Sökning: "voltage stability"

Visar resultat 16 - 20 av 184 avhandlingar innehållade orden voltage stability.

1. 16. A Multichoice Control Strategy for a VSC-HVdc

   Författare :Hector F. Latorre; Mehrdad Ghandhari; Lennart Söder; Kjetil Uhlen; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Control Lyapunov Function; Modal Analysis; Power Oscillation Damping; Transient Stability; Voltage Stability; VSC-HVdc; Electrical engineering; Elektroteknik;

   Sammanfattning : Utilization of power electronics based controllable systems (or devices) in transmission systems has opened new opportunities for the power industry to optimize utilization of the existing transmission systems, and at the same time to keep high system reliability and security. As a member of these controllable systems, Voltage Source Converters-based High Voltage direct current (VSC-HVdc) systems have the ability to rapidly control the transmitted active power, and also to independently exchange reactive power with transmissions systems. LÄS MER

3. 17. Modeling and Control of VSC-HVDC Transmissions

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

   Sammanfattning : 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. LÄS MER

4. 18. On the Internal Dynamics and AC-Motor Drive Application of Modular Multilevel Converters

   Författare :Antonios Antonopoulos; Hans-Peter Nee; Lennart Harnefors; Hirofumi Akagi; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Capacitor-Voltage Control; Controller Interaction; Converter Control; Energy Balance; Lyapunov Stability; Medium-Voltage Drives; Modular Multilevel Converter; Modulation; Open-Loop Control; Optimization; Variable-Speed Drives; Voltage-Source Converter.; Energibalans; Kondensatorspänningsstyrning; Lyapunov-stabilitet; Mellan-spänning drivsystem; Modulation; Modulär multinivåomvandlare; Omvandlarstyrning; Optimering; Regulatorväxelverkan; Spänningsstyva omvandlare; Varvtalsstyrda motordrifter; Öppen styrning.; Electrical Engineering; Elektro- och systemteknik;

   Sammanfattning : This thesis is an effort to investigate the operation and the performanceof modular multilevel converters (M2Cs). Proven to be the most promisingtopology in high-voltage high-power applications, it is necessary to put aneffort in understanding the physical laws that govern the internal dynamicsof such converters, in order to design appropriate control methods. LÄS MER

5. 19. Line protection and Power System Collapse

   Författare :Mattias Jonsson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; voltage stability; numerical relays; power swings; transient stability; power swing detector; out of step protection; back-up protection; distance protection; distance protection statistics; power oscillations; adaptive relaying;

   Sammanfattning : .... LÄS MER

7. 20. Voltage and power stability of HVDC systems

   Författare :Denis Hau Aik Lee; KTH; []
   Nyckelord :;

   Sammanfattning : 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. LÄS MER