Grid-Synchronization Modeling and Its Stability Analysis for Multi-Paralleled Three-Phase Inverter Systems
The issue of synchronization instability and the corresponding low-frequency power oscillation phenomenon between synchronous generators is already found in electric power systems and addressed by various solutions. However, the grid-synchronization behaviors and the potential instabilities between multi-paralleled power electronic inverters is not well-understood due to the different synchronization mechanisms.
CPES researchers present a set of small-signal modeling methodologies to predict the low-frequency behaviors of the grid-synchronization loops in multi-paralleled inverter systems. The proposed model can predict the low-frequency unstable oscillation in large-penetrated renewable-energy systems as well as assess the effectiveness of frequency-based islanding-detection under multi-paralleled inverter conditions.