Dissertations / Theses on the topic 'Electric power meter'

Since the last United Nations Climate Change Conference in 2015 in Paris (the COP 21), world leaders acknowledged climate change. There is no need any more to justify the switch from fossil fuel-based to renewable energy sources. Nevertheless, this transition is far from being straightforward. Besides technologies that are not yet mature -- or at least not always financially viable in today's economy -- the power grid is currently not ready for a rapid and massive integration of renewable energy sources. A main challenge for the power grid is the inadequacy between electric production and consumption that will rise along with the integration of such sources. Indeed, due to their dependence on weather, renewable energy sources are intermittent and difficult to forecast with today's tools. As a commodity, electricity is a quite distinct good for which there must be perfect adequacy of production and consumption at all time and characterized by a very inelastic demand. High shares of renewable energy sources lead to high price volatility and a higher risk to jeopardize the security of supply. Additionally, the switch to renewable energy sources will lead to an electrification of loads and transportation, and thus the emergence of new higher-consumption loads such as electric vehicles and heat pumps. These new and higher-consumption loads, combined with the population growth, will cause over-rated power load increases with less predictable load patterns in the future.This work focuses on issues specific to the distribution power grid in the context of the current energy transition. Traditional low-voltage grids are perhaps the most passive circuits in power grids. Indeed, they are designed primarily using a fit and forget approach where power flows go from the distribution transformer to the consumers and no element has to be operated or regularly managed. In fact, low-voltage networks completely lack observability due to very low monitoring. The distribution grid will especially undergo drastic changes from this energy transition. Distributed sources and new high-consumption -- and uncoordinated -- loads result in new power flow patterns, as well as exacerbated evening peaks for which it is not designed. The consequences are power overloads and voltage imbalances that deteriorate grid components, such as a main asset like the medium-to-low voltage transformer. Additionally, the distribution grid is characterized by end-users that pay a price for electricity that does not reflect the grid situation -- that is, mostly constant over a year -- and allow little to no actions on their consumption.These issues have motivated authorities to propose a global approach to ensure security of electricity supply at short and medium-term. The latter requires, among others, the development of demand response programs that encourage users to take advantage of load flexibility. First, we propose adequate electricity pricing structures that will allow users to unlock the potential of such demand response programs; namely, dynamic pricings combined with a prosumer structure. Second, we propose a fast and robust two-level optimization, formulated as a mixed-integer linear program, that coordinates flexible loads. We focus on two types of loads; electric vehicles and heat pumps, in an environment with solar PV panels. The lower level aims at minimizing individual electricity bills while, at the second level, we optimize the power load curve, either to maximize self-consumption, or to smoothen the total power load of the transformer. We propose a parametric study on the trade-off between only minimizing the individual bills versus only optimizing power load curves, which have proven to be antagonist objectives. Additionally, we assess the impact of the rising share of flexible loads and renewable energy sources for scenarios from today until 2050. A macro-analysis of the results allows us to assess the benefits of load flexibility for every actor of the distribution grid, and depending on the choice of a pricing structure. Our optimization has proved to prevent evening peaks, which increases the lifetime of the distribution transformer by up to 200%, while individual earnings up to 25% can be made using adequate pricings. Consequently, the optimization significantly increases the power demand elasticity and increases the overall welfare by 10%, allowing the high shares of renewable energy sources that are foreseen.<br>Doctorat en Sciences de l'ingénieur et technologie<br>info:eu-repo/semantics/nonPublished

No contexto de Smart Grids, determinar a correta localização das fontes causadoras de Variação de Tensão de Curta Duração (VTCD) não é uma tarefa simples, devido à curta duração destes eventos e também, por sua rápida propagação nas redes de distribuição de energia elétrica. Neste sentido, esse trabalho apresentou um método híbrido recursivo baseado em ferramentas da área de aprendizado de máquinas (algoritmo de agrupamento e base de regras), o qual é capaz de localizar as fontes de VTCD, a partir da análise dos das características dos distúrbios disponibilizadas pelos smart meters instalados no sistema. Assim, o trabalho destinouse ao desenvolvimento de uma plataforma em hardware para aquisição, detecção e classificação dos distúrbios, através de um Sistema Operacional de Tempo Real. Em seguida o algoritmo de agrupamento (k-means) agrupou os dados dos medidores de forma a definir dois clusters, onde um deles correspondeu aos medidores que estão longe da região que ocorreu o distúrbio e o outro, correspondeu aos medidores que estavam localizados próximos da região de ocorrência do distúrbio. Na segunda etapa, um sistema baseado em regras determinou qual dos clusters abrangeu o nó de origem. No entanto, quando o algoritmo determinou uma região muito grande, essa região é introduzida recursivamente, como entrada da metodologia desenvolvida, para refinar a região de localização. O sistema resultante foi capaz de estimar a região de localização com uma taxa de acerto acima de 90%. Assim, o método teve sua concepção adequada ao empregado nos centros de controle e operações de concessionárias de energia elétrica, visando apoiar a decisão do corpo técnico para que ações corretivas fossem estabelecidas de forma assertiva.<br>In the Smart Grids context, the correct location of short-duration voltage variations sources is not a trivial task, because of the short duration of these events and for rapid propagation in the distribution feeder. In this sense, aiming to develop a recursive hybrid method based on machine learning area tools (clustering algorithm and rule base) that is able to locate the sources of short-duration voltage variations, it was used data from smart meters installed along the distribution feeder. The recursive hybrid method, as input, received the disturbance characteristics provided by the meters installed in the system. Thus, this thesis aimed to development of a measurement hardware for signal acquisition, detection, classification through a realtime operating system. Then, k-means clustering algorithm grouped the meters data in order to define two clusters, where one of them corresponded to the meters that were distant from the region that occurred the disturbance and the other one corresponded to the meters, which were located near to the disturbance occurrence region. In a second step, a rule-based system determined which of the clusters corresponded to the source node. When the algorithm determined a very large region, that region was recursively introduced as input of the developed methodology to decrease its size. The resulting system was able to estimate the location region with a accuracy above 90%. Therefore, this method showed a suitable design for employment by operation control centers of power sector concessionaires, aiming to support technical staff decision to stablish assertive corrective actions.

Real time monitoring of the shipboard power system is a complex task to address. Unlike the terrestrial power system, the shipboard power system is a comparatively smaller system but with more complexity in terms of its system operation. This requires the power system to be continuously monitored to detect any type of fluctuations or disturbances. Planning metering systems in the power system of a ship is a challenging task not only due to the dimensionality of the problem, but also due to the need for reducing redundancy while improving network observability and efficient data collection for a reliable state estimation process. This research is geared towards the use of a Genetic Algorithm for intelligent placement of meters in a shipboard system for real time power system monitoring taking into account different system topologies and critical parameters to be measured from the system. The algorithm predicts the type and location of meters for identification and collection of measurements from the system. The algorithm has been tested with several system topologies.

Large penetration of distributed generation from variable renewable energy sources, increased consumption flexibility on the demand side and the electrification of transportation pose great challenges to existing and future electric distribution networks. This thesis studies the roles of several actors involved in electric distribution systems through electricity consumption data analysis and simulation models. Results show that real-time electricity pricing adoption in the residential sector offers economic benefits for end consumers. This occurs even without the adoption of demand-side management strategies, while real-time pricing also brings new opportunities for increasing consumption flexibility. This flexibility will play a critical role in the electrification of transportation, where scheduled charging will be required to allow large penetration of EVs without compromising the network's reliability and to minimize upgrades on the existing grid. All these issues add significant complexity to the existing infrastructure and conventional passive components are no longer sufficient to guarantee safe and reliable network operation. Active distribution networks are therefore required, and consequently robust and flexible modelling and simulation computational tools are needed for their optimal design and control. The modelling approach presented in this thesis offers a viable solution by using an equation-based object-oriented language that allows developing open source network component models that can be shared and used unambiguously across different simulation environments.

Since there is a significant potential to supervise the low voltage network with the assistance of the end-customer smart meters, Vattenfall Eldistribution AB wants to take advantage of such data. Therefore, this project’s overall goal is to investigate how some specific grid disturbances could be detected in certain meter data types. There is a plethora of event data from several different grid areas with their own unique set of customers and power flow. Furthermore, the project aims to propose a detection method within the smart meter’s capability and explore the possibility of using smart meter data to identify the grid’s state. The literature study suggested that the machine learning approaches k-means and SVM were suggested to be used within this study’s scope. Several supervised and unsupervised machine learning algorithms have been identified and applied to power quality issues in various ways. Furthermore, each approach had four cases applied as well to broaden the analysis. After conducting the study, the project results show that smart meter data indeed has the potential to be used in machine learning methods to identify weak grids. However, the study shows that the information gained from smart meter data in its current state alone is not enough to distinguish weak grids from strong grids. For instance, the current data could complement grid data, such as loop impedance and topology data. Future work could include using the same machine learning methods on higher dimensions input data to separate the data points. One way to diversify the data could be to include data describing grid topology and data from PQ-meters. Furthermore, it will be possible to continuously monitor the low voltage grid conditions with future smart meters. In turn, this may give a better insight into how the voltage levels behave for weak and strong grids, respectively.<br>Vattenfall Eldistribution AB har en stor andel smarta mätare som registrerar elkvalitetsproblem på lågspänningsnätet. Detta medför att det finns stor potential att övervaka lågspänningsnätet med hjälp av data från dessa mätare. Därför är det övergripande målet med detta projekt att undersöka hur vissa specifika nätstörningar uppstår i vissa typer av mätdata. Det finns dessutom en uppsjö av data från många olika nätområden där alla har sin egna unika uppsättning av kunder och energi- flöden. Vidare syftar projektet till att utveckla en detekteringsmetod inom smartmätarens kapacitet och utforska möjligheten att använda smarta mätdata för att identifiera nätets tillstånd. Från litteraturstudien drogs slutsatsen att k-means och SVM var de mest lämpade metoderna att användas för denna studie. Flera maskininlärningsmetoder har identifierats och tillämpats på elkvalitetsproblem. Vidare analyserades data för fyra olika fall per metod. Efter att ha genomfört studien visade resultatet att data från smarta mätare sannerligen har potential att analyseras med maskininlärningsmetoder för att identifiera svaga nät. Däremot indikerar studien att den information som kan utvinnas från smarta mätare i det nuvarande läget inte är tillräckligt för att urskilja svaga nät från starka nät. Exempelvis kan data från smarta mätare kompletteras med nätdata, såsom impedans, och information om nätets topologi. Framtida projekt skulle därför kunna applicera samma maskininlärningsmetoder på indata med högre dimensioner för att möjliggöra en separation av data på flera plan. Ett sätt att diversifiera data vore att inkludera exempelvis information som beskriver nättopologi och data från PQ-mätare. Vidare kommer framtida mätare ha möjlighet att övervaka nätets spänning och ström kontinuerligt.

The increasing penetration of distributed generation, responsive loads and emerging smart metering technologies will continue the transformation of distribution systems from passive to active network conditions. In such active networks, State Estimation (SE) tools will be essential in order to enable extensive monitoring and enhanced control technologies. In future distribution management systems, the novel electrical power distribution system SE requires development in a scalable manner in order to accommodate small to massive size networks, be operable with limited real time measurements and a restricted time frame. Furthermore, a significant phase of new sensor deployment is inevitable to enable distribution system SE, since present-day distribution networks lack the required level of measurement and instrumentation. In the above context, the research presented in this thesis investigates five SE optimization solution methods with various case studies related to expected scenarios of future distribution networks to determine their suitability. Hachtel's Augmented Matrix method is proposed and developed as potential SE optimizer for distribution systems due to its potential performance characteristics with regard to accuracy and convergence. Differential Evolution Algorithm (DEA) and Overlapping Zone Approach (OZA) are investigated to achieve scalability of SE tools; followed by which the network division based OZA is proposed and developed. An OZA requiring additional measurements is also proposed to provide a feasible solution for voltage estimation at a reduced computation cost. Realising the requirement of additional measurements deployment to enable distribution system SE, the development of a novel meter placement algorithm that provides economical and feasible solutions is demonstrated. The algorithm is strongly focused on reducing the voltage estimation errors and is capable of reducing the error below desired threshold with limited measurements. The scalable SE solution and meter placement algorithm are applied on a multi-processor system in order to examine effective reduction of computation time. Significant improvement in computation time is observed in both cases by dividing the problem into smaller segments. However, it is important to note that enhanced network division reduces computation time further at the cost of accuracy of estimation. Different networks including both idealised (16, 77, 356 and 711 node UKGDS) and real (40 and 43 node EG) distribution network data are used as appropriate to the requirement of the applications throughout this thesis.

In recent years, due to the combination of technological advances in the fields ofmeasurement instrumentation, communications, home-health care and textile-technology thedevelopment of medical devices has shifted towards applications of personal healthcare.There are well known the available solutions for heart rate monitoring successfully providedby Polar and Numetrex. Furthermore new monitoring applications are also investigated. Amongthese non-invasive monitoring applications, it is possible to find several ones enable bymeasurements of Electrical Bioimpedance.Analog Devices has developed the AD5933 Impedance Network Analyzer which facilitatesto a large extent the design and implementation of Electrical Bioimpedance Spectrometers in amuch reduced space. Such small size allows the development of a fully wearable bioimpedancemeasurement.With the development of a Electrical Bioimpedance-enable wearable medical device in focusfor personal healthcare monitoring, in this project, the issue of power management has beentargeted and a battery-driven Electrical Bioimpedance Spectrometer based in the AD5933 hasbeen implemented. The resulting system has the possibility to operate with a Li-Po battery with apower autonomy over 17 hours.

The necessity of a revolution in the electrical system is obvious, and smart meters will be the solution. The development of smart grids will be built over the new electronic measuring devices, which imply a challenge for the next few years in the engineering field.In order to understand the basics of smart grids, we have carried a description and comparison of both the current and the next-gen electrical systems. Emphasizing the advantages and opportunities obtained by changing into the smart grids, it demonstrates the importance of moving towards a more modern measurement system.A very important issue is to decide which should be the minimum features in Smart Meters, therefore this thesis analyzes the different exiting models and also proposes several suggestions for the future. Finally, it was conducted a report of the current deployment situation of this new technology in various representative countries. Describing the settings and options chosen by each country, we can achieve a conclusion that unifies a standard solution by the choice of the best proposals.

Orientador: Elnatan Chagas Ferreira<br>Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação<br>Made available in DSpace on 2018-08-23T02:39:21Z (GMT). No. of bitstreams: 1 Moro_JeffersonZortea_M.pdf: 4211036 bytes, checksum: df7a8907629ae3a423fc16dbd9f4783e (MD5) Previous issue date: 2013<br>Resumo: Nos últimos anos, grandes esforços vêm sendo feitos com a intenção de mostrar às pessoas o montante de energia gasto por cada eletrodoméstico, uma vez que essa informação leva consigo a principal base do programa de eficiência energética que pode ser feito pelos próprios usuários domésticos. Para ajudar o consumidor a monitorar seus gastos, foi desenvolvido um medidor de energia elétrica, capaz de informar o consumo de cada circuito que compõe a rede elétrica da residência, além de permitir a identificação em tempo real, do consumo de energia elétrica dos diversos equipamentos conectados nesses circuitos. Esse trabalho apresenta um simples e funcional método não intrusivo para se medir o consumo de energia elétrica, de tal forma que pode ser aplicado em programas de eficiência energética, sendo portando a interface que alimenta o consumidor com informações sobre os gastos das diversas cargas<br>Abstract: Currently a large effort are being done with the intention to educate people about how much energy each electrical appliance uses in their houses, since this knowledge is the fundamental basis of energy efficiency programs that can be managed by the household owners. To help the home consumer to monitor their electric power consumption, it was developed an electric power meter, in order to display the spending in each circuit, as well as the real time identification of all equipment plugged in each circuit. This paper presents a simple yet functional non-intrusive method for electric power measurement that can be applied in energy efficiency programs, in order to provide a better knowledge of the energy consumption of the appliances in a home<br>Mestrado<br>Eletrônica, Microeletrônica e Optoeletrônica<br>Mestre em Engenharia Elétrica

It is commonly agreed among energy experts that smart meters (SMs) are the key component that will facilitate the transition towards the smart grid. Fast-peace innovations in the smart metering infrastructure (AMI) are exposing countless benefits that network operators can obtain when they integrate SMs applications into their daily operations.  Following the amendment in 2017, where the Swedish government dictated that all SMs should now include new features such as remote control, higher time resolution for the energy readings and a friendly interface for customers to access their own data; network operators in Sweden are currently replacing their SMs for a new model, also called the second generation of SMs. While the replacement of meters is in progress, many utilities like Hemab are trying to reveal which technical and financial benefits the new generation of SMs will bring to their operations.    As a first step, this thesis presents the results of a series of interviews carried out with different network operators in Sweden. It is studied which functionalities have the potential to succeed in the near future, as well as those functionalities that are already being tested or fully implemeneted by some utilities in Sweden. Furthermore, this thesis analyses those obstacles and barriers that utilities encounter when trying to implement new applications using the new SMs. In a second stage, an alarm system for power interruptions and voltage-quality events (e.g., overvoltage and undervoltage) using VisionAir software and OMNIPOWER 3-phase meters is evaluated. The results from the evaluation are divided into three sections: a description of the settings and functionalities of the alarm, the outcomes from the test, and a final discussion of potential applications. This study has revealed that alarm functions, data analytics (including several methods such as load forecasting, customer segmentation and non-technical losses analysis), power quality monitoring, dynamic pricing, and load shedding have the biggest potential to succeed in Sweden in the coming years. Furthermore, it can be stated that the lack of time, prioritization of other projects in the grid and the integration of those new applications into the current system seem to be the main barrier for Swedish utilities nowadays. Regarding the alarm system, it was found that the real benefits for network operators arrive when the information coming from an alarm system is combined with a topology interface of the network and a customer notifications server. Both applications could improve customer satisfaction by significantly reducing outage time and providing customers with real-time and precise information about the problems in the grid.

Orientador: Moacyr Trindade de Oliveria Andrade<br>Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica<br>Made available in DSpace on 2018-08-05T19:49:11Z (GMT). No. of bitstreams: 1 Vieiralves_EduardodeXerez_M.pdf: 1874956 bytes, checksum: 4f79bc70e42ae0c47e0a35cde1327ad1 (MD5) Previous issue date: 2005<br>Resumo: O equilíbrio econômico-financeiro garantido pelo contrato de concessão firmado pelas concessionárias junto ao poder concedente, tem como prerrogativa uma gestão atuante por parte do agente prestador do serviço, o que evidencia o seu controle técnico e comercial, bem como a promoção do desenvolvimento tecnológico dos serviços concedidos. Neste contexto, é de suma importância que a receita da concessionária, fruto de sua gestão na aquisição da energia a ser utilizada, bem como sua efetiva disponibilidade, seja dirigida ao mercado e aos consumidores com a qualidade requerida, a preços compatíveis com a renda média da população regional e com um percentual de perdas compatível com a tecnologia disponível. O controle das perdas técnicas e comerciais, em empresas do setor elétrico é fundamental para a consecução dos objetivos das concessionárias e da população a ser atendida. A falta de efetivo controle das perdas gera desperdício, ineficiência e redunda em custos elevados. Na região amazônica, as fontes energéticas são suportadas por parques térmicos que queimam material fóssil. Nessas condições o desperdício energético provoca, adicionalmente, danos desnecessários à natureza. As emissões de material particulado e de gases do efeito estufa, na condição de grandes perdas comerciais das empresas do setor elétrico, são mais elevadas, o que fatalmente vai agravar as condições ambientais da vida das gerações futuras. Na região Norte do Brasil, os sistemas elétricos isolados, em função do tipo das fontes energéticas e das grandes distâncias envolvidas, apresentam altos custos de operação e manutenção. As empresas apresentam índices de perdas elevadíssimos, que inviabilizam totalmente o negócio, razão pela qual, até hoje, vários são os mecanismos de subsídios associados ao mesmo, visando a viabilização do serviço de energia elétrica. O presente trabalho visa analisar a situação das perdas comerciais na região, dando ênfase ao ¿Caso Manaus¿, procurando identificar as suas causas e efeitos, tanto para a sociedade em geral como para os empresários do setor. Mais especificamente, se abordará o estudo de caso da empresa Manaus Energia S/A, por ser a maior dos sistemas isolados e por apresentar índices de perdas muito acima do admissível e da média das concessionárias do Setor Elétrico Nacional<br>Abstract: The financial-economical equilibrium guaranteed by the concession contract made by the concessionaries before the granting power, has as a prerogative an acting management by the service agent owner. That evidences its technical and commercial control, as well as the promotion of the technological development of the granted services. In such a context, it is of great importance that the concessionary receipt, product of its management in the acquisition of the energy to be used, as well as in its effective availability, be driven towards the market and the consumers with the quality requested with compatible prices at the middle income of the local population and with a loss percentage balanced to the technology available. The control of such technical and commercial loss in the companies of the electric field is fundamental to the accomplishment of the concessionary objectives and to the population attending.The lack of an effective control about the loss generates waste, non-efficiency and leads to elevated costs. In the Amazon area, the energetic sources are supported by thermic park which burn fossil matter. Besides, in such conditions the energetic waste provokes unnecessary waste to the nature. The emissions of particled material and gases from the greenhouse effect, in the condition of great commercial losses of the electric field companies are higher what will worsen the environmental conditions of the future generations life. In Brazil north region, the isolated electric systems due to the kind of the energetic sources and the great distances involved, lead to high costs of operation and maintenance. The companies show very high losses rates which make the business completely unfeasible, that is the reason, nowadays, due to many are the resources of subsidies associated attempting the availability of the electric energy service. The present work aims to analyze the state of the commercial losses in the region, emphasizing ¿Manaus case¿, searching the causes and effects identification, to the society in general, as to the sector entrepreneurs. More specifically, there will be approached the case study of Manaus Energia S/A company, for being the biggest of the isolated systems and for presenting a loss rate much higher from the admissible and the average of the National Electric Sector concessionaries<br>Mestrado<br>Energia Eletrica<br>Mestre em Engenharia Mecânica

El món de les comunicacions per la xarxa elèctrica (CXE) pot ser dividit en tres grans tipus: CXE en baix voltatge (CXE-BV), en mig voltatge (CXE-MV) i en alt voltatge (CXE-AV). En aquests últims anys, les CXE-BV han atret una gran expectació, ja que les seves capacitats han fet d'aquesta tecnologia una bona opció com alternativa pel bucle local d'accés i pel desplegament de xarxes d'àrea local, focalitzades aquestes últimes en l'entorn domèstic. A més, les CXE-BV inclouen un conjunt d'aplicacions de baixa velocitat orientades a l'operador, com la lectura automàtica de comptadors (LAC), distribució de càrrega, facturació dinàmica, etc. Per altra banda, les CXE-MV i CXE-AV, històricament lligades a tasques de telecontrol i teleprotecció, s'estan començant a considerar com un canal de comunicacions eficient i fiable. El desenvolupament de sistemes digitals i els esforços d'estandardització estan fent d'aquests canals un medi atractiu per a que els operadors elèctrics ofereixin serveis de comunicacions, ja que no necessiten invertir en infraestructura perquè la xarxa elèctrica ja està desplegada.<br/>En aquesta Tesi s'introduiran i es comentaran les particularitats de les tres xarxes elèctriques, després, es mostraran al lector les solucions tecnològiques existents pels canals de BV basats en la norma Europea CENELEC així com pels canals d'AV, mostrant que els sistemes actuals de LAC ofereixen una diversitat freqüencial molt baixa i que els mòdems CXE-AV estan ancorats en estendards antiquats.<br/>Aquest treball es mou per les tres topologies de la xarxa, particularment, en aplicacions orientades a la banda CENELEC, en mesura i modelat de canal, i en mesura i disseny del nivell físic per sistemes CXE-BV, CXE-MV i CXE-AV respectivament. Els sistemes actuals que exploten la banda CENELEC ofereixen mecanismes d'explotació de la diversitat freqüencial del canal molt limitats o nuls, donant lloc a una baixa robustesa en front a interferències i soroll de fons acolorit. Aquest treball proposa un esquema de modulació multiportadora que, mantenint una complexitat baixa, ofereix unes altes prestacions permetent un bon nivell d'explotació de la selectivitat freqüencial. Per al que a CXE-MV respecta, aquesta Tesi desenvolupa un model de canal determinístic-estadístic pels anells urbans de distribució de potència i, finalment, en sistemes CXE-AV, aquest treball proposa, basat en mesures de canal i proves de camp, un nivell físic de banda ampla capaç de incrementar la velocitat de comunicació mentre manté una baixa densitat espectral de potència limitant així la interferència a altres sistemes.<br/>PARAULES CLAU: Power line communications (PLC), low voltage (LV), medium voltage (MV), high voltage (HV), automatic meter reading (AMR), orthogonal frequency division multiplexing (OFDM), multicarrier spread spectrum (MC-SS), communication system design, channel measurements, channel modeling, scattering parameters.<br>El mundo de las comunicaciones por la red eléctrica (CRE) puede ser dividido en tres grandes tipos: CRE en bajo voltaje (CRE-BV), en medio voltaje (CRE-MV) y en alto voltaje (CRE-AV). En estos últimos años, las CRE-BV han atraído una gran expectación, ya que sus capacidades han hecho de esta tecnología una buena opción como alternativa para el bucle local de acceso y para el despliegue de redes de área local, focalizadas estas últimas en el entorno doméstico. Además, las CRE-BV incluyen un conjunto de aplicaciones de baja velocidad orientadas al operador como la lectura automática de contadores (LAC), distribución de carga, facturación dinámica, etc. Por otro lado, las CRE-MV y CRE-AV, históricamente ligadas a tareas de telecontrol y teleprotección, se están empezando a considerar como un canal de comunicaciones eficiente y fiable. El desarrollo de sistemas digitales y los esfuerzos de estandarización están haciendo de estos canales un medio atractivo para que los operadores eléctricos ofrezcan servicios de comunicaciones, ya que no necesitan invertir en infraestructura porque la red eléctrica ya está desplegada.<br/>En esta Tesis se introducirán y se comentarán las particularidades de las tres redes eléctricas, luego, se mostrarán al lector las soluciones tecnológicas existentes para los canales de BV basados en la norma Europea CENELEC así como para los canales de AV, mostrando que los sistemas actuales de LAC ofrecen una diversidad frecuencial muy baja y que los módems CRE-AV están anclados en estándares anticuados.<br/>Este trabajo se mueve por las tres topologías de red, particularmente, en aplicaciones orientadas a la banda CENELEC, en medida y modelado de canal, y en medida y diseño del nivel físico para sistemas CRE-BV, CRE-MV y CRE-AV respectivamente. Los sistemas actuales que explotan la banda CENELEC ofrecen mecanismos de explotación de la diversidad frecuencial del canal muy limitados o nulos, dando lugar a una escasa robustez frente a interferencias y ruido de fondo coloreado. Este trabajo propone un esquema de modulación multiportadora que, manteniendo una complejidad baja, ofrece unas altas prestaciones permitiendo un buen nivel de explotación de la selectividad frecuencial. Por lo que a CRE-MV respecta, esta Tesis desarrolla un modelo de canal determinístico-estadístico para los anillos urbanos de distribución de potencia y, finalmente, en sistemas de CRE-AV, este trabajo propone, basado en medidas de canal y pruebas de campo, un nivel físico de banda ancha capaz de incrementar la velocidad de comunicación mientras mantiene una baja densidad espectral de potencia limitando así la interferencia a otros sistemas.<br/>PALABRAS CLAVE: Power line communications (PLC), low voltage (LV), medium voltage (MV), high voltage (HV), automatic meter reading (AMR), orthogonal frequency division multiplexing (OFDM), multicarrier spread spectrum (MC-SS), communication system design, channel measurements, channel modeling, scattering parameters.<br>The world of Power line communications (PLC) can be divided into three main types: low voltage PLC (LV-PLC), medium voltage PLC (MV-PLC) and high voltage PLC (HV-PLC). These last years, LV-PLC has attracted a great expectation since its wideband capabilities has made this technology a suitable choice for last-mile access and in-home communications. Moreover, LV-PLC also includes a utility oriented low frequency and low speed applications, such as automatic meter reading (AMR), load distribution, dynamic billing and so on. On the other hand, MV-PLC and HV-PLC, historically oriented to teleprotection and telecontrol tasks, are being considered as a reliable communication channel. The development of digital equipment and the standardization efforts are making those channels an attractive medium for electrical utilities telecommunications services, since the network, as well as in LV-PLC, is already deployed. <br/>In this PhD dissertation, the three different PLC topologies are reviewed and the different communications techniques in such channels exposed. Then, a deep technological review of existing AMR solutions for the European CENELEC band, as well as HV-PLC systems is given, showing that existing AMR systems deliver low frequency diversity and HV-PLC systems are anchored in old fashioned standards.<br/>This work walks around the three topologies, specifically, CENELEC band utility oriented applications, channel measurement and modeling and channel measurement and physical layer design, regarding LV-PLC, MV-PLC and HV-PLC respectively. Existing CENELEC compliant systems deliver low or none frequency diversity mechanisms, yielding in a low robustness against colored noise and interference. This work propose a multicarrier based physical layer approach that, while keeping the complexity low, delivers high performance allowing a great level of frequency diversity. Focusing on MV-PLC, a hybrid deterministic-statistical channel model for urban underground rings is developed and, finally, in HV-PLC systems, this work proposes, based on measurements and field tests, a wideband physical layer in order to increase data rate while keeping low both the power spectral density and possible interference to other systems.<br/>KEYWORDS: Power line communications (PLC), low voltage (LV), medium voltage (MV), high voltage (HV), automatic meter reading (AMR), orthogonal frequency division multiplexing (OFDM), multicarrier spread spectrum (MC-SS), communication system design, channel measurements, channel modeling, scattering parameters.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)<br>Neste trabalho é proposto e apresentado um medidor inteligente de energia elétrica considerando os métodos de medição classe S especificados no PRODIST e na norma IEC 61000-4-30. O medidor proposto calcula os valores eficazes de tensão e corrente, as potências aparente, ativa e reativa, o fator de potência, a frequência, as distorções harmônicas e detecta a ocorrência de variações de tensão de curta duração. Como principais contribuições deste trabalho, pode-se citar a avaliação de métodos existentes e a proposta de um novo método para detectar a origem de distúrbios em relação à localização do medidor. Propôs-se também uma interface gráfica que permite o monitoramento dos parâmetros elétricos e de qualidade de energia, e ainda possibilita a interação do consumidor para a obtenção o de informações detalhadas sobre o estado da rede. O medidor pode ser utilizado como um registrador de dados e permite o acesso à sua interface gráfica por meio da utilização da porta de comunicação ethernet. Para a validação inicial, realizaram-se simulações computacionais, a partir de um modelo de consumidor residencial, em diferentes cenários de operação. Na etapa de validação experimental, foi utilizada uma fonte de geração de sinais e realizaram se testes com o medidor conectado à rede de distribuição de baixa tensão. A partir destas etapas foi possível verificar o funcionamento da interface gráfica e validar o funcionamento do medidor inteligente proposto.<br>In this study, a smart meter is presented, which considers the class S measurement methods specified at IEC 61000-4-30 standard and PRODIST. The proposed smart meter calculates RMS voltage and current values, active, reactive and apparent powers, power factor, frequency, harmonic distortions and detects short duration voltage variations. As main contributions of this study, it can be mentioned the evaluation of existing methods and the proposal of a new method to determine on which side of a recording device a disturbance originates. It’s also developed a graphical interface that allows the monitoring of electrical and power quality parameters and it enables consumer interaction to get detailed power grid information. The smart meter can also be used as a data logger and it allows access to its graphical interface through ethernet communication port. For the initial validation, computer simulations were performed through a residential consumer model in different operating scenarios. The experimental validation tests were carried out using an AC power source and the smart meter has been connected to low-voltage distribution grid. Through these steps, it was possible to verify the interface operation and to validate the proposed smart meter operation.

Este trabalho estuda a possibilidade de se adicionar funções de detecção e registro de eventos, que afetam a qualidade de energia elétrica, aos medidores eletrônicos de faturamento. A presença destes medidores na grande maioria dos consumidores ligados à média tensão transforma este recurso em uma poderosa ferramenta de análise. A existência de canais de comunicação remota nestes medidores facilita a coleta dos dados e seu armazenamento. Estes dados transferidos para sistemas com alta capacidade de processamento permitem uma análise mais precisa dos eventos que ocorrem em toda a rede. Foram consideradas as limitações dos medidores de faturamento quanto à sua capacidade de processamento, memória e taxa de amostragem. Os eventos que podem ser detectados com estes medidores ficam restritos a variações de tensão de curta duração (VTCDs) e transitórios oscilatórios de baixa freqüência. As funções criadas para registro de eventos podem ser usadas para registro de sinais em regime permanente, aumentando a capacidade de diagnóstico e análise da qualidade da energia elétrica em locais da rede. São utilizadas como técnicas de detecção de eventos: as variações dos valores eficazes, a decomposição de sinais, a Norma Euclidiana Instantânea (NEI) e a transformada wavelet (TW).<br>This work shows the possibility to add new functions for detection and registration of disturbances that affect power quality to electronic billing meters. The widespread installation of these meters in the power network makes this resource a powerful analysis tool. Remote communication channels in these meters create an easy way for reading and registering such power quality events. Data transferred to powerful processing systems allow accurate analysis of events occurring in the power grid. The limitations on billing meters, namely processing resources, memory availability and sampling rate, were taken into account. Despite these limitations, the electronic meters can handle short duration voltage events and low-frequency oscillatory transients. Those new functions can also be used for registering steady state phenomena, extending the ability to diagnose power quality problems throughout the power network. Techniques like RMS variations, signal decomposition, instantaneous Euclidian norm and wavelet transform were used for detection of the considered power quality events.

The subject of master’s thesis is introduction with the principles of measuring voltage, current and electrical power in DC and AC systems. Is designed measurement system for normal household. Measurement system includes pricing and client billing. User interface Ethernet-based is implemented.

Este estudo desenvolve uma técnica para caracterizar o escoamento bifásico, utilizando sensores de deformação baseados em redes de Bragg em fibras ópticas. Esses sensores apresentam características relevantes, a pequena dimensão e a possibilidade de medição com precisão em um grande número de parâmetros em condições diversas. A unidade sensora é constituída por uma rede de Bragg em fibra óptica posicionada transversalmente em relação ao escoamento e fixado nas paredes do tubo. A pressão hidrodinâmica aplicada pelo escoamento de líquido ou pelo escoamento de líquido e gás induz deformação na fibra óptica, a qual pode ser detectada pela rede de Bragg. Como a pressão aplicada está diretamente relacionada com a vazão mássica, é possível estabelecer uma relação usando o deslocamento do comprimento de onda da ressonância da rede de Bragg para determinar a vazão mássica quando a velocidade de escoamento é bem conhecida. No escoamento bifásico, há uma alteração significativa na força aplicada na fibra óptica, a qual contabiliza as densidades distintas das referidas substâncias. Logo, a deformação da fibra óptica e a correspondente mudança de comprimento de onda de rede de Bragg serão muito diferentes quando no escoamento houver uma bolha de ar ou um pistão de líquido, permitindo, assim a sua detecção à medida que o escoamento flui através do tubo. Devido a sua capacidade de multiplexação e versatilidade, o uso de sensores de redes de Bragg em fibra óptica mostrou ser particularmente adequado para esta aplicação. Uma ferramenta de detecção de 18 sensores quase distribuídos uniformemente ao longo do tubo foi desenvolvida tornando possível a caracterização do escoamento, bem como o acompanhamento das bolhas de ar ao longo de uma grande parte do escoamento. Os ensaios foram realizados em uma planta piloto de escoamento bifásico gás-líquido, onde diversas condições operacionais foram geradas e analisadas. A técnica desenvolvida foi validada através de comparações com modelos termodinâmicos empíricos disponíveis na literatura e também com o sensor wire-mesh, apresentando boa concordância com os valores de referência. O estudo viabiliza a construção futura de sensores para serem empregados na obtenção de parâmetros importantes nos modelos de escoamento multifásico, abrindo muitas oportunidades para ferramentas de medição de laboratório e aplicações de campo.<br>This study developed a technique to characterize the two phase flow using optical fiber Bragg grating strain sensors. These sensors have features such as small size, flexibility, allowing to accurately measure a number of parameters under adverse conditions. The sensor unit consists of optical fiber Bragg grating positioned transversely to the flow and fixed in the pipe walls. The hydrodynamic pressure applied by the liquid or air/liquid flow to the optical fiber induces deformation that can be detected by the optical fiber Bragg grating. Given that the applied pressure is directly related to the mass flow it is possible to establish a relationship using the grating resonance wavelength shift to determine the mass flow when the flow velocity is well known. For two phase flows of air and liquid there is a significant change in the force applied to fiber that is accounted for the very distinct densities of these substances. As a consequence the optical fiber deformation and the correspondent grating wavelength shift as function of the flow will be very different for an air bubble or a liquid slug allowing their detection as they flow through the pipe. Due to its versatility and multiplexing capabilities optical fiber Bragg gratings are particularly suitable for this application. The experiments were performed in a pilot plant using air-water two-phase flows, in which various operating conditions were generated and analyzed. A quasi-distributed sensing tool with 18 sensors evenly spread along the pipe is developed and characterized making possible the characterization of the flow as well as the tracking of the bubbles over a large section of the test bed. The technique developed was validated through comparisons with available empirical mechanical models and also with the wire- mesh sensor, showing good agreement with the reference values. The study allows for the future construction of sensors that can be used to assist empirical models of multiphase flows, and open up plenty of opportunities to both laboratory measurement tools as well as field applications.

I detta examensarbete utreds möjligheten att med hjälp av nya smarta elmätare få en ökad inblick i elkvalitén i elnäten samt att ge nätägare möjligheten att automatiskt eller via fjärrsignal koppla bort solcellsanläggningar i de fall de orsakar dålig elkvalité. Motiveringen till studien har varit att en ökad utbyggnad av solcellsanläggningar med tilhörande växelriktare och en trolig framtida ökning av snabbladdare och andra olinjära laster i näten ökar utmaningen för elnätsföretag att klara gällande krav på elkvalité. Samtidigt har utvecklingen av elmätare gjort att de idag har många funktioner som elnätsföretag kan dra nytta av på sätt som tidigare inte varit möjligt. Studien inleddes med en litteratur-studie där information om vad elmätare idag är kapabla till togs fram. Ett praktiskt test genomfördes på en solcellsanläggning där en elmätare installerades och konfigurerades att koppla bort solcellerna vid över-spänning. Studien har visat att smarta elmätare bör kunna användas som ett långsammare, sekundärt skydd som kopplar bort solceller i de fall som växelriktarna brister i sina säkerhetsfunktioner. Elmätarna kommer också kunna ge nätägare en mängd intressant information om elkvalitén.<br>In this thesis the possibility for smart meters to give utility companies an increased knowledge about the power quality in the grid has been investigated. During the investigation the possibility to use smart meters to automatically or by remote control disconnect solar power units in case of poor power quality caused by the production units has also been researched. The motivation to perform the study was that a future increase in distributed generation, rapid chargers for electric vehicles and other non-linear loads will make it harder for utility companies to meet the demands concerning power quality. At the same time electricity meters has developed over time and are today capable of providing grid operators with functions that has not been possible in the past. The first part of the study focused on obtaining information about what smart meters are capable of today through a literary study. A practical test was conducted on a solar power unit where a smart meter was installed and configured to automatically disconnect the solar power unit in case of over voltage. The study has shown that smart meters could be used as a slower, secondary protection that disconnects the solar power units in cases where the solar inverters safety functions fails. The smart meters will also be able to give grid operators a large amount of information about the power quality in the grid.

The thesis discuses an integration of photovoltaic power stations to electric network. The first part describes connecting conditions of small sources to distribution system, including administrative requirements, feasibility study, and requirements to the energy meters, measuring, control devices, switching devices and protection. The second part is aimed to describe problems of the photovoltaic system. Solar radiation generating and reducing of its intensity incident upon the earth surface are described in this part. The quantum of produced electric power depends on climatic conditions in the fixed area, seasons, etc. This work also discusses the types of photovoltaic cells and their actual efficiency. Inverters are further important components of the photovoltaic system. The parameters of the inverters have a great influence on the total actual efficiency of the photovoltaic system. Different methods of the photovoltaic panels’ connection with the inverters and their advantages and disadvantages are also mentioned. The supporting structure of the photovoltaic panels and eventually transformer are further important components of photovoltaic system. The work also analyze the methods of connection of the photovoltaic power station to distributive low voltage and medium voltage network, electric energy accumulation and possibilities of the sale of produced electric energy. The large number of the connected photovoltaic power stations has negative influences to electric network. The third part contains the design of a photovoltaic power plant with a capacity of 516,24 kWp on the scoped area in southern Bohemia. The project documentation for the location where the power plant is designed is also made. It contains the design of photovoltaic panels, the design of the inverters to get an optimal power load. This part also contains a calculation of the photovoltaic system losses and the design of transformer and the cable junction calculation of the distributive system. The feasibility study of the power plant connected to distributive system is also conducted. Its delivery rate will be connected to the distribution point Řípov (110/22 kV). The calculation results show us that this photovoltaic power plant can be linked to the distribution system. The final part of this paper contains an economic estimate of the photovoltaic power plant operating and the calculation of the return. An Economic return is influenced by the wide range of values that affect the total return rate. The calculation of an operating economy is made for several variants. The return rate in refer to contemporary redemption price for 2010 with no consideration for a bank loan is 7 years. If we consider the bank loan it would be 12 years. The penetrative reduction of the redemption price is expected for 2011. Calculation works with the decline of 30 %. It would extend the rate of return to 11 years without a bank loan or to 22 years with the bank loan. The bank loan is considered to cover 80 % of the investment.

碩士<br>中華大學<br>電機工程學系<br>104<br>In recent years, human increasing emphasis on energy issues like as global warming, greenhouse worsening. First, we must grasp the information of energy consumption if we want to save energy. Through a power meter we can obtain information of electrical power consumption. Transmit the information to the console with the power lines communication. The information will be analyzed after the console received. Then make the decision of re-deployment of electricity to achieve energy-saving. The thesis designed an electrical power meter with power line communication. We use a micro-resistor as current sensing to retrieve current that pass through load of the loop. We also use a set of attenuator to extract the voltage across the load. Then send these two original data into two ADCs' input-pins of System on a Chip (SoC). The SoC will convert the analog signal into digital signal, then calculate a set of parameter, such as the wattage, power factor, frequency of the power, and power consumption accumulation. These parameters will send to the master through the original power lines. The Wi-Fi or Ethernet can be used for communication between PC and the master. The Wi-Fi or Ethernet can be used for communication between PC and the master. A power management system is contained in the PC. The power management system can make integrated analysis. The results can be used to make decisions of electrical energy deployment to achieve energy-saving.

碩士<br>國立臺北科技大學<br>自動化科技研究所<br>102<br>Due to global warming and shortage of energy, the idea of saving energy gradually attracts public’s attention. How to use and save energy efficiently has become an issue worthy of discussion. Therefore, to change the habit of using resources every day, the key is obtain the data usage of these resources first before it can be improved. Advanced Metering Infrastructure (Advanced Metering Infrastructure, AMI) in this case plays a crucial role, and "Intelligent Power meter" is the core to establish "advanced metering system". This paper utilizes MSP430AFE253 processor as the core element for the development of electronic watt-hour meters. This MCU is specifically designed for single-phase electronic watt-hour meters. It has internal analog front-end circuit that can handle AC signals. The MCU has three 24-bit delta-sigma ADCs that is capable of acquiring single-phase voltages and currents simultaneously and it has an additional PGA (Programmable Gain Amplifier) function. The MCU calculates the necessary information, such as Vrms, Irms, KW, KVAR, KVA, PF, etc. after the signals are acquired. In addition, the development of electronic watt-hour meters have communication capabilities. Such functions help to send the data on electric consumption from users back to control center and meter calibration procedures, making electronic digital meter meets the standard error range. If the Intelligent Power Meters provide reactive power information, users can then improve the power factor of the load, reducing line losses. Therefore, this paper uses digital Finite Impulse Response filter (Finite Impulse Response, FIR), response filter (First-FIR, filter) and the translation method through a first-order finite impulse to complete the reactive power calculations.

碩士<br>國立高雄應用科技大學<br>電機工程系<br>97<br>This thesis proposes support vector machine（SVM）based pattern recognition technique to classify electronic power meter faults by establishing and comparing with the historical electronic meter fault data. First, this research is to simulates the current use of electronic meters in the historical fault data and to derives the electronic power meter fault models. Moreover, the SVM network model is applied to train the selected electronic power meter fault data set in order to establish the electronic meter fault multi-layer SVM classifier. The fault meters and their corresponding fault type can be analyzed and the subsequent maintenance works can be processed. Besides, function block diagram and fault tree technique are used for reliability analysis to establish of electronic power meters and calculate the largest failure rate as well as the smallest reliability. Furthermore, the possible fault parts and life time of power meters can be justified by using simple calculation steps. Calculation results can be used as a guidance for installing and producing electronic power meters in the future.

碩士<br>國立高雄應用科技大學<br>電機工程系<br>97<br>This thesis uses regression analysis method to construct the operation life forecast model of electronic power meters based on the field data that can forecast the operation life of electronic power meters. The first step is the on-site investigation and classification of installed electronic power meters in the region of Taiwan. Additionally, the metering error accuracy of electric power meters is captured by the error accuracy of measurement devices, and the effects of installed environment on the electronic power meters are observed. Moreover, the on-site power system parameters are simulated by using the regression analysis model to verify the life forcast model of electronic power meters. Finally, from the viewpoint of economic engineering, economic life analysis model which considers variables of buying cost, maintenance cost, and residuals value of electronic power meters, is derived to assess the life of electronic power meters. Hopefully, the simulation results can be used as a guideline for replacing electronic powers.

Submitted in fulfillment of the requirement for the Degree of Master of Management Sciences Specialising in Business Administration, Durban University of Technology, Durban, South Africa, 2017.<br>In the electricity prepayment metering industry the continuous increase in customers’ expectations and technological innovation demand that leading firms in the industry differentiate themselves from the competition by going beyond customers’ present expectations. Thus, organizations which have set their goals on mere customer satisfaction are, from a customers’ perspective, deemed to be of limited value and may subsequently lack the anticipation and preparation essential to meet the demands of the future. Electricity prepayment metering market competition today is forcing organisations to seek the means to gain customer satisfaction, and thus aim to sustain their future in times of economic instability. The study revealed that the most effective way to retain customer satisfaction is consistent service quality that decreases the cost of attracting new customers and raises sales and market share. The quality of service is one of the most effective factors in creating competitive advantages and advance business. Factors that influence customer satisfaction in the electricity prepayment industry were investigated and tested. The study also attempted to identify the critical factors, as identified in the literature, among those investigated: service quality, customer expectations, customer perception and customer retention. Against this background, the study sought to determine the interrelationship between customer satisfaction and the critical factors of customer satisfaction with Conlog Electricity Prepayment Meters in KwaZulu-Natal. The research developed to ascertain subjects’ perceptions of the critical factors of customer satisfaction; determine the interrelationship among the critical factors of customer satisfaction; and explore the relationship between customer satisfaction and the critical factors of customer satisfaction. The research population comprising of Conlog electricity prepayment metering customers in KwaZulu-Natal was selected and interviewed. Questionnaires were distributed through electronic mail and self-administered for data collection and a sample of twelve respondents was selected for interview. Interviews were analysed using conversational analysis and the data collected from the interviews were merged with the questionnaire data, seeking depth as well as breadth. Data collected from respondents was analysed using descriptive and inferential statistical techniques. The tool utilised to analyze data was the Statistical Package for the Social Sciences (SPSS) version 22 (SPSS Inc., Chicago, Illinois, USA). A p value < 0.05 was considered as statistically significant. Conclusions and recommendations were drawn from the literature and the findings of the study. The results of the study revealed that service quality is the most significant critical factor of customer satisfaction. The study recommends that the management of Conlog can use the specific data obtained from the measurement of service quality in their strategies and plans. The study further recommends that Conlog allocates resources to this effect to provide better service to their customers. The results and findings of the study will provide further information concerning customer satisfaction and customer perception in the prepayment metering industry in KwaZulu-Natal. It will also contribute to future industry research, setting the ground for further research in measuring levels of customer satisfaction in the electricity prepayment industry in South Africa.<br>M

A dissertation submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in ful lment of the requirements for the degree of Master of Science in Engineering. Johannesburg, 2015<br>The work presented extends and contributes to research in Non-Intrusive Load Monitoring (NILM), focussing on steady-state and transient power measurement disaggregation techniques for circuits containing household ap- pliances. Although previous work in this area has produced and evaluated a wide range of NILM approaches, much of it has involved the use of datasets captured from real-world household implementations. In such cases, the lack of accurate ground truth data makes it di cult to assess disaggregation tech- niques. In the research presented, three NILM techniques are comparatively evaluated using measurements from typical household appliances assembled within a laboratory environment, where accurate ground truth data could be compiled to complement the measurements. This allows for the accu- racy of the various disaggregation approaches to be precisely evaluated. It is demonstrated that the correlation of transient event edges in aggregated power measurements to individual appliance transient exemplars performs better than the matching of steady-state power levels against individual ap- pliance state combinations. Furthermore, the transient approach is shown to be the most appropriate technique for further development.<br>MT2017

Utility companies (electricity, gas, and water suppliers), governments, and researchers recognize an urgent need to deploy communication-based systems to automate data collection from smart meters and sensors, known as Smart Metering Infrastructure (SMI) or Automatic Meter Reading (AMR). A smart metering system is envisaged to bring tremendous benefits to customers, utilities, and governments. The advantages include reducing peak demand for energy, supporting the time-of-use concept for billing, enabling customers to make informed decisions, and performing effective load management, to name a few. A key element in an SMI is communications between meters and utility servers. However, the mass deployment of metering devices in the grid calls for studying the scalability of communication protocols. SMI is characterized by the deployment of a large number of small Internet Protocol (IP) devices sending small packets at a low rate to a central server. Although the individual devices generate data at a low rate, the collective traffic produced is significant and is disruptive to network communication functionality. This research work focuses on the scalability of the transport layer functionalities. The TCP congestion control mechanism, in particular, would be ineffective for the traffic of smart meters because a large volume of data comes from a large number of individual sources. This situation makes the TCP congestion control mechanism unable to lower the transmission rate even when congestion occurs. The consequences are a high loss rate for metered data and degraded throughput for competing traffic in the smart metering network. To enhance the performance of TCP in a smart metering infrastructure (SMI), we introduce a novel TCP-based scheme, called Split- and Aggregated-TCP (SA-TCP). This scheme is based on the idea of upgrading intermediate devices in SMI (known in the industry as regional collectors) to offer the service of aggregating the TCP connections. An SA-TCP aggregator collects data packets from the smart meters of its region over separate TCP connections; then it reliably forwards the data over another TCP connection to the utility server. The proposed split and aggregated scheme provides a better response to traffic conditions and, most importantly, makes the TCP congestion control and flow control mechanisms effective. Supported by extensive ns-2 simulations, we show the effectiveness of the SA-TCP approach to mitigating the problems in terms of the throughput and packet loss rate performance metrics. A full mathematical model of SA-TCP is provided. The model is highly accurate and flexible in predicting the behaviour of the two stages, separately and combined, of the SA-TCP scheme in terms of throughput, packet loss rate and end-to-end delay. Considering the two stages of the scheme, the modelling approach uses Markovian models to represent smart meters in the first stage and SA-TCP aggregators in the second. Then, the approach studies the interaction of smart meters and SA-TCP aggregators with the network by means of standard queuing models. The ns-2 simulations validate the math model results. A comprehensive performance analysis of the SA-TCP scheme is performed. It studies the impact of varying various parameters on the scheme, including the impact of network link capacity, buffering capacity of those RCs that act as SA-TCP aggregators, propagation delay between the meters and the utility server, and finally, the number of SA-TCP aggregators. The performance results show that adjusting those parameters makes it possible to further enhance congestion control in SMI. Therefore, this thesis also formulates an optimization model to achieve better TCP performance and ensures satisfactory performance results, such as a minimal loss rate and acceptable end-to-end delay. The optimization model also considers minimizing the SA-TCP scheme deployment cost by balancing the number of SA-TCP aggregators and the link bandwidth, while still satisfying performance requirements.

Dans le domaine de l'électromagnétisme, les réseaux de réluctances sont parfaitement adaptés aux<br />problématiques de pré-dimensionnement. Leur mise en équations est cependant une tâche fastidieuse et souvent<br />source d'erreurs, et souffre d'un manque d'outil adapté.<br />Nous nous proposons ici de formuler cette méthode dans le cas général, puis de l'implémenter dans un outil<br />dédié. Afin d'enrichir les modèles, le calcul des énergies et de la force sont également proposés, ainsi que sa<br />dérivation automatique pour assurer sa compatibilité avec des algorithmes d'optimisation utilisant les gradients.<br />La problématique de simulation des régimes transitoires est également abordée à travers une méthodologie<br />permettant de mettre en place des modèles dynamiques faisant intervenir les couplages avec les parties électrique<br />et mécanique. Une attention particulière est portée sur leur formulation en vue de l'intégration des équations<br />différentielles par des méthodes numériques.