Search for dissertations about: "power losses"

Showing result 16 - 20 of 395 swedish dissertations containing the words power losses.

  2. 16. Dynamic Rating of Power Lines and Transformers for Wind Energy Integration

    Author : Kateryna Morozovska; Patrik Hilber; Rajeev Thottappillil; Rebei Bel Fdhila; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; dynamic line rating; dynamic transformer rating; power transformers; heat balance; thermal modeling; wind power; wind energy integration; reliability analysis; risk analysis; Electrical Engineering; Elektro- och systemteknik;

    Abstract : Dynamic Rating (DR) is usually associated with unlocking the capacity of power lines and transformers using available information on weather conditions. Our studies show that Dynamic Rating is a broad concept that requires further study and development. READ MORE

  4. 17. Estimation of electromagnetic material properties with application to high-voltage power cables

    Author : Yevhen Ivanenko; Sven Nordebo; Martin Norgren; Linnéuniversitetet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Material losses; power cables; cylindrical multipole expansion; Herglotz functions; convex optimization; sum rules; Waves and Signals; Vågor och signaler;

    Abstract : Efficient design of high-voltage power cables is important to achieve an economical delivery of electric power from wind farms and power plants over the very long distances as well as the overseas electric power. The main focus of this thesis is the investigation of electromagnetic losses in components of high-voltage power cables. READ MORE

  5. 18. 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 : 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

  6. 19. On Gate Drivers for MOS-Controlled Power Devices and dv-dt Filters for Train Traction Converters

    Author : Erik Velander; Hans-Peter Nee; Francesco Iannuzzo; KTH; []
    Keywords : Power semiconductor devices; DC-AC power converters; Silicon carbide; Insulated gate bipolar transistors; P-i-n diodes; Schottky diodes; Traction motors; Power MOSFET; Krafthalvledare; DC-AC kraftomvandlare; kiselkarbid; IGBT; P-i-n dioder; Schottky dioder; traktionsmotorer; Effekt-MOSFET; Electrical Engineering; Elektro- och systemteknik;

    Abstract : In this thesis, low-loss gate-drive solutions and a proposed dv/dt-filter have been investigated with focus on train traction converters with dv/dt constraints.By using the silicon carbide (SiC) junction field-effect transistor (JFET), the switching losses can be significantly reduced compared to the commonly used insulated-gate bipolar transistor (IGBT), but complex gate-driver solutions are required for high utilization in terms of loss reduction. READ MORE

  7. 20. Grid Connection of Permanent Magnet Generator Based Renewable Energy Systems

    Author : Senad Apelfröjd; Sandra Eriksson; Frans Dijkhuizen; Uppsala universitet; []
    Keywords : VAWT; H-rotor; Tap Transformer; Cascaded H-bridge Multi-Level; Renewable Energy; Wind power; Wave power; Marine Current Power; Engineering Science with specialization in Science of Electricity; Teknisk fysik med inriktning mot elektricitetslära;

    Abstract : Renewable energy is harnessed from continuously replenishing natural processes. Some commonly known are sunlight, water, wind, tides, geothermal heat and various forms of biomass. The focus on renewable energy has over the past few decades intensified greatly. READ MORE