Sökning: "eddy currents"

Visar resultat 1 - 5 av 36 avhandlingar innehållade orden eddy currents.

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

    Författare :Marguerite Touma Holmberg; Chalmers University of Technology; []
    Nyckelord :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

  3. 2. A lumped element transformer model including core losses and winding impedances

    Författare :David Ribbenfjärd; Göran Engdahl; Arvid Broddefalk; KTH; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; power transformer; hysteresis; dynamic hysteresis; eddy currents; excess eddy currents; leakage flux; winding model; core model; magnetic measurements; magnetic materials; Electrical engineering; Elektroteknik;

    Sammanfattning : In order to design a power transformer it is important to understand its internal electromagnetic behaviour. That can be obtained by measurements on physical transformers, analytical expressions and computer simulations. LÄS MER

  4. 3. Magnetic Leakage Fields and End Region Eddy Current Power Losses in Synchronous Generators

    Författare :Birger Marcusson; Urban Lundin; Göran Engdahl; Uppsala universitet; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; TEKNIK OCH TEKNOLOGIER; NATURAL SCIENCES; ENGINEERING AND TECHNOLOGY; magnetic leakage fields; leakage flux; eddy currents; losses; synchronous generator; Engineering Science with specialization in Science of Electricity; Teknisk fysik med inriktning mot elektricitetslära;

    Sammanfattning : The conversion of mechanical energy to electrical energy is done mainly with synchronous generators. They are used in hydropower generators and nuclear plants that presently account for about 80% of the electric energy production in Sweden. LÄS MER

  5. 4. Three-Dimensional Computation of Eddy Currents in End regions of Synchronous Generators

    Författare :Marguerite Touma; Sonja Lundmark; Chalmers University of Technology; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; anisotropic; non-linear; conductor; eddy current; formulation; coil; source; saturated; finite element method; turbogenerator; three-dimensional; potential; laminated; steady state; hydrogenerator; winding;

    Sammanfattning : .... LÄS MER

  7. 5. Modelling the transient response of windings, laminated steel coresand electromagnetic power devices by means of lumped circuits : With special reference to windings with a coaxial insulation system

    Författare :Pär Holmberg; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; Physics; Transient response; frequency response; electromagnetic transient analysis; circuit modeling; eddy currents; skin effect; windings; coils; magnetic cores; cables; electric machines; rotating electric machines; transformers; Fysik; Physics; Fysik; Electricity; Esp The Study Of Transients and Discharges; elektricitetslära; ssk studiet av transienter och urladdning;

    Sammanfattning : Electromagnetic transients impinging on electromagnetic power devices - such as electric machines, transformers and reactors - can stress the design severely. Thus the magnitudes of the transients are often decisive for the design of the devices. Further, the operation of a device can be transient in itself. LÄS MER