O mundo moderno está cada dia mais conectado por todos os meios tecnológicos que existem hoje. Isto permite que mais e mais pessoas possam se comunicar, tornando a estrada da comunicação virtual obrigatória para a sobrevivência das pequenas, médias e grandes empresas públicas e privadas. O grande avanço tecnológico do século 20 foi à utilização em grande escala do PC (personal computer) comumente chamados de microcomputadores. Este avanço também chegou aos sistemas elétricos de potência, tornando as subestações digitalizadas. Estas subestações sendo digitais correm riscos de invasão cibernética interna ou mesmo externa. Embora a possibilidade de invasão cibernética externa seja pequena, ela existe. Diante dessa situação este trabalho propõe a aplicação de um sistema de segurança, aplicado em um sistema elétrico de potência. O trabalho concentra-se especificamente no estudo dos sistemas de detecção de intruso (SDI), nos seus dois modos básicos: o SDI por abuso e SDI por anomalia utilizando redes neurais artificiais. Estes conceitos serão testados em um sistema elétrico de potência simulado, com uma rede de comunicação baseada em microcomputadores e/ou equipamentos microprocessados, com relés digitais reais. Os Softwares...

As perdas de energia elétrica devidas a furtos e fraudes, também chamadas de Perdas Não-Técnicas (PNT) ou Perdas Comerciais, têm sido matéria prioritária das empresas concessionárias de distribuição de energia elétrica, bem como dos órgãos reguladores, tanto pelo seu crescimento nos últimos anos quanto pelo seu impacto no sistema elétrico brasileiro. As formas de fraude são as mais variadas possíveis, o que gera enormes dificuldades para as concessionárias. Este trabalho tem como objetivo o estudo do problema das PNT utilizando-se de uma abordagem multidisciplinar, que analisa a experiência tanto de concessionárias no Brasil como no exterior. O trabalho discute as melhores práticas para mitigação das mesmas e propõe melhorias nos processos de combate e de prevenção, e nos procedimentos legais para recuperação de receitas, apoiados sobre uma cuidadosa contextualização regulatória. Chamase a atenção para a diversidade sócio-econômica nacional, compara-se com diversos exemplos internacionais, e propõe-se identificar os aspectos mais relevantes a serem considerados na regulação sobre o tema, discutindo procedimentos e metodologias para o equacionamento do montante de recursos a serem aplicados pelas companhias distribuidoras para a adequada redução dessas perdas de energia. Observa-se que grande parte das PNT tem origem em questões de cunho social. O Estado pode e deve estabelecer políticas para resolver tais questões...

Buscou-se refletir de que forma as decisões governamentais afetam o setor energético e como os agentes reagem ao modelo e à instabilidade das regras vigentes. O estudo compreende uma breve revisão da estrutura do atual modelo e dos principais riscos que envolvem a comercialização de eletricidade. Partiu-se do pressuposto que o preço é o maior risco presente no Setor Elétrico Brasileiro (SEB), uma vez que é o reflexo de uma somatória de riscos. Os preços analisados são: i) o preço de curto prazo de energia elétrica (PLD), sua relação com as usinas termoelétricas e o despacho fora da ordem de mérito; ii) a tarifa de energia elétrica no ambiente cativo e livre, as principais variáveis de influência e uma projeção dos valores futuros; e iii) o preço de longo prazo de energia elétrica, uma revisão do resultado dos leilões e a discussão sobre a prorrogação / licitação das concessões de geração pelo governo. Entendendo a estreita relação que existe entre os três preços discutidos (tarifa, PLD e contratação de longo prazo) propõe-se uma metodologia alternativa para formação de carteiras eficientes de recursos de geração com o objetivo de demonstrar a importância de promover a expansão através de um sólido planejamento de longo prazo. Demonstra-se a metodologia em um estudo de caso em que se discute os resultados alcançados. Por fim...

O objetivo deste trabalho é estimar as elasticidades-preço e renda da demanda residencial por energia elétrica no Brasil utilizando dados em painel. A heterogeneidade da economia brasileira faz com que existam diversos padrões de consumo residencial de energia elétrica e diferentes estruturas tarifárias entre as distribuidoras. Nesse sentido, este trabalho utiliza um banco de dados em painel formado por 63 distribuidoras de energia elétrica no Brasil, para o período 1999-2006. Isso permite controlar possíveis efeitos individuais não observáveis existentes entre as distribuidoras. Três métodos de estimação em painel foram aplicados: o Pooled OLS, o de Efeitos Fixos e o de Efeitos Aleatórios. Além disso, também foi testado se no período de racionamento de energia elétrica ocorrido no Brasil em 2001/2002, ocorreu alguma alteração na sensibilidade dos consumidores com relação a variações nas tarifas de energia elétrica e na renda dos consumidores no período. Os resultados mostraram que a utilização de dados em painel produz estimativas de elasticidades preço e renda de acordo com a teoria econômica. Além disso, os resultados ficaram próximos aos da literatura nacional. Os resultados também mostraram que no período do racionamento aumentou a sensibilidade dos consumidores com relação a alterações nas tarifas de energia elétrica.; The objective of this thesis is to estimate the price and income elasticities of residential electric power demand in Brazil using panel data. The heterogeneity of the Brazilian economy leads to the existence of different patterns of residential electric power consumption and different tariffs structures among the electric power utilities companies. In this regard...

Os sistemas elétricos de potência são frequentemente submetidos a perturbações causadas, por exemplo, por um aumento súbito de carga ou por um curto-circuito em uma linha de transmissão. Estas perturbações podem gerar oscilações eletromecânicas no sistema, uma vez que a velocidade dos geradores oscila. Para reduzir tais oscilações, controladores de sistema de potência são utilizados sendo, os mais comuns, controladores do tipo PSS (Power System Stabilizer). Porém, em alguns sistemas, somente o emprego de PSSs não é suficiente para garantir um nível mínimo satisfatório de amortecimento, sendo necessário recorrer a outros tipos de controladores. Desta forma, controladores do tipo FACTS (Flexible Alternating Current Transmission System), principalmente o TCSC (Thyristor Controlled Series Capacitor) se tornaram uma alternativa atraente no auxílio ao amortecimento dos sistemas de potência. O controle do TCSC é feito por um controlador POD (Power Oscilation Damper) que é empregado como controle suplementar do dispositivo. No entanto, apenas o emprego dos controladores não garante um bom amortecimento, fazendo-se necessária uma boa sintonia dos mesmos. A sintonia destes controladores é, na maioria das vezes, feita de forma manual...

This work presents a methodology to analyze electric power systems transient stability for first swing using a neural network based on adaptive resonance theory (ART) architecture, called Euclidean ARTMAP neural network. The ART architectures present plasticity and stability characteristics, which are very important for the training and to execute the analysis in a fast way. The Euclidean ARTMAP version provides more accurate and faster solutions, when compared to the fuzzy ARTMAP configuration. Three steps are necessary for the network working, training, analysis and continuous training. The training step requires much effort (processing) while the analysis is effectuated almost without computational effort. The proposed network allows approaching several topologies of the electric system at the same time; therefore it is an alternative for real time transient stability of electric power systems. To illustrate the proposed neural network an application is presented for a multi-machine electric power systems composed of 10 synchronous machines, 45 buses and 73 transmission lines. (C) 2010 Elsevier B.V. All rights reserved.

This work uses a monitoring system based on a PC platform, where the acoustic emission and electric power signals generated during the grinding process are used to investigate superficial burning occurrence in a surface grinding operation using two types of steel, three grinding conditions and an Al203 vitrified grinding wheel. Acoustic emission signals on the workpiece and grinding power were measured during a surface plunge operation until the grinding burn happened. From the results the standard deviation of the acoustic emission signal and the maximum electric power were calculated for each grinding pass. The proposed DPO parameter is the product between the power level and acoustic emission standard deviation. The results show that both signals can be used for burning detection, and the parameter DPO is the best indicator for the burning studied in this work. This can be explained by the high dispersion of the acoustic emission RMS level associated to the high power consumption when the grinding wheel lose its sharpness.

Phasor Measurement Units (PMUs) optimized allocation allows control, monitoring and accurate operation of electric power distribution systems, improving reliability and service quality. Good quality and considerable results are obtained for transmission systems using fault location techniques based on voltage measurements. Based on these techniques and performing PMUs optimized allocation it is possible to develop an electric power distribution system fault locator, which provides accurate results. The PMUs allocation problem presents combinatorial features related to devices number that can be allocated, and also probably places for allocation. Tabu search algorithm is the proposed technique to carry out PMUs allocation. This technique applied in a 141 buses real-life distribution urban feeder improved significantly the fault location results. © 2004 IEEE.

This work deals with the effects of the series compensation on the electric power system for small-signal stability studies. Therefore, the system is modeled admitting the existence of the compensation and then, the equations are linearized and a linear model is obtained for a single machine-infinite bus power system with a compensator installed. The resulting model with nine defined constants is very similar to the Heffron & Phillips linear model widely used on the existent literature. Finally, simulations are executed for an example system, to analyze the behavior of these constants when loading the system. © 2004 IEEE.

This paper proposes a new approach for optimal phasor measurement units placement for fault location on electric power distribution systems using Greedy Randomized Adaptive Search Procedure metaheuristic and Monte Carlo simulation. The optimized placement model herein proposed is a general methodology that can be used to place devices aiming to record the voltage sag magnitudes for any fault location algorithm that uses voltage information measured at a limited set of nodes along the feeder. An overhead, three-phase, three-wire, 13.8 kV, 134-node, real-life feeder model is used to evaluate the algorithm. Tests show that the results of the fault location methodology were improved thanks to the new optimized allocation of the meters pinpointed using this methodology. © 2011 IEEE.

The system reliability depends on the reliability of its components itself. Therefore, it is necessary a methodology capable of inferring the state of functionality of these components to establish reliable indices of quality. Allocation models for maintenance and protective devices, among others, have been used in order to improve the quality and availability of services on electric power distribution systems. This paper proposes a methodology for assessing the reliability of distribution system components in an integrated way, using probabilistic models and fuzzy inference systems to infer about the operation probability of each component. © 2012 IEEE.

Em substituição ao Modelo Normativo de Empresa de Referência, que vigorava no Brasil desde 2003, a Agência Nacional de Energia Elétrica (ANEEL) implementou, em 2011, metodologia de benchmarking para o cálculo dos custos operacionais regulatórios para cada uma das 63 Concessionárias de Distribuição de Energia Elétrica, baseada na média dos resultados dos modelos de Análise Envoltória de Dados (DEA) e Mínimos Quadrados Corrigidos (COLS). A partir dos problemas identificados nesta metodologia de benchmarking e, fundamentado em estudo das práticas regulatórias internacionais na aplicação de benchmarking para regular os custos operacionais de distribuidoras, o objetivo desta tese é propor uma metodologia de benchmarking para a regulação dos custos operacionais das distribuidoras de energia no Brasil, baseada nos seguintes princípios: uso de base de dados e metodologias estatísticas aplicadas; construção de método para a estimação da eficiência a partir de um modelo estruturado, interpretável e que utiliza técnicas de modelagem econométrica; consideração das particularidades do país: grande heterogeneidade climática, geográfica, socioeconômica e, principalmente, da forma de gestão e propriedade; e factível e simples de ser implementado pelo regulador para o caso brasileiro. Partindo destes princípios...

This project proposes a method for creating, to the extent of their predictability, the proper and timely forecasts of the aquatic ecosystem consequences of electric power system operation. A procedure is developed and intended for use in quantifying the ecological sacrifices associated with a number of desirable regional dispatch schedules. With the use of this technique, associated with a given reliability level, optimum scheduling schemes can be used to evaluate optimum dollar cost - environmental impact pairings. A prerequisite of the model was that it be flexible enough for use in the evaluation of aquasystem impacts from either existing or hypothesized systems, that is, that it could be used either as an operational tool or as a simulation tool. Specifically demonstrated is the feasibility of the quantification of various ecological impacts and its usefulness in effecting compatibility between the power generating facilities and the aquatic ecosystem into which they have been incorporated. The method of quantification involves a probabilistic systems approach which includes a due regard for the vagaries of nature. Essentially calculated is the change in desirability to man of the ecosystem as influenced by the losses of organisms...

Fundamentals of energy-handling electric circuits and electromechanical apparatus. Modeling of magnetic field devices and description of their behavior using appropriate models. Simplification of problems using transformation techniques. Power electric circuits, magnetic circuits, lumped parameter electromechanics, and elements of linear and rotating electric machinery. Modeling of synchronous, induction, and dc machinery. Alternate years. From the course home page: Course Description This course is offered both to undergraduates (6.061) and graduates (6.979), where the graduate version has different problem sets and an additional term project. 6.061 / 6.979 is an introductory course in the field of electric power systems and electrical to mechanical energy conversion. Material encountered in the subject includes: Fundamentals of energy-handling electric circuits and electromechanical apparatus. Modeling of magnetic field devices and description of their behavior using appropriate models. Simplification of problems using transformation techniques. Power electric circuits, magnetic circuits, lumped parameter electromechanics, elements of linear and rotating electric machinery. Modeling of synchronous, induction and dc machinery. The course uses examples from current research.

The investigation conducted by this project concernt China power social universal services include: the investigation on the actuality of the domestic power social universal services or on the other industries and the research and study on abroad services. Through research of the domestic power social universal service, we could realize the actuality of the domestic power social universal services, hold the scale of the requirement, the characteristics of the region, and also the existing problems and obstacles of the universal service, furthermore, calculate the amount of capital that power social universal services needed; then draw the successful experience of domestic and foreign services to make suggestions on the policy, regulatory measures and implementation of programs which are adapt to the development of China power social universal service.

Analysts expect China to continue improving the efficiency of energy production and use, thereby decoupling the traditional relationship between gross domestic product (GDP) and energy consumption. Environmentally acceptable economic growth is closely linked with further improvements in the overall efficiency of energy use. Both of these goals will require a continued increase in the use of coal to produce electricity, along with a more deliberate and rapid transition from direct coal combustion to the use of electricity and other cleaner coal-based fuel sources, especially for cooking, space heating, and industrial furnaces. The opportunity for environmental improvement in conjunction with economic growth lies in the wise adoption of clean coal technologies (CCT) for both the electric power and non-power sectors. This report presents CCT options for the power sector that can help China achieve these twin goals. The CCT options are: 1) air pollution controls for particulates, sulphur dioxide, and nitrous oxide; and 2) advanced electricity generation technologies--supercritical pulverized-coal boilers...

The Electric power industry in Shandong Province faces the dual challenge of economic growth and environmental protection. Analysis of the Electric Power Development Plan of Shandong Province indicates that Shandong Province's current power generation capacity can satisfy demand until 2013. After that, electric power shortages will appear and the gap between supply and demand will reach 149.25 billion kWh by 2020. Projected new coal-fired power stations will consume 103.28 million tonnes of coal and 474.07 million m3 of water resources producing significant extra emissions of SO2, soot, CO2, NOx, waste water, coal ash and slag. These emissions will exceed established environmental capacity and enhance the greenhouse gas contribution by around 50%. Water shortage and depleting coal reserves will restrict electric power development in Shandong Province. Increasing levels of pollutants, especially SO2 and soot, released by the coal-fired power industry, will bring serious pressures to Shandong Province's human population and urban and natural environments. These predictions suggest that a radically new approach to meeting the demands of economic growth is required if Shandong is to improve its air quality and meet international targets for greenhouse gas emissions.; Xueliang Yuan...

1 CD-ROM; This dissertation has arisen in the context of the electric power markets, the study of risk management and the relations between physical production and the electricity transactions using financial contracts in particular. Electricity is very difficult to compare with any other commodity, since it has a peculiar characteristic; electricity “must be produced at exactly the same time as it is consumed”. The technological inability to store electricity efficiently and the characteristics of marginal production costs create jumps in the spot price. The electricity power market is heavily incomplete. Load-matching problems occur because electricity prices show volatility because of unexpected variations due to climatic conditions and other associated risk factors. A branch of the literature in risk management has tried to give a definitive answer to the question of how agents in the markets with non-storable underlying asset could hedge their exposure to volatile price and quantity. The first essay tackles the basis of this question, which is the implication of the price of risk when forward risk premia are presented. This essay also shows how the properties and variations of forward risk premia is explained by risk factors variations on expected spot prices...

A quasi-optimal technique ('quasi' in that the technique discards unreaonable optimums), realized by a dynamially evolving mixed integer program, is used to develop regional electric power maintenanee and production sample schedules, as well as unit commitment sample schedules. This sophisticated, yet omputationally feasible, method is used to develop the bulk dispatch schedules required to meet electric power demands at various preset reliability levels while oentrolling the associated dollar and environmental impact consequences. This report considers a hypothetical system of about twelve power plants situated close to one another on the same river system. The maintenance and unit commitment scheduling mechanisms are used to display the tradeoffs which exist between the economic costs, environmental consequences and reliability levels of all possible optimum schedules. These tradeoff, or transform, surfaces are generated from acoul schedules for system opertio. Also generated is a sample system imulation. Three possible generation expansion plans are compared and their potential operating performances are displayed. These specifically hypothesized expansion plans were tested os two different possible future load demand curves. The results show that there is great value in the use of an accurate dollar and environmental impact simulator. Hypothetical data has been used...

A quasi-optimal technique ('quasi' in that the technique discards unreasonable optimums), realized by a dynamically evolving mixed integer program, is used to develop regional electric power unit commitment schedules for a one week time span. This sophisticated, yet computationally feasible, method is used to develop the hourly bulk dispatch schedules required to meet electric power demands at a given reliability level while controlling the associated dollar costs and environmental impacts. The electric power system considered is a power exchange pool of closely coupled generation facilities supplying a region approximately the size of New England. Associated with a tradeoff between a given cost of production and the relevant ecological factors, an optimum generation schedule is formulated which considers fossil, nuclear, hydroelectric, gas turbine and pumped storage generation facilities; power demands, reliabilities, operating constraints, startup and shutdown factors, geographic considerations, as well as various contracts such as interregional power exchanges, interruptible loads, gas contracts and nuclear fuel optimum batch utilization. A prerequisite of the model was that it be flexible enough for use in the evaluation of the optimum system performance associated with hypothesized expansion patterns. Another requirement was that the effects of changed scheduling factors could be predicted...