Stabilisation of Subsynchronous Controller Interactions using a Robust Data-driven Grid-forming Control in e-STATCOM

The growing penetration of inverter-based resources exacerbates power system stability issues, particularly subsynchronous oscillations (SSOs) caused by controller interactions. Gridforming (GFM) control offers advantages over conventional mitigation, yet its design is often limited by black-box modelling and incomplete system information, leading to reduced robustness. This paper adopts a data-driven framework to design a GFM voltage controller for an enhanced STATCOM to robustly damp SSO. A Type-3 wind power plant connected to a series-compensated network is treated as a black-box system, with voltage dynamics identified via closed-loop frequency response estimation. Frequency-domain objectives are then formulated as a mixed-sensitivity optimisation problem. The resulting controller is…