Search for dissertations about: "DC power transmission"

Showing result 21 - 25 of 62 swedish dissertations containing the words DC power transmission.

  2. 21. High power bipolar junction transistors in silicon carbide

    Author : Hyung-Seok Lee; Carl-Mikael Zetterling; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Silicon Carbide SiC ; power device; biplar junction transistor; TiW; ohmic contact; current gain; Electronics; Elektronik;

    Abstract : As a power device material, SiC has gained remarkable attention to its high thermal conductivity and high breakdown electric field. SiC bipolar junction transistors (BJTs) are interesting for applications as power switch for 600 V-1200 V applications. READ MORE

  4. 22. Nyquist Stability Analysis of a VSC-HVDC System with a Distributed Parameter DC-cable Model

    Author : Yujiao Song; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electric power transmission; Nyquist stability analysis; VSC-HVDC system; Distributed parameter cable model; Small gain theorem.; Weak AC-grid;

    Abstract : Voltage source converter based high voltage direct current (VSC-HVDC) transmission systems have now been in operation since 1997 as it is a reliable and flexible method of power transmission. This thesis focuses on small signal dynamics of such systems, emphasizing stability properties. READ MORE

  5. 23. Device Technology Based on High Temperature Superconductors and Microwave Breakdown in Gases

    Author : Martin Löfgren; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; distortion; penetration depth; surface resistance; transmit-receive switch; coupled-grain model; high-power; microwave; pulse; surface impedance; breakdown; propagation; modulator; air; superconductor; transmission line; resonator; coplanar waveguide; plasma;

    Abstract : This thesis deals with two separate fields of microwave technology. The first section treats microwave characterization and applications of high temperature superconducting (HTS) thin films, while the second section treats microwave breakdown in transmit-receive (TR) switches and in air. Within the first section, four main topics are adressed. READ MORE

  6. 24. Strategies, Methods and Tools for Solving Long-term Transmission Expansion Planning in Large-scale Power Systems

    Author : Desta Zahlay Fitiwi; Lennart Söder; Michel Rivier; Fernando de Cuadra; Andres Ramos; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Transmission expansion planning; uncertainty and variability; optimization; stochastic programming; moments technique; clustering; Electrical Engineering; Elektro- och systemteknik;

    Abstract : Driven by a number of factors, the electric power industry is expected to undergo a paradigm shift with a considerably increased level of variable energy sources. A significant integration of such sources requires heavy transmission investments over geographically wide and large-scale networks. READ MORE

  7. 25. Control of DC voltage in Multi-Terminal HVDC Transmission (MTDC) Systems

    Author : Mohammad Nazari; Mehrdad Ghandhari; Nicklas Johansson; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Abstract : With recent advances in power electronic technology, High-Voltage Direct Current (HVDC) transmission system has become an alternative for transmitting power especially over long distances. Multi-Terminal HVDC (MTDC) systems are proposed as HVDC systems with more than two terminals. These systems can be geographically wide. READ MORE