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2595 Uppsatser om Reactive power - Sida 2 av 173

Utvärdering av konsekvenserna för nätanslutning av vindkraftparker i Sverige vid införandet av nätkoden Requirements for Generators

Grid codes are becoming more demanding on power generating units due to the factthat the complexity of the power grid is increasing. The penetration of wind powerhas grown over the last years and it is clear that wind farms need to be addressedwith the same type of grid codes as conventional generation units. There is howeveran undeniable difference between the technology in conventional synchronousgeneration units, and the asynchronous generation units in wind farms.This thesis has reviewed the current grid code in Sweden and compared it to the newcode proposed by ENTSO-E, ?the Requirements for Generators?, in the aspect ofwind farms with an installed power of 30 MW or more. The comparison has beencomplemented by an analysis of how wind farms of two different technologies(Doubly fed induction generators and full power converters) can meet therequirements and technical proposals have been given on how to be able to meetcompliance with the new grid codes.The Requirements for Generators contains many non-exhaustive and optionalrequirements, because of this it has been difficult to, at this stage, exactly point outthe technical impact on the grid connection of future wind farms in Sweden.

Pengar, press & partiledare : En studie om porträtteringen av makt i svenska tidsskrifter

We have studied how power is portrayed in Swedish journals by analyzing eight portraits of Swedish persons with economic or political power. We have studied how they and their power are described by the journalist in text and picture. We wanted to see which picture the journalist shows of people with power, what properties they are given by the journalist and how this picture is shown by the texts and the pictures. We have also looked if there are any differences between people with political power and people with economic power. We have under our studies noticed that the persons with power are described as very successful and special and this picture are shown in a very clear and unproblematic way..

Acceptansgränsen för solceller i lågspänningsnät : Kan den ökas?

Microproduction, also called distributed generation, is something that has become more and more popular in the electric grid. Microproduction can however lead to unacceptable performance if several units are installed in the same low voltage network. It is therefore good to know a limit where the performance of the low voltage network becomes unacceptable based on given parameters. This limit is usually called hosting capacity.In this report the hosting capacity with respect to voltage and current have been studied in three low voltage networks which are located in Falu Elnäts concession area. This has been done by simulations in a GIS-program where critical times of the grid have been simulated.

Undersökande journalistik : En analys av Uppdrag gransknings dokumentär om IKEA

This essay is about power in the classroom. It is about the power dimension of the student-teacher relationships that arise in that space. The overall aim has been to investigate which categories are fruitful in a power analysis of these relationships. My aim has therefore been to develop power categories and to use them to identify and to categorise cases of power interaction that take place between those particular actors in that particular setting.In order to gather material for my study I have both read literature that approaches the study of the student-teacher relationships from a power perspective and done a series of observations in a high school.My theoretical frame comprises a concept of power and a series of power categories. These categories include strength, authority, inducement, coercion, violence, resistance as well as to possess power, to have power, to exert power, the scope of power and the base of power.

Scenarioanalys över Sveriges elproduktion år 2050 : Kan Sverige försörja sig med 100 % förnybar

The aim of this report was to investigate if Sweden can have 100 % renewable electricity production in the year 2050. The conclusion is that it is possible but under certain conditions. For instance wave power must be in commercial use. When wind power and solar power represent a large percentage of the electric production there will be a lack of electric power during the winter but during the summer there will be a surplus of electric power. Both the surplus and the lack of electric power need to be taken into account.

Jämförande simulering och modellering av framtida järnvägars elenergiförsörjning

In this thesis, the Train Power System Simulator (TPSS) has been compared and verified with the commercial simulator TracFeed® Simulation (TracFeed). The basis for the comparison was a given part of the Swedish railway system, with steel transportation trains. Primarily, emphasis was placed on running time and energy consumption in simulation results. Two transformer systems were analyzed, booster and auto transformers. The high voltage transmission line, parallel to the railroad track, was disconnected in some simulations.

Makt i klassrummet : En maktanalys av relationen mellan lärare och elev

This essay is about power in the classroom. It is about the power dimension of the student-teacher relationships that arise in that space. The overall aim has been to investigate which categories are fruitful in a power analysis of these relationships. My aim has therefore been to develop power categories and to use them to identify and to categorise cases of power interaction that take place between those particular actors in that particular setting.In order to gather material for my study I have both read literature that approaches the study of the student-teacher relationships from a power perspective and done a series of observations in a high school.My theoretical frame comprises a concept of power and a series of power categories. These categories include strength, authority, inducement, coercion, violence, resistance as well as to possess power, to have power, to exert power, the scope of power and the base of power.

Effekten av höghöjdsvistelse på anaerob arbetsförmåga

Syftet med denna studie var att undersöka om vistelse på hög höjd påverkar den anaeroba arbetsförmågan. Sex aktiva universitetsstudenter, fyra män och två kvinnor, deltog frivilligt i studien. Expeditionen till Nepal varade i 40 dagar och under den perioden sov och vandrade försökspersonerna mellan 1400 och 5100 meter över havet. Före och efter expeditionen genomförde försökspersonerna ett anaerobt wingatetest där peak power, average power, minimum power and power drop uppmättes. Resultatet visade en signifikant sänkning av average power efter den genomförda expeditionen på hög höjd, med ett medelvärde på 8.44 ± 0,84 w/kg före expeditionen och 7.81 ± 0,87 w/kg efter expeditionen.

Analys av spänningsstabilitetsberäkningar i det svenska elsystemet

Numerical simulations play a vital role in both static and dynamic stability assessment of electric power systems and the foreseeing of voltage collapse. Simulations performed by Svenska Kraftnät(SvK) are mainly done in the specialized voltage collapse predicting software tool, SPICA and the more all?purpose software tool, ARISTO.The grid operators at SvK use SPICA to predict the maximum transfer limit at specified sections (in this report the section in concerns is the southern part of Sweden i.e. interface1 4). SPICA is mainly used as an online application by using actual states from the grid, these states update every quarter of an hour.This thesis is a continuation of the master thesis SPICA ? ARISTO JÄMFÖRELSE by Jakob Katzman and Johan Fält.

Faktorer som påverkar vindkraftsutbyggnaden

Wind power is expanding rapidly in Sweden. Increasing amounts of wind power sets higher requirements on balancing power and grid expansions and would affect the whole Swedish electricity system. The aim of this report is to examine the factors affecting the wind power expansion in Sweden. How many wind power plants projects will obtain building permissions and what costs and revenues can be expected? How much balancing power will be required and does a changing geographical distribution of the wind power plants reduce the need of balancing power?A survey of the county board?s official applications has been made and out of all the applications, corresponding to 80 TWh produced per year, about half of the applications are expected to obtain a permit with a major portion of them located in the north of Sweden.Especially older wind power plants, deriving revenue from Nord pool, find themselves today in a complicated financial situation.

USA som hård, mjuk och smart makt -En studie av amerikansk utrikespolitik i mellanöstern

This essay is built upon the thoughts of Joseph S. Nye concerning power, and the different ways of exercising that power. The characteristics of Nye's theories are the thoughts about the second face of power, or what he describes as the soft power. The essay seeks to examine what kind of power the US has been in their work for non-proliferation and democracy promotion in the Middle East. It also seeks to find what it is that makes the US to choose to exercise the specific powers.

?Normative Military Power Europe?: a contradiction in terms? : En fallstudie av EU:s militära insats i Somalia i förhållande till Normative Power Europe.

This thesis paper is based on Ian Manners Normative Power Europe-theory with a focus on EU?s military operation in Somalia. By examining documents from EU institutions in the form of reports concerning EU NAVFOR ? Operation ATALANTA ? EUTM Somalia ? EUCAP NESTOR. This study shows that the Normative Power Europe-theory can get expressed and that the EU continues its normative statements in Somalia. This result is an interesting contribution to the theory of Normative Power Europe witch have gotten a lot of critic about how a military operation should effect and diminish the theory..

Maktavstånd och kommunikation - en studie av upplevda och verkliga kulturella skillnader och deras följder

Hofstede constructed a culture dimension called Power Distance, measuring the inequality of Power. Germany and Sweden have relatively similar values according to his world-renowned research. But a series of interviews of Swedish entrepreneurs in Germany shows that these perceive a large difference in inequality of power in the two countries. This essay seeks to explain the difference between these subjective-qualitative experiences and the objective-quantitative data of Hofstedes Power Distance Index. We propose that a combination of differences in communication, exercise and visibility of power and formality influence the way Power Distance is perceived.

Den som ger sig in i leken får leken tåla! : En studie om barns maktlekar

Our essay is about children's exercise of power, oppression or domination in games or when playing on school grounds with one and other. We thought it would be interesting to look into how children in preschool and up to the fifth grade use power acts respective power plays in leisure-time. During four days we visited two different after-school center and carried out observations of children during the school day and later inside the recreation centers during leisure activities. In order to analyze our empirical material in relation to power, we have used Magnus Hörnqvist (2012) interpretation of Michel Foucault's theory of power - Another Foucault. We have also used Åsa Bartholdsson (2008) thesis about The regular exercise of power regime ? about normality and power in school.

EU:s normativa närvarande i Makedonien : - en kvalitativ studie

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..

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