Search for dissertations about: "Fast Fourier analysis"

Showing result 1 - 5 of 34 swedish dissertations containing the words Fast Fourier analysis.

  2. 1. Voltage Transients in the Field Winding of Salient Pole Wound Synchronous Machines : Implications from fast switching power electronics

    Author : Roberto Felicetti; Urban Lundin; Jon Kjellin; Uppsala universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; apparent resistance; cable modeling; current control; transmission line model; eddy currents; field winding; frequency analysis response; Fourier Transform; impedance mismatch; main inductance; overvoltage; parasitic capacitance; partial discharge; quality factor; ringing; slew rate; stray inductance; voltage gradient; winding resonance frequency;

    Abstract : Wound Field Synchronous Generators provide more than 95% of the electricity need worldwide. Their primacy in electricity production is due to ease of voltage regulation, performed by simply adjusting the direct current intensity in their rotor winding. READ MORE

  4. 2. 3-D Characterization and Degradation Analysis of Rock aggregates

    Author : Pasi Tolppanen; KTH; []
    Keywords : 3-dimension; 3-D; laser scanning; aggregate; ballast; characterization; size; shape; volume; roughness; Fast Fourier analysis; fractal; degradation;

    Abstract : .... READ MORE

  5. 3. Automating Power Quality Analysis

    Author : Emmanouil Styvaktakis; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; pattern classification; expert systems; induction motors; power system transients; voltage dips; power system faults; power quality; Kalman filtering; power system monitoring; transformer saturation; short time Fourier transform;

    Abstract : The increased requirements on supervision, control, and performance in modern power systems make power quality monitoring a common practise for utilities. Large databases are created and automatic processing of the data is required for fast and effective use of the available information. READ MORE

  6. 4. Run-Up Transient Analysis for Salient Pole Wound Field Synchronous Motors : Field winding and power electronics implications for a smoother and cooler asynchronous start

    Author : Roberto Felicetti; Urban Lundin; Andreas Binder; Uppsala universitet; []
    Keywords : apparent resistance; cable modeling; current control; transmission line model; eddy currents; field winding; frequency analysis response; Fourier Transform; impedance mismatch; main inductance; overvoltage; parasitic capacitance; partial discharge; quality factor; ringing; slew rate; stray inductance; voltage gradient; winding resonance frequency; asynchronous start; run-up; torque ripple; reluctance torque; Engineering Science with specialization in Science of Electricity; Teknisk fysik med inriktning mot elektricitetslära;

    Abstract : Salient Pole Wound Field Synchronous Machines have better efficiency at full load than asynchronous machines of the same capability. Moreover, where asynchronous machines need inherently to draw a magnetizing current from the grid, Salient Pole Wound Field Synchronous Machines can work efficiently at unity power factor. READ MORE

  7. 5. Source localisation of epileptiform activity in epilepsy of temporal lobe origin

    Author : Göran Lantz; Klinisk neurofysiologi; []
    Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; frequency analysis; ictal; singe photon emission computed tomography; volume conduction; extracranial; intracranial; LORETA; dipole; source localisation; epilepsy; mesolimbic; Fast Fourier Transform; Neurology; neuropsychology; neurophysiology; Neurologi; neuropsykologi; neurofysiologi;

    Abstract : In patients with drug resistant partial epilepsy, who are under consideration for epilepsy surgery, interictal and ictal EEG recorded with extracranial electrodes plays an important role in the localisation of the seizure onset area. During the past years, methods have been developed, which can be used to estimate the location of the source of epileptiform activity in the brain from extracranial EEG data. READ MORE