Low-Frequency Oscillation Analysis with Gridforming Converters

Recently, it has been reported that there exist low-frequency oscillation issues driven by multiple gridforming converters (GFMCs) in realistic power systems. However, the oscillation mechanism remains unclear. To fill this gap, this paper investigates the oscillation issues. First, a testbed for the power system dominated by multiple GFMCs is constructed. Then, we leverage this testbed to investigate the impact of various system parameters on the oscillation issues. It is found that the oscillation stability is affected by various system parameters, including GFMC rated capacities, network impedance, and GFMC virtual inertia and damping. The investigation results are verified by electromagnetic transient simulation platforms.