Analysis and Mitigation Strategies for Inverter Based Resources in Medium Voltage Networks

The rapid integration of inverter-based resources (IBRs) such as photovoltaic and wind supports decarbonization but creates stability challenges in medium-voltage (MV) networks, which inherently have high R/X ratios, low short-circuit capacity, and reduced inertia. These issues intensify microgrids with high IBR penetration, leading to weak grid conditions, frequency instability, and inadequate voltage support. Grid-forming (GFM) controls, including droop control and virtual synchronous machine (VSM) methods, offer synthetic inertia, frequency support, and black-start capability, yet remain limited by current constraints. This paper compares droop and VSM control strategies in interconnected and islanded MV grids and evaluates external reinforcement options such as battery energy storage systems (BESS), synchronous condensers (SC), and static synchronous compensators (STATCOMs) to mitigate short-circuit current deficiencies and enhance voltage stability. The results provide practical insights into combined control and reinforcement strategies to improve the resilience and reliability of IBR rich distribution systems.