In the course of the energy transition, the power grids are undergoing a profound change – from large-scale power plants to small-scale feed-in plants, for example through wind energy or photovoltaic systems in combination with storage systems. Grid-forming converters can make an important contribution to voltage and frequency stabilization in conjunction with battery storage, as they behave like a conventional generator on the grid thanks to a special control algorithm. This characteristic is also called virtual instantaneous reserve or virtual rotating mass and gives the power grid the necessary stability despite decreasing use of conventional power plants, especially in the case of rapidly fluctuating feed-in or purchase power.