Search for dissertations about: "DC power transmission"

Showing result 1 - 5 of 51 swedish dissertations containing the words DC power transmission.

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

    Author : Tim Augustin; Hans-Peter Nee; Marley Becerra; Jürgen Biela; KTH; []
    Keywords : ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; 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

  2. 2. Design and Optimization Considerations of Medium-Frequency Power Transformers in High-Power DC-DC Applications

    Author : Amin Bahmani; Chalmers University of Technology; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Nanocrystalline-Magnetic Core; High-Power Isolated DC-DC Converter; Solid-State Transformers; Leakage Inductance; Isolation Requirements; Medium-Frequency Power Transformer;

    Abstract : Recently, power electronic converters are considered as one of the enabling technologies that can address many technical challenges in future power grids from the generation phase to the transmission and consequently distribution at different voltage levels. In contrast to the medium-power converters (5 to 100 kW) which have beenessentially investigated by the automotive and traction applications, megawatt and medium-voltage range isolated converters with a several kilohertz isolation stage,also called solid-state transformers (SST), are still in an expansive research phase. READ MORE

  3. 3. Some Control Applications in Electric Power Systems

    Author : Magnus Akke; Industriell elektroteknik och automation; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; load switching.; power oscillations; differential equation algorithm; transmission line protection; computer relaying; frequency estimation; DC cable; magnetic compass; Automation; robotics; control engineering; Automatiska system; robotteknik; reglerteknik;

    Abstract : This thesis presents some control applications in electric power systems. The work consists of the four parts: interaction between DC cables and ship steering autopilots; frequency estimation; computer relaying; field tests using load switching to damp power oscillations. READ MORE

  4. 4. On the design of hybrid DC-breakers consisting of a mechanical switch and semiconductor devices

    Author : Jesper Magnusson; Göran Engdahl; Staffan Norrga; KTH; []
    Keywords : ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; DC; circuit breaker; hybrid breaker; DC systems; DC; brytare; hybridbrytare; likström;

    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

  5. 5. DC Distributed Power Systems - Analysis, Design and Control for a Renewable Energy System

    Author : Per Karlsson; Industriell elektroteknik och automation; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Energiforskning; fault detection; load sharing; wind power; DC distributed power system; voltage control; Energy research; Elektronik och elektroteknik; VSC; Electronics and Electrical technology;

    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