Sökning: "reactive power"

Visar resultat 6 - 10 av 160 avhandlingar innehållade orden reactive power.

1. 6. Power System Oscillations - Detection, Estimation and Control

   Författare :Morten Hemmingsson; Industriell elektroteknik och automation; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Elektroteknik; oscillation; power system; damping; power swing; distance protection; detection; estimation; real-time; reactive co-variation; control; Electrical engineering; load modulation; Automation; robotics; control engineering; Automatiska system; robotteknik; reglerteknik;

   Sammanfattning : The topic of this thesis is the electro-mechanical oscillations which to some extent always are present in a power system. The demand of electric power is ever increasing. At the same time, the tolerance of disruptions in the power supply is decreasing. LÄS MER

3. 7. Power control strategies for renewable energy systems : The inverter's role in future power systems

   Författare :Sara Anttila; Cecilia Boström; Sandra Eriksson; Lena Max; Uppsala universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Renewable energy systems; Grid-connection; Inverter; Power control; Engineering Science with specialization in Science of Electricity; Teknisk fysik med inriktning mot elektricitetslära;

   Sammanfattning : Connecting more non-dispatchable renewable energy sources (RESs) will result in a higher power variability and a lower system inertia when the synchronous generators are replaced by inverter-connected RES. Inverter control can be divided in three categories: grid-following, grid-forming (GFM) and grid-supporting. LÄS MER

4. 8. On Some Aspects of Design of Electric Power Ancillary Service Markets

   Författare :Jin Zhong; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; spinning reserve; deregulation; electricity market; reactive power; frequency regulation and optimal power flow; ancillary services;

   Sammanfattning : Ancillary services are defined as all those activities on the interconnected grid that are necessary to support the transmission of power while maintaining reliable operation and ensuring the required degree of quality and safety. There are several activities of the operator that come under the preview of ancillary services. LÄS MER

5. 9. Wind Power - Added Value for Network Operation

   Författare :Nayeem Ullah; Chalmers tekniska högskola; []
   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

7. 10. Study of Induction Machines with Rotating Power Electronic Converter

   Författare :Yanmei Yao; Chandur Sadarangani; Zi-Qiang Zhu; KTH; []
   Nyckelord :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