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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.
261

Systém přizpůsobení zátěže převodníku energie / The system of load matching to the energy converter

Halama, Petr January 2012 (has links)
This master’s thesis deals with energy harvesting from the mechanical energy sources. The mechanical energy may be converted into the electrical by means of a vibrational microgenerator. The thesis deals also with the production of energy from different renewable sources. There have been identified conditions for effective transformation of the remaining energy. In order to satisfy these conditions a circuit for load matching to energy harvester has to be used. Four variants of matching circuit have been designed and analyzed in PSpice or LTspice. It has been designed a system of power factor correction controlled by circuit with discrete components and also by microcontroller. For one of these variants a specific integrated circuit has been used. The designed circuits have been built and their parameters haven been determined by measurement.
262

Wattmetr s podporou komunikace PLC / Energy meter with PLC communication

Szalbot, Michal January 2014 (has links)
Our thesis is about development of equipment, which combine two technology. First technology is wattmeter which is used to energy measurement and second is Power line communication. Wattmeter needs two variables for measurement, voltage and current. Voltage measurement is less difficult than measurement of current. Voltage can be reduce and measured by A/D converter. Current has to be transform to voltage and than can be measured same way. To do that we use current transformer. Than we design program for the microcontroller, involvement and PCB. Wattmeter is connect to PLC modem which has been chosen. Fusing this two technology we create wattmeter network. Next step was program which is used to network control and data collecting. This data are used to create charts in web application.
263

Model mikro sítě s akumulací / Model of microgrid with energy storage

Halás, Andrej January 2015 (has links)
This thesis describes the operation , characteristics and operating conditions of microgrid with energy storage , provides insight into the benefits of using listed concepts . The first part deals with the description of microgrid systems, distribution and shows examples of its use. The second part describes individual elements of the storage systems, energy production and energy transformation used in microgrids . The third part describes the work with PSCAD software. The main goal is to design a micro grid model in PSCAD and validate its function.
264

Náhrada fosilních paliv ve velkých energetických zdrojích / Fossil fuels substitution in large combustion plant

Hájek, Zdeněk January 2010 (has links)
The thesis aims at current issues of using renewable resources here in the Czech Republic, mainly on biomass co-firing with fossil fuels in large combustion plant. The introduction provides an overview of systems for biomass co-firing. Further the using of optimization for solution problem of integration biomass fuels into existing large combustion plants and planning its operation conditions is presented. The main point of this thesis lies in creating of a user interface for modeling and optimization tool. Its functionality will be proved by solving a case study involving the analysis of possibilities for replacing fossil fuels due to the limited availability of coal in the market.
265

Teoreticko-experimentální stanovení měrné energie vířivého čerpadla / Theoretical and experimental setting of the side channel pump specific energy

Dančák, Zdeněk January 2011 (has links)
This master’s thesis deals with side channel pumps. Derivated formula of specific energy is supplemented by other equations and the results of CFD simulation. Further are analysed the mechanism of energy transfer from the impeller and external characteristics of the pump.
266

Potenciál obnovitelných zdrojů na území České republiky ve vztahu k požadavkům Evropské unie

Paluda, Roman January 2017 (has links)
This diploma thesis deals with the relation between the requirements of the European Union for the increase of the share of renewable sources in the energy mix with an emphasis on electricity and the available potential on the territory of the Czech Republic. The energy of water, wind, biomass, solar and geothermal was analyzed in detail. The technological, natural and legislative aspects were assessed. For each of the renewable sources (RES) studied the maximum achievable RES potential was set. On the basis of the facts, the Czech Republic's potential for RES is evaluated, the EU policy in this area is evaluated and several recommendations are made on how to better integrate renewable sources not only in the electricity sector but also in the energy mix in general.
267

Circuits d’interface intégrés sur silicium pour une gestion optimale de la puissance dans les récupérateurs d’énergie vibratoire à transduction capacitive / Smart power management silicon integrated interfaces for capacitive vibration energy harvesters

Bedier, Mohammed 20 December 2017 (has links)
Les vibrations ambiantes representent une source potentielle d'energie pour alimentation des capteurs sans fil autonomes. La transduction electrostatique est une des techniques utilisees pour la conversion de l'energie des vibrations en electricite. De nombreuses realisations des transducteurs et leurs circuits de conditionnement ont deja ete presentees dans la litterature. Pour transmettre l'energie convertie vers une charge utile des interfaces specifiques doivent etre concues. Ce dernier sujet a ete peu aborde dans la litterature. Ce travail etudie une interface avec la charge dans un dispositif de recuperation d'energie vibratoire. L'architecture proposee au cours de cette etude est adaptee aux circuits de conditionnement de type pompe de charge, qui fonctionne selon un cycle charge-tension rectangulaire. L'interface proposee accomplit deux taches. Premierement, il permet de transferer l'energie electrique du circuit de conditionnement vers une charge tout en abaissant la tension d'une maniere adiabatique, c.a.d., en minimisant les dissipations. Deuxiemement, il permet de reguler le debit d'extraction d'energie du circuit de conditionnement en ajustant dynamiquement la puissance de ce transfert. Cela est realise avec un circuit integree en technologie 0.35um CMOS haute tension dont l'architecture est inspiree d'un convertisseur DCDC de type Buck fonctionnant en regime discontinu. La consommation de l'interface est minimisee grace a l'utilisation du regime sous le seuil des transistors MOS pour pratiquement tous les blocs, grace a une alimentation reduite a 1.1V. L'interface consomme en dessous de 100nW, et est capable de gerer des sources d'energie a puissance < 1uW. / Vibrational energy is an attractive power source for self-powered wireless sensors. A mainstream harvesting technique for vibrational energy is electrostatic MEMS harvesters. Various circuit architectures have already been introduced with many successful implementation, yet a load interface that efficiently manages the harvested energy has rarely been reported. In this work a load interface is proposed which is suited for any condition circuit (CC) implementing rectangular QV cycles. In general, a rectangular QV conditioning circuit has an optimum interval of which the energy harvested is maximised, thus the harvested energy should be periodically removed to maintain maximising the harvested energy. This is achieved through the load interface (LI). The LI proposed is a switched inductor capacitive architecture with a LI controller allowing the extraction of the energy in a multiple energy shot fashion. The LI controller incorporate an ultra low power clock for switching events and low power comparator for switching decision. Power consumption is reduced by operating at a low supply voltage (1.1V). The LI is implemented in AMS0.35HV technology with a mixed high voltage-low power control blocks. It takes into account the harvester operation to maximise its extracted energy. It overcomes the constrained limited biasing power, tackles resistive losses and power handling transistor long channels by transferring the energy in a multiple shots fashion. A CMOS implementation is proposed along with simulation results showing an average consumed power of the controller less than 100nW allowing the system to operate with input power levels as low as few hundreds of nano-watts.
268

Nuclear energy in Africa : a legal framework for sustainable energy access / Michelle Barnard

Barnard, Michelle January 2014 (has links)
The promotion of sustainable development is an objective shared by African Union (AU) member states and the pursuance thereof is expressly mandated by the Constitutive Act of the African Union, 2000 and the Treaty Establishing the African Economic Community, 1992. Lack of access to modern energy sources, such as electricity and the heavy reliance on traditional biomass as primary energy source are factors contributing to the non-achievement of the promotion of sustainable development. These factors are collectively referred to as energy poverty. The African Continent as a whole has limited, and in some instances, lack access to modern energy sources while the majority of its population relies heavily on traditional biomass as primary energy source. Africa can accordingly be classified as an energy poor region–a situation which does not bode well for the promotion of sustainable development. Access to reliable, affordable, economically viable, socially acceptable and environmentally sound energy services and resources is fundamental to socio-economic development. Mitigating the impacts of energy poverty and more specifically lack of access to modern energy sources on the sustainable development of Africa depends upon ensuring increased access to modern energy sources. The above-mentioned instruments furthermore contain provisions which link regional cooperation on the formulation of coordinated regional law and policy on areas/matters of common concern with the achievement of the objective of promoting sustainable development in Africa. One of the areas of common concerns listed is that of energy. Regional cooperation must accordingly be geared towards the effective development of the continent‘s energy and natural resources; promoting the development of new and renewable energy in the framework of the policy of diversification of sources of energy; and establishing an adequate mechanism of concerted action and coordination for the collective solution of the energy development problems within the AU. The formulation of coordinated energy law and policy should take place with reference to the specific sources of energy to be regulated. In this regard, the provisions of the Abuja Treaty and other sub-regional energy access initiatives list various sources of energy as forming part of a diversified AU energy mix – one of which is nuclear energy. In this study recommendations are made as to what should be embodied in a coordinated AU regional nuclear legal framework aimed at regulating increased access to nuclear energy capable of contributing towards the promotion of sustainable development. The recommendations are based on an examination of relevant international, regional and sub-regional legal instruments and other initiatives. / PhD (Law), North-West University, Potchefstroom Campus, 2014
269

Nuclear energy in Africa : a legal framework for sustainable energy access / Michelle Barnard

Barnard, Michelle January 2014 (has links)
The promotion of sustainable development is an objective shared by African Union (AU) member states and the pursuance thereof is expressly mandated by the Constitutive Act of the African Union, 2000 and the Treaty Establishing the African Economic Community, 1992. Lack of access to modern energy sources, such as electricity and the heavy reliance on traditional biomass as primary energy source are factors contributing to the non-achievement of the promotion of sustainable development. These factors are collectively referred to as energy poverty. The African Continent as a whole has limited, and in some instances, lack access to modern energy sources while the majority of its population relies heavily on traditional biomass as primary energy source. Africa can accordingly be classified as an energy poor region–a situation which does not bode well for the promotion of sustainable development. Access to reliable, affordable, economically viable, socially acceptable and environmentally sound energy services and resources is fundamental to socio-economic development. Mitigating the impacts of energy poverty and more specifically lack of access to modern energy sources on the sustainable development of Africa depends upon ensuring increased access to modern energy sources. The above-mentioned instruments furthermore contain provisions which link regional cooperation on the formulation of coordinated regional law and policy on areas/matters of common concern with the achievement of the objective of promoting sustainable development in Africa. One of the areas of common concerns listed is that of energy. Regional cooperation must accordingly be geared towards the effective development of the continent‘s energy and natural resources; promoting the development of new and renewable energy in the framework of the policy of diversification of sources of energy; and establishing an adequate mechanism of concerted action and coordination for the collective solution of the energy development problems within the AU. The formulation of coordinated energy law and policy should take place with reference to the specific sources of energy to be regulated. In this regard, the provisions of the Abuja Treaty and other sub-regional energy access initiatives list various sources of energy as forming part of a diversified AU energy mix – one of which is nuclear energy. In this study recommendations are made as to what should be embodied in a coordinated AU regional nuclear legal framework aimed at regulating increased access to nuclear energy capable of contributing towards the promotion of sustainable development. The recommendations are based on an examination of relevant international, regional and sub-regional legal instruments and other initiatives. / PhD (Law), North-West University, Potchefstroom Campus, 2014
270

Srovnání rurálních a urbánních oblastí v Jihočeském regionu podle využití podpory EU pro alternativní zdroje energie / Confrotation of an alternative energy in rural and urban teritorry in south bohemia region

GLASER, Tomáš January 2011 (has links)
This diploma work refers to the subject the Confrotation of an alternative energy in rural and urban teritorry in south bohemia region and the real potential of EU support for the use of alternative sources of alternative energy. Comparing the situation in urban and rural population and the strategy of alternative energy sources.

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