Doubly fed induction generator model for power quality studies

Integration of wind power plant into power grids introduces power quality problems. The use of Doubly Fed Induction Generator into wind farm cause a distortion of the waveforms of voltage and current. The percentage of harmonic distortion is greater if the number of wind turbines is large. If the simulation model are not defined properly, the harmonic distortion result would be incorrect. For power quality studies, it is required that the model represent the wind turbine in a detail form. However, when the wind farm has a high power capacity, a detail simulation model exceed the computational capacity of the software. As an alternative solution, aggregation methodologies of wind turbines are considered. To determine the precision of the simulation, an analysis of detail and aggregate model is being made based on IEC Std. 61400-21: Measurement and assessment of power quality characteristics of grid connected wind turbines. The comparison shows that an aggregate model could represent properly the behavior of large-scale wind farm for power quality studies.