Sökning: "periodic modeling"

Visar resultat 6 - 10 av 55 avhandlingar innehållade orden periodic modeling.

  1. 6. Frequency Analysis of Sampled-Data Systems Applied to a Lime Slaking Process

    Författare :Olof Lindgärde; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; periodic systems; intersample behavior; sampled-data system; lime slaking; multirate sampling; frequency analysis; tank reactor; product inhibited; modeling;

    Sammanfattning : Single-rate and multirate sampled-data (SD) systems as well as linear time periodic (LTP) systems with discrete jumps are analyzed in the frequency domain. The focus of the analysis is both on rejection of disturbances and on robust stability properties. LÄS MER

  3. 7. Computational Multiscale Modeling of Pearlitic Steel

    Författare :Erik Lindfeldt; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Multiscale modeling; homogenization; pearlite; crystal plasticity;

    Sammanfattning : The objective of this thesis is to investigate the possibilities to describe the mechanical behaviorof a pearlitic steel by using computational homogenization, or multiscale modeling. The proposed model contains three scales: the engineering macroscale, the mesoscale representing the colonies of the pearlite and the microscale containing the individual cementite lamellae and the ferrite matrix. LÄS MER

  4. 8. Dynamic Analysis of Harmonics in Electrical Systems

    Författare :Erik Möllerstedt; Institutionen för reglerteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Automation; converter control; modeling; linear time periodic systems; frequency domain analysis; harmonics; power systems; small signal stability; robotics; control engineering; Automatiska system; robotteknik; reglerteknik;

    Sammanfattning : Frequency domain analysis and design of power systems is complicated in the presence of harmonics, switching dynamics, nonlinearities, unbalances, and for systems with mixed ac/dc dynamics. The reason is that linearization of the system does not lead to a time invariant system, but a system with periodically time varying dynamics, which implies that there is coupling between different frequencies. LÄS MER

  5. 9. Homogenization of pseudoparabolic reaction-diffusion-mechanics systems : Multiscale modeling, well-posedness and convergence rates

    Författare :Arthur J. Vromans; Adrian Muntean; Claudia Timofte; Karlstads universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Reaction-diffusion-mechanics system; parameter delimitation; parabolic-pseudoparabolic equations; weak solvability; Rothe method; periodic homogenization; corrector estimates; vanishing thin domains; Matematik; Mathematics;

    Sammanfattning : In this dissertation, parabolic-pseudoparabolic equations are proposed to couple chemical reactions, diffusion, flow and mechanics in heterogeneous materials using the framework of mixture theory. The weak solvability is obtained in a one dimensional setting for the full system posed in a homogeneous domain - a formulation which we have obtained using the classical mixture theory. LÄS MER

  7. 10. Modeling and Linear Quadratic Optimal Control of Wind Turbines

    Författare :Thommy Ekelund; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; periodic system; structural dynamics; yaw control; variable speed; wind turbines; active stall; estimation; LQG; identification;

    Sammanfattning : Control can improve the performance of wind turbines by enhancing the energy capture and reducing dynamic, as well as static, loads. There are several possible configurations of the control system, depending on the available actuators. LÄS MER