Sökning: "Poor damping"

Visar resultat 1 - 5 av 9 avhandlingar innehållade orden Poor damping.

  1. 1. Converter interactions in VSC-based HVDC systems

    Författare :Georgios Stamatiou; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Symbolic eigenvalue expressions; Frequency Domain Analysis; Droop control; Net damping; VSC; Passivity Analysis; MTDC; Poor damping; HVDC;

    Sammanfattning : The main objective of this thesis is to perform stability and control studies in the area of VSC-HVDC. A major part of the investigation focuses on the explanation of poorly-damped conditions and instability that are linked to dc-side resonances. LÄS MER

  3. 2. Analysis of VSC-based HVDC systems

    Författare :Georgios Stamatiou; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; HVDC; MMC; MTDC; Poor damping; Symbolic eigenvalue expressions; Droop control; Passivity Analysis; Net damping; Frequency Domain Analysis; VSC;

    Sammanfattning : The main objective of this thesis is to perform stability and control studies in the area of VSC-HVDC systems. A major part of the investigation focuses on the development of procedures, whose aim is to understand, explain and avoid poorly-damped conditions or instability that may appear due to dc-side resonances, which stem from the interaction of converters and passive elements in such systems. LÄS MER

  4. 3. Power System Oscillations - Detection, Estimation and Control

    Författare :Morten Hemmingsson; Industriell elektroteknik och automation; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Elektroteknik; oscillation; power system; damping; power swing; distance protection; detection; estimation; real-time; reactive co-variation; control; Electrical engineering; load modulation; Automation; robotics; control engineering; Automatiska system; robotteknik; reglerteknik;

    Sammanfattning : The topic of this thesis is the electro-mechanical oscillations which to some extent always are present in a power system. The demand of electric power is ever increasing. At the same time, the tolerance of disruptions in the power supply is decreasing. LÄS MER

  5. 4. On Stabilization of Sensorless Synchronous Motor Drives and Traction Converters

    Författare :Magnus Jansson; Lennart Harnefors; Mats Alakula; Mälardalens högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electronics; Elektronik; elektronik; Electronics;

    Sammanfattning : Avhandlingen behandlar först och främst styrning av elmotordrifter, men vi tittar även på styrning av nätomriktare för stabil framdrivning av tåg.Två industriprojekt är rapporterade i avhandlingen, i form av delrapporterna ”Sensorless Control of Electrically Excited Synchronous Machines”, ABB Corporate Research och ”Stable and Passive Traction”, Bombardier Transportation. LÄS MER

  7. 5. Contribution to Numerical and Experimental Studies of Flutter in Space Turbines. Aerodynamic Analysis of Subsonic or Supersonic Flows in Response to a Prescribed Vibratory Mode of the Structure

    Författare :Hakim Ferria; Pascal Ferrand; Torsten Fransson; François Moyroud; France Ecole Centrale de Lyon Laboratoire de Mécanique des Fluides et d'Acoustique; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; flutter; space turbine; LRANS computation; flutter measurement; shock wave boundary layer interaction; blisk; cut-on cut-off condition; interblade phase angle; combined modes;

    Sammanfattning : Modern turbomachines are designed towards thinner, lighter and highly loaded blades. This gives rise to increased sensitivity to flow induced vibrations such as flutter, which leads to structure failure in a short period of time if not sufficiently damped. LÄS MER