This paper discusses the nonlinear control problem for variable-speed wind energy conversion system. Due to the stochastic operating conditions and the inevitable uncertainties inherent in the system, linear control method comes at the price of poor system performance and low reliability. So, it first develops a detailed model of variable-speed wind energy conversion system, which incorporated a distributed generation and then applies the robust sliding mode incorporating fuzzy tuning schemes designing controller for robust performance of optimizing the generator converter system efficiency. Analysis and experiment show that the method is able achieve smooth and satisfactory rotor speed tracking. In addition, a comparison study have been carried out between the proposed method and the tradition variable speed operation control method that adjust the pitch angle only. It is found that the proposed method could diminish fatigue of mechanism.