Grid-Forming Inverters for Stability Improvements in Bulk Power Systems with High Inverter-Based Resources Penetration

The Grid-Forming Inverter (GFMI) has been increasingly developed in recent years to enhance grid stability in areas with high Inverter-based Resources (IBRs) concentration. This paper assesses the potential stability improvements the GFMI can bring to Bulk-power Systems (BPS) through two distinct studies. The first study was conducted on a larger area, West Texas in ERCOT with more than 35GW of IBRs by replacing the Grid-Following (GFL) Battery Energy Storage Systems (BESSs) with Grid-Forming (GFM) BESSs. The results demonstrate that the GFM BESSs can effectively improve the stability performance such as less voltage dip and overshoot. The second study focused on a local area within ERCOT grid where an instability has been identified at weak grid conditions. In this case, a GFL BESS within the local study area was replaced with a GFM BESS. The findings illustrate that GFM BESS can strengthen the local area and alleviate the stability issue to allow for higher dispatch of IBRs in the local study area.