Search for dissertations about: "soft-switching"

Showing result 1 - 5 of 12 swedish dissertations containing the word soft-switching.

  2. 1. 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

  4. 2. On high-frequency soft-switching DC-converters for high-voltage applications

    Author : Per Ranstad; KTH; []
    Keywords : soft-switching; dc-converter; high-frequency; high-voltage;

    Abstract : .... READ MORE

  5. 3. Cost-effective Cells for High-power Modular Multilevel Converters

    Author : Matthijs Heuvelmans; Staffan Norrga; Hans-Peter Nee; Rik De Doncker; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; MMC; modular multilevel converter; ARCP; IGCT; soft-switching; ZVS; ZCS; snubber; thyristor; SCR; silicon controlled rectifier; HVDC; STATCOM; Electrical Engineering; Elektro- och systemteknik;

    Abstract : The modular multilevel converter (MMC) topology was introduced in 2003and has since been receiving considerable attention from industry and academia.Notable benefits compared to two- or three-level voltage source convertersare its scalability, low switching losses, low output filter requirementsand ease of adding redundancy combined with fail-safe operation. READ MORE

  6. 4. 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. 5. System Aspects and Modulation Strategies of an HVDC-based Converter System for Wind Farms

    Author : Stephan Meier; Hans-Peter Nee; Boon-Teck Ooi; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Isolated AC DC Converter; Mutual Commutation; Soft Switching; Voltage Source Converter; Cycloconverter; Modulation Strategies; Medium-Frequency Transformer; HVDC Transmission; Wind Power; Wind Farms; Electric power engineering; Elkraftteknik; Electrical engineering; Elektroteknik;

    Abstract :   In this thesis, a new HVDC-based converter system for wind farms is investigated. It is based on a mutually commutated soft-switching converter system and provides a unique integrated solution for the wind turbine generator drive systems, the wind turbine interconnection, and the power conversion for HVDC transmission. READ MORE