separately using the mode-matching method, and then the structure is assimilated to a network made up of these basic elements. Since the final result requires optimization because it does not correspond perfectly to the specifications of the structure to be synthesized, we have studied and used three optimization techniques: genetic algorithms, particle swarm optimization and neural networks. To validate our synthesis method, we have successfully applied it to the synthesis of the Tchebychev, Dual-mode, and generalized Tchebychev band-pass filters. Voir les détails
Mots clés : filter, waveguide, Coupling matrix, Mode-matching, Segmentation method, Optimization techniques.
Contribution à l’Etude du Choix Optimal de l’Emplacement du Dispositif UPFC dans les Réseaux Electriques en Utilisant une des Méthodes Artificielles
With the increasing electric power demand, the operation of power system becomes more complex to operate within the indices power quality, and therefore will become less secure. The advent of Flexible Alternating Current Transmission Systems (FACTS) technology has coincided with the major restructuring of the electrical power industry; it can provide significant benefits in increasing system transmission capacity and power flow control flexibility and rapidity. Several types of FACTS exist and choosing the appropriate device depends on the objectives to reach. Unified Power Flow Controller (UPFC) is one of the most effective FACTS devices for enhancing power system security; however, to what extent the performance of UPFC can be brought out, it highly depends upon the location and parameter setting of this device in the system. A lot of research has been done on determining the optimal locations of FACTS devices in power systems. There are several methods permitting to find the optimal locations of FACTS devices according to specified criteria and constraints. Among these methods are found the Genetic Algorithm (GA) method. The latter is a global search and optimization technique which is based on the mechanisms of natural selection and genetics; it can search several possible solutions simultaneously and do not require any prior knowledge of the objective function. In this thesis, genetic algorithms technique is used to solve the problem of choosing the location and rating of FACTS to install. Five types of FACTS devices have been used in this study namely: SVC, TCSC, TCVR, TCPST and UPFC. These FACTS devices are used to maximize the system loadability in the network. Their position and size are determined using coefficients calculated when the load increases. To validate the efficacy of the technique used, has been applied on many IEEE standard electrical network test (14, 30 and 57 bus) using the MATLAB program. Voir les détails
Mots clés : Indices power quality, FACTS, UPFC, GA, global optimization, objective function, SVC, TCSC, TCVR, TCPST, loadability, MATLAB program
Analyse et Traitement de la Qualité d'Energie Electrique en Utilisant des Dispositifs de Contrôledes Réseaux Electriques à UPFC dans le Cas de la Stabilité de la Tension
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Mots clés : Does not exist
Etude de la Performance d’un Dispositif STATCOM Utilisée pour Compenser la Puissance Réactive au Point de Raccordement
The industrial extension during the last decades led to increasing considerable requirements in the electric power, in spite of the significant energy production.The FACTS concept “Flexible Alternative Current Transmission Systems” regroups all devices to basis of electronics of power that permits to improve the exploitation of the electric network. The technology of these systems “static switches” assure a speed superior to the one of the classic electromechanical systems.The objective of this paper is to study the functions of control offered by the STATCOM “STATic COMpensator” in the regulation of the voltage by compensation of the reactive energy. Voir les détails
Mots clés : FACTS, static switches, STATCOM
Contrôle des Transits de Puissance par l’Utilisation d’un UPFC Connecté à une Ligne de Transmission
The FACTS technologies involve conversion andswitching of power electronics in the range of a few tens to few hundred megawatts. The new state devices such as MOSFETs, IGBTs, GTOs and also other suitable power electronic devices are used as controlled switches in FACTS devices. The universal and most flexible FACTS device is the Unified Power Flow Controller “UPFC”, this device is the combination of three compensators characteristic; i.e., impedance, voltage magnitude and phase angle, that are able to produce a more complete compensation [1]. Voir les détails
Mots clés : FACTS, MOSFETs, IGBTs, GTOs, UPFC
Evaluation de Comportement du Dispositif UPFC Connecté au Réseau Electrique pour Contrôler l’Ecoulement de Puissance
This paper presents some structures of the FACTS (series, shunt and hybrid) based on the GTO thyristors. We make an approach on the modelling of the UPFC. First, we present the equivalent diagram of the studied network, then we expose the results of simulation gotten by the software MATLAB/SIMULINK, so their interpretations. Finally, we try to make a comparison between the results, with another proposition of site of the UPFC on the same network. Voir les détails
Mots clés : FACTS, GTO, modelling, UPFC
UPFC Device: Optimal Location and Parameter Settingto Reduce Losses in Electric-Power Systems Using a Genetic-algorithm Method
Ensuring the secure operation of power systems has become an important and critical matter during the present time, along with the development of large, complex and load-increasing systems. Security constraints such as the thermal limits of transmission lines and bus-voltage limits must be satisfed under all of a system’s operational conditions. An alternative solution to improve the security of a power system is the employment of Flexible Alternating-Current Transmission Systems (FACTS). FACTS devices can reduce the flows of heavily loaded lines, maintain the bus voltages at desired levels, and improve the stability of a power network. The Unifed Power Flow Controller (UPFC) is a versatile FACTS device that can independently or simultaneously control the active power, the reactive power and the bus voltage; however, to achieve such functionality, it is very important to determine the optimal location of the UPFC device, with the appropriate parameter setting, in the power system. In this paper, a genetic algorithm (GA) method is applied to determine the optimal location of the UPFC device in a network for the enhancement of the power-system loadability and the minimization of the active power loss in the transmission line. To verify our approach, simulations were performed on the IEEE 14 Bus, 30 Bus, and 57 Bus test systems. The proposed work was implemented in the MATLAB platform. Voir les détails
Mots clés : FACTS, UPFC, GA, loadability, Matlab
Diagnostic des systèmes non linéaires par analyse statistique multi-variée
Le diagnostic de fonctionnement de systèmes peut être défini comme une suite d’opérations qui a pour objet de détecter et de localiser dans un système, les défauts internes (processus lui-même), les défauts externes (actionneur, instrumentation), les modes de fonctionnement anormaux et de caractériser ces défauts ou modes de fonctionnement. Parmi les méthodes employées, on distingue généralement celles utilisant un modèle paramétrique décrivant le comportement du système à surveiller ( méthodes à base de modèle analytique) de celles qui ne s’appuient que sur l’analyse des données prélevées sur les systèmes comme, par exemple, la reconnaissance de formes. L’optimisation des processus et leur fonctionnement passe donc par une mise en place d’un système de surveillance du fonctionnement de ces processus. En effet, pour améliorer la conduite d’un système, il faut connaître, à chaque instant, l’état de fonctionnement de ce système et pouvoir discriminer états normaux et anormaux. Dans certaines situations, il est même nécessaire de prévoir l’évolution de l’état du système et de proposer un pronostic d’évolution des modes de fonctionnement. De plus, il est important de résoudre le problème lié à l’information : l’exploitant a besoin d’informations cohérentes pour gérer son processus. Dans le cadre d’une approche à base de modèle, l’objectif est mieux maîtriser la modélisation des systèmes (y compris les limites de modélisation) pour développer des approches de diagnostic robustes vis-à-vis des incertitudes de modélisation et des imprécisions de connaissance de façon plus générale. La complexité des mécanismes mis en jeu (les cinétiques non linéaires, les paramètres variant dans le temps, l’absence de mesures fiables) impose le développement et l’utilisation de techniques avancées de l’automatique pour développer une stratégie de diagnostic de fonctionnement en temps réel. Il est question donc d’utiliser des techniques de traitement de données pour développer des stratégies de diagnostic des systèmes. Ainsi des techniques d’identification des systèmes qui utilisent les mesures disponibles sur le processus telles que l’analyse en composantes principales (ACP) sont à développer. Il faut rappeler que l’analyse en composantes principales est une méthode linéaire, alors que la plupart des systèmes physiques ont des comportements non linéaires. Ceci a motivé un certain nombre de travaux pour étendre la portée de l’analyse dans un cadre non linéaire. Voir les détails
Mots clés : Sureveillance des capteurs, Analayse en composantes principales (ACP) et (ACPNL), statistique multivariée et ANN