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Resource Management in Delay Tolerant Networks and Smart GridLiang, Hao 22 January 2013 (has links)
In recent years, significant advances have been achieved in communication networks and electric power systems. Communication networks are developed to provide services within not only well-connected network environments such as wireless local area networks, but also challenged network environments where continuous end-to-end connections can hardly be established between information sources and destinations. Delay tolerant network (DTN) is proposed to achieve this objective by utilizing a store-carry-and-forward routing scheme. However, as the network connections in DTNs are intermittent in nature, the management of network resources such as communication bandwidth and buffer storage becomes a challenging issue. On the other hand, the smart grid is to explore information and communication technologies in electric power grids to achieve electricity delivery in a more efficient and reliable way. A high penetration level of electric vehicles and renewable power generation is expected in the future smart grid. However, the randomness of electric vehicle mobility and the intermittency of renewable power generation bring new challenges to the resources management in the smart grid, such as electric power, energy storage, and communication bandwidth management.
This thesis consists of two parts. In part I, we focus on the resource management in DTNs. Specifically, we investigate data dissemination and on-demand data delivery which are two of the major data services in DTNs. Two kinds of mobile nodes are considered for the two types of services which correspond to the pedestrians and high-speed train passengers, respectively. For pedestrian nodes, the roadside wireless local area networks are used as an auxiliary communication infrastructure for data service delivery. We consider a cooperative data dissemination approach with a packet pre-downloading mechanism and propose a double-loop receiver-initiated medium access control scheme to resolve the channel contention among multiple direct/relay links and exploit the predictable traffic characteristics as a result of packet pre-downloading. For high-speed train nodes, we investigate on-demand data service delivery via a cellular/infostation integrated network. The optimal resource allocation problem is formulated by taking account of the intermittent network connectivity and multi-service demands. In order to achieve efficient resource allocation with low computational complexity, the original problem is transformed into a single-machine preemptive scheduling problem and an online resource allocation algorithm is proposed. If the link from the backbone network to an infostation is a bottleneck, a service pre-downloading algorithm is also proposed to facilitate the resource allocation.
In part II, we focus on resource management in the smart grid. We first investigate the optimal energy delivery for plug-in hybrid electric vehicles via vehicle-to-grid systems. A dynamic programming formulation is established by considering the bidirectional energy flow, non-stationary energy demand, battery characteristics, and time-of-use electricity price. We prove the optimality of a state-dependent double-threshold policy based on the stochastic inventory theory. A modified backward iteration algorithm is devised for practical applications, where an exponentially weighted moving average algorithm is used to estimate the statistics of vehicle mobility and energy demand. Then, we propose a decentralized economic dispatch approach for microgrids such that the optimal decision on power generation is made by each distributed generation unit locally via multiagent coordination. To avoid a slow convergence speed of multiagent coordination, we propose a heterogeneous wireless network architecture for microgrids. Two multiagent coordination schemes are proposed for the single-stage and hierarchical operation modes, respectively. The optimal number of activated cellular communication devices is obtained based on the tradeoff between communication and generation costs.
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Unified Reliability Index Development for Utility Quality AssessmentSindi, Hatem 04 January 2013 (has links)
With the great potential smart distribution systems have to cause a paradigm shift in conventional distribution systems, many areas need investigation. Throughout the past few decades, many distribution systems reliability indices have been developed. Varying in their calculation techniques, burden, and purpose of calculation, these indices covered wide range of reliability issues that face both utilities and regulators. The major purpose of the continuous development of reliability indices is to capture a comprehensive idea of systems performance. While systems are evolving to a much more smarter and robust ones, so do the assessment tools need to be improved. The lack of consensus among utilities and regulators on which indices should be used complicate the problem more. Furthermore, regulators still come short when it comes to standard implementation because no final standard have been developed. However, regulators tend to advice or impose certain numbers on utilities based on historic performances. Because of the inevitable comparisons made by regulators on the routinely practiced process of utilities’ reporting of some of their indices, adequate and fair process needs to be implemented. The variation in utilities perspective on the advice or imposed indices cause an additional burden to achieving fair and adequate designs, upgrade requirements, and public goodwill. Some utilities consider these regulators recommendations guidelines; others treat them as strict standards, and yet others consider them goals. In this work, a development of a unified reliability index, which can yield proper performance assessment, fair comparisons, and reflection of all the knowledge imbedded within all current indices, will be developed. The developed unified index provides several benefits, among which is adequate standards design, improved tools for planning and design optimization, and less technical burden on operators. In addition, the development of a unified reliability index required the development of a standard normalization methodology.
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Smart Distribution Power Systems Reconfiguration using a Novel Multi-agent ApproachMansour, Michael January 2013 (has links)
The few past years have witnessed a huge leap in the field of the smart grid communication networks in which many theories are being developed, and many applications are being evolved to accommodate the implementation of the smart grid concepts. Distribution power systems are considered to be one of the first leading fields having the strong desire of applying the smart grid concepts; resulting in the emersion of the smart distribution power systems, which are the future visualization of the distribution systems having both the ability of smart acting, and the capabilities of automation, self-healing, and decentralized control. For the sake of the real implementation of the smart distribution power systems, the main functions performed by the traditional systems have to be performed by the new smart systems as well, taking into account the new features and properties of those smart systems. One of those main functions is the ability of power networks optimal reconfiguration to minimize the system’s power loss while preserving the system radial topology.
The proposed reconfiguration methodology targets the utilization of a hybrid genetic algorithm with two fuzzy controllers that could converge to the global optimal network configuration with the fastest convergence rate consuming the least computational time. The first fuzzy controller is designed to reject any infeasible system configurations that might show up in the population of the genetic algorithm and violate the system radial topology, while the second fuzzy controller is designed to adapt the mutation rate of the genetic algorithm. Consequently, a novel multi-agent system is proposed and designed to perform the reconfiguration application in smart distribution power systems employing the concepts of distributed processing and decentralized control demanded by those systems. A multi-agent system employs a group of intelligent agents that have the capabilities of autonomy, reactivity, pro-activity, and sociality. Those agents cooperate with each other in order to perform a certain function through their powerful abilities to communicate, socialize, and make a common decision in a decentralized fashion based on the information retrieved from the surrounding environment and compiles with their ultimate objective.
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Market-based coordination for domestic demand response in low-carbon electricity gridsElizondo-González, Sergio Iván January 2017 (has links)
Efforts towards a low carbon economy are challenging the electricity industry. On the supply-side, centralised carbon-intensive power plants are set to gradually decrease their contribution to the generation mix, whilst distributed renewable generation is to successively increase its share. On the demand-side, electricity use is expected to increase in the future due to the electrification of heating and transport. Moreover, the demand-side is to become more active allowing end-users to invest in generation and storage technologies, such as solar photovoltaics (PV) and home batteries. As a result, some network reinforcements might be needed and instrumentation at the users’ end is to be required, such as controllers and home energy management systems (HEMS). The electricity grid must balance supply and demand at all times in order to maintain technical constraints of frequency, voltage, and current; and this will become more challenging as a result of this transition. Failure to meet these constraints compromises the service and could damage the power grid assets and end-users’ appliances. Balancing generation, although responsive, is carbon-intensive and associated with inefficient asset utilisation, as these generators are mostly used during peak hours and sit idle the rest of the time. Furthermore, energy storage is a potential solution to assist the balancing problem in the presence of non-dispatchable low-carbon generators; however, it is substantially expensive to store energy in large amounts. Therefore, demand response (DR) has been envisioned as a complementary solution to increase the system’s resilience to weather-dependent, stochastic, and intermittent generation along with variable and temperature-correlated electric load. In the domestic setting, operational flexibility of some appliances, such as heaters and electric cars, can be coordinated amongst several households so as to help balance supply and demand, and reduce the need of balancing generators. Against this background, the electricity supply system requires new organisational paradigms that integrate DR effectively. Although some dynamic pricing schemes have been proposed to guide DR, such as time of use (ToU) and real-time pricing (RTP), it is still unclear how to control oscillatory massive responses (e.g., large fleet of electric cars simultaneously responding to a favourable price). Hence, this thesis proposes an alternative approach in which households proactively submit DR offers that express their preferences to their respective retailer in exchange for a discount. This research develops a computational model of domestic electricity use, and simulates appliances with operational flexibility in order to evaluate the effects and benefits of DR for both retailers and households. It provides a representation for this flexibility so that it can be integrated into specific DR offers. Retailers and households are modelled as computational agents. Furthermore, two market-based mechanisms are proposed to determine the allocation of DR offers. More specifically, a one-sided Vickrey-Clarke-Groves (VCG)-based mechanism and penalty schemes were designed for electricity retailers to coordinate their customers’ DR efforts so as to ameliorate the imbalance of their trading schedules. Similarly, a two-sided McAfee-based mechanism was designed to integrate DR offers into a multi-retailer setting in order to reduce zonal imbalances. A suitable method was developed to construct DR block offers that could be traded amongst retailers. Both mechanisms are dominant-strategy incentive-compatible and trade off a small amount of economic efficiency in order to maintain individual rationality, truthful reporting, weak budget balance and tractable computation. Moreover, privacy preserving is achieved by including computational agents from the independent system operator (ISO) as intermediaries between each retailer and its domestic customers, and amongst retailers. The theoretical properties of these mechanisms were proved using worst-case analysis, and their economic effects were evaluated in simulations based on data from a survey of UK household electricity use. In addition, forecasting methods were assessed on the end-users’ side in order to make better DR offers and avoid penalties. The results show that, under reasonable assumptions, the proposed coordination mechanisms achieve significant savings for both end-users and retailers, as they reduce the required amount of expensive balancing generation.
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Design and Development of a Novel Fast Pilot Protection System for Future Renewable Electric Energy Distribution Management ProjectJanuary 2012 (has links)
abstract: In the future electrical distribution system, it can be predicted that local power generators such as photovoltaic panels or wind turbines will play an important role in local distribution network. The local energy generation and local energy storage device can cause indeterminable power flow, and this could cause severe protection problems to existing simple overcurrent coordinated distribution protection system. An accurate, fast and reliable protection system based on pilot protection concept is proposed in this thesis. A comprehensive protection design specialized for the FREEDM system - the intelligent fault management (IFM) is presented in detail. In IFM, the pilot-differential protective method is employed as primary protection while the overcurrent protective method is employed as a backup protection. The IFM has been implemented by a real time monitoring program on LabVIEW. A complete sensitivity and selectivity analysis based on simulation is performed to evaluate the protection program performance under various system operating conditions. Followed by the sensitivity analysis, a case study of multiple-terminal model is presented with the possible challenges and potential limitation of the proposed protection system. Furthermore, a micro controller based on a protection system as hardware implementation is studied on a scaled physical test bed. The communication block and signal processing block are accomplished to establish cooperation between the micro-controller hardware and the IFM program. Various fault cases are tested. The result obtained shows that the proposed protection system successfully identifies faults on the test bed and the response time is approximately 1 cycle which is fast compared to the existing commercial protection systems and satisfies the FREEDM system requirement. In the end, an advanced system with faster, dedicated communication media is accomplished. By verifying with the virtual FREEDM system on RTDS, the correctness and the advantages of the proposed method are verified. An ultra fast protection system response time of 4ms is achieved, which is the fastest protection system for a distribution level electrical system. / Dissertation/Thesis / M.S. Electrical Engineering 2012
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Evaluation de produits d'effacement sur un ensemble de consommateurs par modélisation bottom-up d'un parc de logements / Assessment of heating loads shedding at large scale through bottom-up modelling of housing stocksCarloganu, Sinziana 08 December 2016 (has links)
Cette thèse se propose d’évaluer les produits d’effacement réalisés sur un ensemble de consommateurs, chacun étant défini par le triplet {bâtiment, systèmes, ménage}. On définit un produit d’effacement par la caractérisation de la déformation de la courbe de charge de l’ensemble des consommateurs suite à l’envoi d’un signal de contrôle (pilotage direct ou signal tarifaire).Deux dimensions ont été considérées dans le cadre de ce travail : l’étude des variables d’influence sur les effacements de consommation en s’appuyant sur des données issues d’expérimentations ainsi que l’élaboration d’un modèle global permettant de reproduire une partie de la diversité observée sur les courbes de charge des clients expérimentateurs.Afin d’analyser un échantillon {bâtiments, systèmes, ménages}, une attention particulière est portée à la dispersion des caractéristiques du bâti (enveloppes, expositions, ...) et aux éventuelles corrélations entre le ménage (mode de vie, choix des équipements, ...) et les systèmes (caractéristiques techniques), notamment pour l’usage "chauffage et climatisation".Un travail de réconciliation de données (issues de statistiques, de travaux sur la caractérisation des logements métropolitains, d’études sur les habitudes de vie des ménages, ...) a permis de proposer une première évaluation en simulation d’effacement de l’usage chauffage au périmètre d’un parc de quelques milliers de logements.L’approche bottom-up proposée permet ainsi de rendre compte de la diversité technique, fonctionnelle et d’origine comportementale de l’usage étudié. / This thesis aims at evaluating load curtailments packages over a set of electricity users, each being defined by the triolet {building, system, household}. We define a load curtailment package by the quantification of the load curve's deformation due to the emission of a control signal (direct control or price incentive).Two dimensions were considered through this work: first the study of the different variables' influence using experimental data, and secondly the construction of a global model which can effectively reproduce the diversity observed on experimental load curves.In order to analyse a sample {building, system, household}, the dispersion of the different caracteristics of the building (envelope, exposure,...) were carefully studied, as well as the possible links between the household (lifestyle, choice of household equipments,...) and the systems (technical caracteristics) especially for the electrical heaters and HVAC systems.We work to reconcile data from different sources (statistical data, data from research on urban building caracterization, on households' habits,...) and we are able to give a first evaluation of load curtailment products over the electrical heating usage in urban environment through numerical simulations of a few thousand housings. The bottom-up approach used accounts for the technical diversity, as well as the functional and behavioral diversity of the studied electrical usage.
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Impacto do gerenciamento pelo lado da demanda no consumo residencial / Impact of demand-side management on residential consumptionMancuzo, Edson [UNESP] 31 May 2017 (has links)
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Previous issue date: 2017-05-31 / O objetivo deste trabalho é apresentar o impacto do gerenciamento pelo lado da demanda no consumo residencial. A Eficiência Energética em uma área residencial pode ser aumentada de diversas formas, e a aplicação do gerenciamento pelo lado da demanda permite o ganho em eficiência e custos, tanto por parte do consumidor quanto por parte da concessionária. Este trabalho aborda a redução das perdas elétricas nos condutores (por efeito Joule) desde a saída dos transformadores de distribuição (MT / BT) até a entrada de energia elétrica de uma residência classe B1 com entrada em 127 / 220V bifásico e carga instalada entre 12 kW e 18 kW. Uma pesquisa foi elaborada para se obter hábitos de uso do consumidor residencial em relação aos equipamentos de sua residência. Um algoritmo para cálculo das perdas foi desenvolvido em Matlab com a finalidade de simular o consumo de energia em residências e linhas de distribuição de baixa tensão da região sudeste do Brasil. Aplicou-se os conceitos do gerenciamento pelo lado da demanda, apresentando o impacto no consumo residencial, assim como os custos relacionados à eficiência. As simulações demonstraram que foi possível otimizar o consumo de energia elétrica assim como diminuir a perda por dissipação nos condutores, reduzindo os custos. / The goal of this paper is to present the impact of the management by the demand side in residential consumption. Energy Efficiency in a residential area can be increased in a number of ways, and the application of demand-side management allows for efficiency and cost gains by both the consumer and the utility. This work deals with the reduction of electrical losses in the conductors (Joule effect) from the output of the distribution transformers (MT / BT) to the electrical input of a class B1 residence with a biphasic 127 / 220V input and a load installed between 12 KW and 18 kW. A research was developed to obtain habits of use of the residential consumer in relation to the equipment of his residence. An algorithm for calculating losses was developed in Matlab with the purpose of simulating the energy consumption in homes and low voltage distribution lines in the southeastern region of Brazil. The management concepts were applied on the demand side, presenting the impact on residential consumption, as well as costs related to efficiency. The simulations demonstrated that it was possible to optimize the consumption of electric energy as well as to reduce the loss by dissipation in the conductors, reducing costs.
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Smart Meter, Feedback et maîtrise de la consommation électrique : Le cas du secteur résidentiel dans la commune de Biot - Alpes Maritimes / Smart Meter, Feedback and control of electricity consumption : The case of the residential sector in the town of Biot – Alpes MaritimesKendel, Adnane 08 December 2015 (has links)
Cette thèse a pour but d’étudier l’impact du retour d’information (feedback) vers les ménages sur leur capacité de maîtrise de leur consommation d’électricité et s’est appuyée sur une expérimentation menée sur le terrain, dans le cadre d’un projet intitulé TicElec, réalisé dans la commune de Biot, dans les Alpes-Maritimes (un département marqué par des contraintes d’approvisionnement en électricité, en périodes froides) et associant l’Université, les Autorités locales et un Bureau d’études. Notre problématique qui a porté sur l’impact de plusieurs types de feedback (inspirée par la typologie des feedback développée par Darby (2006a)) appliqués à trois groupes de consommateurs, sur une durée supérieure à six mois, a montré l’existence de différents comportements de consommation et de maîtrise de la demande d’électricité des ménages étudiés, plus ou moins marqués par le manque d’information sur leurs modes de consommation, c'est-à-dire le maillon faible des stratégies de maîtrise de l’énergie. Nous avons également montré que les résultats varient selon le type d’information transmis, la nature et la durée du feedback, mais que de manière générale, le feedback sur consommation (direct ou indirect) a été efficace pour la maîtrise de la demande d’électricité (par réduction et effacement en pointe), même si la réduction était plus grande chez les groupes à feedback direct, par action sur les comportements de restriction (Curtailment behavior), sans toutefois déclencher les comportements d’efficience (Efficiency behavior) et de maintenance (Maintenance behavior), compte tenu des coûts et des délais de leur mise en œuvre. / This thesis aims to study the impact of feedback to households on their ability to control their electricity consumption and was based on an experiment conducted in the field, as part of a project called TicElec (Technologies de l'Information pour une Consommation Electrique Responsable), produced in the town of Biot, in Alpes-Maritimes (a department marked by power supply constraints in cold periods) and associating University, local authorities and a consulting firm. Our problematic which focused on the impact of several types of feedback (inspired by the typology of feedback developed by Darby (2006a)) applied to three groups of consumers over a period greater than six months, showed the existence of different consumer behavior and control of the electricity demand of households studied, more or less marked by the lack of information about their consumption patterns, that is to say, the weak link in energy management strategies. We also have shown that the results depend on the type of transmitted information, the nature and duration of feedback, but in general, the feedback on consumption (direct or indirect) was effective in controlling the application for electricity (by reduction and erasing peak), although the reduction was greater in groups direct feedback by acting on the Curtailment behavior, without triggering Efficiency behavior and Maintenance behavior, given the costs and time of implementation.
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Contribution on the day-ahead and operational optimization for DC microgrid building-integrated / Contribution pour l'optimisation J-1 et opérationnelle d'un micro-réseau DC intégré au bâtimentTrigueiro dos Santos, Leonardo 27 April 2017 (has links)
Cette recherche se concentre sur l'optimisation d'un micro-réseau en interaction avec le réseau électrique intelligent. Il s'agit de la recherche de solutions optimales pour la conception d'un micro-réseau afin de minimiser les coûts, d'une part, et la possibilité augmenter 1'utilisation des sources renouvelables, d'autre part. La supervision, doit traiter la prise en compte des incertitudes dans la gestion prédictive optimisée des flux de puissance. / This thesis study focuses on a DC microgrid building-integrated satisfying the power balance at the local level and supplying DC loads during both, grid-connected and isolated operation modes. Considering that energy management can be defined as a group of different control strategies and operational practices that together with the new physical equipment and software solutions aims to accomplish the objectives of energy management, the main objective of this thesis is to define the energy management strategies for the building-integrated DC microgrid, aiming to keep the bus voltage stable as well as to reduce the energy cost to the end users and the negative impact to the main grid. Therefore, this research work focuses to optimize and develop the implementation of the designed controller of building-integrated DC microgrid. The proposed DC microgrid consists of PV building-integrated sources, a storage system, a main grid connection for the grid-connected mode and a micro turbine for the off-grid or isolated mode, and a DC load (electric appliances of a tertiary building). The bidirectional connections with the main grid and the storage aim to supply the building’s DC appliances, and sell or store the energy surplus. The results validate the operation of the whole system, ensuring the capability of the proposed supervisory control to manage the energy power flow while ensuring voltage stability. Other goals concern the analyze of the proposed separation between optimization and real time power balance and the usage of the proposed load shedding/restoration algorithm in the microgrid environment are also validate. Regarding the technical contributions, the work of this thesis allowed the creation and the practical development of a test bench for microgrid based on PV sources emulator, which allows the repeatability conditions (closeness of the agreement between the results of successive measurements of the same solar irradiance and air temperature carried out under the same conditions of measurement) and reproducibility (closeness of the agreement between the results of measurements of the same solar irradiation and air temperature carried out under changed conditions of measurement). Numerous experimental tests were carried out and allowed the validation of the proposed concepts.
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Novel performance evaluation of information and communication technologies to enable wide area monitoring systems for enhanced transmission network operationGolshani, Mohammad January 2015 (has links)
The penetration of renewable energy sources has increased significantly in recent years due to the ongoing depletion of conventional resources and the transition to a low carbon energy system. Renewable energy sources such as wind energy are highly intermittent and unpredictable in nature, which makes the operation of the power grid more dynamic and therefore more complex. In order to operate the power system reliably under such conditions, Phasor Measurement Units (PMUs) through the use of satellite technology can offer a state-of-the-art Wide Area Monitoring System (WAMS) for improving power system monitoring, control and protection. They can improve the operation by providing highly precise and synchronised measurements near to real-time with higher frequency and accuracy. In order to achieve such objectives, a high-speed and reliable communications infrastructure is required to transfer time-critical PMU data from remote locations to the control centre. The signals measured by PMUs are transmitted across Local and Wide Area Networks, where they may encounter excessive delays. Signal delays can have a disruptive effect and make applications at best inefficient and at worse ineffective. The main research contribution of this thesis is the performance evaluation of communication infrastructures for WAMS. The evaluation begins from inside substations and continues over wide areas from substations to control centre. Through laboratory-based investigations and simulations, the performance of communications infrastructure in a typical power system substation has been analysed. In addition, the performance evaluation of WAMS communications infrastructure has been presented. In the modelling and analysis, an existing WAMS as installed on the GB transmission system has been considered. The actual PMU packets as received at the Phasor Data Concentrator (PDC) were captured for latency analysis. A novel algorithmic procedure has been developed and implemented to automate the large-scale latency calculations. Furthermore, the internal delays of PMUs have been investigated, determined and analysed. Subsequently, the WAMS has been simulated and detailed comparisons have been performed between the simulated model results and WAMS performance data captured from the actual WAMS. The validated WAMS model has been used for analysing possible future developments as well as to test newly proposed mechanisms, protocols, etc. in order to improve the communications infrastructure performance.
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