Sökning: "geomagnetically induced currents"

Hittade 4 avhandlingar innehållade orden geomagnetically induced currents.

  1. 1. Applications of Unsupervised Deep Learning for Analysing Time-Varying Power Quality Big Data

    Författare :Roger Alves de Oliveira; Math Bollen; Sarah Rönnberg; Matti Lehtonen; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; power quality; power system harmonics; electric power distribution; interharmonics; big data analytics; pattern analysis; unsupervised learning; deep learning; artificial intelligence; geomagnetically induced currents; Electric Power Engineering; Elkraftteknik;

    Sammanfattning : Continuous power quality monitoring allows grid stakeholders to obtain information about the performance of the network and costumer facilities. Moreover, the analysis of continuous monitoring allows researchers to obtain knowledge on power quality phenomena. Power quality measurements result in a large amount of data. LÄS MER

  3. 2. The Sun, Space Weather and Effects

    Författare :Magnus Wik; Fysiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; solar magnetism - solar indices - space weather - solar wind - solar dynamo - geomagnetic activity - wavelet analysis - neural networks - geomagnetically induced currents;

    Sammanfattning : The Sun and the solar magnetic activity is responsible for a variety of effects in space and on the Earth. High energy radiation and charged particles are constantly being emitted from the solar atmosphere interacting with our atmosphere and technological systems in space and on the ground. LÄS MER

  4. 3. Electromagnetic Modelling of Power Transformers with DC Magnetization

    Författare :Seyed Ali Mousavi; Göran Engdahl; S. V. Kulkarni; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Transformer; Hysteresis; DC magnetization; GICs; FEM; reluctance network method;

    Sammanfattning : DC currents that flow through the ground can be injected to the star windings of power transformers from their grounded neutral points and close their path with transmission lines. The geomagnetically induced currents (GICs) and AC/DC convertors of high voltage direct current (HVDC) systems are the sources of such DC currents. LÄS MER

  5. 4. Three-Dimensional Modelling and Inversion of DC resistivity and Time Domain EM data using Multi-Resolution Framework

    Författare :Jingyu Gao; Thorkild Maack Rasmussen; Maxim Smirnov; Bülent Tezkan; Luleå tekniska universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; DC Resistivity; time-domain electromagnetic; forward modelling; data inversion; Prospekteringsgeofysik; Exploration Geophysics;

    Sammanfattning : 3-D forward modelling and inversion techniques play an important role in data interpretation, but they are still computationally challenging tasks. Therefore, this thesis aims to improve forward modelling and inversion performance using novel multi-resolution (MR) grid approach. LÄS MER