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3700 Uppsatser om Urban wind power - Sida 12 av 247

Trafikverkets effektstyrningssystem - EFS 132 kV : Bidraget till minskade förluster

The technological legacy from the early electrification of the Swedish railroads has resulted in a power grid with a lower grid frequency than the national power grid from which it is fed. Energy transfer between these power grids with different frequencies requires substations, adapting the grid frequency for the rail road power grid. For this purpose, a feeding power grid has been built, stretching across the country from Boden in the north to Tälle/Häggvik in the south.Power transfer in the Swedish power grid results in voltage angle differences which increase with increasing loads and transfer distance. These voltage angle differences are transferred from the power feeding substations to the rail road power grid, will in some extent cause loss of energy due to unwanted power flows from north to south.To minimize the losses due to this phenomenon, a power management system called EFS 132 kV has been developed and implemented. The system minimizes the unwanted power flows and controls the desired power flow for a good distribution of loads between the power feeding substations.This thesis investigates the extent of the transmission losses avoided due to the EFS 132 kV that coordinates the idling angles to a common reference point.The results indicate that EFS 132 kV affects the power flow, especially between the northern substations through an improved load distribution.

Utredning av frekvensregleringens påverkan på mekanisk utrustning i en kaplanturbin

As a consequence of increasing wind power installations in the Nordic grid the last years, the need for regulating power has become larger. In the Nordic grid, regulating power is mainly provided by hydro power. One part of the regulating power is called frequency control, which ensures that the grid frequency is stable and close to 50 Hz.However, setting the turbine into frequency controlled operation may cause stress and wear of the components in the mechanical control system. Frequency controlling implies large and frequent servo forces and longer travelling distance of the sliding bearings in the Kaplan turbine.Based on one selected Kaplan turbine, Selsfors G1, measurements and MATLAB calculations have been performed in order to determine forces and movements of the linkage system. With these forces and movements as input, stresses and fatigue have been determined as well as sliding distances, bearing pressures and wear of bearings during a typical lifetime of 40 years.The results indicate that no severe wear exists on the bearings during 40 years of service.

Det självförsörjande passivhuset

The housing sector uses 40 % of the energy in Sweden and half of the electricity usage. Theuse of energy is the main reason to the increasing rate of carbon dioxide in the atmosphere.This is the main motive but also a wish of higher safety, that is a higher rate of selfsufficientenergy production in Sweden, we want to decrease the need of using fossil fuel. Now whenthe energy price rise, the interest in energy issues increase and more people discuss thepossibility of reducing the usage of fossil fuel. A change to renewable energy such as sun,wind and water is the only solution where we can get a sustainable development.One way to contribute to a better use of energy is to build in the principle of passive house.The house is being built with a thick and tight insulation. If you use a heat-exchanger withhigh degree of efficiency and a final heating battery on the ventilation system, the heat fromlamps, devices and the ones living in the house should be enough to fulfil the criteria ofliving.

Analys av designalternativ för snabbare dynamik i kolkraftverk med koldioxidavskiljning

Combustion of fossil fuels is today the dominating source of energy. During combustion,carbon dioxide is formed. The carbon dioxide accumulates in the atmosphere,which raises the global average temperature on earth through the so called greenhouseeffect. The only way to reduce the emissions of carbon dioxide from combustionin a coal fired power plant is through carbon capture and storage (CCS).Post-combustion capture is a technology to separate carbon dioxide from the uegas after the combustion for efficient transport and storage. The steady state operationof coal fired power plants with post combustion capture has already beenthoroughly investigated on a pilot scale, however much work remains to investigatethe plants dynamic operation.

Urban Building vid Hornsbruksgatan

Upgift: att bygga en urban byggnad i Högalidsparken vid Hornsbruksgatan.Idén att bygga i en park är provokativ pga ett starkt intrång i stadens publika liv. Stadsparker har inte endast rekreationsrollen, de är också publika platser: platser för motion, lek, idrott, föreställningar, möten osv. Och i detta projekt - för arbete och boende dessutom.Förslagets mål är att skapa en struktur som suddar bort ett kraftigt avbrott mellan parken och gatan och förenar dem och samtidigt har ett rikt programmatiskt innehåll; att skapa ett attraktivt och eftertraktat publikt rum på taken och ett flexibelt privat rum under det..

Optimering baserad på vinds tillgångar

yield optimization, wind energy, sustainability, maintenance..

Urban Pedagogik: rum för förhandling

En av huvudmålen med arbetet var att få ökad förståelse för hur medborgarnas makt och inflytande utvecklats historiskt inom stadsplanering. Jag var även intresserad av arkitektens roll i denna process. Jag ville som arkitekt, med stadsplanering som huvudfokus, hitta intressanta vägar att arbeta med medborgare och medborgargrupper och att förstå hur ett reellt lokalt inflytande kan ta form. Därför har jag försökt titta på relationer mellan medborgare, arkitekter, planerare, organisationer och kommun/stat. Jag drevs av en övertygelse att jag lättare kommer att finna argument för mina ?sociala ambitioner? som arkitekt om jag förstår de historiska processerna bakom medborgardeltagandet i både Sverige och ur ett internationellt perspektiv.

Kärnkraftens värde i framtiden : en jämförelse med kraftvärmeteknologi från biobränsle

The debate on the future of Nuclear power in Sweden has increased with the discussion on global warming. The uncertainty of fossil fuel- and carbonprices the latest years has aroused considerable interest in Nuclear from power companies, industry and politicians. Nuclear power plants have negligible CO2 emissions and are not directly affected by increased price of emission rights and fossil fuels. The future power production needs to reduce its emissions of greenhouse gases to become sustainable. The purpose of this study is to examine the value for power producers to have the option to invest in Nuclear power and how a Nuclear power venture would affect future electricity prices. The study uses two methods, a traditional cash flow model and real option analysis, to estimate the value of Nuclear power.

Experiment: Tillväxtvilja : En studie om varför småföretagare önskar tillväxt

This thesis treats the normative power of the European Union and its affect on Macedonia. The main purpose has been to look closer with the use of the application of Ian Manners theory of normative power on the Macedonian case. The focus will be to answer the following questions: Does the European Union act as a normative power in relation to Macedonia, if so, how are these values diffused? Has there been any effect of the spreading of these values? Based on six interviews and the available material of European Union strategies for the Macedonian membership I have attempted to understand to what extent the European Union?s normative power has had an influence in Macedonia. The result of my analysis is confirmation of the European Union as a normative power in Macedonia and the understanding of the methods of application..

Ryskt luftmaktsanvändande i Georgien 2008 ? ett fall av Warden?

The Russian-Georgian war of 2008 drastically changed Europe´s and Sweden´s political climate.Russiashowed that it is capable of successfully completing complex campaigns including ground, naval and air assets. However, not much has been said about the theoretical framework and doctrine of the Russian military of today. Even less has been researched about Russian use of air power and applied air theory. Are air power assets still considered primarily as support of ground offensives or has the theoretical framework changed?John A.

Centralitet och periferi i det nya Europa : Städer som regionala nav i samarbete och konkurrens

European cities of today are under the challenge to find ways to stay competitive and flourish in a rapidly changing world, where the old patterns of centrality and periphery not necessarily holds true. New and improved communication networks, a changed political geography in Europe, and the globalisation of not only the financial and industrial markets but also to a certain extent the globalisation of people, have all led to great challenges for cities and regions.In a changed spatial reality the classic monocentric models are challenged by newer models of urbanisation. The polycentric urban region is one such model which has been used to describe urban regions like the Randstad in the Netherlands and the Rhein-Ruhr region in Germany. Regions which lack the single dominant central city of the monocentric models of old, and instead shows a high degree of more equal-sized and sometimes more specialised cities in regional cooperation. The polycentric urban region is in that aspect a possible model for how other urbanised regions in Europe may act to be able to position themselves as attractive urban regions and regional hubs in the European urban network.Polycentric urban regions are not a universal solution, though.

Representativa testnät försvenska eldistributionsnät

This project was started within the Market-Design programme of Elforsk, with the aim of developing representative test systems of Swedish distribution networks. Using such test systems as a basis for reliability and customer interruption cost calculations makes it feasible to analyse the network tariff regulation of Swedish power  istribution companies. In particular, it enables studies of the incentives for companies to invest in system reliability. Until now, the available test systems are either not representative of Swedish conditions, or too small in scale and limited in function.Within this project we have created two test systems. In order to represent the diversity of actual Swedish distribution networks, we have created one test system for urban environments and another for rural environments.

EU som global politisk aktör - En utvärdering av Normative power Europe

What kind of international actor is the European Union and how shall we define it? These are questions that many have tried to answer often by addressing the apparent uniqueness of the EU itself. One of these theories is Normative power Europe. A theory whose main argument is that the EU is best perceived as a changer of norms. My aim with this thesis is to test this claim and to see if the Union should be regarded as a normative power.

Trapphuset

Projektet avser att undersöka hur en byggnad som ska möta en divers användning i urban miljö kan dela på resurser. Projektet avser att fungera som en tvärprogrammerad yta där olika användare växelverkar med sina aktiviteter över dygnets timmar likt ett stafettlopp där avlämningen blir en spännande kontaktyta. De kommersiella aktiviteterna över dagen ska samtidigt kunna fungera som allmän service på kvällstid. Kontaktytan för detta ska verka främjande för spontan social kontakt för både boende passerande och arbetande..

Tillgänglighetsstrategi för kommunala planerare : Ett arbetssätt för att identifiera och planera åtgärder av enkelt avhjälpta hinder

There are many barriers and obstacles that need to be removed to make the urban environment more accessible for people with disabilities. There are currently no adequate tools for urban planners to assess and address these obstacles. Geographical Information Systems (GIS) provide powerful methods for the visualization and analysis of spatial data, including the kind of data important in studies of accessibility. This study suggests a method urban planners can use to identify accessibility obstacles and to propose future actions to fix them.A literature review was conducted to find out what has been done and what is new regarding the accessibility issues. Different methods were evaluated which in turn led to the construction of a multi-step analytical strategy.

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