Search for dissertations about: "Staffan Norrga"

Showing result 1 - 5 of 11 swedish dissertations containing the words Staffan Norrga.

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

    Author : Staffan Norrga; Stefan Östlund; Rik De Doncker; KTH; []
    Keywords : ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; 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

  2. 2. Hybrid Converters for HVDC Transmission

    Author : Panagiotis Bakas; Lennart Harnefors; Staffan Norrga; Hans-Peter Nee; Stephen Finney; KTH; []
    Keywords : ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; High-voltage direct current HVDC ; hybrid alternate-common arm converter HACC ; hybrid converters; line-commutated converters LCCs ; modular multilevel converters MMCs ; thyristors; Hybrid alternate-common-arm converter HACC ; hybrid omvandlare; högspänd likströmsöverföring HVDC ; linjekommuterade omvandlare LCC ; modulära multinivåomvandlare MMC ; tyristorer; Electrical Engineering; Elektro- och systemteknik;

    Abstract : The line-commutated converter (LCC) and the voltage-source converter (VSC) are the two main converter technologies utilized in high-voltage direct current (HVDC) transmission applications. Depending on the application requirements, one technology might be more advantageous than the other. READ MORE

  3. 3. Modeling of Modular Multilevel Converters for Stability Analysis

    Author : Luca Bessegato; Stefan Östlund; Staffan Norrga; Lennart Harnefors; Xiongfei Wang; KTH; []
    Keywords : ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; Modular multilevel converters MMCs ; stability; admittance; frequency-domain analysis; linearization techniques; current control; voltage control; ac ac converters; railway engineering.; Modulära multinivåomvandlare MMC ; stabilitet; admittans; frekvensanalys; linjäriseringsmetoder; strömreglering; spänningsreglering; ac ac omvandlare; järnvägsteknik.; Electrical Engineering; Elektro- och systemteknik;

    Abstract : Modular multilevel converters (MMCs) have recently become the state-of-the-art solution for various grid-connected applications, such as high-voltage direct current (HVDC) systems and flexible alternating current transmission systems (FACTS). Modularity, scalability, low power losses, and low harmonic distortion are the outstanding properties that make MMCs a key technology for a sustainable future. READ MORE

  4. 4. Modulation of Modular Multilevel Converters for HVDC Transmission

    Author : Arman Hassanpoor; Hans-Peter Nee; Staffan Norrga; Rainer Marquardt; KTH; []
    Keywords : ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; HVDC; switching schemes; modulation; high power converters; power grids; Electrical Engineering; Elektro- och systemteknik;

    Abstract : The outstanding features of modular multilevel converters (MMC) have recently gained much attention in the high-voltage direct-current (HVDC) transmission field. Power quality, converter cost and system performance are three crucial aspects of HVDC MMCs which are directly linked to the converter modulation and switching schemes. READ MORE

  5. 5. 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 : ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; 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