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1053 Uppsatser om Medium voltage - Sida 6 av 71
Utvärdering av Raman- och IR-spektroskopi, differentiell svepkalorimetri och dielektrisk spektroskopi för materialstudier på choklad
On a request from the water sewage plant Gryaab in Gothenburg a power quality survey wasperformed. The voltages and currents have continuously been sampled in the incoming 10 kVsubstation HSP01 from April-August 2008. Power quality measurements were also performedin Gryaabs other 10 kV substation HSP04 fed from HSP01 and at the terminals of theinduction motor IN_PU4040 of 1.3 MW which controls one of the four large inflow pumps tothe plant. The reason for the latter measurement was due to registered negative transients eachtime the motor was connected to the grid. The cause of the transients could be explained by thecoupling in the substation, the ageing of the motor which could result in damage of thebearings or resonance in the motor circuit which amplifies high frequency harmonics.
Konstruktion av UPS-modul
This master thesis describes the development of an UPS module. UPS is an acronym for Uninterruptable Power Supply. The UPS module has been developed at the company AerotechTelub AB. The UPS module delivers the necessary voltage and current in case of a power interrupt. If a power interrupt occur, the computer system has one to three minutes available to store data and shut down correctly.
LAN-Uppgradering
The interest in small-scale electricity in Sweden has increased strongly in recent years. The interest is noticeable both among politicians to increase the share of renewables in the energy mix, and among electricity consumers to partially replace purchased electricity with self-produced. This has resulted in a significant increase of electricity production in low voltage grids in recent years, and the trend appears to continue in the coming years. The majority of the new production plants are solar cells, followed by wind turbines, and it is also in these the greatest efforts are made in this paper.Distributed generation is often seen as something positive since it will contribute to reduced transmission losses and reduced voltage drop in the networks, and that it increases the share of electricity from renewable sources. In cases where the grids are not strong enough, or in other ways not adapted to manage the installed production, power quality may be adversely affected.
Energibalans Dåva Kraftvärmeverk
To be able to measure high-surge voltages and transients with short rise times youneed measuring instruments with a high sampling frequency and large Bandwidth.These surges and transients occur primarily at lightning but can also occur at forexample at connecting errors at an electrical switch-gear. This report describes thework with finding two solutions for measuring and log data from these surges andtransients. One temporary solution where a measurement program has beendeveloped. A second solution where different company solutions have been analyzedto decide which fits best. For these measurement solutions two solutions for bringingdown the voltage has been used.
Hantering av småskalig elproduktion : Utveckling av modell för dokumentation och elkvalitetsberäkningar
The interest in small-scale electricity in Sweden has increased strongly in recent years. The interest is noticeable both among politicians to increase the share of renewables in the energy mix, and among electricity consumers to partially replace purchased electricity with self-produced. This has resulted in a significant increase of electricity production in low voltage grids in recent years, and the trend appears to continue in the coming years. The majority of the new production plants are solar cells, followed by wind turbines, and it is also in these the greatest efforts are made in this paper.Distributed generation is often seen as something positive since it will contribute to reduced transmission losses and reduced voltage drop in the networks, and that it increases the share of electricity from renewable sources. In cases where the grids are not strong enough, or in other ways not adapted to manage the installed production, power quality may be adversely affected.
Tillväxt i medelstora företag: En problem- och åtgärdsanalys för tillväxt hos Sveriges "bortglömda" företag
Many sources point to the same conclusion; throughout the history the research sphere, mass media, governmental industry policies and public life in common have not paid the same attention to medium-sized companies as to small, new or large companies in Sweden. Yet, there are some researchers claiming the need for the medium-sized companies to grow, becoming tomorrow?s Swedish new large companies. Hence, the need for understanding the specific growth conditions of the medium-sized companies are definitely clear. This study aims firstly to identify whether there are specific requirements and obstacles for growth in connection to being a medium-sized company.
Mät och loggningsutrustning för spänningstransienter.
To be able to measure high-surge voltages and transients with short rise times youneed measuring instruments with a high sampling frequency and large Bandwidth.These surges and transients occur primarily at lightning but can also occur at forexample at connecting errors at an electrical switch-gear. This report describes thework with finding two solutions for measuring and log data from these surges andtransients. One temporary solution where a measurement program has beendeveloped. A second solution where different company solutions have been analyzedto decide which fits best. For these measurement solutions two solutions for bringingdown the voltage has been used.
Mät och loggningsutrustning för spänningstransienter
To be able to measure high-surge voltages and transients with short rise times youneed measuring instruments with a high sampling frequency and large Bandwidth.These surges and transients occur primarily at lightning but can also occur at forexample at connecting errors at an electrical switch-gear. This report describes thework with finding two solutions for measuring and log data from these surges andtransients. One temporary solution where a measurement program has beendeveloped. A second solution where different company solutions have been analyzedto decide which fits best. For these measurement solutions two solutions for bringingdown the voltage has been used.
Reklamens värde: En kompletterande syn på advertising- och brand equity.
At several occasions, an important question has been brought forward within the world of advertising and media. This is the question of whether or not ?good? advertising should be encouraged by the media. The question has an origin in a belief that such advertising can create values not only for the advertiser, but also for the medium. Although this question has arisen in business media, and although many managers work from the assumption that such relationship exists, there are none or little proof that it actually does.
Kriminaljournalister och Flashback : En intervjustudie om pressetik i ett nytt medium
The aim of our study was to examine Swedish crime reporters? approach to the social medium Flashback. Our main focus was the crime reporters? use of the medium Flashback, and attitude towards their own use of media ethics in relation to the medium Flashback.Flashback as a medium is not obliged to any media ethics and lacks a legally accountable publisher. In the search for information about committed crimes people tends to visit Flashback for the information that the traditional media cannot offer.
Komponentuppdelning av elnätetpå lokalnivå
Sweden will, in accordance with the EU-directive 2003/54/EC, move from post-regulating the electricity power grid-tariffs by using a fictitious grid, to a regulation in advance which uses the actual power grid as a starting point. For this purpose a component breakdown of the grid needs to be made to determine the value of the network and by that the tariff price that is reasonable for the network business in question to charge.The primary breakdown criteria is the voltage-level and type of region. Voltage-level is crucial for the cost and complexity of a grid-part, because the higher the voltagelevel is, there are more and stricter laws and rules to follow. This work is limited to the distributionpart of the grid, in other words voltage levels from 20 kV and below.The type of region is crucial to the type of components you can and want to use. In city environments both overhead-wires and independent substations are undesirable for both practical, safety and aesthetic reasons.
vindkraftens påverkan på elkvaliten
This thesis concerns how the power quality in the grid is affected by the connection of wind power plants. As things are at present, Fortum Distribution AB has a number of wind turbines and wind parks connected to the own grid. As the pressure on building and connecting additional wind power is increasing, so is also the interest of how the already existing wind power generation affects the power quality in the nearby distribution grids. The study is performed by direction of Fortum Distribution AB and is limited to the 10 kV/40 kV-grid in Bohuslän, Sweden. The methods for calculation of power quality are compared to the results of a number of measurements.
Hur skapas ett nytt medium genom att kombinera musik med en serieroman?
Jag har skapat en kort serieroman med tillhörande cd-skiva där bilderna, texten och musiken formar en helhet vilken blir som störst om alla element tas del av samtidigt. Min frågeställning har varit: hur skapas ett nytt medium genom att kombinera musik med en serieroman? Syftet med det här arbetet har varit att skapa ett medium som på bästa sätt drar nytta av musikens och serieromanens styrkor och att kombinera dem på ett sätt som inte gjorts förut. Jag kommer i den här uppsatsen förklara hur jag kom på den här idén, vad jag sedan skapade för produkt och hur min arbetsprocess såg ut. Slutligen resonerar jag kring vad jag kunde gjort annorlunda och hur mitt arbete kan vidareutvecklas..
Uljabuouda vindkraftpark turbinmodellering och stabilitetsanalys
This master thesis has been performed at Solvina in Gothenburg for Skellefteå Kraftand Vattenfall Eldistribution. The aim of it is to investigate the consequences of theinstallation of a wind power plant on the mountain Uljabuouda in the vicinity ofArjeplog. Especially the impacts on voltage and transient stability are examined.Furthermore, the amount of extra strain on the voltage regulation equipment and theneeds for increased regulation capabilities are looked into.The wind power plant is planned to be built by Skellefteå Kraft and connected to a130 kV grid owned by Vattenfall Eldistribution. The work comprehends the followingmain parts:- Theoretical studies aimed at wind turbines and power system stability issues.- Modelling of the type of wind turbines assumed to be built on Uljabuouda.- Simulations of different operation cases and analysis of the simulation results.The results from the simulations show that, as far as voltage stability and extraworkload on tap-changers are concerned, the wind power plant does not, in anysignificant manner, worsen the present conditions. The problem of overloading theline between Arvidsjaur and Vargfors is also minor.
"HBTQ-ungdom, den hårda skolan"
The aim of our study was to examine Swedish crime reporters? approach to the social medium Flashback. Our main focus was the crime reporters? use of the medium Flashback, and attitude towards their own use of media ethics in relation to the medium Flashback.Flashback as a medium is not obliged to any media ethics and lacks a legally accountable publisher. In the search for information about committed crimes people tends to visit Flashback for the information that the traditional media cannot offer.