Integration improvement of DFIG-based wind turbine into the electrical grid

[ENG] This doctoral thesis in electrical engineering is presented as five research works linked together by the same theme. Five articles were published in indexed journals. In this sense, each of these works forms a piece of the puzzle constructed around the subject ”wind farms integration into the electricity grid.” To better understand the articulation between these works, this thesis is structured in three parts: The first part treats the Fault Ride Through (FRT) capability of the Grid-connected DFIG-based Wind Turbine. The first proposed approach is a hybrid method combining two methods (active and passive methods): The active method aims to develop the control of DFIG. In contrast, the passive method is applied for severe voltage faults using hardware protection circuits. Otherwise, the second proposed approach is a control design implemented to the power converters using Proportional-Resonant regulators in a stationary two-phase(α−β) reference frame. The control performance is significantly validated by applying the real-time simulation for the rotor side converter and the hardware in the loop simulation technic for the experiment part of the generator’s grid side converter control. This thesis’s second part presents a new fault diagnosis and fault-tolerant control strategy for doubly fed induction generator with DC output based on predictive torque control. Generally, the current sensor failures can deteriorate the reliability and the performance of the control system and can lead to the malfunction of the predictive control strategy since the rotor-and stator flux cannot be estimated correctly. The proposed fault diagnosis can deal with all types of sensor faults. A non-linear observer adapted to the studied system to achieve smooth operation continuity when two or all the current sensors are faulty. The proposed approach’s feasibility and robustness are achieved by testing different sensor faults on the stator-and rotor-current and under different operation mode cases. The third part focuses on calculating the wind capacity credit by integrating the Moroccan project on the wind energy of 1000 MW in 2020. After introducing the Moroccan Integrated Wind Energy Project, a wind capacity credit assessment program will be implemented on Matlab software, including the complete information about” installed capacity, number of plants, failure rate, types of installed units, peak demand, etc.” This program will be used to calculate the safety rate of an electrical system as well as the capacity credit of Morocco’s electricity production network. The research provides conclusions according to comments and assessment of the impact of this electric energy integration based on wind generation. [SPA] Esta tesis doctoral en ingeniería eléctrica se presenta como cinco trabajos de investigación vinculados entre sí por un mismo tema. Se publicaron cinco artículos en revistas indexadas. En este sentido, cada uno de estos trabajos forma una pieza del rompecabezas construido en torno al tema “Integración de parques eólicos en la red eléctrica”. Para comprender mejor la articulación entre estos trabajos, esta tesis se estructura en tres partes: La primera parte trata la capacidad Fault Ride Through (FRT) de la turbina eólica basada en DFIG conectada a la red. El primer enfoque propuesto es un método híbrido que combina dos métodos (métodos activo y pasivo): El método activo tiene como objetivo desarrollar el control de DFIG. En contraste, el método pasivo se aplica para fallos severos de voltaje usando circuitos de protección de hardware. De lo contrario, el segundo enfoque propuesto es un diseño de control implementado para los convertidores de potencia utilizando reguladores de resonancia proporcional en un marco de referencia estacionario de dos fases (α−β). El rendimiento del control se valida significativamente aplicando la simulación en tiempo real para el convertidor del lado del rotor y la técnica de simulación de hardware en el bucle para la parte experimental del control del convertidor del lado de la red del generador. La segunda parte de esta tesis presenta una nueva estrategia de diagnóstico de fallos y control tolerante de fallos para un generador de inducción doblemente alimentado con salida de CC basado en control predictivo de par. Generalmente, los fallos del sensor de corriente pueden deteriorar la confiabilidad y el rendimiento del sistema de control y pueden conducir al mal funcionamiento de la estrategia de control predictivo ya que el flujo del rotor y el estator no se puede estimar correctamente. El diagnóstico de fallos propuesto puede tratar todo tipo de fallos del sensor. Un observador no lineal adaptado al sistema estudiado para lograr una continuidad de operación suave cuando dos o todos los sensores de corriente están defectuosos. La viabilidad y solidez del enfoque propuesto se logran probando diferentes fallos de sensor en la corriente del estator y del rotor y en diferentes casos de modo de operación. La tercera parte se centra en el cálculo del crédito de capacidad eólica mediante la integración del proyecto marroquí sobre la energía eólica de 1000 MW en 2020. Después de presentar el Proyecto Integrado de Energía Eólica de Marruecos, se implementará un programa de evaluación del crédito de capacidad eólica en el software Matlab, incluido la información sobre “capacidad instalada, número de plantas, tasa de fallos, tipos de unidades instaladas, pico de demanda, etc.” Este programa se utilizará para calcular la tasa de seguridad de un sistema eléctrico, así como el crédito de capacidad de la red de producción de electricidad de Marruecos. La investigación brinda conclusiones según comentarios y evaluación del impacto de esta integración de energía eléctrica basada en la generación eólicaEscuela Internacional de Doctorado de la Universidad Politécnica de CartagenaUniversidad Politécnica de CartagenaPrograma de Doctorado en Energías Renovables y Eficiencia Energétic

Role of different 5-HT receptor subtypes in modulating nociception in the rat

Several lines of evidence have implicated a role for the descending serotonergic system in the modulation of somatosensory transmission and in analgesia. It is now known that serotonin (5-HT) has more than one type of receptor. The aim of the present experiments was to investigate the involvement of different 5-HT receptor sites in antinociception and analgesia. By employing agonists and antagonists selective for different types of 5-HT receptors in ionophoretic experiments, it was shown that 5-HT^ and not 5-HT2 receptors were responsible for mediating the heterogeneous effects of ionophoretically applied 5-HT on rat dorsal horn neurones. Two different 5-HT-j receptor subtypes were found to mediate qualitatively different effects, often on the same cell. Whereas the 5-HT^g site appeared to mediate the selective antinociceptive effect of 5-HT, non-selective effects of ionophoretically applied 5-HT, appeared to be exerted through the 5-HT^ receptor site. Focal brainstem stimulation experiments have demonstrated that both the selective antinociceptive and non-selective inhibitory effects of stimulation in the medullary serotonergic nucleus raphe magnus on dorsal horn neurones are mediated through a 5-HT^-type receptor. Thus a 5-HT-| and not a 5-HT2 receptor antagonist could readily reverse the effects of brainstem stimulation. A pilot behavioural study investigated the analgesic potential of two different 5-HT-| receptor subtype agonists and preliminary evidence appears to confirm the involvement of the 5-HT-|g receptor type in behavioural analgesia. The findings of the present study are discussed in relation to previous reports in the literature

A comparison between series dynamic resistors and CROWBAR circuit protection for LVRT capability of doubly-fed induction generator

In this paper, we will focus on a comparison between two strategies (the Series Dynamic Resistors (SDR) and CROWBAR circuit for Low Voltage Ride Through (LVRT) capability of Doubly-Fed Induction Generator (DFIG), in order to determine different responses of reactive power and active power during the grid faults in line with the requirements determined by the grid codes (GCs). The two strategies are simulated by using MATLAB/Simulink environment

LVRT and HVRT control strategies of doubly- fed induction generator

The Doubly Fed Induction Generator (DFIG) has a high sensitivity to the Grid Faults (GFs), which can cause many problems on the power quality and the production continuity. Actually, the grid connection requirements impose strict laws to respect to Low Voltage Ride Through (LVRT), High Voltage Ride Through (HVRT), and grid support capacities following the Grid Codes (GCs). In fact, when detecting voltage fault, Wind Turbines (WTs) should stay in connection with the grid in order to hold a safe and stable operation. The main objective of this work is to propose LVRT and HVRT strategies able to retain WTs connected to the grid during severe grid voltage faults. The proposed approach is a hybrid method combining two methods (active and passive methods): The first aim is to develop the control of DFIG, while the second is applied for severe voltage faults using hardware protection circuits

Robust face recognition using convolutional neural networks combined with Krawtchouk moments

Face recognition is a challenging task due to the complexity of pose variations, occlusion and the variety of face expressions performed by distinct subjects. Thus, many features have been proposed, however each feature has its own drawbacks. Therefore, in this paper, we propose a robust model called Krawtchouk moments convolutional neural networks (KMCNN) for face recognition. Our model is divided into two main steps. Firstly, we use 2D discrete orthogonal Krawtchouk moments to represent features. Then, we fed it into convolutional neural networks (CNN) for classification. The main goal of the proposed approach is to improve the classification accuracy of noisy grayscale face images. In fact, Krawtchouk moments are less sensitive to noisy effects. Moreover, they can extract pertinent features from an image using only low orders. To investigate the robustness of the proposed approach, two types of noise (salt and pepper and speckle) are added to three datasets (YaleB extended, our database of faces (ORL), and a subset of labeled faces in the wild (LFW)). Experimental results show that KMCNN is flexible and performs significantly better than using just CNN or when we combine it with other discrete moments such as Tchebichef, Hahn, Racah moments in most densities of noises

Caracterización de las diferencias de sexo en las enfermedades cerebrovasculares mediante el metaanálisis de estudios transcriptómicos

[ES] Los accidentes cerebrovasculares son la consecuencia de la interrupción del suministro del flujo sanguíneo a una parte del cerebro, desencadenando una hipoxia cerebral y, por consiguiente, la muerte neuronal. Según la naturaleza del accidente, se pueden distinguir dos tipos principales: accidente cerebrovascular isquémico y accidente cerebrovascular hemorrágico. Se trata de una de las enfermedades con mayores índices de mortalidad y morbilidad a nivel mundial. Esta enfermedad presenta diferencias de prevalencia e incidencia entre mujeres y hombres, siendo la primera causa de muerte para las mujeres a nivel nacional. Esta divergencia en las cifras epidemiológicas es la consecuencia de diferencias en los mecanismos moleculares, cuyo análisis permitiría un mejor diagnóstico y tratamiento de los accidentes. Desafortunadamente, en la mayoría de los estudios biomédicos sobre esta patología, no se tiene en cuenta el sexo como factor clave en la investigación. La elucidación de los mecanismos moleculares responsables de las diferencias existentes entre sexos permite hallar nuevos biomarcadores que mejoran la precisión y la eficacia en el tratamiento de la enfermedad, el diagnóstico y el pronóstico clínicos. Con el fin de cumplir este objetivo, se ha llevado a cabo un metaanálisis con datos provenientes de estudios transcriptómicos seleccionados a partir de una revisión bibliográfica sistemática. Con este abordaje se identificaron funciones específicas en mujeres, relacionadas con la integridad del ribosoma y la mitocondria, y la fosforilación oxidativa; en el caso de los hombres, se encontraron funciones específicas vinculadas a la homeostasis de la barrera hematoencefálica, la respuesta inmune y la guía axonal. No obstante, se requiere de un mayor número de estudios para profundizar en estos hallazgos, además de implementar el sexo como factor clave en el diseño experimental de nuevos trabajos, para comprender mejor las discrepancias existentes entre sexos respecto a esta enfermedad.[EN] Strokes are the consequence of the interruption of the supply of blood flow to a part of the brain, triggering cerebral hypoxia and, consequently, neuronal death. Depending on the nature of the accident, two main types can be distinguished: ischemic stroke and hemorrhagic stroke. It is one of the diseases with the highest mortality and morbidity rates worldwide. This disease presents differences in prevalence and incidence between women and men, being the leading cause of death for women nationwide. This divergence in epidemiological figures is the consequence of differences in molecular mechanisms, the analysis of which would allow a better diagnosis and treatment of accidents. Unfortunately, in most biomedical studies on this pathology, sex is not considered as a key factor in the research. The elucidation of the molecular mechanisms responsible for the existing differences between the sexes allows finding new biomarkers that improve precision and efficacy in the treatment of the disease, the diagnosis and the clinical prognosis. In order to meet this objective, a meta-analysis has been carried out with data from transcriptomic studies selected from a bibliographic systematic review. With this approach, specific functions were identified in women, related to the integrity of the ribosome and mitochondria, and oxidative phosphorylation; in the case of men, specific functions related to blood-brain barrier homeostasis, immune response and axonal guidance were found. However, a greater number of studies is required to delve into these findings, in addition to implementing sex as a key factor in the experimental design of new studies, to better understand the existing discrepancies between the sexes regarding this disease.Hamdani El Amri, YE. (2021). Caracterización de las diferencias de sexo en las enfermedades cerebrovasculares mediante el metaanálisis de estudios transcriptómicos. Universitat Politècnica de València. http://hdl.handle.net/10251/171289TFG

Applications des interactions quadripolaires dans des réactions de macrocyclisation par métathèse de fermeture de cycle

Thèse numérisée par la Division de la gestion de documents et des archives de l'Université de Montréal

LVRT control srategy of DFIG based wind turbines combining passive and active protection

Due to its advantages, Doubly Fed Induction Generator (DFIG) is the most used generator in the wind power area. However, the DFIG provides electrical power at a constant frequency even if the rotor speed varies; also, it allows a better capture of wind energy. Although the DFIG has a high sensitivity regarding the electrical faults, which brings up many challenges in terms of compliance: Power provider and electrical operator (in terms of production continuity and quality of energy). Actually, the grid connection requirements impose strict rules to respect for Low Voltage Ride Through (LVRT) and grid support capabilities following the Grid Code (GC). Therefore, it’s crucial for wind turbines (WT) to propose an advanced control. In fact, when detecting voltage dips, WTs must stay connected to the grid to provide the required reactive power in order to have a safe and reliable operation. The objective of this article is to propose a new LVRT strategy able to keep WTs connected to the grid despite severe voltage dips. The principle of this strategy is to make a connection between the level of dips and the optimal solution to overcome the fault. For this reason, the proposed strategy is based on the combination of two solutions (an active and a passive method): The first aims to improve the control strategy to mitigate the over-current at low voltage dips. The second is applied for severe voltage dips using protection circuits: Series Dynamic Braking Resistor (SDBR) and DC-Chopper