Dans les dernières années, le respect de l’environnement est devenu une des grandes préoccupations des clients du secteur automobile. Les constructeurs cherchent à réduire les émissions carbones de ses produits et les véhicules hybrides ou purement électriques apparaissent comme une alternative viable aux véhicules thermiques. Un des éléments importants de la réussite de la commercialisation des véhicules électriques est la recharge de la batterie qui peut être effectuée par différents moyens, avec des chargeurs embarqués/débarqués, à domicile ou sur la voie-publique. Dans ce domaine un système de charge performant doit notamment être robuste vis-à-vis des contraintes extérieures( perturbations réseaux, impédances de ligne, charges de plusieurs véhicules en même temps), avoir un bon rendement entre la puissance puisée à la prise et celle délivrée à la batterie, maitriser les courants harmoniques rejetés sur le réseau électrique (respect des différentes contraintes réglementaires liées aux perturbations émises). Pour répondre à ces exigences les travaux de cette thèse proposent des commandes innovantes des convertisseurs de puissance contenus dans les chargeurs électriques. Dans un premier temps, la modélisation des convertisseurs de puissance est réalisée en moyenne à la période de commutation et en moyenne généralisée pour d´écrire le processus de génération des harmoniques des courants et tensions des convertisseurs. Des lois de commande non-linéaire fondées sur la théorie de stabilité au sens de Lyapunov sont proposées de fac¸on à induire un comportement en boucle fermée satisfaisant les exigences souhaitées pour les convertisseurs de puissance. La partie commande est complétée par une partie d’observation nécessaire pour l’estimation des signaux non-mesurés et pour l’extraction harmonique. Enfin dans la dernière partie de la thèse, les différentes stratégies de commande sont validées par rapport aux exigences via une co-simulation en reproduisant l’architecture de logiciel model in the loop utilisée dans l’industrie / In the last few years the question of respecting the environment became a central concern of car users. The electric cars respond to the public trend of reducing the toxic emissions of conventional cars. The success of electric cars depends on the charging of the batteries, charging done either at home or on the public domain.The charging system has to respond to the following performance criteria:-robustness to exterior constraints: network perturbations, line impedance, multiple simultaneous charging of vehicles.-a good efficiency for the power transfer between the received power and the power delivered to the battery.-respecting the power distributer constrains for network harmonic pollution.These three points impose the need for efficient control laws for the battery charger. In this context, the power converters (AC / DC - DC / DC) are key components in electrical chargers , an improved control law of these elements can provide a better level of performance for the charger.This work is a continuation of previous work that resulted in several theses with CIFRE funding, in collaboration with Renault in the context of the electric car (but not only):- From an industrial viewpoint, the doctoral student will draw on the expertise, experience and Renault's test facilities in the field of electric traction in the automotive transport.- From an academic point of view the work will benefit from the skills of the working group 'System control’ within the L2S laboratory, in the field of multi-physics modelling, design of control laws and optimization.Supervision will be provided by:- Emmanuel Godoy (Professor, HDR, advisor) and Dominique Beauvois (professor, co-director) of the academic point of view.- Pedro Kvieska (Engineer, Doctor, Ecole Centrale de Nantes) for industrial management within Renault.Objectives of the thesisThe first two years of thesis work will focus on methodological studies of dedicated control laws. During the third year the work will be focused on the implementation of the proposed architectures and control strategies by: implementing of the new control strategies as prototypes on test bench and on the transferability of the proposed control approaches.A big part of the last year will naturally be devoted to the writing of the doctoral thesis and the preparation of the defence.

Master of Science / Department of Architectural Engineering and Construction Science / Fred Hasler / This paper discusses a brief history of electricity, specifically alternating current (AC) and direct current (DC), and how the current standard of AC distribution has been reached. DC power was first produced in 1800, but the shift to AC occurred in the 1880’s with the advent of the transformer. Because the decisions for distribution were made over 100 years ago, it could be time to rethink the standards of power distribution. Compared to traditional AC distribution, DC microgrids are significantly more energy efficient when implemented with distributed generation. Distributed generation, or on-site generation from photovoltaic panels, wind turbines, fuel cells, or microturbines, is more efficient when the power is transmitted by DC. DC generation, paired with the growing DC load profile, increases energy savings by utilizing DC architecture and eliminating wasteful conversions. Energy savings would result from a lower grid strain and more efficient utilization of the utility grid. DC distribution results in a more reliable electrical service due to short transmission distances, high service reliability when paired with on-site generation, and efficient storage. Occupant safety is a perceived concern with DC microgrids due to the lack of knowledge and familiarity in regards to these systems. However, with proper regulation and design standards, building occupants never encounter voltage higher than 24VDC, which is significantly safer than existing 120VAC in the United States. DC Microgrids have several disadvantages such as higher initial cost due, in part, to unfamiliarity of the system as well as a general lack of code recognition and efficiency metric recognition leading to difficult certification and code compliance. Case studies are cited in this paper to demonstrate energy reduction possibilities due to the lack of modeling ability in current energy analysis programs and demonstrated energy savings of approximately 20%. It was concluded that continued advancement in code development will come from pressure to increase energy efficiency. This pressure, paired with the standardization of a 24VDC plug and socket, will cause substantial increases in DC microgrid usage in the next 10 years.

Les systèmes électroniques commutés sont de plus en plus utilisés dans plusieurs domaines domestiques ou industriels: les écrans à cristaux liquides, les appareils électroménagers, l'éclairage, les ordinateurs personnels, les centrales électriques, les véhicules de transport et ainsi de suite. L'efficacité des opérations de toutes les applications dépend du travail essentiel réalisé par des systèmes électroniques à commutation, dont le comportement est déterminé par une interconnexion et un contrôle appropriés des dispositifs analogiques et numériques. Comme motivation de ce travail, nous considérons les convertisseurs DC-DC de puissance. Cette thèse contribue à fournir des solutions aux problèmes de contrôle hybrides et non linéaires des plusieurs types de convertisseurs de puissance. Dans la première partie nous intéressons au problème de la régulation de la tension des convertisseurs de puissance fonctionnant dans le mode de conduction discontinue. Deux convertisseurs de puissance sont considérés: le convertisseur boost et le convertisseur buck-boost. L'objectif de commande est la génération d'une orbite périodique. Notre principale contribution est un algorithme simple et robuste qui donne des formules explicites pour les temps de commutation sans approximations. Les résultats de simulation et expérimentaux sont présentés. Dans la deuxième partie une classe de convertisseurs de puissance qui peut être globalement stabilisé avec un contrôleur PI a été identifiée. Par ailleurs, nous allons prouver que l'observateur I&I peut être combiné avec le contrôleur PI tout en préservant les propriétés de stabilité asymptotique globale de la boucle fermé. La classe se caractérise par une inégalité matricielle linéaire simple. Le nouveau contrôleur est illustré avec le convertisseur très - populaire, et difficile à contrôler, le SEPIC, pour lequel les résultats de simulation et expérimentaux sont présentés. / Switched electronic systems are used in a huge number of everyday domestic and industrial utilities: liquid crystal displays, home appliances, lighting, personal computers, power plants, transportation vehicles and so on. Efficient operations of all such applications depend on the essential “hidden work" done by switched electronic systems, whose behavior is determined by a suitable interconnection and control of analog and digital devices. As a motivation of this work, we consider the DC-DC power converters. This thesis contributes to provide hybrid and nonlinear control problem solutions to several types of power converters. In the first part we are interested in the problem of voltage regulation of power converters operating in discontinuous conducting mode. Two power converters are considered: the boost converter and the buck-boost converter. The system does not admit a (continuous--time) average model approximation, hence is a hybrid system where the control objective is the generation of a periodic orbit and the actuator commands are switching times. Our main contribution is a simple robust algorithm that gives explicit formulas for the switching times without approximations. Simulation and experimental results that illustrate the robustness of the scheme to parameter uncertainty, as well as performance comparisons with current practice, are presented. In the second part a class of power converters that can be globally stabilized with an output-feedback PI controller has been identified. Moreover, we will prove that the I&I observer can be combined with the PI controller preserving the GAS properties of the closed-loop. The class is characterized by a simple linear matrix inequality. The new controller is illustrated with the widely-popular, and difficult to control, single-ended primary inductor converter, for which simulation and experimental results are presented.

Firstly, this thesis investigates the electrical power harmonics in an attempt to utilize harmonic current and its distortion power in a novel idea to reconvert the distortion power into useful power. This is done, in order to feed different DC or AC loads in single and three-phase power system by using passive or active filters and accordingly, develop a new topology of hybrid active power filter (HAPF). In addition, this circuit can be considered as a power factor corrector (PFC) because it reduces the total harmonic distortion (THD) and improves the power factor (PF). Secondly, this thesis works on a new design of active power factor correction (APFC) circuit presenting two circuits with the same design principle: the first design consists of two active switches without an external complex control circuit, while the second design contains a single active switch with an additional control circuit. The main contribution of this circuit is 98% reduction of the inductor's value used in the newly proposed PFC circuit in comparison with the conventional boost converter which may lead to a huge reduction in size, weight and the cost of the new PFC circuit. Also, the active switches depend on a carefully designed switching pattern that results in an elimination of the third order harmonic from the input source current which decreases the value of total current harmonic distortion (THDI) to (14%) and improves the input PF to (0.99). Consequently, the simplicity of the design without requiring a complex control circuit and without a snubber circuit plus the minimum size of inductor, gives the newly proposed circuit the superiority on other PFC circuits. Thirdly, this research aims to describe the distortion power through submitting two novel power terms called effective active power (Pef ) & reactive power (Qef ) terms with a new power diagram called Right-Angled Power Triangle (RAPT) Diagram. In addition, a novel de nition of total apparent power (St) has been submitted in order to illustrate the physical meaning of (St) in non-sinusoidal systems. The new RAPT Diagram is based on the orthogonality law and depends on geometrical summation to describe the relationship between different aspects (apparent-active-reactive) of power, and different components (total-fundamental distortion), drawing a bridge to connect the time domain with the frequency domain in a two-dimensional diagram.

Switched-Capacitor Converters (SCC) suffer from a fundamental power loss deficiency which make their use in some applications prohibitive. The power loss is due to the inherent energy dissipation when SCC operate between or outside their output target voltages. This drawback was alleviated in this work by developing two new classes of SCC providing binary and arbitrary resolution of closely spaced target voltages. Special attention is paid to SCC topologies of binary resolution. Namely, SCC systems that can be configured to have a no-load output to input voltage ratio that is equal to any binary fraction for a given number of bits. To this end, we define a new number system and develop rules to translate these numbers into SCC hardware that follows the algebraic behavior. According to this approach, the flying capacitors are automatically kept charged to binary weighted voltages and consequently the resolution of the target voltages follows a binary number representation and can be made higher by increasing the number of capacitors (bits). The ability to increase the number of target voltages reduces the spacing between them and, consequently, increases the efficiency when the input varies over a large voltage range. The thesis presents the underlining theory of the binary SCC and its extension to the general radix case. Although the major application is in step-down SCC, a simple method to utilize these SCC for step-up conversion is also described, as well as a method to reduce the output voltage ripple. In addition, the generic and unified model is strictly applied to derive the SCC equivalent resistor, which is a measure of the power loss. The theoretical predictions are verified by simulation and experimental results.

Current trends in electric power consumption indicate an increasing use of dc in end-user equipment, such as computers and other electronic appliances used in households and offices. With a dc power system, ac/dc conversion within these loads can be avoided, and losses reduced. AC/DC conversion is instead centralized, and by using efficient, fully controllable power-electronic interfaces, high power quality for both ac and dc systems during steady state and ac grid disturbances can be obtained. Connection of back-up energy storage and small-size generation is also easier to realize in a dc power system. To facilitate practical application, it is important that the shift from ac to dc can be implemented with minimal changes. Results from measurements carried out on common household appliances show that most loads are able to operate with dc supply without any modifications. Furthermore, simple, and yet sufficiently accurate, load models have been derived using the measurement results. The models have been used for further analysis of the dc system, both in steady state and during transients. AC microgrids have gained research interest during the last years. A microgrid is a part of power systems which can operate both connected to the ac grid, and autonomously in island mode when the loads are supplied from locally distributed resources. A low-voltage dc microgrid can be used to supply sensitive electronic loads, since it combines the advantages of using a dc supply for electronic loads, and using local generation to supply sensitive loads. An example of a commercial power system which can benefit from using a dc microgrid is data center. The lower losses due to fewer power conversion steps results in less heat which need to be cooled, and therefore the operation costs are lowered. To ensure reliable operation of a low-voltage dc microgrid, well-designed control and protection systems are needed. An adaptive controller is required to coordinate the different resources based on the load-generation balance in the microgrid, and status of the ac grid. The performance of the developed controller has been studied and evaluated through simulations. The results show that it is possible to extend use of the data center dc microgrid to also support a limited amount of ac loads close to the data center, for example an office building. A protection-system design for low-voltage dc microgrids has been proposed, and different protection devices and grounding methods have been presented. Moreover, different fault types and their impact on the system have been analyzed. The type of protection that can be used depends on the sensitivity of the components in the microgrid. Detection methods for different components have been suggested in order to achieve a fast and accurate fault clearing. An experimental small-scale dc power system has been used to supply different loads, both during normal and fault conditions. A three-phase two-level voltage source converter in series with a Buck converter was used to interconnect the ac and the dc power systems. Together the converters have large controllability, high power quality performance, and allow bi-directional power flow. This topology can preferably be used together with energy storage. The tests confirm the feasibility of using a dc power system to supply sensitive electronic loads. / QC 20100908

Στις μέρες μας οι συνεχώς αυξανόμενες ενεργειακές ανάγκες, καθώς και η απαίτηση των κοινωνιών για ένα πιο καθαρό περιβάλλον, έχουν κάνει τις ανανεώσιμες πηγές ενέργειας όλο και πιο ελκυστικές ως προς την εκμετάλλευση τους. Η αξιοποίηση της αιολικής ενέργειας στην παραγωγή ηλεκτρικής ενέργειας κερδίζει όλο και περισσότερο έδαφος. Η τεχνολογία των αιολικών συστημάτων αναπτύσσεται συνεχώς ,με αποτέλεσμα να υπάρχουν διάφορες κατηγορίες αυτών, ανάλογα με τη χρήση για την οποία προορίζονται. Στην παρούσα διπλωματική μου εργασία, μελετάται ένα αιολικό σύστημα μεταβλητών στροφών που χρησιμοποιεί μία παραλλαγή της επαγωγικής μηχανής Διπλής Τροφοδοσίας. Η διαφοροποίηση του έγκειται στον επιπλέον dc/ac μετατροπέα που χρησιμοποιείται, προκειμένου να ελέγξουμε την τάση που μπορεί να δει ο στάτης. Μ΄ αυτό τον τρόπο, το αιολικό σύστημα μιας γεννήτριας διπλής τροφοδοσίας γίνεται ακόμα πιο αξιόπιστο, συνεχίζοντας την παραγωγή ισχύος και παραμένοντας συνδεδεμένο με το δίκτυο σε περίπτωση σφάλματος στην πλευρά του δικτύου. Στη μελέτη αυτή, αφού εξαγάγαμε το μαθηματικό μοντέλο του συστήματος και το προσομοιώσαμε σε περιβάλλον Matlab - Simulink, δοκιμάσαμε το σύστημα σε συνθήκες ύπαρξης σφάλματος στο δίκτυο. Στο σύστημα εφαρμόστηκαν κλασικές τεχνικές ελέγχου,με στόχο τη διατήρηση της μέγιστης απομάστευσης ισχύος από το σύστημα, την αύξηση της αντοχής του σε σφάλματα από την πλευρά του δικτύου, καθώς και τη μη αποσύνδεση του συστήματος από το δίκτυο σε μία τέτοια περίπτωση. Τέλος, συγκρίναμε τη συμπεριφορά αυτού του συστήματος με τη συμπεριφορά ενός κλασικού αιολικού συστήματος με επαγωγική γεννήτρια Διπλής Τροφοδοσίας και παραθέσαμε τις διαφορές. / The increasingly energy demands in our days and also the modern societies demand for a greener environment, have made the electrical energy production from renewable energy sources more attractive. The use of wind energy in the electrical energy production is having more and more fervent supporters. The technology and the types of the wind systems varies, depending on the use and the environmental conditions. In my diploma thesis I designed, we will study a variation of a wind system with a variable speed operation with a Doubly Fed Induction Generator. In this system we also use a dc/ac converter in order to control the voltage which the stator can “see”. Using this converter the wind system with a DFIG is more reliable and remains connected to the ac grid, maintaining the maximum power production, in case of a fault on grid side. In this thesis, after we made the mathematical model with a great accuracy and simulated using Matlab - Simulink, we tested it under conditions of different voltage sags from the side of the grid. In order to control the system and maintaining the power production power at the maximum level, we used classic control methods, and as a result, we achieved to keep the maximum level of power production and to keep the wind system connected to the grid in a scenario of a grid side fault. Finally, we compared the behavior of the system we designed with the wind system with the classic DFIG and we presented the differences.

A new concept, the multi level voltage/current reinjection ac/dc conversion, is described in this thesis. Novel voltage and current source converter configurations, based on voltage and current reinjection concepts are proposed. These converter configurations are thoroughly analyzed in their ac and dc system sides. The fundamentals of the reinjection concept is discussed briefly, which lead to the derivation of the ideal reinjection waveform for complete harmonic cancellation and approximations for practical implementation. The concept of multi level voltage reinjection VSC is demonstrated through two types of configurations, based on standard 12-pulse parallel and series connected VSC modified with reinjection bridges and transformers. Firing control strategies and steady state waveform analysis are presented and verified by EMTDC simulations. The multi level current reinjection CSC is also described using two configurations based on standard 12-pulse parallel and series connected CSC modified with associated reinjection circuitry. Firing control strategies and steady state waveform analysis are presented and verified by EMTDC simulations. Taking the advantage of zero current switching in the main bridge valves, achieved through multi level current reinjection, an advanced multi level current reinjection scheme, consisting thyristor main bridges and self-commutated reinjection circuitry is proposed. This hybrid scheme effectively incorporates self-commutated capability into a conventional thyristor converter. The ability of the main bridge valves to commutate without the assistance of a turn-off pulse or line commutating voltage under the zero current condition is explained and verified by EMTDC simulations. Finally, the applications of the MLCR-CSC are discussed in terms of a back to back HVDC link and a long distance HVDC transmission system. The power and control structures and closed loop control strategies are presented. Dynamic simulation is carried out on PSCAD/EMTDC to demonstrate the two systems ability to respond to varying active and reactive power operating conditions.

Este trabalho apresenta proposta de modelo matemático para o problema de expansão do sistema de transmissão baseado no fluxo de carga CC considerando a utilização de links CC e FACTS resolvido através de metodologia de solução que considera a primeira e a segunda lei de Kirchhoff em processo enumerativo de branch-and-bound adaptado. A abordagem possui dois pontos em destaque: i) apresenta uma proposta de modelo matemático com possibilidade da utilização direta em problemas de expansão de linhas de transmissão que possuem tanto linhas de transmissão CA, transformadores, links CC e dispositivos FACTS e ii) é um método exato de solução do problema que garante a otimalidade da resposta e traz uma contribuição ao tradicional método branch-and-bound por incluir relaxações adicionais. O método aplicado aos sistemas de 6 barras de Garver e sistema Sul sudeste Brasileiro de 46 barras apresenta respostas adequadas e o modelo matemático testado em um sistema Garver modificado apresenta novas configurações possíveis com redução do custo total do investimento. / This work proposes a mathematical model to the transmission expansion system problem based on the DC power flow model considering the use of DC links and FACTS that is solved using a solution method considering the first and second Kirchhoff’s Law in an enumerative adapted branch-and-bound process. It is possible to highlight two key aspects of the proposed approach: i) presents a mathematical model that can be directly used on expansion transmission systems problems that have AC transmission lines, transformers, DC links and FACTS and ii) is an exact solution method that guarantees the optimum problems’s solutions and contributes to the traditional branch-and-bound method bringing additional relaxations. The solution method applied to Garver’s six-bus network and southeast Brazilian 46 bus network provides correct answers and the mathematical model tested on a modified Garver’s six-bus network presents new possible configurations that enables overall cost reduction to the problem.

Este trabalho apresenta proposta de modelo matemático para o problema de expansão do sistema de transmissão baseado no fluxo de carga CC considerando a utilização de links CC e FACTS resolvido através de metodologia de solução que considera a primeira e a segunda lei de Kirchhoff em processo enumerativo de branch-and-bound adaptado. A abordagem possui dois pontos em destaque: i) apresenta uma proposta de modelo matemático com possibilidade da utilização direta em problemas de expansão de linhas de transmissão que possuem tanto linhas de transmissão CA, transformadores, links CC e dispositivos FACTS e ii) é um método exato de solução do problema que garante a otimalidade da resposta e traz uma contribuição ao tradicional método branch-and-bound por incluir relaxações adicionais. O método aplicado aos sistemas de 6 barras de Garver e sistema Sul sudeste Brasileiro de 46 barras apresenta respostas adequadas e o modelo matemático testado em um sistema Garver modificado apresenta novas configurações possíveis com redução do custo total do investimento. / This work proposes a mathematical model to the transmission expansion system problem based on the DC power flow model considering the use of DC links and FACTS that is solved using a solution method considering the first and second Kirchhoff’s Law in an enumerative adapted branch-and-bound process. It is possible to highlight two key aspects of the proposed approach: i) presents a mathematical model that can be directly used on expansion transmission systems problems that have AC transmission lines, transformers, DC links and FACTS and ii) is an exact solution method that guarantees the optimum problems’s solutions and contributes to the traditional branch-and-bound method bringing additional relaxations. The solution method applied to Garver’s six-bus network and southeast Brazilian 46 bus network provides correct answers and the mathematical model tested on a modified Garver’s six-bus network presents new possible configurations that enables overall cost reduction to the problem.