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Power Supply System for Housis Using Renewable Resources
Gálus, Matej ; Punčochář, Josef (referee) ; Šebesta, Jiří (advisor)
The aim of this thesis is to describe the advantages of simultaneous utilization of photovoltaic and wind electricity in an autonomous system, supplying the household with electricity without connection to the electrical grid. The most used methods of connecting photovoltaic modules and wind generators to chemical batteries are discussed. Several maximum power point tracking methods and their properties are described. A block schematic diagram of an autonomous off-grid system utilizing chemical accumulators is proposed. The system also contains an inverter producing standard mains voltage 230 VAC to supply common household appliances. A Quasi-Square Wave converter topology was chosen for all three power converters. An experimental 180 W output power QSW converter with one controllable switch was designed, simulated with Pspice, manufactured and tested to verify the efficiency of the topology. Excellent agreement was found between predicted and measured efficiency at full output power. Efficiency for reliable operation varies between 89% and 92,2% at full power and depends mainly power inductor and MOSFET used. After successful evaluation of QSW topology, the power converters for the main system were designed. Because of higher power, the converters were designed as four-phase, whereas each phase contains two controllable switches to boost efficiency mainly in low-power area. The most critical and difficult part of the project was to design the mixed-signal control sections for the converters to ensure proper switching of two controllable MOSFETs in each phase. For user interactivity, main control board with graphic LC display, Ethernet module and SD memory card slot was also manufactured.
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Power Supply System for Housis Using Renewable Resources
Gálus, Matej ; Punčochář, Josef (referee) ; Šebesta, Jiří (advisor)
The aim of this thesis is to describe the advantages of simultaneous utilization of photovoltaic and wind electricity in an autonomous system, supplying the household with electricity without connection to the electrical grid. The most used methods of connecting photovoltaic modules and wind generators to chemical batteries are discussed. Several maximum power point tracking methods and their properties are described. A block schematic diagram of an autonomous off-grid system utilizing chemical accumulators is proposed. The system also contains an inverter producing standard mains voltage 230 VAC to supply common household appliances. A Quasi-Square Wave converter topology was chosen for all three power converters. An experimental 180 W output power QSW converter with one controllable switch was designed, simulated with Pspice, manufactured and tested to verify the efficiency of the topology. Excellent agreement was found between predicted and measured efficiency at full output power. Efficiency for reliable operation varies between 89% and 92,2% at full power and depends mainly power inductor and MOSFET used. After successful evaluation of QSW topology, the power converters for the main system were designed. Because of higher power, the converters were designed as four-phase, whereas each phase contains two controllable switches to boost efficiency mainly in low-power area. The most critical and difficult part of the project was to design the mixed-signal control sections for the converters to ensure proper switching of two controllable MOSFETs in each phase. For user interactivity, main control board with graphic LC display, Ethernet module and SD memory card slot was also manufactured.
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Impact of photovoltaic installation to the landscape
KOŘÍNKOVÁ, Zuzana
Initially, at the beginning of my bachelor thesis I am addressing renewable sources and especially I am concentrated on photovoltaic power plants. The boom market of phovoltaic power plants in Czech Republic was mainly during the year 2009 and 2010. The increased number of photovoltaic installations was caused by favourable purgase price of solar energy or green bonus guaranteed for 20 years. The goal of my bachelor thesis is analysis of enviromental impact of photovoltaic power plants on a landscape. The first part of my bachelor thesis is dedicated to description of types of renewable sources, law of the operation of photovoltaic power plants, photovoltaic energy and PV power plants, landscape and enviromental impact on it. The second part introduces description of 3 photovoltaic power plants situated at villages Čejč, Myslív and Kunštát which were all realised and all the information were provided by Ing. Roman Malivánek. In third part were processed results of questionnaire researches in which respondents were asked in a matter of photovoltaic installations and their impact on a landscape. The general assessment of questionnaire researches says that the solar energy is the most preferred, except of esthetic damage of a landscape, also the installations placed on agriculture fields. In general the photovoltaic energy is perceived as economical and practical source of renewable energy. The general opinion is that the photovoltaic installations should be limited on natural surfaces and expanded in settled locations, e.g. on the roofs of shopping centres, industrial halls, parking places, etc.
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