Stability Enhancement of Power Synchronisation Control Based Grid-Forming Inverter Under Varying Network Characteristics

Power synchronisation control (PSC) is commonly used in voltage source inverters due to its grid-forming capability and superior performance under weak grid conditions as compared to other grid-forming inverter (GFMI) strategies. However, there is a notable gap in understanding the application and performance of PSC under various practical operating scenarios, particularly in different network types. This paper addresses this critical shortcoming by conducting an in-depth analysis of PSC-based GFMIs under different network types, utilising a comprehensive mathematical and dynamic simulation models. The analysis reveals that the PSC-based GFMI system encounters instability in predominantly resistive networks. To address this issue, two decoupling strategies, namely virtual power (VP)-based and virtual impedance (VI)-based, are proposed to improve power-sharing accuracy and enhance system stability. Furthermore, the improved performance of these proposed strategies is verified in real-time using the IEEE-39 bus network on the OPAL-RT platform. The validation results reaffirm the suitability of PSC-based GFMI in all practical networks.