Impact of the Reactive Behavior of Grid-Connected Converters on Resonance Stability

Paper in proceeding, 2024

The theory of frequency domain passivity is focused on the active behavior of a system, i.e., the real part of the system impedance. However, as grid-connected converters are inherently non-passive systems, the converter-grid interactions cannot be fully explained by the passivity index alone. Rather, it necessitates consideration of the system’s resonances. This paper provides insights into the reactive behavior of the converter, i.e., the imaginary part of the system impedance, and how it influences the system resonances and hence its stability. It is shown that the converter’s reactive behavior needs to be considered to accurately identify the system resonances and hence predict the resonance instability of the system.