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Visar resultat 1 - 5 av 6 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Sound propagation around off-shore wind turbines

   Författare :Lisa Johansson; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; wind turbine noise; off-shore wind powe; long-rage sound propagation; parabolic equation; scattering; water waves; Building engineering; Byggnadsteknik;

   Sammanfattning : Low-frequency, long-range sound propagation over a seasurface has been calculated using a wide-angel Cranck-NicholsonParabolic Equation method. The model is developed toinvestigate noise from off-shore wind turbines. Thecalculations are made using normal meteorological conditions ofthe Baltic Sea. LÄS MER

3. 2. Vindkraft och lokala förankringsprocesser : Perspektiv på deltagande, förståelse och acceptans

   Författare :Sanna Mels; Lars Aronsson; Lena Grip; Renard S:t Clair; Marie Stenseke; Karlstads universitet; []
   Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; local consultation processes; off-shore wind power; planning; legitimacy; participation; förankring; havsbaserad vindkraft; planering; legitimitet; medborgardeltagande; Kulturgeografi; Human Geography;

   Sammanfattning : This study examines different meanings attached to and practices adopted during Swedish local consultation processes on offshore wind power projects. It analyses the role played by those processes in a democratic planning context, as well as the ways in which they are implemented. It also identifies overarching process models. LÄS MER

4. 3. Energy-efficient Generating System for HVDC Off-shore Wind Turbine

   Författare :Poopak Roshanfekr; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; surface permanent magnet synchronous generator SPMSG ; IGBT active rectifier; high voltage direct current HVDC ; wind energy; dc-link voltage; synchronous reluctance generator SynRG ; annual energy efficiency; diode passive rectifier; finite element method FEM ; interior permanent magnet synchronous generator IPMSG ;

   Sammanfattning : This thesis investigates the design of energy efficient generating systems for off-shore wind turbines. For the generator part of the electric drive system, a surface mounted permanent magnet synchronous generator (SPMSG), an interior permanent magnet generator (IPMSG) as well as a synchronous reluctance generator (SynRG) have been investigated. LÄS MER

5. 4. Design and Assessment of HVDC Off-shore Wind Turbine Generator

   Författare :Poopak Roshanfekr; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; annual energy efficiency.; permanent magnet assisted synchronous reluctance generator PMa-SynRG ; high voltage direct current HVDC ; wind energy; finite element method FEM ; maximum torque per ampere MTPA ; interior permanent magnet synchronous generator IPMSG ;

   Sammanfattning : In this work, design and assessment of a 5 MW wind energy generator with a gearbox is performed to find an energy-efficient generator for HVDC offshore wind turbines, studying aninterior permanent magnet synchronous generator (IPMSG) as well as a permanent magnetassisted synchronous reluctance generator (PMa-SynRG). Quantities such as torque density,torque ripple, losses and amount of magnet material are studied. LÄS MER

7. 5. 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