A Disturbance Observer-based NFTSMC to Improve the Dynamic Stability of WECS-based Microgrids

A disturbance observer-based non-singular fast terminal sliding mode control (NFTSMC) approach is proposed in this paper to improve the dynamic stability of WECS-based microgrids. The approach combines the rapid controllability of power electronic converters with the fast-tracking capability of NFTSMC to provide the necessary grid support to mitigate dynamic instabilities resulting from voltage excursions caused by unexpected network events. The controller is augmented by a disturbance observer to maintain its efficacy in the presence of parameter variations and mismatched uncertainties. The proposed approach was assessed using a test microgrid system subject to different types of network events and mismatched disturbances. The obtained results confirmed the robustness and performance of the proposed scheme.