Search for dissertations about: "voltage and power stability of hvdc systems"

Showing result 1 - 5 of 21 swedish dissertations containing the words voltage and power stability of hvdc systems.

  2. 1. Modeling and Control of VSC-HVDC Links Connected to Weak AC Systems

    Author : Lidong Zhang; Hans-Peter Nee; Alan Wood; KTH; []
    Keywords : Control; modeling; multivariable feedback control; HVDC; power systems; stability; subsynchronous torsional interaction; voltage-source converter; weak ac systems;

    Abstract : For high-voltage direct-current (HVDC) transmission, the strength of the ac system is important for normal operation. An ac system can be considered as weak either because its impedance is high or its inertia is low. READ MORE

  4. 2. Voltage and power stability of HVDC systems

    Author : Denis Hau Aik Lee; KTH; []
    Keywords : ;

    Abstract : This research work had been motivated by the emergence of multiple HVDC links in close proximity within a power system area, such as those in Southem Scandinavia and Northem Europe. Such system tonfigurations, generally known as multi-infeed HVDC systems, are expected to exhibit voltage and power stability problems when one or more of the constit uent AUDC interconnections are weak. READ MORE

  5. 3. Analysis of dc-network stability of VSC-based HVDC grids

    Author : Gustavo Pinares; Chalmers University of Technology; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; power dependent admittance; resonance; HVDC; passivity; Multi-terminal HVDC system; VSC; dc-network stability;

    Abstract : This thesis presents a modelling approach for the investigation of dc-network stability in HVDC grids. It consists on dividing the system under analysis into subsystems such that their individual impact on the stability of the overall system can be studied. READ MORE

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

    Author : Nayeem Ullah; Chalmers University of Technology; []
    Keywords : 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;

    Abstract : 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. READ MORE

  7. 5. Modeling and Control of VSC-HVDC Transmissions

    Author : Hector Latorre; Mehrdad Ghandhari; Luis Rouco; KTH; []
    Keywords : Control Lyapunov Functions; Energy Function; Modal Analysis; Transient Stability; Voltage Stability; VSC-HVDC Transmission.; TECHNOLOGY; TEKNIKVETENSKAP;

    Abstract : Presently power systems are being operated under high stress level conditions unforeseen at the moment they were designed. These operating conditions have negatively impacted reliability, controllability and security margins. FACTS devices and HVDC transmissions have emerged as solutions to help power systems to increase the stability margins. READ MORE