A Non-singular Fast Terminal SMC-based Approach for SSR Mitigation in a DFIG-based WECS

Subsynchronous resonance (SSR) is a critical problem in series compensated transmission lines. If not properly mitigated, SSR can cause serious and sustained oscillations in wind energy systems that can potentially lead to electrical instability and even generator failures. This paper proposes a non-singular fast terminal sliding mode control-based approach to mitigate SSR by accurately regulating the support from superconducting magnetic energy storage (SMES) units. The design combines the fast current support capability of the SMES and fast convergence of NFTSMC to effectively mitigate dynamic instabilities during SSR. The performance of the proposed approach is validated using the IEEE first benchmark model.