Sökning: "Synchronous machines"

Visar resultat 1 - 5 av 59 avhandlingar innehållade orden Synchronous machines.

  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. 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

  4. 3. Three-dimensional Finite Element Computation of Eddy Currents in Synchronous Machines

    Författare :Marguerite Touma Holmberg; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; synchronous machines; finite element method; eddy currents; three-dimensional;

    Sammanfattning : The thesis deals with the computation of eddy-current losses in the end regions of synchronous machines. Various magnetic and electric vector potential formulations of three-dimensional eddy-current problems are investigated. The equations are discretized by the finite element method with nodal or edge finite elements. LÄS MER

  5. 4. Iron Losses in Electrical Machines - Influence of Material Properties, Manufacturing Processes, and Inverter Operation

    Författare :Andreas Krings; Juliette Soulard; Oskar Wallmark; Annette Mütze; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; AC machines; cobalt-iron; eddy current losses; electrical steel sheets; inverter-fed machines; iron alloys; iron loss measurements; machine design; magnetic hysteresis; magnetic losses; magnetic materials; nickel-iron; permanent magnet machines; silicon-iron; soft magnetic composites; slot-less machines; soft magnetic materials; thermal effects.; Electrical Engineering; Elektro- och systemteknik;

    Sammanfattning : As the major electricity consumer, electrical machines play a key role for global energy savings. Machine manufacturers put considerable efforts into the development of more efficient electrical machines for loss reduction and higher power density achievements. LÄS MER

  7. 5. Thermal Analysis and Management of High-Performance Electrical Machines

    Författare :Shafigh Nategh; Chandur Sadarangani; Aldo Boglietti; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Computational fluid dynamics; directly cooled electric machines; finite element analysis; heat transfer; hybrid electric vehicle; induction machines; lumped-parameter thermal model; permanent-magnet assisted synchronous reluctance machines.;

    Sammanfattning : This thesis deals with thermal management aspects of electric machinery used in high-performance  applications  with  particular  focus put  on electric machines designed for hybrid electric vehicle applications.In the first part of this thesis,  new thermal models of liquid (water and oil) cooled electric machines are proposed. LÄS MER