Projeto de torres metálicas de suporte de cabos de energia elétrica - Aplicação da parte 3-1 Eurocódigo 3

Mestrado em Engenharia Civil – Ramo Estruturas

ANN based support for distributed energy resources scheduling in smart grids

The future scenarios for operation of smart grids are likely to include a large diversity of players, of different types and sizes. With control and decision making being decentralized over the network, intelligence should also be decentralized so that every player is able to play in the market environment. In the new context, aggregator players, enabling medium, small, and even micro size players to act in a competitive environment, will be very relevant. Virtual Power Players (VPP) and single players must optimize their energy resource management in order to accomplish their goals. This is relatively easy to larger players, with financial means to have access to adequate decision support tools, to support decision making concerning their optimal resource schedule. However, the smaller players have difficulties in accessing this kind of tools. So, it is required that these smaller players can be offered alternative methods to support their decisions. This paper presents a methodology, based on Artificial Neural Networks (ANN), intended to support smaller players’ resource scheduling. The used methodology uses a training set that is built using the energy resource scheduling solutions obtained with a reference optimization methodology, a mixed-integer non-linear programming (MINLP) in this case. The trained network is able to achieve good schedule results requiring modest computational means.

Remote and mobile experimentation: pushing the boundaries of an ubiquitous learning place

Concepts like E-learning and M-learning are changing the traditional learning place. No longer restricted to well-defined physical places, education on Automation and other Engineering areas is entering the so-called ubiquitous learning place, where even the more practical knowledge (acquired at lab classes) is now moving into, due to emergent concepts such as Remote Experimentation or Mobile Experimentation. While Remote Experimentation is traditionally regarded as the remote access to real-world experiments through a simple web browser running on a PC connected to the Internet, Mobile Experimentation may be seen as the access to those same (or others) experiments, through mobile devices, used in M-learning contexts. These two distinct client types (PCs versus mobile devices) pose specific requirements for the remote lab infrastructure, namely the ability to tune the experiment interface according to the characteristics (e.g. display size) of the accessing device. This paper addresses those requirements, namely by proposing a new architecture for the remote lab infrastructure able to accommodate both Remote and Mobile Experimentation scenarios.

Multiagent System Architecture for Short-term Operation of Integrated Microgrids

The forthcoming smart grids are comprised of integrated microgrids operating in grid-connected and isolated mode with local generation, storage and demand response (DR) programs. The proposed model is based on three successive complementary steps for power transaction in the market environment. The first step is characterized as a microgrid’s internal market; the second concerns negotiations between distinct interconnected microgrids; and finally, the third refers to the actual electricity market. The proposed approach is modeled and tested using a MAS framework directed to the study of the smart grids environment, including the simulation of electricity markets. This is achieved through the integration of the proposed approach with the MASGriP (Multi-Agent Smart Grid Platform) system.

Forest fire detection with a small fixed wing autonomous aerial vehicle

In this work a forest fire detection solution using small autonomous aerial vehicles is proposed. The FALCOS unmanned aerial vehicle developed for remote-monitoring purposes is described. This is a small size UAV with onboard vision processing and autonomous flight capabilities. A set of custom developed navigation sensors was developed for the vehicle. Fire detection is performed through the use of low cost digital cameras and near-infrared sensors. Test results for navigation and ignition detection in real scenario are presented.

Formation Control Driven by Cooperative Object Tracking

In this paper we introduce a formation control loop that maximizes the performance of the cooperative perception of a tracked target by a team of mobile robots, while maintaining the team in formation, with a dynamically adjustable geometry which is a function of the quality of the target perception by the team. In the formation control loop, the controller module is a distributed non-linear model predictive controller and the estimator module fuses local estimates of the target state, obtained by a particle filter at each robot. The two modules and their integration are described in detail, including a real-time database associated to a wireless communication protocol that facilitates the exchange of state data while reducing collisions among team members. Simulation and real robot results for indoor and outdoor teams of different robots are presented. The results highlight how our method successfully enables a team of homogeneous robots to minimize the total uncertainty of the tracked target cooperative estimate while complying with performance criteria such as keeping a pre-set distance between the teammates and the target, avoiding collisions with teammates and/or surrounding obstacles.

Dimensionamento de Uma Cobertura em Elementos Estruturais de Aço Enformados a Frio

O presente relatório versa sobre a análise e dimensionamento de estruturas de aço enformadas a frio. Devido a serem estruturas de elevada esbelteza, frequentemente denominadas “estruturas de aço leve”, apresentam fenómenos de instabilidade tanto a nível local como global, sendo da perspetiva regulamentar abrangidas pelo Eurocódigo 3, nomeadamente pelas Partes 1-1, 1-3 e 1-5. A Parte 1-3 do Eurocódigo 3 diz respeito às regras suplementares de elementos de aço enformados a frio, na qual estão presentes as regras de dimensionamento, bem como as verificações de segurança que deverão ser aplicadas. Nesta, é possível ainda “fazer a ponte” com a Parte 1-1 do Eurocódigo 3, respetiva às regras gerais de projeto de estruturas de aço e com a Parte 1-5 do Eurocódigo 3 relativa a elementos estruturais constituídos por placas. Inicialmente, será realizado um estado da arte, onde será efetuado um enquadramento histórico, apresentando o processo de fabrico destes elementos e o tipo de elementos estruturais originados, concluindo-se com as vantagens/desvantagens dos perfis em aço enformados a frio. Os conceitos teóricos de estabilidade estrutural, os tipos de instabilidade mais comuns nestes elementos, bem como os tipos de análise destes fenómenos farão a ponte com o capítulo que se segue. Relativamente ao dimensionamento destes elementos, será dado enfâse às metodologias preconizadas pelo Eurocódigo 3, Parte 1-3. Este capítulo incidirá, entre outos, nas propriedades das secções transversais, na determinação da resistência destas, onde se contabilizará os efeitos das instabilidades locais de placa e distorcionais, na instabilidade global dos perfis e nas ligações entre os mesmos. Será analisada, posteriormente, a abordagem apresentada pela ECCS relativamente ao dimensionamento de madres travadas por painéis de cobertura. Neste capítulo será apresentada a metodologia para o dimensionamento de vigas com restrição à torção e à translação, bem como a resistência da secção transversal da madre e do seu banzo livre à encurvadura. Finalmente, e ao encontro do que foi proposto pela empresa CCAD-Serviços de Engenharia, Lda, efetuar-se-á o dimensionamento de uma cobertura de um edifício de distribuição, cobertura esta constituída por asnas treliçadas e madres simples. Neste dimensionamento foram consideradas as ações segundo o Regulamento de Segurança e Ações Para Estruturas de Edifícios e Pontes e o Eurocódigo 1, Parte 1-1 que diz respeito às Ações Gerais em Estruturas e Parte 1-4 respeitante às Ações do vento.