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Showing result 1 - 5 of 8 swedish dissertations matching the above criteria.

  2. 1. Magnetizing Currents in Power Transformers : Measurements, Simulations, and Diagnostic Methods

    Author : Claes Carrander; Hans Edin; Göran Engdahl; Rajeev Thottappillil; Amr Adly; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Transformer core; diagnostics; three-phase; no-load; hysteresis; modeling; resonance; remanence; delta; Electrical Engineering; Elektro- och systemteknik;

    Abstract : This thesis demonstrates a method for transformer core diagnostics. The method uses the no-load current of the transformer as an indicator, and gives different characteristic signatures for different types of faults or defects. Using the no-load current for the diagnostic gives high sensitivity. READ MORE

  4. 2. Design of Rare Earth Free Permanent Magnet Generators

    Author : Petter Eklund; Sandra Eriksson; Leijon Mats; Marcus Berg; Oskar Wallmark; Uppsala universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; permanent magnet generators; electrical machine design; ferrite permanent magnet; Engineering Science with specialization in Science of Electricity; Teknisk fysik med inriktning mot elektricitetslära;

    Abstract : Low speed permanent magnet (PM) synchronous generators (SGs) are commonly used in renewable energy. Rare earth (RE) PMs such as neodymium-iron-boron are a popular choice due to their high performance. READ MORE

  5. 3. Rare Earth Metal–Free Permanent Magnet Generators

    Author : Petter Eklund; Sandra Eriksson; Leijon Mats; Sonja Lundmark; Uppsala universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Engineering Science with specialization in Science of Electricity; Teknisk fysik med inriktning mot elektricitetslära;

    Abstract : Permanent magnet (PM) synchronous generators (SGs) are used in renewable energy production. The preferred PM material is neodymium-iron-boron (NdFeB), which has very high performance and, until recently, low cost. READ MORE

  6. 4. 3D Structure and Emplacement of the Alnö Alkaline and Carbonatite Complex, Sweden : Integrated Geophysical and Physical Property Investigations

    Author : Magnus Andersson; Alireza Malehmir; Valentin R. Troll; Bjarne Almqvist; Odleiv Olesen; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Alnö; carbonatite; caldera; reflection seismic; anisotropy of magnetic susceptibility; gravity; magnetic; Geophysics with specialization in Solid Earth Physics; Geofysik med inriktning mot fasta jordens fysik;

    Abstract : Carbonatites are carbonate-rich magmatic rocks that are rare and of great relevance for our understanding of crustal and mantle processes. Although found on all continents and in settings ranging from Archaean to present-day, their deeper plumbing system is still poorly understood. READ MORE

  7. 5. Magnetic properties of Neogene regional dikes from east Iceland with special reference to magma flow

    Author : Per Eriksson; Håkan Mattsson; Luleå tekniska universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Tillämpad geofysik; Applied Geophysics;

    Abstract : This thesis deals with rock magnetic measurements on Neogene dikes from the eastern fjords of Iceland. A vast amount of dikes generally striking north-north-east occur as swarms in the glacially eroded lava pile. READ MORE