KU Leuven

Promotor / Supervisor

Prof. dr. ir. Johan Driesen (promotor)

Samenvatting van het onderzoek / Summary of Research

Since the beginning of this century, Renewable Energy Sources for Electricity (RES-E) and mostly wind power have gained a huge
momentumand are continuously triggering new stability challenges. The rising capacity of RES-E in the generation mix already poses challenges to current operation of power systems and subsequently sets the direction for new approaches to control them. This dissertation deals with operational problems, primarily arising during favorable weather conditions for RES-E and low demand. During such conditions, the framework for system operation of today sets limits to the instantaneous output of RES-E because system operators rely on conventional power plants to provide the necessary grid support. The pursuit for a generation mix with quasi only RES-E requires the provision of support by RES-E. Subsequently, the focus of this dissertation is on enabling RES-E, with a significant share of Variable Speed Wind Turbines (VSWTs) in the provision of grid support, preserving the same level of power system stability.

This dissertation firstly analyzes the impact of proposed support modes of VSWTs on grid stability. Dynamic voltage and frequency support modes are evaluated in grid topologies hosting a rising share of wind power. Such studies show that the effectiveness of supporting modes is highly dependent on the specific grid topology. Additionally, the resulting interaction with other grid elements, such as induction motors and load shedding schemes, provides new insights to fine-tune the support by wind turbines in the future.

Secondly, the potential of rotating kinetic energy in VSWTs is evaluated to smooth power variations from large wind farms, or to assist in the task of system frequency regulation. Tothis end, an optimization framework is constructed to calculate thetrade-off between maximizing energy yield and smoothing power or frequency variations. The results show a significant potential for smoothing that benefits both from the
coordination among individual turbines and from forecasting the prevailing wind.

Volledige tekst van het doctoraat / full text

Examencommissie / Board of examiners

  •   Prof. dr. ir. Johan Driesen (promotor)
  •   Prof. dr. ir. Petrus Verbaeten (voorzitter/chairman)
  •   Prof. dr. Johan Meyers (secretaris/secretary)
  •   Prof. dr. ir. Ronnie Belmans
  •   Prof. dr. ir. William D'haeseleer
  •   De heer Barry Rawn
  •   Prof. dr. Poul Sorensen , Technical university of Denmark