Sökning: "virtual flux"

Visar resultat 1 - 5 av 6 avhandlingar innehållade orden virtual flux.

  1. 1. On Control of Back-to-Back Converters and Sensorless Induction Machine Drives

    Författare :Rolf Ottersten; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; active filtering; flux estimation; sensorless control; induction motor; back-to-back converter; pulsewidth-modulated rectifier; virtual flux; vector current control;

    Sammanfattning : This thesis focuses on design and analysis of the control system structure for back-to-back converter squirrel-cage induction machine drives. Particularly, sensorless control of induction machines, meaning vector control without a mechanical shaft sensor, and vector control of pulsewidth-modulated (PWM) rectifiers are considered. LÄS MER

  3. 2. The value of experimental data and modelling for exploration of hydrological functioning: The case of a till hillslope

    Författare :Nino Amvrosiadi; Jan Seibert; Kevin Bishop; Keith Beven; April James; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : Successfully modeling one system response (e.g. hydrograph or solute transport) sometimes gives the false sense of well-characterizing the modeled system. This is partly because of the well-known equifinality issue; during the calibration process multiple parameter combinations can produce similarly good results. LÄS MER

  4. 3. Experimental and Theoretical Study of Rack Storage Fires

    Författare :Haukur Ingason; Avdelningen för Brandteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; response time; in-rack sprinkler; flame heat transfer; gas velocity; gas temperature; flame height; in-rack fire plume; Rack storage fire; fire growth rate; Technological sciences; Teknik;

    Sammanfattning : A theoretical and experimental study of rack storage fires and responsiveness of sprinklers is presented. Free-burn tests with non-combustible and combustible material were carried out in reduced scale with verification in large scale. LÄS MER

  5. 4. Aspects of QCD and the Photon Structure

    Författare :Christer Friberg; Teoretisk partikelfysik - Geonomgår omorganisation; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; High energy interactions; QCD; Photons; Monte Carlo Event Generator; Leptoquarks; Colour Connections; cosmic rays; Kosmisk strålning; högenergi; Fysicumarkivet A:2000:Friberg;

    Sammanfattning : In a single theoretical framework, real and virtual photon interactions are modeled for gamma-p and gamma-gamma collisions. The description covers aspects from the production of jets to total cross sections, where special emphasis is put on the range of uncertainty in the modeling of a resolved photon component. LÄS MER

  7. 5. Assessing Holocene and late Pleistocene geomagnetic dipole field variability

    Författare :Andreas Nilsson; Kvartärgeologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Geomagnetic field; palaeomagnetism; the Holocene; dipole tilt; dipole moment; cosmogenic radionuclides;

    Sammanfattning : Palaeomagnetic studies of continuous geological archives and archaeological artefacts are required to reconstruct geomagnetic field changes beyond the range of historical observations. In this thesis I assess the reliability of sedimentary palaeomagnetic data and Holocene dipole field reconstructions. LÄS MER