http://dspace.univ-chlef.dz/handle/123456789/1258 2026-04-30T13:40:36Z 2026-04-30T13:40:36Z NEDJAR, Yahia Mohamed Amine http://dspace.univ-chlef.dz/handle/123456789/2427 2026-04-29T10:13:14Z 2026-02-22T00:00:00Z

Modeling of a System Comprising a Dielectric Barrier Discharge in a CH₄/Ar Mixture and a SOFC Fuel Cell NEDJAR, Yahia Mohamed Amine The transition toward sustainable energy systems requires the development of efficient and environmentally friendly technologies for hydrogen production and utilization. Hydrogen, with its high energy density and clean electrochemical conversion into electricity in fuel cells, represents a promising energy carrier for future transportation, power generation, and industrial applications. However, conventional production methods remain energy-intensive and carbon-dependent, motivating the investigation of alternative approaches. Non-thermal plasmas, particularly dielectric barrier discharges (DBDs), offer a promising route for methane conversion and hydrogen production under near-ambient conditions without external heating. In this work, a comprehensive fluid-based plasma model was developed to investigate the behavior of an Ar/CH₄ dielectric barrier discharge. The model incorporates electron energy kinetics, detailed plasma chemistry, and self-consistent transport equations for charged species and electric fields. Parametric simulations were performed to analyze the influence of applied voltage, frequency, and gas composition on discharge dynamics, radical formation, methane conversion, and hydrogen yield. The results demonstrate that argon addition enhances plasma stability and electron density through metastable-assisted processes, improving hydrogen selectivity at intermediate mixing ratios. In a complementary investigation, hydrogen utilization was examined through a Multiphysics model of an anode-supported SOFC. The coupled analysis of mass transport, electrochemical reactions, and thermal effects provided insights into the influence of fuel composition, stoichiometric ratio, and operating temperature on electrochemical performance. The results highlight the sensitivity of cell efficiency and current distribution to hydrogen availability and operating conditions. Overall, this thesis presents two complementary modeling investigations addressing key stages of the hydrogen energy pathway: plasma-assisted production and electrochemical conversion. Although developed independently, these studies contribute to a broader understanding of hydrogen-based energy technologies and support the advancement of cleaner energy systems THÈSE Présentée pour l’obtention du diplôme de DOCTORAT Filière : Électrotechnique Spécialité : Réseaux Electriques

2026-02-22T00:00:00Z ALOUACHE, BENALI http://dspace.univ-chlef.dz/handle/123456789/2423 2026-04-29T09:51:19Z 2026-01-01T00:00:00Z

Modeling and intelligent load frequency control of an islanded microgrid. ( FR : Modélisation et contrôle intelligent de la fréquence de charge d’un microgrid ilôté) ALOUACHE, BENALI This thesis presents a comprehensive study on the modeling, analysis, and control of hybrid microgrid systems with a primary focus on frequency stability. The work begins with a review of microgrid concepts, classifications, and applications, highlighting their role in reducing emissions, improving efficiency, and providing reliable power in isolated regions. Accurate mathematical models of renewable and conventional energy sources, as well as Plug-in Hybrid Electric Vehicles (PHEVs) as flexible storage units, were developed to capture system dynamics and support effective control design. A Multi-Stage PID (MPID) controller was proposed and tuned using both conventional methods (ZN and CDM) and advanced optimization algorithms (CSA and ACO). Results showed significant improvements in frequency regulation compared to classical PID controllers. The study was further extended with Type-1 and Type-2 Fuzzy Logic, which enhanced robustness and adaptability against uncertainties and stochastic variations. The findings confirm that frequency stability is a cornerstone for reliable microgrid operation, especially in islanded mode where renewable energy variability is most pronounced. By integrating advanced control strategies and flexible storage such as PHEVs, hybrid microgrids can achieve higher resilience, flexibility, and sustainability. The proposed framework offers valuable insights for researchers, engineers, and policymakers in developing efficient, clean, and decentralized energy systems that meet growing global electricity demands while supporting long-term energy security and environmental goa THESE Submitted in fulfillment of the requirements for the degree of DOCTORATE (LMD) Option: Electrical engineering

2026-01-01T00:00:00Z REGUIEG, ZAKARIA http://dspace.univ-chlef.dz/handle/123456789/2421 2026-04-28T09:27:53Z 2026-01-01T00:00:00Z

Contribution to the Control of a Hybrid Renewable Energy Generation System Supplying an Active Power Filter with Intelligent Energy Management REGUIEG, ZAKARIA The increasing global demand for clean and sustainable energy has driven the widespread integration of renewable energy sources (RES), particularly photovoltaic (PV) and wind systems, into modern power grids. However, the inherent intermittency of these sources, coupled with the presence of nonlinear loads and the variability of power demand, poses significant challenges to power quality (PQ) and system stability. This thesis presents a comprehensive framework for the design, control, and management of a hybrid PV–wind microgrid that ensures efficient energy utilization and enhanced PQ under dynamic operating conditions. An intelligent energy management system (EMS) is developed to coordinate the energy flow between renewable sources, battery energy storage, and the grid, considering load requirements and system constraints. Advanced artificial intelligence-based Maximum Power Point Tracking (MPPT) techniques are proposed to optimize energy harvesting from RESs in real time. Additionally, series, shunt, and hybrid active power filters are integrated to mitigate harmonic distortions, voltage fluctuations, and waveform unbalance. The proposed system is modeled and validated through simulation studies under various scenarios, including nonlinear loads and grid disturbances. The results demonstrate significant improvements in total harmonic distortion (THD), voltage regulation, energy efficiency, and system reliability, making the framework a robust and scalable solution for next-generation smart and resilient power networks. THÈSE Présentée pour l’obtention du diplôme de DOCTORAT LMD Filière : Electrotechnique Spécialité : Réseaux Electriques

2026-01-01T00:00:00Z DJAFER, Lemya http://dspace.univ-chlef.dz/handle/123456789/2409 2026-03-12T09:04:37Z 2026-01-01T00:00:00Z

Contribution a la Commande des Convertisseurs Multi-niveaux pour L'entraînement d’un Véhicule Electrique Multi-sources DJAFER, Lemya Les véhicules électriques (VEs) suscitent un intérêt croissant en tant que solution prometteuse face à la crise énergétique et aux enjeux environnementaux. Actuellement, les VE utilisent une grande variété de dispositifs d’électronique de puissance pour fournir l’énergie nécessaire au moteur, tout en assurant un fonctionnement efficace à des niveaux de tension élevés. Dans ce contexte, les onduleurs multi-niveaux ont été développés afin de surmonter les limites des convertisseurs conventionnels. Cette thèse a pour objectif de développer une nouvelle structure multiniveaux, visant à améliorer les performances des véhicules électriques alimentés par plusieurs sources d’énergie. Le travail porte notamment sur l’étude d’une nouvelle topologie hybride asymétrique d’onduleur à 21-niveaux, caractérisée par une commutation réduite, dans le but d’optimiser la qualité de la tension de sortie et, par conséquent, les performances globales du VE. L’onduleur proposé est conçu pour alimenter un moteur synchrone à aimants permanents (MSAP). Le contrôle du moteur est d’abord assuré par une commande en mode glissant, la technique (SMC) est trés prisée car elle permet de rejeter efficacement les variations internes des paramètres ainsi que les perturbation extérieurs. Toutefois, en raison des limitations de cette méthode, notamment le phénomène de broutement (chattering), une technique améliorée a été développée : la commande en mode glissant flou hybride (HFSMC), permettant de réduire significativement ce phénomène. Le système global du VE est alimenté par deux sources d’énergie : une pile à combustible en tant que source principale, et un super-condensateur en tant que source secondaire. Des simulations ont été réalisées pour évaluer les performances de la nouvelle topologie d’onduleur, notamment en ce qui concerne l’amélioration de la qualité de la tension de sortie et la réduction du taux de distorsion harmonique total (THD). Une autre série de simulations a également été menée sur le système complet du VE. Les résultats obtenus ont démontré la fiabilité et l’efficacité du système proposé. THÈSE Présentée pour l’obtention du diplôme de DOCTORAT LMD Filière : Electrotechnique Spécialité : Commande électrique

2026-01-01T00:00:00Z