Sökning: "three-phase system"

Visar resultat 1 - 5 av 48 avhandlingar innehållade orden three-phase system.

  1. 1. Faults detection and diagnosis for three phase induction machines

    Författare :Mohammed Obaid Mustafa; George Georgoulas; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Reglerteknik; Control Engineering;

    Sammanfattning : Three phase induction motors have been intensively utilized in industrial applications, mainly due to their efficiency and reliability. These motors have good properties such as: increased stability and robustness, durability, large power to weight ratio, low production costs and controllability easiness. LÄS MER

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

    Författare :Zoran Gajic; Industriell elektroteknik och automation; []
    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

  4. 3. Multilevel three-phase dual active bridge dc-dc converters - A study on converter modulation, capacitive energy requirement, ZVS boundaries, MFT's winding connections, and core losses

    Författare :Babak Alikhanzadehalamdari; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; high-voltage power converters; dual active bridge; harmonic analysis; three-phase system; medium-frequency transformer; capacitor sizing; multilevel converters; high power-density systems; transformer winding connection; core loss modeling; dc collector network; soft-switching converters;

    Sammanfattning : The collection and transmission of power from offshore wind turbines using dc have advantages over the ac system. One of the enabling technologies for deploying dc collection is the dc-dc converter that boosts the dc output from the turbine to the medium-voltage dc level of the collection grid. LÄS MER

  5. 4. Three Phase Controlled Fault Interruption Using High Voltage SF6 Circuit Breakers

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

    Sammanfattning : 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. LÄS MER

  7. 5. High Efficiency Inductive Power Transfer Systems for Vehicle Charging

    Författare :Daniel Pehrman; Chalmers tekniska högskola; []
    Nyckelord :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;

    Sammanfattning : 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. LÄS MER