The generation structure in the German transmission and distribution grid will change significantly in the coming years.
In order to achieve the European climate protection targets as part of the Green Deal and the goal of climate neutrality by 2045, a significant reduction in synchronous generation capacity (type 1 plants) has already been initiated with the planned phase-out of coal-fired power generation and the already completed phase-out of nuclear power in Germany. At the same time, this means a growing share of converter-fed generation capacity (type 2 plants).
This type of plant will dominate the overall behavior of the electricity system in a few years.
This leads to a number of challenges for the system stability of the transmission grids, which are already becoming apparent. This concerns the provision of system inertia (instantaneous reserve), the provision of short-circuit power and other system services that rotating machines in synchronous systems have previously provided through their physical behavior.
Even with a high and, in the near future, exclusive share of converter-based generation, system stability must always be guaranteed by the transmission system operators. The current grid-following control concepts cannot meet the requirement for system stability.
The transmission system operators have therefore formulated a consolidated position on the basic requirements for grid-forming converters that will be needed in the future to ensure system stability.