L’intégration de panneaux photovoltaïques dans un système électrique réduit la consommation des sources fossiles et apporte des avantages environnementaux. Toutefois, l'intermittence et les fluctuations de puissance détériorent la qualité d’alimentation électrique. La solution proposée est d’ajouter des éléments de stockage, coordonnés par un contrôleur local qui gère les flux de puissance entre toutes les sources et la disponibilité énergétique. Ce générateur actif PV peut générer des références de puissance et fournir des services « système » au réseau électrique. Puis les concepts liés au micro réseau sont transposés pour concevoir un système central de gestion de l'énergie d'un réseau électrique résidentiel, qui est alimenté par des générateurs actifs PV et une micro turbine à gaz. Un réseau de communication est utilisé pour échanger des données et des références de puissance. Un système de gestion de l'énergie est développé avec différentes fonctions de contrôle sur des échelles de temps différentes afin de maximiser l'utilisation de l'énergie PV. Une planification opérationnelle quotidienne est conçue par un algorithme déterministe, qui utilise la prédiction d'énergie PV et de la charge. Puis ces références de puissance sont actualisées chaque demi-heure en tenant compte de la disponibilité de l’énergie PV et l’état des unités de stockage. Les erreurs de prévision et les incertitudes sont compensées par le réglage primaire de fréquence. Les résultats de simulation et les tests valident la conception de la commande du générateur actif photovoltaïque ainsi que le système central de gestion de l'énergie du réseau résidentiel étudié / The integration of PV power generation in a power system reduces fuel consumption and brings environmental benefits. However, the PV power intermittency and fluctuations deteriorate the power supply quality. A solution is proposed by adding energy storages, which are coordinated by a local controller that controls the power flow among all sources and implements an inner energy management. This PV based active generator can generate power references and can provide ancillary services in an electric network. Then micro grid concepts are derived to design a central energy management system of a residential network, which is powered by PV based active generators and a gas micro turbine. A communication network is used to exchange data and power references. An energy management system is developed with different time-scale functions to maximize the use of PV power. An operational daily planning is designed by a determinist algorithm, which uses 24 hour-ahead PV power prediction and load forecasting. Then power references are refreshed each half of an hour by considering the PV power availability and the states of energy storage units. Prediction errors and uncertainties are compensated by primary frequency controllers. Simulation and testing results validate the design of the PV active generator local controller and the central energy management system of the studied residential network

Voltage imbalance in low voltage (LV) networks is expected to deteriorate as low carbon technologies, e.g. electric vehicles (EVs) and heat pumps (HPs) are increasingly deployed. The new electrical demand attributable to EVs and HPs would increase the voltage magnitude variation, increasing the possibility of voltages moving outside the statutory LV magnitude limits. Moreover, the single-phase nature of EVs and HPs, which will be connected via a single-phase 'line & neutral' cable to a 3-phase four-wire LV mains cable buried beneath the street, further entangles this voltage management problem; the non-balanced voltage variations in the three phases boost the levels of voltage imbalance. Excessive voltage imbalance and magnitude variation need to be mitigated to limit their adverse effects on the electric network and connected plant. The voltage imbalance in LV networks is conventionally reduced by reinforcing the network, generally at a high cost. Some modern methods for voltage imbalance mitigation have been introduced in recent years. The power electronic converter based methods are inadequate due to the generation of harmonics, significant power losses and short lifetime. Besides, automatic supply phase selection and smart EV charging rely on an advanced smart communication system, which currently is not available. This project aims to develop alternative solutions that mitigate the voltage imbalance seen in LV networks. A voltage balancing method based on Scott transformer (ST) is proposed. This method does not generate harmonics and is independent of the smart communication system. Computer simulations demonstrated the proposed method is able to convert a non-balanced 3-phase voltage into a balanced 3-phase voltage at either a point on the LV feeder or a 3-phase load supply point with the predefined voltage magnitude. Besides, a physical voltage balancing system was created based on the proposed method and it was tested in an LV network in the laboratory. The test results show the balancing system is capable of maintaining a low level of voltage imbalance on the LV feeder by rapidly compensating for the voltage rises and sags caused by single-phase load variations. This voltage balancing method is a potential solution for the network utilities to accommodate the significant penetration of low carbon technologies without breaching the network voltage limits. The impact of EVs and HPs on the LV network voltages is investigated based on a Monte Carlo (MC) simulation platform, which comprises a statistical model of EV charging demand, profiles generators of residential and HP electrical demand, and a distribution network model. The MC simulation indicates the impact of EVs and HPs is related to their distribution; when more than 21EVs and 13HPs are non-evenly distributed on a 96-customer LV feeder, the voltage limits are likely to be violated. Moreover, the effectiveness of the ST based voltage balancing method and the demand response based TOU tariff, implemented either alone or together, in mitigating the impact of EVs and HPs is investigated based on the established MC simulation platform. The results indicate the ST based balancing method alone is able to completely mitigate the voltage limit violations regardless of the penetration levels of EVs and HPs. Moreover, using both of the two investigated methods further enhances the balancing effectiveness of the ST based voltage balancing method.

Les politiques entreprises dans le domaine de la production d’électricité pour lutter contre le changement climatique reposent communément sur le remplacement des moyens de production fossiles et centralisés par de nouveaux moyens de type renouvelables. Ces énergies renouvelables sont en grande partie distribuées dans les réseaux moyenne et basse tension et sont le plus souvent intermittentes (énergies éolienne et photovoltaïque principalement). Les gestionnaires de réseaux s’attentent à ce que ce changement de paradigme induise des difficultés conséquences dans leurs opérations. Les mondes de la recherche et de l’industrie se sont ainsi structurés depuis le milieu des années 2000 afin d’apporter une réponse aux problèmes anticipés. Cette réponse passe notamment par le déploiement de technologies de l’information et de la communication (TIC) dans les réseaux électriques, des centres de contrôle jusqu’au sein même des moyens de production distribués. C’est ce que l’on appelle le Smart Grid. Parmi le champ des possibles du Smart Grid, ces travaux de thèses se sont en particulier attachés à apporter une réponse aux enjeux de stabilité en fréquence du système électrique, mise en danger par la réduction anticipée de l’inertie des systèmes électriques et la raréfaction des moyens de fourniture de réserve primaire (FCR), auxquels incombent le maintien de la fréquence en temps réel. En vue de suppléer les moyens de fourniture de réserve conventionnels et centralisés, il a ainsi été élaboré un concept de coordination de charges électriques délestables distribuées, qui se déconnectent et se reconnectent de manière autonome sur le réseau au gré des variations de fréquence mesurées sur site. Ces modulations de puissance répondent à un schéma préétabli qui dépend de la consommation électrique effective de chacune des charges. Ces travaux ont été complétés d’une étude technico-économique visant à réutiliser cette infrastructure de coordination de charges délestables pour la fourniture de services systèmes ou de produits de gros complémentaires. Ce travail de thèse réalisée au sein des équipes innovation de Schneider Electric et du laboratoire de Génie Electrique de Grenoble (G2Elab), est en lien avec les projets Européens EvolvDSO et Dream, financés dans le cadre du programme FP7 de la Commission Européenne. / Climate change mitigation policies in the power generation industry lead commonly on the replacement of bulk generation assets by Renewable Energy Resources (RES-E). Such RES-E are largely distributed among the medium and low voltage grids and most of them are intermittent like photovoltaic and wind power. System Operators expect that such new power system paradigm induces significant complications in their operations. The communities of research and industry started thus to structure themselves in the mid-2000s in order to respond to these coming issues, notably through the deployment of Information and Communication Technology (ICT) in power systems assets, from the Network Operations Centers (NOCs) down to Distributed Energy Resources (DERs) units. This is the Smart Grid. Among the range of possibilities of the Smart Grid, this Ph.D work aims in priority to provide a solution to handle the issue of frequency stability of the power system that are endangered by the combined loss of inertia of the power system and the phasing-out of conventional assets which used to be in charge of the maintain of the frequency in real time through the supply of Frequency Containment Reserve (FCR). The concept developed lead on a process of coordinated modulation of the level of loads of DERs, whose evolve depending on the system frequency measured in real time on-site. The strategy of modulation of each DER follows a pattern which is determined at the scale of the portfolio of aggregation of the DER, depending on the effective level of load of the DER at normal frequency (i.e. 50Hz in Europe). This work is completed by a cost benefit analysis that assesses the opportunity of sharing of the previous infrastructure of coordinated modulation of DERs for the supply of ancillary services and wholesale products. This thesis conducted within Schneider Electric’s Innovation teams and Grenoble Electrical Engineering Laboratory (G2Elab) is linked with the European projects Dream and EvolvDSO, and funded under European Commission’s FP7 program.

abstract: The smart grid initiative is the impetus behind changes that are expected to culminate into an enhanced distribution system with the communication and control infrastructure to support advanced distribution system applications and resources such as distributed generation, energy storage systems, and price responsive loads. This research proposes a distribution-class analog of the transmission LMP (DLMP) as an enabler of the advanced applications of the enhanced distribution system. The DLMP is envisioned as a control signal that can incentivize distribution system resources to behave optimally in a manner that benefits economic efficiency and system reliability and that can optimally couple the transmission and the distribution systems. The DLMP is calculated from a two-stage optimization problem; a transmission system OPF and a distribution system OPF. An iterative framework that ensures accurate representation of the distribution system's price sensitive resources for the transmission system problem and vice versa is developed and its convergence problem is discussed. As part of the DLMP calculation framework, a DCOPF formulation that endogenously captures the effect of real power losses is discussed. The formulation uses piecewise linear functions to approximate losses. This thesis explores, with theoretical proofs, the breakdown of the loss approximation technique when non-positive DLMPs/LMPs occur and discusses a mixed integer linear programming formulation that corrects the breakdown. The DLMP is numerically illustrated in traditional and enhanced distribution systems and its superiority to contemporary pricing mechanisms is demonstrated using price responsive loads. Results show that the impact of the inaccuracy of contemporary pricing schemes becomes significant as flexible resources increase. At high elasticity, aggregate load consumption deviated from the optimal consumption by up to about 45 percent when using a flat or time-of-use rate. Individual load consumption deviated by up to 25 percent when using a real-time price. The superiority of the DLMP is more pronounced when important distribution network conditions are not reflected by contemporary prices. The individual load consumption incentivized by the real-time price deviated by up to 90 percent from the optimal consumption in a congested distribution network. While the DLMP internalizes congestion management, the consumption incentivized by the real-time price caused overloads. / Dissertation/Thesis / M.S. Electrical Engineering 2013

A automação já é utilizada como ferramenta para se obter a eficiência energética. Este trabalho apresenta e quantifica a potencialidade desta ferramenta com objetivo de diminuir picos de energia, diminuindo também a necessidade de construir rapidamente novas usinas geradoras de energia elétrica, regulando a transmissão e distribuição desta energia, aproveitando recursos renováveis e sustentáveis, tudo isso através de um sistema que já existe implantado em vários países do mundo e tem todas as condições de ser implementado no Brasil. Este sistema é a rede inteligente de energia ou smart grid. Analisa, também, a matriz energética brasileira, apresenta anomalias ocorridas, como apagões regionais e nacionais, verifica a necessidade de energia elétrica para o crescimento do País, propõe soluções para o sistema energético nacional utilizando inovações tecnológicas, como a implantação do sistema smart grid na matriz energética, sempre objetivando melhor eficiência e qualidade da energia, levantando o comportamento dos usuários em busca da implementação destas inovações tecnológicas. A partir de idéias que rompam os paradigmas atuais de busca de energia através de grandes obras propõe este trabalho a mudança de hábito e procedimentos da população, das próprias empresas e dos órgãos públicos brasileiros buscando a diminuição da utilização da energia especialmente nos horários hoje considerados como picos, ou seja, aqueles que demandam a maior geração, transmissão e distribuição da energia utilizada. Apresenta também a necessidade de energia elétrica para desenvolvimento econômico do Brasil, agregando todas as inovações tecnológicas aos processos atuais, buscando minimizar a possibilidade da ocorrência de apagões, ocasionados por ineficiência técnica da matriz energética ou por racionamento de energia. / Automation is already used as a tool to achieve energy efficiency. This paper presents and quantifies the potential of this tool in order to reduce power surges, reducing the need rapidly build new electricity generating plants, transmission and regulating distribution of this energy, using renewable and sustainable resources, all through a system that is already deployed in several countries worldwide and has all the conditions to be implemented in Brazil. This system is the intelligent network of energy or "smart grid". It also analyzes the Brazilian energy matrix, has deficiencies occurred as a regional and national blackouts, there is need of electricity for the growth of the country, proposes solutions to national energy system, using technological innovations such as the deployment of the "smart grid" energy source, always aiming for better energy efficiency and quality, raising the behavior of users seeking the implementation of these technological innovations. From ideas that break current paradigms of seeking power through great works this paper proposes changes in the habits and procedures of the population, own businesses and public agencies are looking to decrease energy use especially in times like now considered "peaks", ie, those that demand the greatest generation, transmission and distribution of energy used. It also shows the need for electricity to Brazils economic development, adding all the technological innovations to the current processes in order to minimize the possibility of the occurrence of blackouts, caused by technical inefficiency of the energy or energy shortages.

Submitted by Patrícia Cerveira (pcerveira1@gmail.com) on 2017-06-14T19:17:38Z No. of bitstreams: 1 Tiago Bornia de Castro Dissertação.pdf: 4966184 bytes, checksum: 7e49563b573266804e94e53d4b7db605 (MD5) / Approved for entry into archive by Biblioteca da Escola de Engenharia (bee@ndc.uff.br) on 2017-06-29T13:48:38Z (GMT) No. of bitstreams: 1 Tiago Bornia de Castro Dissertação.pdf: 4966184 bytes, checksum: 7e49563b573266804e94e53d4b7db605 (MD5) / Made available in DSpace on 2017-06-29T13:48:38Z (GMT). No. of bitstreams: 1 Tiago Bornia de Castro Dissertação.pdf: 4966184 bytes, checksum: 7e49563b573266804e94e53d4b7db605 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Smart grids surgem como a evolução da rede elétrica. Sua proposta é incorporar redes de telecomunicações à rede elétrica, possibilitando o monitoramento em tempo real, rápida detecção/tratamento de falhas, maior facilidade de integração de fontes renováveis entre outros serviços. Porém sua implantação afeta a manutenção do equilíbrio entre a produção e o consumo de energia, que é essencial para a estabilidade da rede elétrica. Com o aumento de fontes renováveis, a predição da energia produzida torna-se mais difícil, devido à natureza intermitente dessas fontes. Fontes de energia renováveis dependem de fatores ambientais que tornam a previsão de geração de energia mais complexa e menos precisa. Portanto, existe uma mudança de paradigma com a modernização de rede de energia: na rede tradicional, a produção adapta-se à demanda, mas nas smart grids, a demanda adapta-se à produção e faz com que o consumo de usuário seja mais eficiente. Os programas de Gerenciamento pelo Lado da Demanda (GLD) surgem como uma solução para ajustar o consumo do usuário à geração. GLD são ações ou decisões tomadas pela empresa de energia para alterar ou modelar o padrão de consumo do usuário. A proposta deste trabalho é a criação de mecanismos de gerenciamento pelo lado da demanda direcionado para o usuário residencial no Brasil diante da implantação das smart grids. Foi criado o DEFLEGER-ECO, mecanismo de economia de energia elétrica usando tarifa branca, nova forma de tarifação que entrará em vigor a partir de 2018, e DEFLEGER-EMER, mecanismo emergencial voltado a redução de demanda durante eventos emergenciais. Devido a inexistência de uma ferramenta para a validação dos mecanismos, também foi desenvolvida uma ferramenta de simulação que é fruto da integração de dois simuladores, o NS-3 e o EnergyPlus. Os modelos foram simulados em quatro perfis de residências com a finalidade de avaliar seus desempenhos. Os mecanismos funcionaram conforme o esperado e uma de das principais contribuições é a possibilidade de atender diversos perfis de usuários residenciais. / Smart grids arise as the power grid evolution. The key idea is to incorporate telecommunications networks to the power grid, allowing real-time monitoring, fast detection/treatment failures, easier integration of renewable sources, and other services. Nevertheless the implementation of smart grids affects the maintenance of the balance between energy production and consumption, which is the essential for the power grid stability. With the increase in the number of renewable sources, prediction of energy produced becomes more difficult due to the intermittent nature of these sources. Renewable power sources depend on environmental factors that make power generation prediction more complex and less accurate. Therefore, there is a paradigm change with the grid modernization: in traditional grid energy, production adapts to the demand, but in smart grids, demand adapts to the production and makes user consumption more efficient. Demand Side Management (DSM) programs arise as one of the solutions to adjust user consumption to supply. DSM is an action or decision made by utility to alter and model user pattern of consumption. The purpose of this work is the creation of DSM mechanisms for Brazilian users. DEFLEGER-ECO was created, an electric energy saving mechanism using the white tariff, a new form of charging that will take effect from 2018, and DEFLEGEREMER, an emergency mechanism aimed at reducing demand during emergency events. Due to the lack of a tool for the validation of the mechanisms, a simulation tool was also developed, which is the result of the integration of two simulators, NS-3 and EnergyPlus. The models were simulated in four residential profiles in order to evaluate their performance. The mechanisms worked as expected and one of the main contributions is the possibility to serve several profiles of residential users.

The UK’s decarbonisation strategy to increasingly electrify heating and transport will change the demand requirement on the electricity system. Additionally, under a climate change future, it is projected that the decarbonised grid will need to be able to operate under higher average temperatures in the UK, increasing the need for comfort cooling during summer and leading to additional electricity demand. These new demands will result in greater variation between minimum and peak demand as well as a significant increase in overall demand. Concurrently, supply-side decarbonisation programmes may lead to more intermittent renewables such as wind, PV, tidal and wave, elevating variability in electricity generation. Coupled with the anticipated higher variation in demand this brings on several challenges in operating the electricity grid. In order to characterise these challenges this research develops a bespoke electricity dispatch model which builds on hourly models of demand and generation. The hourly demand profiles are based on a high electrification of heating, transport and cooling coupled with future temperatures premised on the UKCP09 high emission scenario climate projections. The demand profiles show a significant increase in peak demand by 2050 reaching 194 GW, mainly due to summer cooling loads which contribute 70% of the demand. The cumulative CO2 emissions budgets of the GB power sector that are consistent with avoiding global climate change to 2°C are used to develop two low carbon generation scenarios distinguished by the amount of intermittent renewable generation technologies. The dispatch model tests the capability of generation scenarios with the use of hourly generation models in meeting future demand profiles out to 2050.The outputs from dispatch model indicate that there are shortages and excesses of generation relative to demand from 2030 onwards. The variability analysis outlines low and high generation periods from intermittent technologies along with the pace at which intermittent generation increases or decreases within an hour. The characterisation of variability analysis reveals the type of reserve capacity or smart solutions that are required to maintain the security of electricity supply. The solutions that could address the challenges quantified from the model outputs in operating a decarbonised GB electricity grid are explored using expert interviews. The analysis of the stakeholder interviews suggests smart grid solutions that include technologies as well as changes in operational procedures in order to enhance the operational resilience of the grid. Active Network Management through monitoring and control, demand management, storage systems and interconnectors are proposed to address challenges arising from varying demand and generation variability.

Cette thèse a pour cadre les transmissions sur les réseaux CPL-BE et les réseaux de capteurs à faible capacité. L'état de l'art classique sur la protection de l'information dans la transmission par réseaux de capteurs fait référence à l'utilisation de codage distribué où les relais implémentent des opérations de parité (mélange des flux) sur les data issues des capteurs. Cependant, il est difficile, de par la nature variable de la qualité des liens en liaisons sans fil, de contrôler la qualité du codeur équivalent construit et de maintenir ses performances au cours du temps. C'est pourquoi nous nous sommes orientés dans cette thèse vers la recherche de schémas de codage différents qui résistent mieux à la variation de qualité des liaisons à travers le réseau. Notre choix s'est porté sur le codage par sous-espace inspiré des travaux de Gabidulin. Le but est de former un code qui utilise une métrique simple et résistante pour sécuriser les transmissions sur le réseau. Les codes à métrique de rang répondent bien à ce besoin car il n'y a qu'à contrôler le rang de la matrice obtenue en réception pour vérifier l'intégrité de la transmission. Les codes à métrique de rang et leur algorithme de décodage ont été étudiés dans un premier temps. Puis, les performances du code LRPC proposé concaténé avec les codes convolutifs sont testées dans des schémas de transmission des contextes différents. / This thesis considers the context of transmissions on CPL-BE networks and low-capacity sensor networks. The state of the art on information protection intransmission by sensor networks refers to the use of distributed coding, where therelays implement parity operations (mixing of streams) on data transmitted by thesensors. However, due to the varying nature of the quality of the wireless links, it is difficult to control the quality of the equivalent encoder constructed and to maintain its performance over time. Therefore, in this thesis, we have focused on the search for different coding schemes that are better resist the variation in the quality of the links across the network. Our choice was based on the sub-space coding inspired by Gabidulin's work. The goal is to form a code that uses a simple and resistant metric to secure transmission across the network. Rank metric codes respond well to this need because it only has to control the rank of the matrix obtained in reception to verify the integrity of the transmission. The rank metric codes and their decoding algorithm were studied in a first step. Then, the performance of the proposed LRPC code concatenated with the convolutional codes is tested in transmission schemes of different contexts.

The future power grid will effectively utilize renewable energy resources and distributed generation to respond to energy demand while incorporating information technology and communication infrastructure for their optimum operation. This dissertation contributes to the development of real-time techniques, for wide-area monitoring and secure real-time control and operation of hybrid power systems. To handle the increased level of real-time data exchange, this dissertation develops a supervisory control and data acquisition (SCADA) system that is equipped with a state estimation scheme from the real-time data. This system is verified on a specially developed laboratory-based test bed facility, as a hardware and software platform, to emulate the actual scenarios of a real hybrid power system with the highest level of similarities and capabilities to practical utility systems. It includes phasor measurements at hundreds of measurement points on the system. These measurements were obtained from especially developed laboratory based Phasor Measurement Unit (PMU) that is utilized in addition to existing commercially based PMU’s. The developed PMU was used in conjunction with the interconnected system along with the commercial PMU’s. The tested studies included a new technique for detecting the partially islanded micro grids in addition to several real-time techniques for synchronization and parameter identifications of hybrid systems. Moreover, due to numerous integration of renewable energy resources through DC microgrids, this dissertation performs several practical cases for improvement of interoperability of such systems. Moreover, increased number of small and dispersed generating stations and their need to connect fast and properly into the AC grids, urged this work to explore the challenges that arise in synchronization of generators to the grid and through introduction of a Dynamic Brake system to improve the process of connecting distributed generators to the power grid. Real time operation and control requires data communication security. A research effort in this dissertation was developed based on Trusted Sensing Base (TSB) process for data communication security. The innovative TSB approach improves the security aspect of the power grid as a cyber-physical system. It is based on available GPS synchronization technology and provides protection against confidentiality attacks in critical power system infrastructures.

The big data framework applied to smart meters offers an exception platform for data-driven forecasting and decision making to achieve sustainable energy efficiency. Buying-in consumer confidence through respecting occupants' energy consumption behavior and preferences towards improved participation in various energy programs is imperative but difficult to obtain. The key elements for understanding and predicting household energy consumption are activities occupants perform, appliances and the times that appliances are used, and inter-appliance dependencies. This information can be extracted from the context rich big data from smart meters, although this is challenging because: (1) it is not trivial to mine complex interdependencies between appliances from multiple concurrent data streams; (2) it is difficult to derive accurate relationships between interval based events, where multiple appliance usage persist; (3) continuous generation of the energy consumption data can trigger changes in appliance associations with time and appliances. To overcome these challenges, we propose an unsupervised progressive incremental data mining technique using frequent pattern mining (appliance-appliance associations) and cluster analysis (appliance-time associations) coupled with a Bayesian network based prediction model. The proposed technique addresses the need to analyze temporal energy consumption patterns at the appliance level, which directly reflect consumers' behaviors and provide a basis for generalizing household energy models. Extensive experiments were performed on the model with real-world datasets and strong associations were discovered. The accuracy of the proposed model for predicting multiple appliances usage outperformed support vector machine during every stage while attaining accuracy of 81.65\%, 85.90\%, 89.58\% for 25\%, 50\% and 75\% of the training dataset size respectively. Moreover, accuracy results of 81.89\%, 75.88\%, 79.23\%, 74.74\%, and 72.81\% were obtained for short-term (hours), and long-term (day, week, month, and season) energy consumption forecasts, respectively.