Sökning: "transient stability"

Visar resultat 1 - 5 av 163 avhandlingar innehållade orden transient stability.

  1. 1. Stability of Low-Frequency AC Railways : Models and Transient Stability

    Författare :John Laury; Lars Abrahamsson; Math Bollen; Pablo Arboleya; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electric Power Engineering; Elkraftteknik;

    Sammanfattning : Low-frequency AC railway grids are unique in the sense that a only few countries around the world uses them, still however, they are an important parts of their countries infrastructures. Due to the usage of a dierent frequency than the public grid of the country, conversion of frequency is needed for the interconnection. LÄS MER

  3. 2. Global stability and feedback control of boundary layer flows

    Författare :Espen Åkervik; Dan S. Henningson; Luca Brandt; Dwight Barkley; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Stability; Global Stability; Feedback Control; Control; Estimation; Absolute Convective Instabilities; Model Reduction; Fluid mechanics; Strömningsmekanik;

    Sammanfattning : In this thesis the stability of generic boundary layer flows is studied from a global viewpoint using optimization methods. Global eigenmodes of the incompressible linearized Navier-Stokes equations are computed using the Krylov subspace Arnoldi method. LÄS MER

  4. 3. Wind Turbine Models for Power System Stability Studies

    Författare :Abram Perdana; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; fixed-speed; variable-speed; validation; modelling; power system stability; frequency stability; aggregated model; wind turbine; voltage stability;

    Sammanfattning : The purpose of this thesis is to develop dynamic models of wind turbines for power system stability studies. More specifically, the wind turbine models are mainly intended for voltage and frequency stability studies. LÄS MER

  5. 4. Stability and Receptivity of Three-Dimensional Boundary Layers

    Författare :David Tempelmann; Dan Henningson; Stefan Hein; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Receptivity; stability; optimal growth; three-dimensional boundary layers; parabolised stability equations; adjoint PSE; crossflow instability; Fluid mechanics; Strömningsmekanik;

    Sammanfattning : The stability and the receptivity of three-dimensional flat plate boundary layers is studied employing parabolised stability equations. These allow for computationally efficient parametric studies. Two different sets of equations are used. LÄS MER

  7. 5. Stability and Statistical Analysis of Transient Waves in Fusion Plasmas

    Författare :Gergö Pokol; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; short-time Fourier transform; transient MHD mode; wavelet transform; quasi-linear diffusion; runaway electron; transient transport; stellarator; tokamak disruption; fusion plasma physics; whistler wave;

    Sammanfattning : Thermonuclear energy generation in magnetically confined plasmas offers an appealing energy source for coming generations. Some of the still unsolved problems in fusion plasma physics involve plasma transport and stability of plasma waves. Two such problems are addressed in the present thesis. LÄS MER