A doctoral thesis defence presented from home
A doctoral thesis defence presented from home
A doctoral thesis defence presented from home
Before the state of emergency caused by the coronavirus, Mondragon Unibertsitatea transferred all its activities to digital platforms, including the defences of a doctoral thesis on marine wind energy plants
On 17 March, Carlos Ruiz presented his doctoral thesis Modelling for Harmonic Analysis of AC Offshore Wind Power Plants in an atypical context, the state of emergency caused by Covid-19. Mondragon Unibertsitatea has maintained its facilities closed since the 16 March, and Carlos defended his study from his home, with a research study developed for 3 years in collaboration with the company Ingeteam. The judging panel composed by expert researchers from the Polytechnic University of Catalunya, Polythetic University of Valencia, University Carlos III of Madrid, Ingeteam, and Mondragon Unibertsitatea.
The videoconference brought together a group of ten assistants, and Carlos obtained an OUTSTANDING score. With 3 years of research and weeks of preparation for the last and decisive defence of the thesis, Carlos showed that he had no problems adapting to the changes of the past few days.
Congratulations Carlos! Good work!
“Modeling for Harmonic Analysis of AC Offshore Wind Power Plants”.
- Court:
- President: Luis Sainz Sapera (Universidad Politecnica de Catalunya UPC)
- Vocal: Ramon Manuel Blasco Giménez (Universidad Politécnica de Valencia)
- Vocal: José Luis Rodríguez Amenedo (Universidad Carlos III de Madrid)
- Vocal: Alain Sanchez Ruiz (Ingeteam)
- Secretary: Jon Andoni Barrena Bruña (Mondragon Unibertsitatea)
Abstract
This Ph.D. dissertation presents the work carried out on the modeling, for harmonic analysis, of AC offshore wind power plants (OWPP). The studies presented in this Ph.D. thesis are oriented to two main aspects regarding the harmonic analysis of this type of power system. The first aspect is the modeling and validation of the main power components of an AC offshore wind power plant. Special emphasis is focused on the modeling of wind turbines, power transformers, submarine cables, and the interaction between them. A proposal of a wind turbine harmonic model is presented in this dissertation to represent the behavior of a wind turbine and its harmonics, up to 5 kHz. The distinctive structure of this model consists of implementing a voltage source containing both the fundamental component and the harmonics emitted by the converter. For the case of transformer and submarine cables, the frequency-dependent behavior of certain parameters is modeled for frequencies up to 5 kHz as well. The modeling of the frequency-dependent characteristics, due to skin and proximity effect, is achieved by means of Foster equivalent networks for time-domain simulations. Regarding the interaction between these power components, two complementary modeling approaches are presented. These are the Simulink-based model and an analytical sequence network model of the passive network of the OWPP. A description of model development and parameterization is carried out for both modeling approaches considering a scenario that is defined according to a real offshore wind power plant. On the other hand, the second aspect of this Ph.D. thesis is oriented to the analysis of the issues that appear in offshore wind power plants in relation to harmonic amplification risk, compliance of grid codes in terms of harmonics and power factor, and the design of effective solutions to improve the harmonic emission of the facility. The technical solutions presented in this Ph.D. thesis cover aspects regarding modulation strategies, management of the operation point of the grid side converter of wind turbines by means of changing the setpoint of certain variables, and the design of theconnection filter of the grid side converter. As inferred, these are solutions from the perspective of the wind turbine manufacturer.