This thesis develops a peers-to-peers intelligent air conditioner (A/C) controller which integrates the power line carrier technology and the infrared remote control. The intelligent air conditioner controller is used for the remote temperature setting and load control of air conditioner without requesting extra communication line and modification of the control circuit in the A/C unit. With the A/C controller developed the demand response in residential and commercial areas can be achieved effectively by reducing the peak power demand of A/C units. In order to investigate the PLC signal transmission over the low voltage distribution lines, the mathematical model of low voltage distribution system under high carrier signal frequency is derived. The computer simulation is executed to analyze the transmission characteristics of power line carrier signal. The proposed controller can receive the command issued by the demand response control center over the distribution lines with carrier frequency to execute the remote temperature setting of A/C units. Based on the field measurement of energy by air conditioner, it is found that significantly power demand reduction of air conditioner has been resulted by applying the proposed controller for remote temperature setting of air conditioner.

Thesis--University of Wisconsin--Madison. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 124-129).

This paper investigates the concept of an isolated small wind power system based on a three-phase generator and a direct ac-to-ac conversion. The ac-to-ac conversion is performed by a matrix converter and thus removing the need of a large smoothing capacitor in the typical rectifier-inverter solution. The paper is briefly presenting the operation for a particular topology of a three-phase to single-phase matrix converter. The control of this conversion ensures system’s frequency and voltage stability. Simulation results and practical results are presented to validate the frequency and voltage regulation of the isolated power system.

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Differentiated services (Diffserv) is a scalable architecture and is proposed to provide QoS guarantee services in the current best effort network environment. In this thesis, we will introduce the Diffserv model and the Diffserv router components in detail. Related works proposed by researchers to improve the performance of the Diffserv networks are categorized and discussed. Common challenges in the Diffserv networks are pointed out. Then a weighted fair share algorithm is proposed to solve these challenges.

Made available in DSpace on 2014-06-11T19:35:40Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-09-29Bitstream added on 2014-06-13T19:46:36Z : No. of bitstreams: 1 martinellijunior_lc_dr_guara.pdf: 2129598 bytes, checksum: 077cb099a0427f9857575f0eb35c7028 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Máquinas de absorção são dispositivos que produzem frio ou calor útil utilizando como fonte principal o calor residual de processos ou da queima de combustíveis diversos. Estes sistemas de refrigeração podem ser recomendados para aplicações em sistemas de condicionamento de ar de ônibus e caminhões, onde o espaço disponível para a instalação do mesmo é pequeno. Neste trabalho efetua-se o balanço exergético de uma máquina de absorção que utiliza o calor dos gases de exaustão de um motor de combustão interna (diesel) como fonte de energia. Este sistema é aplicado como ar condicionado veicular alternativo. O cálculo baseia-se em sistema aplicado a um ônibus, onde há um grande fluxo de gases de exaustão a elevadas temperaturas. Conclui-se que o calor residual liberado pelo ônibus é suficiente para acionar o sistema de ar condicionado alternativo, e que em termos exergéticos as maiores irreversibilidades estão associadas ao gerador (desorbedor), indicando de certo modo a necessidade de efetuar melhorias neste componente do sistema de absorção. Finalmente a Análise da Eficiência Ecológica é aplicada, considerando o sistema alternativo para um ônibus com motor Mercedez-Benz. A utilização do mesmo possibilita, além de uma visível economia de combustível, a melhoria da eficiência global e ecológica. / Absorption machines are devices that produce useful cold or heat using the residual heat of systems or combustion of several fuels. These absorption refrigeration systems can be recommended for applications in air conditioning systems of buses and trucks, which have a restricted space available for their installation. This work presents the energetic and exergetic balances of an absorption machine that uses the exhaust gases of an internal combustion engine (diesel) as source of energy. Such system is applied as an alternative vehicular air conditioner. The calculation is based on a bus-installed system where a high flow of exhaust gases at high temperatures is produced. It is concluded that the residual heat released by the bus is sufficient to activate the alternative air conditioning system, and that the largest irreversibilities in exergetic terms are associated to the generator (desorber), indicating somewhat the need to accomplish several improvements in this component of the absorption system. Finally the Ecological Efficiency Analysis are applied considering the alternative system to a bus with a Mercedez-Benz Engine. Using that engine enable an economy of combustion and a global and ecological efficiency better.

Made available in DSpace on 2014-06-11T19:30:10Z (GMT). No. of bitstreams: 0 Previous issue date: 2003-11Bitstream added on 2014-06-13T18:59:52Z : No. of bitstreams: 1 oliveira_la_me_guara.pdf: 2784324 bytes, checksum: 076f01bfc4c089c335c41d4360749ebe (MD5) / Este trabalho analisa edifícios que, devido a sua arquitetura moderna, utilizam grande superfície de vidro nas fachadas apresentando, na maior parte das vezes, problemas de conforto térmico. Como objeto deste estudo decidiu-se por um prédio da UNESP, campus de Guaratinguetá. A análise realizada foi baseada no estudo da insolação (diagrama solar), em medidas locais de temperatura, umidade e no levantamento da carga térmica, objetivando avaliar as condições do edifício e propor soluções visando um melhor conforto térmico com a otimização do consumo de energia elétrica. / This work analyzes buildings that, due to their modern architecture, use a great glass surface in the facades presenting, most of the time, problems of thermal comfort. As object of this study we chose a building of UNESP, campus of Guaratingueta. The accomplished analysis was based on the study of the heatstroke (solar diagram), in measuring temperature places, humidity and in the rising of the thermal load, aiming at evaluating the conditions of the building and to propose solutions seeking a better thermal comfort with the optimization of the consumption of electric energy.

The purpose of this investigation was to determine if a commercial soil conditioner, Superbio, can improve crop yield, and if the "advertised" soil improvement might be due to an increase in the activity and numbers of aerobic cellulose decomposing bacteria following treatment.

Orientador: Paulo José Amaral Serni / Banca: Wilson Komatsu / Banca: Fernando Pinhabel Marafão / Resumo: Dentre as muitas topologias de condicionadores de energia disponíveis na literatura, destaque especial tem sido dado aos filtros ativos de potência, dispositivos tipicamente eletrônicos, controlados digitalmente. Neste sentido, as topologias mais estudadas são as de filtros ativos paralelos, filtros ativos série e filtros ativos universais (série-paralelo). Neste trabalho, foi dada atenção especial ao estudo de um filtro ativo universal, também conhecido coo Condicionador Unificado de Qualidade de Energia (CUQE) ou em inglês, Unified Power Quality Conditioner (UPQC). Assim, dentre os muitos assuntos que permeiam o projeto e implementação deste dispositivo, este trabalho propõe novos algoritmos para a geração de referência dos conversores eletrônicos, bem como algoritmos de inicialização e proteção do CUQE. Os algoritmos de referênciasão baseados em técnicas de álgebra vetorial e filtragem digital, enquantoas rotinas de inicialização e proteção visam à solução de problemas de ordem prática, para que o dispositivo possa ser utilizado em ambiente industrial, como produto. Um estudo sobre os controladores de tensão e corrente também foi realizado e as técnicas mais adequadas estão descritas no trabalho. Destaca-se que todos os algoritmos de geração de referência, proteção, inicialização e os controladores foram avaliados e validados por meio de simulações computacionais e resultados experimentais. No caso dos resultados experimentais, foram realizados ensaios em malha aberta para validação dos algoritmos de referência, bem como ensaios em um protótipo de CUQE, de potência igual a 75 KVA, os quais validaram o desempenho de todos os algoritmos desenvolvidos em um dispositivo real para aplicações industriais / Abstract: Among different topologies of power conditioners found in literature, special emphasis has been given to active power filters (typically power electronic devices with digital control). In this sense, the most studied topologies have been the parallel active filters, the series active filters and the unified active filters (series-parallel). In this work, special attention was given to the study of a Unified Power Quality Conditioner (UPQC). Thus, among many issues that underline the design and implementation of this device, this dissertation proposes new algoritmos for the generation of voltage and current references to the applied power converters, as well algoritmos for the initialization and protection of the UPQC. The reference algorithms are based on vector algebra and digital filtering techniques, while the initialization and protection routines aimed to solve practical problems, so the device can be used in and industrial environment, as a commercial product. The voltage and current controllers were also studied and the most suitable techniques are described. It is noteworthy that all proposed algorithms and controllers have been evaluated and validated by means of computer simulations and experimental results. The experimental validation were performance by means of open loop tests, as well as considering an UPQC prototype (75 KVA rated) in order to validate the overall UPQC development and the performance of the proposed algorithms / Mestre

In this thesis analysis and design of a wide input range DC-DC converter is proposed along with a robust power control scheme. The proposed converter and its control is designed to be compatible to a fuel cell power source, which exhibits 2:1 voltage variation as well as a slow transient response. The proposed approach consists of two stages: a primary three-level boost converter stage cascaded with a high frequency, isolated boost converter topology, which provides a higher voltage gain and isolation from the input source. The function of the first boost converter stage is to maintain a constant voltage at the input of the cascaded DC-DC converter to ensure optimal performance characteristics with high efficiency. At the output of the first boost converter a battery or ultracapacitor energy storage is connected to take care of the fuel cell slow transient response (200 watts/min). The robust features of the proposed control system ensure a constant output DC voltage for a variety of load fluctuations, thus limiting the power being delivered by the fuel cell during a load transient. Moreover, the proposed configuration simplifies the power control management and can interact with the fuel cell controller. The simulation results and the experimental results confirm the feasibility of the proposed system.