Search for dissertations about: "voltage source converter VSC"

Showing result 21 - 25 of 30 swedish dissertations containing the words voltage source converter VSC.

  2. 21. Main Circuits, Submodules, and Auxiliary Power Concepts for Converters in HVDC Grids

    Author : Stefanie Heinig; Hans-Peter Nee; Staffan Norrga; Kalle Ilves; Rainer Marquardt; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Ac–dc power conversion; energy storage; fault tolerance; HVDC converters; HVDC grid; isolated power supply; modular multilevel converter MMC ; power system faults; silicon carbide; submodules; voltage source converter VSC ; Electrical Engineering; Elektro- och systemteknik;

    Abstract : In order to enable the massive introduction of renewable energies the need for high-voltage direct current (HVDC) grids is anticipated. Large, globally interconnected HVDC networks will likely be the most cost-efficient means to balance electricity demand and available generation. READ MORE

  4. 22. Enhanced Active Resonant DC Circuit Breakers for HVDC Grids

    Author : Tim Augustin; Hans-Peter Nee; Marley Becerra; Jürgen Biela; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Active damping; Actuator; DC circuit breakers; DC grid; DC power systems; Fast mechanical switch; Fault handling strategy; Gas discharge devices; HVDC; HVDC circuit breakers; Multilevel converters; Multiterminal HVDC; Power transmission; Spark gaps; Thomson-coil actuator; Vacuum interrupter; Voltage Source Converter VSC ; Electrical Engineering; Elektro- och systemteknik;

    Abstract : High-voltage DC (HVDC) grids are considered promising for the electricity grid expansion required to integrate renewable energy sources into the existing infrastructure. DC fault currents increase rapidly and lack a current zero crossing. READ MORE

  5. 23. Voltage source converters for mitigation of flicker caused by arc furnaces

    Author : Tomas Larsson; KTH; []
    Keywords : ;

    Abstract : The thesis deals with flicker and how to mitigate it bymeans of a Voltage Source Converter (VSC). Flicker, orvariations in illumination intensity, is above a certain levelvery annoying. The background to flicker is voltage amplitudefluctuating in certain frequency intervals caused bytime-fluctuating loads. READ MORE

  6. 24. On Design of a Compact Primary Switched Conversion System for Electric Railway Propulsion

    Author : Tommy Kjellqvist; Stefan Östlund; Alfred Rufer; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Isolated AC DC converter; Mutual commutation; Soft Switching; Cyclo converter; Medium-Frequency Transformer; Electric Railway Propulsion; Electrical engineering; Elektroteknik;

    Abstract : In this thesis, a compact and light primary switched conversion system for AC-fed railway propulsion is investigated. It is characterized by soft switching of all converter stages and a source commutated primary converter comprising series connected valves. READ MORE

  7. 25. Nyquist Stability Analysis of a VSC-HVDC System with a Distributed Parameter DC-cable Model

    Author : Yujiao Song; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electric power transmission; Nyquist stability analysis; VSC-HVDC system; Distributed parameter cable model; Small gain theorem.; Weak AC-grid;

    Abstract : Voltage source converter based high voltage direct current (VSC-HVDC) transmission systems have now been in operation since 1997 as it is a reliable and flexible method of power transmission. This thesis focuses on small signal dynamics of such systems, emphasizing stability properties. READ MORE