Blar i NTNU Open på forfatter "Uhlen, Kjetil"

Development of a test system for identification of turbine dynamics using the dc power flow

Jakobsen, Sigurd Hofsmo; Uhlen, Kjetil (Journal article; Peer reviewed, 2018)

Recent concerns about the frequency quality in the Nordic power system has lead to increased research on hydro turbine governors. Among this research is the use of system identification methods. However, there has been no ...

Dynamic simulation of simultaneous HVDC contingencies relevant for vulnerability assessment of the nordic power system

Solvang, Espen Hafstad; Sperstad, Iver Bakken; Jakobsen, Sigurd Hofsmo; Uhlen, Kjetil (Chapter, 2019)

Large power-infeed of individual HVDC interconnectors may make the power system vulnerable to contingencies involving multiple HVDC interconnectors. This paper describes and demonstrates an approach to quantitative ...

Dynamic Simulations of Simultaneous HVDC Contingencies in the Nordic Power System Considering System Integrity Protection Schemes

Solvang, Espen Hafstad (Master thesis, 2018)

Individual HVDC links connecting the Nordic power system to other synchronous systems may carry gigawatts of power. For the transmission system operators, who must maintain power balance to operate the grid at 50.0 Hz, the ...

Dynamic State Estimation for Electrical Power Grids

Abooshahab, Mohammad Ali (Doctoral theses at NTNU;2021:273, Doctoral thesis, 2021)

Increased electrification of society, as well as increased incidence of distributed power generation, causes more dynamic operation of modern electrical power grids. Methods for monitoring of power grids have traditionally ...

Dynamisk analyse for nettintegrasjon av småkraft

Haukaas, Vebjørn Vidarsson (Master thesis, 2017)

Et distribusjonsnett med mye lokal småkraftproduksjon kan gi stabilitetsutfordringer i nettet. Under Evanger trafostasjon er det i dag seks småkraftverk i drift. I tillegg er det fem småkraftverk som venter konsesjonsbehandling ...

Dynamiske analyser av ny distribuert produksjon i Namsskogan

Svarva, Astrid (Master thesis, 2011)

Denne masteroppgaven omhandler en dynamisk stabilitetsanalyse av et område med mye planlagt distribuert småkraft, og er gitt av NTE Nett AS. Bakgrunnen for oppgaven er en endring av nettet i området, for å tilknytte ny ...

Electric hydraulic interaction

Helle, Ola Høydal (Master thesis, 2011)

The hydraulic models representing hydro turbines and conduit system found instandard model libraries of power system analysis tools are often simplied mod-els. Subsequently, important information about the dynamics of the ...

Estimation of Oscillatory Mode Activity from PMU Measurements

Haugdal, Hallvar; Uhlen, Kjetil; Müller, Daniel; Jóhannsson, Hjörtur (Chapter, 2020)

We propose a method for estimating the activity of oscillatory modes in power systems. The frequencies and mode shapes of the modes of interest are assumed to be known beforehand, either from linear modal analysis or from ...

Estimation of Power System Inertia From Ambient Wide Area Measurements

Tuttelberg, Kaur; Kilter, Jako; Wilson, Douglas; Uhlen, Kjetil (Journal article, 2018)

This study presents a method of estimating the effective inertia of a power system from ambient frequency and active power signals measured by phasor measurement units. Most importantly, we demonstrate that inertia can be ...

Event Detection and its Signal Characterization in PMU Data Stream

Negi, Sanjay Singh; Kishor, Nand; Uhlen, Kjetil; Negi, Richa (Journal article; Peer reviewed, 2017)

The potential application of signal processing techniques is not only to detect the event but also to characterize them according to physical disturbance. In this paper, event detection and its characterization algorithm ...

Event signal characterization for disturbance interpretation in power grid

Negi, Sanjay S.; Kishor, Nand; Negi, Richa; Uhlen, Kjetil (Chapter, 2018)

This paper presents the signal processing approach to detect and characterize the physical events that occur in power system using PMUs signals. A small window is applied so that the extracted spectral features belong to ...

Fault Detection and Prediction in Smart Grids

Andresen, Christian Andre; Torsæter, Bendik Nybakk; Haugdal, Hallvar; Uhlen, Kjetil (Chapter, 2018)

Modern society is to a larger and larger extent dependant on electric energy, and hence the reliance on and utilization of the electric grid is increasing steadily. At the same time the production and consumption patterns ...

Feasibility Studies on a Stand-Alone Hybrid Wind-Diesel System for Fish Farming Applications

Holt, Marius (Master thesis, 2017)

This thesis aims to explore feasibility related to implementing a Hybrid Wind-Diesel System for an offshore fish farm. The primary motivation behind this is to exploit the excellent wind resources along the Norwegian coast ...

Flexibility needs in the future power system

Hillberg, Emil; Zegers, Antony; Herndler, Barbara; Wong, Steven; Pompee, Jean; Bourmaud, Jean-Yves; Lehnhoff, Sebastian; Migliavacca, Gianluigi; Uhlen, Kjetil; Oleinikova, Irina; Pihl, Hjalmar; Norstrom, Markus; Persson, Mattias; Rossi, Joni; Beccuti, Giovanni (Research report, 2019)

Frekvens- og tidsanalyse av vannturbin- og kraftsystemmodeller

Ellingsen, Ole-Kristian H (Master thesis, 2015)

In this report a hydro turbine model and a power system model have been developed. The goal is to develop models capable of preforming in a frequency analysis of the Nordic synchronous area and that these models can help ...

Frequency control and stability requirement on Hydro plants: System identification for performance and stability assessment

Jakobsen, Sigurd Hofsmo (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 ...