The rapid growth of internet-connected smart devices capable of exchanging energy price information and adaptively controlling the consumption of connected loads, has paved the way for transactive control to make inroads in the modern grid. Transactive control frameworks integrate the wholesale and retail energy markets, and enable active participation of end users, thereby playing a key role in managing the rising number of distributed assets.However, the use of internet for the communication of data among the building, distribution,and transmission levels makes the system susceptible to external intrusions. A skilled adversary can potentially manipulate the exchanged data with the intention to inflict damage to the system or increase financial gains. In this thesis, the effect of such data integrity attacks on information exchanged between the distribution systems operator and end-users is investigated. Impact on grid operations is evaluated using different categories like operational, financial, user comfort and reliability parameters. It is shown that attack impact depends on a number of factors like attack duration, time of attack, penetration rate etc besides the attack magnitude. The effect of an attack continues to persist for some time after its removal and hence effective detection and mitigation strategies will be required to ensure system resilience and robustness. / Master of Science / Transactive energy is a framework where price-responsive loads adjust their energy consumption at a certain time according to the real-time energy price sent by the utility. Field demonstrations in recent years have shown that transactive control can effectively manage grid objectives and also monetarily benefit both the electric utility and end-users. Therefore, transactive energy is expected to make inroads into conventional grid operations in the next few years. As successful operation of such a market depends on the information exchanged among different stakeholders, a malicious adversary may try to inject false data and affect system operations. This thesis investigates how manipulating data in the transactive energy platform affects system operations and financial gains of different stakeholders. Understanding system behavior under attack conditions will help in formulating effective detection and mitigation strategies and enhancing system resilience.

Energy systems are evolving into structures in which the role of the consumer is more and more significant. Consumers are no longer the passive entities that in the past had to be supplied in an unidirectional way (from the network to the customer), but can also supply power to the grid through renewable resources, storage capacity through the batteries of their electric vehicles or operating services through the use of their flexibility. However, when discussing on smart grids, electricity supply and consump-tion are the only considered side on many occasions, neglecting other dimensions such as natural gas, sanitary hot water or transport. In this context, this dissertation represents a novel approach to the role of consumers in the natural gas sector. While it is true that electricity consumers have been involved for years in different operation services related to the use of their flexibility (especial-ly in countries such as the United States and more recently in the European Union), the use of demand response resources in the gas sector has been so far non-existent. However, the success of demand response initiatives in electricity systems and their similarity to the gas sector, where their regulatory and technological development has been carried out in parallel in recent years, allows us to expect similar successful re-sults when implementing equivalent programs to gas networks. This dissertation highlights the huge potential that remains unexplored on the demand side of natural gas, which could be used by gas network operators for the solution of technical constraints, balance services or optimization of programming of under-ground storage. This potential is especially interesting at the moment, when the mas-sive installation of smart gas meters has started in some European countries, an infra-structure that would facilitate the use of demand response resources for the better op-eration of gas networks. The dissertation presents, firstly, an exhaustive analysis of the demand response pro-grams currently used in electrical systems around the world, identifying those services that could be equally applicable to the gas sector. The traditional structure based on which gas systems have been developed in different countries is analyzed below. In order to make better use of resources and to optimize its operation, an architecture based on the concept of smart grid is then proposed, identifying the agents that would participate in this structure and emphasizing the role that consumers would play, not only as energy demanders, but also as providers of network services. This active role of demand requires the use of adequate measurement, control and communication technologies, aspect that is also properly analyzed. Based on the results of the analysis mentioned above, this thesis proposes a new meth-odology for the development and evaluation of demand response mechanisms that allow a greater participation of gas consumers in the provision of operating services to the manager of the network, increasing the joint efficiency of the system and reducing the costs associated with such services. The proposed methodology has been successfully applied to the gas network in Italy, where the analyzed operation services have been evaluated in a town of 16,000 inhab-itants located in the central north-Italian area. In that town, consumers have been grouped by end-use, sector and size, which evidences the need to enhance the role of the aggregator for the proper use of the potential of smaller consumers, whether they receive a gas supply directly or through a distributed heat network. The results presented in this dissertation should encourage regulators to empower the use of the consumers' flexibility in order to increase the efficiency of the natural gas system, as it reduces operating costs while favoring the participation of customers in a more dynamic energy structure. / Los sistemas energéticos están evolucionando hacia estructuras en las que el papel desempeñado por el consumidor es cada vez más importante. Hoy en día, los consumidores ya no son los entes pasivos de antaño a los que había que suministrar energía de forma unidireccional (de la red al cliente), sino que también pueden suministrar energía a la red a través de recursos renovables, capacidad de almacenamiento mediante las baterías de sus vehículos eléctricos o servicios de operación a través de la utilización de su flexibilidad. Sin embargo, al hablar de redes inteligentes, en muchas ocasiones se sobreentiende únicamente lo relativo al suministro y consumo de electricidad, obviando otras dimensiones como pueden ser el gas natural, el agua caliente sanitaria o el transporte. En este marco, esta tesis supone un enfoque novedoso en lo que se refiere al papel de los consumidores en el sector del gas natural. Si bien es cierto que los consumidores de electricidad han participado desde hace años en diferentes servicios relacionados con el uso de su flexibilidad, la utilización de la respuesta de la demanda en el sector gasista ha sido hasta ahora inexistente. Sin embargo, el éxito de iniciativas de respuesta de la demanda en los sistemas eléctricos y su similitud con el sector gasista, cuyo desarrollo normativo y tecnológico se ha realizado en paralelo en los últimos años, permite esperar resultados igualmente exitosos al aplicar programas equivalentes a las redes de gas. Esta tesis pone de manifiesto el enorme potencial que permanece inexplorado en el lado de la demanda de gas natural, el cual podría ser utilizado para la solución de restricciones técnicas, servicios de balance u optimización de la programación de los almacenamientos subterráneos. Este potencial resulta especialmente interesante en estos momentos, cuando en algunos países europeos se ha comenzado la instalación masiva de contadores inteligentes de gas. La tesis presenta un análisis exhaustivo de los programas de respuesta de la demanda utilizados en la actualidad en sistemas eléctricos alrededor del mundo, identificándose aquellos servicios que podrían ser aplicables al sector gasista. A continuación se analiza la estructura tradicional en base a la que los sistemas gasistas se han desarrollado en diversos países, proponiéndose a continuación una arquitectura basada en el concepto de red inteligente, donde se identifican los agentes que participarían en esta estructura y se enfatiza el rol que los consumidores desempeñarían no sólo como demandantes de energía, sino también como proveedores de servicios de red. Este papel activo de la demanda necesita de la utilización de tecnologías de medición, control y comunicación adecuadas, aspecto que también se analiza en detalle. En base a los resultados del análisis mencionado, esta tesis propone una nueva metodología para el desarrollo y evaluación de mecanismos de respuesta de la demanda que permitan una mayor participación de los consumidores de gas en la provisión de servicios de operación al gestor de la red, aumentando la eficiencia conjunta del sistema y reduciendo los costes asociados a dichos servicios. La metodología propuesta ha sido aplicada con éxito a la red gasista de Italia, donde los servicios de operación analizados han sido evaluados en una ciudad de 16.000 habitantes, donde los consumidores han sido agrupados por uso final, sector y tamaño. Esto ha puesto de manifiesto la necesidad de potenciar el papel del agregador para valorizar el potencial de los consumidores más pequeños, tanto si reciben un suministro de gas directo o a través de una red de calor distribuido. Los resultados expuestos en esta tesis deberían impulsar a los reguladores a incentivar la utilización de la flexibilidad de los consumidores a fin de incrementar la eficiencia del sistema de gas natural, ya que reduce los costes de operación al tiempo que favorece la particip / Els sistemes energètics estan evolucionant cap a estructures en què el paper exercit pel consumidor és cada vegada més important. Avui dia, els consumidors ja no són els ens passius d'antany als quals calia subministrar energia de forma unidireccional (de la xarxa al client), sinó que també poden subministrar energia a la xarxa a través de recursos renovables, capacitat d'emmagatzematge mitjançant les bateries dels seus vehicles elèctrics o serveis d'operació a través de la utilització de la seva flexibilitat. No obstant això, en parlar de xarxes intel·ligents, en moltes ocasions se sobreentén únicament quant al subministrament i consum d'electricitat, obviant altres dimensions com poden ser el gas natural, l'aigua calenta sanitària o el transport. En aquest marc, aquesta tesi suposa un enfocament nou pel que fa al paper dels consumidors en el sector del gas natural. Si bé és cert que els consumidors d'electricitat han participat des de fa anys en diferents serveis d'operació relacionats amb l'ús de la seva flexibilitat, la utilització de la resposta de la demanda en el sector gasista ha estat fins ara inexistent. No obstant això, l'èxit d'iniciatives de resposta de la demanda en els sistemes elèctrics i la seva similitud amb el sector gasista, el desenvolupament normatiu i tecnològic s'ha realitzat en paral·lel en els últims anys, permet esperar resultats igualment reeixits en aplicar programes equivalents a les xarxes de gas. Aquesta tesi posa de manifest l'enorme potencial que roman inexplorat en el costat de la demanda de gas natural, el qual podria ser utilitzat per a la solució de restriccions tècniques, serveis de balanç o optimització de la programació dels emmagatzematges subterranis. Aquest potencial és especialment interessant en aquests moments, quan en alguns països europeus s'ha començat la instal·lació massiva de comptadors intel·ligents de gas. La tesi presenta una anàlisi exhaustiva dels programes de resposta de la demanda utilitzats en l'actualitat en sistemes elèctrics voltant del món, identificant-se aquells serveis que podrien ser aplicables al sector gasista. A continuació s'analitza l'estructura tradicional sobre la base de la qual els sistemes gasistes s'han desenvolupat en diversos països, proposant-se a continuació una arquitectura basada en el concepte de xarxa intel·ligent, on s'identifiquen els agents que participarien en aquesta estructura i s'emfatitza el paper que els consumidors exercirien no només com a demandants d'energia, sinó també com a proveïdors de serveis de xarxa. Aquest paper actiu de la demanda necessita de la utilització de tecnologies de mesurament, control i comunicació adequades, aspecte que també s'analitza en detall. En base als resultats de l'anàlisi esmentat, aquesta tesi proposa una nova metodologia per al desenvolupament i avaluació de mecanismes de resposta de la demanda que permetin una major participació dels consumidors de gas a la provisió de serveis d'operació al gestor de la xarxa, augmentant l'eficiència conjunta del sistema i reduint els costos associats a aquests serveis. La metodologia proposada ha estat aplicada amb èxit a la xarxa gasista d'Itàlia, on els serveis d'operació analitzats han estat avaluats en una ciutat de 16.000 habitants, on els consumidors han estat agrupats per ús final, sector i grandària. Això ha posat de manifest la necessitat de potenciar el paper de l'agregador per valoritzar el potencial dels consumidors més petits, tant si reben un subministrament de gas directe o mitjançant una xarxa de calor distribuïda. Els resultats exposats en aquesta tesi haurien d'impulsar els reguladors a incentivar la utilització de la flexibilitat dels consumidors a fi d'incrementar l'eficiència del sistema de gas natural, ja que redueix els costos d'operació i alhora afavoreix la participació dels clients en una estructura més dinàmica. / Montuori, L. (2017). Application of demand response strategies for the management of natural gas systems under the smart grid configuration: development of a methodology for technical, economic and environmental evaluation [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/90407

To mitigate the technical challenges faced by the next-generation smart power grid, in this thesis, novel frameworks are developed for optimizing energy management and trading between power companies and grid consumers, who own renewable energy generators and storage units. The proposed frameworks explicitly account for the effect on demand-side energy management of various consumer-centric grid factors such as the stochastic renewable energy forecast, as well as the varying future valuation of stored energy. In addition, a novel approach is proposed to enhance the resilience of consumer-centric energy trading scenarios by analyzing how a power company can encourage its consumers to store energy, in order to supply the grid’s critical loads, in case of an emergency. The developed energy management mechanisms advance novel analytical tools from game theory, to capture the coupled actions and objectives of the grid actors and from the framework of prospect theory (PT), to capture the irrational behavior of consumers when faced with decision uncertainties. The studied PT and game-based solutions, obtained through analytical and algorithmic characterization, provide grid designers with key insights on the main drivers of each actor’s energy management decision. The ensuing results primarily characterize the difference in trading decisions between rational and irrational consumers, and its impact on energy management. The outcomes of this thesis will therefore allow power companies to design consumer-centric energy management programs that support the sustainable and resilient development of the smart grid by continuously matching supply and demand, and providing emergency energy reserves for critical infrastructure. / Master of Science / The next-generation smart power grid is seen as a key enabler for effectively generating, delivering, and consuming electricity in a sustainable manner. Given the increasing demand for energy and the limited nature of various energy resources, the exchange of energy between producers and consumers must be optimally managed to pave the way towards the deployment of smart grid features on a larger scale. In particular, energy management schemes must deal with a complex and dynamic smart grid composed of utility companies, traditional power sources and loads, intermittent renewable energy generators, as well as new consumer-owned devices such as energy storage units and solar panels. In this thesis, we seek to model the different entities in the smart grid and the exchange of energy between them, in order to better understand the operation and effectiveness of various energy management schemes. In addition, this thesis accounts for the non-rational behavior of consumers in the energy trading process, when faced with various sources of uncertainty in the smart grid, including the intermittent renewable energy generation and the dynamic energy price. The results of this thesis will provide utility companies with key insights, crucial to the design of consumer-centric energy management programs, aimed towards matching electricity supply and demand, and insuring power supply to critical infrastructure.

Electric Vehicles (EVs) are active loads as they increase the demand for electricity and introduce several challenges to electrical distribution feeders during charging. Demand Response (DR) or performing load control in commercial buildings along with the deployment of solar photovoltaic (PV) and ice storage systems at the building level can improve the efficiency of electricity grids and mitigate expensive peak demand/energy charges for buildings. This research aims to provide such a solution to make EV penetration transparent to the grid. Firstly, this research contributes to the development of an integrated control of major loads, i.e., Heating Ventilation and Air Conditioning (HVAC), lighting and plug loads while maintaining occupant environmental preferences in small- and medium-sized commercial buildings which are an untapped DR resource. Secondly, this research contributes to improvement in functionalities of EnergyPlus by incorporating a 1-minute resolution data set at the individual plug load level. The research evaluates total building power consumption performance taking into account interactions among lighting, plug load, HVAC and control systems in a realistic manner. Third, this research presents a model to study integrated control of PV and ice storage on improving building operation in demand responsive buildings. The research presents the impact of deploying various combinations of PV and ice storage to generate additional benefits, including clean energy generation from PV and valley filling from ice storage, in commercial buildings. Fourth, this research presents a coordinated load control strategy, among participating commercial buildings in a distribution feeder to optimally control buildings' major loads without sacrificing occupant comfort and ice storage discharge, along with strategically deployed PV to absorb EV penetration. Demand responsive commercial building load profiles and field recorded EV charging profiles have been added to a real world distribution circuit to analyze the effects of EV penetration, together with real-world PV output profiles. Instead of focusing on individual building's economic benefits, the developed approach considers both technical and economic benefits of the whole distribution feeder, including maintaining distribution-level load factor within acceptable ranges and reducing feeder losses. / Ph. D. / Utilities generally meet peak demand through expensive peaking units which are operated only for short periods of time. At the same time the growing demand for Electric Vehicles (EVs) in the U.S. impacts the already burdened distribution feeder during peak hours. EVs are active loads as they increase the distribution feeder’s demand when charging. EV charging may bring about several challenges to the distribution feeder, including reduced load factors, potential transformer overloads, feeder congestion and violation of statutory voltage limits. On the other hand, building owners want to make buildings demand responsive so that they can participate in a demand response program offered by a regional electric grid operator to earn additional revenues. Allowing buildings to be demand-responsive by controlling buildings’ major loads, including HVAC (Heating, Ventilation and Air Conditioning), lighting and plug loads based on demand reduction signals from the grid has proven to provide tremendous savings. Additionally, optimized peak demand reductions at the building level by means of coordinated control of building loads, solar photovoltaic (PV) and ice storage systems can play a major role in flattening the building load shape, thereby decreasing its peak electricity consumption and at the same time mitigating grid stress conditions when needed. This study discusses the impacts of EV charging on a distribution feeder serving demand responsive commercial customers and develops a mitigation strategy to make EV penetration transparent to the grid. The mitigation strategy relies on coordinated control of major loads in demand responsive commercial buildings, ice storage discharge, along with strategically deployed PV. The analysis presented in this study shows that the developed approach can help mitigate EV penetration challenges by reducing the peak distribution system load, reducing feeder losses and improving distribution system load factor.

Yes / Technological advancement on the electricity grid has focused on maximizing its use. This has led to the introduction of energy storage. Energy storage could be used to provide both peak and off-peak services to the grid. Recent work on the use of small units of energy storage like battery has proposed the vehicle to grid system. It is propose in this work to have energy storage device embedded inside the house of the energy consumer. In such a system, consumers with battery energy storage can be aggregated in to a community virtual power plant. In this paper, an optimized energy resource allocation algorithm is presented for a virtual power plant using genetic algorithm. The results show that it is critical to have a pricing scheme that help achieve goals for grid, virtual power plant, and consumers. / Mr. Oghenovo Okpako is grateful to the Niger Delta Development Commission of Nigeria for funding the work. The work has been also supported by the British Council and the UK Department of Business innovations and Skills under the GII funding of the SITARA project.

Yes / Recently, significant advances in renewable energy generation have made it possible to consider consumers as prosumers. However, with increase in embedded generation, storage of electrical energy in batteries, flywheels and supercapacitors has become important so as to better utilize the existing grid by helping smooth the peaks and troughs of renewable electricity generation, and also of demand. This has led to the possibility of controlling the times when stored energy from these storage units is fed back to the grid. In this paper we look at how energy resource sharing is achieved if these storage units are part of a virtual power plant. In a virtual power plant, these storage units become energy resources that need to be optimally scheduled over time so as to benefit both prosumer and the grid supplier. In this paper, a smart energy resources allocation algorithm is presented for a virtual power plants using genetic algorithms. It is also proposed that the cause of battery depreciation be accounted for in the allocation of discharge rates. The algorithm was tested under various pricing scenarios, depreciation cost, as well as constraint. The results are presented and discussed. Conclusions were drawn, and suggestion for further work was made. / Mr. Oghenovo Okpako is grateful for the support of the Niger Delta Development Commission of Nigeria for supporting the work. The work has been also supported by the British Council and the UK Department of Business innovations and Skills under the GII funding of the SITARA project.

Considerando condições anormais que o Sistema Elétrico de Potência (SEP) está sujeito, a proteção de seus elementos é um tópico importante. Dentre os equipamentos a serem protegidos, destacam-se os geradores devido a representarem elevado custo de investimento e estarem sujeitos a multas por paradas não programadas. Desta forma, com base em pesquisa bibliográfica, observa-se que não existem estudos abrangentes para a proteção individual de máquinas síncronas aplicadas à geração eólica. Além disso, considerando o contexto das smart grids, a presença de baterias e a possibilidade da operação ilhada podem alterar a dinâmica das situações de falta. Portanto, faz-se necessário um estudo do comportamento dos aerogeradores em situações de falha, sabendo que o esquema de proteção depende do tipo de gerador e da maneira como este está conectado ao SEP. Neste sentido, esta pesquisa propôs incluir uma bateria para operar com um gerador eólico de velocidade variável de forma complementar, suavizando a potência de saída e tornando o sistema de conversão de energia eólica forte o suficiente para operar no modo ilhado. A metodologia estabelece vários tipos de falhas para investigar o comportamento da turbina eólica em tais condições. Para realizar as simulações de falta, foi utilizado um simulador digital de tempo real (RTDS®). Com base nisso, um esquema composto por funções de proteção convencionais foi especificado e testado usando o software MATLAB®. Além disso, simulações em laço fechado foram realizadas com relés comercial e universal. Os resultados obtidos com o esquema proposto são bastante promissores. / Considering abnormal conditions to which the Electric Power System (EPS) may be subjected, the protection of its elements is an important topic. Among the equipments to be protected, the generators are highlighted, because they represent a high investment cost and are subjected to penalties for unscheduled stoppages. Hence, based on literature, it is observed that there are no comprehensive studies and standards for individual protection of Synchronous Generators (SGs) applied to Wind Energy Conversion System (WECS). Furthermore, considering the smart grids context, the presence of batteries and the possibility of island operation may change the dynamic of fault situations. Therefore, it is necessary to study and analyse the behavior of wind turbines in fault situations, knowing that the protection scheme is dependent on the generator type and the way it is connected to the EPS. In order to study these issues, this research proposed to include a battery to operate with a full-variable speed wind generator in a complementary way, smoothing the output power and making the WECS strong enough to operate in the island mode. The methodology establishes several fault types to investigate the wind turbine behavior in such conditions. In order to conduct the fault simulations, a real time digital simulator (RTDS®) was used. Based on this, a scheme composed by conventional protection functions were specified and tested using the MATLAB® software. Furthermore, hardware-in-the-loop simulations were performed with commercial and universal relays. Very good results in favor of the proposed scheme are presented.

A importância das novas tecnologias de informação, automação, monitoramento e sistemas eletrônicos inteligentes têm aumentado significativamente nos últimos anos. Essas tecnologias desempenham um papel fundamental na sociedade moderna e contribuem de forma decisiva para a resolução de importantes desafios para uma sociedade que quer ser mais próspera, internacionalmente competitiva, saudável, segura e sustentável. Como eixo de \"inovação\", essas tecnologias são fatores importantes para todos os setores produtivos da economia. O motor destas tecnologias, entretanto, é a energia, particularmente a eletricidade. Assim, em uma sociedade cujo estilo de vida é fortemente dependente dela, desenvolver tecnologias que permitam não somente a geração, mas também a distribuição de energia de forma barata e limpa e que garantam seu fornecimento ao longo do tempo com a máxima eficiência é uma questão prioritária. Os sistemas baseados em redes inteligentes (do inglês: Smart Grid) vêm, justamente, atender a esses requisitos, representando o que há de mais moderno no setor elétrico, com aumento e diversificação de fontes de geração distribuída na forma de pequenos geradores, maior interação consumidor-distribuidor de energia, integração de diferentes fontes de geração renováveis (ex.: solar, eólica etc.). O cenário energético nacional está avançando de forma muito rápida. Nas distribuidoras, o foco claramente está na redução de perdas comerciais e de custos operacionais, principalmente por meio da modernização dos ativos e da crescente instalação de dispositivos eletrônicos inteligentes nos clientes de baixa tensão (ex.: medidores eletrônicos, dispositivos eletrônicos inteligentes para monitoramento e diagnóstico, relés digitais etc.). Esta tese de doutorado apresenta uma solução com tecnologia nacional que disponibiliza todos os benefícios do Smart Grid através dos equipamentos mais importantes e estratégicos presentes na topologia das Redes de Distribuição Subterrânea Secundária Trifásica: os Protetores de Redes. A partir do centro nevrálgico das Redes de Distribuição Subterrâneas (RDS), cuja topologia está presente nos centros de alta concentração de carga das principais metrópoles do Brasil, a solução desenvolvida pode viabilizar técnica e economicamente a modernização da automação da RDS, com tecnologia nacional de baixo custo, proporcionando igualmente a incorporação dos avanços do Smart Grid e da Geração Distribuída. Este salto tecnológico significaria para as distribuidoras de energia elétrica entre outros benefícios: Melhor controle do processo para uma melhor otimização da rede, desde integração das intermitentes fontes renováveis até uma interação mais dinâmica com os consumidores; Maior flexibilidade às concessionárias em relação ao uso da energia para atingir o grande objetivo social de redução do efeito estufa e otimização do consumo de energia reduzindo perdas e desperdícios; No curto prazo, os benefícios diretos da melhoria do gerenciamento da indisponibilidade, gerenciamento otimizado dos ativos e do capital, melhoria no planejamento, processos e serviços de fornecimento e usos finais de energia, aumento de eficiência de manutenção, redução de perdas técnicas e comerciais, otimização do investimento na compra de novos protetores com menores custos podendo superar a demanda reprimida pelos altos custos de alternativas importadas. / The importance of new technologies in the field of, automation, monitoring, information technology and electronic systems have increased significantly in recent years. These technologies play a basic role in the modern society and contribute of decisive way for the resolution of important challenges for a society that is in search of a more prosperous life, internationally competitive, healthful, safe and sustainable. As a key of \"innovation\", these technologies are key factors for all the productive sectors of the economy in the society. The fuel for the engine of these technologies, however, is the energy, particularly the electricity. Thus, in a society whose life style is strongly dependent of electricity, to develop technologies that not only allow the generation, but also the distribution of energy in a cheap and clean way and which could guarantee its supply throughout the time with the maximum efficiency is a priority issue. The systems based on intelligent networks fully meet these requirements, representing what there is of most modern in the electric sector. The Brazilian energy scenario is quickly changing over the recent years toward modernization, with more distributed generation, in the form of smaller generators, more customer interaction, the integration of more variable resources such as wind and solar, and more renewables overall. For the Power Utilities, especially in the Distribution Sector, the focus is clearly in the reduction of commercial losses and operational costs, mainly by means of the modernization of the assets and an increase in the installation of intelligent electronic devices at consumers side (e.g.: electronic energy meters, intelligent electronic devices for condition monitoring, digital relays etc.). This work presents a solution developed based on Brazilian technology that incorporates all the benefits of smart grid to the most important equipment that is present in the topology of the Low-Voltage Secondary Network Distribution System: the Network Protector. From the neuralgic center of these Low-Voltage Secondary Network Systems, which topology is used in the most important cities in Brazil, which has a high load concentration, the solution presented here make it feasible technically and economically the use of smart grid topology profiting from its great benefits such as: Allow utilities to better optimize the grid to support a number of public policies, from intermittent renewable integration to more dynamic interfaces with customers; Offer utilities more flexibility relative to how they use energy toward the greater societal objectives of reducing greenhouse gases and energy consumption. In the short and mid term, a smarter grid offers utilities operational benefits (outage management, improved processes, maintenance and workforce efficiency, reduced losses, etc.) as well as benefits associated with improved asset management (system planning, better capital asset utilization, etc.), lower investment to acquire new Network Protectors.

Face à l'explosion du trafic mobile entraînée par le succès des smartphones, les opérateurs de réseaux mobiles (MNOs) densifient leurs réseaux à travers le déploiement massif des stations de base à faible portée (SBS), capable d’offrir des services très haut débit et de remplir les exigences de capacité et de couverture. Cette nouvelle infrastructure, appelée réseau cellulaire hétérogène (HetNet), utilise un mix de stations de base hiérarchisées, comprenant des macro-cellule à forte puissance et des SBS à faible puissance.La prolifération des HetNets soulève une nouvelle préoccupation concernant leur consommation d'énergie et empreinte carbone. Dans ce contexte, l'utilisation de technologies de production d'énergie dans les réseaux mobiles a suscité un intérêt particulier. Les sources d'énergie respectueuses de l'environnement couplées à un système de stockage d'énergie ont le potentiel de réduire les émissions carbone ainsi que le coût opérationnel énergétique des MNOs.L'intégration des énergies renouvelables (panneau solaire) et du stockage d'énergie (batterie) dans un SBS gagne en efficacité grâce aux leviers technologiques et économiques apportés par le smart grid (SG). Cependant, l'architecture résultante, que nous appelons Green Small-Cell Base station (GSBS), est complexe. Premièrement, la multitude de sources d'énergie, le phénomène de viellissement du système et le prix dynamique de l'électricité dans le SG sont des facteurs qui nécessitent planification et gestion pour un fonctionnement plus efficace du GSBS. Deuxièmement, il existe une étroite dépendance entre le dimensionnement et le contrôle en temps réel du système, qui nécessite une approche commune capable de résoudre conjointement ces deux problèmes. Enfin, la gestion holistique d’un HetNet nécessite un schéma de contrôle à grande échelle pour optimiser simultanément les ressources énergétiques locales et la collaboration radio entre les SBSs.Par conséquent, nous avons élaboré un cadre d'optimisation pour le pré-déploiement et le post-déploiement du GSBS, afin de permettre aux MNOs de réduire conjointement leurs dépenses d'électricité et le vieillissement de leurs équipements. L'optimisation pré-déploiement consiste en un dimensionnement du GSBS qui tient compte du vieillissement de la batterie et de la stratégie de gestion des ressources énergétiques. Le problème associé est formulé et le dimensionnement optimal est approché en s'appuyant des profils moyens (production, consommation et prix de l'électricité) à travers une méthode itérative basée sur le solveur non-linéaire “fmincon”. Le schéma de post-déploiement repose sur des capacités d'apprentissage permettant d'ajuster dynamiquement la gestion énergétique du GSBS à son environnement (conditions météorologiques, charge de trafic et coût de l'électricité). La solution s'appuie sur le fuzzy Q-learning qui consiste à combiner le système d'inférence floue avec l'algorithme Q-learning. Ensuite, nous formalisons un système d'équilibrage de charge capable d'étendre la gestion énergétique locale à une collaboration à l'échelle réseau. Nous proposons à ce titre un algorithme en deux étapes, combinant des contrôleurs hiérarchiques au niveau du GSBS et au niveau du réseau. Les deux étapes s'alternent pour continuellement planifier et adapter la gestion de l'énergie à la collaboration radio dans le HetNet.Les résultats de la simulation montrent que, en considérant le vieillissement de la batterie et l'impact mutuel de la conception du système sur la stratégie énergétique (et vice-versa), le dimensionnement optimal du GSBS est capable de maximiser le retour sur investissement. En outre, grâce à ses capacités d'apprentissage, le GSBS peut être déployé de manière plug-and-play, avec la possibilité de s'auto-organiser, d'améliorer le coût énergétique du système et de préserver la durée de vie de la batterie. / Pushed by an unprecedented increase in data traffic, Mobile Network Operators (MNOs) are densifying their networks through the deployment of Small-cell Base Stations (SBS), low-range radio-access transceivers that offer enhanced capacity and improved coverage. This new infrastructure – Heterogeneous cellular Network (HetNet) -- uses a hierarchy of high-power Macro-cell Base Stations overlaid with several low-power (SBSs).The augmenting deployment and operation of the HetNets raise a new crucial concern regarding their energy consumption and carbon footprint. In this context, the use of energy-harvesting technologies in mobile networks have gained particular interest. The environment-friendly power sources coupled with energy storage capabilities have the potential to reduce the carbon emissions as well as the electricity operating expenditures of MNOs.The integration of renewable energy (solar panel) and energy storage capability (battery) in SBSs gain in efficiency thanks to the technological and economic enablers brought by the Smart Grid (SG). However, the obtained architecture, which we call Green Small-Cell Base Station (GSBS), is complex. First, the multitude of power sources, the system aging, and the dynamic electricity price in the (SG) are factors that require design and management to enable the (GSBS) to efficiently operate. Second, there is a close dependence between the system sizing and control, which requires an approach to address these problems simultaneously. Finally, the achievement of a holistic management in a (HetNet) requires a network-level energy-aware scheme that jointly optimizes the local energy resources and radio collaboration between the SBSs.Accordingly, we have elaborated pre-deployment and post-deployment optimization frameworks for GSBSs that allow the MNOs to jointly reduce their electricity expenses and the equipment degradation. The pre-deployment optimization consists in an effective sizing of the GSBS that accounts for the battery aging and the associated management of the energy resources. The problem is formulated and the optimal sizing is approximated using average profiles, through an iterative method based on the non-linear solver “fmincon”. The post-deployment scheme relies on learning capabilities to dynamically adjust the GSBS energy management to its environment (weather conditions, traffic load, and electricity cost). The solution is based on the fuzzy Q-learning that consists in tuning a fuzzy inference system (which represents the energy arbitrage in the system) with the Q-learning algorithm. Then, we formalize an energy-aware load-balancing scheme to extend the local energy management to a network-level collaboration. We propose a two-stage algorithm to solve the formulated problem by combining hierarchical controllers at the GSBS-level and at the network-level. The two stages are alternated to continuously plan and adapt the energy management to the radio collaboration in the HetNet.Simulation results show that, by considering the battery aging and the impact of the system design and the energy strategy on each other, the optimal sizing of the GSBS is able to maximize the return on investment with respect to the technical and economic conditions of the deployment. Also, thanks to its learning capabilities, the GSBSs can be deployed in a plug-and-play fashion, with the ability to self-organize, improve the operating energy cost of the system, and preserves the battery lifespan.

Considerando condições anormais que o Sistema Elétrico de Potência (SEP) está sujeito, a proteção de seus elementos é um tópico importante. Dentre os equipamentos a serem protegidos, destacam-se os geradores devido a representarem elevado custo de investimento e estarem sujeitos a multas por paradas não programadas. Desta forma, com base em pesquisa bibliográfica, observa-se que não existem estudos abrangentes para a proteção individual de máquinas síncronas aplicadas à geração eólica. Além disso, considerando o contexto das smart grids, a presença de baterias e a possibilidade da operação ilhada podem alterar a dinâmica das situações de falta. Portanto, faz-se necessário um estudo do comportamento dos aerogeradores em situações de falha, sabendo que o esquema de proteção depende do tipo de gerador e da maneira como este está conectado ao SEP. Neste sentido, esta pesquisa propôs incluir uma bateria para operar com um gerador eólico de velocidade variável de forma complementar, suavizando a potência de saída e tornando o sistema de conversão de energia eólica forte o suficiente para operar no modo ilhado. A metodologia estabelece vários tipos de falhas para investigar o comportamento da turbina eólica em tais condições. Para realizar as simulações de falta, foi utilizado um simulador digital de tempo real (RTDS®). Com base nisso, um esquema composto por funções de proteção convencionais foi especificado e testado usando o software MATLAB®. Além disso, simulações em laço fechado foram realizadas com relés comercial e universal. Os resultados obtidos com o esquema proposto são bastante promissores. / Considering abnormal conditions to which the Electric Power System (EPS) may be subjected, the protection of its elements is an important topic. Among the equipments to be protected, the generators are highlighted, because they represent a high investment cost and are subjected to penalties for unscheduled stoppages. Hence, based on literature, it is observed that there are no comprehensive studies and standards for individual protection of Synchronous Generators (SGs) applied to Wind Energy Conversion System (WECS). Furthermore, considering the smart grids context, the presence of batteries and the possibility of island operation may change the dynamic of fault situations. Therefore, it is necessary to study and analyse the behavior of wind turbines in fault situations, knowing that the protection scheme is dependent on the generator type and the way it is connected to the EPS. In order to study these issues, this research proposed to include a battery to operate with a full-variable speed wind generator in a complementary way, smoothing the output power and making the WECS strong enough to operate in the island mode. The methodology establishes several fault types to investigate the wind turbine behavior in such conditions. In order to conduct the fault simulations, a real time digital simulator (RTDS®) was used. Based on this, a scheme composed by conventional protection functions were specified and tested using the MATLAB® software. Furthermore, hardware-in-the-loop simulations were performed with commercial and universal relays. Very good results in favor of the proposed scheme are presented.