Sökning: "HVDC Grids"

Visar resultat 11 - 15 av 26 avhandlingar innehållade orden HVDC Grids.

1. 11. VSC-HVDC for Industrial Power Systems

   Författare :Cuiqing Du; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; voltage dips; vector controller; VSC-HVDC; outer controller; current limit; industrial power systems.;

   Sammanfattning : The recent developments in semiconductors and control equipment have made the voltage source converter based high voltage direct current (VSC-HVDC) feasible. Due to theuse of VSC technology and pulse width modulation (PWM) the VSC-HVDC has a number of potential advantages as compared with classic HVDC, such as short circuit current reduction, rapid and independent control of active and reactive power, etc. LÄS MER

3. 12. Performance Quantification of Interarea Oscillation Damping Using HVDC

   Författare :Joakim Björk; Karl H. Johansson; Lennart Harnefors; Robin Preece; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; HVDC transmission control; interarea oscillations; power oscillation damping; small-signal stability; frequency control; controllability; MIMO control; decoupling control; multivariable interaction; Electrical Engineering; Elektro- och systemteknik;

   Sammanfattning : With the transition towards renewable energy, and the deregulation of the electricity market, generation patterns and grid topology are changing. These changes increase the need for transfer capacity. One limiting factor, which sometimes leads to underutilization of the transmission grid, is interarea oscillations. LÄS MER

4. 13. Silicon-Carbide-Based High-Voltage Submodules for HVDC Voltage-Source Converters

   Författare :Keijo Jacobs; Hans-Peter Nee; Staffan Norrga; Marc Hiller; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Silicon carbide; HVDC converters; voltage source converters; modular multilevel converters; submodule topologies; metal-oxide-semiconductor field-effect transistor MOSFET ; insulated-gate bipolar-transistor IGBT ; power semiconductor devices; high-voltage; Electrical Engineering; Elektro- och systemteknik;

   Sammanfattning : In order to transition to renewable energy sources and simultaneously meet the increasing demand for electrical energy, highly flexible and efficient grids are required. High-voltage direct-current (HVDC) transmission and grids are foreseen to be a vital part of the future electricity grid. LÄS MER

5. 14. Modeling and Verification of Ultra-Fast Electro-Mechanical Actuators for HVDC Breakers

   Författare :Ara Bissal; Göran Engdahl; Elena Lomonova; KTH; []
   Nyckelord :Actuators; Armature; Capacitors; Circuit breakers; Coils; Damping; Eddy currents; Elasticity; Electro-mechanical devices; Electromagnetic forces; Finite element methods; HVDC transmission; Image motion analysis; Magnetic domains; Magnetic flux; Magnetic forces; Magnetic materials; Magnets; Thermal analysis; Electrical Engineering; Elektro- och systemteknik;

   Sammanfattning : The continuously increasing demand for clean renewable energy has rekindled interest in multi-terminal high voltage direct current (HVDC) grids. Although such grids have several advantages and a great potential, their materialization has been thwarted due to the absence of HVDC breakers. LÄS MER

7. 15. On the robust stability analysis of VSC-HVDC systems

   Författare :Yujiao Song; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; symbolic eigenvalue expressions; distributed parameter cable model; AC-grid interaction; VSC-HVDC system; passivity theorem; small gain theorem; Nyquist stability analysis;

   Sammanfattning : This thesis focuses on small signal stability analysis of VSC-HVDC systems, emphasizing the system stability robustness with regard to the connected AC-grid and the distributed parameter DC-grid model respectively. In addition, for strong AC-grid connected systems, analytical eigenvalue expressions are provided to investigate the impact of physical or control parameters on the system stability for both two-terminal and multi-terminal VSC-HVDC systems. LÄS MER