Blar i NTNU Open på forfatter "Ljøkelsøy, Kjell"
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Challenges and Rationale for Laboratory Research of Offshore Grids
Ljøkelsøy, Kjell; D'Arco, Salvatore; Tande, John Olav Giæver (Journal article; Peer reviewed, 2012)Offshore power systems will be characterized by a large penetration of power electronics converters and power cables, resulting in complex behaviors that can be quite different from traditional AC systems. Analyzing such ... -
Design and Operation Principles of DC Circuit Breakers - Development of a Solid State DC Breaker for the NTNU/SINTEF Smart Grid and Renewable Energy Laboratory
Norum, Eivind Ødegaard (Master thesis, 2016)Exciting high voltage direct current (HVDC) transmission systems are mainly point-to-point connections. A multi-terminal HVDC grid consisting of three or more inter connected converter stations is suggested in order to ... -
Driver stage implementation with improved turn-on and turn-off delay for wide band gap devices
Spro, Ole Christian; Guidi, Giuseppe; Ljøkelsøy, Kjell; Hernes, Magnar; Midtgård, Ole-Morten; Undeland, Tore Marvin (Chapter, 2018)This paper presents a driver topology intended for WBG devices with the goal of improving the switching performance. In particular, the initial delay time of the switching transient was targeted. In high power and high ... -
Experimental Verification of a Voltage Droop Control for Grid Integration of Offshore Wind Farms Using Multi-terminal HVDC
Torres Olguin, Raymundo E.; Årdal, Atle Rygg; Støylen, Hanne; Endegnanew, Atsede Gualu; Ljøkelsøy, Kjell; Tande, John Olav Giæver (Journal article; Peer reviewed, 2014)This paper presents an experimental verification of a voltage droop control for a multi-terminal HVDC system for the grid integration of offshore wind farms. The laboratory setup is composed by four voltage-source converter ... -
Laboratory Testing of Multi-terminal VSC-HVDC
Teearu, Kalle (Master thesis, 2013)This report documents laboratory testing of multi-terminal HVDC system in down-scaled model. First, analytical method for solving DC power flow is introduced and explained. Power flow equations are set up and implemented ... -
Laboratory Verification of the Modular Converter for a 100 kV DC Transformerless Offshore Wind Turbine Solution
Gjerde, Sverre Skalleberg; Ljøkelsøy, Kjell; Undeland, Tore Marvin (Journal article; Peer reviewed, 2013)In this paper, an experimental verification of the control of a modular series connected voltage source converter suitable for an HVDC transformerless offshore wind turbine is presented. The test bench is built around a ... -
Minimization of dead time effect on bridge converter output voltage quality by use of advanced gate drivers
Hove, Håvard Lefdal; Spro, Ole Christian; Peftitsis, Dimosthenis; Guidi, Giuseppe; Ljøkelsøy, Kjell (Chapter, 2019)This paper presents a voltage-controlled multistage gate driver topology for delay time minimization that improves the converter output voltage quality while supplying a motor load. Three gate driver topologies for SiC ... -
Predictive Control applied to Power Electronics Conversion Systems - From Simulation to Implementation
Kvinge, Katrine Skjelanger (Master thesis, 2015)Model predictive control has been a topic of research for approximately three decades, and is considered one of the most important advances in process control. In this project, a model to simulate predictive control applied ...