CONTRIBUTION À L’AMÉLIORATION DES PERFORMANCES DES FILTRES ACTIFS

Le problème de la pollution harmonique dans les réseaux de distribution électrique est en augmentation à cause du développement remarquable des semiconducteurs qui représentent des charges non linéaires. Il existe de nombreuses solutions anciennes, comme les filtres passifs, encore utilisés jusqu’à présent, mais ils présentent des inconvénients comme l’inadaptation lors d’un changement de charge par exemple, et l’apparition de résonance avec l’impédance du réseau. Par conséquent, les chercheurs se sont tournés vers les filtres actifs, et ils étaient effectivement efficaces pour éliminer les harmoniques dans le réseau, mais ils sont très coûteux dans les applications industrielles, alors les scientifiques ont recouru à nouveau à l’hybridation entre les deux types précédents "actif" et "passif" pour obtenir un troisième type, qu’ils ont appelé "filtre actif hybride". Dans cette modeste thèse, nous avons étudié le ’filtre actif’ et le ’filtre actif hybride’ en utilisant des techniques intelligentes telles que la logique floue afin de découvrir quels types de filtres sont les plus efficaces. L’étude est basée sur la simulation sous (Matlab/Simulink), et les résultats sont bons et confirment l’efficacité des modèles proposés

Self tunning filter for three levels four legs shunt active power filter with fuzzy logic controller

The low harmonic distortion and reduced switching losses are the advantages of using the multilevel inverter. For this purpose, the three-level inverter is used in this paper as a three-phase four-leg shunt active power filter (SAPF). The SAPF is used to eliminate the harmonic current to compensate the reactive power current, and to balance the load currents under an unbalanced non-linear load. A fuzzy logic controller and self-tuning filters (STF) are used to control the active power filter (APF) and generate the reference current. To demonstrate the validity of the proposed control strategy, we compared it with a conventional p − q theory, under distortion voltage conditions and unbalanced non-linear load. The Matlab-Simulink toolbox is used to implement the algorithm of Fuzzy logic control. The performance of the SAPF controller is found very effective and adequate as compared with the p − q theory

Modeling of Charge Transfer Inefficiency in a CCD with High Speed Column Parallel Readout

Charge Coupled Devices (CCDs) have been successfully used in several high energy physics experiments over the past two decades. Their high spatial resolution and thin sensitive layers make them an excellent tool for studying short-lived particles. The Linear Collider Flavour Identification (LCFI) collaboration is developing Column-Parallel CCDs (CPCCDs) for the vertex detector of a future Linear Collider. The CPCCDs can be read out many times faster than standard CCDs, significantly increasing their operating speed. An Analytic Model has been developed for the determination of the charge transfer inefficiency (CTI) of a CPCCD. The CTI values determined with the Analytic Model agree largely with those from a full TCAD simulation. The Analytic Model allows efficient study of the variation of the CTI on parameters like readout frequency, operating temperature and occupancy.Comment: 5 pages, 13 figures, presented on behalf of the LCFI Collaboration, proceedings IEEE 2008 Nuclear Science Symposium, Dresden, Germany, and 11th Topical Seminar on Innovative Particle and Radiation Detectors (IPRD08) 2008, Siena, Ital

Modeling of radiation hardness of a CCD with high-speed column parallel readout

Charge Coupled Devices (CCDs) have been successfully used in several high energy physics experiments over the past two decades. Their high spatial resolution and thin sensitive layers make them an excellent tool for studying short-lived particles. The Linear Collider Flavour Identification (LCFI) collaboration is developing Column-Parallel CCDs (CPCCDs) for the vertex detector of a future Linear Collider. The CPCCDs can be read out many times faster than standard CCDs, significantly increasing their operating speed. Radiation hardness is an important aspect in the CCD development. Bulk radiation damage in the silicon leads to electron traps and hence to charge transfer inefficiency (CTI). The effects of the two trap levels 0.17 and 0.44 eV are considered. We have extended our Analytic Model to include the effects of the shape of the signal charge packet and the clock voltage on the CTI determination. The CTI values determined with the Analytic Model largely agree with those from a full TCAD simulation