Understanding Converter Interactions Using Active and Reactive Characteristics: A Comparison Between Grid-Following and Grid-Forming Control

Paper in proceeding, 2025

This paper investigates the impact of active and reactive characteristics of grid-connected converters for system stability assessment. In particular, the reactive characteristics of the converter and the connecting grid are used to identify system resonances, while active-power characteristics (passivity) indicate the risk of destabilizing the different resonances. Through a comparison between grid-forming and grid-following control, it is shown that the passivity theory might be insufficient in assessing the risk for instability in grid-connected converter systems. Theoretical findings are validated via time-domain simulations.