Sökning: "HVDC"

Visar resultat 21 - 25 av 103 avhandlingar innehållade ordet HVDC.

  1. 21. Distributed Control of HVDC Transmission Grids

    Författare :Davood Babazadeh; Lars Nordström; Oriol Gomis; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; co-simulation; cyber-physical system; DC slack bus; distributed control; HVDC grids; power injection; topology processor; wind farms; Electrical Engineering; Elektro- och systemteknik;

    Sammanfattning : Recent issues such as priority access of renewable resources recommended by European energy directives and increase the electricity trading among countries lead to new requirements on the operation and expansion of transmission grids. Since AC grid expansions are limited by legislative issues and long distance transmission capacity, there is a considerable attention drawn to application of HVDC transmission grids on top of, or in complement to, existing AC power systems. LÄS MER

  3. 22. Steady state analysis of HVDC grid with Wind Power Plants

    Författare :Kalid Yunus; Chalmers tekniska högskola; []
    Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; ARIMA; electricity price; meshed HVDC grid; WPP; transmission tariff; temporal and spatial correlation; electricity market; VSC HVDC; wind speed modelling; secondary supervisory controller; LRMC; SRMC; PV; primary controller; investment cost;

    Sammanfattning : The idea of building a multi-terminal, even a meshed HVDC grid in the North Sea, that can inter-connect surrounding nations, is being discussed widely. Such a system is expected to be realised in steps through the interconnection of wind power plants and electricity markets. LÄS MER

  4. 23. The synthesis, surface modification and use of metal-oxide nanoparticles in polyethylene for ultra-low transmission-loss HVDC cable insulation materials

    Författare :Amir Masoud Pourrahimi; Ulf W. Gedde; Alexander Bismarck; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; polyethylene; metal-oxide nanoparticles; heat treatment; surface coating; humidity resistance; interfacial adhesion; nanocomposite; HVDC insulation; polyeten; metalloxid nanopartiklar; värmebehandling; ytmodifiering av partiklarna; fukt inverkan; gränsskiktsvidhäftning; nanokomposit; HVDC isolering; Fiber- och polymervetenskap; Fibre and Polymer Science;

    Sammanfattning : Polyethylene composites which contain low concentrations of metal-oxide nanoparticles e.g. ZnO and MgO are emerging materials for the use in insulations of extruded high-voltage direct-current (HVDC) cables. LÄS MER

  5. 24. Protection for Multiterminal HVDC Grids - A Digital Contribution

    Författare :Ilka Jahn; Staffan Norrga; Hans-Peter Nee; Dirk Westermann; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; HVDC transmission; power system protection; IED; real-time systems; test bench; field programmable gate array; open-source hardware; open-source software; power engineering education; Electrical Engineering; Elektro- och systemteknik;

    Sammanfattning : The aim of this thesis is to (1) enhance understanding of mechanisms that are important for the protection of high-voltage direct-current (HVDC) grids, and (2) suggest possible technical solutions. To that end, digital technologies were used both in simulation, as well as in a laboratory environment. LÄS MER

  7. 25. A Multichoice Control Strategy for a VSC-HVdc

    Författare :Hector F. Latorre; Mehrdad Ghandhari; Lennart Söder; Kjetil Uhlen; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Control Lyapunov Function; Modal Analysis; Power Oscillation Damping; Transient Stability; Voltage Stability; VSC-HVdc; Electrical engineering; Elektroteknik;

    Sammanfattning : Utilization of power electronics based controllable systems (or devices) in transmission systems has opened new opportunities for the power industry to optimize utilization of the existing transmission systems, and at the same time to keep high system reliability and security. As a member of these controllable systems, Voltage Source Converters-based High Voltage direct current (VSC-HVdc) systems have the ability to rapidly control the transmitted active power, and also to independently exchange reactive power with transmissions systems. LÄS MER