Analyzing the Short Circuit Current Characteristics in Grids with 100% Grid Forming Inverter-Based Resources

Future power systems will experience decommissioning of traditional generators and a growing utilization of Inverter-Based Resources (IBRs), the rising penetration of such IBRs may significantly impact the Short Circuit (SC) current characteristics especially when operating power grids under 100% scenarios where Grid Forming (GFM) IBRs would be utilized. As a result, this paper investigates the transient SC current characteristics of power grids under 100% penetration scenario of IBRs focusing on GFM converters based on Droopcontrol, under a three-phase symmetrical fault. This includes the effect of different fault locations, overcurrent limits, fault impedances, and fault inception times on the SC current contribution as well as the impact of such scenario on the SC characteritics and dynamics of the faults. The simulations are performed in DIgSILENT Power Factory, where a modified version of the IEEE 9-Bus Test Systems is used to demonstrate the findings of this paper.