Sökning: "unbalanced magnetic pull."

Visar resultat 1 - 5 av 6 avhandlingar innehållade orden unbalanced magnetic pull..

  1. 1. Analysis and control of magnetic forces in synchronous machines

    Författare :J. J. Pérez-Loya; Urban Lundin; Anouar Belahcen; Uppsala universitet; []
    Nyckelord :eccentricity; electromagnetics; electromagnetic forces; excitation; magnetic fields; magnetic forces; magnetic thrust bearing; rotor drive; split rotor; starting; synchronous generators; synchronous machines; synchronous motors; unbalanced magnetic pull; Engineering Science with specialization in Science of Electricity; Teknisk fysik med inriktning mot elektricitetslära;

    Sammanfattning : In a synchronous machine, radial, tangential, and axial forces are generated. In this thesis, three different technologies to control them are proposed. The first one, involves the utilization of the radial forces that arise between the rotor and the stator. LÄS MER

  3. 2. Measurement and modelling of unbalanced magnetic pull in hydropower generators

    Författare :Mattias Wallin; Urban Lundin; Antero Arkkio; Uppsala universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Damper winding; eddy currents; field winding short circuit; finite element method; hydropower generator; parallel circuits; rotor eccentricity; salient poles; synchronous generators; synchronous machines; UMP; unbalanced magnetic pull.; Engineering Science with specialization in Science of Electricity; Teknisk fysik med inriktning mot elektricitetslära;

    Sammanfattning : Hydropower research is often perceived to be an old and exhausted field of study but with ageing equipment and the need for more intermittent operation caused by an increased share of other renewable energy sources new challenges lie ahead.The main focus of this dissertation are the electromagnetic forces resulting from nonuniform air gap flux, whether it be caused by rotor eccentricity or a faulty field winding. LÄS MER

  4. 3. Improving the functionality of synchronous machines using power electronics

    Författare :Fredrik Evestedt; Urban Lundin; C. Johan. D. Abrahamsson; Jon Kjellin; Uppsala universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Power electronics; Synchronous machines; Excitation systems; Magnetic thrust bearing; Starting synchronous machines; Split rotor; Rotating electronics; Magnetic fields; Measurement systems; Unbalanced magnetic pull; Harmonics; Engineering Science with specialization in Science of Electricity; Teknisk fysik med inriktning mot elektricitetslära;

    Sammanfattning : With the advent of modern power electronics there is reason to explore what can be achieved when it is applied to a mature technology like synchronous machines. In this text several concepts will be presented on how it is possible to control forces and how to get better performance out of synchronous machines by using power electronics. LÄS MER

  5. 4. On the dynamics of an hydropower generator subjected to unbalanced magnetic pull : characterisation and analysis

    Författare :Yogeshwarsing Calleecharan; Rolf Gustavsson; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Hållfasthetslära; Solid Mechanics;

    Sammanfattning : Eccentricity leading to unbalanced magnetic pull (UMP) in rotating electrical machines is a significant concern in industry. The UMP arises due to magnetic flux crossing the air-gap between the rotor and stator, and can be more intense than the useful peripheral force that the machine develops. LÄS MER

  7. 5. Contributions to the electromechanics of unbalanced magnetic pull in a synchronous hydropower generator

    Författare :Yogeshwarsing Calleecharan; Timo Holopainen; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Hållfasthetslära; Solid Mechanics;

    Sammanfattning : Misalignment between the rotor geometrical axis and the geometrical stator axis in a hydropower generator is usually present at standstill and when the machine is under operation. Now, rotor-stator eccentricity in a rotating electrical machine is a harbinger to abnormal operating conditions of the machine. LÄS MER