Sökning: "snubber design"

Visar resultat 1 - 5 av 6 avhandlingar innehållade orden snubber design.

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

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

   Sammanfattning : 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. LÄS MER

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

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

   Sammanfattning : 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. LÄS MER

4. 3. Ultrahigh-Voltage Silicon Carbide Device Performance, Requirements, and Limitations in High-Power Applications

   Författare :Daniel Johannesson; Hans-Peter Nee; Staffan Norrga; Muhammad Nawaz; Alberto Castellazzi; KTH; []
   Nyckelord :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;

   Sammanfattning : 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. LÄS MER

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

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

   Sammanfattning : 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. LÄS MER

7. 5. 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