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2540 Uppsatser om Hydroelectric power - Sida 1 av 170

Tidssynkroniserade mätningar i vattenkraftstationer

Vattenfall and Svenska Kraftnät perform start-up tests, where hydropower generators are used to power up the electrical grid in case of a blackout. To monitor the electrical grid, Phasor Measurement Units (PMU) are used. Each PMU is individually equipped with a GPS-receiver to precisely timestamp the data relative to the official time UTC. During the test, it is also of interest to timestamp the measurement signals from individual hydropower generators to later compare with PMU-data, and thus study the power grids impact on the generator. The aim is to work out an appropriate method to make these measurements and to build a data acquisition system, capable of timestamp data relative to UTC, from a generator in one of Vattenfalls Hydroelectric power stations. The problem is that the generator is located in an underground station which hampers the reception of GPS-signals and wiring should be avoided if possible. Time synchronization has been solved by using Vattenfalls network, which is synchronized by the network protocol NTP.

Hot och risker med dricksvattenförsörjning : Förutsättningari tid och rum för bevarande av Sundsvalls och Timrås dricksvattenförsörjning

This study describes what impact activity within Wifstas, Matfors,Grönstas and Nolbys water protection areas have on the quality of the drinkingwater. It considers the use of the area, environmentally dangerous activitiesin the past and present, the geology?s part, what harm Hydroelectric power damsmay cause if they break and how climate change might affect the area in thefuture. It also takes into consideration activities outside the waterprotection areas which might have a suspected impact on the water quality. Theresults of the study are that pollution from infrastructure such as roads, orwastewater from treatment plants may cause occasional contamination of thedrinking water, foremost due to flooding.

Vattenflödets betydelse för fångster av lekvandrande lax (Salmo salar) och öring (Salmo trutta) : En utvärdering av laxfällan vid vattenkraftverket i Forshaga

Many watersheds have lost stocks of migrating fish species because of the development of hydroelectric plants and other fragmenting barriers. The remaining stocks of migrating Atlantic salmon (Salmo salar) and brown trout (Salmo trutta) in River Klarälven, Sweden are five times smaller compared to one hundred years ago. A fish-trap at the hydroelectric plant in Forshaga has been vital for the continued existence of the stocks. This is the first hydroelectric plant of eight, blocking the way to the spawning grounds. Spawners are collected in the trap for both hatchery and transport by truck upstream and past seven more hydroelectric plants to the spawning grounds, where they are released for possible natural reproduction.

Den urbaniserade Umeälven : Vattenkraftverken som utsträckt urbanisering

This paper examines the power producing dams along the Ume-river as an integral part of and a result from the urbanization process in Sweden during industrial capitalism. The aim of the paper is to contribute to the knowledge of the urbanization process in Sweden in general and of its traces along the Ume river in the county of Västerbotten in particular. The paper applies the theory of concentrated urbanization and extended urbanization put forward by Neil Brenner and Christian Schmid (2015) and argues that the building of power producing dams along the Ume-river is part of an extended urbanization process. This becomes particularly evident when examining the vast physical structures that is the dams, situated in an otherwise remote and sparsely populated area. These vast physical structures are also very well connected to a nation wide electric grid that has connections to bordering countries as well.

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..

Reglering av turbins ledskenor i vattenkraftverkmed hjälp av elektriska ställdon

Hydropower is the largest renewable energy source available in today's society. Operation and production is handled by high-tech electronics. This thesis is done on behalf of Statkraft Sweden AB who wants to explore the possibility of replacing the hydraulic cylinder with an electric actuator, generally as well as a case of a small power station on the river Nissan. Whether it is the chaplain or francis turbine vanes are actuated by hydraulic cylinders. Because of Gustavsberg hydropower is inconstant operation, this report is based on power calculations, which are read and computed according to the available hydraulic diagram.

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.

Småskalig vattenkraft vid Olofsfors bruksmuseum : Med faunapassage

In Sweden there are 1894 small-scale hydropower plants in operation, which together generate 4.3 TWh of electricity per year according to Swedish hydropower compound (SVKF, 2011). This corresponds to the annual consumption of about 860,000 Swedish households (based on an annual consumption of 5000 kWh). In the mid-1950s there were around 4000 small-scale hydropower plants in operation in Sweden before cheap fossil fuels and uranium competed with them, in the current situation only 1,894 of these are in use. If slumbering small hydropower plants once again would be taken into use and some new ones are built, we would be able to extract about 7 TWh of renewable electricity from these annually in Sweden, representing about 1.4 million households.The thesis intends to calculate and construct a Hydroelectric power plant at the existing dam in Olofsfors and give suggestions on how the power station should run during the time that fish migration is greatest in Leduån.The turbine and generator to the station in Leduån at Olofsfors is designed by the height of the fall and the water flow through the dam. The turbine selected for the station is a CK-1000RM turbine with a 4-pole 250 kW generator from Cargo & power turbine Sweden AB, which is expected to deliver 1.2 GWh per year.

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.

Analys och dimensionering av robusta kilspårsförband

This master thesis comprises analysis and dimensioning of a keyed joint between a generator axis and a hub with aid from the FEM-software ANSYS Workbench 13.0.The generator axis is a part of a Hydroelectric power station that generates electricity with a reactions turbine, a Kaplan turbine. The existing keyway consists of one parallel key with the width 90 mm and height 45 mm. Due to a planned increase of the power of the generated power with 32 % a design study was needed to see if the keyed joint would be suitable for the extra force. Because of the fact that the axis diameter is bigger than the standards covers/recommends a the keyway had to be re-dimensioned. In an earlier assignment from Skellefteå Kraft AB to Sweco Energuide the keyway was planned to be properly dimensioned, but no final solution was approved.During this master thesis a number of different numerical tests were made.

Undersökning av energiförbrukning och konceptutveckling av mer energisnåla frukostmaskiner

This master thesis comprises analysis and dimensioning of a keyed joint between a generator axis and a hub with aid from the FEM-software ANSYS Workbench 13.0.The generator axis is a part of a Hydroelectric power station that generates electricity with a reactions turbine, a Kaplan turbine. The existing keyway consists of one parallel key with the width 90 mm and height 45 mm. Due to a planned increase of the power of the generated power with 32 % a design study was needed to see if the keyed joint would be suitable for the extra force. Because of the fact that the axis diameter is bigger than the standards covers/recommends a the keyway had to be re-dimensioned. In an earlier assignment from Skellefteå Kraft AB to Sweco Energuide the keyway was planned to be properly dimensioned, but no final solution was approved.During this master thesis a number of different numerical tests were made.

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.

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.

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