Sökning: "reactive power"

Visar resultat 26 - 30 av 160 avhandlingar innehållade orden reactive power.

1. 26. Synchronous Voltage Reversal Control of Thyristor Controlled Series Capacitor

   Författare :Lennart Ängquist; KTH; []
   Nyckelord :ThyristorControlled Series Capacitor; TCSC; FACTS; reactive power compensation; boost control; phasor estimation; Quantitative Feedback Theory; subsynchronous resonance; SSR;

   Sammanfattning : Series compensation of transmission lines is an effectiveand cheap method of improving the power transmission systemperformance. Series capacitors virtually reduces the length ofthe line making it easier to keep all parts of the power systemrunning in synchronism and to maintain a constant voltage levelthroughout the system. LÄS MER

3. 27. Voltage Source Converters with Energy Storage Capability

   Författare :Hailian Xie; Hans-Peter Nee; Lennart Ängquist; Ambra Sannino; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Voltage source converter; StatCom; Energy storage; Active power compensation; Phase jump; Voltage dip; VSC; Weak network; Flux modulation; deadbeat control; Electric power engineering; Elkraftteknik;

   Sammanfattning : This project deals with voltage source converters with energy storage capability. The main objective is to study the possible benefits of energy storage to a power system with a VSC as the interface between them. First of all, a converter control system is proposed for a two level VSC. LÄS MER

4. 28. On Techno-economic Assessment of a Multi-terminal VSC-HVDC in AC Transmission Systems

   Författare :Feng Wang; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Transmission Grid.; Loss minimization; AC DC system; Transmission expansion planning; Multi-terminal VSC-HVDC; Cost minimization; Cost-benefit analysis; Electric power system; Optimal power flow;

   Sammanfattning : The Voltage Source Converter based Multi-Terminal high voltage Direct Current transmission system (VSC-MTDC) is currently considered as an attractive technical option for increased transmission capacity and improved controllability and flexibility of an electric power grid, thanks to its unique performance characteristics, and the possibility of using the extruded XLPE cables. In the planning process of embedding a VSC-MTDC system into an ac transmission grid, one must assess the potential values in terms of improved energy efficiency, i. LÄS MER

5. 29. Electromagnetic Modelling of Power Transformers with DC Magnetization

   Författare :Seyed Ali Mousavi; Göran Engdahl; S. V. Kulkarni; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Transformer; Hysteresis; DC magnetization; GICs; FEM; reluctance network method;

   Sammanfattning : DC currents that flow through the ground can be injected to the star windings of power transformers from their grounded neutral points and close their path with transmission lines. The geomagnetically induced currents (GICs) and AC/DC convertors of high voltage direct current (HVDC) systems are the sources of such DC currents. LÄS MER

7. 30. On Stability Enhancement in AC/DC Power Systems through Multi-terminal HVDC Controllers

   Författare :Omar Kotb; Mehrdad Ghandari; Oriol Gomis Bellmunt; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; AC DC power system; hybrid MTDC; multi-terminal HVDC; small signal stability; VSC-MTDC; Electrical Engineering; Elektro- och systemteknik;

   Sammanfattning : Due to the increasing share of renewable energy sources in modern power systems and electricity market deregulation, heavy inter-regional and cross-border power flows are becoming a commonplace in system operation. Moreover, large-scale integration of renewable energy sources is expected to pace up, therefore new solutions have to be developed to integrate these intermittent sources, which are also characterized by being distributed over large geographical areas, such as offshore wind farms. LÄS MER