Dynamic Equivalent Network Methods for Grid Forming Performance Test

Grid-forming control is becoming essential for IBRs and HVDC systems. Conventional performance assessments based on Thevenin equivalents are no longer sufficient, as they fail to capture key dynamics including system inertia, frequency behavior, and active–reactive power coupling. Detailed EMT network models with synchronous generators and power electronic devices are therefore recommended. However, such models increase computational burden, modelling complexity, and raise confidentiality issues. To address these challenges, dynamic network equivalent (DNE) models are required. This paper proposes two DNE methods. The first method relies on a simplistic low-order analytical model to estimate system inertia, suitable when detailed network data are unavailable. The second method is a…