Internal Voltage Source Saturation Impact on Stability Limits of Grid Forming Converter

This paper investigates the converter constraints on internal voltage source (IVS) dynamics due to weak grid disturbances. Current limit constraint affects grid synchronization and grid-forming (GFM) capability during and post fault disturbance. The effect of IVS saturation limits is shown to be significant, as it shifts the peak power capability towards increasing delta as limits increase. This provides more power throughput from the system and increased stability limits with larger critical clearing time. Along with mathematical analysis, a simulation case study on 10kW system is presented in this paper.