Les Réseaux de capteurs sans fil (WSN) sont une technologie émergente avec des applications potentielles dans divers domaines de la vie quotidienne, tels que la surveillance structurelle et environnementale, la médecine, la surveillance militaire, les explorations robotisées, etc. Les nœuds de capteurs doivent fonctionner pendant une longue période avec des batteries capacité limitée, par conséquent le facteur plus important dans les WSN est la consommation d'énergie. Dans cette thèse, nous proposons des techniques d'optimisation algorithmiques dynamiques, et adaptative pour la réduction de l'énergie. Tout d'abord, un modèle énergétique précis est présenté. Ce modèle repose sur des mesures réelles de courant consommé pour différents scénarios qui peuvent se produire lors de la communication entre les nœud. Il en est conclu que la couche MAC joue un rôle essentiel dans la réduction de l'énergie consommée. Ensuite, un protocole MAC dynamique est présenté. Il adapte de manière dynamique l’intervalle de réveil des nœuds de capteurs à partir d’une estimation du trafic. L’algorithme adaptatif modélisé de façon heuristique pour comprendre le comportement de convergence des paramètres algorithmiques. Le protocole est appliqué sur des réseaux de capteurs corporels et il surclasse les autres protocoles MAC en termes de latence ainsi que de consommation d'énergie ce qui permet donc d'augmenter la durée de vie de trois à six fois. Enfin, une technique basée sur l’optimisation adaptative de la puissance d'émission radio est appliquée sur des canaux variant dans le temps. La puissance de sortie est réglée dynamiquement au meilleur niveau de puissance selon l’état du canal, ce qui diminue la consommation d’un facteur deux. / Wireless Sensor Networks (WSN) are a fast emerging technology with potential applications in various domains of daily-life, such as structural and environmental monitoring, medicine, military surveillance, robotic explorations etc. WSN devices are required to operate for a long time with limited battery capacity, therefore, the most important constraint in WSN is energy consumption. In this thesis, we propose algorithmic-level dynamic and adaptive optimization techniques for energy reduction in WSN. First, an accurate energy model is presented. This model relies on real-time power measurements of various scenarios that can occur during communication between sensor nodes. It is concluded that MAC layer plays a pivotal role for energy reduction. Then, a traffic-aware dynamic MAC protocol is presented which dynamically adapts the wake-up schedule of sensor nodes through traffic estimation. An adaptive algorithm is designed for this purpose that is heuristically modeled to understand the convergence behavior of algorithmic parameters. The proposed protocol is applied to body area networks and it outperforms other low-power MAC protocols in terms of latency as well as energy consumption and consequently increases the lifetime from three to six times. Finally, an SNR-based adaptive transmit power optimization technique is applied under time-varying channels. The output power is dynamically tuned to best power level under slow varying channel, which results in an average gain by two times.

Thermal energy storage (TES), the storage of heat or cooling, is a cost-effective energy storage technology that can greatly enhance the performance of the energy systems with which it interacts. TES acts as a buffer between transient supply and demand of energy. In solar thermal systems, TES enables the power output of the plant to be effectively regulated, despite fluctuating solar irradiance. In district energy systems, TES can be used to shift loads, allowing the system to avoid or take advantage of peak energy prices. The benefit of TES, however, can be significantly enhanced by dynamically optimizing the complete energy system. The ability of TES to shift loads gives the system newfound degrees of freedom which can be exploited to yield optimal performance. In the hybrid solar thermal/fossil fuel system explored in this work, the use of TES enables the system to extract nearly 50% more solar energy when the system is optimized. This requires relaxing some constraints, such as fixed temperature and power control, and dynamically optimizing the over a one-day time horizon. In a district cooling system, TES can help equipment to run more efficiently, by shifting cooling loads, not only between chillers, but temporally, allowing the system to take advantage of the most efficient times for running this equipment. This work also highlights the use of TES in a district energy system, where heat, cooling and electrical power are generated from central locations. Shifting the cooling load frees up electrical generation capacity, which is used to sell power to the grid at peak prices. The combination of optimization, TES, and participation in the electricity market yields a 16% cost savings. The problems encountered in this work require modeling a diverse range of systems including the TES, the solar power plant, boilers, gas and steam turbines, heat recovery equipment, chillers, and pumps. These problems also require novel solution methods that are efficient and effective at obtaining workable solutions. A simultaneous solution method is used for optimizing the solar power plant, while a static/dynamic decoupling method is used for the district energy system. / text

The popularity of the internal combustion engine (ICE) vehicles has contributed to global warming problem and degradation of air quality around the world. Furthermore, the vehicles??? massive demand on gas has played a role in the depletion of fossil fuel reserves and the considerable rise in the gas price over the past twenty years. Those existing challenges force the auto-industry to move towards the technology development of vehicle electrification. An electrified vehicle is driven by one or more electric motors. And the electricity comes from the onboard energy storage system (ESS). Currently, no single type of green energy source could meet all the requirements to drive a vehicle. A hybrid energy storage system (HESS), as a combination of battery and ultra-capacitor units, is expected to improve the overall performance of vehicles??? ESS. This thesis focuses on the design of HESS and the development of a HESS prototype for electric vehicles (EVs) and hybrid electric vehicles (HEVs). Battery unit (BU), ultra-capacitor unit (UC) and a DC/DC converter interfacing BU and UC are the three main components of HESS. The research work first reviews literatures regarding characteristics of BU, UC and power electronic converters. HESS design is then conducted based on the considerations of power capability, energy efficiency, size and cost optimization. Besides theoretical analysis, a HESS prototype is developed to prove the principles of operation as well. The results from experiment are compared with those from simulation.

L’objectif de cette thèse est de dimensionner et régler un système hybride de production d’énergie pour un site isolé de type insulaire, basé sur des énergies renouvelables marines. De manière préliminaire divers systèmes de production d’énergie renouvelable marine ont d’abord été étudiés et comparés de manière qualitative à des systèmes de production d’énergie classiques. Plusieurs types de système de stockage d’énergie ont également été étudiés, comparés et évalués dans le cas du site considéré. Cette analyse préliminaire a été étendue aux différents types de transmissions d’énergie offshore et de méthodes de réglage des convertisseurs associés aux sources renouvelables. A partir de l’étude des caractéristiques du site et de l’analyse statistique des ressources renouvelables (vents, courants marins) une méthode de dimensionnement des éléments du système de production est présentée, dans l’objectif de minimiser les émissions de CO2 et le coût du système sur son cycle de vie. Pour cela, une solution de gestion de la puissance basée sur la logique floue est proposée pour le type de site considéré et comparée à une solution plus classique basée sur des règles logiques. Pour finir, une étude détaillée des différentes méthodes de réglage du système hybride côté réseau est présentée. Trois niveaux de réglage sont considérés : réglage d’une source unique, réglage d’une ferme de plusieurs sources et réglage global du système hybride. Plusieurs modes de réglage sont considérés pour chaque niveau. / This PhD thesis models a renewable-based hybrid power supply system applied in an islanded context and investigates sizing and regulation strategies of such a hybrid system. First, various marine energy production technologies were reviewed and compared to common renewable resources. As well, various energy storage technologies were reviewed, compared, and evaluated to fit the chosen site characteristics. A brief investigation on offshore energy transmission and inverter regulations methods is presented. Then, a study of the site characteristics, and the availability of the different renewable energy resources in the area are presented. This energy study constitutes the basis of the proposed system sizing method, where minimizing the cost and the CO2 emissions are considered as the main objectives. Furthermore, a fuzzy logic power management approach is proposed for the islanded microgrid. Finally, a detailed study of the system components grid-side inverter regulation is presented. Three regulation levels were investigated: the single inverter, the renewable farm, and the hybrid system. In this context, different regulation strategies are considered at each level.

The rise in population causes serious issues in larger cities since the electrical grid is becoming overloaded. Simultaneously, the demand on more sustainable energy production and the use of renewable energy sources increase. Renewable energy based off-grid electrical systems are a possible solution to decrease the magnitude of these issues. The purpose of this thesis is to compare solar cells, solar thermal collectors and PVT (Photovoltaic thermal hybrid solar collectors) and design the most suitable combination of solar panels for a selfsufficient multi-family house in Jönköping, Sweden. The solar panels were compared from a cost and energy production perspective, then a suitable renewable energy system with all three types of panels was constructed and optimized using Opti-CE, which is a MATLABbased software. During the course of this thesis, an interview was made with Hans-Olof Nilsson who is a co-founder of Nilsson Energy and owner of a self-sufficient off-grid house. The results show that PVT-panels have higher energy production per area and 22% higher LCC (life cycle cost) than regular solar cells in combination with solar thermal collectors. Optimization results indicate that the house cannot be self-sufficient by installing solar panels on the given roof area only, rather the area of installed solar collectors should be increased to a minimum of 1497𝑚2 . With the given roof area of 900𝑚2 the house can only be self-sufficient a maximum of 75% of the time. The results also indicate that the introduction of compact systems with the simultaneous decrease of cost will make renewable off-grid energy systems more attractive in the future.

The increasing popularity and improvements in the blockchain technology that offers decentralized communication and transactions in the form of cryptocurrencies that have now days a market value of almost 1.3 Trillion dollars and a huge potential to contribute to other fields such as health care, financial transactions, information technology, secure data exchange, data storage and many others has been pushing towards more integrating of renewable energies in this field. The process of approving and inserting the information and contracts with Bitcoins on the blockchain is called mining of Bitcoin and accounts for a large electricity consumption which has been estimated to be around 120 Terawatt_hour (TWH) worldwide in 2023. To keep this field of technology improving and strengthen its development, leading it towards more usage of clean energy will benefit the field and most importantly will help our societies to face climate change and align with the United Nations sustainable goals regarding integrating and increasing the usage of renewable energies and sustainable methods in all fields of life and industry.  The purpose of this study is to assess the feasibility of building a mining farm for bitcoin powered by renewable energies, solar and wind, by using photovoltaics systems and wind turbines with the integration of storage mediums to utilize the clean energy as much as possible. The project is done by firstly conducting a literature review about the technologies used followed by choosing the most appropriate alternatives that fit best for the current project properties and goals. After choosing the components and methods to be used , the technical feasibility is analyzed by simulating the hybrid energy system using a code program written in the software MATLAB which optimizes and calculates on one hand the electricity production of the system that is used for the hourly reliability in meeting the load demand of the mining devices and on the other hand the total cost of the system which will be built upon to estimate the levelized cost of energy and hence analyze the economic feasibility of the project.After conducting the simulation and financial calculations, the results show that the project is technically feasible and the reliability can be as high as around 8650 hours of the year, however, to achieve a 100 percent reliability a support power should be used such as a diesel generator which has also been done in this work. The economic feasibility indicates that the project will be profitable based on the installed capacities and mined Bitcoins, however a storage medium and a support power production source are vital for the success of such a project.

Due to the result of the sudden fossil fuels over-night price rises of 1973/1974, coupled with the depletion of the traditional energy resources, many initiatives globally have addressed the efficient use of these resources. Since then, several renewable energy sources have been introduced as alternatives to traditional resources to protect environmental resources and to improve quality of life. Globally, there are more than a quarter of the human population experiencing an energy crisis, particularly those living in the rural areas of developing countries. One typical example of this is Nigeria. This is a country with approximately 80% of her population consistently relying on combustible biomass from wood and its charcoal derivative. Nigeria has an abundant amount of both renewable and fossil fuel resources, but due to the lack of a reasonable energy policy (until recently), it has concentrated on traditional fossil fuels alone. Renewable energy is now Globally considered as a solution for mitigating climate change and environmental pollution. To assess the sustainability of renewable energy systems, the use of sustainability indicators is often necessary. These indicators are not only able to evaluate all the sustainability criteria of the renewable energy sources,1 but also can provide numerical results of sustainability assessment for different objective systems.

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Ce mémoire porte sur l'étude d'un système de gestion d'énergie électrique dans un système multi-sources soumis à des perturbations exogènes. L'application visée est l'alimentation d'une propulsion hybride diesel/électrique équipée d'un système d'absorption des pulsations de couple. Les perturbations exogènes considérées peuvent être transitoires ou persistantes. Une perturbation transitoire correspond à une variation rapide du couple de charge, due par exemple à une accélération ou une décélération du véhicule. Une perturbation persistante provient du système de compensation des pulsations de couple générées par le moteur thermique. Le premier objectif du contrôle est de maintenir constante la tension du bus continu. Le deuxième objectif est d'absorber dans un système de stockage rapide constitué de super condensateur ces perturbations qui peuvent à terme provoquer une usure prématurée de la batterie. Le troisième objectif est de compenser l'auto-décharge dans le super condensateur en maintenant constante sa tension nominale. Les deux sources (batterie et super condensateur) sont reliées au bus continu par l'intermédiaire de deux convertisseurs boost DC/DC. La commande consiste à piloter les rapports cycliques de chaque convertisseur. C'est un système non linéaire où la commande est multiplicative de l'état. L'approche classique consistant à résoudre les équations Francis-Byrnes-Isidori ne s'applique pas directement dans ce cas où la sortie et la matrice d'interconnection dépendent de la commande. De plus, si cette approche est bien adaptée au rejet de perturbations persistantes, elle montre ces limites pour le rejet de perturbations non persistantes combiné à des objectifs de régulation. Notre approche a consisté à écrire le système sous un formalisme Port-Controlled Hamiltonian et à s'affranchir de la contrainte de la dépendance de la matrice d'interconnection avec la commande en utilisant la théorie des perturbations singulières. La commande du système dégénéré peut ensuite être calculée par une approche passive. Les performances de cette commande ont été testées en simulation et à l'aide d'un banc d'essai expérimental. Les résultats montrent l'efficacité du système d'absorption des différents types de perturbation tout en respectant les deux objectifs de régulation. / This thesis presents the research of energy management in a battery/ultracapacitor hybrid energy storage system with exogenous disturbance in hybrid electric vehicular application. Transient and harmonic persistent disturbances are the two kinds of disturbances considered in this thesis. The former is due to the transient load power demand during acceleration and deceleration, and the latter is introduced from the process of the internal combustion engine torque ripples compensation. Our control objective is to absorb the disturbances causing battery wear via the ultracapacitor, and meanwhile, to maintain a constant DC voltage and to compensate the self-discharge in the ultracapacitor to maintain it operating at the nominal state of charge. The object system is nonlinear due to the multiplicative relation between the input and the state. The traditional approach to solve Francis-Byrnes-Isidori equations cannot be directly applied in this case since the interconnect matrix depends on the control input. Besides, even if this approach is well suited to the rejection of persistent disturbances, it shows the limits for the case of non-persistent disturbances which is also our object. Our contributed control method is realized through a cascade control structure based on the singular perturbation theory. The ultracapacitor current with the fastest motion rate is controlled in the inner fast loop through which we impose the desired dynamic to the system. The reduced system controlled in the outer slow loop is a Hamiltonian system and the controller is designed via interconnection and damping assignment. Simulations and experiments have been carried out to evaluate the control performance. A contrast of the system responses with and without the control algorithm shows that, with the control algorithm, the ultracapacitor effectively absorbs the disturbances; and verifies the effectiveness of the control algorithm.

A continuous increase in demands from the utility grid and traction applications have steered public attention toward the integration of energy storage (ES) and hybrid ES (HESS) solutions. Modern technologies are no longer limited to batteries, but can include supercapacitors (SC) and flywheel electromechanical ES well. However, insufficient control and algorithms to monitor these devices can result in a wide range of operational issues. A modern day control platform must have a deep understanding of the source. In this dissertation, specialized modular Energy Storage Management Controllers (ESMC) were developed to interface with a variety of ES devices. The EMSC provides the capability to individually monitor and control a wide range of different ES, enabling the extraction of an ES module within a series array to charge or conduct maintenance, while remaining storage can still function to serve a demand. Enhancements and testing of the ESMC are explored in not only interfacing of multiple ES and HESS, but also as a platform to improve management algorithms. There is an imperative need to provide a bridge between the depth of the electrochemical physics of the battery and the power engineering sector, a feat which was accomplished over the course of this work. First, the ESMC was tested on a lead acid battery array to verify its capabilities. Next, physics-based models of lead acid and lithium ion batteries lead to the improvement of both online battery management and established multiple metrics to assess their lifetime, or state of health. Three unique HESS were then tested and evaluated for different applications and purposes. First, a hybrid battery and SC HESS was designed and tested for shipboard power systems. Next, a lithium ion battery and SC HESS was utilized for an electric vehicle application, with the goal to reduce cycling on the battery. Finally, a lead acid battery and flywheel ES HESS was analyzed for how the inclusion of a battery can provide a dramatic improvement in the power quality versus flywheel ES alone.