Search for dissertations about: "current account"

Showing result 6 - 10 of 540 swedish dissertations containing the words current account.

  2. 6. Electrochemical characterisation of porous cathodes in the polymer electrolyte fuel cell

    Author : Frédéric Jaouen; KTH; []
    Keywords : polymer electrolyte fuel cell; cathode; mass transport; porous electrode; modelling; agglomerate model; electrochemical impedance spectroscopy; current interrupt; transient techniques; non-noble catalysts;

    Abstract : Polymer electrolyte fuel cells (PEFC) convert chemicalenergy into electrical energy with higher efficiency thaninternal combustion engines. They are particularly suited fortransportation applications or portable devices owing to theirhigh power density and low operating temperature. READ MORE

  4. 7. Solar Wind and Geomagnetic Activity - Predictions Using Neural Networks

    Author : Hans Gleisner; Astronomi - Genomgår omorganisation; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Geophysics; kosmisk kemi; rymdvetenskap; magnetosphere; solar wind; space weather; geomagnetic activity; geomagnetism; ring current; auroral electrojet; neural networks; forecasting; Astronomy; space research; Astronomi; cosmic chemistry; physical oceanography; meteorology; Geofysik; fysisk oceanografi; meteorologi; Fysicumarkivet A:2000:Gleisner;

    Abstract : This thesis shows how artificial neural networks (ANNs) can be applied to predict geomagnetic activity from solar-wind data. It introduces and summarizes five papers where development of ANN models are reported, and where predictions of geomagnetic activity are discussed. READ MORE

  5. 8. Aspects on Wind Turbine Protections and Induction Machine Fault Current Prediction

    Author : Marcus Helmer; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; saturation; Induction generator; Short circuit currents; Slip ring Generator; skin effect;

    Abstract : This thesis presents detailed modelling of the induction machine with the main objective being accurate fault current prediction. The thesis focus mainly on mains connected induction machines and the response due to severe disturbances in the supply voltage, such as three-phase short-circuit faults. READ MORE

  6. 9. Magnetic Leakage Fields and End Region Eddy Current Power Losses in Synchronous Generators

    Author : Birger Marcusson; Urban Lundin; Göran Engdahl; Uppsala universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; magnetic leakage fields; leakage flux; eddy currents; losses; synchronous generator; Engineering Science with specialization in Science of Electricity; Teknisk fysik med inriktning mot elektricitetslära;

    Abstract : The conversion of mechanical energy to electrical energy is done mainly with synchronous generators. They are used in hydropower generators and nuclear plants that presently account for about 80% of the electric energy production in Sweden. READ MORE

  7. 10. Coupling and Absorption of Lower Hybrid Waves in Current Profile Control Experiments in the JET Tokamak

    Author : Annika Ekedahl; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Abstract : Current drive with radio frequency waves in the lower hybrid frequency range is an important method of current profile control via non-inductive current drive in tokamaks. This thesis is concerned with profile control experiments, carried out with the lower hybrid current drive system in the Joint European Torus (JET) tokamak, with the aim to explore scenarios for operation in high confinement regimes with peaked pressure profiles. READ MORE