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11215 Uppsatser om Stand-alone power system - Sida 2 av 748
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.
Chalmers oanvända datorkraft - Distribuering av arbete och energihantering med HTCondor
Chalmers University of Technology today have numerous computers which are never powereddown, at the same time there is a need for more computation power for researchers.Hence, we have investigated the possibility to use the computers for computing power andsecondly, if there is no work to be done, to put them into power saving mode.We have made a thorough study where we compared different distributing systems andin the end HTCondor was chosen as the best to implement. HTCondor is an excellent systemfor opportunistic use of computing power, i.e. make use of computers that no one elseis currently using. The system is used at several universities around the world with goodresults and would be excellent at Chalmers, where there is a need for such a system.Our implementation shows that HTCondor is well capable of handling unused computingpower. HTCondor can handle most file types that may be run on the system.
Metoder för kartläggning och analys av nätförluster i lågspänningsnät
An important process for grid companies in order to reduce power losses in electricity distribution grids is to figure out where and how they appear. This report describes the factors that cause power losses in low voltage distribution grids and methods for how they could be measured and analyzed. Measurement data for consumed and injected energy were collected for twelve low voltage distribution grids owned by Gävle Energi AB in order to analyze the size of the power losses and how the measurement uncertainty affects the collected data. Then models of three of the grids were created in MATLAB in order to analyze the data and the power losses were calculated to be compared to the collected data. Curve fitting were also used as a method in order to analyze the power losses from collected data.The results show that the losses in the studied grids are low.
Power supply monitoring for wireless sensor platforms
Most of the portable electronic devices use a battery as a primary power source. Nowadays, when the applications are becoming smaller and smaller and more power efficient, the designer needs to concentrate more on reducing power consumption, using secondary power sources and introducing power storage devices. Multiple power source availability and a power storage device on the board will make the applications much more useful and efficient in everyday use. This thesis proposes a power supply unit (PSU) for wireless sensor platforms which is capable of supplying a sensor node with energy from multiple sources, as well as status information from the PSU. Present power storage devices, like electric double-layer capacitors (EDLCs) and batteries, have become more and more common as their characteristics have developed.
Validering av vattenkraftmodeller i ARISTO
This master thesis was made to validate hydropower models of a turbine governor,Kaplan turbine and a Francis turbine in the power system simulator ARISTO atSvenska Kraftnät. The validation was made in three steps. The first step was to makesure the models was implement correctly in the simulator. The second was tocompare the simulation results from the Kaplan turbine model to data from a realhydropower plant. The comparison was made to see how the models could generatesimulation result that was similar to the reference power station.
Molnet och dess möjligheter och utmaningar : En kvalitativ studie i hur molnet förändrar systemutvecklingsarbetet
As companies grow, their need for computing power will increase, which traditionally resulted in companies having to invest in more IT resources. Now, with cloud computing, companies can easily hire computer power over the Internet, on-demand. Cloud computing offers a highly scalable environment where companies can store data and host their services. This paper employs a qualitative study with interviews and literature studies to explore opportunities and challenges associated with cloud computing from a system developer perspective. The aim of the paper is to find out how cloud computing changes the conditions for system development. The paper contributes with four different opportunities and challenges that the system developer must handle to succeed in the world of cloud computing.
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.
Utveckling av ett användbart IT-stöd : för att stödja operativa arbetsrutiner
Nuclear power production carries potential risks both for the environment and for the work force. Different safety measures are employed and they stem from local rules as well as from regulatory authorities. This work describes the development of a safety promoting tool at Forsmark Power Plant, one of Sweden?s three Nuclear power plants. We describe the development of a computer based system for Pre-Job Briefing and Post-Job Debriefing.
Produktivitet och lönsamhet vid skörd av skogsbränsle i klen björkgallring :
The aim of the study was to compare productivity in first thinning of birch stands, when either energy- or pulpwood was harvested. The systems total profitability was also compared by including forwarding and chipping costs. A Gremo 950 HPVR harvester was used and the same driver was used under the entire study. During the pulpwood harvest a Logmax 4000b harvester head was used and a feller buncher head made by Silvatec was used during the energy wood harvest. Six study unit pairs were located in a birch dominated stand outside Ängelholm in Skåne.
Anstaltens ambivalenta funktion : En studie av den samtida kriminalvårdsdiskursen
Due to the attention of several escapes, rescue attempts and hostage situations from Swedish prisons during the year of 2004 a debate about correctional system and safety arose. It resulted in official reports and proposals to improve the safety of the institutions. The incidents of 2004 will most likely have an effect on the discourse of the correctional system. The purpose with this study is to analyse which discourses that today can be distinguished in the correctional system and thereby will be the foundation of the correctional systemof tomorrow. The method used to answer the purpose of the study is a Foucauldian based discourse analysis.
Modeller för studier av ursprungsmärkt el
The EU has decided that it should be possible for consumers to get information about the origin of the electricity they buy. Therefore, there is a need to examine different systems for electricity disclosure. In this thesis two ways of disclosure have been studied:? Certificate system. A certificate system involves two parallel markets, one for trading electrical energy and one for trading certificates of origin.? Separated Markets.
NATO:s luftkrig i Kosovo utifrån Wardens teorier
John A. Warden III is one the most mentioned air power theoretic of his time.He has written a number of theories concerning air power and the best way to use this to win wars.The author of this paper gives a short resume of what he consider are the central thoughts in John Warden´s theories. These thoughts result in four factors; Enemy as a system, centre of gravity, parallel attack/concentration and finally air superiority. These factors are then being used to inves-tigate if NATO used Wardens theories during the Kosovo war in 1999.The reason for the author to choose the Kosovo war specifically is due to the fact that NATO during the war only used air power as an instrument to get Serbia´s president Milosevic to the negotiation table but also the fact that this would turn out to be quite a challenge for NATO.The conclusion is that out of the four factors only one is traceable throughout the entire operation, and that is air superiority. Regarding the other three factors they can only be found in parts of the operation..
Enskilda skogsägares mål på avdelningsnivå ? en kvalitativ studie
Half of Sweden's productive forest land is owned by individual forest owners. Research studies show that forest owners have more objectives with their forest than a high net present value, and that the suggestions of the forest management plans doesn?t always correspond to
the forest owners? objectives.
Through a qualitative study we conducted a discussion about objectives at stand level with the aim of making a more specific formulation of the forest owners? objectives.
We asked about the forest owners' objectives at stand level, what forest management they conduct in order to achieve the objectives and how this management affects the net present value of the property. Based on the results of the interviews, we analyzed what kind of factors decide where the objectives place themselves in the landscape and if the objectives at stand level are consistent with the overall objectives for the property.
Many forest owners questioned the idea of talking about objectives at stand level, and they didn?t always have their objectives clearly defined.
En snäll tantroman gör ingen skada en kritisk studie om skyltning och makt
The purpose of our thesis is to take a closer look at what lies behind the display of fiction in public libraries. Through interviewing ten librarians and analysing their statements, it examines the mechanisms behind the displaying of books. The analysis was conducted through the application of two different theories, one by Aant Elzinga and one by Douglas Raber. Elzingas theory concerns methods of working, while Rabers theory concerns the purpose of public libraries and attitudes towards power. The following conclusions were drawn from analysing the statements.
Analys av skillnader mellan internationell och svensk rapportering av inträffade händelser på kärnkraftverk
Report of diploma work conducted at the Swedish Radiation Safety Authority (SSM) as part of the bachelors program in Nuclear Engineering at Uppsala University.All nuclear power plants in Sweden are obliged to report any deficiency in their barriers or the defense in depth in obedience to SSM?s regulations concerning safety in nuclear facilities. In addition, there is an international system for reporting such events. The purpose of this thesis is to study the Swedish report system and to analyze the differences between Swedish and international event reporting.In the Swedish system, SSM?s regulations are effectuated by means of event reports classified as category 1-3, designed individually at each Swedish facility.