Sökning: "voltage collapse"

Visar resultat 1 - 5 av 19 uppsatser innehållade orden voltage collapse.

  1. 1. Off-State Stress Effects in AlGaN/GaN HEMTs : Investigation of high-voltage off-state stress impact on performance of and its retention in hybrid-drain ohmic gate AlGaN/GaN HEMTs

    Master-uppsats, KTH/Skolan för elektroteknik och datavetenskap (EECS)

    Författare :Ivan Krsic; [2023]
    Nyckelord :HEMT; GaN; off-state stress; memory effects; drain leakage current; dynamic RDSon; threshold voltage instabilities; charge redistribution; HEMT; GaN; stress i avslaget tillstånd; minneseffekter; läckströmmen; dynamisk RDSon; instabiliteten hos styrets tröskelspänning; omfördelningen av laddningar;

    Sammanfattning : High electron mobility transistors (HEMTs) realized using AlxGa1-xN/GaN are relatively new technology which is prominent for high-speed and high-power applications. Some of the main problems with this technology were identified as dynamic RDSon, current collapse and threshold voltage instabilities due to the off-state stress. LÄS MER

  3. 2. Centralised MPC for Long-term Voltage Stability Control of Power System

    Master-uppsats, KTH/Skolan för elektroteknik och datavetenskap (EECS)

    Författare :Johan Hallberg; [2023]
    Nyckelord :Voltage stability; Model predictive control; Tap-changing transformer; Capacitor bank; Spänningsstabilitet; Model prediktiv reglering; Lindningskopplare; Kondensatorbank;

    Sammanfattning : In a power system it is important to keep voltages at specific levels at network buses. Deviations from that can lead to reduced efficiency of transferred power or, in more severe cases, widespread power outages affecting large parts of society. There exists a variety of power system devices that have the ability to regulate the voltage levels. LÄS MER

  4. 3. Protection of HVDC Grids Against Blackouts (Simulation)

    Kandidat-uppsats, KTH/Skolan för elektroteknik och datavetenskap (EECS)

    Författare :Amal Al-Ammari; Dinah Atchan; [2021]
    Nyckelord :High Voltage Direct Current HVDC ; Voltage derivative dv=dt algorithm; Traveling wave algorithm; PSCAD simulation; Multi-terminal grid; Fault detection; Threshold value; Offshore HVDC; DC breaker; Voltage collapse;

    Sammanfattning : In the search for green energy to combat climatechange, a shift from conventional energy sources such as coal,oil, and nuclear towards Renewable Energy Sources (RES) isneeded. This shift poses a threat to the stability of the powergrids as RES do not contribute with rotating mass in the system. LÄS MER

  5. 4. Filter Design for an HVDC protection IED

    Master-uppsats, KTH/Skolan för elektroteknik och datavetenskap (EECS)

    Författare :Evgeny Genov; [2020]
    Nyckelord :;

    Sammanfattning : A selective fault detection approach is necessary for successful implementation of multi-terminal high-voltage direct-current (HVDC) grids. Fault detection is per- formed by an intelligent electronic device (IED) that takes in voltage and current measurements, performs fault detection algorithms, and outputs, e.g. LÄS MER

  7. 5. Effects of load modelling on Voltage Impasse Regions (VIR)

    Master-uppsats, KTH/Skolan för elektroteknik och datavetenskap (EECS)

    Författare :Maria Angeles Antolin Linan; [2019]
    Nyckelord :load models; power system dynamics; quasi-dynamic approach; voltage collapse; Voltage Impasse Regions VIR ; lastmodeller; kraftsystemdynamik; kvasi-dynamisk tillvägagångssätt; spänningskollaps; Voltage Impasse Region VIR ;

    Sammanfattning : Voltage Impasse Region (VIR) is a phenomenon in power systemswhose dynamics are describe by a set of Differential AlgebraicEquations (DAE). VIR denotes a state-space area where voltagecausality is lost, i.e. the Jacobian of the algebraic part of DAEis singular. LÄS MER