Search for dissertations about: "three-phase"

Showing result 6 - 10 of 88 swedish dissertations containing the word three-phase.

  2. 6. High Efficiency Inductive Power Transfer Systems for Vehicle Charging

    Author : Daniel Pehrman; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; dual-active bridge; power flow control; bi-directional; electric vehicles; electromagnetic fields; inductive power transfer; high efficiency; high power; three-phase;

    Abstract : Awareness of climate change due to greenhouse gas emissions and air pollution has led to a transition from internal combustion engine vehicles to electric vehicles. Wireless charging by inductive power transfer is a promising solution for charging electric vehicles. READ MORE

  4. 7. 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

  5. 8. 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

  6. 9. On the supraharmonics in single-phase and three-phase installations

    Author : Jil Sutaria; Sarah Rönnberg; Math Bollen; Andrés Pavas Martinez; Luleå tekniska universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electric Power Engineering; Elkraftteknik;

    Abstract : Society has increasingly started depending on the continuity of internet services, the interruption can be crucial for vital societal functions. It is therefore important to maintain continuous and reliable operations of e.g., installations housing sensitive IT (Information Technology) loads. READ MORE

  7. 10. Three Phase Controlled Fault Interruption Using High Voltage SF6 Circuit Breakers

    Author : Richard Thomas; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; controlled switching; high voltage; hypothesis testing; circuit breakers; fault interruption; least mean squares regression; power system protection;

    Abstract : A method is presented for implementing controlled fault interruption,using high voltage, SF6 circuit breakers on three phase high voltage powernetworks. The main goal of the method is to synchronize the opening or tripcommands to each phase of a circuit breaker with respect to target currentzero times so that each phase will interrupt with a preselected arcingtime. READ MORE