Sökning: "HVDC"
Visar resultat 1 - 5 av 129 uppsatser innehållade ordet HVDC.
1. Humidity dependent conductivity of air in HVDC applications and the role of surfaces
Uppsats för yrkesexamina på avancerad nivå, Uppsala universitet/Fasta tillståndets fysikSammanfattning : High Voltage Direct Current (HVDC) bushings are insulated devices designed to facilitate the safe passage of electric current across an earthed barrier. Understanding air conductivity is of utmost importance in the design of HVDC components, which is determined by ion density and ion mobility. LÄS MER
2. Stray capacitance study for HVDC Classic : The use of PSCAD and Mathcad to calculate the equivalent stray capacitance
Uppsats för yrkesexamina på avancerad nivå, Uppsala universitet/ElektricitetsläraSammanfattning : The reactors placed in the thyristor valve designed by Hitachi Energy have reactor losses which are dependent on the stray capacitance. To find out the stray capacitance, and further get to know the reactor losses, a PSCAD simulation is performed. LÄS MER
3. Control Aid Implementation -Modelling and simulation of triple extruder-
Master-uppsats, Lunds universitet/Kemiteknik (CI)Sammanfattning : In the production of their High Voltage Direct Current Cables (HVDC) and High Voltage Alternating Current Cables (HVAC), NKT uses triple extruders to create layers of insulation and semi-conduction. A model to predict the effect of extruder inputs on the cable’s insulation and semi-conducting layers has been created and trained to predict the extruder in discrete time. LÄS MER
4. Investigation of charge injection at electrode-dielectric interface relevant for HVDC cables : Simulation of charge injection and transport dynamics in electrical insulation for HVDC cables
Uppsats för yrkesexamina på avancerad nivå, Uppsala universitet/Tillämpad mekanikSammanfattning : A bipolar charge transport (BCT) model is used to simulate charge injection and transportdynamics inside insulation material which are used in a high voltage direct current (HVDC)cable. Gaining knowledge about space charge density and electric field distribution in theinsulation material enables minimising charge injection at the metal-insulator interface andavoiding unnecessary energy loss. LÄS MER
5. Evaluation of key performance indices for frequency quality : A method for evaluating frequency stability in the Nordic power system
Master-uppsats, KTH/Skolan för elektroteknik och datavetenskap (EECS)Sammanfattning : The Nordic power system is in a changing phase, with more power electronic interfaced connections, and HVDC connections to other synchronous areas, which impacts the frequency quality. This is a challenge for the transmission system operator of Sweden, Svenska Kraftnät, who, with the other Nordic transmission system operators, is responsible for the physical balancing of the Nordic power system. LÄS MER