Search for dissertations about: "snubber design"

Showing result 1 - 5 of 6 swedish dissertations containing the words snubber design.

  2. 1. Energy Evaluation for DC/DC Converters in DC-Based Wind Farms

    Author : Lena Max; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; DC DC converter; loss evaluation; measurements; hard switching converters; wind energy; resonant converters; snubber design;

    Abstract : In this thesis the suitability of three topologies for DC/DC converters in a DC wind farm grid is investigated from an energy efficiency and energy production cost point of view. The three selected topologies are the fullbridge converter, the single active bridge converter and the series parallel resonant converter. READ MORE

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

    Author : Jesper Magnusson; Göran Engdahl; Staffan Norrga; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; 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. 3. Ultrahigh-Voltage Silicon Carbide Device Performance, Requirements, and Limitations in High-Power Applications

    Author : Daniel Johannesson; Hans-Peter Nee; Staffan Norrga; Muhammad Nawaz; Alberto Castellazzi; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; 4H-SiC; Current Filamentation; Device Characterization; Dynamic Avalanche; JTE Structure; Junction Termination Extension Design; SiC BJT; SiC GTO Thyristor; SiC IGBT; SiC MOSFET; SiC PiN Diode; Silicon Carbide; TCAD Simulation; Wide bandgap device; Electrical Engineering; Elektro- och systemteknik;

    Abstract : The increased awareness of the on-going climate change accelerates the electric energy system transformation from fossil-fueled power sources towards systems with larger portions of renewable energy sources. Moreover, the grid infrastructure requires reinforcements to cope with increasing electrical energy demand. READ MORE

  6. 4. Studies on Current Commutation in Hybrid DC-breakers

    Author : Jesper Magnusson; Göran Engdahl; Magne Runde; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Commutation; Hybrid DC-breakers; Electrical Engineering; Elektro- och systemteknik;

    Abstract : Compared to conventional AC-circuit breakers, a DC-breaker has to act fast and force the current down to zero. Many different DC-breaker topologies are available, and this thesis is focused on the hybrid DC-breaker comprising a mechanical switch and high power semiconductors. READ MORE

  7. 5. High Frequency Model of Electrified Railway Propulsion System for EMC Analysis

    Author : Kelin Jia; Rajeev Thottappillil; Hans Bängtsson; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electromagnetic compatibility; railway; propulsion system; multitransmission line; ac motor modeling; vector fitting; fast transient;

    Abstract : A model of the electrified railway propulsion system working in a wide frequency range is studied in this thesis. The high frequency modeling is the first stage to study and predict the Electromagnetic compatibility (EMC) problems in the electrified railway propulsion system, which are safety and reliability issues of high concern. READ MORE