Environmentally friendly renewable energy technologies such as wind and solar energy systems are among the fleet of new generating technologies driving the demand for distributed generation of electricity. Power Electronics has initiated the next tech¬nological revolution and enables the connection of distributed generation (DG) systems to the grid. The challenge is to achieve system functionality without extensive custom engineering, yet still have high system reliability and generation placement flexibility. Nowadays, it is a general trend to increase the electricity production using DG systems. If these systems are not properly controlled, their connection to the utility network can generate problems on the grid side. Therefore, considerations about power generation, safe running and grid synchronization must be done before connecting these systems to the utility network. This thesis introduces a new grid-synchronization, or more visibly a new “power signal processor” adaptive notch filtering (ANF) tool that can potentially stimulate much interest in the field and provide improvement solutions for grid-connected operation of DG systems. The processor is simple and offers high degree of immunity and insensitivity to power system disturbances, harmonics and other types of pollutions that exist in the grid signal. The processor is capable of decomposing three-phase quantities into symmetrical components, extracting harmonics, tracking the frequency variations, and providing means for voltage regulation and reactive power control. In addition, this simple and powerful synchronization tool will simplify the control issues currently challenging the integration of distributed energy technologies onto the electricity grid. All converter-interfaced equipments like FACTS (flexible ac transmission systems) and Custom Power Controllers will benefit from this technique. The theoretical analysis is presented, and simulation and experimental results confirm the validity of the analytical work. / Thesis (Ph.D, Electrical & Computer Engineering) -- Queen's University, 2009-01-27 11:37:07.279

No description available.

[pt] Com o uso da teoria das probabilidades consegue-se um método para medida da confiabilidade dos sistemas de potência, bastante preciso. O presente trabalho consubstancia a teoria que envolve o cálculo da confiabilidade de um sistema de geração, o planejamento desse sistema, a programação da manutenção das unidades geradoras - de modo a manter um nível de confiabilidade constante durante um ano - e um programa de computador como ilustração dos métodos apresentados. / [en] The use of probability theory is a tool for a accurate reliability evaluation of power systems. This paper explains the theory envolving, reliability analysis of a generating system, planning of those systems, maintenance scheduling of generating units to maintain a constant reliability level during the year and a computer program to ilustrate all the introduced methods.

In this thesis, components and parameters based power models (PMs) are produced to measure the power consumption (PC) of cloud radio access network (CRAN) architecture. In components PM, the power figure of each component within C-RAN is evaluated. After, this model is parametrised such that the computation complexity of each component is converted to a straightforward, but accurate method, called parameterised PM. This model compares cooling and total PC of traditional LTE architecture with C-RAN. This comparison considered different parameters such as, utilised bandwidth, number of antenna, base band units (BBUs) and remote radio heads (RRHs). This model draws about 33% reduction in power. Next, this PC model is updated to serve and exhibit the cost of integrating software defined networks (SDNs) with C-RAN. Alongside, modelling the power cost of the control plane units in the core network (CN), such as serving gateway (SGW), packet gateway (PGW) and mobility management entity (MME). Although there is power cost, the proposed model shows the directions to mitigate it. Consequently, a simplified PM is proposed for virtualisation based C-RAN. In this model, the power cost of server virtualisation by hosting several virtual machines (VMs) is shown, in a time and cost effective way. The total reduction in the PC was about 75%, due to short-cutting the number of active servers in the network. Alongside, the latency cost due to such technique is modelled. Finally, to enable efficient virtualisation technology, live migrating the VMs amongst the servers is vital. However, this advantageous situation is concurrent with VM's migration time and power cost. Therefore, a model is proposed to calculate the power cost of VM's live migration, and shows the effect of such decision upon the total PC of the network/C-RAN. The proposed work converts the complexity of other proposed PMs, to a simplified and costless method. Concurrently, the time cost is added to the imposed virtualisation's time cost to formulate the total delay expected prior to these techniques' execution.

[pt] Este trabalho apresenta um método geral e prático, baseado em técnicas de convolução discreta, para avaliar o valor esperado e a variância dos índices de freqüência e duração (FeD) da perda de carga de um sistema de geração. O método proposto modela sem qualquer restrição unidades geradoras com estados operativos de capacidade reduzida simultaneamente com todos possíveis estados de carga. O valor esperado e a variância dos índices de freqüência e duração da perda de carga são calculados, tratando as taxas de transição entre estados de geração e os picos de carga previstos como variáveis aleatórias. Técnicas de agregação são utilizadas para modelar as incertezas das disponibilidades da capacidade de geração das unidades hidráulicas. Sob este aspecto, os índices de confiabilidade são também variáveis aleatórias. A determinação da expansão da capacidade de geração na presença de incertezas é a proposta sob um novo enfoque. Este método avalia limites de confiança ( ou percentis) não só para os índices de perda de carga, mas também para os índices de Freqüência e Duração da falha. Assim, a expansão da capacidade de geração é reutilizada utilizando os percentis dos índices de risco em vez de se utilizar apenas seus valores médios. O método FeD proposto é utilizado para avaliar o impacto das incertezas nos parâmetros dos geradores e da carga, em sistemas típicos da geração, incluindo o Sistema Teste da confiabilidade do IEEE e uma configuração planejada para 1991 do Sistema Sul-Sudeste Brasileiro. / [en] This work presents a practical and general method base on discrete convolution techniques for evaluating the expectation and variance of the frequency and duration (FeD) reliability indices, for a single area system. The proposed method models simultaneously and without any restriction, derated generating capacity generation units with all possible load levels. The expectation and variance of Frequency and duration reability indices are evaluated based on discrete convolution, treating the the generating unit transition rates and forecast peak loads as random variables. Clustering techniques are used to model the incertainties in the output capacities of hydraulic units. Under this interpretation, the reliability indices are also random variables. The generation capacity expansion problem under uncertainties, for a single-area system, is addressed from a new point of view. This method determines confidence limits (or percenties) not only for the loss of load indices but also for the frequency and duration failure indices. The generating capacity expansion is then calculated through risk indices percenties instead of the usual expected values. The proposed FeD method is then used for evaluating the impact of load and generating parameter uncertainties on typical systems including the IEEE Reliability Test System, and the Brazlian South/Southeastern Generating System.

[pt] Este trabalho consiste em se determinar técnicas de modelagem de bacias hidráulicas utilizando o conceito de espaço de estado, e escolha de um dos métodos que seja mais objetivo e prático para aplicação generalizando o estudo de Mendonza [1]. São estudados quatro métodos de obtenção do sistema em espaço de estado que são, método de expansão em frações parciais, programação interativa, modelo controlável e modelo observável. Pela característica de simplicidade de obtenção do modelo, foi escolhido este último que simplifica bastante a aplicação em bacias hidráulicas. Esta teoria é aplicada em seguida a duas bacias hidráulicas para obtenção dos modelos de sistema discretos em espaço de estado e são feitas simulações para as bacias do Rio Peixe e do Rio Grande. Os dados numéricos utilizados neste trabalho são hipotéticos. / [en] This thesis consists in determine moulding techiques of hydraulics basin using the state space representation, and choicing one of the most objective and practical methods for application, generalizing the study of Mendonza [1]. Are studied four methods for obtaining the system in state space which are, partial-fraction expansion method, interative programming, controllable model and observable model. By the simplicity characteristic to obtain the model, was chosen the last one to simplify enough the application in hydraulics basins. This theory is applied in sequence to two hydraulics basins for the obtaining of the models of discrete systems in state space and the simulations were done for the Rio do Peixe and Rio Grande basins. The numerical data used in this thesis are hypothetic.

Submitted by Rosangela Silva (rosangela.silva3@unioeste.br) on 2018-06-25T22:08:59Z No. of bitstreams: 2 Rosemar_C_ Dal Ponte.pdf: 2801946 bytes, checksum: 918b897f2bd7a01d32f68e66f844088d (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-06-25T22:08:59Z (GMT). No. of bitstreams: 2 Rosemar_C_ Dal Ponte.pdf: 2801946 bytes, checksum: 918b897f2bd7a01d32f68e66f844088d (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2018-03-09 / With the constant increase in the need for electric energy, the use of wind energy emerges as an alternative capable of meeting these demands. Taking into account that several regions of the country have a great potential for wind power, it is necessary to develop technologies and investments to ensure the growth of this energy source. The objective of this project was to study the technical-economical viability of a vertical axis wind turbine, which used a washing machine motor, a servomotor and an alternator for electric power generation, in order to verify which generation system presents better efficiency. In addition, the unit costs of the energy produced in each generation system were determined and compared to the value of the electricity tariff charged by the concessionaire for rural consumers. From the collected data of voltages and electric currents, the power and the wind-mechanical, mechanical-electrical and wind-electric efficiencies of each generator system were calculated, allowing a comparison between these values. The alternator presented the best wind-mechanical efficiency (5.02%) and the best wind-electric efficiency (0.47%). The motor of the washing machine showed the best mechanical-electrical efficiency (11.33%). The results showed that the systems have little efficiency in the generation of electric energy, and the cost of energy generated indicates values much higher than those practiced by the local electric power company. / Com o aumento constante da necessidade de energia elétrica, a utilização da energia eólica surge como uma alternativa capaz de suprir essas demandas. Levando em consideração que várias regiões do País possuem um grande potencial de aproveitamento eólico, faz-se necessário o desenvolvimento de tecnologias e investimentos para garantir o crescimento dessa fonte de energia. O objetivo deste projeto foi estudar a viabilidade técnico-econômica de um aerogerador de eixo vertical, que utilizou, para geração de energia elétrica, um motor de máquina de lavar, um servomotor e um alternador, com a finalidade de verificar qual sistema de geração apresenta melhor eficiência. Além disso, foram determinados os custos unitários da energia produzida em cada sistema de geração, e comparados com o valor da tarifa de energia elétrica cobrada pela concessionária, para consumidores rurais. A partir dos dados coletados de tensões e correntes elétricas, foram calculadas as potências e as eficiências eólico-mecânica, mecânico-elétrica e eólico-elétrica de cada sistema gerador, possibilitando uma comparação entre esses valores. O alternador apresentou a melhor eficiência eólico-mecânica (5,02%) e a melhor eficiência eólico-elétrica (0,47%). Já o motor da máquina de lavar evidenciou a melhor eficiência mecânico-elétrica (11,33%). Os resultados demonstraram que os sistemas têm pouca eficiência na geração de energia elétrica, e o custo da energia gerada aponta valores muito superiores aos praticados pela concessionária de energia elétrica local.

The design of autonomous agents capable of performing a given goal in a 3D domain continues to be a challenge for computer animated story generation systems. We present a novel prototype which consists of a 3D engine and a planner for a simple virtual world. We incorporate the 2D planner into the 3D engine to provide 3D animations. Based on the plan, the 3D world is created and the objects are positioned. Then the plan is linearized into simpler actions for object animation and rendered via the 3D engine. We use JINNI3D as the engine and WARPLAN-C as the planner for the above-mentioned prototype. The user can interact with the system using a simple natural language interface. The interface consists of a shallow parser, which is capable of identifying a set of predefined basic commands. The command given by the user is considered as the goal for the planner. The resulting plan is created and rendered in 3D. The overall system is comparable to a character based interactive story generation system except that it is limited to the predefined 3D environment.

[pt] A busca de uma maior eficiência na produção de energia elétrica, tem levado vários países a reestruturar seus setores elétricos tradicionalmente sob o controle de governos federais ou estaduais, como na Inglaterra, Espanha, Nova Zelândia, Argentina, Chile, Peru (motivo deste trabalho) e atualmente no Brasil, onde o lucro das empresas privadas esta ligada à eficiência da operação de seus sistemas elétricos. Esta tese apresenta uma alternativa de planejamento da operação ótima e determinação das variáveis duais que podem ser usadas como indicadores para elaborar estruturas tarifarias em sistemas hidrotérmicos, baseado na teoria de grafos, onde, a principal vantagem é a simplicidade e a eficiência: os algoritmos de busca ótima em grafos são cerca de 200 a 300 vezes mais rápidos que os modelos tradicionais de otimização linear e não linear [17]. O modelo de operação do sistema hidrotérmico, considera as restrições hidráulicas, cenários históricos de afluências e projetos de expanção para o horizonte de estudo. / [en] The search for more efficiency in the production of eletrical energy, has led several countries to re- structure their eletric sectors, traditionally under control of federal, or state governments like in England, in /spain, in New Zeland, in argentina, in Chile, in Peru (object of this work), and now in Brasil. In this new structure the profit of the private enterprises ough to go tied to the efficiency of their electric systems. This thesis introduces an alternative form for optimal operation planning, and for determination of dual variables that can be used as indicators for rate-schedule structures in hydrothermal systems based on graph theory. The main advantage are simplicity, and efficiency: the algorithm for optimal search in graph is 200 to 300 times faster than the general purpose methods of linear and non- linear optimization. The operations model of the hydrothermal system considers the hydraulic constraint, historical influx scenarius, and capacity expansion projects within the study horizon.

<div>Hydrous hydrazine (N₂H₄·H₂O) is a promising hydrogen carrier for convenient storage and transportation owing to its high hydrogen content (8.0 wt%), low material cost and stable liquid state at ambient temperature. Particularly, generation of only nitrogen as byproduct, in addition to hydrogen, thus obviating the need for on-board collection system for recycling, ability to generate hydrogen at moderate temperatures (20-80 °C) which correspond to the operating temperature of a proton exchange membrane fuel cell (PEMFC), and easy recharging using current infrastructure of liquid fuels make hydrous hydrazine a promising hydrogen source for fuel cell electric vehicles (FCEVs). Since hydrogen can be generated from catalytic hydrazine decomposition, the development of active, selective and cost-effective catalysts, which enhance the complete decomposition (N₂H₄ → N₂+2H₂) and simultaneously suppress the incomplete decomposition (3N₂H₄ → 4NH₃+N₂), remains a significant challenge.</div><div>In this dissertation, CeO₂ powders and various Ni-based catalysts for hydrous hydrazine decomposition were prepared using solution combustion synthesis (SCS) technique and investigated. SCS is a widely employed technique to synthesize nanoscale materials such as oxides, metals, alloys and sulfides, owing to its simplicity, low cost of precursors, energy- and time-efficiency. In addition, product properties can be effectively tailored by adjusting various synthesis parameters which affect the combustion process.</div><div>The first and second parts of this work (Chapters 2 and 3) are devoted to investigating the correlation between the synthesis parameters, combustion characteristics and properties of the resulting powder. A series of CeO₂, which is a widely used material for various catalytic applications and a promising catalyst support for hydrous hydrazine decomposition, and Ni/CeO₂ nanopowders as model catalysts for the target reaction were synthesized using conventional SCS technique. This demonstrated that crystallite size, surface property and concentration of defects in CeO₂ structure which strongly influence the catalytic performance, can be effectively controlled by varying the synthesis parameters such as metal precursor (oxidizer) type, reducing agent (fuel), fuel-to-oxidizer ratio and amount of gas generating agent. The tailored CeO₂ powder exhibited small CeO₂ crystallite size (7.9 nm) and high surface area (88 m²/g), which is the highest value among all prior reported SCS-derived CeO₂ powders. The Ni/CeO₂ catalysts synthesized with 6 wt% Ni loading, hydrous hydrazine fuel and fuel-to-oxidizer ratio of 2 showed 100% selectivity for hydrogen generation and the highest activity (34.0 h^-1 at 50 ºC) among all prior reported catalysts containing Ni alone for hydrous hydrazine decomposition. This superior performance of the Ni/CeO₂ catalyst is attributed to small Ni particle size, large pore size and moderate defect concentration.</div><div>As the next step, SCS technique was used to develop more efficient and cost-effective catalysts for hydrous hydrazine decomposition. In the third part (Chapter 4), noble-metal-free NiCu/CeO₂ catalysts were synthesized and investigated. The characterization results indicated that the addition of Cu to Ni/CeO₂ exhibits a synergistic effect to generate significant amounts of defects in the CeO₂ structure which promotes catalytic activity. The 13 wt% Ni_0.5Cu_0.5/CeO₂ catalysts showed 100% H₂ selectivity and 5.4-fold higher activity (112 h^-1 at 50 ºC) as compared to the 13 wt% Ni/CeO₂ (20.7 h^-1). This performance is also superior to that of most reported non-noble metal catalysts and is even comparable to several noble metal-based catalysts. In the fourth part (Chapter 5), low Pt loading NiPt/CeO₂ catalysts were studied. The modified SCS technique was developed and applied to prepare NiPt/CeO₂ catalysts, that overcomes the typical problem of conventional SCS which leads to deficiency of Pt at catalyst surface due to the diffusion of Pt into bulk CeO₂. The Ni_0.6Pt_0.4/CeO₂ catalysts with 1 wt% Pt loading exhibited high activity (1017 h^-1 at 50 ºC) along with 100% H₂ selectivity owing to the optimum composition of NiPt alloy, high metal dispersion and a large amount of CeO₂ defects. Its activity is higher than most of the reported NiPt-based catalysts which typically contain high Pt loading (3.6-42 wt%).</div><div>Next, the intrinsic kinetics of hydrous hydrazine decomposition over the NiPt/CeO₂ catalysts, which are necessary for efficient design and optimization of the hydrous hydrazine-based hydrogen generator system, were investigated (Chapter 6). From the experimental data obtained at different reaction temperatures, the intrinsic kinetic model based on the Langmuir-Hinshelwood mechanism was established. The developed model</div><div>provides good predictions with the experimental data, especially over a wide range of initial reactant concentration, describing well the variation of reaction order from low to</div><div>high reactant concentration.</div><div>Finally, the conclusions of the dissertation and recommendations for future work are summarized in Chapter 7.</div>