Grid-forming plant controls for self-supply and black start applications of battery energy storage systems

With the increasing share of renewable generation and inverter-based resources, new providers of grid services like black start capability are required. This paper presents a plant level control concept of a battery energy storage system which allows for an easy and efficient integration of project specific information into one generic controls software. While many black start solutions to date are very project specific and not easy to re-use, this approach enables scalability, reliability and a faster project delivery of black start applications. Based on three different configurations (single busbar, bus coupler and double busbar), the control concept itself as well as the implementation in the Fluence Operating System will be introduced and validated on a hardware- in-the-loop setup. This includes self-supply, black start and hybrid operation modes as well as swapping algorithms for State of Charge balancing.