Is it advisable for a State to eliminate the annulment action of its Law of Arbitration? Can the parties, by virtue of their party autonomy, waive the annulment action?.In the present article, the author demonstrates that the annulment action has a psychological and a legal-political basis, since, on the one hand, it satisfies the psychological need to challenge or contradict, which is inherent of human beings and; on the other, within the framework of Constitutional State it constitutes a democratic tool that guarantees the control of power. / ¿Es aconsejable que un Estado elimine el recurso de anulación de su Ley de Arbitraje? ¿Pueden las partes en virtud de su autonomía privada renunciar al recurso de anulación?.En el presente artículo, el autor demuestra que el recurso de anulación tiene un sustento psicológico y un sustento jurídico-político, puesto que satisface, por un lado, la necesidad psicológica de impugnar o contradecir, la cual es inherente el ser humano y; por el otro, en el marco de un Estado Constitucional constituye una herramienta democrática que garantiza el control de poder.

A utilização de conversores multiníveis tem sido uma importante alternativa para aplicações de alta potência e média tensão, graças aos altos níveis de potência alcançáveis por estas estruturas. Recentemente, esta topologia de conversores foi aplicada em sistemas com fontes alternativas para alimentar um sistema de geração distribuída, nos quais diferentes fontes de energia eram utilizadas. Com base nas características dos conversores multinível e sua potencial aplicabilidade em sistemas de geração distribuída, este trabalho tem como objetivo construir um sistema multinível conectado a rede de distribuição para utilização de fontes alternativas de energia como fontes primárias. Considerando que a energia fornecida pelas fontes alternativas pode sofrer variações, propõe-se a integração de sistemas armazenadores de energia, como capacitores, ao sistema multinível. Por isso, este trabalho desenvolve uma estratégia de controle para máxima transferência de potência ativa entregue à rede a fim de obter um fluxo ótimo. A topologia multinível deste trabalho possui em sua configuração dois módulos inversores conectados em série. Neste caso, é possível que pelo menos um desses inversores funcione com uma modulação em baixa frequência processando a maior parcela de potência. Assim, duas estratégias de controle modulação de fase e modulação de amplitude para a transferência de potência realizada pelo inversor de baixa frequência são analisadas. As vantagens e desvantagens de cada um dos métodos são expostas e então a estratégia mais adequada, no caso a modulação de amplitude, é utilizada na operação do conversor multinível. Além disso, são apresentados a modelagem das plantas e o projeto dos controladores de cada um dos módulos inversores. Por fim, a validação da proposta é feita através dos resultados de simulações e experimentais que mostram a capacidade do sistema de geração em transferir potência constante para a rede de distribuição e manter a corrente quase sem distorções em fase com a tensão. / The utilization of multilevel converters has been an important alternative for medium voltage applications with high power and power quality demand, thanks to the high power levels achievable for this kind of structure. Recently, this converter topology was proposed as a new possibility in renewable energy source applications, mainly in system delivering power to the grid, where different renewable energy resources may be used. Based on the characteristics of multilevel converters, and their potential applicability in distributed generation systems, this study aims to build a multilevel system that could be powered by renewable energy sources as primary sources and then connect them to a distribution grid. However, considering the energy produced by alternative sources can vary, it is analyzed the integration of a storage energy system in this multilevel topology. Taking into account this ends, the main concern of this study is related to the development of a control strategy to maximize the active power transferred to the grid. The multilevel topology employed in this study has two H-bridge inverter modules connected in series forming a cascaded configuration. Therefore, it is possible that at least one of these inverters, operating with a low frequency of modulation, process the majority of power with lower amount of losses. On this way, two control strategies for power transfer are analyzed. The advantages and disadvantages of each method are presented, and the most appropriated strategy is used in the operation of the multilevel converter system. In addition, it has been presented the design criteria for each controller and finally the validation of the proposed approach is done by mains of simulations and experimental results which show the ability of the converter to transfer constant active power to the grid and keep the grid current in phase with the grid voltage.

Le régulateur PID (Proportionnel-Intégral-Dérivée) est la commande par retour d'état la plus connue. Elle permet d'aborder un bon nombre de problèmes de commande, particulièrement pour des systèmes faiblement non linéaire et dont la performance requise est relativement modeste. En plus, en raison de sa simplicité, la commande PID est largement utilisée en l'industrie. Étant donnés que les méthodes de réglage de la commande PID sont basées sur la linéarisation, la synthèse d'un contrôleur autour d'un point d'équilibre est relativement simple, néanmoins, la performance sera faible dans des modes de fonctionnement loin du point d'équilibre. Pour surmonter ce désavantage, une pratique courante consiste en adapter les gains du PID, procédure connue sous le nom de séquencement de gain (ou gain-scheduling en anglais). Il y a plusieurs désavantages à cette procédure, comme la commutation des gains de la commande et la définition -non triviale- des régions de l'espace d'état dans lesquelles cette commutation aura lieu. Ces deux problèmes se compliquent quand la dynamique est fortement non linéaire. Dans d'autres méthodes, la synthèse de la commande utilise des schémas empiriques, ce qui ne permet pas l'analyse de la stabilité globale du processus. Dans ce contexte, ce travail de thèse a pour objectif de synthétiser des contrôleurs PI, basés sur la passivité, de telle sorte que la stabilité globale du système en boucle fermé soit garantie. L'un des avantages à utiliser la passivité est son attrait intuitif, qui exploite les propriétés physique des systèmes. L'idée centrale dans un système passive est que l'écoulement d'énergie entrante au système provenant de l'extérieur n'est pas inférieur à l'incrément de son énergie de stockage. Par conséquence, ces systèmes ne peuvent pas stocker plus d'énergie que celle fournie, dont la différence correspond à l'énergie dissipée. En introduisant le concept d'énergie, cette méthodologie nous permet de formuler le problème de commande en celui de trouver un système dynamique dont la fonction de stockage d'énergie prend la forme désirée. En incorporant le concept d'énergie cette méthode devient accessible à la communauté de praticiens et permets de fournir des interprétations physique de l'action de commande. Dans cette thèse, une méthodologie constructive de commande PI basée sur la passivité est présentée et motivée par des applications à des systèmes physiques. / One of the best known forms of feeding back a system is through a three-term control law called PID (Proportional-Integral-Derivative) controller. PID controllers are sufficient for many control problems, particularly when process dynamics are not highly nonlinear and the performance requirements are modest. Besides, because of its simple structure, the PID controller is the most adopted control scheme by industry and practitioners, beeing the PI the form mostly employed. Since the PI tuning methods are based on the linearization, commissioning a PI to operate around a single operating point is relatively easy, however, the performance will be below par in wide operating regimes. To overcome this drawback the current practice is to re-tune the gains of the PI controllers based on a linear model of the plant evaluated at various operating points, a procedure known as gain-scheduling. There are several disadvantages of gain-scheduling including the need to switch (or interpolate) the controller gains and the non-trivial definition of the regions in the plants state space where the switching takes place - both problems are exacerbated if the dynamics of the plant is highly nonlinear. In other common scenarios, a little information about the process dynamics or only a "good" linear approximation is taken into account when designing the control design. This impedes to analyse the global stability of the system. In this context, the current thesis work is aimed at the designing of PI controllers, based on the passivity theory, such that the stability of the closed-loop system is guarantied. One of the main advantages of passivity concepts is that they offer a physical and intuitive appeal. The primary idea in passive systems is that the power flowing into the system is not less that the increase of storage. Thus, they cannot store more energy than is supplied to it from the outside, with the difference being the dissipated energy. Thus, introducing the concept of energy, this methodology allows to recast the control problem as finding a dynamical system such that system energy function takes the desired form. Also, with this formulation, the communication between practitioners and control theorists is facilitated, incorporating prior knowledge of the system and providing physical interpretations of the control action. In this thesis, a constructive methodology for deriving PI passivity-based controllers is presented and motivated by the application to physical systems.

[pt] O objetivo desta dissertação é realizar uma introdução aos estudos e às aplicações dos Esquemas de Proteção de Sistemas -EPSs- usados para manter a segurança dos Sistemas de Energia Elétrica. Um pequeno conjunto de definições e conceitos das áreas de proteção, confiabilidade e análise de desempenho de sistemas de potência é apresentado com o objetivo de distinguir os EPSs das proteções convencionais de componentes do sistema. Isto também ajuda a entender as funções dos EPSs com mais clareza. Os EPSs são usados para manter a integridade do sistema quando este está submetido a fenômenos que provocam instabilidade ou desligamentos em cascata. A classificação e a descrição destes fenômenos, bem como a aplicação dos EPSs estão mostradas nesta dissertação. A estrutura geral dos EPSs, as formas de classificá-los e as diferentes ações usadas pelos EPSs para controlar as perturbações são objeto de análise do trabalho. Para exemplificar, é dada uma visão de como se situam os EPSs no Sistema Interligado Brasileiro (SIB) e também pelo restante do mundo. Alguns EPSs usados no Brasil mereceram destaque especial.As análises dos principais blecautes ocorridos no Brasil e na América do Norte são apresentadas, de forma resumida, no apêndice I. Dessas análises são tiradas muitas lições para implementar medidas que minimizam o risco de interrupções no suprimento de energia. Também é feita uma comparação do grau de severidade dos grandes blecautes ocorridos no Brasil e, para os dois maiores, é realizada uma estimativa dos seus respectivos custos de interrupção. Procurou-se também, no apêndice II, estabelecer os requisitos básicos para a implantação de EPSs que usem tecnologia baseada em microprocessadores.Com base na experiência vivida nos estudos desenvolvidos pelo grupo que analisou a segurança do SIB após o blecaute de 11-MAR-99, foram estabelecidos critérios e procedimentos para analisar a segurança do sistema e realizar estudos de implantação de EPSs. E, como desfecho, é realizado um breve estudo do SIB, onde é analisado o desempenho dos EPSs para controlar graves emergências que podem ocorrer no presente momento. / [en] The objective of this dissertation is to accomplish an introduction to the studies and the applications of the System Protection Schemes -SPSs- used to maintain the Electric Energy Systems safety. A small group of definitions and concepts from the protection,reliability and power systems performance analysis areas is presented with the objective of distinguishing SPSs from the conventional system component protections. It also helps in understanding the functions of the SPSs with more clarity. The SPSs are used to maintain the integrity of the system when it is submitted to phenomena that provoke instability or cascade circuit outages. The classification and the description of these phenomena, as well as the SPSs application are shown in this dissertation. The general structure of the SPSs, the ways of classifying them and the different actions used by SPSs to control the disturbances are the objectives of the analysis of this work. In order to exemplify, a vision is given of how the SPSs are located in the Brazilian Interconnected System -BIS- and also in the rest of the world. Some SPSs used in Brazil deserved special attention.The analyses of the main blackouts that occurred in Brazil and in North America are presented, in a summarized term, in appendix I. Considerable knowledge is obtained from these analyses, leading to implementation measures that minimize the risk of interruptions in the energy supply. A comparison is also made of the degree of severity of the great blackouts that happened in Brazil and, for the two largest, an estimate of their respective interruption costs is made. In appendix II, an attempt was also made to establish the basic requirements for the SPSs implementation using microprocessing technology. Based on the experience lived during the studies developed by the group that analyzed the safety of the BIS after the blackout on March 11/1999, criteria and procedures to analyze the safety of the system and to accomplish studies of SPSs implantation were established. Finally, a brief study of the BIS is done, where the SPSs performances are analyzed to verify the ability to control serious emergencies that can happen in the present moment.

Dissertation submitted in fulfilment of the requirements for the degree Master of Technology: Quality in the Faculty of Engineering at the Cape Peninsula University of Technology, 2013 / Many top performing businesses, which achieve superior levels of success and sustainability, have a sound, implemented, and well maintained, Quality Management System (QMS). The correlation between business success and an implemented management system has been shown in numerous papers. This research, which culminates in a quantitative measure of QMS performance, was conducted at Eskom’s Koeberg Nuclear Power Station (KNPS). The power station is the operating leg of the Koeberg Operating Unit (KOU). The researcher is a QMS lead auditor in the KNPS Quality Assurance Department. A program of audits is planned based on the KOU quality and safety manual and the national regulatory licencing requirements. The audit monitoring program is then implemented over a three year period and considers all the management system processes which impact on nuclear safety and business performance. The individual audits each consider ISO 9001 criteria in context of the business area audited. Each major business area (e.g. design, maintenance, etc.) within the power station adheres to all generic ISO 9001 QMS clauses and considerations, such as documentation management, records management, etc. Each process or business area audit is thus effectively a QMS audit. The audit results, when combined are therefore a representative measure of the overall organisational QMS performance. The potential value to be gained from the audit results and data accrued over the monitoring period has not been optimised to maximise the return on investment to Eskom. The research problem statement thus proposes that the performance measurement capability of the quality management system at Eskom's Koeberg Power Station is insufficient. This diminishes management's ability to identify business risk resulting from management system deficiencies, which impacts negatively on business performance. The research question seeks to determine how the performance measurement capability of the QMS can be improved to assist management in identifying business risk resulting from quality management system deficiencies in order to improve business performance. The research objectives are supported by the literature study, which identifies the quality management methods currently used in order to measure and subsequently improve business performance. It also shows how QMS performance measurement, when deconstructed and analysed can provide the required insight for supporting management decision making. The research approach is considered inductive in that a theory is developed based on the collection and the analysis of that data. Applied research, will thus serve as the basis of the research methodology as it is considered the most appropriate research approach, based on the need to answer practical questions around the measurement of QMS performance philosophy. The research shows that by introducing additional theming and severity data into the secondary audit findings data, it is possible over time to extract high level strategic direction information when analysing the additional metadata. The dimensions and value of the QMS Performance measuring instrument are: Ø A cause and effect theming philosophy of audit findings providing an additional context to business improvement advice to management. Ø The provision of a QMS process deficiency locator / identifier which targets management action areas for improvement. Ø The provision of a quantitative measure of the management system performance, providing a reference from which to improve. By providing a quantifiable measure of an organisations QMS performance, a reference point is provided to gauge QMS performance and also render a definitive measure to enable performance improvement of the business.

The intentions of the so-called "More Electrical Aircraft" (MEA) are higher efficiency and lower weight. A main topic here is the application of electrical instead of hydraulical, pneumatical and mechanical systems. The necessary power electronic devices have intermediate DC-links, which are typically supplied by a three-phase system with active B6 and passive B12 rectifiers. A possible alternative is the B6 diode bridge in combination with an active power filter (APF). Due to the parallel arrangement, the APF offers a higher power density and is able to compensate for harmonics from several devices. The use of the diode bridge rectifier alone is not permitted due to the highly distorted phase current. The following investigations are dealing with the development of an active power filter for a three-phase supply with variable frequency from 360 to 800 Hz. All relevant components such as inductors, EMC-filters, power modules and DC-link capacitor are designed. A particular focus is put on the customized power module with SiC-MOSFETs and SiC-diodes, which is characterized electrically and thermally. The maximum supply frequency slope has a value of 50 Hz/ms, which requires a high dynamic and robustness on the control algorithm. Furthermore, the content of 5th and 7th harmonics must be reduced to less than 2 %, which demands a high accuracy. To cope with both requirements, a two-stage filter algorithm is developed and implemented in two independent signal processors. Simulations and laboratory experiments confirm the performance and robustness of the control algorithm. This work comprehensively presents the design of aerospace rectifiers. The results were published in conferences and patents. / Hauptziele des sogenannten "More Electrical Aircraft" (MEA) sind Effizienzerhöhung und Gewichtseinsparung. Ein Schwerpunkt hierbei ist die Nutzung von elektrischen statt hydraulischen, pneumatischen und mechanischen Systemen. Die notwendigen Leistungselektroniken haben DC-Zwischenkreise, welche mittels aktiven B6 und passiven B12 Gleichrichtern aus dem Dreiphasennetz gespeist werden. Eine mögliche Alternative ist die B6 Diodenbrücke in Kombination mit einem aktiven Netzfilter, welcher aufgrund der parallelen Anordnung eine höhere Leistungsdichte aufweist und darüber hinaus mehrere Geräte gleichzeitig entstören kann. Die alleinige Nutzung einer Diodenbrücke ist aufgrund des hohen Anteils von Stromharmonischen nicht zulässig. Diese Arbeit beschäftigt sich mit der Entwicklung eines aktiven Filters für ein Dreiphasensystem mit variabler Frequenz von 360 bis 800 Hz. Es werden alle relevanten Bauteile wie Induktivitäten, EMV-Filter, Leistungsmodule und Zwischenkreiskondensator ausgelegt. Besonderes Augenmerk liegt auf dem kundenspezifischen Modul mit SiC-Dioden und SiCMOSFETs, welches vollständig elektrisch und thermisch charakterisiert wird. Die Änderung der Netzfrequenz beträgt bis zu 50 Hz/ms, was eine hohe Dynamik und Robustheit von der Filterregelung verlangt. Weiterhin ist im statischen Fall eine hohe Genauigkeit gefordert, da die 5. und 7. Harmonische auf unter 2% geregelt werden müssen. Um beiden Anforderungen gerecht zu werden, wird ein zweistufiger Regelungsalgorithmus entwickelt der auf zwei digitalen Signalprozessoren implementiert wird. Simulationen und Labormessungen bestätigen die Robustheit des Regelungskonzeptes. Diese Arbeit stellt umfassend die Entwicklung von Luftfahrtgleichrichtern dar. Die Ergebnisse wurden in Konferenzen und Patenten veröffentlicht.