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Metodologia de Controlo Preditivo para Otimização Energética de Equipamentos Domésticos no Sector Residencial

Publication . Oliveira, David José Santos; Catalão, João Paulo da Silva; Pouresmaeil, Edris

Esta dissertação tem como objetivo principal implementar a técnica de controlo preditivo em algumas cargas residenciais. Pretende-se que a técnica de controlo preditivo seja implementada nas cargas residenciais, para que se possa conseguir um melhor aproveitamento da energia, e uma consequente redução da conta da eletricidade. Uma vez que o sector residencial tem um grande impacto percentual ao nível do consumo energético mundial, e uma redução de energia consumida neste sector é algo necessário, para reduzir os gases com efeitos de estufa que advêm da produção de eletricidade. Para tal efeito, foram então feitas simulações com a duração de 24 horas, em cargas residenciais como o ar condicionado, o termoacumulador e o frigorífico. Cada carga é modelada em tempo discreto, e para tal foram sempre utilizados parâmetros reais, com o objetivo de aproximar os resultados o mais próximo possível da realidade. Assim, foi possível aplicar a técnica de controlo preditivo em algumas cargas como o ar condicionado. Outras cargas como a máquina de lavar roupa, foram simuladas para serem observados os seus efeitos ao nível de consumo e eficiência energética quando juntos com outros equipamentos. Durante a aplicação do controlo preditivo, este foi estudado de tal forma que foi possível aprofundar os conhecimentos sobre ele e assim, explorar funções adicionais que levaram à obtenção de resultados melhorados acima do que era previsto inicialmente. Foi ainda desenvolvido um programa para prever cenários de consumo ótimo, em função das cargas utilizadas nas habitações. Os resultados foram todos obtidos a partir do software Matlab/Simulink onde foi utilizada a toolbox do controlo preditivo (MPC). Todos os resultados obtidos foram bastante satisfatórios, tendo em conta o objetivo inicial de reduzir a energia consumida e consequentemente reduzir o custo da eletricidade.

2015-6-3Master thesis

Open access

Optimal behavior of a PEV parking lot in renewable-based power systems

Publication . Gil, Fábio Alexandre da Silva; Catalão, João Paulo da Silva; Shafie-Khah, Miadreza

There have been a lot of developments in terms of Plug-in Electric Vehicles (PEVs) regarding many different subjects, and with some variations between authors. On this basis, it is intended to sum up a lot of contents being approached, and help understanding them. Followed by the development and analysis of a model in order to better understand the functionality of these new developments. First a state of the art is presented where the new development are presented, these will include management of the PEV’s, uncontrolled or controlled (i.e. aggregated) and their capability of using V2G and G2V technologies are analyzed. Afterwards, electricity markets are approached where real world applications are shown and different market types are categorized in order to a better understanding of the subject. The interaction of the PEVs with some renewable energy resources (e.g. solar, wind and biomass) is presented. To finalize, models of PEVs are categorized and multiple types of modules, the related variables, applied methods, and the considered parameters are presented. For a case analysis, a model that includes a parking lot of PEVs will be studied, which includes renewable energy resources, wind and solar. The objective is to analyze the impact of these on the market participation of the parking lot and also on the distribution grid. These analyses will be made on size variations, grid placement and also constraint variations of the model.

2015-7-3Master thesis

Open access

Nova metodologia multiobjetivo de apoio à decisão para problemas de reconfiguração de sistemas de distribuição de energia elétrica

Publication . Santos, Sérgio da Fonseca; Catalão, João Paulo da Silva

Os sistemas de distribuição de energia elétrica são geralmente estruturados como sistemas que contêm poucas malhas mas a maioria deles opera com uma topologia radial, principalmente para acomodar a proteção coordenada. Obter a configuração radial ótima sob vários critérios tem sido um tema de investigação ativo nas últimas duas décadas. Motivado pelo elevado esforço computacional requerido e pela não linearidade do problema, a maioria das metodologias propostas, mono-objetivo ou multiobjetivo, usam várias meta-heurísticas. Nesta dissertação, o problema de reconfiguração de sistemas de distribuição é formulado como sendo de programação linear inteira-mista multiobjetivo, respeitando as restrições de radialidade. Implementando uma versão melhorada do método de e-Restrições permite gerar uma representação adequada do conjunto de Pareto, sendo uma nova contribuição relativamente a estudos anteriores. O objetivo consiste em determinar as configurações radiais ótimas durante vários intervalos de tempo, minimizando as perdas de energia ativa e os custos emergentes das operações de switching. A metodologia proposta é inicialmente testada em sistemas de 16 e 69 nós, sendo posteriormente testada num sistema real baseado na Ilha de S. Miguel nos Açores.

2014-7-7Master thesis

Open access

Reserve services provision by demand side resources in systems with high renewables penetration using stochastic optimization

Publication . Paterakis, Nikolaos; Catalão, João Paulo da Silva

It is widely recognized that renewable energy sources are likely to represent a significant portion of the production mix in many power systems around the world, a trend expected to be increasingly followed in the coming years due to environmental and economic reasons. Among the different endogenous renewable sources that may be used in order to achieve reductions in the carbon footprint related to the electricity sector and increase the economic efficiency of the generation mix, wind power generation has been one of the most popular options. However, despite the potential benefits that arise from the integration of these resources in the power system, their large-scale integration leads to additional problems due to the fact that their production is highly volatile. As a result, apart from the typical sources of uncertainty that the System Operators have to face, such as system contingencies and intra-hour load deviations, through the deployment of sufficient levels of reserve generation, additional reserves must be kept in order to maintain the balance between the generation and the consumption. Furthermore, a series of other problems arise, such as efficiency loss because of ramping of conventional units, environmental costs because of increased emissions due to suboptimal unit commitment and dispatch and more costly system operation and maintenance. Recently, it has been recognized that apart from the generation side, several types of loads may be deployed in order to provide system services and especially, different types of reserves, through demand response. The contribution of demand side reserves to accommodate higher levels of wind power generation penetration is likely to be of substantial importance in the future and therefore, the integration of these resources in the system operations needs to be thoroughly studied. This thesis deals with the aspects of demand response as regards the integration of wind power generation in the power system. First, a mapping of the current status of demand response internationally is attempted, followed also by a discussion concerning the opportunities, the benefits and the barriers to the widespread adoption of demand side resources. Then, several joint energy and reserve market structures are developed which explicitly incorporate demand side resources that may contribute to energy and reserve services. Two-stage stochastic programming is employed in order to capture the uncertainty of wind power generation. Moreover, several aspects of demand response are considered such as the capability of providing contingency and load following reserves, the appropriate modeling of industrial consumer processes load and the load recovery effect. Finally, this thesis investigates the effect of demand side resources on the risk that is associated with the decisions of the System Operator through appropriate risk management techniques, proposing also a novel methodology of handling risk as an alternative to the commonly used technique.

2015Doctoral thesis

Open access

Decision-Making Under Uncertainty for Market Bidding Strategies of Wind and Photovoltaic Technologies

Publication . Martins, Renata Filipa Morais; Catalão, João Paulo da Silva; López, Agustín Alejandro Sánchez de La Nieta

Electrical energy sector has been changing over the past years due to economic and environmental causes. The climate changes over the last decades have led to the Kyoto Protocol agreement in order to address these environmental concerns. The appointed solution which is proposed as an answer to these concerns is the production of electrical energy through renewable energy sources (RES). RES not only contribute to these environmental goals, but also are an opportunity to reduce the economic challenges that countries face due to fossil fuel dependence. However, it is important to address the challenges that come from adopting RES as a means of energy production. Several RES such as wind and solar production, which are strongly dependent on weather conditions, could have a negative impact on market structures. The production from these types of sources can introduce significant uncertainty to electricity markets, which could further hinder their use. If the investments on RES production units such as wind and solar are to be successful, decision-making models could help the investors to be confident regarding the investment, increasing the promotion of the use of these technologies. In this dissertation, two bidding strategies in the day-ahead market are presented. The proposed strategies maximize the profits from offering the wind and photovoltaic production in the dayahead market, improving the production management.

2015-7-3Master thesis

Open access