Sökning: "Electric currents"

Visar resultat 36 - 40 av 105 avhandlingar innehållade orden Electric currents.

  1. 36. Dielectric response and partial discharge measurements on stator insulation at varied low frequency

    Författare :Nathaniel Taylor; Hans Edin; Shesha Jayaram; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electric power engineering; Elkraftteknik;

    Sammanfattning : This is a study of potential improvements of diagnostic methods used on high-voltage generators and motors.  It considers offline electrical measurements on the main insulation of stator windings, where a sinusoidal voltage is applied between the winding and the stator-core, and the total current through the insulation (dielectric spectroscopy, DS) and the rapid current-pulses arising from discharges (partial discharge, PD) are measured. LÄS MER

  3. 37. Transient Stability in Low Frequency Railways with Mixed Electronic and Rotational Generation

    Författare :John Laury; Thorsten Schütte; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electric Power Engineering; Elkraftteknik;

    Sammanfattning : Transient stability concerns the ability of a power system to maintain synchronism after a large disturbance. Transient stability plays an important role in guaranteeing operational security and reliability and has been extensively studies for large 50 Hz and 60 Hz transmission systems. LÄS MER

  4. 38. On SiC JFET converters: components, gate-drives and main-circuit conditions

    Författare :Björn Ållebrand; Hans-Peter Nee; Lutz Josef; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Power JFET; SiC JFET; Silicon Carbide; PSpice; Simulations; Gate drive; Blanking times; Normally-on; Modeling; Commutation transients; Electric power engineering; Elkraftteknik;

    Sammanfattning : This thesis deals with Silicon Carbide Junction Field Effect Transistors (SiC JFETs) - how to use them to their full potential in power electronic circuits, how to model them in a power electronic simulation program, and how a gate drive can be built. To fully utilize the low on-state losses of SiC JFETs it is suggested that SiC JFETs should not be equipped with anti-parallel diodes. LÄS MER

  5. 39. Artificial Intelligence-Based Characterization and Classification Methods for Power Quality Data Analytics

    Författare :Azam Bagheri; Math Bollen; Surya Santoso; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Power System; power Quality; Voltage Dip; Big Data; Deep Learning; Machine Learning; Active Learning; Consensus Contriol; Electric Power Engineering; Elkraftteknik;

    Sammanfattning : One of the important developments in the electric power system is the fast increasing amount of data. An example of such data is formed by the voltages and currents coming from power-quality measurements. LÄS MER

  7. 40. On the supraharmonics in single-phase and three-phase installations

    Författare :Jil Sutaria; Sarah Rönnberg; Math Bollen; Andrés Pavas Martinez; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electric Power Engineering; Elkraftteknik;

    Sammanfattning : Society has increasingly started depending on the continuity of internet services, the interruption can be crucial for vital societal functions. It is therefore important to maintain continuous and reliable operations of e.g., installations housing sensitive IT (Information Technology) loads. LÄS MER