High Share Participation of Grid-Forming InverterBased Resources in Grid Frequency and Voltage Support

The call for a drastic increase in non-synchronous inverter-based resources (IBRs) like wind power, re-emerges challenges like voltage and frequency support. The conventional Grid-Following (GFL) controllers are unable to fully support the grid, hence hindering the higher integration of IBRs in power systems. Contrariwise, Grid-Forming (GFM) controls with Synchronous Generation (SG) -like abilities can potentially support the grid. Here a type of virtual synchronous machine called Synchronverter-based GFM (SynC-GFM) is adopted to investigate a system with a 98% share of IBRs. A comparison is drawn between extended Direct Voltage Control (DVC-GFM) and SynC-GFM. It was found that the SynC-GFM controlled and stabilized the voltages and frequency better when the system was exposed to a three-phase short circuit fault and sudden load change. Besides, the inertia constant and integral gain (inertia dual in voltage control loop) are adjustable, hence its variation impact on RoCoF and voltage respectively was also investigated. The test-bed system here is based on DigSilent PowerFactory software that contains two wind farms and SG sources. This study is hoped to be a gateway for a sustainable 100%-IBRs-based power system.