Made available in DSpace on 2014-06-11T19:30:50Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-04-08Bitstream added on 2014-06-13T18:40:58Z : No. of bitstreams: 1 manso_jcg_dr_ilha.pdf: 1797560 bytes, checksum: 27c1272d6d4916bb798bc0d05ed927c8 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Ensino Pesquisa e Extensão de Ilha Solteira (FEPISA) / Esta tese visa ao estudo da valorização de serviços ancilares de reserva, particularmente, a reserva utilizada na regulação de freqüência e que é fornecida pelos geradores hidrelétricos. O objetivo principal do trabalho é desenvolver propostas que indiquem os custos reais desses serviços. Na valorização desses custos, busca-se motivar as empresas geradoras para que assumam a responsabilidade pela prestação de tais serviços, assim como garantir uma remuneração apropriada. Essa valorização é realizada em função da disponibilidade e do uso da reserva, sob uma operação segura e econômica do sistema. Para alcançar o objetivo proposto, inicialmente se realiza uma revisão das características técnicas e dos métodos de valorização dos serviços de reserva em diferentes sistemas. Posteriormente, ilustram-se as características do setor elétrico brasileiro, com a finalidade de contextualizar a valorização no marco de regulação , comercialização e operação correspondentes. Seguidamente, apresentam-se duas propostas de valorização. A primeira considera o ponto de vista de um agente gerador, cujo objetivo é estabelecer o valor do serviço a partir dos custos incorridos no fornecimento. Esses custos incluem, principalmente, os custos pela disponibilidade e pelo uso do serviço. Dentro desses componentes de custo, destaca-se o custo por perdas de eficiência, o qual é calculado utilizando um algoritmo de despacho ótimo de unidades. Essa abordagem é aplicada no cálculo do custo da reserva na usina hidrelétrica de Ilha Solteira. Nesse cálculo são utilizados dados da Companhia Energética de São Paulo - CESP. A segunda proposta considera o ponto de vista do operador de rede, em um ambiente de mercado, no qual os agentes participantes podem ofertar pela disponibilidade da reserva. Para a atribuição dessa reserva utiliza-se um despacho ótimo hidrelétrico, que inclui rest / This work presents a reserve ancillary services pricing research. Particularly, the reserve that is used for frequency regulation and that is provided by hydroelectric generators. The development of pricing methodologies, that show real reserve delivery costs, is the main target of this project. Ancillary services pricing procures incentives to motivate agents to take responsibilities in the service supply and ensuring an appropriated remuneration. This pricing is based on the use and availability costs of reserve; under an economic and reliable system operation. In order to do that, firstly an overview of technical characteristics and pricing methods of the ancillary services in different systems is presented. Then, in order to fit this pricing methodology to the corresponding regulation, commercialization and operation rules, an introduction of the Brazilian electrical sector is realized. Next, two reserve ancillary services pricing methods are presented. The first one considers a hydraulic generator point of view. In this case, the aim is to set up the real value of the services by mean of a generator costs analysis. These costs include, basically, availability and use costs. Inside these cost components, efficiency costs are highlighted, and a single generator unit commitment dispatch is used to calculate them. This proposal is applied to calculate the ancillary service reserve costs in the Ilha Solteira hydroelectric generator, using data from the Companhia Energ´etica of S˜ao Paulo (CESP). The second pricing method considers the operator system point of view, under a market environment. In these circumstances, agents are free to set up a price offer for the availability of the reserve. To attribute the reserve, an optimal hydroelectric dispatch is used, considering electrical and hydraulic constraints. This methodology is tested in two systems. The first one represents a didactic three bus

Maintenance of power plants is aimed at extending the life and reducing the risk of sudden breakdown of power generating units. Traditionally, power generating units have been scheduled for maintenance in periods to ensure that the demand of the system is fully met and the reliability of the system is maximized. However, in a deregulated power industry, the pressure of maintaining generating units is also driven by the potential revenue received by participating in the electricity market. Ideally, hydropower generating units are required to operate during periods when electricity prices are high and to be able to be taken offline for maintenance when the price is low. Therefore, determination of the optimum time periods for maintenance of generating units in a power system has become an important task from both a system reliability and an economic point of view. Due to the extremely large number of potential maintenance schedules, a systematic approach is required to ensure that optimal or near-optimal maintenance schedules are obtained within an acceptable timeframe. Metaheustics are high-level algorithmic frameworks that aim to solve combinatorial optimisation problems with a large search space in a reasonable computational run time. Inspired by the foraging behavior of ant colonies, Ant Colony Optimisation (ACO) is a relatively new metaheuristic for combinatorial optimisation. The application of ACO to a number of different applications has provided encouraging results when applied to scheduling, including the job-shop, flow-shop, machine tardiness and resource-constrained project scheduling problems. In this thesis, a formulation is developed that enables ACO to be applied to the generalized power plant maintenance scheduling optimisation (PPMSO) problem. The formulation caters for all constraints generally encountered as part of real-world PPMSO problems, including system demands and reliability levels, precedence rules between maintenance tasks, public holidays and minimum outage durations in the case of shortening of maintenance tasks. As part of the formulation, a new heuristic and a new local search strategy have been developed. The new ACO-PPMSO formulation has been tested extensively on two benchmark PPMSO problems from the literature, including a 21-unit and a 22-unit problem. It was found that the ACOPPMSO formulation resulted in significant improvements in performance for both case studies compared with the results obtained in previous studies. In addition, the new heuristic formulation was found to be useful in finding maintenance schedules that result in more evenly spread reserve capacity and resource allocations. When tested using a modified version of the 21-unit and the 22-unit problems, the new local search strategy specifically designed for duration shortening was found to be effective in searching locally for maintenance schedules that require minimal shortening of outage duration. The ACO-PPMSO formulation was also successfully able to cater for all constraints as specified in both original and the modified versions of the two benchmark case studies. In order to further test the ACO-PPMSO formulation developed, it was first applied to a scaled-down version of the Hydro Tasmania hydropower system (five power stations) and then to the full system (55 generating units). As part of the studies, the ACO-PPMSO formulation was linked with the simulation model used by Hydro Tasmania to assess the impact of various maintenance schedules on the total energy in storage of the system at the end of the planning horizon, the total thermal generation, the total number of days where the reliability level is not met, as well as the total unserved energy throughout the planning horizon. A number of constraints were considered, including the anticipated system demands, a 30% capacity reliability level, the minimum and maximum durations between related maintenance tasks, the precedence constraints and the minimum outage duration of each task in the case of shortening of maintenance tasks. The maintenance schedule was optimised for the maximum end-of-horizon total energy in storage, the minimum thermal generation and the minimum total outage durations shortened and deferred, under 77 different inflow conditions. The optimal maintenance schedule obtained compared favourably with that obtained by Hydro Tasmania over many years based on experience. Specifically, the ACO-PPMSO schedule results in higher end-of-horizon total energy in storage and satisfies both hard and soft constraints, which overall equates to over $0.5 million dollars of savings when compared to the schedule obtained using the practitioners’ experience and engineering judgment. The ACO-PPMSO algorithm was also shown to be a useful decision-making tool for scheduling maintenance under different circumstances when tested with four scenarios commonly encountered in practical maintenance scheduling problems. In conclusion, the ACO-PPMSO formulation developed, tested and applied as part of this thesis research provides a powerful and flexible means of obtaining optimal or near-optimal maintenance schedules for power plants. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1294672 / Thesis (Ph.D.) -- University of Adelaide, School of Civil and Environmental Engineering, 2007

Resumo: Esta tese visa ao estudo da valorização de serviços ancilares de reserva, particularmente, a reserva utilizada na regulação de freqüência e que é fornecida pelos geradores hidrelétricos. O objetivo principal do trabalho é desenvolver propostas que indiquem os custos reais desses serviços. Na valorização desses custos, busca-se motivar as empresas geradoras para que assumam a responsabilidade pela prestação de tais serviços, assim como garantir uma remuneração apropriada. Essa valorização é realizada em função da disponibilidade e do uso da reserva, sob uma operação segura e econômica do sistema. Para alcançar o objetivo proposto, inicialmente se realiza uma revisão das características técnicas e dos métodos de valorização dos serviços de reserva em diferentes sistemas. Posteriormente, ilustram-se as características do setor elétrico brasileiro, com a finalidade de contextualizar a valorização no marco de regulação , comercialização e operação correspondentes. Seguidamente, apresentam-se duas propostas de valorização. A primeira considera o ponto de vista de um agente gerador, cujo objetivo é estabelecer o valor do serviço a partir dos custos incorridos no fornecimento. Esses custos incluem, principalmente, os custos pela disponibilidade e pelo uso do serviço. Dentro desses componentes de custo, destaca-se o custo por perdas de eficiência, o qual é calculado utilizando um algoritmo de despacho ótimo de unidades. Essa abordagem é aplicada no cálculo do custo da reserva na usina hidrelétrica de Ilha Solteira. Nesse cálculo são utilizados dados da Companhia Energética de São Paulo - CESP. A segunda proposta considera o ponto de vista do operador de rede, em um ambiente de mercado, no qual os agentes participantes podem ofertar pela disponibilidade da reserva. Para a atribuição dessa reserva utiliza-se um despacho ótimo hidrelétrico, que inclui rest / Abstract: This work presents a reserve ancillary services pricing research. Particularly, the reserve that is used for frequency regulation and that is provided by hydroelectric generators. The development of pricing methodologies, that show real reserve delivery costs, is the main target of this project. Ancillary services pricing procures incentives to motivate agents to take responsibilities in the service supply and ensuring an appropriated remuneration. This pricing is based on the use and availability costs of reserve; under an economic and reliable system operation. In order to do that, firstly an overview of technical characteristics and pricing methods of the ancillary services in different systems is presented. Then, in order to fit this pricing methodology to the corresponding regulation, commercialization and operation rules, an introduction of the Brazilian electrical sector is realized. Next, two reserve ancillary services pricing methods are presented. The first one considers a hydraulic generator point of view. In this case, the aim is to set up the real value of the services by mean of a generator costs analysis. These costs include, basically, availability and use costs. Inside these cost components, efficiency costs are highlighted, and a single generator unit commitment dispatch is used to calculate them. This proposal is applied to calculate the ancillary service reserve costs in the Ilha Solteira hydroelectric generator, using data from the Companhia Energ'etica of S˜ao Paulo (CESP). The second pricing method considers the operator system point of view, under a market environment. In these circumstances, agents are free to set up a price offer for the availability of the reserve. To attribute the reserve, an optimal hydroelectric dispatch is used, considering electrical and hydraulic constraints. This methodology is tested in two systems. The first one represents a didactic three bus / Orientador: Antonio Padilha Feltrin / Coorientador: José Maria Yusta Loyo / Banca: Rubén Augusto Romero Lázaro / Banca: Carlos Roberto Minussi / Banca: Ricardo Bernardo Prada / Banca: Thales Souza / Doutor

ANEEL; FINEP; CAPES; CNPQ; Fundação Araucária / Neste trabalho é apresentada uma aplicação de sensores à fibra ótica baseados em redes de Bragg encapsulados em compósito de resina polimérica com reforço de fibra de vidro. Foram avaliadas três resinas epóxi comerciais. O objetivo do trabalho é caracterizar os compósitos e investigar a viabilidade de embeber sensores a fibra ótica, baseados em redes de Bragg em fibras óticas em compósito epóxi. Na caracterização das amostras, foram realizados: Ensaios para avaliar a tensão residual após a cura das amostras. Nos ensaios, foram utilizados sensores FBGs incrustados no compósito. Ensaios para avaliar a temperatura de transição vítrea através da técnica Calorimetria Exploratória Diferencial (DSC). Ensaios de tração axial e flexão simples utilizando máquina de teste universal e ensaios para avaliar o comportamento do compósito quando sujeito a uma carga fixa e temperatura variando de 20 °C até a temperatura limite da transição vítrea do compósito. Os resultados mostram um elevado grau de integração das FBGs no compósito epóxi. Um dos resultados é promissor para aplicações em um gerador de alta potência e em ambientes hostis com temperatura de trabalho até 127 °C. / This work presents an application of optical fiber sensors based on Bragg gratings encapsulated in polymeric composite resin with glass fiber reinforcement. Three commercial epoxy resins were evaluated. The main objective of the study is to characterize the composites and investigate the feasibility of embedding the optical fiber sensors based on Bragg gratings in epoxy composite. In the characterization of the samples tensile tests were performed to evaluate the residual stress after the curing process. The residual stress was investigated by mains of a FBG sensor embedded in the composite. Additionally, tests were conducted to evaluate the glass transition temperature by DSC technique. The values of the axial tensile and simple flexural stress were investigated using a universal testing machine. In addition, tests were performed for evaluating the composite behavior when subjected to a fixed load and variable temperature ranging from 20 °C to the temperature limit of the glass transition of the composite. The results show a high level of integration of the FBGs with the epoxy composite. One of the results is promising for applications in a high power generator and in hostile environments working at temperatures up to 127 °C. / 5000

Hydropower maintains its position as the most important source of renewable electric energy in the world. The efficiency of large hydropower plants is unsurpassed, and after more than hundred years of development, the technology is mature and highly reliable. While new hydro resources are currently being developed in Asia and South America, most European countries go through a phase of intense refurbishment and upgrading of existing plants. Challenges faced by the hydropower industry include a knowledge transfer to new generations and the adaptation of unit designs to meet new operational requirements. As with all branches of engineering, the use of computerized design tools has revolutionized the art of hydropower plant design and the analysis of its performance. In the present work, modern tools like coupled field-circuit models and semi-analytic permeance models are used to address different aspects of electromagnetic analysis of generators in large hydropower plants. The results include the presentation of a mathematical model that uses concepts from rotating field theory to determine the air-gap flux density waveform in a hydroelectric generator. The model was succesfully used to evaluate armature voltage harmonics and damper bar currents at no-load and load conditions. A second study is concerned with the importance of losses due to rotational fields in core loss calculations. It is found that dynamic and rotational effects typically increase the total core loss estimates with about 28% in large hydroelectric generators. In a third study, linear models for the calculation of salient pole shoe form factors at an arbitrary level of magnetic loading are presented. The effect of the damper winding configuration on the damping capability of salient-pole generators is then evaluated in a separate study. The predicted impact of the coupling between damper cages on adjacent poles on the damping torque production is verified in a set of experiments.