Modeling variable speed wind turbine for power system dynamic studies

With the increasing amount of wind power in the generation mix it is evident that the influence of wind power on the power system dynamics is going to be significant in the near future. This has necessitated the requirement to provide simple and accurate fundamental frequency models for the wind turbines, to be used in bulk power system dynamic studies. This paper presents the work done on modeling a fully rated converter based variable speed variable pitch wind turbine aimed at analyzing slow system dynamics. In order to derive realistic results, it is needed to take into account both wind speed variations and slow dynamics related to blade pitch control. This work suggests a structure for the model and provides insight in to the modeling aspects for all key components of the wind turbine. The results highlight the importance of secondary support and fast governor action in such a system.