https://dspace.univ-ouargla.dz/jspui/handle/123456789/212 2026-07-06T14:32:05Z 2026-07-06T14:32:05Z Khaled Mohammed Said, Benzaoui https://dspace.univ-ouargla.dz/jspui/handle/123456789/41095 2026-07-06T09:45:34Z 2025-01-01T00:00:00Z

Titre: Multilevel direct torque control of sensorless two five-phase induction machines connected in parallel Auteur(s): Khaled Mohammed Said, Benzaoui Résumé: Railway traction, naval propulsion, and robotics are just a few examples of numerous industrial sectors that exploit the multi-machine drive, more than one electrical machine drive. Which is currently comprising n three-phase machines parallel-connected in different configurations. However, it lacks the means of independent control of each machine in the drive due to the Master-Slave and Averaging control schemes utilized in the three-phase system. Therefore, this thesis considers the concept of an independently controlled two-machine drive constituted of two multiphase induction machines (IM) parallel-connected to a single multi level multiphase voltage source inverter (VSI), to enhance the concept of multi-phase multi machine drive when compared to its three-phase counterpart. Where the five-phase IM (FPIM) topology is proposed based on a cost-effective technique study, by exploiting the additional degrees of freedom (DOF) offered by this topology. The fundamentals of the independent control concept of the parallel operation of the two-machine drive is derived from the fact that the AC machines, disregarding the phase number, require the control of only one set of current components. Thus, the extra current set can be exploited to control independently the other machines in the drive with the proper stator phase connection. Nevertheless, this concept faces numerous challenges due to the inherited control difficulties of the IM and the multi-level topologies of the VSI, the parallel operation complexity, and the poor performance of the traditional control strategies, especially during the low-speed operation. For this reason, the direct torque control (DTC) technique presents an interesting solution to overcome the aforementioned challenges, offering robust and dynamic performance. Nevertheless, every technique has its pros and cons; for instance, it presents a high content of flux/torque ripples, in addition to the size and complexity of the switching table (ST), which reduces the performance of the suggested concept of the two-machine drive. For this reason, an AI-based DTC technique, exploiting the artificial neural networks (ANN) benefits, to improve xx Abstract the robustness and enhance the performance of the drive resulting in the reduction of the developed flux/torque ripples. This latter is achieved by replacing the hysteresis controllers (HC) and the ST of the conventional method by ANNs-based controller; thus, resulting in a simple yet more robust structure. Moreover, to further optimize the performance, size and improve the aforementioned cost effective technique study based two-machine drive’s fault-tolerant capability, Machine Model based (MM) sensorless methods are investigated to observe and estimate the machine’s critical state variables to achieve the optimum performance of the DTC technique and the drive by addressing the drawback of the utilized open-loop estimator especially during the low-speed operation. Where the three proposed MM techniques based on Model reference adaptive system (MRAS), Sliding mode observer (SMO), and Virtual current sensor (VCS) results in higher performance regarding the speed tracking during the transient and steady state operation, negligible estimation error, and better rejection of external disturbances in different operating scenarios. On the other hand, a preventive mitigation approach to tackle the Common-Mode Voltage (CMV) generated by the PWM-controlled VSI’s discrete voltages is considered. For this reason, a modified DTC is discussed, utilizing the concept of virtual voltage vector (VVV). These VVVs are synthesized based on a selected switching states capable of reducing the CMV peak to-peak values. Thus, improving the drive’s reliability and reducing the maintenance’s time and cost by addressing the inherited drawback of the multi-level VSI from its roots. Description: Electrical Machines

2025-01-01T00:00:00Z RAMDANI, Madjeda https://dspace.univ-ouargla.dz/jspui/handle/123456789/40809 2026-06-17T09:49:09Z 2026-01-01T00:00:00Z

Titre: Contribution à l'étude d'un système multi-sources Auteur(s): RAMDANI, Madjeda Résumé: Cette thèse porte sur la conception d’un système hybride basé sur l’hydrogène vert pour alimenter la station de dessalement d’eau d’Ifrit El Gara, située à Ouargla, en Algérie. Cette station consomme en moyenne environ 818.37 kWh par jour et produisant un volume moyen quotidien d'eau dessalée estimé à 7 875 mètres cubes par jour, en s’appuyant actuellement sur l’énergie électrique fournie par le réseau national et en utilisant la technologie de l’osmose inverse pour le processus de dessalement. L’étude vise à évaluer la faisabilité technique et économique du remplacement de l’énergie conventionnelle par des sources d’énergie renouvelable et de l’hydrogène vert, dans le cadre de la promotion de la durabilité énergétique dans les régions désertiques. Le travail comprend une analyse des performances des composants principaux du système, Optimiser les paramètres des composants du système via des algorithmes métaheuristiques, notamment l'algorithme SSA, ainsi que des expériences en laboratoire visant à augmenter la production d’hydrogène. En outre, une étude technico-économique réalisée à l’aide du logiciel HOMER Pro permet de déterminer la configuration optimale du système et d’évaluer sa viabilité économique. Description: Electrotechnique

2026-01-01T00:00:00Z GUEHRAR, Youcef https://dspace.univ-ouargla.dz/jspui/handle/123456789/40681 2026-05-12T10:17:03Z 2026-01-01T00:00:00Z

Titre: Elaboration d’une méthodologie de conception de stations de production décentralisée d’origine renouvelable en Algérie. Auteur(s): GUEHRAR, Youcef Résumé: تقدم هذه الأطروحة منهجية متكاملة لتحسين تصميم محطات الطاقة الشمسية الكهروضوئية اللامركزية في الجزائر. في مواجهة الإمكانات الاستثنائية للطاقة الشمسية في البلاد واعتمادها المستمر على المواد البيترولية، يطور هذا العمل نهجاً شاملاً يجمع بين التحليل التقني للشبكة (طرق LSF/VSI)، والتحسين بسرب الجسيمات (PSO)، والتحليل المكاني متعدد المعايير (GIS-BWM). عند تطبيقها على شبكة نقوسة، تثبت المنهجية فعاليتها من خلال تحقيق انخفاض كبير في فقدان الطاقة النشطة، وتحسن ملحوظ في ملف الجهد، وتحديد مواقع التركيب المثلى. تؤكد التحليلات الاقتصادية جدوى الحلول المقترحة، والتي تساهم أيضاً في خفض انبعاثات ثاني أكسيد الكربون. يوفر هذا البحث إطاراً عملياً لاتخاذ القرارات لدعم التحول الطاقوي في الجزائر نحو نظام كهربائي أكثر مرونة واستدامة.; This thesis proposes an integrated methodology for optimizing the design of decentralized photovoltaic power stations in Algeria. Confronting the country's exceptional solar potential and its persistent dependence on hydrocarbons, this work develops a holistic approach combining technical network analysis (LSF/VSI methods), particle swarm optimization (PSO), and multicriteria spatial analysis (GIS-BWM). Applied to the N'Goussa network, the methodology demonstrates its effectiveness with a significant reduction in active power losses, a substantial improvement in the voltage profile, and the identification of optimal installation sites. Economic analyses confirm the viability of the proposed solutions, which also contribute to reducing CO₂ emissions. This research provides an operational decision-making framework to support Algeria's energy transition towards a more resilient and sustainable electrical system.; Cette thèse propose une méthodologie intégrée pour optimiser la conception de stations photovoltaïques décentralisées en Algérie. Face au potentiel solaire exceptionnel du pays et à sa dépendance persistante aux hydrocarbures, ce travail développe une approche holistique combinant analyse technique du réseau (méthodes LSF/VSI), optimisation par essaims particulaires (PSO) et analyse spatiale multicritère (SIG-BWM). Appliquée au réseau de N'Goussa, la méthodologie démontre son efficacité avec une réduction significative des pertes actives, une amélioration substantielle du profil de tension et l'identification de sites d'implantation optimaux. Les analyses économiques confirment la viabilité des solutions proposées, qui contribuent également à la réduction des émissions de CO₂. Cette recherche fournit un cadre décisionnel opérationnel pour accompagner la transition énergétique algérienne vers un système électrique plus résilient et durable. Description: Génie électrique

2026-01-01T00:00:00Z BOURAMDANE, ABDERRAOUF https://dspace.univ-ouargla.dz/jspui/handle/123456789/40641 2026-05-03T10:08:15Z 2025-01-01T00:00:00Z

Titre: Comparative Study of four mini Photovoltaic Power Plants of different Technologies and Inclinations for Grid Injection Auteur(s): BOURAMDANE, ABDERRAOUF Description: Electrotechnics

2025-01-01T00:00:00Z