Search for dissertations about: "Power Transformer"

Showing result 16 - 20 of 78 swedish dissertations containing the words Power Transformer.

  2. 16. 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

  4. 17. On Power-system Benefits, Main-circuit Design, and Control of StatComs with Energy Storage

    Author : Hailian Xie; Hans-Peter Nee; Lennart Ängquist; Timothy Green; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Energy storage; Voltage source converter; VSC; Static synchronous compensation; StatCom; Active power compensation; Phase jump; Voltage dip; Weak network; Flux modulation; Deadbeat current control; Transformer saturation; Dual thyristor converter; dc interface; Electrical engineering; Elektroteknik; Electric power engineering; Elkraftteknik;

    Abstract : Static synchronous compensation (StatCom) is an application that utilizes a voltage source converter (VSC) to provide instantaneous reactive power support to the connected power system. Conventionally, StatComs are employed for reactive power support only. READ MORE

  5. 18. On soft-switching isolated AC/DC converters without auxiliary circuit

    Author : Staffan Norrga; Stefan Östlund; Rik De Doncker; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electrical power technology; voltage source converter; cycloconverter; isolated converter; medium frequency transformer; soft switching; modulation; commutation; wind power; electric traction; Elkraftteknik; Electric power engineering; Elkraftteknik;

    Abstract : The thesis is concerned with a class of power electronic converter systems that permit bidirectional AC/DC conversion with galvanic separation of the AC and DC sides by a transformer operating at elevated frequency. The systems consist of a capacitively snubbered voltage source converter and a cycloconverter, separated by the mentioned transformer. READ MORE

  6. 19. 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

  7. 20. A lumped element transformer model including core losses and winding impedances

    Author : David Ribbenfjärd; Göran Engdahl; Arvid Broddefalk; KTH; []
    Keywords : 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;

    Abstract : 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. READ MORE