Search for dissertations about: "HVDC converters"

Showing result 16 - 20 of 38 swedish dissertations containing the words HVDC converters.

  2. 16. High-Efficiency SiC Power Conversion : Base Drivers for Bipolar Junction Transistors and Performance Impacts on Series-Resonant Converters

    Author : Georg Tolstoy; Hans-Peter Nee; Stig Munk-Nielsen; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Silicon Carbide; Bipolar Junction Transistor BJT ; Resonant converter; Series-resonant converter SLR ; Base drive circuits; High- Efficiency Converters; High-Frequency Converters; Electrical Engineering; Elektro- och systemteknik;

    Abstract : This thesis aims to bring an understanding to the silicon carbide (SiC) bipolar junction transistor (BJT). SiC power devices are superior to the silicon IGBT in several ways. They are for instance, able to operate with higher efficiency, at higher frequencies, and at higher junction temperatures. READ MORE

  4. 17. A Novel Oil-immersed Medium Frequency Transformer for Offshore HVDC Wind Farms

    Author : Mohammad Kharezy; Per Olof Hedekvist; Yuriu Serdyuk; Thomas Hammarström; Karsten Backhaus; RISE; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; prototype design methodology; finite element analysis; HVDC insulation design; medium frequency transformer; Wind energy; DC-DC power converters;

    Abstract : In this project, a design of an oil type medium frequency transformer for offshore wind farm applications is proposed. The design is intended for applications when series coupling of the output of the DC/DC converters of the wind turbine on their secondary side is done to achieve a cost-effective high voltage solution for collecting energy from offshore wind parks. READ MORE

  5. 18. The control of VSC-HVDC and its use for large industrial power systems

    Author : Cuiqing Du; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; VSC-HVDC; inner current controller; outer controller; PWM; dc dc converter; voltage dips; dc networks;

    Abstract : With the recent developments in semiconductors and control equipment, Voltage Source Converter based High Voltage direct Current (VSC-HVDC) has become feasible. Due to the use of VSC technology and Pulse Width Modulation (PWM), it has a number of potential advantages: short circuit current reduction; rapid, independent control of the active and reactive power, etc. READ MORE

  6. 19. Feasibility of HVDC for city infeed

    Author : Paulo Fischer de Toledo; KTH; []
    Keywords : ;

    Abstract : It is well recognized that direct current and direct voltageoffer special advantages for both land and sea cable systems,both with regard to power transmission capability, losses, aswell as possible transmission length due to no capacitivecurrents. As cable systems were used very early in largecities, one of the first applications considered for HVDC wasto use it for city infeed and some schemes were also built. READ MORE

  7. 20. Cascaded Converters with Gate-Commutated Thyristors : Experimental Verification and Auxiliary Power Supply

    Author : Tomas Modeer; Hans-Peter Nee; Staffan Norrga; Dragan Jovcic; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Abstract : This thesis describes an effort to investigate the use of gate-commutated thyristors(GCTs) in cascaded converters. Cascaded converters, such as modularmultilevel converters (M2Cs) and cascaded H-bridge converters (CHBs), haveproved to be especially suitable in high-voltage, high-power applications. READ MORE