Sökning: "eddy currents"

Visar resultat 6 - 10 av 37 avhandlingar innehållade orden eddy currents.

  1. 6. Electromagnetic transformer modelling including the ferromagnetic core

    Författare :David Ribbenfjärd; Göran Engdahl; David Jiles; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Power transformer; hysteresis; dynamic hysteresis; dynamic magnetization; eddy currents; excess losses; leakage flux; winding model; core model; magnetic measurements; magnetic materials; Electric power engineering; Elkraftteknik;

    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

  3. 7. Modeling of losses in power transformers from dc to the low kilohertz range

    Författare :Julius Krah; Göran Engdahl; Roland Eriksson; Anthony Moses; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electrical power technology; power transformer; losses; magnetic hysteresis; magnetic measurement systems; medium frequency; eddy currents; skin effect; thermal diffusion; Elkraftteknik; Electric power engineering; Elkraftteknik;

    Sammanfattning : The development of HVDC converters, local generation and tractions systems increases the demand for power converters. While a lot of studies have been conducted on the power electronics, there are still open questions concerning the contained power transformer that operates at a few kilohertz. LÄS MER

  4. 8. Impedance of Soft Magnetic Multilayers : Application to GHz Thin Film Inductors

    Författare :Andrey Gromov; KTH; []
    Nyckelord :inductor; impedance; magnetic; eddy currents; FMR;

    Sammanfattning : A theoretical approach to calculating impedance of metallicmagnetic/conductor layered structures is developed. Thefrequency range considered extends to the ferromagneticresonance region of soft magnetic films (of the order of 1GHz). LÄS MER

  5. 9. Modelling approaches for audio frequency power transformers

    Författare :Julius Krah; KTH; []
    Nyckelord :power transformer; audio frequency; loss; hysteresis; eddy currents; skin effect. Leakage inductance;

    Sammanfattning : The development of HVDC converters, local generation andtractions systems increases the demand for power converters.While a lot of studies have been conducted on the powerelectronics, there are still open questions concerning thecontained power transformer that operates at a few kilohertz. LÄS MER

  7. 10. Run-Up Transient Analysis for Salient Pole Wound Field Synchronous Motors : Field winding and power electronics implications for a smoother and cooler asynchronous start

    Författare :Roberto Felicetti; Urban Lundin; Andreas Binder; Uppsala universitet; []
    Nyckelord :apparent resistance; cable modeling; current control; transmission line model; eddy currents; field winding; frequency analysis response; Fourier Transform; impedance mismatch; main inductance; overvoltage; parasitic capacitance; partial discharge; quality factor; ringing; slew rate; stray inductance; voltage gradient; winding resonance frequency; asynchronous start; run-up; torque ripple; reluctance torque; Engineering Science with specialization in Science of Electricity; Teknisk fysik med inriktning mot elektricitetslära;

    Sammanfattning : Salient Pole Wound Field Synchronous Machines have better efficiency at full load than asynchronous machines of the same capability. Moreover, where asynchronous machines need inherently to draw a magnetizing current from the grid, Salient Pole Wound Field Synchronous Machines can work efficiently at unity power factor. LÄS MER