Assessment of the solicitation induced by grid forming control on battery energy system storages

All over the world, Grid Forming (GFM) capability is starting to be required from both generation and storage devices. As GFM control will help stabilize the grid, it might create additional flows and stress in the storage and inverter compared to traditional Grid Following (GFL) control. To evaluate the change in behavior on the device and to provide both qualitative and quantitative insights on the expected solicitations, this paper will simulate the response to real voltage measurements and to step events for different types of Energy Storage Module (ESM) installations: GFL and GFM control of the ESM and with or without provision of ancillary services such as Frequency Sensitive Mode or Voltage Control. After briefly introducing the test network as well as inverter control and ancillary services, the first part will give statistical results on real data from Phasor Measurement Unit (PMU) measurements, showing that GFM solicitations is negligible compared to the one due to the provision of ancillary services. The last part will illustrate that even if GFM control introduces negligible changes in daily operation, it will nevertheless deliver stabilizing property, as expected, in case of network event such as phase shift or voltage amplitude step, and that the associated solicitation remains reasonable and limited in time.