Search for dissertations about: "DC power transmission"
Showing result 6 - 10 of 62 swedish dissertations containing the words DC power transmission.
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6. On the design of hybrid DC-breakers consisting of a mechanical switch and semiconductor devices
Abstract : The interest of using direct current in networks for both transmission and distribution of power is increasing due to the higher efficiency compared to the alternating current used today. As no natural zero crossings exist in direct current, the interruption of fault currents becomes a challenge. READ MORE
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7. DC Distributed Power Systems - Analysis, Design and Control for a Renewable Energy System
Abstract : Renewable energy systems are likely to become wide spread in the future due to environmental demands. As a consequence of the dispersed nature of renewable energy systems, this implies that there will be a distributed generation of electric power. READ MORE
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8. Electromagnetic Modelling of Power Transformers with DC Magnetization
Abstract : DC currents that flow through the ground can be injected to the star windings of power transformers from their grounded neutral points and close their path with transmission lines. The geomagnetically induced currents (GICs) and AC/DC convertors of high voltage direct current (HVDC) systems are the sources of such DC currents. READ MORE
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9. Distributed Control of HVDC Transmission Grids
Abstract : 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. READ MORE
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10. System Aspects and Modulation Strategies of an HVDC-based Converter System for Wind Farms
Abstract : In this thesis, a new HVDC-based converter system for wind farms is investigated. It is based on a mutually commutated soft-switching converter system and provides a unique integrated solution for the wind turbine generator drive systems, the wind turbine interconnection, and the power conversion for HVDC transmission. READ MORE