Search for dissertations about: "HVDC grids"

Showing result 1 - 5 of 26 swedish dissertations containing the words HVDC grids.

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

   Author : Tim Augustin; Hans-Peter Nee; Marley Becerra; Jürgen Biela; KTH; []
   Keywords : 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;

   Abstract : 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. READ MORE

4. 2. Distributed Control of HVDC Transmission Grids

   Author : Davood Babazadeh; Lars Nordström; Oriol Gomis; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; co-simulation; cyber-physical system; DC slack bus; distributed control; HVDC grids; power injection; topology processor; wind farms; Electrical Engineering; Elektro- och systemteknik;

   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

5. 3. Analysis of dc-network stability of VSC-based HVDC grids

   Author : Gustavo Pinares; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; power dependent admittance; resonance; HVDC; passivity; Multi-terminal HVDC system; VSC; dc-network stability;

   Abstract : This thesis presents a modelling approach for the investigation of dc-network stability in HVDC grids. It consists on dividing the system under analysis into subsystems such that their individual impact on the stability of the overall system can be studied. READ MORE

6. 4. Modulation of Modular Multilevel Converters for HVDC Transmission

   Author : Arman Hassanpoor; Hans-Peter Nee; Staffan Norrga; Rainer Marquardt; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; HVDC; switching schemes; modulation; high power converters; power grids; Electrical Engineering; Elektro- och systemteknik;

   Abstract : The outstanding features of modular multilevel converters (MMC) have recently gained much attention in the high-voltage direct-current (HVDC) transmission field. Power quality, converter cost and system performance are three crucial aspects of HVDC MMCs which are directly linked to the converter modulation and switching schemes. READ MORE

7. 5. Efficient Modeling of Modular Multilevel Converters for HVDC Transmission Systems

   Author : Noman Ahmed; Hans-Peter Nee; Tim Green; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; High-Voltage dc; Modular Multilevel Converter; Voltage-Source Converter; HVDC Grids; Multiterminal DC Systems; Hybrid HVDC Breaker; Modeling; Electrical Engineering; Elektro- och systemteknik;

   Abstract : The drive towards getting more and more electrical energy from renewable sources, requires more efficient electric transmission systems. A stronger grid, with more controllability and higher capacity, that can handle power fluctuations due to a mismatch between generation and load is also needed. READ MORE