GFM-Benchmark

To achieve the climate protection goals, in addition to the expansion of renewable generation, renewable and storage power plants need to take over extensive system services as well as essential properties, such as the formation of the grid, for a stable power system operation at all times. 

To ensure that this grid-forming behavior meets the requirements for stable system operation in all grid states, new verification methods are necessary. Together with its partners, Fraunhofer ISE is developing an appropriate procedure and testing it with various grid-forming devices. On the one hand, optimizations of the verification procedure will be derived from this, and on the other hand, a comprehensive market overview of the current state of the art of grid-forming inverters will be possible.

In today's power grid, essential properties such as the formation of the grid - i.e. the provision of a grid voltage with a stable amplitude and frequency - are provided almost exclusively by conventional large-scale power plants.

Therefore, it is now undisputed that to successfully achieve climate protection goals, in addition to the expansion of renewable generation, it is necessary to install large capacities of grid-forming converter systems in the grid to ensure system stability. These must be able to take over the grid-forming characteristics, such as voltage source behavior.

For this purpose, the fully integrated network components with grid forming properties planned by the transmission system operators (TSO) are by far not enough. The planned grid forming TSO assets, such as STATCOM, grid boosters and HVDC converter stations, in the long term can only cover a certain part of the system demand of grid-forming power, but not all of it. Therefore, these grid forming characteristics must also be supplied to a significant extent by customer facilities.

The lack of guidelines on the dynamic behavior of grid-forming systems has which leads to room for interpretation by manufacturers regarding the implementation and parameterization of corresponding devices. Furthermore, there is still no generally applicable procedure for the prove of grid-forming properties.

To improve this, this project will provide an overview on the GFM behavior and the implementation interpretation of different manufacturers. For this purpose, measurements will be carried out with as many of devices from different participating manufacturers as possible. To enable a comparison of the investigated devices, a corresponding test and evaluation procedure as well as a catalog of requirements will be developed in this project together with the participating TSOs, 50Hertz Transmission GmbH, Amprion GmbH, Tennet TSO GmbH, TransnetBW GmbH as well as participating manufacturers of GFM converters. 

In summary, the project has three objectives:

1. Analysis of the current state of the art regarding the performance and implementation of grid-forming inverters.
2. Broad-based collection of experience and knowledge with the verification and conformity testing of grid-forming converters.
3. Determination of necessary further development potential for grid-forming inverters for system stabilization.

The results of the project will be presented to the expert public in various workshops.