Abstarct: The increasing need for energy and limitation of fossil energy sources in the world reveals the necessity of using renewable energies more than ever. Due to the increasing growth of energy consumption in the world and the limitation of fossil fuels sources, and the environmental pollutions resulted from the consumption of fossil energy sources and production of greenhouse gases, it would be necessary to use the other clean energy sources. Meanwhile, the use of wind energy due to a high power-plant capacity of such renewable energies has been more focused. Essentially, a robust controller design strategy is baxsed on this principle that robust controller should be designed in a way that makes the best possible performance for the closed-loop control system in an uncertainty set of the model. With this descxription, it has been cleared that the best possible performance or negligibly a minimum required performance in the uncertainty set of the model (H_∞ controller design) not only is related to the controller but also to the form of model's uncertainty set. H_∞ controller is one of the robust control methods that can guarantees the system's stability and performance considering the noise measurement, input and output disturbances and also the system with uncertainty against the changes in operating conditions and the parameters and structure of system. In this thesis, we have studied a comprehensive dynamic model for wind energy conversion system (WECS) with proper detailed electrical and mechanical parts, and then the system modeling with uncertainty was investigated by considering the dynamical equation for the system and determining the system with uncertainty for a robust controller design with H_∞ technique- aiming for active and reactive power control of doubly fed induction generator (DFIG) and wind turbine in the presence of parametric changes.