Revealing Cascading Failure Vulnerability in Evolving Power Grids with Increasing Penetration of Inverter-Based Resources

The increasing integration of inverter-based resou- rces is a prominent trend in power systems, which may increase the risk of large-scale blackouts. This paper proposes a complex network-based cascading failure model that incorporates the failure mechanism of power electronics-based (PE-based) nodes. This model facilitates the evaluation of cascading failure vulnerability in power electronics-penetrated (PE-penetrated) power systems, accounting for the impact of an increasing penetration level of inverter-based resources. Focusing on generation nodes with inverter-based resources (PE-based nodes) that may deviate from their stable operating limits during cascading failure and disconnect from the grid, we introduce a novel mechanism to characterize their failure behavior. Through a case study conducted on the IEEE 39-bus system, the model demonstrates its ability to accurately replicate the salient features observed in two real blackout events. Furthermore, simulation outcomes from the IEEE 118-bus system indicate the substantial impact of PE-based node failure on the cascading failure process. These results also underscore the effectiveness of utilizing the proposed model to prevent underestimating power outage risks within PE-penetrated power grids. This work emphasizes the critical importance of considering the penetration of inverter-based resources across different scenarios to safeguard the resilience of evolving power grids.