A Stability Margin Indicator for Transient Stability of Inverter-Dominated Mesh Power Networks

The increasing penetration of inverter-based resources, such as solar photovoltaic and wind turbines, is transforming modern power systems, leading to a reduction in mechanical inertia and posing new challenges to transient stability (TS) analysis. This paper presents a novel method for indicating transient stability in inverter-dominated mesh networks by introducing a quantitative stability margin indicator. The study focuses on grid-forming inverters and grid-following inverters in multi-cluster mesh network configurations. By deriving a generalized expression for the local common bus voltage and analysing the power and current flow, the proposed method provides a quantitative value and a computationally-efficient tool to determine the TS margin without solving differential equations. Extensive simulations validate the effectiveness of the proposed indicator and tool, demonstrating their capability for TS analysis in complex power networks.