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536 Uppsatser om Recovery voltage - Sida 7 av 36
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.
Pilotinstallation av fast och fjärravläst nätstationsmätning : Identifiering av för- och nackdelar med nätstationsmätning, Mälarenergi Elnät AB
Today?s electrical grid companies understand that better knowledge of and information about their grid can help realize a smart grid network. One way to gain better knowledge and information about the low voltage network is to install measuring equipment on the substation transformer´s secondary low voltage side that measures the low voltage network losses for that specific substation. By doing so, grid companies can, due to the calculation of the low voltage network losses, identify and address issues such as illegal power dissipation, unmeasured power outtakes, and unsatisfied technical documentation for the substations low voltage network.During 2012, Mälarenergi Elnät AB had a total electrical network loss (both medium and low voltage network losses included) of three to four percent of their total distributed electrical volume. Converting this energy volume into a monetary figure this accounts for a loss of around 30 million Swedish crowns.
Utmattningssyndrom och KASAM. En möjlighet till en ökad känsla av sammanhang?
Some people who recovered from exhaustion disorder report that their lives feel more meaningful after the disease than before, despite residual symptoms and difficulties. This experience of increased meaningfulness has been linked to sense of coherence, SOC. The research question was whether individuals with exhaustion disorder at onset has a weak SOC, and if there is a general increase towards a higher SOC value ??during the recovery process. In a cross-sectional study, data were gathered on the SOC value via the SOC 29 form.
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.
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.
"Man måste vara egoistisk för att kunna hjälpa andra" : -En studie om hanteringen av service recovery på Icehotel och Björkliden
Service recovery innebär företags försök att uppväga kunders negativa reaktioner på ett misslyckande vid leverans av en tjänst. Det här är ett relativt välutforskat ämne, men fokus är nästan uteslutande på kunden och hur den ska hanteras. Kundperspektivet är dock bara en av tre delar som ingår i service recovery. Förutom att göra kunderna nöjda, behöver företag arbeta aktivt med att förbättra processerna samt ge medarbetarna rätt förutsättningar för att hantera misslyckanden och därefter återhämta sig. Det sistnämnda, kallat employee recovery, upplever vi ha blivit bortprioriterat och nonchalerat i en majoritet av tidigare forskning inom service recovery.
Om krigsupplevelser och krisbearbetning : en studie om hur några svenskar från Libanon upplevde kriget mot Libanon sommaren 2006
This study is a qualitative investigation where surveys where performed on five Swedes from Lebanon. The purpose with the survey was to learn how these persons were affected by the war against Lebanon in the summer 2006, how they reacted to it and what measures they took to overcome their crisis. The result shows that the state of crisis of the interviewed persons was caused by several factors, such as the war being both unexpected and intensive. Other causes was the worry that their children would be hurt by the effects of the war as well as the material and human losses that the war brought.The interviewed persons responded with both negative and positive reactions, which may have affect their recovery process. Some of them where offered physiological support in Sweden by their municipalities.
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.
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.
Tillfrisknande från ätstörning - en studie baserad på kvinnors erfarenhet av ätstörningar
Aim:In this study, women were interviewed about their experiences of recovering from an eating disorder - The aim has been to investigate the factors that contributed to recovery and with guidance of these factors, find factors that can be used in a preventive intervention.Method: A qualitative approach was used to design and conduct interviews, the design of the study was descriptive and a semistructured interview was used. The local affiliation of The Swedish Eating Disorder Association was contacted and provided contact with 10 women who participated in the interview. To participate in the study the women had to be recovered from their eating disorder for at least two years. The women who patricipated in the study were between 22 and 36 years old and had been recovered for 2- 16 years. Data were analyzed and coded then categories with similar themes about the factors that were important for recovery wad etablished.
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.