Second-order sliding-mode control of DFIG-based wind turbines

Traditional vector control schemes which comprise proportional-integral (PI) controller for the Wind turbine-driven DFIGs have the drawbacks such as parameter tuning difficulties, inferior dynamic performances and poor robustness. Thus, based on the analysis of the mathematical model of the DFIG-based wind turbines, this paper addresses a non-linear control algorithm based on 2-SMC. The super-twisting algorithm is adopted to control the rotor side converter (RSC) and the grid side converter (GSC) at a fixed switching frequency. In addition, single power (or voltage) control loops instead of cascaded current and power (or voltage) control loops are used for the RSC and the GSC, which simplify the design of the controllers. Simulation results evidence both the high dynamic performance and the superior robustness achieved with proposed control scheme.