Dissertationen: „Plan Grid“

1

Pavlovic, Dorian, und Steinbrenner John Nyberg. „Ledare utan plan : Uppgift- och relationsorienterat ledarskap inomrestaurangbranschen under coronapandemin“. Thesis, Högskolan i Skövde, Institutionen för handel och företagande, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:his:diva-20139.

Der volle Inhalt der Quelle

Annotation:

Studien handlar om att skapa förståelse kring huruvida restaurangchefer är i högre grad uppgifts- eller relationsorienterade i sitt ledarskap samt hur de hanterat corona pandemin. Studien har tagit utgångspunkt i insamling av empirisk data, för att vidare analysera materialet med hjälp av den teoretiska referensramen. Under den teoretiska referensramen har data samlats in kring de berörda ledarstilarna och hur de skiljer sig från varandra, samt hur en kris och krishantering kan se ut. Studiens empiriska avsnitt utgår ifrån en kvalitativ metod insamling där sju restaurangchefer intervjuades. Respondenterna och dess restauranger är belägna i Göteborg. Uppsatsens empiriska resultat stödjer teoretiska referensramen som implementeras i analysavsnittet.Författarna presenterar slutligen i slutsatsen att restaurangcheferna använder en kombination av uppgifts- och relationsorienterat ledarskap. Författarna kan dessutom fastslå att ingen chef utesluter den ena ledarskapsstilen. Studien visar tydliga samband där restaurangcheferna är antingen mer relations- eller uppgiftsorienterade i sitt ledarskap. I analysavsnittet visar det sig att restaurangcheferna hanterar krisen på olika sätt. De relationsorienterade restaurangcheferna var innovativa och arbetade med att skapa ytterligare intäkter, medans den uppgiftsorienterade ledaren effektiviserade organisationen och kapade kostnader. Ledarna har dock varit tydliga att ingen krisstrategi formats i förväg. Samtliga ledare har agerat reaktivt under den rådande pandemin då ingen liknande händelse inträffat dessförinnan.
The study is about creating an understanding of whether restaurant managers are more task- or relationship-oriented in their leadership and how they have handled the corona pandemic. The study is based on two parts, one of which is the collection of empirical data, the other from the theoretical frame of reference. During the theoretical frame of reference, data has been collected on the relevant leadership styles and how they differ from each other, as well as what a crisis and crisis management can look like. The empirical section of the study is based on a qualitative collection method where seven restaurant managers were interviewed. The respondents and their restaurants are located in Gothenburg. The empirical evidence of the thesis is supported in the theoretical frame of reference that is implemented in the analysis section.The authors presents in the conclusion that restaurant managers use a combination of task and relationship-oriented leadership. The authors can also state that no manager excludes a leadership style. The study shows clear connections where restaurant managers are either more relational or task-oriented in their leadership. In the analysis section, it turns out that the restaurant managers handle the crisis in different ways. The relationship-oriented restaurant managers were innovative and worked to create additional revenue, while the task-oriented leader streamlined the organization and reduced costs. However, the leaders have been clear that no crisis strategy has been formulated in advance. All leaders have acted reactively during the current pandemic because no similar event has occurred before.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

2

Prat, Joaquin, Alvaro Romero, Sandra Rodriguez und Julio Farje. „Optimization of the control process in residential buildings using technological tools“. Institute of Electrical and Electronics Engineers Inc, 2020. http://hdl.handle.net/10757/656567.

Der volle Inhalt der Quelle

Annotation:

Many construction companies worldwide continue to implement different methodologies to optimize time and improve management in the execution of works; however, a lack of control in projects continues to be observed. For this reason, one of the most common problems currently is the incompletion of scheduled work. Due to this, it is necessary to keep better control of the projects at the execution stage so that the contractor can optimally, quickly, and easily manage the progress of all the specialties involved. In this sense, this research develops the use of the Plan Grid Application for data collection in the field and the Power Bi software for the automatic processing and information visualization through a management dashboard where indicators are shown to reflect the progress and actual performance of the activities as well as the main non-compliance causes, which leads to optimize the control process and the time spent by its administrators to carry out this management.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

3

Isik, Ozgur Emre. „Theory And Practice: Socio-political And Philosophical Dynamics In The Evolution Of The Grid-plan In Ancient Greek Cities“. Master's thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/12609643/index.pdf.

Der volle Inhalt der Quelle

Annotation:

Social, political and philosophical dynamics which supposedly played an important role in the formation of the grid-plan in ancient Greek cities are explored in this thesis. In this respect, the thesis aims to expose the socio-political and philosophical matrix of Greek society in which the grid was implemented with an emphasis on the concepts of equality, rationality and geometric harmony. Having formulated a theoretical framework, it concentrates on several cases from different regions and contexts in the Mediterranean in order to confirm this framework. The thesis investigates the nature of the Greek grid-plan within three main parts
first the grid-plans of non-Greek cultures with which ancient Greeks had close contacts
second the relationship between the grid-plan and political power in Greek poleis with special attention to the formation of &
#8216
egalitarian&
#8217
ideals in society
third the physical expressions of the philosophical concepts of perfection, mathematical regularity and geometrical equality in the cosmos on urban pattern.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

4

Marusic, Tibor. „Ray Cast/Dose Superposition algorithm for proton grid therapy“. Thesis, Stockholms universitet, Medicinsk strålningsfysik (tills m KI), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-148174.

Der volle Inhalt der Quelle

Annotation:

Purpose: To develop a Ray Cast/Dose Superposition (RC/DS) algorithm for proton grid therapy. Its functionality needed to include automatic positioning of small proton pencil beams in a grid-pattern and superimposing thin beam Monte Carlo (MC) dose distribution data on a Computer Tomography (CT) density volume. The purpose was to calculate and store un-weighted volumetric dose distributions of individual proton energies for subsequent optimization. Materials & Methods: Using the programming language Python 3.6, CT and Volume Of Interest (VOI) data of various patients and phantoms were imported. The target VOI was projected to either two or four planes, corresponding to the number of used gantry positions. Rays were then traced through the CT voxels, which were converted from Hounseld Units to density using a look up table, to calculate Water Equivalent Distance and proton energy needed to reach the proximal and distal edge of the target volume. With automated grid-pattern beam positioning, thin beam MC calculated depth dose distribution files were interpolated, scaled and superimposed on the CT volume for all beamlet positions. The algorithm reliability was tested on several CT image sets, the proton range estimation compared to a commercial TPS and the depth dose interpolation analyzed using MC simulations. Results: The RC/DS algorithm computation time was on average around 6 hours and 30 minutes for each CT set. The dose distribution output visually conformed to target locations and maintained a grid pattern for all tested CT sets. It gave unwanted dose artifacts in situations when rays outside the beamlet center passed a significant length of low/high density regions compared to the center, which yielded dose distributions of unlikely shape. Interpolating MC dose distribution values showed comparability to true MC references of same energy, yielding results with 0.5% difference in relative range and dose. Conclusions: The developed algorithm provides unweighted dose distributions specific for small beam proton grid therapy and has been shown to work for various setups and CT data. Un-optimized code caused longer computation times then intended but was presumed faster than MC simulations of the same setup. Efficiency and accuracy improvements are planed for in future work.
Proton grid therapy group

APA, Harvard, Vancouver, ISO und andere Zitierweisen

5

Carlsson, Anna. „Grekiska städer, stadsplaner och bebyggelse : En jämförande studie över klassiska städer i norra Grekland“. Thesis, Uppsala universitet, Institutionen för arkeologi och antik historia, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-446915.

Der volle Inhalt der Quelle

Annotation:

This thesis is a study of four cities and their city-plans. The purpose of the paper is to understand similarities and differences between cities in northern Greece during the Classical period. This is done with a comparative method and Kevin Lynch’s theory of the image of the city. The method and the theory are the foundation for the study. The research question used to be able to fulfil the purpose of the paper is Which similarities and differences exist in the construction of Classical cities in northern Greece and why does these similarities and differences exist? The general plans of the chosen cities are studied, not individual buildings and remains. Aspects such as roads, the placement of city walls, agora, public buildings, and residential areas are compared in the paper. The four cities that were studied in the paper were Amphipolis, Olynthus, Pella, and Thasos. All located in Macedonia or on Chalcidice and Thasos. They were selected based on a few criteria. All were known cities from the Classical period, had been excavated to quite a large extent and were not only religious places or burial grounds. The cities are not exact copies of each other. Olynthus and Pella are built after the Hippodamian plan, but Amphipolis and Thasos are built over time with an organic city-plan. Buildings, structures, and central places are the same in the different cities but how the cities are structured and how buildings are placed vary. The terrain, the landscape, traditions, philosophical ideas could all be part of the cause why the four compared cities have been structured differently. The land the cities have been built on vary which affect how a city can be planned and built. The result of the thesis is that the cities in northern Greece have similarities in what types of buildings and structures can be found in them. How the city is structured and organized are the differences in the city-plans and to which degree depends on multiple factors.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

6

Wallin, Micah R. „China’s Wind Energy Development and Prediction“. The Ohio State University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=osu1275450139.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

7

Du, Plessis Louis Kemp. „Integrating non-dispatchable renewable energy into the South African grid : an energy balancing view / L.K. du Plessis“. Thesis, North-West University, 2013. http://hdl.handle.net/10394/9648.

Der volle Inhalt der Quelle

Annotation:

The integration of dispatchable renewable energies like biomass, geothermal and reservoir hydro technologies into an electrical network present no greater challenge than the integration of conventional power technologies for which are well understood by Eskom engineers. However, renewable energies that are based on resources that fluctuate throughout the day and from season to season, like wind and solar, introduce a number of challenges that Eskom engineers have not dealt with before. It is current practice for Eskom‟s generation to follow the load in order to balance the demand and supply. Through Eskom‟s load dispatching desk at National Control, generator outputs are adjusted on an hourly basis with balancing reserves making up only a small fraction of the total generation. Through the Integrated Resource Plan for Electricity of 2010, the Department of Energy has set some targets towards integrating renewable energy, including wind and solar generation, into the South African electricity market consequently introducing variability on the supply side. With demand that varies continually, maintaining a steady balance between supply and demand is already a challenging task. When the supply also becomes variable and less certain with the introduction of non-dispatchable renewable energy, the task becomes even more challenging. The aim of this research study is to determine whether the resources that previously helped to balance the variability in demand will still be adequate to balance variability in both demand and supply. The study will only concentrate on variable or non-dispatchable renewable energies as will be added to the South African electrical network according to the first two rounds of the Department of Energy‟s Renewable Energy Independent Power Producer Procurement Programme. This research study only looks into the balancing challenge and does not go into an analysis of voltage stability or network adequacy, both of which warrant in depth analysis.
Thesis (MIng (Development and Management Engineering))--North-West University, Potchefstroom Campus, 2013.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

8

Eygun, Kihlberg Adrian. „Trädsligheter - Hotell i Mariefred“. Thesis, KTH, Arkitektur, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-173749.

Der volle Inhalt der Quelle

Annotation:

Grundförutsättningarna för projektet var uppgiften att skapa ett mindre hotell i småstaden Mariefred som skulle relatera till staden på ett meningsfullt sätt. För att hantera hotelltypologins motstridiga behov av å ena sidan publika, livfulla ytor å andra sidan privata, lugna rum tog projektet inspiration av de rogivande träden på den i övrigt livfulla tomten som angavs i uppgiften. Hotellets olika rum, rumsgrupper och planlösning har därmed inspirerats av en trädanalogi. I projektet har även flödande rumssamband undersökts för att hantera verksamhetens stora behov av kommunikationsytor. I byggnaden har dessa försökts minimerats och planlösningen präglas istället av funktionsspecifika rumsgrupperingar ordnade efter förmodade flöden av gäster, personal och övrig logistik. Utrymme för flexibilitet i planlösning var även en del av processen med följden av stor variation av sammankopplade hotellrum eller möjlighet till extraprogram i bottenplan. En betydande utmaningen i processen var att låta trädanalogin vara en inspiration för meningsfull arkitektur utan att landa i det alltför pretentiösa. En annan stor utmaning var att få de flödande, flexibla rumssambanden till en funktionell planlösning och fortfarande ha möjlighet att utveckla projektet arkitektoniskt i övrigt.
The basis of the project was the assignment of creating a small hotel in the town of Mariefred that would relate to the town in a meaningful way. To handle the conflicting needs of the hotel typology consisting of - on the one hand public, vibrant parts and on the other hand private, quiet hotel rooms - the project took inspiration from the trees in the assigned site which gave peace to a relatively lively place. The hotel’s various rooms, group of rooms and the plan has thus been inspired by a tree analogy. The project also has examined a plan characterised of rooms and functions connected in a flow with minimised space solely dedicated for circulation. Groups of rooms with specific functions is organised according to presumed flows of guests, staff and other logistics. Flexibility in the plan was also part of the process with the result of a big variety of interconnected hotel rooms and the possibility of temporary additional programs on the ground floor. A significant challenge in the process was to let the tree analogy stay as an inspiration for meaningful architecture without being pretentious. Another big challenge was to get the flowing, flexible room relationships to a functional floor plan and still be able to develop the project architecturally otherwise.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

9

Moutinho, André Luiz Ribeiro. „Grid computacional utilizando a arquitetura universal plug and play“. Instituto Tecnológico de Aeronáutica, 2005. http://www.bd.bibl.ita.br/tde_busca/arquivo.php?codArquivo=201.

Der volle Inhalt der Quelle

Annotation:

Devido ao grande avanço no desenvolvimento de hardware e em tecnologias de redes de alta velocidade, além da necessidade de aplicações que demandam cada vez mais poder de processamento em contextos de uso colaborativos, surge a necessidade de aplicações que aproveitem ao máximo o que as novas tecnologias de hardware e rede têm a oferecer. É neste contexto o Grid Computacional emerge como uma tecnologia inovadora no sentido de permitir a criação de aplicações distribuídas envolvendo uma ampla gama de recursos. A demanda de pesquisa nesta área ainda é grande, principalmente em algumas áreas da computação distribuída como a disseminação e recuperação de dado e informações. Esse trabalho é focado nessa necessidade e propões a utilização de alguns protocolos do padrão da indústria Universal Plug and Play de conectividade entre dispositivos inteligentes para a implementação de Grid Computacional através de alguns cenários típicos de aplicações em Grid. Esses protocolos podem ser muito úteis na construção de serviços do middleware do grid computacional relativos à disseminação e recuperação de dados e informações.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

10

Felix, Isbi. „Dynamic analysis of the impact of grid connection of "La Higuera" hydropower plant to the transmission grid“. Thesis, KTH, Elektriska energisystem, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-118929.

Der volle Inhalt der Quelle

Annotation:

Studies regarding the development of a new hydropower plant exploiting the water resources offered by the upper Tinguiririca river, located about 150 km south-east of the capital Santiago in Chile, has been done by Pacific Hydro Ltd from Australia and Lahmeyer International from Germany. These studies have resulted in proposals to construct two Hydropower Stations, �La Higuera� and �Confluencia�. Both hydropower stations will have a total installed capacity of 300 MW. When setting up a new hydropower plant, it is important to foresee how the hydropower plant would affect the existing transmission grid in different situations during operation as well as how events in the grid may affect the La Higuera and/or Confluencia hydropower stations. In this report three kind of analysis are highlighted, which are static analysis, large signal stability and rotor angle stability. To perform these analyses a simulation tool named DigSilent is used. DigSilent is used to perform these analyses in a simulated network of the studied transmission system. These two hydropower stations as shown in the results will improve the existing transmission system by enhancing the stability margins in the presence of a fault. When performing the simulation of the existing transmission system with the newly installed hydropower plant we could see that it had a poor damping after a disturbance; this might be due to the large distance between production plants and the existing loads. This phenomenon can be alleviated if a power system stabilizer (PSS) is integrated in the hydropower plant. The final conclusion is that the integration of the two hydropower plants will improve the existing transmission system in Chile.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

11

Lundkvist, Johanna. „Feasibility study of a VirtualPower Plant for Ludvika“. Thesis, Uppsala universitet, Fasta tillståndets fysik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-201895.

Der volle Inhalt der Quelle

Annotation:

This thesis is a feasibility study of avirtual power plant (VPP) in centralSweden and part of a project withInnoEnergy Instinct and STRI. The VPPconsists of a wind park, small hydroplant as well as solar photovoltaic andenergy storage. The 50 kVsubtransmission network was modeled inorder to evaluate the network servicesthat could be provided by coordinatingexisting distributed energy resources inthe network. Simulations where performedusing measured hourly variations inproduction and consumption of allnetwork nodes. The studied networkservices included both reactive andactive power control.The aim of this thesis is to evaluatethe potential contribution from the VPPfor capacity firming in order to allow abalance responsible party to meet placedbids on the day-ahead spot market,minimize peak load in order to reducesubscribed power, decrease networklosses, the contribution from reactivepower control using the power convertersis studied. Comparisons of the economicgains from spot and balance markets ofthe VPP distributed energy resources aremade for each operation case.Sponsor: InnoEnergy
InnoEnergy Instinct

APA, Harvard, Vancouver, ISO und andere Zitierweisen

12

Havránek, Miroslav. „Větrná elektrárna grid-off, princip, účinnost, návratnost“. Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2013. http://www.nusl.cz/ntk/nusl-220157.

Der volle Inhalt der Quelle

Annotation:

This Master´s thesis deals with problematics of wind powered generators and their use in off-grid systems. In its first chapters aspects of wind as a power source are analyzed. Further on the thesis focuses on individual components of the off-grid systems. Also designing procedures of these systems are presented in the paper. The key parts of the thesis are 3 off-grid wind power system designs, which can be used to power a family house, and their energetical and economical evaluation.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

13

Cabala, Ľuboš. „Spolupráce mikro zdrojů v rámci malé smart grid“. Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2013. http://www.nusl.cz/ntk/nusl-220153.

Der volle Inhalt der Quelle

Annotation:

This thesis concerns with design of micro sources and their implementation in Micro grid system. In the first part the work is aimed at definition of smart - grid, where describes their advantages, disadvantages and necessary changes, which has to be made in current distribution network for implementation this system. Further on the thesis concerns with detailed description of Micro grid, configuration of this kind of network, the issues in implementation and possibilities to provide ancillary services. The work also describes marginally virtual power plants, presents definition, components and types of virtual power plants. The final chapter describes the creation of micro sources in System modeler and subsequent testing of consumption cover to operate in island mode.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

14

Wertheimer, Howard Seth. „The use of grid and geometry as tools for design“. Thesis, Georgia Institute of Technology, 1985. http://hdl.handle.net/1853/21605.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

15

Chang, Young Min. „Eulerian shape design sensitivity analysis and optimization for plane elasticity with fixed grid“. [Gainesville, Fla.] : University of Florida, 2004. http://purl.fcla.edu/fcla/etd/UFE0004040.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

16

Chennells, Michael. „A grid feedback incorporated economic power dispatch model for a cogeneration ferrochrome plant“. Diss., University of Pretoria, 2014. http://hdl.handle.net/2263/45901.

Der volle Inhalt der Quelle

Annotation:

An energy saving opportunity exists in mining and smelting industries such as the Ferrochrome industry, in the form of waste heat extraction and recovery. The mining and smelting of metals requires the use of high-power, AC or DC electric-arc furnaces that melt raw feed material in order to separate and produce useful metals from the feed. The smelting of raw materials into metals inside arc furnaces produces large quantities of hot gas as by-products, according to specific process-controlled chemical reactions. These hot gases combined with small feed dust particles thrown up from the feed process must be extracted from the smelting process and therefore from the furnaces themselves. The furnaces operate at internal temperatures around 1 500 oC and therefore the extracted hot material, referred to as the smelting process off-gas, is extracted at extremely high temperatures and thermal energy levels. The implementation of a bottoming cycle cogeneration system allows for the extraction and recovery of thermal energy from the furnace off-gases which can then be used to generate additional useful electrical energy via the heat exchanger and electrical energy generation components of the proposed cogeneration system. This additional energy improves the energy savings of the smelting process and the entire plant since thermal energy that was previously dissipated into the atmosphere and wasted is now used to generate additional and useful electricity. This additional electricity can either be used to power the furnace loads associated with the smelting of the raw materials into metals, thereby supplementing the utility grid electrical supply to the plant, or it can be fed back to or wheeled through the utility grid to be supplied to third party customers and consumers. This however creates a power dispatch and optimal power flow problem. The power dispatch and optimal power flow problem is solved and controlled through the implementation of an Economic Power Dispatch (EPD) model. The model considers the operating conditions of the furnaces in order to determine how much additional electrical energy can be generated from the available thermal energy, recovered from the smelting process via the proposed cogeneration system. The model then utilises information regarding all costs associated with the consumption and generation of electrical energy as a result of the smelting and heat recovery cogeneration system operation. With these considerations the model then determines the optimal manner in which to dispatch the cogeneration generated electrical energy between the furnace loads and the utility grid so as to achieve the maximum possible overall system associated energy savings. The model is implemented as a half-hourly cogeneration-generated optimal power dispatch schedule. The consideration of a bottoming cycle cogeneration system for heat recovery and additional electrical energy generation, and the development and implementation of an Economic Power Dispatch (EPD) model for the control of the dispatch of cogeneration generated power between the furnace loads and the utility grid, allow for considerable system associated energy savings. These savings are obtained due to the reduced net electrical energy required from the utility grid, and the financial incentives and rebates obtained due to the feed of electrical energy back to and through the utility grid to third party consumers.
Dissertation (MEng)--University of Pretoria, 2014.
tm2015
Electrical, Electronic and Computer Engineering
MEng
Unrestricted

APA, Harvard, Vancouver, ISO und andere Zitierweisen

17

Mejia, Guerra Maria Katherine. „Characterization of the Building Blocks of the Maize Gene Regulatory Grid“. The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1448452906.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

18

Huang, Yu Linlin. „A design visualization machine : an agile prototype for architectural plans on a finite grid“. Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/81655.

Der volle Inhalt der Quelle

Annotation:

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Architecture, 2013.
Cataloged from PDF version of thesis.
Includes bibliographical references (p. 64-65).
This thesis project proposes a rapid visualization machine that can produce agile prototypes of simple architectural plans on a finite grid system. While various visualization systems to demonstrate instantaneous three dimensional form generations have been implemented recently by automobile industries and artists, a small scale visualization machine for architectural planning purposes has not been tested. Through careful analysis of the minimalist architectural plans of Ludwig Mies van der Rohe and research into the schematic plans of Palladian villas, it was determined that 1) fundamental structural components are the column and the wall, and 2) simple architectural plans can be well represented by a finite grid system on which those components are laid out. The proposed system is composed of repeatable, independent modular pieces; each houses one column unit and two wall units that can be extruded or restructured depending on the designs of the user. Those components are driven by servo motors which translate into agile movements to instantly reflect any change of layout a designer draws in the software. The current machine design with a 4 x 4 module grid can create a completely enclosed 3 x 3-grid plan and is able to visualize simple plans layouts. With the increased number of modules in the machine, a higher number of combinatorial plan schematics can be represented and more complex architectural plans can be visualized. The analysis of plans suggest a finite 12 x 12 module grid on the machine, or a 11 x 11-grid plan, is sufficient in the context of visualization for commonly practiced residential designs of architecture.
by Yu Linlin Huang.
S.B.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

19

Straka, Michal. „Využití fotovoltaických systémů v Off-grid aplikacích“. Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2012. http://www.nusl.cz/ntk/nusl-219396.

Der volle Inhalt der Quelle

Annotation:

This masters thesis deals with the use of off-grid photovoltaic systems. First we explain the problems associated with the power and energy potential of photovoltaic system components, design of photovoltaic systems for autonomous operation and the financial evaluation. The result of the masters thesis is to create an application used to design the island system in the whole output range (the smallest power systems to house systems application). The conclusion of the masters thesis is devoted to designing three type of projects from our application – a garden cottage, a family cottage and the house.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

20

Jack, Katherine G. „Residential Grid-Connected Photovoltaics Adoption in North Central Texas: Lessons from the Solarize Plano Project“. Thesis, University of North Texas, 2016. https://digital.library.unt.edu/ark:/67531/metadc862819/.

Der volle Inhalt der Quelle

Annotation:

Residential Grid-Connected Photovoltaics (GPV) systems hold remarkable promise in their potential to reduce energy use, air pollution, greenhouse gas emissions, and energy costs to consumers, while also providing grid efficiency and demand-side management benefits to utilities. Broader adoption of customer-sited GPV also has the potential to transform the traditional model of electricity generation and delivery. Interest and activity has grown in recent years to promote GPV in north central Texas. This study employs a mixed methods design to better understand the status of residential GPV adoption in the DFW area, and those factors influencing a homeowner's decision of whether or not to install a system. Basic metrics are summarized, including installation numbers, distribution and socio-demographic information for the case study city of Plano, the DFW region, Texas, and the United States. Qualitative interview methods are used to gain an in-depth understanding of the factors influencing adoption for the Solarize Plano case study participants; to evaluate the effectiveness of the Solarize Plano program; and to identify concepts that may be regionally relevant. Recommendations are presented for additional research that may advance GPV adoption in north central Texas.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

21

Knapp, Sandra V. „Does GRID Alternatives Impact Greenhouse Gas Emissions Reduction Targets in Central Coast Climate Action Plans?“ DigitalCommons@CalPoly, 2016. https://digitalcommons.calpoly.edu/theses/1613.

Der volle Inhalt der Quelle

Annotation:

As of March 2016, GRID Alternatives’ 179 solar electric system installations on low-income housing contributed 103 metric tons of carbon (MT CO2e) emissions reduction for the climate action plans’ Energy or Renewable Energy climate action measures that pertain to solar electric installations in the cities of: Arroyo Grande, Atascadero, Paso Robles, and San Luis Obispo and San Luis Obispo County. In 2007, the San Luis Obispo County Air Pollution Control District (APCD) created a team of government agencies to design climate action plans (CAP) that met the emission reduction goals set out by AB 32 and the 2008 Climate Change Scoping Plan (Rincon Consultants, 2014, p. 1-2). Each CAP outlines its greenhouse gas (GHG) baseline emissions and GHG emissions reduction targets in metric tons of carbon (MT CO2e) and identifies climate action measures to reach GHG emissions reduction targets. The climate action measure that pertains to Energy or Renewable Energy, specifically solar electric system installations, is examined in this study. GRID Alternatives, a non-profit solar installer that implements its Solar Affordable Housing Program, was selected by the California Public Utilities Commission (CPUC) in 2008, to serve as the statewide program manager for the California Solar Initiative’s $108 million incentive program called the Single-family Affordable Solar Homes (SASH) program, which is the country's first dedicated solar rebate program for low-income families (GRID, 2016a, p. 2). In 2010, GRID Alternatives opened its Central Coast office in Atascadero to serve five central coast counties and tracks CO2 emission reductions for each installation. My objective is to determine the impact that GRID Alternatives’ solar electric installations in the cities of Arroyo Grande, Atascadero, Paso Robles, and San Luis Obispo and in San Luis Obispo County have on their respective CAPs’ GHG emissions reduction targets for the Energy or Renewable Energy climate action measure that pertains to solar electric installations.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

22

Qwemesha, Mbuyisi. „The Relevance Of Load Following Capability Of Nuclear Power Plant For The South African Grid“. Master's thesis, Faculty of Engineering and the Built Environment, 2021. http://hdl.handle.net/11427/33000.

Der volle Inhalt der Quelle

Annotation:

The main focus of this study is to evaluate whether load following operation can be performed using the existing South African nuclear power plant. Of which, knowing that will assist in determining whether the addition of load following capabilities on the planned nuclear fleet is justifiable or not. In this report the relevance of Koeberg Nuclear Power Plant to adapt to the demand is examined and the effects on plant operation simulated. The report analyses the operation of the existing nuclear power plant (Koeberg units) in South Africa and describes the regulations that govern safe operation of the plant. The Koeberg plant is analyzed based on the current design i.e. operating as a baseload station. This allows a prediction of the Koeberg plant response to big load variations. The simulation results of the load variation are analyzed and the results used to make the conclusion that the Koeberg units are not capable of load following safely. Modifying the Koeberg units from being base load station to load following will require changing the Safety Analysis Report and therefore affect the Koeberg license NIL-01.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

23

Draganescu, Mihai. „Study of supercritical coal-fired power plant dynamic responses and control for grid code compliance“. Thesis, University of Warwick, 2015. http://wrap.warwick.ac.uk/73963/.

Der volle Inhalt der Quelle

Annotation:

The thesis is concerned with the study of the dynamic responses of a supercritical coal-fired power plant via mathematical modelling and simulation. Supercritical technology leads to much more efficient energy conversion compared with subcritical power generation technology so it is considered to be a viable option from the economic and environmental aspects for replacement of aged thermal power plants in the United Kingdom. However there are concerns for the adoption of this technology as it is unclear whether the dynamic responses of supercritical power plants can meet the Great Britain Grid Code requirement in frequency responses and frequency control. To provide answers to the above concerns, the PhD research project is conducted with the following objectives: to study the dynamic responses of the power plant under different control modes in order to assess its compliance in providing the frequency control services specified by the Great Britain Grid Code; to evaluate and improve the performance of the existing control loops of the power plant simulator and in this regard a controller based on the Dynamic Matrix Control algorithm was designed to regulate the coal flow rate and another controller based on the Generalized Predictive Control algorithm was implemented to regulate the temperature of the superheated steam; to conduct an investigation regarding frequency control at the power plant level followed by an analysis of the frequency control requirements extracted from the Grid Codes of several European and non-European countries. The structure and operation of the supercritical power plant was intensively studied and presented. All the simulation tests presented in this thesis were carried out by the mean of a complex 600 megawatts power plant simulator developed in collaboration with Tsinghua University from Beijing, China. The study of the conducted simulation tests indicate that it is difficult for this type of power plant to comply with the frequency control requirements of the Great Britain Grid Code in its current control method. Therefore, it is essential to investigate more effective control strategies aiming at improving its dynamic responses. In the thesis, new Model Predictive Control power plant control strategies are developed and the performance of the control loops and consequently of the power plant are greatly improved through implementation of Model Predictive Control based controllers.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

24

Alrayes, Norah Mousa. „Approximation of p-modulus in the plane with discrete grids“. Diss., Kansas State University, 2018. http://hdl.handle.net/2097/38767.

Der volle Inhalt der Quelle

Annotation:

Doctor of Philosophy
Department of Mathematics
Pietro Poggi-Corradini
This thesis contains four chapters. In the first chapter, the theory of continuous p-modulus in the plane is introduced and the background p-modulus properties are provided. Modulus is a minimization problem that gives a measure of the richness of families of curves in the plane. As the main example, we compute the modulus of a 2-by-1 rectangle using complex analytic methods. We also introduce discrete modulus on a graph and its basic properties. We end the first chapter by providing the relationship between connecting modulus and harmonic functions. This is the fact that computing the modulus of the family of walks from a to b is equivalent to minimizing the energy over all potentials with boundary values 0 at a and 1 at b. In the second chapter, we are interested in the connection between the continuous and the discrete modulus. We study the behavior of side-to-side modulus under some grid refinements and find an upper bound for the discrete modulus using the concept of Fulkerson duality between paths and cuts. These calculations show that the refinement will lower the discrete modulus. Since connecting modulus can also be computed by minimizing the Dirichlet energy of potential functions, we recall an argument of Jacqueline Lelong-Ferrand, that shows how refining a square grid in a ``geometric'' fashion, naturally decreases the 2- the energy of a potential. This monotonicity can be used to prove the convergence between continuous and discrete modulus. We first review the linear theory of discrete holomorphicity and harmonicity as provided by Skopenkov and Werness. Instead of reviewing their work in full generality, we present the outline of their arguments in the special case of square grids. Then use these results to prove the convergence between the continuous and discrete case. We believe that our method of proof generalizes to the full case of quadrangular grids that Werness studies. In the third chapter, we show how to generalize all our proofs for 2-modulus to the case of quadrangular grids with some geometric conditions on the lengths of edges and the angles between them. In the last chapter, a connection with potentials when p is not 2 is discussed in the square grid case. We study the behavior of side-to-side p-modulus under the same refinements as before and we find upper bound for the p-modulus, but only when p > 2. The rest of the chapter is dedicated to generalizing the results from Chapter 2 to the case 2 < p.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

25

Wan, Ka-ho, und 溫家豪. „Transition finite elements for mesh refinement in plane and plate bending analyses“. Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2004. http://hub.hku.hk/bib/B29478546.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

26

Ro, Kyoungsoo. „Two-Loop Controller for Maximizing Performance of a Grid-Connected Photovoltaic-Fuel Cell Hybrid Power Plant“. Diss., Virginia Tech, 1997. http://hdl.handle.net/10919/30378.

Der volle Inhalt der Quelle

Annotation:

The study started with the requirement that a photovoltaic (PV) power source should be integrated with other supplementary power sources whether it operates in a stand-alone or grid-connected mode. First, fuel cells for a backup of varying PV power were compared in detail with batteries and were found to have more operational benefits. Next, maximizing performance of a grid-connected PV-fuel cell hybrid system by use of a two-loop controller was discussed. One loop is a neural network controller for maximum power point tracking, which extracts maximum available solar power from PV arrays under varying conditions of insolation, temperature, and system load. A real/reactive power controller (RRPC) is the other loop. The RRPC meets the system's requirement for real and reactive powers by controlling incoming fuel to fuel cell stacks as well as switching control signals to a power conditioning subsystem. The RRPC is able to achieve more versatile control of real/reactive powers than the conventional power sources since the hybrid power plant does not contain any rotating mass. Results of time-domain simulations prove not only effectiveness of the proposed computer models of the two-loop controller, but also their applicability for use in transient stability analysis of the hybrid power plant. Finally, environmental evaluation of the proposed hybrid plant was made in terms of plant's land requirement and lifetime CO2 emissions, and then compared with that of the conventional fossil-fuel power generating forms.
Ph. D.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

27

Žák, Jiří. „Studie blackoutu s ohledem na jadernou elektrárnu Dukovany“. Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2013. http://www.nusl.cz/ntk/nusl-220179.

Der volle Inhalt der Quelle

Annotation:

The entire diploma thesis analyses causes, consequences and repercussions of an electricity grid network blackout and its impact to the respective consumers. Remarkable blackouts recorded since 1965 are briefly described and basic available information is considered. The grid standard fixing measures and electricity delivery priorities are characterized. The thesis also pays attention to entire Czech Republic grid availability and its blackout endurance as well as to its robustness within last several years. Indirect Fukushima event influence to the Czech Republic electricity system is mentioned. The main part of the thesis comprises of four big European grid blackouts causes and consequences, their comparison to each other and to the Dukovany nuclear power plant grid blackout drill scenario. The preventive and standard corrective measures against blackouts are pointed out.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

28

Sanguinetti, Scheck Juan Ignacio. „Neural bases of navigation in foraging and play“. Doctoral thesis, Humboldt-Universität zu Berlin, 2019. http://dx.doi.org/10.18452/19974.

Der volle Inhalt der Quelle

Annotation:

Für die meisten Säugetiere ist Navigation eine essentielle kognitive Fähigkeit. Im Bereich der Neurowissenschaften gab es immense Fortschritte im Verständnis neuronaler Grundlagen von Navigation. Diese Dissertation beschäftigt sich mit der neuronalen Grundlage von Navigation im Hinblick auf Hirnstruktur (d.h. Parasubikulum) und ethologisch relevante Verhaltensweisen (d.h. Heimkehr und Spielverhalten). Im ersten Kapitel konzentriere ich mich auf das Verhältnis von Struktur und Funktion im Parasubikulum. Wir postulieren, dass das Parasubikulum durch seine selektive Vernetzung mit dem entorhinalen Kortex, durch seine starke interne Konnektivität, sowie wegen dem hohen Grad räumlich selektiver Aktivitätsmuster seiner Neurone im Bezug auf die Kontrolle von Gitterzellaktivität und räumlicher Navigation eine herausragende Stellung einnimmt. Im zweiten Kapitel untersuche ich die neuronale Grundlage von Heimkehr. Wir nutzen die starke Verbundenheit von Laborratten zu ihrem Zuhause. Wir zeigen, dass das Parasubikulum und der entorhinale Kortex keinen expliziten Heimvektor besitzen und dass die Präsenz des Zuhauses keine globale Veränderung der neuralen Repräsentation des Raums hervorruft. Allerdings führte die Präsenz des Zuhauses oder anderer geometrischer Objekte zu einer Verzerrung von Gitterzellen. Im dritten Kapitel unteruche ich Navigation im Hinblick auf Spielverhalten. Ratten erlernen das Versteckspiel schnell und verhalten sich erstaunlich regelkonform. Zeigen Ratten spielspezifische Vokalisationen. Gleichzeitige Ableitungen neuronaler Aktivität im medialen präfrontalen Kortex offenbarten starke und spezifische Antworten der meisten Nervenzellen auf verschiedene Phasen des Spiels des spezifischen Spielkontextes wiederspiegeln. Diese Arbeit liefert durch ihren ethologischen Ansatz und durch Verhaltensanalysen von sich frei verhaltenden Tieren einen wichtigen Beitrag zum besseren Verständnis neuronaler Grundlagen von Navigation im Säugetiergehirn.
Navigation is an essential cognitive skill in the life of most animals. Animals move along space to procure the advantages of different places in the environment, and to adapt to ever changing resources, dangers and needs. This thesis addresses the neural bases of navigation in the context of brain structure (i.e. the parasubiculum) and ethologically relevant behaviors (i.e. homing and playing). In the first chapter I focus on the structure function relation of the parasubiculum: an understudied area of the rat’s parahippocampal cortex. We performed the most comprehensive study of the parasubiculum up to date and propose that, because of its selective connectivity with the medial entorhinal cortex, its internal connectivity, and the high spatial and head directional tuning of its neurons, the parasubiculum sits in remarkable position to control grid cell activity and navigation. In the second chapter, I study the neural bases of homing. We use the lab-rat' s strong attachment to its home cage to study whether brains maintain an online home vector. We show, that the parasubiculum and medial entorhinal cortex do not have an explicit home vector representation, and that the presence of home did not affect global encoding of space. However, we do find that grid cells are distorted by the home or other geometrical features affecting the internal environment. In the third chapter, I study navigation in an interspecies role-playing game. We played 'Hide and Seek' with rats and found that they acquired the game easily and played by the rules. Rats were strategic and developed game specific vocalizations patterns. We recorded from the medial prefrontal cortex and found that neurons respond sharply to different phases of the game, and may encode as well the context in which this events take place. By emphasizing ethological approaches and free behaviors this thesis contributes to an increased understanding of the neural underpinnings of navigation in the mammalian brain.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

29

Daglish, Jonathan. „A Prefeasibility Analysis of a PV Mini Grid with Ice Plant on Buvu Island in Lake Victoria“. Thesis, KTH, Skolan för industriell teknik och management (ITM), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-264252.

Der volle Inhalt der Quelle

Annotation:

Improving energy access through the provision of sustainable electrification is fundamental to reducing poverty and facilitating development in many areas of rural Sub Saharan Africa. The region currently suffers from severe energy inequality, with 81% of people relying on traditional forms of biomass for direct energy provision. A major reason for this is that centralised grid infrastructure in many countries remains under maintained and grid extension to remote rural areas poses as too much of a financial burden to governments. Solar PV mini grids are gaining increasing attention from policy makers, researchers, and developers in the region as they pose as a means of leapfrogging the necessity for centralised fossil-fuel based infrastructures. Despite this, a high number of mini grid projects in SSA remain in their pilot stage. A major reasoning for this is the difficulty associated with accurately predicting the future electricity demand of currently un-electrified communities, and following on from that, it is also difficult to incentivize local economies once electricity is made available. The aim of this work was to assess the feasibility of Buvu Island on Ugandan Lake Victoria housing a PV mini grid and ice plant so as to provide power to its three un-electrified communities, and flaked ice to the local fishing industry. Structured interviews were first held with developers in the region so as to assess current weaknesses in mini grid design methodologies and following from that the literature was used to develop a suitable methodology. Data gathered in the field was used to predict the electricity demand of the island, and the HOMER optimization tool was used to size an appropriate system. The modelled system includes an AC-coupled PV array, a lead acid battery bank, a back-up generator, and a converter. Within Uganda, it is the role of the grid operator to provide capital investment for the distribution network. Accordingly, within this study, such a system has been proposed and costed, however this does not impact upon mini grid feasibility. A full financial analysis was used to as to assess the feasibility of the mini grid and ice plant project over a twenty year lifetime. A reference scenario returned promising results, with an IRR of 23.5%, DSCR of 529%, and NPV of $114,651 assuming that daily electricity demand is 695 kWh / day, and 2.5 tonnes of flaked ice are sold per day. The business model is highly dependent on the sale of ice and if average sales drop below under 1.6 tonnes per day over the project lifetime the system becomes unviable. To overcome the problems associated with unpredictability of demand and encouraged new uses of electricity, the mini grid in this work is scaled to match current demand on the island – thus mitigating such risks. Additionally, a sensitivity study is included so as to fully characterise the range of mini grid operative models that may need be considered, and indeed the likely financial outcomes.
Att förbättra energitillgången genom tillhandahållande av hållbar elektrifiering är grundläggande för att minska fattigdomen och underlätta utvecklingen i många områden i Afrika söder om Sahara. Regionen lider för närvarande av allvarlig energifattigdom, då hela 81% av befolkningen förlitar sig på traditionella former av biomassa för energiförsörjning. En viktig orsak till detta är att den centraliserade nätinfrastrukturen i många länder förblir dåligt underhållen och att nätutvidgning till avlägsna landsbygdsområden utgör en för stor kostnad. PV-mini-nät får ökad uppmärksamhet från beslutsfattare, forskare och utvecklare i regionen då de utgör ett sätt att minska beroendet av centraliserad, fossilbränslebaserad infrastruktur. Trots detta kvarstår ett stort antal mini-nätprojekt i Afrika fortfarande i uppstartsfasen. En anledning till detta är svårigheten i att förutsäga det framtida elbehovet för de för närvarande oelektrifierade samhällena. Syftet med detta arbete var att bedöma lönsamheten av ett PV mini-nät lokaliserat på Buvu Island i Victoriasjön, Uganda. Strukturerade intervjuer hölls först med utvecklare i regionen för att utvärdera de nuvarande svagheterna i designmetoderna för mini-nät. Därefter användes litteratur för att utveckla en lämplig metodik. Data som samlats in genom fältarbete användes för att förutsäga öns efterfrågan på el, och optimeringsverktyget HOMER användes för att anpassa ett lämpligt system. Det modellerade systemet inkluderar en AC-kopplad solpanel, en batteribank, en reservgenerator och en omvandlare. I Uganda är det nätoperatörens ansvar att tillhandahålla kapitalinvesteringar för distributionsnätet. Följaktligen, inom denna studie, har sådana system föreslagits och kostnadsförts. Detta påverkar dock inte lönsamheten av mini-nät på ön. En fullständig ekonomisk analys användes för att bedöma lönsamheten under en tjugoårsperiod. Ett referensscenario gav lovande resultat, med IRR på 23,5%, DSCR på 529% och NPV på $ 114 651 förutsatt att den dagliga efterfrågan på el är 695 kWh, och 2,5 ton is säljs per dag. Affärsmodellen är mycket beroende av försäljningen av is och om den genomsnittliga försäljningen sjunker under 1,6 ton per dag under projektets livslängd förlorar systemet sin lönsamhet. För att komma över problemen förknippade med oförutsägbarhet av efterfrågan och uppmuntra till ny användning av elektricitet, anpassas mini-nätet i detta arbete för att matcha den nuvarande efterfrågan på ön. Dessutom inkluderas en känslighetsanalys för att fullständigt karakterisera utbudet av de olika modeller av mini-nät som kan behöva övervägas.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

30

Mathur, Tushar. „STUDY OF SPECTRUM ALLOCATION SCHEMES IN GENERALIZED MULTI PROTOCOL LABEL SWITCHED CONTROL PLANE ENABLED FLEXI GRID NETWORKS“. Miami University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=miami1438339701.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

31

Casimir, Justin. „TECHNO-ECONOMIC ANALYSIS OF A PHOTOVOLTAIC POWER PLANT SUPPLYING ELECTRICITY FOR A LARGE SCALE REVERSE OSMOSIS DESALINATION UNIT IN AGADIR, MOROCCOJustin Casimir“. Thesis, Högskolan i Gävle, Akademin för teknik och miljö, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-14833.

Der volle Inhalt der Quelle

Annotation:

Legislation about the water use in Morocco including the watering of green spaces is about to change. Indeed, the watering of green spaces will have to be made from waste water treatment plant. This report focuses on a golf course located in Agadir which is subject to the new regulation. The option studied through this paper is the desalination of salt water powered by solar energy. This paper focuses specifically on the generation of solar energy. The aim of the report is to compare the levelized cost of water express in €/m3 for three different alternatives: A) water from the drinking water plant; B) water from a reverse osmosis desalination plant driven by electricity from the national grid; C) water from a reverse osmosis desalination plant driven mainly by solar energy and some electricity from the national grid.The paper will first present the boundary conditions for the case study (part I), the technical analysis (part II-A & B) and then the economic analysis (part II-C). Part III presents the results, based on the simulation results from the software PVsyst, for both the technical and economic analysis and part IV explains the technical part in more detail.In the conclusion, the writer of the report would recommend to another in depth economic analysis in few years as the capital cost for the system with the reverse osmosis desalination plant and the photovoltaic plant is at the moment too high. However, regarding at the levelized cost of water, this case study become competitive with the other alternative. Moreover, looking at the environmental issues (water depletion, greenhouse gas emission) one could decide to take action and therefore take some economic risks.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

32

Duncan, Corey Scott. „Techno-economical modeling of a PtG plant for operational optimization in the context of gas grid injection in France“. Thesis, KTH, Kemiteknik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-288978.

Der volle Inhalt der Quelle

Annotation:

Klimatförändringar är den enskilt största utmaningen som mänskligheten står inför under 2000-talet. För att ta itu med denna utmaning förutses förnybara energikällor en stor ökning av andelen primärenergi globalt. Den naturliga variabiliteten hos sol och vind kräver att energilagring används tillsammans med dem för en energisystemövergång. Power-to-Gas (PtG) -teknologier erbjuder en attraktiv lösning genom att möjliggöra omvandling av elektrisk energi till vätgas eller metan, vilket möjliggör integration över nätverk och sektorövergripande integration. Denna avhandling undersöker lönsamheten för en PtG-anläggning med enprimär applikation för att producera syntetisk metan (SNG) för injektion av naturgas(NG). En teknik-ekonomisk modell skapades för att simulera anläggningens drift under ett år och extrapolera resultaten för projektets livslängd. Modellen designades baserat på ett pilotprojekt som utvecklades i Frankrike med namnet HYCAUNAIS och har använt partner-samt litteraturdata för bearbetning. På grund av begränsningar i den lokala NG-nätkapaciteten undersöktes era scenarier som inkluderade att lägga till ytterligare investeringar som möjliggör ökad driftstid och intäktsströmmar, inklusive: fast elpris eller day-ahead (DA) marknadsdeltagande; nätuppgradering för ökad NG-nätkapacitet; och CH4 och H2 mobilitet. Elektrolysörers deltagande i frekvensbegränsningsreserven (FCR) ansågs också förökad lönsamhet. Resultaten visade att standardfallsscenariot (inga ytterligare investeringar) med deltagande på DA-elmarknaden var det mest attraktiva när det gäller tre undersökta mål: nettonuvärde (NPV), återbetalningsperiod (PBP) och nivåniserad metankostnad (LCOM). Driftstiden för standardfallet befanns vara cirka 90% av året; produktionen hindrades inte av begränsad nätkapacitet tillräckligt för att anse ytterligare investeringar nödvändiga. Vidare bör deltagande på DA-marknaden bestämmas av en upphörd betalningsvilja (WTP) för el i motsats till marginell vinst (MP). Att använda WTP som avgörande faktor tillät ökade driftstimmar och lägre LCOM. Men i alla undersökta scenarier var inga lönsamma; vilket innebär att marknadsförhållandena fortfarande måste förbättras kraftigt innan PtG kan få fart. En känslighetsanalys gjordes på standardfallsscenariot för att se vilka parametrar som påverkar lönsamheten mest och bör vara i fokus för vidare forskning och utveckling. SNG-taxan visade sig vara den mest inytelserika på NPV, vilket krävde att en tariff på minst 188 e=MWh (120 e=MWh användes för modellering) för att vara lönsam. Elpriset var det näst mest inytelserika och krävde ett genomsnittligt marknadspris på 25 e=MWh för att vara lönsamt. Eftersom PtG-teknik kan ge era externa fördelar som inte realiseras ekonomiskt av investerare, kan intäktsgenerering av dem ge ett sätt att förbättra lönsamheten. Detta inkluderar nätbalansering och exibilitet, avkolning, lägre nätkostnader ochförbättrad energisäkerhet. Sammanfattningsvis måste kapitalkostnaderna för utrustning,elpriser och avgifter i samband med dessa samt taxor för gröna gaser förbättras dramatiskt för att SNG-produktionen ska vara en attraktiv lösning för minskning och avkolning av el.
Climate change is the single largest challenge facing humanity in the 21st century. To tackle this challenge, renewable energies are seeing a large increase in primary energy share globally. The natural variableness of solar and wind requires energy storage to be used in conjuction with them for an energy system transition. Power-to-Gas (PtG) technologies offer an attractive solution by allowing conversion of electrical energy to hydrogen or methane, enabling cross-energy-network and cross-sectoral integration. This thesis investigates profitability of a PtG plant with a primary application of producing synthetic methane (SNG) for natural gas (NG) grid injection. A techno-economical model was created to simulate plant operation over one year and extrapolate the results for the project lifespan. The model was designed based off of a pilot project being developed in France named HYCAUNAIS and used partner as well as literature data for processing. Due to limitations inlocal NG grid capacity, several scenarios were investigated that included adding additional investments that allow increased operational time and revenue streams, including: fixed electrical price or day-ahead (DA) market participation; mesh upgrade for increased NG grid capacity; and CH4 and H2 mobility. Electrolyser participation in the frequency containment reserve (FCR) was also considered for increased profitability. The results determined the standard case scenario (no additional investments) with participation in the DA electricity market was the most attractive in terms of three objectives investigated: net present value (NPV), payback period (PBP) and levelized cost of methane (LCOM). The operational hours of the standard case was found to be approximately 90% of the year; production was not hindered by limited grid capacity sufficiently to deem additional investments necessary. Further, participation in the DA market should be determined by a cut-off willingness to pay (WTP) for electricity as opposed to marginal profit (MP). Using WTP as the determining factor allowed increased operational hours and lower LCOM. However, in all of the scenarios investigated, none were profitable; meaning that market conditions still need to greatly improve before PtG can gain momentum. A sensitivity analysis was done on the standard case scenario to see which parameters influence profitability the most and should be the focus of further research and development. The SNG tariff was found to be the most influential on NPV, requiring a tariff of at least 188 e=MWh (120 e=MWh was used for modeling) to be profitable. Electricity price was the second most inuential and required an average market price of 25 e=MWh to be profitable. As PtG technologies can provide several external benefits that are not economically realized by investors, monetization of them could provide a means of improving profitability. This includes, grid balancing and exibility, decarbonization, lower grid costs and improved energy security. Inconclusion, capital costs of equipment, electricity prices and fees associated to them, and tariffs for green gases all need to improve dramatically for SNG production tobe an attractive solution for electricity curtailment and decarbonization.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

33

Holmberg, Bårman Joakim. „Power to Gas : Background & techno-economic scenario analysis at Söderåsen Biogas plant“. Thesis, KTH, Energiteknik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-228060.

Der volle Inhalt der Quelle

Annotation:

Power to gas is an emerging energy storage technology with great versatility. This thesis investigates the economic prospects of investing in such a facility via a case study linked to the Söderåren biogas plant in southern Sweden.The basis for this study is cash flow scenario analysis based on revenues and costs, which are referred as scenario parameters. Each of these parameters have different options to choose from, with nominal values chosen as the most likely options for each scenario parameter. In current market condition it was observed that installing power to gas is not profitable. However after exploring numerous combinations of scenarios, it was found that the electrical grid fee charges and higher ancillary service income was critical to achieve a viable business case for power to gas. Another scenario achieved profitability with a small margin which occurred when the grid fee was removed, referred as “grid fee off”. Both the most likely scenario and grid fee off scenario included sensitivity analysis. This was used to observe the impact of net present value when changing one parameter at a time.
Power to gas/ El till gas är en teknik på frammarsch med mångsidiga egenskaper. Den här master uppsatsen ämnar att undersöka om power to gas är lönsamt att investera idag vid en anläggning i södra Sverige vid namn Söderåsen/Wrams biogasanläggning. Samt överskåda under vilka ekonomiska den skulle kunna bli lönsam. Resultaten kan extrapoleras till liknande biogasanläggningar med liknande ekonomiska förutsättningar.Grunden för denna studie är analys av kassaflödesscenarion baserat på intäkter och kostnader, vilket kommer att refereras till som scenarioparametrar. Var och en av dessa parametrar har olika alternativ att välja mellan, där en av dessa parametrar antas vara det mest troliga alternativet att hända verkligheten. I nuvarande marknadsförhållanden observerades det att installation av el till gas inte är lönsam. Däremot efter att ha undersökt en mängd olika scenario, tillsammans 90 stycken kombinationer av scenarier (mer finns i bilagan), visade det sig att nätavgiften var avgörande för att uppnå en bärkraftig affärssituation för el till gas. Ett alternativt scenario med slopad nätavgift illustreras därefter. Känslighetsanalys sker i det mest troliga scenariot och i det alternativa scenariot utav projektets nuvärde för belysa ändring av enskilda scenario parametrars inverkan på resultatet.En intressant men osäker ekonomisk möjlighet diskuteras kring möjligheterna att ersätta uppgraderingsenheten för konventionella biogasenheter helt och hållet. Det diskuteras hur vissa parametrar korrelerar samt ifall det går att ekonomiskt motivera an slopning av nätavgiften.Slutligen tas rekommendationer till framtida studier upp.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

34

Herrero, Sofia Helena. „Framing Hudson Square: A Stair Encloses a Converging Grid in the City“. Thesis, Virginia Tech, 2014. http://hdl.handle.net/10919/25287.

Der volle Inhalt der Quelle

Annotation:

This thesis explores an alternate typology for a residential high rise in the Hudson Square neighborhood in Manhattan. The units that make up the building are organized with stairs and corridors placed along the interior perimeter of the unit which both bound the central floor space and expose it, creating a layered vertical circulation space around a central, permeable core. The collective organization of units within the building recapitulate their interior organization to form the building object creating a whole that is governed by the same organizational rules as the parts. The building is created as an object in the city meant to frame the duality between transparency and reflection, between lines and surfaces and ultimately between exhibition and anonymity.
Master of Architecture

APA, Harvard, Vancouver, ISO und andere Zitierweisen

35

Leitman, Valentín. „Koncept nabíjecí stanice s možností off-grid provozu pro elektrokola“. Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2017. http://www.nusl.cz/ntk/nusl-319544.

Der volle Inhalt der Quelle

Annotation:

This thesis deals with charging stations for electric bicycles powered by renewable energy. The aim of this work is to make a proposal for the hybrid charging stations for electric bicycles, which will work independently and, if necessary, will be backed up by a network. In this thesis is entered theoretical information on the issue of electric bicycles, the batteries, charging stations, the connectors of chargers, and photovoltaic systems. The practical part of this thesis is the basic design of the charging station and its design of the mathematical model of the individual parts in Simulink program, which are linked to the actual design of the charging station. In conclusion, this thesis deals with energy and economic analysis of the proposed system, therein included various methods of assessing investment recommendations of appropriate processing methods and overall assessment of the subject.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

36

Olaleye, Akeem Kehinde. „Modelling and operational analysis of coal-fired supercritical power plant integrated with post-combustion carbon capture based on chemical absorption under UK grid requirement“. Thesis, University of Hull, 2015. http://hydra.hull.ac.uk/resources/hull:13227.

Der volle Inhalt der Quelle

Annotation:

Fossil-fuel fired power plants are subjected to stringent operational regime due to the influx of renewable resources and the CO2 emission reduction target. This study is aimed at modelling and analysis of supercritical coal-fired power plant (SCPP) integrated with post-combustion CO2 capture (PCC) and its response electricity grid demand constraints. Current status of dynamic modelling of SCPP integrated with PCC was reviewed to identify the gaps in knowledge. It was observed that no accurate dynamic model of an SCPP integrated with PCC had been reported in open literature. A steady state model of the SCPP integrated with PCC was developed with Aspen Plus®. The model was validated with the reference plant and it was found that the relative error is about 1.6%. The results of the conventional and advanced exergetic analysis showed that the energy/exergy consumption and the efficiency of the integrated system can be improved by recovering the avoidable exergy destruction in the whole system. Dynamic models of SCPP once-through boiler based on lumped parameter and distributed parameter approaches were compared. The distributed parameter model gave a more accurate prediction of the SCPP boiler dynamics at different load levels. Analysis of the strategies for operating the SCPP under the UK grid requirement as regards to primary frequency response was performed using the validated SCPP model. The results show that using turbine throttling approach, extraction stop or condensate stop individually was not sufficient to meet the grid requirement. A combination of turbine throttling, extraction stop and/or condensate stop can achieve a 10% increase in maximum continuous rating (MCR) of the power plant within 10 seconds to 30 seconds of primary frequency change as required by the UK grid. The dynamic model of SCPP was integrated with a validated and scaled-up model of PCC. Analysis of the strategies for operating the SCPP integrated with PCC under the UK grid requirement as regards to primary frequency response was undertaken. The results show that the stripper stop mechanism is not sufficient for the 10% MCR required for the primary response. The results show that the combination of stripper stop mechanism with extraction stop can meet the 10% MCR requirement for integrated plant operating at above 75% of its full capacity. The throttling and stripper stop configuration only barely meets the demand at full load capacity. The condensate stop combination with the stripper stop mechanism on the other hand could not meet the frequency response requirement at any load level.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

37

Kurzweg, Sabine Eva Maria Johanna. „Standardizing quarter degree grid data for plant species in the Western Central Bushveld for more explicit use in spatial models / Sabine Eva Maria Johanna Kurzweg“. Thesis, North-West University, 2011. http://hdl.handle.net/10394/9516.

Der volle Inhalt der Quelle

Annotation:

South Africa is a megadiverse country, and its biodiversity is endangered by population pressure and the development needs of a developing country. In order to address the rapid decline in biological diversity, biodiversity planning has become a key focus area that aims at identifying priority areas for species and ecosystem conservation within and outside of formally protected areas. Plant conservation hotspots are identified by the quantification of indicator taxa such as plant taxa richness, rarity and endemism. But the urgent and enormous task of biodiversity assessment for conservation planning requires that we make most of what we know. Therefore, this study seeks to make a contribution by finding new ways of biodiversity pattern estimation from the extrapolation of incomplete sets of plant species distribution data at the Quarter Degree Grid level. Incomplete sampling across the grids of a study area results in false records of species absence and thus a biased biodiversity estimation. As a possible solution, plant distribution data for the western Central Bushveld Bioregion has been standardized using two profiles, namely the ‘Centroid Grid’ and ‘Integrated Grid’ profile. The former involves the strengthening of under-sampled grids by extrapolating species occurrences from three adjacent grids with the most similar vegetation units, whereas the latter integrates phyto-diversity data for the four grids intersecting at each grid reference point. Standardized data has proved to provide a means to counter the bias in plant diversity data linked to Quarter Degree Grids by a) strengthening of under-sampled grids and b) visibly smoothing out the gaps between under- and well-sampled grids, which resulted in improved biodiversity estimation for more representative spatial biodiversity modelling. Interpolation created geo-referenced polygons for more explicit use in the identification of areas of conservation concern at bioregional scale. However, well-sampled grids still dominate the outcomes of the analysis by creating spatial sampling bias. Therefore, this approach to calibrate Quarter Degree Grid resolution of spatial data is an additional attempt to achieve more representative mapping of biodiversity patterns, which is a prerequisite for strategic conservation planning for ‘living landscapes’.
Thesis (MSc (Environmental Sciences))--North-West University, Potchefstroom Campus, 2012

APA, Harvard, Vancouver, ISO und andere Zitierweisen

38

Auerbach, Alex. „Keep Calm and Play On: The Effects of Grit, Mindfulness, and Goal Orientation on Sport Anxiety and Performance“. Thesis, University of North Texas, 2018. https://digital.library.unt.edu/ark:/67531/metadc1248529/.

Der volle Inhalt der Quelle

Annotation:

Achievement motivation theory suggests there are two primary approaches to achievement tasks: to appear competent or to develop a skill. These two different approaches to performance yield different affective and behavioral responses. Athletes holding a performance goal orientation tend to respond to challenges with behaviors exemplifying learned helplessness and increased anxiety. Athletes holding a mastery goal orientation tend to respond to challenges with greater effort and experience less sport-related anxiety. Individual athlete factors, such as grit, mindfulness, and achievement orientation may influence how athletes experience their environment and their levels of sport anxiety, and may interact with athletes' achievement motives to influence performance. I used hierarchical multiple regressions to test the main effects of feedback and mindfulness, and feedback and goal orientation, to determine if either mindfulness or goal orientation moderated the effects of feedback on performance. I also used simple regression to determine the relative predictive strength of mindfulness, grit, and goal orientation on athletes' experience of sport anxiety. Mindfulness, but not goal orientation, was a significant moderator of the feedback-shooting performance relationship, but particularly for athletes low in mindfulness; mastery-goal orientation, independently of feedback, was also a significant predictor of task performance. Mindfulness also emerged as the strongest predictor of reduced sport anxiety. These results suggest that, for athletes low in mindfulness, mastery-involving feedback may be especially helpful. Further, mindfulness may also reduce athlete's sport-related concentration disruption, worry, and somatic anxiety.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

39

Fradinho, Bastos Ivan. „Marketing Introduction Plan for the New Generation of Sustainable Circuit Breakers LTA 420 kV : A real-life case for implementation at Hitachi ABB Power Grids“. Thesis, KTH, Kemiteknik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-297294.

Der volle Inhalt der Quelle

Annotation:

En strömbrytare är en säkerhetsanordning som är utformad för att bryta strömmen om ett problem uppstår. Det finns ett flertal olika typer av brytare beroende vilket spänningsområde som avses. Brytare för lågspänning används för hushållsapparater, medan högspänningstyper används för överföring av spänning i elnätet. Högspänningsbrytare använder idag svavelhexafluorid (SF6)-gas, som ett isolerande medium för att släcka den elektriska ljusbåge som bildas när strömmen bryts. SF6 är dock problematiskt för miljön, då dess globala uppvärmningspotential (GWP) är 23 500 gånger högre jämfört med koldioxid (CO2). Företaget Hitachi ABB Power Grids har utvecklat AirPlus™-tekniken som ersätter SF6-gasen med en koldioxidbaserad gasblandning. Examensarbetet fokuserade på att utvärdera möjligheten att minska användningen av SF6 genom AirPlus™-tekniken och hur tekniken skulle kunna en introduceras på marknaden. Slutligen så utvecklades en strategi för hur detta skulle kunna ske. Studien innefattar den bakomliggande informationsinhämtningen och analysen av data, marknadsutvärdering och utvecklingen av marknadsstrategin. Detta utfördes genom att utvärdera AirPlus™-tekniken och dess konkurrenter, samt genom en kvalitativ och kvantitativ analys av implementeringen av LTA 420 kV-brytaren på marknaden. Sammanfattningsvis så visar studien att marknadsintroduktionen av strömbrytaren LTA 420 kV är genomförbar. Även om koldioxid tekniskt inte har samma prestanda som SF6, är tekniken fortfarande bra och ger starka kundfördelar: GWP minskar med över 99,9%, användningen överensstämmer med miljöregler, den ger lägre ägandekostnader, färre kontroller, lägre kostnad för hantering av koldioxidgasen, och fungerar väl vid extremt låga temperaturer. De viktigaste utmaningarna för Hitachi ABB Power Grids relaterar till konkurrensen på marknaden. Det är därför tillrådligt att företaget arbetar med en effektiv marknadsintroduktion för att säkerställa en stor marknadsandel.
A circuit breaker is a safety device designed to interrupt power if a problem is detected. There are several kinds of circuit breakers for different applications. Low-voltage circuit breakers are used for household appliances, while high-voltage types are used for transmission networks. High-voltage circuit breakers use sulfur hexafluoride (SF6) gas as an insulating medium, which extinguishes the electric arc that is formed when power is cut. However, it is a huge hazard for the environment, as its global warming potential (GWP) is 23,500 times higher than that of CO2 gas. The company Hitachi ABB Power Grids developed the AirPlus™ technology, which replaces the SF6 gas with a carbon dioxide (CO2) based gas mixture. The presented degree project has evaluated the feasibility of reducing the use of SF6 through the AirPlus™ technology and then developed a strategy for the company Hitachi ABB Power Grids for the market introduction of the eco-efficient LTA 420 kV circuit breaker. This study covers the background research, market evaluation, and market strategy. It was done through research about the AirPlus™ technology and its competitors, so as qualitative and quantitative analysis of the LTA 420 kV circuit breaker implementation in the market. In conclusion, the study shows that the market introduction of the LTA 420 kV circuit breaker is feasible. Although CO2 is not as good an insulation medium as SF6, it is still good and presents strong customer benefits: GWP reduced by over 99.9%, compliance with new regulations, lower cost of ownership, fewer regulatory controls, reduced cost of handling the gas, and well-functioning at extremely low temperatures. The main concerns for Hitachi ABB Power Grids are related to market competition. Thus, it is advisable that the company works on an effective market introduction to assure a large market share.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

40

Gaudray, Gordon. „A behavioral model of solar/diesel/Li-ion hybrid power systems for off-grid applications : Simulation over a lifetime of 10 years in constant use“. Thesis, KTH, Kraft- och värmeteknologi, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-160967.

Der volle Inhalt der Quelle

Annotation:

Remote hybrid power systems (RHPS) serve local off-grid loads or various island grids when no grid extension is possible. They combine renewable resources, conventional generators and energy storage systems in order to balance the load at any moment, while ensuring power quality and energy security similar to large centralized grids. Modelling such a complex system is crucial for carrying out proper simulations for predicting the system’s behavior and for optimal sizing of components. The model should include an estimation of the renewable resource availability over the period of the simulation, a prediction of the load consumption and time variation, the choice of technologies, a prior dimensioning approach, an energy dispatching strategy between the components and, finally, the behavioral model of all components. This study limits its scope to the simulation of a RHPS composed of solar PV panels, a diesel generator set, and a Li-ion battery bank supplying a dynamic isolated load with a daily demand variation between 10 kW and 80 kW. Methods for building load scenarii are explained first and then, rules of thumbs for selecting the technologies and pre-sizing the components are reviewed. Commonly used dispatching strategies are described before detailing the algorithm of a Matlab behavioral model for the system’s components with an emphasis on the proper prediction of performance and aging for the Li-ion battery model. Finally, a 10-year simulation is carried out over a case study and the results are analyzed.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

41

Dolinský, Filip. „Ostrovní systémy“. Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2018. http://www.nusl.cz/ntk/nusl-378496.

Der volle Inhalt der Quelle

Annotation:

Master thesis deals with usage issues of autonomous, self-sufficient and decentralized systems. In the first part convectional and experimental sources for autonomous systems are disclosed. Second chapter deals with accumulation of electrical and thermal energy and possibilities of applications. 3rd part is focused on pilot project realized for autonomous and smart systems, which were built in last years. In the 4th chapter electrical and thermal energy consumption curves are made on daily and monthly basis for 4 type objects. In the fifth part issue of autonomy is explained, and for type buildings solutions are made with additional return on investment. The last chapter is focused on calculation of thermal accumulator and briefly discloses small district heating.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

42

Bartel, Kyle. „Allocating Optimal Grid-Connected Solar Photovoltaic Power Plant Sites : GIS-Based Multi-Criteria Modeling of Solar PV Site Selection in the Southern Thompson-Okanagan Region, British Columbia, Canada“. Thesis, Högskolan i Gävle, Akademin för teknik och miljö, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-15859.

Der volle Inhalt der Quelle

Annotation:

Fossil fuels and non-renewable resources are being replaced with, as modern day society has coined the term, green energy. This movement towards green energy creates a demand for renewable energy resources, such as solar photovoltaic (PV) systems. This study used Geographic Information Systems (GIS) in conjunction with Remote Sensing (RS) practices and two weighting systems the Analytical Hierarchy Process (AHP) and Rank-Order methods for PV site selection. Six multi-criteria models were developed using spatial factors and constraining images to locate potential photovoltaic power plant sites for three settings of fixed axis PV arrays. This analysis was performed at a macro regional scale and further analysis is encouraged for micro site selection.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

43

Lenoir, Jean-Michel. „Temps de cohérence temporelle de structures turbulentes porteuses de scalaires passifs au sein d'une turbulence homogène quasi-isotrope“. Phd thesis, Université Claude Bernard - Lyon I, 2011. http://tel.archives-ouvertes.fr/tel-00819861.

Der volle Inhalt der Quelle

Annotation:

Le but principal du présent travail est ainsi de réaliser une expérience de mélange par la turbulence, dans laquelle il est possible de déterminer et de quantifier les temps de cohérence des différentes échelles spatiales des fluctuations du champ de vitesse et du champ de concentration qu'il transporte et mélange. La turbulence est ici voisine de la situation idéale statistiquement homogène et isotrope, et la configuration est conçue pour qu'il en soit de même pour le champ de concentration. La turbulence est créée par une grille placée perpendiculairement à un écoulement uniforme à l'extérieur des couches limites qui se développent le long des parois de la veine d'essais à section carrée constante. L'écoulement de la présente étude est un écoulement d'eau, dans lequel le champ de concentration est celui d'une solution de Rhodamine B injectée au niveau de la grille à travers des injecteurs équi-répartis le long des barreaux de celle-ci. Ce choix, dicté par la technique de mesure du champ de concentration par Fluorescence Induite par Laser, permet en outre de mesurer le champ de vitesse par une autre technique optique, elle aussi non-intrusive. Pour se rapprocher le plus de la théorie d'un mélange idéal statistiquement homogène et isotrope sans vitesse moyenne, on considère dans l'expérience, conformément à l'hypothèse de Taylor, que toutes les échelles associées à chacun de ces champs, sont convectés à la vitesse moyenne U de l'écoulement, et l'on suit une "boîte de turbulence" qui se déplace à cette vitesse le long de la veine. Par suite déterminer l'état de la turbulence en un point donné de cette boite à l'instant t et à l'instant t'=t+dt, revient à l'étudier dans l'expérience à t à l'abscisse x de la veine d'essai, et à t' à l'abscisse x+dx , avec dx=Udt, où se trouve le point de la boîte aux deux instants successifs. Les résultats expérimentaux concernant les échelles pour lesquelles l'isotropie statistique est satisfaite, permettent alors de vérifier une phénoménologie de l'évolution de la cohérence temporelle des diverses échelles spatiales du champ des fluctuations de concentration fondée sur les idées de Comte-Bellot et Corrsin. Cette expérience, est en outre l'occasion de donner des résultats sur les densités de probabilité de diverses propriétés statistiques des champs de fluctuation de vitesse.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

44

de, Groot Martijn. „Development of a Plug and Play Solution for Commercial Off-grid Solar Refrigeration : Presenting a Battery Supported System Providing the AC Power Required to run a Coolfinity 300L Commercial Refrigerator“. Thesis, KTH, Skolan för industriell teknik och management (ITM), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-302991.

Der volle Inhalt der Quelle

Annotation:

In this report the design and testing of a plug and play system to run Coolfinity’s Icevolt 300 refrigerator on solar panels is discussed. Such a system will be able to provide adequate cooling for food & beverages in area’s with unreliable or no electricity available. Currently such systems are only available for small chest refrigerators, while the Icevolt 300 is a large standing commercial refrigerator with a glass door. This is ideal for shops, cafés restaurants and smaller distribution centres. The system contains a solar charge controller, a battery and an inverter. First the component specifications and required solar panels are calculated. From those calculations system components are evaluated. A custom casing is designed to fit the components. An OEM is chosen and the chosen Inverter is tested extensively. The tests show that the inverter does not have any problems starting the Icevolt 300 compressor at a reduced voltage. Many battery manufacturers are evaluated and samples from three different manufacturers are obtained and tested. Samples of one of the manufacturers match specifications and have no issues with the high start up power of the compressor. A full system test proofs that the system works, but also indicates that the original refrigerator consumption estimate was too low. This means more PV panels are needed than originally estimated. With the information from the tests a new model is build that estimates the performance more accurate. A program is written to estimate the performance and decide the PV panels required. The pilot series of the case showed a lot of improvements are needed in the case design, especially on cost. A test is prepared in Mali but no test data is obtained yet. Based on the work done it would be recommend to investigate DC direct refrigerators instead of continuing the path of PV to AC systems.
I denna rapport diskuteras design och testning av ett plug and play - system för att köra Coolfinity’s Icevolt 300 -kylskåp på solpaneler. Ett sådant system kommer att kunna tillhandahålla tillräcklig kylning för mat och dryck i områden med opålitlig eller ingen tillgänglig el. För närvarande är sådana system endast tillgängliga för små kylboxar, medan Icevolt 300 är ett stort stående kommersiellt kylskåp med en glasdörr. Detta är idealiskt för butiker, kaféer och mindre distributionscentra. Systemet innehåller en laddningsregulator för solpaneler, ett batteri och en växelriktare. Först beräknas komponentspecifikationerna och nödvändiga solpaneler. Utifrån dessa beräkningar utvärderas systemkomponenter. Ett anpassat hölje är utformat för att passa komponenterna. En OEM väljs och den valda växelriktaren testas utförligt. Testerna visar att växelriktaren inte har några problem att starta Icevolt 300 -kompressorn med reducerad spänning. Många batteritillverkare utvärderas och prover från tre olika tillverkare erhålls och testas. Prover från en av tillverkarna matchar specifikationerna och har inga problem med kompressorns höga starteffekt. Ett fullständigt systemtest bevisar att systemet fungerar, men indikerar också att den ursprungliga uppskattningen av kylförbrukningen var för låg. Det betyder att fler PV -paneler behövs än vad som ursprungligen beräknades. Med informationen från testerna byggs en ny modell som uppskattar prestandan mer exakt. Ett program skrivs för att uppskatta prestanda och bestämma vilka PV -paneler som krävs. Pilotserien för höljet visade att många förbättringar behöver göras vad beträffar höljets design, särskilt vad gäller kostnaden. Ett test förbereds i Mali men inga testdata har erhållits ännu. Baserat på det utförda arbetet skulle det rekommenderas att undersöka direkta DC -kylskåp istället för att fortsätta vägen för PV till AC-system.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

45

Guo, Baoling. „Modélisation et commandes avancées de systèmes hydro-électriques à vitesse variable“. Thesis, Université Grenoble Alpes (ComUE), 2019. http://www.theses.fr/2019GREAT016.

Der volle Inhalt der Quelle

Annotation:

Cette thèse s'inscrit dans le cadre du projet Innov'hydro, qui regroupe cinq laboratoires de Grenoble INP conjoints avec le CNRS et l'Université Grenoble Alpes et vise à mener une étude sur l'ensemble constitué par la turbine et le générateur électrique. Dans ce cadre, cette thèse menée dans G2Elab est dédiée aux techniques de contrôle avancées pour convertir de manière efficace l’énergie hydraulique en énergie électrique.Lorsque la centrale hydroélectrique est connectée aux réseaux comme fournisseur, à savoir le «mode PQ», elle délivre la quantité exacte de puissance active et réactive en fonction de la demande réelle ou permet d'exploiter au maximum la ressource primaire disponible. Cette thèse se focalise sur le dernier cas: le convertisseur côté machine confirme la vitesse de rotation optimale pour atteindre la puissance maximale; le convertisseur côté réseau assure la tension constante du circuit intermédiaire et envoie une alimentation de bonne qualité au réseau. Une topologie conventionnelle basée sur un générateur synchrone à aimant permanent (PMSG) est implémentée. Elle est composée d'une turbine hydraulique, de PMSG, de convertisseurs de source de tension dos à dos avec PWM en interaction avec le réseau.Une centrale hydroélectrique à vitesse variable (VS-HEP) est un système non linéaire variant dans le temps, perturbé par diverses incertitudes. Ainsi, cette thèse est dédiée à l’amélioration de la robustesse du contrôle et de la capacité de rejet des perturbations. Les contributions de cette thèse sont les suivantes:1. Modèle hydraulique et application de PHIL• Un modèle hydraulique tridimensionnel à échelle réduite est établi de manière flexible pour diverses conditions de fonctionnement en laboratoire.• Le modèle dynamique de l'actionneur à aubes directrices est introduit afin de prendre en compte les effets de la dynamique induite sur l'ensemble des performances électriques.• Sur la base du benchmark PHIL en temps réel flexible du G2Elab, un banc d'essai hydraulique à vitesse variable est construit, en cours d'adaptation pour le modèle à échelle réduite proposé.2. Contrôle avancé de la robustesse élevée et de la capacité de rejet de perturbations• Un contrôleur de vitesse basé sur ADRC est proposé pour améliorer les performances de suivi de vitesse, permettant ainsi un fonctionnement MPPT efficace. Un observateur de couple est intégré pour atténuer les effets des variations de couple hydraulique.• Un contrôleur ESO est implémenté dans la boucle de contrôle DC-Link. Il atteint une plus grande robustesse et améliore la dynamique de contrôle. Et il est simple à concevoir et à employer pour des ingénieurs.3. Technique de synchronisation basée sur ESO• Un ESO-PLL amélioré est proposé. Les incertitudes internes et les perturbations externes dans le système PLL sont estimées via ESO et activement compensées par une dynamique en boucle fermée en temps réel, ce qui permet une grande robustesse dans la gestion des perturbations.• Un intégrateur généralisé (GI)-ESO est proposé pour les systèmes présentant des perturbations sinusoïdales à haute fréquence. Un intégrateur généralisé est introduit pour estimer la perturbation haute fréquence dans la conception.• Une PLL basée sur GI-ESO est proposée pour les utilitaires distordus. Les erreurs haute fréquence apparaissant dans la phase estimée peuvent être éliminées en utilisant le GI-ESO.4. Gestion optimale des centrales hydroélectriques à stockage pompé• Une approche de programme dynamique est utilisée pour gérer de manière optimale le temps de pompage et de génération d'un système hydroélectrique hybride à stockage par pompage.• Les bénéfices de tous les régimes de fonctionnement à vitesse variable et à vitesse fixe sont comparés.• Les bénéfices quotidiens augmentent par rapport au mode de fonctionnement normal. Parallèlement, les restrictions hydrauliques et la consommation d’eau peuvent être respectées
This PhD thesis is in the frame of project Innov'hydro, which involves five joint Grenoble INP laboratories with the CNRS and Grenoble Alpes and aims to review the assembly composed by the turbine and the electric generator. Within this frame, this thesis carried out in G2Elab, is dedicated to advanced control techniques for efficiently converting the hydraulic energy into electric power.When the hydro-electric plant is connected with the grids as a supplier, namely `PQ mode', it either delivers the exact amount of active and reactive power according to the actual demand or allows to exploit the maximum of the available primary resource. This thesis is targeting on the latter case: The machine-side converter confirms the optimal rotational speed to achieve the maximum power; the grid-side converter ensures the constant DC-link voltage, and to send the good quality power to the grid. A conventional variable-speed direct drive Permanent Magnet Synchronous Generator (PMSG)-based topology is implemented, it is composed of a hydraulic turbine, a PMSG, back-to-back voltage source converters with PWM interacting with the three-phase grid.A Variable-Speed Hydro-Electric Plant (VS-HEP) is a nonlinear time-varying system disturbed by various uncertainties. Thus, this thesis devotes more efforts to improving the control robustness and disturbance rejection ability. The contributions of this thesis are as follows:1. Hydraulic model and PHIL implementation• A reduced-scale hydraulic model is flexibly established for various laboratory operation conditions.• The dynamic model of guide vane actuator is introduced in order to take into account the effects of the induced dynamics on the whole electric performance.• Based on the flexible real-time PHIL benchmark in G2Elab, a variable speed hydraulic test rig is built, being adapted to the proposed reduced-scale model.2. Advanced control of high robustness and disturbance rejection ability• An ADRC-based speed controller is proposed to improve the speed tracking performance, thus enabling efficient MPPT operation. Besides, a torque observer is incorporated to mitigate the effects caused by hydraulic torque variations. Experimental results prove its advantages for VS-HEP application.• An enhanced ESO-based controller is implemented into DC-link control loop. It achieves higher robustness and improve control dynamics. And it is simple to design and employ for practical engineers.3. ESO-based synchronization technique• An enhanced ESO-PLL is proposed. The internal uncertainties and external disturbances in PLL system are estimated via ESO and actively compensated into closed-loop dynamics in real-time, which can achieve high robustness in dealing with disturbances.• A Generalized Integrator (GI)-ESO is proposed for system with high-frequency sinusoidal disturbances. A generalized integrator is introduced to estimate the high-frequency disturbance in the design.• A GI-ESO-based PLL is proposed for under power quality degradation issues (unbalanced voltage, harmonics, and voltage offset). The high-frequency errors appearing in the estimated phase can be eliminated by employing the GI-ESO.4. Optimal management of pumped-storage hydro-electric plant• A forward dynamic program approach is used to optimally manage the pumping and generating operation time for a hybrid pumped-storage hydro-electric system.• The profits for all operation regimes of variable speed operation and fixed speed are compared.• The daily profits increase compared with the normal operation mode, meanwhile, it can maintain the hydraulic restrictions and water consumption to local residents

APA, Harvard, Vancouver, ISO und andere Zitierweisen

46

Seménka, Petr. „Stavebně technologický projekt administrativní budovy firmy Ray Service, a.s. ve Starém Městě“. Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2020. http://www.nusl.cz/ntk/nusl-409943.

Der volle Inhalt der Quelle

Annotation:

The content of this thesis is a construction technology project of a new office and production building for company Ray Service a.s. in Staré Město near Uherské Hradiště. The thesis contains technical reports, construction technology study, design of transport ways, technological regulations of demolition and earthworks and regulations for construction of foundation structures. Furthermore is made design of the main machine assembly, inspection and test plan and the design of the construction site, including a technical report. Finally is made a project for the construction of area roads including time plan, LEED certification, noise study and comparison of the main lifting mechanisms.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

47

Santo, Luca. „AA-CAES physical modelling: integration of a 1D TES code and plant performance analysis“. Thesis, Uppsala universitet, Tillämpad kärnfysik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-360448.

Der volle Inhalt der Quelle

Annotation:

The focus of this thesis work was the development of an approachto couple a previosly existing Thermal Energy Storage (TES) modelwritten in C++ with a Simulink/Simscape plant model to simulate anAdvanced Adiabatic Compressed Air Energy Storage (AA-CAES) plant.After the creation and validation of such tool, the complete modelwas used to run simulations, with the aim of assessing the AA-CAESplant's performance under multiple patterns of charge anddischarge.Most of the works found in the literature only provide values ofstorage efficiency obtained from analytical approaches, whilethose that use simulation tools provide average values ofefficiencies when the plant is performing a series of identicalcycles of charge and discharge. During this thesis project,instead, simulations were performed for consecutive irregularcycles determined as the plant response to the electric grid powerrequest. The average efficiency values obtained provide thereforea better representation of how the plant would perform in realapplications.The results show that, under the assumptions made, the AA-CAESplant's overall storage efficiency is influenced very weakly byalterations of the charge-discharge patterns, and that goodperformances can be expected not only for identical chargedischargeconsucutive cycles, but for any pattern that observesthe cavern pressure limits, as long as the thermal energy storageis sized wisely.In addition, a sensitivity analysis was performed in order toassess the influence of turbomachinery efficiency on overallstorage efficiency, for a specified plant layout. The results showthat the turbine efficiency is the most affecting parameter to theplant's performance, while the impact of the main compressors'sinefficiency is mitigated by the thermal recovery that takes placein the TES.The present work confirms that AA-CAES is a promising technologyand that storage efficiencies above 70% can be achieved even inrealistic production scenarios.Finally, future steps for more accurate simulations of plants'performances and more detailed energy production scenarios areproposed.MSc ET 18007Examinator: Joakim WidénÄmnesgranskare: Ane HåkanssonHandledare:

APA, Harvard, Vancouver, ISO und andere Zitierweisen

48

Cerman, Marek. „Ekonomické aspekty využití energie z fotovoltaické elektrárny“. Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2013. http://www.nusl.cz/ntk/nusl-220175.

Der volle Inhalt der Quelle

Annotation:

The major topic of this master‘s thesis is to create a complex model of general photovoltaic power plant (PVP). First chapters are engaged in research of photovoltaic. Growth of globally installed power and analysis of situation in Czech Republic are described in this section. The spectrum of conditions is introduced, from current legislative framework up to local Sun radiation. The actual technologies and their advantages are depicted, especially rate of utilization of energy. Expected trends of future development of conversion efficiency are mentioned, with prediction of production costs of photovoltaic. In context with those aspects, the question of grid parity achievement arises. The own assembled model of photovoltaic power plant has been created in Microsoft Excel. The mathematical apparatus is described in a separate chapter, individually solving technical part, which main result – the amount of yearly generated electricity, is applied for economical calculation. Final results are the usual economic indicators, mainly: Net Present Value (NPV), Internal Rate of Return (IRR), Levelized Cost of Electricity (LCOE). There is series of aspects defined by user in the model which may impact the amount of produced electricity and economics of user’s project, such as use of loan, replacement of converters, operational costs etc. These aspects are frequently neglected by project sellers. In the end, intended photovoltaic power plants of 2.75 kWp and 28.98 kWp are simulated by the model in real conditions of 2013. Sensitivity of impact of both proposals to the aspects mentioned above has been analyzed. In the conclusion the achieved results are summarized and the key factors which determine the PVP’s economic efficiency are assessed.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

49

Prokop, Ondřej. „Analýza provozu uzlu sítě po připojení jaderného bloku velkého výkonu“. Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2016. http://www.nusl.cz/ntk/nusl-242013.

Der volle Inhalt der Quelle

Annotation:

The thesis deals with the analysis of the grid node operation after the connection the nuclear unit. The aim of the master´s thesis is to describe the influence of network´s faults to a nuclear unit. Thesis is dealing with three fundamental problems. An influence of short circuits and power imbalance on the synchronous generator of nuclear power plant and its operation of the island network. The thesis is focused especially on the nuclear unit. However, in the case of any failure in the network, it´s necessary to check other units and their protections in the test system because unit failure could cause the disintegration of the power network. For the purposes of the simulation a test system of the power network has been developed. The test system was optimized in the LUG software, which is used to calculate the power network. Transient simulations are performed in the MODES software. Single faults are configured with scenarios. Results are generated into output files. Analysis of influence network´s faults on the synchronous generator of nuclear power plants. The ability of the synchronous generator to restore the primary steady state or hold the new steady state during changes in operating parameters of the network is one of the important parts of the safe and reliable operation of the power network. During the short circuit the damped transient actions occur. With the extension of the short circuit duration, the amplitude of the transient action increases. The risk of the stability loss of a synchronous generator increases. Therefore, the critical clearing time of a short circuit is being defined, which is the time when there is not any loss of stability. Critical clearing time of research generator is sufficient to turn off the short circuit with the help of its protection (the worst case is 0,8 s). For example, by comparison with the hydroelectric power plant, the critical clearing time is much longer. Models of other power plants have been designed with high reliability so in the case of these faults, it doesn’t cause the disintegration of the power network. Creation of island grid is characterized by strong current surges. Units must be resistant to these surges. In the island grid fast changes of the electrical parameters often occurs. Therefore, units must respond to these changes as quickly as possible and in the broadest limits. For this purpose an island operation regulator is being used. In the case of surplus island grid in steam power plants a dump condenser can be used. This is an important ability of steam power plants because the units are able to react quickly to changes of electrical parameters in island grid. The main result of this thesis is the behavior of the nuclear power plant during various faults in the power network. Researched generator of the nuclear power plant is highly stable against faults in the power network based on the findings. The results allow to continue in this topic with real network and real unit of nuclear power plant.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

50

Sagnol, Loba. „Experimental and analytical study of the reinforcement of pavements by glass fibre grids“. Thesis, Strasbourg, 2017. http://www.theses.fr/2017STRAD042.

Der volle Inhalt der Quelle

Annotation:

Cette thèse traite de l’effet des grilles en fibre de verre, utilisées pour renforcer les structures routières, sur la liaison entre deux couches d’enrobés bitumineux, la durée de vie en fatigue et le module de rigidité des ´éprouvettes cylindriques renforcées, ainsi que sur les déflexions mesurées sur une section de route renforcée in situ. Des essais de cisaillement (LEUTNER) ainsi que de module et de fatigue (ITT) ont été conduit sur des éprouvettes renforcées et non renforcées en utilisant différentes grilles, différentes émulsion ainsi que différentes quantités d’émulsion. Pour ces essais, une surface de test a été construite in-situ, de laquelle les ´éprouvettes ont ´été extraites. Une section de route in-situ a ´également été construite, renforcée avec 3 différentes grilles et avec deux sections de références. Les déflexions de la chaussée ont été déterminées avant et après les travaux. Une modélisation de la structure a été faites basée sur les résultats des mesures de déflexion
This PhD-study evaluates the impact of glass fibre grids, used to reinforced asphalt structures, on the bonding between two asphalt layers, the fatigue life and the stiffness modulus of reinforced cylindrical specimens as well as on the deflections measured on a reinforced in-situ road section. Shear tests (LEUTNER) as well as modulus-tests and fatigue-tests (ITT) were conducted on reinforced and unreinforced specimens, using different grids, different emulsions and different emulsion quantities. For this tests, an outdoor test-surface was constructed, from which the specimens were extracted. A in-situ road test section was also constructed, reinforced with 3 different grids and having two reference sections. The deflections of the road were determined before and after the construction works. A modelisation of the structure, based on the deflection measurements, was made

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Dissertationen zum Thema „Plan Grid“

Geben Sie eine Quelle nach APA, MLA, Chicago, Harvard und anderen Zitierweisen an