Stability Enhancement of Power Synchronisation Control Based Grid-Forming Inverter Under Varying Network Characteristics
Chalitha Liyanage, Inam Ullah Nutkani, Lasantha Meegahapola, Mahdi Jalili
Abstract
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.