Sökning: "HVDC power cables"

Visar resultat 11 - 15 av 17 avhandlingar innehållade orden HVDC power cables.

1. 11. Some Control Applications in Electric Power Systems

   Författare :Magnus Akke; Industriell elektroteknik och automation; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; load switching.; power oscillations; differential equation algorithm; transmission line protection; computer relaying; frequency estimation; DC cable; magnetic compass; Automation; robotics; control engineering; Automatiska system; robotteknik; reglerteknik;

   Sammanfattning : This thesis presents some control applications in electric power systems. The work consists of the four parts: interaction between DC cables and ship steering autopilots; frequency estimation; computer relaying; field tests using load switching to damp power oscillations. LÄS MER

3. 12. Feasibility of HVDC for city infeed

   Författare :Paulo Fischer de Toledo; KTH; []
   Nyckelord :;

   Sammanfattning : It is well recognized that direct current and direct voltageoffer special advantages for both land and sea cable systems,both with regard to power transmission capability, losses, aswell as possible transmission length due to no capacitivecurrents. As cable systems were used very early in largecities, one of the first applications considered for HVDC wasto use it for city infeed and some schemes were also built. LÄS MER

4. 13. Managing uncertainties through efficient calculation of transients and harmonic propagation in power systems

   Författare :Oscar Lennerhag; Math Bollen; Jan Lundquist; David Thomas; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Overvoltages; harmonics; uncertainties; stochastic methods; Electric Power Engineering; Elkraftteknik;

   Sammanfattning : The electric power system is undergoing changes including large-scale introduction of renewable energy sources together with HVDC/FACTS, changes in the network such as increased amount of high voltage cables, industrial electrification, and changes in the load composition. These changes will impact the system in different ways and lead to challenges that must be addressed to facilitate planning, dimensioning, and operation of the system in a secure and economical way. LÄS MER

5. 14. Polyethylene Blends, a Material Concept for Future HVDC-cable Insulation

   Författare :Mattias Andersson; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; polymer blends; nanocomposites; polyethylene; conductivity; thermomechanical properties; High-voltage insulation; tie-chain;

   Sammanfattning : High-voltage cables are a critical component of tomorrow’s power grids that seamlessly integrate hydro, wind and solar power. Further improvements in transmission capacity of both high-voltage alternating- and direct-current, HVAC and HVDC, cables are likely reached through improved insulation materials. LÄS MER

7. 15. Ultrahigh-Voltage Silicon Carbide Device Performance, Requirements, and Limitations in High-Power Applications

   Författare :Daniel Johannesson; Hans-Peter Nee; Staffan Norrga; Muhammad Nawaz; Alberto Castellazzi; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; 4H-SiC; Current Filamentation; Device Characterization; Dynamic Avalanche; JTE Structure; Junction Termination Extension Design; SiC BJT; SiC GTO Thyristor; SiC IGBT; SiC MOSFET; SiC PiN Diode; Silicon Carbide; TCAD Simulation; Wide bandgap device; Electrical Engineering; Elektro- och systemteknik;

   Sammanfattning : The increased awareness of the on-going climate change accelerates the electric energy system transformation from fossil-fueled power sources towards systems with larger portions of renewable energy sources. Moreover, the grid infrastructure requires reinforcements to cope with increasing electrical energy demand. LÄS MER