Tesis doctoral de Andreas Sumper
Over the last decades, large amount of wind turbine generation systems (wtgs) were installed in power grids. Although the amount of wind energy in power systems compared to the conventional energy resource is still small, countries like germany, spain or denmark has reached an important level of integration of wtgs in their systems. On 4 november 2006, one of the most severe blackout in the history of ucte occurred in europe. The power imbalances during the disturbance caused severe frequency deviation which had impact on the power generation from wtgs. Events like these shows the increasing interest to study how wtgs operate at different system frequencies and with subsequent fault events. This is also true for weak power systems and power systems on islands. the present work is analyzing the dynamic performance of fixed speed wind turbine generating systems during system fault events. Although fixed wind turbine are not longer installed massively, over large years those kind of machines were installed in large proportions in power systems. Therefore there is an increasing interest to study the dynamic performance of fixed speed wtgs, specially during grid fault events. the present dissertation has three main contributions. First, the short term voltage stability of wtgs with single and double cage induction generators is studied. Secondly, the impact of frequency variations on the operation of fixed speed wtgs is analyzed. Finally, the short term voltage stability at different system frequencies is discussed. the first contribution studies possible improvements of short-term grid voltage stability of fixed speed wind turbines using double cage induction generators instead of single cage induction generators. The performed analysis shows that for voltage stability studies of fixed speed wind turbines with induction generators (either single or double cage), the mechanical rotor turbine model is preferable to be a detailed aerodynamic model. To demonstrate that the suggested modeling approaches can be used for the analysis of real installations and to show the influence of detailed rotor torque modeling, simulations of real situations are presented. the second contribution discuses the impact of system frequency variations on fixed speed induction generators used in wind turbine generation systems (wtgs). An analytic method to predict the values of angular speed, torque and current during and after a frequency disturbance is presented. the proposed method permits to establish the operation limits in order to keep the wtgs connected during frequency variations and to adjust frequency relay settings. The proposed method was validated by digital simulation. finally, the short-term grid voltage stability of fixed speed wind turbines for different system frequencies is studied. As system frequency changes modifies the generator characteristics, if those changes occur, short-term grid voltage stability is modified. Static and dynamic voltage stability is analyzed and simulations of real situations are presented.
Datos académicos de la tesis doctoral «Dynamic performance of fixed speed wind turbine generating systems during system fault events«
- Título de la tesis: Dynamic performance of fixed speed wind turbine generating systems during system fault events
- Autor: Andreas Sumper
- Universidad: Politécnica de catalunya
- Fecha de lectura de la tesis: 07/07/2008
Dirección y tribunal
- Director de la tesis
- Oriol Gomis Bellmunt
- Tribunal
- Presidente del tribunal: joan Rull duran
- mircea Chindris (vocal)
- Manuel Román lumbreras (vocal)
- sergio Herraiz jaramillo (vocal)