As the network evolves rapidly, its dynamic behaviour is becoming increasingly complex, potentially introducing new performance challenges for inverter control. The control and performance requirements for inverters are also evolving in tandem with these network changes. This project aims to enhance our understanding of emerging and applied VSC HVDC modelling and controls, which includes evaluating their suitability for the required performance, examining the interaction and instability mechanisms of multiple converters, and providing validated generic models of these systems. This understanding is essential for identifying the necessary control and performance requirements, gaps in specifications, and areas for modelling improvement. Ultimately, this will help mitigate risks for Great Britain's future network and support the energy transition needed to achieve the Net Zero target.
Benefits
VSC-HVDC technology, particularly its control systems, is a crucial component in the journey towards net zero and the integration of significant amounts of offshore wind energy, as well as connecting to European electrical energy markets. By enhancing our understanding of the emerging control requirements and solutions, this project will help mitigate risks associated with this technology, inform the development of technical specifications and grid codes, and provide insights into the impact of integrating new HVDC networks with existing AC systems.
Learnings
Outcomes
2025/2026
The project is still at an early stage, findings to date are below:
- Recent developments in VSC HVDC control have included development of more advanced grid-forming controllers, the application of advanced control methodologies particularly machine learning), analysis of VSC control interactions, tuning of VSC control for operation with the legacy grid, and work on grids codes.
- However no one common agreed terminology or set of requirements for grid-forming (GFM) control appear to have emerged.
- Work on the impact of converter limits on GFM would benefit from further work, as would work on supplemental control loops and other advanced (e.g. non-linear) methods to supplement GFM control. Most work to date has focused on HVDC monopoles. Limited work has been published on multi-infeed and multi-terminal HVDC systems. Further work on system energisation using VSC HVDC would also be beneficial.
Recommendations for further work
2025/2026
The project is still at an early stage, thus no recommendations for follow-on work beyond the scope of the current project work packages yet.
Lessons Learnt
2025/2026
A summary report for work-package 1 has been produced: ‘Evolution Scan on Evolving VSC HVDC Control Developments’, March 22nd 2026 revised version. Areas in HVDC control in which present R&D is limited, and which would benefit from further work, have been identified.
Early-stage findings highlight the importance of establishing a common terminology and standardised requirements for grid-forming (GFM) control. Greater emphasis should be placed on understanding converter limits and their impact on GFM performance, alongside the development of supplementary and advanced (e.g. non-linear or AI-based) control strategies. Furthermore, future work should prioritise more complex system configurations, such as multi-infeed and multi-terminal HVDC systems, as well as system energisation studies, to ensure solutions are scalable and applicable to real-world networks.
Dissemination
2025/2026
- ‘Review on Evolving VSC-HVDC Control Developments’, A. Korompili et al, Energy Transmission Competency Hub, HVDC Colloquium, 19-20 March 2026, Leuven, Belgium.
