Search for dissertations about: "Instantaneous frequency"

Showing result 1 - 5 of 42 swedish dissertations containing the words Instantaneous frequency.

  2. 1. Spectral Analysis for Signal Detection and Classification : Reducing Variance and Extracting Features

    Author : Isabella Reinhold; Statistical Signal Processing Group; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Multifönster; Tids-frekvensanalys; Instantaneous frequency; Multitaper; Signal resolution; Reassignment method; Time-frequency analysis;

    Abstract : Spectral analysis encompasses several powerful signal processing methods. The papers in this thesis present methods for finding good spectral representations, and methods both for stationary and non-stationary signals are considered. READ MORE

  4. 2. Coordinated Frequency Control Between Interconnected AC/DC Systems

    Author : Danilo Obradovic; Mehrdad Ghandari; Robert Eriksson; Jonas Persson; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Power System Dynamics; Frequency Stability; Small Signal Stability; HVDC Supplementary Power Control; Electrical Engineering; Elektro- och systemteknik;

    Abstract : With ambitions of reducing the environmental pollution, power systems integrate larger shares of Renewable Energy Sources (RES) to phase out conventional thermal and nuclear generators. Since RES (such as wind and solar power) are connected to the grid through power electronics devices, they do not inherently contribute to system inertia. READ MORE

  5. 3. Frequency Response by Wind Farms in Islanded Power Systems with High Wind Power Penetration

    Author : Mattias Persson; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Synthetic inertia; rate of change of frequency; inertia emulation; variable speed wind turbine; frequency control;

    Abstract : The integration of variable speed wind turbines (VSWT) in power systems keep increasing inorder to reduce the emission of green house gases. This increase of power electronic converterinterfaced generation causes a decrease of power system inertia and issues previously existingin power systems tend to become more complicated and new solutions should be evaluated. READ MORE

  6. 4. The Non-Linear Instantaneous Least Squares Approach to Signal Parameter Estimation

    Author : Jakob Ängeby; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; aliasing; polynomial-phase signals; synthetic aperture radar auto-focusing; non-linear least squares; time-frequency estimation; estimation theory; non-stationary processes; non-uniform sampling;

    Abstract : Estimation of parameters of non-stationary signals observed in noise is a challenging and difficult task, motivated by applications such as radar and mobile tele-communication. Here, a novel method for signal parameter estimation named the Non-linear Instantaneous Least Squares (NILS) approach is presented, which can be applied to linear and non-linear signals, and to both uniformly and non-uniformly sampled data. READ MORE

  7. 5. Experimental Studies of Turbulent Mixing in Impinging Jets

    Author : Rong Ding; Strömningsteknik; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; LDV; Gases; fluid dynamics; plasmas; Gaser; fluiddynamik; plasma; PIV LIF; TR- LIF; TR- PIV; perturbed- and swirling- impinging jets; passive control; frequency spectrum; turbulent fluxes; impinging jets; turbulent mixing;

    Abstract : This thesis concerns the experimental study of mixing and flow characteristic in turbulent circular impinging jets without and with jet orifice manipulators (i.e. passive-fixed perturbations atthe nozzle exit), without and with swirl. READ MORE