Search for dissertations about: "Multilevel method"

Showing result 1 - 5 of 58 swedish dissertations containing the words Multilevel method.

  2. 1. Adaptive Finite Element Methods for Optimal Control Problems

    Author : Karin Kraft; Göteborgs universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; dual weighted residual; adaptive; Newton method; variational inequality; vehicle dynamics.; multilevel algorithm; discontinuous Galerkin method; a posteriori error estimate; finite element method; optimal control; control constraint;

    Abstract : In this thesis we study the numerical solution of optimal control problems. The problems considered consist of a systemof differential equations, the state equations, which are governed bya control variable. The goal is to determine the states and controls which minimize a given cost functional. READ MORE

  4. 2. Adaptive Finite Element Methods for Optimal Control Problems

    Author : Karin Kraft; Göteborgs universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; finite element method; discontinuous Galerkin method; optimal control; a posteriori error estimate; dual weighted residual; adaptive; multilevel algorithm; Newton method; control constraint; variational inequality; vehicle dynamics.;

    Abstract : In this thesis we study the numerical solution of optimal control problems. The problems considered consist of a system of differential equations, the state equations, which are governed by a control variable. The goal is to determine the states and controls which minimize a given cost functional. READ MORE

  5. 3. Multilevel Power Converters with Smart Control for Wave Energy Conversion

    Author : Deepak Elamalayil Soman; Mats Leijon; Jan Isberg; Sebastain Nielebock; Gopal Mondal; Uppsala universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Multilevel power converter; FPGA control; Wave Energy; Three-level boost converter; Three-level buck-boost converter; Variable-renewable-energy; Three-level neutral point clamped inverter; Linear generator; DC-link; AC2AC direct converter; Modular multilevel converter; Engineering Science with specialization in Science of Electricity; Teknisk fysik med inriktning mot elektricitetslära;

    Abstract : The main focus of this thesis is on the power electronic converter system challenges associated with the grid integration of variable-renewable-energy (VRE) sources like wave, marine current, tidal, wind, solar etc. Wave energy conversion with grid integration is used as the key reference, considering its high energy potential to support the future clean energy requirements and due the availability of a test facility at Uppsala University. READ MORE

  6. 4. On Numerical Solution Methods for Block-Structured Discrete Systems

    Author : Petia Boyanova; Maya Neytcheva; Oleg Iliev; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Preconditioning techniques; Finite element method; Two-by-two block matrices; Optimal order methods; AMLI method; Cahn-Hilliard equation; Multiphase flow; Inexact Newton method; Beräkningsvetenskap med inriktning mot numerisk analys; Scientific Computing with specialization in Numerical Analysis;

    Abstract : The development, analysis, and implementation of efficient methods to solve algebraic systems of equations are main research directions in the field of numerical simulation and are the focus of this thesis. Due to their lesser demands for computer resources, iterative solution methods are the choice to make, when very large scale simulations have to be performed. READ MORE

  7. 5. Inverter Design for SiC-based Electric Drive Systems with Optimal Redundant States Control of Space Vector Modulation

    Author : Georgios Mademlis; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electric Vehicle; Common Mode Voltage; Power Hardware-in-the-Loop; Tidal power; Voltage balancing; Silicon Carbide SiC ; Medium Voltage Converters; Multilevel; Neutral Point Clamped NPC ; Maximum Power Point Tracking MPPT ; Space Vector Modulation;

    Abstract : The need for inverters with ever increasing power density and efficiency has recently become the driving factor for research in various fields. Increasing the operating voltage of the whole drive system and utilizing newly developed SiC power switches can contribute towards this goal. READ MORE