Sökning: "harmonics"

Visar resultat 1 - 5 av 125 avhandlingar innehållade ordet harmonics.

  1. 1. Dynamic Analysis of Harmonics in Electrical Systems

    Detta är en avhandling från Department of Automatic Control, Lund Institute of Technology (LTH)

    Författare :Erik Möllerstedt; Lunds universitet.; Lund University.; [2000]
    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

  2. 2. On Control of Permanent-Magnet Synchronous Motors in Hybrid-Electric Vehicle Applications

    Detta är en avhandling från Department of Automatic Control, Lund Institute of Technology (LTH)

    Författare :Oskar Wallmark; [2004]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; phase-locked loop; signal injection; Electric drive; sensorless control; harmonics; position estimation; speed estimation; hybrid-electric vehicle; permanent-magnet synchronous motor; electric vehicle; vector control;

    Sammanfattning : This thesis deals with design and analysis of the control system structure for electric drives equipped with permanent-magnet synchronous motors with a salient rotor. The intended application is propulsion in electric- and hybrid-electric vehicles. LÄS MER

  3. 3. Partial Discharges Studied with Variable Frequency of the Applied Voltage

    Detta är en avhandling från Stockholm : KTH

    Författare :Hans Edin; KTH.; [2001]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; diagnostic methods; partial discharges; phase resolved; variable frequency; dielectric spectroscopy; dielectric response; harmonics; insulation; TECHNOLOGY Electrical engineering; electronics and photonics; TEKNIKVETENSKAP Elektroteknik; elektronik och fotonik;

    Sammanfattning : This thesis concerns partial discharge (PD) diagnostics withvariable frequency of applied voltage in the frequency range 1mHz - 400 Hz. The exploration of a new type of spectroscopythat combines partial discharge analysis and dielectricresponse is demonstrated. LÄS MER

  4. 4. Linear Time-Varying Systems : : Modeling and Reduction

    Detta är en avhandling från Department of Automatic Control, Lund Institute of Technology (LTH)

    Författare :Henrik Sandberg; Lunds universitet.; Lund University.; [2002]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; linear time-varying; model reduction; balanced truncation; error bounds; power converters; harmonics; periodic modeling; inverter locomotive;

    Sammanfattning : Linear time-invariant models are widely used in the control community. They often serve as approximations of nonlinear systems. For control purposes linear approximations are often good enough since feedback control systems are inherently robust to model errors. In this thesis some of the possibilities for linear time-varying modeling are studied. LÄS MER

  5. 5. On Power Electronics Interface for Distributed Generation Applications and its Impact on System Reliability to Customers

    Detta är en avhandling från Department of Automatic Control, Lund Institute of Technology (LTH)

    Författare :Fainan Magueed; [2005]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; LCL-filter; vector control; voltage dips; L-filter; power quality; voltage regulation; harmonics; distributed generation; weak grid; VSC; strong grid;

    Sammanfattning : Distributed generation (DG) is being employed as a means of achieving increased reliability for electrical power systems as regarded by consumers. As the most of DG technologies utilize renewable sources, the power electronic interface plays a vital role to match the characteristics of a DG unit with the grid requirements. LÄS MER