Advanced search

Showing result 1 - 5 of 37 swedish dissertations matching the above criteria.

  2. 1. A calibration system for instrument transformers with digital output

    Author : Jon Ivar Juvik; RISE; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; instrument transformers; measurement uncertainty; current transformers; phase displacement; phase measurement; calibration; potential transformers; phase error; digital signal processing;

    Abstract : .... READ MORE

  4. 2. Dielectric diagnostics of oil-paper insulated current transformers

    Author : Roberts Neimanis; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Abstract : .... READ MORE

  5. 3. Differential Protection for Arbitrary Three-Phase Power Transformers

    Author : Zoran Gajic; Industriell elektroteknik och automation; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; electric power systems; power transformers; differential protection; power system protection;

    Abstract : 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. READ MORE

  6. 4. On methods of measuring magnetic properties of power transformers

    Author : Claes Carrander; Göran Engdahl; Anders Bergqvist; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; No-load; magnetizing current; losses; diagnostics; delta; three-phase; power transformer; magnetic core; electrical steel; measurements; simulation; Electrical Engineering; Elektro- och systemteknik;

    Abstract : The core of a power transformer can weigh hundreds of tons, and represents a significant part of the total ownership cost of the transformer, in terms of both the construction cost and of the monetary cost of losses. It is therefore desirable to have a method of diagnosing the core to ensure optimal performance, and to enable the operator to plan repairs of damaged or defective cores. READ MORE

  7. 5. Magnetizing Currents in Power Transformers : Measurements, Simulations, and Diagnostic Methods

    Author : Claes Carrander; Hans Edin; Göran Engdahl; Rajeev Thottappillil; Amr Adly; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Transformer core; diagnostics; three-phase; no-load; hysteresis; modeling; resonance; remanence; delta; Electrical Engineering; Elektro- och systemteknik;

    Abstract : 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. READ MORE