Sökning: "HVDC"
Visar resultat 21 - 25 av 103 avhandlingar innehållade ordet HVDC.
21. Distributed Control of HVDC Transmission Grids
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
22. Steady state analysis of HVDC grid with Wind Power Plants
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
23. The synthesis, surface modification and use of metal-oxide nanoparticles in polyethylene for ultra-low transmission-loss HVDC cable insulation materials
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
24. Protection for Multiterminal HVDC Grids - A Digital Contribution
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
25. A Multichoice Control Strategy for a VSC-HVdc
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