Search for dissertations about: "converter ac ac"

Showing result 1 - 5 of 62 swedish dissertations containing the words converter ac ac.

  2. 1. On the Internal Dynamics and AC-Motor Drive Application of Modular Multilevel Converters

    Author : Antonios Antonopoulos; Hans-Peter Nee; Lennart Harnefors; Hirofumi Akagi; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Capacitor-Voltage Control; Controller Interaction; Converter Control; Energy Balance; Lyapunov Stability; Medium-Voltage Drives; Modular Multilevel Converter; Modulation; Open-Loop Control; Optimization; Variable-Speed Drives; Voltage-Source Converter.; Energibalans; Kondensatorspänningsstyrning; Lyapunov-stabilitet; Mellan-spänning drivsystem; Modulation; Modulär multinivåomvandlare; Omvandlarstyrning; Optimering; Regulatorväxelverkan; Spänningsstyva omvandlare; Varvtalsstyrda motordrifter; Öppen styrning.; Electrical Engineering; Elektro- och systemteknik;

    Abstract : This thesis is an effort to investigate the operation and the performanceof modular multilevel converters (M2Cs). Proven to be the most promisingtopology in high-voltage high-power applications, it is necessary to put aneffort in understanding the physical laws that govern the internal dynamicsof such converters, in order to design appropriate control methods. READ MORE

  4. 2. A new Auxiliary Converter Topology with SiC Components for Railway Applications

    Author : LUYU WANG; Industriell elektroteknik och automation; []
    Keywords : Auxiliary converter; Multilevel converter; ; Silicon Carbide transistors;

    Abstract : Smaller size and lower weight are always the targets of the power electronic product development. This work introduces two new topologies of auxiliary converters which have the feature of fewer components and fewer number of energy conversion stages comparing with the conventional auxiliary converter used in railway applications. READ MORE

  5. 3. Wireless Control of Modular Multilevel Converter Submodules

    Author : Baris Ciftci; Hans-Peter Nee; Lennart Harnefors; Staffan Norrga; James Gross; Lars Kildehöj Rasmussen; Remus Teodorescu; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; 5G mobile communication; autonomous control; converter control; distributed control; electromagnetic interference; emerging technology; fault ride-through; modular multilevel converter MMC ; prototype; wireless control; Electrical Engineering; Elektro- och systemteknik;

    Abstract : The modular multilevel converter (MMC) has extensively been used in high-voltage, high-power applications such as high-voltage dc transmission systems and flexible alternating current transmission systems. The control of MMC submodules is conventionally realized using wired communication systems. READ MORE

  6. 4. Modeling of Modular Multilevel Converters for Stability Analysis

    Author : Luca Bessegato; Stefan Östlund; Staffan Norrga; Lennart Harnefors; Xiongfei Wang; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; 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

  7. 5. 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