Analyzing Dynamic Stability in Power Systems with High Penetration of Grid-Forming Inverters

The growing integration of Inverter-Based Resources (IBR) in electric power systems worldwide presents a significant challenge, which is the loss of inertia, due to the replacement of synchronous generators with inverters. This shift necessitates inverters to take on a more active role in the voltage and frequency control of the grid. It has led to the development and ongoing research of multiple control strategies and technologies. This paper addresses the dynamic stability of a power system with high penetration of IBR grid-forming inverters (GFMI) given by Mathworks/Simscape [14], utilizing droop control and virtual synchronous machines (VSM) as control methods. Additionally, current limiting methods, such as Virtual Impedance (VI) and Current Limiting (CL) are employed to manage over-current conditions typically encountered during faults, thereby ensuring the secure operation of GFMI under various control configurations. The simulation results show that the performance of IBRs and their impact on the power system dynamic stability significantly depends on the chosen control methods, underscoring the need for effective power control and current limiting techniques to ensure reliable grid operation. <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sup>