Control of a hybrid storage system (HSS) comprising a RedOx-Flow Battery and a High Speed Flywheel for a hybrid compensation system

As individual technologies for storing energy feature characteristic advantages and disadvantages, they are suitable for distinct purposes each. In appliances that demand for heterogeneous requirements, the combination of two or more different storage technologies in a HSS appears to be advantageous. Here, requirements regarding the performance of the storage system are determined by the energy demand of a hybrid compensation system for provision of ancillary services in medium voltage grids. By a suitable design of the different storages within the HSS, a costly oversizing of one single storage technology considering the desired pupose can be prevented. Operating conditions unfavorable for a specific technology can be absorbed by another. In HSS, a common control system ensures that the present storage technologies are utilized in a way that total storage efficiency is best and that usability for the application is maximized. Within the present article, a HSS consisting of a RedOx-Flow Battery (RFB) and a high speed flywheel energy storage (FES) is introduced and evaluated.