Abstract
Wind energy is predicted to account for a higher share of the world's total power generation in the future. However, as wind power becomes more prevalent in the grid, it poses new challenges in terms of grid reliability and stability. This opens up new possibilities for the development of control methods capable of supporting the grid during voltage disruptions as well as enhancing power quality issues. This paper proposes a sliding mode control scheme for a direct-drive PMSG based wind energy conversion system. Nonlinear Sliding Mode Control (SMC) has the merit of robustness and good disturbance rejection capability, making it effective in responding to grid disturbances. The SMC chattering effect, on the other hand, increases the overall harmonic distortion injected into the grid. In this paper, the demerit of SMC has been minimized with the proper selection of SMC reaching law and the inclusion of an LCL filter and its dynamics in the design of the SMC control law. Moreover, MATLAB/Simulink simulation results have shown that the proposed control strategy has a better performance than the optimally tuned proportional-integral control during grid voltage disturbances.