Joint Nordic perspective on grid-forming converters presented in new report
The Nordic transmission system operators have, in a new report, agreed on a technical perspective on grid-forming converters – a crucial solution to meet the changing needs of the power system and ensure future operational reliability.
As an increasing share of generation, storage and consumption connects to the grid through converters, the fundamental characteristics of the power system are changing. Traditional sources of system strength and inertia may not be as dominant as they are today, meaning that new technical solutions are needed to maintain a stable and robust network.
The converters connected to the power system today are typically grid-following, meaning that they synchronize to the existing grid voltage and frequency. If too large a share of converters is grid-following, the stability of the power system may be adversely affected. Grid-forming converters, on the other hand, can establish voltage and frequency on their own. This allows them to contribute to inertia and damping of oscillations, enable stable operation even in weak grids, and support system restoration after an outage. Converters with grid-forming capabilities are therefore a prerequisite for ensuring operational security as the share of converters continue increasing.
The Nordic transmission system operators – Statnett, Energinet, Fingrid and Svenska kraftnät – have within the collaboration Converter-Dominated Nordic Grid (ConDoN) developed a common Nordic view on grid-forming. The report summarizes typical functionalities included in the concept of grid-forming and discusses principles for testing and verification of these capabilities. The work builds on European experiences but is adapted to Nordic conditions.
The Nordic TSOs are already introducing requirements for grid-forming capability in HVDC links, STATCOM installations and battery energy storage systems. This is a direct response to the growing need for measures to preserve system stability. Future implementation in wind and solar power will follow as European network codes evolve.
By establishing a common technical foundation, the Nordic TSOs aim to provide clarity for developers and manufacturers, support pilot projects and practical verification of grid-forming behavior, and thereby contribute to a secure and reliable power system – today and in the future.