Commande algorithmique d'un système mono-onduleur bimachine asynchrone destiné à la traction ferroviaire

L'objectif de ce travail est de modéliser et de caractériser le comportement d’un système mono-onduleur bimachine asynchrone appliqué à la traction ferroviaire (bogie d’une locomotive BB 36000) en vue de la conception de sa commande. La première partie de ce mémoire est consacrée à la description détaillée du système globale. L’analyse de l’influence des perturbations internes (variations paramétriques d’une machine) et externes (décollement du pantographe, patinage, broutement) de ce système est faite dans le cas d’une structure de commande vectorielle classique appliqué à chaque moteur de l'entraînement (structure de traction classique). Dans la deuxième partie, une nouvelle structure de propulsion est proposée. Elle est constituée d’un onduleur à deux niveaux de tension à modulation de largeur d’impulsion, alimentant en parallèle les deux machines asynchrones qui à leur tour permettent de créer la force de traction transmise aux essieux du bogie. La caisse de la locomotive représente une charge commune pour les deux moteurs. Plusieurs stratégies de commande coopérative sont étudiés, il s’agit des commandes : moyenne simple, moyenne double, maître - esclave alternée et moyenne différentielle. Une stratégie d’observation des modes électriques adéquate à ces différentes contrôles est étudie par la suite. Cet ensemble de commandes est validé à l’aide d’un logiciel de simulation SABER. Il correspond à une quasi-expérimentation dans la mesure où le système à contrôler est modélisé en langage MAST et toute la commande discrète en langage C dans l'environnement de SABER. La troisième partie est dédiée à la suppression du capteur mécanique ensuite appliqué dans les commandes coopératives précédemment proposées. Les méthodes partielles de reconstruction de la vitesse sont : la rélation d’autopilotage, le filtre de Kalman mécanique, l’observateur à structure variable et MRAS. Finalement la description de la configuration matérielle pour la réalisation expérimentale est présentée. ABSTRACT : The goal of this work concerns the modelling and the behaviour characterisation of a single inverter dual induction motor system applied to a railway traction bogie (BB36000) in order to concept its control. First part of this job is dedicated to the detailed description of overall system. The influence analysis of the internal perturbations (motor parameters variation) and, external perturbations (pantograph detachment, adherence loss, stick-slip) of the system have made considering the field oriented control applied to each motor of the bogie (classical traction structure). In a second part, a novel propulsion structure is proposed. It is composed by a single pulsewidth modulated two level voltage source inverter. It supplies two parallel connected induction motors, which generate the transmitted traction force to the bogie wheels. The locomotive case represents the common load for the two motors. Several co-operative control strategies (CS) are studied. They are: the mean CS, the double mean CS, the master – slave switched CS and, the mean differential CS. In addition, an appropriated electric modes observer structure for these different controls has studied. These controls have validated applying the perturbations to the models using the solver SABER. This special approach is equivalent to quasi-experimentation, because the mechanical and the electrical system components have modelled using MAST language and, the sample control has created by a C code programme in the SABER environment. Third part is dedicated to the mechanical sensor suppression and, its adaptation in the cooperative control strategies. The partial speed reconstruction methods are : the fundamental frequency relation, the mechanical Kalman filter, the variable structure observer and the MRAS. Finally, the hardware system configuration of the experimental realisation is described

Hyperthermia studies using inductive and ultrasound methods on E. coli bacteria and mouse glioma cells

The survival of Escherichia coli bacteria and mouse glioma cells were studied under different temperatures using direct heating in water, ultrasound, and magnetic fluid hyperthermia. The survival of these microorganisms depended on whether the heating mode was continuous or discontinuous, surviving more in the former than in the discontinuous heating mode. Whereas Escherichia coli bacteria did not survive at temperatures ≥50∘C, the mouse glioma cells did not survive at temperatures ≥48∘C

Assessing some advanced oxidation processes in the abatement of phenol aqueous solutions

In this work, phenol oxidation in aqueous solution promoted by the effect of the oxidizing agents H2O2, O3 and UV radiation and their synergy in four different advanced oxidation processes (O3, O3/UV, H2O2/O3 and O3/H2O2/UV) were assayed. Studies were performed with a closed-loop hydraulic circuit set up with a relatively high volume of solution (500 cm3) during 90 min of treatment time. Parameters such as concentration for oxidizing species, pH, presence of UV irradiation were evaluated. The resulting degradation efficiencies were evaluated using GC-MS. The agents here used were selected considering their ease of handling and low toxicity, generation of deposited matter or sludge, so a filtration treatment for the analysis of the samples was not required. In all cases, it was observed that with increasing treatment time better degradation efficiencies were obtained. The best results were obtained with the combination of O3/H2O2/UV where up to 95% degradation was attained at pH 9, which is due to active species generated in the process, e.g., O3 and OH˙, on the contaminant. SPE was performed for determining the presence of several by-products, mainly: catechol, resorcinol and hydroquinone, which were identified

Innovative Curved-Tip Reactor for Non-Thermal Plasma and Plasma-Treated Water Generation: Synergistic Impact Comparison with Sodium Hypochlorite in Dental Root Canal Disinfection

Non-thermal plasmas (NTPs), known as cold atmospheric plasmas (CAPs), hold great potential for diverse medical applications, including dentistry. However, traditional linear and rigid dielectric barrier discharge reactors used for NTP generation encounter limitations in accessing oral cavities and root canals. To address this issue, we have developed an innovative NTP reactor featuring an angled end for improved accessibility. The central copper electrode, with a 0.59 mm diameter and adjustable length for desired angulation, is coated with zircon powder (ZrSiO4) to ensure stable NTP generation. This central electrode is housed within a stainless steel tube (3 mm internal diameter, 8 mm external diameter, and 100 mm length) with a 27° angle at one end, making it ergonomically suitable for oral applications. NTP generation involves polarizing the reactor electrodes with 13.56 MHz radio frequency signals, using helium gas as a working medium. We introduce plasma-treated water (PTW) as an adjunctive therapy to enhance biofilm eradication within root canals. A synergistic approach combining NTP and PTW is employed and compared to the gold standard (sodium hypochlorite, NaOCl), effectively neutralizing Enterococcus faecalis bacteria, even in scenarios involving biofilms. Moreover, applying NTP in both gaseous and liquid environments successfully achieves bacterial inactivation at varying treatment durations, demonstrating the device’s suitability for medical use in treating root canal biofilms. The proposed NTP reactor, characterized by its innovative design, offers a practical and specific approach to plasma treatment in dental applications. It holds promise in combatting bacterial infections in root canals and oral cavities

Healing of Recurrent Aphthous Stomatitis by Non-Thermal Plasma: Pilot Study

Recurrent aphthous stomatitis (RAS) is a common disease in the oral cavity characterized by recurrent ulcers (RU). Usually, these cause acute pain without definitive treatment. The present study determines the efficacy of non-thermal plasma (NTP) for treating RU. NTP is applied to the patient’s RU using a radiofrequency generator connected to a point reactor. The power density applied to the ulcer is 0.50 W/cm2, less than 4 W/cm2, which is the maximum value without biological risk. Each patient received two treatments of three minutes each and spaced 60 min apart at a distance of 5 mm from the RU. From a sample of 30 ulcers in patients treated for RU with an average age of 37 years, they stated that the pain decreased considerably and without the need for ingestion of analgesics and antibiotics. Regeneration took place in an average of three days. The NTP proved to be an excellent therapeutic alternative for the treatment of RU since it has a rapid effect of reducing pain and inflammation, as well as adequate tissue regeneration