Sökning: "unity power factor"

Visar resultat 1 - 5 av 12 avhandlingar innehållade orden unity power factor.

  1. 1. Study of Induction Machines with Rotating Power Electronic Converter

    Författare :Yanmei Yao; Chandur Sadarangani; Zi-Qiang Zhu; KTH; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Brushless induction machine; efficiency improvement; optimum efficiency; rotating power electronic converter; unity power factor; variable power factor; wound rotor induction machine; Electrical Engineering; Elektro- och systemteknik;

    Sammanfattning : This thesis investigates a novel induction machine topology that uses a rotating power electronic converter. Steady-state and dynamic performance of the topology is studied to understand its operational principle. Furthermore the potential of improving its efficiency and power factor is investigated. LÄS MER

  2. 2. Analysis and Control Aspects of Brushless Induction Machines with Rotating Power Electronic Converters

    Författare :Naveed ur Rehman Malik; Chandur Sadarangani; Luca Peretti; KTH; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; Doubly-fed induction generator; extended vector control; induction machine; internal model control; Lindmark concept; low voltage ride through; passive resistive network; rotating power electronic converter; rotating exciter; symmetrical faults; synchronous machine; unity power factor; unsymmetrical faults; vector control; wind turbines.; Järnvägsgruppen - Elsystem; Järnvägsgruppen - Elsystem;

    Sammanfattning : This thesis deals with the steady-state, dynamic and control aspects of new type of brushless configuration of a doubly-fed induction machine in which the slip rings and carbon brushes are replaced by rotating power electronics and a rotating exciter. The aim is to study the stability of this novel configuration of the generator under mechanical and grid disturbances for wind power applications. LÄS MER

  3. 3. Modelling, Analysis, and Control Aspects of a Rotating Power Electronic Brushless Doubly-Fed Induction Generator

    Författare :Naveed ur Rehman Malik; Chandur Sadarangani; Torbjörn Thiringer; KTH; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; Brushless doubly-fed induction generator; dual vector control; dynamic model; induction machine; internal model control; Lindmark concept; low-voltage ride-through; passive resistive network; rotating power electronic converter; rotating exciter; symmetrical faults; synchronous machine; thermal model; unity power factor; unsymmetrical faults; vector control; wind turbines.; Electrical Engineering; Elektro- och systemteknik; Energiteknik; Energy Technology;

    Sammanfattning : This thesis deals with the modeling, analysis and control of a novel brushlessgenerator for wind power application. The generator is named as rotatingpower electronic brushless doubly-fed induction machine/generator (RPEBDFIM/G).A great advantage of the RPE-BDFIG is that the slip power recoveryis realized in a brushless manner. LÄS MER

  4. 4. Wind Power - Added Value for Network Operation

    Författare :Nayeem Ullah; Chalmers University of Technology; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; torsional oscillation; reactive power ancillary service; voltage stability; power system simulator.; STATCOM; non-minimum phase system; Variable speed wind turbine; frequency control; sensitivity analysis; transient stability; small-signal stability;

    Sammanfattning : This dissertation deals with the investigation on different value added properties of variable speed wind turbines (VSWT) that stem from the flexible controllability of converter interfaced wind turbines (WT). Improvements in voltage and transient stability of a nearby grid, small-signal stability improvement on the power system, frequency control support for the network operation, as well as thetechnical and the economic issues related to the reactive power ancillary service provision, are among the issues covered. LÄS MER

  5. 5. Optimization of Rotations in FFTs

    Författare :Fahad Qureshi; Oscar Gustafsson; Mario Garrido; Jarmo Takala; Linköpings universitet; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Discrete Fourier transform; Fast Fourier transform; twiddle factor multiplication;

    Sammanfattning : The aims of this thesis are to reduce the complexity and increasethe accuracy of rotations carried out inthe fast Fourier transform (FFT) at algorithmic and arithmetic level.In FFT algorithms, rotations appear after every hardware stage, which are alsoreferred to as twiddle factor multiplications. LÄS MER