Browsing Institutt for elkraftteknikk by Title
Now showing items 1312-1331 of 2415
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Local Electric Field in Mass-Impregnated HVDC Cables
(Journal article; Peer reviewed, 2017)Detailed knowledge of the electric field in the insulation of mass-impregnated HVDC cables is important in order to understand their breakdown mechanisms and to improve their design. When calculating the local electric ... -
Local Flexibility Market - TSO and DSO coordination
(Master thesis, 2022)Akkurat nå er det europeiske energisystemet i endring. Energien som produseres, kommer i større grad fra fornybar energi og desentralisert generasjon. Selv om dette har miljøfordeler, følger det også med en del tekniske ... -
Localisation of ground faults in power systems with distributed production
(Master thesis, 2008)Summary Distribution power systems experience a lot of faults due to high network utilisation and reduced investment in the infrastructure. Single phase faults are the most common. The standard distribution systems are ... -
Lokalisering av kortslutninger i høyspent distribusjonsnett
(Master thesis, 2017)I denne masteroppgaven er en foreslått metode for impedansbasert feillokalisering i høyspent distribusjonsnett presentert og testet. Metoden baserer seg på kortslutningsstrømmer som eneste måleverdi og tradisjonelle ... -
Long Step out Umbilicals for Oil and Gas Subsea Pump or Compressor Application - Starting of Permanent Magnet Machine
(Master thesis, 2012)Topside Variable Speed Drive (VSD) feeding a subsea load via a long cable is not a new technological challenge and many features in systems feeding asynchronous machines are well known. For a synchronous machine the situation ... -
Long Term Planning in Restructured power Systems: Dynamic Modelling of Investments on New Power Generation under Uncertainty
(Dr. ingeniøravhandling, 0809-103X; 2003:106, Doctoral thesis, 2003)This thesis describes the development of three decision support models for long-term investment planning in restructured power systems. The model concepts address the changing conditions for the electric power industry, ... -
Long-term hydrothermal Scheduling with aggregate and individual Reservoirs
(Master thesis, 2016)This thesis is a comparative analysis of two commensurable models used in long-term hydrothermal scheduling. The first model is the EMPS model, which is the most prevalent tool for long-term planning in the Norwegian power ... -
Long-term operational planning for flexible residential buildings with seasonal storage and capacity-based grid tariffs
(Peer reviewed; Journal article, 2024)When performing operation of the energy system in a building, it is difficult to accurately represent the uncertain long-term objectives in the short-term window, and the correlation between long-term objectives. This work ... -
Long-term Peak Power and Energy Forecasting in Norwegian Electricity Grids
(Master thesis, 2021)Elkraftbransjen opplever i disse tider store endringer og rask utvikling innenfor mange teknologiske områder. Innføringen av grønne teknologier og flere digitale løsninger legger grunnlag for nye muligheter for produsenter, ... -
Long-term Scheduling of Hydro Power Systems in Multiple Markets
(Master thesis, 2015)Hydropower scheduling models are vital for achieving an optimal utilization of water stored in reservoirs. The high percentage of flexible hydropower generation in Norway has led to scarce volumes in the reserve markets, ... -
A Long-term Strategy Framework for Flexible Energy Operation of Residential Buildings
(Doctoral theses at NTNU;2022:251, Doctoral thesis, 2022)Within the European power system, the electricity mix is experiencing more presence of variable power production due to the green shift. This shift causes increased need for flexibility measures to combat instability, which ... -
Long-term Value of Flexibility from Flexible Assets in Building Operation
(Peer reviewed; Journal article, 2022)In this work, we investigate how flexible assets within a residential building influence the long-term impact of operation. We use a measured-peak grid tariff (MPGT) that puts a cost on the highest single-hour peak import ... -
Longitudinal AC Breakdown Voltage of XLPE-XLPE Interfaces Considering Surface Roughness and Pressure
(Journal article; Peer reviewed, 2017)The interfacial breakdown between two dielectric surfaces has been reported to represent one of the principal causes of failure for power cable joints and connectors; thus, a better understanding of interfacial breakdown ... -
Longitudinal AC Electrical Breakdown Strength of Polymer Interfaces: Experimental and theoretical examination of solid-solid interfaces considering elasticity, surface roughness, and contact pressure
(Doctoral theses at NTNU;2019:93, Doctoral thesis, 2019)All electrical insulation systems consist of a combination of different insulating and conductive materials. The alternating current (AC) breakdown strength (BDS) of insulation systems is limited by the lowest BDS of either ... -
Loss Analysis in Laminated Iron Cores using COMSOL Multiphysics and LiveLink for Matlab
(Master thesis, 2018)A framework for loss analysis using COMSOL and LiveLink for Matlab is presented in this thesis. The loss analysis is based on Steinmetz' theory on iron core losses. IEC standard 60404-8-4:2013 gives a method of presenting ... -
Loss Calculations on Roebel-bars using Finite Element Analysis
(Master thesis, 2008)This thesis concern 3D modeling and loss calculations on roebel-bars. The finite element program ANSYS has been used to do loss calculations on transposed as well as on untransposed conductors in order to investigate how ... -
Loss Modeling of Large Hydrogenerators for Cost Estimation of Reactive Power Services and Identification of Optimal Operation
(Peer reviewed; Journal article, 2022)As a result of the worldwide energy transition, reactive power generation has started to become a more scarce resource in the power grid. Until recently, reactive power has been an auxiliary grid service that classical ... -
Losses and Inductive Parameters in Subsea Power Cables
(Master thesis, 2009)Four samples of galvanized steel armour for sub sea power cables are tested with an electric steel tester. The samples exhibit different remanence magnetization and permeability. The effects of permeability on loss in sub ... -
Low Frequency AC Transmission - Investigating the Dynamics of an Export Cable for Offshore Wind Power Applications
(Master thesis, 2016)In the following thesis, the properties of a 16 2/3 Hz, low frequency alternating current (LFAC) export cable was examined in both steady state and dynamic conditions, as part of a simplified offshore transmission system. ... -
Low Frequency Alternating Current (LFAC) Transmission Systems for Offshore Wind Farms - Case Studies on the Use of LFAC, Based on Horns Rev 3 Offshore Wind Farm
(Master thesis, 2017)This thesis investigates the use of low frequency alternating current (LFAC) for the longdistance transmission of the power extracted from offshore wind farms. It is based on the measurement of power flow in different nodes ...