This paper discusses a robust control of a wind energy conversion chain based on a Permanent Magnet Synchronous Generator. This command is evaluated in the context of controlling the speed of PMSG and to control the active and reactive power injected into the grid, to increase the power generated and thus improve the efficiency of wind power system. A non-linear controller was implanted. The control of wind systems mainly uses the Proportional Integral controller. However, this type of regulators does not give good control performance because of the disturbance and nonlinearity of the wind systems. Therefore, a nonlinear robust control strategy based on Second-Order Sliding Mode is implanted. In order to validate the proposed control strategy, a system dynamics model proposed was modeled and simulated in MATLAB / Simulink environment.