Sökning: "high voltage direct current HVDC"

Visar resultat 21 - 25 av 56 avhandlingar innehållade orden high voltage direct current HVDC.

  1. 21. Surface Charge Dynamics on Polymeric Insulating Materials for High Voltage Applications

    Författare :Shahid Alam; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; HVDC insulation.; gas neutralization; decay rate; Surface charging; electrical conductivity; surface potential; charge transport; ambient pressure;

    Sammanfattning : To meet increasing demands in electric energy, it is essential to enhance production of electricity from renewable energy sources (solar, wind and hydro). Such generation sites, however, are usually separated from consumption sites by long distances. LÄS MER

  3. 22. 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

  4. 23. Polyethylene Blends, a Material Concept for Future HVDC-cable Insulation

    Författare :Mattias Andersson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; polymer blends; nanocomposites; polyethylene; conductivity; thermomechanical properties; High-voltage insulation; tie-chain;

    Sammanfattning : High-voltage cables are a critical component of tomorrow’s power grids that seamlessly integrate hydro, wind and solar power. Further improvements in transmission capacity of both high-voltage alternating- and direct-current, HVAC and HVDC, cables are likely reached through improved insulation materials. 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. Steady state analysis of HVDC grid in the North Sea with offshore wind power plants

    Författare :Kalid Yunus; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; scheduled exchange power; NPV; transmission fee tariff; primary controller; ARIMA; external AC grid connection; secondary supervisory controller; meshed HVDC transmission grid; VSC HVDC; WPP;

    Sammanfattning : In this thesis, some of economical and technical aspects of expanding the HVDC (High Voltage Direct Current) transmission systems in the North Sea are studied at steady state. In the thesis, it is assumed that the expansion of the system is made by connecting WPPs (Wind Power Plants) to the system which is built for power exchange. LÄS MER