A high robust control scheme of grid-side converter for DFIG system

In this study, a high robust control—second-order sliding-mode control (SOSMC) scheme is proposed to improve the DC-link voltage dynamic performance of the grid-side converter (GSC) for the doubly-fed induction generator (DFIG) system under the wind turbine power disturbance and DC-link capacitance parameter disturbance. In general, the wind speed is change with the environment and further has an effect on the power generation of the DFIG system. Besides, the capacitance of DC-link capacitor may change with the working condition. To address this issue, a SOSMC scheme is proposed to replace the conventional proportional integral (PI) control for the DC-link voltage controller of the GSC for the DFIG system in this study. By using the non-linear SOSMC controller, the DFIG system is robust to the disturbance of the wind speed and the parameter of DC-link capacitance. Compared with the conventional PI control scheme, the DFIG system with the proposed SOSMC scheme is much more robust, which has been verified in the MATLAB/Simulink platform.