No description available.

In July 2012, a paper by Gutfraind et al. introduced the neighbor-aided network installation problem, which asks for "a minimal cost ordering of the vertices of a graph, where the cost of visiting a node is a function of the number of neighbors that have already been visited." Additionally, in a 2018 paper by Cummings et al., two greedy heuristics were implemented to estimate solutions to the NANIP-Blackstart problem. This paper will evaluate the performance of the greedy heuristics introduced by Cummings et al., and compare their performance to a new heuristic. In addition to comparing heuristics, we will also look at varying the blackstart node and cost function. This analysis will be conducted by testing the heuristics on power networks from the SuiteSparse Matrix Collection and NIST Matrix Market. The goal of this body of work is to better understand the variables at play in the NANIP-Blackstart problem in order to work towards better estimated solutions.

abstract: Understanding the graphical structure of the electric power system is important in assessing reliability, robustness, and the risk of failure of operations of this criti- cal infrastructure network. Statistical graph models of complex networks yield much insight into the underlying processes that are supported by the network. Such gen- erative graph models are also capable of generating synthetic graphs representative of the real network. This is particularly important since the smaller number of tradi- tionally available test systems, such as the IEEE systems, have been largely deemed to be insucient for supporting large-scale simulation studies and commercial-grade algorithm development. Thus, there is a need for statistical generative models of electric power network that capture both topological and electrical properties of the network and are scalable. Generating synthetic network graphs that capture key topological and electrical characteristics of real-world electric power systems is important in aiding widespread and accurate analysis of these systems. Classical statistical models of graphs, such as small-world networks or Erd}os-Renyi graphs, are unable to generate synthetic graphs that accurately represent the topology of real electric power networks { networks characterized by highly dense local connectivity and clustering and sparse long-haul links. This thesis presents a parametrized model that captures the above-mentioned unique topological properties of electric power networks. Specically, a new Cluster- and-Connect model is introduced to generate synthetic graphs using these parameters. Using a uniform set of metrics proposed in the literature, the accuracy of the proposed model is evaluated by comparing the synthetic models generated for specic real electric network graphs. In addition to topological properties, the electrical properties are captured via line impedances that have been shown to be modeled reliably by well-studied heavy tailed distributions. The details of the research, results obtained and conclusions drawn are presented in this document. / Dissertation/Thesis / Masters Thesis Electrical Engineering 2015

Observando-se as diversas aplicações de robôs na área de serviços é possível perceber uma crescente busca por manipulação de ferramentas em lugares elevados utilizando dispositivos robóticos, visto que tais tarefas exigem a utilização de diversos equipamentos de segurança e apresentam um alto risco à presença humana. Os exemplos mais comuns desse tipo de tarefa são: inspeção de: máquinas de grande porte, tanques de armazenamento, silos, postes, linhas de transmissão e distribuição de energia elétrica, etc. Com o intuito de aplicar robôs a essas tarefas, e consequentemente aumentar a segurança e eficiência dessas operações, foi realizado, primeiramente neste trabalho, um estudo sobre as classes de robôs manipuladores existentes. Para tanto adotou-se uma classificação que separa os robôs de acordo com o número de juntas, o que gera uma divisão em três diferentes grupos, robôs discretos, robôs do tipo serpente e robôs contínuos. Ao analisar as três classes, observa-se que os robôs contínuos possuem mais graus de liberdade que os outros grupos, apresentando como estrutura uma coluna vertebral continuamente deformável, que em oposição aos tradicionais manipuladores robóticos elo/junta/elo, possuem mecanismos mais simplificados, controle menos complexo devido ao menor número de atuadores e podem interagir com obstáculos encontrados em seu ambiente sem criar grandes forças de contato. Ao utilizar configurações extrínsecas, ou seja, posicionando os atuadores fora da estrutura do robô, e transmitindo o movimento utilizando cabos, é possível construir robôs com alta isolação elétrica, o que é de grande utilidade para operações que envolvem tarefas nas proximidades de redes elétricas de alta tensão. Apesar das diversas vantagens, não foram encontradas na literatura aplicações de robôs contínuos na realização de tarefas em alturas elevadas. Levando em consideração as vantagens oferecidas pelos robôs contínuos, este trabalho propõe o estudo e a aplicação de um robô do tipo contínuo que possua uma arquitetura mais adequada para realizar trabalhos a alturas elevadas. Com o intuito de demonstrar as vantagens oferecidas por essa arquitetura, será realizado um estudo de caso no qual o objeto a ser inspecionado são as cruzetas de madeira em postes de distribuição de energia elétrica. Em uma segunda etapa, elabora-se o projeto mecânico do robô contínuo proposto, onde são detalhados os mecanismos propostos e são feitas simulações utilizando o método dos elementos finitos para analisar o comportamento da estrutura quando submetida a carregamentos. Em uma terceira etapa, adotando-se uma estratégia de controle seqüencial é elaborado o projeto de controle. Em uma ultima etapa, com o intuito de analisar o funcionamento do robô é construído um protótipo, com o qual são feitos os testes. / Among several applications of robots in the service field, it is possible to percept an increasing interest in manipulate tools in higher positions using automatic devices, due to the fact that such activities are high risked operations and demands the use of several safety equipments. The most common examples of this kind of activity are the inspection of machines, silos, electrical distribution poles, etc. With the aim of apply robots to these activities and increase the safety and efficiency in these operations, as a first step in this work is done the study of different kinds of manipulators. Adopting a classification based on the number of joints, it is possible to separate robots in three different classes: discrete robots, snake-like robots and continuum robots. By analyzing these classes, it is possible to say that continuum robots have more degrees of freedom than the robots of others groups; Compared with the classic discrete robots, continuum robots have simplified mechanisms, simpler control scheme due to the small number of actuators and, in the case of an obstacle, they can contour the obstacle without generating high contact forces. By positioning the actuators out of the robot structure and transferring the motion using cables, i.e., adopting an extrinsic actuation, it is possible to build continuum robots with high electric insulation that is important in applications in which the robot must work near of an electrical distribution network. Despite these advantages, no previous works concerning the use of continuum robots to work in higher positions were found in the literature. Considering the advantages offered by continuum robots, this work proposes a study and application of a continuum robot that uses a more suitable architecture to work in higher positions. Aiming to demonstrate the advantages provided by this architecture, It will be used a case study, in which, the object to be inspected is the wood cross-arms of an electrical poles used in the electrical distribution networks. In a second step, it is done the mechanical project of the robot, where the proposed mechanisms are explained and structural simulations using the finite element method are performed in order to analyze how the structure would react to loads. In a third step, by adopting a strategy of sequential control, it is done the control project. In the last step, with the aim of analyze the robot in practical situation, a prototype is built, which is used to perform the tests.

Observando-se as diversas aplicações de robôs na área de serviços é possível perceber uma crescente busca por manipulação de ferramentas em lugares elevados utilizando dispositivos robóticos, visto que tais tarefas exigem a utilização de diversos equipamentos de segurança e apresentam um alto risco à presença humana. Os exemplos mais comuns desse tipo de tarefa são: inspeção de: máquinas de grande porte, tanques de armazenamento, silos, postes, linhas de transmissão e distribuição de energia elétrica, etc. Com o intuito de aplicar robôs a essas tarefas, e consequentemente aumentar a segurança e eficiência dessas operações, foi realizado, primeiramente neste trabalho, um estudo sobre as classes de robôs manipuladores existentes. Para tanto adotou-se uma classificação que separa os robôs de acordo com o número de juntas, o que gera uma divisão em três diferentes grupos, robôs discretos, robôs do tipo serpente e robôs contínuos. Ao analisar as três classes, observa-se que os robôs contínuos possuem mais graus de liberdade que os outros grupos, apresentando como estrutura uma coluna vertebral continuamente deformável, que em oposição aos tradicionais manipuladores robóticos elo/junta/elo, possuem mecanismos mais simplificados, controle menos complexo devido ao menor número de atuadores e podem interagir com obstáculos encontrados em seu ambiente sem criar grandes forças de contato. Ao utilizar configurações extrínsecas, ou seja, posicionando os atuadores fora da estrutura do robô, e transmitindo o movimento utilizando cabos, é possível construir robôs com alta isolação elétrica, o que é de grande utilidade para operações que envolvem tarefas nas proximidades de redes elétricas de alta tensão. Apesar das diversas vantagens, não foram encontradas na literatura aplicações de robôs contínuos na realização de tarefas em alturas elevadas. Levando em consideração as vantagens oferecidas pelos robôs contínuos, este trabalho propõe o estudo e a aplicação de um robô do tipo contínuo que possua uma arquitetura mais adequada para realizar trabalhos a alturas elevadas. Com o intuito de demonstrar as vantagens oferecidas por essa arquitetura, será realizado um estudo de caso no qual o objeto a ser inspecionado são as cruzetas de madeira em postes de distribuição de energia elétrica. Em uma segunda etapa, elabora-se o projeto mecânico do robô contínuo proposto, onde são detalhados os mecanismos propostos e são feitas simulações utilizando o método dos elementos finitos para analisar o comportamento da estrutura quando submetida a carregamentos. Em uma terceira etapa, adotando-se uma estratégia de controle seqüencial é elaborado o projeto de controle. Em uma ultima etapa, com o intuito de analisar o funcionamento do robô é construído um protótipo, com o qual são feitos os testes. / Among several applications of robots in the service field, it is possible to percept an increasing interest in manipulate tools in higher positions using automatic devices, due to the fact that such activities are high risked operations and demands the use of several safety equipments. The most common examples of this kind of activity are the inspection of machines, silos, electrical distribution poles, etc. With the aim of apply robots to these activities and increase the safety and efficiency in these operations, as a first step in this work is done the study of different kinds of manipulators. Adopting a classification based on the number of joints, it is possible to separate robots in three different classes: discrete robots, snake-like robots and continuum robots. By analyzing these classes, it is possible to say that continuum robots have more degrees of freedom than the robots of others groups; Compared with the classic discrete robots, continuum robots have simplified mechanisms, simpler control scheme due to the small number of actuators and, in the case of an obstacle, they can contour the obstacle without generating high contact forces. By positioning the actuators out of the robot structure and transferring the motion using cables, i.e., adopting an extrinsic actuation, it is possible to build continuum robots with high electric insulation that is important in applications in which the robot must work near of an electrical distribution network. Despite these advantages, no previous works concerning the use of continuum robots to work in higher positions were found in the literature. Considering the advantages offered by continuum robots, this work proposes a study and application of a continuum robot that uses a more suitable architecture to work in higher positions. Aiming to demonstrate the advantages provided by this architecture, It will be used a case study, in which, the object to be inspected is the wood cross-arms of an electrical poles used in the electrical distribution networks. In a second step, it is done the mechanical project of the robot, where the proposed mechanisms are explained and structural simulations using the finite element method are performed in order to analyze how the structure would react to loads. In a third step, by adopting a strategy of sequential control, it is done the control project. In the last step, with the aim of analyze the robot in practical situation, a prototype is built, which is used to perform the tests.

No description available.

Power networks are one of the most complex systems in the field of electrical and computer engineering. In power networks, power supply-demand balancing can be achieved in a static or a dynamic model. In a static model, the power network cannot be easily adapted to intentional or unintentional network topology changes because the network design is predetermined, whereas in a dynamic model, the power network can be dynamically constructed and reconfigured at run-time, which leads to a more nimble, flexible, and stable system. In this dissertation, a novel Market-based Multi-agent System (MMS) is proposed to solve supply-demand balancing and power restoration problems in a dynamic model. The power network is modeled as a market environment consisting of Belief-Desire-Intention (BDI) agents representing three characters: 1) consumer, 2) supplier, and 3) middleman. The BDI agents are able to negotiate power supply and demand of the power network, with consumers exploring the market and exchanging power information with neighboring middlemen and suppliers. So long as all consumers and suppliers establish supply-demand relationships represented in tree data structures, a qualified minimal access structure is found as the lower bound of the system reliability. When contingencies occur, the agents can quickly respond and restore loads guided by the relationships using minimum computational resource. Based on case studies and simulation results, the proposed approach delivers more effective performance of contingencies response and better computation time efficiency as the scale of the power network expands. The proposed MMS shows promises for solving various real-world power supply-demand and restoration problems, and serves as a solid foundation for future power networks refinement and improvement. / Electrical and Computer Engineering

Yes / This paper proposes a new index to determine the static voltage stability of the load buses in a power network for certain operating conditions and hence identifies load buses which are close to voltage collapse. The proposed index is formulated from the quadratic equation derived from a two-bus network and is computed using the apparent power and the line impedance. The proposed index shows how far the load buses from their voltage stability limit and hence the most sensitive bus can be identified according to maximum loadability. 14 bus IEEE reliability test system is used to study the performance of the proposed index for its validity. A comparison is also made between proposed index and some other indices found in the literature. The results are discussed and key conclusion drawn.

La densité de puissance est devenue la principale préoccupation lorsqu'un circuit numérique est conçu. Comme pour tous les systèmes embarqués, chaque nouvelle génération de système numérique a plus d'applications que la précédente et exige en fin de compte une plus grande densité de puissance. C'est pourquoi de nombreux chercheurs et concepteurs industriels se sont penchés sur de nouvelles méthodes de réduction de la consommation énergétique des circuits numériques. La logique adiabatique est un style de conception prometteur qui peut réduire la dissipation d'énergie dynamique. La logique adiabatique est différente de la logique conventionnelle en deux principaux points : 1) l’alimentation d’une porte logique adiabatique est un signal à 4 phases, et 2) l’énergie stockée dans la porte est récupérée. Afin de respecter ces principes, la logique adiabatique nécessite une alimentation spéciale. Étant donné que l’objectif d’une telle alimentation est d’agir comme une horloge, elle est appelée alimentation-horloge. L'objectif de cette thèse est de concevoir et d'optimiser une alimentation-horloge ainsi que son réseau de distribution. Cette thèse a été financée par l'Agence Nationale pour la Recherche, ANR, avec le projet ADIANEMS2 (numéro de subvention : ANR-15-CE24-0013). / Power density has become the primary concern when a digital core is designed. As in any embedded systems, each new digital core generation has more applications than the previous one and ultimately demands more power density. This is why many researchers and industrial designers have been looking into novel methods for reducing power consumption of digital circuit. Adiabatic logic is a promising design style, which can reduce the dynamic energy dissipation. Adiabatic logic is different than conventional logic in two main points: 1) adiabatic gate are charged with a 4-phase power signal, and 2) the energy, which is stored in the gate, is recovered. In order to fulfill these principles, the adiabatic logic needs a special power supply. As the purpose of such supply is to act as a clock also, it is referred as power-clock supply. The aim of this thesis is to design and optimize a power-clock supply and its delivery network. This thesis has been funded by the French National Research Agency, ANR, with the project ADIANEMS2 (Grant number: ANR-15-CE24-0013).

<p>Utsikterna att kunna genomföra en återstart av de två små vattenkraftverk som behandlas i denna rapport år goda. Förutsättningarna är gynnsamma i så måtto att planerna för återstarten ligger väl i linje med praxis som etablerats genom avgöranden i de högre rättsliga instanserna gällande liknande fall. Ägaren planerar att driva verksamheten i stort sett så som den ursprungligen bedrevs, vilket visat sig betydelsefullt för att få återupptag av nedlagd vattenkraftverksamhet godkänt Dessa kraftverk är små, väldigt små. Detta betyder att investeringskostnaderna måste minimeras om det skall finns någon chans att uppnå en acceptabel återbetalningstid för investeringen. Några kostnader kan inte påverkas alls, till exempel anslutningen till elnätet. Vissa, såsom de för nya tuber, intagsgaller, samt kabel och utrustning till kraftverken, kan påverkas i någon mån genom att omsorgsfullt välja leverantörerna av utrustningen, samt välja de mest kostnadseffektiva (ofta liktydigt med de enklaste men ändå fungerande) lösningarna. Några få komponenter, såsom generatorn, kan gå att få tag på som begagnade, vilket hjälper till att hålla nere kostnaderna. Slutligen bör inte de pengar som finns att spara på att göra så mycket som möjligt av arbetet själv underskattas.</p> / <p>The prospects of achieving a restart of the two small hydropower plants studied in this report are good. The basic conditions are favourable in the sense that the plans for a restart are well in line with accepted procedures such as established by decisions in the highest courts regarding similar cases. The owner plans to run the operation in essentially the same way it was originally run, a circumstance which has proven to be important when seeking to get restart of discontinued hydropower activities approved. These power plants are small, very small. This means that investment costs has to be minimized if there is to be any chance of achieving an acceptable pay-off time for the investment. Some can't be affected at all, such as the cost for getting connected to the power network. Some, such as those of new tubes, intake bars and electrical wiring and equipment for the plants, can be affected to some extent by carefully choosing the suppliers of the equipment and choosing the most cost-efficient (in most cases synonymous with the simplest but yet functional) solutions. A few components, such as the generator, can possibly be obtained as used equipment, which helps keeping the costs down. Lastly, the potential of saving money by doing as much as possible of the work yourself should not be underestimated.</p>