Sökning: "pressboard"

Hittade 5 uppsatser innehållade ordet pressboard.

  1. 1. A micro-CT investigation of density changes in pressboard due to compression

    Uppsats för yrkesexamina på avancerad nivå, Uppsala universitet/Tillämpad mekanik

    Författare :Johan Stjärnesund; [2018]
    Nyckelord :Micro computed tomography; μCT; pressboard; density; densification;

    Sammanfattning : Pressboard, a high-density cellulose-based product, is used both as load bearing structures and dielectric insulation in oil-filled power transformers. During transformer operation, mechanical forces and vibrations are applied on the material. LÄS MER

  2. 2. Synchrotron tomography of pressboard during in-situ compression loading : Construction of compression rig, image acquisition procedure and methods for image processing

    Uppsats för yrkesexamina på avancerad nivå, Uppsala universitet/Tillämpad mekanik; Uppsala universitet/Tillämpad mekanik

    Författare :Åsa Jonsson; Grim Skarsgård; [2015]
    Nyckelord :Pressboard; Synchrotron X-ray micro Computed Tomography; stress relaxation;

    Sammanfattning : Pressboard, a high density cellulose-based material used for insulation in high voltage power transformers, exhibits stress relaxation during compressive loading. Investigating the micro-mechanical mechanisms responsible for the relaxation can lead to modifications of the production process to control the behaviour of the material. LÄS MER

  3. 3. Mechanical Characterization and Simulations of Laminated Pressboard.

    Magister-uppsats, KTH/Hållfasthetslära (Inst.)

    Författare :Lovisa Westermark; [2014]
    Nyckelord :;

    Sammanfattning : Pressboard is a cellulose-based material, which is used in transformers as insulation as well as for providing structural support. The micro-structure of pressboard consists of networks of cellulose fibers, which has good mechanical properties as well as exceptional electrical insulation properties. LÄS MER

  4. 4. Modeling of Ion Injection in Oil-Pressboard Insulation Systems

    Uppsats för yrkesexamina på avancerad nivå, Uppsala universitet/Fasta tillståndets elektronik

    Författare :Christian Sonehag; [2012]
    Nyckelord :Ion drift diffusion model; Ion injection; Transformer insulation;

    Sammanfattning : To make a High Voltage Direct Current (HVDC) transmission more energy efficient, the voltage of the system has to be increased. To allow for that the components of the system must be constructed to handle the increases AC and DC stresses that this leads to. One key component in such a transmission is the HVDC converter transformer. LÄS MER

  5. 5. Measurement of ion mobility in dielectric liquids

    H-uppsats, Chalmers tekniska högskola/Institutionen för material- och tillverkningsteknik

    Författare :Mohsen Shafiee Zadeh; [2011]
    Nyckelord :UHVDC; UHVDC converter transformer; Ion drift model; Ion mobility; transformer oil;

    Sammanfattning : Rising energy demand and at the same time global effort to reduce greenhouse gases are strong pushes for harvesting renewable energy sources in remote areas far away from consumption centers. Ultra High Voltage Direct Current is a highly efficient way to transfer bulk power over long distances. LÄS MER