Sökning: "Alfred Rufer"

Hittade 4 avhandlingar innehållade orden Alfred Rufer.

  1. 1. Hybrid energy storage systems : Capacity optimization and environmental implication of hybrid energy storage systems in renewable power systems

    Författare :Yang Jiao; Daniel Månsson; Alfred Rufer; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electrical Engineering; Elektro- och systemteknik;

    Sammanfattning : Electricity production contributes a large share of greenhouse gas emissions that lead to climate change. At present, power generation in many parts of the world still heavily depends on fossil fuels. To prevent global warming, the electricity sector is supposed to transition from the current fuel mix to renewable energy sources. LÄS MER

  3. 2. On Design of a Compact Primary Switched Conversion System for Electric Railway Propulsion

    Författare :Tommy Kjellqvist; Stefan Östlund; Alfred Rufer; KTH; []
    Nyckelord :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;

    Sammanfattning : 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. LÄS MER

  4. 3. Assessment of energy storage systems for power system applications based on equivalent circuit modeling

    Författare :Cong-Toan Pham; Daniel Månsson; Alfred Rufer; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Energy storage system; Assessment; Equivalent circuit model; Suitability; ; Electrical Engineering; Elektro- och systemteknik; Energy Technology; Energiteknik;

    Sammanfattning : Climate change triggered the rethinking of our current energy system. A restructuring is necessary and in progress with the goal to improve our energy supplychain in efficiency and sustainability. This has led to the increased use of renewable energy sources such as solar and wind power. LÄS MER

  5. 4. Control and Design Aspects of Components and Systems in High-Voltage Converters for Industrial Applications

    Författare :Per Ranstad; Hans-Peter Nee; Alfred Rufer; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; High-voltage converter; resonant converter; high-voltage transformer; transformer parasitics; IGBT; soft-switching; control; Electric power engineering; Elkraftteknik;

    Sammanfattning : High-frequency dc-dc converters are widely used in power electronic applications, both in consumer products and industrial products. By operating the converter at higher frequencies both a smaller size and better control characteristics can be obtained. LÄS MER