Sökning: "transformers"

Visar resultat 1 - 5 av 72 avhandlingar innehållade ordet transformers.

  1. 1. Lifetime modeling and management of transformers

    Detta är en avhandling från Stockholm : KTH Royal Institute of Technology

    Författare :Johanna Rosenlind; KTH.; [2013]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; transformers; lifetime modeling; asset management; thermal modeling; lifetime estimation;

    Sammanfattning : This work have studied and developed lifetime estimation methods for the power transformer and how these could be used for asset management purposes. It is researchperformed in the intersection of the fields of reliability theory, statistical analysis, and stochastic process theory applied to lifetime estimations and management of transformers. LÄS MER

  2. 2. Differential Protection for Arbitrary Three-Phase Power Transformers

    Detta är en avhandling från Department of Industrial Electrical Engineering and Automation, Lund Institute of Technology

    Författare :Zoran Gajic; Lunds universitet.; Lund University.; [2008]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; electric power systems; power transformers; differential protection; power system protection;

    Sammanfattning : This thesis describes how to provide standardized, current based, differential protection for any three-phase power transformer, including phase-shifting transformers with variable phase angle shift and transformers of all construction types and internal on-load tap-changer configurations. The use of standard transformer differential protection for such applications is considered impossible in the protective relaying standards and practices currently applied. LÄS MER

  3. 3. Magnetizing Currents in Power Transformers Measurements, Simulations, and Diagnostic Methods

    Detta är en avhandling från Stockholm : KTH Royal Institute of Technology

    Författare :Claes Carrander; KTH.; [2017]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Transformer core; diagnostics; three-phase; no-load; hysteresis; modeling; resonance; remanence; delta; Electrical Engineering; Elektro- och systemteknik;

    Sammanfattning : This thesis demonstrates a method for transformer core diagnostics. The method uses the no-load current of the transformer as an indicator, and gives different characteristic signatures for different types of faults or defects. Using the no-load current for the diagnostic gives high sensitivity. LÄS MER

  4. 4. 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

    Detta är en avhandling från Uppsala : Acta Universitatis Upsaliensis

    Författare :Pär Holmberg; Uppsala universitet.; [2000]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; 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; NATURAL SCIENCES Physics; NATURVETENSKAP 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

  5. 5. Dynamic Rating of Power Lines and Transformers for Wind Energy Integration

    Detta är en avhandling från Stockholm : KTH Royal Institute of Technology

    Författare :Kateryna Morozovska; KTH.; [2018]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; dynamic line rating; dynamic transformer rating; power transformers; heat balance; thermal modeling; wind power; wind energy integration; reliability analysis; risk analysis; Electrical Engineering; Elektro- och systemteknik;

    Sammanfattning : Dynamic Rating (DR) is usually associated with unlocking the capacity of power lines and transformers using available information on weather conditions. Our studies show that Dynamic Rating is a broad concept that requires further study and development. LÄS MER