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Visar resultat 1 - 5 av 83 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Enhanced Active Resonant DC Circuit Breakers for HVDC Grids

   Författare :Tim Augustin; Hans-Peter Nee; Marley Becerra; Jürgen Biela; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Active damping; Actuator; DC circuit breakers; DC grid; DC power systems; Fast mechanical switch; Fault handling strategy; Gas discharge devices; HVDC; HVDC circuit breakers; Multilevel converters; Multiterminal HVDC; Power transmission; Spark gaps; Thomson-coil actuator; Vacuum interrupter; Voltage Source Converter VSC ; Electrical Engineering; Elektro- och systemteknik;

   Sammanfattning : High-voltage DC (HVDC) grids are considered promising for the electricity grid expansion required to integrate renewable energy sources into the existing infrastructure. DC fault currents increase rapidly and lack a current zero crossing. LÄS MER

3. 2. On Techno-economic Assessment of a Multi-terminal VSC-HVDC in AC Transmission Systems

   Författare :Feng Wang; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Transmission Grid.; Loss minimization; AC DC system; Transmission expansion planning; Multi-terminal VSC-HVDC; Cost minimization; Cost-benefit analysis; Electric power system; Optimal power flow;

   Sammanfattning : The Voltage Source Converter based Multi-Terminal high voltage Direct Current transmission system (VSC-MTDC) is currently considered as an attractive technical option for increased transmission capacity and improved controllability and flexibility of an electric power grid, thanks to its unique performance characteristics, and the possibility of using the extruded XLPE cables. In the planning process of embedding a VSC-MTDC system into an ac transmission grid, one must assess the potential values in terms of improved energy efficiency, i. LÄS MER

4. 3. Operation and control of HVDC links embedded in AC systems

   Författare :Jenny Paulinder; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; load voltage dependency; system overload; AC DC interaction; HVDC; voltage instability; control of hvdc converters;

   Sammanfattning : .... LÄS MER

5. 4. Coordinated Frequency Control Between Interconnected AC/DC Systems

   Författare :Danilo Obradovic; Mehrdad Ghandari; Robert Eriksson; Jonas Persson; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Power System Dynamics; Frequency Stability; Small Signal Stability; HVDC Supplementary Power Control; Electrical Engineering; Elektro- och systemteknik;

   Sammanfattning : With ambitions of reducing the environmental pollution, power systems integrate larger shares of Renewable Energy Sources (RES) to phase out conventional thermal and nuclear generators. Since RES (such as wind and solar power) are connected to the grid through power electronics devices, they do not inherently contribute to system inertia. LÄS MER

7. 5. On Stability Enhancement in AC/DC Power Systems through Multi-terminal HVDC Controllers

   Författare :Omar Kotb; Mehrdad Ghandari; Oriol Gomis Bellmunt; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; AC DC power system; hybrid MTDC; multi-terminal HVDC; small signal stability; VSC-MTDC; Electrical Engineering; Elektro- och systemteknik;

   Sammanfattning : Due to the increasing share of renewable energy sources in modern power systems and electricity market deregulation, heavy inter-regional and cross-border power flows are becoming a commonplace in system operation. Moreover, large-scale integration of renewable energy sources is expected to pace up, therefore new solutions have to be developed to integrate these intermittent sources, which are also characterized by being distributed over large geographical areas, such as offshore wind farms. LÄS MER