A principal motivação para o surgimento do conceito de Smart Grid é a otimização do uso das redes de energia através da inserção de novas tecnologias de medição, automação e telecomunicações. A implementação desta complexa infra-estrutura produz ganhos em confiabilidade, eficiência e segurança operacional. Além disso, este sistema tem como principais objetivos promover a geração distribuída e a tarifa diferenciada de energia para usuários residenciais, provendo ferramentas para a participação dos consumidores no gerenciamento global do fornecimento de energia. Considerando também o uso de dispositivos de armazenamento de energia, o usuário pode optar por vender ou armazenar energia sempre que lhe for conveniente, reduzindo a sua conta de energia ou, quando a geração exceder a demanda de energia, lucrando através da venda deste excesso. Esta pesquisa propõe um Sistema Inteligente de Suporte à Decisão baseado em técnicas de aprendizado por reforço como uma solução para o problema de decisão sequencial referente ao gerenciamento de energia de uma Smart Home. Resultados obtidos mostram um ganho significativo na recompensa financeira a longo prazo através do uso de uma política obtida pela aplicação do algoritmo Q-Learning, que é um algoritmo de aprendizado por reforço on-line, e do algoritmo Fitted Q-Iteration, que utiliza uma abordagem diferenciada de aprendizado por reforço ao extrair uma política através de um lote fixo de transições adquiridas do ambiente. Os resultados mostram que a aplicação da técnica de aprendizado por reforço em lote é indicada para problemas reais, quando é necessário obter uma política de forma rápida e eficaz dispondo de uma pequena quantidade de dados para caracterização do problema estudado. / The main motivation for the emergence of the Smart Grid concept is the optimization of power grid use by inserting new measurement, automation and telecommunication technologies into it. The implementation of this complex infrastructure also produces gains in reliability, efficiency and operational safety. Besides, it has as main goals to encourage distributed power generation and to implement a differentiated power rate for residential users, providing tools for them to participate in the power grid supply management. Considering also the use of energy storage devices, the user can sell or store the power generated whenever it is convenient, reducing the electricity bill or, when the power generation exceeds the power demand, make profit by selling the surplus in the energy market. This research proposes an Intelligent Decision Support System as a solution to the sequential decision-making problem of residential energy management based on reinforcement learning techniques. Results show a significant financial gain in the long term by using a policy obtained applying the algorithm Q-Learning, which is an on-line Reinforcement Learning algorithm, and the algorithm Fitted Q-Iteration, which uses a different reinforcement learning approach called Batch Reinforcement Learning. This method extracts a policy from a fixed batch of transitions acquired from the environment. The results show that the application of Batch Reinforcement Learning techniques is suitable for real problems, when it is necessary to obtain a fast and effective policy considering a small set of data available to study and solve the proposed problem.

As Redes Elétricas Inteligentes podem ser entendidas como o uso intensivo de tecnologias de informação e comunicação nas redes elétricas, permitindo um fluxo bidirecional de informações e eletricidade pela rede, de forma a obter uma infraestrutura capaz de automaticamente monitorar, proteger e otimizar a operação de seus elementos. A modernização da infraestrutura elétrica no sentido das Redes Elétricas Inteligentes é inevitável e trará profundas mudanças em todos os segmentos do sistema elétrico. Embora a tecnologia necessária para essa modernização já exista a um custo razoável, ainda restam várias questões que devem ser resolvidas. Indefinições em relação aos padrões a serem adotados, regulamentações, segurança, privacidade e vários aspectos tecnológicos dificultam uma implementação coerente, adiando essa modernização. Assim, este trabalho busca apresentar esse cenário em relação às Redes Elétricas Inteligentes, investigando as tendências e situação atual. Dentre essas tendências, há um grande interesse em definir e implementar mecanismos que incentivem uma maior conscientização dos consumidores em relação ao seu uso de energia, além de uma participação ativa dos mesmos no mercado de energia. Isso exigirá a utilização de ferramentas que possibilitem a redução de custos através do uso mais eficiente da energia. Assim, é também proposto um framework para a construção e análise dessas ferramentas que buscam auxiliar os consumidores nesse cenário em formação. O framework proposto foi construído utilizando uma abordagem por Sistemas Multiagentes e possibilita a construção, simulação e análise de diversos sistemas, em diferentes cenários, com variados tipos de equipamentos, tanto reais como virtuais, sob diferentes protocolos de comunicação e com a possibilidade de uso de diversos algoritmos para a operação conjunta dos equipamentos. / Smart Grids can be understood as the intensive use of information and communication technologies over the electricity networks, allowing a bidirectional flow of information and electricity through the network. It is a system that tries to optimize the supply and demand of energy through the integration of distributed generation and renewable energy resources, and through the active participation of consumers as well as an intense trade relationship between all the segments of the electricity sector. The modernization of the electrical infrastructure towards Smart Grids is inevitable and it will bring deep changes in all segments of the electrical system. Although the necessary technology for this modernization already exists at a reasonable cost, there are still several issues to be solved. Uncertainties regarding standards to be adopted, regulations, security, privacy and many technological aspects difficult a consistent implementation and, therefore, delay this modernization. Thus, this study aims to present the Smart Grid scenario, by the investigation of its current situation and tendencies. Among these tendencies, there is a great interest to define and implement mechanisms to encourage consumer to take care about their electrical energy use and to stimulate their active participation in the energy market. This will require tools that will help them to reduce costs through a more efficient use of energy. Therefore, this work proposes also a framework for the development and analysis of these tools that help consumers at this scenario under construction. The proposed framework is built using a Multiagent System approach which allows the construction, simulation and analysis of various systems in different scenarios. In addition, it allows the use of several types of equipments, both real and virtual, under different communication protocols and with the possible use of various algorithms for a joint operation of all Smart Grid equipments.

The use of smart grids is a reality in several developed countries, being a natural evolution for the electrical grids of any developing country, like Brazil. This evolution takes place through the interaction of communication systems with the electrical grids in a bidirectional communication of both data and energy flow using different protocols and communication technologies. Its validation occurs by the physical installation of equipments, or alternatively by computational simulators. This paper demonstrates through simulation the use viability of DNP3 (Distributed Network Protocol) encapsulated over TCP/IP over PLC (Power Line Communication). The network simulator software NS-2 was employed for PLC channel modeling and DNP3 implementation. Some quality parameters, such as packet loss, latency and thoughput, were evaluated under several scenarios. / A utilização de redes inteligentes de energia é uma realidade em diversos países desenvolvidos, sendo uma evolução natural para a rede elétrica de qualquer país em vias de desenvolvimento, como é o caso do Brasil. Essa evolução dá-se por uma interação dos sistemas de comunicação com as redes elétricas, em uma comunicação bidirecional, tanto de dados como de fluxo de energia, utilizando para isso protocolos e tecnologias de comunicação diferentes, cuja validação ocorre com uma instalação física dos equipamentos associados, ou, como alternativa, por simulação computacional. Este trabalho demonstra através de simulações a viabilidade do uso do protocolo DNP3 (do inglês Distributed Network Protocol) encapsulado em TCP/IP e em PLC (do inglês Power Line Communication) para aplicações em redes inteligentes, exceto para atividades que necessitem de comunicação em tempo real. Foram empregados o software de simulação de redes NS-2 para modelagem do canal PLC e do protocolo DNP3 e verificados parâmetros de qualidade, como perda de pacotes, latência e vazão de dados sob diversos cenários de aplicações. / São Cristóvão, SE

Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2016-08-19T12:10:26Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) DISSERTAÇÃO FINAL - IGOR CAVALCANTE TORRES - 04_02_16.pdf: 6108263 bytes, checksum: d12cf897ea7f4db94d6b29273d3c061a (MD5) / Made available in DSpace on 2016-08-19T12:10:27Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) DISSERTAÇÃO FINAL - IGOR CAVALCANTE TORRES - 04_02_16.pdf: 6108263 bytes, checksum: d12cf897ea7f4db94d6b29273d3c061a (MD5) Previous issue date: 2016-02-04 / CAPEs / Este trabalho descreve a operação e desempenho de um sistema fotovoltaico ligado à rede, alocado em um escritório comercial na cidade de Maceió, Alagoas. O gerador é composto por três subsistemas independentes, totalizando potência total de 1,6 kWp e conectada à rede elétrica local. Os subsistemas são compostos por tecnologias comerciais: Si-p e Si-m, permitindo a avaliação do desempenho operacional dessas tecnologias na condição de clima tropical marítimo. Para realizar a análise, o sistema foi particionado em três subsistemas distintos, onde inicialmente os subsistemas I e II operavam com um fator de dimensionamento de 1,42 e o subsistema III com um fator de 0,98. Cada arranjo dos geradores do subsistema I e II opera com quatro módulos de 140 Wp totalizando uma potência total de 560 Wp, sendo as células de silício policristalino e monocristalino, respectivamente. O subsistema III possui quatro módulos de 130 Wp, de silício policristalino totalizando 520 Wp. Para as tecnologias comerciais estudadas nos subsistemas I, II e III, sob as mesmas variabilidades climatológicas (irradiância, temperatura ambiente e velocidade do vento), condições padrão de instalação elétrica, FDI e inversores idênticos (800 W) os subsistemas I e II obtiveram os mesmo níveis de eficiência de conversão fotovoltaica máxima (13%), produtividade mensal média (145 kWh/kWp), coeficientes de desempenho bem próximos (78%). A eficiência de conversão, CCCA, para os inversores que estavam com FDI igual a 1,42, (subsistemas I e II) mostrou-se uma boa eficiência em toda a faixa de operação, entre 89 – 94%. Em contrapartida, o inversor que estava operando com um FDI igual a 0,87 (subsistema III), provou-se menos eficiente, tendo uma eficiência em torno de 81%. O desempenho operacional do seguidor do ponto de máxima potência mostrou-se ineficiente, porque o arranjo fotovoltaico estava trabalhando com tensão fixa em quase todo o tempo de operação. / This paper describes the operation and performance of a photovoltaic system connected to the network allocated on a commercial office in the city of Maceió, Alagoas. The generator consists of three independent subsystems, adding up of 1.6 kWp output installed and connected to the local power grid. The subsystems consist of commercial technologies: p-Si and m-Si, allowing the evaluation of the operating performance of these technologies in the maritime tropical climate condition. To perform the analysis the system has been partitioned into three distinct subsystems which initially subsystems I and II operated with a scale factor of 1.42 and subsystem III with a factor of 0.98. Each arrangement subsystems I and II operates four modules of 140 Wp adding up a total output of 560 Wp, using cells polycrystalline and monocrystalline silicon, respectively. The subsystem III has four modules of 130 Wp polycrystalline silicon with a total of 520 Wp. For commercial technologies studied the subsystems I, II and III under the same climate variability (irradiance ambient temperature, wind speed) electrical standard conditions, FDI and inverters (800 W), subsystems I and II obtained the same level of maximum photovoltaic efficiency conversion (13%), average monthly productivity (145 kWh / kWp), coefficient of performance (78%). The conversion efficiency, DC-AC, for inversors with FDI 1.42 (subsystems I and II) had a good efficiency across the operating rate, between 89-94%. However, the inverter were operating with a FDI equal 0.87 (subsystem III), was less efficient, having an efficiency around 81%. The operating performance at the point of maximum power proved to be inefficient, because the PV system array was working with fixed voltage for almost all operating time.

Optimization problems are vital in physical sciences, commercial and finance matters. In a nutshell, almost everyone is the stake-holder in certain optimization problems aiming at minimizing the cost of production and losses of system, and also maximizing the profit. In control systems, the optimal configuration problems are essential that have been solved by various newly developed methods. The literature is exhaustively explored for an appropriate optimization method to solve such kind of problems. Particle Swarm Optimization is found to be one of the best among several optimization methods by analysing the experimental results. Two novel PSO variants are introduced in this thesis. The first one is named as N State Markov Jumping Particle Swarm Optimization, which is based on the stochastic technique and Markov chain in updating the particle velocity. We have named the second variant as N State Switching Particle Swarm Optimization, which is based on the evolutionary factor information for updating the velocity. The proposed algorithms are then applied to some widely used mathematical benchmark functions. The statistical results of 30 independent trails illustrate the robustness and accuracy of the proposed algorithms for most of the benchmark functions. The better results in terms of mean minimum evaluation errors and the shortest computation time are illustrated. In order to verify the satisfactory performance and robustness of the proposed algorithms, we have further formulated some basic applications in power system operations. The first application is about the static Economic Load Dispatch and the second application is on the Dynamic Economic Load Dispatch. These are highly complex and non-linear problems of power system operations consisting of various systems and generator constraints. Basically, in the static Economic Load Dispatch, a single load is considered for calculating the cost function. In contrast, the Dynamic Economic Load Dispatch changes the load demand for the cost function dynamically with time. In such a challenging and complex environment the proposed algorithms can be applied. The empirical results obtained by applying both of the proposed methods have substantiated their adaptability and robustness into the real-world environment. It is shown in the numerical results that the proposed algorithms are robust and accurate as compared to the other algorithms. The proposed algorithms have produced consistent best values for their objectives, where satisfying all constraints with zero penalty.

Environmental concerns and long term energy security are the key drivers behind most current electric energy policies whose primary aim is to achieve a sustainable, reliable and affordable energy system. In a bid to achieve these aims many changes have been taking place in most power systems such as emergence of new low carbon generation technologies, structural changes of power system and introduction of competition and choice in electricity supply. As a result of these changes, the level of uncertainties is growing especially on generation side where the locations and available capacities of the future generators are not quite clear-cut. The transmission network needs to be flexibly and economically robust against all these uncertainties. The traditional operation of the network under preventive control mode is an inflexible practice which increases the total system cost. Corrective control operation strategy, however, can be alternatively used to boost the flexibility, to expedite the integration of the new generators and to decrease the overall cost. In this thesis, the main focus is on development of new techniques and methodologies that can be used for modelling and solving a transmission planning problem under the assumption that post-contingency corrective actions are plausible. Three different corrective actions, namely substation switching, demand response and generation re-dispatch are investigated in this thesis. An innovative multi-layer procedure deploying a genetic algorithm is proposed to calculate the required transmission capacity while substation switching is deployed correctively to eradicate the post-fault network violations. By using the proposed approach, a numerical study shows that the network investment reduces by 6.36% in the IEEE 24 bus test system. In another original study, generation re-dispatch corrective action is incorporated into the transmission planning problem. The ramp-rate constraints of generators are taken into account so that the network may be overloaded up to its short-term thermal rating while the generation re-dispatch action is undertaken. The results show that the required network investment for the modified IEEE 24 bus test system can be reduced by 23.8% if post-fault generation re-dispatch is deployed. Furthermore, a new recursive algorithm is proposed to study the effect of price responsive demands and peak-shifting on transmission planning. The results of a study case show that 7.8% of total investment can be deferred. In an additional study on demand response, a new probabilistic approach is introduced for transmission planning in a system where direct load curtailment can be used for either balancing mechanism or alleviating the network violations. In addition, the effect of uncertainties such as wind power fluctuation and CO2 emission price volatility are taken into account by using Monte Carlo simulation and Hypercube sampling techniques. Last but not least, a probabilistic model for dynamic thermal ratings of transmission lines is proposed, using past meteorological data. The seasonal correlations between wind power and thermal ratings are also calculated. £26.7 M is the expected annual benefit by using dynamic thermal ratings of part of National Grid's transmission network.

The modern smart grid would involve deep integration between measurement nodes, communication systems, artificial intelligence, power electronics and distributed resources. On one hand, this type of integration can dramatically improve the grid performance and efficiency, but on the other, it can also introduce new types of vulnerabilities to the grid. To obtain the best performance, while minimizing the risk of vulnerabilities, the physical power system must be designed as a security aware system. In this dissertation, an interoperability and communication framework for microgrid control and Cyber Physical system enhancements is designed and implemented taking into account cyber and physical security aspects. The proposed data-centric interoperability layer provides a common data bus and a resilient control network for seamless integration of distributed energy resources. In addition, a synchronized measurement network and advanced metering infrastructure were developed to provide real-time monitoring for active distribution networks. A hybrid hardware/software testbed environment was developed to represent the smart grid as a cyber-physical system through hardware and software in the loop simulation methods. In addition it provides a flexible interface for remote integration and experimentation of attack scenarios. The work in this dissertation utilizes communication technologies to enhance the performance of the DC microgrids and distribution networks by extending the application of the GPS synchronization to the DC Networks. GPS synchronization allows the operation of distributed DC-DC converters as an interleaved converters system. Along with the GPS synchronization, carrier extraction synchronization technique was developed to improve the system’s security and reliability in the case of GPS signal spoofing or jamming. To improve the integration of the microgrid with the utility system, new synchronization and islanding detection algorithms were developed. The developed algorithms overcome the problem of SCADA and PMU based islanding detection methods such as communication failure and frequency stability. In addition, a real-time energy management system with online optimization was developed to manage the energy resources within the microgrid. The security and privacy were also addressed in both the cyber and physical levels. For the physical design, two techniques were developed to address the physical privacy issues by changing the current and electromagnetic signature. For the cyber level, a security mechanism for IEC 61850 GOOSE messages was developed to address the security shortcomings in the standard.

The rapidly expanding power system grid infrastructure and the need to reduce the occurrence of major blackouts and prevention or hardening of systems against cyber-attacks, have led to increased interest in the improved resilience of the electrical grid. Distributed and decentralized control have been widely applied to computer science research. However, for power system applications, the real-time application of decentralized and distributed control algorithms introduce several challenges. In this dissertation, new algorithms and methods for decentralized control, protection and energy management of Wide Area Monitoring, Protection and Control (WAMPAC) and the Active Distribution Network (ADN) are developed to improve the resiliency of the power system. To evaluate the findings of this dissertation, a laboratory-scale integrated Wide WAMPAC and ADN control platform was designed and implemented. The developed platform consists of phasor measurement units (PMU), intelligent electronic devices (IED) and programmable logic controllers (PLC). On top of the designed hardware control platform, a multi-agent cyber-physical interoperability viii framework was developed for real-time verification of the developed decentralized and distributed algorithms using local wireless and Internet-based cloud communication. A novel real-time multiagent system interoperability testbed was developed to enable utility independent private microgrids standardized interoperability framework and define behavioral models for expandability and plug-and-play operation. The state-of-theart power system multiagent framework is improved by providing specific attributes and a deliberative behavior modeling capability. The proposed multi-agent framework is validated in a laboratory based testbed involving developed intelligent electronic device prototypes and actual microgrid setups. Experimental results are demonstrated for both decentralized and distributed control approaches. A new adaptive real-time protection and remedial action scheme (RAS) method using agent-based distributed communication was developed for autonomous hybrid AC/DC microgrids to increase resiliency and continuous operability after fault conditions. Unlike the conventional consecutive time delay-based overcurrent protection schemes, the developed technique defines a selectivity mechanism considering the RAS of the microgrid after fault instant based on feeder characteristics and the location of the IEDs. The experimental results showed a significant improvement in terms of resiliency of microgrids through protection using agent-based distributed communication.

Under de senaste åren har blockchain-tekniken fått mer och mer uppmärksamhet. Det har visat speciella fördelar i digital valuta, eftersom det distribueras och dess data inte kan ändras. Med fler länder som presenterar idén om kraftsysteminnovationen har ett stort antal distribuerade kraftkällor dykt upp. Nätanslutningen för dessa distribuerade kraftkällor leder till instabil nätdrift och ökar svårigheten att hantera kraftigt. Därför finns det ett akut behov av en lösning som kan realisera direkt transaktion av distribuerad kraftförsörjning. Denna artikel gör en fördjupad analys av blockchain-tekniken, inklusive hasalgoritm, konsensusmekanism, Merkle-träd, smart kontrakt etc. Och sedan studeras Ethereum och smarta nät. Den här artikeln realiserar automatisering och intelligens för mätning av eltransaktioner genom smart kontraktsteknik som tillhandahålls av Ethereum. En blockchain privat kedja skapas och sedan distribueras det smarta kontraktet i den privata kedjan. Med fördelarna med blockchaintekniken ovan kommer lagring av kraftdata och krafttransaktioner att vara mer trovärdig och mer transparent. Sammantaget designar och bygger detta papper ett smart grid-system baserat på blockchain-smarta teknik. Systemet kan inte bara användas för smarta nätsystem utan även för andra energisystem. Denna artikel ger en referens för tillämpning av blockchain-teknik. / In recent years, blockchain technology has received more and more attention. It has shown special advantages in digital currency, because it is distributed and its data cannot be altered. With more countries put forward the idea of the power system innovation, a large number of distributed power sources have emerged. The grid connection of these distributed power sources will lead to unstable grid operation and greatly increase the difficulty of management. Therefore, there is an urgent need for a solution that can realize direct transaction of distributed power supply. This article makes an in-depth analysis of the blockchain technology, including hash algorithm, consensus mechanism, Merkle tree, smart contract, etc. And then the Ethereum and smart grids are studied. This article realizes automation and intelligence of the electricity transaction measurement through the smart contract technology provided by Ethereum. A blockchain private chain is created and then the smart contract is deployed into the private chain. With the advantages of blockchain technology aforementioned, the storage of power data and the power transactions will be more credible and more transparent. All in all, this paper designs and builds a smart grid system based on the smart contract technology of blockchain. The system can be used not only for smart grid systems but also for other energy trading systems. This article provides a reference for the application of blockchain technology.

The diploma thesis provides an insight into the remote control and disconnection of DSO supply points phenomenon. The remote or local disconnection/connection of supply point is allowed by the breaker function. The automatic disconnection of supply point is enabled by the limiter function. Due to the anticipated implementation of smart meters in the Czech Republic in the future, this work contains the comprehensive description of breaker/limiter function with proposed possibilities of use in the Czech Republic. The thesis deals with the current breaker/limiter function use in the Czech Republic and in other countries. It introduces the smart meter installation in pilot projects to analyze the breaker/limiter function use in other countries. The thesis is focused on the technical solution of breaker/limiter. Moreover, it describes the ways of connecting the breaker, settting the limiter, connecting/disconnecting a supply point and breaker operation. Further, the thesis introduces the ways of activating the breaker by a customer and defines in which cases it is possible to limit and interrupt the electricity supply in the Czech Republic currently. The main aim of thesis is to describe the specific possibilities of breaker/limiter function use in the Czech Republic. With regard to the function use in other countries and the limiting or interrupting the electricity supply by DSO according to energy law, the possibilities of use are proposed. Each possibility of use is analyzed when implementing the breaker function or the breaker/limiter function. The benefits are defined for a DSO and for a customer. The proposed uses are evaluated in terms of applicability and valid legislation in the Czech Republic. The result of this work is the summary of information about breaker/limiter function which is one of the new features in the implementation of smart metering. The function installation and the implementation of possibilities described in the thesis depends on the DSO decision.