[pt] Programas de estabilidade transitória são ferramentas indispensáveis no planejamento e na operação de sistemas de potência. Compensadores estáticos têm por objetivo o controle de tensão em regime permanente e a melhoria da estabilidade transitória e dinâmica. São equipamentos modernos que encontram no sistema de transmissão brasileiro um vasto campo de aplicação. Este trabalho envolveu a implementação de um programa de estabilidade transitória (TRANSTAB) no computador CYBER 170-853 da PUC/RJ e a inclusão neste programa de um modelo de compensadores estáticos tipo reator controlador por tiristores e de uma rotina de geração de relatórios de saída. O TRANSTAB faz uso das mais modernas técnicas de simulação e está fartamente documentado ao longo deste trabalho. São feitas sugestões de inclusão de modelos que visam adequar o programa ao sistema elétrico brasileiro. Foi realizada uma rápida revisão acerca dos tipos, aplicados e princípios de funcionamento dos compensadores estáticos. O seu sistema de controle foi objeto de uma análise mais detalhada principalmente nos aspectos com a sua representação e modelagem em estudos de estabilidade. / [en] A transient stability program is a very important tool for power system planning and operation. Static compensators are designed to provide voltage control on normal operation and to improve the transient and dinamic stability. They are modern equipments with a great field of application on the brazilian transmission system. This work envolves the transient stability program (TRANSTAB) implementation in PUC´s computer (CYBER 170- 835) and the inclusion of a static compensator (Thyristor Controlled Reactor Type) model and a new output printout routine in this program. The TRANSTAB program makes use of the most recent simulation techniques and it is very well documented in this work. Suggestions are made on the inclusion of new equipment models, in order to extend the program modelling capability. A quick review is made on the static compensator types, applications, and functioning basics. Its control system is the object of a more detailed study, mainly on the aspects related to the modelling and representation on stability studies.

Much research has been done on the concept of why people remain religious, formulating Rational Choice Theory. This involves the idea of compensators and religious expectations. In addition, other research and subsequent theories go into the duality of religious expectations and relational compensators—these relational compensators include love, support, forgiveness, and kindness from others. However, research has rarely explicitly explored what reportedly encourages individuals to stay in religious institutions despite religious demands. Through qualitative interviews with 198 highly religious families, this study analyzed the various expectations and demands individuals and families encounter, as well as the relational blessings they report receiving as a result of their religiosity. Findings indicate a complex connection between religious expectations and relational compensators, where some expectations are relational and may provide blessings for individuals who follow them. These findings indicate that some highly religious individuals do not view fulfilling certain religious expectations as a sacrifice. More research should be done to better understand why religious individuals of varying levels of religiosity remain religious as well.

Multifunctional voltage source converters (VSCs) are desired for shipboard power systems. The opportunity to extend the functionality of a particular VSC on demand, combined with power system reconfiguration strategies may provide desired redundancy to back up power electronic converters that might be destroyed as a result of a battle damage or material casualty. The space for power electronics may be downsized if the VSCs are capable of performing multiple functions. In addition, the flexibility of the energy management can be enhanced in shipboard power systems if a single VSC can perform multiple functions. The functionality of a VSC in many cases is restricted to a single task or set of tasks by its control architecture. Despite the great number of different control strategies suggested for VSCs, nearly all use similar methods for generation of the reference signals. These methods generally depend upon the use of filters to extract reference signals for the components that are to be injected into or drawn from the system. These methods of control are not flexible. The main objective of the dissertation is the development of a flexible reference signal generator for VSCs that allows online maximization of its possible functions. Furthermore, the switching frequency of a VSC is generally above 10 kHz for many applications, and carries a significant amount of high frequency noise. This necessitates the use of EMI filters, which carry an extra cost and increase the overall bulk of the power electronics. This may not be acceptable for shipboard power systems, where the space and weight requirements are usually stringent. Thus, in addition to investigation of various reference signal generator (RSG) strategies for VSCs, alternative solutions to attenuate EMI levels in the shipboard power system environment are explored.

The purpose of this thesis is to use automation to create appropriate models in PSS/E with the data from Hardware-in-Loop real-time simulations. With the increase in technology of power electronics, the use of High Voltage Direct Current Technology and Flexible Alternating Current Transmission System devices in the electrical power system have increased tremendously. Static Var Compensators are widely used and it is important to have accurate and reliable models for studies relating to power systems planning and interaction. An automation method is proposed to find the parameters of an SVC model in PSS/E with the data from the Hardware-in- loop real-time simulation of the SVC physical controller using Hypersim. The effect of the SVC on the system under steady state and fault conditions are analyzed with HIL simulation of an SVC physical controller in Hypersim and its corresponding model in PSS/E in the IEEE 14 bus system. The parameters of the SVC model in PSS/E can be effectively varied to bring its response closer to that of the response from HIL simulations in Hypersim. An error function is used as a measure to understand the extent of difference between the model and the physical controller.

In spite of their high technical maturity, load sensing systems (LS) have system-inherent energy losses that are largely due to the operation of parallel actuators with different loads at the same pressure level. Hereby, the pressure compensators of the system are crucial. So far, excessive hydraulic energy has been throttled at these compensators and been discharged as heat via the oil. The research project “Reduction of System Inherent Pressure Losses at Pressure Compensators of Hydraulic Load Sensing Systems” aims to investigate a novel solution of reducing such energy losses. The pressure of particular sections can be increased by means of a novel hydraulic circuit. Therefore, a recovery unit is connected in series with a hydraulic accumulator via a special valve in the reflux of the actuators. The artificially increased pressure level of the section reduces the amount of hydraulic power to be throttled at the pressure compensators. As long as a section fulfills the switching condition of the valve, pressure losses at the respectiv pressure compensator can be reduced. Thus, via a suitable recovery unit excessive energy can be regenerated and can be directed to other process steps eventually.

Submitted by Emanuel Varela Cardoso (emanuel.varela@ufcg.edu.br) on 2018-08-28T23:11:21Z No. of bitstreams: 1 MARCOS BATISTA KETZER – TESE (PPGEEI) 2017.pdf: 19636979 bytes, checksum: 464380f92f3fb477252ab2b6f6cd2655 (MD5) / Made available in DSpace on 2018-08-28T23:11:21Z (GMT). No. of bitstreams: 1 MARCOS BATISTA KETZER – TESE (PPGEEI) 2017.pdf: 19636979 bytes, checksum: 464380f92f3fb477252ab2b6f6cd2655 (MD5) Previous issue date: 2017-01-30 / Esta tese de doutorado apresenta as contribuições realizadas no desenvolvimento de controladores eletrônicos modulados por largura de pulso para compensadores estáticos de potência aplicados na mitigação de. componentes harmônicas de tensão e corrente. Entre as novidades das técnicas aqui apresentadas, destacam-se as seguintes características: maior integração viabilizada pela redução do número de sensores para operação, e projeto robusto, considerando modelagem e sintonia, otimizando tolerância às incertezas e imunidade ao ruído nas malhas de realimentação. As soluções apresentadas contribuem para redução de custos de fabricação, assim como manutenção dos equipamentos, uma vez que o conjunto de componentes eletrônicos necessários na composição do equipamento é reduzida. Dentro do apresentado contexto, esta tese é dividida em três partes, agrupando um conjunto de contribuições distintas em cada caso, exploradas com diferentes topologias de circuitos. Na primeira e segunda parte são apresentadas duas soluções de controladores sensorless, o primeiro baseado na orientação dos sinais, e o segundo baseado na modulação. Enquanto a primeira e segunda parte focam na realização digital dos controladores, na terceira parte é apresentada uma solução em circuito integrado analógico-misturado, com potencial aplicação em sistemas de alta densidade. Também na terceira parte é discutida uma solução considerando circuitos de gerenciamento de energia com dois estágios de conversão. A fim de demonstrar a viabilidade técnica das contribuições, simulações numéricas e resultados experimentais obtidos em laboratório a partir de protótipos são apresentados. Análises da operação em regime permanente e transitórios são discutidos, mostrando que um desempenho satisfatório e estável é obtido através das técnicas propostas. / This doctoral dissertation presents a set of contributions considering the development of pulse width modulated electronic controllers for static power compensators, applied in the mitigation of harmonic components of voltage and current. Among the novelties of the presented techniques, the following charact.eristics are highlighted: greater integration made possible with the reduction of the number of sensors, and robust design, considering the modeling and tuning, optimizing the tolerance for uncertainties and noise immunity in the feedback schemes. The presented solutions contribute for the reduction of manufacturing costs, since the set of electronic components for the equipment composition is reduced. In the presented context, this thesis is divided in three parts, grouping a set of distinct contributions in each case, which is explored with different circuit topologies. In the first and second parts two main solutions for sensorless controllers are presented, the first based in the signals orientations, and the second in the modulation. Whereas the first and second part focuses on the digital realization of the controllers, the third part presents an analog-mixed integrated circuit solution, with potential applications in high-density systems. In addition, the third part discusses a solution considering power management circuits with two-stage conversion. In order to demonstrate the technical feasibility of the presented contributions, numerical simulations and experimental results obtained through laboratory prototypes are presented. Analysis of the steady-state regime and transients are discussed, showing that a satisfactory performance is obtained through the proposed techniques.

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Dans le présent document on aborde trois divers thèmes liés au contrôle et au calcul stochastiques, qui s'appuient sur la notion d'équation différentielle stochastique rétrograde (EDSR) dirigée par une mesure aléatoire. Les trois premiers chapitres de la thèse traitent des problèmes de contrôle optimal pour différentes catégories de processus markoviens non-diffusifs, à horizon fini ou infini. Dans chaque cas, la fonction valeur, qui est l'unique solution d'une équation intégro-différentielle de Hamilton-Jacobi-Bellman (HJB), est représentée comme l'unique solution d'une EDSR appropriée. Dans le premier chapitre, nous contrôlons une classe de processus semi-markoviens à horizon fini; le deuxième chapitre est consacré au contrôle optimal de processus markoviens de saut pur, tandis qu'au troisième chapitre, nous examinons le cas de processus markoviens déterministes par morceaux (PDMPs) à horizon infini. Dans les deuxième et troisième chapitres les équations d'HJB associées au contrôle optimal sont complètement non-linéaires. Cette situation survient lorsque les lois des processus contrôlés ne sont pas absolument continues par rapport à la loi d'un processus donné. Etant donné ce caractère complètement non-linéaire, ces équations ne peuvent pas être représentées par des EDSRs classiques. Dans ce cadre, nous avons obtenu des formules de Feynman-Kac non-linéaires en généralisant la méthode de la randomisation du contrôle introduite par Kharroubi et Pham (2015) pour les diffusions. Ces techniques nous permettent de relier la fonction valeur du problème de contrôle à une EDSR dirigée par une mesure aléatoire, dont une composante de la solution subit une contrainte de signe. En plus, on démontre que la fonction valeur du problème de contrôle originel non dominé coïncide avec la fonction valeur d'un problème de contrôle dominé auxiliaire, exprimé en termes de changements de mesures équivalentes de probabilité. Dans le quatrième chapitre, nous étudions une équation différentielle stochastique rétrograde à horizon fini, dirigée par une mesure aléatoire à valeurs entières sur $R_+ times E$, o`u $E$ est un espace lusinien, avec compensateur de la forme $nu(dt, dx) = dA_t phi_t(dx)$. Le générateur de cette équation satisfait une condition de Lipschitz uniforme par rapport aux inconnues. Dans la littérature, l'existence et unicité pour des EDSRs dans ce cadre ont été établies seulement lorsque $A$ est continu ou déterministe. Nous fournissons un théorème d'existence et d'unicité même lorsque $A$ est un processus prévisible, non décroissant, continu à droite. Ce résultat s’applique par exemple, au cas du contrôle lié aux PDMPs. En effet, quand $mu$ est la mesure de saut d'un PDMP sur un domaine borné, $A$ est prévisible et discontinu. Enfin, dans les deux derniers chapitres de la thèse nous traitons le calcul stochastique pour des processus discontinus généraux. Dans le cinquième chapitre, nous développons le calcul stochastique via régularisations des processus à sauts qui ne sont pas nécessairement des semimartingales. En particulier nous poursuivons l'étude des processus dénommés de Dirichlet faibles, dans le cadre discontinu. Un tel processus $X$ est la somme d'une martingale locale et d'un processus adapté $A$ tel que $[N, A] = 0$, pour toute martingale locale continue $N$. Pour une fonction $u: [0, T] times R rightarrow R$ de classe $C^{0,1}$ (ou parfois moins), on exprime un développement de $u(t, X_t)$, dans l'esprit d'une généralisation du lemme d'Itô, lequel vaut lorsque $u$ est de classe $C^{1,2}$. Le calcul est appliqué dans le sixième chapitre à la théorie des EDSRs dirigées par des mesures aléatoires. Dans de nombreuses situations, lorsque le processus sous-jacent $X$ est une semimartingale spéciale, ou plus généralement, un processus de Dirichlet spécial faible, nous identifions les solutions des EDSRs considérées via le processus $X$ et la solution $u$ d’une EDP intégro-différentielle associée. / In the present document we treat three different topics related to stochastic optimal control and stochastic calculus, pivoting on thenotion of backward stochastic differential equation (BSDE) driven by a random measure.After a general introduction, the three first chapters of the thesis deal with optimal control for different classes of non-diffusiveMarkov processes, in finite or infinite horizon. In each case, the value function, which is the unique solution to anintegro-differential Hamilton-Jacobi-Bellman (HJB) equation, is probabilistically represented as the unique solution of asuitable BSDE. In the first chapter we control a class of semi-Markov processes on finite horizon; the second chapter isdevoted to the optimal control of pure jump Markov processes, while in the third chapter we consider the case of controlled piecewisedeterministic Markov processes (PDMPs) on infinite horizon. In the second and third chapters the HJB equations associatedto the optimal control problems are fully nonlinear. Those situations arise when the laws of the controlled processes arenot absolutely continuous with respect to the law of a given, uncontrolled, process. Since the corresponding HJB equationsare fully nonlinear, they cannot be represented by classical BSDEs. In these cases we have obtained nonlinear Feynman-Kacrepresentation formulae by generalizing the control randomization method introduced in Kharroubi and Pham (2015)for classical diffusions. This approach allows us to relate the value function with a BSDE driven by a random measure,whose solution hasa sign constraint on one of its components.Moreover, the value function of the original non-dominated control problem turns out to coincide withthe value function of an auxiliary dominated control problem, expressed in terms of equivalent changes of probability measures.In the fourth chapter we study a backward stochastic differential equation on finite horizon driven by an integer-valued randommeasure $mu$ on $R_+times E$, where $E$ is a Lusin space, with compensator $nu(dt,dx)=dA_t,phi_t(dx)$. The generator of thisequation satisfies a uniform Lipschitz condition with respect to the unknown processes.In the literature, well-posedness results for BSDEs in this general setting have only been established when$A$ is continuous or deterministic. We provide an existence and uniqueness theorem for the general case, i.e.when $A$ is a right-continuous nondecreasing predictable process. Those results are relevant, for example,in the frameworkof control problems related to PDMPs. Indeed, when $mu$ is the jump measure of a PDMP on a bounded domain, then $A$ is predictable and discontinuous.Finally, in the two last chapters of the thesis we deal with stochastic calculus for general discontinuous processes.In the fifth chapter we systematically develop stochastic calculus via regularization in the case of jump processes,and we carry on the investigations of the so-called weak Dirichlet processes in the discontinuous case.Such a process $X$ is the sum of a local martingale and an adapted process $A$ such that $[N,A] = 0$, for any continuouslocal martingale $N$.Given a function $u:[0,T] times R rightarrow R$, which is of class $C^{0,1}$ (or sometimes less), we provide a chain rule typeexpansion for $u(t,X_t)$, which constitutes a generalization of It^o's lemma being valid when $u$ is of class $C^{1,2}$.This calculus is applied in the sixth chapter to the theory of BSDEs driven by random measures.In several situations, when the underlying forward process $X$ is a special semimartingale, or, even more generally,a special weak Dirichlet process,we identify the solutions $(Y,Z,U)$ of the considered BSDEs via the process $X$ and the solution $u$ to an associatedintegro PDE.