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Redevelopment of South China Athletic Association盧偉芳, Lo, Wai-fong. January 1996 (has links)
published_or_final_version / Architecture / Master / Master of Architecture
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A Distributed Intelligent Lighting Solution and the Design and Implementation of a Sensor Middleware SystemFischer, Michael 30 April 2015 (has links)
This thesis addresses a multi-phase research and development project that spanned nearly
four years, targeted at providing an ultra high-efficiency, user-friendly, and economic
intelligent lighting solution for commercial facility applications, initially targeting
underground parking specifically. The system would leverage the strengths of four key
technologies: high brightness white Light Emitting Diodes (LEDs), wireless sensor and
actuator networks, single board computers, and cloud computing. An introduction to
these technologies and an overview of how they were combined to build an intelligent
lighting solution is given, followed by an in-depth description of the design and
implementation of one of the main subsystems – the Sensor Middleware System –
residing on a single board computer.
Newly-available LED luminaires (a.k.a. light fixtures) bring the combination of high
efficiency, reliability, illumination quality, and long-lifetime to the lighting market.
Emerging low-power – and recently low-cost – 802.15.4 wireless networks offer high
controllability and responsiveness to deployed luminaires and sensors. The cost-
associativity, low maintenance, and easy build-up of Internet Data Center “cloud”
computing resources make data collection and remote management infrastructure for
Building Automation Systems accessible to even small companies. Additionally, these
resources can be much more appropriately sized and allocated, which reduces energy use.
These technologies are combined to form an Intelligent Lighting System (ILS). Fitting
well within the Internet of Things paradigm, this highly distributed messaging-based
“system of systems” was designed to be reliable through loose coupling – spanning
multiple network layers and messaging protocols. Its goal was to deliver significant
energy savings over incumbent technologies, configurable and responsive lighting service
behaviour, and improved experience for users within the facility (pedestrians and drivers)
and those interacting with its web-based tools (building managers and ILS
administrators). The ILS was partitioned into three main subsystems as follows. The
installed Wireless Field Network (WFN) of luminaires and sensors provided coordinated
scheduled and real-time output level adjustment (i.e. dimming), with the help of motion
sensor triggers. The Monitoring and Configuration System (MCS) in the cloud provided
remote data collection and a web-based monitoring and configuration Graphical User
Interface application. Network hardware and Message-Oriented Middleware (MOM)
were responsible for tying these subsystems together. The MOM layer that provided the
message brokering, translating, envelope wrapping, and guaranteed delivery services
between the WFN and MCS, as well as field supervisory and quality-of-service functions
for the WFN, was called the Sensor Middleware System (SMS). It was hosted on a
single board computer located at the facility. / Graduate
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Glödljus vs. LED-ljus : En rumslig analys av ljuskvalitén i hemmiljö / Incandescent light vs. LED light : A spatial analysis of lighting quality in home environmentsAttila, Csikós January 2014 (has links)
Det finns fortfarande för många hushåll i Sverige som använder mest glödljus för belysning, i form av glödlampor eller halogenlampor. Detta orsakar en väsentlig del av det onödiga överskott av koldioxidutsläpp som är en av orsakerna till den globala uppvärmningen. Därför avser detta examensarbete att försöka skapa en grönare miljö genom att studera och uppmärksamma faktorer som påverkar val av ljuskällor i belysningssammanhang. Syftet med examensarbetet är att få en ökad förståelse för hur LED-ljuset upplevs i hemmiljö. Arbetet ska visa hur LED-ljuskällans nuvarande kvalité bedöms utifrån individuella rumsupplevelser samt om ytterligare kvalitetsförbättringar behövs. Detta görs för att kunna vända allmänhetens inställning i en mer positiv riktning gentemot LED, vilket kan bidra till en mer ekologiskt hållbar miljö. För att undersöka hur LED fungerar i hemmiljö genomfördes en experimentell studie med syfte att besvara följande frågor: hur upplevs LED-ljusets kvalité jämfört med halogenljusets, hur tror man att det egna välmåendet påverkas av halogenljus respektive LED-ljus, hur påverkas rumsupplevelsen och rumskaraktären om halogenljus ersätts med LED-ljus och finns det några skillnader mellan ljusdesigners och icke ljusdesigners upplevelse av halogenljus och LED-ljus i hemmiljö? Det byggdes upp två likadana försöksrum som hade samma förutsättningar både storleksmässigt, inredningsmässigt och belysningsmässigt. Den enda skillnaden var de installerade ljuskällorna, då det användes halogenlampor i det ena rummet och LED-lampor i det andra rummet. En enkätundersökning genomfördes, resultatet analyserades och en utförlig rumsanalys gjordes. Resultatet visade att ljuset, oavsett ljuskälla, påverkade deltagarnas välmående och rumsupplevelse på olika sätt, beroende på vilken yrkesgrupp de tillhörde. Det visade sig också att skillnaden i ljuskvalitén mellan halogenljus och LED-ljus inte längre är omfattande. Dagens LED-lampor utvecklas alltså positivt och är redan en värdig ersättare till glöd- och halogenlampor. / There are still too many households in Sweden that use mostly incandescent light for lighting, using incandescent or halogen bulbs. This causes a substantial part of the unnecessary surplus of carbon-dioxide that is one of the reasons for global warming. Therefore, this degree project aims to promote a greener environment by studying and paying attention to factors that have an influence in the lighting context. The purpose of this degree project is to gain a better understanding of how the LED light is experienced in a home environment. The work will show how LED light source's current quality is evaluated based on individual room experiences, and if additional quality improvements are needed. The objective is to turn the public's attitude in a more positive direction where LED can contribute to a more ecologically sustainable environment. To investigate how LEDs are perceived in home environments an experimental study was performed which was based on the following research questions: How is LED light quality experienced compared to halogen light, how is personal wellbeing perceived in relationship to halogen and LED light, how are room experience and room character affected if halogen light is replaced by LED light in a home environment and are there any differences in these experiences between lighting designers and non lighting designers? Two identical test-rooms were used. They were identical in size, interior design and lighting design. Halogen bulbs were used in one room and LED lights were used in the other room. A survey was used to get answers to the questions above. The results have been analyzed and detailed room analysis was also made. The results showed that the light, regardless of light-source, influenced the participant's well-being and their room experience in different ways, depending on the occupational group they belonged to. It was also found that the difference in quality of light between halogen light and LED light is no longer significant. The presently available LED lights are improving and are worthy replacements for incandescent and halogen lamps.
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The effects of complexity, choice and control on the behaviour and the welfare of captive common marmosets (Callithrix jacchus)Badihi, Inbal January 2006 (has links)
There are numerous guidelines recommending that captive primates live in complex environments in which they have the opportunity to make choices and the ability to control aspects of the environment, despite the lack of quantitative evidence to suggest these qualities improve welfare. Complexity, choice and control (the ‘Three Cs’) are inter-related and therefore it is complicated to separate their effects. The main aim of this thesis was to examine how the ‘Three Cs’ affect welfare, using the common marmoset (Callithrix jacchus) as a model. Behavioural measures and preference tests were used to determine the impact and significance of the ‘Three Cs’ on welfare. Experimental manipulations were natural (i.e. access to outside runs), or unnatural (e.g. pressing a button to control additional illumination). In a series of different studies, marmosets were moved to larger and more complex enclosures, were allowed to choose between indoor cages and outdoor complex enclosures and were able to control additional white light or coloured lights in their home enclosures. The results of these studies show that appropriate levels of each of the ‘Three Cs’ had a positive influence on the welfare of the marmosets, especially on youngsters. Although having control over light, and increased illumination itself improved welfare, providing a choice of access to outside runs (which were more complex and allowed the marmosets greater control over their activities) resulted in the greatest welfare improvement for marmosets of all ages. Loss of access, or control, did not appear to have a negative impact. The marmosets were housed in pairs or in family groups, in the different studies. A cross-study comparison shows that the composition of the groups affected the behavioural response of adult marmosets to environmental enrichment. Unexpectedly, it was also found that, when housed in standard laboratory conditions, adult marmosets were more relaxed when housed in pairs than when housed with their offspring. A secondary aim of the thesis was to quantify welfare indicators and activity budgets of common marmosets in a range of different social and physical contexts, and to compare this with the behaviour of wild marmosets, to increase our understanding of what is “normal” in captive situations. It is concluded that it is critical to sub-divide locomotion and inactivity into different levels to interpret these measures accurately. Levels of calm locomotion increased in enriched environments, while levels of relaxed inactivity and scent marking decreased. A number of recommendations for the care and housing of marmosets are made.
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從傳統照明跨足LED照明之策略佈局-以OSRAM公司為例 / The strategy of traditional lighting company entering LED lighting industry- A case study of OSRAM洪于舒 Unknown Date (has links)
過去台灣LED產業伴隨著面板業的發展而崛起,但目前正是投入LED照明,放眼進千億美元市場的機會,本研究針對傳統照明大廠OSRAM於技術、專利、與商業策略等角度分析,探討LED照明的佈局策略,期望能給台灣LED廠商一些啟發。整體而言,LED照明取代傳統照明的趨勢是肯定的,關鍵在於LED照明的價格走勢以及政府政策的支持。目前雖然LED照明市場仍然以美國為主,但以整體亞洲市場而言,市佔率已經越來越高。而亞洲區域市場最重要的國家-中國,目前在LED照明應用市場僅次美國,差距已經越來越小,未來極可能成為最主要的市場。
在一開始進入半導體照明時,OSRAM受惠於母公司Siemens,在專利、技術上就已取得領先,OSRAM並採取垂直整合的策略,從磊晶、晶粒、封裝、模組都有佈局,使LED的生產更有效率。除此之外,由於未來LED照明產業的趨勢是照明整合服務,OSRAM也透過併購的方式,補強照明設備、照明系統的能力。未來OSRAM不僅供應LED元件,也提供照明解決方案,觸手一路延伸至終端應用。OSRAM初期都是以合資為主以分散風險,若合資公司經營順利,OSRAM便以併購的方式,強化OSRAM的全球佈局。此外,OSRAM 建立了一個平台,聚集了熱管理、光學、電子相關的專業廠商,以及照明整合的系統廠商,形成產業群聚,一方面可以鞏固供應商、被供應商關係,一方面透過產業群聚的效果,建立緊密的合作網路。此外,於經營策略方面,不僅提供整合型產品,開拓銷售管道,且透過生產基地的轉移,降低生產成本,並隨著市場導向,轉換銷售區域,加強於亞太地區的在地化發展。最後,OSRAM之專利申請策略配合市場需求,且除了LED以外,也鞏固OSRAM於省電燈的領先地位;在專利授權部份,OSRAM採取開放式專利授權策略,為Nichia增加競爭者,也為自身帶來大量的授權金以及代工廠商。
研究結論顯示,OSRAM成功的因素在於掌握專利、品牌以及通路,以及LED元件垂直整合的供應鏈,並積極的貼近市場,瞭解市場趨勢,將LED光源技術的挑戰成功的轉化成OSRAM新的產品線。因此本研究建議台灣廠商應與中國之照明廠商合作,台灣廠商於LED技術以及製造仍具優勢,但缺乏品牌以及通路的佈局,台灣LED廠商與其自己發展品牌,不如以代工的方式與既有的傳統照明品牌廠商合作,與中國照明廠商合力抵抗來自國際照明廠的威脅。此外,台灣廠商應認清產業定位,台灣於半導體、電子領域擁有領先技術,可以從LED照明產業鏈的中游模組切入,像是熱處理或是驅動IC等,會是台灣廠商切入照明產業的利基。 / The LED manufactures in Taiwan now actively involved in the general lighting application of LED. In order to provide the manufacturers with some suggestions, the main goal of this thesis is to study OSRAM’s LED lighting layout and strategy, including patent, technology and business strategy. In the long run, LED lighting replacing traditional lighting is in a positive direction. Key factors are the price of LED lamps and the support of government policies. At the present time, the US market is still the main market. However, the market share in Asia-Pacific is steadily increasing. The most important country in the Asia-Pacific region, China, is getting closer and very likely to become the most important market in the near future.
Benefited from parent company, Siemens, OSRAM took the leading position at the beginning of semiconductor lighting. OSRAM then adopted the strategy of vertical integration of epitaxy, chip process, packaging and end applications. Therefore, OSRAM can manufacture LED products in a more efficient way. Furthermore, OSRAM also reinforces the capability of the lighting fixtures and lighting systems via mergers, acquisitions, and joint ventures. OSRAM not only provides LED components but also lighting systems and solutions. To spread risks, OSRAM use joint ventures instead of mergers and acquisitions in the beginning. Once the company has operated smoothly, OSRAM will then merge the company. In addition, OSRAM has established a platform to gather companies that provide electronic, optical, or thermal solutions. Industry cluster is formed. With the effect of cluster, the relationship between buyers and suppliers is enhanced. About business strategies, OSRAM developed integrated products to extend channels and moved manufacturing overseas. Referring to patent application strategy, OSRAM meet the demand of market. In addition to LED-related patents, OSRAM also filed many efficient lamp patents these years. And OSRAM actively licensed patents to other companies, not only created competitors against Nichia but also received licensing fee.
In conclusion, the main reasons why OSRAM succeed are the strategies of brand, channel and patent. As the lack of branding and channel, this study suggests that Taiwan manufacturers could cooperate with traditional lighting companies in China. With the OEM service of Taiwan manufacturers, supplying LED components, and the channels and brand of China lamp manufacturers, Taiwan and China may have a chance to compete with other international companies. In addition, Taiwanese firms should recognize their positions in the industry value chain. In addition to building a brand, investing in LED lamp, there’ll be a better choice to develop midstream light engines like thermal management or driver IC.
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Avaliação das emissões conduzidas e radiadas geradas por unidade eletrocirúrgica e sistema de iluminação com lâmpadas fluorescentes em equipamentos médicosMoraes, Fábio Brignol de 16 December 2013 (has links)
Este trabalho apresenta um estudo sobre interferência eletromagnética, emissões radiada e conduzida, gerados pelo sistema de iluminação e pela unidade de eletrocirurgia (bisturi eletrônico) numa sala cirúrgica de um hospital da cidade de Pato Branco/PR. O trabalho consistiu em medidas de emissões conduzidas e radiadas de sistemas de iluminação fluorescentes em laboratório e de emissões conduzidas e radiadas “in loco” da unidade de eletrocirurgia. Além disso, foi feito estudo de referenciais sobre as normas, nacionais e internacionais, que incidem sobre estes dois sistemas. Como resultado do trabalho tem-se um panorama sobre a situação das emissões conduzidas e radiadas, pelos sistemas de iluminação fluorescente e unidade eletrocirúrgica utilizados no hospital. / This work presents a study on electromagnetic interference radiated and conducted emissions generated by the lighting system and the electrosurgery unit (eletric scalpel) in na operating room of a hospital in Pato Branco / PR. The work consisted of measurements of conducted and radiated emission of fluorescent lighting systems in the laboratory of conducted and radiated “in loco” electrosurgery unit emissions. Futhermore, a study was made of references on standarts, national and international, that focus on these two systems. Because of the work, has an overview on the situation of conducted and radiated emissions, the fluorecent lighting used in electrosurgical unit and hospital systems.
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Estratégias de roteamento e de controle de acesso ao meio para redes de sensores sem fio destinadas a redes urbanas / Routing and medium access control strategies for wireless sensor networks in urban networksRodrigo Palucci Pantoni 31 January 2012 (has links)
Este trabalho propõe estratégias de roteamento e de controle de acesso ao meio destinadas as redes urbanas, motivadas pelo monitoramento e controle de variáveis elétricas relacionadas à iluminação pública. Tais estratégias foram desenvolvidas segundo requisitos da aplicação, trabalhos encontrados na literatura, limitações do protocolo IEEE 802.15.4 e as especificações RFC 5548 e IEEE 802.15.4e (draft). As estratégias desenvolvidas foram incorporadas a protocolos encontrados na literatura, as quais geraram protocolos aperfeiçoados para redes urbanas, dentre eles GGPSR e gradiente em função da maior distância, utilizados para o tráfego divergente e convergente, respectivamente. O protocolo GGPSR é composto pelo algoritmo geográfico GPSR, geocast e retransmissões para os vizinhos seguindo o critério do GGPSR em caso de falha. O protocolo baseado na maior distância é composto pelo algoritmo do gradiente, o qual utiliza a maior distância no caso de receptores com pesos de gradiente iguais e retransmissões seguindo o mesmo critério. Foi utilizado um modelo de propagação realista, no qual foi aplicada a estratégia de mapeamento de vizinhos dos nós de acordo com a distância aproximada fornecida pelo atributo do pacote RSSI. Além disso, para ambos os tipos de tráfego, foi aplicado o mecanismo de controle de acesso ao meio RIT com o objetivo de minimizar o consumo energético. A avaliação dos protocolos gerados a partir dessas estratégias foi feita em simulação utilizando a ferramenta NS-2 integrada em cenários de grande escala fornecidos pela concessionária de iluminação pública Elektro, segundo os critérios de energia remascente da rede, média de atraso fim a fim e taxa de entrega fim a fim. Os resultados obtidos mostram que os protocolos gerados superam protocolos propostos na literatura; além disso, a estratégia baseada na distância obtida pelo atributo RSSI viabiliza a aplicação do protocolo GGPSR. Em relação à aplicação do RIT com a estratégia de parâmetros em função do gradiente, esta se mostrou mais eficiente em comparação com os parâmetros de RIT iguais para todos os nós. / This work proposes routing and medium access control strategies for urban networks, particularly related to monitoring and control of electric variables in the street lighting system. Such strategies were developed according to application requirements, studies in the literature, limitations of the IEEE 802.15.4 protocol, and RFC 5548 and IEEE 802.15.4e (draft) specifications. Strategies were incorporated into protocols found in the literature, which generated specific improved protocols for urban networks, including GGPSR and Gradient based on the farthest neighbor, applied to divergent and convergent traffic, respectively. The GGPSR protocol is composed by the GPSR algorithm, geocast and retransmissions to neighbors according to the GGPSR criterion when a failure occurs. The protocol based on the longest distance comprises the gradient algorithm, which considers the longest distance when receivers have equal gradient weights and retransmissions follow the same criterion. A realistic propagation model was used, implementing the strategy to map neighboring nodes according to the approximate distance provided by the RSSI packet attribute. Moreover, for both traffic ypes, the RIT medium access control mechanism was used in order to minimize energy consumption. Protocols generated by these strategies were evaluated through simulation in NS-2 tool applied to large scale scenarios provided by public street lighting concessionaire Elektro, according to the criteria of remaining energy network, end-to-end average delay and end-to-end delivery rate. Results show that the generated protocols outperform protocols proposed in the literature; in addition, the strategy based on the distance obtained by the RSSI attribute enables the use of the GGPSR protocol. Regarding the use of RIT considering the parameters as a function of the gradient, this strategy is more efficient compared to using the same RIT parameters for all nodes.
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Amélioration des simulations thermiques dans les systèmes d'éclairage automobiles / Improvement of the accuracy of thermal simulations in automotive lighting systemsDauphin, Myriam 10 April 2014 (has links)
Les systèmes d'éclairage automobiles sont conçus pour éclairer la route de manière optimale. Une dégradation des optiques et des matériaux plastiques peut altérer la qualité du faisceau lumineux. En phase de conception, les simulations thermiques visent à minimiser les coûts engendrés par les tests expérimentaux réalisés sur des maquettes. Avec le développement de nouvelles optiques, la méthode numérique des ordonnées discrètes, utilisée pour le calcul des transferts radiatifs, souffre d'un manque de précision en raison d'une discrétisation spatiale limitée pour les réflexions spéculaires. Une augmentation de la discrétisation pourrait mener à des temps de calculs importants. Pour palier à ce problème, la méthode de Monte Carlo a été choisie afin d'évaluer les densités de flux aux parois dans le cas des surfaces opaques, ou un terme source radiatif dans le cas des matériaux semi-Transparents. Notre algorithme est implémenté dans l'environnement de développement EDStar. Cet environnement inclut la bibliothèque de synthèses d'images PBRT permettant de reproduire les trajets optiques dans une géométrie 3D complexe. L'étude porte sur des produits d'éclairage composés de lampes, ainsi le développement d'un modèle numérique fiable requiert des paramètres pertinents en entrée de modèle. Les travaux ont donc été scindés en trois axes d'études. Le premier inclut une phase de caractérisation des propriétés thermiques d'une lampe à incandescence (25W). Différentes méthodes de mesures ont été étudiées pour déterminer la température du filament, moteur des transferts thermiques, et la température de l'enveloppe. Le second axe consiste à développer un modèle des transferts radiatifs dans le système d'éclairage. L'objectif est de localiser les zones de concentration du rayonnement et estimer leur étendue. Enfin, le troisième axe vise à coupler le calcul radiatif à des simulations thermiques dans l'outil de CFD Fluent. La CFD (Computational Fluid Dynamics) est ici nécessaire pour résoudre les problèmes convectifs couplés aux autres transferts thermiques dans un produit industriel. / Automotive lighting systems are designed to illuminate the road optimally. Degradation of optical properties or plastics materials may altering the quality of lighting. In the design stage, thermal simulations are intended to minimize the costs of experimental tests performed on prototypes. With the apparition of new headlights optics, the Discrete Ordinates method (DO) is not suitable in certain cases due to a lack of accuracy when dealing with specular reflections and refractions. A raise of the spatial discretization could lead to significant time computation. To overcome this problem, we chose the Monte Carlo method in order to estimate flux densities to the walls in the case of opaque surfaces, or to estimate a radiative source term in the case of semi-Transparent media. Our algorithm is implemented in EDStar coding environment. This environment includes the PBRT synthesis images library allowing the use of raytracing techniques with our algorithm, thus reproducing optical paths of rays in a complex 3D geometry. The development of a reliable numerical model requires relevant parameters in input. This need led us to split the work into three main parts. The first axis includes a characterization phase of thermal properties of an incandescent lamp (25W) in order to model its radiative emission. Different measurements methods have been investigated to determine the temperature of the filament, which is the origine of heat transfers, and the temperature of the glass envelope. The second axis consists in obtaining a precise distribution of flux density distributions in order to locate hot spots and assess their extent. Finally, the third part of study is to couple the radiative calculation to CFD (Computational Fluid Dynamics) simulations. CFD is here necessary to solve problems with convective phenomena coupled with other heat transfers in an industrial product.
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Integração de conversores estáticos aplicados a sistemas de iluminação pública / An integration of static converters applied to public lighting systemsMarchesan, Tiago Bandeira 20 December 2007 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This work presents a family of integrated electronic ballasts applied to the public lighting system. The electronic ballasts are designed to supply High-Pressure Sodium lamps according to the desired lamp operation characteristics. The viability of use High-Pressure Sodium lamps in the public lighting system of Santa Maria city is studied along this work. Another topic addressed, is the acoustic resonance phenomenon occurrence. It is explained based on a large number of works previously presented in the literature, in order to choose for a reliable method to supply the lamp. The incremental impedance of the High-Pressure Sodium lamp is defined in the frequency domain. This model is used to analyze the lamp and ballast interaction. The presented integrated electronic ballasts to supply High-Pressure sodium lamps take the advantage of low cost and simplicity providing a stable lamp operation. / Este trabalho apresenta uma proposta de integração de conversores estáticos para alimentação de lâmpadas de vapor de sódio de alta pressão (HPS), baseando-se, fundamentalmente, na viabilidade de aplicação deste tipo de lâmpadas a sistemas de iluminação pública. Ao longo do trabalho, é discutida a viabilidade de aplicação das lâmpadas HPS ao sistema de iluminação pública existente na cidade de Santa Maria- RS, evidenciando os parâmetros técnicos necessários ao projeto e desenvolvimento de reatores eletrônicos. A abordagem do fenômeno da ressonância acústica é feita de forma consistente, avaliando-se trabalhos previamente publicados, a fim de se chegar a um método confiável para se alimentar a lâmpada HPS sem a excitação deste fenômeno. Além disso, uma análise do modelo de pequenos sinais da lâmpada traz uma visão dos principais estágios a serem empregados no reator para garantir um funcionamento estável do sistema. A metodologia de integração proposta para alimentação de lâmpadas HPS, através de reatores eletrônicos, sem a excitação do fenômeno da ressonância acústica, busca a redução de custos e a simplicidade do sistema, sem deixar de considerar os procedimentos necessários a uma operação estável e confiável.
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Sistematização do projeto de reatores eletrônicos para alimentação de lâmpadas de vapor de sódio em alta pressão para iluminação pública / Design of a commercial approach of electronic ballasts to supply high-pressure sodium lamps in public lightingCosta, Rafael Eduardo da 27 February 2009 (has links)
Conselho Nacional de Desenvolvimento Científico e Tecnológico / This thesis presents an electronic ballast prototype to supply high-pressure sodium lamps used in public lighting. The goal is to develop a commercial approach able to replace the still commonly used electromagnetic ballasts, performing improvements in the public lighting system. Along this thesis, the state of art in lighting area is presented, especially in public lighting. Following, a bibliographic review about electronic ballasts to supply highpressure sodium lamps is done. Special attention is given to the low frequency square waveform supplying method, which is used in this thesis. Also, the features desired in electronic ballasts so they can operate the lamp reliably and according to the standards are
discussed. From this review, the proposed topology is defined and its design is presented. A discrete control method is developed to guarantee the safe operation of the ballast during all lamp stages. A microcontroller is used to perform the control routines. Finally, experimental
results are obtained, validating the proposed work. / Este trabalho apresenta uma proposta de sistematização do projeto de um reator eletrônico para alimentação de lâmpadas de vapor de sódio em alta pressão, para aplicação em
iluminação pública. Com isto, pretende-se criar um dispositivo que venha a substituir os reatores eletromagnéticos, ainda comumente utilizados nesta aplicação, de modo a
proporcionar melhorias nos atuais sistemas de iluminação pública. Ao longo deste trabalho, é feita uma revisão do estado da arte na área de iluminação, dando ênfase à iluminação pública. Em seguida, é apresentada uma revisão bibliográfica acerca dos métodos de alimentação de
lâmpadas de vapor de sódio a partir de reatores eletrônicos, destacando-se a alimentação deste tipo de lâmpada com forma de onda quadrada em baixa freqüência, método utilizado neste trabalho. Também são discutidas as características que um reator eletrônico deve possuir para
enquadrar-se nas normas vigentes e alimentar a lâmpada de forma confiável. A partir desta revisão, a topologia proposta é definida e seu projeto é apresentado. Uma metodologia de
controle discreto é desenvolvida de forma a garantir a operação adequada do reator durante todas as etapas de funcionamento da lâmpada. Um microcontrolador é utilizado para executar as rotinas de controle. Finalmente, resultados experimentais são obtidos, de forma a validar o trabalho proposto.
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