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236 Uppsatser om Hydropower stations - Sida 9 av 16
Utvärdering av fjädrande statorfötter : Nytt koncept i vattenkraftgeneratorer
This thesis is an evaluation of a new design concept for statorfeets in Gallejaur hydro power plant. Founder of the work is Vattenfall AB Vattenkraft. During the 70- and 80´s nuclear power began to be phased in to the Swedish grid, which meant that hydropower became an important source of rules. The generators began running in so called intermittent operations instead of basic operations, which meant 300-600 start/stop per year instead of one-ten numbers start/stop per year. In order to deal with the thermal forces that arise at every start and stop suppliers began to mount so called sliding joints, which is to take advantage of these forces and maintain the stator shape.
Mätning av axiella magnetiska läckflöden i vattenkraftsgeneratorer
This thesis describes a method of measuring axial magnetic leakage flux in an operational hydropower generator. Axial magnetic leakage flux is the magnetic flux at the ends of a rotating generator, which goes through the stator parallel to the rotor axis. This flux can cause circulating currents in the stator iron, giving rise to losses, and can in the worst case overheat a generator, causing it to melt down. To measure the axial flux, and how it affects the generator temperature, a measurement system was constructed on behalf of Vattenfall. The system consists of search coil sensors and a signal-processing unit with amplifiers and active filtering. To confirm the behaviour of the axial leakage flux and the functionality of the measurement system, a test installation was made.
Miljöbilar - ett steg närmare en bättre miljö
This report concentrates on why more people do not choose an environmentally friendly car instead of a conventional car. To find this answer we have used theories that include decision - behavior and environment - philosophy. We have also made four surveys, which includes several interviews. The results of these interviews, together with the secondary data we have found, have been analyzed against the theories made by our choice. We have found that the stimulus that we have today isn?t enough to make more people choose an environmentally friendly car instead of a conventional car.
Validering av glidande statorfötter på Hissmofors G6 och G7
Jämtkraft AB has recently modernized its hydropower station at Hissmofors by replacing four older worn out units with two new units. The generators uses a concept with sliding stator feet to deal with the thermal movements that occur in the stator during operation when the unit is operating intermittently. At other sites, this method revealed shortcomings in the reliability. This has made Jämtkraft AB feel uncertainty about its function and therefore want to investigate it during an early stage. The generators have a built-in monitoring system for the sliding stator feet and by using data from there the function of the sliding stator feet has been investigated. The study focused on how the different stator feet move relative to each other and how the eccentricity and deviation from roundness changed during operation. The results show that there are several indications that the function of the sliding stator feet is not satisfactory.
Har du tid att vänta
In today's society, more and more people traveling with transports such as trains and buses. With this type of travel it often exists waiting at stations that in many cases perceives as negative. Previous research demonstrates that distraction can get people to experience the waiting as less negative. This paper aims to examine how waiting can be affected by distraction, and if it is possible to use a second type of waiting as a distraction. The authors have chosen to focus on travelers who are waiting.
Digitala fotogrammetriska arbetsstationer för skoglig flygbildstolkning :
SCA Skog has taken the initiative to this Master?s thesis. Today SCA Skog has a great need to update their informtion on young forest stands across large areas. Traditional field inventory methods for updating stand databases are expensive and time consuming. However, the inventory could be made more efficient if stand boundaries and stand characteristics are derived from aerial photographs.
Polisens arbete med unga prostituerade : en kvalitativ studie om polisens syn på och arbete med unga prostituerade
Prostitution is a large and multifaceted subject. In this study, the purpose is to gain an insight into how the police officers work and act when they get in contact with young prostitutes. The study contains answers and opinions from five police officers which were conducted through semi-structured interviews in this qualitative study. The results were analysed based on a social constructive perspective and Goffman?s stigma theory.
En modell för att kostnadseffektivt öka produktionen inom aluminium-bearbetning
The purpose of this study is from a case study develop a model that aims to cost effectively improve productivity in a manufacturing production process. The study highlights the importance of having knowledge about customer needs and using a holistic process perspective when improving productivity to identify the relations between the process stations and by this find problems that cause waste and losses in productivity. Tools and methods used to make production more efficient such as single minute exchange of die, spaghetti diagram, 5s and master production schedule is presented an applied in the model to see how these effect costs, productivity etc.Maintenance effects on quality and productivity in a manufacturing company will as well be covered in this thesis. The results and conclusions finally reveals how the process improvement tools, maintenance and production planning for example effects each other and why it is important to establish an attitude in the company where continuous process improvement should be emphasized..
Ruttdetektering av tågtrafik
This master thesis investigates the possibilities of using GPS-information from trains to create a model of a railway system, register the routes of the the trains and predict how the trains will travel in the railway system.The thesis work was done at Icomera AB which is a company that specializes in internet connected vehicle solutions.We describe how the GPS-information is sent from the trains in the form of samples and investigate limitations and possibilities with the available information. About three million samples from 83 SJ-trains were analysed and the samples were filtered with the intent of removing erroneous information. We here found that about 30 % of the samples from the trains were unreliable.A solution for how the samples from the trains can be used to create a model of the railway system traveled by the trains is presented. We use a large set of historical samples and use cluster nodes and Hermite curves to generate a graph that represent the railway system with stations, nodes and the railway itself. A fully automatic solution is not presented since it did not fit into the time frame of the thesis; instead we created a simple tool which can be used to manually finish the model of the railway system.Furthermore, we describe how the railway system and the samples from the train can be used to register the routes the trains travel.
Klövviltets besöksfrekvens och bete i sydsvenska poppelplanteringar
Energy is an essential part of the society and for a sustainable future we need to use the energy resources in a sustainable way. The forest is Sweden?s most important resource for renewable energy and a higher production combined with shorter rotation periods (time from planting to clear cutting) can increase the access to energy. The tree genus poplar (Populus spp.) is interesting as energy resource as it has both high production and short rotation period.
But browsing ungulates are a major threat to the establishment of poplar plants and therefore the poplar plantations need to be fenced in today. To use fences is expensive and time consuming; this makes it interesting to find more cost-effective solutions where there is no need to fence.
The aim with this study was to look at the ungulates? occupation rate and browsing pressure in poplar plantations without fence.
Utredning av möjlighet att automatisera trucktrafik
This master thesis investigates the possibilities of using GPS-information from trains to create a model of a railway system, register the routes of the the trains and predict how the trains will travel in the railway system.The thesis work was done at Icomera AB which is a company that specializes in internet connected vehicle solutions.We describe how the GPS-information is sent from the trains in the form of samples and investigate limitations and possibilities with the available information. About three million samples from 83 SJ-trains were analysed and the samples were filtered with the intent of removing erroneous information. We here found that about 30 % of the samples from the trains were unreliable.A solution for how the samples from the trains can be used to create a model of the railway system traveled by the trains is presented. We use a large set of historical samples and use cluster nodes and Hermite curves to generate a graph that represent the railway system with stations, nodes and the railway itself. A fully automatic solution is not presented since it did not fit into the time frame of the thesis; instead we created a simple tool which can be used to manually finish the model of the railway system.Furthermore, we describe how the railway system and the samples from the train can be used to register the routes the trains travel.
Förstudie för kvalitetssäkringav glidande förband vid Hissmoforsvattenkraftsstation : -Specifikt för aggregat G6 och G7
Jämtkraft AB which is a power production company in Sweden has bought two newhydro power units to their station in Hissmofors. The two new generators are using aconcept with sliding stator feet to handle the thermal expansion.The concept with sliding stator feet on hydro electric generators has not beenworking satisfactory on many hydro power stations in Sweden and has caused a lot ofcosts due to long downtimes.The new station in Hissmofors is very important for Jämtkraft AB, and therefore theywant to know how to make sure that the sliding stator feet are working as theyshould. According to theories and a simplified model of the generator the stator feetdisplacement should be around 1 -1,6 mm.The generators are delivered with a surveillance system that will measure thedisplacement of the sliding stator feet. The signal from the system isn?t accessible forJämtkraft AB but it will alarm when the sliding stator feet are malfunctioning.To secure the function of the sliding feet a logger for the surveillance system or adifferent measurement system must be used; if both systems are used Jämtkraft cansecure the function of the surveillance system..
Distribution av sjukvårdens förbrukningsvaror en beskrivning av hur distributionssystemet kan förändras
This master thesis investigates the possibilities of using GPS-information from trains to create a model of a railway system, register the routes of the the trains and predict how the trains will travel in the railway system.The thesis work was done at Icomera AB which is a company that specializes in internet connected vehicle solutions.We describe how the GPS-information is sent from the trains in the form of samples and investigate limitations and possibilities with the available information. About three million samples from 83 SJ-trains were analysed and the samples were filtered with the intent of removing erroneous information. We here found that about 30 % of the samples from the trains were unreliable.A solution for how the samples from the trains can be used to create a model of the railway system traveled by the trains is presented. We use a large set of historical samples and use cluster nodes and Hermite curves to generate a graph that represent the railway system with stations, nodes and the railway itself. A fully automatic solution is not presented since it did not fit into the time frame of the thesis; instead we created a simple tool which can be used to manually finish the model of the railway system.Furthermore, we describe how the railway system and the samples from the train can be used to register the routes the trains travel.
Växelvis boende: Flexibla bostäder för "varannan vecka-familjen"
This master thesis investigates the possibilities of using GPS-information from trains to create a model of a railway system, register the routes of the the trains and predict how the trains will travel in the railway system.The thesis work was done at Icomera AB which is a company that specializes in internet connected vehicle solutions.We describe how the GPS-information is sent from the trains in the form of samples and investigate limitations and possibilities with the available information. About three million samples from 83 SJ-trains were analysed and the samples were filtered with the intent of removing erroneous information. We here found that about 30 % of the samples from the trains were unreliable.A solution for how the samples from the trains can be used to create a model of the railway system traveled by the trains is presented. We use a large set of historical samples and use cluster nodes and Hermite curves to generate a graph that represent the railway system with stations, nodes and the railway itself. A fully automatic solution is not presented since it did not fit into the time frame of the thesis; instead we created a simple tool which can be used to manually finish the model of the railway system.Furthermore, we describe how the railway system and the samples from the train can be used to register the routes the trains travel.
Analys av trängsel på motorväg: Beräkningsmodeller för medelflöden/medelhastigheter samt utformning av påfartsreglering i Göteborg
This master thesis investigates the possibilities of using GPS-information from trains to create a model of a railway system, register the routes of the the trains and predict how the trains will travel in the railway system.The thesis work was done at Icomera AB which is a company that specializes in internet connected vehicle solutions.We describe how the GPS-information is sent from the trains in the form of samples and investigate limitations and possibilities with the available information. About three million samples from 83 SJ-trains were analysed and the samples were filtered with the intent of removing erroneous information. We here found that about 30 % of the samples from the trains were unreliable.A solution for how the samples from the trains can be used to create a model of the railway system traveled by the trains is presented. We use a large set of historical samples and use cluster nodes and Hermite curves to generate a graph that represent the railway system with stations, nodes and the railway itself. A fully automatic solution is not presented since it did not fit into the time frame of the thesis; instead we created a simple tool which can be used to manually finish the model of the railway system.Furthermore, we describe how the railway system and the samples from the train can be used to register the routes the trains travel.