The transformer is one of the most common and most important electric machines for power companies. Cost of investment and the economic worth of a transformer are counted in millions of SEK. Because of that, proper maintenance actions that may lead to longer technical life time should be the aim in all situations.The aim with the report was to perform transformer diagnosis by dissolved gas analysis on Umeå Energi AB´s power Transformers and a risk assessment. The report should also contribute to longer life time for the Transformers.Oil samples were taken from each transformer two times. The first sample in summer 2013 and the second in April 2014.

Problem StatementAfter the hurricane Gudrun in January 2005 EON Elnät Sverige AB started the project KRAFTTAG, were 17,000 km of the airborne power grid shall be replaced with cables underground. The Transformers in the airborne power grid shall be dismounted, renovated if necessary and then conveyed to stations, of type kiosk.Additional new Transformers, more than planned, have been bought. This is due to the dysfunctional transformer flow from the demolished power supply to projects, were the new power supply is built, the general picture is complicated, since the reconstruction involves other companies and many employees at E.ON.PurposeThe purpose of this master thesis is to map and understand the existing transformer flow. The objective is to make a recommendation on how to increase the level of E.ON? s transformer recycling.Methodthe authors have worked with a system approach, including both qualitative and quantitative data.

As break downs of production Transformers are costly and often result in long outages it is essential for reliability of operation that the Transformers are manufactured to be robust. The aim of this M.Sc. thesis is to investigate if deviations should be made from the standard IEC 60076 ? Power Transformers in order to describe a robust large power transformer for procurement.The investigation has been conducted in three stages. In the first stage a definition of the term robust was developed in consultation with the client Vattenfall Vattenkraft.

Umeå Energi are working towards a goal, that in the year of 2018, they will be completely climate neutral. As a part of this, one target is to reduce their grid losses by 4 % of the 2012 level, which corresponds to an overall reduction of the grid losses of just over 1.7 GWh. In many residential areas, the distribution grid is designed and rated for electric heating as the heating in the houses. As many of the houses later has been converted to other types of heating, their electricity use has decreased and the total power output from many of the secondary substations has decreased significantly. Because of this, many of these stations today are well oversized, which in turn means that the energy losses in these stations are unnecessarily high.In this degree project, 25 secondary substations have been studied, all located in residential areas in and around central Umeå.

Efter fem år på Konstfack lämnar jag snart denna studietillvaro för att gå ut i verkligheten som inredningsarkitekt och möbelformgivare. Det blir ett nytt sammanhang för mig att adaptera till. Mitt examensarbete handlar därför om hur jag kan transformera den typ av arbete jag gjort i skolan till verkligheten som kommer efter skolan. Jag ser en risk i verklighetens tillvaro där jag tror att många fantastiska idéer blir reducerade till slutresultat som är berövande på de kvaliteter som varit upphov till idéerna. Jag har därför arbetat med hur jag kan minska avståndet mellan min tankevärld och den nya verklighet jag vill översätta mina tankar till.

Movies can be a source to enjoyment, cultural enrichment and relaxation. But movies are also filled with messages and subtext, that effects the one who watches the movie. One of the effects are the reproducing of stereotypes and racism. This essay concentrates on the five best grossing science fiction movies in Sweden between the years 2009 ? 2014.

Historically Transformers with system earth equipment have been modeled as open circuits in zero sequence. This approximation has been satisfying, but lately it has been discovered that equipment on one side of the transformer have responded to faults that occurred at the other side. Most of these problems took place when the majority of the system on the secondary side of the transformer contained cables. These findings have led to questioning whether or not the former model of the transformer in zero sequence is correct. This report investigates if it is necessary to represent the transformer in zero sequence in another way than it is usually done today.

I detta projekt undersöker vi om man kan bygga en maskinaktivitetssensor medhjälp av en enkretsdator som genom en accelerometer mäter en maskinsvibrationer. Sensorn skall generera en statussignal. Accelerometern ger enmätbar signal baserad på maskinens vibrationer. Enkretsdatorn används för attsampla, transformera och analysera signalen och generera statusinformation.Med LabView kan vi spara, studera och analysera olika signaler och olikatransformer. Vi studerar maskinvibrationer i LabView och beslutar att 5 kHzsampling räcker för att fånga intressanta vibrationer.

New technology makes it possible to remotely measure all consumers in a power network onan hourly basis and store the values in a database.This thesis work describes the conversion process between automatic meter reading systemMActor and calculation software Xpower.Then the possible differences between calculations of power networks using load curves incombination with a yearly estimate of consumption and calculations using hourly measuredvalues is examined.The result of the comparison shows that, for the power network under inspection, nosignificant difference could be noticed. This does not mean that calculations using hourlymeasured values would be unnecessary. I believe that in a near future calculations using hourmeasurements will be the primary choice for many power companies to whom technology isavailable.Also some basic calculations of fundamental power network parameters, such as power factorand loses, are presented using hourly measured distribution Transformers in combinations withits hourly measured loads.The report is written in Swedish.

The dissertation deals with an account of actual problem, which can arise within EMC and power quality. The cause of power interruption and what can be done to minimise the power interruption is discussed. It also includes a definition of planning levels and which factors one needs to have control over to carry out a possible planning strategy and how the local distributions net could be more secure. The electrical net could be secure but no system can be free from interruption.The dissertation examines two distribution Transformers: GLA40T1 (Glansås) and T399 in Tranås Energy which don?t have regulators.

Examensarbetet har utförts vid ABB Power Transformers i Ludvika i plåtverkstaden, där stora transformatorlådor svetsas ihop. Tillsammans med vår handledare på företaget utformades ämnet för examensarbetet att bedöma luftkvalitet och arbetsmiljö vid punktsvetsning i koppar. Det fanns misstanke om att exponeringen för koppar var hög och en utvärdering av luftkvaliteten behövde därmed göras. Ingen tidigare exponeringsmätning vid svetsning i koppar har genomförts i plåtverkstaden. Syftet med examensarbetet var att utvärdera och komma fram till tre åtgärdsförslag för att skapa en bättre arbetsmiljö vid punktsvetsning samt att begränsa exponeringen av svetsrök som bildas vid svetsning i koppar. Tre åtgärder var företagets önskemål.

A substation must be properly protected against lightning and other external effects to the equipment in the station or staff, for that we use relay protection. They should also protect against internal errors which may occur as ground faults. There are different types of protection relays, but most common are overcurrent-, distance-, residual current- and differential protection.The purpose of this thesis was to deepen our knowledge of relay protection and to use the theoretical knowledge we got from the university studies in the work process. In the process we discovered which parameters were the most essential and calculated these for all relay protections on the substation. We also carry out a comparison between two brands of relay protection, ABB and Alstom.During our work we will test and simulate the over-current relays in a program called NEPLAN, the program will also calculate the fault currents.

Denna uppsats avser att utforska förskolebarns köns- och subjektskapande i och i förhållande till lekar med ett actiontema, som Superman, tjyv och polis och Transformers. Genom deltagande observation har jag samlat empiri som jag med feministiskt poststrukturellt perspektiv och diskursanalys analyserat. Studien går i motstånd mot en uppfattning om dessa actionlekar som sprungna ur ett maskulint behov. Genom att titta på hur tecknet ?kille? kopplas ihop med andra tecken, visar studien hur actionlekarna istället går att förstå som en arena där ting och företeelser konstrueras som maskulina.

The dependency of continuous electricity supply is high in the Swedish society today, at the same time no one is willing to pay for a too costly or over dimensioned power distribution system. The owners of the distribution systems are the ones responsible for this balance act of maintaining a high quality of electricity delivery to customers at a reasonable cost.In this master thesis a limited part of the primary distribution system (10 kV), owned by Mälarenergi Elnät AB and located in the city centre of Västerås, was chosen for a deeper analysis of its reliability. Its ability to handle outages of system components (N-1 and N-2 contingency analysis) was investigated to find out potential weak spots and parts of the grid that showed signs of being overdimensioned.The results of the performed simulations showed that in 74 % of the studied N-1 contingencies cases, consisting of outages of a bus bar in a distribution substation, the system could handle this without causing outages in other parts of the grid. For the N-2 contingencies 61 % passed the test. It was also found that one of the two included high voltage substations could alone supply the investigated part of the grid.

AbstractAbetong in Falkenberg manufactures, among other things, small prefabricated concrete buildings for housing various installations, such as electric Transformers.The aim of this dissertation is to reduce the time needed to design such buildings, by way of finding a number of standardized buildings. Standardized in such a manner as to incorporate both the needs of the manufacturer (Abetong) and its customers.To analyze the needs of the parties the work has included a market survey and calculations on the strength of these buildings.One survey was a letter questionnaire to all of Abetong?s customers who have, in the past, ordered these types of building. The aim of the questionnaire was to establish how the customers want these buildings designed.Another survey conducted was an inventory of all of Abetong?s previous projects where these types of building were manufactured.