Thèses sur le sujet « Power state machine generation »

De nombreux protocoles Total Order Broadcast uniformes ont été conçus au cours des 30 dernières années. Ils peuvent être classés en deux catégories: ceux qui visent une faible latence, et ceux qui visent à haut débit. Latence mesure le temps nécessaire pour effectuer un seul message diffusé sans prétention, alors que le débit mesure le nombre d'émissions que les processus peuvent compléter par unité de temps quand il y a discorde. Tous les protocoles qui ont été conçus pour autant faire l'hypothèse que le réseau sous-jacent ne sont pas partagées par d'autres applications en cours d'exécution. Ceci est une préoccupation majeure à condition que dans les centres de données modernes (aka Clouds), l'infrastructure de mise en réseau est partagée par plusieurs applications. La conséquence est que, dans de tels environnements, le total des protocoles afin de diffusion uniformes présentent des comportements instables.Dans cette thèse, j'ai conçu et mis en œuvre un nouveau protocole pour la Total Order Broadcast uniforme qui optimise la performance lorsqu'il est exécuté dans des environnements multi-Data Centers et le comparer avec plusieurs algorithmes de l'état de l'art.Dans cette thèse, je présente deux contributions. La première contribution est MDC-Cast un nouveau protocole pour Total Order Broadcast dans lesquelles il optimise les performances des systèmes distribués lorsqu'ils sont exécutés dans des environnements multi-centres de données. MDC-Cast combine les avantages de la multidiffusion IP dans les environnements de cluster et unicast TCP/IP pour obtenir un algorithme hybride qui fonctionne parfaitement entre les centres de données.La deuxième contribution est un algorithme conçu pour déboguer les performances dans les systèmes distribués en boîte noire. L'algorithme n'est pas encore publié car il nécessite plus de tests pour une meilleure généralisation
Many uniform total order broadcast protocols have been designed in the last 30 years. They can be classified into two categories: those targeting low latency, and those targeting high throughput. Latency measures the time required to complete a single message broadcast without contention, whereas throughput measures the number of broadcasts that the processes can complete per time unit when there is contention. All the protocols that have been designed so far make the assumption that the underlying network is not shared by other applications running. This is a major concern provided that in modern data centers (aka Clouds), the networking infrastructure is shared by several applications. The consequence is that, in such environments, uniform total order broadcast protocols exhibit unstable behaviors.In this thesis, I provide two contributions. The first contribution is MDC-Cast a new protocol for total order broadcasts in which it optimizes the performance of distributed systems when executed in multi-data center environments. MDC-Cast combines the benefits of IP-multicast in cluster environments and TCP/IP unicast to get a hybrid algorithm that works perfectly in between datacenters.The second contribution is an algorithm designed for debugging performance in black-box distributed systems. The algorithm is not published yet due to the fact that it needs more tests for a better generalization

This thesis reports upon investigations undertaken into the electrical performance of high power subsea transmission cables and is specifically focused upon their harmonic behaviour, an understanding of which is fundamental for developing accurate computer based models to evaluate the performance of existing or new offshore generation schemes. A comprehensive literature search has been undertaken in the areas of offshore generation, offshore power transmission schemes and harmonic performance of subsea cable systems. Subsea cable configurations, types and anatomy are presented to give an appreciation of the arrangement of subsea power cables. Mathematical equations and computer based algorithms have been developed to model subsea transmission system behaviour where the electrical parameters derived from natural physical phenomena such as skin effects, proximity effects and mutual couplings are included. Proximity effect is examined to determine the consequences of whether it needs to be considered for each subsea cable arrangement. Bonding solutions for subsea transmission are investigated to study the effect they have on resonance frequency and harmonic response for different cable lengths. The resulting analysis for various cable arrangements explains how geometric arrangements affect the harmonic impedance and harmonic resonance. The harmonic distortion in HVAC offshore transmission systems is also studied to demonstrate the importance of considering all power components in a subsea power transmission system for harmonic evaluation. In addition, the harmonic distortions of the VSC- HVDC link and associated harmonic power loss are examined. The effects of switching frequency, smoothing capacitor bank size, cable materials and transmission method on harmonic performances of the VSC-HVDC system with varying cable lengths is discussed and therefore subsea power cable harmonic behaviour interacted with subsea transmission systems is investigated. The novel contribution of this work is claimed to be in the development of superior models of subsea cables, transmission schemes and associated performance studies, which should lead to significant improvements over existing models and their results.

Centralized model predictive control (MPC) is often considered impractical, inflexible and unsuitable for controlling large-scale systems due to several factors such as large computational effort and difficulty to meet all operational objectives. Therefore, industrial large-scale systems are usually controlled by a distributed control framework. In this thesis, novel sequential nonlinear Distributed Model Predictive Control (DMPC) algorithms for large-scale systems that can handle constraints are proposed. The proposed algorithms are based on nonlinear MPC strategy, which uses a state-dependent nonlinear model to reduce the complexity of solving optimization problem. In this distributed framework, the overall system is divided into several interconnected subsystems and each subsystem is controlled by local MPC. These local MPCs solve convex optimization problem and exchange information via one directional communication channel at each sampling time to achieve the global performance. The proposed algorithms are applied to an industrial power plant model to improve power generation efficiency. A non-linear dynamic model of Combined Cycle Power Plant (CCPP) using the laws of physics was first developed and simulated using decentralized PID controllers. Then, a supervisory controller using linear constrained MPC was designed to tune the performance of the PID controllers. Next, a supervisory centralized nonlinear model predictive control (NMPC) algorithm based on state-dependent models was developed to control the nonlinear plant over a wide operating range. Finally, two sequential DMPC algorithms based on state-dependent models were developed. The lack of states measurement were handled by designing nonlinear distributed state estimation algorithms using state-dependent differential Riccati equation (SDDRE) Kalman filter. Numerical simulation results show that the performance of the proposed DMPC algorithms is close to the centralized NMPC but computationally more efficient compared to the centralized one.

International Telemetering Conference Proceedings / October 29-November 02, 1990 / Riviera Hotel and Convention Center, Las Vegas, Nevada
Telemetry encoders commonly use programmable memory devices for the storage of data used to control the multiplexed output format. The manual generation of this program control information is tedious and error prone. A telemetry format compiler has been developed to automate this process. A high level definition of the format information is processed to result in a binary object file which is programmed into the memory of the encoder and executed by the state machine controlling the encoding.

This thesis deals with the performance of a Wind Energy Conversion System operating as a power generator and Active Filter simultaneously. As a power generator, the Wind Energy Conversion System converts wind energy into electric energy; as an Active Filter, it sinks the harmonic currents injected by Non-Linear Loads connected at the same feeder. Three control systems are developed to ensure the described operation; a specific study regarding the compensation of the triplen harmonics is carried out; Doubly-Fed Induction Generator derating is defined; and an engineering economic analysis is performed to determine the profitability of the proposed operation. The Wind Energy Conversion System performance as generator and Active Filter has been studied for steady-state analysis, fast transients and low transients. It is concluded that the proposed control systems allow operating the Wind Energy Conversion System as power generator and harmonic compensator both during steady state and transient operation; the described operation causes power loss increase and voltage distortion that determine the choice of the component and require system derating.

To improve photovoltaic system efficiencies, concentrating spectral dividers are used to separate solar light, and to focus each spectral portion onto photovoltaic cells of matching spectral response. In this investigation, an optical analysis is developed to study the feasibility for use of a Fresnel half-lens as a concentrating spectral divider. To facilitate the analysis, an existing curved-base linear Fresnel lens ray-trace model has been modified and expanded. Solar limb-darkening has been incorporated into the theory by means of a digitized sun model. The lens model allows for variation of lens geometrical characteristics. Transmission losses due to Fresnel reflection and bulk absorption are taken into account. The distribution of the concentrated solar flux in the lens image plane is modeled such that spectral regions may be examined separately. Concentration ratio profiles are used to derive and evaluate a quantity of spectral separation.A computer program has been used to generate data, based on the theoretical model, for example lenses. The spectral separation, transmission and concentration properties for each example lens have been systematically studied with respect to lens geometry. The effects of solar limb-darkening are determined by comparison with the data from a model that assumes a uniform solar source. Results of the study are discussed in detail.Ball State UniversityMuncie, IN 47306

The extended finite state machine (EFSM) is a powerful modelling approach that has been applied to represent a wide range of systems. Despite its popularity, testing from an EFSM is a substantial problem for two main reasons: path feasibility and path test case generation. The path feasibility problem concerns generating transition paths through an EFSM that are feasible and satisfy a given test criterion. In an EFSM, guards and assignments in a path‟s transitions may cause some selected paths to be infeasible. The problem of path test case generation is to find a sequence of inputs that can exercise the transitions in a given feasible path. However, the transitions‟ guards and assignments in a given path can impose difficulties when producing such data making the range of acceptable inputs narrowed down to a possibly tiny range. While search-based approaches have proven efficient in automating aspects of testing, these have received little attention when testing from EFSMs. This thesis proposes an integrated search-based approach to automatically test from an EFSM. The proposed approach generates paths through an EFSM that are potentially feasible and satisfy a test criterion. Then, it generates test cases that can exercise the generated feasible paths. The approach is evaluated by being used to test from five EFSM cases studies. The achieved experimental results demonstrate the value of the proposed approach.

Keeping a contingency reserve in power systems is necessary to preserve the security of real-time operations. This work studies two different approaches to the optimal allocation of energy and reserves in the day-ahead generation scheduling process. Part I presents a stochastic security-constrained unit commitment model to co-optimize energy and the locational reserves required to respond to a set of uncertain generation contingencies, using a novel state-based formulation. The model is applied in an offer-based electricity market to allocate contingency reserves throughout the power grid, in order to comply with the N-1 security criterion under transmission congestion. The objective is to minimize expected dispatch and reserve costs, together with post contingency corrective redispatch costs, modeling the probability of generation failure and associated post contingency states. The characteristics of the scheduling problem are exploited to formulate a computationally efficient method, consistent with established operational practices. We simulated the distribution of locational contingency reserves on the IEEE RTS96 system and compared the results with the conventional deterministic method. We found that assigning locational spinning reserves can guarantee an N-1 secure dispatch accounting for transmission congestion at a reasonable extra cost. The simulations also showed little value of allocating downward reserves but sizable operating savings from co-optimizing locational nonspinning reserves. Overall, the results indicate the computational tractability of the proposed method. Part II presents a distributed generation scheduling model to optimally allocate energy and spinning reserves among competing generators in a day-ahead market. The model is based on the coordination between individual generators and a market entity. The proposed method uses forecasting, augmented pricing and locational signals to induce efficient commitment of generators based on firm posted prices. It is price-based but does not rely on multiple iterations, minimizes information exchange and simplifies the market clearing process. Simulations of the distributed method performed on a six-bus test system showed that, using an appropriate set of prices, it is possible to emulate the results of a conventional centralized solution, without need of providing make-whole payments to generators. Likewise, they showed that the distributed method can accommodate transactions with different products and complex security constraints.

Software testing is a tedious and very expensive undertaking. Automatic test data generation is, therefore, proposed in this research to help testers reduce their work as well as ascertain software quality. The concept of test driven development (TDD) has become increasingly popular during the past several years. According to TDD, test data should be prepared before the beginning of code implementation. Therefore, this research asserts that the test data should be generated from the software design documents which are normally created prior to software code implementation. Among such design documents, the UML state machine diagrams are selected as a platform for the proposed automated test data generation mechanism. Such diagrams are selected because they show behaviours of a single object in the system. The genetic algorithm (GA) based approach has been developed and applied in the process of searching for the right amount of quality test data. Finally, the generated test data have been used together with UML class diagrams for JUnit test code generation. The GA-based test data generation methods have been enhanced to take care of parallel path and loop problems of the UML state machines. In addition the proposed GA-based approach is also targeted to solve the diagrams with parameterised triggers. As a result, the proposed framework generates test data from the basic state machine diagram and the basic class diagram without any additional nonstandard information, while most other approaches require additional information or the generation of test data from other formal languages. The transition coverage values for the introduced approach here are also high; therefore, the generated test data can cover most of the behaviour of the system.

Today society is facing numerous challenges associated with energy management system. The centralized power generation system is depending on the fossil fuels to generate energy which is harmful to the environment, and it is unable to fulfill the rising demand for electricity. The decentralized power generation system could easily be integrated with renewable energy sources which could satisfy the growing demand for electricity without damaging the environment. This thesis explores the proper energy distribution system (smart grid) which could be fully equipped with the digitalized technology and be integrated with renewable energy sources and decentralized system. Peer-reviewed articles and government reports have been reviewed in order to get the impact of digitalized technology on overall energy management system, as well as the smart grid services commercialized through the business models. The result shows that the cost of transmission lines is reduced by using decentralized power generation system which helps to provide clean energy at low price to the end consumers. Furthermore, the thesis claims that smart grid is a disruptive technology which encourages energy producers and distributors to adopt a rapid change in the energy market along with changing their business model.  Finally, it has been explored that smart grid could provide three services, such as demand response, integration of renewable energy, and grid to vehicle services. These services could successfully be commercialized through business model innovation which enables energy providing and distributing firms to create and capture value regarding profit.

Thanks for the great support who were involved in the completion of this project.

З моменту утворення станово-представницької монархії в Англії і до сьогодні пройшло досить багато часу, але минуле і до сьогодні має значний вплив на формування сучасного державного апарату будь-якої країни. Яскравим прикладом є Англія у XIII - XV ст., оскільки саме в цей період влада короля була обмежена Вестмінстерським парламентом, який був скликаний Едуардом І в 1272 р. Функції даного парламенту є дещо схожими із сучасними функціями держави.

The first part of this dissertation presents an innovative method for the assessment of generation system reliability. In this method, genetic algorithm (GA) is used as a search tool to truncate the probability state space and to track the most probable failure states. GA stores system states, in which there is generation deficiency to supply system maximum load, in a state array. The given load pattern is then convoluted with the state array to obtain adequacy indices. In the second part of the dissertation, a GA based method for state sampling of composite generation-transmission power systems is introduced. Binary encoded GA is used as a state sampling tool for the composite power system network states. A linearized optimization load flow model is used for evaluation of sampled states. The developed approach has been extended to evaluate adequacy indices of composite power systems while considering chronological load at buses. Hourly load is represented by cluster load vectors using the k-means clustering technique. Two different approaches have been developed which are GA parallel sampling and GA sampling for maximum cluster load vector with series state revaluation. The developed GA based method is used for the assessment of annual frequency and duration indices of composite system. The conditional probability based method is used to calculate the contribution of sampled failure states to system failure frequency using different component transition rates. The developed GA based method is also used for evaluating reliability worth indices of composite power systems. The developed GA approach has been generalized to recognize multi-state components such as generation units with derated states. It also considers common mode failure for transmission lines. Finally, a new method for composite system state evaluation using real numbers encoded GA is developed. The objective of GA is to minimize load curtailment for each sampled state. Minimization is based on the dc load flow model. System constraints are represented by fuzzy membership functions. The GA fitness function is a combination of these membership values. The proposed method has the advantage of allowing sophisticated load curtailment strategies, which lead to more realistic load point indices.

La sophistication grandissante des dispositifs intelligents ultra-portatifs, tels que les smartphones ou les tablettes,crée un besoin d'amélioration des performances des organes de conversion de puissance.La tendance des technologies d'acheminement de puissance évolue progressivement vers une fréquence plus élevée, une meilleure densité d'intégration et une plus grande flexibilité dans les schémas d'asservissement. La modulation dynamique de tension est utilisée dans les circuits intégrés de gestion de puissances(DVS PMICs)des transmetteurs RF alors que la modulation DVFS est utilisée dans les PMICs dédiées au CPUs et GPUs. Des DCDC flexibles et fonctionnant à haute fréquence constituent aujourd'hui la solution principale en conjonction avec des régulateurs à faible marge de tension (LDO).L'évolution vers des solutions à base de HFDCDC de faibles dimensions pose un défi sérieux en matière de 1)stabilité des boucles d'asservissement,2)de complexité des architectures de contrôle imbriquant des machines d'état asynchrones pour gérer une large dynamique de puissance de sortie et 3)de portabilité de la solutions d'une technologie à une autre.Les solutions les plus courantes atteignent aujourd'hui une gamme de 2 à 6 Mhz de fréquence de découpage grâce à l'usage de contrôleurs à hystérésis qui souffrent de la difficulté à contenir la fréquence de découpage lors des variations de la tension ou du courant en charge.Nous avons voulu dans ce travail étendre l'usage des méthodes de conception et de modélisation conventionnelles comme le modèle petit signal moyen, dans une perspective de simplification et de création de modèles paramétriques. L'objectif étant de rendre la technique de compensation flexible et robuste aux variations de procédés de fabrication ou bien aux signaux parasités inhérents à la commutation de puissance.Certes, le modèle moyen petit signal, au demeurant bien traité dans la littérature, réponds amplement à la problématique de compensation des DCDCs notamment quand la stabilité s'appuie sur le zéro naturel à haute fréquence inhérent à la résistance série ESR de la capacité de sortie, mais les HFDCDC actuels utilisent des capacités MLCC ayant une très faible ESR et font appel à des techniques de compensation paramétriques imbriquant le schéma de compensation dans la génération même du rapport cyclique. La littérature existante sur le fonctionnement de la machine d'état, se contente d'une description simpliste de convertisseurs PWM/PFM mais ne donne que très peu d'éléments sur la gestion des opérations synchrones/asynchrones alternant PWM,PFM,écrêtage de courant, démarrage ou détection de défaillance. Dans ce travail, notre études est axée sur les deux aspects suivants:1)La modélisation paramétrique et la compensation de la boucle d'asservissement de HFDCDC et 2)la portabilité de la conception de la machine d'états du contrôleur notamment lorsqu'elle intègre des transitions complexes entre les modes.Dans la première section, nous avons développé un modèle petit signal moyen d'un convertisseur Buck asservi en mode courant-tension et nous l'avons analysé pour faire apparaitre les contributions proportionnelle, intégrale et dérivé dans la boucle. Nous avons démontré la possibilité d'utiliser le retour en courant pour assurer l'amortissement nécessaire et la stabilité de la boucle pour une large dynamique de variations des conditions de charge.Dans la seconde section, nous avons développé une architecture de machine d'états sophistiquée basé sur la méthode d'Huffman avec un effort substantiel d'abstraction que nous a permis de la concevoir en description RTL pour une gestion fiable du fonctionnement asynchrone et temps réel.Notre contribution théorique a fait l'objet d'une réalisation d'un PMIC de test comportant deux convertisseurs Buck cadencés à 12MHz en technologie BiCMOS 0.5um/0.18um. Les performances clefs obtenues sont:une surtension de 50mV pendant 2us suite à l'application d'un échelon de courant de 300mA
The continuous sophistication of smart handheld devices such as smartphones and tablets creates an incremental need for improving the performances of the power conversion devices. The trend in power delivery migrates progressively to higher frequency, higher density of integration and flexibility of the control scheme. Dynamic Voltage Scaling Power Management ICs (DVS PMIC) are now systematically used for powering RF Transmitters and DVFS PMICS using Voltage and Frequency scaling are used for CPUs and GPUs. Flexible High frequency (HF) DC/DC converters in conjunction with low dropout LDOs constitute the main solution largely employed for such purposes. The migration toward high frequency/small size DCDC solutions creates serious challenges which are: 1) the stability of the feedback loop across a wide range of loading voltage and current conditions 2) The complexity of the control and often-non-synchronous state machine managing ultra large dynamics and bridging low power and high power operating modes, 3) The portability of the proposed solution across technology processes.The main stream solutions have so far reached the range of 2 to 6 MHz operation by employing systematically sliding mode or hysteretic converters that suffer from their variable operating frequency which creates EMI interferences and lead to integration problems relative to on-chip cross-talk between converters.In this work we aim at extend the use of traditional design and modeling techniques of power converters especially the average modeling technique by putting a particular care on the simplification of the theory and adjunction of flexible compensation techniques that don't require external components and that are less sensitive to process spread, or to high frequency substrate and supply noise conditions.The Small Signal Average Models, widely treated in the existing literature, might address most needs for system modeling and external compensation snubber design, especially when aiming on the high frequency natural zero of the output capacitor. However, HFDCDC converters today use small size MLCC capacitors with a very low ESR which require using alternative techniques mixing the compensation scheme with the duty cycle generation itself. The literature often provides a simplistic state machine description such as PWM/PFM operations but doesn't cover combined architectures of synchronous / non synchronous mode operations such as PWM, PFM, Current Limit, Boundary Clamp, Start, Transitional and finally Fault or Protection modes.In our work, we have focused our study on two main axes: 1) The parametric modeling and the loop compensation of HFDCDC and 2) the scalability of the control state machine and mode inter-operation. In the first part, we provided a detailed small signal averaged model of the “voltage and current mode buck converter” and we depicted it to emphasize and optimize the contributions of the Proportional, Integral and Derivative feedback loops. We demonstrated the ability to use the current feedback to damp and stabilize the converter with a wide variety of loading conditions (resistive or capacitive). In the second part, we provided architecture of the mode control state machine with different modes like the PWM, PFM, soft-start, current limit,… .The technique we have used is inspired by Huffman machine with a significant effort to make it abstract and scalable. The state machine is implemented using RTL coding based on a generic and scalable approach.The theoretical effort has been implemented inside a real PMIC test-chip carrying two 12MHz buck converters, each employing a voltage and current mode feedback loop. The chip has been realized in a 0.5um / 0.18um BiCMOS technology and tested through a dedicate Silicon validation platform able to test the analog, digital and power sections. The key performance obtained is a 50mV load transient undershoot / overshoot during 2us following a load step of 300mA (slope 0.3A/ns)

Programmable Electronic Medical Systems (PEMS) are safety-critical system. They have effects on people health and, in case of malfunctions, they can seriously compromise human safety. For this reason, the software installed on these devices must be guaranteed through rigorous processes to assure safety and reliability. Moreover, correct operation of a medical device depends upon the controlling software, whose development should adhere to certification standards. The rigorous process presented in this thesis is based on the Abstract State Machines (ASMs) formal method, a mathematically based technique for the specification, analysis and development of software systems. The ASM formal approach proposes an incremental life cycle model for software development based on model refinement. It covers the main software engineering activities (specification, validation, verification, conformance checking), and it is supported by a wide range of tools which are part of the Asmeta (ASM mETAmodeling) framework. In this thesis, the ASM development approach and its supporting Asmeta framework are used to propose a rigorous development process for PEMS. The final goal is to provide a process able to guarantee the development of correct and controllable systems in a correct and controllable way. The definition of this process has leaded to some improvements of the method, mainly regarding the textual and graphical notations, and the automatic code generation from models. A new rigorous notation, Unified Syntax for Abstract State Machine (UASM), has been defined to provide a stable language kernel for ASMs. Formal models are not widely used in practice, since they are considered difficult to develop and understand. For this reason, we here make a proposal of a tool for a graphical representation of ASM models in order to increase the readability. Moreover, we have devised a methodology to generate the desired source code from ASM models. The tool automatically translates the formal specification into the target code (C++ for Arduino in the present case) and it keeps true the system behavior and the properties verified during validation and verification. The hemodialysis machine and the stereoacuity test are used as real case studies to show the applicability and effectiveness of the ASM-based development process in the area of PEMS.

L’intégration de l’énergie éolienne, qui est une ressource renouvelable très utilisée, n’est pas toujours facile pour le micro-réseau urbain. Dans cette thèse, une éolienne urbaine basée sur une machine synchrone à aimants permanents (MSAP) est étudiée pour être intégrée dans un micro-réseau urbain à courant continu. Un état de l'art concernant les énergies renouvelables, les micro-réseaux à courant continu et les stratégies de contrôle de la production d'énergie éolienne, est réalisée. Basé sur un modèle d’éolienne urbaine répondant à la demande du système électrique, qui se compose d’un émulateur de vent et de pales, un MSAP et un convertisseur DC/DC, cette thèse propose des méthodes de poursuite du point de puissance maximale satisfaisant à l’obligation de produire de l’énergie dans la mesure du possible. Une stratégie de contrôle à puissance limitée répond correctement. De simples à complexes, quatre algorithmes MPPT, P&O à pas fixe, P&O à pas variable avec la méthode Newton-Raphson améliorée, P&O à pas variable à base de logique floue et une méthode indirecte de type lookup table, sont étudiés et implémentés pour être comparés à l’aide de trois profils de vitesse du vent. Par expérimentation, les algorithmes MPPT et PLC sont comparés, analysés et discutés. Résumant tous les résultats expérimentaux, la méthode lookup table peut gérer toutes les exigences du mode de fonctionnement MPPT en présentant la meilleure performance, mais, dans le mode de fonctionnement PLC, la P&O à base de logique floue présente les meilleures performances
The integration of the wind power, which is one mostly used renewable resource, is always one challenger for urban microgrid. In this thesis, one urban wind turbine based on a permanent magnet synchronous machine (PMSM) is studied in order to be integrated into a DC urban microgrid. A state of the art concerning the renewable energies, DC microgrid, and control strategies of wind power generation is done. Based on a model of urban wind turbine fitting the demand of urban electric system, which consists of an emulator of wind speed and blades, a PMSM and a DC/DC converter, this thesis proposes the maximum power point tracking (MPPT) methods satisfying the requirement of producing energy as much as possible, and power limited control (PLC) strategies answering the demand of flexible energy production. From simple to complex, four MPPT algorithms including Perturbation and Observation (P&O) fixed step-size method, P&O with improved Newton-Raphson method, P&O with fuzzy logic method and lookup table method are studied and implemented to be compared with each other using three wind velocity profiles. According to the experience about MPPT subject, four PLC algorithms are introduced and implemented to be analyzed and compared with each other with one power demand profile calculated randomly. Summarizing all experimental results, the lookup table method can handle all requirement of MPPT operating mode supplying the best performance, however, in the condition of more flexible power demand operating mode, the combination of P&O and fuzzy logic method presents the best performance and potential which can be achieved in future works

Les systèmes intégrés sont souvent des systèmes hétérogènes avec des contraintes fortes de consommation électrique. Ils embarquent aujourd'hui des actionneurs, des capteurs et des unités pour le traitement du signal. Afin de limiter l'énergie consommée, ils peuvent tirer profit des techniques évènementielles que sont l'échantillonnage non uniforme et l'électronique asynchrone. En effet, elles permettent de réduire drastiquement la quantité de données échantillonnées pour de nombreuses classes de signaux et de diminuer l'activité. Pour aider les concepteurs à développer rapidement des plateformes exploitant ces deux techniques évènementielles, nous avons élaboré un flot de conception nommé ALPS. Il propose un environnement permettant de déterminer et de simuler au niveau algorithmique le schéma d'échantillonnage et les traitements associés afin de sélectionner les plus efficients en fonction de l'application ciblée. ALPS génère directement le convertisseur analogique/numérique à partir des paramètres d'échantillonnage choisis. L'élaboration de la partie de traitement s'appuie quant à elle sur un outil de synthèse de haut niveau synchrone et une méthode de désynchronisation exploitant des protocoles asynchrones spécifiques, capables d'optimiser la surface et la consommation du circuit. Enfin, des simulations au niveau porteslogiques permettent d'analyser et de valider l'énergie consommée avant de poursuivre par un flot classique de placement et routage. Les évaluations conduites montrent une réduction d'un facteur 3 à 8 de la consommation des circuits automatiquement générés. Le flot ALPS permet à un concepteur non-spécialiste de se concentrer sur l'optimisation de l'échantillonnage et de l'algorithme en fonction de l'application et de potentiellement réduire d'un ou plusieurs ordres de grandeur la consommation du circuit
Integrated systems are mainly heterogeneous systems with strong powerconsumption constraints. They embed actuators, sensors and signalprocessing units. To limit the energy consumption, they can exploitevent-based techniques, namely non-uniform sampling and asynchronouscircuits. Indeed, they allow cutting drastically the amount of sampleddata for many types of signals and reducing the system activity. To helpdesigners in quickly developing platforms that exploit those event-basedtechniques, we elaborated a design framework called ALPS. It proposes anenvironment to determine and simulate at algorithmic level the samplingscheme and the associated processing in order to select the mostefficient ones depending on the targetted application. ALPS generatesdirectly the analog-to-digital converter based on the chosen samplingparameters. The elaboration of the processing unit uses a synchronoushigh-level synthesis tool and a desynchronization method that exploitsspecific asynchronous protocols to optimize the circuit area and powerconsumption. Finally, gate-level simulations allow analyzing andvalidating the energy consumption before continuing with a standardplacement and routing flow. The conducted evaluations show a reductionfactor of 3 to 8 of the consumption of the automatically generatedcirctuis. The flow ALPS allow non-specialists to concentrate on theoptimization of the sampling and the processing in function of theirapplication and to reduice the circuit power consumptions by one toseveral orders of magnitude

This Master´s thesis deals with problematics related to the connection of new decentralized power sources into electrical power grid. Due to advantageous legislative support of these new, especially photovoltaic power sources, a massive amount of these sources have been connected into the power grid between years 2009 and 2010. For theoretical understanding of processes during a steady-state, the initial parts of this paper are focused on a procedure which solves steady-state on every power line mentioned. When we speak of decentralized power sources connection, it is necessary to mention the connected legislative. National distribution grid operators in collaboration with national regulatory commission have decided on a legislative document Rules of distribution grid operation, which puts a set of demands and requirements on applicants wishing to connect a new power source to the grid. The text of this thesis is focused mainly on demands required after the latest change in 1/2010. Practical part of this work deals with verification of new power source influence on a related power grid and meeting the legislatively required demands. The most important demands are voltage change due to new power source operation and its transfer to other voltage levels, higher harmonics injection, power output fluctuation and last, not least, changes in load flow directions. For reasons previously mentioned an analysis is made and possibilities of reducing or removing of these influences are introduced. To achieve these goals, two computer programs, Siemens Sinaut Spectrum and NetCalc are used.

With the increase in the level of global warming, renewable energy based distributed generators (DGs) will increasingly play a dominant role in electricity production. Distributed generation based on solar energy (photovoltaic and solar thermal), wind, biomass, mini-hydro along with use of fuel cells and micro turbines will gain considerable momentum in the near future. A microgrid consists of clusters of load and distributed generators that operate as a single controllable system. The interconnection of the DG to the utility/grid through power electronic converters has raised concern about safe operation and protection of the equipments. Many innovative control techniques have been used for enhancing the stability of microgrid as for proper load sharing. The most common method is the use of droop characteristics for decentralized load sharing. Parallel converters have been controlled to deliver desired real power (and reactive power) to the system. Local signals are used as feedback to control converters, since in a real system, the distance between the converters may make the inter-communication impractical. The real and reactive power sharing can be achieved by controlling two independent quantities, frequency and fundamental voltage magnitude. In this thesis, an angle droop controller is proposed to share power amongst converter interfaced DGs in a microgrid. As the angle of the output voltage can be changed instantaneously in a voltage source converter (VSC), controlling the angle to control the real power is always beneficial for quick attainment of steady state. Thus in converter based DGs, load sharing can be performed by drooping the converter output voltage magnitude and its angle instead of frequency. The angle control results in much lesser frequency variation compared to that with frequency droop. An enhanced frequency droop controller is proposed for better dynamic response and smooth transition between grid connected and islanded modes of operation. A modular controller structure with modified control loop is proposed for better load sharing between the parallel connected converters in a distributed generation system. Moreover, a method for smooth transition between grid connected and islanded modes is proposed. Power quality enhanced operation of a microgrid in presence of unbalanced and non-linear loads is also addressed in which the DGs act as compensators. The compensator can perform load balancing, harmonic compensation and reactive power control while supplying real power to the grid A frequency and voltage isolation technique between microgrid and utility is proposed by using a back-to-back converter. As utility and microgrid are totally isolated, the voltage or frequency fluctuations in the utility side do not affect the microgrid loads and vice versa. Another advantage of this scheme is that a bidirectional regulated power flow can be achieved by the back-to-back converter structure. For accurate load sharing, the droop gains have to be high, which has the potential of making the system unstable. Therefore the choice of droop gains is often a tradeoff between power sharing and stability. To improve this situation, a supplementary droop controller is proposed. A small signal model of the system is developed, based on which the parameters of the supplementary controller are designed. Two methods are proposed for load sharing in an autonomous microgrid in rural network with high R/X ratio lines. The first method proposes power sharing without any communication between the DGs. The feedback quantities and the gain matrixes are transformed with a transformation matrix based on the line R/X ratio. The second method involves minimal communication among the DGs. The converter output voltage angle reference is modified based on the active and reactive power flow in the line connected at point of common coupling (PCC). It is shown that a more economical and proper power sharing solution is possible with the web based communication of the power flow quantities. All the proposed methods are verified through PSCAD simulations. The converters are modeled with IGBT switches and anti parallel diodes with associated snubber circuits. All the rotating machines are modeled in detail including their dynamics.

Nous proposons dans cette thèse les approches de test pour la composition de services web. Nous nous intéressons aux test unitaire et d’intégration d’une orchestration de services web. L’aspect de vérification d’exécution en-ligne est aussi consideré. Nous définissons une plateforme de test unitaire pour l’orchestration de services web qui compose une architecture de test, une relation de conformité et deux approches de test basés sur le modèle de machine à l’états finis étendues temporisés: l’approche offline où les activités de test comme la génération de cas de test temporisé, l’exécution de test et l’assignement de verdict sont appliquées en séquentielle tandis que ces activités sont appliquées en parallèle dans l’approche online. Pour le test d’intégration d’une orchestration, nous combinons deux approches: active et passive.Au debut, l’approche active est utilisée pour activer une nouvelle session d’orchestration par l’envoi d’un message de requête SOAP. Après, tous les messages d’entré et de sortie de l’orchestration sont collectés et analysés par l’approche passive.Pour l’aspect de vérification d’exécution en-ligne, nous nous intéressons à la vérification d’une trace qui respecte un ensemble des constraintes, noté règles, ou pas. Nous avons proposé extendre le langage Nomad en définissant des constraintes sur chaque action atomique et un ensemble de corrélation de données entre les actions pour définir des règles pour le service web. Ce langage nous permet de définir des règles avec le temps futur et passé, et d’utiliser des opérations NOT, AND, OR pour combiner quelque conditions dans le contexte de la règle. Ensuite, nous proposons un algorithme pour vérifier l’exactitude d’une séquence des messages en parallèle avec le moteur de collecte de trace
In this thesis, we propose the testing approaches for web service composition. We focus on unit, integrated testing of an orchestration of web services and also the runtime verification aspect. We defined an unit testing framework for an orchestration that is composed of a test architecture, a conformance relation and two proposed testing approaches based on Timed Extended Finite State Machine (TEFSM) model: offline which test activities as timed test case generation, test execution and verdict assignment are applied in sequential, and online which test activities are applied in parallel. For integrated testing of an orchestration, we combines of two approaches: active and passive. Firstly, active approach is used to start a new session of the orchestration by sending a SOAP request. Then all communicating messages among services are collected and analyzed by a passive approach. On the runtime verification aspect, we are interested in the correctness of an execution trace with a set of defined constraints, called rules. We have proposed to extend the Nomad language, by defining the constraints on each atomic action (fixed conditions) and a set of data correlations between the actions to define the rules for web services. This language allows us to define a rule with future and past time, and to use the operations: NOT, AND, OR to combines some conditions into a context of the rule. Afterwards, we proposed an algorithm to check correctness of a message sequence in parallel with the trace collection engine. Specifically, this algorithm verifies message by message without storing them

Orientador: Júlio Borges de Souza
Resumo: O transformador de estado sólido tem se apresentado como uma ferramenta indispensável na construção das novas redes elétricas inteligentes, uma vez que essa nova estrutura de rede altera o layout tradicional, viabilizando a conexão de fontes de energia descentralizadas. Contudo, essa conexão de sistemas de geração distribuída na rede originou a bidirecionalidade do fluxo de potência, resultando em um novo panorama para as atividades de operação e manutenção das redes para as distribuidoras de energia. A análise dos possíveis impactos técnicos gerados na rede de distribuição deve ser realizada, com o intuito de garantir um nível de qualidade energética dentro dos padrões estabelecidos pela Agência Nacional de Energia Elétrica – ANEEL. Dentre os impactos, destacam-se a elevação do nível de tensão e a alteração do fator de potência, ambos, produzidos pelo excesso de potência injetada na rede por este novo cenário de geração de energia. Nesse contexto, esta dissertação tem como principal objetivo analisar o comportamento de uma rede de distribuição genérica com penetração de geração distribuída e avaliar o perfil de tensão diante de diferentes níveis de inserção dessa geração na rede. As características de ajuste de tensão instantânea e capacidade de interação com sistemas de armazenamento que o transformador de estado sólido possui foram empregadas no auxílio da regulação dos níveis de tensão que se apresentaram fora dos padrões determinados pela resolução 794/2018 da ANEEL, qua... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: The solid state transformer has been presented as an essential tool in the construction of new intelligent electric grids, since this new network structure changes the traditional layout, making possible the connection of decentralized energy sources. However, this connection of distributed generation systems in the network created the bidirectionality of the power flow, resulting in a new panorama for the power distributors concerning the networks activities of operation and maintenance. The analysis of the possible technical impacts generated in the distribution network should be carried out with the purpose of guaranteeing a level of energy quality within the standards established by the National Electric Energy Agency (ANEEL). Among the impacts, we highlight the elevation of the voltage level and the change in the power factor, both produced by the excess power injected into the grid by this new energy generation scenario. In this context, the main objective of this dissertation is to analyze the behavior of a generic distribution network with distributed generation penetration and to evaluate the voltage profile before different levels of insertion of this generation in the network. The solid state transformer has instantaneous voltage adjustment characteristics and interaction capacity with storage systems, which were used to aid in the regulation of voltage levels that were out of the standards determined by ANEEL resolution 794/2018, when a high level of distributed g... (Complete abstract click electronic access below)
Mestre

Este trabalho apresenta uma estratégia de controle coordenado para potência reativa e tensão terminal de um grupo moto gerador (GMG) para uso em um sistema de geração distribuída (GD). A partir da construção de uma superfície fuzzy, baseada no comportamento do erro e da derivada do erro de uma malha de controle, foi realizada a sintonia de controladores fuzzy PD+I para potências ativa e reativa e tensão terminal. O controlador coordenado fuzzy PD+I ajusta automaticamente a tensão nos terminais da máquina e a potência reativa fornecidas à rede de distribuição. A estratégia coordenada é dada através de um parâmetro que regula a malha de potência reativa a partir do erro de tensão terminal, priorizando o ajuste da tensão e ponderando a malha de controle de potência reativa. Para avaliar o desempenho do sistema de controle, a GD é conectada a uma rede de distribuição e submetida a eventos como entrada e saída de cargas locais. O conjunto de cargas locais é composto por um motor de indução, uma carga RLC e um retificador trifásico não controlado. Sete cenários foram simulados para avaliar a estratégia de controle em diferentes regimes de operação do GMG. Resultados para tensão terminal, fator de potência e fluxo de potências entre o sistema, as cargas e a rede, ilustram a eficiência da estratégia de controle apresentada. A estratégia de controle coordenado para potência reativa e tensão terminal se mostrou capaz de melhorar os índices de fator de potência controlando o fluxo de potência do barramento em que a GD estava conectada, sem prejudicar a tensão terminal do gerador, mantendo a GD em limites seguros de operação.
This work presents a coordinated control strategy to terminal voltage and reactive power for a diesel generation set used as a distributed gerenation system (DG). From desired control actions, a fuzzy surface was designed for fuzzy PD+I controllers. Fuzzy PD+I controllers automatically adjust the terminal voltage and the reactive power delivered to the grid. The coordinated control strategy weighs the control action for the reactive power through a variable parameter, prioritizing the terminal voltage adjustment. To illustrate the system control performance, the DG is connected to a grid dynamic model and the system is subjected to connection and disconnection of loads at the local bus. The local loads set was composed of an induction machine, a RLC load and an uncontrolled three-phase rectifier. Seven scenarios were simulated to evaluate the control strategy in different DG regime of operation. Results for terminal voltage, power factor and reactive power among the DG, the local loads and the grid, illustrates the control strategy efficiency improved the power factor by regulating the reactive power injected at the bus, maintaining the DG terminal voltage in safe operation limits.

A Arquitetura Orientada a Serviços (SOA) é um estilo arquitetural formado por um conjunto de restrições que visa promover a escalabilidade e a flexibilidade de um sistema, provendo suas funcionalidades como serviços. Nos últimos anos, um estilo alternativo foi proposto e amplamente adotado, que projeta as funcionalidades de um sistema como recursos. Este estilo arquitetural orientado a recursos é chamado de REST. O teste de serviços web em geral apresenta vários desafios devido a sua natureza distribuída, canal de comunicação pouco confiável, baixo acoplamento e a falta de uma interface de usuário. O teste de serviços RESTful (serviços que utilizam o REST) compartilham estes mesmos desafios e ainda necessitam que suas restrições sejam obedecidas. Estes desafios demandam testes mais sistemáticos e formais. Neste contexto, o teste baseado em modelos (TBM) se apresenta como um processo viável para abordar essas necessidades. O modelo que representa o sistema deve ser simples e ao mesmo tempo preciso para que sejam gerados casos de teste com qualidade. Com base nesse contexto, este projeto de mestrado propõe uma abordagem baseada em modelos para testar serviços RESTful. O modelo comportamental adotado foi a máquina de estados de protocolos UML, capaz de formalizar a interface do serviço enquanto esconde o seu funcionamento interno. Uma ferramenta foi desenvolvida para gerar automaticamente os casos de teste usando critérios de cobertura de estados e transições para percorrer o modelo
Service Oriented Architecture (SOA) is an architectural style consisting of a set of restrictions aimed at promoting the scalability and flexibility of a system, providing its functionalities as services. In recent years, an alternative style was proposed and widely adopted, which designs the system\'s functionalities as resources. This resource oriented architectural style is called REST. In general, the test of web services has several challenges due to its distributed nature, unreliable communication channel, low coupling and the lack of a user interface. Testing RESTful web services (services that use REST) share these same challenges and also need to obey the REST constraints. These challenges require a more systematic and formal testing approach. In this context, model based testing presents itself as a viable process for addressing those needs. The model that represents the system should be simple and precise enough to generate quality test cases. Based on this context, this work proposes a model based approach to test RESTful web services. The behavioral model used was the UML protocol state machine, which is capable to provide a formalization of the service interface, while hiding its internal behaviour. A tool was developed to automatically generate test cases using the state and transition coverage criteria to traverse the model

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CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Neste trabalho são propostas duas formulações de importantes ferramentas para análise de redes em regime permanente, onde são consideradas equações que descrevem o comportamento do controle primário e secundário de frequência em sistemas elétricos de potência. A primeira proposta é baseada em uma formulação do problema de fluxo de potência convencional e a segunda uma formulação do fluxo de potência ótimo. A formulação de fluxo de potência proposta é desenvolvida a partir de uma metodologia genérica de representação de dispositivos de controle. Esta metodologia consiste em incorporar as equações que modelam dispositivos de controle ao problema básico de fluxo de potência em coordenadas polares, formando um sistema de equações de ordem (2nb+nc). O fluxo de potência desenvolvido é capaz de estimar os desvios de frequência do sistema devido a uma perturbação da carga. Por outro lado, o fluxo de potência ótimo proposto é capaz de identificar montantes e locais de corte carga, de forma a manter a frequência do sistema em uma faixa aceitável de operação. A formulação proposta de FPO consiste em incluir no problema equações de igualdade e desigualdade associadas com o controle primário de frequência e geração de potência ativa. Os desenvolvimentos propostos para o fluxo de potência convencional foram implementados no ambiente MatLab®. Para solução do fluxo de potência ótimo utilizou-se um pacote comercial de otimização, denominado LINGO®. A avaliação do fluxo de potência e fluxo de potência ótimo propostos é feita através do estudo de sistemas tutoriais e do sistema New England. A validação da análise de desvios de frequência é feita através da utilização do programa ANATEM, desenvolvido pelo CEPEL. Os resultados obtidos mostram as vantagens da utilização das formulações propostas.
This work proposes a new formulation for both the conventional power flow and the optimal power flow formulation, in which the steady-state equations describing the primary and secondary frequency control in electrical power systems are included. The proposed power flow formulation is based on a flexible methodology for the representation of control devices. Such methodology incorporates equations that model control devices into the basic power flow formulation in polar coordinates, generating an augmented system of equations having order (2nb + nc). The developed power flow is able to estimate the system frequency deviation due to a load disturbance. On other hand, the proposed optimum power flow formulation is able to identify the minimum load shedding necessary to maintain the system frequency in an acceptable range of operation. The proposed OPF formulation includes additional equality and inequality constraints to represent the steady state primary frequency control as a function of the active power generation. The proposed development for the conventional power flow was made using the MATLAB® environment. The optimal power flow solution used a commercial optimization package called LINGO®. The evaluation of the proposed power flow and optimal power flow formulations were made through the study of small test systems and the New England test system. Validations of the frequency deviation analysis were made using the program ANATEM, developed by CEPEL. The results obtained show the advantages of using the proposed formulations.

Model-Based Software Engineering (MBSE) a été proposé comme une méthodologie prometteuse de développement de logiciels pour surmonter les limites de la méthodologie traditionnelle basée sur la programmation pour faire face à la complexité des systèmes embarqués. MBSE favorise l’utilisation de langages de modélisation pour décrire les systèmes d’une manière abstraite et fournit des moyens pour générer automatiquement de différents artefacts de développement, p.ex. code et documentation, à partir de modèles. Le développement d’un système complexe implique souvent de multiples intervenants qui utilisent différents outils pour modifier les artefacts de développement, le modèle et le code en particulier dans cette thèse. Les modifications apportées aux artefacts évoquent le problème de cohérence qui nécessite un processus de synchronisation pour propager les modifications apportées dans l’un artefact aux autres artefacts. Dans cette étude, le problème de la synchronisation des modèles d’architecture basés sur les éléments UML composite structure (UML-CS) et UML state machine (UML-SM) du langage de l’Unified Modeling Language (UML), et le code orienté objet est présenté. UML-CSs sont utilisés pour décrire l’architecture du logiciel basée sur les composants et UML-SMs pour les comportements discrets liés aux événements des systèmes réactifs. Le premier défi est de permettre une collaboration entre les architectes de logiciels et les programmeurs produisant de modèle et de code, en utilisant différents outils. Il soulève le problème de synchronisation où il existe de modifications simultanées des artefacts. En fait, il existe un écart de perception entre les langages à base de diagramme (langages de modélisation) et les langages textuels (langages de programmation). D’une part, les programmeurs préfèrent souvent utiliser la combinaison familière d’un langage de programmation et d’un environnement de développement intégré. D’autre part, les architectes logiciels, travaillant à des niveaux d’abstraction plus élevés, favorisent l’utilisation des modèles et préfèrent donc les langages à base de diagramme pour décrire l’architecture du système. Le deuxième défi est qu’il existe un écart d’abstraction significatif entre les éléments du modèle et les éléments du code: les éléments UML-CS et UML-SM sont au niveau d’abstraction plus élevé que les éléments du code. L’écart rend la difficulté pour les approches de synchronisation actuelles car il n’y a pas de façon facile de réflecter les modifications du code au modèle. Cette thèse propose une approche automatisée de synchronisation composée de deux principales contributions corrélées. Pour aborder le premier défi, on propose un patron méthodologique générique de synchronisation entre modèle et code. Il consiste en des définitions des fonctionnalités nécessaires et plusieurs processus qui synchronisent le modèle et le code en fonction de plusieurs scénarios définis où les développeurs utilisent différents outils pour modifier le modèle et le code. Cette contribution est indépendante de UML-CSs et UML-SMs. La deuxième contribution traite du deuxième défi et est basée sur les résultats de la première contribution. Dans la deuxième contribution, un mapping bidirectionnel est présentée pour réduire l’écart d’abstraction entre le modèle et le code. Le mapping est un ensemble de correspondances entre les éléments de modèle et ceux de code. Il est utilisé comme entrée principale du patron méthodologique générique de synchronisation entre modèle et code. Plus important, l’utilisation du mapping fournit les fonctionnalités définies dans la première contribution et facilite la synchronisation des éléments de UML-CS et UML-SM et du code. L’approche est évaluée au moyen de multiples simulations et d’une étude de cas
Model-Based Software Engineering (MBSE) has been proposed as a promising software development methodology to overcome limitations of traditional programming-based methodology in dealing with the complexity of embedded systems. MBSE promotes the use of modeling languages for describing systems in an abstract way and provides means for automatically generating different development artifacts, e.g. code and documentation, from models. The development of a complex system often involves multiple stakeholders who use different tools to modify the development artifacts, model and code in particular in this thesis. Artifact modifications must be kept consistent: a synchronization process needs to propagate modifications made in one artifact to the other artifacts. In this study, the problem of synchronizing Unified Modeling Language (UML)-based architecture models, specified by UML composite structure (UML-CS) and UML state machine (UML-SM) elements, and object-oriented code is presented. UML-CSs are used for describing the component-based software architecture and UML-SMs for discrete event-driven behaviors of reactive systems. The first challenge is to enable a collaboration between software architects and programmers producing model and code by using different tools. This raises the synchronization problem of concurrent artifact modifications. In fact, there is a perception gap between diagram-based languages (modeling languages) and text-based languages (programming languages). On the one hand, programmers often prefer to use the more familiar combination of a programming language and an Integrated Development Environment. On the other hand, software architects, working at higher levels of abstraction, tend to favor the use of models, and therefore prefer diagram-based languages for describing the architecture of the system. The second challenge is that there is a significant abstraction gap between the model elements and the code elements: UML-CS andUML-SM elements are at higher level of abstraction than code elements. The gap makes current synchronization approaches hard to be applied since there is no easy way to reflect modifications in code back to model. This thesis proposes an automated synchronization approach that is composed of two main correlated contributions. To address the first challenge, a generic model-code synchronization methodological pattern is proposed. It consists of definitions of necessary functionalities and multiple processes that synchronize model and code based on several defined scenarios where the developers use different tools to modify model and code. This contribution is independent of UML-CSs and UML-SMs. The second contribution deals with the second challenge and is based on the results from the first contribution. In the second contribution, a bidirectional mapping is presented for reducing the abstraction gap between model and code. The mapping is a set of correspondences between model elements and code elements. It is used as main input of the generic model-code synchronization methodological pattern. More importantly, the usage of the mapping provides the functionalities defined in the first contribution and eases the synchronization of UML-CS and UML-SM elements and code. The approach is evaluated by means of multiple simulations and a case study

The main goal of this thesis is to design control board for the experimental electroporation device and to develop control firmware. The first chapter of this work focuses on the electroporation phenomenon itself. Behaviour of the cell model in external electrical field is described there as well as simulation and overview of how electroporation affects living tissue. It also explains the main requirements for parameters of the electroporation pulses as well as need for ECG synchronization. Furthermore, some remarks are given about novel high frequency electroporation method, which involves use of nanosecond bipolar high voltage pulse bursts. The second chapter briefly introduces commercial electroporation device called Nanoknife, including control part, power part, and it's limits. The third chapter consists of introduction of the novel experimental electroporation device developed at BUT. Power part of this device is discussed as well. Next chapter focuses on design of the control board for this device and also on description of the particular schematic parts. There is a control algorithm explanation in the fifth chapter of this thesis followed by the brief manual to machine operation.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
This work aims to analyze the dynamic performance of a synchronous generator and its controls in a distributed generation system, as well as evaluate the impacts of its operation when connected to the distribution grid, using for this task the ATPDraw interface/tool of software ATP. Within this context, it is firstly necessary to obtain suitable models to represent the synchronous machine control systems (voltage regulator, speed governor and stabilizer system) in ATPDraw. Furthermore, for stability analysis, it is developed a mathematical technique to calculate the machine power angle which is represented in ATPDraw by a device (icon). The adjustments of voltage and speed control system parameters are performed by some adopted procedures which are verified using two electric systems: the first one with a synchronous generator connected to the distribution grid; and the second with three distinct generators forming a multimachine system. In these systems some disturbances are applied such as load shedding and short-circuit to accomplish the studies. Finally, with the previous results, it is carried out some dynamic performance studies of a synchronous generator of an independent producer connected to a distribution grid so as to assess aspects of power quality (voltage magnitude), stability and to evaluate the influence of machine controls during the system response for a given load shedding.
Este trabalho tem como objetivo analisar o desempenho dinâmico de um gerador síncrono e seus controles, num sistema de geração distribuída, assim como avaliar os impactos causados por este quando da sua operação conectado às redes de distribuição, utilizando a interface ATPDraw do software ATP. Neste contexto, é primeiramente necessário obter modelos adequados para representar os sistemas de controle da máquina síncrona (regulador de tensão e regulador de velocidade e estabilizador do sistema) no ATPDraw. Além disso, para análise de estabilidade é desenvolvido uma técnica matemática para o cálculo do ângulo de potência da máquina a qual é representada no ATPDraw por um dispositivo (ícone). Para ajustar os parâmetros dos sistemas de controle de tensão e de velocidade são apresentados alguns procedimentos adotados, sendo estes verificados por meio de dois sistemas elétricos: o primeiro com um gerador síncrono conectado a uma rede de distribuição; e o segundo composto por três geradores distintos formando um sistema multimáquinas. Nesses sistemas são aplicados distúrbios do tipo rejeição de carga e curto-circuito para realização dos estudos. Finalmente, com os resultados obtidos anteriormente, são realizados estudos do desempenho dinâmico de um gerador síncrono de um produtor independente, conectado a rede de distribuição, para avaliar aspectos de qualidade de energia (magnitude de tensão), de estabilidade e verificar as influências dos controles da máquina durante a resposta do sistema para uma dada rejeição de carga.
Mestre em Ciências

Establishing and maintaining successful communication stands as a critical prerequisite for achieving the goals of inducing and studying advanced computation in small-scale living neuronal networks. The following work establishes a novel and effective method for communicating arbitrary "sensory" input information to cultures of living neurons, living neuronal networks (LNNs), consisting of approximately 20 000 rat cortical neurons plated on microelectrode arrays (MEAs) containing 60 electrodes. The sensory coding algorithm determines a set of effective codes (symbols), comprised of different spatio-temporal patterns of electrical stimulation, to which the LNN consistently produces unique responses to each individual symbol. The algorithm evaluates random sequences of candidate electrical stimulation patterns for evoked-response separability and reliability via a support vector machine (SVM)-based method, and employing the separability results as a fitness metric, a genetic algorithm subsequently constructs subsets of highly separable symbols (input patterns). Sustainable input/output (I/O) bit rates of 16-20 bits per second with a 10% symbol error rate resulted for time periods of approximately ten minutes to over ten hours. To further evaluate the resulting code sets' performance, I used the system to encode approximately ten hours of sinusoidal input into stimulation patterns that the algorithm selected and was able to recover the original signal with a normalized root-mean-square error of 20-30% using only the recorded LNN responses and trained SVM classifiers. Response variations over the course of several hours observed in the results of the sine wave I/O experiment suggest that the LNNs may retain some short-term memory of the previous input sample and undergo neuroplastic changes in the context of repeated stimulation with sensory coding patterns identified by the algorithm.

The present thesis focuses on two appealing paradigms that are expected to characterize the next generation of communication systems: microfluidic networking and Machine to Machine (M2M) Communications. Concerning the former topic, we show how it is possible to introduce switching and routing mechanism in microfluidic systems. We define some simple mathematical models that capture the macroscopic behavior of droplets in microfluidic networks. Then, we use them to implement a simulator that is able to reproduce the motion and predict the path of droplets in a generic microfluidic system. We validate the simulator and apply it to design a network with bus topology. Finally, we prove the feasibility of attaining molecular communication in this domain by describing a simple protocol that exploits droplets length/interdistance modulation to send information. The research activity on M2M, instead, is aimed at the investigation of two critical issues that are expected to affect Machine-Type Communication (MTC), i.e. energy efficiency and massive access. Regarding energy efficiency, we address the problem of delivering a fixed data payload over a Rayleigh fading wireless channel with the purpose of minimizing the average total energy cost, given by the sum of the transmit energy and an overhead circuit energy, to complete it. This scenario is well suited for uplink cellular MTC in future 5G Internet of Things (IoT) use cases, where the focus is more on device energy efficiency than on throughput. We describe the optimal transmission policies to be used under various coordinated access scenarios with different levels of channel state information and transmitter/receiver capabilities, and show the corresponding theoretical bounds. In the last part of the work, we study the asymptotic performance of uncoordinated access schemes with Multi Packet Reception (MPR) and Successive Interference Cancellation (SIC) techniques for contention resolution at the receiver. The corresponding results in terms of throughput in a massive access M2M scenario are finally evaluated and discussed.
La presente tesi si focalizza sullo studio di due importanti paradigmi che si prevede possano caratterizzare i sistemi di comunicazione di prossima generazione: le reti microfluidiche e le comunicazioni Machine to Machine (M2M). Riguardo alle reti microfluidiche, in questo lavoro illustriamo come sia possibile introdurre elementi di switch e meccanismi di routing all’interno di sistemi microfluidici. Definiamo poi alcuni semplici modelli matematici che descrivono il comportamento macroscopico di gocce all’interno di tali reti. Questi ultimi sono quindi sfruttati per implementare un simulatore che è capace di riprodurre il movimento e predire il percorso delle gocce in un generico sistema microfluidico. Dopo averlo validato sperimentalmente, il simulatore è impiegato per progettare una rete microfluidica con topologia a bus. Infine, viene dimostrato come sia possibile realizzare comunicazioni molecolari in questo ambito tramite la formalizzazione e la descrizione di un protocollo che sfrutta la modulazione della lunghezza/interdistanza delle gocce per trasferire informazione. L’attività di ricerca in merito alle comunicazioni M2M, invece, è finalizzata allo studio di due importanti criticità insite nelle Machine-Type Communications (MTCs), ovvero l’efficienza energetica e l’accesso simultaneo di massa (massive access). Per quanto concerne l’efficienza energetica, viene affrontato il problema di trasmettere un payload di una certa lunghezza fissata attraverso un canale wireless affetto da Rayleigh fading con lo scopo di minimizzare il costo totale medio dell’utente finale, dato dalla somma dell’energia di trasmissione e di quella di circuito, per completare l’operazione. Tale scenario ben si applica al contesto di trasmissioni cellulari per applicazioni di tipo IoT nelle future reti 5G, dove l’attenzione è rivolta maggiormente all’efficienza energetica dei dispositivi rispetto al throughput, in quanto le UE hanno tipicamente capacità computazionali ed energetiche esigue e si limitano ad inviare sporadicamente pacchetti molto brevi. Vengono quindi descritte le strategie ottime di trasmissione da adottare in un contesto di accesso coordinato a seconda del livello di dettaglio sulle informazioni di canale e delle potenzialità di trasmettitore/ricevitore, illustrando i corrispondenti limiti teorici. Nell’ultima parte del lavoro vengono studiate le prestazioni asintotiche di schemi di accesso non coordinati quando si utilizzano tecniche di Multi Packet Reception (MPR) e Successive Interference Cancellation (SIC) per la risoluzione delle collisioni al ricevitore. I risultati corrispondenti, in termini di throughput, per uno scenario M2M con massive access sono infine ricavati e discussi.

This thesis deals with the analysis, design and test of three-phase high efficiency electrical motors, with particular reference to motors with a rotor winding. At first, the background and the motivations of this work are described. The bibliography on the subjects is deeply examined and a selection of the most relevant papers can be found in the reference. In this scenario, the main objective of this thesis are illustrated. The Line-Start (LS) Synchronous Machine (SyM) design is a subject under investigation since the beginning of the last century, when solid state power converters was not available to drive SyMs. The LS SyM diffusion was limited by the intrinsic difficulties in its design and by the availability of the cheaper and more robust Induction Machine (IM). The working principle of IM and LS SyM are briefly described, as well as the state of the art of the techniques of analysis. Recently, there is a renewed interest on LS SyMs due to the new efficiency requirements and fast analysis techniques are required for the LS SyM design. A Finite-Element (FE) aided analytical model is developed to simulate the LS SyM dynamic. The aim is to develop a model that gives reliable solutions with limited computational efforts compared with other analysis techniques. With this procedure, the LS SyM rotor parameters can be quickly calibrated to fulfill the dynamic load requirements. An innovative analysis technique of LS SyM steady state condition is described. Such an analysis is carried out in the same reference frame used for classical SyMs. It is shown that the analysis can be used to optimize some machine parameters. The issues in LS SyM manufacturing are introduced, with particular reference to the die casting process. The possibility to apply the recent improvements in the SRM design to LS SyM is discussed from the manufacturing point of view. Stochastic optimization has been adopted for the design of electrical motors to reduce the torque ripple, increase the average torque and reduce the losses. The LS SyM torque ripple reduction, achieving at the same time a high average torque, is an important issue even though this topic is not treated extensively in the literature for LS SyM. For this reason, a stochastic optimization is considered in this thesis for the design of a new LS SyM lamination. The analysis is applied on a small size, 2-pole, three-phase LS SyM as this category is still not found in the motor market. The optimization is carried out considering the necessity to achieve a robust design, suitable for the industrial production, as such a LS SyM must be competitive with the workhorse of electrical motors, the IM. One of the most promising design is prototyped. Its performance are compared with the corresponding IM. To demonstrate the feasibility in adopting LS SyM in the large-scale production, an innovative LS SyM design is proposed. The main aim is to use the same lamination for motors of different number of poles so as to reduce the manufacturing cost. A tradeoff between contrasting aspects is necessary in the design step. The performance achievable by these rotor structures are quantified. An analytical model that describes the mutual interaction between coupled electrical circuits in machines with complex rotor structure is developed. Such a model is useful to analyze the parasitic torques in the torque characteristic of motors with rotor cage such as IM and LS SyM. The literature reveals that this topic has been discussed extensively for IM. As regards LS SyM, there is a lack of theoretical studies regarding harmonic phenomena due to the complex machine structure. This part of the thesis aims to fill this gap. The high and unstable cost of rare-earth PMs, together with the advances in solid-state control technology, leads designers to reconsider IM for variable speed drive (VSD) applications. To the aim of making the IM suitable for the full-speed sensorless control, a particular cage design is considered. An intentionally created saliency is introduced in the rotor so as to allow the rotor position to be estimated by means of a high frequency (HF) injected signal in the stator winding also at zero-speed. Different experimental tests are carried out on IMs with asymmetrical rotor cage to validate the analysis techniques and quantify the achievable performance. As far as the HF signal injection sensorless technique is concerned, the cross-saturation differential inductance of SyMs represents an issue. It causes a rotor position estimation error, reducing the region in which such technique is effective. The proper-ties of the cross-saturation inductance are deeply discussed. It is originally shown that the cross-saturation inductance depends from certain machine parameters. With such an analysis, a designer can consider the effect of the cross-saturation inductance in any model-based control algorithm. A rotor winding is added in Surface-mounted permanent-magnet machine (SPM) to create a HF anisotropy that is useful to detect the rotor position by means of a HF signal injection. Such a configuration is called ”ringed-pole”. In literature, this technique has been used on small-size machines. In certain configuration, the presence of the additional rotor winding causes significant rotor losses. This part of the thesis studies the rotor losses in ringed pole machines by means of FE analysis and analytical models. The aim is to investigate if the ringed-pole technique can be adopted also for large machines from the point of view of additional losses. With few exceptions, the work described in this thesis is always supported by means of experimental measurements. Dedicated experiments has been designed. Their results are compared with those achieved with analytical models or FE analysis.
Questo lavoro di tesi è incentrato sull’analisi, la progettazione e la prototipazione di macchine elettriche trifase ad alto rendimento, con particolare riferimento a motori dotati di avvolgimenti rotorici. Inizialmente si descrivono le motivazioni di questo lavori di tesi e il contesto in cui essa si inserisce, illustrandone i principali obiettivi. Una dettagliata analisi bibliografica è alla base del lavoro svolto. Una selezione di questi lavori si trova nelle referenze. I motori sincroni autoavvianti (LS SyM) sono stati introdotti nella prima metà del novecento e la loro progettazione è soggetto di ricerca sin da allora. Essi non si sono mai affermati a causa della loro difficile progettazione e per la disponibilità del più robusto ed economico motore ad induzione (IM). Dopo aver descritto il principio di funzionamento di IM e LS SyM, se ne illustrano le tecniche di analisi sviluppate fino al giorno d’oggi. Negli ultimi anni vi è un rinnovato interesse verso i LS SyM grazie agli stringenti requisiti di rendimento. Vi è quindi la necessità di tecniche di progettazione veloci ed affidabili per LS SyM. I risultati di simulazioni agli elementi finiti sono stati combinati a modelli analitici per descrivere la complessa dinamica di LS SyM. L’obiettivo è quello di ottenere una risposta sufficientemente precisa in tempi molto più brevi rispetto ad altre tecniche di analisi. In questo modo si rende possibile una rapida e precisa calibrazione dei parametri rotorici necessari per soddisfare determinati requisiti di carico dinamico. Parte di questa tesi è dedicata allo sviluppo di una tecnica di analisi per LS SyM in condizioni di regime. Tale analisi `e condotta nello stesso sistema di riferimento usato nei classici modelli per macchine sincrone non autoavvianti. Si mostra che l’analisi proposta permette anche di ottimizzare alcuni parametri di macchina. Negli ultimi anni vi sono stati numerosi sviluppi nella progettazione di macchine sincrone a riluttanza, con o senza l’assistenza di magneti permanenti. In questa tesi si è voluto investigare sulla possibilità di applicare tali sviluppi ai LS SyM, tenendo in considerazione i vincoli costruttivi legati alla presenza della gabbia rotorica. Lo scopo è quello di ridurre il volume di magneti permanenti utilizzati per contenere i costi di produzione. Si è affrontato il problema dell’industrializzazione dei LS SyM, con particolare riferimento al processo di pressofusione del rotore. Nell’intento di ridurre il ripple di coppia, incrementare la coppia media e ridurre le perdite dei motori elettrici, recenti lavori propongono l’utilizzo di algoritmi di ottimizzazione stocastica nella fase di progettazione. I suddetti obiettivi sono basilari anche per LS SyM, anche se per questo tipo di motori la letteratura è meno fornita. Per questo motivo si è voluto utilizzare un algoritmo di ottimizzazione nella fase di progettazione della lamiera di un LS SyM. L’analisi è applicata ad un LS SyM trifase a 2 poli di piccola taglia, dato che ancora non si trovano nei cataloghi dei principali costruttori. L’ottimizzazione è sviluppata considerando la necessità di ottenere un progetto robusto e comunque adatto alla produzione industriale, dato che tale LS SyM deve essere competitivo con l’ormai consolidato IM. Una promettente struttura rotorica è stata prototipata. Le prestazioni ottenute sono confrontate con quelle del corrispondente IM. Si è proposta un innovativa configurazione di LS SyM per dimostrare la fattibilità del loro utilizzo su scala industriale. Lo scopo è quello di utilizzare la stessa lamiera per motori con un diverso numero di poli, riducendo di conseguenza il costo di produzione. Per fare ciò è necessario un compromesso tra aspetti contrastanti nel progetto. In questa parte di tesi, si è voluto quantificare le prestazioni ottenibili da tali geometrie nelle diverse configurazioni. In questa tesi si è sviluppato un modello analitico per caratterizzare l’interazione di circuiti elettrici accoppiati in strutture complesse quali quelle dei LS SyM. Questa analisi mira ad essere uno strumento per la determinazione analitica delle coppie parassite in motori dotati di gabbia rotorica come LS SyM e IM. La letteratura riporta un gran numero di lavori riguardanti la descrizione di coppie parassite nella caratteristica di coppia di motori IM. In LS SyM, l’analisi delle coppie parassite è molto più complessa a causa della struttura di macchina. In letteratura, gli studi analitici riguardanti gli effetti di armoniche di MMF in motori LS SyM sono pochi ed incompleti. L’elevato ed instabile prezzo dei magneti permanenti, assieme allo straordinario sviluppo dell’elettronica allo stato solido, ha spinto a riconsiderare il motore ad induzione per applicazioni a velocità variabile. In questo scenario, si è considerato un avvolgimento rotorico a gabbia di scoiattolo in cui i conduttori sono asimmetrici. Tale asimmetria permette il riconoscimento sensorless della posizione rotorica tramite iniezione di segnali ad alta frequenza negli avvolgimenti di statore anche a velocità molto basse. Sono stati condotti test sperimentali su prototipi di IM con gabbia asimmetrica allo scopo di verificare le tecniche di analisi e di quantificare le prestazioni ottenibili da tali geometrie. Proseguendo l’analisi delle problematiche riscontrate in controlli di tipo sensorless con iniezione di segnale, si sono approfondite le proprietà della mutua induttanza differenziale causata dal fenomeno della saturazione incrociata tra asse d e q in macchine sincrone. Essa causa un errore nella stima della posizione rotorica, riducendo di fatto l’applicabilità del controllo sensorless con iniezione di segnale. Dopo aver discusso in dettaglio le propriet`a di tale induttanza, si `e dimostrato che essa dipende da alcuni parametri di macchina. Con i risultati ottenuti, può essere intrapresa una serie di accorgimenti nel controllo della macchina volta a mitigare l’effetto negativo dell’induttanza mutua dovuta alla saturazione incrociata. Uno o più avvolgimenti rotorici possono essere introdotti anche in motori sincroni a magneti permanenti superficiali, allo scopo di estendere l’applicabilità del controllo sensorless con iniezione di segnale anche a questo tipo di motori. In questo tipo di macchine, denominate ”ringed-pole”, tali avvolgimenti rotorici possono essere sede di perdite importanti nel funzionamento a regime. In letteratura, questa tecnologia è stata applicata a motori di piccola taglia. In questo contesto, si sono studiate le perdite rotoriche di macchine ”ringed-pole” tramite analisi agli elementi finiti e modelli analitici. Lo scopo è quello di verificare se l’uso di tale tecnologia può essere esteso a macchine di taglia superiore dal punto di vista delle perdite rotoriche. Con poche eccezioni, gli argomenti di questa tesi sono validati tramite misure sperimentali. I risultati delle prove sperimentali sono confrontati con quelli provenienti da modelli analitici o da analisi agli elementi finiti.

Ce travail de thèse est consacré au développement de sources lasers femtosecondes à haute cadence, de forte puissancemoyenne (>10 W) avec des énergies supérieures à 100 μJ. Ce type de sources est primordial pour le développementd’applications industrielles variées (micro-usinage athermique, chirurgie oculaire, …) ainsi qu’en recherchefondamentale pour l’étude de l’interaction laser matière.Après un chapitre d’introduction sur l’état de l’art des chaînes lasers de forte puissance moyenne à base de matériauxdopés ytterbium, la réalisation d’une chaîne laser de forte puissance moyenne compacte à base de fibre photoniquemicrostructurée à large aire modale sera présentée. Il sera notamment démontré les principales limitations en termed’énergie et de puissance moyenne. D’une part, le fort confinement de l’impulsion lumineuse dans le coeur de la fibrefavorise l’accumulation d’effets non-linéaires lors de l’amplification et détériore la qualité de l’impulsion. D’autrepart, en raison du diamètre de coeur important (> 70 μm) choisit pour lutter contre l’effet précèdent, le guidage dumode fondamental TEM00 de ces fibres est très critique et devient sensible à la charge thermique interne à la fibre.Cette source laser a été utilisée dans le cas de deux applications bien spécifiques : le perçage de plaques d’acierépaisses pour une finalité de déminage (relatif au cadre du financement de cette thèse par la Direction Générale del’Armement) et à la génération d’harmoniques d’ordres élevées à très haute cadence (relatif au domaine d’expertisedu CELIA). Ces deux applications sont traitées au cours du troisième chapitre.A la vue des limitations observées et afin de disposer de chaînes lasers plus énergétiques et offrant des duréesd’impulsions encore plus courtes, une nouvelles architecture d’amplification a été proposée : le pompage fortebrillance de matériaux dopés Ytterbium. Ce concept présenté dans le dernier chapitre utilise le développement desources fibrées monomodes continues émettant à 976 nm. Cette architecture d’amplification a été utilisée afin deréaliser d’une part un oscillateur sub-70 fs et de forte puissance moyenne (>2,3 W) à une cadence de 73 MHz etd’autre part : un amplificateur type « booster » à fort gain. Deux expériences qui ont été réalisées avec des cristauxd’Yb:CaF2. Ce matériaux présente en effet l’avantage d’avoir un très large spectre d’émission (>60 nm) propice à lagénération et amplification d’impulsions femtosecondes mais aussi d’être « compatible » avec les chaînes de trèsforte puissance grâce à sa très bonne conductivité thermique
This work concerns the development of high repetition rate femtosecond lasers with high average power (>10 W)and energies in excess of 100 μJ. Such lasers are paramount for the development of new industrial applications(athermal micro-drilling, eye surgery, ...) and for fundamental research on high repetition rate laser matter interactionstudies.After a brief introduction and the state of the art summary on high-average power femtosecond laser with ytterbiumdoped materials, a compact high-average power femtosecond laser with a large mode area microstructured rod typeamplifier will be presented. It will browse the main limitations in terms of energy and average power. Limitationsare mainly due to the strong confinement of the electric field propagating in the fibre core leading to non-linear effectsaccumulated during the amplification. On the other hand, for larger core diameter (> 70 μm), the fundamental modeguiding (TEM00) is very weak and thus very sensitive to the internal thermal load of the fibre.This laser source has been used in two specific applications: athermal drilling of thick stainless steel plate for mineclearing(an application of interest for the Direction Générale de l’Armement) and High order Harmonics Generationat high repetition rate (related to CELIA activities). These two applications are presented in the third chapter.In order to stretch the limits and generate more energetic and a shorter pulse, a new amplification scheme has beenproposed, namely high brightness optical pumping of ytterbium doped materials. This concept presented in the lastchapter benefits from the development of high average power single-mode fibre lasers source emitting at 976 nm.This amplification scheme allowed us to realize a high average power Kerr-lens oscillator delivering pulses with apulse duration below than 70 fs and an average power of 2.3W at a repetition rate of 73 MHz. In a second phase, wealso developed a « booster » amplifier with a high single- pass-gain. These two results have been obtained by usingYb-doped CaF2 crystals. This material presents the advantage to have a very broad emission bandwidth (> 60nm)suitable to generate and amplify femtosecond pulses and to be compatible with high average power laser due to hisvery good thermal conductivity

L'objectif de cette thèse est de proposer l'approche la plus appropriée afin de minimiser le coût d'intégration de petite éolienne dans un micro-réseau DC urbain. Une petit éolienne basé sur un machine synchrone à aimant permanent (MSAP) est considéré à étudier. Un état de l'art concernant les énergies renouvelables, micro-réseau DC, et la production d'énergie éolienne, est fait. Comme le capteur mécanique de cette structure est relativement d'un coût élevé, les différents types de contrôle pour un système de conversion éolienne sont présentés afin de choisir une structure active de conversion d'énergie et un MSAP sans capteur. Par conséquent, un estimateur de vitesse/position est nécessaire pour contrôler le système. Ainsi, les méthodes différentes proposées dans la littérature sont considérées et classifiées à étudier dans les détails, puis les plus efficaces et largement utilisés sont à vérifier dans la simulation et expérimentalement pour le système étudié. Les méthodes choisies sont: estimation de la flux de rotor avec boucle à verrouillage de phase (PLL), observateur à mode glissement (SMO), observateur de Luenberger d'ordre réduit, et filtre de Kalman étendu (EKF). Face à d'autres méthodes, l'estimateur basé sur un modèle EKF permet une commande sans capteur dans une large plage de vitesse et estime la vitesse de rotation avec une réponse rapide. Le réglage des paramètres EKF est le problème principal à sa mise en œuvre. Par conséquent, pour résoudre ce problème, la thèse présente une méthode adaptative, à savoir réglage-adaptatif d’EKF. En conséquence, et grâce à cette approche, le coût total du système de conversion est réduite et la performance est garantie et optimisée
The aim of this thesis is to propose the most appropriate approach in order to minimize the cost of integration of a wind generator into a DC urban microgrid. A small-scale wind generator based on a permanent magnet synchronous machine (PMSM) is considered to be studied. A state of the art concerning the renewable energies, DC microgrid, and wind power generation is done. As the mechanical sensor for this structure is relatively of high cost, various types of wind conversion system control are presented in order to choose an energy conversion active structure and a sensorless PMSM. Therefore, a speed/position estimator is required to control the system. Thus, different methods proposed in literatures are considered and classified to be studied in details, and then the most effective and widely used ones are to be verified in simulation and experimentally for the studied system. The methods which are chosen are: rotor flux estimation with phase locked loop (PLL), sliding mode observer (SMO), Luenberger observer of reduced order, and extended Kalman filter (EKF). Facing to other methods, the EKF model-based estimator allows sensorless drive control in a wide speed range and estimates the rotation speed with a rapid response. The EKF parameters tuning is the main problem to its implementation. Hence, to solve this problem, the thesis introduces an adaptive method, i.e. adaptive-tuning EKF. As a result and grace to this approach, the total cost of conversion system is reduced and the performance is guaranteed and optimized

Virtual prototyping is today an essential technology for modeling, verification, and re-design of full HW/SW platforms. This allows a fast prototyping of platforms with a higher and higher complexity, which precludes traditional verification approaches based on the static analysis of the source code. Consequently, several technologies based on the analysis of simulation traces have proposed to efficiently validate the entire system from both the functional and extra-functional point of view. From the functional point of view, different approaches based on invariant and assertion mining have been proposed in literature to validate the functionality of a system under verification (SUV). Dynamic mining of invariants is a class of approaches to extract logic formulas with the purpose of expressing stable conditions in the behavior of the SUV. The mined formulas represent likely invariants for the SUV, which certainly hold on the considered traces. A large set of representative execution traces must be analyzed to increase the probability that mined invariants are generally true. However, this is extremely time-consuming for current sequential approaches when long execution traces and large set of SUV's variables are considered. Dynamic mining of assertions is instead a class of approaches to extract temporal logic formulas with the purpose of expressing temporal relations among the variables of a SUV. However, in most cases, existing tools can only mine assertions compliant with a limited set of pre-defined templates. Furthermore, they tend to generate a huge amount of assertions, while they still lack an effective way to measure their coverage in terms of design behaviors. Moreover, the security vulnerability of a firmware running on a HW/SW platforms is becoming ever more critical in the functional verification of a SUV. Current approaches in literature focus only on raising an error as soon as an assertion monitoring the SUV fails. No approach was proposed to investigate the issue that this set of assertions could be incomplete and that different, unusual behaviors could remain not investigated. From the extra-functional point of view of a SUV, several approaches based on power state machines (PSMs) have been proposed for modeling and simulating the power consumption of an IP at system-level. However, while they focus on the use of PSMs as the underlying formalism for implementing dynamic power management techniques of a SoC, they generally do not deal with the basic problem of how to generate a PSM. In this context, the thesis aims at exploiting dynamic assertion mining to improve the current approaches for the characterization of functional and extra-functional properties of a SoC with the final goal of providing an efficient and effective system-level virtual prototyping environment. In detail, the presented methodologies focus on: efficient extraction of invariants from execution traces by exploiting GP-GPU architectures; extraction of human-readable temporal assertions by combining user-defined assertion templates, data mining and coverage analysis; generation of assertions pinpointing the unlike execution paths of a firmware to guide the analysis of the security vulnerabilities of a SoC; and last but not least, automatic generation of PSMs for the extra-functional characterization of the SoC.

碩士
國立交通大學
電子研究所
83
Power consumption is now an important issue in VLSI design, so is in Finite State Machine (FSM) state assignment. In this thesis, a model of computing FSM's state probability with given input signal probability and transition densities has been proposed. The difference between the state transition probabilities calculated by our approach and those by exhaustive simulation is less than 10%. It is a significant improvement in comparison with former methods. Besides, we propose a new method for state assignment, which choose some representative edges from the weighting graph to be assigned as distance one to minimize state line transition counts. Experimental results show that this method has reduce more than 8% of state line transitions.

The research is motivated by the need to address two major challenges in wind power integration: how to mitigate wind power fluctuation and how to ensure stability of the farm and host grid. It is envisaged that wind farm power output fluctuation can be reduced by using a specific type of buffer, such as an energy storage system (ESS), to absorb its negative impact. The proposed solution, therefore, employs ESS to solve the problems. The key research findings include a new technique for calculating the desired power output profile, an ESS charge-discharge scheme, a novel direct-calculation (optimization-based) method for determining ESS optimal rating, and an ESS operation scheme for improving wind farm transient stability. Analysis with 14 wind farms and a compressed-air energy storage system (CAES) shows that the charge-discharge scheme and the desired output calculation technique are appropriate for ESS operation. The optimal ESSs for the 14 wind farms perform four or less switching operations daily (73.2%-85.5% of the 365 days) while regulating the farms output variation. On average, the ESSs carry out 2.5 to 3.1 switching operations per day. By using the direct-calculation method, an optimal ESS rating can be found for any wind farm with a high degree of accuracy. The method has a considerable advantage over traditional differential-based methods because it does not require knowledge of the analytical form of the objective function. For ESSs optimal rating, the improvement in wind energy integration is between 1.7% and 8%. In addition, a net increase in grid steady-state voltage stability of 8.3%-18.3% is achieved by 13 of the 14 evaluated ESSs. For improving wind farm transient stability, the proposed ESS operation scheme is effective. It exploits the use of a synchronous-machine-based ESS as a synchronous condenser to dynamically supply a wind farm with reactive power during faults. Analysis with an ESS and a 60-MW wind farm consisting of stall-regulated wind turbines shows that the ESS increases the farm critical clearing time (CCT) by 1 cycle for worst-case bolted three-phase-to-ground faults. For bolted single-phase-to-ground faults, the CCT is improved by 23.1%-52.2%.
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