Search for dissertations about: "Lennart Harnefors"

Showing result 1 - 5 of 10 swedish dissertations containing the words Lennart Harnefors.

  2. 1. On analysis, control and estimation of variable-speed drives

    Author : Lennart Harnefors; KTH; []
    Keywords : ;

    Abstract : .... READ MORE

  4. 2. 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

  5. 3. Hybrid Converters for HVDC Transmission

    Author : Panagiotis Bakas; Lennart Harnefors; Staffan Norrga; Hans-Peter Nee; Stephen Finney; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; 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

  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. Fundamental Control Performance Limitations for Interarea Oscillation Damping and Frequency Stability

    Author : Joakim Björk; Karl H. Johansson; Lennart Harnefors; Joe H. Chow; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Power system control; HVDC transmission control; interarea oscillations; power oscillation damping; small-signal stability; fundamental control limitations; frequency stability; hydro power; wind power; non-minimum phase; zero dynamics; eigenvalue analysis; Electrical Engineering; Elektro- och systemteknik;

    Abstract : With the transition towards renewable energy and the deregulation of the electricity markets, the power system is changing. Growing electricity demand and more intermittent power production increase the need for transfer capacity. Lower inertia levels due to a higher share of renewables increase the need for fast frequency reserves (FFR). READ MORE