Sök:

Sökresultat:

3597 Uppsatser om Electrical test on engines - Sida 4 av 240

Magnetfält alstrade kring nätstationer i samband med lokaldistribution av elkraft : Magnetic fields generated by electrical substations during distribution of electric power

Abstract: This report covers primarily the work of documenting electromagnetic fields generated by one of the later parts in the electrical power distribution chain: The electrical substation, wherein 10 kV is transformed to 400 V for use by private consumers. Thus it is one of the most widespread and frequently occurring parts in the Swedish power grid and of particular interest, as electrical substations are found everywhere in populated areas, often in close vicinity to people and animals.The report deals with a number of formulated questions and/or hypothesis? stated at the onset of the work undertaken, theory that is relevant for the topics the report covers, the details of the field work undertaken and the following analysis of the readings, which in term provide answers for the questions stated in the beginning. It also covers what is the currently known short term and long term risks associated with electromagnetic fields in the power frequent spectrum and of varying intensity in the vicinity of humans.The analysis also provides recommendations and identifies several points to carefully consider when planning for new installations or replacements of some parts of existing installations.For enhanced reading comprehension there is, aside from sections with pictures and attached explanatory texts and templates, several graphs, one-line diagram and maps of the power grid among the appendixes to the rapport..

Infärgning och samarbete på El-programmet : staining and cooperation in the Electrical program

This work is about collaboration and staining in the upper secondary school Electrical program. How should the coloring go to in order to increase students' motivation and thus facilitate students' learning is the main subject with the work. The study has shown that there is a functional co-operation today, and that students believe that if the cooperation would increase. It would also in-crease their motivation to improve..

Inbäddade kartor för geografiska presentationer på webbsidor

This is a survey of different techniques that may be used for embedding geographicdata into web pages. Different models of GIS communication are examined and a testsubject in the form of an application is implemented and evaluated.The test application (?StudentKarta? eng. ?Student Map?) lets students submit theirresidential data and shows their position as pins on an embedded Map.An expire date is used to let the pins fade away and disappear.The application uses the popular Google map engines to display the geographicalpresentations.

Google, Yahoo! och Live Search: en evaluering av tre webbsöktjänster

The purpose of this Master?s thesis is to evaluate three general query-based web search engines. The search engines chosen are Google, Yahoo! and Live Search. The topics, which where transformed into twenty queries, are based on real users? information needs, taken from an ask-a-question service.

Utveckling av en Multi-Zonsmodell för NOx Bildning i Diesel Motorer

This thesis work is the last part of the Master of Science education inmechanical engineering at KTH, Stockholm.The aim of this project was the development of a Multi-zone modelfor NOxformation in Diesel engines. Because of the stringent emissionlegislations, great effort is made to decrease the fuel consumption and theharmful emissions of internal combustion engines. Computer simulationsplay a decisive role in this context because they substitute the expensiveand time-consuming laboratory tests.The model is based on a multi-zone approach and uses the wellknownExtended Zeldovich Mechanism which gives a relation to calculatethe NO formation rate using the concentration of different gas speciesinvolved in the process.All the most important phenomena involved in the Diesel combustionhave been modelled. A special attention is then paid to the equilibriumconcentration calculation; this is a significant part of the model whichstrongly influences the following steps.A Simulink model has also been developed. This second version isbased on the previous model and it is made especially to allow theconnection with other external softwares, GT-power in this case.

Axle Link - en kortslutningsskyddad säker DC-överföring

Denna examensrapport redogör för hur man kan få en kortslutningsskyddadoch säker inkoppling av en DC-länk mellan två skiljda elektriska system.Rapporten bygger på hur en lastbil ska kunna få en större säkerhet för attbibehålla sina elektriska bromsar om tex ett av bromssystemen tappar sinordinarie matning.Lastbilens bromssystem består idag av två skiljda elektriska system med ett 24volts strömförsörjande batteri vardera. Det ingår två stycken elektriskabromsar i varje system. Om det tex blir fel på en av bromsarna och dennapåverkar ett av systemen vill man kunna koppla bort denna enskilda bromsmed sitt system. Man vill även kunna försörja den fungerande bromsen somsitter i samma system via en så kallad Axle Link. Denna strömmatningslänksitter mellan två hjulpar på samma axel.I denna studie undersöktes möjligheten att realisera en kortslutningsskyddadoch säker DC-överföring via en Axle Link, i första hand med diskretakomponenter.

Eltest på motormontering

Scania utvecklar och tillverkar lastbilar, bussar, industri- och marinmotorer. Största delen av Scania Sverige ligger i Södertälje, där även den mesta utvecklingen av produkterna sker. Företaget är verksamt i ca 100 länder och har 34 000 anställda. Forskning och utveckling består av ca 2 400 anställda. [1]Scania Motormontering Södertälje tillverkar motorer för Scanias europeiska produktion av lastbilar och bussar.

Simulering av elektriska förluster i en vindkraftpark : Utveckling av programvaran Wind Farm ElectricSystem Calculator (WFESC)

When planning new wind farms, the cost for the internal electrical grid is estimated to account for 8-9 % of the total investment cost. On top of that, the cost for accumulated reduced income over several years (due to electrical losses), has to be added. The economic lifespan is relatively long (about 20 years) which means that an error in the loss calculation could lead to a bad decision basis. The accumulated reduced incomes due to electrical losses can be higher than the initial investment cost for the internal electrical grid.Today, Statkraft Sweden is using a template number when estimating the electrical losses in a wind farm. The actual losses are probably lower than the template number which could lead to an unnecessary high loss cost when planning a new wind farm.The aim of this M.Sc.

Framtidens driftcentral : En analys av den framtida driften av ett svenskt elna?t

Active work to increase the efficiency of energy use is taking place in Sweden and throughout all of Europe. Electricity is an important part in our society?s energy system which means that the electrical grid operators and associated therewith has a central role in this work. Monitoring and controlling the electrical grids are managed from the distribution system operator?s DC, dispatch center.The aim of this report is to examine how the operations in a typical DC on the Swedish electricity distribution network will look like in five to ten years.

Google Scholar eller Scirus för vetenskapligt material på webben? En utvärdering och jämförelse av återvinningseffektivitet.

This thesis evaluates and compares the retrieval effectiveness of the two search engines Google Scholar and Scirus, which both specialises in indexing scholarly material on the web as well as journal articles. Thirty search queries are used and the first twenty retrieved documents for each query are examined for topical relevance and scholarly content. The search queries are based on legitimate information needs taken from a scientific questionbox on the web. Queries are expressed with advanced search operators and are the same for both search engines. Precise relevance criteria are set up and a binary scale is used when judging.

Hastighets- och positionsinterface för motorer

The environmental requirements and laws on combustion engine emissions are very tough today andthey will become even more stringent in the future. To achieve these requirements there are highdemands on the control systems for these engines. An improved precision in the measurement of anengine's speed and position gives the electronic control system an even better timing when it comes tofuel injection and ignition. This makes the engine more fuel efficient, reducing the emissions. This thesisis part of a collaborative project between Hoerbiger Control Systems and subsidiaries.

Att skapa en snabb, sökdriven e-handelssajt : en studie med backend-lösningar i fokus

AbstractThis study examines the technologies appropriate in developing back-and solutions for search-driven user interfaces of e-commerce sites. The study is based on existing research in search-driven user interfaces of e-commerce sites from a design point of view, but instead the focus of this study lies within a back-end perspective. This choice of focus is a result of the gap that was encountered within research and other literature when it comes to general advice in how e-commerce sites best should build back-end solutions to support search driven user interfaces. The technologies that have been examined and compared are traditional relational databse management systems (RDMS) and the newer so called No-SQL database management systems, and also traditional search engines and the newer variant s of search engines. The study concludes that in some cases it is appropriate to combine traditional and newer technologies when it comes to databases, while the comparison of search engines indicates that there are some newer search en gines that have the ability to meet more of the needs that can be identified on the back-end solutions.Primary data consists of interviews made ?face to face? with experts on the subject and questionnaires addressed to selected e-commerce companies via e-mail.

En beskrivning av manuellt test : Svagheter och styrkor med och utan stöd avett testverktyg

Test is an area in system development. Test can be performed manually or automated. Test activities can be supported by Word documents and Excel sheets for documenting and executing test cases and as well for follow up, but there are also new test tools designed to support and facilitate the testing process and the activities of the test. This study has described manual test and identified strengths and weaknesses of manual testing with a testing tool called Microsoft Test Manager (MTM) and of manual testing using test cases and test log templates developed by the testers at Sogeti. The result that emerged from the problem and strength analysis and the analysis of literature studies and firsthand experiences (in terms of creating, documenting and executing test cases) addresses the issue of the following weaknesses and strengths.

att synas på internet - ett praktiskt företagsperspektiv

Today Internet is clogged up and packed with homepages and information from both private persons and commercial companies. This has led to a decreased availability for a company to be noticed. The most common tool for consumers to use while searching for products online is via search engines. But because of the nature of these, not all companies can have good placements. Our research question was, "How do small online-companies attract consumers to their website"? The purpose of this thesis is to identify how a company works through online-communications and how to attract consumers to their home page.

Testbänk för luftlager

Test bench for air bearingsThis thesis work consisted of bringing forward and defining the test parameters relevant for a test bench and constructing a test bench that can test and verify the largest existing air bearings that are of use in Micronic Laser Systems AB machines. Because the knowledge about air bearings is limited it is thought that with the help of the test bench the knowledge would increase and in that way improve the air bearings.After learning more about air bearings and their purpose at Micronic Laser Systems AB, I started the concept phase for the test bench. For each part in the test bench I consulted my two tutors, Torbjörn Hedevärn and Johan Bergqvist, at Micronic Laser Systems AB. The final concepts where documented as 3D-modells in Solidworks and some of them have been tested in Solidworks FEM-program.The test bench is designed so that, with the help of a pneumatic cylinder, 25 kilo weights are placed on the air bearing to test its stiffness, damping and the pressure performance under its surface area. To test these parameters the test bench has to have a pressure meter, accelerometer and a microcator.

<- Föregående sida 4 Nästa sida ->