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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
71

A design scheme of energy management, control, optimisation system for hybrid solar-wind and battery energy storages system

Sarban Singh, Ranjit Singh January 2016 (has links)
Hybrid renewable energy system was introduced to improve the individual renewable energy power system’s productivity and operation-ability. This circumstance has led towards an extensive technological study and analysis on the hybrid renewable energy system. The extensive technological study is conducted using many different approaches, but in this research the linear programming, artificial intelligence and smart grid approaches are studied. This thesis proposed a complete hardware system development, implementation and construction of real-time DC Hybrid Renewable Energy System for solar-wind-battery energy source integrated with grid network support. The proposed real-time DC HRES hardware system adopts the hybrid renewable energy system concept which is composed of solar photovoltaic, wind energy system, battery energy storage system and grid network support. The real-time DC HRES hardware system research work is divided into three stages. Stage 1 involves modelling and simulation of the proposed system using MATLAB Simulink/Stateflow software. During this stage, system’s methodological design and development is emphasised. The obtained results are considered as fundamental finding to design, develop, integrate, implement and construct the real-time DC HRES hardware system. Stage II is designing and developing the electronic circuits for the real-time DC HRES hardware system using PROTEUS software. Real time simulation is performed on the electronic circuits to study and analyse the circuit’s behaviour. This stage also involves embedded software application development for the microcontroller PIC16F877A. Thus, continuous dynamic decision-making algorithm is developed and incorporated into microcontroller PIC16F877A. Next, electronic circuits and continuous dynamic decision-making algorithm are integrated with the microcontroller PIC16F877A as a real-time DC HRES hardware system to perform real time simulation. The real-time DC HRES hardware system simulation results are studied, analysed and compared with the results obtained in Stage 1. Any indifference between the obtained results in Stage 1 and Stage 2 are analysed and necessary changes are made. Stage 3 involves integrating, implementation and construction of real-time DC HRES. The continuous dynamic decision-making algorithm is also incorporated into the real microcontroller PCI16F877A development board. Real-time DC HRES’s experimental results have successfully demonstrated the system’s ability to perform supervision, coordination, management and control of all the available energy sources with lease dependency on the grid network. The obtained results demonstrated the energy management and optimisation of the available energy sources as primary power source deliver.
72

Real-time state estimation of a distributed electrical power system under conditions of deregulation

Kusekwa, Mashauri A. D. January 2010 (has links)
Thesis (DTech (Electrical Engineering))--Cape Peninsula University of Technology, 2010. / Static state estimation is a mathematical procedure in which physical measurements from sub-stations and physical model are combined in an optimal way. That is, the measurements obtained from the sub-stations are used with the physical model and the states of the power system are selected or calculated such that the states match the measurements in some best way. The states of a power system are the bus voltage magnitude and voltage angle of each bus of the system. Static state estimation is an increasingly common part of electrical power utility energy management systems (EMS). It plays a critical part in a day-to-day operation of a power system utility. The system measurements obtained from static estimation are used for realtime operations like optimal power flow calculations and contingency analysis. Proper system operations with regards to avoidance of insecure conditions includes situational awareness, therefore, the static estimator plays an important role in power system security. A further motivation: in increasingly electrical power deregulation, more economic operations mean savings for customers and electrical power provider alike. Economic benefit might be realized if system operators have a more accurate situational awareness of the system through improved power system state estimator. The objective of the study was to develop method, algorithm and MATLAB program for solution of power system state estimation using parallel processing techniques. In achieving the objective, the study has concentrated on development of an approximate Tanzanian power system network model comprising of 30 buses and used as a case study; decomposing the bus admittance matrix of the model into 3 interconnected sub-systems; development of mathematical model for real and reactive power injections, real and reactive power flows in the transmission lines and tie-lines connecting the sub-systems; development of measurement data model for voltage magnitude, real and reactive power injections, real and reactive power flows; formulating of a constrained weighted least absolute value state estimation problem; development of decomposition-coordination method and algorithm; and formulating algorithm and MATLAB program for solving the constrained state estimation problem using parallel processing technique.
73

Controle social na política de financiamento da educação: uma análise da atuação dos conselhos do FUNDEB na Região Metropolitana de Campina Grande – PB

ANDRADE, Fellipe Almeida de 29 July 2016 (has links)
Submitted by Irene Nascimento (irene.kessia@ufpe.br) on 2017-01-27T16:44:29Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) FellipeAndrade_Dissertação_VersãoFinal 6 vias.pdf: 2595465 bytes, checksum: aa417f9c06c9f1836959271c7d842b0e (MD5) / Made available in DSpace on 2017-01-27T16:44:29Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) FellipeAndrade_Dissertação_VersãoFinal 6 vias.pdf: 2595465 bytes, checksum: aa417f9c06c9f1836959271c7d842b0e (MD5) Previous issue date: 2016-07-29 / O presente estudo realiza uma análise da atuação dos Conselhos Municipais de Controle Social – CACS da principal política de financiamento da educação no Brasil: o Fundo de Manutenção e Desenvolvimento da Educação Básica e de Valorização dos Profissionais do Magistério – FUNDEB. O principal objetivo é investigar o grau de contribuição destes colegiados – que contam com a representação de diversos segmentos ligados ao ensino e também de seus principais beneficiários – para o cumprimento das finalidades do financiamento educacional, tendo como referência a administração municipal. São analisadas a estrutura organizacional, as regras de funcionamento, os meios de execução do controle social e os impactos da atividade do CACS diante do que a legislação outorga-lhe como prerrogativas. O campo da pesquisa é a Região Metropolitana de Campina Grande, no Estado da Paraíba, e o marco temporal é o período compreendido entre os anos de 2010 a 2014. O exame realizado permitiu verificar que os Conselhos existem e são relativamente atuantes, mas padecem de limitações causadas pela sua dependência junto ao Poder Público, pelos vícios persistentes na eleição de seus membros, pela precariedade da formação inicial e continuada dos conselheiros e pelo escopo restrito das informações a que, obrigatoriamente, têm acesso. / This study conducts an analysis of the performance of the main Municipal Social Control Councils (CACS) of education financing policy in Brazil: the Fund for the Development of Basic Education and the Magisterium of the Professional Valuation – FUNDEB. The main objective is to investigate the degree of contribution of these councils - which have representation from various sectors linked to education and also its main beneficiaries - for the fulfillment of the purposes of educational funding, with reference to the municipal administration. Were analyzed the organizational structure, operating rules, the means for the implementation of social control and the impact of the Council's activity before the law grants you as prerogatives. The field of research is the metropolitan area of Campina Grande, in the state of Paraiba, and the timeframe is the period between the years 2010-2014. The examination has shown that the Councils exist and are relatively active, but suffer from limitations caused by their dependence on the government, the persistent flaws in the election of your members, the precariousness of initial and continuing training of counselors and the restricted scope of the information must have access.
74

High Frequency Switching of SiC Transistors and its Applications to In-home Power Distribution / SiCトランジスタの高周波スイッチングとその家庭内電力配電への応用

Takuno, Tsuguhiro 26 March 2012 (has links)
Kyoto University (京都大学) / 0048 / 新制・課程博士 / 博士(工学) / 甲第16855号 / 工博第3576号 / 新制||工||1540(附属図書館) / 29530 / 京都大学大学院工学研究科電気工学専攻 / (主査)教授 引原 隆士, 教授 木本 恒暢, 教授 小野寺 秀俊 / 学位規則第4条第1項該当
75

A control strategy for the power system of a hybrid vehicle

Furrutter, Marco Klaus 24 October 2012 (has links)
M.Ing. / The increase in awareness of the environmental problems resulting from emissions released from vehicles have forced governments and car manufactures to invest more time in to the designing a vehicle that is an alternative to petrol driven vehicles. This dissertation aims to introduce a control strategy to manage the flow of energy of different power sources that may be found on a vehicle. Hybrid vehicles are a possible solution to reducing carbon emissions that play a part in global warming. In this dissertation, di erent hybrid vehicles are de ned and their components discussed in detail. The possibility of more than one energy source to power the vehicle introduces more exibility in terms of the drivetrain but this increases the complexity of the energy control management. The goal is to optimize the energy control management to reduce fuel consumption and therefore reduce emissions. Operating procedures for the various hybrid con gurations are discussed. Simulations of the Energy Management System of the hybrid electric vehicle are used to develop the control optimization algorithm. Various control optimization procedures are discussed. Satisfactory results from the simulations allow the implementation of the hybrid onto a platform entered into the South African Solar Challenge 2010, which covered a distance of 4000 km. The Energy Management system selected for the parallel hybrid electric vehicle demonstrated fuel savings, which meant a reduction in emissions, which is the goal of any hybrid vehicle. Further investigations include more intelligent controllers to adjust the parameters of the energy management controller to allow for adaptation to various driving conditions, e.g. urban and motorway driving.
76

L'information dans les sociétés cotées / The information in the limited companies

Kumbe Ngome, Marx Lénine 09 January 2015 (has links)
Depuis les scandales financiers notamment d’Enron, Worldcom, Vivendi et Parmalat, la transparence est au cœur de tous les débats dès que la situation l'exige. Ainsi, tout le monde appelle à la transparence. Cette invocation est partagée par des politiciens, des avocats, des économistes, des financiers et l'opinion publique. Ainsi transparence souhaité par tous et qui correspond à la quantité d'informations diffusées par les entreprises, est devenu l'instrument privilégié de la régulation des marchés financiers. De nombreux pays occidentaux ont adopté des lois pour garantir la sécurité des marchés et des investisseurs. En France, il existe des lois comme la loi sur les Nouvelles Régulations Economiques (NRE) de 2001, la loi sur La Sécurité Financière (LSF) de 2003 et la loi Breton de 2005. Au niveau européen, il existe aussi des lois et les plus importantes sont la Directive Transparence de 2013, sur l'harmonisation des obligations de transparence concernant à l'information sur les émetteurs dont les valeurs mobilières sont admises à la négociation sur un marché réglementé, Directive concernant les Marchés d’Instruments Financiers (MiFID) 2014, la directive Abus de Marché (MAD) de 2014 et European Market Infrastructure Regulation (EMIR) de 2012. Cependant au sein des sociétés, on assiste à une instrumentalisation de l’information, orchestrant des « guerres » entre dirigeants et actionnaires. La transparence est ainsi détournée de son rôle premier pour satisfaire les intérêts égoïstes de ces personnes. Grâce à une manipulation de l’information dont il est dépositaire, le dirigeant peut mettre en place des stratégies dans le but de conserver son fauteuil. Les actionnaires dépositaires du contrôle de la société, peuvent opérer un contrôle purement économique, et n’agiront pas dans l’intérêt de la société mais dans leur intérêt patrimonial, en fonction d’une stratégie de création de valeur et d’investissement préalablement arrêtée. / Since financial scandals including Enron, Worldcom, Vivendi and Parmalat, transparency is at the heart of all discussions as soon as the situation requires. Thus, everyone calls for transparency. This invocation is shared by politicians, lawyers, economists, financiers and public opinion. Thus the transparency desired by all and which corresponds to the amount of information published by companies, became the privileged instrument of regulation of financial markets. Many Western countries have adopted laws to guarantee the safety of the markets and investors. In France, there are laws such as Act New Regulations Economic (NRE) of 2001, the Law on Security Finance (LSF) of 2003 and 2005 Breton law. A European level, there are also laws and the most important are the 2013 Transparency Directive, on harmonization of the transparency requirements for information about issuers whose securities are admitted to trading on a regulated market, Directive concerning the markets in Financial Instruments (MiFID) of 2014, Market Abuse Directive Abuse (MAD) of 2014 and 2012 European Market Infrastructure Regulation (EMIR). However within societies, there is a manipulation of information, orchestrating “wars” between officers and shareholders. Transparency is thus diverted from its role as first to satisfy the selfish interest of these persons. Through the manipulation of information which he is the depositary, the leader can implement policies ti keep his chair. The custodians of the control of the company shareholders, can operate a purely economic control, and will not act in the interest of society but in their heritage interest, based on a previously stopped creating value and investment strategy.
77

Eco-routing and scheduling of Connected and Autonomous Vehicles

Houshmand, Arian 19 May 2020 (has links)
Connected and Autonomous Vehicles (CAVs) benefit from both connectivity between vehicles and city infrastructures and automation of vehicles. In this respect, CAVs can improve safety and reduce traffic congestion and environmental impacts of daily commutes through making collaborative decisions. This dissertation studies how to reduce the energy consumption of vehicles and traffic congestion by making high-level routing decisions of CAVs. The first half of this dissertation considers the problem of eco-routing (finding the energy-optimal route) for Plug-In Hybrid Electric Vehicles (PHEVs) to minimize the overall energy consumption cost. Several algorithms are proposed that can simultaneously calculate an energy-optimal route (eco-route) for a PHEV and an optimal power-train control strategy over this route. The results show significant energy savings for PHEVs with a near real-time execution time for the algorithms. The second half of this dissertation tackles the problem of routing for fleets of CAVs in the presence of mixed traffic (coexistence of regular vehicles and CAVs). In this setting, all CAVs belong to the same fleet and can be routed using a centralized controller. The routing objective is to minimize a given overall fleet traveling cost (travel time or energy consumption). It is assumed that regular vehicles (non-CAVs) choose their routing decisions selfishly to minimize their traveling time. A framework is proposed that deals with the routing interaction between CAVs and regular uncontrolled vehicles under different penetration rates (fractions) of CAVs. The results suggest collaborative routing decisions of CAVs improve not only the cost of CAVs but also that of the non-CAVs. This framework is further extended to consider congestion-aware route-planning policies for Autonomous Mobility-on-Demand (AMoD) systems, whereby a fleet of autonomous vehicles provides on-demand mobility under mixed traffic conditions. A network flow model is devised to optimize the AMoD routing and rebalancing strategies in a congestion-aware fashion by accounting for the endogenous impact of AMoD flows on travel time. The results suggest that for high levels of demand, pure AMoD travel can be detrimental due to the additional traffic stemming from its rebalancing flows, while the combination of AMoD with walking or micromobility options can significantly improve the overall system performance.
78

Damping Interarea Oscillations in Power Systems with DFIG

Thapa, Ravi Chandra January 2011 (has links)
With rapid depletion of fossil fuels and increasing environmental concerns, the trend to capture renewable energy, especially through wind energy resources, is increasing. The doubly fed induction generator (DFIG) is the most widely used generator for wind energy conversion because of its various advantages over other types of generators. In a DFIG, the rotor is fed through back to back converters via slip rings. The converters enable the generation control. This control property can be used to support reliable operation of a grid network system. Interarea oscillation has been a major factor in limiting power transfers in interconnected power systems. Poorly damped modes can trigger oscillatory instability, potentially leading to cascading blackouts in such systems. We consider a two-area system where DFIG based wind generation is integrated with conventional synchronous generators. A simple controller is proposed for the DFIG to improve damping of interarca oscillations. To support the proposition, case studies are conducted in Matlab/Simulink. The effectiveness of the proposed controller is then analyzed by eigenvalue analysis and verified with time domain simulation results. The results show that a properly tuned controller can increase the damping of dominant oscillatory mode by nearly 5% while improving the area transfer by about 200 MW of wind power. The results further show that with the proposed control strategy, damping of dominant oscillatory mode increased by more than 10%. / North Dakota State University. Graduate School / North Dakota State University. Department of Electrical and Computer Engineering
79

<strong>A REFLECTIVE PROCESS ON ABLEIST DESIGN ASSUMPTIONS | DISABILITY, FOOD ACCESS, AND THEIR RELATIONSHIP TO DESIGN</strong>

Tayler Lynn Wullenweber (16377945) 15 June 2023 (has links)
<p>Accessibility often isn’t recognized to the abled-bodied. The objects, systems and tools of access aren’t even noticed until those without disabilities need it or become disabled themselves. Building on my initial academic and scholarly research, I conducted a case study at The Wabash Center; a facility that serves people with disabilities in the local West Lafayette and surrounding communities. I spent three months observing, journaling, and identifying key patterns that revealed the tensions in food access issues at the facility. These patterns included community, agency, dependency and assistance, and accountability. The issues I identified at The Wabash Center all fall under the overarching issue of power and control. Power and control describes the notion that is often exercised by abled-bodies in the presence of people with disabilities. In this context, food and food access is used as a form of power and control. It is commonly found that the issue of power and control is embedded in design and the way that designers conduct their processes. To better understand the systemic relationships and issues of food access, it was imperative to analyze the internal interactions of how disabled people negotiate in an institutionalized setting. This thesis discusses the reflection process of my efforts to look critically at my own assumptions about disability, food access, and its relationship to design.</p>
80

Assessing the Effectiveness of Workload Measures in the Nuclear Domain

Mercado, Joseph 01 January 2014 (has links)
An operator's performance and mental workload when interacting with a complex system, such as the main control room (MCR) of a nuclear power plant (NPP), are major concerns when seeking to accomplish safe and successful operations. The impact of performance on operator workload is one of the most widely researched areas in human factors science with over five hundred workload articles published since the 1960s (Brannick, Salas, & Prince, 1997; Meshkati & Hancock, 2011). Researchers have used specific workload measures across domains to assess the effects of taskload. However, research has not sufficiently assessed the psychometric properties, such as reliability, validity, and sensitivity, which delineates and limits the roles of these measures in workload assessment (Nygren, 1991). As a result, there is no sufficiently effective measure for indicating changes in workload for distinct tasks across multiple domains (Abich, 2013). Abich (2013) was the most recent to systematically test the subjective and objective workload measures for determining the universality and sensitivity of each alone or in combination. This systematic approach assessed taskload changes within three tasks in the context of a military intelligence, surveillance, and reconnaissance (ISR) missions. The purpose for the present experiment was to determine if certain workload measures are sufficiently effective across domains by taking the findings from one domain (military) and testing whether those results hold true in a different domain, that of nuclear. Results showed that only two measures (NASA-TLX frustration and fNIR) were sufficiently effective at indicating workload changes between the three task types in the nuclear domain, but many measures were statistically significant. The results of this research effort combined with the results from Abich (2013) highlight an alarming problem. The ability of subjective and physiological measures to indicate changes in workload varies across tasks (Abich, 2013) and across domain. A single measure is not able to measure the complex construct of workload across different tasks within the same domain or across domains. This research effort highlights the importance of proper methodology. As researchers, we have to identify the appropriate workload measure for all tasks regardless of the domain by investigating the effectiveness of each measure. The findings of the present study suggest that responsible science include evaluating workload measures before use, not relying on prior research or theory. In other words, results indicate that it is only acceptable to use a measure based on prior findings if research has tested that measure on the exact task and manipulations within that specific domain.

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