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Visar resultat 1 - 5 av 175 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. Auroral Electric Fields From Satellite Observations and Numerical Modelling

    Författare :Tomas Karlsson; KTH; []
    Nyckelord :Satellite measurements; electric fields; ionosphere; magnetosphere; diverging electric fields; downward current region; black aurora; westward travelling surge; auroral bulge; subauroral ion drifts SAID ; subauroral electric fields SAEF ; mid-latit; TECHNOLOGY; TEKNIKVETENSKAP;

    Sammanfattning : This thesis is about electrodynamics of thehigh-latitude/auroral region of near-Earth space. The work ismainly based on electric field measurements made by the doubleprobe instrument on the Freja satellite at altitudes ofapproximately 800-1700 km, together with measurements fromother instruments on the same satellite, and ground-basedinstrumentation. LÄS MER

  2. 2. Prediction of Cooling Air Flow in Electric Generators

    Författare :Pirooz Moradnia; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; CFD; Multiple Reference Frame; PIV; Total Pressure Measurements; Electric Generator; Experimental Measurements; 5-hole Pressure Probe Measurements; Flow Prediction; OpenFOAM;

    Sammanfattning : The cooling air flow in hydro power electric generators is investigated experimentally and numerically. A fully predictive numerical approach is presented and validated, in which the inlet and outlet boundaries are eliminated from the computational domain. LÄS MER

  3. 3. Infrared laser spectroscopic methods for temperature and electric field strength measurements

    Författare :Svante Höjer; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; molecular beam; electric field strength; high voltage components; sulfur hexafloride; ammonia; optical sensors; insulating gases; nitric oxide; industrial applications; Stark effect; Tunable diode laser absorption spectroscopy TDLAS ;

    Sammanfattning : .... LÄS MER

  4. 4. Highly Dynamic Drives for Electric Hybrid Vehicles : Electric Machine Design and Dynamic Test Method

    Författare :Yury Loayza Vargas; Industriell elektroteknik och automation; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electric Hybrid Vehicles; Electric Machine Design; Dynamic Testing; Dynamic loading; Synthetic Loading; FPGA; Torque Measurement; Field weakening controller FWC ; IPMSM; FEMM; LabVIEW; Dynamic Testing Technique; Dynamic Test Method; CompactRIO;

    Sammanfattning : Electric Hybrid Vehicles (EHVs) play a crucial role in the development towardsa more environmental friendly transportation. An alternative to solve someactual challenges with hybridization of vehicles is studied at the Division ofIndustrial Electrical Engineering and Automation (IEA) at Lund Universityin cooperation with the automotive industry. LÄS MER

  5. 5. Increasing Energy Efficiency in Electric Trains Operation : Driver Advisory Systems and Energy Storage

    Författare :Nima Ghaviha; Erik Dahlquist; Markus Bohlin; Fredrik Wallin; Rob M.P. Goverde; Mälardalens högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Driver Advisory System; Catenary-free Operation; Electric Train; Electric Multiple Unit; Battery; Energy Efficiency; Energy Storage; Speed Profile Optimization; Energy- and Environmental Engineering; energi- och miljöteknik;

    Sammanfattning : Electric traction is the most efficient traction system in the railway transportation. However, due to the expensive infrastructure and high power demand from the grid, the share of electric trains in the railway transportation is still lower than other trains. LÄS MER