The Optimal Ratio of GFM-Converters to GFL-Converters for Transient Voltage Regulation with Weak Grid Condition

High proportion of renewable energy connected to the grid has facilitated integration of grid-forming (GFM) and grid-following (GFL) converters in the power system. However, the large-scale integration of converters and renewable energy has greatly changed the operational characteristics of the traditional grid, especially transient voltage characteristics. The grid with proper ratio of GFM-converters to GFL-converters may have ideal transient voltage characteristics. This paper proposes a configuration method to determine the appropriate ratio between GFM and GFL converters based on the analysis of the stability of PLL to improve the stability of transient voltage.