Blar i Institutt for elkraftteknikk på dokumenttype "Doctoral thesis"
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Experimental Studies of Streamer Phenomena in Long Oil Gaps
(Doctoral Theses at NTNU, 1503-8181; 2013:106, Doctoral thesis, 2013)In this study, the characteristics of non-breakdown and breakdown streamers have been investigated through the effects of dissolved gases/air, carbon particles, additives, reduced pressure, liquid chemistry and voltage ... -
Fault Localization in Medium Voltage Distribution Networks with Distributed Generation
(Doktoravhandlinger ved NTNU, 1503-8181; 2011:182, Doctoral thesis, 2011)Being part of a larger research project named “Distribution 2020”, the focus of this work has been on increasing the automation of the fault handling in distribution networks, taking into consideration the increasing number ... -
Framework for Analytical-based Digital Twin Development of Electric Drives Using Slotless PM Machines
(Doctoral theses at NTNU;2023:335, Doctoral thesis, 2023)This Ph.D. thesis investigates and develops analytical models and techniques to build the foundation for the digital twin development of electric drives using slotless permanent magnet (PM) machines. The idea is to rely ... -
Frequency control and stability requirement on Hydro plants: System identification for performance and stability assessment
(Doctoral theses at NTNU;2019:303, Doctoral thesis, 2019)The Nordic transmission system operators (TSOs) have proposed new draft requirements for the providers of frequency containment reserves. These requirements include extensive tests to determine the dynamics of hydro power ... -
Frequency Converter Solutions and Control Methods for Varible Speed Operation of Pumped Storage Plants
(Doctoral theses at NTNU;2023:399, Doctoral thesis, 2023)Pumped storage hydropower plants (PSHP) are widely used for bulk energy storage around the world. The variable speed operation of these plants further enables their capability to regulate the power in pump mode as well. ... -
Fuel Cell Assisted PhotoVoltaic Power Systems
(Doktoravhandlinger ved NTNU, 1503-8181; 2012:158, Doctoral thesis, 2012)Distributed generation (DG) systems as local power sources have great potential to contribute toward energy sustainability, energy efficiency and supply reliability. This thesis deals with DGs that use solar as primary ... -
Grid Integration of Offshore Wind Farms using Hybrid HVDC Transmission: Control and Operational Characteristics
(Doktoravhandlinger ved NTNU, 1503-8181; 2013:101, Doctoral thesis, 2013)The transmission of offshore wind energy is one of the most relevant challenges since the best wind conditions are located far from shore. High-voltage DC (HVDC) is the most feasible option for the grid integration of ... -
High frequency modeling of power transformers: Stresses and Diagnostics
(Doktoravhandlinger ved NTNU, 1503-8181; 2005:30, Doctoral thesis, 2005)In this thesis a reliable, versatile and rigorous method for high frequency power transformer modeling is searched and established. The purpose is to apply this model to sensitivity analysis of FRA (Frequency Response ... -
Hydrogen Production from Wind and Hydro Power in Constrained Transmission Grids
(Doctoral theses at NTNU;2022:54, Doctoral thesis, 2022)Hydrogen (H2) production from variable renewable energy (VRE) sources can be an important technology for reducing CO2 emissions. Integrating electrolytic H2 production into the electricity system can contribute to this ... -
Impact of Zero Energy Buildings on the Power System: A study of load profiles, flexibility and system investments
(Doctoral theses at NTNU;2017:35, Doctoral thesis, 2017)This thesis investigates the impacts of introducing energy efficient and electricity generating buildings, called ZEBs, into a power system with a high share of renewables. Detailed knowledge of electricity demand is ... -
Improvements in protection of medium voltage resonant grounded networks with distributed sources
(Doctoral theses at NTNU;2018:386, Doctoral thesis, 2018)The increasing penetration of distributed generation into medium voltage networks creates challenges for traditional protective schemes developed for conventional radial systems with unidirectional power flows. Moreover, ... -
Integrated Power System Balancing in Northern Europe - Models and Case Studies
(Doctoral Theses at NTNU, 1503-8181; 2012:150, Doctoral thesis, 2012)Maintaining a continuous balance between generation and load is crucial for the safeguarding of the power systems. In order to effectively deal with the various uncertainties that contribute to the real-time imbalance in ... -
Integration of Electric Vehicles into Power Distribution Systems – The Norwegian Case Study; Using High-Performance Multi-Period AC Optimal Power Flow Solver
(Doctoral theses at NTNU;2020:332, Doctoral thesis, 2020)With the massive increase in the integration of Electric Vehicles (EVs), their share of energy consumption has shifted from fossil fuels to electricity. This shift in turn heavily relies on the safe, reliable and cost-efficient ... -
Integration of Regulating Power Markets in Northern Europe
(Doctoral Theses at NTNU, 1503-8181; 2012:160, Doctoral thesis, 2012)In order to ensure a stable operation of the power system, Transmission System Operators have to balance production and consumption of electiricty continuously. For this purpose balancing services are utilised. With the ... -
Internal Partial Discharges at High DC Voltage and the Effect of Superimposed AC Voltage
(Doctoral theses at NTNU;2020:327, Doctoral thesis, 2020)The power electronic equipment needed in HVDC grids produces an AC ripple voltage with amplitude of around one-hundredth of the main DC voltage. The high voltage can result in partial discharges (PDs), which are a sign of ... -
Investigating the Role of Active Loads in the Future Electrical Grid Dominated by Power Electronics
(Doctoral Theses at NTNU, 1503-8181; 2014:174, Doctoral thesis, 2014)The advancements in power electronics in the past decade have resulted in a wide spread use of power electronically interfaced generation units and loads in both AC and DC distribution systems. Power electronics plays an ... -
Investigation of Permanent Magnet Machines for Downhole Applications: _ Design, Prototype and Testing of a Flux-Switching Permanent Magnet Machine
(Doctoral Theses at NTNU, 1503-8181; 2011:23, Doctoral thesis, 2011)The current standard electrical downhole machine is the induction machine which is relatively inefficient. Permanent magnet (PM) machines, having higher efficiencies, higher torque densities and smaller volumes, have widely ... -
INVESTIGATION OF THE MATRIX CONVERTER IN A DC SERIES-CONNECTED WIND FARM: Modulation, Control and Efficiency
(Doctoral thesis at NTNU;2016:16, Doctoral thesis, 2016)In this thesis a wind energy conversion system for series-connection of DC wind turbines is considered. The wind park topology offers the advantage of a high voltage transmission without the need of an offshore platform ... -
Investigation on Fault Current Making in Medium Voltage Switchgear in Air
(Doctoral theses at NTNU;2022:106, Doctoral thesis, 2022)Closing a switch under a fault condition could result in extensive electrical contact wear and a possible switch failure. A load break switch (LBS), as one of the critical components in medium voltage (MV) power grids, ... -
IRONLESS PERMANENT MAGNET GENERATORS FOR DIRECT-DRIVEN OFFSHORE WIND TURBINES
(Doctoral thesis at NTNU;2015:138, Doctoral thesis, 2015)Since the beginning of this century, the offshore wind power industry has witnessed fast development, as the result of the increasing awareness of climate change and the need for diversifying power supply. Offshore has ...