The shift toward sustainable renewable energy with converter-based generation has significantly reduced system inertia introducing serious challenges in maintaining voltage and frequency stability, particularly under weak grid conditions with low short-circuit ratios. While grid-forming converters are under active development to address these issues, the reality is that most existing converters remain grid-following. Our proposed solution, Unified Advanced Vector Control (UAVC), is specifically designed to operate with grid-following converters – and can be added as a software-only retrofit to converters already in service. Adding UAVC enhances converters’ stability and, in many cases, reduces or could even eliminate the need for expensive reactive compensation devices such as synchronous condensers.

Unlike classical control approaches, UAVC is based on a single fixed-parameter robust controller that guarantees stable performance across a wide range of grid strengths and operational conditions. By minimizing the H-infinity norm of the system, UAVC inherently decouples voltage and power dynamics, offering robust control even during faults and other grid disturbances. Extensive simulation results demonstrate UAVC’s ability to deliver reliable fault ride-through and increase grid hosting capacity; all without the need for hardware changes. In addition, the UAVC framework can be adapted to support grid-forming operation providing a unified path toward stabilising both existing and future converter-dominated networks.